JPH0448106B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a color developer composition for pressure-sensitive paper, and more specifically, by contacting with a leuco dye or the like,
The present invention relates to a color developer composition for pressure-sensitive paper, which is capable of forming clear and high-density images, and which significantly suppresses discoloration of the formed recorded images and the background due to exposure to light rays. Prior Art and Technical Problems of the Invention Conventionally, the combination of a leuco dye and a color developer made of an acidic substance has been widely used in various information recording applications, such as pressure-sensitive recording, heat-sensitive recording, electrophotographic recording, and printing. In particular, in the field of pressure-sensitive paper, a paper substrate with a layer of color developer on one side is used as a so-called stamp paper. Color developers are known to include organic ones such as various phenols, phenolic resins, zinc salicylate and its derivatives, and those made of inorganic solid acids such as silica, aluminum silicate, clay minerals or acid-treated products thereof. However, while inorganic solid acid-based products have excellent heat resistance, solvent resistance, printing and transcription properties, etc., they have defects in coloring performance and fading due to the effects of light, heat, and moisture. is recognized. For example, a color developer made of amorphous silica gives a clear colored image when combined with a leuco dye, but
The images formed have extremely poor light fastness, for example, after 2 hours of exposure to a weather-o-meter, the image density decreases to less than 50%. In addition, although aluminosilicate clay minerals or their acid-treated products have slightly better light resistance than amorphous silica,
Images tend to fade when exposed to water. Additionally, coatings using these clay minerals or their acid treatments tend to turn yellow when exposed to light, and this background discoloration can cause the image formed to appear greenish. The problem is that it causes discoloration. On the other hand, organic color developers such as organic compounds containing phenolic hydroxyl groups lack properties as fillers, so in order to give printing ink absorbency and writing characteristics to pressure-sensitive stamp paper, it is necessary to After all, it is essential to use an inorganic filler. It is actually practiced to mix acid clay or its acid-treated product with an organic color developer as a filler and color developer, but in this case, it is also necessary to reduce the yellowing tendency of the background due to exposure. Despite the differences, it will be shown. Furthermore, when a filler that is inert to the leuco dye, such as kaolin or calcium carbonate, is added to the leuco dye, the density of the formed image is inevitably diluted to some extent. OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to provide a color developer composition for pressure-sensitive paper comprising a combination of an inorganic system and an organic system, which eliminates the above-mentioned drawbacks of conventional color developers. Another object of the present invention is to provide a color developer composition for pressure-sensitive paper which has excellent density and sharpness of formed images, and which suppresses discoloration of the image and background upon exposure to light. Still another object of the present invention is to provide a color developer composition for pressure-sensitive paper that has excellent workability in coating paper and drying properties. Structure of the Invention According to the present invention, there is provided a color developer composition for pressure-sensitive paper that is characterized by containing synthetic sauconite-type zinc phyllosilicate and a phenolic hydroxyl group-containing organic compound and having excellent light resistance. In this composition, the synthetic sauconite zinc phyllosilicate and the phenolic hydroxyl group-containing organic compound can be present in a weight ratio of 50:50 to 98:2. Preferred Embodiments of the Invention The present invention will be described in detail below with respect to its preferred embodiments. Synthetic sauconite type zinc phyllosilicate Synthetic sauconite used in the present invention
Type zinc phylosilicate has the chemical composition of the formula Zn ₃ Si ₄ O ₁₀ (OH) ₂ as the main component. The synthetic mineral optionally has up to 5 moles of water of hydration per unit cell. This synthetic sauconite-type zinc phyllosilicate is
It mainly has a three-layer structure in which two SiO ₄ tetrahedral layers are sandwiched with a ZnO ₆ octahedral layer in between, and there is also a SiO ₄ tetrahedral layer and a ZnO ₆ octahedral layer. A two-layer structure bonded in layers may be contained within a range that does not impair the essence of a three-layer structure, and unreacted silica components and non-reacted silica components may be contained within a range that satisfies the properties described below. There is no problem even if a crystalline silicate component and/or a small amount of a raw metal compound are contained. Sauconite type zinc phyllosilicate exhibits, for example, the X-ray diffraction image shown in FIG. 1 of the attached drawings, and its relative intensity ratio (I/I ₀ ×100) is as shown in Table A below. Section A Surface spacing d x (Å) relative strength I/I ₀ 9-16 100 4.5-4.6 40-60 3.1-3.3 20-40 2.4-2.7 50-80 1.5-1.6 50-80 Synthetic sauconite used in the present invention Zinc phyllosilicates exhibit several properties not found in known natural or synthetic zinc phyllosilicates. These characteristics include significantly high oil absorption and BET specific surface area, typically between 80 and 160ml/100ml.
g, especially oil absorption of 90 to 140ml/100g (JIS
K5101) and 50 to 200 m ² /g, especially 80 to 150
m ² /g BET specific surface area. In addition, this synthetic mineral has excellent dye adsorption properties, and is certified as JIS K.
Methylene blue decolorizing power measured at -1470 is 100
It shows a large value reaching more than ml/g, especially more than 250 ml/g. Furthermore, this zinc phyllosilicate has properties as a solid acid and is particularly excellent in the ability to develop color from leuco dyes. In general, the characteristics of a solid acid are acid strength (H ₀ )
It is expressed by two characteristics: and acidity. When a solid acid is neutralized with a base such as n-butylamine, the acid strength is neutralized in order from high to low, so use an indicator corresponding to each acid strength to indicate the neutralization point. When performing neutralization titration using
A cumulative distribution curve of acidity corresponding to each acid strength is obtained. An indicator with a pKa of -3.0, the acidity (milliequivalents/g) of the solid acid determined as a dicinnamal acetone indicator is _A1 , an indicator with a pKa of +4.8,
If the acidity (milliequivalent/g) of a solid acid determined using methyl red as an indicator is _A2 , then the acidity is
A ₁ is the acidity of something with high acid strength (strong acid),
On the other hand, A ₃ = A ₂ − _{A 1} is an acid with low strength (weak acid)
represents the acidity of The sauconite type zinc phyllosilicate used in the present invention has an acidity of low acid strength, that is, A ₃ =A ₂ -A ₁
The value of 0.3 to 2.0 meq/g, especially 0.6 to 1.5
Characterized by a relatively large range of milliequivalents/g, while the acidity A ₁ of high acid strength is
Although it varies depending on the synthesis method, it is generally 0.01 to
It is in the range of 0.1 meq/g. however,
A high acidity A ₁ of a high acid strength product is not desirable from the viewpoint of use in combination with an organic color developer, and the neutralization treatment described below reduces A ₁ to 0.01 meq.
It is desirable to suppress it to a range of less than g. The layered zinc phyllosilicate used in the present invention is a combination of active silicic acid, amorphous silica, or other easily reactive silica raw materials, and zinc oxide or hydroxide, or the oxide or hydroxide under reaction conditions. is synthesized by hydrothermally treating a compound capable of producing the above composition in a stoichiometric amount sufficient to achieve the above composition. As the activated silicic acid, activated silicic acid obtained by acid treatment of clay minerals is particularly advantageously used. That is, by using this activated silicic acid as a raw material, a phyllosilicate having excellent pigment properties, such as fine particle size and homogeneity, can be easily obtained. In the present invention, by using activated silicic acid as a raw material, synthetic layered zinc phyllosilicate having the above-mentioned fine structure and having a significantly large specific surface area and adsorption performance can be easily obtained. This seems to be because the presence of layered silica facilitates recombination into zinc phyllosilicate with a fine layered structure while maintaining the shape of layered silica. In the present invention, raw clay minerals include smectite group clay minerals, for example, so-called montmorillonite group clay minerals such as acid clay, bentonite, subbentonite, and fuller's earth, and one or more of beidellite, saponite, nontronite, and the like.
Combinations of more than one species are preferably used. Clay minerals other than those mentioned above, such as kaolin group clay minerals such as kaolin and halloysite, chain clay minerals such as attapulgite, sepiolite, and palygorskite, may also be used. For example, kaolin does not have reactivity with acids in its original state, but when it is calcined to form metakaolin, the reaction with acids is easily carried out. Acid treatment of clay minerals has a surface index of clay minerals [001]
The X-ray diffraction peak of the product virtually disappears and the product
It is preferable that the molar ratio of Al ₂ O ₃ :SiO ₂ is in the range of 1:11 to 1:99. The acid treatment conditions can be based on conditions known per se. for example,
As the acid, mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as benzenesulfonic acid, toluenesulfonic acid, and acetic acid are used, but mineral acids such as sulfuric acid are generally used. The method of contacting the clay mineral with the acid may be arbitrary. For example, a slurry activation method in which clay and acid are brought into contact with each other in a slurry state, a granular activation method in which granulated clay and acid are brought into solid-liquid contact, and clay. A mixture of and acid is reacted dry (inside the granules),
Next, a dry activation method or the like may be employed in which by-product salts are extracted. The amount of acid used varies depending on the acid treatment conditions, but the molar ratio of Al ₂ O ₃ :SiO ₂ in the product is within the range mentioned above, and Fe 2 O 3 and Fe ₂ O ₃ in the clay mineral are
Any material may be used as long as MgO or other basic components such as alkali metal components are substantially removed. for example,
In the dry activation method, acid treatment is performed using 0.3 to 1.5 equivalents, particularly 0.6 to 1.2 equivalents of acid or acid aqueous solution relative to the base-forming component in the clay mineral. The reaction conditions are
A temperature of 60 to 300°C and a time of 10 to 600 minutes are determined so that the above requirements are met. The extraction of the soluble base components from the reaction product is carried out in an aqueous medium with a pH below 1 so that their hydrolysis is prevented. It is desirable that the particle size of the acid-treated clay is as fine as possible, and particles with a particle size of 5μ or less account for 20% of the total.
% by weight or more, especially 30% by weight or more, and particles larger than 20μ are smaller than 30% by weight of the whole, especially 10
It is preferable to adjust the particle size so that it is smaller than % by weight before using it in the reaction. As other silica raw materials, silica gel, silica flour, silica sand powder, whitebait, etc. can also be used. Zinc raw materials include zinc oxide (zinc white),
Hydroxides or compounds capable of forming said oxides or hydroxides under the reaction conditions may be used. A typical example of such a compound is zinc carbonate. The ratio of both raw materials is stoichiometric. During the hydrothermal treatment, both raw materials are made into an aqueous slurry with a solid content concentration of 2 to 30% by weight, and this aqueous slurry is charged into an autoclave and heated. Make it react. Reaction conditions: 110 to 200℃
temperature is used, in which case the pressure of the reaction system is 0.5
Maintained at 15.5Kg/cm ² gauge. The reaction time varies depending on temperature and pressure, but is suitably in the range of 0.5 to 10 hours. Although reaction under pressure is preferred, zinc phylosilicate can also be obtained by hydrothermal treatment under non-pressurized conditions. The product is washed with water, dried, crushed, and
Processes such as classification are performed to produce products. As already pointed out, the acidity of high acid strength
When a lower _A1 is desirable, especially in the case of stamp papers to which desensitizing ink is applied, the resulting zinc phylosilicate can be suspended with a florescent alkali, etc. so that the pH of the suspension is in the range of 9 to 10. It is better to neutralize it. The particle size of the zinc phyllosilicate is not particularly limited, but it is generally desirable to have a median diameter of 1 to 6 microns, particularly 1.5 to 4 microns. Organic Color Developer In the present invention, the above-mentioned sauconite zinc phyllosilicate is used as a color developer in combination with a phenolic hydroxyl group-containing organic compound. Suitable examples of such phenolic hydroxyl group-containing organic compounds are aromatic oxycarboxylic acids or metal salts thereof or phenolic resins, especially novolak type phenolic resins. Specific compound names of the former are as follows, although they are not limited thereto. 3.5-diisopropylsalicylic acid, 5-tertbutylsalicylic acid, 5-cyclohexylsalicylic acid, 5-phenylsalicylic acid, 5-(α,α-dimethylbenzyl)salicylic acid, 3.5-ditertbutylsalicylic acid, 3.5-dicyclohexylsalicylic acid, 3.5-di( These include α,α-dimethylbenzyl)salicylic acid, 3-cyclohexyl-5-(α,α-dimethylbenzyl)salicylic acid, and 2-hydroxy-5-methyl-1-naphthoic acid. These compounds can be used in the form of free oxycarboxylic acids or in the form of metal salts such as zinc, magnesium, cadmium, aluminium, lead, titanium, calcium, cobalt, nickel, manganese and the like. A preferred metal salt is a zinc salt. As the phenol resin, those obtained by knitting and polymerizing various phenols and aldehydes such as formaldehyde in the presence of an acid catalyst, or in the presence of an alkali catalyst and then an acid catalyst are preferably used.
Here, the phenols include bifunctional phenols, especially those of the formula Phenols in which R is an alkyl group, a cycloalkyl group, an allyl group, or a halogen, especially p-cresol, p-ethylphenol, p-tertiarybutylphenol, p-cyclohexylphenol, p-phenylphenol, p- - Chlorphenol and the like. The molecular weight of the phenolic resin used is generally
A range of 250 to 1000 is desirable. These phenolic resins can also be used in the form of metal salts, such as zinc salts. Composition As mentioned above, the color developer composition for pressure-sensitive paper in the present invention is characterized in that it contains a combination of synthetic sauconite-type zinc phyllosilicate and a phenolic hydroxyl group-containing compound. In other words, as shown in the example below, the density and sharpness of the image can be significantly improved by using both of these developer components in combination, compared to the case where either one of the developer components is used. In addition, the light resistance (discoloration and fading tendency) when subjected to a light exposure test is also significantly improved. Moreover, surprisingly, the synthetic sauconite-type zinc phyllosilicate used in the present invention has little to no photoyellowing that is observed in conventional inorganic color developers. Synthetic sauconite zinc phyllosilicate and phenolic hydroxyl group-containing compound are 50:50 to 98:
2, preferably at a weight ratio of 70:30 to 95:5. If the amount ratio of zinc phylosilicate is outside the above range, there will be no synergistic effect in improving density and sharpness, and there will be no special advantage from using the two in combination. In addition to the above-mentioned components, the color developer composition of the present invention may contain components known per se in accordance with known formulations. For example, a binder may be added to impart adhesion or adhesion to paper. As the binder, an aqueous latex binder such as styrene-butadiene copolymer latex;
One or a combination of two or more of self-emulsifying binders such as self-emulsifying acrylic resins; water-soluble binders such as starch carboxymethyl cellulose, polyvinyl alcohol, cyanoethylated starch, and casein are used. In addition, inert fillers such as kaolin, calcium carbonate, talc, zinc oxide, etc. may be added to increase the amount of the composition for coating on paper or to further improve the writing and printing properties. The leuco dye developer composition of the present invention is particularly useful for producing stamp paper for pressure-sensitive recording. In the production of stamp paper, the combined developer content is 5 to 50% by weight, especially 15 to 40% by weight, and the binder is 1 to 10% by weight.
An aqueous slurry containing a color developer in an amount of 1 to 10 g/m ² , particularly 3 to 8 g/m ² is prepared, and dried. The developer compositions of the present invention also exhibit many advantages in the production of pressure sensitive papers. That is, when used as a color developer for leuco dyes, it provides extremely significant advantages over conventional inorganic solid acid color developers in terms of coatability, workability, and handling as recording paper. Acid-treated products of montmorillonite clay minerals, which are currently used industrially as color developers for pressure-sensitive paper, have a high viscosity when made into an aqueous coating solution, making it difficult to coat at high concentrations, and low solid content. Since the coating must be applied in high concentrations, it has the disadvantage that the cost of heat energy for drying increases. this is,
This is also thought to be due to the fact that the acid-treated clays have swelling properties with water. The layered crystal zinc phyllosilicate used as a component in the present invention has little tendency to increase in viscosity even at relatively high solids concentrations and has excellent coating properties, which also reduces drying energy costs in the coating process. can be done. In addition, the above-mentioned acid-treated clay minerals have a high abrasion tendency, and tend to wear out various tools and equipment in the pressure-sensitive paper manufacturing process, and may also peel off from the coating layer. Although there is a tendency for leuco dye capsules to rupture and form so-called smudges, the layered crystalline synthetic zinc phyllosilicate used in the present invention has less tendency to wear, peel, and smudge. Furthermore, the composition containing this synthetic zinc phyllosilicate has excellent adhesion and adhesion to paper,
It can be applied to paper with a small amount of binder. In the present invention, all leuco dyes used in this type of pressure-sensitive recording can be used as the leuco dye, such as triphenylmethane-based leuco dyes, fluoran-based leuco dyes, spiropyran-based leuco dyes, and rhodamine lactam-based leuco dyes. leuco dye,
Auramine-based leuco pigments, phenothiazine-based leuco pigments, etc. are used alone or in combination of two or more. In combination with a top paper provided with a layer of microcapsules of these leuco dyes, it is used for pressure-sensitive recording. The invention is illustrated by the following example. Test method The test method for each item in this specification was as follows: 1. X-ray diffraction In this example, an
2125D1, counting device 5071) was used. The diffraction conditions are as follows. Target Cu Filter Ni Detector SC Voltage 35KVP Current 15mA Count full scale 8000c/s Time constant 1sec Scanning speed 2°/min Chart speed 2cm/min Radiation angle 1°Slit width 0.3mm Illumination angle 6°2 BET specific surface area [SA] The specific surface area of each powder was measured according to the so-called BET method using nitrogen gas adsorption. For details, please refer to the following literature. J.A. A.M. Chemical Society,
1938, Volume 60, Page 309 (Reporter S. Brunauer, PH
(Emmett, E.Teller) In this specification, the specific surface area is measured by drying it to 150℃ in advance and measuring it to 0.5 to 0.6.
Transfer to a weighing bottle, dry for 1 hour in a constant temperature dryer at 150°C, and immediately weigh accurately. This sample was placed in an adsorption sample tube and heated to 200°C, degassed until the degree of vacuum within the adsorption sample tube reached 10 ^-4 mmHg, and after cooling, the adsorption sample tube was placed in liquid nitrogen at approximately -196°C. The amount of N ₂ gas adsorbed is measured at 4 to 5 points between pN ₂ /p ₀ =0.05 to 0.30 (pN ₂ : nitrogen gas pressure, p ₀ = atmospheric pressure at the time of measurement). Then, the adsorption amount of _N2 gas after subtracting the dead volume is 0℃,
Convert it to the adsorption amount at 1 atm and substitute it into the BET formula to get Vm
[cc/g] (indicating the amount of nitrogen gas adsorption required to form a monomolecular layer on the sample surface) is determined. Specific surface area SA
=4.35×Vm [m ² /g] 3 Color development ability measurement Place the stamp paper in a desiccator containing saturated saline (75%
RH) and store in the dark at room temperature (25°C).
Leave it for about 24 hours after application, then take it out and expose it indoors (constant temperature and humidity: about 25°C, humidity about 60%RH) for 16 hours, then develop the color. Color development is done by applying microcapsules containing an instant color-forming leuco dye, CVL (crystal violet lactone), as an auxiliary mixture of BLMB (benzoyl leuco methylene blue) and Fluoran-based leuco dye (colors red). This is done by placing a commercially available transfer paper and the stamp paper so that their coated surfaces face each other, and rotating them under pressure between two steel rolls to crush the microcapsules almost completely. The color development ability of each stamp paper is the color development (color development) density (hereinafter simply referred to as density) after 1 hour of color development (color development).
Densitometer (manufactured by Fujifilm, Fuji
Densitometer Model FSD-103) and expressed as the density value. A high concentration indicates a high color developing ability. 4 Discoloration and fading The color-receiving stamp paper used for measurement in (3. Developing ability measurement) above was exposed indoors under the same conditions (approximately 700 lux x 10 hours/day), and after 15 days, the color fading occurred. The density of the colored surface is measured using a densitometer and is defined as the residual density. At this time, the discoloration and fading of the colored surface of the stamp paper and the yellowing of the background are visually observed to judge whether it is good or bad. 5 Desensitizing ink coating characteristics Flexo-type desensitizing ink using ethylene oxide adduct of stearylamine as a desensitizing agent was diluted with a mixed solvent of ethyl acetate and IPA denatured alcohol (1:1) (ink: solvent = 1:9). ), apply one drop onto the stamp paper using a dropper, and let it dry in the air to coat the stamp. The resulting desensitized ink-coated receiving stamp paper was stacked with the transfer paper and coated side facing each other in the same manner as in the method described above (3. Developing ability measurement), and was sandwiched between two steel rolls and rotated under pressure. The microcapsules are almost completely crushed. At this time, the difficulty in developing color on the surface coated with the desensitized ink (=desensitization) is visually observed to judge whether it is good or bad. Further, one drop of undiluted desensitizing ink is dropped onto the stamp paper using a dropper, and the ease with which the ink dries (=ink setting property) is visually observed to judge whether it is good or bad. 6 Acidity measurement method Acidity by dicinnamal acetone coloration [A ₁ ] 0.1g of the sample whose water content was determined in advance (glass, 30c.c.) (110℃)
(on a dry matter basis) and accurately weigh each. Place these in a desiccator containing saturated saline (75%RH)
and leave it to absorb moisture for at least 24 hours in an oven at a temperature of 80℃. At this time, the moisture content of the sample is almost at the equilibrium value (12
~30%). Next, add normal butylamine of known titer to each sample.
Add 0.01 normal benzene solution per 1 g of sample or in increments of 0.01 milliequivalent, add benzene (reagent special grade) so that the total volume of each liquid is 10 ml, seal tightly, and fill with water. low-energy ultrasonic bath (manufactured by Branson Instruments Company, Blasonik)
Model 220) and mix while applying ultrasonic waves to disperse the sample well (about 5 seconds). Then, set it in a shaker and shake for 16 hours to ensure that the sample is constantly dispersed. Add 2 drops (0.05 to 0.1 ml) of a 0.1 (W/V)% benzene solution of Dicinnamal acetone,
Shake well again. At this time, the minimum amount of n-butylamine (milliequivalents/g) that no longer produces purple or reddish coloration is the acidity [A ₁ ] (=strong acid amount). Acidity [A ₂ ] and Acidity [A ₃ ] by methyl red coloring 0.1 g of the sample whose water content was determined in advance (110℃
(on a dry matter basis) and accurately weigh each. Place these in a desiccator containing saturated saline (75%RH)
and leave it to absorb moisture for at least 24 hours in an oven at a temperature of 80℃. At this time, the moisture content of the sample is almost at the equilibrium value (12
~30%). Next, add normal butylamine of known titer to each sample.
Add 0.01 normal benzene solution per 1 g of sample or in increments of 0.01 milliequivalent, add benzene (reagent special grade) so that the total volume of each liquid is 10 ml, seal tightly, and fill the container. low-energy ultrasonic bath (manufactured by Branson Instruments Company, Blasonik)
Model 220) and shake while applying ultrasonic waves to disperse the sample well (about 5 seconds). Then, set in a shaker and shake for 16 hours to ensure that the sample is constantly dispersed. Methyl red (O
- Add 2 drops (0.05 to 0.1 ml) of a 0.1 (W/V)% benzene solution of [[P-(dimethylamino)phenyl]azo]benzoic acid) to each,
Shake well again. At this time, the hue of the color (red to yellow) is determined using the JIS color chart (supervised by the JIS Color Chart Committee, Foundation).
Published by Japanese Standards Association, produced by Japan Color Research Institute,
Compare with JIS Z8721 compliant standard color chart) and compare the corresponding JIS hue.
The amount of n-butylamine (milliequivalents/g) added to (H)5YR or something with a similar hue is the acidity [A ₂ ],
From this, the acidity [A ₃ ]=[ _{A 2 ]} −[A ₁ ] (=the amount of weak acid) is obtained by subtracting [A 1 ] determined by the above measurement method. Reference Example 1 250g of roughly crushed acidic clay from Nakajo Town, Niigata Prefecture and formed into a linear shape (diameter: 3mm) was mixed with aluminum, magnesium, and the like contained in the clay.
Total gram equivalent number of basic metal components such as calcium, iron, sodium, potassium, and titanium (1.14
Add sulfuric acid equivalent to 3.5 times the number of gram equivalents (gram equivalent/100g dry matter), that is, 700 ml of 34% sulfuric acid,
Acid treatment was performed by heating in a water bath at 85°C for 15 hours.
The mixture was filtered and washed with water to obtain a cake. A small amount of the cake was dried at 110℃, crushed, and quantitatively analyzed.
SiO ₂ min was 92.7% (110°C dry matter basis).
Place the resulting cake in a pot mill, add water and wet mill with Korean balls, add 15% SiO ₂ min.
A slurry containing (1st step) Next, 200 g of the obtained slurry (SiO ₂ minutes: 30
g) and 30g of zinc oxide (first grade reagent) in an autoclave container, add 370g of water,
The hydrothermal synthesis reaction was carried out at 160° C. for 5 hours under stirring conditions of revolutions per minute. After cooling, the reaction product was taken out, water was separated by filtration, and then dried at 130°C. The dried product was ground in a small tabletop sample mill to obtain a fine white powder. (Second Step) When this product was analyzed by X-ray diffraction, it was found to be sauconite-type zinc phyllosilicate. Example 1 A color developer composition containing the synthetic sauconite-type zinc phyllosilicate (1) obtained in Reference Example 1 and zinc 3,5-diisopropylsalicylate as an organic compound containing a phenolic hydroxyl group, and a texture formed by coating the same. A stamp paper for stamping paper was prepared as follows. Dissolve 0.2 g of sodium hexametaphosphate and 0.1 g of sodium hydroxide in 15 g of water, add 9 g of the above Sauconite-type zinc phylosilicate powder (1) and 1 g of zinc 3.5-dipropylsalicylate, disperse, and then add starch (Japan) as a binder. food chemical engineering
10 g of a 10% aqueous solution (MS4800, manufactured by Co., Ltd.) and 2 g of 50% SBR latex (Dow620) were added. A 10% aqueous sodium hydroxide solution was added to adjust the pH to 9, water was further added to make the total amount 40 g, and the mixture was thoroughly stirred to obtain a uniform coating solution. Apply the coating liquid thus obtained to 40g/ ^m2 of base paper.
Apply the coating using a coating rod (wire diameter: 0.15mm to 0.25mm) so that a solid content of g/m ² is coated, air dry, and then dry in a dryer at 110℃ for 3 minutes to form a stamp paper. Obtained. Example 2 A color developer composition containing the synthetic sauconite-type zinc phyllosilicate (1) obtained in Reference Example 1 and p-phenylphenol-formaldehyde condensation resin as the phenolic hydroxyl group-containing organic compound, and coating it thereon. A stamp paper for pressure-sensitive paper was prepared as follows. In Example 1, p-phenylphenol was used instead of 1 g of zinc 3.5-dipropylsalicylate.
The same method was used except that 2.5 g of a 40% suspension of formaldehyde condensation resin was used to obtain a developer coating composition and stamp paper coated with the same. Reference example 2 200g of slurry obtained in the first step of reference example 1
(SiO ₂ minutes: 30g) and 30g of zinc oxide were placed in an autoclave container (1), and 370g of water was added to the container.
The hydrothermal synthesis reaction was carried out at 160° C. for 5 hours under stirring conditions of revolutions per minute. After cooling, take out the reactant and add sodium hydroxide aqueous solution under stirring to make a slurry.
After adjusting the pH to 9.5 and separating water by filtration,
Dry at 130°C. The dried product was ground in a small tabletop sample mill to obtain a fine white powder. When this product was analyzed by X-ray diffraction, it was found to be sauconite-type zinc phyllosilicate. Example 3 Synthetic sauconite zinc phyllosilicate (2) obtained in Reference Example 2, zinc 3-cyclohexyl 5-(α,α-dimethylbenzyl)salicylate as a phenolic hydroxyl group-containing organic compound, and kaolin as a general inorganic pigment. A developer composition containing zinc oxide and a pressure-sensitive stamp paper coated with the developer composition were prepared as follows. Dissolve 0.2 g of sodium hexametaphosphate in 15 g of water and use the above sauconite type zinc phyllosilicate (2).
4 g of powder, 3-cyclohexyl 5-(α,α-
1 g of zinc dimethylbenzyl salicylate, 2.5 g of kaolin powder (manufactured by JM Hyuba Co., Ltd., Hydraperce)
g and zinc oxide (manufactured by Wako Pure Chemical Industries, Ltd., reagent grade 1)
After adding 25g and dispersing, 10g as a binder.
10 g of % starch aqueous solution and 2 g of 50% SBR-latex were added. Add 10% sodium hydroxide aqueous solution to adjust the pH to 9, and then add water to bring the total volume.
After weighing 40 g, the coating solution was sufficiently stirred to be uniform. Apply the coating liquid thus obtained to 40g/ ^m2 of base paper.
Apply the coating using a coating rod (wire diameter: 0.15mm to 0.25mm) so that a solid content of g/m ² is coated, air dry, and then dry in a dryer at 110℃ for 3 minutes to form a stamp paper. Obtained. Example 4 Synthetic sauconite-type zinc phyllosilicate (2) obtained in Reference Example 2, p-tertiarybutylphenol-formaldehyde condensation resin as an organic compound containing a phenolic hydroxyl group, and further generally containing kaolin and calcium carbonate as inorganic pigments. A developer composition and a pressure-sensitive stamp paper coated with the developer composition were prepared as follows. In Example 3, 3-cyclohexyl 5-
(α,α-dimethylbenzyl)zinc salicylate 1
2.5 g of a 40% suspension of p-butylphenol-formaldehyde condensation resin is used instead of g, and 2.5 g of light calcium carbonate (Brilliant 15, manufactured by Shiraishi Kogyo Co., Ltd.) is used instead of 2.5 g of zinc oxide. Except for the above, the same method was used to obtain a color developer coating composition and stamp paper coated with the developer coating composition. Comparative Example 1 In Example 1, 0.01g of sodium hydroxide
The color developer coating composition and A stamp paper coated with it was obtained. Comparative Example 2 In Example 2, 0.01g of sodium hydroxide
The same method was used except that 4.5 g of kaolin powder and 4.5 g of light calcium carbonate were used in place of 9 g of sauconite-type zinc phylosilicate (1) powder. And a stamp paper coated with the same was obtained. Comparative Example 3 In Example 1, 4 g of Silton (manufactured by Mizusawa Chemical Industry Co., Ltd.) and kaolin powder were used as a conventionally known inorganic color developer (or filler) in place of 9 g of Sauconite-type zinc phyllosilicate (1) powder. 2.5g and zinc oxide
The same method was used except that 2.5 g was used to obtain a color developer coating composition and stamp paper coated with the developer coating composition. Comparative Example 4 The same method as in Example 2 was used except that 4 g of silton, 2.5 g of kaolin powder, and 2.5 g of light calcium carbonate were used instead of 9 g of powder of sauconite-type zinc phylosilicate (1). A coating liquid composition and stamp paper coated with the same were obtained. Comparative Example 5 0.2 g of sodium hexametaphosphate and 0.2 g of sodium hydroxide were dissolved in 15 g of water, and 10 g of a conventionally known inorganic color developer Silton was added and dispersed.
10g of 10% starch aqueous solution and 50% as binder
2g of SBR latex was added. A 10% aqueous sodium hydroxide solution was added to adjust the pH to 9.5, water was further added to make the total amount 40 g, and the mixture was thoroughly stirred to obtain a uniform coating solution. The following procedure was carried out in exactly the same manner as in Example 1 to obtain a color developer coating composition and stamp paper coated with the developer coating composition. Comparative Example 6 In Comparative Example 5, 0.1g of sodium hydroxide
The same method was used except that 10 g of Sauconite-type zinc phylosilicate (1) powder was used in place of 10 g of Silton, and the color developer coating composition and stamp paper coated with the same were prepared. I got it. Comparative example 1
-6 are shown in Table 1 in comparison.

【table】

[Table] Functions and Effects of the Invention As mentioned above, the color developer composition for pressure-sensitive paper of the present invention forms images with superior density and clarity compared to conventional color developers upon contact with leuco dyes. In addition, the pressure-sensitive paper using this composition has almost no tendency to discolor or fade due to the formed image or background light, and this composition also has remarkable applicability to paper. It has the advantage of being excellent.

[Brief explanation of the drawing]

Figure 1 shows the Cu-
This is an X-ray diffraction spectrum using Kα rays.

Claims (1)

[Scope of Claims] 1. A color developer composition for pressure-sensitive paper with excellent light resistance, characterized by containing synthetic sauconite-type zinc phyllosilicate and a phenolic hydroxyl group-containing organic compound. 2 Synthetic sauconite-type zinc phyllosilicate and phenolic hydroxyl group-containing organic compound in a ratio of 50:50 to
A composition according to claim 1 containing in a weight ratio of 98:2. 3. The composition according to claim 1, wherein the synthetic zinc phyllosilicate has an oil absorption of 80 to 160 ml/100 g and a specific surface area of 50 to 200 m ² /g. 4. The composition according to claim 1, wherein the phenolic hydroxyl group-containing organic compound is an aromatic oxycarboxylic acid or a metal salt thereof. 5. The composition according to claim 1, wherein the phenolic hydroxyl group-containing organic compound is a phenolic resin.