JPS6021875B2 - recording material - Google Patents

Description

[Detailed description of the invention] The present invention relates to recording materials.

In particular, it relates to improvements in color developers that develop color upon contact with nearly colorless compounds (hereinafter referred to as color formers). Traditionally, color formers and adsorbed or reactive compounds (hereinafter referred to as complex agents) that develop color when in contact with the color formers, such as clay materials such as acid clay, activated white clay, attapulgite, zeolite, bentonite, kaolin, and salicylic acid, have been used. , tannic acid, gallic acid, organic acids such as phenolic compounds, or metal salts thereof, and recording materials utilizing coloring reactions with acidic polymers such as phenol-formaldehyde resins are well known.

Here, the color former is a substance that generates color by donating electrons or accepting protons such as acids, and the color developer is a substance that accepts electrons or donates brotons.

Recording materials that specifically utilize this phenomenon include sensho copy paper (for example, U.S. Pat. Nos. 2,505,470 and 2,505,488).
No. 9, No. 2550471, No. 2548366, No. 2
No. 712507, No. 2730456, No. 273045
No. 7, No. 3418250, Tarubatsu No. 491-28411, JP-A-50-4400), and thermal recording paper (e.g., JP-A No. 43-416, U.S. Pat. No. 293,900).
No.) There are energizing recording papers, etc.

Furthermore, a printing method is also known in which a colored image is obtained by supplying ink containing a color developer through a medium such as a stencil onto a sheet coated with a color developer (German patent application (O
LS) No. 1939624). When utilizing the above phenomenon, it is necessary to apply pressure or heat using a pencil or typewriter, or to bring the head coloring agent into contact with other coloring agents. The most typical form of recording material is pressure-sensitive copying paper.

The color former layer of pressure-sensitive copying paper is prepared by dissolving the color former in a solvent such as alkylated naphthalene, alkylated diphenyl, alkylated diphenylalkane, or triarylmethane, and dispersing it in a binder or containing it in microcapsules. It can be obtained by coating it on a support such as paper, plastic film, resin-coated paper, etc. On the other hand, the coloring agent is dissolved or dispersed together with a binder in a medium such as water and applied to a support to obtain a color developer sheet.

In this case, synthetic latex is generally used as the binder because of its strong film surface strength and low viscosity of the coating liquid. Generally, the color former and developer are applied to the same or opposite or different sides of the support.

Then, the coloring agent in the microcapsule is released by writing pressure or hitting pressure, and when it comes into contact with the color developer, it develops a color, and a record corresponding to the pressure can be obtained. As mentioned above, various color developers are known, but there are still some points to be improved.

For example, when a color developer sheet is left in the air, its complexion ability may deteriorate over time. Since such a decrease in color developing ability has a significant effect on commercial value, improvements are desired. Another drawback that needs to be improved is that over time, the binder absorbs floating matter in the air or decomposes due to sunlight or ultraviolet rays, causing the surface of the head colorant to turn yellow. be. Therefore, the objects of the present invention are, first, to prevent the deterioration of color developing ability over time, second, to improve complexion ability, and third, to reduce yellowing of the color developing surface. The fourth purpose is to manufacture a recording material that meets the above objectives.The fifth purpose is to manufacture a recording material that effectively uses a small amount of metal.

The above-mentioned object of the present invention is to contact a water-soluble aluminum salt, zinc salt, calcium salt, or magnesium salt with a clay mineral in the presence of water, and to form a clay mineral with the metal salt adsorbed thereon, a phenol resin, and/or an aromatic resin. This was achieved by a recording material characterized in that it contains zinc, aluminum, tin, magnesium or calcium salts of carboxylic acids. Clay minerals used in the present invention include acid clay, activated clay, attapulgide, kaolin, genji, and waxite talc.

Among these, clays having a three-layer structure, such as acid clay and activated clay, are preferred. In particular, those having an average particle size of about 15 microns or less and whose aqueous dispersion exhibits acidity are preferred.

The proportion of the metal salt to the clay mineral is about 0.5% to about 2% by weight in terms of metal oxide or hydroxide.
About 5%, especially without 1, and about 15% can exhibit a sufficient effect.

The method for adsorbing metal salts onto clay minerals is carried out by bringing metal salts and clay minerals into contact in the presence of water, as described above.

For example, first, an aqueous dispersion of clay minerals is prepared, a predetermined amount of metal salt is added to this dispersion, adsorbed thereon, and then kept at a temperature of 15,000 to 450 oo for 60 minutes to about 30%. When performing heat treatment, the aqueous dispersion may be heated as it is, but it is better to heat the dispersion after the water content is reduced to about 20% or less. As a result of examination using X-rays, no metal salts were detected in the clay mineral treated with metal salts. Therefore, it is thought that after the metal salt is adsorbed, it reacts with the clay mineral surface to form a completely different compound.
It is not clear why clay minerals treated with metal salts are effective as head coloring agent compositions.

Compared to the case of using metal oxides and hydroxides, the reason why the effect is sufficient with a very small amount is that the metal ions are concentrated near the surface of the clay mineral, which reduces the effective surface area of the metal salt. It is thought that this is due to the chopsticks being slightly enlarged. In addition, when attempting to achieve the same effect as the present invention by simply using a clay mineral and a metal oxide or hydroxide, it is preferable to use a metal salt-treated clay mineral of the present invention. Therefore, an amount of metal of about 1 pm or more is required.

The use of metal salts is not preferable in terms of drainage measures, and from this point of view, the effect of using a small amount effectively as in the present invention can be understood. The phenolic resins used in the present invention are typically novolak-type phenolic resins, alkenylphenol oligomers, and the like.

Specific examples of phenolic resins include phenol or those substituted with one or more groups having about 1 or less carbon atoms such as halogen atoms, alkyl groups, aryl groups, and alkoxy groups, and aldehyde (formaldehyde). etc.), and ketones (methyl ethyl ketone, etc.).

Specific combinations include p-phenylphenol-formaldehyde, p-nonylphenol-formaldehyde, p-octylphenol-formaldehyde, p-Q.Q-dimethylbenzylphenol-formaldehyde, p-Q- Examples include methylbenzylphenol-formaldehyde, t-butylphenol-formaldehyde, and mixtures containing two or more of the alkylphenols and their isomers and formaldehyde. Further, the aromatic carboxylic acids in the metal salts of aromatic carboxylic acids include those represented by the following general formula.

General formula [wherein R, R2, R3, R4, and R5 are each a hydrogen atom, a halogen atom, a hydroxy group, an amino group, an alkylamino group, a nitro group, an aldehyde group, an alkyl group,
cycloalkyl group, aryl group, alkylaryl group,
Represents a group having less than a number of carbon atoms, such as an aralkyl group or an alkoxy group.

R,, R2 or R3, R4 may open to each other to form a five- or six-membered ring. ]Among the compounds of the above general formula, particularly useful compounds include at least one of R or R5.
is a hydroxy group, and o
- and p- positions are substituted with an alkyl group, an aryl group, an aralkyl group, etc.

Specific examples of aromatic carboxylic acids include 2,4-dichlorobenzoic acid, p-isopropylbenzoic acid, 2,5-dinitrobenzoic acid, pt-butylbenzoic acid, N-phenylanthranilic acid, 4-methyl -3-nitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 3,5-dinitrosalicylic acid, 5-t-butylsalicylic acid, 3-phenylsalicylic acid, 3-methyl-5-
t-butylsalicylic acid, 3,5-di-tenamylsalicylic acid, 3-cyclohexylsalicylic acid, 5-cyclohexylsalicylic acid, 3-methyl-5-isoamylsalicylic acid, 5-isoamylsalicylic 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, (o, m,
p), 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, anacardic acid, 1-naphthoic acid, 2-
Examples include naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, thiosalicylic acid, and preferred ones include 3,5-di(Q-methylbenzyl)salicylic acid,
3-(Q-methylbenzyl)-5-(Q.o-dimethylbenzyl)salicylic acid, 3-(4'-Q.Q'-dimethylbenzyl)phenyl-5-(Q.Q-dimethylbenzyl)salicylic acid, 3.5- di-t-butylsalicylic acid,
3,5-di-t-octylsalicylic acid, 3-cyclohexyl-5-(Q-Q-dimethylbenzyl)salicylic acid,
Examples include 3-phenyl-5-(Q-Q-dimethylbenzyl)salicylic acid, 3,5-di(Q-Q-dimethylbenzyl)salicylic acid, and 3,5-di(Q-Q-dimethylbenzyl)salicylic acid. Settle.

Further, to the metal salt-treated clay mineral of the present invention, an oxide of a metal selected from the group of zinc, aluminum, calcium, magnesium, titanium, nickel, cobalt, manganese, iron, tin, copper, vanadium and chromium, hydroxide,
A metal compound such as a silicate or carbonate may be used in combination.

Preferred examples of such metal compounds include zinc oxide, aluminum oxide, zinc silicate, aluminum silicate, calcium hydroxide, zinc carbonate, calcium carbonate, and magnesium carbonate. When preparing a complexion agent coating solution, it is generally necessary to
A sexual binder is used.

These are selected from the viewpoints of film surface strength and color developer dispersibility. Water-soluble I binders include proteins (e.g.
gelatin, albumin, casein, etc.), cellulose (
(e.g., carboxymethyl cellulose, hydroxyethyl cellulose, etc.), water-soluble natural polymer compounds such as sutucarose (e.g., agar, sodium alginate, carboxymethyl starch, gum arabic, etc.); polyvinyl alcohol, polyvinyl pyrrolidoso, polyacrylic acid. ,
Water-soluble synthetic polymers and other latexes are used, such as polyacrylamide, styrene-butadiene-methacrylic acid latex, acrylonitrile-butadiene acrylic acid latex, styrene-hydro-maleic acid copolymer, and the like.

In this case, the amount used is preferably 2 parts by weight or less per 10 parts by weight of the color developer, and the total amount of binder is preferably about 4 parts by weight or less.

The recording sheet of the present invention can be obtained by applying and drying a coating liquid in which the above binder and pigment are dispersed or dissolved in water onto a support such as paper, synthetic paper, or film.

In this case, resin powder, talc, inorganic pigments, dispersants, antifoaming agents, antioxidants, etc. may be added to the coating liquid in order to improve the surface properties of the coated surface.

(For example, U.S. Patent Nos. 2,711,375, 3,625,736,
3836383, total 46331, British patent 123234
7 etc.). As for the coating method, a method used by those skilled in the art is used, such as an air knife coater, a roll coater, a blade coater, a size press coater, a curtain coat, etc., and it is possible to coat one layer or multiple layers at the same time. . The amount of application varies depending on the type of head coloring agent used, but the head coloring agent is applied approximately 0.3 to 6 times per day. If the amount is too small, sufficient colored bears cannot be obtained, and the upper limit is determined primarily by economic reasons rather than performance. The color forming agent that reacts with the color developer used in the recording sheet of the present invention is not particularly limited, but specific compounds of these color forming agents include {1' triarylmethane compounds such as 3,3-bis(p dimethylaminophenyl)-6-dimethylaminophthalide, crystal violet lactone, 3,3-bis(D-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-(1,2- dimethylindol-3-yl)phthalide, 3-(o-dimethylaminophenyl)-3-(
2-methylindole-3-yl)phthalide, 3-(p
-dimethylaminophenyl)-3-(2-phenylindol-3-yl)phthalide, 3.3-bis-(1.2
-dimethylindol-3-yl)-15 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
1p-dimethylaminophenyl-3-(1-methylpyrrol-2-yl)-6-dimethyl-aminophthalide, etc.;
■As diphenylmethane compounds, 4,4'-pis-dimethylaminobenzhydrin benzyl ether, N-halophenylleucoauramine, N-2,4,5-trichlorophenylleucoauramine, etc.; {31 xanthene compounds as Rhodamine B-anilinolactam, Rhodamine B-p nitroanilinolactam, Rhodamine B
-p-chloroanilinolactam, 7-dimethylamino-2-methoxyfluoran, 7-diethylamino-2-methoxyfluoran, 7-diethylamino-3-methoxyfluoran, 7-diethylamino-3-chlorofluoran, 7 -diethylamino-3-chloro-2-methylfluorane, 7-diethylamino-2,2-dimethylfluorane, 7-diethylamino-3-acetylmethylaminofluorane, 7-diethylamino-3'-methylaminofluorane, 3. 7-diethylaminofluorane, 7-diethylamino-3-dibenzylaminofluorane, 7
-Diethylamino-3-methylbenzylaminofluoran, 7-diethylamino-3-chloroethylmethylaminofluoran, 7-diethylamino-3-diethylaminofluoran, etc.; ■As a thiazine compound, benzylleucomethylene blue , p-nitrobenzylleucomethylene blue, etc.: (5} As a spiro compound, 3
-Methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3-dichloro-spirodinaphthopyran, 3-pendyl-spirodinaphthopyran, 3
- Methylnaphthol (3-methoxybentho)-spiropyran, 3-propyl-spirogibenzopyran, etc.
Alternatively, a mixture thereof can be mentioned.

These are determined by the application and desired properties. The color former is dissolved in a solvent and encapsulated, or dispersed in a binder solution and applied to the support.

As a 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 terphenyl, alkylated naphthalene, triarylmethane, chlorinated paraffin, and the like. Methods for producing capsules include a method using coacervation of a hydrophilic colloid sol described in U.S. Pat.
No. 97, No. 950443, No. 989264, No. 10
There are interfacial polymerization methods described in No. 91076 and the like.
The effects obtained by the color developer using the metal salt-treated clay mineral of the present invention are listed below.

First, the weather resistance and durability of the colored image are improved. Second, less metal may be used.

Thirdly, the stability of color developing ability over time is improved.

Next, an example of a method for producing metal salt-treated clay minerals will be shown. 100 parts of acid clay (pH of the aqueous dispersion is approximately 5.6) is dispersed in 250 parts of water, and a 1% by weight aqueous solution of magnesium chloride is added to this.
An anchor was added, and the mixture was maintained at 25qC under rope azusa for a period of time. Then, after removing the top liquid by decantation, 250
qo for 45 minutes. The magnesium content of the white powder thus obtained was approximately 2.9% in terms of magnesium hydroxide. Similarly, using a zinc chloride aqueous solution,
A metal salt treated clay mineral containing about 5.6% zinc was prepared.

Next, the effect of the recording material of the present invention was confirmed using a color former sheet.

Microcapsules containing a color former are produced, for example, according to US Pat. No. 2,800,457, and specific examples thereof are shown below.

All "parts" below refer to "parts by weight." Add 1 part acid-treated pork skin gelatin and 1 part gum arabic to 4 parts water at 40qC.
0.2 parts of funnel oil was added as an emulsifier, and 4 parts of color former oil was emulsified and dispersed therein.

The color former oil was prepared by dissolving 2% crystal violet lactone in diisopropylnaphthalene. When the size of the oil droplets reaches 5 microns on average, stop the emulsification, add 4,000 ml of water, strain the whole 90 parts, and continue the process.

Then, 10% acetic acid was added to adjust the pH of the solution to 4.0-4.
2 to cause coacervation. The rope prayer is continued for 2 minutes, and then cooled with ice water to gel the coacervate film deposited around the oil droplets. When the liquid temperature reaches 20q0, add 7 parts of 37% formalin.

1000 and adjust the pH to 9 by adding 15% caustic soda aqueous solution.

Next, flood the water for 20 minutes while shaking the rope, and bring the temperature of the liquid to 5,000. The microphone thus obtained.

After the capsule dispersion was cooled to 30° C., it was coated and dried at a coating weight of 6 days/day using 40 days/day of paper as the solid content. In the manner described above, a sheet having a microcapsule layer containing crystal violet lactone as a coloring agent was obtained.

Example 1 7$ water, 2 parts zinc salt treated activated clay (zinc content 5.6%) obtained by the above method (zinc content 5.6%) and 3,5-di-te-butylsalicylic acid and 20% hydroxide Two parts of the NatoIJum solution were added and mixed, and then dispersion treatment was performed for 1 hour using an attractor.

Next, 4 parts of styrene-butadiene latex (hereinafter referred to as SBR latex) in terms of solid content was added to prepare a coating liquid.
This coating solution was coated on a 500 ml base paper using a coating rod so that the solid content was coated with 5 ml solids and dried to obtain a head coloring agent sheet. Comparative Example 1 A complexion seal was obtained in the same manner as in Example 1, except that activated clay was used in place of the zinc salt-treated activated clay in Example 1.

Comparative Example 2 In place of the zinc salt-treated activated white clay 2 anchor part in Example 1, activated white clay 2 foundation part and zinc oxide were converted into zinc amount of 1.12
A color developer sheet was obtained in the same manner as in Example 1 except that the developer sheet was used in the same manner as in Example 1.

Comparative Example 3 A color developer sheet was obtained in the same manner as in Example 1 except for zinc 3.5-di-tert-butylsalicylate.

Comparative Example 4 A head coloring agent sheet was obtained in the same manner as in Comparative Example 1 except for zinc 3,5-di-tert-butylsalicylate.

Comparative Example 5 A color developer sheet was obtained in the same manner as in Comparative Example 2 except for zinc 3.5-di-tert-butylsalicylate.

Comparative Test A microcapsule sheet containing Ku IJ Stalviolet Lactone as a coloring agent was layered on the head colorant sheets of Example 1 and Comparative Examples 2 to 5, and color was developed under a load pressure of 150k9/base.

After being left in the storeroom for one day, the reflection spectrum of the colored body was measured, and the absorbance at the absorption maximum was defined as the fresh concentration. Next, this colored material 0 was irradiated with a fluorescent lamp (700 lux) for one week, and then the reflection spectrum was measured, and the weather resistance was compared based on the concentration of the colored material. The results are shown in the table. It can be seen from the table that a color developer with excellent weather resistance of the color former can be obtained by using zinc salt-treated activated clay and 3,5-G in combination with zinc rt-butylsalicylate.

Furthermore, a color developer sheet having excellent aging resistance was similarly obtained by using zinc 3,5-di(Q-methylbenzyl)salicylate instead of zinc 3,5-di-ten-butylsalicylate.

Further, even when p-phenylphenol-formaldehyde resin was used instead of zinc 3,5-di-ten-butylsalicylate, a complexion sheet having excellent weather resistance and properties was similarly obtained.

Furthermore, a similarly excellent head coloring agent sheet was obtained by using magnesium-treated activated clay instead of zinc salt-treated activated clay.

Claims (1)

[Claims] 1. A water-soluble aluminum salt, zinc salt, calcium salt, or magnesium salt is brought into contact with a clay mineral in the presence of water, and the clay mineral adsorbs the metal salt, a phenolic resin, and/or a zinc salt of an aromatic carboxylic acid, aluminum. A recording material characterized in that it contains a salt, a tin salt, a magnesium salt or a calcium salt.