JPS6372589A - Color developing sheet for pressure-sensitive copying paper - Google Patents

Abstract

PURPOSE:To obtain a color developing sheet having a color forming property equal to or more than that of a color developing sheet using an inorg. solid acid or a p-phenylphenol novolac resin and imparting a color image not easily fading by water, a plasticizer and light, by using kaolinite type clay mineral as pigment. CONSTITUTION:Kaolinite type clay mineral is used in a color developing layer, which contains a color developer composed of a metallic compound of a co- condensation resin using salicylic acid and alpha, alpha'-dialkoxy-p-xylene as main monomer components and a binder component, as pigment. A proper amount of a benzotriazole, benzophenone or Ni-complex type singlet oxygen quencher is together used in the metallic compound of the salicylic acid co-condensation resin in a mixed molten state in order to enhance light fastness still more. The kaolinite type clay mineral is applied to base paper along with the metallic compound color developer of the salicylic acid co-condensation resin to provide fundamental characteristics as costing paper such as sufficient whiteness, non- transparency, ink receptivity and ink glass etc.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a color developer sheet for pressure-sensitive copying paper, and more specifically, a novel color developer sheet that uses a novel salicylic acid cocondensation resin metallization as a color developer. This invention relates to a color developer sheet for pressure-sensitive copying paper.

(Prior Art) Pressure-sensitive copying paper is also called carbonless paper, and is a copying paper that develops color by mechanical or impact pressure, such as when writing or using a typewriter, and can make multiple copies at the same time. There are so-called transfer-type papers and those called single color-forming papers, and their color-forming mechanism is based on a color-forming reaction between an electron-donating colorless dye and an electron-accepting color developer. Taking a transfer type pressure-sensitive copying paper as an example, this will be explained as shown in FIG. 1 as follows.

On the back side of the top paper 1 and the middle paper 2, microcapsules 4 with a diameter of several microns to more than ten microns are applied, which are made by dissolving a colorless pressure-sensitive dye in non-volatile oil and wrapping it in a polymer film such as gelatin. has been done. The surfaces of the middle paper 2 and the top paper 3 are coated with a paint containing a color developer 5 which has the property of causing a reaction and color development when it comes into contact with the above-mentioned pressure-sensitive dye. To make a copy, press top - (middle) - (middle)
- If you stack them in the order shown below (the dye-containing coated surface and the developer-containing coated surface face each other) and apply local pressure such as writing pressure 6 or typing pressure, the capsule 4 in that area will break and the pressure-sensitive dye A copy record is obtained by transferring the solution to the color developer 5.

As an electron-accepting color developer, fll USP 2.712
．． 507, inorganic solid acids such as acid clay and attapulgide, (2) substituted phenols and diphenols disclosed in Japanese Patent Publication No. 40-9309, (3)
) ρ-substituted phenol-formaldehyde polymer disclosed in Japanese Patent Publication No. 42-20144, (4) Japanese Patent Publication No. 49-1972
Aromatic carboxylic acid metal salts disclosed in Japanese Patent Publication No. 10856 and Japanese Patent Publication No. 52-1327 have been proposed, and some of them have been put into practical use.

The performance conditions that a color developer sheet should have include not only excellent coloring properties that remain unchanged immediately after sheet production and even after long-term storage, but also little yellowing during storage and exposure to sunlight and other radiation, and a color image that is robust and resistant to radiation. Examples include not easily disappearing or discoloring due to water or plasticizers.

Conventionally proposed color developers and sheets coated with them have advantages and disadvantages in terms of performance8.For example, inorganic solid acids are inexpensive, but they absorb gas and moisture in the air during storage, resulting in yellowing of the paper surface. p-phenylphenol-novolak resin, which is most commonly used as a p-substituted phenol-formaldehyde polymer, has poor color development. However, the coated paper turns yellow when exposed to sunlight or during storage (particularly due to nitrogen oxides in the air), and the colored image fades significantly. Further, although aromatic carboxylic acid metal salts have good coloring properties, yellowing properties, and fading properties due to light, their resistance to water or plasticizers is still not sufficient.

In addition, conventional pressure-sensitive copying paper color developing sheets had the problem that their coloring ability, especially the initial coloring density, decreased if they were stored for a long time after being coated or stored at high temperatures. .

(Problems to be Solved by the Invention) An object of the present invention is to provide a color developer sheet for pressure-sensitive copying paper using a novel color developer that improves the above-mentioned drawbacks.

(Means for Solving the Problems) The present inventors have made extensive research to achieve the above object, and as a result, have completed the present invention.

That is, the present invention provides (1) salicylic acid and α.

A feature is that a kaolinite group clay mineral is used as a pigment in a color developer layer containing a metal compound color developer and a binder component of a co-condensed resin containing α''-dialkoxy-p-xylene as a main monomer component. The present invention relates to a color developing sheet for pressure-sensitive copying paper.

The color developing sheet using the novel color developer, binder, and kaolinite group clay mineral of the present invention is produced by using an inorganic solid acid or p
- It has the same or better color development than a color developing sheet using a phenylphenol novolak resin, and the color image has resistance to fading easily due to water, plasticizers, and light.

Furthermore, it has the advantage of being able to provide a color developing sheet at a low cost, which has greatly improved resistance to yellowing due to sunlight irradiation and is extremely convenient for handling and storage.

Furthermore, the color developing sheet of the present invention has improved color development performance (especially color development speed) after long-term storage or high-temperature storage, which is a common problem in color development sheets using gold salt resin-based color developers. ) has the excellent feature of significantly improving the decreasing tendency of

The salicylic acid cocondensation resin used in the present invention is a novel resin that has never been produced before.

α, α′, which are essential components of the cocondensation resin used in the present invention
- Dialkoxy p-xylene is reacted with a phenolic compound to give the corresponding phenolic resin, and this resin is further reacted with a basic compound such as hexamethylenetetramine to cure it, as a so-called thermosetting polymeric composition. Used (Special Publication No. 47-15111)
.

However, these thermosetting polymer compositions use carbolic acid, alkylphenols, phenylphenols, para-aminophenol, pyrogallol, and phloroglycitol as phenolic compounds;
Nothing is known about the reaction with salicylic acid.
Alcohol is produced by the dealcoholization reaction, but in the case of phenolic compounds containing organic carboxylic acids, that is, salicylic acid, which is a component of the present invention, salicylic acid esters and a mixture of these resins are produced by reaction with the alcohol produced under an acidic catalyst. It is thought that this has not been considered yet because it is easily expected that it would be difficult to obtain the intended target product.

However, the present inventors surprisingly found that in addition to salicylic acid and α,α'-dialkoxy ρ-xylene, or their main monomer components, mesitylene and/or
Alternatively, when p-substituted phenol is further reacted as a monomer component in the presence of an acid catalyst at a reaction temperature of 110°C or higher, almost no side reactions such as esterification reactions occur, and a salicylic acid phenol cocondensation resin is produced. I found out what I can get.

α,α1-dialkoxy p-xylene as the main monomer component of the cocondensation resin used in the present invention is preferably α,α′-dimethoxy p-xylene, α,α9-jetoxy p-xylene, α,αゝ-Di-n-propoxy p-xylene, α, α9-isopropoxy p-xylene, α, α′-di-n-butoxy p-xylene,
α, α1-di-5ec-butoxy p-xylene, α,
Examples include α°-diisobutyl-p-xylene.

The other major monomer component is salicylic acid.

When obtaining a cocondensation resin consisting of these main monomer components, the amount of these components used is α per mole of salicylic acid.
, α°-dialkoxy p-xylene from 0.1 to 1.0
It is a molar ratio.

In addition to the above-mentioned main monomer components, a co-condensation resin containing mesitylene and/or p-1 substituted phenol as a monomer component can also be used.

The p-substituted phenols used in such cocondensation resins include p-alkylphenols having 1 to 12 carbon atoms, p-cycloalkylphenols,
Examples include p-aralkylphenols and p-phenylphenol.

Examples of p-alkylphenol include p-cresol, p-
-ethylphenol, p-isopropylphenol, p
-5ec-butylphenol, p-tert-butylphenol, p-tert-octylphenol, p-nonylphenol and the like. Examples of p-cycloalkylphenol include p-cyclopentylphenol and p-cycloalkylphenol.
- Cyclohexylphenol. Examples of p-aralkylphenol include p-benzylphenol and p-benzylphenol.
-α-methylbenzylphenol, p-α, α-dimethylbenzylphenol, and the like.

These phenols may be used alone or in combination of two or more.

In addition to the main monomer components of salicylic acid and α,α°-dialkoxy p-xylene, mesitylene and p- When using together with Tl-substituted phenol, the amount of mesitylene used is:
The molar ratio is 0.1 to 15, preferably 0.5 to 10, per mole of salicylic acid, and the amount of p-substituted phenol used is preferably 0.1 to 15, preferably 0.1 to 15, per mole of salicylic acid. is a molar ratio of 0.5 to 10. Also, α
The amount of α'-dialkoxy ρ-xylene to be used is preferably 0.1 to 1.0 mol, preferably 0.3 to 0.8 mol, per 1 mol of the combination of the three components of mesitylene salicylate and pM-converted phenol. It is a ratio.

Further, when only mesitylene is used, the amount of mesitylene used is 0.1 to 20 molar ratio, preferably 0.5 to 10 molar ratio per 1 mole of salicylic acid.

Further, the amount of α,α1-dialkoxy p-xylene used is 0.1 to 1.0 molar ratio, preferably 0.1 to 1.0 molar ratio, per 1 mole of the combination of two components of salicylic acid and mesitylene.
The molar ratio is 3 to 0.8.

Further, when only p-"lA phenol is used, the amount of p-substituted phenol used is 0.1 to 50 molar ratio, preferably 0.5 to 20 molar ratio per 1 mole of salicylic acid. , α, α°-dialkoxy p-xylene is used in an amount of 0.1 to 1.0 per mole of the combination of two components, salicylic acid and p-substituted phenol.
0 molar ratio, preferably 0.3 to 0.8 molar ratio.

The reaction temperature needs to be at least 110°C; if it is lower than 110°C, the reaction will be extremely slow and the formation of side reactions such as esterification will increase (also, the reaction time should be shortened as much as possible). A temperature range of about 130 DEG to 240 DEG C. is preferred for this purpose, and the reaction time is 1 to 20 hours.Acid catalysts include inorganic or organic acids, especially mineral acids, such as hydrochloric acid, phosphoric acid, sulfuric acid or formic acid. , or a free sol fluorine catalyst such as zinc chloride, stannic chloride, or ferric chloride, alone or in combination with an organic sulfonic acid such as methanesulfonic acid or p-toluenesulfonic acid. The amount of the catalyst used is approximately 0.01 to 5% of the total weight of salicylic acid, α,α°-dialkoxy p-xylene, and optionally mesitylene and/or p-1 substituted phenol. That's fine.

The best method for producing the resin used in the present invention is as follows:
A predetermined amount of salicylic acid and α, αゝ-dialkoxy p
- In addition to xylene or these main monomer components, if mesitylene and/or p-substituted phenol are used as monomer components, add these, add the catalyst at the same time, and raise the temperature as it is to react at the predetermined temperature. let

The alcohol produced as the reaction progresses is trapped outside the system. If necessary, ml of alcohol remaining in the system is removed from the thread using nitrogen.

After the reaction is completed, the contents are discharged, cooled, and then pulverized to obtain the desired product. In addition, if unreacted salicylic acid remains in the resin, it can be removed by washing the resin with hot water or using benzene, toluene, xylene, monochlorobenzene,
A method of dissolving the material in an organic solvent such as methyl isobutyl ketone or cyclohexanone and washing with hot water is used.

Several known methods can be applied to produce the metallized product from the salicylic acid cocondensation resin thus produced.

For example, it can be produced by reacting the alkali metal salt of the present resin with a water-soluble polyvalent metal salt in water or a solvent in which both are soluble.

That is, after reacting an alkali metal hydroxide, carbonate, alkoxide, etc. with a resin to obtain an alkali metal salt of the resin or an aqueous solution, alcohol solution, or water-alcohol mixed solution of the alkali metal salt, a water-soluble polyhydroxide is prepared. This is a method of producing it by reacting valent metal salts. It is desirable to react about 0.5 to 1 gram equivalent of water-soluble polyvalent metal salt per mole of salicylic acid in the resin.

It can also be produced by mixing a resin with a polyvalent metal salt of an organic carboxylic acid such as formic acid, acetic acid, propionic acid, valeric acid, caproic acid, stearic acid or benzoic acid, and heating and melting the mixture. In some cases, a basic substance such as ammonium carbonate, ammonium bicarbonate, ammonium acetate, or ammonium benzoate may be added and melted by heating. It can be produced by using oxides or halides and heating and melting them with organic ammonium carboxylates such as ammonium formate, ammonium acetate, ammonium caproate, ammonium stearate, ammonium benzoate, or basic substances such as ammonia.

When producing a metallized resin by heating and melting, the melting temperature is usually 100 to 180°C, and the reaction time depends on the resin composition, melting temperature, type of polyvalent metal salt, and amount used.
It takes about 1 to several hours. Regarding the amount of polyvalent metal salt used, organic carboxylates, carbonates, oxides, and hydroxides of polyvalent metals should be used so that the metal is present at 1% to about 20% by weight based on the total weight of the resin. It is desirable to use it.

There is no particular standard regarding the amount of the basic substance to be used, but it is usually used in an amount of 1 to 15% by weight based on the total weight of the resin. When using a basic substance, it is more preferable to mix it with a polyvalent metal salt beforehand.

The metals of the metallized salicylic acid cocondensation resin used in the present invention include metals excluding alkali metals such as lithium, sodium, and calylum, and preferable polyvalent metals include magnesium, aluminum, calcium, copper, zinc, and tin. , barium, cobalt and nickel. Among these, zinc is particularly effective.

The salicylic acid cocondensation resin metallized product used as the color developer of the present invention may be benzotriazole-based, benzophenone-based, or Ni
Of course, it is also included in the embodiment of the present invention to co-use an appropriate amount of a complex system-heavyt oxygen quencher or the like.

The kaolinite group clay mineral used in the present invention is a naturally occurring hydrated aluminum silicate generally referred to as kaolin, which is a fine powder having a white hexagonal plate-like structure. It is generally purified using the water-hi method (classifying a substance suspended in water), and although it differs depending on the production area, it is generally
It is expressed as -5iOt・^hos・28zO,
Contains small amounts of oxides such as Fe, Ti, Mg, Ca, and Na. When producing a color developing sheet, these kaolins are used by being dispersed in water using a high-speed stirrer such as a Cowles Digolver together with a dispersant such as sodium hexametaphosphate or sodium polycarboxylate.
It can be obtained as a pre-dispersed clay to which the required type of dispersant is added in advance, and this form is preferable for preparing the water-based paint for the color developing sheet of the present invention.

Such kaolin is coated onto a base paper along with a salicylic acid co-condensed resin metallized color developer to provide the basic properties of a coated paper, such as sufficient whiteness, opacity, ink receptivity, and ink gloss. Excellent performance never seen before as an anger pressure copying paper (color development performance, color fastness, yellowing resistance, long-term storage, stability of color development ability with high temperature storage)
I will provide a.

It is difficult to obtain such excellent overall physical properties when calcium carbonate, aluminum hydroxide, titanium oxide, etc., which are widely used in the same way as kaolin, are used as pigments for HaHa coating.

When producing the color developing sheet of the present invention, in addition to a color developer consisting of a metalized salicylic acid cocondensation resin, a known color developer such as an inorganic solid acid such as activated clay, an organic polymer such as a phenol-formal acid resin, or There is no problem in using polyvalent metal modified products thereof or polyvalent metal salts of aromatic carboxylic acids in combination.

Furthermore, in addition to the kaolinite group clay minerals, calcium carbonate, aluminum hydroxide, zinc oxide, activated clay, etc. may also be used in combination as pigments.

To produce the color developing sheet of the present invention, the salicylic acid cocondensation resin metallization is generally used in the form of an aqueous suspension of fine particles.

Such an aqueous suspension of (A) a color developer, (B) a kaolinite group clay mineral (used as a slurry previously dispersed in an aqueous system), and (C) a binder, such as synthetic rubber latex or modified starch. , modified polyvinyl alcohol, and (D) others (dusting prevention agent, fluorescent whitening agent, viscosity property modifier, antifoaming agent), etc., and adjust the viscosity and solid content according to the coating method used. A method is used in which a coating liquid is prepared in advance, applied to a support such as paper, and dried.

As a coating method, an air knife coater, a bar coater, a blade coater, a Tarabia coater, a roll coater, etc. are generally used.

In the aqueous coating liquid used in this application, the salicylic acid co-condensed resin metallization, which is a color developer, accounts for 5 to 50% of the total solid content.
, and kaolinite group clay minerals account for 40 to 9 of the total solid content.
It is common to use 0% and 5 to 30% of the binder component.

The amount of aqueous coating liquid applied to the support is 1 gem by dry weight.
More preferably, it is 2 to 10 g/m''.

The color developer sheet of the present invention requires only a small amount of color developer component and coating liquid to be applied, and the concentration, viscosity, etc. of the aqueous coating liquid can be changed over a relatively wide range, and the mechanical and thermal properties of the aqueous coating liquid Due to its excellent stability, both on-machine coating and off-machine coating are possible, and it has great advantages not only in terms of performance but also in the process of producing angry pressure collar paper.

(Functions and Effects) The present invention uses a metallized co-condensed resin containing salicylic acid and α,α'-dialkoxy p-xylene as main monomer components as a color developer, and a kaolinite group clay mineral as a pigment. Provided is a novel color developer sheet for pressure-sensitive copying paper with excellent performance and coating suitability.

The color developer sheet of the present invention differs from previously known color developer sheets with respect to the physical properties required for a pressure-sensitive copying paper: (1) It provides excellent color development performance (color development speed, density);

■ Excellent stability of colored images upon exposure to light or contact with solvents such as plasticizers.

■ The color image has excellent water resistance and will not disappear under humid conditions or upon contact with water.

■ There is very little change in coloring ability even after long-term storage or storage at high temperatures.

■ The coated surface does not yellow even when it comes into contact with light or NOx gas components in the air.

It has extremely excellent features such as these, making it possible to expand its use to applications for which conventional pressure-sensitive paper was considered unsuitable, and its practical significance is extremely significant.

Prior to working examples, a method for producing a color developer sheet and a method for evaluating its performance as a pressure-sensitive copying paper will be described below.

The color developer used on each side was wet milled in the presence of a small amount of anionic polymeric surfactant to form an aqueous suspension with a solids content of 40% by weight (average particle size 2.5μ).

Next, using this suspension, an aqueous coating liquid (solid content: 30% by weight) having the following composition is prepared.

Aqueous coating liquid composition Solid content Mlt ratio pigment
100 Color developer 17 Synthetic rubber latex 8 Oxidized starch 12 Anti-dusting agent 1.5 Notes Synthetic rubber latex Mitsui Toatsu Polylac 52-A Oxidized starch Egg cornstarch Ace B Anti-dusting agent Nissin Chemical DEF-922F This water-based coating liquid 40g/a using Meyer bar coater
A pressure-sensitive copying paper developer sheet is created by applying and drying the coating to a dry coating amount of 6 g/+w on high-quality paper.The method for evaluating the performance of the color developer sheet obtained in this way as a pressure-sensitive paper is as follows: It is as follows.

(1) 0 color development rate and density (conducted in a thermostatic chamber at 20°C and 65χRH) Commercial blue coloring paper containing crystal violet lactone (CνL) as the main pressure-sensitive dye (NW-4 manufactured by Jujo Paper Co., Ltd.)
07), the color developing sheet (lower paper) obtained in the example
Lay them on top of each other with their two cloth sides facing each other, and use an electronic typewriter to engrave and color them.

The reflectance 30 seconds and 24 hours after stamping is measured using a TSS type Hunter colorimeter (using an amber filter) and displayed as a Y value.

(2) Light fastness of 0 color image (The color developer sheet developed using the method in step 11 was irradiated with light for 4 hours using a carbon arc fade meter (Suga Test Instruments PAL-5 model), and the color image after the test was Hunter colorimeter (
The color was measured and displayed using an amber filter. The smaller the difference before and after the test, the less fading of the colored image due to light, which is preferable.

(3) Melamine/formaldehyde resin film microcapsules with an average particle size of 5.0μ were prepared using plasticizer-resistant dioctibata (DOP) (DOP) as a core material, and a small amount of a starch-based binder was added. The coating solution was applied onto high-quality paper using an air knife coater and dried to a dry coating amount of 5 g/[10P micro force coated paper was prepared. The DOP microcapsule-coated paper and the coloring surface of the color developing sheet colored in step 1 were placed opposite each other, and then passed through a super calendar roll having a linear pressure of 100 Kg/cn to uniformly infiltrate the coloring surface with oop.

The concentration one hour after the test is expressed as a Y value using a Σ-80 color difference meter. The lower the Y value and the smaller the difference from the pre-test value, the better the plasticizer resistance of the colored image.

(4) Water Resistance of 1. Colored Image The color developing sheet developed by method 1 was immersed in water for 2 hours, and changes in the density of the colored image were observed with the naked eye.

(5) Yellowing of developer sheet (5-1) Yellowing due to NOX Based on JIS L-1055 (nitrogen oxide gas fastness test method for dyed products and dyes)
The sample was stored for 1 hour in a sealed container in an atmosphere of N011 gas generated by the reaction between sodium nitrite) and H3pot (phosphoric acid), and the degree of yellowing was examined.

One hour after the end of the test, the WB value is displayed using a Σ-80 color difference meter. WB of untested sheet with large WB value
The smaller the difference from the value, the less yellowing under NO atmosphere.

(5-2) Yellowing due to light The color developing sheet is irradiated with a carbon arc fade meter (manufactured by Suga Test Instruments) for 4 hours, and after the test, it is displayed as a WB value using a Σ-80 color difference meter. The larger the WB value and the smaller the difference from the -B value of the untested sheet, the smaller the yellowing caused by light irradiation.

f6), Heat resistance of one-color sheet It was evaluated by measuring the tendency for coloring ability to decrease during long-term storage or high-temperature storage (in particular, changes in coloring density immediately after coloring).

Each color developing sheet was stored in a constant temperature bath at 50°C for 100 hours, and then combined with a commercially available top paper for blue coloring (Jujo Nga-40-cho), passed through a calendar roll with a linear pressure of 50 kg/cm to develop color. .

10 seconds after color development, the color density at the mouth is displayed as a Y value using a Σ-80 color difference meter. A color development test was similarly conducted, and the smaller the change compared to the untreated color development density, the better the long-term storage and heat stability.

Synthesis Example 1 In a reactor, 138 g (r, 0 mol) of salicylic acid, 361 g (3,0 mol) of mesitylene, α, α°-dimethoxy p
- Charge 332 g (2.0 mol) of xylene and charge the catalyst with p
-2.0g of toluenesulfonic acid and 2.0g of anhydrous zinc chloride
added. Next, heat while stirring to a temperature of 150~
When the reaction was carried out at 160°C for 4 hours, 133g of methanol was distilled out. After the reaction was completed, 2000 g of toluene was distilled.
a+f was added to dissolve the reaction product. After adding 4000 IIll of warm water to this and stirring under reflux for 30 minutes, the lower aqueous layer was separated and removed. After repeating this extraction and separation operation of unreacted monomers with hot water two more times, the solvent toluene was distilled off under reduced pressure. The molten resin was then discharged to obtain a pale brown transparent resin.

100 g of the obtained co-condensed resin was placed in a flask and heated to melt at a temperature of 150 to 160°C, and then a mixture of 21 g of zinc oxide and 2.0 g of ammonium bicarbonate was mixed with 30 g of ammonium bicarbonate while stirring. Added slowly over a period of minutes. Thereafter, the mixture was stirred at 160 to 170°C for 1 hour to complete the reaction. 2-(2゛-hydroxy-3',5'-di[-butylphenyl)-5-chlorobenzotriazole] while melting it on the yarn.3. Add Og, dissolve and mix, and add Zn compound of pale yellow transparent salicylic acid cocondensation resin (color developer [A
]) was obtained.

Synthesis Example 2 In a reactor were placed 138 g (1.0 mol) of salicylic acid, 240 g (2.0 mol) of mesitylene, 206 g (1.0 mol) of p-tert-octylphenol, and 332 g (2.0 mol) of α,α'-dimethoxy p-xylene. mol) of p-toluenesulfone M3. Added Og. Then, the reaction mixture was heated with stirring to carry out a reaction at a temperature of 150 to 160° C. for 4 hours, and 112 g of methanol was distilled out.

After the reaction was completed, 2000 m6 of toluene was added to dissolve the reaction composition. After adding 4000 ml of warm water to this and stirring under reflux for 30 minutes, the lower aqueous layer was separated and removed. After repeating this extraction and separation operation of unreacted monomers with hot water two more times, the solvent toluene was distilled off under reduced pressure. The molten resin was then discharged to obtain a pale brown transparent resin.

100 g of the obtained salicylic acid-mesitylene-p-tert-octylphenol cocondensation resin was placed in a flask and heated to melt at a temperature of 150 to 160°C. Next, a mixture of 14 g of zinc benzoate and 8.5 g of ammonium bicarbonate was added to the molten resin while stirring for 1 W.
Added gradually over 0 minutes. After this, 155-1
The reaction was completed by stirring at a temperature of 65° C. for 1 hour. After the reaction was completed, 0.5 g of (2,2-thiobis(4-t-octylphenolate))-n-butylamine nickel was added and 1! i2 The mixture was stirred and melted to obtain a pale yellow and transparent salicylic acid cocondensation resin Zn compound (color developer [B]).

Example-1 Zn compound of the salicylic acid cocondensation resin obtained in Synthesis Example-1 as a color developer (color developer<A)), and kaolin as a pigment.
A color developing sheet was prepared using Kaobright (manufactured by Thiefs).

Example-2 Kaolin (Burgess Kaolin) was used as a pigment.
C1ay N.

A color developing sheet was prepared in the same manner as in Example-1 except that 10) was used.

Example 3' A color developer sheet was prepared in the same manner as in Example 1, except that kaolin (Zikrite MC, ---Zikrite chemical mining type) was used as the pigment.

Comparative Examples-1 to 2 The following examples were carried out except that aluminum hydroxide (Hydras Bath-m-manufactured by Showa Denko) (Comparative Example-1) and calcium carbonate (Tama Pearl TP423---manufactured by Okutama Kogyo) were used as pigments, respectively. A color developer sheet was obtained in the same manner as in Example-1.

Comparative Example 3 A color developer sheet was prepared using p-phenylphenol formaldehyde resin (Mitsui Toatsu Chemical RB) as a color developer and kaolin (Kaolinite - manufactured by Thele) as a component.

Comparative Example-4 As a color developer, 2.5-di-α-methylbenzyl-salicyl #IZn and low molecular weight polystyrene (manufactured by Sanyo Chemical Co., Ltd.,
Calcium carbonate (TP-12
3) was used to create a color developing sheet.

Example-4 Salicylic acid cocondensation resin obtained in Synthesis Example-2 as a color developer (
Color developer (B) A color developer sheet was prepared using kaolin [υE90] as a III material.

Comparative Example-5 Calcium carbonate (Whiten SSB Red---
A color-developing sheet was obtained in the same manner as in Example-4, except that a color-developing sheet (manufactured by Shiroishi Kogyo) was used.

Comparative Example 6 Zn salt of salicylic acid/nonylphenol formaldehyde condensate (manufactured by Stinectady, HR) was used as a color developer.
A color developing sheet was obtained in the same manner as in Example 4 except that J) was used.

The performance evaluation results for the color developing sheets of Examples 1 to 5 and Comparative Examples 1 to 5 are summarized in Table 1.

As is clear from the results in Table 1, it is clear that the color developing sheet containing the novel metallized salicylic acid co-condensed resin of the present invention and the kaolinite group clay mineral has excellent properties.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of pressure-sensitive copying paper. In FIG. 1, each symbol is as follows. 1. Bottom paper 2. Middle paper 3. Bottom paper 4. Microcapsules 5. Color developer 6. Pen pressure patent applicant Mitsui Toatsu Chemical Co., Ltd. Figure 1

Claims (1)

[Claims] 1) (1) Salicylic acid and α,α'-dialkoxy-
A pressure-sensitive copying paper characterized in that a kaolinite group clay mineral is used as a pigment in a color developer layer containing a co-condensed resin metallized color developer containing p-xylene as a main monomer component and a binder. Color developer sheet. 2) The co-condensed resin metallized product is salicylic acid-mesitylene-
The color developing sheet according to claim 1, which is a metalized product of α,α'-dimethoxy-p-xylene cocondensation resin. 3) The color developing sheet according to claim 1 or 2, wherein the metallization is a Znide.