JP2850364B2 - Thermal transfer recording film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Object of the Invention [Industrial Application Field] The present invention relates to a heat-sensitive transfer recording film, and more specifically, a heat-sensitive ink layer on one surface of a substrate.
The present invention relates to a thermal transfer recording film having a stick prevention layer on the other side.

[Conventional technology]

The thermal transfer recording film is used in printers, recorders, and the like of various office equipment that employ the thermal transfer recording method.

In the thermal transfer recording method, a recording paper as a material to be transferred is brought into contact with a thermal ink layer provided on a film as a substrate, and a thermal head on a side opposite to the ink layer uses a pulse signal to transfer the substrate film. Select heating. The ink layer heated through the film is transferred to the recording paper by melting or sublimation to form a recorded image, has no noise during printing, has good heat resistance and chemical resistance of printing,
This recording method has advantages such as excellent storage stability.

In a thermal transfer recording film used in such a thermal transfer recording method, a part of the film is melted due to a high temperature of the thermal head, and the molten resin is fixed to the thermal head, so that the transport of the film becomes poor, There is a problem that sticking occurs, which makes it difficult to transfer graphics and the like to recording paper. In order to solve this problem, the following various stick preventing layers are provided on the film surface in contact with the thermal head. That was generally done. That is, there have been proposals to provide a metal layer such as aluminum as a stick prevention layer, apply silicone, paraffin, or the like, use a thermosetting resin layer such as urethane, epoxy, or melamine, or use an ethyl cellulose layer.

However, all of these have insufficient stick prevention effects, and when a thermosetting resin is used, a high-temperature, long-time heat treatment is required for its curing, resulting in poor workability and practicality. There were problems such as scarcity. In addition, even if the stick has an effect of preventing sticking, there are problems such as poor adhesion to a pace film, poor film formability, and corrosion of a thermal head.

As a means for solving such a problem, the above-mentioned polydimethylsiloxane produced by copolymerizing a silicone-based macromonomer having a radical polymerizable group bonded to one end of polydimethylsiloxane with an alkyl (meth) acrylate or the like is used. It has been proposed to use a graft polymer having dimethylsiloxane as a branch component as a stick inhibitor and to provide a stick prevention layer comprising the same (Japanese Patent Application Laid-Open Nos. 62-30082 and 62-1575). The above-mentioned graft polymer has good film-forming properties, and in the state of a coated film, a branch component composed of polydimethylsiloxane having heat resistance and lubricity is provided on the surface, that is, on the side opposite to the base film. Since the trunk component mainly composed of monomer units such as alkyl (meth) acrylate having orientation and adhesiveness is oriented toward the base material, the adhesion to the base material is excellent, and the sticking is suppressed. Was also said to be good.

However, conventional silicone-based macromonomers,
Especially the general formula (N is a positive number; R ₁ and R ₂ are monovalent saturated aliphatic hydrocarbon groups having 1 to 10 carbon atoms); (R is a hydrogen atom or a methyl group; m is 0 or 1; l is an integer of 0 to 2 when m = 0, and 2 when m = 1;
Is 1, 2 or 3; R ₃ methyl group, ethyl group or phenyl group; X
Is an alkoxy group having 1 to 10 carbon atoms, an acetoxy group or a chlorine atom. The silicone-based macromonomer obtained by condensation with the organosilicon compound having a (meth) acryloyl group represented by the formula (1) contains unreacted silicone, that is, silicone having no radically polymerizable group. When a silicone-based graft polymer produced from the above as a raw material is used as a stick inhibitor, the following problems still remain.

That is, a normal heat-sensitive transfer recording film is formed by applying a stick preventing agent to a base film and winding it up.
Thereafter, it is manufactured by a method in which it is rewound and a thermal ink is applied to the other surface. However, the silicone-based graft polymer contains a small amount of silicone to which the organosilicon compound is not added (hereinafter referred to as unreacted silicone). When used as an anti-stick agent, unreacted silicone migrates to the surface on which the heat-sensitive ink layer is provided during winding or storage of the wound roll, and the ink is applied. In the process of performing ink repelling, it is difficult to obtain a uniform ink layer, and the obtained thermal transfer recording film also undergoes a similar transition from the stick prevention layer to the thermal ink layer during storage in a roll, As a result, there is a problem that the transfer printing on the recording paper becomes unclear.

As a method for solving the above-mentioned problem caused by the unreacted silicone, the present inventors have proposed a compound represented by the general formula which is one of the organosilicon compounds represented by the above general formula. (R is a hydrogen atom or a methyl group; m is 0 or 1; l is an integer of 0 to 2 when m = 0, and 2 when m = 1; X
Is an alkoxy group having 1 to 10 carbon atoms, an acetoxy group or a chlorine atom. ) And an organic silicon compound represented by the general formula (N is a positive number of 100 to 600; R ₁ and R ₂ are monovalent saturated aliphatic hydrocarbons having 1 to 10 carbon atoms, a phenyl group or a halogenated hydrocarbon group) and 1 mole of silicone By performing a condensation reaction at a molar ratio of 1.3 to 3 moles of the organosilicon compound per mole, it is possible to obtain a silicone macromonomer having a very low content of unreacted silicone, and to obtain a silicone macromonomer and another radical polymerizable monomer. A patent application has been filed for a thermal transfer recording film provided with a stick prevention layer comprising a silicone-based graft polymer obtained by radical copolymerization with a monomer (Japanese Patent Application No. 63-37620).

However, even in the thermal transfer recording film of the above patent application, the adhesion of the stick inhibitor to the film is insufficient, and the heat resistance of the stick inhibitor has not yet reached the desired level. is there.

(B) Configuration of the Invention [Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above problems, and as a result, have completed the present invention.

That is, the present invention provides a heat-sensitive transfer recording film, comprising a heat-sensitive ink layer on one side of a film as a base material and a stick prevention layer made of a silicone-based graft polymer on the other side. A system-based graft polymer is obtained by combining an organosilicon compound represented by the following general formula (A) and a silicone represented by the following general formula (B) with an organosilicon compound of 1.3 to 3 per mol of silicone.
A step of synthesizing a silicone macromonomer by performing a condensation reaction at a molar ratio, and a step of synthesizing the silicone macromonomer, the α, β-unsaturated carboxylic acid and other radically polymerizable monomers synthesized in the above step. Produced by the step of polymerizing, the unit comprising the silicone-based macromonomer as a branch component, the unit comprising the α, β-unsaturated carboxylic acid and other radically polymerizable monomer units, and having a Tg of 80 ° C. or higher. A graft polymer having a polymer as a trunk portion, wherein the graft polymer contains 1 to 30% by weight of the α, β-unsaturated carboxylic acid unit based on the total amount of all the constituent units. Is a heat-sensitive transfer recording film.

General formula (A) (R is a hydrogen atom or a methyl group; m is 0 or 1; l is an integer of 0 to 2 when m = 0, and 2 when m = 1; X
Is an alkoxy group having 1 to 10 carbon atoms, an acetoxy group or a chlorine atom. ) General formula (B) (N is a positive number of 100 to 600; R ₁ and R ₂ are a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, a phenyl group or a monovalent halogenated hydrocarbon group.) Hereinafter, the present invention will be described. This will be described in more detail.

[Organosilicon compound] The organosilicon compound used in the present invention is represented by the general formula (A) (R is a hydrogen atom or a methyl group; m is 0 or 1; l is an integer of 0 to 2 when m = 0, and 2 when m = 1; X
Is an alkoxy group having 1 to 10 carbon atoms, an acetoxy group or a chlorine atom. ), Specifically, γ
-(Meth) acryloyloxypropyltrimethoxysilane, r- (meth) acryloyloxypropyltrichlorosilane, 3- (2- (meth) acryloyloxyethoxy) propyltrimethoxysilane, 3- (2- (meth) acryloyloxyethoxy) ) Propyltrichlorosilane, 5-((meth) acryloyloxy) bentyltrimethoxysilane, 5-((meth) acryloyloxy) bentyltrichlorosilane and the like.

Among them, r-methacryloyloxypropyltrimethoxysilane is most preferable in terms of availability and low cost.

〔silicone〕

The silicone in the present invention has the general formula (B) (N is a positive number of 100 to 600; R ₁ and R ₂ are a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, a phenyl group or a halogenated hydrocarbon group). For example, Toshiba Silicone Co., Ltd. product name XF39
05 magnitude.

Examples of the monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms in the general formula (B) include a methyl group, an ethyl group, and a decyl group, and examples of the monovalent halogenated hydrocarbon group include: 3,3,3-trifluoropropyl group, 4,
Examples thereof include a 4,4-trifluoro-3,3-difluorobutyl group and a 2-chloroethyl group. Particularly preferred as R ₁ and R ₂ is a methyl group.

The silicone-based macromonomer derived from a silicone having a high molecular weight in which n exceeds 600 in the general formula (B) has a low copolymerizability with a radically polymerizable monomer, so that a large amount of unpolymerized macromonomer remains. In silicone-based macromonomers derived from silicones having n less than 100, the bifunctional silicone-based macromonomer in which an organosilicon compound is added to both ends of the silicone contained therein has a short molecular chain length. Too much, gelation occurs during copolymerization with the radical polymerizable monomer due to the macromonomer. Silicones wherein n is from 200 to 500 are more preferred.

[Production of silicone macromonomer]

The silicone-based macromonomer in the present invention is a silicone-based macromonomer obtained by subjecting the organosilicon compound and silicone to a condensation reaction in the range of 1.3 to 3 mol of the organosilicon compound per 1 mol of silicone.

Most of the above-mentioned condensation reactions follow the chemical reaction formula shown below, and as described in detail below, a catalyst is optionally used in an organic solvent inert to organosilicon compounds and silicone. Etc. can be used.

When the molar ratio of the organosilicon compound to the silicone is less than 1.3 mol per mol of the silicone, the resulting silicone macromonomer contains a large amount of unreacted silicone. In a heat-sensitive transfer recording film in which is used as a stick inhibitor, repelling of the ink occurs when the heat-sensitive ink is applied.

When the amount of the organosilicon compound exceeds 3 mol, the viscosity of the obtained silicone-based graft polymer is significantly increased.
The leveling property is also poor, and it is difficult to obtain a thin and uniform coating at the time of coating.

 The condensation reaction will be described in more detail.

For example, X of the organosilicon compound represented by the general formula (A)
Is a chlorine atom, a solution of silicone and an acid acceptor in a suitable solvent shown below at a concentration of 10 to 50% by weight,
Organosilicon compound or its compound in a suitable solvent shown below
If a solution dissolved at a concentration of ~ 50% by weight is dropped at room temperature,
The reaction proceeds smoothly immediately. After the reaction, the generated acid acceptor hydrochloride is separated by filtration, and then, if necessary, is washed with water, and the solvent is evaporated to obtain a desired silicone macromonomer. The solvent that can be used in this reaction is preferably a solvent that dissolves both reaction components and is inert to both components under the reaction conditions. Suitable solvents include, for example, diethyl ether, tetrahydrofuran, acetone, benzene, toluene, xylene, and mineral spirits. And the like. As the acid acceptor, known amines can be used, for example, pyridine, triethylamine,
Aniline and the like are preferably used. The amount of the acid acceptor used is preferably about 1.2 times the molar amount of hydrochloric acid generated by the dehydrochlorination reaction.

When X of the organosilicon compound represented by the general formula (A) is an alkoxy group having 1 to 10 carbon atoms, a macromonomer is obtained by a dealcoholization condensation reaction between silicone and the organosilicon compound. This reaction can be carried out without a catalyst, but catalysts conventionally used in transesterification reactions to promote the reaction, such as sulfuric acid, p-toluenesulfonic acid, sodium hydroxide, potassium hydroxide,
Potassium acetate, dibutyltin dilaurate and the like can be used, and preferred catalysts include p-toluenesulfonic acid. The amount of the catalyst is preferably about 0.01 to 5% by weight based on the total amount of the silicone and the organosilicon compound.

The reaction temperature in the dealcoholization condensation reaction is from 50 ° C.
150 ° C. is preferable, and the reaction time is preferably 1 to 20 hours.
In addition, this reaction can be performed without a solvent or with a solvent, and usable solvents include benzene, toluene,
Xylene, mineral spirit and the like can be mentioned.

After the completion of the reaction, it is preferable to remove the used catalyst. As a removing method, a known method can be applied, but a method of removing the catalyst by adsorbing it on an ion exchange resin is easy in operation.

When X of the organosilicon compound represented by the general formula (A) is an acetoxy group, a macromonomer is obtained by a deacetic acid condensation reaction between the silicone and the organosilicon compound. In this case, the same operation as in the case where X is an alkoxy group can be used for the reaction operation.

(Silicone graft polymer)

In the present invention, the silicone-based graft polymer (hereinafter simply referred to as a graft polymer) includes the silicone-based macromonomer (hereinafter simply referred to as a macromonomer), α,
It is a graft polymer obtained by radical copolymerization of β-unsaturated carboxylic acid and other radically polymerizable monomers, and, as described above, the Tg of the polymer constituting the backbone thereof is 80 ° C. or higher, Moreover, the α, β-
A graft polymer wherein the amount of unsaturated carboxylic acid units is from 1 to 30% by weight, based on the total amount of all constituent units of the graft polymer.

The preferred amount of the macromonomer used in the radical copolymerization for obtaining the silicone-based graft polymer is 2 to 60% by weight, more preferably 5 to 50% by weight, based on the total amount of the whole monomers to be subjected to the copolymerization. %.

When the amount of the macromonomer is less than 2% by weight, the stick preventing effect is not sufficient when used as a stick preventing agent. Phase is easily separated during storage, and it is difficult to obtain a stable solution.

Examples of the α, β-unsaturated carboxylic acid include monounsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, diunsaturated carboxylic acids such as maleic acid and fumaric acid, and half esters thereof, and maleic anhydride. And acrylic acid and methacrylic acid are preferred because of their excellent polymerizability.

In the present invention, it is necessary to introduce the α, β-unsaturated carboxylic acid unit into the backbone polymer in the graft polymer in the above-mentioned amount. If the amount of the unit is less than 1% by weight, the graft polymer The stick prevention layer having poor heat resistance and high heat resistance cannot be obtained. On the other hand, if it exceeds 30% by weight, phase separation occurs during polymerization for obtaining the graft polymer or during storage. A more preferred amount of the α, β-unsaturated carboxylic acid unit in the graft polymer is 3 to 20% by weight.

The radical polymerizable monomer used in addition to the macromonomer and the α, β-unsaturated carboxylic acid is a graft polymer formed by the radical polymerizable monomer unit and the α, β-unsaturated carboxylic acid unit. Any monomer can be used as long as it can make the Tg of the polymer constituting the backbone of the polymer 80 ° C. or higher. For example, from the following monomers and the like, one or more monomers are appropriately selected and used. be able to. The preferred use amount is 40 to 97% by weight based on the total amount of all monomers subjected to polymerization to obtain a graft polymer.

Other radical polymerizable monomers that can be used in the present invention include methyl acrylate, alkyl acrylates such as ethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
Alkyl methacrylate such as butyl methacrylate, hydroxyethyl methacrylate, hydroxyalkyl methacrylate such as hydroxypropyl methacrylate,
Styrene, α-methylstyrene, acrylonitrile and the like can be mentioned, and preferred are methyl methacrylate and t-butyl methacrylate.

Further, an organic silicon monomer such as vinyltriethoxysilane and γ-methacryloxypropyltrimethoxysilane is used together with the radical polymerizable monomer in a small amount such that gelation does not occur during the production of the graft polymer. You may.

The Tg of the polymer forming the backbone of the graft polymer is 80
If it is less than ℃, when used as a stick inhibitor, it is easily softened by high-temperature heating by a thermal head,
Does not withstand long-term use.

The Tg or glass transition temperature of the trunk polymer is calculated by the following formula based on the Tg of the homopolymer of each monomer constituting the trunk polymer and the polymerization ratio of the monomer in the trunk polymer. Tg.

As the radical copolymerization method for obtaining the graft polymer, for example, a known method such as a radiation irradiation method and a method using a radical polymerization initiator can be used. It is preferable from the viewpoint of easy control of the molecular weight of the graft polymer to be formed, and it is preferable to use a solution polymerization method using a solvent.

Since the graft polymer in the present invention is a so-called amphiphilic graft polymer having a strongly hydrophilic carboxylic acid-containing polymer and a backbone polymer and a strongly hydrophobic silicone as a branch polymer, when a solution polymerization method is employed, The choice of the solvent is important, and preferred solvents are acetone, methyl ethyl ketone, ketone solvents such as methyl isobutyl ketone, ethyl acetate, acetic acid ester solvents such as butyl acetate, and other polar solvents such as tetrahydrofuran, dimethylformamide, and dimethyl sulfoxide. A ketone solvent or a mixed solvent of a ketone solvent and another solvent is more preferable.

As the radical polymerization initiator, any one used in general radical polymerization can be used, and an appropriate one may be selected according to the polymerization method. For example, as the inorganic radical polymerization initiator, ammonium persulfate is used, and as the organic radical polymerization initiator, peroxyketal, hydroperoxide, cycloalkyl peroxide, diacyl peroxide, peroxydicarbonate, Azo compounds represented by oxyesters and azobisisobutyronitrile, and the like,
In that a relatively low polymerization temperature can be adopted, side reactions are suppressed, and a graft polymer with a clear structure can be obtained with high purity.
Organic peroxides and azo compounds having a low decomposition temperature are preferred, and azo compounds are particularly preferred. As an azo compound, both nitrogen atoms of the azo bond are bonded to the third carbon atom,
The remaining valence of the third carbon atom is preferably 1 to
And azo compounds satisfied by a nitrile, carboxyalkyl, cycloalkylene or alkyl group up to 18, and azobisisobutyronitrile (hereinafter AIBN).
) Is most preferred.

In the case of copolymerization by an ultraviolet irradiation method, a known sensitizer is used as a radical polymerization initiator. On the other hand, in the case of copolymerization by an electron beam irradiation method, it is not necessary to use a radical polymerization initiator.

The amount of the radical polymerization initiator is generally from 0.01 to 5% by weight, preferably from 0.1 to 2% by weight, based on the total weight of the polymerizable component.

The temperature of the radical copolymer is preferably equal to or higher than the decomposition temperature of the radical polymerization initiator, but if the reaction temperature is too high, a side reaction such as a crosslinking reaction occurs. Generally, the temperature is between 50 and 150C, preferably between 60 and 100C.

The polymerization time is generally 3 to 100 hours, preferably 10 to 25 hours.
Time.

The number average molecular weight (number average molecular weight in terms of polystyrene by gel permeation chromatography) of the graft polymer produced by the above method is 25,000 to 100,
000.

[Formation of stick prevention layer]

The formation of the stick prevention layer on the base film is performed by coating the organic solvent solution of the graft polymer with a gravure roll coater, a reverse roll coater or a method such as an air knife coating method. It can be carried out by a method such as a method of coating on the surface of paper such as a film made of film or a condenser paper, a cellophane paper and then heating and drying.

As a material of the base film, polyethylene terephthalate (hereinafter abbreviated as PET) is preferable in terms of heat resistance and base strength, and the thickness of the film is not particularly limited, but is usually 2 to 50 μm, preferably 3 to 10 μm. It is.

In forming the stick prevention layer, a polyvalent isocyanate compound or a melamine curing agent may be used in combination with the graft polymer.

Since the graft polymer in the present invention contains a carboxyl group, the stick preventing layer can be cross-linked and cured by using the above reactive compound in combination. When a hydrolyzable functional group bonded to a silicon atom is present in the graft polymer to be used, crosslinking and curing can be performed using the functional group in the presence of a catalyst such as dibutyltin dilaurate.

In addition, as a stick inhibitor, together with the graft polymer, an acrylic resin, an epoxy resin, an unsaturated polyester resin, and furthermore, as long as the properties of stick prevention and the like provided by the graft polymer are not impaired. A curable composition comprising a radical polymerizable component as a polymer precursor such as polyester polymethacrylate or polyester polyacrylate disclosed in JP-A 120889 can be blended.

The allowable amounts of these resins are not constant depending on the types of resins to be compounded.However, in order to simultaneously exhibit excellent characteristics of silicone, excellent adhesion to a base material, etc., the total amount of the graft polymer and these resins is required. 50% by weight or less on the basis is desirable.

Also, talc, calcium carbonate, carbon black, silica powder, etc., for improving the heat resistance of the anti-stick layer, a fluororesin powder, etc., for improving the slipperiness of the resulting thermal transfer recording film, and further, the film is charged. For prevention, a known antistatic agent or the like may be added to the organic solvent solution of the graft polymer to coat the base film.

The coating amount (solid content) of the film of the graft polymer on the film is preferably 0.01 to ² g / m ^{2 in} terms of flexibility, thermal transfer efficiency of the thermal head, and cost.
More preferably, it is 0.05 to 1 g / m ² .

[Thermal ink layer]

The heat-sensitive ink layer in the present invention can be formed by a known method using a heat-sensitive ink composed of a thermoplastic resin, a dye, a pigment, and the like, which has conventionally been generally used for forming the layer.

As the thermoplastic resin, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, vinyl acetate-vinyl chloride copolymer, styrene-acrylonitrile copolymer, styrene-
Acrylonitrile-butadiene copolymer, styrene-acrylate-acrylamide copolymer, styrene-butadiene copolymer, poly (meth) acrylate, polyacrylonitrile, acrylonitrile-vinyl acetate copolymer, polyvinyl acetate, polyamide and Copolyester and the like.

As the dye, an oil-soluble dye is preferable. For example, oleozole fast blue EL (manufactured by Sumitomo Chemical Co., Ltd.),
Various oil-soluble dyes such as oleozole first black BL (manufactured by Sumitomo Chemical Co., Ltd.) and Sumiblast Blue OR (manufactured by Sumitomo Chemical Co., Ltd.) are commercially available. Can be used.

When the pigment is contained in the heat-sensitive ink layer, the pigment to be used may be an organic pigment or an inorganic pigment.Examples of the organic pigment include known organic pigments belonging to azo dye series, anthraquinone series, indigoid series and cyanine series. Examples of the inorganic pigment include carbon black.

Further, an appropriate amount of various oils, various dispersants, plasticizers, stabilizers and the like may be added to the heat-sensitive ink layer as needed.

The thermal ink can be coated on the base film by the same coating method as in the formation of the stick prevention layer.

(Examples, Reference Examples and Comparative Examples)

Hereinafter, the present invention will be described more specifically with reference to Examples, Reference Examples, and Comparative Examples.

The amount of unreacted silicone present in the macromonomer in Reference Examples 1 to 5 was determined by the following method of measuring the amount of unpolymerized silicone in the graft polymer produced from the macromonomer. Also,
Parts and% represent parts by weight and% by weight, respectively.

Unreacted silicone weight: stirrer, was placed a condenser, N ₂ inlet tube, 150 parts of toluene in a flask equipped with a dropping funnel, the macromonomer 20
Part and methyl methacrylate (hereinafter abbreviated as MMA) 80
Part of AIBN and 1 part of AIBN into a dropping funnel, toluene was bubbled with N ₂ , and then the temperature was raised to 80 ° C.
It was added dropwise over time to polymerize. After aging at this temperature for 1 hour, 1 part of AIBN was added, and the mixture was further heated at the same temperature for 2 hours. The resulting solution was distilled under reduced pressure to obtain a white solid graft polymer.

This graft polymer was pulverized, and 20 g of the powder and n-hexane 1 were put in an Erlenmeyer flask, and allowed to stand at room temperature for 24 hours to extract unreacted silicone. Next, filtration was performed, and the obtained filtrate was distilled under reduced pressure to remove n-hexane, whereby unreacted silicone oil was obtained as a residue. The amount determined by the following equation was used as a scale indicating the amount of unreacted silicone.

For analysis of the silicone in the graft polymer before extraction, about 0.2 g of the copolymer was precisely weighed in a platinum crucible, and about 3 ml of concentrated sulfuric acid was added thereto.
The mixture was heated at 2 ° C. for 2 hours, and the silicone was converted into SiO ₂ and weighed.

Reference Examples 1 to 5 A flask equipped with a stirrer, a condenser, and a thermometer was charged with α, ω-dihydroxypolydimethylsilyl. N was an average of 300] 111 g (0.005 mol), 0.12 g of p-toluenesulfonic acid, 74 g of toluene, and 37 g of methyl ethyl ketone (hereinafter abbreviated as MEK) were charged.
Was added in the amount shown in the column of each reference example. Next, the mixed solution was heated at 70 ° C. for 3 hours. After cooling, 30 g of a basic anion exchange resin (A-21 manufactured by Organo Corporation) was added to the reaction solution, and the mixture was neutralized by stirring at 40 ° C. for 2 hours. The ion exchange resin was removed by filtration, the filtrate was distilled under reduced pressure, and the solvent was removed to obtain a colorless and transparent oily macromonomer. As a result of analyzing the filtrate by gas chromatography, γ-methacryloyloxypropyltrimethoxysilane was not detected, and the reaction rate was 100%.

The number average molecular weight (number average molecular weight in terms of polystyrene by gel permeation chromatography) of the obtained macromonomer was as shown in Table 1.

For the macromonomer obtained in Reference Examples 1 to 5, the result of measuring the amount of unreacted silicone by the above-described measurement method is as follows:
Reference Example 1; 8%, Reference Example 2; 5%, Reference Example 3; 5%, Reference Example 4; 3
%, Reference Example 5; 2%. From the above results, the macromonomer obtained under the reaction conditions in which the reaction molar ratio of silicone / organosilicon compound is within the range specified in the present invention, when the graft polymer was produced using this, It can be seen that the amount of unreacted silicone therein is extremely small.

Examples 1 to 4. 100 parts of MEK was previously charged in a flask equipped with a stirrer, a condenser, a thermometer, a dropping funnel, and a nitrogen inlet tube (hereinafter referred to as solution A). Macromonomer 30 parts shown in 2, MM as monomer for trunk polymer
A60 parts, methacrylic acid 10 parts [Tg of the trunk polymer is 119 ° C .; Tg of each homopolymer of MMA and methacrylic acid is T
g (MMA) = 378 ° K, Tg (methacrylic acid) = 501 ° K], and 1.0 part of a polymerization initiator AIBN (hereinafter referred to as solution B). Heating,
Then, the solution B was added dropwise over 2 hours. Thereafter, after aging at the same temperature for 1 hour, 0.3 part of AIBN was additionally charged, and the mixture was maintained at the same temperature for another 2 hours to complete the polymerization.

The obtained reaction solution was diluted with MEK to a solid content of 15% to a thickness of 6%.
μ PET film with a bar coater, and
After drying by heating for 0 second, a colorless and transparent graft polymer coating film having a thickness of 0.5 μm was provided.

Cut out the film provided with the stick prevention layer obtained in this way, stack the five sheets so that they alternately contact the front and back, sandwich them between two glass plates, and apply 60 g of them under a load of 40 g / cm ^2.
For 24 hours. Then, 50 parts of paraffin wax part, 25 parts of carbana wax, ethylene-vinyl acetate copolymer 10 were added to the surface of the film without the stick prevention layer.
And a hot-melt ink composed of 15 parts of carbon black was subjected to hot melt coating so as to have a thickness of 40 μm. The result of evaluating the degree of cissing of the ink at that time is as follows:
It is as shown in Table-12.

The thermal transfer recording sheets obtained in Examples 1 to 4 were subjected to a sticking evaluation test by changing the voltage and pulse width actually applied to the thermal head by 1.0 mJ / do.
Recording was performed from t to 3.0 mJ / dot, and the printing quality and the effect of preventing sticking were observed. As a result, even at 3.0 mJ / dot, sticking did not occur, good printing was obtained, and stable running performance was exhibited.

In addition, when the dynamic friction coefficient of the stick prevention layer made of the graft polymer obtained in Examples 1 to 4 was measured using the following device, each value was in the range of 0.04 to 0.05, and extremely good lubricity was obtained. Indicated.

Apparatus HEIDON (TYPE: HEIDON)
-14D ・ REC / 14D ・ ANL) Measurement conditions Contact: Stainless steel ball with a diameter of 10mm, load 50g Movement speed: 150mm / min Example 5 Performed except for using the macromonomer synthesized in Reference Example 2 as the macromonomer. A graft polymer was obtained in the same manner as in Examples 1 to 4, a stick layer was formed on the PET film, and the same press heat treatment as in each of the above examples was performed.

Next, as the ink composition, Sumiplast RED-FB
(Sumitomo Chemical Co., Ltd.) Using an ink prepared by uniformly mixing and dispersing 10 parts of a sublimable dye, 10 parts of hydroxyethylcellulose, 40 parts of toluene and 10 parts of isopropyl alcohol in a ball mill for 24 hours. The degree of cissing was checked.

As a result, no cissing of the ink was observed.
In addition, as a sticking evaluation test, the resulting thermal transfer recording film was recorded from 1.0 mJ / dot to 3.0 mJ / dot by changing the voltage and pulse width actually applied to the thermal head, and the printing quality and sticking prevention effect were evaluated. As a result of observation, sticking did not occur even at 3.0 mJ / dot, a good impression was obtained, and stable running performance was exhibited.

Comparative Example 1 A graft polymer solution was obtained by the same operation as in Examples 1 to 4 except that the macromonomer synthesized in Reference Example 1 was used as a monomer component, and then the obtained graft polymer solution was used. When the ink was applied to the opposite surface of the film provided with the stick prevention layer in the same manner as in Nos. 1 to 4, ink repelling was partially observed.

Example 6 and Comparative Example 2 (Example 6) Using 100 parts of MEK / MIBK = 1/1 (weight ratio) as a polymerization solvent, 30 parts of a macromonomer synthesized in Reference Example 4 as a monomer component, 45 parts of MMA, 20 parts of butyl methacrylate, 5 parts of methacrylic acid [Tg of the trunk polymer is 82 ° C .; Tg of each homopolymer of the trunk monomer is Tg (MMA) = 378 ° K, Tg (butyl methacrylate) = 293 ° K, Tg (methacrylic acid) = 501K]
A graft transfer polymer solution was obtained in the same manner as in Examples 1 to 4, except that the above-mentioned was used. Then, a thermal transfer recording film was produced in the same manner as above using the obtained graft polymer solution.

(Comparative Example 2) Except for using 32.5 parts of MMA, 32.5 parts of butyl methacrylate, and 5 parts of acrylic acid as the monomer for the trunk polymer (the Tg of the trunk polymer is 60 ° C), the same procedure as in Example 6 was carried out. A thermal transfer recording film was manufactured.

The thermal transfer recording films produced in Example 6 and Comparative Example 2 were subjected to the same evaluation tests as those performed on the thermal transfer recording films produced in Examples 1 to 4, and as a result, the film of Example 6 was obtained. In this case, there is no ink cissing, transfer printing is good, and 3.0mJ / dot
Also, no sticking occurred and stable running performance was exhibited.

On the other hand, in the film of Comparative Example 2, ink repelling did not occur, but sticking occurred at 2.0 mJ / dot, and stable running properties could not be obtained.

Example 7 100 parts of the graft polymer solution obtained in Example 1 was added to MEK
After diluting to a solid content of 15% with an aqueous solution, 6.5 parts of coronate EH (manufactured by Nippon Polyurethane Co., Ltd.) as an isocyanate compound was added, and an evaluation test was performed on the thermal transfer film in the same manner as in Example 1. There is no hajiki at all,
Transfer printing was good, and sticking did not occur even at 3.0 mJ / dot, and stable running properties were exhibited. Also,
When the dynamic friction coefficient was measured, it was 0.030, and the lubricity was extremely good.

Example 8 As a monomer component, 5 parts of the macromonomer synthesized in Reference Example 2, 85 parts of MMA, and 10 parts of methacrylic acid (Tg of the trunk polymer)
At 132 ° C., a graft polymer solution was obtained by the same polymerization method as in Examples 1 to 4, and then an evaluation test was performed on a heat-sensitive transfer film having a stick protective layer formed using the obtained graft polymer solution. .

As a result, there was no repelling of the ink, the transfer printing was good, and even at 3.0 mJ / dot, sticking did not occur and stable running properties were exhibited. The dynamic friction coefficient was measured to be 0.060, and the lubricity was extremely good.

Comparative Example 3 A graft polymer solution was obtained in the same manner as in Example 1 except that 30 parts of the macromonomer obtained in Reference Example 2 was used as the macromonomer and 70 parts of MMA was used as the monomer for the trunk polymer. In the same manner as in Example 1, a thermal transfer recording film was produced.

About the obtained thermal transfer recording film, Examples 1 to
As a result of performing the same test as in Example 4, no repelling of the ink occurred, but sticking occurred at 3.0 mJ / dot, and stable running performance was not obtained.

(C) Effects of the Invention The silicone graft polymer of the present invention contains only a small amount of unreacted silicone, has a sufficiently large molecular weight of the branch component, and contains α, β- Since the polymer is a graft polymer having an unsaturated carboxylic acid unit and a Tg point of the polymer of 80 ° C. or higher, the heat-sensitive transfer recording film of the present invention provided with a stick prevention layer using this as a stick prevention agent is lubricated. Good
It is useful as a heat-sensitive transfer recording film that has no repelling phenomenon of the heat-sensitive ink, has excellent stick prevention effect, and has particularly excellent heat resistance, and has long-term running stability.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41M 5/38-5/40

Claims (1)

(57) [Claims] 1. A heat-sensitive transfer recording film comprising a base film having a heat-sensitive ink layer on one surface and a stick-preventing layer made of a silicone-based graft polymer on the other surface. A graft polymer is obtained by subjecting an organosilicon compound represented by the following general formula (A) and a silicone represented by the following general formula (B) to a condensation reaction at a ratio of 1.3 to 3 mol of the organosilicon compound per 1 mol of the silicone. A step of synthesizing a silicone-based macromonomer, and a step of copolymerizing the silicone-based macromonomer, α, β-unsaturated carboxylic acid and other radically polymerizable monomer synthesized in the above step, A unit composed of a macromonomer as a branch component, and the α, β-unsaturated carboxylic acid and other radical polymerization It consists of a monomer unit, and a Tg
A graft polymer containing a polymer having a temperature of 80 ° C. or higher as a trunk component, the graft polymer containing 1 to 30% by weight of the α, β-unsaturated carboxylic acid unit based on the total amount of all the constituent units. A heat-sensitive transfer recording film characterized in that: General formula (A) (R is a hydrogen atom or a methyl group; m is 0 or 1; l is an integer of 0 to 2 when m = 0, and 2 when m = 1; X
Is an alkoxy group having 1 to 10 carbon atoms, an acetoxy group or a chlorine atom. ) General formula (B) (N is a positive number of 100 to 600; R ₁ and R ₂ are a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, a phenyl group or a monovalent halogenated hydrocarbon group.)