JPH0796660A - Color developing sheet for pressure-sensitive recording - Google Patents

Abstract

PURPOSE:To obtain the color developing sheet enhanced in color forming properties and preservability by adding at least one kind of a metal salt of a specific salicylic acid derivative and at least one kind of an a-olefin oligomer. CONSTITUTION:In a copy sheet utilizing the color forming reaction of an electron donating color former and an electron acceptive developer, at least one kind of a metal salt of a salicylic acid derivative represented by general formula (wherein R1 is an isononyl group or an isodecyl group and R2 is an alkyl group or cycloalkyl group which may have a substituent) and at least one kind of an alpha-olefin oligomer are added. As nuclear substituted salicylic acid, 3isononyl-5- methoxysalicylic acid, 3-isononyl-5-ethoxysalicylic acid, 3-isononyl-5-(2- methoxyethoxy)salicylic acid and 3-isononyl-5-(2-ethoxyethoxy)salicylic acid are designated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive recording material, and more particularly to a pressure-sensitive recording color-developing sheet having improved color developability and storability.

[0002]

2. Description of the Related Art Pressure-sensitive copying sheets (so-called carbonless sheets) include electron-donating color formers (hereinafter referred to as color formers) such as crystal violet lactone and benzoyl leuco methylene blue, and activated clay, bentonite, phenolic resins, aromatic carbons. A copy sheet that utilizes the color-developing reaction of an electron-accepting developer such as polyvalent metal salt of acid (hereinafter referred to as "developing agent"). An upper sheet in which the obtained color-forming agent-containing microcapsules are applied to the back surface of the support, and a lower sheet in which a color developer is applied to the front surface of the support are overlapped so that the respective application surfaces face each other, and the upper sheet Is a copy sheet for forming a colored image on a lower sheet by pressure-printing the surface of the sheet with a writing or typewriter.

When a large number of copies are desired, the intermediate sheet having the developer coated on the surface of the support and the microcapsules coated on the back surface is placed between the upper sheet and the lower sheet. Only the necessary number is inserted. A so-called self-coloring sheet in which the above-mentioned microcapsules and a color developer are formed on the same surface of a support as a laminated or mixed layer is also well known as one form of the pressure-sensitive copying sheet. The demand for pressure-sensitive copying sheets has expanded remarkably in a wide variety of areas, centering on general vouchers, delivery vouchers, unified vouchers, contract documents, computer sheets, etc., as their applications have expanded.

By the way, in recent years, the color development used for a pressure-sensitive recording material for the purpose of improving color density and color developing speed, improving light resistance of a color image, and improving various resistance under various use conditions. The drug is being studied,
Various proposals have been made. For example, Japanese Patent Laid-Open No. 4-267
Japanese Patent Publication No. 182 proposes a method in which an α-olefin oligomer is used in combination for the purpose of improving the coloring density and the coloring speed of an aralkylsalicylic acid derivative such as 3,5-bis (α-methylbenzyl) salicylate. . However, the coloring density and the coloring speed obtained by such combined use are not always sufficiently satisfactory, and the water resistance of the white paper part and the light resistance of the white paper part and the color image are not sufficient, and further improvement is required. Has been done.

[0005]

In view of the above situation, the present inventors have been keen on a color-developing sheet for pressure-sensitive recording which can be sufficiently satisfied not only in color density and color development speed but also in water resistance and light resistance. As a result of repeated studies, when an α-olefin oligomer is used in combination with a metal salt of a specific salicylic acid derivative,
It was found that a target color developing sheet can be obtained, and the present invention has been completed.

[0006]

The present invention is characterized by containing at least one metal salt of a salicylic acid derivative represented by the following general formula [Chemical formula 1] and at least one α-olefin oligomer. Is a color-developing sheet for pressure-sensitive recording.

[0007]

[Chemical 1]

[In the formula, R ₁ represents an isononyl group or an isododecyl group, and R ₂ represents an alkyl group or a cycloalkyl group which may have a substituent. ]

[0009]

In the above general formula [Chemical Formula 1], R ₁ represents an isononyl group or an isododecyl group. Such an isononyl group is a group which can be considered to be produced by nuclear substitution of a propylene trimer (isononene). Is defined as a group that can be considered to be produced by nuclear substitution of propylene tetramer (isododecene).

R ₂ represents an alkyl group or a cycloalkyl group which may have a substituent, and when the alkyl group or the like has a substituent, preferred examples of the substituent are:
Examples thereof include an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an arylsulfonyl group which may have a substituent, and an aryl group which may have a substituent. . Preferable specific examples of R ₂ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, secondary butyl group, amyl group, isoamyl group, hexyl group, octyl group, isooctyl group, 2-ethylhexyl group. , 2-methoxyethyl group, 2
-Ethoxyethyl group, 2-isopropoxyethyl group, 2
-Butyloxyethyl group, 2-isobutyloxyethyl group, 2-phenoxyethyl group, 2- (4-methoxyphenoxy) ethyl group, 1-methyl-2-methoxyethyl group, 1-methyl-2-ethoxyethyl group, 1-methyl-
2-phenoxyethyl group, 3-phenoxypropyl group,
3- (4-methoxyphenoxy) propyl group, 3-phenylsulfonylpropyl group, 3- (4-methylphenyl) sulfonylpropyl group, 3-methoxybutyl group, 4
-Methoxybutyl group, 4-ethoxybutyl group, 2- (2
-Methoxyethoxy) ethyl group, 2- (2-ethoxyethoxy) ethyl group, benzyl group, 4-methylbenzyl group, 2-phenylethyl group, cyclohexyl group and the like.

Preferred specific examples of the nucleus-substituted salicylic acid represented by the general formula [Chemical Formula 1] include all combinations of preferred examples of R ₁ and R ₂ , but more preferred specific examples are 3 -Isononyl-5-methoxysalicylic acid, 3-isononyl-5-ethoxysalicylic acid, 3-
Isononyl-5-isopropoxysalicylic acid, 3-isononyl-5- (2-methoxyethoxy) salicylic acid, 3
-Isononyl-5- (2-ethoxyethoxy) salicylic acid, 3-isononyl-5- (2-phenoxyethoxy)
Salicylic acid, 3-isononyl-5- [2- (4-methoxyphenoxy) ethoxy] salicylic acid, 3-isononyl-5-cyclohexyloxysalicylic acid, 3-isododecyl-5-methoxysalicylic acid, 3-isododecyl-5.
-Ethoxysalicylic acid, and 3-isododecyl-5-
Includes cyclohexyloxysalicylic acid

In the present invention, the metal salt of the salicylic acid derivative is preferably a zinc salt, an aluminum salt, a magnesium salt, a calcium salt, a sodium salt, a nickel salt or the like, and particularly preferably a zinc salt.

Specific examples of the α-olefin oligomer used in the present invention include, for example, 1-octene oligomer, 1-decene oligomer, 1-dodecene oligomer, 1-tetradecene oligomer, 1-hexadecene oligomer, Examples include 1-octadecene oligomers, oligomers of a mixture of several kinds of α-olefins, and hydrogenated products thereof. Among these α-olefin oligomers, those having a molecular weight of 400 or more are preferable, and oligomers having a molecular weight of 450 or more are particularly preferable. The α-olefin oligomer is preferably liquid at room temperature.

The amount of the α-olefin oligomer used is not particularly limited, but is 5 to 200% by weight, preferably 5 to 200% by weight, based on the metal salt of the salicylic acid derivative represented by the general formula [Chemical Formula 1]. It is desirable to adjust the content to be in the range of 10 to 150% by weight.

In the present invention, the metal salt of the above specific salicylic acid derivative is used as the color developer, but other known color developer such as phenol derivative, salicylic acid derivative, aromatic carboxylic acid may be used as required. The metal salts, acid clay, bentonite, novolac resins, metal-treated novolac resins, metal complexes and the like can also be used in combination. In the pressure-sensitive recording color developing sheet of the present invention, the amount of the color developing agent used is 50 to 3000% by weight, preferably 100 to 2000% by weight of the electron donating colorless dye.

In the present invention, the method for mixing the color developer and the α-olefin oligomer is not particularly limited. For example, both are dissolved in an organic solvent and an aqueous medium containing a water-soluble polymer or the like is used. There are a method of emulsifying and dispersing, a method of separately emulsifying and dispersing them in an aqueous medium containing a water-soluble polymer, and a method of further dispersing both in a solid state and then mixing. Among these, a method in which both are dissolved in an organic solvent and emulsified and dispersed in an aqueous medium containing a water-soluble polymer or the like is preferable, and in particular, an organic dispersion is prepared by heating an aqueous dispersion of the developer. A more preferable method is a method in which the developer composition is removed by distillation, prepared as an aqueous dispersion of a developer composition consisting of spherical particles, and subjected to atomization treatment with a sand mill or the like, if necessary.

The organic solvent used for emulsifying and dispersing the color developer and the α-olefin oligomer has a boiling point of 200.
Halogenated hydrocarbons, aromatic hydrocarbons, esters, ketones, ethers, amides and nitriles having a temperature of not higher than 0 ° C. are preferable. Among them, the solubility in water at room temperature is 5
The following are more preferable. Specific examples of the organic solvent include chloroform, methyl chloroform, benzene, toluene, xylene, chlorobenzene, ethyl acetate, butyl acetate, isopropyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and dimethyl acetamide. Further, as the water-soluble polymer used in the emulsification, polyvinyl alcohol, maleic anhydride-isobutylene copolymer, carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylamide, polyacrylic acid, acrylamide-alkyl acrylate copolymer, ether-modified polyvinyl alcohol , Polyvinylpyrrolidone, starch, casein, gum arabic, gelatin, and other synthetic or natural polymers.

The aqueous dispersion of the developer composition thus obtained is usually used as an adhesive, for example, starch, casein,
Gum arabic, carboxymethyl cellulose, polyvinyl alcohol, styrene-butadiene copolymer latex, vinyl acetate latex, etc. are blended to form a developer layer coating liquid. Inorganic pigments such as zinc, magnesium oxide, titanium oxide, aluminum hydroxide, calcium carbonate, magnesium sulfate, and calcium sulfate, and various auxiliaries known in the field of manufacturing pressure-sensitive recording materials can be appropriately added.

The method of applying the coating liquid is not particularly limited, and for example, an on-machine or off-machine coater equipped with an appropriate coating device such as an air knife coater, roll coater, blade coater, rod coater, curtain coater, paper,
It is coated and dried on a support such as a plastic sheet, synthetic paper, resin coated paper, etc. so that the dry weight is about ² to 10 g / m ² .

The color-developing agent sheet used in combination with the color-developing sheet of the present invention is generally a solvent (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkyl), which may be used alone or in combination with an electron-donating colorless dye. Terphenyl, chlorinated paraffin, and other synthetic oils: cotton oil, castor oil, and other vegetable oils: animal oils: mineral oils, as well as mixtures of these), and dissolve them in microcapsules to make paper or plastic sheets. It is prepared by a method of coating and drying a support such as synthetic paper or resin coated paper.

Examples of such electron-donating colorless dyes include triphenylmethanephthalide compounds, fluorane compounds,
Phenothiazine compounds, indolylphthalide compounds, leuco auramine compounds, rhodamine lactam compounds,
Various known compounds such as triphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds can be used. The microencapsulation method can also be appropriately selected from the coacervation method, the interfacial polymerization method, the in-situ method, and the like.

The color-developing sheet of the present invention is not limited to a so-called upper sheet, but it is a color-developing layer or a color-developing layer of a medium-color sheet or a mixed layer type or laminated type self-coloring sheet. It also includes layers.

[0023]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Parts and% in the examples mean parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 [Preparation of color developer dispersion] 100 g of a zinc salt of 3-isododecyl-5-methoxysalicylic acid and 25 g of an α-olefin oligomer (Lipoloop 60: manufactured by Lion) are mixed with 100 g of toluene at 70 ° C. A toluene solution was prepared by dissolving. Separately, 300 g of water containing 6 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98% is used as an internal volume of 1000
Into a cc stainless steel beaker, the above toluene solution was added to a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) with stirring at 3000 rpm. At the end of adding the toluene solution, the rotation speed is 10,000 per minute.
Rotate to stir for 2 minutes, then stir the dispersion.
The mixture was transferred to a hard glass three-necked flask having an internal volume of 1000 cc equipped with a thermometer and a distillation port. The flask was heated while slowly rotating the stirrer so that toluene and water were distilled from the distillation port. When this operation was continued at 100 ° C. for about 1 hour, the dispersion liquid contained almost no toluene. This was cooled to obtain an aqueous dispersion containing about 32% of the color developer. The average particle size of the resulting developer-dispersed particles was 0.9 μm. Next, this aqueous dispersion was treated with a sand grinder (MODEL NO.OSG-8G, manufactured by Igarashi Kikai Co., Ltd.) under the condition of 2 Kg / min to prepare an aqueous dispersion of a developer having an average particle size of 0.87μ. did.

[Preparation of developer coating liquid] 16 parts of the 32% aqueous developer dispersion obtained above, 85 parts of calcium carbonate, 10 parts of zinc oxide, and 100 parts of water are mixed and dispersed, and 10 parts of a binder is further added. % Aqueous solution of polyvinyl alcohol, 50 parts of 50% carboxy-modified SBR latex (trade name: SN-307, manufactured by Sumitomo Dow), and 200 parts of water were mixed and dispersed to prepare a developer coating solution.

[Production of lower paper] 40 g of the above-mentioned developer coating liquid
/ M ² of the base paper was coated and dried with an air knife coater so that the dry weight was 5 g / m ^2, and further calendered to prepare a pressure-sensitive recording lower paper.

[Preparation of Microcapsule Dispersion] In a stirring and mixing container equipped with a heating device, 150 parts of a 3% aqueous solution of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was added to prepare an aqueous medium for capsule preparation. And Separately, 100 parts of alkyldiphenylethane and 3- (4
-Diethylamino-2-ethoxyphenyl) -3- (1
-Ethyl-2-methylindol-3-yl) phthalide 2 parts and 3,3-bis (p-dimethylaminophenyl)-
Dissolve 3 parts of 6-dimethylaminophthalide, and further 2 parts of hexamethylene diisocyanate trimer (trade name: Sumidule N-3200, manufactured by Sumitomo Bayer) and polymethylene polyphenyl isocyanate (trade name: Millionate MR40).
(0, manufactured by Nippon Polyurethane Industry Co., Ltd.) A solution obtained by dissolving 5 parts is used as a capsule core substance in the above-mentioned aqueous medium for capsule preparation using a TK homomixer at 10000 rpm for 1 minute.
It was emulsified and dispersed for a minute. 1 part of diethylenetriamine was added to this emulsified dispersion, and the mixture was stirred at room temperature for 30 minutes, then the temperature of the system was raised to 70 ° C., and the reaction was continued for 3 hours while continuing stirring. The temperature was lowered to room temperature to prepare a polyurea resin / polyurethane resin wall membrane capsule having an average particle diameter of 5.5μ.

[Preparation of microcapsule coating liquid] To 100 parts of the above-mentioned microcapsule dispersion (solid content), 80 parts of wheat starch granules and 15 parts of carboxy-modified SBR latex (solid content) were added to bring the solid content concentration to 20%. A microcapsule coating solution was obtained by preparing the above.

[Production of Medium Paper] The above microcapsule coating liquid was applied to the opposite surface of the lower paper with an air knife coater so as to have a dry weight of 3 g / m ² and dried to obtain an intermediate paper for pressure-sensitive recording. .

Example 2 In Example 1, instead of 25 parts of an α-olefin oligomer (Lipoloop 60: manufactured by Lion), an α-olefin oligomer (Lipoloop 40: manufactured by Lion) was used.
An aqueous dispersion containing about 32% of a color developer was obtained in the same manner as in Example 1 except that 25 parts was used. The average particle size of the developer-dispersed particles after the sand grinder treatment was 1.0 μm. Thereafter, a pressure-sensitive recording medium paper was obtained in the same manner as in Example 1.

Comparative Example 1 In the same manner as in Example 1 except that 25 parts of toluene was used in place of 25 parts of the oligomer of α-olefin (Lipoloop 60: manufactured by Lion), a developer of about 32 was used. An aqueous dispersion containing 10% was obtained. The average particle size of the developer dispersion particles after the sand grinder treatment was 1.1 μm. Thereafter, a pressure-sensitive recording medium paper was obtained in the same manner as in Example 1.

Comparative Example 2 In Example 1, 2,2 'was used in place of 25 parts of the oligomer of α-olefin (Lipoloop 60: manufactured by Lion).
-Methylenebis (4-methyl-6-tert-butylphenol) in the same manner as in Example 1 except that 25 parts were used.
An aqueous dispersion was obtained containing about 32% developer. The average particle diameter of the developer dispersion particles after the sand grinder treatment is 0.9.
It was μ. Thereafter, a pressure-sensitive recording medium paper was obtained in the same manner as in Example 1.

Comparative Example 3 In Example 1, instead of 25 parts of an oligomer of α-olefin (Lipoloop 60: manufactured by Lion Corporation), triethylene glycol-bis [3- (3-tert-butyl-5-] was used.
Methyl-4-hydroxyphenyl) propionate] 2
An aqueous dispersion containing about 32% of a color developer was obtained in the same manner as in Example 1 except that 5 parts were used. The average particle size of the developer-dispersed particles after the sand grinder treatment was 1.0 μm. Thereafter, a pressure-sensitive recording medium paper was obtained in the same manner as in Example 1.

Comparative Example 4 In Example 1, 3,5-bis (α) was used instead of 100 g of the zinc salt of 3-isododecyl-5-methoxysalicylic acid.
An aqueous dispersion containing approximately 32% of a color developer was obtained in the same manner as in Example 1 except that 100 g of a zinc salt of -methylbenzyl) salicylic acid was used. The average particle size of the developer dispersion particles after the sand grinder treatment was 0.9 μm. Less than,
In the same manner as in Example 1, a pressure-sensitive recording medium paper was obtained.

The following six quality comparison tests were performed on the obtained six types of pressure-sensitive recording medium papers, and the results are shown in Table 1. [Coloring property] Two sheets of pressure-sensitive recording medium paper are prepared, set so that the color developing surface and the capsule surface face each other, and color is developed by a drop-type color tester (weight: 150 g, height: 20 cm). The color density one hour after the pressing was measured with a Macbeth reflection densitometer. (The larger the value, the better the color development.)

[Low-Temperature Coloring Property] Under the atmosphere of a temperature of 0 ° C., two prepared pressure-sensitive recording medium sheets were left for 10 hours. Under that condition, the developer surface and the capsule surface are set to face each other, and the color is developed by a drop-type color tester (weight: 200 g, height: 20 cm), and the color is developed 10 seconds and 3 minutes after the pressing. The density was measured with a Macbeth reflection densitometer.
(The higher the value, the better the low temperature color development.)

[Light resistance (coloring part)] Two pressure sensitive recording medium papers were prepared and set so that the color developing surface and the capsule surface face each other, and a drop type color tester (weight: 150 g, height :
(20 cm), and the color density one hour after the pressing is measured with a Macbeth reflection densitometer (D ₁ ), and then the color developing surface is exposed to sunlight for 5 hours, and then the color density is measured again ( D ₂ ) and the light resistance (color-developed portion) were determined by the following formula.
(The closer the value is to 100, the better the light resistance (coloring part).) Light resistance (coloring part) = (D ₂ / D ₁ ) × 100

[Light resistance (blank paper part)] After exposing the developing surface of the pressure-sensitive recording medium paper to sunlight for 5 hours, the developing surface and the capsule surface are set to face each other, and a drop-type color tester is used. (Weight: 150 g, height: 20 cm) The color was developed, and the color density one hour after the pressing was measured with a Macbeth reflection densitometer (D ₃ ), and the light resistance (white paper part) was determined by the following formula.
(The closer the value is to 100, the better the light resistance (white paper part).) Light resistance (white paper part) = (D ₃ / D ₁ ) × 100

[0039]

[Table 1]

[0040]

As is clear from Table 1, the pressure-sensitive recording color developing sheet of the present invention has excellent color density and color developing rate at both room temperature and low temperature, and also has excellent light resistance. It was a colored sheet.

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[Procedure amendment]

[Submission date] October 4, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

By the way, in recent years, the color development used for a pressure-sensitive recording material for the purpose of improving color density and color developing speed, improving light resistance of a color image, and improving various resistance under various use conditions. The drug is being studied,
Various proposals have been made. For example, Japanese Patent Laid-Open No. 4-267
Japanese Patent Publication No. 182 proposes a method in which an α-olefin oligomer is used in combination for the purpose of improving the coloring density and the coloring speed of an aralkylsalicylic acid derivative such as 3,5-bis (α-methylbenzyl) salicylate. . However, color density and color development speed obtained by such combined use is not intended be satisfied necessarily sufficiently, also the water resistance and the colored image, rather than light fastness of blank portions and color image is also sufficient, further improvement is requested Has been done.

Claims (3)

[Claims] 1. A pressure-sensitive recording color-developing sheet containing at least one metal salt of a salicylic acid derivative represented by the following general formula [Chemical formula 1] and at least one oligomer of an α-olefin. . [Chemical 1] [In the formula, R ₁ represents an isononyl group or an isododecyl group, and R ₂ represents an alkyl group or a cycloalkyl group which may have a substituent. ] 2. A salicylic acid derivative represented by the general formula [Chemical Formula 1] is 3-isononyl-5-methoxysalicylic acid, 3-
Isononyl-5-ethoxysalicylic acid, 3-isononyl-5-isopropoxysalicylic acid, 3-isononyl-5
-(2-Methoxyethoxy) salicylic acid, 3-isononyl-5- (2-ethoxyethoxy) salicylic acid, 3-isononyl-5- (2-phenoxyethoxy) salicylic acid, 3-isononyl-5- [2- (4-methoxy Phenoxy) ethoxy] salicylic acid, 3-isononyl-5-cyclohexyloxysalicylic acid, 3-isododecyl-5
The color-developing sheet for pressure-sensitive recording according to claim 1, which is at least one selected from the group consisting of -methoxysalicylic acid, 3-isododecyl-5-ethoxysalicylic acid, and 3-isododecyl-5-cyclohexyloxysalicylic acid. 3. The α-olefin oligomer has a molecular weight of 4
The pressure-sensitive recording color-developing sheet according to claim 1, which is at least 00.