JPS6067191A - Chemical-resistant thermal recording paper improved in blurring of ink - 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 The present invention relates to a thermal recording paper whose main components are a dye precursor and a color developer that develops color when the dye precursor is heated. This product provides thermal recording paper that is less susceptible to deterioration due to chemicals.Thermal recording paper consists of (11) coated with carbon or colored dyes and pigments on a substrate, and coated with an opaque thermofusible substance on top of that. A method in which the opaque layer becomes transparent by heating and an image is formed by the colored layer below. (2) A method in which a complex compound of an electron donor and an electron acceptor is formed by heat. (3) A method such as crystal violet lactone. There is a method in which a dye precursor and an acidic color developer such as a phenol compound are dispersed discontinuously, applied, and heated to dissolve one or both of them to develop color. Because the color tone, problem of scum, etc. are excellent overall (3)
This method is used in general facsimiles, printers, etc.

The characteristics required for this type of thermal recording paper include, of course, sensitivity suitable for various uses, as well as white background, long-term stability and non-disappearance of colored pigments, and There is no generation of residue, no adhesion (sticking) to the thermal head during recording, etc. Excellent products with many of these claims can be manufactured, but for practical handling after recording, hand creams and If you touch it with a hand covered with hair styling oil, if you overlap it with diazo photosensitive paper that has just been developed, or if you use a fluorescent pen to make underlines or other *V marks, the image may disappear or the background color may appear. It has the disadvantage of causing fog and making it difficult to read the recorded image.@This decoloring phenomenon is caused by the lactone ring of the color-forming lactone compound ring-opened with an acidic developer being dibutyl phthalate, dioctyl phthalate, dioctyl phthalate, etc. This is thought to be due to ring closure in the presence of plasticizers such as esters. In addition, the Capri phenomenon is thought to be due to the solvent contained in the developer of the diazo photosensitive paper and the fluorescent pen dissolving the color developer and causing a color-forming reaction on contact with the dye precursor. It has also been proposed that this phenomenon can be prevented by forming a film on the thermosensitive recording paper to prevent penetration of the plasticizer. 'Cvj Kaisho 54-1
28347, JP-A-54-3549) The present inventors also developed an overcoat agent with chemical resistance and filed a state patent application in Japanese Patent Application No. 55-182557 and @Gan No. 56-981. There is.

However, regarding the surface properties of the overcoat layer,
Thermal recording A is mainly composed of water-soluble madder molecules.
It is easy to cause so-called blocking, in which the front and back surfaces of t() partially adhere to each other.
Since this can lead to destruction of the overcoat layer, paper breakage, etc., attempts have been made to prevent this by adding various waterproofing agents and mold release agents.

Furthermore, in order to improve the protection efficiency against water and oil, water and oil repellents such as fluororesin are added to the overcoat layer to improve water and oil resistance.

However, these additives cause the inconvenience that when printing, stamping, writing, etc. are carried out, the ink bleeds extremely, and in some cases becomes unreadable. In order to improve this drawback, it is possible to improve the effect to some extent by adding white M family with a large oil-absorbing lid, but this will inhibit the formation of a film-like film, reduce the color development sensitivity, and cause wear of the facsimile heat head, so the quantity is limited. There are limitations and the current situation is unsatisfactory. As a result of intensive research into thermal recording paper that does not cause the generation of heat and has good print quality, the present invention was arrived at. An object of the present invention is to provide a chemical-resistant thermal paper with improved ink bleeding, which is characterized by containing a network product of an aromatic aldehyde and a polyhydric alcohol having a valence of 5 or more in the coating layer. The main components used in the present invention will be explained in detail below, but the present invention is not limited thereto unless it goes beyond the gist of the present invention.

Typical examples of dye precursors that develop color with phenolic substances or Ef acids are shown in Table 1. (1) Crystal violet lactone (2) 3-indolino-3-p-dimethylaminophenyl-6-dimethyl Aminophthalide (3) 3-diethylamine-7-talolofluorane (
4) 3-diethylamino-7-cyclotetrahexylaminofluorane (5) 3-zenalamino-5-methyl-7-monobutylfluorane (6) 3-diethylamino-6-methyl-7-anilinofluorane ( 7) 3-diethylamino-6-methyl-7-p-butylanilinofluorane (8) 2-(N-phenyl-N-ether)aminofluorane (9) 3-diethylamino-7-dibenzylaminofluorane (10) 3-cyclohexylamino-6-chlorofluorane (1◇3-diethylamino-6-methyl-7-xylidinofluorane α2) 2-anilino-3-methyl-6-(N-ethyl-
p-Toluidino)fluoran (L3) 3-pyrrolidino-6-methyl-7-anilinofluoran α4) 3-pyrrolidino-7-cyclohexylaminofluorane (15) 3-hyhericino-6-methyl-7-)luidino Fluoran 06) 3-piperidino-6-methyl-tuanilinofluoran (17) 3- (N-methylcyclohexylamino)
-6-Mef-7-anilinofluorane α8) 3-diethylamino-7-(m-trifluoromethylanilino)fluoran (19) 3-diethylamino-6-metal-7-talolofluoran, used in the present invention Typical examples of phenolic substances or organic acids (color developers) are shown in Table 2.

Table-2 (1) 4.4'-isopropylidenediphenol (2
) 4.4'-Impropylidene bis(2-chlorophenol) (3) 4.4'-Impropylidene bis(2-tert-butylphenol) (4) 4.4'-Secondary-butylidene diphenol (5 ) 4.4+-(1-Methyl-n-hexylidene)diphenol (6) 4-7dynylphenol (7) 4-hydroxydiphenoxide (8) Methyl-4-hydroxybenzoate (9)
Phenyl-4-hydroxybenzoate (10) 4-
Hydroxyacetophenone (11) Salicyl is anilide (12) 4.4'-Cyclohexylidene diphenol 6B>4.4'-Cyclohexylidene bis(2-methylphenol) (14) 4.4'-Benzylidene diphenol (1
5) 4.41-thiobis(6-tert-butyl-
3-methylphenol) (16) 4.4'-impropylidene bis(2-methylfugnol) α7) 4.4'-ethylenebis(2-methylphenol) (1B) 4.4'-cyclohexyl Cylidenebis(2-inglobylphenol) (19) 2.2'-dihydroxydiphenyl@) 2
．． 2″-methylenebis(4-chlorophenol)□□□
)2.2'-methylenebis(4-methyl-6-t-)'
Chilphenol) (zz)1. xI-bis(4-hydroxyphenol)
-Cyclohexane■) 2.2-bis(41-hydroxyphenyl)propane QA) Novolac type phenolic resin (25) Halogenated novolac type phenolic resin (2
6) α-Naphthol (m) 3.5-di-t-butylsalicylic acid (29)
3.5-di-α-methylbenzylsalicylic acid (10)
3-Methyl-5-t-butylsalicylic acid (31) Phthalic acid mononanilido paraethoxybenzoic acid (32) Parabenzyloxybenzoic acid (33) Parahydroxybenzoic acid benzyl ester Uninvented thermal recording paper can be produced by the following method. can be obtained by That is, a phenol substance, an organic acid, and a dye precursor that develops color with the phenol substance or organic acid are ground and dispersed separately or simultaneously in a grinder into fine particles, and a binder, g.
@'ti'5 is prepared by mixing with T'Mf's and adding each T'Mf's additive depending on safety. Examples of binders include starch, hydroxyethyl cellulose, methyl cellulose, polyvinyl alcohol,
Water-soluble binders such as styrene-maleic anhydride copolymer, styrene-butadiene copolymer, polyacrylamide, carboxymethylcellulose, gum arabic, and casein can be used.As the pigment, for example, water Aluminum oxide, heavy and low-grade calcium carbonate, zinc oxide, titanium oxide, barium sulfate, lurica gel, activated clay, Merck, clay, Chochinwhite, kaolinite, calcined kaolinite, diatomaceous earth, synthetic kaolinite, polyolefin particles, polystyrene grain.

Examples include urine accumulation and formalin resin particles.

Next, regarding the material forming the overcoat layer in the present invention, water-soluble polymer compounds are generally preferred;
Among them, it is best to use alginate alone or in combination with one or more selected polymer compounds such as hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. Anko 56-1524
No. 55) Condensation products of aromatic aldehydes and polyhydric alcohols of 5 or more valences, which are the characteristics of the present invention, include
Examples of polyhydric alcohols of 0.5 or higher, for which so-called gelling agents described in No. 8465, JP-A-54-33533, etc., include arabitol, xylitol, nrubitol, mannitol, etc. can be used. Examples of aromatic aldehydes include penmetaldehyde and nuclear-substituted benzaldehyde. Examples of substituents include one or a combination of two or more of alkyl groups, alkoxyl groups, hydroxyl groups, halogens, etc. Garuri, the monkey is used.

The amount of the condensation product of aromatic aldehydes and polyhydric alcohol of 5 or more hydrides added to the overcoat layer is 0.5% or more, preferably 1 to 60%. The weight percentage is good in terms of ink bleed I edge effect, color development sensitivity, and printability.

If the amount of Mugi M Kai Rl added is less than 0.5%, the ink bleed prevention effect tends to be insufficient.In addition, if it exceeds 60%, the ink Q bleed prevention effect is insufficient. However, since it inhibits heat conduction to the coloring 11I, it tends to have a negative effect on coloring sensitivity and printability.In addition, one type of water resistant agent, water repellent, antifoaming agent, ultraviolet absorber, or It is preferable to use two or more yuzu citrons in combination to impart aqueous properties and light resistance, and to prevent the formation of pinholes.

However, in the invention, the thickness of the dried oat coating layer is 0.5 μm or more, preferably 3 to 12 μm.
However, in terms of chemical resistance and coloring sensitivity, if the thickness of the coating is less than 0.5 μm, the chemical resistance will not be sufficient, and if it is less than 12 μm, the coloring sensitivity will tend to decrease. The support to which the O heat-sensitive centrifugal liquid is applied is generally white paper, but any material such as self-produced paper or one-component resin film can be used. [Example 1] Input Liquid B Liquid A and B liquid was ground and dispersed in a separate ball mill for 24 hours to prepare a coating liquid with the following formulation.The prepared coating liquid had a basis weight of 481.
The OO liquid 0 was coated on a 1/d base paper so that the coating amount after drying was 51/d and dried at 60°C for 1 minute to produce g-thermal recording paper.The OO liquid 0 was pulverized in a ball mill for 48 hours. .

D. Overcoat the above thermal recording paper with the prepared coating liquid to a dry film thickness of approximately 5 pm, and use a super-calender to obtain a Bekk smoothness of approximately 400 seconds. Paper was made.

[Implementation series]

D and E of Example 1 were ground in a ball mill for 48 hours.
For the liquid, use 9Fcp=liquid instead of liquid C, apply an overcoat layer to the above heat-sensitive recording paper so that the dry film thickness is about 5 μm, and apply a super calender to the Bekk smoothness of about 40.
The heating time was set to 0 seconds, and an overcoated thermosensitive recording paper was produced.

[Comparative example 1] F liquid Solution F was ground in a ball mill for 48 hours.

In addition to the D solution in Example 1, the 0 solution was replaced with IcF solution JD.
Using Liquid 6.9, overcoat the above thermosensitive recording +R so that the dry film thickness is about 5 μm, and apply K with a super calender so that the Beck smoothness is about 400 seconds, and apply overcoat/111. A thermal recording paper was produced.

[Comparative Example 2] Using a solution obtained by removing Solution C from Solution D in Example 1, apply the overcoat layer to the above paper so that the dry film thickness is about 5 μml, and check Beck smoothness with a super calender. was set to about 400 seconds, and an overcoated thermal recording paper was produced.

[Example 3] Diazo developer resistance test: The Samurai overcoated thermal recording paper in Example 1.2 and Comparative Example 1.2 was tested using Banafax UP- manufactured by Matsushita Electric Power Co., Ltd.
920 to an optical density of 1.20, apply diazo photosensitive paper (developer R100PY) to the overcoated surface.
8D) and the paper immediately after the development process, the paper was allowed to stand at room temperature for 3 minutes, and the presence or absence of deterioration in legibility of the coloring area due to fogging in the background area was observed. Through the above test, the degree of membrane rupture of the overcoat layer can be determined.

Example 1.2 and Comparative Examples 1 and 20 A stamp with Shachihata
2. After stamping with a red ink stamp and leaving it at room temperature for 24 hours, bleeding of the ink was observed.

As a result, in the comparative example, there was no deterioration in the reading of the colored part due to the fogging phenomenon of the background part caused by the developer for diazo photosensitive paper, but there was severe ink smearing on stamps, etc.
Most of the fil readings ended up being Ai Komachi.

On the other hand, the product of the present invention not only has no deterioration in legibility caused by the developer for diazo photosensitive paper, but also has no bleeding between stamps, etc., and there is no observable smearing of letters, which is extremely satisfactory. It was a great experience.

Claims (1)

[Claims] A thermosensitive coloring layer is provided whose main components are a colorless or light-colored dye precursor and a color developer that reacts with the dye precursor when heated, and a water-soluble polymer compound is further provided on this thermosensitive coloring layer. A chemical-resistant heat-sensitive recording paper provided with an overcoat layer mainly consisting of: Chemical-resistant thermal recording paper with improved ink bleeding 0