JPH02192988A - Thermosensitive recording medium and resin composition for thermosensitive recording medium overcoat - Google Patents

Abstract

PURPOSE:To use a basic material of synthetic resin, provide a highly glossy surface and ensure that no refuse settles, no sticking occurs and the wear of a thermal head and a thermal pen is minimized by using an active energy beam-curable resin composition in which inorganic particles are dispersed as a resin composition for an overcoat. CONSTITUTION:This thermosensitive recording medium consists of a thermosensitive coloring layer and an overcoat layer of an active energy beam- curable resin composition in which inorganic particles are dispersed arranged on a basic material of synthetic resin. The active energy beam-curable resin composition contains 0.01 to 25 parts by weight of inorganic particles with an oil absorption of 60ml/100g and an average particle diameter of 5mum or less per 100 parts by weight of the resin constituent. In addition, the composition contains 0.2 to 15 parts by weight of pigment with an oil absorption of 60 to 300ml/100g and an average particle diameter of 0.1 to 3mum per 100 parts by weight of the resin constituent.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermosensitive recording medium. Specifically, the present invention relates to a heat-sensitive recording medium having a high-gloss surface and provided on a synthetic resin base material having an overcoat layer and a heat-sensitive coloring layer made of a specific composition.

(Prior art) Thermal recording media, typified by thermal paper, are made by trapping a coloring agent such as a leuco compound and an acidic substance as a coloring agent separately, or using a coloring agent such as an organic acid metal or metal salt. An organic reducing agent, which is a coloring agent, is separately dispersed into fine particles in a medium of water or an organic solvent containing a water-soluble binder or an organic solvent-based binder, and the two are mixed to form paper 1 synthetic paper 1 synthetic paper. It is applied onto a base material such as a resin film. A specific example of such a thermosensitive recording medium is as follows.

For example, Japanese Patent Publication No. 44-3680, Japanese Patent Publication No. 45-14
It is disclosed in Japanese Patent Application Laid-Open No. 039, Japanese Patent Application Laid-open No. 17344/1983, and is well known. Since such heat-sensitive recording media are made by applying a dispersion of fine particles of several micrometers or less onto a base material and drying them, the surface is lined with fine particles of several micrometers or less and is uneven, resulting in low gloss. have. As a technique for obtaining a heat-sensitive recording medium with a high-gloss surface, there is a proposal to provide an intermediate I- layer with exceptional smoothness 1 m above the heat-sensitive recording medium, and then overcoat it with 'VC [child beam curing resin]. (Unexamined Japanese Patent Publication No. 59-26291,
tr! frs+ Publication No. 62-279980).

(Problem to be solved by the invention) However, when heating color by heat in or heat head.

The components of the heat-sensitive recording medium melt and stick to the heat head or heat 4, causing scum to adhere, reducing the density and sharpness of the colored image, and distorting the colored image.1 Inconvenient paper feeding or heat. There is a tendency to deteriorate the so-called head matching property, which causes wear of the head or the thermal pen.

In particular, heat-sensitive recording media with high-gloss surfaces made of synthetic paper or synthetic resin sheets have a smooth surface, so the thermal edge P
The contact area with is large! @The friction resistance increases and staking becomes more likely to occur. In addition, for some reason, dust may enter between the surface of the thermal recording medium and the thermal head.Since the surface of the recording medium is smooth, the dust cannot be removed and continuous VCf+) can easily be removed from the image. There is a problem with this.

(lLl! Means for solving the problem) In view of the current situation, a base material made of synthetic resin is used, which has a high gloss surface, is free from adhesion of residue and sticking, and is resistant to abrasion of thermal heads or thermal pens. As a result of intensive research with the aim of obtaining a heat-sensitive recording medium with slightly poor so-called head matching properties, we have developed a specific active energy ray-curable resin composition in which inorganic fine particles are dispersed as an overcoat resin composition. The inventors discovered that heat-sensitive recording media do not have the above-mentioned drawbacks even when they use a base material made of synthetic resin, which led to the completion of the present invention.

Namely, 1 the present invention provides 1 a heat-sensitive recording medium comprising a base material made of a synthetic resin and an overcoat layer of an active energy ray-curable resin composition in which heat-sensitive color forming I- and inorganic fine particles are dispersed; The present invention provides a resin composition for overcoating a heat-sensitive recording medium, which is characterized by containing an active energy ray-curable compound and inorganic fine particles.

In the present invention, the combination K of the coloring agent and the coloring agent contained in the thermosensitive coloring 1- is not limited in any way, as long as it is a combination that causes a coloring reaction when the two come into contact with each other due to heat. Any of these can be used; for example, a combination of a colorless or light-colored basic dye and an inorganic or organic acidic substance.

There are combinations of higher fatty acid metal salts such as ferric stearate and ;ff machine reducing agents such as gallic acid.

From the viewpoint of image clarity, a combination of a basic dye and an acidic substance is preferred.

Examples of colorless to light-colored basic dyes include triphenylmethane, triphenylmethanephthalide, fluoran, and leuco-auramine dyes.

Typical examples include diphenylmethane type, phenothiazine type, phenoxazine type, spiropyran type, indoline type, and indigo ring, among which fluorane type is preferred. Examples of inorganic or organic acidic substances that develop color upon contact with basic colorless dyes include 4,4'-isopropylidene phenol, 4-tert-butylphenol, 4-phenylphenol, and 4-hydroxydiphenoxide. , α-naphthol, β-naphthol, methyl-4-
Hydroxybenzoate, benzyl-4-hydroxybenzoate, 4'-hydroxyacetophenone, 4-tertiaryoctylcatechol, 2,2'-dihydroxydiphenyl, 2,2'-methylenebis(4-chlorophenol), 4,4'- Various phenolic substances such as secondary butylidene bis (2-methylphenol) and 4,4'-isopropylidene bis (2,6-cyphthylphenol), fatty acids such as benzoic acid, salicylic acid, tartaric acid, and gallic acid, aromatic Representative examples include carboxylic acids, with benzyl-4-hydroxybenzony) and 2,2'-dihydroxydiphenyl being preferred.

In the thermosensitive recording material of the present invention, the ratio of the color forming agent to the color forming agent in one color forming layer is appropriately selected depending on the color forming agent and color forming agent used. From 1 to 50 parts by weight, preferably from 1 to 10 parts by weight, of the acidic substance is used.

To prepare a coating solution containing these substances, the coloring agent and the coloring agent are generally dispersed together or separately using water as a dispersion medium and stirring or grinding using a mill, attritor sand grinder, etc. , as a coating liquid.

Such a coating liquid contains polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, and hydroxyethyl cellulose as binders.

Polyacrylic acid, casein, gelatin, starch.

Water-soluble binders such as polyvinylpyrrolidone, polyacrylamide and fatty conductors thereof are included.

In addition, in combination with these water-soluble binders, water-dispersible binders such as styrene-butadiene copolymer, vinyl acetate, and polyacrylic acid ester can also be used. These binders are used in an amount of 10-401F based on the total solid content, preferably 15 to 30% by weight.
Fluorescent dyes, N colorants, inorganic pigments, sensitizers, etc. can also be added.

In the heat-sensitive recording material of the present invention, the method of forming the recording I4 is not particularly limited, and can be formed according to conventionally well-known and commonly used techniques, such as air knife coating, pariper blade coating, pure It is formed by applying and drying a coating liquid f, such as blade coating or short dwell coating.

The amount of the Mayu coating liquid to be applied is not limited to 1:00, but it is usually in the range of 2 to 1217 m'', preferably 3 to 10117 m'' in terms of dry weight.

As the base material used in the present invention, in order to improve the gradation of the 1Li1I image, a paper or a film containing synthetic resin as a main component, such as synthetic paper or a synthetic resin film, is used.

Synthetic papers include synthetic resin films with paper-like appearance and physical properties, and synthetic fibers made by wet or dry processes. Among these, synthetic paper, in which 1 synthetic resin film is given paper-like appearance and physical properties, is particularly preferred.Manufacturing methods for such synthetic paper include coating the surface of 1 synthetic resin film with a white pigment, and 1 synthetic paper. There is a method of adding a filler or a foaming agent to a resin film to make it opaque, and any of these methods can be used as the base material of the present invention.

1. The synthetic resin film used as a base material in the present invention includes conventionally known synthetic resin films such as polyester films, polyolefin films, cellulose films, and polyamide films.

In the heat-sensitive recording medium of the present invention, an overcoat layer obtained by curing with active energy rays is provided on the surface of the heat-sensitive coloring layer thus obtained.

An intermediate layer may be provided in between. The coating material used for the intermediate layer may be any coating material that does not attack the heat-sensitive coloring layer, but generally a coating material whose main component is a water-based resin is used.

Examples of water-soluble resins used in the intermediate layer include, for example, completely saponified t7'h, partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, a reaction product of polyvinyl alcohol and a polyhydric carboxylic acid, or a reaction product of these. esterified products of, carboxy-modified polyvinyl alcohol, sulfonic acid-modified I-rivinyl alcohol, olefin v-based z-lipinyl alcohol, nitrile-modified yl? Rivinyl alcohol, amide modification? Rivinyl alcohol, male lolidone-modified polyvinyl alcohol, epoxy-modified polyvinyl alcohol; poly(meth)acrylamide, aldehyde-modified poly(meth)acrylamide, polystyrene-maleic anhydride copolymer, or 2 to an extent that does not impair water solubility. - Polymers copolymerized with hydroxyethyl (meth)acrylic acid ester, acrolein, N-vinylpyrrolidone, (meth)acrylonitrile, vinyl acetate, vinyl chloride, etc.; methylcellulose, ethylcellulose, hydroxyethylcellulose,
Cellulose derivatives such as carboxin methylcellulose; casein; gum arabic; water-soluble polymers such as starches 1 such as oxidized starch, etherified starch, dialdehyde starch, and esterified starch; and styrene-butanoene copolymer emulsions.

vinyl acetate-vinyl chloride-ethylene copolymer emul)
Examples include emulsions such as methacrylate-butadiene copolymer emulsion and methacrylate-butadiene copolymer emulsion.

Among these water-soluble resins, various modified vinyl alcohols, 4+7 vinyl alcohols, cellulose derivatives, and casein are preferred, and 4HC acetoacetylated polyvinyl alcohol, carboxy-modified polyvinyl alcohol, and epoxy-modified polyvinyl alcohol are more preferred.

There are no particular limitations on the amount of water-based resin used, but
The content in the total solid content of the coating liquid is usually 10 to 95i%
, preferably in the range of 15 to 90% by weight.

In addition, a pigment can be added to the intermediate layer 1 to increase the smoothness. Specific examples of pigments include calcium carbonate, aluminum oxide, and titanium dioxide.

Silicon dioxide, aluminum hydroxide, barium sulfate.

Examples include inorganic pigments such as zinc sulfate, talc, kaolin, clay, and calcined recolloidal silica, organic powders such as styrene microgale, nylon powder, polyethylene powder, urea/formalin resin filler, and raw starch granules. Regarding the usage amount of 7, generally the resin component 1
5-500 for 00 parts by weight! Part 80
It is preferable to mix in a range of about 4.1 parts by weight to 350 parts by weight.

Furthermore, glyoxal, methylolmelamine, potassium persulfate, ammonium persulfate, and sodium persulfate may be added to the coating solution forming the middle 1') I'I layer, if necessary.

Waterproofing agents such as ferric chloride, magnesium chloride, boric acid, ammonium chloride, etc. may be added, and if necessary, zinc stearate, calcium stearate, stearamide, polyethylene wax.

Carnauba wax, rough-in wax, ester wax and other lubricants, sodium dioctyl sulfosuccinate,
Sodium dodecylbenzenesulfonate, lauryl alcohol sulfate ester sodium salt, alginate,
Various auxiliary agents such as a surfactant such as a fatty acid metal salt, an ultraviolet absorber such as a benzophenone type or a triazole type, an antifoaming agent, and a fluorescent dye 5 coloring dye can also be added as appropriate.

The coating liquid that forms the intermediate layer is generally prepared as an aqueous coating liquid, and is mixed with a mixer or an attritor as necessary.
- The mixture is sufficiently mixed and dispersed using a mixing/stirring machine such as a lumill or a roll mill, and then coated onto the heat-sensitive recording layer using various known coating devices. After coating, it can also be dried by irradiating it with ultraviolet rays or electron beams.

In addition, when all of the curing agents are used together, the curing agent can be applied not only in the coating liquid forming the intermediate layer, but also separately from the coating liquid forming the intermediate layer. It has the advantage of being able to select a strong hardening agent without having to worry about the entire pot life.

The coating amount of the coating liquid forming intermediate 1- is not particularly limited, but if it is less than 0.117 m'', the desired effect of the present invention cannot be sufficiently obtained.

If the length exceeds 2017 m'', the recording sensitivity of the thermal recording medium may be significantly reduced, so the dry weight is generally 0.1 m.
~2017m", preferably o,s ~ioy/m
``It is desirable to adjust within a certain range.

The thermosensitive recording medium of the present invention has one or more intermediate layers formed in this manner. An overcoat layer obtained by curing with active energy rays is provided on the surface of the heat-sensitive coloring layer, which does not have any coating.
Also, since it is exposed to high temperatures, it requires abrasion resistance, toughness, and heat resistance. The resin composition for overcoating a heat-sensitive recording medium used to obtain such coating film performance contains an active energy ray-curable compound and inorganic fine particles. It contains a prepolymer as an essential component, preferably an active energy ray-curable reactive diluent (B), and optionally an active energy ray-curable /F'
Examples of the active energy ray-curable prepolymer compound mentioned here include (11 polyether (meth)acrylate). Specific examples of prepolymers include 1.2.6-hexanetriol/
Polyether (meth)acrylate synthesized from propylene oxide/acrylic acid, trimethylolpropane/ethylene oxide/methacrylic acid, trimethylolzolonoyan/clopylene oxide/acrylic acid, and intererythritol/ethylene oxide/acrylic acid; (2) Polyester ( Specific examples of meth)acrylate prepolymers include adipic acid/1.6-hexanediol/acrylic acid, co/% phosphoric acid/1,4-butasonol/acrylic acid, cono-phosphoric acid/trimethylolethane/acrylic acid. (3) Specific examples of polyol (meth)acrylate-based prepolymers include intertaerythritol pentaacrylate, pentaerythritol triacrylate, etc. Methacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexamethacrylate, 2,2-bis(4-acryloxyethoxyphenyl)pronotan, 2,2-bis(
4-acryloxyshedoxyphenyl) guronosin, 2
,2-bis(4-methacryloxyjethoxyphenyl)
7'.

/4' 7 , 2.2- (meth)acrylate or polyol (meth)acrylate such as 2-his(4-acryloxyethoxyphenyl) 7' o non; (4) Specific examples of epoxy (meth)acrylate-based prepoly are: Diglycidyl etherified bisphenol A/acrylic acid, diglycidyl etherified polybisphenol A/acrylic acid, triglycidyl etherified glycerin/acrylic acid, triglycidyl etherified trimethylolethane/methacrylic acid, diglycidyl etherified aniline/acrylic acid Epoxy (meth)acrylates such as (5) amide urethane (meth)acrylate type grederimers include r-butyrolactone/N-methylethanolamine/bis(4-isocyanatocyclohexyl)methane/2-hydroxyethyl acrylate; r-butyrolactone/N-methylethanolamine/2.6-
) Amide urethane (meth)acrylate such as lylene diisocyanate/tetraethylene glycol/2-hydroxyethyl acrylate; (6) Specific examples of urethane (meth)acrylate-based prepolymer include 2,6-tolylene diisocyanate diacrylate, isophorone diisocyanate acrylate, isophorone diisocyanate dimethacrylate, urethane acrylate synthesized from hexanediol/isophorone diisocyanate/2-hydroxyethyl acrylate, and urethane acrylate such as hexamethylene diisocyanate diacrylate; (7) Specific examples of spiroacetal (meth)acrylate presomers include , diarylidene (lid erythritol/2)
- Spiroacetal acrylate synthesized from hydroxyethyl acrylate: (8) Polybutadiene (
Specific examples of meth)acrylate-based gredirimers include engineering, l? Examples include acrylated polybutadiene synthesized from oxylated butadiene/2-hydroxyethyl acrylate, and these may be used alone or in combination of two or more.

Among these, the above-mentioned active ingredient has excellent heat resistance and abrasion resistance.

General formula (1) %Formula% [In the formula, n is an integer of 1 to 4, and at least 3 or more X's represent the general formula: CH2=C-C0O-R2- (in the formula.

R1 represents a hydrogen atom or a methyl group, R2 is a single bond,
Fullylene group having 1 to 8 carbon atoms or 1 to 8 carbon atoms
represents a polyoxyalkylene group having an alkylene group. ) represents the group shown.

The remainder is an alkyl group or hydroxyl group having 1 to 8 carbon atoms.

Amino group 1 formula: Group or formula represented by (-OR3SH (in the formula, R represents an alkylene group having 1 to 8 carbon atoms, and 1m is a positive integer): -(-OR'-) -OH(
2, R5 and m are the same as above. ) represents a group represented by ] Preferably, the compound represented by the formula (1) is particularly preferably used in combination with a radically polymerizable compound having a triazine ring, an incyanurate ring, or a cyanurate ring skeleton.

Specific examples of the compound represented by the general formula (1) include dipentaerythritol tetraacrylate, di-R-interacrylate, dipentaerythritol hexaacrylate, tri(-entaerythritol bentaacrylate, tripentaerythritol hexaacrylate, tri( Examples include porcine acrylate to metaerythritol.

It was a residue. Examples of radically polymerizable unsaturated compounds having a triazine ring, an isocyanurate ring skeleton, or a cyanurate ring skeleton include triallyl cyanurate, triallylisocyanurate, 1,3.5-)lyacryloylhexahydro-8-)lyazine, di(meth)acrylic acid ester of tris(2-hydroxyethyl)isocyanuric acid,
Tri(meth)acrylic acid ester of tris(2-hydroxyethyl)isocyanurate, an alcohol prepared by ring-opening addition of 0.5-3 mol of l-cabrolactone to 1 mol of tris(2-hydroxyethyl)isocyanurate (
meth)acrylic acid ester, polybasic acid Nlk product), polyhydric alcohol containing 5 or more moles of lith(hydroxyalkyl)in cyanurate and (meth)acrylic acid, polyester poly(meth) Acrylate, triglycidyl tris(hydroxyethyl)in cyanurate K (meth)acrylate obtained by reacting with (meth)acrylic acid, JP-A-1973
General formula (II) described in 8-87117...■) (However, R in the formula represents a hydrogen atom or a methyl group, R' represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, There is a radically polymerizable unsaturated compound obtained by reacting an incyanuric acidic conductor represented by (n is an integer from 1 to 20) with 1 m or 2 m1 or more of a polyisocyanate compound.

In the present invention, active energy ray-curable reactive diluents (B) which are preferable for use with component (g) include 1 such as (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate. ,
2-ethylhexyl (meth)acrylate, lauryl (
Meta) acrylate.

Decyl (meth)acrylate, stearyl (meth)acrylate, n-hexyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate , Ethoxypolyethylene glycol (meth)acrylate, Methoxypolypropylene glycol (meth)acrylate, Phenoxyethyl (meth)acrylate, Phenoxypolyethylene glycol (meth)acrylate, Alkylphenoxyethyl (meth)acrylate, Alkylphenoxypolyalkylene glycol (meth)acrylate% 2-hydroxy-3-phenyloxypropyl (meth)acrylate, tetrahydrofurfuryloxypolyalkylene glycol (meth)acrylate, dicyclointenyl (meth)acrylate, dicyclobentenyloxyalkyl (meth)acrylate, dicyclopentenyloxy Polyalkylene glycol (meth)acrylate, 2-hydroxyalkyl (meth)acryloyl phosphate, vinyl acetate, vinyl gropionate, polyfluoroalkyl (meth)acrylate, ethylene glycol di(meth)acrylate, propanediol di(
Meta) acrylate.

Butanediol di(meth)acrylate, neobentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate,
meth) acrylate, polypropylene gel 1 nokoldi(
meth)acrylate, hydroxypino 413 phosphate neointyl glycol ester di(meth)acrylate,
Trimethylolpronone di(meth)ac 1 root.

trimethylolglopantri(meth)acrylate,
Dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, (meth)acryloylmorpholine, N-methyl (meth)acrylamide, N, N- & methyl (meth)acrylamide 9%N,
N-dimethylaminoglovir (meth)ac IJ amide, N-methoxymethyl (meth)ac IJ amide, N-
Ethoxymethyl(meth)acrylamide, N-n-butoxymethyl(meth)ac)noramide, N,N'-methylenebis(meth)acrylamide, N-1+ role(meth)acrylamide 0°1.3-zo (meth)acrylamidomethyl 2-imitzoline, glycitul(meth)acrylate, glycerol di(meth)acrylate, glycerol mono(meth)acrylate, glycerol(
meth)acrylate alkylate, glycerol (meth)acrylate alkylate, 2-(1-aziridyl)
-ethyl (meth)acrylate, 2-vinylpyridine,
Examples include 4-vinylpyridine, vinylpyrrolidone, vinylcaglolactam, divinylbenzene, trivinylbenzene, and also carbamoyloxyalkyl (meth)acrylate, caprolactone-modified (meth)acrylate, and the like. Note that it is possible to add one or more types of reactive diluent (B) Vi.

Particular K Among the components (B), it is preferable to include a reactive diluent having a hydrophilic group in order to improve the adhesion with the intermediate layer. Examples of the hydrophilic group include a phosphoric acid group, a calgenic acid group, an acrylamide group, a pyrrolidone group, a morpholyl group, an amino group, a hydroxyl group, an epoxy group, a caprolactam group, an incyanato group, and a tetrahydrofurfuryl group. Specific examples include 2-hydroxyethyl (meth)acryloyl phosphate, (meth)acrylic acid, β-hydroxyethyl (meth)acrylate/phthalic anhydride (1/1)
Reactant, N-methyl (meth)acrylamide.

N,N-dimethylaminoethyl (meth)acrylamide, N-n-butoxymethyl (meth)acrylamide,
N,N'-methylenebis(meth)acrylamide 5-vinylpyrrolidone, (meth)acryloylmorpholine, diethyl aminoethyl (meth)acrylate, β-hydroxyethyl (meth)acrylate, β-hydroxyglobil (meth)acrylate, glycitol ( Examples include meth)acrylate, vinylcaprolactam, β-hydroxyethyl (meth)acrylate/isophorone diisocyanate (1/1) reaction product, and tetrahydrofurfuryl (meth)acrylate.

Specific examples of compounds that do not meet the active energy ray curability disadvantage, of course, are alkyl (meth)acrylate polymers, epoxy resins, liquid polybutadiene, liquid polybutadiene derivatives, liquid chlorogrene, and liquid polyintadiene. , dicyclopentadiene derivatives, saturated polyester oligomers, polyether oligomers, 1-liquid polyamides, polyisocyanate oligo9mers, xylene resins, ketone resins.

Petroleum resin, fluorine-based oligomer, silicone-based oligomer i -
Examples include r-, l-resulfide oligomers. In particular, alkyl [meth)acrylate polymers are preferred, and specific examples include methyl methacrylate% 5ee
- Homophores such as butyl methacrylate, cyclohexyl methacrylate, isobutyl methacrylate, benzyl methacrylate, phenyl methacrylate, ethyl methacrylate; methyl methacrylate/styrene =
80/20 parts by weight, methyl methacrylate/ethyl acrylate)=9515. Methyl methacrylate/methyl acrylate) = 90/10% methyl methacrylate/n-
Butyl methacrylate = 40/60, methyl methacrylate/ethyl methacrylate = 30/70, methyl methacrylate/ethyl acrylate = 70/30. Methyl methacrylate/methyl acrylate/methacrylic acid = 60/3515. Methyl methacrylate/lauryl methacrylate = 90710, methyl methacrylate/
Methyl acrylate/2-hydroxyethyl methacrylate) = 80/1515.

Methyl methacrylate)/1so-butyl methacrylate/dimethylaminoethyl methacrylate = 80/151
Mention may be made of copolymers such as 5.

These polymers may be used alone or in a mixture of 2 ai or more.

The above active energy ray-curable prepo IJ? −(g)
, reactive diluent (B) and active energy ray curability!廂! (The compounding ratio of Q is usually 40% of component (3) when the total is 100% by weight.)
~100 weight%, (weight component 0 to 60% by weight) and (0 weight component 0 to 40 weight%), especially for overcoats with appropriate viscosity, little curing shrinkage, and particularly less sticking. (A) in that a resin composition is obtained;
Ingredients 50-95! The preferable range is 10 to 50 parts by weight of component (B) and 5 to 35 parts by weight of component (C).

In the case of curing with ultraviolet rays, components (A) and (B) contain one or more compounds having at least one methacryloyloxy group or acryloyloxy group as a polymerizable group. It is preferable to use the above.

The preferred blending amount of the inorganic fine particles is the above resin component (4),
(0.1 to 2 parts by weight per 100 parts by weight of odor and (0)
It is within the range of 0 parts by weight, and it is particularly effective in improving sticking and provides excellent gloss.
．． 2 to 15 parts by weight is preferred.

Regarding the size K of the inorganic fine particles, it is preferable that the average particle diameter is 5 μm or less, and in particular, 0.0.
1 to 3 μm is preferable.

For oil absorption fi- of inorganic fine particles, 60m17100
It is preferably 60 to 300 m171001 or more.

A specific example of inorganic fine particles is calcium carbonate.

Zinc oxide, aluminum oxide, titanium dioxide, silicon dioxide, aluminum hydroxide, barium sulfate, zinc sulfate,
Examples include talc, kaolin, clay, and fired recolloidal silica. Among these, extender pigments are preferred, and calcium carbonate is particularly preferred.

It refers to ionizing radiation such as active energy rays, ultraviolet rays, electron beams, alpha rays, beta rays, and r rays, and when ultraviolet rays are used, a photopolymerization initiator and/or photosensitizer is added to the overcoat resin composition. It is preferable to contain an agent,
The r-ray line 1! Dissociative radiation! When using No. 1, it cures quickly even without containing a photopolymerization initiator or photosensitizer, so there is no need to add any photopolymerization initiator or photosensitizer.

Here are the photopolymerization initiators and photosensitizers that are added to the overcoat resin composition as needed.

Examples of photopolymerization initiators for zocal polymerization include carmenyl compounds such as benzoin, benzoin isobutyl ether, benzyl, benzophenone, p-chlorobenzophenone% p-methoxybenzophenone, and tetramethylthiuram monosulfide.

Sulfur compounds such as tetramethylthiuram disulfide, azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile, and 79-oxide compounds such as penzoylno, monooxide, and ditertiary-butyl peroxide, etc. Examples of photosensitizers include amine compounds such as aliphatic amines and aromatic amines, ureas such as 0-tolylthiourea, sodium diethyldithiophosphate, and s-benzylisothiuronium p-1 luenesulfonate. Examples include sulfur compounds such as N,N-disubstituted p-aminobenzonitrile compounds, nitrites such as tri-n-butylphosphine, and other nitrogen compounds such as N-nitrosohydroxylamine derivatives.

These photopolymerization initiators and photosensitizers are
For a total of 1100 parts of the and (C') components, 0.
It is usually used in the range of 01 to 1031f parts,
Preferably it is in the range of 1 to 8 parts by weight. If the amount added exceeds 10 parts by weight, storage stability deteriorates, which is not preferable.

In addition, during curing, not only active energy rays but also
Curing may be performed in combination with heat. However, the heat must be heated to such an extent that the heat-sensitive recording medium does not develop color. When curing using heat and active energy rays in combination, a radical polymerization initiator and a curing accelerator may be added to the overcoat resin composition.

Specific examples of the radical polymerization initiator include penzoyl peroxide, t-butylbenzoate, etc., and the total amount of the components (4), (B), and (C') is 10
It is usually added in an amount of 0.01 to 10 parts by weight per 0 parts by weight.

Examples of the curing accelerator include cobalt naphthenate, zinc naphthenate, zomethylaniline, dibutyltin laurate, etc.
The amount used is usually 0.001 to 5 parts by weight, preferably 0.005 to 4 parts by weight.

In addition, when curing is performed using both heat and ultraviolet rays.

It is possible to use the above radical polymerization initiator together with a photopolymerization initiator and/or a photosensitizer. The total amount added is preferably 0.01 to 10 ffift per 100 weights of the above-mentioned components (B) and (C').

In addition, when curing is performed by using active energy rays and heat in combination, it does not matter which one comes first. That is, it may be cured by heat and then cured by active energy rays, or it may be irradiated with active energy rays and then thermally cured. Alternatively, active energy rays may be irradiated while heating.

In the overcoat resin composition of the present invention.

Furthermore, each additive may be contained as necessary, and if desired, it may be diluted with a solvent before use.

The above additives include thermal polymerization inhibitors, organic silane compounds, leveling agents, antifoaming agents, slip agents,
They include coating surface improvers such as crater preventers and wetting improvers, plasticizers, colorants, and the like.

Among them, it is preferable to add organic silane compounds because they improve the adhesion with the first coloring layer or the intermediate layer, such as aminozologyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane,
Silane coupling agents having a 7-mino group such as N-β-(N-vinylbenzylaminoethyl)-r-aminozolopyltrimethoxysilane and hexamethylzosiladene, β
-(3,4-Ephoxycyclohexyl)ethyltrimethoxysilane and other silane coupling agents have an epoxy group, and 3-mercagtoglobil trimethoxysilane and other silane coupling agents have a mercapto group. Generally, 0.0% is added to 100 parts by weight of the total amount of the (B) and <C+ acid components. O1-10 heavy background, weight 0.
It is used in a range of 0.05 to 5 parts by weight.

The coating surface improving agent is usually used in an amount of 0.001 to 5 parts by weight per 100 parts by weight of the total amount of the above-mentioned components (B), ((5) and (c)).

It is preferably used in a range of 0.005 to 4 parts by weight.

The overcoat resin composition is coated after being thoroughly mixed using a suitable mixing agitator such as a mixer, but the viscosity can be adjusted by heating if necessary.

The coating method is not particularly limited, but examples include gravure coating, roll coating, air knife coating, kiss coating, spray coating, and Kake f7Jl coating.

Dip coat, spinner coat, wheeler coat, brush coat, solid screen: ff-),
There are also printing methods such as fire-per-coat and flow coating, and offset printing and letterpress printing. Among them, gravure coat, roll coat, air knife coat,
Kisco), 'Tsuya-Percoat, and Flowcoat are preferred because they provide a coated surface with high gloss.

Regarding Seifu-JIK, a resin composition for overcoat,
Although not necessarily limited, usually 0.1F to 2
017m", preferably #'i0.5~Loll/,
It is 1.

The atmosphere for irradiating active energy rays such as ultraviolet rays and a-coson rays is preferably an inert gas atmosphere such as nitrogen gas or charcoal gas, or an atmosphere with a reduced oxygen concentration, but it may also be a normal air environment.

(Example) The present invention will be explained in more detail with reference to Examples below.
Of course, it is not limited to these.

Further, unless otherwise specified, parts and % in Examples p indicate parts by weight and i#% by weight, respectively.

Example 1 (1) Preparation of liquid (color former dispersion) 3-diethylamino-6-methyl-7-5.0 parts Anilinofluorane stearic acid amide 10.0 parts Water
25.
5 front needle 4
7.5 parts This composition was ground in a paint seeker until the average particle size was 3/Jnl.

■ Preparation of (U) liquid (coloring agent dispersion) Bisphenol A 17° 5 parts Calcium carbonate 17.5 parts 10% polyvinyl alcohol aqueous solution 7.5 parts Water
50.0
Total 92
．． 5 parts of this composition in a paint shaker to an average particle size of 3
Be sure to crush it until it becomes μm.

■ Creation of record 1- (1) 47.5 parts of solution (92.5 parts of IIJ solution 40% aqueous glyoxol solution 2.
5 parts lO% polyvinyl alcohol aqueous solution 2
5.0m water
7.5 parts 175.0 parts This composition was sufficiently stirred and mixed, and -1 was adjusted to 8 with a 50% triethanolamine aqueous solution to obtain a coating liquid for thermal recording 1@.

The obtained coating liquid was applied to the surface of synthetic paper (Oji Yuka Synthetic Paper and Yupo FPG #60) made by forming a film of a composition containing polypropylene, fillers, and additives using a Meyer bar after drying. Apply so that the amount of coating is 817 m'',
Dry and cure in a dryer at ℃ to obtain a heat-sensitive recording medium.

■Formation of intermediate layer Calcium carbonate 10 parts water
10 part front needle
120 parts of this composition was dispersed in a paint shaker.

Apply this coating liquid onto the recording layer of the heat-sensitive recording medium obtained in the previous section.
The amount of application after drying using Meyer Par is 41! /m”K
Apply VCm cloth and dry and harden it in a dryer at 50°C.
The idea was to create a thermal recording medium with an intermediate layer.

■ Formation of an overcoat layer An overcoat resin composition having the composition shown in Table 1 is applied on the intermediate layer of a heat-sensitive recording medium having an intermediate layer in a dry coating amount of 4.
1! /m”, and then using an ultraviolet lamp (made by Ikey Arlite HO3-L31 Eye Graphics ■,
The coated film was cured by irradiating ultraviolet rays at a distance of 17 cg from the rung and a conveyance speed of 30 m/min using a 3-lamp) to obtain a heat-sensitive recording medium having an overcoat layer according to the present invention.

(2) Quality Performance Test Next, a quality performance test was conducted on the above heat-sensitive recording medium. The results are shown in Table-2. The test items and seven methods are as follows.

1) Sticking: When printing was performed on a thermal recording medium using a commercially available image printer (Sony UP-7011), the state of adhesion of the sample to the thermal head was visually determined.

Good without stickiness) ○, Sticky (bad) X, Sticky!
7 (bad as chopsticks) XX.

2) Debris adhesion: When printing was performed on a thermal recording medium using the above-mentioned image printer, the state of deposits on the thermal head was visually determined.

Good with no residue) ○, with residue (bad) ×, with residue (very bad) × × 3) 7'1J mark missing: Continuous on 5 image planes when printing on a thermal recording medium with the above-mentioned image printer The state of print omission that appeared on the surface was visually determined.

(Good, no print missing) ○, Print missing (bad) ×, Print missing (very bad) × × 4) Printed with an image printer with print density of two dimensions (peta black)
The concentration was measured using a Macbeth reflection densitometer (RD-10OR, manufactured by Macbeth).

5) Glossiness: The glossiness of the surface of the heat-sensitive recording medium before printing is measured using a digital glossy needle (GM-3D, Murakami Color Technology Research Institute!!
Measurements were taken at a 60' angle of incidence.

6) Plasticizer-resistant dual-color secondary thermal recording media.

It was sandwiched between plasticizer-containing vinyl chloride wraps (three layers), brought into contact with the coloring surface, and applied with a pressure of 10 g/α3. The degree of decolorization of the image after being left at an ambient temperature of 40° C. for one day and night was visually determined.

Good with no change) ○, Slightly washed out color (bad) ×, More than half of the color faded (severely bad) was rubbed back and forth with gauze 5 times, and the degree of decolorization of the image was visually determined.

Good with no change) 01 Surface slightly warped (bad) ×
, Discoloration (remarkably poor) × × 8) Humidity resistance: After leaving the colored printed heat-sensitive recording medium in a constant temperature room at 40° C. and 95% RH for one day and night.

The degree of decolorization of the image was visually determined.

(Good with no change) ○, Slightly discolored (bad) ×, More than half of the discolored (remarkably fast) After 30 minutes, the salad oil was wiped off with -ze, and the degree of decolorization of one image was determined.

Good with no change) ○, Slightly discolored (bad) ×, More than half discolored (severely bad) × × / / / / 1) DP5A Nidipentaerythritol to Butaacrylate 2) DP6A Nidiintaerythritol to Hexaacrylate 3) Epoxy acrylate: Lipoxy 5P-1509 manufactured by Showa Kobunshi Isho 4) Urethane acrylate: Epecryl 220 manufactured by UCB, Belgium s) YFF17 ester acrylate: UC, Belgium
Epecryl 810 manufactured by Company B 6) HEA: Hydroxyethyl acrylate 7) N
-VP: N-vinylpyrrolidone 8) PA: 2-acryloyloxyethyl phosphate 9) DgAEA: Diethylaminoethyl acrylate 10) AA Niacrylic acid 11) 3P2A: ) Lipropylene glycol diacrylate 12) Acrylic polymer A: Butyl methacrylate /
Methyl methacrylate) = 60/40 copolymer, '
rg 50°C 13) High molecular weight tertiary amine: Ubecryl P115 manufactured by UCB, Belgium 14) High molecular weight penzophenone: Ubecryl P36 manufactured by UCB, Belgium 15) CADOX B-CH2O: Arm oxide manufactured by Kayaku Nouri ■ 16) Epoxysilane: r-glycidoxyzolobyltrimethoxysilane 17) Aminosilane: N+β-aminoethyl)r-aminopropylmethyldimethoxysilane 18) Kayaset Blue N: Nippon Kayaku ■ dye 19) Fine Seal -40: Made by Tokuyama 9-Tatsu ■ Siri force fine particles average particle diameter 1.5-1.8 μm Oil absorption: 1t270-300 m//100,920) Mizukashiru P-527: Mizusawa Chemical Industry MW Calcium carbonate fine particles average particle size 1.8 μm Oil absorption 140 ~180d/101 21) Callite SA: Calcium carbonate fine particles manufactured by Shiraishi Kogyo ■ Average particle size 3.3 μm Oil absorption i80 ~ 100 m//100,9 22) Mizukashiru P-78D: Calcium carbonate fine particles manufactured by Mizusawa Chemical Industry ■ Average particle size 8 .0μm oil absorption [230ml/1001 23) S-300: Sumitomo Cement (manufactured by decoy calcium carbonate fine particles average particle size 0.8μm oil absorption 35%/100.9) The average particle size is determined by Coulter Counter (A/4'- This is a value measured from a char tube (50 μm) K.

The oil absorption is the linseed oil absorption according to JIS K-5101K.

Examples 2 to 3 A thermosensitive recording medium having an overcoat layer was obtained in the same manner as in Example 1 except for the following except that the composition shown in Table IK was used as the overcoat layer. Then, a quality performance test was conducted in the same manner. The results are shown in Table-2.

Example 4 A surface-treated polyester film (Lumirror F60 manufactured by Toshi@) was used as the base material to which the coating liquid for the heat-sensitive recording layer was applied, and the composition shown in Table 1 was used as the overcoat layer. A thermosensitive recording medium having an overcoat layer was obtained in the same manner as above.

Next, quality performance tests were conducted in the same manner. Table 2 of the results
Shown below.

Examples 5-8 The following composition was used as the intermediate layer.

A thermosensitive recording medium having an overcoat layer was obtained in the same manner as in Example 4 except for using the composition shown in Table 1 as the overcoat layer. We also conducted quality performance tests in the same manner. The results are shown in Table 21C.

Example 9 A substrate with a basis weight of 4517
The following composition was applied to a base paper with a thickness of 50 μm so that the coating amount after drying was 511 parts m”, and after drying, 200 μm
, an electron beam with an absorption M amount of 3 Mrad is applied at an accelerating voltage of kV, and then calendering is performed to obtain a Bekk smoothness of 20
The surface smoothness of 00 seconds was also compared using Yugami paper.

Diethylene glycol diacrylate 10
1 part Methyl ethyl ketone 20 parts Total 100 parts Oats 1 - As a coating layer, the composition shown in Table IK was used.
Except for this, a thermosensitive recording medium having an overcoat 1 was obtained in the same manner as in Example 8, and then a quality performance test was conducted in the same manner as in Example 1. The results are shown in Table-2.

Example 10 The following composition was used as the intermediate layer.

Calcium carbonate water total: 10 parts 10 parts 120 parts A thermosensitive recording medium having an overcoat layer was obtained in the same manner as in Example 9, except that the composition shown in Table IK was used as the overcoat layer. We carefully conduct quality performance tests. The results are shown in Table-2.

Example 11 The composition shown in Table IK was used as the overcoat layer, and after irradiation with ultraviolet rays in the same manner as in Example 10, the layer was heated to 60°C.
The coating film was cured for 5 minutes, and then left at room temperature for 24 hours to obtain a heat-sensitive recording medium having an overcoat layer.Then, a quality performance test was conducted in the same manner as in Example 1. The results are shown in Table-2.

Example 12 Using the composition shown in Table 1 as an overcoat layer, VC was applied onto the intermediate layer so that the dry coating amount was 317 m'', and an electron beam irradiation device 1tcEs was applied.
From company X's 411ICB150 type) K, 4 Mr.
A thermosensitive recording medium having an overcoat layer was obtained in the same manner as in Example 9 except for irradiating ad and curing the coating film.
Next, a quality performance test was conducted in the same manner as in Example 1. The results are shown in Table-2.

Comparative Examples 1 to 4 A thermosensitive recording medium having an overcoat layer was obtained in the same manner as in Example 1 except for using the composition shown in Table IK as the overcoat layer, and then a quality performance test was conducted in the same manner. The results are shown in Table-2.

(Effects of the Invention) A thermosensitive recording medium using the overcoat resin composition of the present invention has a high gloss surface property even when using a base material made of a synthetic resin, and has good head matching properties. It has the advantage of being excellent.

Agent Patent Attorney Katsutoshi Takaa

Claims (1)

[Claims] 1. A thermosensitive recording medium comprising, on a base material made of synthetic resin, a thermosensitive coloring layer and an overcoat layer of an active energy ray-curable resin composition in which inorganic fine particles are dispersed. . 2. The active energy ray-curable resin composition has an oil absorption of 60
ml/100g, inorganic fine particles with an average particle size of 5 μm or less,
The heat-sensitive recording medium according to claim 1, which contains 0.01 to 25 parts by weight per 100 parts by weight of the resin component. 3. The active energy ray-curable resin composition has an oil absorption of 60
~300ml/100g, an extender pigment with an average particle size of 0.1 to 3 μm, 0.2 to 15 parts by weight per 100 parts by weight of the resin component.
2. The heat-sensitive recording medium according to claim 1, wherein the heat-sensitive recording medium contains parts by weight. 4. The active energy ray-curable resin composition has the general formula (
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [In the formula, n is an integer from 1 to 4, and at least 3 or more X are general formulas: ▲Mathematical formulas, chemical formulas, tables, etc. ▼(In the formula, R^1 represents a hydrogen atom or a methyl group, and R^2 represents a single bond, an alkylene group having 1 to 8 carbon atoms, or a
Represents a polyoxyalkylene group having ~8 alkylene groups. ) and the remainder has 1 carbon atom
~8 alkyl group, hydroxyl group, amino group, formula: ■OR^3
■_mH (in the formula, R^3 represents an alkylene group having 1 to 8 carbon atoms, and m is a positive integer) or a group represented by the formula ■OR^3■_mOH (in the formula, R^3 and m are the same as above). ] The heat-sensitive recording medium according to claim 2, which contains a compound represented by the following. 5. The heat-sensitive recording medium according to claim 4, wherein the active energy ray-curable resin composition also contains a reactive diluent having a hydrophilic group. 6. The heat-sensitive recording medium according to claim 5, further comprising an intermediate layer containing a water-based resin as a main component between the heat-sensitive coloring layer and the overcoat layer. 7. A resin composition for overcoating a heat-sensitive recording medium, comprising an active energy ray-curable compound and inorganic fine particles. 8. 0.01 inorganic fine particles with an oil absorption amount of 60 ml/100 g and an average particle size of 5 μm or less per 100 parts by weight of the resin component.
The resin composition according to claim 7, containing ~25 parts by weight. 9. Oil absorption amount as inorganic fine particles: 60-300ml/100
g, an extender pigment with an average particle size of 0.1 to 3 μm, and resin component 1
8. The resin composition according to claim 7, containing 0.2 to 15 parts by weight based on 0.00 parts by weight. 10. The active energy ray-curable compound has the general formula (I
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [In the formula, n is an integer from 1 to 4, and at least 3 or more X are general formulas: ▲There are mathematical formulas, chemical formulas, tables, etc. ▼(In the formula, R^1 represents a hydrogen atom or a methyl group, and R^2 represents a single bond, an alkylene group having 1 to 8 carbon atoms, or a carbon atom number 1
Represents a polyoxyalkylene group having ~8 alkylene groups. ) and the remainder has 1 carbon atom
~8 alkyl group, hydroxyl group, amino group, formula: ■OR^3
Group or formula represented by ■_mH (in the formula, R^3 represents an alkylene group having 1 to 8 carbon atoms, and m is a positive integer): ■OR^3■_mOH (in the formula, R^3 represents an alkylene group having 1 to 8 carbon atoms, and m is a positive integer) 3 and m are the same as above. ] The resin composition according to claim 8, which contains a compound represented by the following. 11. The resin composition according to claim 10, wherein the active energy ray-curable compound also contains a reactive diluent having a hydrophilic group.