CN110741237A - Material for pressure measurement - Google Patents

Abstract

The present invention provides a material for pressure measurement, comprising: microcapsules A, containing electron-donating dye precursors; and microcapsules B, containing a solvent with a melting point or a pour point below 30°C and a polarizer with a melting point exceeding 30°C. Organic compounds that do not contain electron-donating dye precursors.

Description

Materials for pressure measurement

technical field

The present invention relates to a material for pressure measurement.

Background technique

The material for pressure measurement (that is, the material used in the pressure measurement) is used for applications such as a bonding process of liquid crystal glass, solder printing on a printed circuit board, and pressure adjustment between rolls. As an example of the material used in the pressure measurement, there is, for example, a pressure measurement film typified by Prescale (trade name; registered trademark) provided by Fujifilm Corporation.

In recent years, pressure measurement materials for measuring minute pressures have been studied.

For example, in Japanese Patent Laid-Open No. 2009-019949, there is proposed a pressure measurement material whose color density difference ΔD before and after pressurization at 0.05 MPa is 0.02 or more, so as to obtain visual recognition or readability under minute pressure taken concentration.

In addition, Japanese Patent Laid-Open No. 2009-063512 discloses a material for pressure measurement, which is a two-piece type pressure measurement material that can obtain good color development at low pressure, focusing on the number average wall thickness in microcapsules σ and the surface roughness Ra of the developer layer suppress color development by rubbing.

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention

As can be seen from the above-mentioned Japanese Patent Laid-Open No. 2009-019949 and Japanese Patent Laid-Open No. 2009-063512, studies are being conducted on pressure measurement materials for measuring minute pressure.

However, in recent years, against the background of the development of high-functioning and high-definition products, the need to more precisely grasp the area to which minute pressure is applied has increased.

For example, in the field of liquid crystal panels, as a bonding method, a vacuum bonding method may be adopted to cope with the enlargement of the area. In this case, it is necessary to precisely grasp the area to which a pressure of less than 0.1 MPa (that is, atmospheric pressure) is applied. .

In addition, in the field of smartphones, with the thinning of modules, from the viewpoint of improving the yield at the time of bonding, bonding under a micro pressure of 0.05 MPa or less is required. Therefore, in the field of smartphones, it is necessary to precisely grasp the area to which a minute pressure of 0.05 MPa or less is applied.

In the above case, the measurable pressure range of the commercially available pressure measurement film, that is, the pressure range in which color development is obtained by pressurization, is in the range of 0.05 MPa or more. Therefore, when a weak pressure of less than 0.05 MPa is applied to a commercially available pressure measurement film, the color development required for detection is insufficient, or even if the color development is obtained, it is difficult to obtain the concentration level required for judging the pressure difference.

In the prior art, a material has been proposed, such as the material for pressure measurement described in Japanese Patent Laid-Open No. 2009-019949, which optimizes the color development density difference ΔD before and after pressing at 0.05 MPa. However, if the sensitivity is increased so that a visually recognizable or readable density and density level can be obtained by applying a minute pressure of less than 0.05 MPa, there is a problem that color development due to friction or the like during processing tends to occur. .

Therefore, it is expected to establish a technology that can develop a good color even in a pressure range of 0.05 MPa or less, and can obtain a color (ie, a concentration level) corresponding to a slight pressure difference, and can suppress unnecessary friction caused by friction or the like. hair color.

An object of one embodiment of the present invention is to provide a material for pressure measurement which is excellent in the gradation of color development under a minute pressure of 0.05 MPa or less, and which suppresses color development by friction.

Means for solving technical problems

Specific methods for solving the above-mentioned problems include the following aspects.

<1> A material for pressure measurement, comprising: a microcapsule A containing an electron-donating dye precursor; and

Microcapsule B contains a solvent whose melting point or pour point is below 30°C and a polar organic compound whose melting point exceeds 30°C, and does not contain an electron-donating dye precursor.

<2> The material for pressure measurement according to <1>, wherein the polar organic compound having a melting point of more than 30° C. is a compound having an alkyl group having 12 or more carbon atoms and an amide bond.

<3> The material for pressure measurement according to <1>, wherein the polar organic compound having a melting point exceeding 30° C. is selected from the group consisting of salicylic acid-based compounds, salts of salicylic acid-based compounds, phenol-based compounds, and sulfonamide-based compounds at least one of the group consisting of compounds.

<4> The material for pressure measurement according to any one of <1> to <3>, wherein the volume-based median diameter D50B of the microcapsules B is larger than the volume-based median diameter D50A of the microcapsules A .

<5> The material for pressure measurement according to any one of <1> to <4>, comprising: a first material in which the color-forming agent layer containing the microcapsules A is disposed on the first substrate; and a second material material, the developer layer containing the electron-accepting compound is arranged on the second substrate,

At least one of the first material and the second material contains microcapsules B.

<6> The material for pressure measurement according to <5>, wherein on the color former layer of the first material, the color former layer of the second material having the same area as the color former layer of the first material and The color former layers of the first material are in contact and overlap, and the difference in density from the color development density after rubbing by repeatedly moving the first material with respect to the second material 20 times minus the density before rubbing is less than 0.02.

<7> The material for pressure measurement according to any one of <1> to <6>, wherein the concentration after applying pressure at 0.04 MPa to develop color is subtracted from the concentration after applying pressure at 0.05 MPa to develop color The concentration difference of 0.20 or more.

Invention effect

According to an embodiment of the present invention, there is provided a material for pressure measurement which is excellent in the gradation of color development under a micro pressure of 0.05 MPa or less, and which suppresses color development by friction.

Detailed ways

Hereinafter, the material for pressure measurement of the present invention will be described in detail.

In this invention, the numerical range represented using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

In the numerical range described in stages in the present invention, the upper limit value or the lower limit value described in a certain numerical range may be replaced by the upper limit value or lower limit value of the numerical value range described in another stage. In addition, in the numerical range described in this invention, the upper limit value or the lower limit value described in a certain numerical range can be replaced with the value shown in an Example.

In the present invention, in the case where a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition refers to the total amount of the above-mentioned various substances present in the composition, unless otherwise specified.

In the present invention, a combination of two or more preferred aspects is a more preferred aspect.

<Material for pressure measurement>

The material for pressure measurement of the present invention contains: microcapsule A containing an electron-donating dye precursor; and microcapsule B containing a solvent having a melting point or a pour point of 30° C. or lower (hereinafter, appropriately abbreviated as “specific solvent”) .) and a polar organic compound having a melting point or a pour point of more than 30°C (hereinafter, abbreviated as "specific polar organic compound" as appropriate.), and does not contain an electron-donating dye precursor.

The electron-donating dye precursor contained in the microcapsules A develops color by being brought into contact with an electron-accepting compound that is a color-developing agent that colors the electron-donating dye precursor.

As the specific polar organic compound contained in the microcapsules B, in the measurement of the pressure or pressure distribution utilizing the color-developing reaction between the electron-donating dye precursor and the color-developing agent, it is possible to select which can improve the sensitivity, color-developing property, etc. Compounds to measure properties.

Materials used for pressure measurement have been proposed and widely used in the past, and these materials are suitable for detection of pressures in the range of 0.05 MPa or more applied during pressurization. On the other hand, in recent years, along with higher functionalization and higher definition of products, the required pressure detection capability is in the range of less than 0.05 MPa. Materials for pressure measurement described in JP 2009-019949 A and JP 2009-063512 A have been conventionally provided, but the pressure range suitable for detection may deviate from the pressure range required in recent years.

On the other hand, it is difficult to design a material for pressure measurement so that good color development can be obtained under a small pressure and that a concentration level can be developed corresponding to a wide pressure range. For example, if the sensitivity is increased in order to detect under a small pressure, as a result of excessive color development under a small pressure, the pressure range in which the concentration level appears is likely to be narrowed, and the color develops due to slight friction during processing. Unexpected color development is likely to be mixed in the measurement area.

In view of the above problems, in the material for pressure measurement of the present invention, microcapsules A and B are mixed, and the microcapsules A contain an electron-donating dye precursor, and the microcapsules B contain a melting point or a pour point of 30° C. The following solvents (specific solvents) and polar organic compounds (specific polar organic compounds) having a melting point of more than 30° C. do not contain an electron-donating dye precursor.

As a result, the material for pressure measurement of the present invention can provide a color development balance that can achieve a micro pressure, excellent gradation of color development even under a micro pressure of 0.05 MPa or less, and suppression of color development due to friction. material for pressure measurement.

Here, the "gradation of color development" refers to the property that the color development density increases as the applied pressure increases. Particularly preferred gradation of color development is a property in which the color development density increases linearly with increasing pressure (ie, the pressure is proportional to the color development density) in a pressure range of 0.06 MPa or less.

Specifically, when pressure is applied to the material for pressure measurement of the present invention, the microcapsules A are destroyed, whereby the electron-donating dye precursor and the electron-accepting compound (ie, the color developer) come into contact with each other to form a color-developing region. When the applied pressure is not uniform in the applied area, color development is performed at a density corresponding to the pressure, and a color development area having a density level is formed.

When the microcapsules A and the microcapsules B are mixed in the material for pressure measurement of the present invention, when an unexpected micro pressure is applied, the microcapsules B are destroyed, thereby suppressing the destruction of the microcapsules A, thereby preventing unnecessary hair color. That is, the microcapsule B has a function of suppressing the destruction of the microcapsule A by the destruction of the microcapsule B itself (ie, a function as a virtual capsule).

When the microcapsule A is destroyed, the specific solvent contained in the microcapsule B can improve the reactivity of the electron-donating dye precursor and the developer. In addition, the specific polar organic compound contained in the microcapsules B can be selected in the measurement of the pressure or pressure distribution utilizing the color-developing reaction of the electron-donating dye precursor and the color developer, which can contribute to the improvement of the sensitivity. , chromogenic properties and other measurement properties of compounds. Therefore, by containing the microcapsules B, the measurement performance of the material for pressure measurement is further improved.

From this, it is considered that the material for pressure measurement of the present invention can suppress unnecessary color development under minute pressure caused by friction or the like, is excellent in color development under minute pressure, and can reproduce a wide pressure range. concentration level.

[Microcapsule A]

The microcapsule A is a microcapsule containing an electron-donating dye precursor as a color-developing component. The microcapsules A preferably contain a solvent, and if necessary, may contain other components such as auxiliary solvents and additives.

-Electron donating dye precursor-

The electron-donating dye precursor is not particularly limited as long as it has the property of donating electrons or accepting protons such as acids (hydrogen ions; H ⁺ ) to develop color, but it is preferably colorless.

In particular, as an electron-donating dye precursor, it has partial skeletons such as lactone, lactam, sultone, spiropyran, ester, and amide, and these parts are preferable when contacting with an electron-accepting compound described later. A colorless compound with an open or cracked backbone.

For the use of pressure-sensitive carbon paper or thermal recording paper, known electron-donating dye precursors can be used. For example, triphenylmethane phthalide-based compounds, fluoran-based compounds, phenothiazine-based compounds, indolylphthalide-based compounds, white gold amine-based compounds, rhodamine lactam-based compounds, triphenylmethane-based compounds Various compounds such as compounds, diphenylmethane-based compounds, triazene-based compounds, spiropyran-based compounds, and fluorene-based compounds.

For details of the above-mentioned compounds, the description of Japanese Patent Laid-Open No. 5-257272 can be referred to.

The electron-donating dye precursors may be used alone or in combination of two or more.

From the viewpoint of improving the color development in a micro pressure range of 0.05 MPa or less and developing a high concentration under micro pressure, that is, from the viewpoint of developing a concentration change (concentration gradient) corresponding to a wide pressure range, the molar absorptivity ( ε) High electron donating dye precursors. The molar absorptivity (ε) of the electron-donating dye precursor is preferably 10000 mol ^-1 ·cm ^-1 ·L or more, more preferably 15000 mol ^-1 ·cm ^-1 ·L or more, still more preferably 25000 mol ^-1 ·cm ^-1 ·L or more.

As a preferable example of the electron-donating dye precursor whose ε is within the above-mentioned range, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2- Methylindol-3-yl)-4-azaphthalide (ε=61000), 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-n-octyl- 2-Methylindol-3-yl)phthalide (ε=40000), 3-[2,2-bis(1-ethyl-2-methylindol-3-yl)vinyl]-3- (4-Diethylaminophenyl)-phthalide (ε=40000), 9-[ethyl(3-methylbutyl)amino]spiro[12H-benzo[a]xanthine-12,1' (3'H)isobenzofuran]-3'-one (ε=34000), 2-anilino-6-dibutylamino-3-methylfluoran (ε=22000), 6-diethyl Amino-3-methyl-2-(2,6-dimethylaniline)-fluoran (ε=19000), 2-(2-chloroanilino)-6-dibutylaminofluoran (ε=21000 ), 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (ε=16000), 2-anilino-6-diethylamino-3-methylfluoran (ε = 16000) and so on.

When using one electron-donating dye precursor having a molar absorptivity ε within the above-mentioned range alone, or when using two or more electron-donating dye precursors having a molar absorptivity ε within the above-mentioned range in combination, the The proportion of electron-donating dye precursors with a molar absorption coefficient (ε) of 10000 mol ^-1 ·cm ^-1 ·L or more in the total amount of electron dye precursors is increased. The color property is preferably in the range of 10 mass % to 100 mass %, more preferably in the range of 20 mass % to 100 mass %, and further Preferably it is the range of 30 mass % - 100 mass %.

When using two or more types of electron-donating dye precursors, it is preferable to use together two or more types of electron-donating dye precursors each having ε of 10000 mol ⁻¹ ·cm ⁻¹ ·L or more.

The molar absorptivity (ε) can be calculated from the absorbance when the electron-donating dye precursor is dissolved in a 95% acetic acid aqueous solution. Specifically, in the 95% acetic acid aqueous solution of the electron-donating dye precursor whose concentration was adjusted so that the absorbance might be 1.0 or less, the length of the measuring cell was Acm and the concentration of the electron-donating dye was Bmol. /L, and when the absorbance is C, it can be calculated by the following formula.

Molar absorption coefficient (ε)=C/(A×B)

-Solvent-

The microcapsules A preferably contain at least one solvent.

As the solvent, a known solvent can be used for the use of pressure-sensitive carbon paper or thermal recording paper.

Specific examples of the solvent include alkylnaphthalene-based compounds such as diisopropylnaphthalene, diarylalkane-based compounds such as 1-phenyl-1-xylylethane, and alkanes such as isopropylbiphenyl. Aromatic hydrocarbons such as biphenyl-based compounds, triarylmethane-based compounds, alkylbenzene-based compounds, benzylnaphthalene-based compounds, diarylalkylene-based compounds, and arylindan-based compounds; aliphatic hydrocarbons such as isoparaffins Hydrocarbons; natural animal and vegetable oils such as soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, coconut oil, castor oil, fish oil; high-boiling fractions of natural products such as mineral oil; etc.

A solvent can be used individually by 1 type or in mixture of 2 or more types.

The mass ratio (solvent:precursor) of the solvent contained in the microcapsules A to the electron-donating dye precursor is preferably in the range of 98:2 to 30:70, and more preferably 97:70 in terms of color development. The range of 3 to 40:60 is more preferably the range of 95:5 to 50:50.

-Auxiliary solvent-

The microcapsules A may contain auxiliary solvents as needed.

As the auxiliary solvent, a solvent having a boiling point of 130° C. or lower can be mentioned.

More specifically, examples of the auxiliary solvent include ketone-based compounds such as methyl ethyl ketone, ester-based compounds such as ethyl acetate, and alcohol-based compounds such as isopropyl alcohol.

-Other ingredients-

The microcapsules A may contain other components other than the above as necessary.

As other components, additives such as ultraviolet absorbers, light stabilizers, antioxidants, paraffins, and odor inhibitors can be mentioned.

-Volume-based median diameter of microcapsules A (D50A)-

The volume-based median particle diameter (hereinafter, also referred to as "D50A") of the microcapsules A is not particularly limited, but is preferably larger than 10 μm and smaller than 40 μm.

When D50A is less than 40 μm, the color development property does not become too high, and therefore, the color development due to friction or the like can be further suppressed.

When D50A is larger than 10 μm, the surface unevenness of the layer containing the microcapsules A (for example, the coating unevenness in the method of forming the coloring agent layer containing the microcapsules A) can be further suppressed.

As D50A, it is preferable that it is 20 micrometers - 35 micrometers, and it is more preferable that it is 25 micrometers - 35 micrometers.

In the present invention, "the volume-based median diameter of the microcapsules" means that when the entire microcapsule is divided into two parts with the particle diameter at which the cumulative volume becomes 50% as a threshold, the larger diameter side and the smaller diameter The sum of the volumes of the particles on the side becomes the same diameter.

Specifically, the volume-based median diameter of the microcapsules in the microcapsules of the present invention is determined by the following method.

First, a dispersion of microcapsules is obtained. The obtained dispersion liquid is coated on an arbitrary support, and dried to form a coating film. The surface of the obtained coating film was photographed by an optical microscope at a magnification of 150 times, and the sizes of all the microcapsules in the range of 2 cm×2 cm were measured and calculated.

-Number average wall thickness of microcapsules A-

The number average wall thickness of the microcapsules A depends on various conditions such as the material of the capsule wall and D50A, but is preferably 0.01 μm to 0.15 μm, more preferably 0.01 μm to 0.15 μm from the viewpoint of color development in a micro pressure range of 0.05 MPa or less. 0.02μm～0.10μm.

In the present invention, the wall thickness of the microcapsule refers to the thickness (μm) of the capsule wall of the microcapsule (eg, the resin film forming the microcapsule). Here, the concept of the so-called microcapsule includes both the microcapsule A and the microcapsule B described later.

The number-average wall thickness of microcapsules refers to the thickness (μm) of each capsule wall of five microcapsules obtained by scanning electron microscopy (SEM), and the obtained measured value of the thickness of the capsule wall (5 measured values). value) obtained by performing a number average (ie, a simple average).

Specifically, first, the microcapsule-containing liquid is applied on an arbitrary substrate (for example, a first substrate) and dried to form a coating film. A cross-sectional slice of the obtained coating film was prepared, and the cross-section was observed using SEM. Any five microcapsules were selected from the obtained SEM images. The cross sections of the selected five microcapsules were observed, and the thickness of the capsule wall in each of the five microcapsules was determined. The measured values of the thickness of the capsule wall (five measured values) were number-averaged, and the obtained number-average value was used as the number-average wall thickness of the microcapsules.

As the ratio of the number-average wall thickness of the microcapsules A to D50A of the microcapsules A (that is, the number-average wall thickness/D50A ratio), from the viewpoint of color development in a micro-pressure range of 0.05 MPa or less, preferably 1.0×10 ^-3 to 4.0×10 ^-3 , more preferably 1.3×10 ^-3 to 2.5×10 ^-3 .

[Microcapsule B]

Microcapsule B contains a solvent (specific solvent) with a melting point or a pour point of 30°C or lower and a polar organic compound (specific polar organic compound) with a melting point of more than 30°C, and does not contain electron donating properties as a color-emitting component Microcapsules of dye precursors. The microcapsules B may further contain auxiliary solvents, additives, and the like as needed.

The microcapsule B has a function as a virtual capsule that suppresses the destruction of the microcapsule A, and the measurement performance of the pressure measurement material of the present invention is further improved by the specific polar organic compound and the specific solvent released to the outside of the capsule when the microcapsule B is destroyed .

-Solvents with melting point or pour point of 30°C or less-

The microcapsule B contains a solvent (specific solvent) having a melting point or a pour point of 30°C or lower.

The specific solvent contained in the microcapsule B may be only one type or two or more types. A specific solvent can function as an oil component.

The specific solvent contained in the microcapsules B is not particularly limited as long as it can be used as the oil component contained in the microcapsules B and has a melting point or a pour point of 30°C or lower. A specific solvent is a solvent that can dissolve or disperse a specific polar organic compound.

When the melting point or the pour point of the specific solvent is 30° C. or lower, when the material for pressure measurement of the present invention is used, for example, it is at room temperature which is the most versatile measurement environment (specifically, the recommended measurement environment). When used in a temperature environment close to (25°C), the content of the microcapsules B in the material for pressure measurement is in a fluid state.

The melting point or the pour point of the specific solvent is 30°C or lower, which can be judged by whether or not the contents of the microcapsules are in a fluid state when observed with the naked eye at 30°C. The state in which the contents of the microcapsules show fluidity is an index that the melting point or pour point of the specific solvent is 30°C or lower.

When the measurement is performed in more detail, it can be confirmed, for example, by the test method described in JIS K2269 (1987).

When two or more specific solvents are contained, the melting point or the pour point of the specific solvent may be confirmed by whether or not it is in a liquid state when visually observed at 30° C. in a state where two or more are mixed.

Moreover, when a specific solvent is a commercial item on the market, when there exists a literature value, such as a bibliographic value as a melting point or a pour point, the literature value can be utilized.

Specifically, as the specific solvent contained in the microcapsule B, among the compounds disclosed as the solvent which can be contained in the microcapsule A, a compound having a melting point or a pour point of 30° C. or less is exemplified. From the viewpoints of color development and solubility or dispersibility of specific polar organic compounds, diarylalkane-based compounds such as 1-phenyl-1-xylylethane (melting point: ≤ -50°C), iso-chain Aliphatic hydrocarbons such as alkanes, etc.

As a specific solvent, a commercial item can be used. As an example of the specific solvent of a commercial item, IP solvent 1620 (synthetic isoparaffin, Idemitsu Kosan Co., Ltd., pour point: <-70 degreeC), IP solvent 2835 (synthetic isoparaffin, Idemitsu Kosan) can be mentioned Co., Ltd., flow point: <-70°C), HISOL (registered trademark) SAS296 (mixture of 1-phenyl-1-xylylethane and 1-phenyl-1-ethylphenylethane , pour point: -47.5 ℃, Nippon Oil Corporation) and so on.

From the viewpoint of expressing the effect expected for the specific polar organic compound, if the inside of the microcapsule B has fluidity, the mass ratio of the specific solvent contained in the microcapsule B to the specific polar organic compound described later (specific Solvent: specific polar organic compound) is not particularly limited. For example, when the solubility of the specific solvent with respect to the specific polar organic compound is high, the ratio of the specific solvent can be reduced in the mass ratio of the specific solvent to the specific polar organic compound. This mass ratio may be set mainly in consideration of the balance between the solubility of the specific solvent with respect to the specific polar organic compound and the viscosity of the state in which the specific polar organic compound is dissolved in the specific solvent.

-Polar organic compounds with melting point over 30°C-

The microcapsule B contains a polar organic compound (specific polar organic compound) whose melting point exceeds 30°C.

The specific polar organic compound contained in the microcapsule B may be only one type or two or more types.

In the microcapsule B, as long as the inside of the microcapsule B has fluidity, the content of the specific polar organic compound is not particularly limited. The mass ratio of the specific solvent to the specific polar organic compound may be appropriately set in consideration of the balance between the solubility of the specific solvent with respect to the specific polar organic compound and the viscosity of the state in which the specific polar organic compound is dissolved in the specific solvent. .

As the specific polar organic compound contained in the microcapsules B, an organic compound having a melting point exceeding 30° C. and having a polarity can be selected, and the pressure or pressure of the color-developing reaction between the electron-donating dye precursor and the color developer can be used. A compound that contributes to the improvement of measurement performance such as sensitivity and color development in the measurement of distribution.

The melting point of a specific polar organic compound can be confirmed by a general method (capillary method) which is a melting point measurement method by visual observation. Specifically, it can be confirmed by the melting point measurement method described in JIS K6220-1 (2015).

In the present invention, the polar organic compound refers to a compound having at least one atom selected from an oxygen atom, a nitrogen atom, and a sulfur atom.

In the specific polar organic compound, as a partial structure having at least one atom selected from an oxygen atom, a nitrogen atom, and a sulfur atom, specifically, an amide bond, a urethane bond, a urea bond, an ether bond can be mentioned. bond, ester bond, sulfonyl bond, sulfonamide group, amino group, hydroxyl group, carboxyl group and sulfo group, etc. These partial structures may contain only one type or two or more types in the molecular structure of the polar organic compound.

The specific polar organic compound is preferably a compound (ie, a sensitizer) that promotes a color-development reaction by an electron-donating dye precursor and a color-developing agent that colors the electron-donating dye precursor, or a compound having Electron-donating dye precursors are color-developing compounds (ie, color-developing agents).

When the color developer is contained in the microcapsules B, the material for pressure measurement of the present invention preferably combines both the color developer not contained in the microcapsules and the microcapsules B containing the color developer. By using the color-developing agent not contained in the microcapsules and the color-developing agent-containing microcapsules B, the effect of improving the color developing ability can be obtained, and undesired color development can be suppressed.

The specific organic compound that can function as a sensitizer includes polar organic compounds known as sensitizers that promote the reaction between an electron-donating dye precursor and an electron-donating dye precursor, and the melting point exceeds 30. ℃ compounds. As this specific organic compound, compounds used as sensitizers in the use of pressure-sensitive carbon paper or heat-sensitive recording paper can be selected. In addition, a commercial item can be used as a specific organic compound which can function as a sensitizer.

As a specific organic compound which can function as a sensitizer, the compound which has an amide bond, the compound which has a sulfonamide group, the compound which has a urea bond, the compound which has a urethane bond, the compound organic compound etc. are mentioned preferably.

Among them, as the specific organic compound that can function as a sensitizer, a compound having an amide bond is preferable, a compound having an aliphatic group and an amide bond (hereinafter, also referred to as fatty acid amide.) is more preferable, and a compound having an amide bond is more preferable. A compound of an alkyl group and an amide bond (hereinafter, also referred to as a saturated fatty acid amide.).

From the viewpoint of diffusivity and compatibility, compounds having an alkyl group having 12 or more carbon atoms and an amide bond are particularly preferable. As an example of a compound which has a C12 or more alkyl group and an amide bond, the example mentioned later can be mentioned as a specific example of a saturated fatty acid amide, Of these, a stearic acid amide is especially preferable.

Examples of specific organic compounds that can function as sensitizers include fatty acid amides (specifically selected from long-chain fatty acid amides having 16 or more carbon atoms in total) described in Japanese Patent Laid-Open No. 5-010485. , N-alkyl-substituted long-chain fatty acid amides with a total carbon number of 20 or more and N,N-dialkyl-substituted long-chain fatty acid amides with a total carbon number of 26 or more and whose molecular weight is 250 or more).

In addition, as other examples of the specific organic compound that can function as a sensitizer, the compounds described in paragraph 0031 of Japanese Patent Laid-Open No. Hei 06-210948, and paragraph 0045 of International Publication No. WO 2013/141224A1 can be mentioned. The compound described in and the compound described in the 0063 paragraph of International Publication No. 2013/065704A1, and the like.

Examples of the specific organic compound that can function as a sensitizer include the above-mentioned compounds, and specifically, the compounds shown below can be exemplified, but are not limited to these compounds. In addition, the melting points of the compounds exemplified below all exceeded 30°C.

Saturated fatty acid amides (for example, lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, etc.), unsaturated fatty acid amides (for example, oleic acid amide, erucic acid amide, etc.) ), N-substituted fatty acid amides (eg, N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl amide erucamide, etc.), methylolamide (eg, hydroxymethyl stearic acid amide, etc.), saturated fatty acid bisamides (eg, methylene bis stearic acid amide, ethylene bis capric acid amide, ethylene bis-lauric acid amide, ethylene bis-stearic acid amide, ethylene bis-hydroxy stearic acid amide, ethylene bis-behenic acid amide, hexamethylene bis-stearic acid amide, hexamethylene bis-stearic acid amide Cilic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearic acid amide sebacic acid amide, etc.), unsaturated fatty acid bisamides (for example, ethylene bis-oleic acid amide, ethylene bis-erucic acid amide, hexamethylene bis-oleic acid amide, N,N'-dioleyl Diacid amide, N,N'-dioleyl sebacic acid amide, etc.), aromatic bisamide (eg, m-xylylene bis-stearamide bis-stearic acid amide, m-xylyl dihydroxy Stearic acid amide, N,N'-cysteine isophthalic acid amide, etc.), fatty acid ester amide (for example, stearic acid ethyl stearate, etc.),

β-Naphthylbenzyl ether, N-stearyl urea, N,N'-distearyl urea, β-naphthoic acid phenyl, 1-hydroxy-2-naphthoic acid phenyl, 2-(p-methyl) Benzyloxy)naphthalene, 2-benzyloxynaphthalene, 1,4-dimethoxynaphthalene, 1-methoxy-4-benzyloxynaphthalene, N-stearyl urea, 1,2-bis(3 -Methylphenoxy)ethane, 1,2-diphenoxyethane, 1-phenoxy-2-(4-chlorophenoxy)ethane, 1,2-diphenoxymethyl Benzene, 1,4-butanediol phenyl ether, dibenzyl terephthalate, dimethyl terephthalate, dibenzyl oxalate, bis(4-chlorobenzyl) oxalate, bis(4-chlorobenzyl) oxalate -methylbenzyl) ester, methyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, (4'-chlorobenzyl) 4-hydroxybenzoate, 1,2-bis(4'-hydroxybenzene) Formate) ethyl ester, 1,5-bis(4'-hydroxybenzoic acid) amyl ester, 1,6-bis(4'-hydroxybenzoic acid) hexyl ester, 4,4'-dimethoxybenzophenone , 4,4'-dichlorobenzophenone, 4,4'-difluorobenzophenone, diphenylsulfone, 4,4'-dichlorodiphenylsulfone, 4,4'-difluorodiphenylsulfone , 4,4'-dichlorodiphenyl disulfide, diphenylamine, 2-methyl-4-methoxydiphenylamine, N,N'-diphenyl-p-phenylenediamine, 1-(N- Phenylamino)naphthalene, 1,3-diphenyl-1,3-propanedione, N-stearyl-N'-(2-hydroxyphenyl)urea, N-stearyl-N'-( 3-hydroxyphenyl) urea, N-stearyl-N'-(4-hydroxyphenyl) urea and other compounds.

As a specific organic compound which can function as a color developer, among electron acceptor compounds known as a color developer for developing electron-donating dye precursors, an electron acceptor compound having a melting point of more than 30° C. can be mentioned. Such an electron-accepting compound can be selected from compounds used for pressure-sensitive copying paper or thermal recording paper. Moreover, as a specific organic compound which can function as a color developer, a commercial item can be used.

Among them, from the viewpoints of reactivity and diffusivity, as the specific organic compound that can function as a color developer, those selected from the group consisting of salicylic acid-based compounds, salicylic acid-based compound salts, phenol-based compounds, and sulfonamide-based compounds are preferred. at least one of the group of compounds.

The salicylic acid-based compound refers to a compound having a partial structure derived from salicylic acid in its molecular structure. The phenol-based compound refers to a compound having a partial structure derived from phenol in its molecular structure. The sulfonamide-based compound refers to a compound having a sulfonamide group in its molecular structure.

In the material for pressure measurement of the present invention, specific examples of the specific organic compound that can function as a color developer will be described later.

From the viewpoint of reactivity, a salt of a salicylic acid-based compound or a phenol-based compound is more preferred, and the salicylic acid-based compound salt is preferably a metal salt of a 3,5-disubstituted salicylic acid derivative, more preferably Metal salts (zinc salts, nickel salts, aluminum salts, calcium salts, etc.) of 3,5-diaralkyl-substituted salicylic acid derivatives, particularly preferably 3,5-di-α-methylbenzylsalicylic acid zinc. As a phenol type compound, 2,4'- dihydroxydiphenyl sulfone or 4,4'- dihydroxydiphenyl sulfone is especially preferable.

Examples of specific organic compounds that can function as color-developing agents include the above-mentioned compounds. Specifically, among the compounds described in the respective documents shown below, compounds that can function as color-developing agents can be preferably mentioned. Electron-accepting compounds. In addition, the melting points of the compounds exemplified below all exceeded 30°C.

Examples of specific organic compounds that can function as color-developing agents include the compounds described in paragraph 0046 of Japanese Patent Laid-Open No. 2009-063512, and the compounds described in paragraph 0015 of Japanese Patent Laid-Open No. 6-183141 The compound described in No., the compound described in the 0008 paragraph of Japanese Patent Laid-Open No. 5-104850, the compound described in International Publication No. 2013/141224, the compound described in International Publication No. 0032 in International Publication No. 2011/108411 The compound described in paragraph number ~0038, the compound described in J.Jpn.Soc.Colour Mater., 88[11], 378-382 (2015), and the like.

As an example of the specific organic compound which can function as a color developer, the following compounds are mentioned.

3,5-di-tert-butylsalicylic acid, 3,5-di-tert-octylsalicylic acid, 3,5-di-tert-nonylsalicylic acid, 3,5-di-tert-dodecyl Salicylic acid, 3-methyl-5-tert-dodecylsalicylic acid, 3-tert-dodecylsalicylic acid, 5-tert-dodecylsalicylic acid, 5-cyclohexylsalicylic acid, 3,5-bis(α,α-dimethylbenzyl)salicylic acid, 3-methyl-5-(α-methylbenzyl)salicylic acid, 3-(α,α-dimethylbenzyl) base)-5-methylsalicylic acid, 3-(α,α-dimethylbenzyl)-6-methylsalicylic acid, 3-(α-methylbenzyl)-5-(α,α -Dimethylbenzyl)salicylic acid, 3-(α,α-dimethylbenzyl)-6-ethylsalicylic acid, 3-phenyl-5-(α,α-dimethylbenzyl) ) salicylic acid, 3,5-dibenzylsalicylic acid, 3,5-bis-α,α-dimethylbenzylsalicylic acid, 3,5-bis(α-methyl-α-toluidine) base) salicylic acid, 3,5-bis(-α-methylbenzyl)salicylic acid, 3-α-benzylated phenethylsalicylic acid, 3-α-methyl-α-ethylpentane Base-5-α,α-dimethylbenzylsalicylic acid, 3-cumyl-5-tert-octylsalicylic acid, 3-cumyl-5-tert-butylsalicylic acid, 3-tert-butyl -5-cumylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3,5-di-tert-octylsalicylic acid, 3,5-di-tert-nonylsalicylic acid, 3,5-di-tert-nonylsalicylic acid 5-Bis(methylcumyl)salicylic acid, 3,5-dicumylsalicylic acid, 3-α-methylbenzyl-6-methylsalicylic acid, 3-α-benzylated phenethyl Alkyl-6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-6-methylsalicylic acid, 3,5-bis(-α-benzylated phenethyl)salicylic acid Acid, 3,5-Bis(benzylatedbenzyl)salicylic acid, 3,5-Bis(α-methylbenzyl)-6-methylsalicylic acid, 3-α-Tolylethyl-6 -Methylsalicylic acid, 3,5-bis(α,α-dimethylbenzyl)-6-methylsalicylic acid, 3,5-di-tert-octyl-6-methylsalicylic acid, 3-α-Dimethylphenethyl-6-methylsalicylic acid, 3-α-ethylphenethyl-6-methylsalicylic acid, 3-α-isopropylphenylethyl-6 - Methylsalicylic acid, 3-α-benzylated benzylphenethyl-6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-6-ethylsalicylic acid, 3-Nonyl-6-methylsalicylic acid, 3-dodecyl-6-methylsalicylic acid, methyl salicylate, ethyl salicylate, Isoamyl salicylate ), isopentyl salicylate, phenyl salicylate, benzyl salicylate, 4-n-octyloxysalicylic acid, 4-n-butylsalicylic acid, 4-n-pentanedihydroxy Salicylic acid, 3-n-dodecyloxysalicylic acid, 3-n-octanoyloxysalicylic acid, 4-n-n-octyloxycarbonylaminosalicylic acid, 4-n-octanoyloxycarbonylamino Compounds such as salicylic acid, carboxyl-modified terpene phenol resin, salicylic acid resin which is a reaction product of 3,5-bis(α-methylbenzyl)salicylic acid and benzyl chloride, or their metal Salts (such as zinc, nickel, aluminum and calcium),

2,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(hydroxyphenyl)butane, 2 ,2-bis(hydroxyphenyl)pentane, 2,2-bis(hydroxyphenyl)heptane, 1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)acetic acid Butyl ester, benzyl bis(4-hydroxyphenyl)acetate, bis(3-methyl-4-hydroxyphenyl)sulfone, 4-hydroxyphenyl-4'-methylphenylsulfone, 3-chloro-4 -Hydroxyphenyl-4'-methylphenylsulfone, 3,4-dihydroxyphenyl-4'-methylphenylsulfone, 4-isopropylphenyl-4'-hydroxyphenylsulfone, 4- Hydroxy-4'-n-propoxydiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-allyloxydiphenylsulfone, bis(3-allyl -4-hydroxyphenyl)sulfone, 4-hydroxyphenyl-4'-benzyloxyphenylsulfone, 4-isopropylphenyl-4'-hydroxyphenylsulfone, bis(2-methyl-3 -tert-butyl-4-hydroxyphenyl) sulfide, methyl 4-hydroxybenzoate, benzyl p-hydroxybenzoate, oligomers of hydroxybenzoate, (4'-chloro-4-hydroxybenzoic acid) benzyl), 1,2-bis(4'-hydroxybenzoic acid) ethyl ester, 1,5-bis(4'-hydroxybenzoic acid) amyl ester, 1,6-bis(4'-hydroxybenzoic acid) hexyl ester, dimethyl 3-hydroxyphthalate, octadecyl gallate, lauryl gallate or its metal salt, salicylamide, salicylanilide, 4,4'-butylene bis(6- tert-butyl-3-methylphenol), 4,4'-bis(p-toluenesulfonylaminocarbonylamino)diphenylmethane, 4,4'-bis(o-toluenesulfonylaminocarbonylamino)diphenylmethane , 4,4'-bis(p-toluenesulfonylaminocarbonylamino)diphenyl sulfide, 4,4'-bis(p-toluenesulfonylaminocarbonylamino)diphenyl ether, N-p-toluenesulfonyl-N'- 3-(p-toluenesulfonyloxy)phenylurea, N-(p-toluenesulfonyl)-N'-(p-butoxycarbonyl)urea, N-(p-toluenesulfonyl)-N'-phenylurea , sulfonylurea derivatives, N-(4-hydroxyphenyl)-4-toluenesulfonamide, N-(2-hydroxyphenyl)-4-toluenesulfonamide, N-phenyl-4-hydroxybenzenesulfonamide Wait.

-The volume-based median diameter of the microcapsules B (D50B)-

The volume-based median particle diameter (hereinafter, also referred to as "D50B") of the microcapsules B is preferably set according to the purpose of increasing the color density and suppressing color development by friction.

For example, the material for pressure measurement of the present invention can be used for high-pressure measurement that does not require much consideration of the inhibition of color development by friction. In this case, the smaller the volume-based median diameter D50B of the microcapsules B, The higher the color density of the high-pressure portion, the higher the gradation can be.

On the other hand, in the measurement of a micro pressure of 0.05 MPa or less, from the viewpoint of further suppressing color development due to friction, the volume-based median diameter D50B of the microcapsules B is preferably larger than the volume-based median diameter of the microcapsules A. Value particle size D50A. As a result, the effect of the microcapsules B to suppress color development due to friction is more effectively exhibited.

The D50B of the microcapsules B is preferably more than 40 μm and less than 150 μm. When the D50B of the microcapsules B is larger than 40 μm, the effect of suppressing color development due to friction is more effectively exhibited.

-Number Average Wall Thickness of Microcapsules B-

The number average wall thickness of the microcapsules B depends on various conditions such as the material of the capsule wall and D50B, but from the viewpoint of more effectively exerting the function of the microcapsules B, it is preferably 50 nm to 1000 nm, and more preferably 100 nm to 800 nm.

The ratio of the number-average wall thickness of the microcapsules B to D50B of the microcapsules B (that is, the number-average wall thickness/D50B ratio) is preferably 2.0×10 ⁻³ to 1.5×10 ⁻² , and more preferably 2.5× 10 ^-3 to 8.0×10 ^-3 .

The microcapsule B is a capsule that does not contain an electron-donating dye precursor as a color-developing component.

"The electron-donating dye precursor is not contained in the microcapsule B" means that the electron-donating dye precursor is substantially not contained in the microcapsule B, and is preferably 0 (zero) mass %.

The microcapsule B can have the same composition (capsule wall material, etc.), production conditions, and capsule properties as the microcapsule A, except that the microcapsule B contains a specific solvent and a specific polar organic compound, and does not contain an electron-donating dye precursor. (capsule wall thickness, particle size, etc.).

The microcapsules B may further contain auxiliary solvents, additives, and the like as needed. In this case, components such as the auxiliary solvent and additives contained in the microcapsules B can be selected from the same components as the auxiliary solvents and additives that can be contained in the microcapsules A.

The material for pressure measurement of the present invention may contain two or more types of microcapsules A having different median particle diameters, or two or more types of microcapsules B having different median particle diameters.

When two or more types of microcapsules A having different median particle diameters are contained, the number of microcapsules with large diameters that are destroyed decreases as the pressure increases, and then the microcapsules with small diameters are destroyed and colored, so the pressure is high. The color density in the area of is increased, and as a result, it becomes a material for pressure measurement which is more excellent in the density level in the high density area.

The methods for producing the microcapsules A and B described above are not particularly limited, and conventionally known methods can be applied. For example, refer to the methods described in paragraphs 0036 to 0044 of Japanese Patent Laid-Open No. 2009-019949.

Hereinafter, more specific structural examples of the material for pressure measurement of the present invention will be described, but the material for pressure measurement of the present invention is not limited to the following aspects.

The material for pressure measurement of the present invention preferably has a so-called two-plate form including a first material including a color-developing agent layer and a second material including a color-developing agent layer.

The material for pressure measurement of the present invention may have a so-called monolithic form having a laminated structure including a color former layer and a color developer layer on a base material.

Hereinafter, the material for pressure measurement of the present invention may be referred to as "material for pressure measurement A" having a two-piece form, and "material for pressure measurement B" having a single-piece form in some cases.

The pressure measurement using the two-piece type pressure measurement material A is performed by overlapping the first material and the second material in the direction in which the surface of the color-forming agent layer of the first material is in contact with the surface of the color-forming agent layer of the second material. and proceed. Specifically, the first material and the second material in a superimposed state are arranged at the location where the pressure or pressure distribution is to be measured, and the measurement can be performed by applying pressure to the first material and the second material in this state.

The pressure measurement using the single-piece type pressure measurement material B can be performed by arranging the pressure measurement material B alone at the location where the pressure or pressure distribution is to be measured, and applying pressure to the pressure measurement material B in this state.

The pressure may be any of point pressure, line pressure, and surface pressure.

In the material for pressure measurement of the present invention, the two-piece type material A for pressure measurement has a small color-developing density difference (density difference) for recognizing a minute pressure difference in a minute pressure range of 0.05 MPa or less. Therefore, it can be used particularly preferably in the measurement of the pressure or the pressure distribution when the surface pressure for which it is difficult to grasp the pressure difference is applied.

In the pressure measurement material A or B, the microcapsules A are contained in the color-forming agent layer, and the microcapsules B are contained in at least one of the layers constituting the pressure measurement material A or B.

Among the layers constituting the pressure measurement material A or B, the layer containing the microcapsules B may contain only one type of microcapsules B, or may contain two or more types (for example, two or more types with different median particle diameters on a volume basis). .

<Material A for pressure measurement (two-piece type)>

When the material for pressure measurement of the present invention is a two-piece type (that is, the material for pressure measurement A), it is preferable to use a method including a first material, and the coloring agent layer containing the microcapsules A is arranged on the first base. and a second material, wherein the color developer layer containing the electron-accepting compound is disposed on the second substrate, and at least one of the first material and the second material contains microcapsules B.

The details of the microcapsules A and the microcapsules B in the material A for pressure measurement are as described above, and the preferred embodiments are also the same.

In the material A for pressure measurement, the microcapsules B may be contained in the first material, and the microcapsules B may be contained in the second material. Further, in the material A for pressure measurement, both the first material and the second material may contain the microcapsules B, and either the first material or the second material may contain the microcapsules B.

In the material A for pressure measurement, the layer containing the microcapsules B may be the color former layer of the first material, the layers other than the color former layer of the first material, the color former layer of the second material, and the color former layer of the second material. Any of the layers other than the color developer layer in the second material.

The pressure measurement material A is more preferably a form in which the color-forming agent layer in the first material is a layer containing the microcapsules B, or a form in which the color-developing agent layer in the second material is a layer containing the microcapsules B.

Examples of the structure of the layer containing the microcapsules B in the material A for pressure measurement include the following forms 1A to 4A, but are not limited to these. In addition, each aspect may include other arbitrary layers (for example, an easy-adhesion layer, etc.).

～Mode 1A～

A mode having a first material and a second material in which the color-forming agent layer containing microcapsules A and microcapsules B is arranged on a first substrate, and the second material is arranged on the second substrate There is a developer layer containing a developer.

- Mode 2A

A mode having a first material and a second material, wherein the first material includes a coloring agent layer containing microcapsules A and another layer containing microcapsules B on the first substrate in this order from the first substrate side, and the second The material includes a developer layer containing a developer on the second base material.

～Mode 3A～

A mode having a first material and a second material, wherein the other layer containing the microcapsules B and the coloring agent layer containing the microcapsules A are arranged on the first base material in this order from the first base material side in the first material. In the second material, a color developer layer is disposed on the second base material.

～Mode 4A～

A mode having a first material and a second material, the first material having a color-forming agent layer containing microcapsules A arranged on a first substrate, and the second material having a color-developing agent layer arranged on the second substrate agent and the developer layer of microcapsule B.

When at least one of the color-forming agent layer in the first material or the color-forming agent layer in the second material contains the microcapsules B, from the viewpoint of more effectively suppressing color development by friction, the microcapsules B are Capsule B is preferably contained in the color-forming agent layer in the first material.

In the material A for pressure measurement, D50A of the microcapsules A is more than 10 μm and less than 40 μm, and D50B of the microcapsules B is more than 40 μm and less than 150 μm. The more preferable ranges of each of D50A and D50B are as described above, respectively.

When the D50B of the microcapsules B is less than 150 μm, the unevenness of the layer containing the microcapsules B (for example, the coating unevenness in the method of coating to form the color former layer) can be further suppressed. In addition, when the microcapsules B are contained in the color former layer, and when D50B is less than 150 μm, the coefficient of variation (CV value; Coefficient of Variation; hereinafter, also referred to as the particle size distribution of the color former layer) CV value.) will not become too large, so the gradation of the hair color is further improved. In addition, the CV value will be described later.

When the material A for pressure measurement develops color, it is only necessary to show a visually recognizable or readable concentration and concentration level, but it is preferable to subtract the application at 0.04 MPa from the concentration after applying pressure at 0.05 MPa to develop color. The density difference (ΔD1) of the density after color development under pressure is 0.20 or more.

The larger the value of ΔD1 at which color is developed from the color former layer, the better, and when the value is 0.20 or more, the material for pressure measurement of the present invention can be more favorable when a slight pressure of 0.05 MPa or less is applied to develop color. Reproduces visually identifiable or readable concentrations and concentration levels.

The color development density is a value measured using a reflection densitometer (for example, RD-19I manufactured by Greda Macbeth).

In addition, the material A for pressure measurement is preferably placed on the color-forming agent layer of the first material so that the color-forming agent layer of the second material and the color-forming agent layer having the same area as the color-forming agent layer of the first material are brought into contact with and overlapped with each other. The density difference (ΔD2) of the color development density after rubbing minus the density before rubbing is suppressed to be less than 0.02 by repeatedly moving the first material with respect to the second material 20 times.

If ΔD2 is less than 0.02, the color development that can be visually recognized or readable by rubbing is suppressed to a small amount.

The smaller the ΔD2 value, the more preferable it is, the case where it is less than 0.01 is more preferable, and the case where it is zero (ie, no color development) is still more preferable.

Hereinafter, the first material and the second material in the material A for pressure measurement will be described.

[First material]

The material A for pressure measurement includes a first material, and the color-forming agent layer containing the microcapsules A containing the electron-donating dye precursor in the first material is arranged on the first substrate.

The first material includes a first base material and a color former layer disposed on the first base material.

[First Substrate]

The shape of the first base material in the material A for pressure measurement may be any of a sheet shape, a film shape, a plate shape, and the like.

When the material for pressure measurement is a two-piece type, the first base material in the first material and the second base material in the second material may be the same or different.

As a specific example of a 1st base material, paper, a plastic film, a synthetic paper, etc. are mentioned.

Specific examples of the paper include high-quality paper, medium-quality paper, groundwood paper, neutral paper, acid paper, recycled paper, coated paper, machine-coated paper, art paper, and cast-coated paper. , fine coated paper, tracing paper, recycled paper, etc.

Specific examples of plastic films include polyester films such as polyethylene terephthalate films, cellulose derivative films such as cellulose triacetate, polyolefin films such as polypropylene and polyethylene, and polystyrene films. .

Specific examples of the synthetic paper include those obtained by biaxially stretching polypropylene, polyethylene terephthalate, etc. to form a large number of microvoids (Yupo, etc.), using polyethylene, polypropylene, polyethylene terephthalate, etc. Synthetic paper made of synthetic fibers such as ethylene terephthalate and polyamide, a part of paper laminated with these synthetic papers, single-sided or double-sided synthetic paper, and the like.

Among them, from the viewpoint of further increasing the color density due to pressurization, a plastic film and a synthetic paper are preferable, and a plastic film is more preferable.

[color former layer]

The color-forming agent layer in the first material contains microcapsules A containing an electron-donating dye precursor.

The color-forming agent layer may contain only one type of microcapsules A, or may contain two or more types. For example, two or more types of microcapsules A having different median particle diameters based on volume may be contained. The color-forming agent layer may contain other components as needed.

In the first material, the color-forming agent layer preferably contains not only the microcapsules A that contribute to color development when pressure is applied, but also contains no electron-donating dye precursor but contains a specific solvent and a specific polarity Microcapsules B which are organic compounds and do not develop color under pressure, more preferably contain microcapsules B having a larger median particle diameter than that of microcapsules A (D50A<D50B). By including the microcapsules B in the color-forming agent layer, when an unexpected minute pressure is applied, the microcapsules B are first destroyed to prevent the destruction of the microcapsules A, so that unexpected color development properties can be suppressed. In addition, when the microcapsules A are destroyed by the specific solvent and the specific polar organic compound released outside the microcapsules, the sensitivity and color development are further improved. Thereby, unnecessary color development due to friction or the like can be suppressed, and the measurement performance can be further improved.

From the viewpoint of improving the color-developing property in the micro-pressure range of 0.05 MPa or less, the content (eg, coating amount) of the color-forming agent layer species of the electron-donating dye precursor is preferably 0.1 g/m ² by mass after drying -5 g/m ² , more preferably 0.1 g/m ² - 4 g/m ² , still more preferably 0.2 g/m ² - 3 g/m ² .

The content in the color-forming agent layer of the microcapsules A (the coating amount in the case of coating) is preferably 50% by mass to 80% by mass relative to the total solid content mass of the color-forming agent layer, and more preferably 60% by mass. mass % to 75 mass %.

When the color former layer contains the microcapsules B, the content of the microcapsules B in the color former layer (in the case of coating, the coating amount) is preferably based on the total solid content mass of the color former layer. It is 5 mass % - 30 mass %, More preferably, it is 10 mass % - 25 mass %.

The color-forming agent layer may contain other components than the microcapsules A and B.

As other components, water-soluble polymer binders (for example, fine powder of starch or starch derivatives, buffers such as cellulose fiber powder, polyvinyl alcohol, etc.), hydrophobic polymer binders (for example, vinyl acetate, acrylic, styrene/butadiene copolymer latex, etc.), surfactants, inorganic particles (such as silica particles), optical brighteners, defoaming agents, penetrants, ultraviolet absorbers and Preservatives etc.

Examples of the surfactant used in the color former layer include sodium alkylbenzenesulfonate (eg, NEOGEN T from DKS Co. Ltd., etc.) as an anionic surfactant, and nonionic surfactants. The polyoxyalkylene lauryl ether (for example, NOIGEN LP70 of DKS Co. Ltd., etc.) and so on.

Examples of silica particles used in the color former layer include fumed silica, colloidal silica, and the like.

Regarding the silica particles, as an example of a commercially available product, the Snowtex series (for example, Snowtex (registered trademark) 30) of Nissan Chemical Corporation can be mentioned.

The CV value of the particle size distribution of all the particles contained in the color former layer is preferably 35% to 150%.

When the CV value is within the above-mentioned range, the particle distribution in the color former layer, particularly the relative variation of the microcapsules, is small, so that the color development property against micro pressure and the color development prevention property due to friction or the like are well balanced.

The CV value is preferably 40% to 110%, and more preferably 40% to 80%.

In addition, the CV value represents the relative variation of the particles of the color-forming agent layer, and is a value obtained as follows.

CV value (%) = standard deviation / arithmetic mean particle size × 100

The arithmetic mean particle diameter and the standard deviation are values calculated by photographing the surface of the color-forming agent layer with an optical microscope at 150 times, and measuring the size of all the microcapsules in the range of 2 cm×2 cm.

～Formation of color former layer～

The color-forming agent layer in the material A for pressure measurement can be applied (eg, coated) to the first base by, for example, applying (eg, coating) a color-forming agent layer-forming coating liquid containing the components of the color-forming agent layer and a liquid component (eg, water) described above. on wood and allowed to dry.

The coating liquid for forming a color-forming agent layer can be prepared, for example, by preparing an aqueous dispersion of microcapsules A, and mixing the aqueous dispersion of microcapsules A and other components as necessary.

In the case of forming a color-forming agent layer containing two or more types of microcapsules A having different D50A and the like, it is preferable to prepare an aqueous dispersion for each of the two or more types of microcapsules A, and use the obtained two or more types of microcapsules A. An aqueous dispersion of the microcapsules A was used to prepare a coating liquid for forming a color-forming agent layer.

In the case where the color-forming agent layer contains the microcapsules B, the coating liquid for forming the color-forming agent layer for forming the color-forming agent layer preferably prepares an aqueous dispersion of the microcapsules A and an aqueous dispersion of the microcapsules B, respectively, and Using the obtained aqueous dispersion of microcapsules A, the aqueous dispersion of microcapsules B, and other components, a coating liquid for forming a color-forming agent layer was prepared.

When the coating liquid for color former layer formation is apply|coated to a base material to form a color former layer, it can apply|coat by a well-known coating method.

As the coating method, for example, an air knife coater, a rod coater, a bar coater, a curtain coater, a gravure coater, an extrusion coater, a die coater, a slide coater, a Coating methods such as bead coater and knife coater.

The thickness of the color-forming agent layer is not particularly limited, and can be selected according to the purpose and the like.

The thickness of the color former layer (when the diameter of the microcapsules is larger than the layer thickness, the thickness excluding the microcapsules exposed from the layer surface) is preferably 0.01 μm to 0.10 μm, and more preferably 0.02 μm to 0.07 μm.

[Material 2]

The material for pressure measurement of the present invention includes a second material in which a color developer layer containing an electron-accepting compound is disposed on a second substrate.

The second material includes a second base material and a color developer layer disposed on the second base material.

[Second base material]

As a 2nd base material, the same base material as a 1st base material is mentioned.

In the material for pressure measurement of the present invention, the material of the first base material and the material of the second base material may be the same or different.

[color developer layer]

The color developer layer contains at least an electron-accepting compound as a color developer, and may further contain other components such as a binder, a pigment, and an additive, if necessary. In addition, the color-developing agent contained in the microcapsules is not included in the so-called color-developing agent.

Examples of the electron-accepting compound include inorganic compounds and organic compounds.

Specific examples of the inorganic compound include acidic clays, activated clays, attapulgite, zeolite, clay substances such as bentonite and kaolin, and the like.

Specific examples of the organic compound include metal salts of aromatic carboxylic acids, phenol resins, metal salts of carboxylated terpene phenol resins, and the like.

Among them, acid clays, activated clays, zeolites, kaolins, metal salts of aromatic carboxylic acids, and metal salts of carboxylated terpene phenol resins are preferred, and acid clays, activated clays, kaolins, and metal salts of aromatic carboxylic acids are more preferred. .

Preferable specific examples of metal salts of aromatic carboxylic acids include 3,5-di-tert-butylsalicylic acid, 3,5-di-tert-octylsalicylic acid, 3,5-di-tert-butylsalicylic acid Nonylsalicylic acid, 3,5-di-tert-dodecylsalicylic acid, 3-methyl-5-tert-dodecylsalicylic acid, 3-tert-dodecylsalicylic acid, 5- tert-dodecylsalicylic acid, 5-cyclohexylsalicylic acid, 3,5-bis(α,α-dimethylbenzyl)salicylic acid, 3-methyl-5-(α-methylbenzyl) base) salicylic acid, 3-(α,α-dimethylbenzyl)-5-methylsalicylic acid, 3-(α,α-dimethylbenzyl)-6-methylsalicylic acid, 3-(α-methylbenzyl)-5-(α,α-dimethylbenzyl)salicylic acid, 3-(α,α-dimethylbenzyl)-6-ethylsalicylic acid, 3-phenyl-5-(α,α-dimethylbenzyl)salicylic acid, carboxyl-modified terpene phenol resin, as 3,5-bis(α-methylbenzyl)salicylic acid and benzyl Zinc salts such as salicylic acid resins, nickel salts, aluminum salts, calcium salts, etc., which are the reaction products of chlorine.

As the color developer contained in the color developer layer, among the specific organic compounds that the microcapsules B can contain, a compound that can function as a color developer can be used.

The content in the developer layer of the electron-accepting compound (coating amount in the case of coating) is preferably 0.1 g/m ² to 30 g/m ² by dry mass. More preferably, it is 3 g/m ² to 20 g/m ² in the case of an inorganic compound, 0.1 g/m ² to 5 g/m ² in the case of an organic compound, and still more preferably 5 g/m in the case of an inorganic compound. m ² to 15 g/m ² , and in the case of an organic compound, it is 0.2 g/m ² to 3 g/m ² .

The color-developer layer can be formed by preparing a preparation liquid for color-developer layer formation and forming a film. For example, the color developer layer can be formed by applying the preparation liquid for forming a color developer layer on the support by a method such as coating and drying it.

The preparation liquid for forming a color developer layer may be a dispersion liquid in which the electron accepting compound is dispersed in water or the like.

The dispersion liquid in which the electron-accepting compound is dispersed can be prepared by mechanically dispersing the inorganic compound in water when the electron-accepting compound is an inorganic compound, and when the electron-accepting compound is an organic compound It can be prepared by mechanically dispersing an organic compound in water or dissolving it in an organic solvent.

For details, the method described in Japanese Patent Laid-Open No. 8-207435 can be referred to.

The obtained dispersion liquid of the electron-accepting compound can be used as it is as a preparation liquid (for example, a coating liquid) for forming a color-developing agent layer for forming a color-developing agent layer containing the electron-accepting compound.

The color developer layer can contain additives such as binders, pigments, optical brighteners, antifoaming agents, penetrants, antiseptics, etc., in addition to the above-mentioned electron accepting compounds.

The color developer layer preferably also contains the microcapsules B.

The specific polar organic compound contained in the microcapsules B contained in the color-developing agent layer may be a compound having a sensitizing ability or a compound having a color-developing ability. One of the preferred modes is a mode in which the microcapsules B contain a compound having a sensitizing ability as a specific polar organic compound.

The details of the microcapsules B contained in the color developer layer are as described above, and the preferred ranges are also the same.

When the color developer layer contains the microcapsules B, the content of the microcapsules B in the color developer layer (the coating amount in the case of coating) is preferably based on the total solid content mass of the color developer layer. It is 5 mass % - 30 mass %, More preferably, it is 10 mass % - 25 mass %.

Examples of the binder include styrene-butadiene copolymer latex, vinyl acetate-based latex, acrylate-based latex, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene-copolymer, starch, phenolic Synthetic or natural macromolecular substances such as protein, gum arabic, gelatin, carboxymethyl cellulose, methyl cellulose, etc.

Examples of pigments include kaolin, calcined kaolin, kaolin aggregates, ground calcium carbonate, various forms (rice grain shape, angular shape, spindle shape, IGA (hair ball) shape, spherical shape, aragonite-based columnar shape, random shape shape, etc.), light calcium carbonate, talc, rutile-type or anatase-type titanium dioxide, etc.

When forming the color-developing agent layer by applying the preparation liquid for forming a color-developing agent layer, the coating can be performed by a known coating method, and the same coating method as in the case of forming the color-developing agent layer can be applied.

[Easy bonding layer]

The first base material or the second base material may be a base material with an easily bonding layer.

The first material preferably has a first base material, an easily bonding layer and a color former layer arranged from the side of the first base material. It is preferable to provide an easily bonding layer in order to improve the adhesiveness of a 1st base material and a color former layer.

Also, in the easy-adhesive layer, when the composition containing the microcapsules is applied and dried, the microcapsules and the easy-adhesion layer are inhibited from electrostatically interacting (for example, hydrogen bonding) and agglomerating. Thereby, when the pressure is measured, the effect of breaking the microcapsules by the minute pressure is enhanced.

The easy-bond layer may be a layer comprising a urethane polymer and/or a blocked isocyanate.

There is no restriction|limiting in particular as thickness of an easily bonding layer, According to the objective etc., it can select.

The thickness of the easily bonding layer is preferably 0.005 μm to 0.2 μm, and more preferably 0.01 μm to 0.1 μm.

<Material for single-piece pressure measurement>

When the material for pressure measurement of the present invention is a monolithic type (that is, the material for pressure measurement B), the material for pressure measurement B includes a color developer containing an electron-accepting compound on the substrate in this order from the substrate side The laminated structure of the layer and the color-forming agent layer containing the microcapsules A is preferably an aspect in which the microcapsules B are contained in at least one layer included in the laminated structure.

The layer of the laminated structure containing the microcapsules B may be any of a color former layer, a color former layer, or other layers other than the color former layer and the color former layer.

Examples of the structure of the layer containing the microcapsules B in the material B for pressure measurement include the following forms 1B to 5B, but are not limited to these. In addition, each aspect may include other arbitrary layers (for example, an easy-adhesion layer, etc.).

～Mode 1B～

A form in which a color former layer containing microcapsules A and microcapsules B and a color former layer containing a color developer are arranged on the base material in this order from the base material side.

- Mode 2B

A form in which a color-developing agent layer containing a color-developing agent, another layer containing the microcapsules B, and a color-forming agent layer containing the microcapsules A are arranged on the base material in this order from the base material side.

～Mode 3B～

On the base material, a color former layer containing a color developer and microcapsules B, and a color former layer containing microcapsules A are arranged in this order from the base material side.

～Mode 4B～

A form in which a color-developing agent layer containing a color-developing agent and a color-developing agent layer containing the microcapsules A and B are arranged in this order from the base material side on the base material.

～Mode 5B～

A form in which a color-developing agent layer containing a color-developing agent, a color-forming agent layer containing microcapsules A, and other layers containing microcapsules B are arranged on the base material in this order from the base material side.

One of the preferable aspects of the single-piece type pressure measurement material B is an aspect in which the microcapsules B containing a specific polar organic compound having a sensitizing ability are contained in the color-developing agent layer containing the color-developing agent.

In addition, an aspect in which the microcapsules A and the microcapsules B are in the same layer can also be expected to improve the diffusivity and compatibility of the compound contributing to the color-forming reaction, which is preferable.

As a base material in the material B for pressure measurement, the same base material as the 1st base material in the material A for pressure measurement can be mentioned.

The details of the microcapsules A and the microcapsules B in the material B for pressure measurement are as described above, and the preferred embodiments are also the same.

The details of each layer, such as the color-forming agent layer, the color-developing agent layer, and other layers containing the microcapsules B, contained in the material for pressure measurement The matters already explained for each layer, such as the toner layer and other layers containing the microcapsules B, are the same.

In addition, the production of the pressure measurement material B can be the same as the production of the pressure measurement material A except that each layer, such as a color former layer and a color developer layer, is formed on a single substrate.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it deviates from the gist of the invention. In addition, unless otherwise specified, "%" and "part" are quality standards.

[Example 1]

<Preparation of liquid containing microcapsule A1>

Solution A was obtained by dissolving 20 parts of the following compound (A) as an electron-donating dye precursor in 57 parts of linear alkylbenzene (JXTG Nippon Oil & Energy Corporation, olefin grade L).

The obtained solution A was stirred, and 15 parts of synthetic isoparaffin 1 (Idemitsu Kosan Co., Ltd., IP solvent 1620) and N,N,N',N'-tetrakis dissolved in 1.2 parts of ethyl acetate were added. (2-hydroxypropyl) ethylenediamine (ADEKA CORPORATION, ADEKA polyether EDP-300) 0.2 part, and the solution B was obtained.

The obtained solution A was stirred, and the solution C was obtained by adding 1.2 parts of trimethylolpropane adducts (DIC CORPORATION, Vernock D-750) of toluene diisocyanate dissolved in 3 parts of ethyl acetate.

Next, the said solution C was added to the solution which melt|dissolved 9 parts of polyvinyl alcohol (PVA-205, Kuraray Co., Ltd.) in 140 parts of water, and emulsification dispersion was performed. 340 parts of water was added to the obtained emulsion, and it heated to 70 degreeC while stirring, and it cooled after stirring for 1 hour. Water was further added to the cooled liquid to adjust the solid content concentration.

As described above, the microcapsule A1-containing solution (solid content concentration 19.6%) containing the microcapsule A1 containing the electron-donating dye precursor was obtained. The microcapsule A1 is contained in the microcapsule A in the present invention.

[Chemical formula 1]

In the microcapsules A1 contained in the microcapsule A1-containing solution, the volume-based median diameter (D50A) was 30 μm, the number average wall thickness was 0.054 μm, and δ ^A /D50A was 1.8×10 ⁻³ .

The median particle diameter (D50A) and number average wall thickness of the microcapsules A1 were calculated as follows.

First, the solution containing the microcapsules A1 was applied on a polyethylene terephthalate (PET) sheet (TOYOBO CO., LTD. Cosmo Shine (registered trademark) A4300) with a thickness of 75 μm with an easy-adhesion layer. and drying to obtain a coating film.

The surface of the obtained coating film was photographed by an optical microscope at 150 times, and the circle-equivalent diameters of all the microcapsules A1 in the range of 2 cm×2 cm were measured, and the D50A of the microcapsules A1 was calculated from the obtained results.

A cross-sectional slice of the above-mentioned coating film was prepared, five microcapsules A1 were selected from the cross-section, the thickness (μm) of each capsule wall was obtained by a scanning electron microscope (SEM), and the obtained values were simply averaged. The number average wall thickness of the microcapsules A1 was calculated.

<Preparation of Microcapsule B1-Containing Liquid (1)>

15 parts of synthetic isoparaffin 1 (Idemitsu Kosan Co., Ltd., IP solvent 1620, specific solvent, flow point: <-70°C) and N,N,N',N dissolved in 3 parts of ethyl acetate 0.4 part of '-tetrakis(2-hydroxypropyl)ethylenediamine (ADEKACORPORATION, ADEKA polyether EDP-300), added to the stirring aromatic oil (HISOL (registered trademark) SAS296 (1-phenyl-1-xylene) A solution D was obtained in 78 parts of a mixture of ethyl ethane and 1-phenyl-1-ethylphenyl ethane, Nippon Oil Corporation, specific solvent, pour point: <-47.5°C).

The obtained solution D was stirred, and 3 parts of a trimethylolpropane adduct (DIC CORPORATION, Vernock D-750) of toluene diisocyanate dissolved in 107 parts of ethyl acetate and stearic acid amide (Nihon Kasei CO. ., LTD., AMIDE AP-1, specific polar organic compound, melting point: 101° C.) 5 parts to obtain solution E.

Next, the said solution E was added to the solution which melt|dissolved 69 parts of polyvinyl alcohol (PVA-205, Kuraray Co., Ltd.) in 140 parts of water, and emulsification dispersion was performed. 340 parts of water was added to the obtained emulsion, and it heated to 70 degreeC while stirring, and it cooled after stirring for 1 hour. Water was further added to the cooled liquid to adjust the concentration.

As described above, a microcapsule B1-containing liquid (solid content concentration 19.6%) containing microcapsules B1 containing aromatic oil and isoparaffin as a specific solvent, and stearin as a specific polar organic compound was obtained Acid amide, and contains no electron-donating dye precursors. The microcapsule B1 is contained in the microcapsule B in the present invention. The specific solvent in the microcapsule B1 contains aromatic oil as a main solvent.

Stearic acid amide is a specific polar organic compound that functions as a sensitizer.

In the microcapsule B1, the median particle diameter (D50B) under the volume standard was 55 μm, the number average wall thickness was 0.10 μm, and the δB/D50B was 1.8×10 ⁻³ .

The methods for measuring D50B and the number average wall thickness of the microcapsules B1 are the same as the methods for measuring D50A and the number average wall thickness of the microcapsules A1, respectively.

<Preparation of Coating Liquid (1) for Color-Forming Agent Layer Formation>

18 parts of the microcapsule A1-containing liquid obtained above, 2 parts of the microcapsule B1-containing liquid obtained above, 63 parts of water, 1.8 parts of colloidal silica (Nissan Chemical Corporation, Snowtex (registered trademark) 30), carboxymethyl 1.8 parts of a 10% aqueous solution of base cellulose Na (DKS Co. Ltd., CELLOGEN 5A), 30 parts of a 1% aqueous solution of carboxymethyl cellulose Na (DKS Co. Ltd., CELLOGEN EP), sodium alkylbenzenesulfonate ( 0.3 part of a 15% aqueous solution of DKS Co. Ltd., NEOGEN T) and 0.8 part of a 1% aqueous solution of NOIGEN LP70 (DKS Co. Ltd.) were mixed and stirred for 2 hours to obtain a coating liquid for forming a color former layer (1).

<Preparation of the first material>

On a polyethylene terephthalate (PET) sheet (TOYOB O CO., LTD., Cosmo Shine (registered trademark) A4300, first base material) with an easy-adhesion layer having a thickness of 75 μm, dried The obtained coating liquid (1) for forming a color-forming agent layer was applied by a bar coater so that the mass after it became 2.8 g/m ² , and was dried to form a color-forming agent layer.

As described above, the first material in which the color-forming agent layer containing the microcapsules A1 and B1 is arranged on the first base material is obtained.

<Preparation of Coating Liquid (1) for Forming Color Developer Layer>

Using a sand mill, 10 parts of zinc 3,5-di-α-methylbenzyl salicylate, 100 parts of calcium carbonate, 1 part of sodium hexametaphosphate, and 200 parts of water as electron-accepting compounds were prepared into all particles. The dispersion liquid was obtained by dispersing so that the average particle diameter of 2 μm might be obtained.

To the obtained dispersion liquid, 100 parts of a 10% aqueous solution of polyvinyl alcohol (PVA-203, KURARAY CO., LTD.), 10 parts of styrene-butadiene latex as solid content, and 450 parts of water were added, thereby A coating liquid (1) for forming a color developer layer containing an electron-accepting compound was prepared.

<Preparation of the second material>

On a polyethylene terephthalate (PET) sheet (second base material) having a thickness of 75 μm, the color developer layer obtained above was applied so that the solid content coating amount would be 4.0 g/m ² . The coating liquid (1) for forming is formed, and is dried to form a developer layer.

As described above, the second material in which the color developer layer containing 3,5-di-α-methylbenzylzinc salicylate as the electron-accepting compound was arranged on the second base material was obtained.

As described above, the two-piece pressure measurement material (1) including the first material and the second material was obtained.

[Example 2]

In the preparation of the microcapsule B1-containing liquid of Example 1, except that 5 parts of stearic acid amide was changed to 5 parts of zinc 3,5-di-α-methylbenzyl salicylate (melting point: 125°C) Other than that, in the same manner as in Example 1, a two-piece type pressure measurement material (2) was produced.

[Example 3]

In the preparation of the microcapsule B1-containing liquid of Example 1, except that 5 parts of stearic acid amide was changed to 5 parts of 2,4-dihydroxydiphenylsulfone (melting point: 184° C.), the same as Example 1 In the same manner, a two-piece pressure measurement material (3) was produced.

[Example 4]

Except having changed 5 parts of stearic acid amide to 5 parts of 4-hydroxy-4'-isopropoxydiphenyl sulfone (melting point: 128°C) in preparation of the microcapsule B1-containing liquid of Example 1, In the same manner as in Example 1, a two-piece type pressure measurement material (4) was produced.

[Example 5]

<Preparation of Coating Liquid (2) for Color-Forming Agent Layer Formation>

In the preparation of the coating liquid (1) for forming a coloring agent layer of Example 1, except that 2 parts of the liquid containing the microcapsules B1 were not used, the same as the coating liquid (1) for forming a coloring agent layer was used. The coating liquid (2) for forming the coloring agent layer was prepared in the manner of the above-mentioned method.

<Preparation of the first material>

On a polyethylene terephthalate (PET) sheet (TOYOB O CO., LTD., Cosmo Shine (registered trademark) A4300, first base material) with an easy-adhesion layer having a thickness of 75 μm, dried The above-obtained coating liquid (2) for forming a color-forming agent layer was applied by a bar coater so that the mass after that was 2.6 g/m ² and dried to form a color-forming agent layer.

As described above, the first material in which the color-forming agent layer containing the microcapsules A and not containing the microcapsules B is arranged on the first base material is obtained.

<Preparation of the second material>

A color developer layer was prepared in the same manner as in Example 1, except that 40 parts of the microcapsule B1-containing liquid was also added in the preparation of the coating liquid (1) for forming a color developer layer of Example 1. Forming coating liquid (2). In Example 1, except having used the coating liquid (2) for forming a color developing agent layer which was changed to the coating liquid for forming a color developing agent layer (1), it was produced in the same manner as in Example 1. 2nd material.

As described above, the two-piece pressure measurement material (5) including the first material and the second material is obtained.

[Example 6]

The same coating liquids as the coating liquid (1) for color developer layers and the coating liquid (1) for color former layers prepared in Example 1 were prepared, respectively.

On a polyethylene terephthalate (PET) sheet (TOYOB O CO., LTD., Cosmo Shine (registered trademark) A4300, substrate) with an easy-adhesion layer having a thickness of 75 μm, a solid coating was applied. The color developer layer coating liquid (1) was applied by a bar coater so that the cloth amount became 4.0 g/m ² to form a color developer layer. Next, on the color-developing agent layer, the coating liquid for color-forming agent layer (1) was superimposed and applied by a bar coater so that the solid content coating amount was 2.8 g/m ² to form a color-forming agent layer. .

As described above, the monolithic pressure measurement material (6) in which two layers of the color developer layer and the color former layer are stacked on the substrate in this order from the substrate side was obtained.

As described above, the monolithic pressure measurement material (6) provided with the color former layer and the color former layer was obtained.

[Example 7]

In the preparation of the microcapsule B1-containing solution (1) of Example 1, except that the emulsification conditions were changed so that the capsule particle size was 30 μm, a microcapsule B2-containing microcapsule was prepared in the same manner as in Example 1. Capsule B2 contains liquid (solid content concentration 19.6%).

In the microcapsule B2 contained in the microcapsule B2-containing liquid, the median particle diameter (D50A) in the volume standard was 30 μm, the number average wall thickness was 0.054 μm, and the δ ^A /D50A was 1.8×10 ⁻³ .

In the preparation of the coating liquid (1) for forming a color-forming agent layer of Example 1, 2 parts of the microcapsule B2-containing liquid was used in place of the 2 parts of the microcapsule B1-containing liquid (1), except that 2 parts of the microcapsule B2-containing liquid were used. A coating liquid (3) for forming a toner layer was prepared in the same manner as in Example 1.

In Example 1, except that the coating liquid (3) for forming a coloring agent layer was used in place of the coating liquid for forming a coloring agent layer (1), it was carried out in the same manner as in Example 1 to prepare the first 1st material and 2nd material.

As described above, the two-piece pressure measurement material (7) including the first material and the second material is obtained.

[Example 8]

In the preparation of the microcapsule B1-containing solution (1) of Example 1, synthetic isoparaffin 2 (Idemitsu Kosan Co., Ltd., IP solvent 2835, specific solvent, fluid) was used instead of 15 parts of synthetic isoparaffin 1 A microcapsule B1-containing liquid (2) containing the microcapsules B2 was prepared in the same manner as in Example 1, except for 15 parts of points: <-60°C).

In the preparation of the coating liquid (1) for forming a color former layer of Example 1, except that 2 parts of the microcapsule B1-containing liquid (2) was used instead of the 2 parts of the microcapsule B1-containing liquid (1), In the same manner as in Example 1, a coating liquid (4) for forming a coloring agent layer was prepared.

In Example 1, except that the coating liquid (4) for forming a coloring agent layer was used in place of the coating liquid for forming a coloring agent layer (1), a second coating liquid was prepared in the same manner as in Example 1. 1st material and 2nd material.

As described above, a two-piece pressure measurement material (8) including the first material and the second material is obtained.

[Comparative Example 1]

<Preparation of liquid containing microcapsule B3>

A microcapsule B3-containing solution containing microcapsules B3 was obtained in the same manner as in the preparation of the microcapsule B1-containing solution except that 5 parts of stearic acid amide was not used in the preparation of the microcapsule B1-containing solution of Example 1 ( Solid content concentration 19.6%).

<Preparation of Coating Liquid (C1) for Color-Forming Agent Layer Formation>

In the preparation of the coating liquid (1) for forming a color-forming agent layer of Example 1, except that 2 parts of the liquid containing the microcapsules B1 was changed to 2 parts of the liquid containing the microcapsules B3, the color-forming agent layer was formed with A coating liquid (C1) for forming a coloring agent layer was prepared in the same manner as the coating liquid (1).

<Preparation of the first material>

On a polyethylene terephthalate (PET) sheet (TOYOB O CO., LTD., Cosmo Shine (registered trademark) A4300, first base material) with an easy-adhesion layer having a thickness of 75 μm, dried The coating liquid for color former layer formation (C1) obtained above was applied by a bar coater so that the mass after it became 2.8 g/m ² and dried to form a color former layer.

As described above, the first material in which the color-forming agent layer containing the microcapsules A1 and the microcapsules B3 not containing the specific organic compound is arranged on the first base material is obtained.

<Preparation of the second material>

The second material was produced in the same manner as in Example 1.

As described above, the two-piece type comparative pressure measurement material (9) provided with the first material and the second material was obtained.

[Comparative Example 2]

<Preparation of the first material>

In the preparation of the first material of Example 5, the same procedures as in Example 5 were carried out except that the color-forming agent layer was formed on the first substrate using the coating liquid for color-forming agent layer formation (2). method to produce the first material.

The second material was produced in the same manner as in Example 1.

As described above, a two-piece type comparative pressure measurement material ( 10 ) including the first material and the second material was obtained.

[Comparative Example 3]

In the preparation of the first material of Example 6, except that the specific polar organic compound was not used, it was carried out in the same manner as in Example 6 to obtain a color-developing agent layer and a color-forming agent layer in which two layers were laminated in this order from the base material side. The monolithic pressure measurement material (11).

<Measurement and Evaluation>

The following measurements and evaluations were performed using the obtained pressure measurement materials (1) to (11).

In addition, below, the materials for pressure measurement (1)-(11) are abbreviated as evaluation samples (1)-(11), respectively.

(1) Gradation of color development (difference in density: ΔD1)

About each sample for evaluation, the gradation of color development was evaluated based on the density difference of the color development density when the pressure of 0.05 MPa was applied, and the color development density when the pressure of 0.04 MPa was applied. The evaluation method and evaluation criteria are as follows.

In the following evaluation criteria, the larger the numerical value of the evaluation rank, the more excellent the gradation of color development. The most excellent evaluation grade for the gradation of the hair color is "5".

The results are shown in Table 1.

-Evaluation method-

Regarding the two-piece-type pressure measurement materials (1) to (4) and (6) to (10), the first material and the second material were each cut to a size of 5 cm×5 cm and used as samples for evaluation.

The samples for evaluation overlap in the direction in which the surface of the color former layer of the first material and the surface of the color former layer of the second material are in contact. The superimposed first material and the second material are sandwiched between two glass plates with smooth surfaces and placed on a table, and then a spindle is placed on the two glass plates, thereby sandwiching between the two glass plates. A pressure of 0.04 MPa or 0.05 MPa was applied to the first material and the second material for 120 seconds to develop color.

After pressing, the first material and the second material were peeled off, and the density of the color-developing region formed on the color developer layer of the second material was measured using a reflection densitometer RD-19I (manufactured by Gret ag Macbeth).

The single-piece type pressure measurement materials (5) and (11) were cut out to a size of 5 cm×5 cm, and used as samples for evaluation.

As for the single-piece type pressure measurement material, the prepared sample for evaluation was sandwiched between two glass plates with smooth surfaces and placed on a table, and then a spindle was placed on the two glass plates to sandwich the two. The sheet held in 2 glass plates was subjected to a pressure of 0.04 MPa or 0.05 MPa for 120 seconds to develop color.

After pressurization, the density|concentration of the color-developing area formed on the color-developing agent layer of the sample for evaluation was measured using the reflection densitometer RD-19I (made by Gretag Macbeth).

For each sample for evaluation in which the density of the color-developing region was measured as described above, the color-developing region when a pressure of 0.04 MPa was applied to develop color was subtracted from the density of the color-developing region when a pressure of 0.05 MPa was applied to develop color. The concentration difference (ΔD1) of the concentration.

-Evaluation criteria-

5: ΔD1 is 0.20 or more.

4: ΔD1 is 0.15 or more and less than 0.20.

3: ΔD1 is 0.12 or more and less than 0.15.

2: ΔD1 is 0.10 or more and less than 0.12.

1: ΔD1 is less than 0.10.

(2) Inhibition of color development by friction (difference in density: ΔD2)

About each sample for evaluation, the color development suppression by rubbing was evaluated. The evaluation method and evaluation criteria are as follows. The results are shown in Table 1.

～Dual type～

-Evaluation method-

The two-piece type pressure measurement materials (1) to (4) and (6) to (10) were cut out to the size of 10 cm×15 cm for the first material and the second material, respectively, and used as samples for evaluation.

The color developer layer of the first material and the color developer layer of the second material of the sample for evaluation were brought into contact and overlapped, and the first material was repeatedly moved with respect to the second material 20 times in the overlapped state to rub.

After rubbing, the density of the color-developing region formed on the color developer layer of the sample for evaluation was measured using a reflection densitometer RD-19I (manufactured by Gretag Macbeth).

～Single-piece type～

-Evaluation method-

The single-piece pressure measurement materials (5) and (11) were each cut into a size of 10 cm×15 cm, and used as evaluation samples.

For each of the pressure measurement materials (5) and (11), two samples for evaluation were prepared. Among the two samples for evaluation, when one is set as sample A for evaluation and the other is set as sample B for evaluation, the base material side of sample A for evaluation and the side of sample B for evaluation are set. The color-forming agent layer side was in contact with and overlapped, and the evaluation sample B was repeatedly moved 20 times with respect to the evaluation sample A in the overlapped state to rub.

After rubbing, the density of the color-developing region formed on the color-forming agent layer of Sample B for evaluation was measured using a reflection densitometer RD-19I (manufactured by Gretag Macbeth).

The initial density before rubbing was subtracted from the color development density after rubbing to calculate the density difference (ΔD2).

ΔD2 is an allowable range of less than 0.02, preferably 0.01 or less, and more preferably 0.00 (ie, no color development).

[Table 1]

In Table 1, the description of "-" indicates that the corresponding component is not contained, or the corresponding measurement has not been carried out or

Evaluation.

Hereinafter, the details of the specific solvents described in Table 1 are summarized.

· Synthetic isoparaffin 1 (Idemitsu Kosan Co., Ltd., IP solvent 1620, synthetic isoparaffin, pour point: <-70°C)

· Synthesis of isoparaffin 2 (Idemitsu Kosan Co., Ltd., IP solvent 2835, pour point: <-60°C)

Aroma oil (mixture of 1-phenyl-1-xylylethane and 1-phenyl-1-ethylphenylethane, HISOL (registered trademark) SAS296: specific solvent, Nippon Oil Corporation, pour point: <-47.5℃)

As shown in Table 1, the material for pressure measurement of the Examples has a color density difference (ΔD1) of 0.12 or more ( Evaluation level 3, 4, or 5), excellent gradation of color development under a slight pressure of 0.05 MPa or less, and suppression of color development due to rubbing to a concentration difference (ΔD2) of less than 0.02, and color development due to rubbing was confirmed also suppressed.

On the other hand, in the material for pressure measurement of Comparative Example 1 containing the microcapsules A and the microcapsules not containing the specific polar organic compound and not containing the microcapsules B, the color development due to friction was suppressed, but the color development was The gradation is poor in comparison with the pressure measurement material of each example.

In the material for pressure measurement of Comparative Example 2 containing only the microcapsules A and not containing the microcapsules B, both the gradation of color development and the inhibition of color development by rubbing were poor.

In the material for pressure measurement of the monolithic type Comparative Example 3 containing the microcapsules A and the microcapsules not containing the specific polar organic compound, and not containing the microcapsules B, the color development caused by friction was suppressed, but the color development The layering was poor in comparison with the pressure measurement material of the Examples.

The disclosure of Japanese Patent Application No. 2017-129235 filed on June 30, 2017 is incorporated herein by reference in its entirety.

All documents, patent applications, and technical standards described in this specification are incorporated by reference in this specification to the same extent as the case where each document, patent application, and technical standards are specifically and separately described to be used by reference.

Claims (7)

1, pressure measurement materials comprising:

a microcapsule A containing an electron donating dye precursor; and a microcapsule B containing a solvent having a melting point or a pour point of 30 ℃ or lower and a polar organic compound having a melting point of more than 30 ℃ and containing no electron-donating dye precursor.

2. The material for pressure measurement according to claim 1, wherein,

the polar organic compound having a melting point of more than 30 ℃ is a compound having an alkyl group having 12 or more carbon atoms and an amide bond.

3. The material for pressure measurement according to claim 1, wherein,

the polar organic compound having a melting point of more than 30 ℃ is at least selected from the group consisting of salicylic acid-based compounds, salts of salicylic acid-based compounds, phenol-based compounds and sulfonamide-based compounds.

4. The material for pressure measurement according to any one of claims 1 to 3, wherein,

the volume-standard median particle diameter D50B of the microcapsule B is larger than the volume-standard median particle diameter D50A of the microcapsule a.

5. The pressure measurement material according to any of claims 1 to 4, comprising:

a1 st material in which a color former layer containing the microcapsules A is disposed on a1 st substrate; and

a 2 nd material in which a color developer layer containing an electron accepting compound is disposed on a 2 nd substrate,

at least of the 1 st material and the 2 nd material contain the microcapsule B.

6. The material for pressure measurement according to claim 5, wherein,

on the color agent layer of the 1 st material, the color developer layer of the 2 nd material having the same area as the color agent layer of the 1 st material is in contact with and overlaps with the color agent layer of the 1 st material, and a difference in color density obtained by subtracting the density before friction from the color density after the 1 st material is repeatedly moved 20 times with respect to the 2 nd material is less than 0.02.

7. The material for pressure measurement according to any one of claims 1 to 6, wherein,

the difference in concentration between the concentration after color development under 0.04MPa and the concentration after color development under 0.05MPa is 0.20 or more.