JPS6034474B2 - Color developer for pressure-sensitive recording paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head coloring agent for pressure-sensitive recording paper, and more particularly to an improvement of a phenol-aldehyde condensate used as a color developer.

Pressure-sensitive recording methods generally utilize a reaction between a colorless electron-donating organic compound (hereinafter referred to as a color former) and an electron-accepting complex substance (hereinafter referred to as a color developer) that can react to form a colored product. This is what I did.

Known color developers include inorganic clays such as acid clay, activated white clay, attapulgite, zeolite, bentonite, and kaolin, and phenol/aldehyde condensates (specifically, para-substituted bifunctional phenol/formaldehyde condensates). . Phenol-aldehyde condensate has better moisture resistance than inorganic clays when it reacts with a coloring agent (
It has an excellent ability to form colored images (its coloring ability is not affected by humidity in the air, and colored prints do not disappear), and it has already been put to practical use as a color developer and has undergone many improvements. That is, Japanese Patent Publication No. 42-20144 and Japanese Patent Publication No. 46-37451 disclose the use of a para-substituted bifunctional phenol/aldehyde condensate as a color developer.

However, although the color developers shown above have excellent performance in forming color-fast colored images, (1) the color development ability is still insufficient.

■ Poor durability (easily discolored to yellow due to sunlight exposure or indoor equipment).

■ Poor oil resistance (for example, if colored paper is contaminated with gasoline, plasticizers such as phthalates, ethyl alcohol, etc., the color will not develop or the colored print will disappear).

It has drawbacks such as:

Further, Japanese Patent Publication No. 47-20971 discloses that a divalent metal salt such as zinc chloride is added to a para-substituted bifunctional phenol/formaldehyde condensate when preparing a coating solution.

Further, JP-A-48-25744 describes a zinc salt of a para-substituted bifunctional phenol/formaldehyde condensate (substantially a zinc salt of a paraphenylphenol/formaldehyde condensate). However, even these coloring agents have not yet satisfied all of the requirements of color developing ability, weather resistance, and oil resistance, and there is still a strong demand for improved performance of pressure-sensitive recording paper, and improvements to color developers are strongly desired. There is. An object of the present invention is to provide an improved color developer for pressure-sensitive recording paper, and to produce pressure-sensitive recording paper with excellent color development ability, weather resistance, oil resistance, and green resistance at a low cost. It has the following advantages.

The above-mentioned object of the present invention is to
A polyvalent metal salt of a condensate obtained by co-condensing a species or two or more species with an aldehyde in the presence of an acidic catalyst by adding one or more trifunctional or more functional phenols. This is achieved by including it as a main component of a color developer. The rose-substituted bifunctional phenols used in the present invention include p-cresol, p-ethylphenol, and p-p.

Pyrphenol, p-secondary butylphenol,
p-tertiarybutylphenol, p-amylphenol, p-cyclohexylphenol, p-hef. Tylphenol, p-tertiary octylphenol, p
Dodecylphenol, p-nonylphenol, p-chlorophenol, p-fromphenol, p-phenylphenol, p-cumylphenol, p-phenolsulfonic acid, p-phenolcarboxylic acid, p-phenol It is a para-substituted bifunctional phenol having two functional groups in its molecule that react with aldehydes such as carboxylic acid esters. One or more of these may be used, but p-tert-butylphenol, p-tert-octylphenol, and p-phenylphenol are preferred in view of the color tone of the resulting resin and the difficulty in manufacturing. More preferred are p-tert-butylphenol and p-tert-octylphenol. The aldehyde used in the present invention includes formaldehyde (formalin, paraformaldehyde), acetaldehyde, butyraldehyde, etc., but formaldehyde is generally used.

Acidic catalysts used in the present invention include hydrochloric acid, sulfuric acid, phosphoric acid,
Generally speaking, inorganic or organic acids such as oxalic acid, acetic acid, formic acid, para-toluenesulfonic acid, benzenesulfonic acid, and phenolsulfonic acid are used, but hydrochloric acid and oxalic acid are preferred from the viewpoint of the color tone of the resulting product.

The trifunctional or higher functional phenol used in the present invention has 3 functional groups in its molecule that react with aldehydes, such as phenol, m-cresol, bisphenol A, bisphenolsulfone, resorcinol, Q-naphthol, 3-naphthol, and catechol. These are the phenols listed above.

One or more of these phenols may be used, and phenol, bisphenol A, and bisphenol sulfone are particularly preferred because they are practical and highly effective. In the present invention, the metal salts used as polyvalent metal salts include polyvalent metal salts such as zinc, magnesium, tin, cadmium, aluminum, gold, titanium, calcium, cobalt, iron, nickel, copper, and manganese. Metal hydrochlorides, nitrates,
Examples include sulfates, formates, acetates, benzoates, hydroxybenzoates, salicylates, borates, phosphates, and the like. Based on the color tone of the condensate produced, zinc salt,
Aluminum salts, calcium salts and magnesium salts are preferred. Next, the mode of manufacturing the color developer of the present invention will be described in detail.

■ One or more para-substituted bifunctional phenols and three
After a condensation reaction in the presence of an acidic catalyst with or without addition of an organic solvent such as benzene, toluene, xylene, or trichloroethylene to one or more functional or higher functional phenols and an aldehyde, dehydration and soot removal are performed. Then, add an appropriate amount of an alkaline substance (e.g. ammonium carbonate, sodium hydroxide, etc.), add a polyvalent metal salt (e.g. zinc dibenzoate, zinc acid, etc.), and raise the reaction temperature to 150-200 ml.
00 and cooled to obtain a solid color developer as referred to in the present invention.

This solid color developer is used in attritors and sand grinders.
It can be wet-pulverized in the coexistence of a surfactant, a dispersant, etc. using a wet-pulverizer such as the following, to produce a blushing agent for pressure-sensitive recording.
■ One or more para-substituted bifunctional phenols and three
After a condensation reaction of one or more functional or higher phenols and an aldehyde in the presence of an acidic catalyst with or without the addition of an organic solvent such as benzene, toluene, xylene, or trichloroethylene, the aldehyde is directly treated with an alkaline substance ( For example, it is dissolved or dispersed in a solution (eg, sodium hydroxide), or after dehydration and desolvation, it is dissolved or dispersed in an alkaline substance.

Next, an appropriate amount of a polyvalent metal salt (eg, zinc chloride, aluminum chloride, etc.) is gradually added to this solution to obtain the color developer referred to in the present invention. In this case, it is also possible to prepare a dispersion that can be used as a head coloring agent for pressure-sensitive recording as it is without carrying out a wet grinding step. However, after washing the color developer with water, it is preferable to crush the wet cake in a wet pulverizer to obtain a color developer for pressure-sensitive recording. Furthermore, the present invention involves the reaction of a para-substituted bifunctional phenol, a trifunctional or higher functional phenol, and an aldehyde by first performing a resolization reaction using an alkali catalyst such as sodium hydroxide, potassium hydroxide, calcium hydroxide, or barium hydroxide. , neutralized to pH 4 to 6 with sulfuric acid, phosphoric acid, hydrochloric acid, etc. (after washing with water to remove neutralized salts if necessary), carrying out a novolac condensation reaction with or without addition of an acidic catalyst, and then reacting with a metal salt. It also includes doing. When producing the color developer of the present invention, para substitution 2
Trifunctional or higher functional phenol is used in an amount of 1 mol or less per 1 mol of functional phenol, preferably 0.05 to 0.8 mol.

In addition, the aldehyde is 0.5 to 0 per mole of these para-substituted bifunctional phenols and trifunctional or higher functional phenols.
．． Although it is preferable to use 9 mol, the present invention is not limited thereto. The amount of the polyvalent metal salt used is 1 to 1% by weight, and preferably 2 to 8% by weight, based on the weight of the resin. If the amount of metal is too large, wet pulverization becomes difficult and the stability of the dispersion becomes poor, resulting in deterioration of workability when coating on recording paper. The improved color developer thus obtained has a greater color developing ability than conventionally known color developers.

(High color density and fast color development) Also, weather resistance,
It has excellent oil resistance. For example, para substitution 2
Most of the condensates obtained from functional phenols currently used as color developers for pressure-sensitive recording paper are condensates of phenylphenol and formaldehyde. The colorant is superior in color developing ability, weather resistance, and oil resistance. It is also possible to use a cocondensate of a para-substituted bifunctional phenol and a trifunctional or higher functional phenol as a color developer, but this is incomparable to the color developer of the present invention. Although metal salts of condensates made of paraphenylphenol are already known, they are inferior in color developing ability, film resistance, and oil resistance to those of the present invention. In the present invention, by co-condensing trifunctional or higher functional phenols and further forming metal salts, it is thought that a synergistic effect is brought about and the head color ability, film resistance and oil resistance are improved.

By improving the color developing ability, it is possible to reduce the amount of head coloring agent applied in order to obtain the same color density, which leads to a substantial cost reduction of the pressure-sensitive recording paper. Further, the head coloring agent of the present invention can be used in combination with an inorganic material such as acid clay or activated clay kaolin, or an inorganic pigment. Hereinafter, examples will be used to explain in detail how useful the metal salt of an integrated product of para-substituted bifunctional phenol, trifunctional phenol, and aldehyde is as a color developer.

However, the present invention is not limited to the examples.
Further, all "parts" and "%" described herein indicate "parts by weight" and "% by weight" unless otherwise specified. Example
1 40 parts of P-phenylphenol, 100 parts of bisphenol sulfone (manufactured by NICCA Chemical Industries), 1 part of 37% formalin
14 parts, oxalic acid isobe, and xyreso 15 parts were placed in a reaction vessel and after refluxing for 3 hours, dehydrated, treated with a shedding agent, and burned.
Ammonium bicarbonate (N ratio HC03) at an internal temperature of 170 pm
37 parts, and zinc acetate (C&COOZnCOOCH3.
On the 2nd day (20), 44 parts were added in portions to obtain a zinc salt of the condensate.

Example 2 40 parts of P-phenylphenol, 10 parts of bisphenol sulfone, 114 parts of 37% formalin, 1 part of oxalic acid
Ikari Kaku and 150 parts of xylene were placed in a reaction pot and refluxed for 3 hours. After dehydration and solvent removal, the internal temperature was raised to 170°C. After that, 100 parts of 5.9% sodium hydroxide aqueous solution was added. to dissolve and disperse aluminum chloride (AIC).
A small amount of 116 parts of 13.Mother LO) was added to obtain a precipitate.

This precipitate was separated in a furnace, washed with water, and air-dried to obtain an aluminum salt of a condensate. Example 3 The condensate obtained in Example 2 was dissolved and dispersed in 100% aqueous 1.7% sodium hydroxide solution, and then dissolved in zinc chloride (Zn
28 parts of C12) were added in portions to obtain a precipitate.

This precipitate was separated in a furnace, washed with water, and air-dried to obtain a zinc salt of a condensate. Example 4 30 parts of P-phenyl phenol, 200 parts of bisphenol A, 12 parts of 37% formalin, 2 parts of concentrated hydrochloric acid (35.5%), and 15 parts of xylene were placed in a reaction vessel and refluxed for 5 hours. After the reaction, the reaction mixture was dehydrated and solvent removed, heated, and at an internal temperature of 160 qo, 73 parts of ammonium bicarbonate and 88 parts of zinc acetate were added in portions to obtain a zinc salt of the condensate.

Example 5 30 parts of P-phenylphenol, 50 parts of p-tertiary octylphenol, 150 parts of phenol
1 part, 234 parts of 37% formalin, 2 parts of concentrated hydrochloric acid, and 15 parts of xylene were placed in a reaction vessel, and after 5 hours of reflux reaction, they were dehydrated, removed with a defoliant, and heated to 73 parts of ammonium bicarbonate and acetic acid at an internal temperature of 170 oo. 88 parts of zinc was added in portions to obtain a zinc salt of the condensate.

Example 6 p-tertiarybutylphenol 35 parts, 75 parts phenol, 75 parts bisphenol sulfone, 37% formalin 19 groups, oxalic acid 1 part, and xylene 10 parts B
was placed in a reaction vessel and reacted under reflux for 6 hours, after which it was dehydrated, desolventized, heated, and at an internal temperature of 170°C, 7 parts of ammonium bicarbonate and 88 parts of zinc acetate were added in portions to obtain a zinc salt of the condensate. .

Example 7 375 parts of p-tertiary octylphenol, 75 parts of phenol, 1 part of bisphenol A5, 196 parts of 37% formalin, 1 part of oxalic acid and 10 parts of xylene were placed in a reaction vessel and refluxed for 7 hours, followed by dehydration. The solvent was removed, the mixture was heated at an internal temperature of 170 qo, and 37 parts of ammonium bicarbonate and 44 parts of zinc acetate were added in portions to obtain a zinc salt of the condensate.

Example 8 A zinc salt of a condensate was obtained in the same manner as in Example 7, except that 73 parts of ammonium bicarbonate and zinc acetate Isobe were used.

Example 9 A zinc salt of the condensate was obtained in the same manner as in Example 7, except that 10 parts of ammonium bicarbonate and 132 parts of zinc acetate were used.

Example 10 40 parts of P-phenol carboxylic acid, 10 parts of phenol, 207 parts of 37% formalin, and 25 parts of 50% sodium hydroxide aqueous solution were placed in a reaction vessel, refluxed for 4 hours, and then adjusted to pH 4 with concentrated sulfuric acid. Neutralize to 6 parts, then add 2 parts of concentrated hydrochloric acid, carry out reflux reaction for 1 hour, and then add 3 parts of concentrated hydrochloric acid.
．． 100 parts of a 4% aqueous sodium hydroxide solution was added and dissolved.

Next, 55 parts of zinc chloride was gradually added at room temperature to obtain a precipitate.

This precipitate was separated in a furnace, washed with water, and air-dried to obtain a zinc salt of a condensate. Comparative example 1 P-phenylphenol 50 base, 37% formalin 1
43 parts of ammonium bicarbonate, 5 parts of oxalic acid, and 20 parts of xylene were placed in a reaction pot and refluxed for 4 hours, then dehydrated, desolvented, and fired at an internal temperature of 17,000 to produce 37 parts of ammonium bicarbonate, 62 parts of zinc dibenzoate, was added in portions to obtain the zinc salt of the condensate.

Comparative example 2 P-phenylphenol 50 anchors, 37% formalin 1
43 parts of oxalic acid, 5 parts of xylene, and 20 parts of xylene were placed in a reaction vessel, and after refluxing for 4 hours, dehydration and solvent were removed to bring the internal temperature to 130.
The mixture was heated to ℃ to obtain a condensate.

Comparative Example 3 375 parts of p-tertiary octylphenol, 75 parts of phenol, 196 parts of bisphenol A5, 196 parts of 37% formalin, 1 part of oxalic acid, and 10 parts of xylene were placed in a reaction vessel and refluxed for 7 hours, followed by dehydration. The solvent was removed and the mixture was heated to a boiling point of 17,000 to obtain a condensate.

Table 1 shows the test results on pressure-sensitive recording paper for Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and Comparative Examples 1, 2, and 3. Table 1 Test results A: Phenols on trifunctional membrane B: Para-substituted bifunctional phenols Test method: 1 Preparation of coating solution and method of making developer sheet Obtained by Examples and Comparative Examples A mixture consisting of 40 parts of a color developer, 2 parts of an anionic surfactant, and 58 parts of water was wet-pulverized with an attritor so that the particle size of the pigment was 5 microns or less to obtain an emulsified dispersion.

Using this emulsified dispersion, the following components were blended to obtain a coating composition. This coating mixture was applied onto the paper surface using a coating rod at a dry weight ratio of 5 days/day, and left to dry at room temperature for 1 day to obtain a mauve colored sheet, which was used in each test.

Preparation performance test method for coating formulation: 'a- Color developing ability: A microcapsule sheet containing crystal violet lactone was layered on the above color developer sheet and color was developed under a load pressure of 500k9/c tiger.
The degree of color development after a period of time was measured using a reflection color difference meter (manufactured by Nippon Denshoku).

The value is shown in reflectance (%), and the lower the value, the higher the color density. [b} Weather resistance: The above color developer sheet was irradiated with sunlight for 1 hour, and the reflectance measured with a reflection colorimeter before and after was used. Weather resistance was expressed by the following formula.

Weather resistance: Suicide Kasumi Wings Sagi Mai Flea Chin Yi X・oo The larger the value, the better the weather resistance.

tc} Oil resistance: The colored developer sheet (24 hours after coloring) was immersed in gasoline for 1 second to observe changes in the colored image.

The degree of change in the color image was expressed as follows. ○No change, △Slight disappearance.

Claims (1)

[Claims] 1. When condensing one or more para-substituted bifunctional phenols and an aldehyde in the presence of an acidic catalyst, one or more trifunctional or more functional phenols are added for co-condensation. A color developer for pressure-sensitive recording paper, which contains as a main component a polyvalent metal salt of a condensate. 2. The color developer for pressure-sensitive recording paper according to claim 1, wherein the para-substituted bifunctional phenol is one or more of para-phenylphenol, para-tertiary octylphenol, and para-tertiary butylphenol. . 3. The color developer for pressure-sensitive recording paper according to claim 1 or 2, wherein the trifunctional or higher functional phenol is one or more of phenol, bisphenol A, and bisphenol sulfone. 4. The pressure-sensitive material according to claim 1, 2, or 3, wherein the cocondensation ratio is 1 mole or less of trifunctional or higher functional phenol per 1 mole of para-substituted bifunctional phenol. Color developer for recording paper. 5. Pressure-sensitive recording paper according to claim 1, 2, 3, or 4, wherein the metal salt of the condensate is one or more salts of zinc, calcium, and aluminum. Color developer. 6. A microscope for pressure-sensitive recording paper according to claim 1, 2, 3, 4, or 5, characterized in that the metal content is 1 to 10% by weight. Colorant.