JP4956167B2 - Film-forming transfer sheet and method for forming coating film using the same - Google Patents

Description

  The present invention relates to an ultraviolet curable coating film forming transfer sheet useful as a transfer sheet capable of forming a coating film such as a dry paint film by transfer, and a method for forming a coating film using the same.

  At present, the coating film on the surface of plastic parts such as automobiles is almost always applied by spraying an organic solvent-based paint. Such spray painting process has environmental problems that cause environmental pollution due to deterioration of working environment due to organic solvents, or low painting efficiency, high equipment costs such as painting booth, drying / curing equipment and solvent recovery equipment We have cost problems such as.

  As a method for solving such a problem, a technique called dry paint film has been proposed and is being studied for practical use. The coating film formation method using a dry paint film is different from conventional coating and coating film forming methods, and a layer of a dry film previously coated is transferred onto a substrate such as a plastic part, and this layer is used as a coating film. Is. In the process of forming the coating film, the generation of waste paints that are difficult to discharge and recycle organic solvents that lead to environmental destruction is almost completely suppressed, which is preferable in terms of environmental impact.

  For example, in Non-Patent Document 1 (Hirotaka Arai, Kennori Kanayama, painting alternative technology using dry paint film, “Molding”, 11th issue, No. 5, p392 to p396 (1999)) Is described.

  This coating film forming method is to form a coating film at the same time when the substrate is molded (insert molding, vacuum molding, etc.). Therefore, the film is thermoplastic and needs to have considerable flexibility (when heated) to follow the molding stress of the substrate. At the same time, the base material needs to be a thermoplastic that can be molded at a relatively low temperature, and engineering plastics and metals having heat resistance and high strength are not suitable. Furthermore, the film at the time of coating film formation does not have sufficient fluidity and smoothness, and as a result, it is difficult to obtain a coating film having a high appearance (high gloss, high definition, etc.). Also, it cannot be said that the coating film hardness is high, and there is a disadvantage that it is inferior in killing resistance and cleaning resistance. Furthermore, since the coating film is not cross-linked, there are disadvantages in that the coating film strength is not sufficient at high temperature such as summertime and the like.

  In order to eliminate the above disadvantages, Patent Document 1 (Japanese Patent Laid-Open No. 2001-246706) and Patent Document 2 (Japanese Patent Laid-Open No. 2002-240822) describe the formation of a curable coating film between a pair of guard films. A laminated film for forming a coating film in which the coating film forming layer contains an oxetanyl group-containing compound is proposed, and the coating film forming layer is disclosed to form a coating film by cationic polymerization by light irradiation. Yes.

JP 2001-246706 A JP 2002-240822 A Hirotaka Arai, Kennori Kanayama, Painting alternative technology with dry paint film, "Molding" 11th issue No. 5, p392-p396 (1999)

  The coating film forming layer of the laminated film for forming a coating film of Patent Document 1 is cured by cationic polymerization, and the obtained coating film has a crosslinked structure. However, cationic systems are generally susceptible to temperature and humidity. That is, it cannot be said that it is advantageous for industrial use in terms of safety of acid remaining in the coating film, metal corrosiveness, and curing speed.

  Accordingly, the present invention is advantageous for industrial use, and is an ultraviolet curable coating film forming transfer capable of forming a tough coating film by transferring and curing a coating film on various substrates. The purpose is to provide a sheet.

  In addition, the present invention is advantageous for industrial use, and it is possible to form a tough and good finished coating film with high productivity by transferring and curing the coating film to various substrates. An object of the present invention is to provide an ultraviolet curable transfer sheet for forming a coating film.

  Furthermore, an object of the present invention is to provide a method of forming a coating film by radical polymerization using ultraviolet rays, using the above-mentioned transfer sheet for forming a coating film.

The above purpose is
A coating film-forming transfer sheet comprising a coating film-forming layer for forming a coating film comprising a photocurable composition that can be deformed by pressurization and a release sheet provided on at least one surface of the coating film-forming layer. There,
The photocurable composition comprises a polymer and a reactive diluent having an ethylenically unsaturated group, and the reactive diluent having an ethylenically unsaturated group has at least one hydroxyl group as a polar group, And a compound having at least two groups selected from an acryloyl group and a methacryloyl group,
And the glass transition temperature before photocuring of a coating-film formation layer is less than 20 degreeC, The transfer sheet for coating-film formation characterized by the above-mentioned
Can be achieved. Adhesiveness with a base material improves by including the reactive diluent which has said ethylenically unsaturated group and polar group.

  The above-mentioned transfer sheet for forming a coating film of the present invention is also free from the viscosity pointed out in Patent Document 2, that is, has good shape retainability and good workability and finish. Furthermore, the curing is obviously faster than that of the cationic system, and since it is excellent in killing resistance, it is possible to shorten the tact (processing time).

  The suitable aspect of the transfer sheet for coating-film formation of this invention is enumerated below.

1) The glass transition temperature after 300 mJ / cm ² ultraviolet irradiation of the coating layer is 50 ° C. or higher (preferably 65 ° C. or higher). A tough coating is obtained.

  2) The polymer has a glass transition temperature of 80 ° C. or higher, and excellent transferability and high coating strength after curing are easily obtained.

  3) The polymer is an acrylic resin. Appropriate combination with a reactive diluent makes it easy to achieve both good transferability and excellent curability.

  4) The acrylic resin is an acrylic resin containing at least 50% by mass of repeating units of methyl methacrylate. Appropriate combination with a reactive diluent makes it easy to achieve both good transferability and excellent curability.

  5) The acrylic resin is an acrylic resin having a hydroxyl group.

  The acrylic resin having a hydroxyl group is methyl methacrylate, at least one kind of alkyl (meth) acrylic acid ester having 2 to 10 carbon atoms, and the number of carbon atoms having an alcohol residue having hydroxyl group. It is preferably a copolymer with at least one of 2 to 4 alkyl (meth) acrylic acid esters. It is particularly preferable to have 50% by mass or more of methyl methacrylate. Appropriate combination with a reactive diluent makes it easy to achieve both good transferability and excellent curability.

  6) The acrylic resin is an acrylic resin having an ethylenically unsaturated group.

  The acrylic resin is a copolymer of methyl methacrylate, at least one kind of (meth) acrylic acid ester having an alcohol residue of 2 to 10 carbon atoms and glycidyl (meth) acrylate, and the glycidyl It is preferably obtained by reacting a carboxylic acid having a polymerizable functional group with the group. Appropriate combination with a reactive diluent makes it easy to achieve both good transferability and excellent curability.

  The acrylic resin is a copolymer of methyl methacrylate, at least one kind of (meth) acrylic acid ester having an alcohol residue of 2 to 10 carbon atoms, and a carboxylic acid having a polymerizable functional group. The carboxylic acid group is preferably obtained by reacting glycidyl (meth) acrylate. Appropriate combination with a reactive diluent makes it easy to achieve both good transferability and excellent curability.

  7) Further, polyisocyanate (preferably diisocyanate) is included. Post-crosslinking before photocuring is possible, and the shape retention of the film before transfer is improved.

  8) The number average molecular weight of the polymer is 100,000 or more and / or the weight average molecular weight is 100,000 or more. In particular, the number average molecular weight is preferably 100,000 to 300,000 and the weight average molecular weight is preferably 100,000 to 300,000. By making the molecular weight, the composition of the acrylic resin, and the ratio of the reactive diluent suitable as described later, particularly excellent transferability and high curing rate can be obtained. The number average molecular weight is measured by GPC (gel permeation chromatography) using a polystyrene standard.

9) a compound having a hydroxyl group and an acryloyl group and / or methacryloyl groups above SL is a compound represented by the following formula (I):

[However, R ¹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and may be the same or different from each other;
R ² represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl group having 1 to 5 carbon atoms,
R ³ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and may be the same or different from each other;
R ⁴ represents an alkylene group having 1 to 5 carbon atoms,
X and Y each independently represents an acryloyloxy group or a methacryloyloxy group, and n represents 0 or 1. ]
It is a compound represented by these. By using this compound, the adhesion to the substrate is improved.

In the general formula (I),
R ¹ represents a hydrogen atom,
R ² represents a hydrogen atom, methyl, ethyl or hydroxymethyl group,
R ³ represents a hydrogen atom,
R ⁴ represents a methylene group,
It is preferable that X and Y each independently represent an acryloyloxy group or a methacryloyloxy group, and n represents 0 or 1.

Furthermore, in the general formula (I),
R ¹ represents a hydrogen atom,
R ² represents a hydrogen atom,
R ³ represents a hydrogen atom,
It is preferable that X and Y each independently represent an acryloyloxy group or a methacryloyloxy group, and n represents 0.

10 ) The film thickness unevenness of the coating film forming layer is in the range of ± 3 μm. Thereby, the smoothness excellent in the coating film after transfer and curing can be obtained.

11 ) A photocurable composition contains 0.1-10 mass% of photoinitiators.

12 ) It has a colored layer and / or an adhesive layer between the coating film forming layer and the release sheet. Generally, a coating film forming layer exists on the side of the release sheet that is removed after curing. A laminate composed of a release sheet that is peeled first, an adhesive layer, a colored layer, a coating film forming layer, and a release sheet that is removed after curing is preferable. A coating film forming layer may be used for the adhesive layer. That is, you may have a colored layer and a coating-film formation layer between a coating-film formation layer and a peeling sheet.

13 ) It is preferable that a peeling sheet consists of a peeling layer provided in the surface with a plastic film (especially polyethylene terephthalate film).

14 ) Release sheets are provided on both surfaces of the coating film forming layer. Handling becomes easy.

15 ) One release sheet (release sheet to be removed after curing) includes a plastic film and a release layer provided on the release film and in contact with the coating film-forming layer. It consists of a condensation reaction product of siloxane and hydrogenated polysiloxane. The polysiloxane having a hydroxyl group is preferably dimethylpolysiloxane.

  Another release sheet (release sheet to be removed before transfer) The second release sheet includes a plastic film and a release layer provided thereon and in contact with the coating film-forming layer. It is formed from the thermoplastic resin or thermosetting resin which does not contain an atom, or these resins and a silane coupling agent. Alternatively, the release layer of the second release sheet is an addition reaction product of a polysiloxane having an unsaturated double bond group and a hydrogenated polysiloxane (the polysiloxane having an unsaturated double bond group is dimethylpolysiloxane). Is preferable). Moreover, the 2nd peeling sheet does not need to have a peeling layer.

Furthermore, the present invention provides
The following steps (1) to (3):
(1) A step of removing one release sheet when release sheets are provided on both surfaces of the transfer sheet for coating film formation of the present invention ;
(2) The surface of the coating film forming transfer sheet is placed on the surface of the plastic part so that the surface of the coating film forming layer is in contact with the surface of the plastic part, and the surface of the coating film forming layer is pressed by pressing them. And (3) a step of irradiating and curing ultraviolet rays from the other release sheet of the laminate;
There is also a method for forming a coating film characterized by comprising

  The suitable aspect of the formation method of the coating film of this invention is enumerated below.

1) The ultraviolet irradiation of (3) is performed with an irradiation energy of at least 300 mJ / cm ² .

  2) The glass transition temperature of the coating film-forming layer obtained in (3) is 50 ° C. or higher.

  The coating film forming layer of the transfer sheet for forming a coating film of the present invention contains a polymer and a reactive diluent having an ethylenically unsaturated group, and the glass transition temperature of the coating film forming layer before photocuring is less than 20 ° C. Therefore, it is easy to directly press-bond (laminate) to the substrate, and then the coating film forming layer is radically polymerized by ultraviolet rays. Therefore, the coating film is cured, cross-linked and tough, so it is durable. An excellent coating film-protected substrate can be obtained. In addition, the transfer sheet for forming a coating film of the present invention is flexible enough to be transferred even at room temperature, so unlike conventional thermoplastic dry paint films, there is no need to form a film by molding. In addition, it can be applied to substrates made of various materials such as engineering plastics and metals that are not molded, yet it is possible to obtain a tough coating film with excellent adhesion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a typical example of an embodiment of a transfer sheet for forming a coating film used in the present invention. In the coating film forming transfer sheet 10, the coating film forming layer 11 is provided with a first release sheet 12 b on one surface and a second release sheet 12 a on the other surface. The coating film forming layer 11 is generally a clear layer, but may contain a titanium oxide pigment, an aluminum pigment, or the like (however, if it is excessively contained, it will hinder ultraviolet curing). The first release sheet 12b and the second release sheet 12a may be the same release sheet. Generally, the release sheet is provided such that a release layer is provided on a plastic sheet, and the release layer is in contact with the surface of the coating film forming layer 11. It is preferable that the 1st peeling sheet 12b and the 2nd peeling sheet 12a have mutually different peelability so that it may mention later. Generally, in the transfer sheet 10 for forming a coating film, the second release sheet 12a is removed, and the exposed surface of the coating film forming layer 11 is pressure-bonded to the substrate surface. Therefore, the second release sheet 12a may be omitted, but it is preferable that the second release sheet 12a is provided because it is easy to handle.

  The coating film-forming layer 11 of the present invention is a layer that is easily deformed by pressure so that it can be accurately transferred by pressing the uneven surface of the substrate, and has good adhesion to the substrate surface after curing. Layer. Therefore, the coating film forming layer 11 is composed of a photocurable composition containing a polymer and a reactive diluent having an ethylenically unsaturated group (radical polymerizable carbon-carbon double bond), and the coating film forming layer The glass transition temperature before photocuring is less than 20 ° C.

In the present invention, the photocurable composition preferably contains a polymer having a glass transition temperature of 80 ° C. or higher as the polymer. Thereby, the uneven | corrugated shape of a base material can be transcribe | transferred easily, and subsequent hardening can also be performed at high speed. Further, since the cured (300 mJ / cm ² or more) coating film also has a high Tg (preferably 50 ° C. or more, particularly 65 ° C. or more), its shape can be maintained for a long time without changing.

  When the polymer has a hydroxyl group, the coating film forming layer 11 can contain a diisocyanate to slightly crosslink the polymer and the like. It is particularly advantageous to have a greatly constrained layer. Diisocyanates are effective to some extent even in polymers without hydroxyl groups. Moreover, as a polymer (preferably having a glass transition temperature of 80 ° C. or higher), having an ethylenically unsaturated group is advantageous for speeding up curing because it can react with a reactive diluent. The film thickness unevenness of the coating film forming layer is preferably in the range of ± 3 μm.

  FIG. 2 is a cross-sectional view showing a preferred example of an embodiment of a transfer sheet for forming a coating film used in the present invention. In the coating film forming transfer sheet 20, the coating film forming layer 21 is provided with a first release sheet 22b on one surface, and a colored layer 23, an adhesive layer 24, and a second release sheet 22a on the other surface. It has been. The colored layer 23 is a colored layer (enamel layer) that is generally colored by blending a pigment such as a titanium oxide pigment or an aluminum pigment. The coating film forming layer 21 is generally a clear layer, but may contain the above-described pigment (if it is contained excessively, it will hinder ultraviolet curing). A printing layer may be provided between the coating film forming layer 21 and the colored layer 23. The adhesive layer 24 is provided in order to improve adhesion to various substrates, but may not be provided. The colored layer 23 may have a function of an adhesive layer. The adhesive layer 24 and the colored layer 23 may be composed of the coating film-forming layer of the present invention. However, when the color is deep, the curing by ultraviolet rays is hindered, so the content of raw materials and the like should be suppressed as much as possible. In some cases, the adhesive layer 24 may be provided on the release sheet side in advance.

  In general, the transfer sheet 20 for forming a coating film has the second release sheet 22a removed and pressure-bonds the exposed surface of the adhesive layer 24 to the substrate surface.

As shown in FIG. 1, when the coating-film formation layer 11 is a clear layer single layer, layer thickness is 2-200 micrometers, Preferably it is 5-100 micrometers. If the layer thickness is less than the lower limit, the surface of the substrate cannot be sufficiently concealed or protected, and if the layer thickness exceeds the upper limit, the hardness of the coating film cannot be sufficiently increased and may be easily damaged. When providing the layer 23, a coating-film formation layer (clear layer) is 5-100 micrometers, Preferably it is 10-80 micrometers, A colored layer is 10-150 micrometers, Preferably it is 20-80 micrometers. This improves the appearance of the coating film.

  The adhesive layer 24 has a film thickness of 0.01 to 100 μm, preferably 0.05 to 80 μm. If it is less than the lower limit, sufficient adhesive strength may not be obtained, and if it exceeds the upper limit, the weather resistance of the coating film may deteriorate.

Formation of a coating film on a base material such as molded plastic is performed as shown in FIG. 3, for example. The second release sheet 32a is peeled off from the coating film forming transfer sheet 30 (1), and is applied to the surface of the substrate (preferably pressurized or pressurized under vacuum), and the coating film forming layer 31 is applied to the surface of the substrate 35. (2), the coating film forming layer is cured by irradiation with ultraviolet rays (generally via a first release sheet) (300 mJ / cm ^2). (3), and then the first release sheet is removed to obtain a substrate coated with a tough coating film (glass transition temperature is preferably 50 ° C. or higher) (4). In this case, for example, it is possible to emboss the surface of the coating film forming layer by embossing the surface of the first release sheet that contacts the coating film forming layer. As a result, a matte surface can be obtained. The substrate 35 used is not only a normal plastic but also an engineering plastic that is not molded (for example, polyamide, polyimide, polyether ether) because of the excellent flexibility of the transfer sheet of the present invention as described above. It can be applied to substrates of various materials such as ketones), metals (eg, anodized, stainless steel (SUS403, 410, etc.)).

  As a method for pressurizing the coating film forming layer, for example, after a transfer sheet for coating film formation is pasted on the surface of the substrate, pressurizing with a pressure roll or between two rolls (eg, a rolling roller) under reduced pressure. Pressing with a press such as a simple press, pressing with an iron, pressing with vacuum, pressing under vacuum, pressing with a molding die when molding the substrate surface Etc. Preferably, it is a method capable of applying a pressure of 0.01 MPa (0.1 atm) or more to the coating film-forming transfer sheet. When the pressure applied during pressure bonding is 0.01 MPa (0.1 atm), it may be difficult to form a coating film having excellent adhesion.

  The temperature at the time of pressure-bonding the surface of the substrate (uneven shape) and the coating film forming layer is preferably a low temperature (preferably normal temperature) of 100 ° C. or less. The layer after curing of the coating layer is generally a layer having a Tg of 50 ° C. or higher (especially 65 ° C. or higher), and the cured coating is formed on the substrate surface with high adhesive strength. 1 release sheet can be easily peeled off.

  Moreover, pressurization of the coating-film formation layer in this invention can be performed by the press under pressure reduction using the apparatus of a double vacuum chamber system, for example. This will be described with reference to FIG. FIG. 4 shows an example of a double vacuum chamber type laminator. The laminator includes a lower chamber 44, an upper chamber 42, a silicone rubber sheet 43, and a heater 45. In the lower chamber 44 in the laminator, a laminate 49 of the base material and the coating film forming transfer sheet is placed. Both the upper chamber 42 and the lower chamber 44 are evacuated (depressurized). The laminated body 49 is heated by the heater 45, and then the upper chamber 42 is returned to atmospheric pressure while the lower chamber 34 is evacuated, and the laminated body is pressure-bonded. Cool and take out the laminate and move to the next step. Thereby, defoaming is sufficiently performed at the time of exhaust, and the stamper or the substrate and the transfer sheet for coating film formation can be pressure-bonded in a state without bubbles.

The base material on which the coating film is formed using the coating sheet-forming transfer sheet as described above is further irradiated with ultraviolet rays (preferably 300 mJ / cm ² or more) and, if necessary, heated. It is preferable because durability such as coating strength, adhesion, chemical resistance and weather resistance can be improved.

  The transfer sheet for forming a coating film used in the present invention comprises a photocurable composition that contains a polymer and a reactive diluent (polymerizable monomer, oligomer) having an ethylenically unsaturated group and can be deformed by pressurization. It has a coating film forming layer.

  The photocurable composition of the present invention generally comprises the polymer (preferably a polymer having a glass transition temperature of 80 ° C. or higher), an ethylenically unsaturated group (generally a carbon-carbon double bond group, preferably a (meth) acryloyl group). ) Reactive diluents (monomers and oligomers), photopolymerizable initiators, and optionally other additives.

As the reactive diluent having an ethylenically unsaturated group, which is a general constituent requirement of the photocurable composition of the present invention, for example, as a (meth) acrylic monomer, 2-hydroxyethyl (meth) acrylate, 2 -Hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl polyethoxy (meth) acrylate, benzyl (Meth) acrylate, isobornyl (meth) acrylate, phenyloxyethyl (meth) acrylate, tricyclodecane mono (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, Leroy Le morpholine, N- vinylcaprolactam, o- phenylphenyl oxyethyl (meth) acrylate, 2-hydroxy-3-acryloyloxy propyl methacrylate,
Neopentyl glycol di (meth) acrylate, neopentyl glycol dipropoxy di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, nonanediol di (meth) acrylate,
Glycerin diacrylate, glycerin acrylate methacrylate, glycerin dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane acrylate methacrylate, trimethylolpropane dimethacrylate,
(Meth) such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, ditrimethylolpropane tetra (meth) acrylate Acrylate monomers;
Polyol compounds (for example, ethylene glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butyl-1, Polyols such as 3-propanediol, trimethylolpropane, diethylene glycol, dipropylene glycol, polypropylene glycol, 1,4-dimethylolcyclohexane, bisphenol A polyethoxydiol, polytetramethylene glycol, the polyols and succinic acid, maleic acid Polyester polyols which are reaction products of polybasic acids such as itaconic acid, adipic acid, hydrogenated dimer acid, phthalic acid, isophthalic acid, terephthalic acid, etc., or their acid anhydrides, and the above-mentioned polyols and ε-capro Polycaprolactone polyols which are reaction products with kuton, reaction products of the above-mentioned polyols with ε-caprolactone of polybasic acids or anhydrides thereof, polycarbonate polyols, polymer polyols, etc.) and organic polyisocyanates ( For example, tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, dicyclopentanyl diisocyanate, hexamethylene diisocyanate, 2,4,4′-trimethylhexamethylene diisocyanate, 2,2 ′, 4 -Trimethylhexamethylene diisocyanate and the like) and hydroxyl group-containing (meth) acrylate (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxy Roxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, cyclohexane-1,4-dimethylol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, glycerin di (meth) acrylate, etc.) Polyurethane (meth) acrylate, which is a reaction product of
Examples thereof include (meth) acrylate oligomers such as bisphenol type epoxy (meth) acrylate, which is a reaction product of bisphenol type epoxy resin such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, and (meth) acrylic acid. These compounds having a photopolymerizable functional group can be used alone or in combination of two or more.

The reactive diluent of the present invention includes a reactive diluent having a hydroxyl group as a polar group .

  The reactive diluent having a hydroxyl group is generally a compound having a hydroxyl group and an acryloyl group and / or a methacryloyl group. For example, the above-mentioned 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Examples thereof include 4-hydroxybutyl (meth) acrylate and 2-hydroxy-3-phenyloxypropyl (meth) acrylate.

In the present invention, the compound having a hydroxyl group and an acryloyl group and / or a methacryloyl group includes one or more hydroxyl groups and two or more acryloyl groups and / or methacryloyl groups (that is, one or more acryloyl groups and 1 A compound having one or more methacryloyl groups, two or more acryloyl groups, or two or more methacryloyl groups) . For example, as such a compound, two or more (meth) acrylic acids are condensed with a polyhydric alcohol having three or more hydroxyl groups (eg, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, etc.). Can be mentioned.

  The compound having the hydroxyl group and the acryloyl group and / or methacryloyl group is represented by the following formula (I):

[However, R ¹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and may be the same or different from each other;
R ² represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl group having 1 to 5 carbon atoms,
R ³ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and may be the same or different from each other;
R ⁴ represents an alkylene group having 1 to 5 carbon atoms,
X and Y each independently represents an acryloyloxy group or a methacryloyloxy group, and n represents 0 or 1. ]
It is preferable that it is a compound represented by these.

In the general formula (I), R ¹ represents a hydrogen atom, R ² represents a hydrogen atom, methyl, ethyl or hydroxymethyl group, R ³ represents a hydrogen atom, R ⁴ represents a methylene group, It is preferable that X and Y each independently represent an acryloyloxy group or a methacryloyloxy group, and n represents 0 or 1. In particular, in the general formula (I), R ¹ represents a hydrogen atom, R ² represents hydrogen, R ⁴ represents hydrogen, and X and Y are each independently an acryloyloxy group or a methacryloyloxy group. And n preferably represents 0.

  Preferred examples of the compound of the general formula (I) include glycerin diacrylate (particularly 1,3-diacryloyl-propanetriol), glycerin acrylate methacrylate (particularly 1-acryloyl-3-methacryloyl-propanetriol (trade name G- 201P; manufactured by Kyoeisha Chemical Co., Ltd.)), glycerin dimethacrylate (particularly 1,3-dimethacryloyl-propanetriol (trade name G-101P; manufactured by Kyoeisha Chemical Co., Ltd.)), trimethylolpropane diacrylate, trimethylol Examples thereof include propane acrylate methacrylate and trimethylol propane dimethacrylate, and glycerol acrylate methacrylate and glycerol dimethacrylate are particularly preferable. In this invention, what has both acrylate and a methacrylate in a polyhydric alcohol is preferable.

  Such a specific compound is generally contained in a proportion of 5 to 70% by mass, preferably 5 to 50% by mass, particularly preferably 5 to 30% by mass, based on the reactive diluent. Thereby, favorable adhesiveness with the said base-material surface is acquirable.

  Examples of the polymer (preferably having a glass transition temperature of 80 ° C. or higher) include acrylic resins, polyvinyl acetate, vinyl acetate / (meth) acrylate copolymers, ethylene / vinyl acetate copolymers, polystyrene and copolymers thereof, poly Vinyl chloride and its copolymer, butadiene / acrylonitrile copolymer, acrylonitrile / butadiene / styrene copolymer, methacrylate / acrylonitrile / butadiene / styrene copolymer, 2-chlorobutadiene-1,3-polymer, chlorinated rubber, Styrene / butadiene / styrene copolymer, styrene / isoprene / styrene block copolymer, epoxy resin, polyamide, polyester, polyurethane, cellulose ester, cellulose ether, polycarbonate, polyvinyl acetal, etc. Can.

  In the present invention, an acrylic resin is preferable from the viewpoint of good transferability and excellent curability. As described above, the acrylic resin is particularly preferably an acrylic resin having an ethylenically unsaturated group or an acrylic resin having a hydroxyl group. In addition, when the acrylic resin contains at least 50% by mass (especially 60 to 90% by mass) of methyl methacrylate repeating units, it is easy to obtain an acrylic resin having a Tg of 80 ° C. or more, and good transferability and high-speed curability are also obtained. It is easy and preferable.

  In general, the acrylic resin having an ethylenically unsaturated group is an acrylic resin having an ethylenically unsaturated group, wherein at least methyl methacrylate and an alkyl (meth) acrylic acid ester having 2 to 10 carbon atoms are used. A copolymer of one kind and glycidyl (meth) acrylate, in which a carboxylic acid having an ethylenically unsaturated group is reacted with the glycidyl group, or methyl methacrylate and an alcohol residue having 2 to 10 carbon atoms. It is a copolymer of at least one alkyl (meth) acrylic acid ester and a carboxylic acid having an ethylenically unsaturated group, and the carboxylic acid group is reacted with glycidyl (meth) acrylate.

  It is a copolymer of methyl methacrylate, at least one kind of alkyl (meth) acrylate ester having 2 to 10 carbon atoms in the alcohol residue, and glycidyl (meth) acrylate. Methyl methacrylate is preferably contained as a repeating unit in an amount of 50% by mass or more (particularly 60 to 90% by mass) in the polymer. Appropriate combination with the reactive diluent makes it easy to achieve both good transferability and excellent curability. Alkyl (meth) acrylic acid ester having 2 to 10 carbon atoms (especially 3 to 5 carbon atoms) as an alcohol residue includes ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, Examples thereof include n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like. n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferred. Further, such a (meth) acrylic acid ester is preferably contained in the polymer as a repeating unit in general in an amount of 5 to 30% by mass, particularly 10 to 30% by mass. The glycidyl (meth) acrylate or carboxylic acid having a polymerizable functional group is preferably contained in the polymer in an amount of generally 5 to 25% by mass, particularly 5 to 20% by mass as the repeating unit. The glycidyl group or carboxylic acid group of the obtained copolymer is reacted with a carboxylic acid or glycidyl (meth) acrylate having a polymerizable functional group, respectively.

  The hydroxyl group-containing acrylic resin generally includes methyl methacrylate, at least one kind of alkyl (meth) acrylic acid ester having 2 to 10 (particularly 3 to 5) carbon atoms, and alcohol residues. Is a copolymer with at least one alkyl (meth) acrylic acid ester having 2 to 4 carbon atoms having a hydroxyl group. Methyl methacrylate is preferably contained as a repeating unit in an amount of 50% by mass or more (particularly 60 to 90% by mass) in the polymer. Appropriate combination with the reactive diluent makes it easy to achieve both good transferability and excellent curability. Alkyl (meth) acrylic acid ester having 2 to 10 carbon atoms (especially 3 to 5 carbon atoms) as an alcohol residue includes ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, Examples thereof include n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like. n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferred. Further, such a (meth) acrylic acid ester is preferably contained in the polymer as a repeating unit in general in an amount of 5 to 30% by mass, particularly 10 to 30% by mass. Examples of the alkyl (meth) acrylic acid ester having 2 to 4 carbon atoms in which the alcohol residue has a hydroxyl group include 2-hydroxyethyl methacrylate and hydroxypropyl methacrylate. In general, it is preferably contained in an amount of 5 to 25% by mass, particularly 5 to 20% by mass.

  The acrylic resin having an ethylenically unsaturated group can be produced, for example, as follows.

  One or a plurality of (meth) acrylic monomers (preferably methyl methacrylate, at least one (meth) acrylic acid ester having an alcohol residue of 2 to 10 carbon atoms, and a glycidyl group). A compound having 1 ethylenically unsaturated group (preferably glycidyl (meth) acrylate) or a carboxylic acid having a polymerizable functional group in the presence of a radical polymerization initiator and an organic solvent such as a solution polymerization method A glycidyl group-containing acrylic resin (a) or a carboxyl group-containing acrylic resin (b), which is a copolymer, is obtained by a known method, and the blending ratio of monomers such as (meth) acrylic monomer is glycidyl group-containing acrylic. It is 10 to 45 mass% with respect to solid content conversion total amount of resin (a) or carboxyl group-containing acrylic resin (b). It is preferable.

  Subsequently, a carboxylic acid having an ethylenically unsaturated group is added to the obtained glycidyl group-containing acrylic resin (a), or one glycidyl group and an ethylenically unsaturated group are added to the obtained carboxyl group-containing acrylic resin (b). An acrylic photocurable resin (A) or an acrylic photocurable resin (B) is obtained by adding one compound (preferably glycidyl methacrylate) and heating as necessary. This blending ratio is preferably blended so that the molar ratio of glycidyl group to carboxyl group is 1 / 0.9 to 1/1, and more preferably 1/1. If the glycidyl group is excessive, viscosity and gelation may occur in long-term stability, and if the carboxyl group is excessive, skin irritation increases and workability decreases. Further, in the case of 1/1, there is no residual glycidyl group, and the storage stability is remarkably improved. The reaction can be carried out by a known method in the presence of a basic catalyst, a phosphorus catalyst or the like.

  The (meth) acrylic monomer that can be used as a main component constituting the acrylic resin that includes the above OH or ethylenically unsaturated group and can be used in the present invention is acrylic acid or methacrylic acid. Various esters can be mentioned. Examples of various esters of acrylic acid or methacrylic acid include methyl (meth) acrylate ((meth) acrylate means acrylate and methacrylate; the same applies hereinafter), ethyl (meth) acrylate, n-propyl (meth) acrylate, n- Alkyl (meta) such as butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, and tridecyl (meth) acrylate ) Acrylate, ethoxyethyl (meth) acrylate, alkoxyalkyl (meth) acrylate such as butoxyethyl (meth) acrylate, 2-methoxyethoxyethyl (meth) acrylate, 2-ethoxyethoxyethyl Alkoxyalkoxyalkyl (meth) acrylates such as meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, butoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol ( Dialkylamino such as alkoxy (poly) alkylene glycol (meth) acrylate such as (meth) acrylate, pyrenoxide adduct (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate An alkyl (meth) acrylate etc. can be mentioned. Further, an aromatic compound containing an unsaturated group (eg, styrene) may be used.

  In the present invention, as described above, as the main component of the acrylic monomer, at least one of methyl methacrylate and an alkyl (meth) acrylate having 2 to 10 carbon atoms as an alcohol residue is used. Is preferred.

  The polymer of the present invention (preferably having a glass transition temperature of 80 ° C. or higher) preferably has a number average molecular weight of 100,000 or more, particularly 100,000 to 300,000, and a weight average molecular weight of 100,000 or more, particularly 100,000 to 300,000.

  Furthermore, in the present invention, as the polymer (preferably having a glass transition temperature of 80 ° C. or higher), a polymer having both a functional group having an active hydrogen such as a hydroxyl group and an ethylenically unsaturated group can also be used. As such a reactive polymer, for example, a homopolymer or copolymer (that is, an acrylic resin) mainly obtained from the acrylic monomer, and an ethylenically unsaturated group and active hydrogen are present in the main chain or side chain. It has a functional group. Therefore, such a reactive polymer includes, for example, methyl methacrylate, the one or more (meth) acrylates, and a (meth) acrylate having a functional group such as a hydroxyl group (eg, 2-hydroxyethyl (meth) acrylate). ) And the resulting polymer reacts with a functional group of the polymer and a compound having a photopolymerizable group, such as isocyanatoalkyl (meth) acrylate. In that case, the polymer which has a hydroxyl group and a photopolymerizable functional group as a functional group which has active hydrogen is obtained by adjusting and using the amount of isocyanatoalkyl (meth) acrylate so that a hydroxyl group may remain.

  Alternatively, in the above, an ethylenically unsaturated group having an amino group as a functional group having an active hydrogen by using a (meth) acrylate having an amino group instead of a hydroxyl group (eg, 2-aminoethyl (meth) acrylate) A containing polymer can be obtained. Similarly, an ethylenically unsaturated group-containing polymer having a carboxyl group or the like as a functional group having active hydrogen can also be obtained.

  In the present invention, an acrylic resin having the ethylenically unsaturated group via a urethane bond is also preferable.

  The polymer having a functional group having an ethylenically unsaturated group and active hydrogen generally contains 1 to 50 mol%, particularly 5 to 30 mol% of an ethylenically unsaturated group. As the ethylenically unsaturated group, an acryloyl group, a methacryloyl group, and a vinyl group are preferable, and an acryloyl group and a methacryloyl group are particularly preferable.

  Diisocyanates that can be added to the photocurable composition of the present invention include tolylene diisocyanate (TDI), isophorone diisocyanate, xylylene diisocyanate, diphenylmethane-4,4-diisocyanate, dicyclopentanyl diisocyanate, hexamethylene diisocyanate, 2 4,4'-trimethylhexamethylene diisocyanate and 2,2 ', 4-trimethylhexamethylene diisocyanate. Polyisocyanate cyanates such as trifunctional or higher functional isocyanate compounds such as a TDI adduct of trimethylolpropane can also be used. Of these, a hexamethylene diisocyanate adduct of trimethylolpropane is preferred.

  It is preferable that the diisocyanate of this invention is contained in 0.2-4 mass% in the photocurable composition (nonvolatile content), especially 0.2-2 mass%. Appropriate crosslinking is provided to prevent the transfer layer from exuding, and good transfer to the substrate surface is also maintained. The reaction between the compound and the polymer proceeds gradually after forming the coating film-forming layer on the release sheet, and reacts considerably at room temperature (generally 25 ° C.) and 24 hours. It is considered that the reaction proceeds even after the coating solution for forming the coating layer is prepared and before the coating solution is applied. Since it is preferable to cure to some extent after forming the coating film-forming layer and before winding it in the roll state, if necessary, heat it during the formation of the coating film-forming layer or thereafter before winding in the roll state. Reaction may be promoted.

  As described above, the photocurable composition of the present invention generally comprises a polymer, a reactive diluent (monomer and oligomer) having an ethylenically unsaturated group (preferably a (meth) acryloyl group), and a photopolymerizable initiator. And if desired, it is composed of other additives. The mass ratio of polymer to reactive diluent is preferably in the range of 20:80 to 80:20, particularly 30:70 to 70:30.

  The coating film forming layer of the present invention has a glass transition temperature of 20 ° C. or lower. Thereby, when the coating-film formation layer obtained is crimped | bonded to the base material uneven surface, it can have the flexibility which can closely follow the uneven surface also at normal temperature. In particular, when the glass transition temperature is in the range of 15 ° C. to −50 ° C., particularly 15 ° C. to −10 ° C., the following property is obtained. If the glass transition temperature is too high, a high pressure and a high pressure are required at the time of attachment, leading to a decrease in workability. If it is too low, a sufficient altitude after curing cannot be obtained.

The storage elastic modulus at a frequency of 1 Hz of the coating film-forming layer of the present invention is preferably 1 × 10 ⁷ Pa or less at 25 ° C., and particularly preferably in the range of 1 × 10 ^{4 to} 6 × 10 ⁵ Pa. Moreover, it is preferable that it is 8 * 10 < ⁴ > Pa or less in 80 degreeC, and it is especially preferable that it is the range of 1 * 10 < ⁴ > -5 * 10 < ⁵ > Pa. This enables accurate and quick transfer.

Further, the coating film-forming layer comprising the photocurable composition is preferably designed so that the glass transition temperature after irradiation with ultraviolet rays of 300 mJ / cm ² is 50 ° C. or higher, preferably 65 ° C. or higher. A tough coating film can be obtained by short-time ultraviolet irradiation. The coating film-forming layer comprising the photocurable composition of the present invention can be advantageously obtained mainly by using the preferred polymer and reactive diluent.

  As the photopolymerization initiator, any known photopolymerization initiator can be used, but one having good storage stability after blending is desirable. Examples of such photopolymerization initiators include benzoin series such as acetophenone series and benzyldimethyl ketal, thiophenone series such as benzophenone series, isopropylthioxanthone, and 2-4-diethylthioxanthone, and other special types include methylphenylglycol. Oxylate can be used. Particularly preferably, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, Examples include benzophenone. These photopolymerization initiators may contain one or two or more kinds of known and commonly used photopolymerization accelerators such as benzoic acid-based or tertiary amine-based compounds such as 4-dimethylaminobenzoic acid as required. Can be mixed and used. Moreover, it can be used by 1 type, or 2 or more types of mixture of only a photoinitiator. In general, the photocurable composition (nonvolatile content) preferably contains 0.1 to 20% by mass, particularly 1 to 10% by mass of a photopolymerization initiator.

  Among the photopolymerization initiators, examples of the acetophenone-based polymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, and 2-hydroxy-2. -Methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methyl Propan-1-one, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2 As benzophenone polymerization initiators such as morpholinopropane-1, Benzophenone, benzoyl benzoate, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, 4-Benzzoiru 4'-methyl diphenyl sulfide, etc. 3,3'-dimethyl-4-methoxybenzophenone may be used.

  As the acetophenone-based polymerization initiator, in particular, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2 -Morpholinopropane-1 is preferred. As the benzophenone polymerization initiator, benzophenone, benzoylbenzoic acid, and methyl benzoylbenzoate are preferable. Tertiary amine photopolymerization accelerators include triethanolamine, methyldiethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, ethyl 2-dimethylaminobenzoate. , Ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate and the like can be used. Particularly preferably, as the photopolymerization accelerator, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, etc. Is mentioned.

  In the present invention, in addition to the reactive diluent having an ethylenically unsaturated group and the photopolymerization initiator, it is preferable to add the following thermoplastic resin and other additives as required.

  As another additive, a silane coupling agent (adhesion promoter) can be added. As this silane coupling agent, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy Propyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β There are (aminoethyl) -γ-aminopropyltrimethoxysilane and the like, and one of these can be used alone or two or more of them can be used in combination. As for the addition amount of these silane coupling agents, 0.01-5 mass parts is sufficient normally with respect to 100 mass parts of said polymers (solid content).

  Similarly, an epoxy group-containing compound can be added for the purpose of improving adhesiveness. Examples of the epoxy group-containing compound include triglycidyl tris (2-hydroxyethyl) isocyanurate; neopentyl glycol diglycidyl ether; 1,6-hexanediol diglycidyl ether; acrylic glycidyl ether; 2-ethylhexyl glycidyl ether; Examples thereof include phenol glycidyl ether; pt-butylphenyl glycidyl ether; adipic acid diglycidyl ester; o-phthalic acid diglycidyl ester; glycidyl methacrylate; Further, the same effect can be obtained by adding an oligomer containing an epoxy group having a molecular weight of several hundred to several thousand or a polymer having a weight average molecular weight of several thousand to several hundred thousand. The addition amount of these epoxy group-containing compounds is sufficient to be 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer (solid content), and at least one of the epoxy group-containing compounds is added alone or in combination. Can do.

  As another additive, a hydrocarbon resin can be added for the purpose of improving workability such as workability and bonding. In this case, the added hydrocarbon resin may be either a natural resin type or a synthetic resin type. In natural resin systems, rosin, rosin derivatives, and terpene resins are preferably used. For rosin, gum-based resins, tall oil-based resins, and wood-based resins can be used. As the rosin derivative, rosin obtained by hydrogenation, heterogeneity, polymerization, esterification, or metal chloride can be used. As the terpene resin, a terpene phenol resin can be used in addition to a terpene resin such as α-pinene and β-pinene. In addition, dammar, corbal and shellac may be used as other natural resins. On the other hand, in the synthetic resin system, petroleum resin, phenol resin, and xylene resin are preferably used. As the petroleum resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, copolymer petroleum resin, hydrogenated petroleum resin, pure monomer petroleum resin, and coumarone indene resin can be used. As the phenol resin, an alkyl phenol resin or a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used.

  Although the addition amount of resin, such as the said hydrocarbon resin, is selected suitably, 1-20 mass parts is preferable with respect to 100 mass parts of said polymers (solid content), More preferably, it is 5-15 mass parts.

  In addition to the above additives, the photocurable composition of the present invention may contain a small amount of an ultraviolet absorber, an antioxidant, a dye, a processing aid and the like. In some cases, additives such as silica gel, calcium carbonate, and fine particles of silicone copolymer may be included in a small amount.

  The transfer sheet for coating film formation comprising the photocurable composition of the present invention comprises the phosphorus atom-containing compound of the present invention, a polymer (preferably Tg of 80 ° C. or higher), and a reactive diluent (monomer and oligomer) having an ethylenically unsaturated group. ), If desired, diisocyanate cyanate and optionally other additives are mixed uniformly, kneaded with an extruder, roll, etc., and then formed into a predetermined shape by a film forming method such as calendar, roll, T-die extrusion, inflation, etc. It can be used after film formation. When using a support, it is necessary to form a film on the support. More preferably, the photocurable adhesive film-forming method of the present invention is obtained by uniformly mixing and dissolving each constituent component in a good solvent, and then applying this solution to a separator precisely coated with silicone or fluororesin. , A gravure roll method, a Myer bar method, a lip die coating method or the like, and a method of forming a film by drying a solvent.

  The transfer sheet for forming a coating film used in the present invention generally has a coating film forming layer made of a photocurable composition that can be deformed by pressurization, and a release sheet on one side or both sides thereof. Furthermore, it is preferable to have a specific first release sheet provided on one side and a second release sheet having different properties from the first release sheet provided on the other side.

  The first release sheet generally has a release layer made of a condensation reaction product of a polysiloxane having a hydroxyl group and a hydrogenated polysiloxane. That is, the first release layer of the first release sheet that is in contact with the surface of the coating film forming layer has high peelability so that the stamper can be easily removed (generally, the peelable low molecular weight component is low or the surface tension is low). On the other hand, the second release layer, which is the surface in contact with the surface of the photocurable layer of the second release sheet, is required to have an adhesive property between the transfer layer and the substrate surface, so that the release property is not so high. No (generally low peelable low molecular weight component or surface tension is not so low).

  The release layer of the first release sheet needs to be a layer composed of a condensation reaction product of a polysiloxane having a hydroxyl group and a hydrogenated polysiloxane as described above, but what is the release layer of the second release sheet? It can be a layer. The release layer of the second release sheet is a general release layer, and is generally a layer that does not lower the adhesiveness of the transfer layer to the reflective layer, and preferably has a lower surface tension than the release layer of the first release sheet. .

  As described above, the release layer of the first release sheet of the present invention is a layer formed from a polysiloxane having a hydroxyl group (preferably dimethylpolysiloxane) and a hydrogenated polysiloxane (preferably dimethylpolysiloxane). Generally, these are heated and subjected to an addition reaction in the presence of a catalyst such as a tin compound, whereby the release layer of the present invention (a layer having a relatively low surface tension) is obtained.

  The first release layer can be obtained by dissolving or dispersing the silicone resin or the like in a solvent, applying it to a transparent film by reverse roll coating, gravure coating, bar coating, doctor blade coating, etc., and heating for an appropriate time. . The heating temperature is generally 100 to 150 ° C, preferably 120 to 140 ° C, and the heating time is generally 10 to 60 seconds, preferably 20 to 30 seconds. In general, the thickness of the first release layer is preferably 300 to 1500 nm and 500 to 800 nm. When the layer thickness is less than the above range, the coatability is not stable and it may be difficult to obtain a uniform coating film. On the other hand, if the coating is thickened beyond the above range, the adhesion and curability of the release layer itself may decrease.

  On the other hand, the release layer of the second release sheet is a general release layer, and may be a layer made of any of the following resins. That is, the release layer of the second release sheet may be formed from a thermoplastic resin or thermosetting resin that does not contain silicon atoms, or may be formed from a thermoplastic resin or a thermosetting silicone resin. . The release layer of the second release sheet of the present invention is preferably a reactive silicone resin. In particular, it is preferable to use a polysiloxane (preferably dimethylpolysiloxane) having an unsaturated double bond group (preferably a vinyl group) and a hydrogenated polysiloxane (preferably dimethylpolysiloxane). Instead of the polysiloxane having an unsaturated double bond group, a polyalkylene oxide having an unsaturated double bond group can also be used.

  The release layer of the second release sheet may be formed from a thermoplastic resin or thermosetting resin that does not contain silicon atoms, or may be a thermoplastic resin or a thermosetting silicone resin other than those described above.

  The second release layer can be obtained by dissolving or dispersing the silicone resin or the like in a solvent, applying it to a transparent film by reverse roll coating, gravure coating, bar coating, doctor blade coating, etc., and heating for an appropriate time. . The heating temperature varies depending on the type of resin used. In general, it is 100 to 150 ° C., preferably 120 to 140 ° C., and the heating time is generally 10 to 60 seconds, preferably 20 to 30 seconds. In general, the thickness of the second release layer is preferably 300 to 1500 nm and 500 to 800 nm. When the layer thickness is less than the above range, the coatability is not stable and it may be difficult to obtain a uniform coating film. On the other hand, if the coating is thickened beyond the above range, the adhesion and curability of the release layer itself may decrease.

  Examples of plastic films for release sheets (eg, first and second release sheets) include polyester resins such as polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate, nylon 46, modified nylon 6T, nylon MXD6, and polyphthalamide. In addition to polyamide resins such as polyphenylene sulfide, ketone resins such as polythioether sulfone, sulfone resins such as polysulfone and polyether sulfone, polyether nitrile, polyarylate, polyether imide, polyamide imide, polycarbonate, A transparent resin film mainly composed of an organic resin such as polymethyl methacrylate, triacetyl cellulose, polystyrene, or polyvinyl chloride can be used. Among these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate films can be suitably used, and polyethylene terephthalate films are particularly preferable. The thickness is preferably 10 to 200 μm, particularly preferably 30 to 100 μm.

  The transfer sheet for forming a coating film used in the present invention has a coating film forming layer made of a photocurable composition that can be deformed by pressure, and the first and second release sheets described above on both sides thereof. The transfer sheet for forming a coating film is preferably annealed. That is, it is preferable to manufacture the above-described optical information recording medium using the annealed coating film forming transfer sheet. The annealing treatment is preferably performed by storing the transfer sheet at a temperature of 30 to 100 ° C., particularly 40 to 70 ° C., for 1 hour to 30 days, particularly 10 hours to 10 days. In general, the transfer sheet is preferably annealed in a roll state (a wound state). By such annealing treatment, it is considered that the component (release component) that promotes the peeling of the release layer of the first release sheet proceeds to the coating film forming layer, and the stamper can be easily removed.

  As a material for the substrate 21 having irregularities on the surface, a transparent organic resin having a glass transition temperature of 50 ° C. or higher is preferable. Examples of such a support include polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate. In addition to polyester resins, nylon 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, and sulfone resins such as polysulfone and polyether sulfone Organic resin such as polyether nitrile, polyarylate, polyether imide, polyamide imide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride It can be used transparent resin substrate that. Among these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate are excellent in terms of transferability and birefringence, and can be suitably used. The thickness is preferably 200 to 2000 μm, particularly preferably 500 to 1500 μm.

  The organic polymer film material 26 is preferably a transparent organic resin having a glass transition temperature of 50 ° C. or higher. Examples of such a support include polyester resins such as polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate, and nylon. 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, polysulfone, sulfone resins such as polyether sulfone, polyether nitrile, Transparent tree mainly composed of organic resins such as polyarylate, polyetherimide, polyamideimide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride Substrate can be used. Among these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate are excellent in terms of transferability and birefringence, and can be suitably used. The thickness is preferably 10 to 200 μm, particularly preferably 50 to 100 μm.

  In the thus obtained coating sheet-forming transfer sheet of the present invention, it is preferable that the light transmittance in the wavelength region of 380 to 420 nm of the coating film forming layer is 70% or more.

  The film-forming transfer sheet has a light transmittance of 70% or more in the wavelength region of 380 to 420 nm (preferably 380 to 800 nm), in order to prevent the intensity of the read signal from being lowered by the laser. Furthermore, the light transmittance in the wavelength region of 380 to 420 nm is preferably 80% or more.

  The transfer sheet for forming a coating film of the present invention can be easily obtained by forming a film by applying or extruding the photocurable composition of the present invention on a release sheet by a conventional method. Accordingly, since the coating film forming layer of the transfer sheet for forming a coating film according to the present invention can be provided in the form of a film in which the film thickness accuracy is precisely controlled, the bonding with the substrate and the stamper is easy and accurate. It can be done well. In addition, as described above, this bonding can be cured at room temperature for 1 to several tens of seconds with light after being temporarily pressure-bonded at 20 to 100 ° C. by a simple method such as a pressure-bonding roll or a simple press as described above. Due to the self-adhesive force, the laminated body is unlikely to be displaced or peeled off, so that it can be freely handled until photocuring.

When the coating sheet for forming a coating film of the present invention is cured, many light sources that emit light in the ultraviolet to visible region can be used as the light source. For example, ultra-high pressure, high pressure, low pressure mercury lamp, chemical lamp, xenon lamp, halogen lamp, mercury Examples thereof include a halogen lamp, a carbon arc lamp, an incandescent lamp, and a laser beam. The irradiation time is not generally determined depending on the type of the lamp and the intensity of the light source, but is about 0.1 to several tens of seconds, preferably 0.5 to several seconds. The ultraviolet irradiation amount is preferably 300 mJ / cm ² or more.

  In order to accelerate curing, the laminate may be preheated to 30 to 80 ° C. and irradiated with ultraviolet rays.

  The following examples further illustrate the present invention.

[ Comparative Example 1 ]
<Preparation of transfer sheet for coating film formation>
(Preparation of polymer 1 having a hydroxyl group)
Polymer blend 1
Methyl methacrylate 74.6 parts by mass n-butyl methacrylate 13.2 parts by mass 2-hydroxyethyl methacrylate 12.1 parts by mass AIBN 5 parts by mass Toluene 50 parts by mass Ethyl acetate 50 parts by mass

  The mixture having the above composition was heated to 70 ° C. with gentle stirring to initiate polymerization, and stirred at this temperature for 8 hours. Polymer 1 (acrylic resin) having a hydroxyl group having a hydroxyl group in the side chain was obtained. Obtained. The solid content was adjusted to 36% by mass (polymer solution 1).

  The obtained polymer 1 had a Tg of 90 ° C. and a weight average molecular weight of 110,000.

Composition formulation 1
Polymer solution 1 having a hydroxyl group (solid content) 100 parts by mass Hexanediol diacrylate 100 parts by mass (KS-HDDA; manufactured by Nippon Kayaku Co., Ltd.)
10 parts by mass of trimethylolpropane triacrylate (TMP-A; manufactured by Kyoeisha Chemical Co., Ltd.)
Diisocyanate (BXX5627, manufactured by Toyo Ink Mfg. Co., Ltd.) 1.5 parts by mass Irgacure 651 (manufactured by Ciba Geigy Co., Ltd.) 2 parts by mass Hydroquinone monomethyl ether (MEHQ) 0.05 parts by mass Uniformly dissolve and knead the mixture having the above composition. Then, the whole surface was coated on a release sheet (width 140 mm, length 300 m, thickness 75 μm; trade name No. 23, manufactured by Fujimori Kogyo Co., Ltd.) to form a coating film forming layer having a dry thickness of 25 μm. The same release sheet as above was affixed to the opposite side of the film and rolled up into a roll to obtain a roll (diameter 260 mm) of a coating sheet-forming transfer sheet. The Tg of the coating film forming layer was −20 ° C.

[Example 1 ]
In Comparative Example 1 , a roll (260 mm in diameter) of the coating sheet-forming transfer sheet was obtained in the same manner except that the composition 1 was changed to the following composition 2.
Composition formulation 2
Polymer solution 1 having a hydroxyl group (solid content) 100 parts by mass Hexanediol diacrylate 50 parts by mass (KS-HDDA; manufactured by Nippon Kayaku Co., Ltd.)
10 parts by mass of trimethylolpropane triacrylate (TMP-A; manufactured by Kyoeisha Chemical Co., Ltd.)
70 parts by mass of 2-hydroxy-3-acryloyloxypropyl methacrylate (G-201P; manufactured by Kyoeisha Chemical Co., Ltd.)
Diisocyanate (BXX5627, manufactured by Toyo Ink Co., Ltd.) 1.5 parts by mass Irgacure 651 (manufactured by Ciba Geigy) 2 parts by mass Hydroquinone monomethyl ether (MEHQ) 0.05 parts by mass

[Example 2 ]
In Comparative Example 1 , a roll (260 mm in diameter) of a coating sheet-forming transfer sheet was obtained in the same manner except that the composition 1 was changed to the following composition 3.

Composition 3
Polymer solution 1 having a hydroxyl group (solid content) 100 parts by mass Hexanediol diacrylate 50 parts by mass (KS-HDDA; manufactured by Nippon Kayaku Co., Ltd.)
10 parts by mass of trimethylolpropane triacrylate (TMP-A; manufactured by Kyoeisha Chemical Co., Ltd.)
70 parts by mass of 1,3-dimethacryloyl-propanetriol (G-101P; manufactured by Kyoeisha Chemical Co., Ltd.)
Diisocyanate (BXX5627, manufactured by Toyo Ink Co., Ltd.) 1.5 parts by mass Irgacure 651 (manufactured by Ciba Geigy) 2 parts by mass Hydroquinone monomethyl ether (MEHQ) 0.05 parts by mass

[ Comparative Example 2 ]
In Comparative Example 1 , a roll (260 mm in diameter) of the coating sheet-forming transfer sheet was obtained in the same manner except that the composition 1 was changed to the following composition 4.

Composition 4
Polymer solution 1 having a hydroxyl group (solid content) 100 parts by mass Hexanediol diacrylate 50 parts by mass (KS-HDDA; manufactured by Nippon Kayaku Co., Ltd.)
10 parts by mass of trimethylolpropane triacrylate (TMP-A; manufactured by Kyoeisha Chemical Co., Ltd.)
70 parts by mass of 2-hydroxypropyl acrylate (HOP-A; manufactured by Kyoeisha Chemical Co., Ltd.)
Diisocyanate (BXX5627, manufactured by Toyo Ink Co., Ltd.) 1.5 parts by mass Irgacure 651 (manufactured by Ciba Geigy) 2 parts by mass Hydroquinone monomethyl ether (MEHQ) 0.05 parts by mass

[Comparative Example 3 ]
In Comparative Example 1 , a commercially available dry paint film (AVLOY; manufactured by Mitsubishi Chemical Corporation) was prepared in place of the roll (diameter 260 mm) of the coating sheet forming transfer sheet.

[ Reference Example 1 ]
In Comparative Example 1 , in the preparation of the composition blend, the blended mixture was uniformly dissolved and kneaded, and applied to the entire surface of the release layer of the second release sheet 1 described below to form a coating layer having a dry thickness of 25 μm. Then, the following first release sheet 1 is attached to the opposite side of the sheet so that the release layer and the transfer layer are in contact with each other, wound up into a roll, and a full-edge type roll (260 mm diameter) )

(Second release sheet 1)
Second release layer 1 formulation (addition type silicone)
TPR6700 (manufactured by Toshiba Silicone Co., Ltd .; 100 parts by mass CM670 (platinum catalyst, manufactured by Co., Ltd.) 1 part by weight Toluene 499 parts by weight On the surface of the PET film (width 300 mm, length 300 m, thickness 75 μm), second peeling The mixture of layer 1 was roll-coated and then heated at 140 ° C. for 30 seconds to cause an addition reaction to form a second release layer 1 having a thickness of 500 nm.

(First release sheet 1)
1st release layer 1 formulation (condensation type silicone)
XS56-A3075 (manufactured by Toshiba Silicone Co., Ltd.); 100 parts by mass YC6831 (tin catalyst, manufactured by Toshiba Silicone Co., Ltd.) 4 parts by mass YC6919 (tin catalyst, manufactured by Toshiba Silicone Co., Ltd.) 2 parts by mass Toluene 2000 parts by mass PET film On the back surface (width 300 mm, length 300 m, thickness 75 μm), the mixture of the first release layer 1 was roll-coated, then heated at 150 ° C. for 10 seconds to cause addition reaction, and the first 500 nm thick first A release layer 1 was formed.

(1) Evaluation of Transfer Sheet for Coating Film Formation (1-1) Measurement of Glass Transition Temperature (Tg) The release sheets on both sides are removed from the obtained transfer sheet for coating film formation, and the length is 20 mm and the width is 4 mm (thickness). 25 μm) to obtain a sample.
Using a TMA (Thermal Mechanical Analysis) apparatus SS6100 (manufactured by SII Nanotechnology Co., Ltd.), Tg of the sample was sample temperature: 30 to 120 ° C., temperature rising rate: 5 ° C./min, tensile tension: 4.9 × The measurement was performed at 10 ⁵ Pa.
When the test was performed under the above conditions, the graph shown in FIG. 4 was obtained, and the intersection of the tangent line of the stable region and the tangent line from the maximum slope of the stretch region was defined as the glass transition temperature.

(2) Formation and evaluation of coating film on substrate surface (2-1) Formation of coating film on substrate surface One release sheet (second release sheet) is peeled off from the transfer sheet for coating film formation, and the surface is uneven. (Sand blasting DI (Ra: 10 nm)) An alumite part and a SUS301 part were subjected to pressure bonding of the coating film forming layer of the coating sheet-forming transfer sheet obtained in Examples 1 to 4 or Comparative Example 1 at room temperature. Affixed with weight, and then UV-irradiated on the other release sheet (first release sheet) using a metal halide lamp (600 mW / cm) under the condition of an integrated light quantity of 300 mJ / cm ² (irradiation distance 20 cm, irradiation time) 1.0 second), UV curing was performed, and the release sheet (first release sheet) was removed after curing.

(2-2) Adhesiveness of coating film Based on JIS-G-0202, the coating film was cut with a cutting knife, the peeled state of the cut portion was observed, and evaluated as follows.

  ○: No peeling of the coating film is observed Δ: Some peeling of the coating film is observed

(2-3) Measurement of glass transition temperature (Tg) A sample obtained in the same manner as in (1-1) was irradiated with UV under the condition of an integrated light quantity of 300 mJ / cm ² , and as in (1-1). Tg was measured.

The integrated light quantity (300 mJ / cm ² ) was measured on the surface of the layer using UV Power Pack (UV-A band measurement) manufactured by Fusion UV Systems Japan Co., Ltd.

  The test results obtained are shown in Table 1.

When the coating film-forming transfer sheet obtained in Examples 1 and 2 was used, it could be easily molded at room temperature, but the commercial film (Comparative Example 3 ) could not be molded. In addition, when two different types of release sheets were used for the reference example 1 , particularly excellent adhesion was exhibited.

It is sectional drawing which shows the representative example of embodiment of the transfer sheet for coating-film formation according to this invention. It is sectional drawing which shows the preferable example of embodiment of the transfer sheet for coating-film formation according to this invention. It is a figure which shows one example of the formation method of the coating film to the base material of this invention. It is the schematic for demonstrating the pressing method using the apparatus of a double vacuum chamber system. It is a graph used for determination of glass transition temperature (Tg).

Explanation of symbols

11, 21, 31 Coating film forming layer 12a, 22a, 32a Second release sheet 12b, 22b, 32b First release sheet 23 Colored layer 24 Adhesive layer 35 Base material

Claims (17)

A coating film-forming transfer sheet comprising a coating film-forming layer for forming a coating film comprising a photocurable composition that can be deformed by pressurization and a release sheet provided on at least one surface of the coating film-forming layer. There,
The photocurable composition comprises a polymer and a reactive diluent having an ethylenically unsaturated group, and the reactive diluent having an ethylenically unsaturated group has at least one hydroxyl group as a polar group, And a compound having at least two groups selected from an acryloyl group and a methacryloyl group,
And the glass transition temperature before photocuring of a coating-film formation layer is less than 20 degreeC, The transfer sheet for coating-film formation characterized by the above-mentioned. The transfer sheet for coating film formation according to claim 1, wherein the glass transition temperature of the coating film forming layer after irradiation with ultraviolet rays of 300 mJ / cm ² is 50 ° C. or higher.   The transfer sheet for forming a coating film according to claim 1, wherein the glass transition temperature of the polymer is 80 ° C. or higher.   The transfer sheet for coating film formation according to any one of claims 1 to 3, wherein the polymer is an acrylic resin.   The transfer sheet for forming a coating film according to claim 4, wherein the acrylic resin is an acrylic resin containing at least 50% by mass of repeating units of methyl methacrylate.   The transfer sheet for coating film formation according to claim 4 or 5, wherein the acrylic resin is an acrylic resin having a hydroxyl group.   The transfer sheet for coating film formation according to any one of claims 4 to 6, wherein the acrylic resin is an acrylic resin having an ethylenically unsaturated group.   The transfer sheet for coating film formation according to any one of claims 1 to 7, wherein the photocurable composition further contains diisocyanate.   The transfer sheet for forming a coating film according to any one of claims 1 to 8, wherein the polymer has a weight average molecular weight of 100,000 or more. The transfer sheet for coating film formation according to any one of claims 1 to 9 , wherein the film thickness unevenness of the coating film forming layer is in the range of ± 3 µm. The transfer sheet for coating-film formation of any one of Claims 1-10 in which a photocurable composition contains 0.1-10 mass% of photoinitiators. The transfer sheet for coating film formation according to any one of claims 1 to 11 , further comprising a colored layer and / or an adhesive layer between the coating film forming layer and the release sheet. The transfer sheet for coating film formation according to any one of claims 1 to 12 , further comprising a colored layer and a coating film forming layer (adhesive layer) between the coating film forming layer and the release sheet. The transfer sheet for coating film formation according to any one of claims 1 to 13 , wherein release sheets are provided on both surfaces of the coating film forming layer. The following steps (1) to (3):
(1) When the release sheet is provided on both surfaces of the coating sheet-forming transfer sheet according to any one of claims 1 to 14 , the step of removing one of the release sheets;
(2) The surface of the coating film forming transfer sheet is placed on the surface of the plastic part so that the surface of the coating film forming layer is in contact with the surface of the plastic part, and the surface of the coating film forming layer is pressed by pressing them. And (3) a step of irradiating and curing ultraviolet rays from the other release sheet of the laminate;
A method for forming a coating film, comprising: The method for forming a coating film according to claim 15 , wherein the ultraviolet irradiation of (3) is performed with an irradiation energy of at least 300 mJ / cm ² . The method for forming a coated coating film according to claim 15 or 16 , wherein the coating film-forming layer obtained in (3) has a glass transition temperature of 50 ° C or higher.

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