JPS5841759B2 - record sheet - Google Patents

Description

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

More specifically, the present invention relates to a novel recording sheet that reacts with a coloring agent to form a colored image.

Colorless basic dye precursor substance (hereinafter referred to as color former).

) and an adsorbed or acid-reactive compound (hereinafter referred to as a color developer) that develops a color upon contact with this color former.

) [For example, acid clay, activated clay. Akpargite,
Clay materials such as zeolite, bentonite, and kaolin:
Organic acids such as succinic acid, tannic acid, gallic acid, alkyl-substituted phenols, and bisphenol A; metal salts of aromatic carboxylic acids such as zinc salts and aluminum salts of alkyl-substituted salicylic acids; acidic polymers such as P-phenylphenol formaldehyde resin] Recording sheets that utilize a coloring reaction with are generally well known.

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

Recording sheets that specifically utilize this phenomenon include pressure-sensitive copying paper (for example, U.S. Pat. Nos. 2,505,470 and 2,5
No. 05,489, No. 2,550,471, No. 2.54
No. 8,366, No. 2,712,507, No. 2.730
, No. 456, No. 2,730,457, No. 3.418,
250, etc.) and thermal recording paper (for example, Special Publication No. 43-41)
No. 60 and U.S. Pat. No. 2,939,009).

Furthermore, a printing method is also known in which a colored image is obtained by supplying ink containing a color former to a sheet coated with a color developer through a medium such as a stencil.

(German patent application (OLS) no. 1.939,624),
.

For recording using the above phenomenon, pressure from a ballpoint pen, typewriter, etc., heat from a heating element, electric current, etc., and other physical conditions are safe.

The most typical form of recording sheet is pressure-sensitive copying paper.

Pressure-sensitive copying paper is prepared by dissolving color abrasives in a solvent such as alkylated naphthalene, alkylated diphenylmethane, alkylated diphenyl, cuphenyl, or chlorinated paraffin, and dispersing this in a binder or incorporating it into microcapsules. It is obtained by coating a support such as paper, plastic sheet, or resin-coated paper.

On the other hand, when the developer is dissolved in a solvent such as an organic solvent, the developer solution is directly impregnated into the support, or it is dissolved or dispersed together with a binder in a medium and then applied to the support.

Generally, the color former and developer are applied to the same or opposite sides of the support or to different sides of the support.

These developer-coated sheets have several points that should be improved.

That is, when clays such as activated clay are used as color developers, they have the disadvantage that colored images such as crystal violet disappear due to polar solvents such as water and glycols.

On the other hand, when a phenol resin such as p-phenylphenol-formaldehyde resin is used as a color developer, it has drawbacks such as the color developer surface being easily yellowed by light.

Furthermore, aldehydes such as formaldehyde are used in the synthesis of phenol resin, and the use of highly toxic formaldehyde is undesirable because it is accompanied by many difficulties.

Furthermore, when phenolic compounds such as alkyl-substituted phenols and bisphenol A are used as color developers, the color developing ability gradually decreases, probably because these compounds dissipate over time or diffuse into the support. There are drawbacks such as:

Furthermore, when alkyl-substituted phenol, bisphenol A, etc. are used, the initial color developing ability is also undesirably low.

Improvements have been desired since such drawbacks have a significant impact on commercial value.

The present inventors previously proposed the use of a dimer of a compound represented by the following general formula CI) as a color developer in order to improve the above-mentioned drawbacks.

However, the color developing agent proposed above does not have sufficient color developing ability.
It had drawbacks such as insufficient light fastness of the developed image (2) insufficient moisture resistance of the developed surface.

The object of the present invention is to provide a color developing sheet that improves the above-mentioned drawbacks.

As a result of various studies, the present inventors have found that the above object can be completely achieved by simultaneously using a dimer of a compound represented by the following general formula and a metal salt of an aromatic carboxylic acid.

Here, R1, R2, R3 are hydrogen atoms or alkyl groups,
(preferably C1-Cl8) aryl group, aralkyl group (preferably the alkyl residue is C1-C18), and n is 1-4. The hydroxyl group is most preferably in the para position.

A synthesis example of the compound represented by the general formula CI) is shown below.

General formula (n) General formula CI) [Syhydroxydiaryorealkane] [Alkenylphenol dimerization 111 → Mainly dimer (including monomer and oligomer of trimer or higher) The method of thermal decomposition is general It is obtained by thermally decomposing the compound of formula (n) in an anhydrous state in the presence of an alkali or alkaline earth metal oxide, hydroxide, alcoholade, phenolate, or the like.

Further, the dimerization method can be obtained by heating at least one compound of general formula (1) to 15-130°C.

These are Japanese Patent Application Publication No. 50-30852 and British Patent No. 90306.
I am familiar with 2.

From the above, the dimer of the present invention can be synthesized more safely and easily than phenol resin.

Examples of compounds of general formula CI) C alkenylphenol include p-impropenylphenol, 2-(p
-hydroxyphenyl)2-butene, 2(p-hydroxyphenyl)2-pentene, α(p-hydroxyphenyl)-styrene, 1-(p-hydroxyphenyl)-1
-isobutyne, p-cyclohexenylphenol, 2-
(p-hydroxyphenyl)-3-methyl-2-butene, 2(p-hydroxyphenyl)-2-hexene, 2(
p-hydroxyphenyl)-2-hexatecene, m-methyl-p-isopropenylphenol, 2(o-isopropyl-p-hydroxyphenyl)2-butene, 2(o
-phenyl-p-hydroxyphenyl)2-pentene,
2(o-tertbutyl-p-hydroxyphenyl)2
-Pentene km-isopropenylphenol, 1-(p
Examples include compounds such as -hydroxyphenyl)-1-propylene.

Moreover, the metal salt of aromatic carboxylic acid is a metal salt of aromatic carboxylic acid such as copper, lead, magnesium, calcium, zinc, aluminum, tin, or nickel.

Specific examples of aromatic carboxylic acids include benzoic acid, chlorobenzoic acid (o, m y p ), and nitrobenzoic acid (
o + rn * p ), toluic acid (o, m, 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 -tertbutylbenzoic acid, N-phenylanthranilic acid, 4-methyl-3-nitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 3,5-dinitrosalicylic acid, 5 t
ertbutylsalicylic 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-ynamylsalicylic acid, 5-isoamylsalicylic acid, 3,5-
Di-5ec-butylsalicylic acid, 5-nonylsalicylic acid, 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-5tert-butylbenzoic acid, 2,4-cresotinic acid, 5,5-methylenedisalicylic acid, acetaminobenzoic acid (o , m, p), 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, anacardic acid, 1-naphthoic acid, 2-naphthoic acid, 1hydroxy-2
-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-
Hydroxy-1-naphthoe L 3-phenyl-5-(α
, α-dimethylbenzyl)salicylic acid, thiosalicylic acid, 2-carboxybenzaldehyde, and the like.

In order to produce the color developer sheet of the present invention, a dimer of the compound represented by the general formula CI) (in addition to the dimer, a monomer and an oligomer of trimer or higher may be included) and an aromatic carbon There is a method in which a metal salt of an acid is dissolved in an organic solvent, and if necessary, a binder and an inorganic pigment are added thereto, and the support is coated or impregnated.Another method is to disperse the color developer of the present invention in water. However, if necessary, a binder, an inorganic pigment, etc. can be added and applied to the support.

In this case, the effects of the present invention are not hindered by the addition of silicone oil, octyl alcohol, etc., and other small amounts of additives used in the art for the purpose of defoaming and foam suppression.

When using the color developer of the present invention dissolved in an organic solvent,
Alcohols such as methanol, ethanol, butanol, ethyl acetate, butyl acetate, ethyl lactate, n-butyl lactate, ethyl glycolate, n-butyl β-oxypropionate, isobutyl β-oxypropionate, n-propyl β-oxypropionate Esters, esters such as α-hydroxyisobutyric acid methyl ester, α-hydroxy n-butyric acid ethyl ester, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Dissolved in hydrocarbons such as benzene, toluene, xylene, etc. and impregnated onto a support. Or apply.

In this case, white carbon, talc, titanium oxide, calcium carbonate,
Inorganic pigments such as calcium hydroxide can be added.

In this case, the binder is polymethyl methacrylate, polyacrylic ester, polyvinyl acetate, M2 vinyl-
Vinyl chloride copolymer, polyvinyl butyral, polystyrene, linear saturated polyester resin, ethyl cellulose,
Cellulose acetate.

Nitrocellulose or the like is dissolved and applied to a support such as paper, plastic sheet, or resin-coated paper.

On the other hand, when used in an aqueous system, the dimer of the compound represented by general formula (I) (hereinafter referred to as alkenylphenol dimer) and the metal salt of aromatic carboxylic acid are pulverized into fine powder and dispersed in water. Alternatively, the solution dissolved in a solvent such as ethyl acetate or benzene may be emulsified in water, or the aromatic carboxylic acid and aldanylphenol dimer may be dissolved in an aqueous alkaline solution, and then copper, aluminum, zinc, tin, It is used by adding and reacting salts such as nickel.

In this case, inorganic pigments such as white carbon, talc, kaolin, waxite, titanium oxide, calcium carbonate, and calcium hydroxide can be added, and as a binder, proteins (such as gelatin, albumin, casein, etc.) can be added.
, cellulose (e.g. carboxymethyl cellulose, hydroxyethyl cellulose, etc.), saccharose (agar, sodium alginate, carboxymethyl starch, gum arabic, etc.), water-soluble natural polymer compounds such as polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide. In addition to water-soluble synthetic polymer compounds such as acrylic acid ester copolymer latex, vinyl acetate latex, styrene-butadiene copolymer latex, etc., it can be applied to supports such as paper, plastic sheets, resin-coated paper, etc. do.

In the above coating liquid, the amount of the binder used is 1 to 50 parts, preferably 5 to 40 parts, and particularly preferably 10 to 30 parts, based on 100 parts by weight of solid content such as color developer and inorganic pigment.

If the amount of binder used is too small, sufficient film surface strength cannot be obtained, and if it is too large, the color developing ability decreases and this is not desirable in terms of cost.

The amount of inorganic pigment used is 10 to 10,000 parts by weight, and 50 to 500 parts by weight per 100 parts by weight of the color developer.
It is preferably 0 parts by weight, particularly preferably 50 to 1000 parts by weight.

Furthermore, conventional color developers such as acid clay, activated clay, phenol, and formalin resin can also be used in the recording sheet of the present invention.

In the present invention, the metal salt of aromatic carboxylic acid is added in an amount of 0.01 to 30 parts by weight, preferably 0.05 to 2 parts by weight, per 1 part by weight of the alkenylphenol dimer.

Next, in the present invention, when using an organic solvent as a medium, there are printing methods such as flexo stamping and gravure printing, and in the case of an aqueous coating liquid using water as a medium, Methods used among those skilled in the art may be used, such as air knife coating, roll coating, blade coating, size press coating, and the like.

The amount of color developer applied is 0.1 to 5 g/rn2, preferably 0.2 to 3 El/m", and particularly preferably O13 to 2 g/m".

If the coating amount is below the lower limit, sufficient color developing ability will not be obtained, and the upper limit is determined primarily for economic reasons rather than performance.

The color former that reacts with the color developer used in the recording sheet of the present invention is not particularly limited, but specific compounds of these color formers include triarylmethane compounds such as 3
, 3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide or crystal violet lactone, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-( 1゜2-dimethylindol-3-yl)phthalide, 3-(
p-dimethylaminophenyl)-3-(2-methylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-phenylindol-3-yl)phthalide, 3,3-bis -(1,2-dimethylindol-3-yl)-5dimethylaminophthalide, 3,
3-bis(1,2-dimethylindol-3-yl)-
6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazol-3-yl)-5-dimethylaminophthalide, 3,3-bis-(2-phenylindol-3-yl)-5-dimethylamino phthalide, 3-p-dimethylaminophenyl-3-(1-methylpyrrol-2-yl)-6-dimethyl-aminophthalide, etc.; as a diphenylmethane compound, 4,4'-bis-dimethylaminobenzhydrin Benzyl ether, N-halophenyl leuco auramine, N-2,4,5-1-lichlorophenyl leuco auramine, etc.: As xanthene compounds, rhodamine B-anilinolactam, rhodamine Bp nitroanilinolactam, rhodamine B- p-chloroanilinolactam, 3-dimethylamino-7-medoxyfluoran, 3-diethylamino-7-medoxyfluoran, 3-
Diethylamino-6-medoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-chloro-6-methylfluorane, 3-diethylamino-6,8-dimethylfluorane, 3-diethylamino-7 -acetylmethylaminofluorane, 3-diethylamine-7-methylaminofluorane, 3,7-dinithylaminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-methylbenzylamino- Fluoran, 3-diethylamine-7-phenylamino-6-methylfluoran, 3-diethylamine-7-chloronitylmethylaminofluorane, 3-diethylamino-7-dichloroethylaminofluorane, etc.: As a thiazine compound, penzoyl fluorane 3-methyl-spiro-compounds such as comethylene blue and p-nitrobenzylleucomethylene blue
dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3.3'-cyclospirodinaphthopyran, 3-
benzyl spiro-dinaphthopyran, 3-methylnaf)
Examples include -(3-methoxy-benzo)-spiro-pyran, 3-propyl-spiro-dibenzopyran, and mixtures thereof.

The colored abrasive is dissolved in a solvent and encapsulated, or dispersed in a binder solution and applied to a support.

As a solvent, natural or synthetic oils can be used alone or in combination.

Examples of solvents include cottonseed oil, kerosene, paraffin, naphthenic oil, alkylated biphenyls, alkylated terphenyls,
Examples include chlorinated paraffins and alkylated naphthalenes.

For methods of manufacturing capsules, see U.S. Patent No. 2,800,
457, a method using coacervation of a hydrophilic colloid sol described in British Patent No. 867.797, British Patent No. 950.443, British Patent No. 98.
There are interfacial polymerization methods described in No. 9,264 and No. 1.091,076.

The effect of the recording sheet of the present invention was confirmed using the following color former sheet.

Microcapsules containing colored shavings are manufactured, for example, according to US Pat. No. 2,800,457, and specific examples thereof are shown below.

Hereinafter, "parts" and mixing ratios all indicate values by weight.

4 parts of acid-treated pork skin gelatin and 10 parts of gum arabic
Dissolved in 400 parts of water at 0°C and added 0.0 parts of funnel oil as an emulsifier.
2 parts, and 40 parts of color-forming cutting oil is emulsified and dispersed therein.

The coloring agent oil was prepared by dissolving two portions of crystal violet lactone in diimpropylnaphthalene.

When the size of the oil droplets reaches 5 microns on average, emulsification is stopped, water at 40°C is added to the mixture to make a total of 900 parts, and stirring is continued.

At this time, care must be taken to ensure that the liquid temperature does not drop below 40°C.

Next, add 10 cups of acetic acid to adjust the pH of the solution to 4.0-4.
2 to cause coacervation.

Stirring is continued further, and after 20 minutes have elapsed, the mixture is cooled with ice water to gel the coacervate film deposited around the oil droplets.

When the liquid temperature reaches 20°C, add 7 parts of 37φ formalin.

While the temperature was at 10°C, a 15φ caustic soda aqueous solution was added to adjust the pH to 9.

Subsequently, the mixture was heated for 20 minutes while stirring to bring the liquid temperature to 50°C.

After adjusting the temperature of the microcapsule dispersion thus obtained to 30°C, 16g of the solid content was placed on a 4.0j; l/m" paper.
′“′.

It was coated and dried so that the coating amount was Gc. (As described above, a microcapsule sheet containing crystal violet lactone as a coloring agent was obtained.

Example 1 10 parts of the color developer shown in Table 1 and 3 parts of ethyl cellulose were dissolved in 50 parts of ethanol. 1 After dispersing 20 parts of kaolin in this solution, 59 parts m" of high-quality paper was coated with a coating rod on a 5097 m" high-quality paper. The color developer sheet of the present invention was obtained by coating and drying so as to coat a solid content of .

Example 2 40 parts of the color developer shown in Table 1 and 6 parts of the naphthalene sulfonic acid formalin condensate were ball milled for 1 day together with 54 parts of water.

Next, 100 parts of the dispersion of this dimer, 160 parts of kaolin, and 80 parts of styrene-butadiene copolymer latex (solid content concentration 50%) as a binder were added to 500 parts of water and mixed with thorough stirring. It was made into a coating liquid.

Apply this coating solution to 50 ji / tn” base paper.
/m'' solid content was coated using a coating rod and dried to obtain a color developer sheet of the present invention.

Comparative Examples 1 to 2 A developer sheet was obtained in the same manner as in Example 1 except that the compounds shown in Table 1 were used.

Comparative Examples 3 to 4 Color developer sheets were obtained in the same manner as in Example 2 except that the compounds shown in Table 1 were used.

Table 1 shows the performance of the developer sheets of actual cases and comparative examples.

Test Method The color developing sheets obtained in the above Examples and Comparative Examples were tested for performance using the following method.

Color developing ability: Layering the color developing sheet and the capsule sheet containing the crystal violet lactone mentioned above,
Color was developed under pressure at 600 kg/crtt, and after standing in a dark place for one day, the concentration of 610 mμ was measured using a Toshiba Beckman DB spectrophotometer.

Lightfastness: The colored body obtained in the same manner as above was irradiated with sunlight ☆★ for 1 hour, and then the density was measured, and the lightfastness value was calculated using the following formula.

Moisture resistance: Recording sheet at RH90φ, 50℃,
After standing in the atmosphere for 20 hours, the coloring operation was carried out using the method described above, the density was measured, and the moisture resistance value was calculated using the following formula.

As is clear from the results in Table 1, it can be seen that the color developer sheet of the present invention has excellent color developing ability, light resistance, and moisture resistance.

That is, compared to the case where an alkenylphenol dimer or an aromatic carboxylic acid metal salt is used alone as a color developer, when both are used in combination, color developer ability, light resistance, and moisture resistance are greatly improved.

From the above results, it can be said that the color developer sheet of the present invention is extremely useful.

Claims (1)

[Scope of Claims] 1. A color developer layer that forms a color image by contacting a color former is provided on a support, and the color developer layer is represented by the general formula [I] as a color developer. A recording sheet comprising a dimer of a compound and a metal salt of an aromatic carboxylic acid. (Here, an alkyl group. R1+ R2t R3 each represents a hydrogen atom, an aryl group, or an aralkyl group, and n represents an integer from 1 to 4.)