JPH04349468A - Transfer paper for electrophotography - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic transfer paper, and more particularly to an electrophotographic transfer paper that has excellent runnability in equipment and excellent image stability.

0002

[Prior Art] In electrophotographic copiers, printers, and facsimile machines, a charge image is formed on the surface of a photosensitive drum or photosensitive belt containing selenium, amorphous silicon, or an organic semiconductor, and a charge image of opposite polarity to this charge image is formed on the surface of a photosensitive drum or photosensitive belt. The toner particles are attached to the charge image to form a visible image, either by developing with toner particles of the same polarity (positive toner) or by reversal development with toner particles of the same polarity (negative toner), and then exposing the transfer paper to light. The visible image is transferred to the transfer paper by bringing it into contact with the surface and applying corona discharge treatment from the back side of the paper, and then fixed to the transfer paper by heat, light, pressure, etc. to form a printed image.

[0003] Such an electrophotographic copying machine is called a PPC (plain paper copying machine) because it can make copies on ordinary paper, and the electrophotographic transfer paper (PPC) used is called a PPC (plain paper copying machine).
Paper) is also considered to be a plain paper type paper. However, in reality, problems such as image stability (the ability to faithfully transfer the toner image developed on the photoreceptor and firmly fix the toner to the paper in the fixing process) and runnability (the ability to carry heavy Because there are subtle differences in transfer paper (no occurrence of feeding or misfeeding, and small curling), satisfactory results have not been obtained with transfer paper that has the same quality as ordinary high-quality paper.

For example, in high humidity conditions, paper tends to be wavy, wrinkled, and curled, leading to paper jams in the paper feed section and uneven toner transfer in the transfer section. In addition, in heat-fixing copiers, the toner is fixed using a heated roll or an oven, but since the heat is heated to about 120 to 240 degrees Celsius, the moisture in the paper evaporates instantly, causing the paper to shrink and curl significantly. This may reduce the running performance within the equipment.

Furthermore, with the progress of office automation in recent years, various functions have been improved in copiers, printers, and facsimile machines that use electrophotography, and there is also a trend toward increasing added value in usage methods. being done. For example, in copying machines, speed increases,
In addition to improvements in mechanical configuration functions such as scaling, trimming, automatic double-sided copying, and automatic document feeding, improvements in exposure methods, toner quality, recording processes, etc. have improved midtone reproducibility, single-color recording, and multi-color recording. , recording quality such as full-color recording has been improved, and development is progressing from simple monochrome copying machines to high-quality color copying machines that can handle color printed matter. In terms of printers, we are developing page printers and color printers, or printing out data from computers.
Efforts are being made to increase added value, such as by creating postcards and pamphlets for direct mail, and developments are also underway to make facsimile machines more color-friendly and faster.

For this reason, various quality improvements have been made to electrophotographic transfer paper. For example, the base paper is coated with and impregnated with an organic acid having a specific fluorocarbon group to prevent curls and wrinkles caused by changes in humidity. , Method for obtaining transfer paper for electrophotography that suppresses the occurrence of waviness (Japanese Patent Application Laid-Open No. 57-111540
No.), a method of applying and drying a water-based liquid of water-soluble or emulsion resin on the wire side surface of base paper to suppress curling and obtain transfer paper without double feeding (JP-A-59-17
558), a method for obtaining transfer paper with good texture by reducing curls and fixing roll wrinkles by specifying thickness, density, smoothness, air permeability, stiffness, ash content, and moisture content (Japanese Patent Laid-Open No. 63-30
No. 9700), a coating layer is provided on Yankee machine paper, and curling is prevented by specifying the smoothness of the coating layer.
Method for enabling high-quality recording (Japanese Patent Application Laid-Open No. 1-292354
Proposals such as No. 1) have been made. However, even with the electrophotographic transfer paper obtained using these methods, it has not yet reached the point where it satisfies all quality characteristics such as image stability and runnability in equipment, and it is difficult to use in copying machines, printers, and facsimile machines. Further improvement in quality is desired in response to the increasing functionality of products such as Lee.

[0007]

[Problems to be Solved by the Invention] In view of the current situation, the present inventors have proposed that controlling the characteristics of heat-fixing type electrophotographic transfer paper using specific elements will be particularly effective in preventing curling caused by changes in the environment. The present inventors have now completed the present invention based on their findings that the toner image stability is suppressed, the running properties of the paper within the device are improved, and excellent characteristics are obtained in terms of image stability of the toner image.

[0008]

[Means for Solving the Problems] The present invention provides a thermal fixing type electrophotographic transfer paper whose ratio of the maximum value to the minimum value of the microwave transmission intensity obtained by microwave measurement of the transfer paper is 1. Transfer paper for electrophotography, characterized in that the initial contact angle θ with respect to water on the surface of the paper is 75°≦θ≦120°, and the rate of change of the contact angle is 0.5°/second or less. It is.

[0009]

[Function] In general, paper stock for papermaking is made from chemical pulp such as LKP, NKP, mechanical pulp, etc. depending on the desired paper quality.
Waste paper pulp, etc. is used as appropriate, and internal additives such as fillers, sizing agents, retention improvers, freeness improvers, paper strength enhancers, dyes, etc. are added as necessary, and processed using various preparation devices. mixed and prepared. After passing through a screening process using screens and cleaners, it is led to the wire part of the paper machine, where it is finished as paper through dehydration and drying processes.

[0010] By the way, in the papermaking process, the paper stock that becomes slurry flows out onto the wire at high speed and is dehydrated, so that more fibers are oriented in the longitudinal direction (the flow direction of the raw material on the paper machine). Usually, the tensile strength and stiffness in the vertical direction are considerably stronger than in the horizontal direction (width direction). Therefore, this vertical and horizontal difference (non-uniformity) causes stress distortion of the pulp fibers, and is one of the causes of curling. When the amount of water contained in the obtained paper changes, this stress strain becomes a factor, further promoting curling. This is because, for example, when the environment of paper changes from low humidity to high humidity, water molecules are absorbed by hydroxyl groups, which are hydrophilic groups in the fibers, due to moisture absorption, causing the fibers to swell and elongate. In addition, fibers become soft due to moisture absorption, which causes paper stiffness to deteriorate and causes waving, wrinkles, and the like.

Therefore, in the transfer paper of the present invention, the arrangement of the pulp fibers is made as random as possible and adjusted to eliminate the orientation itself, and furthermore, the paper is resistant to changes in paper moisture due to changes in the environment. Reduce dimensional changes,
This improves the running properties of the transfer paper and also improves the image stability. Specifically, as mentioned above, the ratio of the maximum value and minimum value of the microwave transmission intensity of the paper determined by the microwave measurement method is set to 1.60 or less, and the initial contact angle θ of the paper surface with water is set to 75°≦ θ≦120°, and the rate of change of the contact angle is adjusted to 0.5°/sec or less. Note that by satisfying the above three conditions at the same time, a synergistic effect is exhibited and a transfer paper having desired characteristics can be obtained, and if even one of these conditions is lacking, the desired effect cannot be obtained.

Methods for measuring the fiber orientation of paper include, for example, thermal expansion method, mechanical breaking strength method, X-ray diffraction method, ultrasonic method, microwave measurement method, NMR method, polarized fluorescence method, dielectric measurement method, etc. However, in the transfer paper of the present invention, for example, a microwave-based molecular orientation meter developed by Kanzaki Paper Co., Ltd. is used to measure the microwave transmission intensity to determine the fiber orientation of the paper. It is. This device (Japanese Unexamined Patent Publication No. 59
According to No. 188546), it is possible to quickly, easily, and accurately measure a sheet in a non-contact and non-destructive manner. In addition, the microwave is 300MHZ ~ 30GHZ
This refers to electromagnetic waves in the frequency range of
The orientation of molecules can be evaluated from the anisotropy of the dielectric constant.

Incidentally, in the above molecular orientation meter used in the present invention, the sample (sheet) set in the cavity resonator system is rotated while vertically irradiating the sample (sheet) with polarized microwaves.
By changing the angle between the reference direction of the sample and the microwave polarization plane, the angular dependence of the microwave transmitted intensity is determined. index) and orientation angle (the deviation between the molecular chain axis and the reference direction). Note that since the interaction between microwaves and molecules becomes stronger in the direction in which the molecules are oriented, the transmitted intensity becomes smaller in the oriented direction. Therefore, in the case of paper made with a paper machine, the microwave transmission intensity is generally small in the vertical direction and large in the horizontal direction, and can be recognized as having a maximum value in the horizontal direction and a minimum value in the vertical direction.

In the transfer paper of the present invention, the ratio of the maximum value to the minimum value of the transmitted microwave intensity (hereinafter referred to as the Dmax /Dmin ratio) determined by the microwave measurement method is 1.60 or less, Preferably, it is adjusted to 1.50 or less. Incidentally, Dmax /Dmin
When the ratio exceeds 1.60, the fiber orientation is strong and the stress strain of the pulp fibers becomes too large, resulting in poor paper curl and curling. Also, because the difference in strength between paper strength and stiffness in the vertical and horizontal directions becomes large, depending on the paper feeding direction,
There is a possibility that the running performance of the transfer paper within the equipment will be reduced. Note that setting the Dmax/Dmin ratio to 1 means that the pulp fibers are completely randomly oriented, so it is difficult to obtain such a value in paper made with an actual paper machine.

[0015] The orientation pattern of the pulp fibers can be adjusted by adjusting, for example, the type of pulp fibers, the number of parts mixed, the machine speed, the speed at which the pulp slurry flows onto the wire at the inlet (J = jet speed), and the wire speed (W). = wire speed) ratio (J/W ratio), forming board and hydrofoil arrangement, wire shake and dandy roll suitability, etc., but the transfer paper of the present invention has the specific characteristics as described above. These methods are adjusted in combination as appropriate. It goes without saying that it is necessary to harmonize the texture of the paper with other paper qualities, and the optimum values for machine speed and J/W ratio vary depending on the type and characteristics of each machine. Adjust accordingly depending on the machine.

In the transfer paper of the present invention, in order to improve the dimensional stability of the paper due to changes in paper moisture due to environmental changes,
The initial contact angle θ of the surface of the transfer paper with water is 75°≦θ≦
120°, preferably in the range of 80°≦θ≦110°, and the rate of change of the contact angle is adjusted in the range of 0.5°/second or less, preferably 0.35°/second or less. .

[0017] As an index of the water repellency of paper, there are Steckigt size index, Cobb water absorption method, etc., but compared to these methods, the contact angle method referred to in the present invention shortens the water repellency of the paper support. It can be measured in time and accurately, and is an excellent indicator for confirming the effects of the present invention. This contact angle is measured based on American Pulp and Paper Technology Association Standard T458 om-84 "Paper Surface Wetting (Contact Angle Method)". That is, the contact angle between a distilled water droplet and the paper surface is measured.The initial contact angle refers to the contact angle 5 seconds after the water droplet is dropped, and the rate of change in the contact angle is determined by the following equation. R = (θ - θ') / 55, R = rate of change of contact angle, θ = initial contact angle (contact angle after 5 seconds), θ' = contact angle after 60 seconds

Incidentally, if the initial contact angle θ is less than 75°, adsorption of water to the hydroxyl groups of cellulose fibers in the paper will be promoted, resulting in large dimensional changes in the transfer paper, resulting in paper jams due to curling and toner This may cause problems such as a drop in transfer efficiency. However, if the contact angle θ is larger than 120°, the hydrophilicity of the transfer paper decreases, making it more likely to be charged with static electricity, which may cause problems with heavy running of the transfer paper during transfer and deterioration of image quality due to uneven toner transfer. Become. Additionally, if the rate of change in contact angle is greater than 0.5°/sec, moisture changes due to changes in the paper environment will increase, resulting in curling,
Paper curls such as waving can become extremely bad, leading to running troubles during transfer and dimensional changes in the paper.
This may cause a decrease in toner transfer efficiency, etc.

A convenient method for adjusting the contact angle θ of the transfer paper is to appropriately adjust the addition of an internal sizing agent and/or the application of a surface sizing agent to the transfer paper. Examples of internal sizing agents for this purpose include alkyl ketene dimer sizing agents, alkenyl succinic anhydride sizing agents,
There are stearic anhydride-based sizing agents, petroleum resin-based sizing agents, rosin-based sizing agents, wax-based sizing agents, cationic synthetic sizing agents, etc. Surface sizing agents include, for example, various starches, various polyacrylamides, various polyvinyl alcohols, Examples include carboxyl methyl cellulose, acrylic esters, α-olefin maleic anhydride copolymers, styrene-acrylic copolymers, cationic synthetic sizing agents, and latex.

[0020] When applying the surface sizing agent to the base paper, the method is not particularly limited, and examples thereof include a two-roll or metering blade type size press, a gate roll, a bill blade, a short dwell coater, and a roll. Various methods such as a coater, an air knife coater, and a blade coater can be appropriately selected and used.

[0021] Furthermore, when a cationic synthetic sizing agent that has the ability to self-fix to fibers over a wide range of pH ranges is used as an internal sizing agent or a surface sizing agent, the dimensional change in the paper is less than when other sizing agents are used. The application of such a sizing agent is one of the preferred embodiments of the present invention. Also, among the cationic synthetic sizing agents, at least
By using a copolymer consisting of a monomer having a hydrophobic group having 8 to 30 carbon atoms, an amine compound having at least one amino group, and an epoxy compound, the contact angle defined in the present invention can be easily adjusted. becomes. Specific examples of such sizing agents include, for example, epoxidized products made by reacting polyamines with copolymers of styrene and acrylic esters, and epoxidized products made by reacting polyamines with copolymers of α-olefins and maleic anhydride. There are epoxidized products made by reacting fatty acids with polyamines, and epoxidized products made by reacting fatty acids with polyamines. Among them, carbon number 12-22
A synthetic sizing agent containing a copolymer obtained by epoxidizing a reaction product of a fatty acid and a polyalkylene polyamine or a reaction product obtained by adding other components to this is even more superior in the effects of the present invention. , most preferably used.

Specific examples of fatty acids having 12 to 22 carbon atoms include lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, palmitoleic acid,
Oleic acid, vaccenic acid, linoleic acid, linoleic acid,
These include arachidonic acid, ricinoleic acid, cerebronic acid, alkylsuccinic acid, alkenylsuccinic acid, etc. Specific examples of polyalkylene polyamines include diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, and dimethyl. Examples include propylene diamine. Other components constituting the copolymer include, for example, rosin, α,β-unsaturated polybasic acid-added rosin, α,β-unsaturated polybasic acid-added petroleum resin, urea, adipic acid, maleic acid, Examples include phthalic acid, formic acid, formalin, etc., and these are used as appropriate. Further, specific examples of the epoxy compound include epihalohydrins such as epichlorohydrin, epibromohydrin, and methylepichlorohydrin.

The amount of the synthetic sizing agent used is adjusted to give the transfer paper the specific contact angle of the present invention, but is generally 0.01 to 2.0% by weight, more preferably 0.01 to 2.0% by weight based on the pulp. It is adjusted within a range of about 0.05 to 1.5% by weight. The cationic synthetic sizing agent as described above may be used alone, but other internal sizing agents or surface sizing agents may be used in combination as appropriate to the extent that the desired effects of the present invention are not hindered. .

If necessary, internal fillers commonly used in the industry may be added to the paper stock, such as talc, kaolin, clay, calcined kaolin, delamic kaolin, and heavy calcium carbonate. , light calcium carbonate, magnesium carbonate, aluminum hydroxide, titanium dioxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, magnesium silicate, calcium silicate, magnesium sulfate, calcium sulfate, white carbon, aluminosilicate, silica, sericite Examples include mineral fillers such as bentonite and smectite, organic synthetic fillers such as polystyrene resin fine particles, urea formalin resin fine particles, and fine hollow particles, but fillers contained in waste paper, broque, etc. can also be effectively recycled.

Among these various fillers, fillers with an average particle diameter of about 0.1 to 12 μm, preferably about 0.3 to 9 μm, are excellent in improving smoothness, opacity, paper strength, stiffness, etc. It is particularly preferably used because it provides a transfer paper that is also excellent in office suitability such as writing and stamping properties. Further, a filler having a powder whiteness of 75% or more, preferably 80% or more is preferable from the viewpoint of improving the whiteness of the product.

[0026] In addition, various conventionally used anionic, nonionic, cationic or amphoteric retention aids and freeness improving agents may be added to the paper stock to the extent that the desired effects of the present invention are not impaired. Internal additives for paper making such as additives and various paper strength enhancers may be selected as necessary, for example, Al, Fe, etc.
, Sn, Zn, and other polyvalent metal compounds (basic aluminum compounds such as aluminum sulfate, aluminum chloride, sodium aluminate, basic aluminum chloride, basic polyaluminum hydroxide, and water-soluble alumina sol that is easily dispersible in water) aluminum compounds, ferrous sulfate, ferric chloride, etc.)
and various starches, various polyacrylamides, polyethyleneimines, polyamines, polyamine polyamides, epichlorohydrin resins, vegetable gums, polyvinyl alcohol, latex, polyethylene oxide, hydrophilic crosslinked polymer particle dispersions, etc., derivatives or modified products thereof, and colloidals. One or more types of silica etc. are used. Also,
Internal additives for papermaking such as dyes, optical brighteners, pH adjusters, antifoaming agents, pitch control agents, and slime control agents can also be added depending on the purpose of the paper.

In the surface sizing method, a pigment, a conductive agent, a dimensional stabilizer, a fluorescent whitening agent, a dye, etc. can be appropriately used in combination with a surface sizing agent. Examples of conductive agents include sodium chloride, calcium chloride, sodium aluminate, etc. inorganic salts, soaps, surfactants such as phosphates, quaternary ammonium salts,
Examples include polyacrylates, polymer electrolytes such as styrene-maleic anhydride copolymers, and inorganic conductive substances such as silica, alumina, and montmorillonite. Examples of dimensional stabilizers include synthetic resins such as epoxy resins, urea resins, glyoxal resins, uron resins, ethylene urea resins, triazone resins, dialdehyde starch, ketoaldehyde resins, and polyethylene imine, and zirconium carbonate salts. Examples include polyvalent metal compounds. Note that the dimensional stabilizer may be internally added to the paper stock.

[0028] There are no particular limitations on the type or manufacturing method of pulp fibers, and for example, chemical pulps such as softwood pulp and hardwood pulp obtained by KP, SP, AP methods, etc., SCP, B
CTMP, CTMP, CGP, RGP, SGP, TMP
Examples include various mechanical pulps such as, recycled pulps such as DIP, waste paper pulps, and the like. Furthermore, non-wood pulp such as hemp pulp, synthetic pulp, organic synthetic fibers such as aramid fibers, and inorganic fibers such as glass fibers and ceramic fibers can also be used.

[0029] Transfer paper made from mechanical pulp, recycled pulp such as DIP, or waste paper pulp is relatively susceptible to the effects of moisture, but if adjusted based on the above-mentioned specific provisions of the present invention, desired characteristics can be achieved. The transfer paper having the above can be efficiently manufactured. In addition, when preparing the paper stock, the relative dielectric constant (SC) of the paper stock was set to 1.5 mS in any system.
/cm or less, and the zeta potential is 0.
When adjusted to a value close to that level, the transfer paper of the present invention can be stably obtained.

The papermaking method is not particularly limited, and examples include an acidic papermaking method in which the pH of the papermaking is around 4.5, a weakly acidic papermaking method in which the pH of the papermaking process is around 4.5, a method containing an alkaline filler such as calcium carbonate as a main component, and a weakly acidic papermaking method in which the pH of the pulp slurry during papermaking is approximately 6. It is applicable to all papermaking methods such as the so-called neutral papermaking method, which has a weak alkalinity of ~9. Further, as the paper machine, a Fourdrinier paper machine, a twin wire paper machine, a cylinder paper machine, a Yankee paper machine, etc. can be used as appropriate.

The thus obtained transfer paper of the present invention can be used as PPC paper as it is, but it can also be used as a base paper and coated with a coating composition containing pigment and adhesive as main components. Since good image quality can be obtained by forming the coating layer in this manner, such an embodiment is one of the preferred embodiments of the present invention. Pigments include various pigments commonly used in general coated paper, such as kaolin, calcined kaolin, delamic kaolin, aluminum hydroxide, satin white, talc, heavy calcium carbonate, light calcium carbonate, calcium sulfate, barium sulfate, Mineral pigments such as titanium dioxide, silica, zinc oxide, magnesium oxide, magnesium carbonate, white carbon, aluminosilicate, colloidal silica, bentonite, sericite, smectite, polystyrene resin particles, urea-formalin resin particles, micro hollow particles, and others. One or more organic pigments may be used as appropriate depending on the quality target of the coated paper.

Examples of adhesives include proteins such as casein, gelatin, soybean protein, and synthetic proteins, conjugated diene polymer latex such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic ester, and / or acrylic polymer latex such as methacrylic acid ester polymer or copolymer, ethylene-
Vinyl polymer latex such as vinyl acetate copolymer, or alkali-soluble or alkali-insoluble polymer latex modified with a monomer containing a functional group such as a carboxyl group, polyvinyl alcohol, Conventional coatings such as synthetic resin adhesives such as modified polyvinyl alcohol and melamine resin, various starches such as cationic starch, oxidized starch, enzyme-modified starch, and thermochemically modified starch, and cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose. One or more types of paper adhesives are appropriately selected and used. Note that adhesives generally contain 10 pigments.
It is blended in a range of about 1 to 200 parts by weight to 0 parts by weight.

[0033] Depending on the application, the coating composition may contain a conductive agent,
Various auxiliary agents such as antifoaming agents, colorants, optical brighteners, ultraviolet inhibitors, lubricants, dispersants, pH adjusters, mold release agents, flow modifiers, solidification accelerators, and water resistance agents are blended as appropriate. Good too. The coating composition thus prepared is applied to one or both sides of the base paper in an amount of about 0.5 to 10 g/m<2> per side. Further, the coating composition may be a single coated layer or may have a multilayer structure of two or more layers, and in the case of a multilayer structure, the coating composition can be changed as appropriate.

Coating devices for forming the coating layer include, for example, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, a die slot coater, a gravure coater, a champlex coater, and a brush. Conventional coating equipment such as a coater, gate roll coater, size press coater, etc. can be used as appropriate. Of course, these devices may be on-machine or off-machine coaters. In addition, after drying to a moisture content of generally 4 to 9% by weight, a super calender, which can be turned on or off as necessary, can be used.
Pressure finishing can also be applied by passing the paper through a soft calender, matte super calender, etc.

[0035]

[Examples] The present invention will be explained in more detail with reference to Examples below, but it is of course not limited to the scope thereof. In addition, unless otherwise specified, parts and % in the examples indicate parts by weight and % by weight, respectively.

Example 1 10 parts of NBKP (freeness/csf: 520cc),
Talc with an average particle size of 7.5 μm was added as a filler to a pulp slurry containing 90 parts of LBKP (freeness/csf: 460 cc) so that the ash content of the transfer paper was 10%, and further, as a sizing agent per pulp. Rosin size (manufactured by Arakawa Chemical Co., Ltd./Size Pine N-771) was 0.
A paper stock prepared by adding 5 parts of sulfuric acid and 3.0 parts of sulfate was made into paper using a Fourdrinier paper machine at a J/W ratio of 1.02, and at the same time, in the size press process, oxidized starch (Ace A/ Oji Cornstarch Co., Ltd.) and sodium chloride were coated and dried to give a solid content of 1.5 g/m 2 and 0.1 g/m 2 , respectively, to obtain a transfer paper having a basis weight of 64 g/m 2 .

Regarding the transfer paper obtained in this way, the Dmax/Dmin ratio measured by a molecular orientation meter, the initial contact angle on the paper surface and the rate of change of the contact angle, the runnability in a copying machine, curling, and image stability were determined as follows. Measure and evaluate using methods,
The obtained results are shown in Tables 1 and 2.

[Measurement of Dmax/Dmin ratio] Transfer paper is measured in the width direction of the width of the paper machine, from the operation side of the paper machine to the front, center (2 points), back (drive side) and 4 points. divide,
The samples taken from each category were measured using a microwave molecular orientation meter manufactured by Kanzaki Paper Industries Co., Ltd. to determine the Dmax/Dmin ratio. [Measurement of initial contact angle and rate of change of contact angle on transfer paper surface] American Pulp and Paper Technology Association Standard T458 om-8
The initial contact angle when using distilled water was determined by the method specified in 4. In addition, FA is used as a device to specify the contact angle.
A CE contact angle meter CA-D model (manufactured by Kyowa Interface Science) was used. Note that the initial contact angle means the contact angle 5 seconds after the droplet contacts the paper, and the rate of change in the contact angle was determined from the following equation. R = (θ-θ') /55 R = rate of change of contact angle, θ = initial contact angle (contact angle after 5 seconds), θ' = contact angle after 60 seconds

[Evaluation of running performance] Electrophotographic copying machine (XE
ROX 5043 (manufactured by Fuji Xerox Co., Ltd.) was used to copy 500 sheets of transfer paper that had been humidity-controlled under the following environmental conditions, and the runnability was evaluated based on the following evaluation criteria. (1) Environmental conditions (i) Humidity control at 20℃, 30RH% for 3 hours (ii) 20
Humidity control at ℃, 60RH% for 3 hours (iii) 20℃, 8
Humidity control for 3 hours at 0RH% (2) Running performance evaluation criteria Running troubles (double feeding and number of paper jams) when copying 500 sheets under each environmental condition: ◎...1 sheet or less, ○...2 to 5 sheets, △... 6
~10 sheets, ×…11 sheets or more

[Measurement of degree of curl] In the above runnability evaluation, the center part of the side having the radius of curvature of the transfer paper copied under the conditions of 20° C. and 80RH% was hung with a clip, and the radius of curvature R (cm) was determined. The degree of curl was calculated from the following formula. (Rounded to the second decimal place) Curl degree = (1/R) x 100 [Measurement of image density] In the above runnability evaluation, 20°C,
The color density of the solid area of the copy image of the transfer paper copied under 80RH% condition was measured using a Macbeth densitometer (RD-100 R type/
(manufactured by Macbeth).

[Evaluation of Copy Image Quality] In the runnability evaluation described above, the image quality of the copied image on the transfer paper copied under each environmental condition was comprehensively visually evaluated using the following evaluation criteria. ◎: Excellent with no stains in the background area or small omissions in the copied image area. ○: Good with almost no stains in the background area or small omissions in the copied image area. △: Inferior, with stains in the background area and small omissions in the copied image area.

Example 2 In the paper stock preparation of Example 1, the filler was changed from talc to light calcium carbonate with an average particle size of 3.0 μm, and the sizing agent was changed from rosin to alkyl ketene dimer (Harcon W, manufactured by Dick Hercules). 0.1 part, and the added amount of sulfuric acid was changed to 0.5 part, and 1.0 part of cationic starch was added as a paper strength agent, and anionic polyacrylamide (manufactured by Arakawa Chemical Co., Ltd., ARAFIX) was added as a retention improver. 504
) was added in the same manner as in Example 1 except that 0.03 part of paper was added and the J/W ratio was set to 0.98 to make a neutral paper.
A transfer paper of m2 was obtained. Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

Example 3 In the paper stock preparation of Example 2, the filler was replaced with a mixed filler of light calcium carbonate and sericite (mixing ratio 3:1) with an average particle size of 3.0 μm, and the sizing agent was replaced with an alkyl ketene dimer. was replaced with 1.2 parts of an epoxidized product of the reaction product of α-olefin, maleic anhydride copolymer, and propanediamine, and the J/W ratio was changed to 1.03, and the oxidized starch in the size press process was replaced with polyvinyl alcohol. (manufactured by Kuraray,
A transfer paper having a basis weight of 64 g/m<2> was obtained in the same manner as in Example 2 except that PVA-117) was used. Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

Example 4 In the paper stock preparation of Example 1, the sizing agent was changed from rosin size to an epoxidized product of the reaction product of stearic acid and polyalkylene polyamine (manufactured by Kindai Kagaku Co., Ltd., N-815).
A transfer paper having a basis weight of 64 g/m<2> was obtained in the same manner as in Example 1, except that the paper was made using a twin wire paper machine under the conditions of 7 parts and a J/W ratio of 1.01. And Example 1
The transfer paper was measured and evaluated in the same manner as above, and the results are shown in Table 1.
and are listed in Table 2.

Example 5 In Example 1, the J/W ratio was set to 0.99, and the epoxidized product of the reaction product of stearic acid and polyalkylene polyamine used in Example 4 was used together with oxidized starch and sodium chloride in the size press step. The adhesion amount is 0.1g/solid content.
A transfer paper having a basis weight of 64 g/m2 was obtained in the same manner as in Example 1, except that the coating was applied so that the transfer paper had a weight of 64 g/m2. Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

Example 6 The pulp composition of Example 2 was changed to 20 parts of NBKP and 4 parts of LBKP.
0 part, replaced with 40 parts of DIP containing 50% waste newspaper, and in paper stock preparation, the filler was replaced with heavy calcium carbonate with an average particle size of 4.0 μm, and the sizing agent was replaced with alkenyl succinic anhydride (
Oji National Co., Ltd., Five Run 81)) was added to 0.25 parts of oxidized starch and sodium chloride in the size press process, along with ammonium salt of a copolymer of α-olefin and maleic anhydride (Misawa Ceramic Chemical Co., Ltd., Hamakote AK). -400) with a solid content of 0.1g/
A transfer paper having a weight of 64 g/m<2> was obtained in the same manner as in Example 2, except that the coating was applied so that the transfer paper had a weight of 64 g/m<2>. Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

Example 7 100 parts of light calcium carbonate with an average particle size of 1.0 μm and oxidized starch (manufactured by Oji Cons Co., Ltd.,
A coating composition consisting of 30 parts of Ace A) and 1 part of sodium chloride was coated on both sides using a gate roll coater so that the solid content was 5.0 g/m2. A transfer paper of m2 was obtained. And Example 1
The transfer paper was measured and evaluated in the same manner as above, and the results are shown in Table 1.
and are listed in Table 2.

Comparative Example 1 Example 1 except that the J/W ratio of Example 1 was changed to 0.92.
In the same manner as above, a transfer paper having a basis weight of 64 g/m2 was obtained. Then, the transfer paper was measured and evaluated in the same manner as in Example 1,
The results are shown in Tables 1 and 2.

Comparative Example 2 In Example 2, the amount of alkyl ketene dimer as a sizing agent was changed from 0.1 part to 0.03 part, and J/W
A transfer paper having a basis weight of 64 g/m2 was obtained in the same manner as in Example 2, except that the ratio was changed to 1.04. Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

Comparative Example 3 In Example 1, the α-olefin used in Example 6 was used together with oxidized starch and sodium chloride in the size press process.
Transfer paper of 64 g/m2 was obtained in the same manner as in Example 1, except that the ammonium salt of the copolymer of maleic anhydride was coated at a solid content of 0.5 g/m2. . Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

Comparative Example 4 In Example 6, the amount of alkenyl succinic anhydride used as a sizing agent was changed to 0.1 part, and ammonium salt of α-olefin and maleic anhydride copolymer was used in the size press step. A transfer paper having a basis weight of 64 g/m<2> was obtained in the same manner as in Example 6, except that this was not done. Then, the transfer paper was measured and evaluated in the same manner as in Example 1, and the results are listed in Tables 1 and 2.

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[Table 1]

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[Table 2]

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Effects of the Invention As is clear from the results in Tables 1 and 2, all of the transfer papers obtained by the examples of the present invention exhibited less shrinkage and curling due to moisture changes, etc.
The transfer paper had excellent runnability with no paper jams or double feeding within the copying machine, and also had excellent image stability.

Claims (4)

[Claims] Claim 1: A thermal fixing type electrophotographic transfer paper, in which the ratio of the maximum value to the minimum value of the microwave transmission intensity obtained by microwave measurement of the transfer paper is 1.60 or less, and the paper surface has a Initial contact angle θ with water is 75°≦θ
≦120°, and the contact angle change rate is 0.5°/
A transfer paper for electrophotography, characterized in that the transfer time is less than seconds. [Claim 2] The sizing agent has at least 8 or more carbon atoms.
2. The electrophotographic transfer paper according to claim 1, wherein a copolymer consisting of a monomer having 30 hydrophobic groups, an amine compound having at least one amino group, and an epoxy compound is used. [Claim 3] The sizing agent has at least 12 to 2 carbon atoms.
3. The electrophotographic transfer paper according to claim 2, which is a copolymer consisting of three fatty acids, a polyalkylene polyamine, and an epoxy compound. 4. The electrophotographic transfer paper according to claim 1, wherein a coating layer containing a pigment and an adhesive as main components is provided on the surface of the paper.