JPH01259983A - Iron chelate recording sheet - Google Patents

Abstract

PURPOSE:To improve coloring properties without decreasing whiteness by employing basic white pigment by incorporating it in advance in a base material for printing. CONSTITUTION:After basic white pigment is contained in advance in and/or on a base material, it is coated with iron (III) compound containing nonaqueous ink. The iron compound preferably includes organic phosphorus compound containing P-O...Fe<3+> and/or P-S...Fe<3+> bond. The pigment preferably includes calcium carbonate and particularly soft calcium carbonate. Thus, a recording sheet having preferable coloring properties and whiteness can be obtained.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a recording sheet that utilizes a coloring reaction caused by the formation of a complex between a ligand compound and an iron (m) compound, and particularly relates to a recording sheet that can be obtained by printing. This invention relates to a recording sheet with excellent color development.

"Conventional technology" From the combination of electron-donating color formers such as crystal violet lactone and benzoyl leucomethylene blue and electron-accepting color developers such as activated clay, phenol resin, and polyvalent metal salts of aromatic carboxylic acids. Leuco-based recording materials are well known. In these recording media, a clear colored image can be obtained on a relatively white recording layer, but the colored image has poor light resistance and the color tone tends to change. In addition, there was a defect that the colored image faded due to line markers, cellophane tape, etc., so it could not be used for important documents.

Therefore, in order to eliminate the above-mentioned defects, various chelate-based recording materials that utilize a color-forming reaction caused by complex formation between a ligand compound and a metal compound have been studied, and these materials have been developed to improve the light resistance of colored images and the change in color tone over time. Efforts are being made. The present inventors also developed an iron chelate recording material that obtains a colored image by the reaction of a specific organic iron (III) compound with a ligand compound, and previously published Japanese Patent Application Laid-open Nos. 58-38191 and 59-38.
No. 088, No. 59-46126, No. 59-64386
No. 59-79790, etc. but,
Although these iron chelate recording materials are superior to leuco recording materials in terms of light resistance and plasticizer resistance, it is difficult to obtain recording sheets containing iron (I[[) compounds by printing. In this case, there is still room for improvement regarding its performance.

"Problem to be Solved by the Invention" That is, a recording sheet obtained by printing a non-aqueous ink containing an iron (III) compound on a support has better color development and sheet strength than a recording sheet coated with an aqueous coating liquid. It had the disadvantage of poor whiteness. Therefore, as a result of intensive research to improve these difficulties, the inventors discovered that a recording sheet with good color development and whiteness could be obtained by using a specific support as printing paper, leading to the completion of the present invention. .

"Means for Solving the Problems" The present invention is characterized in that a basic white pigment is contained in and/or on the base material, and a non-aqueous ink containing an iron (I[) compound is further applied. This is an iron chelate recording sheet.

In other words, the gist of the present invention is to provide a basic white pigment that improves color development when added to an ink, but cannot be used in large quantities in an ink because iron (I[I) compounds tend to cause coloration. It has been discovered that by pre-containing a base material and using it for printing, it is possible to obtain a recording sheet that exhibits excellent color development without reducing its whiteness.

"Action".

The iron (III) compounds used in the present invention include: (1) organophosphorus compounds having P-OH and/or P-SH bonds, (2) carboxylic acids, thio acids, dithio acids, (5) 5-O
Examples include single or composite iron salts or mixed iron salts of organic sulfur compounds having H bonds, and siloxane compounds such as polyferrophenylmethylsiloxane.

Among them, P −'O...Fe'+ and/or P −S
An organic phosphorus compound having an Fe'' bond is preferable because it is pale in color and exhibits good color development.

Examples of the organic phosphorus compound having a P-OH and/or P-8H bond used in the present invention include the following general formula (
Compounds represented by I) to (X■) can be mentioned.

Rt Rt -P-XIH(I) RaX+ P XaH(ff) X+Rs RbXz P-XsH(III) ■ z H XIH Rq X z -P -X x H(Vl )X s
HX z H RItXz -P -XaH(IX)3H XsRra XzRIbX Sumire RI? -P X z H(X n )X, HX
6H Rza COOP X 3 Rts
(X V )X, H X+ lI Rz h COOP -X s H(X VI )X,
H RztXz -P NHRzs
(X■)X, H 3H [In the formula, X+, Xz+Xs, Xs, Xs, X6. X? each represents an oxygen atom or a sulfur atom, and each of R+ to R3 represents an alkyl group or an aryl group. ] R1””R1! The alkyl group represented by includes saturated and unsaturated substituted and unsubstituted alkyl groups, and may be any of a straight-chain alkyl group, a branched alkyl group, and a cycloalkyl group. Preferably, the number of carbon atoms is in the range of 1 to 20, excluding the carbon atoms in the group part, and the aryl group represented by R8-R29 includes both unsubstituted aryl groups and substituted aryl groups. and the number of carbon atoms excluding the carbon atoms in the substituent part is 6 to 6
14 is preferable, and specific examples thereof include phenyl group, naphthyl group, and anthryl group.

In addition, R, and Rz, R3 and R,, Rs and R4, RI3
and R14SRIS and R1 &, R1? and R11 and RI9
and R2゜, alkyl or aryl groups attached to the same phosphorus atom directly or via an oxygen or sulfur atom may be bonded to each other to form a 5- or 6-membered ring, and if the group is aryl In the case of groups, they may be bonded at different positions of the same aromatic ring to form a 5- or 6-membered ring.

The carboxylic acid, thioic acid, and dithioic acid used in the present invention have the following general formula (XIX), where X and Y represent an oxygen atom or a sulfur atom. [Specific examples of the alkyl group or aryl group represented by R include the same saturated and unsaturated substituted and unsubstituted alkyl groups and substituted and unsubstituted aryl groups as exemplified in R0 to R19 of the above-mentioned organic phosphorus compounds. can be mentioned.

Examples of organic sulfur compounds having a 5-OH bond include sulfonic acid, sulfinic acid, sulfuric acid ester, etc., but specific examples include benzenesulfonic acid, alkylbenzenesulfonic acid, naphthalenesulfonic acid, alkylnaphthalenesulfonic acid, and polystyrene. Sulfonic acid, dialkyl sulfosuccinic acid, alkylbenzenesulfinic acid,
Examples include alkyl sulfate esters.

Furthermore, for the purpose of changing the color tone of a colored image, for example, Ti4° is added to the organic iron (III) salt as described above.

Fe Z k , Co t *, N 1 t +
It is also possible to use other metal salts having metal ions such as , Cu t ” in the form of complex or mixed salts with organic iron(III) salts.

The iron (III) compound-containing non-aqueous ink used in the present invention is prepared by dispersing or dissolving the iron (ml) compound as described above in a non-aqueous medium, and further adding resin, pigment, ultraviolet absorber, and antioxidant as necessary. It is prepared by adding fluorescent dyes, colored dyes, photopolymerization initiators, waxes, dryers, thickeners, gelling agents, ligand capsules, capsule protectants, etc.

The blending amount of the iron (I [ The amount is more preferably 10 to 100 parts by weight.

Incidentally, if the amount is less than 5 parts by weight, the coloring property is poor, and if it exceeds 200 parts by weight, the printability is poor. ' As the printing method used in the present invention, methods known in the art such as letterpress printing, intaglio (gravure) printing, lithographic (offset) printing, and screen printing are appropriately used, but the ease of preparing the printing ink Alternatively, flexographic printing is particularly preferred in terms of color development.

As the non-aqueous medium used in the present invention, those known in the printing industry can be used as appropriate, but specific examples include benzene, toluene, xylene, cyclohexane, hexane, ligroin, methyl isobutyl ketone, methyl acetate. , ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monobutyl ether, diethylene glycol motsubutyl ether acetate, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-7'tanol, n-hexanol, cyclohexanol, 2-ethylhexyl alcohol, polyethylene glycol diacrylate, propylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, hexanediol diacrylate, 1,2-butanediol diacrylate , reaction product of epoxy resin and acrylic acid, reaction product of methacrylic acid, pentaerythritol and acrylic acid, condensation product of maleic acid, diethylene glycol and acrylic acid, methyl methacrylate, butyl methacrylate, styrene, vegetable oil (linseed oil, drying oil such as flower oil, semi-drying oil such as soybean oil, non-drying oil such as castor oil), processed oil (dehydrated castor oil, polymerized oil, maleated oil, vinylated oil, urethanized oil), mineral oil (machine oil, Spindle oil) and the like are used to prepare evaporative drying type, radiation curing type, oxidative polymerization type inks, etc. Among these, in the case of flexographic printing, media containing alcohol as a main component are particularly preferred in terms of ease of handling.

Specific examples of the resin include rosin (gum rosin, wood rosin, tall oil rosin), natural resins such as shellac, copal, dalman, giltnite, and zein, hardened rosin, ester gum and other rosin esters, maleic acid resin, Fumaric acid resin, duplex rosin, polymerized rosin,
Rosin-modified phenolic resin, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethylhuman waxyethylcellulose, carboxymethyl cellulose, cellulose acetate propionate, cellulose acetate butyrate,
Semi-synthetic resins such as nitrocellulose, phenolic resins, xylene resins, urea resins, melamine resins, ketone resins, coumaron/indene resins, petroleum resins, terpene resins, cyclized rubber, chlorinated rubber, alkyd resins, polyamide resins, acrylic resins, poly Vinyl chloride, vinyl chloride, vinyl acetate copolymer, polyvinyl acetate, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer Examples include synthetic resins such as polymers, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl butyral (butyral resin), polyvinylpyrrolidone, chlorinated polypropylene styrene resin, epoxy resin, and polyurethane.

These resins are appropriately selected5 depending on the type of non-aqueous medium to be used, etc., and the method disclosed in, for example, "Printing Ink Technology" CMC Co., Ltd. edition, etc., can be used as appropriate. Can be adopted.

Pigments include oxides, hydroxides, carbonates, sulfates, halogen compounds of aluminum, zinc, magnesium, calcium, titanium, etc., colloidal silica, acid clay, activated clay, attapulgite, zeolite, bentonite, kaolin, calcined kaolin, etc. clay, melamine resin,
Examples include organic pigments such as urea resins.

In the present invention, the support used for printing with the iron(III) compound-containing non-aqueous ink is a base white pigment containing a basic white pigment by internal addition, surface size, coating, etc., or a basic white pigment and polypropylene, polystyrene, etc. Synthetic paper obtained by stretching a mixture of synthetic resins, or a film whose surface is coated with a basic white pigment-containing paint, etc.
In particular, paper obtained by applying or applying a basic white pigment together with a binder and a dispersant is particularly preferred in terms of its effects.

The basic white pigment in the present invention is one in which the pH of the liquid prepared by dispersing or dissolving the pigment in water is 7 or more, and examples thereof include calcium hydroxide, magnesium hydroxide, sodium silicate, and silicic acid. Examples include potassium, calcium silicate, magnesium silicate, lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, magnesium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, magnesium hydroxide carbonate, and satin white.

Among these, calcium carbonate, especially light calcium carbonate, is a preferred pigment because it provides particularly excellent quality in terms of whiteness and color development.

In the present invention, it is also possible to use neutral or acidic pigments in addition to the above-mentioned basic white pigments, and specific examples include zinc oxide, titanium oxide, silica, acid clay, and the like.

Examples of the binder used when preparing a basic white pigment-containing coating solution include proteins such as gelatin, albumin, and casein, cereal starch, pregelatinized starch, oxidized starch,
Starches such as etherified starch and esterified starch, celluloses such as carboxymethylcellulose and hydroxyethylcellulose, water-soluble natural polymer compounds such as polysaccharides such as agar, sodium alginate, and gum arabic; polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid ,
Water-soluble synthetic polymer compounds such as polyacrylamide, maleic acid copolymer, etc.; styrene/butadiene latex, acrylonitrile/butadiene latex, acrylic ester latex, vinyl acetate latex, methyl methacrylate/butadiene latex, and these Latices such as carboxy-modified (e.g. acrylic acid) latex; polyester, polystyrene, chlorinated rubber, polyvinyl acetate, polyvinyl chloride, polybutadiene,
Acrylic acid ester, vinyl chloride/vinyl acetate copolymer, styrene/butadiene/acrylic acid copolymer, polyethylene, ethylene/vinyl acetate copolymer, styrene/acrylic acid copolymer, polyvinylidene chloride, vinylidene chloride/acrylic acid Examples include oil-soluble polymer compounds such as copolymers, phenol resins, urea/formalin resins, and melamine resins.

The basic white pigment-containing coating liquid is applied to paper, synthetic paper, or film, but the amount of application (coating amount) in that case is not particularly limited, and is usually in the range of 0.5 to 15 g/rrf. be. Note that the amount of iron (I[[) compound-containing non-aqueous ink to be applied to the support is not particularly limited, but
Usually 0.2-10g/rI? , more preferably 0.5~
It is about 5 g/rd.

There are no particular limitations on the ligand compound that forms a complex with the iron (III) compound and provides a colored image.
Examples include various ligand compounds and easily ion-exchangeable chelate compounds. Specifically, for example, di-n-butylammonium di-n-butyldithiocarbamate,
t-octylammonium, t-octyldithiocarbamate, stearyltrimethylammonium ethylene bisdithiocarbamate, dibenzothiazyl disulfide, toluene-3,4-dithiol, benzoylacetone, dibenzoylacetone, salicylic acid, 3,5-di(
α-methylbenzyl) salicylic acid, hydroxynaphthoic acid, naphthoic acid hydroxyethylamide, 2-hydroxy-1-natthaldehyde, trobolone, hinokitiol, methoxyhydroxyacetophenone, resorcinol,
t-butylcatechol, dihydroxybenzenesulfonic acid, gallic acid, ethyl gallate, propyl gallate, isoamyl gallate, octyl gallate, lauryl gallate, stearyl gallate, benzyl gallate, tannic acid, pyrogallol tannin, protocatechuic acid, Ethyl protocatechiate, pyrogallol-4-carboxylic acid, alizarin, N-nitrosonaphthylhydroxyamine ammonium salt, diphenylcarbazide, 8-hydroxyquinoline, dichloro-8-hydroxyquinoline, dibromo-8-hydroxyquinoline, chlorobromo-8-hydroxy Quinoline, methyl-8-hydroxyquinoline, butyl-8-hydroxyquinoline, lauryl-8-hydroxyquinoline, methylenebis(8-hydroxyquinoline)
, N-benzoyl-N-phenylhydroxylamine,
Salicylaldoxime, anthranilic acid, quinolinecarboxylic acid, nitrone naphthol, 2-mercaptoimidacillin, diphenylthiocarbazone, 6-nitoxy 2
．． 2.4-) trimethyl-1,2-dihydroquinoline,
6-phenyl-2,2,4-)dimethyl-1,2-dihydroquinoline, 6-zosil-2,2,4-trimethyl-
1,2-dihydroquinoline, 2-imidacyline, phenyl-α-naphthylamine, phenyl-β-naphthylamine, zinc butyl xanthate, zinc salicylate, 3,5
-Zinc di(α-methylbenzyl)salicylate and the like.

Specifically, the recording sheet of the present invention can be used as pressure-sensitive copying paper, heat-sensitive recording paper, electrically conductive heat-sensitive recording paper, etc., but the following describes the most typical form of use in pressure-sensitive copying paper. explain.

Pressure-sensitive copying papers are broadly divided into transfer type and single type, and transfer type pressure-sensitive copying papers include top paper (CB) in which a microcapsule layer containing a ligand compound is provided on the back side of the support.
Bottom paper (CF) in which a coloring layer containing an iron (III) compound is provided on the surface of the support, and inner paper in which the coloring layer and capsule layer are provided on separate sides of the support when multiple copies are desired. (C
FB) are used in appropriate combinations. In addition, in the case of a single pressure-sensitive copying paper, the microcapsules containing a ligand compound and the iron (I[I) compound are used as a laminate or a mixed layer on the same surface of the support. Furthermore, there is also a single pressure-sensitive copying paper set in which a capsule layer is provided on the back side of the single-piece pressure-sensitive copying paper, and the above-mentioned lower paper and upper paper are appropriately combined.

When a ligand compound is microencapsulated, if the material is liquid, it can be encapsulated as is, but generally the material is dispersed or dissolved in a hydrophobic medium to be microencapsulated.

As the hydrophobic medium, for example, various media already known in the field of pressure-sensitive copying paper can be appropriately selected and used, such as vegetable oils, mineral oils, aromatic hydrocarbons, alcohols, organic Acids, esters, organic phosphorus compounds, ethers, amides, ketones, carbonates, etc. are used.

Note that the microencapsulation method is appropriately selected depending on the properties of the recording material required, such as the conventionally known coacervation method, interfacial polymerization method, 1n-situ method, etc. However, in order to obtain pressure-sensitive copying paper with higher performance, it is preferable to use synthetic resin as the coating material.
When the wall is made of a melamine formaldehyde resin as described in Japanese Patent No. 84881, capsules with extremely excellent performance can be obtained.

Note that these microcapsules can also contain an antioxidant, an ultraviolet absorber, and an organic base, if necessary.

The microcapsules thus obtained may contain water-soluble or latex binders, capsule protectants, dispersants, antifoaming agents, preservatives, and fluorescence enhancers used in the field of ordinary pressure-sensitive copying paper, if necessary. A whitening agent, a colored dye, a pH adjuster, etc. are added as appropriate to prepare a microcapsule coating solution, which is coated on a support to form a CB surface.

Furthermore, a CF surface is formed by printing the non-aqueous ink containing an iron(III) compound on a basic white pigment-containing support to form a pressure-sensitive copying paper as described above. Furthermore, when the present invention is applied to recording sheets other than pressure-sensitive copying paper, such as thermal recording paper and current-carrying thermal recording paper, a ligand compound and iron (I Using the [[) compound and further adding various auxiliaries as necessary to form a non-aqueous ink, this is printed on a basic white pigment-containing support to obtain the desired recording sheet.

"Examples" In order to make the effects of the present invention even clearer, Examples and Comparative Examples are given below, but the present invention is not limited to these Examples. In addition, unless otherwise specified, parts and % in the examples indicate parts by weight and % by weight, respectively.

Example 1 <m> 20% of the sodium salt of U di(isopropylphenyl) phosphate in alcoholic ink
% solution, 270 parts of water and ferric chloride (FeC).
1s・6H! A solution containing 270 parts of O) was added with strong stirring to form a pale yellow salt, which was then suction filtered, washed and dried to obtain a fine powder.

Next, add ethyl cellulose No. to 20 parts of ethanol.

14 (manufactured by Vercules) and 100 parts of the above-mentioned iron salt powder were added, and an alcohol-based ink containing an iron (II) compound was obtained under strong stirring.

Voice: Fair-skinned person Contains: 160 parts of Gino's water, 2 parts of sodium polyacrylate, 90 parts of light calcium carbonate,
After adding 10 parts of titanium oxide and stirring and dispersing it vigorously, carboxy-modified styrene-butadiene copolymer latex 18
part (solid content), gelatinized starch 5 parts (solid content), phosphoric acid 2 parts (
Solid content) was added to obtain a coating liquid.

The obtained coating liquid was applied to a base paper of 40 g/ryf with a dry weight of 7 g.
/rd using an air knife coater to obtain a basic white pigment-containing support.

Next, the above iron (Il
IF) Compound-containing alcohol-based ink with ink coverage of 1
．． A base paper was prepared by flexographic printing to a weight of 5 g/rd.

An internal phase oil was obtained by heating and dissolving 20 parts of stearyl gallate in a mixed solution of 40 parts of diethyl adipate and 40 parts of di-n-butyl adipate. A 20% aqueous solution of caustic soda was added to 200 parts of a 3% aqueous solution of ethylene-maleic anhydride copolymer (trade name: EMA-31/manufactured by Monsanto) to adjust the pH.
This internal phase oil was emulsified in a liquid with a particle size of 4.8, and the average particle size was 15.
After cooling down to μ, raise the temperature of the system to 75°C.

Subsequently, 80 parts of a 50% melamine formaldehyde precondensation aqueous solution (trade name: Cymel 350, manufactured by Mitsui Toatsu Chemical Co., Ltd.) was added to this system, and the mixture was further emulsified at 75° C. to give an average particle size of 9 μm. Next, while stirring at 75°C,
．． After adjusting the pH to 3.8 by adding IN-sulfuric acid dropwise over 2 hours, the mixture was heated to 90° C. and kept at that temperature for 4 hours to obtain a milky white capsule dispersion.

Next, 50 parts of wheat starch powder, 30 parts of bulb powder, and 40 parts of carboxy-modified styrene-butadiene copolymer latex (solid content concentration 50%) were added and mixed to this dispersion so that the solid content concentration was 23%. Water was added to obtain a capsule coating solution. The obtained coating liquid was applied to a 40 g/- base paper using an air knife coater so that the dry weight was 6 g/rd to obtain a top paper.

The bottom sheet of the pressed paper had good whiteness, and when the top and bottom sheets were stacked and printed on with a typewriter, they showed good color development.

Comparative Example 1 An alcohol-based ink containing an iron (I [ I used flexographic printing to create the base paper.

When the upper paper prepared in the same manner as in Example 1 and the lower paper were overlapped and printed using a typewriter, the color development was considerably inferior to that in Example 1.

"Effect J As is clear from the examples, the pressure-sensitive copying paper obtained according to the present invention exhibited good whiteness and excellent colored images.

Claims (4)

[Claims] (1) In an iron chelate recording sheet obtained by coating a non-aqueous ink containing an iron (III) compound on a support, a basic white pigment is pre-contained in and/or on the support. An iron chelate record sheet featuring: (2) Claim in which the basic white pigment is calcium carbonate (
1) Iron chelate type recording sheet as described. (3) The iron chelate system according to claim (1), wherein the iron (III) compound is a compound having P-O...Fe^3^+ and/or P-S...Fe^3^+ bonds. Record sheet. (4) The iron chelate recording sheet according to claim 1, wherein the main medium of the iron (III) compound-containing nonaqueous ink is alcohol.