JP3452752B2 - Sticking inhibitor for thermal transfer recording film and thermal transfer recording film - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an anti-sticking agent and a heat-sensitive transfer recording film used in a heat-sensitive transfer recording system.

[0002]

BACKGROUND OF THE INVENTION This type of heat-sensitive transfer recording film comprises a substrate film and a heat-sensitive ink layer provided on one side of the base film. The heat-sensitive transfer recording film has the heat-sensitive ink layer side in contact with a recording paper. Then, a pulse signal is sent from a thermal head arranged on the side opposite to the heat-sensitive ink layer side to selectively heat a predetermined portion of the heat-sensitive ink layer through the base film, and the heat-sensitive ink layer at this portion is heated. and forms a recording image is transferred onto the recording sheet by melting. Such a thermal transfer recording system has advantages that there is no noise during printing and that the recorded image has good heat resistance, water resistance, chemical resistance, plasticizer resistance, and excellent storage stability. However, on the other hand, the base film is partially melted due to the high temperature of the thermal head, and the melt adheres to the thermal head, resulting in poor transfer of the thermal transfer recording film, or the thermal sensitivity of the thermal transfer recording film. There is a problem that so-called sticking occurs, which makes it difficult to transfer from the conductive ink layer to recording paper. As a sticking prevention measure, a sticking prevention layer is provided on the thermal head side of the base film. Conventionally, as the above-mentioned sticking prevention layer, a metal layer such as aluminum, a coating layer of a lubricating material such as silicon or paraffin, a thermosetting resin layer such as polyurethane, epoxy resin or melamine resin, a fibrin derivative layer such as ethyl cellulose, etc. Is proposed. However, any of the above-mentioned conventional sticking prevention layers have insufficient sticking prevention effect, and in the case of a thermosetting resin, high temperature heating is required for a long time for curing, resulting in poor workability and poor practicality, In addition, there is a problem that the adhesion to the base film is poor even if there is an effect of preventing sticking.

[0003]

As a means for solving the above problems, it has been proposed to use a graft copolymer layer having polydimethylsiloxane as a branch component as an anti-sticking layer (JP-A-1-214475).

[0004]

However, in such a graft copolymer, silicon having no radically polymerizable group remains as unreacted silicon, and a sticking inhibitor is applied to a base film and wound up. In this case, the unreacted silicon migrates to the heat-sensitive ink-coated surface on the opposite side of the base film during winding or winding and storage, which may cause cissing when applying the heat-sensitive ink. In addition, the resulting heat-sensitive transfer recording film also has a problem that the unreacted silicon migrates to the heat-sensitive ink layer side during storage and causes transfer failure.

[0005]

As a means for solving the above-mentioned conventional problems, the present invention provides one surface of a base film.
Sensitivity transferred to recording paper by heating and melting it
Sticky for thermal transfer recording film with ink layer
A ring inhibitor, an azo group containing polydimethylsiloxane amide of poly dimethyl siloxane block copolymer produced by copolymerizing a vinyl monomer as an initiator scan ticking inhibitor, more base Recording paper by heating and melting on one side of the film
It is composed of a polydimethylsiloxane block copolymer prepared by providing a heat-sensitive ink layer to be transferred to the other surface and copolymerizing a vinyl monomer with an azo group-containing polydimethylsiloxane amide as an initiator on the other surface. The present invention provides a heat-sensitive transfer recording film having a sticking prevention layer.

[0006]

[Polydimethylsiloxane block copolymer]

The polydimethylsiloxane block copolymer used in the sticking prevention layer of the heat-sensitive transfer recording film of the present invention has the following structure. (A ¹ * a ² ) _l a ¹ * (a ¹ * a ² ) _m a ² * (a ¹ * a ² ) _n where l, m, and n are integers from ^{1 to} 10, and a ¹ is the following. A polydimethylsiloxane moiety having a structure,

[Chemical 1] a ² is a vinyl polymer portion. First, a polymer initiator method is applied to synthesize the polydimethylsiloxane block copolymer. In the polymer initiator method, for example,

[Chemical 2] When a polymer azo initiator (azo group-containing polydimethylsiloxane amide) having a polydimethylsiloxane moiety introduced therein is used and a copolymerizable vinyl monomer is copolymerized using the polymer initiator, the efficiency is improved. A block copolymer can be produced well. Further, if a polymeric initiator such as a peroxide type polymer initiator or an azo type polymer initiator is used, the polymerization can be carried out in two steps. For example, when an azo type polymer initiator is used,

[Chemical 3]

[Chemical 4] Here, m, n, n ', and l are integers of 1 or more, M ₁ is a macromonomer having the following structure,

[Chemical 5]

[Chemical 6] M ₂ is a vinyl monomer copolymerizable with M ₁ . R is an example

[Chemical 7]

[Chemical 8] Etc.

[Copolymerizable Vinyl Monomer] Examples of the copolymerizable vinyl monomer used in the above-mentioned polymer initiator method include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate. , N-butyl acrylate, iso-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, stearyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-
Propyl methacrylate, n-butyl methacrylate, is
o-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, stearyl methacrylate,
Aliphatic or cyclic acrylates and / or methacrylates such as lauryl methacrylate, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether and iso-butyl vinyl ether, styrenes such as styrene and α-methylstyrene. Nitrile monomers such as acrylonitrile and methacrylonitrile, fatty acid vinyls such as vinyl acetate and vinyl propionate, halogen-containing monomers such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride, ethylene, propylene , Olefins such as isoprene, dienes such as chloroprene and butadiene, acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, crotonic acid, atropic acid, citraconic acid, and α, β-unsaturated carboxylic acids , Acrylamide, methacrylamide, N, N-methylolacrylamide, N, N
Amides such as dimethyl acrylamide, diacetone acrylamide, methyl acrylamide glycolate methyl ether, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminopropyl methacrylate,
N, N-dimethylaminoethyl acrylate, N, N-
Amino group-containing monomers such as diethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate,
Glycidyl acrylate, glycidyl methacrylate,
Epoxy group-containing monomer such as glycidyl allyl ether,
2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, allyl alcohol, cardura E
And acrylic acid, methacrylic acid, itaconic acid, maleic acid, a reaction product with maleic acid, crotonic acid and the like, other vinylpyrrolidone, vinyl pyridine, vinyl carbazole and the like, further as a vinyl monomer having a hydrolyzable silyl group,
γ-methacryloxypropyltrimethoxysilane, γ-
Silane coupling agents such as methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropylmethoxyethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane Can be used. The above monomers may be used alone or in combination of two or more. The above examples do not limit the present invention.

[Method for Producing Polydimethylsiloxane Block Copolymer] The polydimethylsiloxane block copolymer according to the present invention comprises a vinyl monomer copolymerizable with the above-mentioned polydimethylsiloxane introduced polymer initiator. It is produced by adding and polymerizing. The above polymerization reaction is usually carried out in a solution. In the solution polymerization, toluene, aromatic hydrocarbon solvents such as xylene, acetone, methyl ethyl ketone, ketone solvents such as methyl isobutyl ketone, ethyl acetate, propyl acetate, isobutyl acetate, ester solvents such as butyl acetate, methanol, It can be used alone or as a mixed solvent of alcohol solvents such as ethanol, isopropanol, butanol, and isobutanol. In the solution polymerization, for example, benzoyl peroxide, lauryl peroxide, cumene hydroperoxide, dicumyl peroxide, t-butylperoxyisopropyl carbonate, t-
A polymerization initiator such as butyl perbenzoate, di-t-butyl peroxide, azobisisobutyronitrile, and azobisvaleronitrile can be used in combination, but it is not always necessary to use them. In the polydimethylsiloxane block copolymer thus obtained, the siloxane content is 1 to 60% by weight, preferably 5 to 40% by weight,
The content ratio of other copolymerizable vinyl monomer is 99 to 4
The content is 0% by weight, preferably 95 to 60% by weight, and it is desirable that a vinyl monomer having an OH group or an epoxy group is contained therein. The polydimethylsiloxane block copolymer thus obtained is highly compatible with other synthetic resins and is extremely effective as a compatibilizing agent, and therefore, for example, silicone resin, polyvinyl acetoacetal, polyvinyl butyral, etc. It is also possible to use a mixture of synthetic resins.

[Production of Thermal Transfer Recording Film] Examples of the base film used in the present invention include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyester, polyamide, polyimide,
There are engineering plastic films such as polyethylene terephthalate, polycarbonate, polyacetal, polyphenylene oxide, plastic films such as cellophane, and fibrin derivative films.
The sticking prevention layer is formed by coating the polydimethylsiloxane block copolymer of the present invention on one surface of the base film. When forming the sticking prevention layer, a solution prepared by dissolving the polydimethylsiloxane block copolymer in an organic solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, benzene, toluene, xylene, and tetrahydrofuran, The base film surface is coated with a spray, roll coater, knife coater, air knife coater or the like, and heated and dried if desired. The coating amount of the organic solvent solution is usually 0.01 to 5 g / m as solid content.
^{2 is} preferably 0.05 to ² g / m ² , and the thickness of the sticking prevention layer formed is usually 0.01 to 5 μm.
It is preferably 0.05 to 2 μm. The organic solvent solution of the polydimethylsiloxane block copolymer is toluene diisocyanate, tolylene diisocyanate, paraphenylene diisocyanate, polyvalent isocyanate compounds such as hexamethylene diisocyanate and melamine,
A cross-linking agent such as alcohol-modified melamine may be added.
The addition of the above-mentioned crosslinking agent can improve the heat resistance of the sticking prevention layer. Further, a curing catalyst such as dibutyltin dilaurate may be added to the organic solvent solution. Further, in the organic solvent solution, for example, another synthetic resin such as an acrylic resin, an epoxy resin, an unsaturated polyester resin, a polymer precursor such as polyester polymethacrylate, or polyester polyacrylate may be added to improve the performance of the sticking prevention layer. It may be added in an amount that does not damage it, and a filler such as calcium carbonate, carbon black or silica powder may be added. A heat-sensitive ink layer is formed on the other surface of the substrate film having the sticking prevention layer formed on one surface. As the heat-sensitive ink layer, those which have been conventionally used are used and are composed of a thermoplastic resin, a dye, a pigment and the like.
Examples of the thermoplastic resin include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, vinyl acetate-vinyl chloride copolymer, styrene-acrylonitrile copolymer. , Acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-
Acrylic acid ester-acrylamide copolymer, poly (meth) acrylic acid ester, polyvinyl acetate, thermoplastic polyamide, thermoplastic polyester, etc. are used, and as a dye, Oleosol Fast Blue EL (manufactured by Sumitomo Chemical Co., Ltd.) , Oil-soluble dyes such as Oreosol First Black BL (manufactured by Sumitomo Chemical Co., Ltd.) or Sumiplast Blue OR (manufactured by Sumitomo Chemical Co., Ltd.) are preferable, and when a pigment is added, an azo dye-based or anthraquinone-based dye is used. , Indigo-based and cyanine-based organic pigments, carbon black, chrome yellow,
An inorganic pigment such as titanium oxide is used. If desired, oils such as paraffin oil, silicone oil, mineral oil and terpene, a plasticizer such as dioctyl phthalate and dibutyl phthalate, a dispersant and a stabilizer may be further added to the heat-sensitive ink. The heat-sensitive ink is applied to the surface of the base film by the same method as the method for applying the sticking prevention layer.

[0010]

EXAMPLES [Example 1] (Production of Silicone Block Copolymer A-1) Isopropyl alcohol 20 was placed in a 500 ml flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube.
0 parts, 45 parts of methyl methacrylate, 15 parts of n-butyl methacrylate, 20 parts of 2-hydroxyethyl methacrylate, VPS-0501 (Wako Pure Chemical Industries, Ltd. product name: azo group-containing polydimethylsiloxane amide silicone chain length 5000) 20 After a certain portion was charged and stirred until it became uniform, the temperature was raised to 80 ° C. and the polymerization was completed in 5 hours. In this way, the solid content is 33.3% by weight (hereinafter simply referred to as%
To obtain a resin liquid. The obtained reaction solution was diluted with methyl ethyl ketone to a solid content of 5%, coated on a 25 μm PET film with a bar coater, and dried by heating at 100 ° C. for 3 minutes to obtain a colorless and transparent polydimethylsiloxane block having a thickness of 0.5 μm. A polymer coating was created.

Example 2 (Production of Silicone Block Copolymer A-2) VPS-0501 of Example 1 was prepared with the same equipment as in Example 1.
VPS-1001 (Wako Pure Chemical Industries, Ltd. product name:
Azo group-containing polydimethylsiloxane amide A resin liquid having a solid content of 33.3% was obtained by the same composition and operation as in Example 1 except that the silicone chain length was changed to 10000).
The obtained reaction solution was diluted with methyl ethyl ketone to a solid content of 5%, coated on a 25 μm PET film with a bar coater, and dried by heating at 100 ° C. for 3 minutes to obtain a colorless and transparent polydimethylsiloxane block having a thickness of 0.5 μm. A polymer coating was created.

Example 3 (Production of Silicone Block Copolymer A-3) With the same equipment as in Example 1, 45 parts of methyl methacrylate of Example 1, 15 parts of n-butyl methacrylate and 50 parts of methyl methacrylate, n-butyl methacrylate 10
A resin liquid having a solid content of 33.3% was obtained by the same composition and operation as in Example 1 except that the parts were changed.

The obtained reaction solution was diluted with methyl ethyl ketone to a solid content of 5%, coated on a 25 μm PET film with a bar coater, and dried by heating at 100 ° C. for 3 minutes to give a colorless transparent polydimethylsiloxane having a film thickness of 0.5 μm. A coating film of the system block copolymer was prepared.

Comparative Example 1 Isopropyl alcohol 20 was prepared using the same equipment as in Example 1.
0 parts, 45 parts of methyl methacrylate, 15 parts of n-butyl methacrylate, 20 parts of 2-hydroxyethyl methacrylate, FM-0725 (trade name of Chisso Corporation: methacryloyl type polydimethylsiloxane with one terminal silicone chain length 10,000) 20 parts, azo 1 part of bisisobutyronitrile was charged, the temperature was raised to 80 ° C., and the polymerization was completed in 5 hours. Thus, a resin liquid having a solid content of 33.3% was obtained. 5% solid content of the obtained reaction solution with methyl ethyl ketone
Diluted to 25 μm on a PET film with a bar coater and heated and dried at 100 ° C. for 3 minutes to give a film thickness of 0.5 μm.
A colorless and transparent polydimethylsiloxane-based graft copolymer coating film was prepared.

Comparative Example 2 All the same as Comparative Example 1 except that FM-0725 of Comparative Example 1 was changed to FM-0721 (trade name of Chisso Corporation: methacryloyl type polydimethylsiloxane with one terminal silicone chain length 5000). Solid content 33.3 depending on blending and operation
% Resin solution was obtained. The obtained reaction solution was diluted with methyl ethyl ketone to a solid content of 5%, coated on a 25 μm PET film with a bar coater, and dried by heating at 100 ° C. for 3 minutes to obtain a colorless transparent polydimethylsiloxane graft copolymer having a thickness of 0.5 μm. A polymer coating was created.

The films provided with the anti-sticking layers prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were cut out, and five of them were stacked so that they were alternately in contact with the front and back, and were sandwiched between two glass plates, 40 g. ² at 40 ° C with a load of / cm 2
Heated for 4 hours. After that, 50 parts of paraffin wax, 25 parts of carnauba wax, ethylene-vinyl acetate copolymer 1 were formed on the surface of the film having no sticking prevention layer.
A heat-sensitive ink consisting of 0 part and 15 parts of carbon black was applied to a thickness of 4.0 μm. Table 1 shows the results of evaluation of the degree of cissing of the ink at that time.

[0017]

[Table 1]

Further, five sheets of the heat-sensitive transfer recording sheets obtained in the above Examples and Comparative Examples were stacked so that the heat-sensitive ink coated surface and the sticking prevention layer were in contact with each other,
Scissors between two glass plates, apply a load of 40 g / cm ² ,
Heated at 60 ° C. for 24 hours. Recording was performed on these thermal transfer recording sheets up to 1.0 to 3.0 mj / dot by changing the voltage and pulse width actually applied to the thermal head. Table 2 shows the results of observation of the printing state and the sticking prevention property at that time.

[0019]

[Table 2] The sheets provided with the anti-sticking layer obtained in Examples 1 to 3 did not cause sticking and did not cause uneven printing. The sheets obtained in Comparative Examples 1 and 2 did not cause sticking, but partially inhibited transfer due to transfer of unreacted silicon to the printed surface.

[0020]

INDUSTRIAL APPLICABILITY The polydimethylsiloxane block copolymer used as the sticking prevention layer in the sticking prevention layer or the heat-sensitive transfer recording film of the present invention has a block structure of polydimethylsiloxane and vinyl monomer, No reactive silicone is present. Therefore, the heat-sensitive transfer recording film of the present invention has excellent properties such that it has good slipperiness, does not cause cissing of the heat-sensitive ink, and does not cause transfer inhibition of the heat-sensitive ink.

Continuation of front page (56) Reference JP-A-8-258439 (JP, A) JP-A-5-229271 (JP, A) JP-A-2-235693 (JP, A) JP-A-10-175379 (JP , A) JP-A-9-118081 (JP, A) JP-B 2-333053 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/38-5/40 CAPLUS (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A base film is heat-melted on one surface.
Has a heat-sensitive ink layer that is transferred to recording paper by
It is an anti-sticking agent for thermal transfer recording film.
Te, consisting polydimethylsiloxane block copolymer produced by copolymerizing a vinyl monomer with an azo group-containing polydimethylsiloxane amide as an initiator
Scan ticking inhibitor 2. A base film, which is heated and melted on one surface thereof .
By providing a heat-sensitive ink layer that is transferred to recording paper by
A sticking prevention layer made of a polydimethylsiloxane block copolymer produced by copolymerizing a vinyl monomer with an azo group-containing polydimethylsiloxane amide as an initiator is provided on the other surface. Thermal transfer recording film