TW201420344A - Polyvinyl alcohol-based film and manufacturing method thereof, laminate for heat transfer printing using polyvinyl alcohol-based film and heat transfer printing method using same - Google Patents

Abstract

This invention aims to provide a polyvinyl alcohol-based resin film, a method of manufacturing the polyvinyl alcohol-based film, a laminate for heat transfer printing using the polyvinyl alcohol-based film and a heat transfer printing using the same, which have excellent mold release property to be better applied to a base film for a laminate for heat transfer printing. The polyvinyl alcohol-based film of this invention is characterized by comprising, relative to 100 parts by weight of (A) polyvinyl alcohol-based resin, 1 to 15 parts by weight of (B) polyalkylene glycol having a weight average molecular weight less than 1000.

Description

Polyvinyl alcohol film, method for producing the same, and thermal transfer laminate using polyvinyl alcohol film and thermal transfer method using same

The present invention relates to a polyvinyl alcohol-based film which can be preferably used as a base film for a laminate for thermal transfer, and more particularly, it is excellent in mold release property and can provide an excellent surface of the obtained decorative molded article. A polyvinyl alcohol-based film of a laminate for thermal transfer, a method for producing the polyvinyl alcohol-based film, a laminate for thermal transfer using the polyvinyl alcohol-based film, and a laminate for use in the thermal transfer Thermal transfer method.

As a method of attaching a molded article, there is a method of transferring a transfer layer of a film for transfer using a film for transfer. Since the transfer film is formed by laminating a transfer layer on the base film, the transfer layer is a resin layer which serves as a protective layer for protecting the surface of the transfer material after transfer, and further includes a pattern layer on the resin layer. , then the layer and so on.

The transfer method is roughly classified into a hydraulic transfer method and a thermal transfer method.

The hydraulic transfer method is a method in which a surface on the transfer layer side of the film for hydraulic transfer is floated on the surface of the water, and the transfer material such as a molded article is brought into contact with the transfer layer from above the film. Then, the transfer layer is transferred onto the object to be transferred, and thereafter, the object to be transferred is taken out, washed with water to dissolve and remove the base film, and the pattern or the like is transferred to the object to be transferred. A polyvinyl alcohol-based film excellent in water solubility is used as a base film in such a hydraulic transfer method (see, for example, Patent Documents 1 and 2).

On the other hand, in the thermal transfer method, it is used for a thermoplastic resin film or the like. The film for thermal transfer in which the transfer layer is laminated in a peelable state on the base film. The resin layer to be a protective layer is usually composed of a resin composition having excellent surface properties such as hardness and solvent resistance. The thermal transfer method using the transfer film having such a configuration is a method in which the base film is peeled off from the transfer layer by pressing the surface on the transfer layer side of the transfer film onto the surface of the transfer target. And transferring the transfer layer to the surface of the object to be transferred.

As a base film of such a film for thermal transfer, a polyester resin film such as a polyethylene terephthalate film is used in the past, but the polyester resin film usually has a high affinity with the transfer layer. A release agent layer such as a melamine resin, a polyfluorene-based or a fluorine-based resin is interposed between the transfer layer and the base film to ensure mold release property. However, such release agent treatment is disadvantageous in terms of environment and cost, so the industry seeks a base film that does not require a release agent treatment.

In this case, in recent years, research has been conducted on the case where a polyvinyl alcohol-based film is also applied to a base film of a laminate for thermal transfer. For example, Patent Document 3 discloses that a decorative film (a film for thermal transfer) in which a decorative layer (corresponding to a transfer layer) is provided on one surface of a transparent film (corresponding to a base film) is used, and polyvinyl alcohol is used. A resin film is used as a transparent film. Further, in Patent Document 4, a transfer film obtained by sequentially laminating a release layer, a pattern layer, and an adhesive layer on one surface of a base film is used as a resin film containing a polyvinyl alcohol resin as a main component. The base film.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-152622

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2011-11540

[Patent Document 3] Japanese Patent Laid-Open No. Hei 7-40515

[Patent Document 4] Japanese Patent Laid-Open Publication No. Hei 9-277458

However, although a polyvinyl alcohol-based film is known as a film having excellent mold release property, when it is used as a base film of a film for thermal transfer without using a release agent, it is still required to be substantially superior to the conventional one. Modularity. The fact is that a commercially available polyvinyl alcohol-based film does not have such a high degree of mold release property. Further, even if the base film of the film for hydraulic transfer is used as the base film of the film for thermal transfer, the mold release property cannot be satisfied.

Further, in recent years, the industry has demanded improvement in productivity in the production of decorative materials using thermal transfer printing, and excellent mold release properties have been demanded from the viewpoint of high-precision design formability. Moreover, the polyvinyl alcohol-based film is also being studied as a release film. However, in the case of the polyvinyl alcohol-based film specifically used in the above patent documents, it is difficult to satisfy the above requirements.

In order to improve the mold release property of the polyvinyl alcohol-based film, the present applicant has proposed a vinyl alcohol-based resin as a main component, and contains oxyethylene in an amount relatively larger than the usual content of a surfactant which is usually used. And an oxypropylene surfactant, whereby a polyvinyl alcohol-based film having excellent mold release property is obtained (Japanese Patent Application No. 2012-070747).

Since the surfactant has a function as a release agent, it has been previously used in a polyvinyl alcohol film in order to improve the release property of a metal surface of a roll or a belt as a film forming apparatus and a film-formed polyvinyl alcohol film. The case where a surfactant is formulated as a release agent. However, the mold release property required for the base film of the laminate for thermal transfer can be easily removed from the layer formed by the temporarily formed laminate without passing through the release agent layer, and is much higher than that of the polyvinyl alcohol system. The mold release required at the manufacturing site of the film. Therefore, the surfactant used in the film formation or the content thereof is usually insufficient.

In this respect, the polyvinyl alcohol-based film proposed in the above-mentioned application (Japanese Patent Application No. 2012-070747) contains a specific surfactant which is more than usual, and can satisfy the high degree of demolding. Sexual requirements. However, when a laminate for thermal transfer using the polyvinyl alcohol-based film as a base film is used, it is known that a new problem such as whitening of the surface of the obtained decorative molded article occurs. The whitening of the surface is a major problem in the manufacture of decorative accessories that emphasize the beauty of the surface.

Under such a background, an object of the present invention is to provide a decorative molded article which has excellent releasability and which is excellent in the aesthetic appearance of a transfer surface even when it is applied to manufacture of an accessory using a thermal transfer method. A polyvinyl alcohol-based film which is a base film of a laminate for thermal transfer, a method for producing the polyvinyl alcohol-based film, and a laminate for thermal transfer using the polyvinyl alcohol-based film and a thermal transfer method .

As a result of intensive studies by the present inventors, it has been found that by blending a specific amount of a polyalkylene glycol having a relatively small molecular weight which is generally not used as a releasing agent with respect to a polyvinyl alcohol-based resin, it is possible to provide excellent mold release property without The surface of the molded article is whitened and excellent in gloss, thereby completing the present invention.

In other words, the present invention relates to a polyvinyl alcohol-based film containing a polyalkylene glycol (B) 1 to 15 having a weight average molecular weight of 1,000 or less based on 100 parts by weight of the polyvinyl alcohol-based resin (A). Parts by weight.

It is preferably a polyvinyl alcohol-based film which can be used for a laminate for transfer, and specifically, the above-mentioned polyvinyl alcohol after thermal transfer of a curable resin layer and a printed layer laminated on a polyvinyl alcohol film. The laminated body for heat transfer in which the film is peeled off, and contains 1 to 15 parts by weight of the polyalkylene glycol (B) having a weight average molecular weight of 1,000 or less based on 100 parts by weight of the polyvinyl alcohol-based resin (A). .

It is preferred that the polyalkylene glycol (B) has a weight average molecular weight of from 300 to 1,000. Further, it is preferred that the polyalkylene glycol (B) is polypropylene glycol.

The total content of the plasticizer is preferably less than 20 parts by weight based on 100 parts by weight of the polyvinyl alcohol-based resin (A). Further, it is preferred that the polyvinyl alcohol-based resin (A) has a 4% by weight aqueous solution viscosity of 5 to 70 mPa at 20 ° C. s.

The method for producing a polyvinyl alcohol-based film of the present invention comprises the steps of: flow casting containing a weight average molecular weight with respect to 100 parts by weight of the polyvinyl alcohol-based resin (A) The polyvinyl alcohol-based resin aqueous solution obtained by polymerizing 1 to 15 parts by weight of the alkyl diol (B) in an amount of 1,000 or less is formed into a film. It is preferable that the concentration of the aqueous solution of the polyvinyl alcohol-based resin is 10 to 30% by weight.

In the laminated system for thermal transfer of the present invention, a curable resin layer [II] is laminated on the base film [I] composed of the polyvinyl alcohol film of the present invention, and a layer is laminated on the curable resin layer [II]. There are printed layers [III]. In other words, the laminated body for thermal transfer of the present invention is characterized in that the base film [I], the curable resin layer [II], and the printed layer [III] composed of the polyvinyl alcohol-based film of the present invention are sequentially passed. Laminated.

In the thermal transfer method of the present invention, the printed layer [III] of the laminated body for thermal transfer of the present invention is adhered to the surface of the transfer target, and is carried out from the side of the base film [I] of the laminated body for thermal transfer. a step of transferring the printed layer [III] onto the transfer target by heating and pressurizing, and irradiating the thermal transfer layer body adhered to the transfer target surface with an active energy ray to make the hardenability The step of hardening the resin layer [II]; after the curing, the step of peeling off the base film [I] from the transfer target.

Moreover, the thermal transfer method according to another aspect of the present invention includes the step of disposing the base film [I] of the laminated body for thermal transfer of the present invention in a fixed mold with a molding die; and ejecting the molding resin. The step of filling the substrate to be transferred with the printing layer [III] of the laminated body for thermal transfer described above, and the step of peeling off the base film [I] after the formation of the transferred body.

Further, a polyalkylene glycol represented by polyethylene glycol is known to be added to a polyvinyl alcohol-based film as one of plasticizers for imparting flexibility. In the present invention, it is characterized in that instead of using a polyalkylene glycol as a plasticizer, a polyalkylene glycol is used in order to improve mold release property. Further, even if the total content of the plasticizer contains the polyalkylene glycol (B) contained as an essential component, it is usually less than the amount of the plasticizer contained in the polyvinyl alcohol film.

In the present invention, a polyalkylene having a weight average molecular weight within a specific range The content of the diol is less than that which is usually used as a plasticizer, and a polyvinyl alcohol-based film suitable for a laminate for thermal transfer excellent in mold release property can be obtained, and a surface can be produced by thermal transfer. A decorative molded article excellent in gloss and surface whitening resistance. The inventors believe that the release property of the base film is improved by imparting a moderate hydrophobicity to the polyvinyl alcohol-based film by the polyalkylene glycol. Further, the inventors of the present invention thought that the polyalkylene glycol which bleeds out to the surface due to exudation adhered to the polyvinyl alcohol-based film as a base film due to moderate hydrophilicity, and was removed together with the polyvinyl alcohol-based film after transfer. The amount remaining on the surface of the protective layer is small and there is no problem, and as a result, the whitening of the decorative molded article can be suppressed.

The polyvinyl alcohol-based film of the present invention has very excellent mold release properties. Therefore, it is useful for applications such as a separator or a protective film that require mold release. Further, when it is used as a base film for a laminate for thermal transfer, it can be used without interposing a release agent layer, and further, it is possible to provide a decorative molded article having no whitening and having an excellent glossy surface.

[Polyvinyl alcohol film]

First, the polyvinyl alcohol-based film of the present invention will be described.

The polyvinyl alcohol-based film of the present invention contains the polyvinyl alcohol-based resin (A) and the polyoxyalkylene glycol (B) having a weight average molecular weight of 1,000 or less and 1 to 15 parts by weight.

(1) Polyvinyl alcohol resin (A)

The polyvinyl alcohol-based resin (A) used in the present invention is obtained by polymerizing a vinyl ester-based compound according to a usual method and then saponifying it. In the present invention, the polyvinyl alcohol-based resin (A) may be used alone or in combination of two or more kinds as needed.

Examples of the vinyl ester-based compound include vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl phthalate, vinyl laurate, and versatic acid. ) vinyl ester, vinyl palmitate, vinyl stearate, and the like. These may be used singly or in combination of two or more, and vinyl acetate may be preferably used practically.

Moreover, as the polyvinyl alcohol-based resin (A) used in the present invention, it is preferred to use a polyvinyl alcohol resin which is usually not modified, or a partially modified modified polyvinyl alcohol-based resin. The modified polyvinyl alcohol-based resin may be one obtained by copolymerizing a vinyl ester-based compound with another monomer in a small amount. In this case, the ratio of the monomer is within a range not inhibiting the effects of the present invention, for example, 10 mol. It is at most or less than the ear, preferably at least 7 mol%.

Examples of the other monomer include olefins such as ethylene, propylene, isopropylene, α-octene, α-dodecene, and α-octadecene; acrylic acid, methacrylic acid, crotonic acid, and cis-butene. Unsaturated acids such as diacid, maleic anhydride and itaconic acid or salts or monoalkyl or dialkyl esters thereof; nitriles such as acrylonitrile and methacrylonitrile; acrylamide and methacryl Amines such as amines; olefin sulfonic acids such as ethanedisulfonic acid, allylsulfonic acid and methallylsulfonic acid or salts thereof, alkyl vinyl ethers; polyoxyethylene (meth) allyl ether, poly a polyoxyalkylene (meth)allyl ether such as oxypropylene (meth)allyl ether; a polyoxyalkylene group such as polyoxyethylene (meth) acrylate or polyoxypropylene (meth) acrylate (A) Polyoxyalkylene (meth) acrylamide such as acrylate, polyoxyethylene (meth) acrylamide, polyoxypropylene (meth) acrylamide, polyoxyethylene [1-(methyl) Acrylamide-1,1-dimethylpropyl]ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene ethylene Amine, dipropyl Acid acetoacetamide, N-propylene guanamine methyl trimethyl ammonium chloride, allyl trimethyl ammonium chloride, dimethyl diallyl ammonium chloride, dimethyl allyl ketene, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, and the like. These other monomers may be used singly or in combination of two or more.

Further, in the present invention, the term "(meth)allyl" means allyl or methallyl, and the so-called (meth)acrylic group means an acrylic group or a methacrylic group, so-called (A) base) Acrylate means acrylate or methacrylate.

Further, when the polymerization (or copolymerization) is carried out using the above vinyl ester-based compound, a known polymerization method can be used, and a solution polymerization using an alcohol such as methanol, ethanol or isopropyl alcohol as a solvent is usually carried out. Further, in addition to solution polymerization, emulsion polymerization or suspension polymerization may be carried out.

Further, the polymerization reaction is carried out by using a known radical polymerization catalyst such as azobisisobutyronitrile, ethylene peroxide, benzammonium peroxide or ruthenium peroxide, and the reaction temperature is usually selected from 35 ° C to the boiling point. Good is about 50~80 °C.

Then, when the obtained vinyl ester-based polymer is saponified, the vinyl ester-based polymer is dissolved in an alcohol and carried out in the presence of a basic catalyst. The alcohol may, for example, be methanol, ethanol or butanol, and the concentration of the vinyl ester-based copolymer in the above alcohol may be appropriately selected in the range of 20 to 50% by weight.

As the basic catalyst in the saponification, an alkali catalyst such as a hydroxide or an alcoholate of an alkali metal such as sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide or potassium methoxide can be used. The amount of the above-mentioned basic catalyst to be used may be appropriately selected within the range of from 1 to 100 mmol equivalents based on the vinyl ester polymer. Further, saponification may be carried out by an acid catalyst depending on the case.

The polyvinyl alcohol-based resin (A) can be obtained in this manner.

Further, it is also preferred to use a polyvinyl alcohol-based resin having a 1,2-diol structure in a side chain as the polyvinyl alcohol-based resin (A), and a polyvinyl alcohol having a 1,2-diol structure in the side chain. The resin can be obtained, for example, by (i) a method of saponifying a copolymer of vinyl acetate and 3,4-diethyloxy-1-butene, and (ii) a vinyl acetate and a carbonic acid. Saponification of vinyl ethylene glycol copolymer and decarboxylation method, (iii) saponification and decoupling of copolymer of vinyl acetate and 2,2-dialkyl-4-vinyl-1,3-dioxolane A method of ketalization, (iv) a method of saponifying a copolymer of vinyl acetate and glycerol monoallyl ether.

In the present invention, the average degree of saponification of the above polyvinyl alcohol-based resin (A) is usually It is 70 mol% or more, for example, the average saponification degree is preferably 70 to 90 mol% in the application which is suitable for processing adaptability at a high temperature of 100 ° C or higher, and on the other hand, the average degree of saponification in the application which emphasizes heat resistance. It is preferably 90 mol% or more. However, the average degree of saponification according to processing conditions or purpose can be appropriately selected from the range of 70 mol% or more. In addition, when the average degree of saponification of the polyvinyl alcohol-based resin (A) is too low, not only the film strength is lowered, but also the film tends to be peeled off from the casting surface during production.

Further, the above average degree of saponification is measured in accordance with JIS K 6726.

Further, the viscosity of the 4% by weight aqueous solution at 20 ° C of the polyvinyl alcohol-based resin (A) is preferably 5 to 70 mPa. The range of s is more preferably 15~60mPa. The range of s. If the viscosity of the 4% by weight aqueous solution is too low, the strength of the film tends to decrease. On the other hand, when the viscosity of the 4% by weight aqueous solution is too high, the viscosity tends to be high and it is difficult to form a film. Further, the viscosity of the 4% by weight aqueous solution at 20 ° C described above was measured in accordance with JIS K 6726.

(2) Polyalkylene glycol (B)

The polyalkylene glycol (B) used in the present invention is contained in order to improve the release property of the polyvinyl alcohol-based film during thermal transfer printing.

In the present invention, in terms of whitening resistance and surface gloss, the weight average molecular weight of the polyalkylene glycol (B) is preferably 1,000 or less, more preferably 800 or less, still more preferably 600 or less. It is preferably 100 or more, more preferably 200 or more, still more preferably 300 or more. When the weight average molecular weight is too large, whitening tends to occur, and it is difficult to obtain a glossy decorative molded article. On the other hand, if it is too small, there is a case where the mold release property is lowered.

Further, in the present invention, the carbon number of the alkyl group of the oxygen-extended alkyl group in the polyalkylene glycol (B) is preferably from 2 to 6, more preferably from 2 to 4, still more preferably 3. When the carbon number of the alkyl group is too short, the mold release property tends to be lowered, and if it is too long, the whitening of the surface tends to be remarkable.

Further, in the present invention, the number of structural units of the oxygen-extended alkyl group in the polyalkylene glycol (B) is preferably from 4 to 30, particularly preferably from 5 to 20. When the number of the cells is too small, the mold release property tends to decrease, and if it is too large, the whitening of the surface tends to become remarkable.

In the present invention, specific examples of the polyalkylene glycol (B) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol glyceryl ether, polypropylene glycol glyceryl ether, and polypropylene glycol. Diglyceryl ether or the like is particularly preferably polypropylene glycol in terms of mold releasability.

The above-mentioned polyalkylene glycol (B) may be used alone or in combination of two or more.

In the present invention, the content of the polyalkylene glycol (B) is preferably from 1 to 15 parts by weight based on 100 parts by weight of the polyvinyl alcohol-based resin (A) in terms of mold release property and film appearance. More preferably 2 to 10 parts by weight, particularly preferably 3 to 8 parts by weight. When the content of the polyalkylene glycol (B) is too large, the surface of the decorative molded article obtained by thermal transfer is whitened, and if it is too small, the mold release property is lowered.

(3) Other ingredients

The polyvinyl alcohol-based film of the present invention is not limited to a polyvinyl alcohol-based film produced from a composition containing only the polyvinyl alcohol-based resin (A) and the polyalkylene glycol (B). It is also preferred to produce a polyvinyl alcohol-based film by appropriately preparing a surfactant or a plasticizer. Further, the filler may be formulated within the range not impairing the object of the present invention.

(3-1) Surfactant

The surfactant is formulated to improve the release property of the metal surface of the roll or belt of the film forming apparatus of the polyvinyl alcohol film and the film formed.

As the surfactant, examples of the nonionic surfactant include polyoxyalkylene alkyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene alkyl esters, and sorbents. Alkyd fatty acid esters, polyoxyalkylene alkylamines, polyoxyalkylene alkyl amides, polypropylene glycol ethers, acetylene glycols, allyl phenyl ethers, and the like.

Further, an anionic surfactant, a cationic surfactant, or an amphoteric surfactant may be used. As the anionic surfactant, for example, a carboxylic acid type such as potassium laurate or a sulfate type such as octyl sulfate may be used. A sulfonic acid type anionic surfactant such as dodecyl sulfonate. Examples of the cationic surfactant include amines such as laurylamine hydrochloride and months. a quaternary ammonium salt such as cinnamate trimethylamine chloride or a pyridinium salt such as lauryl pyridinium chloride. Examples of the amphoteric surfactant include N-alkyl-N,N-dimethylammonium betaine and the like.

The surfactant may be used alone or in combination of two or more.

The blending amount of the surfactant to be blended in the polyvinyl alcohol-based resin (A) may be a degree that does not impair the object of the present invention, and may be, for example, not whitened, etc., as long as it does not bleed out. The degree of deterioration of the surface characteristics of the film surface may be 1 part by weight or less, preferably 0.8 part by weight or less, and particularly preferably 0.5 part by weight or less based on 100 parts by weight of the polyvinyl alcohol-based resin.

(3-2) Plasticizer

The plasticizer is formulated to impart flexibility to the film.

Examples of the plasticizer include glycerin such as glycerin, diglycerin, and triglycerin, and a trihydric or higher polyhydric alcohol such as trimethylolpropane, mannitol, sorbitol, or pentaerythritol. These may be used alone or in combination of two or more.

The amount of the plasticizer to be blended in the polyvinyl alcohol-based resin (A) is preferably 10 parts by weight or less, more preferably 8 parts by weight or less based on 100 parts by weight of the polyvinyl alcohol-based resin (A). When the amount of the plasticizer to be added is too large, the ductility of the film tends to be difficult to handle, and the surface appearance of the decorative article obtained by whitening or the like tends to decrease. Further, the content of the plasticizer can be appropriately selected depending on the kind of the plasticizer. For example, if it is a glycerin having a high plasticity effect, about 0.5 to 5 parts by weight is sufficient. On the other hand, it is known that the polyalkylene glycol (B) contained as an essential component functions as a plasticizer, and the plasticizing effect is lower than that of glycerin which is generally preferably used. Therefore, in the case of using a polyalkylene glycol as a plasticizer, it is necessary to use 20 parts by weight or more. In the case where the polyalkylene glycol (B) contained as an essential component is regarded as a plasticizer in order to enhance the mold release property, the polyalkylene glycol (B) and the other compound are also molded. The total content of the chemical agent was set to be less than 20 parts by weight. Therefore, in this issue In the Ming Dynasty, the amount of plasticizer is less than that usually provided in the polyvinyl alcohol film.

(3-3) filler

Examples of the filler include starch (not only various unprocessed products, but also etherified, oxidized, and modified products), organic powders such as polymethyl methacrylate, inorganic powders such as talc, mica, and cerium oxide. . These may be used singly or in combination of two or more. Among them, starch can be preferably used.

The amount of the filler to be blended in the polyvinyl alcohol-based resin (A) is preferably 20 parts by weight or less, and particularly preferably 15 parts by weight or less based on 100 parts by weight of the polyvinyl alcohol-based resin (A). When the amount of the above filler is too large, the film strength tends to decrease in practical use.

(3-4) Other additives

Further, an antioxidant (phenol-based, amine-based, etc.), a stabilizer (phosphorus ester, etc.), a coloring material, a fragrance, a bulking agent, an antifoaming agent, and an anti-aging agent may be appropriately formulated within a range that does not impair the effects of the present invention. Rust, UV absorber, and other water-soluble polymer compounds (sodium polyacrylate, polyvinylpyrrolidone, dextrin, chitosan, chitin, methyl cellulose, hydroxyethyl cellulose, etc.) additive.

Since the polyvinyl alcohol-based film of the present invention having the above-described configuration is excellent in mold release property, when it is used as a laminate for thermal transfer, it is not provided between the curable resin layer and the polyvinyl alcohol film. The release agent layer can be easily peeled off from the curable resin layer (protective layer) transferred to the surface of the decorative molded article and the polyvinyl alcohol-based film as the base film after the thermal transfer, and further, by heat transfer The decorative molded article obtained by printing is excellent in surface glossiness or surface whitening resistance.

In addition, although the polyvinyl alcohol-based film of the present invention can provide excellent mold release property as described above, it retains the properties of the conventional polyvinyl alcohol-based film, that is, hydrophilicity, water solubility, organic solvent resistance, and gas barrier properties. Since it is excellent in the characteristics, it is not limited to the base film of the laminated body for thermal transfer, and it can also be used as a base film of the laminated body for hydraulic transfer, and it can also be used as the use of another polyvinyl- Known use.

[Method for Producing Polyvinyl Alcohol Film]

Hereinafter, a method for producing the polyvinyl alcohol-based film of the present invention will be described.

First, the polyvinyl alcohol-based resin (A), the polyalkylene glycol (B), an optional surfactant, a plasticizer, other additives, and the like are blended in a specific amount, and dissolved in water to prepare. An aqueous solution of a polyvinyl alcohol resin.

The concentration of the aqueous solution of the polyvinyl alcohol-based resin is usually preferably from 10 to 30% by weight, particularly preferably from 15 to 25% by weight. When the concentration is too low, the stability of the film thickness tends to decrease, and if it is too high, the viscosity tends to be high and the film formation tends to be difficult.

Then, it is produced by casting a polyvinyl alcohol-based resin aqueous solution from a T-die onto a film forming tape or a film forming drum, and drying it to form a film, which is further carried out as needed. Heat treatment.

Here, the film forming belt refers to an endless belt that is stretched between a pair of rolls, and the polyvinyl alcohol-based resin aqueous solution that has flowed out of the T-shaped mold is cast on the endless belt and dried. The endless belt is preferably made of, for example, stainless steel, and the outer peripheral surface thereof is subjected to mirror polishing.

In addition, the above-mentioned film-forming roller is a roller-type roller that rotates, and the polyvinyl alcohol-based resin aqueous solution that has flowed out of the T-shaped mold is cast on one or more rotating drum-type rolls and dried.

The drying temperature is usually preferably from 80 to 160 ° C, particularly preferably from 90 to 150 ° C, in the case of using a film-forming tape. When the drying temperature is too low, there is a tendency that the drying is insufficient and the peeling of the self-contained material becomes heavy. If the drying temperature is too high, the moisture content becomes too low and the film tends to become brittle.

Further, in the case of using a film forming drum, the first film forming film is usually preferably 80 to 100 ° C, particularly preferably 82 to 99 ° C. When the drying temperature is too low, there is a tendency that the drying is insufficient and the peeling from the drum becomes heavy. If the drying temperature is too high, the water content tends to be too low, and the film tends to become brittle. Here, the first film forming film described above refers to a polyvinyl alcohol resin which flows out from the T-shaped mold. The drum type roller on the most upstream side of the aqueous solution casting.

After the drying, heat treatment may be carried out as needed. Examples of the heat treatment method include a hot roll (including a calender roll), hot air, far infrared ray, and dielectric heating. Further, the heat-treated surface is preferably a surface opposite to the surface contacting the film forming belt or the film forming drum. Further, the moisture content of the film subjected to the heat treatment is usually preferably about 4 to 8% by weight. Further, the moisture content of the film after the heat treatment is usually preferably from 2 to 6% by weight.

In addition, the moisture content of the polyvinyl alcohol-based film can be measured, for example, using a Karl Fischer moisture meter ("MKS-210" manufactured by Kyoto Electronics Manufacturing Co., Ltd.).

The heat treatment by the heat treatment machine described above is usually preferably carried out at 50 to 130 ° C, more preferably 60 to 120 ° C. In other words, when the temperature of the heat treatment is too low, there is a tendency that curling occurs on the surface in contact with the film forming tape or the film forming first roll, and the film becomes soft. Therefore, if the temperature of the heat treatment is too high, the film becomes soft. When the winding is stretched without wrinkles, the alignment in the longitudinal direction becomes stronger and the width tends to be shortened. Further, the time required for the heat treatment is also set to 0.2 to 15 seconds, preferably 0.5 to 12 seconds, depending on the surface temperature thereof in the case of the heat treatment roll. The above heat treatment is usually carried out by a drying roll for drying the film, usually by another heat treatment roll or a float dryer or the like.

A polyvinyl alcohol-based film can be obtained in this manner.

The film thickness of the polyvinyl alcohol-based film of the present invention is preferably 15 to 100 μm, more preferably 20 to 80 μm, still more preferably 30 to 60 μm.

The water content of the polyvinyl alcohol-based film obtained as described above is preferably in the range of 0.5 to 8% by weight, more preferably 1 to 6% by weight. When the water content is too low, the polyvinyl alcohol film tends to be brittle, and if the water content is too high, adhesion tends to occur.

As a method of adjusting the moisture content of the polyvinyl alcohol-based film, for example, the following methods can be mentioned. That is, the moisture content of the polyvinyl alcohol-based film within the above range can be set in accordance with the method of adjusting the moisture content as shown below.

(i) The moisture content is adjusted by a method of humidifying and dehumidifying the polyvinyl alcohol-based film by drying the polyvinyl alcohol-based resin aqueous solution and lowering the temperature of the dryer when the film is formed. Since the temperature of the aqueous resin solution affects the drying efficiency depending on the temperature, it is adjusted in the range of 70 to 98 °C. Further, in the case of drying, it is preferably carried out in a hot air dryer having a temperature gradient of preferably between 150 and 50 ° C, more preferably between at least two of 145 to 60 ° C. Preferably, it is further dried for 1 to 12 minutes, more preferably for 1 to 11 minutes.

If the gradient of the drying temperature is too large or the drying time is too long, there is a tendency to dry excessively. On the other hand, if the gradient of the drying temperature is too small or the drying time is too short, there is a tendency that the drying is insufficient.

The above temperature gradient is gradually changed between 150 and 50 ° C in stages, and it is generally effective to slowly increase the temperature from the start of drying to the highest drying temperature in the temporarily set drying temperature range until it becomes specific. The water content, which in turn slowly reduces the drying temperature, thereby becoming the ultimate target moisture content. It is carried out in order to control crystallinity, mold release property, productivity, etc., for example, 120 ° C - 130 ° C - 115 ° C - 100 ° C, 130 ° C - 120 ° C - 110 ° C, 115 ° C - 120 ° C - 110 ° C - The temperature gradient setting such as 90 ° C can be suitably selected.

(ii) The moisture content is adjusted by humidifying and dehumidifying the polyvinyl alcohol film by passing it through a humidity control tank before winding the polyvinyl alcohol film.

(iii) The moisture content is adjusted by heat-treating the polyvinyl alcohol-based film before heat-rolling the polyvinyl alcohol-based film or after winding up the polyvinyl alcohol-based film.

Moreover, the polyvinyl alcohol-based film of the present invention may be provided with a concave-convex pattern such as a satin-finished surface pattern, an embossed pattern, or a matte pattern, and the uneven pattern may be formed using an embossing roll or the like.

Further, the polyvinyl alcohol-based film of the present invention can be used as an unstretched film as it is, and can be used as a film which is uniaxially stretched or biaxially stretched.

In the case of using the stretched film, the stretching method can be applied to a well-known method, and as a usual method, for example, (1) chuck-type extension, (2) roll extension, ( 3) Tenter extension and the like. (1) It is suitable for the production of batch type stretch film, and (2) suitable for uniaxial extension. Moreover, although the scale of the apparatus is large, (3) it is effective to produce an extended film on an industrial scale. The successive biaxial stretching can also be performed by combining (2) and (3). The stretching method may be any one of uniaxial stretching, successive biaxial stretching, and simultaneous biaxial stretching, wherein from the viewpoint of uniformity of film thickness, it is preferred to combine the two axes of (2) and (3) extend.

The total stretch ratio of the stretched film is preferably from 1.5 to 16 times, particularly preferably from 2 to 12 times, and more preferably from 3 to 10 times, in terms of surface uniformity of the film. Or in the case of biaxial stretching, in terms of surface uniformity of the film, it is preferred that the stretching ratio is extended to 1.5 to 10 times, particularly 2 to 8 times, and further 3 to 5 times in the longitudinal direction. The direction is extended to 1.5 to 10 times, especially 2 to 8 times, and further 3 to 5 times. Further, it is preferable that the vertical and horizontal directions are the same magnification. When the stretching ratio is too low, uneven stretching tends to remain, and when the stretching ratio is too high, the film tends to be easily broken.

The storage of the polyvinyl alcohol-based film is preferably carried out by a conventionally known moisture-proof package, and stored in an air-dried state at 10 to 25 ° C.

[Laminated body for thermal transfer]

The laminated system for thermal transfer of the present invention is obtained by laminating a base film [I], a curable resin layer [II], and a printed layer [III] composed of the above polyvinyl alcohol-based film of the present invention. Specifically, a curable resin layer [II] is laminated on the base film [I], and a printed layer [III] is laminated on the curable resin layer [II]. Further, it is also preferable to provide an adhesive layer [IV] which will be described later on the printed layer [III].

(1) Base film [I]

As the base film [I], the above polyvinyl alcohol-based film of the present invention can be used. As the polyvinyl alcohol-based film, a film which is not stretched or a film which is uniaxially stretched or biaxially stretched may be used as it is.

In the present invention, the thickness of the base film [I] is particularly preferably set in the range of 5 to 120 μm, more preferably 10 to 100 μm, and still more preferably 20 to 80 μm.

Further, in the present invention, the surface roughness (Ra) of the curable resin layer [II] side of the base film [I] is preferably 1 μm or less, and particularly preferably 0.001 to 0.7 μm, in terms of surface glossiness. Further, it is preferably 0.01 to 0.5 μm. If the surface roughness (Ra) is too large, the surface gloss tends to decrease. In addition, even if the surface roughness (Ra) is less than 0.001 μm, there is almost no tendency to improve the surface gloss. In the base film [I], as a method of adjusting the surface roughness (Ra) of the curable resin layer [II] side to the above range, the surface of the casting belt when the base film [I] is formed into a film is exemplified. A method in which the thickness is 1 S or less, or the stretching ratio at the time of film formation of the base film [I] is at least 1.5 times or more, or a combination of the two.

In addition, the surface roughness (Ra) was obtained by measuring the arithmetic mean roughness (Ra) in accordance with JIS B 0601-2001 using "Color 3D Laser Microscope VK-9700" manufactured by Keyence Corporation.

(2) Curable resin layer [II]

The curable resin layer [II] is the outermost layer of the decorative molded article due to the peeling of the base film [I], and is cured during the period before or after peeling off the base film [I] to form a protective layer to be protected. A protective layer on the surface of the transfer body.

Examples of the material constituting the curable resin layer [II] include a polyacrylic resin, a polyester resin, a polyvinyl chloride resin, a cellulose resin, a rubber resin, a polyurethane resin, and a polyvinyl acetate resin. A thermoplastic resin; an active energy ray-curable resin composition such as an ultraviolet curable resin composition or an electron beam curable resin composition; a thermosetting resin composition or the like. As the protective layer, from the viewpoint of imparting chemical resistance and abrasion resistance, it is preferred to use an active energy ray-curable resin composition.

The active energy ray-curable resin composition is preferably composed of, for example, an acrylic resin or a (meth)acrylic acid urethane-based compound.

The acrylic resin may, for example, be a homopolymer or a copolymer of an acrylate monomer or an acrylic copolymer having a copolymerizable component of another ethylenically unsaturated monomer.

Examples of the acrylate-based monomer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and hexyl (meth)acrylate. , 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, dimethylaminoethyl (meth)acrylate Ester, isooctyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, 2-methoxyethyl (meth)acrylate, butoxy B (meth)acrylate An ester, methoxytriethylene glycol (meth) acrylate or the like, wherein an alkyl acrylate having an alkyl group having a carbon number of 1 to 12 is preferred, and methyl (meth) acrylate is particularly preferably used. Ethyl methyl acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate.

Examples of the other ethylenically unsaturated monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxypropyl 3-chloro(meth)acrylate. Tetrahydrofurfuryl methacrylate, 3-phenoxypropyl 2-hydroxy(meth)acrylate, diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, N-hydroxyl a hydroxyl group-containing unsaturated monomer such as methyl (meth) acrylamide; a glycidyl group-containing unsaturated monomer such as glycidyl methacrylate or allyl glycidyl methacrylate; isocyanate 2- Isocyanate group-containing unsaturated monomer such as propylene methoxyethyl ester or 2-methyl propylene methoxyethyl isocyanate; acrylamide, methacrylamide, N-(n-butoxyalkyl) An amidino group-containing unsaturated monomer such as acrylamide or N-(n-butoxyalkyl)methacrylamide; acrylamide-3-methylbutylmethylamine, dimethylaminoalkylpropene An amine group-containing unsaturated monomer such as guanamine or dimethylaminoalkyl methacrylamide; an olefin sulfonic acid such as ethanedisulfonic acid, allylsulfonic acid or methallylsulfonic acid; Acrylamide-2-methylpropane Unsaturated monomeric acids, styrene sulfonic acid or salts of sulfonic acid group; styrene, vinyl acetate, acrylonitrile, acrylamide and the like.

The content ratio (copolymerization ratio) of the acrylate monomer and the other ethylenically unsaturated monomer is not particularly limited, and for example, the acrylate monomer is preferably 20 to 100% by weight. The other ethylenically unsaturated monomer is 0 to 80% by weight, more preferably 40 to 100% by weight of the acrylate monomer, and 0 to 60% by weight of the other ethylenically unsaturated monomer. Preferably, the acrylate monomer is 80 to 100% by weight, and the other ethylenically unsaturated monomer is 0 to 20% by weight. When the content ratio of the acrylate-based monomer is too small, the durability of the cured product (protective layer) of the curable resin layer, such as water resistance and moist heat resistance, tends to decrease.

The acrylic resin can be easily produced by, for example, a method in which the above-mentioned polymerization component is radically copolymerized in an organic solvent, which is well known in the art to which the present invention pertains.

The acrylic resin used as the active energy ray-curable resin composition preferably has a glass transition temperature (Tg) of 20 to 130 ° C, more preferably 30 to 120 ° C, still more preferably 40 to 110 ° C. When the glass transition point (Tg) is too low, the curable resin layer such as the active energy ray-curable resin composition has adhesiveness, which causes a problem in the post-treatment (coiling in the step, poor printing). When the curable resin layer such as the active energy ray-curable resin composition is cured to form a protective layer, it tends to become brittle.

Further, the weight average molecular weight (Mw) of the acrylic resin is preferably from 10,000 to 500,000, more preferably from 20,000 to 100,000, still more preferably from 30,000 to 80,000.

When the weight average molecular weight (Mw) of the acrylic resin is too small, the curable resin layer before curing may be softened and adhesive, and may cause a problem in performing post-treatment on the layer (in the step) When the tendency of the film is too large, the film tends to have a uniform film thickness when the curable resin layer is hard to be obtained, and the hardness of the film after drying is higher than necessary. There is a problem in the post-implementation treatment (causing cracking of the coating film, peeling of the coating, etc.).

The (meth)acrylic acid urethane-based compound is a (meth) acrylate-based compound having a urethane bond in a molecule, and a hydroxyl group-containing (meth)acrylic compound and a polyvalent isocyanate compound can be used. Further, it is produced by reacting a desired polyol.

Examples of the hydroxyl group-containing (meth)acrylic compound include, for example: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth)acrylic acid 6 -hydroxyhexyl ester, 2-(methyl)propenyloxyethyl 2-hydroxypropyl phthalate, 2-hydroxy-3-(methyl)propenyl propyl propyl (meth)acrylate, Ester-modified 2-hydroxyethyl (meth)acrylate, neopentyl alcohol tri(meth)acrylate, dipentaerythritol penta (meth) acrylate, caprolactone modified dipentaerythritol (Meth) acrylate, caprolactone modified pentaerythritol tri(meth) acrylate, oxyethylene modified dipentaerythritol penta (meth) acrylate, ethylene oxide modified pentaerythritol III As the (meth) acrylate or the like, a hydroxyl group-containing (meth)acrylic compound having three or more acryl fluorenyl groups can be preferably used. Further, these may be used alone or in combination of two or more.

Examples of the polyvalent isocyanate compound include polyisocyanates such as aromatic, aliphatic, and alicyclic resins, and examples thereof include toluene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane. Isocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, hydrogenated dimethyl diisocyanate, xylylenediisocyanate, hexamethylene diisocyanate, trimethylhexamethylene Diisocyanate, tetramethyl dimethyl diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, diphenyl phenyl diisocyanate, Polyisocyanate such as lysine diisocyanate, triisocyanate, naphthalene diisocyanate or a trimer compound or polymer compound of such polyisocyanate, biuret type polyisocyanate, water-dispersible polyisocyanate ( For example, "AQUANATE100", "AQUANATE110", "AQUANATE200", "AQUANATE210", etc. manufactured by Japan Polyurethane Co., Ltd. Or the reaction product of the polyisocyanate and the polyol.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, and polybutylene glycol. 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, trimethylolethane, trimethylolpropane, polytrimethylolpropane, new Pentaerythritol, polyneopentaerythritol, sorbose a polyol such as an alcohol, mannitol, glycerin, polyglycerin or polytetramethylene glycol; having at least one structure of polyoxyethylene, polyoxypropylene, oxyethylene/oxypropylene block or random copolymerization Polyether polyol; as the polyol or polyether polyol with maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, adipic acid, isophthalic acid a polyester polyol such as a condensate of a polybasic acid; a caprolactone-modified polyol such as a caprolactone-modified polytetramethylene polyol; a polyolefin-based polyol; a polybutadiene polyol such as a hydrogenated polybutadiene polyol; An olefinic polyol or the like.

Further, examples of the polyhydric alcohol include 2,2-bis(hydroxymethyl)butyric acid, tartaric acid, 2,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, and 2,2-double. (hydroxymethyl)propionic acid, 2,2-bis(hydroxyethyl)propionic acid, 2,2-bis(hydroxypropyl)propionic acid, dihydroxymethylacetic acid, bis(4-hydroxyphenyl)acetic acid, a carboxyl group-containing polyol such as 4,4-bis(4-hydroxyphenyl)pentanoic acid or uronic acid, or a sulfonic acid group or a sulfonate group-containing polyol such as sodium 1,4-butanediol sulfonate .

In the case of using a reaction product of a polyisocyanate and a polyhydric alcohol, for example, a polyisocyanate having an isocyanate group at the terminal obtained by reacting the above polyol with the above polyisocyanate may be used. In the reaction of the polyisocyanate with the polyol, in order to promote the reaction, it is also preferred to use a metal catalyst such as dibutyl dilaurate or a 1,8-diazabicyclo[5.4.0]undecene-7. The amine is a catalyst or the like.

The method for producing the (meth)acrylic acid urethane-based compound may, for example, be a method in which a hydroxyl group-containing (meth)acrylic compound and a polyvalent isocyanate compound are mixed in an inert gas atmosphere, usually It is allowed to react at 30 to 80 ° C for 2 to 10 hours. In the reaction, a urethane catalyst such as tin octylate, di-n-butyltin dilaurate, lead octylate, potassium octylate, potassium acetate, stannous octoate or triethylenediamine is preferably used.

The weight average molecular weight of the (meth)acrylic acid urethane-based compound is preferably from 300 to 4,000, more preferably from 1,000 to 3,500, still more preferably from 1,200 to 3,000. When the weight average molecular weight is too small, the curable resin layer tends to have insufficient cohesive strength, and if it is too large, the viscosity tends to be too high, and the production tends to be difficult.

In addition, the weight average molecular weight is a weight average molecular weight converted from a standard polystyrene molecular weight, and can be used in a high-performance liquid chromatography apparatus (Shodex GPC system-11 type, manufactured by Showa Denko Corporation). ") Three columns in series: Shodex GPC KF-806L (excluding the limit molecular weight: 2 × 10 ⁷ , separation range: 100 ~ 2 × 10 ⁷ , theoretical number of plates: 10,000 plates / root, filler material: styrene - The divinylbenzene copolymer and the filler particle size: 10 μm) were measured.

In this manner, an active energy ray-curable resin composition containing an acrylic resin and a (meth)acrylic acid urethane-based compound can be obtained, and when the active energy ray-curable resin composition is an ultraviolet curable resin composition, Preferably, it further contains a photopolymerization initiator. In the case of an electron beam curable resin composition, a photopolymerization initiator is not required.

Examples of the photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, and 4-( 2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2- Phytyl (4-thiomethylphenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4- Acetophenones such as morphylphenyl)butanone and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone oligomer; benzoin, benzoin methyl ether, benzoin Benzoin such as diethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzylidene-4'- Base-diphenyl sulfide, 3,3',4,4'-tetra(perbutylbutoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-phenyl Mercapto-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzoammonium bromide, (4-benzylidenebenzyl)trimethyl Benzophenones such as ammonium chloride; 2-isopropyl 9-oxosulfur 4-isopropyl 9-oxosulfur 2,4-diethyl 9-oxosulfur 2,4-dichloro 9-oxosulfur 1-chloro-4-propoxy 9-oxosulfur , 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-9-oxygen 9-oxosulfurate such as -9-ketone internal race chloride 2,4,6-trimethylbenzylidene-diphenylphosphine oxide, bis(2,6-dimethoxybenzylidene)-2,4,4-trimethyl-pentyl a phosphine oxide such as phosphine oxide or bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide; Further, these photopolymerization initiators may be used alone or in combination of two or more.

Further, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (michlerone), 4,4'-diethylaminobenzophenone, or the like may be used in combination. 2-Dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoic acid (n-butoxy)ethyl ester, 4-dimethylaminobenzene Isoamyl formate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone Etc. as such additives.

Among these, it is preferred to use benzyldimethylketal, 1-hydroxycyclohexyl phenyl ketone, benzamidine isopropyl ether, 4-(2-hydroxyethoxy)-phenyl (2- Hydroxy-2-propyl)one, 2-hydroxy-2-methyl-1-phenylpropan-1-one.

In the present invention, the thickness of the curable resin layer [II] is preferably from 1 to 150 μm, particularly preferably from 2 to 120 μm, and more preferably from 5 to 100 μm, in terms of abrasion resistance and chemical resistance. . When the thickness is too small, the abrasion resistance or the chemical resistance tends to be lowered. When the thickness is too large, the film cutting property after the transfer is lowered, which tends to cause burrs or the like.

When the curable resin layer [II] is formed, the gravure printing method is used by a coating method such as a gravure coating method, a roll coating method, a bar coating method, a knife coating method, or a lip coating method. The above-mentioned raw material resin or raw material resin composition may be laminated by a printing method such as a screen printing method.

When the active energy ray-curable resin composition is used, a layer composed of an active energy ray-curable resin composition (curable resin layer [II]) may be laminated on the base film [I] until The printed layer [III] is transferred onto the transfer target, and the active energy ray is irradiated at any stage before the base film [I] is peeled off to be cured, or the active energy ray is irradiated after the base film [I] is peeled off. Hardened to form a protective layer (hard coat).

For example, it can be cured by: (a) after laminating the active energy ray-curable resin composition layer on the base film, irradiating the active energy ray to harden it; (b) laminating the active energy ray on the base film After the curable resin composition layer, a printing layer to be described later is formed, and then the active energy ray is irradiated from the base film side to be cured; (c) the layer is laminated to a later-described subsequent layer, and then the active energy ray is irradiated from the base film side to be hardened. (d) making the thermal transfer laminate of the present invention and being transferred Subsequently, the printed body is irradiated with an active energy ray from the base film side to be cured; (e) After the thermal transfer laminated body of the present invention and the transfer target are attached, the base film is peeled off and irradiated with an active energy ray to be cured. In the aspect of the followability of the transfer target at the time of thermal transfer, the method of (d) or (e) which is hardened after transfer is preferable, and the method of (e) is particularly preferable. Further, the laminated body for thermal transfer of the present invention may be provided as a laminate obtained by curing a curable resin layer as in the above (a) to (c), and is preferably as (d) and (b) above. e) A laminate comprising a layer of a curable resin layer before hardening is provided.

When the curable resin layer is cured by irradiation of the active energy ray, the active energy ray can be used as an active energy ray, for example, in addition to electromagnetic waves such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, and electromagnetic waves such as X-rays and gamma rays. Radiation, neutron radiation, etc., in terms of hardening speed, ease of obtaining the irradiation device, price, etc., it is advantageous to harden by ultraviolet irradiation.

As a method of hardening by ultraviolet irradiation, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, or the like which emits light having a wavelength region of 150 to 450 nm is used for irradiation of 0.01 to 10 J/cm. ² or so. After the ultraviolet irradiation, it may be heated as needed to achieve complete hardening.

(3) Printed layer [III]

The printing layer [III] is a layer on which a pattern or the like is printed, and as the material of the printing layer, a colored ink containing a pigment or a dye of a suitable color as a coloring agent may be used as the binder. Vinyl resin, polyamine resin, polyester resin, acrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose A resin such as an ester resin or an alkyd resin.

As a method of forming the printing layer [III], a usual printing method such as a lithography method, a gravure printing method, or a screen printing method can be used. In particular, in order to perform multicolor printing or gray scale display, a lithography method or a gravure printing method is preferred.

(4) Adhesive layer [IV]

In the laminated system for thermal transfer of the present invention, the base film [I], the curable resin layer [II], and the printed layer [III] are laminated, and it is preferable that a laminate layer is laminated on the printed layer [III]. IV].

Next, the layer [IV] is used to connect the layered body to the surface to be transferred. The adhesive layer [IV] may be formed as long as the adhesion between the printed layer and the molded article is weak. As the material of the adhesive layer [IV], a resin suitable for the heat sensitivity or pressure resistance of the material of the transfer target can be suitably used, and examples thereof include a polyester resin, an acrylic resin, and a polystyrene resin. Polyamide-based resin, chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, scented samarium-indene resin, and the like.

Examples of the method for forming the adhesive layer [IV] include a coating method such as a gravure coating method, a roll coating method, a bar coating method, and a knife coating method, and printing such as a gravure printing method or a screen printing method. law. Further, the adhesive sheet formed of the above material may be bonded by a lamination method or the like to form an adhesive layer [IV]. Further, the layer [IV] may also serve as the printing layer [III].

The thickness of the subsequent layer [IV] is preferably from 0.5 to 50 μm, particularly preferably from 1 to 40 μm, and more preferably from 2 to 30 μm, in terms of the followability of the adherend. When the thickness is small, the followability to the transfer target at the time of transfer tends to decrease, and if it is too thick, the cost tends to be high, which is uneconomical.

[Method of Using the Thermal Transfer Laminate of the Present Invention: Thermal Transfer Method]

A thermal transfer method using the laminate for thermal transfer of the present invention will be described.

(2) Method of decorating the transferred body surface

The first method of the thermal transfer method of the present invention is characterized in that the printed layer [III] of the laminated body for thermal transfer of the present invention is adhered to the surface of the transferred body, and the laminated body for thermal transfer is used. The base film [I] side is heated and pressurized to transfer the printing layer [III] to the object to be transferred, and the thermal transfer layered body that is in close contact with the transferred body surface is irradiated with active energy. Line, and a step of curing the curable resin layer [II]; and a step of peeling off the base film [I] from the transfer target after curing. The details will be described below.

First, the transfer layer of the thermal transfer laminated body (which is the opposite side of the base film [I], becomes the adhesive layer [IV] when the transfer layer has the adhesive layer [IV], and has no adhesive layer [ In the case of IV], the printed layer [III] is adhered to the surface to be transferred. Next, a heat-resistant rubber-like elastomer which is set to a temperature of about 80 to 270 ° C and a pressure of about 490 to 1960 Pa is used by using a transfer machine such as a roll transfer machine or a reversible transfer machine having a heat-resistant rubber-like elastic body such as ruthenium rubber. Heat and pressure are applied from the side [I] of the base film of the laminate for transfer. Thereby, the layer [IV] or the printed layer [III] is followed by the surface of the object to be transferred.

After cooling, the curable resin layer [II] is cured by active energy ray irradiation or the like to form a protective layer (hard coat layer), and finally the base film [I] is peeled off from the base film [I] and the protective layer ( The peeling occurred at the boundary surface of the hardened curable resin layer [II]: hard coat layer, and the transfer was completed.

(2) A method of decorating the surface of a resin molded article as a transfer target by a simultaneous transfer method by injection molding

In the second method of the thermal transfer method of the present invention, the surface of the resin molded article as the transfer target is decorated by a simultaneous transfer method by injection molding, which comprises: subjecting the above-described thermal transfer of the present invention The base film [I] of the laminate is disposed so as to face the fixed mold of the mold for molding; the molding resin is injected and filled in the mold for molding, and the printed layer on which the laminate for thermal transfer is subsequently formed is formed [III] The step of transferring the substrate; the step of peeling off the base film [I] after the formation of the transferred body. The details are as follows.

First, the thermal transfer laminated body is fed into the molding die so that the base film becomes the fixed mold (usually the female mold) side. The heat transfer transfer layer may be fed into a single piece of the thermal transfer layered body at a time, or may be intermittently fed into a necessary portion of the long laminated body. In the case of using a long thermal transfer laminate, it is only necessary to use a feed device having a positioning mechanism. The printing layer [III] of the laminated body for thermal transfer and the molding die may be registered. Further, when the thermal transfer laminated body is intermittently fed, the position of the thermal transfer laminated body is detected by the sensor, and the thermal transfer is fixed by the movable mold (male mold) and the fixed mold (female mold). In the case of the laminated body, the laminated body for thermal transfer can be often fixed at the same position, and the positional shift of the printed layer [III] is not generated, which is convenient.

After the molding die is closed, the molten molding resin is injected from the gate and filled in the mold to form the transfer target. At the same time as the formation of the transfer target, the laminate for thermal transfer is fed, and the laminate for thermal transfer is followed by the surface of the transfer target.

Examples of the molding resin which is a material of the transfer target include a polystyrene resin, a polyolefin resin, an ABS (Acrylonitrile Butadiene Styrene) resin, and AS (Acrylonitrile Styrene). A general-purpose resin such as a nitrile-styrene resin or an AN resin. Further, a polyphenylene ether-polystyrene resin, a polycarbonate resin, a polyacetal resin, an acrylic resin, a polycarbonate modified polyphenylene ether resin, or a polybutylene terephthalate resin can also be used. General engineering resin such as ultra high molecular weight polyethylene resin or polyfluorene resin, polyphenylene sulfide resin, polyphenylene ether resin, polyarylate resin, polyether phthalimide resin, polyimine resin, liquid crystal polyester Super engineering resin such as resin or polyallyl heat-resistant resin. Further, a composite resin to which a reinforcing material such as glass fiber or inorganic filler is added may be used. The object to be transferred composed of the resins may be any of transparent, translucent, and opaque. Further, the transferred body may be colored or uncolored.

After cooling the resin molded article as the transfer target, the molding die is opened to take out the resin molded article. In the method of continuously feeding the laminated body for thermal transfer, the peeling strength of the base film and the curable resin layer of the laminated body for thermal transfer of the present invention is much smaller than the peeling strength of the transfer body and the transfer layer. When the molded article is released from the mold, peeling of the curable resin layer from the base film is caused. In other words, when it is easy to feed the laminated body for thermal transfer one by one, the base film can be simply peeled off from the molded article taken out.

In this way, a molded article in which the curable resin layer is the outermost layer is obtained. When the curing of the curable resin layer is not completed at the time of demolding and taking out, the curing is terminated. The hardened curable resin layer [II] is a protective layer of the molded article.

The decorative molded article obtained in this manner is excellent in surface glossiness and excellent in surface whitening resistance. Although the reason is not clear, it is speculated that the reason may be as follows: the polyalkylene glycol (B) exuded between the base film [I] and the curable resin layer [II] is moderately tight to the base film when the base film is peeled off. Therefore, the amount of the remaining resin on the surface of the curable resin layer is less than that of the curable resin layer, and the amount of whitening of the decorative molded article can be suppressed.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples as long as the gist of the invention is not exceeded.

In addition, the case of "part" and "%" in the example means the weight basis.

[Evaluation of samples for evaluation]

(1) Demoulding

The release property of the base film [I] from the sample for evaluation was evaluated by hand using the following criteria.

○: The base film can be easily peeled off.

△: Although the sample for self-evaluation was peeled off, it was accompanied by peeling sound.

X: There was difficulty in peeling off the base film, and peeling marks remained on the surface of the protective layer.

(2) Surface gloss of the protective layer

In the sample for evaluation, after the base film [I] was peeled off, the fluorescent lamp was reflected on the surface of the protective layer (hardened curable resin layer), and the fluorescent lamp was clearly observed by the following reference. Degree is evaluated.

○: The outline of the fluorescent lamp can be clearly seen.

△: The outline of the fluorescent lamp can be blurred.

×: The outline of the fluorescent lamp cannot be confirmed.

(3) Resistance to surface whitening

The surface of the protective layer (hardened curable resin layer) was visually observed, and surface whitening was evaluated by the following criteria.

○: 2 out of 10 people were evaluated as whitish.

△: 3 to 5 out of 10 people were evaluated as whitish.

×: Six out of 10 people were evaluated as whitish.

[Production of laminated body No. 1 for thermal transfer]

(1) Production of polyvinyl alcohol film

Formulated as a polyalkylene glycol (B) polypropylene glycol (weight average molecular weight 400) in 100 parts of polyvinyl alcohol (A) (average saponification degree 88 mol%, 4% aqueous solution viscosity 30 mPa.s (20 ° C)) 4 parts, and further, 0.3 parts of polyoxyalkylamino ether as a surfactant, 1 part of glycerin as a plasticizer, and adjusted to a polyvinyl alcohol-based resin aqueous solution having a solid content concentration of 18% (doped) ()).

The adjusted polyvinyl alcohol-based resin aqueous solution was ejected from a T-die to a rotating stainless steel endless belt whose surface temperature was adjusted to 90 ° C, and cast into a film to obtain a polyvinyl alcohol film having a thickness of 40 μm.

(2) Active energy ray-curable resin composition

50 parts of the solid component of the polymethyl methacrylate "MN" manufactured by Kaneka Co., Ltd., and an amine amide group manufactured by Nippon Synthetic Chemical Industry Co., Ltd. by 2-butanone at a total solid content concentration of 50%. 40 parts of the solid component of the formate "UV-3520" and 10 parts of the photopolymerizable monomer "Viscoat #300" manufactured by Osaka Organic Chemical Industry Co., Ltd. were diluted and mixed, and 100 parts of the solid solution was obtained in the obtained solution. "Irgacure 819" manufactured by Nagase Industrial Co., Ltd., which is a photopolymerization initiator, was mixed in a three-part manner.

(3) Design printing ink

An ink for gravure printing comprising 10 parts of a black pigment, 5 parts of nitrocellulose, 15 parts of an alkyd resin, 30 parts of toluene, 30 parts of ethyl acetate, and 10 parts of isopropyl alcohol was prepared.

(4) Coating liquid for the subsequent layer

Polrester "SP-185" (polyester resin) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. was heated under a heating loop condition to be 20% with respect to a mixed solvent of 4:1 (by weight) of toluene and 2-butanone. Stir and dissolve.

(5) Production of laminated body for thermal transfer

Then, using the polyvinyl alcohol film obtained above as the base film [I], a laminated body for thermal transfer was produced as follows.

The active energy ray-curable resin composition was applied onto the base film [I] by a bar coater so as to have a thickness of 160 μm, and dried at 80 ° C for 15 minutes to prepare a base film [I]. The buildup layer (α) of the curable resin layer [II] having a thickness of 80 μm is laminated on the upper layer.

By using the above printing ink and forming a lattice pattern on the surface of the hardened resin layer [II] of the laminate (α) by the gravure printing method, the base film [I] / curable resin layer [II] / The layered body (β) composed of the printed layer [III].

Furthermore, the coating liquid for thermocompression bonding layer was applied to the surface of the printed layer [III] of the laminated body (β) by a bar coater so as to have a thickness of 100 μm, and dried at 80 ° C for 15 minutes. Thereby, a thermocompression bonding layer [IV] having a thickness of 20 μm is formed, and a laminate (γ) composed of the base film [I] / the curable resin layer [II] / the printing layer [III] / the bonding layer [IV] is obtained. (Laminated body for thermal transfer).

(6) Production of samples for evaluation

Using the obtained laminate (γ), samples for evaluation were prepared as described below, and the following evaluations were carried out.

The laminate (γ) and the blue glass substrate (thickness 2.8 mm) are heated to The laminate was preheated in a dryer at 130 ° C for 3 minutes, and the thermal compression bonding agent of the laminate (γ) was melted, and the adhesive layer [IV] surface was pressed against the blue glass substrate by a hand roller to prepare a bonded sample.

The obtained bonded sample was irradiated with ultraviolet rays of 1000 mJ over the base film [I], and the curable resin layer [II] was cured to form a protective layer (hardened curable resin layer: hard coat layer) to prepare a sample for evaluation. The sample for evaluation prepared was evaluated for mold release property, surface glossiness, and surface whitening resistance based on the above evaluation method. The results are shown in Table 1.

<Laminar body No. 2 to 8 for thermal transfer>

Regarding the composition of the composition for a polyvinyl alcohol-based film, as shown in Table 1, a polypropylene glycol (PPG) or polyethylene glycol (PEG) having a different weight average molecular weight or a polyalkylene glycol is not formulated. A polyvinyl alcohol film and a thermal transfer layer were obtained in the same manner as in No. 1, except that the surfactant (polyoxyalkylamine ether or polyoxyethylene polyoxypropylene lauryl ether) was used in an amount of 1 shown. body. The polyvinyl alcohol film and the laminated body for thermal transfer were evaluated in the same manner as in No. 1 by the above evaluation method. The results are shown together in Table 1.

The release property of the base film of the laminated body for thermal transfer of No. 1 to 4 is practically problem-free, and The surface whitening of the obtained decorative molded article is suppressed, and the surface gloss of the decorative molded article is not problematic. On the other hand, in No. 5, since the base film was peeled off at the time of thermal transfer, surface glossiness was also inferior, and surface whitening occurred. When No. 6 was used as the polyalkylene glycol in the case of using a polypropylene glycol having a weight average molecular weight of 1200, the mold release property was satisfied, but whitening occurred on the surface of the decorative molded body, and the surface gloss was also inferior. Further, in the case where a large amount of polypropylene glycol having a weight average molecular weight of 400 was used, No. 7 was able to satisfy the mold release property, but was whitened on the surface of the decorative molded article due to an excessive content.

Further, in Nos. 1 to 4 according to the examples of the present invention, the weight average molecular weight of the polyalkylene glycol of No. 2 is relatively low, so that the effect on mold release property is relatively small, and the stretching of No. 4 is small. Since the content of the alkyl diol is too small, the effect on mold release property is relatively small. Therefore, it is understood that in order to suppress whitening of the surface of the decorative molded body and to obtain excellent mold release property, it is preferable to contain a weight-average molecular weight of 1,000 or less, preferably 300 to 1000, of a polyalkylene glycol of 1 to 15 weight. The portion preferably contains 2 to 10 parts by weight. Further, it is also known that if the amount of the specific polyalkylene glycol is small, the mold release property or the surface gloss is affected, and if the amount of the specific polyalkylene glycol is large, the surface whitening resistance is obtained. Sexual effects.

[Industrial availability]

Since the polyvinyl alcohol-based film of the present invention is excellent in mold release property, it is useful as a base film for a separator or a film for transfer, and is particularly expected to be a base film for thermal transfer printing.

Claims (11)

A polyvinyl alcohol-based film containing 1 to 15 parts by weight of a polyalkylene glycol (B) having a weight average molecular weight of 1,000 or less based on 100 parts by weight of the polyvinyl alcohol-based resin (A). The polyvinyl alcohol-based film of claim 1, wherein the polyalkylene glycol (B) has a weight average molecular weight of from 300 to 1,000. The polyvinyl alcohol-based film of claim 1, wherein the polyalkylene glycol (B) is polypropylene glycol. The polyvinyl alcohol-based film of the first aspect of the invention, wherein the total content of the plasticizer is less than 20 parts by weight based on 100 parts by weight of the polyvinyl alcohol-based resin (A). The polyvinyl alcohol-based film of claim 1, wherein the polyvinyl alcohol-based resin (A) has a 4% by weight aqueous solution viscosity of 5 to 70 mPa at 20 ° C. s. A polyvinyl alcohol-based film which is a user of a laminate for thermal transfer, and which comprises a polyalkylene glycol having a weight average molecular weight of 1,000 or less per 100 parts by weight of the polyvinyl alcohol-based resin (A) (B) ) 1~15 parts by weight. A method for producing a polyvinyl alcohol-based film comprising the steps of: casting a weight of 1 to 15 by weight of a polyalkylene glycol (B) having a weight average molecular weight of 1,000 or less based on 100 parts by weight of the polyvinyl alcohol-based resin (A). The obtained polyvinyl alcohol-based resin aqueous solution was formed into a film. The method for producing a polyvinyl alcohol-based film according to claim 7, wherein the concentration of the polyvinyl alcohol-based resin aqueous solution is 10 to 30% by weight. A laminated body for thermal transfer, which comprises a base film [I] composed of a polyvinyl alcohol-based film according to any one of claims 1 to 5, a curable resin layer [II], and a printing layer. Layer [III] is formed. A thermal transfer method comprising the step of adhering a printed layer [III] of a thermal transfer laminated body according to claim 9 of the invention to a transferable body surface, and a base film from the thermal transfer laminated body [I] side is heated and pressurized, thereby a step of transferring the printing layer [III] to the object to be transferred, and irradiating the layered body for thermal transfer which is adhered to the surface of the transferred body with an active energy ray to cure the curable resin layer [II] a step; and a step of peeling off the base film [I] from the transfer target after hardening. A thermal transfer method comprising the steps of: arranging a base film [I] of a thermal transfer laminated body according to claim 9 of the invention to a fixed mold of a molding die; and ejecting and molding the molding resin In the above-mentioned molding die, a step of forming a transfer target of the printing layer [III] on which the laminated body for thermal transfer is carried out is formed, and a step of peeling off the base film [I] after molding of the transfer target.