JPH08175039A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE: To provide a thermal transfer recording medium improved in printing properties by sufficiently preventing the generation of sticking and preventing the hot melt from a heat-resistant protective layer or the refuse due to the peeling or abrasion of the heat-resistant protective layer from adhereing to a thermal head. CONSTITUTION: In a thermal transfer recording medium wherein a thermal transfer ink layer is provided on the surface of a base material and a heat- resistant protective layer is provided on the rear surface coming into contact with a thermal head of the base material, the heat-resistant protective layer is mainly composed of an org. polymeric substance having no crosslinked structure and the film strength of the heat-resistant protective layer is 10mN or more and the contact angle to pure water of the surface therfeof is 95 deg. or more and the coefficient of dynamic friction thereof is 0.07 or less. The heat- resistant protective layer is based on a modified copolymer consisting of a backbone polymer composed of a polymer having active hydrogen excepting cellulose and a cellulose derivative and a branched polymer composed of a copolymer of reactive silicone and a vinyl monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium, and more particularly to a thermal transfer recording medium suitable for use in a thermal transfer recording system using a thermal head.

[0002]

2. Description of the Related Art In a thermal transfer recording system, a thermal transfer ink layer of a thermal transfer recording medium consisting of a substrate and a thermal transfer ink layer provided on the surface thereof is brought into pressure contact with a transfer paper, and a thermal head is placed on the back surface of the substrate. Send a pulsed signal current to the head in contact with it to heat the thermal head,
The heat causes the thermal transfer ink layer to be melted or sublimated so that the transfer paper is printed and recorded. By the way, conventionally, a plastic film such as polyethylene terephthalate has been widely used as a substrate of a thermal transfer recording medium. The plastic film is easily fused to the thermal head during thermal transfer recording, which may cause a sticking phenomenon such as stopping the transportation of the thermal transfer recording medium or breaking the thermal transfer recording medium. In order to prevent the occurrence of such a sticking phenomenon, various proposals have been made to provide a heat-resistant protective layer on the back surface of the base material (the surface in contact with the thermal head). For example, JP-A-55-7467, JP-A-60-201989, and JP-A-63-1.
For example, JP-A-72688 proposes using a silicone resin, an epoxy resin, a melamine resin, a phenol resin, a fluororesin, an aromatic polyamide or the like as a heat resistant protective layer. However, there is a drawback that the slipperiness cannot be sufficiently prevented and sticking cannot be sufficiently prevented by using these resins alone.

JP-A-61-143195 proposes the use of a silicone graft or a block acrylic copolymer as a heat resistant protective layer, which improves the sticking prevention, but the acrylic component The film forming property is insufficient, the heat-resistant protective layer may be peeled off from the substrate, and the heat-resistant protective layer is liable to be worn, which causes defective running of the thermal transfer recording medium. JP-A-1
-212281, JP-A-1-234292, and the like, it is proposed to provide a heat-resistant protective layer in which silicone oil is added to ethyl cellulose resin, and a heat-resistant protective layer in which silicone oil is added to cellulose ester resin containing an acetate group. However, the addition of silicone oil improves the lubricity of the heat-resistant protective layer and improves the sticking prevention, but the silicone component easily migrates to the surface of the thermal head, causing the head stain due to the silicone component and degrading the print quality. There are drawbacks.

Japanese Unexamined Patent Publication (Kokai) No. 4-126294 proposes to provide a heat-resistant protective layer composed of a mixture of an acrylic silicone graft polymer and a reaction product of an amino-modified silicone oil and a polyfunctional isocyanate.
In this heat-resistant protective layer, the migration of the silicone component to the surface of the thermal head is improved, but the film-forming property of the acrylic component and the adhesiveness with the substrate are insufficient, and the heat-resistant protective layer peels from the substrate, Also, the drawback of wear has not been sufficiently improved. JP-A-5-58067, JP-A-5-162472, and the like propose the use of a silicone polyvinyl butyral copolymer or a silicone-modified cellulose acetate phthalate as a heat-resistant protective layer, which improves the film forming property. However, there is a drawback in that the heat resistance is insufficient and the hot melt adheres to the thermal head to deteriorate the printing quality.

Further, in the above-mentioned conventional techniques, in order to improve heat resistance and film-forming property, a hydroxyl group residue or the like in the resin is often used to carry out a crosslinking reaction with isocyanate, melamine, epoxide or the like. However, there are manufacturing problems such as the need for a curing step after coating the heat-resistant protective layer and the shortening of the pot life of the coating liquid.

[0006]

The conventional thermal transfer recording medium having a heat-resistant protective layer does not sufficiently prevent the occurrence of sticking, and the heat-melted material from the heat-resistant protective layer or scraps due to peeling or abrasion of the heat-resistant protective layer is generated. It has the drawback that it adheres to the thermal head and reduces the printing quality of thermal transfer recording, or that running defects occur due to lack of lubricity, peeling of the heat-resistant protective layer from the base material, wear of the heat-resistant protective layer, etc. However, it is difficult to obtain a thermal transfer recording medium in which all of these drawbacks have been solved.

Therefore, the object of the present invention is to solve these problems and prevent the sticking from occurring sufficiently, and the hot melt from the heat-resistant protective layer or scraps from the heat-resistant protective layer due to peeling or abrasion adheres to the thermal head. It is an object of the present invention to provide a thermal transfer recording medium which is prevented from having a good print quality and is excellent in running property.

[0008]

The above object of the present invention is to provide a heat transfer recording medium comprising a heat transfer ink layer on the surface of a base material and a heat resistant protective layer on the surface of the back surface of the base material that contacts the thermal head. The protective layer is mainly composed of an organic polymer substance having no crosslinked structure, and the heat-resistant protective layer has a film strength of 1
It is achieved by a thermal transfer recording medium characterized in that the contact angle of pure water on the surface of the heat resistant protective layer is 95 ° or more and the coefficient of dynamic friction is 0.07 or less.

The film strength, the contact angle to pure water, and the coefficient of dynamic friction in the present invention are values measured by the following methods. That is, the film strength is a value obtained by measuring the breaking point or the wear starting point of the heat-resistant protective layer of the thermal transfer recording medium under the following conditions using a Lesca CSR-02 scratch strength tester (manufactured by Lesca). Stage tilt angle: 0 ° 30 'Stylus diameter: 100 μm Needle pressure: 50 gf Amplitude: 30 μm

The contact angle to pure water was 24 ± 4 ° C. using a FACE automatic contact angle meter CA-Z (manufactured by Kyowa Interface Science Co., Ltd.).
Is a value obtained by measuring the contact angle of pure water on the surface of the heat-resistant protective layer of the thermal transfer recording medium at room temperature. The dynamic friction coefficient was measured by using a HEIDON surface property tester (manufactured by Shinto Kagaku Co., Ltd.) and a load of 50 was applied to the surface of the heat-resistant protective layer of the thermal transfer recording medium.
It is a value measured under the conditions of gf point contact and an objective 9.5 mm diameter quartz glass.

According to the present invention, the film is mainly composed of an organic polymer material having no crosslinked structure and has a film strength of 10 mN or more,
By providing a heat-resistant protective layer having a contact angle of pure water of 95 ° or more and a dynamic friction coefficient of 0.07 or less on the surface of the base material that abuts the thermal head, sticking is sufficiently prevented and heat-resistant protection is provided. The thermal melt from the layer or debris due to peeling or abrasion of the heat-resistant protective layer is prevented from adhering to the thermal head, and the print quality is excellent, and the lubricity is good. It is possible to obtain a thermal transfer recording medium which has less peeling and abrasion of the heat-resistant protective layer and is excellent in running property.

Particularly, the dynamic friction coefficient of the surface of the heat resistant protective layer is set to 0.
If the contact angle with pure water is 070 or less and 95 ° or more, sticking is sufficiently prevented. By setting the film strength of the heat-resistant protective layer to 10 mN or more, the heat-resistant protective layer can be peeled off from the substrate due to the frictional force with the thermal head, and the wear of the heat-resistant protective layer can be reduced. Contact angle to pure water is 95 °
With the above, it is possible to prevent the hot melt from adhering to the thermal head. Further, in particular, by setting the dynamic friction coefficient of the heat-resistant protective layer to 0.070 or less, running defects can be prevented.

Further, the above-mentioned object of the present invention is a thermal transfer recording medium comprising a thermal transfer ink layer on the surface of a base material and a heat resistant protective layer on the surface of the back surface of the base material, which is in contact with the thermal head. -In a layer containing a modified copolymer composed of a trunk polymer composed of a polymer having active hydrogen excluding a polymer and a cellulose derivative, and a branched polymer composed of a copolymer of a reactive silicone and a vinyl monomer It is achieved by a thermal transfer recording medium characterized in that
Heat resistance mainly composed of a trunk polymer composed of a polymer having active hydrogen except cellulose and a cellulose derivative, and a modified copolymer composed of a branch polymer composed of a copolymer of a reactive silicone and a vinyl monomer The protective layer has excellent heat resistance and lubricity, and also has good film-forming properties and good adhesion to the substrate. By providing this heat-resistant protective layer on the surface of the back surface of the substrate that contacts the thermal head, sticking may occur. The thermal transfer recording medium is excellent in print quality and is excellent in runnability by preventing thermal melt from the heat-resistant protective layer or debris caused by peeling or abrasion of the heat-resistant protective layer from adhering to the thermal head. Can be obtained.

Further, a modified copolymer composed of a trunk polymer composed of a polymer having active hydrogen except cellulose and a cellulose derivative, and a modified copolymer composed of a branch polymer composed of a copolymer of a reactive silicone and a vinyl monomer. By using the main component, a heat resistant protective layer having a film strength of 10 mN or more, a contact angle of pure water on the surface of 95 ° or more, and a dynamic friction coefficient of 0.07 or less can be obtained. The thermal transfer recording medium has a sticking prevention, printing quality and running property, and is particularly preferable.

The polymer constituting the trunk polymer in the present invention has active hydrogen, and the function required for polymerization is that a radical copolymerization initiation point can be formed by hydrogen abstraction. Examples of such a polymer include polyethylene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, polypropylene, polystyrene, vinyl chloride resin, vinyl chloride vinyl acetate copolymer, vinyl chloride acrylate copolymer. Coal, vinyl chloride acrylonitrile copolymer, ethylene vinyl chloride copolymer, polyvinyl alcohol, polyvinyl formal, polyvinyl acetoacetal, polyvinyl butyral, polyvinyl nitrate, polyvinyl ether, polyamide resin, polyimide, polyamide imide, polyester resin, Examples thereof include polycarbonate and polyacetal, which may be used alone or in combination of two or more kinds.

These polymers can be appropriately selected in consideration of polymerization reactivity, heat resistance as a heat-resistant protective layer, film-forming property, adhesion to a substrate, etc., but polyvinyl acetoacetal and polyvinyl butyral are selected. In terms of polymerization reactivity and heat resistance as a heat-resistant protective layer, N-methoxymethylated nylon among polyamide resins is particularly preferable in terms of film-forming property as a heat-resistant protective layer and adhesiveness to a substrate, The use of these can better prevent sticking and adhesion of the hot melt to the thermal head. The amount of the trunk polymer in the entire modified copolymer can be changed depending on the polymerization reactivity, the required heat resistance, the film forming property, the adhesiveness with the substrate, etc., but is 1 to 80% by weight, particularly 5 The range of -60 wt% is preferred.

The reactive silicone used in the modified copolymer is a silicone compound having a functional group such as an OH group or an epoxy group at one end, and a polyalkylsiloxane having a radically polymerizable unsaturated group at one end. There are compounds and the like, and the molecular weight thereof is preferably about 100 to 50,000. These compounds may be used alone or 2
One or more species may be used in combination, and particularly by using a reactive silicone having a molecular weight of less than 500 and a reactive silicone having a molecular weight of 5000 or more in combination, the film strength does not decrease for a long time. The amount of reactive silicone in the whole modified polymer is preferably in the range of 5 to 60% by weight, particularly preferably 10 to 40% by weight. When a reactive silicone having a molecular weight of less than 500 and a reactive silicone having a molecular weight of 5000 or more are used in combination, the reactive silicone having a molecular weight of less than 500 is preferably 1 to 50% by weight, particularly preferably 5 to 30% by weight, and having a molecular weight of 5000 or more. The reactive silicone is preferably 0.5 to 30% by weight, more preferably 1 to 20% by weight.

Specific examples of the reactive silicone include the following. That is, as the reactive silicone oil having a molecular weight of less than 500, those having a functional group such as OH group, epoxy group, SH group, COOH group and unsaturated double bond at one end as shown in Table 1 and Table 2, Further, polydimethylsiloxane-based polymer reaction initiators shown in Table 3 can also be used.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

As the reactive silicone oil having a molecular weight of 5,000 or more, those having L + M + N ≧ 61 in the reactive silicone oil (1) and N ≧ in (2)
64, N ≧ 65 in (3),
N ≧ 65 in (4), L in (5)
Those having + M + N ≧ 63 and those having N ≧ 62 in (6) can be used.

The vinyl monomer used in the above modified copolymer is one that can be copolymerized with the trunk polymer and the reactive silicone, and specific examples thereof include methyl acrylate, ethyl acrylate and n-butyl acrylate. , I-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, tetrahydrofurfuri acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, methyl vinyl ether, ethyl vinyl ether , N
-Propyl vinyl ether, n-butyl vinyl ether,
i-Butyl vinyl ether, styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxy Propyl acrylate, 2-hydroxypropyl methacrylate, allyl alcohol, glycidyl acrylate, glycidyl methacrylate, glycidyl allyl ether, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, citraconic acid, acrylamide, methacrylamide, N -Methylol acrylamide, N-methylol methacrylamide, NN-dimethyl acrylamide, NN-dimethylaminoethyl methacrylate, NN-diethylaminoe Methacrylate, vinyl monomers diacetone acrylamide. In addition, silane coupling agents such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane can also be used. These monomers may be used alone or in combination of two or more.

The branch polymer in the modified copolymer has a greater effect of improving heat resistance and preventing sticking than the adhesiveness to the substrate itself, and when selecting the vinyl monomer, the glass at the homopolymer level is used. Transition point (Tg)
Is important, and the glass transition point at the homopolymer level is preferably 80 ° C. or higher. In particular, methyl methacrylate (Tg: 105 ° C), methacrylic acid (Tg
g: 130 ° C.) and the like are also preferable from the viewpoint of copolymerization reactivity.
The amount of vinyl monomer in the modified copolymer is 10 to 85.
About wt% is preferable. Further, as the branch polymer,
A silicone-acrylic copolymer is particularly preferable.

The modified copolymer in the present invention is usually produced by solution polymerization. For example, (1) by adding a reactive silicone and a vinyl monomer together with a polymerization initiator to a solution of a polymer having active hydrogen under stirring and reacting them, or (2) using a heavy hydrogen compound having active hydrogen. It is composed of a polymer having active hydrogen by introducing an unsaturated group into the polymer, and adding a reactive silicone and a vinyl monomer together with a polymerization initiator to the solution of the polymer under heating and stirring to cause a reaction. It is possible to obtain a modified copolymer composed of a trunk polymer and a branched polymer composed of a copolymer of a reactive silicone and a vinyl monomer.

Examples of the solvent include aromatic hydrocarbon solvents such as toluene and xylene, acetone, methyl ethyl ketone,
A ketone solvent such as methyl isobutyl ketone, an ester solvent such as ethyl acetate or butyl acetate, an alcohol solvent such as ethanol or isopropanol, or a mixed solvent thereof can be used. As the polymerization initiator, benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, dicumyl peroxide, t-butylperoxyisopropyl carbonate,
Oil-soluble polymerization initiators such as t-butyl perbenzoate, di-t-butyl peroxide, azobisisobutyronitrile, and azobisvaleronitrile can be used.

As a method for graft polymerizing a branch polymer on a trunk polymer composed of a polymer having active hydrogen,
As in (1), there is a method by a hydrogen abstraction reaction, and as in (2), there is a method in which a graft active site is given in advance.
Regarding (1), it is possible to use a polymerization initiator having a large hydrogen abstraction action such as benzoyl peroxide, dicumyl peroxide, t-butyl peroxyisopropyl carbonate, t-butyl perbenzoate, and di-t-butyl peroxide. preferable. In the method (2), an unsaturated group is introduced into the trunk polymer with methacryloyl isocyanate, isocyanate ethyl methacrylate or the like in the OH group of polyvinyl acetal, or esterified with maleic anhydride, itaconic anhydride, etc. The method of introducing an unsaturated group into is effective.

As described above, a modified copolymer comprising a trunk polymer composed of a polymer having active hydrogen except cellulose and a cellulose derivative and a branch polymer composed of a copolymer of reactive silicone and a vinyl monomer. Coalescence can be produced without carrying out a crosslinking reaction with a crosslinking agent, etc., and there is an advantage that a curing step after coating the heat-resistant protective layer is unnecessary and there is no problem in terms of pot life of the coating liquid. .
Further, the above modified copolymer makes it possible to obtain a heat-resistant protective layer which is excellent in film-forming property, heat resistance and lubricity without having a crosslinked structure. The fact that this heat-resistant protective layer does not have a crosslinked structure can be confirmed by being soluble in toluene and / or methyl ethyl ketone.

The modified copolymer composed of the trunk polymer and the branched polymer composed of the copolymer of the reactive silicone and the vinyl monomer in the present invention will be described with reference to the conceptual diagram shown in FIG. As shown in FIG. 1, since the silicone component 3 is chemically bonded to the vinyl polymer portion 2 of the branch polymer, it does not cause head contamination due to migration of the silicone component to the surface of the thermal head, and the silicone component has Sticking can be sufficiently prevented by slipperiness and releasability. Further, the heat resistance of the vinyl polymer in the branch polymer can suppress the thermal softening by the thermal head to a low level, and the adhesion of the hot melt to the surface of the thermal head can be prevented. Furthermore, the good film-forming property of the trunk polymer and the adhesiveness to the substrate prevent the heat-resistant protective layer from peeling from the substrate, and dust from the heat-resistant protective layer may adhere to the thermal head. To be prevented.

As the heat-resistant protective layer in the present invention, a layer formed by mixing the modified copolymer with a polymer having active hydrogen as a trunk polymer component of the modified copolymer can be used. Thereby, the film strength of the heat-resistant protective layer can be further enhanced. Even if polyester, polyvinyl butyral, polyamide, etc. are mixed with ordinary silicone-modified acrylic resin, the film strength is not improved due to poor compatibility, but as in the present invention, the modified copolymer and its activity as a trunk polymer component By mixing with a polymer having hydrogen, the compatibility is greatly improved and the film strength can be increased. The mixing ratio of the co-polymeric polymer and the polymer having active hydrogen as the trunk polymer component is 90:10 to 5
It is preferably in the range of 0:50. As the polymer having active hydrogen, a polymer having high heat resistance is preferable, and a polymer having a glass transition temperature of 100 ° C. or higher is particularly preferable from the viewpoint of preventing adhesion of the hot melt to the surface of the thermal head.

Further, as the heat-resistant protective layer in the present invention, a layer obtained by mixing the modified copolymer with a modified silicone oil having a reactive functional group can be used. This makes it possible to prevent the occurrence of sticking and prevent the hot melt from adhering to the surface of the thermal head. Examples of the functional group introduced into the modified silicone oil having a reactive functional group include methylstyrene, long-chain alkyl, polyether, carbinol, amine, epoxy, carboxyl, higher fatty acid, mercapto and methacryl. The modified silicone oil having these reactive functional groups may have one type of functional group introduced, or may have two or more types of functional group introduced. The modified silicone oil having these reactive functional groups is appropriately selected in consideration of the adhesion of the hot melt to the surface of the thermal head, the heat resistance of the heat resistant protective layer, the film formability, the film strength, the lubricity, and the like. be able to. Among them, amino-modified silicone oil and epoxy-modified silicone oil are particularly preferable in terms of film-forming property and film strength. The modified silicone oil has an equivalent weight of the reactive functional group of 5,000.
It is preferably mg / mol or less, particularly 1000
It is preferably less than or equal to mg / mol.

The amount of the modified silicone oil having a functional group reactive with the modified copolymer is 3 to 6% by weight.
Is preferred. When the amount is large, the lubricity is poor, and when the amount is small, the prevention of adhesion of the hot melt to the surface of the thermal head tends to be poor. Further, when the contact angle of pure water on the surface of the heat-resistant protective layer made of the modified copolymer and the modified silicone oil having a reactive functional group is 110 ° or more, the occurrence of sticking is prevented, and the thermal melt on the surface of the thermal head is prevented. It is preferable from the standpoint of preventing adhesion of dust and debris. There are two typical synthetic methods of modified silicone oil, an equilibration reaction with an acid or alkali catalyst and an addition (or condensation) reaction with a silicone oil having Si-H.
Different synthetic methods are used depending on the type of organic group. Generally, the former is the preferred synthetic method including productivity.

In order to form the heat-resistant protective layer in the present invention, a solution of the modified copolymer, a mixed solution of the modified copolymer and a polymer having active hydrogen as a trunk polymer component of the modified copolymer, Alternatively, a mixed solution of a modified copolymer and a modified silicone oil having a reactive functional group may be applied to the back surface of the substrate with a wire bar or the like and dried. The thickness of the heat-resistant protective layer in the present invention is 0.01 to 2.00 μm.
Is preferable, and 0.04 to 0.6 μm is particularly preferable.

The modified copolymer of the present invention is dissolved in a solvent such as methyl ethyl ketone, coated on the back surface of the substrate, and dried to form a heat-resistant protective layer, whereby the modified copolymer is microphase-separated in the coated state. The structure can be formed. The microphase-separated structure is a state in which the block / graft polymer is microphase-separated in a solution to form stable micelles, and a microdomain structure is formed in a coated solid state. With this structure, contradictory properties such as releasability and adhesiveness, heat resistance and mechanical strength can be provided.

Examples of the substrate for the thermal transfer recording medium of the present invention include polycarbonate, polyarylate, polyetherimide, polysulfone, polyphenyl ether, polyamideimide, polyimide, polyethylene naphthalate, polyphenyl sulfide, polyether ether ketone and fluororesin. In addition to films such as polyethylene terephthalate, polybutylene terephthalate, polybutylene naphthalate, polyethylene, polypropylene,
Polystyrene, polyvinyl chloride, polyvinylidene chloride,
A film such as nylon can be used. A film having biaxial orientation is preferred. The thickness of the base material is preferably 6 μm or less from the viewpoint of sensitivity in thermal transfer recording.

As the thermal transfer ink layer in the thermal transfer recording medium of the present invention, a conventionally known ink layer can be used as it is without any particular limitation. That is, the thermal transfer ink layer used in the present invention is composed of colorants, waxes, resins and additives such as lubricants and surfactants. In this case, for example, carbon black, red iron oxide, ray liquid C, fast sky blue, benzidine yellow, phthalocyanine green, phthalocyanine blue, direct dyes, oil dyes, basic dyes, and other pigments and dyes are used as the colorant. .

Examples of the waxes include carnauba wax, oliculie wax, candelilla wax, Japan wax, cane wax, montan wax, ozokerite, microcrystalline wax,
Examples thereof include natural waxes such as ceresin wax and paraffin wax, and synthetic waxes such as Fischer-Tropsch wax, low molecular weight polyethylene, oxidized wax, and hydrogenated wax.

Examples of the resins include polyacrylic acid, polyacrylic acid ester, polymethacrylic acid,
Polymethacrylic acid ester, polyacrylamide, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, polyvinyl chloride, vinyl resins such as polyvinylidene chloride, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose,
Examples include cellulose resins such as methyl cellulose and cellulose acetate, polyester resins, polyacetal resins, epoxy resins, terpene resins, rosin resins, fluororesins, and silicone resins. As additives, fatty acids, metal salts of fatty acids, fatty acid esters, fatty acid amides,
Inorganic salts, nonionic surfactants, cationic surfactants, anionic surfactants, amphoteric surfactants and the like can be used and are not particularly limited. The thermal transfer ink layer can be formed by a known method.

[0039]

EXAMPLES Next, the present invention will be described more specifically by showing Examples and Comparative Examples. All parts, percentages and ratios shown below are based on weight. The production examples of the modified copolymer according to the present invention are shown below.

Production Example 1 10 parts of S-REC KS-5 (trade name of Sekisui Chemical Co., Ltd .: polyvinyl acetal) and 50 parts of methyl ethyl ketone were charged into a 500 ml flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introducing tube. After the temperature was raised to 70 ° C. to dissolve it, the mixture was cooled to 20 ° C., 1 part of methacryloyl isocyanate was charged and reacted for 30 minutes to introduce an unsaturated double bond. To the resulting unsaturated group-containing polyvinyl acetoacetal solution was charged 80 parts of toluene and 80 parts of ethanol, and the temperature was raised to 70 ° C again. Separately prepared FM-0
725 (Product name of Chisso Corporation: Reactive Silicone
Molecular weight 10,000) 5 parts, 3-methacryloxypropyltris (trimethylsiloxy) silane (molecular weight 422.
8) A mixed solution of 15 parts, 60 parts of methyl methacrylate, 10 parts of methacrylic acid, and 1 part of azobisisobutyronitrile was added dropwise with a dropping funnel over 2 hours, and then kept at the same temperature for 4 hours. Thus, a resin liquid having a solid content of 32% was obtained. This is designated as resin liquid A.

Production Example 2 In Production Example 1, FM-0725 was added to 5 parts of AK-30 (trade name of Toagosei Kagaku Kogyo Co., Ltd .: reactive silicone, number average molecular weight: 30000) and 3-methacryloxypropyltris (trimethylsiloxy). ) Silane 1- (3
-Methacryloxypropyl) -1,1,3,3,3-pentamethyldisiloxane (molecular weight 274.5) except that 15 parts were replaced by the same procedure as in Production Example 1 to obtain a resin liquid having a solid content of 33%. . This is designated as resin liquid B.

Production Example 3 A Denka Butyral # 600 was placed in the same flask as in Production Example 1.
20 parts of 0-C (trade name: polyvinyl butyral manufactured by Denki Kagaku Kogyo Co., Ltd.), 80 parts of toluene and 80 parts of butanol were charged and the temperature was raised to 110 ° C. Separately prepared FM-07
21 (trade name, manufactured by Chisso Corporation: reactive silicone, molecular weight 5000) 10 parts, 3-methacryloxypropyltris (trimethylsiloxy) silane (molecular weight 422.
8) A mixed solution of 15 parts, 45 parts of methyl methacrylate, 10 parts of methacrylic acid and 1 part of t-butylperoxyisopropyl carbonate was added dropwise over 2 hours, and then 11
The temperature was raised to 5 ° C. to complete the polymerization. This is a resin liquid C.

Production Example 4 100 parts of Resin A obtained in Production Example 1 and S-REC KS
30 parts of -5, 35 parts of toluene and 35 parts of ethanol were charged and stirred for 1 hour to obtain a resin liquid having a solid content of 31%. This is referred to as a resin liquid D.

Production Example 5 In a flask similar to that used in Production Example 1, Toresin F-30 (trade name: N-methoxymethylated nylon manufactured by Teikoku Kagaku Sangyo Co., Ltd.) 1 was used.
0 parts, 60 parts of methyl methacrylate, 30 parts of AK-5 (trade name of Toagosei Chemical Industry Co., Ltd .: silicon macromonomer, molecular weight of about 5000), BIC-75 (trade name of Kayaku Akzo Co., Ltd .: t-butylperoxyisopropyl) (Carbonate) 0.5 part, toluene 10 parts, methyl alcohol 20 parts, and cyclohexanone 10 parts were charged and reacted at 80 ° C. for 4 hours, and then a solution of 0.05 part of BIC-75 dissolved in 20 parts of toluene was prepared. The mixture was added and further reacted at 80 ° C. for 4 hours. Thus, a milky white resin liquid was obtained. This is a resin liquid E.

Production Example 6 A flask similar to that used in Production Example 1 was charged with methyl ethyl ketone 200.
Part, S-REC KS-5 (10 parts) were charged, dissolved at 70 ° C. by heating, and treated with methacryloyl isocyanate in the same manner as in Production Example 1, and then separately prepared FM-07.
25 A mixed solution of 20 parts, 60 parts of methyl methacrylate, 10 parts of methacrylic acid, and 1 part of azobisisobutyronitrile was added dropwise over 2 hours, and the same operation as in Production Example 1 was performed to obtain a resin liquid having a solid content of 33%. It was This is a resin liquid F.

Production Example 7 A resin liquid having a solid content of 33% was obtained in the same manner as in Production Example 6, except that FM-0725 was replaced with 3-methacryloxypropyltris (trimethylsiloxy) silane. This is a resin liquid G.

Comparative Production Example 1 Methyl ethyl ketone 200 was placed in the same flask as in Production Example 1.
Part was charged and the temperature was raised to 70 ° C, and separately prepared AK-30
35 parts, methyl methacrylate 55 parts, methacrylic acid 1
2 parts of a mixed solution of 0 part and 1 part of azobisisobutyronitrile
A resin liquid having a solid content of 34% was obtained by dropping over time. This is a resin liquid H.

The thermal transfer recording media of Examples and Comparative Examples of the present invention are shown below. Example 1 A resin solution obtained by adding a methyl ethyl ketone / cyclohexanone (9/1) solvent to the resin liquid A obtained in Production Example 1 to dilute it to a solid content of 4% was prepared. Apply to the back surface of terphthalate (PET) film with a wire bar and dry at 100 ° C for 5 seconds.
A heat resistant protective layer having a thickness of about 0.3 μm was formed. A dispersion liquid of the following thermal transfer ink components was applied to the surface of the film and dried to form a thermal transfer ink layer having an adhesion amount of about 2.8 g / m2, to obtain a thermal transfer recording medium. Thermal transfer ink components Carnauba wax 6 parts Paraffin wax 8 parts Carbon black 4 parts Toluene 82 parts

Example 2 A resin solution obtained by diluting the resin liquid B obtained in Production Example 2 with a solvent of methyl ethyl ketone / cyclohexanone (9/1) so as to have a solid content of 4% was about 4.5 μm. Thick P
Apply to the back of ET film with a wire bar, 100 ℃
And dried for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 3 A resin solution obtained by adding methyl ethyl ketone / cyclohexanone (9/1) solvent to the resin liquid C obtained in Production Example 3 to dilute it to a solid content of 4% was about 4.5 μm. Thick P
Apply to the back of ET film with a wire bar, 100 ℃
And dried for 5 seconds to form a heat-resistant protective layer having a thickness of about 0.5 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 4 A resin solution obtained by diluting the resin liquid D obtained in Production Example 4 with a solvent of methyl ethyl ketone / cyclohexanone (9/1) so as to have a solid content of 4% was about 4.5 μm. Thick P
Apply to the back of ET film with a wire bar, 100 ℃
And dried for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 5 The resin liquid E obtained in Production Example 5 was mixed with methyl ethyl ketone / cyclohexanone / isopropyl alcohol (5/2 /
3) A solvent was added to dilute the solution so that the solid content became 4%, and the obtained resin solution was applied to the back surface of a PET film having a thickness of about 4.5 μm with a wire bar and dried at 100 ° C. for 5 seconds.
A heat resistant protective layer having a thickness of about 0.3 μm was formed. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 6 A resin solution obtained by diluting the resin liquid F obtained in Preparation Example 6 with a solvent of methyl ethyl ketone / cyclohexanone (9/1) so as to have a solid content of 4% was about 4.5 μm. Thick P
Apply to the back of ET film with a wire bar, 100 ℃
And dried for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 7 A resin solution obtained by adding methyl ethyl ketone / cyclohexanone (9/1) solvent to the resin liquid G obtained in Production Example 7 to dilute it to a solid content of 4% was about 4.5 μm. Thick P
Apply to the back of ET film with a wire bar, 100 ℃
And dried for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 8 A resin solution obtained by adding methyl ethyl ketone / cyclohexanone (9/1) solvent to the resin liquid B obtained in Production Example 2 to dilute it to a solid content of 4% was added a carboxy-modified silicone. Oil (functional group equivalent 2330 mg / mol) of 4% methyl ethyl ketone / cyclohexanone (9/1)
The solution was added at 95: 5, and the solution was added to about 4.
A 5 μm thick PET film was coated on the back surface with a wire bar and dried at 100 ° C. for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 9 A resin solution obtained by adding methyl ethyl ketone / cyclohexanone (9/1) solvent to the resin liquid B obtained in Production Example 2 to dilute it to a solid content of 4% was added an amino-modified silicone. 4% of oil (functional group equivalent 1500mg / mol)
Methyl ethyl ketone / cyclohexanone (9/1) solution was added so that the ratio was 95: 5, and the solution was about 4.5 μm.
Apply with a wire bar on the back of m thick PET film,
It was dried at 100 ° C. for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Example 10 A resin solution obtained by adding methyl ethyl ketone / cyclohexanone (9/1) solvent to the resin liquid B obtained in Production Example 2 to dilute it to a solid content of 4% was added an amino-modified silicone. A 4% methyl ethyl ketone / cyclohexanone (9/1) solution of oil (functional group equivalent 840 mg / mol) was added at 95: 5, and the solution was about 4.5 μm.
Apply with a wire bar on the back of thick PET film, and
It was dried at 00 ° C. for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. In addition, on the surface of the film,
A thermal transfer ink layer was provided in the same manner as in 1. to obtain a thermal transfer recording medium.

Comparative Example 1 A resin solution obtained by diluting the resin solution H obtained in Comparative Production Example 1 with methyl ethyl ketone to a solid content of 4% was applied to the back surface of a PET film having a thickness of about 4.5 μm. It was applied with a wire bar and dried at 100 ° C. for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Comparative Example 2 A 4% solution of polyvinyl acetoacetal / alcohol-modified silicone oil (90/10) in methyl ethyl ketone / toluene (5/5) was applied to the back surface of a PET film having a thickness of about 4.5 μm using a wire bar, It was dried at 100 ° C. for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Comparative Example 3 The resin solution H obtained in Comparative Production Example 1 and KS-5 (polyvinyl acetal) 5% methyl ethyl ketone solution were diluted with methyl ethyl ketone to a solid content ratio of 80/20 to obtain a total solid content of 4%. To obtain a coating liquid. Apply this with a wire bar on the back side of a PET film with a thickness of about 4.5 μm.
It was dried at 0 ° C. for 5 seconds to form a heat resistant protective layer having a thickness of about 0.3 μm. Further, a thermal transfer ink layer was provided on the surface of the film in the same manner as in Example 1 to obtain a thermal transfer recording medium.

With respect to the thermal transfer recording media obtained in the above Examples and Comparative Examples, the film strength of the heat resistant slip protective layer, the contact angle of pure water on the surface of the heat resistant slip protective layer, and the coefficient of dynamic friction were measured by the methods described above. . Table 4 shows the measurement results.
Show. Further, printing was performed using the thermal transfer recording media obtained in Examples and Comparative Examples to prevent sticking, stain resistance of the thermal head (whether or not the hot melt adheres to the surface of the thermal head (heat melt adherence), and Presence or absence of physically removed debris on the surface of the thermal head (debris adhesion)]
Was evaluated. The evaluation results are shown in Table 5. The printing method and evaluation criteria are as shown below.

(1) Sticking Prevention Property Thermal transfer printing was performed under the following printing conditions, and the presence or absence of wrinkles due to sticking and the presence or absence of stick sound were evaluated. Printing conditions: Thermal head: Thin-film line thermal head (density 8 / mm) (Kyocera) Applied energy: 25mJ / mm2 Printing speed: 50mm / sec Platen pressing: 350gf / cm Receiving paper: White PET (Lintec) label Printing pattern: CODE39 horizontal bar code (Narr
ow 2: Wide 5dot) Cord width 30mm Length about 40mm

(2) Thermal Head Contamination Property Under the above printing conditions, thermal transfer printing was performed continuously for 100 m using a CODE39 vertical bar code (Narrow 2: Wide 6 dot) as a printing pattern, and the hot melt adhered to the thermal head heating element. The presence or absence (adhesion of hot melt) and the presence or absence of adhesion of physically removed scraps to the thermal head heating element (adhesion of scraps) were evaluated.

[0064]

[Table 4]

[0065]

[Table 5]

As is clear from Table 5, in the thermal transfer recording medium of the present invention, sticking is sufficiently prevented, and a hot melt from the heat-resistant protective layer, or dust due to abrasion of the heat-resistant protective layer adheres to the thermal head. Is prevented
The print quality was good. The thermal transfer recording media of the examples were also excellent in running property.

[0067]

According to the present invention, the occurrence of sticking can be sufficiently prevented, and the heat melt from the heat resistant protective layer or the debris due to the peeling or abrasion of the heat resistant protective layer can be prevented from adhering to the thermal head. It is possible to obtain a thermal transfer recording medium which is excellent in printing quality, has good sliding property, and has less peeling of the heat-resistant protective layer from the base material and abrasion of the heat-resistant protective layer and excellent running property.

[Brief description of drawings]

FIG. 1 is a conceptual diagram illustrating a constitution of a modified polymer which is a main component of a heat resistant slip protective layer in the present invention.

[Explanation of symbols]

 1 backbone polymer 2 vinyl polymer part in branch polymer 3 silicone part in branch polymer

Front page continuation (72) Inventor Yoichi Iwaki 8-3 Ninomachi, Mizuho-ku, Nagoya, Aichi Natcopaint Co., Ltd. (72) Inventor Shigekazu Teranishi 8-3 Ninocho, Mizuho-ku, Nagoya, Aichi Natcopaint Incorporated (72) Inventor Susumu Kawakami 8-3 Ninocho, Mizuho-ku, Nagoya, Aichi Natco Paint Co., Ltd. (72) Inventor Hironori Hata 8-3 Nino-cho, Mizuho-ku, Nagoya, Aichi Natco Paint Co., Ltd. Within

Claims (13)

[Claims] 1. A thermal transfer recording medium comprising a heat transfer ink layer on the surface of a substrate and a heat resistant protective layer on the surface of the back surface of the substrate which contacts the thermal head, wherein the heat resistant protective layer has no organic structure. A thermal transfer recording medium mainly composed of a molecular substance, wherein the heat-resistant protective layer has a film strength of 10 mN or more, a contact angle of pure water on the surface of the heat-resistant protective layer of 95 ° or more, and a dynamic friction coefficient of 0.07 or less. . 2. A thermal transfer recording medium comprising a heat transfer ink layer provided on the surface of a substrate and a heat resistant protective layer provided on the surface of the back surface of the substrate which contacts the thermal head, wherein the heat resistant protective layer comprises cellulose and a cellulose derivative. Thermal transfer characterized by being a layer whose main component is a modified copolymer consisting of a trunk polymer composed of a polymer having active hydrogen to be removed and a branch polymer composed of a copolymer of a reactive silicone and a vinyl monomer recoding media. 3. The thermal transfer recording medium according to claim 2, wherein the polymer having active hydrogen is polyvinyl acetoacetal or polyvinyl butyral. 4. The thermal transfer recording medium according to claim 2, wherein the branch polymer is a silicone-acrylic copolymer. 5. A thermal transfer recording medium according to claim 2, wherein the proportion of the reactive silicone in the modified copolymer is 5 to 60% by weight. 6. The thermal transfer recording medium according to claim 2, wherein the reactive silicone in the branch polymer comprises a reactive silicone having a molecular weight of less than 500 and a reactive silicone having a molecular weight of 5000 or more. 7. The heat resistant protective layer comprises a modified copolymer and a cellulose.
And a polymer mixture having active hydrogen except for cellulose and a cellulose derivative.
5. The thermal transfer recording medium according to 5 or 6. 8. The thermal transfer recording medium according to claim 7, wherein the glass transition temperature of the polymer having active hydrogen is 100 ° C. or higher. 9. The thermal transfer recording medium according to claim 2, wherein the heat-resistant protective layer comprises a mixture of a modified copolymer and a modified silicone oil having a reactive functional group. 10. The thermal transfer recording medium according to claim 9, wherein the reactive functional group equivalent of the modified silicone oil is 5000 mg / mol or less. 11. The thermal transfer recording medium according to claim 9, wherein the reactive functional group of the modified silicone oil is an amino group or an epoxy group. 12. A heat-resistant protective layer having a film strength of 10 mN or more, a contact angle of pure water on the surface of the heat-resistant protective layer of 95 ° or more, and a dynamic friction coefficient of 0.07 or less. The thermal transfer recording medium according to 4, 5, 6, 7, 8, 9, 10, or 11. 13. The thermal transfer recording medium according to claim 9, 10 or 11, wherein the contact angle of pure water on the surface of the heat-resistant protective layer is 110 ° or more.