JPS5837916B2 - Method for manufacturing color developer sheet - Google Patents

Description

[Detailed description of the invention] The present invention relates to a color developer sheet for pressure-sensitive recording.

More specifically, the present invention relates to a method for manufacturing a color developer sheet coated with or containing a color developer that reacts with a substantially colorless organic compound to obtain a colored body.

It has been known for a long time that a colored image is obtained through a contact reaction between an electron-donating, almost colorless organic compound (hereinafter referred to as a color former) and an electron-accepting solid acid (hereinafter referred to as a color developer).

As a method that specifically utilizes this phenomenon, there is also known a printing method that obtains a colored image by supplying ink containing a color former to a sheet coated with a color developer (for example, a U.S. patent). Patent application (OLS) 1,9 3 9,9
6 No. 2).

Known color developers include clays such as acid clay, activated clay, and acpal guide, novolac type phenol-formalin resin, and metal salts of aromatic carbon.

Generally, a color developer sheet is prepared by applying a coating liquid obtained by mechanically dispersing a color developer together with an inorganic pigment, a binder, a dispersant, and other additives onto a paper surface.

The color developer sheet thus obtained had the following drawbacks.

1) Since a large amount of coating is required, the rigidity of the developer sheet is reduced and curling is likely to occur, resulting in poor printability of the resulting developer sheet.

Furthermore, it cannot be applied using a paper machine scythe press device, which limits the amount of application.

2) Since color developer particles exist on the paper surface together with pigments, when characters, ruled lines, etc. are printed on these particles, the color developer, pigments, etc. are likely to peel off, which is a so-called picking problem.

3) Since the color developer particles are adhered to the paper surface with a binder,
The active sites of the color developer are covered and cannot exhibit sufficient color developing ability.

4) When adjusting the coating, a dispersing device such as a ball mill, chemist, attritor, sand mill, etc. is required, and the degree of dispersion has a large effect on performance such as color developing ability, so variations in performance can be avoided. It is.

The present inventors dissolved an aromatic carboxylic acid metal salt in an organic medium with a boiling point of 150°C to 310°C, emulsified this in water, and applied a coating liquid to a support paper or made paper. It has been found that the above-mentioned drawbacks can be improved by adding it to paper stock.

The metal salts of aromatic carboxylic acids used in the present invention include copper, lead, magnesium, calcium,
Metal salts of zinc, aluminum, tin, nickel, etc.

Specific examples of aromatic carboxylic acids include benzoic acid, chlorobenzoic acid (o, m, p), nitrobenzoic acid (o9m, p), toluic acid (otm, p), and 4-methyl-3-nitrobenzoic acid. Acid, 2-chloro-4-nitrobenzoic acid, 2,3-dichlorobenzoic acid, 2,4-dichlorobenzoic acid, p-isopropylbenzoic acid, 2,5-dinitrobenzoic acid, p-tertbutylbenzoic acid acid, N-phenylanthranilic acid, 4-methyl-3-nitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 3,5-dinitrosalicylic acid, 5-te
rt-butylsalicylic acid, 3-phenylsalicylic acid, 3
Methyl-5-tert-butylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3,5-di-tert-
amylsalicylic acid, 3-cyclohexylsalicylic acid, 5
-Cyclohexylsalicylic acid, 3-methyl-5-isoamylsalicylic acid, 5-ynamylsalicylic acid, 3,5-
Di-sec-butylsalicylic acid, 5-nonylsalicylic acid, 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-5-tert-butylbenzoic acid, 2,4-cresotinic acid, 5,5-methylenedisalicylic acid, acetaminobenzoic acid Acid (o, m, p), 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, anacardic acid, nonaphthoic acid, 3,5-di-α,α-dimethylbenzylsalicylic acid, 3,5-di-α Examples include methylbenzylsalicylic acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, thiosalicylic acid, and 2-carboxybenzaldehyde.

The solvent used in the present invention has a boiling point of 150 DEG C. to 310 DEG C., and is preferably an organic solvent capable of dissolving a metal salt of an aromatic carboxylic acid, which is a color developer, by a factor of 10 or more.

Examples include aliphatic or aromatic esters, biphenyl derivatives, naphthalene derivatives, biphenyl alkanes, and the like.

Specifically, methyl amyl acetate (1,3-dimethylbutyl acetate), 2-ethyl butyl acetate,
2-ethylexyl acetate, amyl propionate, n-butyl butyrate, iso-butyl-iso-butyrate, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 2,2,4- Trimethyl-1,3-pentanediol diisobutyrate, 2,
4 dimethyl-2,4-pentanediol diacetate,
2,2-dimethyl-1,3-butanediol diisobutyrate, 2-methyl-2,4-pentanediol dipropionate, 2,3,3,4tetramethyl-2,4-pentanediol monoacetate, amyl Lactate, 2
-Methylbiphenyl, 3-methylbiphenyl, 3t
3-dimethylbiphenyl, 2,4-dimethylbiphenyl, 2,6-dimethylbiphenyl, 2,4.6-trimethylbiphenyl, cyclohexylbenzene, bicyclohexylbenzene, monoisopropylbiphenyl,
These include monoisopropylnaphthalene, diisopropylnaphthalene, methylphenylxylylmethane, and the like.

Among the above, aliphatic esters having 8 to 25 carbon atoms are particularly preferred.

A petroleum fraction homogeneous solvent having a boiling point of 150° C. to 310° C. can be used in combination with these solvents as a diluent.

If a solvent with a boiling point of 150° C. or higher is used, significant evaporation occurs during the coating or papermaking process, resulting in poor workability.

On the other hand, a solvent with a boiling point of 310° C. or higher is not advantageous because it is difficult to evaporate during the drying process after coating or paper making.

That is, if the solvent remains in the coated paper, the color developing ability, the resistance of the color former, etc. will be impaired.

The metal salt of aromatic carboxylic acid is dissolved in the above solvent in an amount of 5 to 70 times, preferably 10 to 50 times.

This organic solvent solution is emulsified in water using a stirrer or the like to form a coating liquid.

In this case, ionic or nonionic surfactants, water-soluble polymers, latexes, inorganic pigments, etc. may be added.

The organic solvent solution is 5% to 100%, preferably 3% to water.
It is emulsified by adding about 0 to 80 parts.

The coating solution obtained in this way is applied to paper or added to paper stock during papermaking, but the final amount is 0.1 g/m2 to 3.0 g/m2 as a metal salt of aromatic carboxylic acid. Preferably 0.2g/m2 to 1. Og/m2 is suitable.

The color former that reacts with the color developer sheet of the present invention to form a colored image is well known in the art and is not particularly limited, but specific examples of compounds are as follows.

3,3-bis(p-
dimethylaminophenyl)-6-dimethifaminophthalide or crystal violet lactone, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(p-
Dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-methylindol-3-yl)phthalide, 3-(p -dimethylaminophenyl)-
3-(2-phenylindol-3-yl)phthalide,
3,3-bis-(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-bis(1
,2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazol-3-yl)-5-dimethylaminophthalide, 3,3
-bis-(2-phenylindol-3-yl)-5 dimethylaminophthalide, 3-p-dimethylaminophenyl-3-(1-methylpyrrol-2-yl)-6-dimethyl-aminophthalide etc.; Diphenylmethane compounds such as 4,4/-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl leuco auramine, N-2,4.5-toIJ chlorophenyl leuco auramine, etc.: xanthene compounds As Rhodamine B-
Anilinolactam, Rhodamine B-p-nitroanilinolactam, Rhodamine B-p-chloroanilinolactam, 3-dimethylamino-7-methoxyfluoran, 3-
Diethylamino-7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-
Chloro-6-methylfluorane, 3-diethylamino-6,8-dimethylfluorane, 3-diethylamino-7-acetylmethylaminofluorane, 3-diethylamino-7-methylaminofluorane, 3,7-diethylaminofluorane, 3-diethylamino -7-dibenzylaminofluorane, 3-diethylamine-7-methylbenzylaminofluorane, 3-diethylamino-7-phenylamino-3-methylaminofluorane, 3-diethylamino-7-chloroethylmethylaminofluorane, 3 Diethylamino-7-dichloroethylaminofluorane, etc.; thiazine compounds such as penzoylleucomethylene blue, p-nitrobenzylleucomethylene blue, etc.; spiro compounds such as 3-methyl-spirodinaphthopyran, 3-ethylspirodinaphthopyran, 3 , 3'-dichlorospirodinaphthopyran, 3-penzylspirodinaphthopyran, 3-methyl-(3-methoxybenzo)-spiropyran, 3-7'-ropyru-spirodibenzopyran, etc., or a mixture thereof. .

The coloring agent is dissolved in a solvent and encapsulated, or dispersed in a binder solution and applied to the support according to a conventional method.

As the solvent, natural or synthetic oils can be used alone or in combination.

Examples of solvents include cottonseed oil, kerosene, paraffin, naphthenic oil, alkylated biphenyl, alkylated terphel, chlorinated halaffin, alkylated naphthalene, and the like.

For methods of manufacturing capsules, see, for example, US Pat.
0 0,4 5 7, 2,8 0 0,4 5
Method using core cell partition of hydrophilic colloid sol described in No. 8, British Patent No. 8 6 7, 7 9 7
No. 95 0.4 4 3, No. 9 8 9.2
There are interfacial polymerization methods described in No. 6 4, No. 1,09 1,07 6, and the like.

The performance of the color developer sheet of the present invention was tested using the following color former sheet.

Adjustment of Color Former Sheet A 10 parts of acid-treated gelatin having an isoelectric point of 8.0 and 10 parts of gum arabic were dissolved in 60 parts of water at 40°C, and 0.2 part of sodium alkylbenzene sulfonate was added as an emulsifier. This was emulsified with 50 parts of color former oil.

The coloring agent oil is an oil consisting of 4 parts diisopropyl biphenyl and 1 part kerosene, and 2 parts crystal violet lactone.
．． 5 weight φ and penzoyl leucomethylene bull 2.0 weight ratio were dissolved.

40 when the average size of emulsified droplets is 8 microns.
100 parts of water at ℃ was added to suppress the progress of emulsification.

While continuing to stir, add 210 parts of water at 30°C,
The pH of the system was adjusted to 4.4 by adding 0φ hydrochloric acid.

The liquid was further cooled to 8°C while stirring, and then 1.5 parts of 20% glutaraldehyde was added.

Subsequently, 30 parts of a 10fb carboxymethyl starch solution was poured, and then a 25% sodium hydroxide solution was added dropwise to adjust the pH to 8.5, and the liquid temperature was heated to 30°C to form microcapsules with hardened walls. I got it.

Disperse 10 parts of cellulose floc in this liquid,
Color former sheet 1-A was obtained by coating 6 g/m2 of solid paper on 2 m2 of paper.

Next, the present invention will be explained in more detail with reference to Examples.

In addition, the blending ratio in the examples indicates parts by weight.

Example 1 Zinc 3,5-di-α-methylbenzylsalicylate 50
1 part was added to 100 parts of 2.2.4-trimethyl-1,3-pentanediol diisobutyrate, and the mixture was heated and dissolved at 90°C.

Add this to 300 parts of water, and add 1 part as a surfactant.
0.1 part of a 0φ sodium sulfosuccinate aqueous solution was added, and an emulsion was adjusted using an ultrasonic disperser so that the emulsion had an average particle size of 1 μm.

This was coated and dried on 40 g/m2 of high-quality paper using an air knife coating device so that the amount of zinc 3,5-di-α-methylbenzylsalicylate was 0.5 g/m2 to obtain a color developer sheet.

Example 2 100 parts of softwood sulfite pipe was beaten to 40SR, and a paper stock containing 1 part of melamine formaldehyde resin, 2 parts of maleated rosin sizing agent, and 2 parts of sulfuric acid was made using an ordinary Fourdrinier paper machine. The paper was made into paper with a basis weight of 40 g/m2, and the emulsion in Example 1 was applied and dried on-machine using a size press so that the amount of zinc 3,5-di-α-methylbenzylsalicylate was 0.5 g/m2. A developer sheet was obtained.

Example 3 100 parts of softwood sulfite pulp was beaten to 40SR, and the emulsion obtained in Example 1 was added to a paper stock containing 1 part of melamine formaldehyde resin, 2 parts of maleated rosin sizing agent, and 2 parts of sulfuric acid. The solution was added in an amount of 1 part of zinc 3,5-di-α-methylbenzylsalicylate.

The thus-completed paper stock was made into paper with a basis weight of 409/m2 using an ordinary Fourdrinier paper machine and dried with a multi-barrel dryer to produce a color developer sheet.

Comparative Example 1 10 parts of zinc 3,5-di-α-methylbenzylsalicylate, 40 parts of kaolin, 4 parts of polyvinyl alcohol, and 10 parts of styrene-butadiene latex (50% concentration) were added to 250 parts of water, and the mixture was homogenized using an attritor. A coating liquid was obtained.

This was coated and dried in the same manner as in Example 1 to obtain a color developer sheet.

Comparative Example 2 In Example 2, coating was attempted in the same manner as in Example 2, except that the coating liquid of Comparative Example 1 was used as the coating liquid instead of the emulsion of Example 1, but the amount of coating was reduced to the required amount. I couldn't give you that.

That is, it is difficult to control the coating amount of a typical dispersion-type developer solution that is not an emulsion using a size press.

Comparative Example 3 In Example 3, the same amount of attritor dispersion of zinc 3,5-di α-methylbenzylsalicylate was added instead of the zinc 3,5-di α-methylbenzylsalicylate emulsion, and the same procedure was repeated. A developer sheet was obtained.

Performance The color former sheet A was placed opposite the color developer sheet obtained in the comparative example and the comparative example, and the densities of the copied images were compared by writing with a ballpoint pen.

In addition, in order to compare printability, paper stiffness and surface picking strength were tested.

[The picking strength was measured using an RI tester (Mei Seisakusho).

] The results are shown in Table 1.

It can be seen that the color developer sheet obtained by the method of the present invention is superior in performance such as copy density, paper stiffness, and picking strength compared to the color developer sheet obtained by the conventional method.

Claims (1)

[Claims] 1 Dissolve an aromatic carboxylic acid metal salt in an organic solvent with a boiling point of 150°C to 310°C, emulsify it with water and apply a coating liquid onto the support paper, or add it to the paper stock during paper making. A method for producing a color developer sheet for pressure-sensitive recording, characterized in that: