JPH0542358B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of the Invention) The present invention relates to a color developer sheet for pressure-sensitive copying, and more particularly to a color developer sheet for pressure-sensitive copying that has improved slip properties and printing workability. (Prior Art) Conventionally, color formers are substances that generate color by donating electrons or accepting protons such as acids, and color developers are substances that accept electrons or donate protons, for example, With clay materials such as acid clay, activated clay, attapulgite, zeolite, bentonite, and kaolin, organic acids such as salicylic acid, tannic acid, gallic acid, and phenolic compounds, or their metal salts, and acidic polymers such as phenol formaldehyde resins. Pressure-sensitive recording materials that utilize color reactions are well known; for example, U.S. Pat.
No. 2550471, No. 2548366, No. 2712507, No.
No. 2730456, No. 2730457, No. 3418250, JP-A-Sho
It is described in No. 49-28411, Japanese Unexamined Patent Publication No. 50-44009, etc. The color former layer of pressure-sensitive copying paper is dissolved in a solvent, and after being dispersed in a binder or contained in microcapsules, it can be applied to paper, plastic film, etc.
It is obtained by coating on a support such as resin-coated paper. On the other hand, the color developer 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. 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 microcapsules is released by writing pressure or hitting pressure, and when it comes into contact with the color developer, it develops color.
Records can be obtained according to pressure. As mentioned above, various color developers are known for use in pressure-sensitive recording materials. However, when clays that are currently widely used as color developers, such as activated clay and acid clay, are used, they have drawbacks such as poor light resistance and water resistance of the coloring material, and poor stability over time. There is. Organic color developers are known as color developers that do not have these drawbacks. A coating liquid (A) obtained by mechanically dispersing a color developer using an organic color developer in water together with an inorganic pigment, a binder, a dispersant, and other additives is applied to the support, or a color developer is applied to the support. A coating solution (B) obtained by dissolving the solution in an organic solvent and emulsifying it in water and adding an inorganic pigment, a binder, and other additives is applied to the support, or
It is generally prepared by applying a coating liquid mixed with (B) to a support. Although the color developer sheets obtained by these methods have various excellent properties, they have the disadvantage of low workability due to poor slipperiness of the coated surface during printing work, etc. I see, this is something that needs to be improved. (Object of the Invention) The object of the present invention is to provide a color developer for pressure-sensitive recording that has excellent light resistance, water resistance, and stability over time, and improves the slipperiness of the coated surface and improves printing workability. The objective is to provide a drug sheet. (Structure of the Invention) An object of the present invention is to provide a color developer sheet for pressure-sensitive copying using an organic color developer with an average particle size of 0.3 μm to 5.0 μm.
This was achieved by a color developer sheet for pressure-sensitive copying, which is characterized by containing 0.5 g/m ² to 5.0 g/m ² of aluminum hydroxide. As the organic color developer used in the present invention, aromatic carboxylic acids and metal salts thereof, and phenolic resins are preferable. Examples of these aromatic carboxylic acids and metal salts thereof include those described in Japanese Patent Publication No. 10856/1983. Specific examples of these aromatic carboxylic acids are:
Benzoic acid, chlorbenzoic acid (o, m and p), nitrobenzoic acid (o, m and p), toluic acid (o,
m and p), 4-methyl-3-nitrobenzoic acid,
2-chloro-4-nitrobenzoic acid, 2,3-dichlorobenzoic acid, 2,4-dichlorobenzoic acid, p-
Isopropylbenzoic acid, 2,5-dinitrobenzoic acid, p-tert-butylbenzoic acid, N-phenylanthranilic acid, 4-methyl-3-nitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-
Bidroxybenzoic acid, 3,5-dinitrosalicylic acid, 5-tert-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-isoamylsalicylic acid, 3,5-di-
sec-butylsalicylic acid, 5-nonylsalicylic acid,
2-Nidroxy-3-methylbenzoic acid, 2-hydroxy-5-tert-butylbenzoic acid, 2,4-cresotic acid, 5,5-methylenedisalicylic acid, acetaminobenzoic acid (o, m, p), 2, 4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, anacardic acid, 1-naphthoic acid, 3,5-
Di-α,α-dimethylbenzylsalicylic acid, 3,
5-di-α-methylbenzylsalicylic acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2
Examples include -hydroxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, thiosalicylic acid, and 2-carboxybenzaldehyde. Examples of metals forming metal salts with the aromatic carboxylic acids include copper, lead, magnesium, calcium, zinc, aluminum, tin, and nickel. Furthermore, for phenolic resins,
Phenol formaldehyde resin, phenol acetaldehyde resin, and phenol acetylene resin are known as so-called novolak type phenolic resins as shown in No. 20144. For example, p-alkylphenols such as p-cresol, p-ethylphenol, p-butylphenol, p-cyclohexylphenol, p-octylphenol, p-nonylphenol, allylphenols such as p-phenylphenol, aralkylphenols such as α-naphthylphenol, β-naphthylphenol, cumylphenol, and benzylphenol; halogenated phenols such as p-chlorophenol;
Examples include polycondensation resins of formaldehyde or acetaldehyde, and so-called metal salt-modified phenol resins obtained by modifying these with zinc, manganese, etc. Two or more types of these color developers can also be used. The color developer is mechanically dispersed in an aqueous system using a ball mill, attritor sand mill, etc. to form the coating liquid (A). At this time, if an inorganic pigment is added in combination, desirable effects such as improved dispersion efficiency and color developing ability can be obtained. On the other hand, the color developer is dissolved in an organic solvent, and this organic solvent solution is emulsified in water using a stirrer or the like to form a coating liquid (B). In this case, adding an ionic or nonionic surfactant or a water-soluble polymer has the advantage that a stable emulsion can be prepared in a short time. Furthermore, when an inorganic pigment is used in the preparation of the coating solution, desirable effects such as improvement in coating suitability, hiding power, and color development ability can be obtained. Examples of organic solvents include aliphatic or aromatic esters, biphenyl derivatives, naphthalene derivatives,
Biphenyl alkanes, etc. can be mentioned. Specifically, methyl amyl acetate (1,
3-dimethylbutyl acetate), 2-ethylbutyl acetate, 2-ethylhexyl acetate, amyl propitilate, 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, 2,3,3,4-tetramethyl-2,4-
Pentanediol monoacetate, amilitectate, 2-methylbiphenyl, 3-methylbiphenyl, 3,3-dimethylbiphenyl, 2,
4-dimethylbiphenyl, 2,6-dimethylbiphenyl, 2,4,6-trimethylbiphenyl, cyclohexylbenzene, bicyclohexylbenzene, monoisopropylbiphenyl, monoisopropylnahetalene, diisopropylnaphthalene, 1- These include isopropiophenyl-2-phenylethane, 1-isopropylphenyl-1-phenylethane, 1,1-ditolylethane, 1-ethylphenyl-1-1 phenylethane, 1-phenyl-1-xylylethane, and the like. A poor solvent such as a petroleum distillate having a boiling point of 150°C to 310°C may be used in combination with these solvents as a diluent. Inorganic pigments include magnesium, aluminum, calcium, titanium, manganese, nickel,
Oxides, hydroxides, carbonates, silicates of polyvalent metals such as zinc, zirconium, molybdenum, tin, antimony, and lead (e.g., zinc oxide, calcium oxide,
titanium oxide, zinc hydroxide, magnesium hydroxide,
(magnesium carbonate, calcium carbonate, aluminum silicate, etc.), kaolin, talc, activated clay, etc. In the present invention, in the above-mentioned formulation, the amount of coated paper is 0.5 g/m ² to 5.0 g/m ² , preferably 1.0 g/m ² to
3.0g/ ^m2 average particle size 0.3μm~5.0μm preferably
Although it is necessary to contain aluminum hydroxide of 0.6 μm to 5.0 μm, it may be used in combination with other pigments. However, it is preferable that the proportion of aluminum hydroxide in the total amount of pigment is 20% to 100% (by weight). Aluminum hydroxide having an average particle size of 0.5 .mu.m or less is not sufficiently effective in improving slipperiness, and also has the disadvantage of increasing the amount of binder required and deteriorating ink setting properties. Furthermore, aluminum hydroxide having a particle size of 5.0 μm or more causes roughness on the coated surface. Those with large roughness have the disadvantage that printing ink does not adhere well to them. Regarding usage, 0.5
If it is less than g/m ² , the effect of improving slipperiness is insufficient. Coating liquid (A) and coating liquid (B) are applied to a support alone or in combination with a binder added thereto. These binders include those generally known in the art, such as latexes such as styrene-butadiene copolymer latex, polyvinyl alcohol, maleic anhydride-isobutylene copolymer, starch, casein, gum arabic, gelatin, and carboxymethyl. Synthetic or natural polymeric substances such as cellulose and methylcellulose can be used. The final amount of organic developer applied to the support is
0.1g/ ^m2 to 3.0g/ ^m2 , preferably 0.2g/ ^m2 to
1.0 g/m ² is suitable. Hereinafter, the color developer sheet for pressure-sensitive copying of the present invention will be specifically explained with reference to Examples, but the invention is not limited to the Examples. Example 1 10 parts of zinc 3,5-di-α-methylbenzylsalicylate was added to 20 parts of 1-isopropylphenyl-2-phenylethane and dissolved by heating at 90°C. This 2
% polyvinyl alcohol (PVA-205 manufactured by Kuraray)
Added to 50 parts of aqueous solution and further added 10 parts as a surfactant.
An emulsion was prepared by adding 0.1 part of % sodium sulfosuccinate aqueous solution using a homogenizer so that the average particle size of the emulsion was 3 μm. Next, a dispersion was prepared using 20 parts of zinc oxide, 1 part of sodium hexametaphosphate, and 100 parts of water using a Keddy Mill, and then 80 parts of aluminum hydroxide was added to 100 parts of water.
part and 1 part sodium hexametaphosphate average particle size
After mixing the above emulsion with the dispersion using a sand grinder to give a particle size of 4.5 μm, 100 parts of a 10% PVA-110 (manufactured by Kuraray) aqueous solution and carboxy-modified SBR latex (SN-307, Sumitomo) were added as a binder. Coating liquid (A) was obtained by adding 10 parts (as solid content) (manufactured by Naugatux) and adding water to make the solid content concentration 20%. Next, 10 parts of zinc 3,5-di-α-methylbenzylsalicylate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate, and 100 parts of water were uniformly dispersed using a sand grinder so that the average particle size was 3 μm. . Add 80 parts of aluminum hydroxide to the resulting dispersion and add water.
Add 100 parts of sodium hexametaphosphate and 1 part of sodium hexametaphosphate dispersed to 4.5 μm using a sand grinder, and add 10% PVA-110 (manufactured by Kuraray) aqueous solution.
100 parts and carboxy-modified SBR latex (SN-
307 manufactured by Sumitomo Naugatux) 10 parts (as solid content)
was added and water was added so that the solid content concentration was 20% to obtain a coating liquid (B). Coating liquid (A) and coating liquid (B) were mixed at A/B=50/50 in terms of zinc 3,5-di-α-methylbenzylsalicylate to obtain coating liquid C. Apply 5.0g/m ² of the obtained coating liquid C to 50g/m ² base paper.
The color developer sheet was coated using an air knife coater and dried to obtain a color developer sheet. Example 2 Except for using aluminum hydroxide dispersed to have an average particle size of 1.7 μm instead of using aluminum hydroxide dispersed to have an average particle size of 4.5 μm in Example 1. A color developer sheet for pressure-sensitive copying was prepared in the same manner as in Example 1. Example 3 Except for using aluminum hydroxide dispersed to have an average particle size of 0.7 μm instead of using aluminum hydroxide dispersed to have an average particle size of 4.5 μm in Example 1. A color developer sheet for pressure-sensitive copying was prepared in the same manner as in Example 1. Example 4 Instead of using 80 parts of aluminum hydroxide dispersed to have an average particle size of 4.5 μm in Example 1, 35 parts of aluminum hydroxide, 35 parts of calcium carbonate, and 10 parts of silton were used to disperse the average particle size of 2.5 μm. A color developer sheet for pressure-sensitive copying was prepared in the same manner as in Example 1, except that the color developer sheet was dispersed to a particle size of .mu.m. Example 5 Except for using aluminum hydroxide dispersed to have an average particle size of 0.5 μm instead of using aluminum hydroxide dispersed to have an average particle size of 4.5 μm in Example 1. A color developer sheet for pressure-sensitive copying was prepared in the same manner as in Example 1. Comparative Example 1 Instead of using aluminum hydroxide dispersed with an average particle size of 4.5 μm in Example 1, the same aluminum hydroxide was used with an average particle size of 7.5 μm.
A color developer sheet for pressure-sensitive copying was prepared in the same manner as in Example 1 except that a color developer sheet for pressure-sensitive copying was used. Comparative Example 2 Except that instead of using aluminum hydroxide dispersed to have an average particle size of 4.5 μm in Example 1, aluminum hydroxide dispersed to have an average particle size of 0.27 μm was used. Example 1
A developer sheet for pressure-sensitive copying was prepared in the same manner as above. Comparative Example 3 The same procedure was carried out as in Example 1 except that instead of using aluminum hydroxide dispersed to have an average particle size of 4.5 μm, calcium carbonate was used dispersed to have an average particle size of 2.0 μm. A developer sheet for pressure-sensitive copying was prepared in the same manner as in Example 1. (Performance comparison) (1) Slip property Fix with coated side A facing up. Furthermore, fix another sheet with the coated side B facing downward to a 500 g weight with an area of 8 cm x 8 cm. Coated surfaces A and B were overlapped, a weight was pulled, and the force required to start moving was measured using a U-gauge (manufactured by Shinkoh), and the result was determined as a static mass coefficient. The smaller the value, the easier it is to slip. Practically speaking, it needs to be 0.75 or less. (2) Ink setting property Ink (Toyo Ink, Bright Gunjo) 2.0
Apply it on coated surface A with an RI tester so that it is 150 g/cm ² and face it to the other coated surface ^B.
After 30 seconds, 1 minute, and 2 minutes, the sample was passed through the rolls of the RI tester again. The ink setting properties were examined by looking at the ink stains on the coated surface B. The radius standard is as shown below, but from a practical standpoint, it is desirable that it be C or more. A: Almost no stains are observed. B: Contamination is observed 30 seconds after ink application. C: Staining is observed even after 1 minute of ink application. D: Significant staining is observed even after 2 minutes of ink application. (3) Roughness of the coated surface The coated surface was rubbed with a fingertip and roughness was marked with an ×, and smooth one with a mark of ○.

[Table] As shown in Table 1, it can be seen that all the examples of the present invention have good ink setting properties and slip properties. There is also no roughness on the coated surface, and the printing ink is good.

Claims (1)

[Claims] 1. A developer sheet for pressure-sensitive copying using an organic color developer, characterized in that it contains aluminum hydroxide with an average particle size of 0.3 μm to 5.0 μm in an amount of 0.5 g/m ² to 5.0 g/m ² color developer sheet.