WO2006077664A1

WO2006077664A1 - Photopolymerizable melt coating composition and method of forming coating film

Info

Publication number: WO2006077664A1
Application number: PCT/JP2005/011369
Authority: WO
Inventors: Tsutomu Mizutani; Makoto Kimura; Tetsushi Yamamoto
Original assignee: Mizutani Paint Co., Ltd.
Priority date: 2005-01-20
Filing date: 2005-06-21
Publication date: 2006-07-27
Also published as: JP2006198511A

Abstract

A photopolymerizable composition suitable for application by melt coating. The photopolymerizable composition, which is solid at room temperature and is to be applied by melt coating, comprises a photocurable resin which is solid at room temperature and a polyfunctional polymerizable compound (e.g., a poly(meth)acrylate of an alkane polyol or oligomer thereof). The photopolymerizable composition may have a melting temperature of about 45-75°C. It may have a melt viscosity, as measured at the melt coating temperature, of about 50-500 Pa·s. Use of the composition enables a hard coating film to be easily and efficiently formed. The coating film (cured coating film) can be formed by applying the photopolymerizable composition to a base by melt coating, heating the resultant coating film, and curing the heated coating film by irradiation with actinic rays.

Description

Specification

Photopolymerizable melt coating composition and coating film forming method

Technical field

The present invention relates to a photopolymerizable composition suitable for melt coating, a method for producing the same, and a method for forming a coating film using the composition.

Background art

Conventionally, as a photopolymerizable composition (photo-curing paint), a liquid UV-curable resin composition has been known. The method of use is a coating film forming method in which a liquid ultraviolet curable resin composition is applied to a substrate and irradiated with ultraviolet rays. However, since a liquid ultraviolet curable resin composition penetrates into a porous substrate such as a wood material, it is difficult to form a uniform coating, particularly a thick film. On the other hand, as a method of forming a coating film, a method of applying an ultraviolet curable powder coating to a substrate is also known!

[0003] For example, JP-A-8-301957 (Patent Document 1) discloses a radiation curable powder composition containing a terminal methacryl group-containing crystalline polyester. This document describes a radiation curable powder composition deposited on an article by spraying with a triboelectric or electrostatic gun (electrostatic coating) or in a fluidized bed (fluid dipping method) at 80-150 ° C. It describes a coating method in which an ultraviolet ray or an accelerated electron beam is irradiated after heating and melting. The UV curable powder composition deposited on the article is heated and melted at 80 to 150 ° C in a forced circulation oven or using an infrared lamp, spread, smooth and uniform. It is also described to obtain a continuous coating. It also describes that it can be applied to wood. In addition, in order to increase the hardness of the cured coating film, polymerizable diluents such as tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, etc. It is described that 0 to 20 parts by weight of a saturated oligomer) may be added per 100 parts by weight of the powder composition. However, when a polymerizable diluent is added, the powder composition is likely to be blocked, and storage and handling properties are greatly impaired.

[0004] Japanese Patent Application Laid-Open No. 2002-212506 (Patent Document 2) describes a porous substrate (such as a porous metal). An ultraviolet curable powder coating containing a wax, which is a powder coating for application, has been disclosed. This document describes that a powder coating material adhered to a porous substrate by electrostatic coating is heated and melted, and then cured by irradiation with ultraviolet rays. Is stated to be suppressed! RU

[0005] According to the electrostatic coating, a coating film having a film thickness of about 30 to 150 m can be formed in one coating. However, in the case of electrostatic coating, the coating efficiency on the base material is about 50 to 70%, and the paint that has not been applied is collected or discarded. The collected powder paint has a different particle size distribution compared to normal paint, and therefore, when used again for electrostatic coating, the appearance of the coating film may be impaired. In addition, a uniform and thick film cannot be formed on an electrically insulating substrate such as a wooden material. Furthermore, it is difficult to form a coating film with a good appearance that makes it difficult to control the coating amount.

[0006] On the other hand, in the fluid immersion, it is necessary that the fluidity of the powder coating is good! In addition, since the thickness of the formed coating film depends on the heat capacity of the substrate, it is difficult to control the film thickness. Furthermore, when the base material is a wood material, it is difficult to heat to a high temperature.

[0007] Also, in the case of V, deviation, the powder coating wraps around to the back surface of the base material, so that it is difficult to apply only to the desired surface of the base material. Furthermore, it is difficult to obtain a hard coating film even if the powder coating is used for light irradiation.

[0008] Although the above-described deviation method is used, usually, in order to form a smooth coating film, after the coating film is heated and melted, the coating film is irradiated with ultraviolet rays and cured. Therefore, it is suitable for forming a highly glossy coating film. However, even if an anti-foaming agent is used to form a low gloss coating, the gloss of the coating is increased. Therefore, it is difficult to form a coating film having a desired gloss.

Patent Document 1: Japanese Patent Application Laid-Open No. 8-301957 (Claims, paragraph number [0037], paragraph number [0045], paragraph number [0046])

Patent Document 2: Japanese Patent Application Laid-Open No. 2002-212506 (Claim 1, Example)

Disclosure of the invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to provide a hard coating that is simple and efficient by melt coating. It is an object of the present invention to provide a photopolymerizable composition capable of forming a film, a method for producing the same, and a method for forming a coating film using the composition.

[0010] Another object of the present invention is to provide a photopolymerizable composition capable of efficiently forming a thick coating film having a low melting temperature and melt viscosity even when it is solid at room temperature, a method for producing the same, and a composition thereof. An object of the present invention is to provide a method for forming a coating film using an object.

[0011] Still another object of the present invention is to provide a photopolymerizable composition capable of efficiently forming a uniform and thick film with high coating efficiency regardless of the type of substrate, a method for producing the same, and this composition. The object of the present invention is to provide a method for forming a coating film using an object.

Another object of the present invention is to provide a coating film forming method capable of adjusting the gloss of a cured coating film by a simple operation and a method for adjusting the gloss of a cured coating film.

[0013] Still another object of the present invention is to provide a coating film forming method and a method for adjusting the gloss of the cured coating film, which can adjust the gloss (degree of frosting) of the cured coating film in a wide range by a simple operation. There is to do.

Means for solving the problem

[0014] As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention are composed of a photocurable resin and a polyfunctional polymerizable compound, and are a solid or viscous photopolymerizable composition at room temperature. When the coating is melt coated on the substrate, a uniform coating film can be formed with a coating efficiency close to 100%. Sarakuko irradiates the coating film formed with the photopolymerizable composition with actinic rays. In the method of curing by heating and then irradiating actinic rays, the gloss of the cured coating can be easily adjusted by partially curing (pre-curing) the coating with actinic rays prior to heating. I found what I could do and completed the present invention.

That is, the photopolymerizable melt coating composition of the present invention (hereinafter sometimes simply referred to as a photopolymerizable composition, composition, etc.) is a photopolymerizable composition that is solid or viscous at room temperature. Thus, it is composed of a photocurable resin solid at room temperature and a polyfunctional polymerizable compound. The photopolymerizable composition may have a melt viscosity at a melt coating temperature of about 50 to 500 Pa · s.

[0016] The polyfunctional polymerizable compound may be a polyfunctional polymerizable compound having a plurality of (meth) atalyloyl groups. For example, the polyfunctional polymerizable compound may be a polyol monomer, a dye A poly (meth) acrylate of a polyol component (polyhydroxy component) selected from a monomer and a trimer, wherein the polyol is at least one selected from alkanediol, alkanetriol, and alkanetetraol forces. Good. Typically, the polyfunctional polymerizable compound is C alkanetriol and C alkanetetraol.

3-10 4-10

It may be at least one dimer poly (meth) ate acrylate selected from the above. The ratio of the multifunctional polymerizable compound may be about 5 to 30 parts by weight with respect to 100 parts by weight of the photocurable resin.

[0017] The photopolymerizable composition may further contain a photopolymerization initiator, and the ratio of the photopolymerization initiator is 0.5 to 50% by weight with respect to 100 parts by weight of the polyfunctional polymerizable compound. It may be about 1 part. Representative photopolymerizable compositions include a photocurable resin that is solid at room temperature, a dimer of alkanetriol or alkanetetraol, and a trimer force selected from tri-hexa (meth) acrylates of selected polyol components. It is composed of at least one selected polyol poly (meth) acrylate and a photopolymerization initiator, and the proportion of the poly (meth) acrylate is based on 100 parts by weight of the photocurable resin. The composition includes 8 to 25 parts by weight, and the ratio of the photopolymerization initiator is 1 to 30 parts by weight with respect to 100 parts by weight of the poly (meth) acrylate.

[0018] The photopolymerizable composition can be produced, for example, by melting and kneading a solid photocurable resin and a polyfunctional polymerizable compound at room temperature, solidifying by cooling, and then pulverizing.

In the present invention, a coating film is formed by melt coating the photopolymerizable composition on a substrate, heating the formed coating film, and irradiating the heated coating film with an actinic ray to cure. Methods are also included.

[0020] In the coating film forming method, in order to suppress (or adjust) the gloss of the coating film (cured coating film), the coating film formed by the melt coating is irradiated with actinic rays to be partially cured (preliminary). The coating film may be heated after being hardened. In such a pre-cured coating film forming method, V, the total amount of actinic light irradiation energy G1 irradiated to the coating film before heating and actinic light irradiation energy G2 irradiated to the coating film after heating G1ZG2 can be about 1Z 99 to 30Z70! / ヽ.

In the coating film forming method, as described above, the gloss of the coating film is suppressed or reduced by preliminary curing. Can be reduced. Such reduction in gloss can be adjusted by adjusting the energy of actinic rays irradiated in the preliminary curing. Therefore, the present invention includes a pre-curing step in which the coating film formed from the photopolymerizable composition is partially cured by irradiation with actinic rays, a heating step in which the partially cured coating film is heated, And a curing process in which the coating film after heating is cured by irradiating it with actinic rays. The gloss of the cured coating film is determined by the actinic radiation irradiation energy in the preliminary curing process (specifically, by adjusting the irradiation energy). Also included is a method of adjusting

The invention's effect

[0022] According to the photopolymerizable composition of the present invention, a hard coating can be easily and efficiently formed by melt coating. In addition, since the photopolymerizable composition of the present invention has a relatively low melting temperature and melt viscosity, it can be efficiently formed even by a thick coating film by melt coating. In addition, porous substrates that are difficult to form a uniform coating film, substrates that have high electrical insulation and are difficult to electrostatically coat, and substrates that are difficult to heat-flow and difficult to flow (for example, wood materials) However, regardless of the type of substrate, a uniform and thick film can be efficiently formed with high coating efficiency. Furthermore, in the present invention, the gloss of the cured coating film can be adjusted by a simple operation. In particular, by adjusting the degree of pre-curing, the filler content, etc., the gloss (degree of matting) of the cured coating can be adjusted over a wide range by a simple operation.

Brief Description of Drawings

FIG. 1 is a schematic diagram for explaining a coating state by a roll coater method used in an example of the present invention.

Detailed Description of the Invention

[Photopolymerizable melt coating composition]

The photopolymerizable melt coating composition (photopolymerizable composition) of the present invention comprises at least a photocurable resin and a polyfunctional polymerizable compound, and is at room temperature (temperature 15 to 25 ° C). Solid or viscous. The viscosity of the viscous photopolymerizable composition may be, for example, 200 Pa ′ s or more at 25 ° C., usually 300 Pa ′ s or more, preferably 500 Pa ′ s or more, more preferably lOOOPa ′ s or more. . The viscosity of the photopolymerizable composition can be measured using, for example, a B-type viscometer, but is usually not measurable at 25 ° C. In such a case The relationship between the temperature measured with a B-type viscometer and the temperature may be extrapolated. In particular, the photopolymerizable composition of the present invention may be solid at room temperature. In the present invention, a thick film can be efficiently formed even with a photopolymerization composition that is solid at room temperature.

[0025] Since the photopolymerizable composition of the present invention contains a polyfunctional polymerizable compound !, it can form a hard coating film, and can be applied with a relatively low melting temperature and melt viscosity. High leveling of the coating film. Moreover, since it is used for melt coating, a uniform and thick film can be formed regardless of blocking.

The melting temperature of the photopolymerizable composition is usually about 40 to 100 ° C., for example, 45 to 80 °, although it depends on the type of photocurable resin and the ratio of the polyfunctional polymerizable compound. C, preferably 45 to 75 ° C, more preferably about 45 to 70 ° C (particularly 50 to 60 ° C). The melt viscosity of the photopolymerizable composition is usually about 50 to 500 Pa's at the 1S melt coating temperature depending on the type of photocurable resin and the ratio of the polyfunctional polymerizable compound. It may be 100 to 400 Pa's, preferably about 150 to 350 Pa's, more preferably about 180 to 320 Pa's (specifically 200 to 310 Pa's). The melt coating temperature is a temperature at which the photopolymerizable composition melts, and may be, for example, 40 to 200 ° C, preferably 45 to 150 ° C, more preferably 50 to about LOO ° C. . Specifically, for example, when a viscosity measuring device (picometer) is used and measured at a melting temperature (for example, a temperature of 95 ° C.) and a rotation speed of 0.1 rpm, the viscosity after 100 seconds ( Melt viscosity) may be, for example, about 150 to 350 Pa's, preferably 180 to 320 Pa.s, more preferably about 200 to 310 Pa · s! / ヽ.

[0027] [Photocurable resin]

As photocurable resin, it is solid at room temperature (temperature 15-25 ° C) and has a photopolymerizable group (for example, a, j8-ethylenically unsaturated bond group such as (meth) atalyloyl group) The resin is not particularly limited as long as it has a resin, photocurable polyester resin, photocurable acrylic resin, photocurable epoxy (meth) acrylate resin, photocurable urethane (meth) acrylate resin Examples thereof include fat and photocurable silicone-based resin. These photocurable resin can be used alone or in combination of two or more.

[0028] The photocurable polyester-based resin has a saturated or unsaturated polyester resin having a functional group (hydroxyl group, carboxyl group, etc.) and a reactive group for the functional group. A polymerizable group-containing polyester-based resin (for example, (Metal), which is formed by the reaction of a polymerizable unsaturated compound (for example, a polymerizable compound having a reactive group with respect to the functional group and a (meth) atallyloyl group). ) Ataliloyl group-containing polyester-based resin, etc.), photocurable unsaturated polyester-based resin (for example, polyesters obtained using unsaturated dicarboxylic acid components such as maleic anhydride and maleic acid as dicarboxylic acid components) For example, greaves). As the photocurable polyester-based resin, a polyester-based resin having a (meth) atalyloyl group is usually used.

[0029] polyester榭脂having a functional group, mainly composed of a dicarboxylic acid component (e.g., 70 to 100 mole ^_0/0, preferably 80 to: LOO mol ^_0/0, more preferably 90 to: LOO mol ⁰ / ₀ degree) and a polycarboxylic acid component, composed mainly of a diol component (e.g., 70 to: LOO mol%, is preferred properly 80 to: LOO mol ^_0/0, more preferably 90 to about 100 mole ^_0/0 Or a product of an ester reaction with a polyol component.

[0030] Examples of the dicarboxylic acid component include aliphatic dicarboxylic acids (for example, C fatty acids such as malonic acid, succinic acid, dartaric acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid).

2-20 aliphatic dicarboxylic acids), aromatic dicarboxylic acids (for example, isophthalic acid, terephthalic acid, anhydrous phthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.)

8-16

Acid anhydrides) and alicyclic dicarboxylic acids (for example, C alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and tetrahydrophthalic acid or anhydrides thereof).

8-12

. Dicarboxylic acid component is a lower alkyl ester (C alkyl such as methyl ester)

It may be a reactive derivative such as 1-3 ester). These dicarboxylic acid components can be used alone or in combination of two or more.

[0031] Of these dicarboxylic acid components, linear C aliphatic dicarboxylic acids (particularly linear C

6-16 6 Aliphatic dicarboxylic acid), c Aromatic dicarboxylic acid (especially benzene dicarboxylic acid,

-12 8-12

Phthalenedicarboxylic acid) or C alicyclic dicarboxylic acid (especially C alicyclic dicarboxylic acid)

8-12 8-10

At least one dicarboxylic acid selected from

[0032] The dicarboxylic acid component is introduced in combination with a polycarboxylic acid (for example, a tricarboxylic acid such as trimellitic acid or pyromellitic acid or tetracarboxylic acid or an acid anhydride thereof) as necessary to introduce a branched structure. Well, ... [0033] Examples of the diol component include alkylene glycol (for example, C 4 alkylene glycol such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, 1,3-butanediol, neopentyl glycol, and hexanediol).

2-12

1), (poly) oxyalkylene glycol (for example, (poly) oxy C alkylene glycol such as diethylene glycol and dipropylene glycol), alicyclic diol (for example,

2-4

, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc.

6-10 oral alkanediols), aromatic diols (for example, bisphenols such as bisphenol A, bisphenols such as bisphenol A-C alkylene oxide-capped bisphenols C)

2-4 2-alkyleneoxide adducts). These diol components can be used alone or

Four

Can be used in combination of two or more. Of these diol components, C alkylene

2-8

Glycols (such as ethylene glycol) and C cycloalkanediols (1,4-cyclo

6-8

In many cases, at least one selected from hexanediol and 1,4-cyclohexanedimethanol is used.

[0034] The diol component may be used in combination with a polyol component (for example, a triol such as glycerin or trimethylolpropane, or a tetraol such as pentaerythritol) if necessary to introduce a branched structure.

[0035] The concentration of the functional group (carboxyl group, hydroxyl group) of the polyester-based resin should be in a range where photopolymerizability can be imparted by reaction with a polymerizable unsaturated compound, for example, acid value or hydroxyl value. (OH value) 5 to 200 mgKOHZg, preferably 10 to 150 mgKOH, more preferably 20 to about LOOmgKOHZg.

[0036] Examples of the polymerizable compound having a reactive group with respect to the functional group of the polyester-based rosin and a (meth) atalyloyl group include compounds having a reactive group with respect to a carboxyl group [for example, glycidyl (meta ) Atalylate, hydroxy C alkyl (meth) atarylate

2-6 Hydroxyalkyl (meth) acrylate, etc.], a compound having a reactive group for hydroxyl group [eg, vinylphenylisocyanate, (meth) phthalate having an isocyanate group (eg, tolylene diisocyanate, isophorone) A reaction product of a polyisocyanate component such as diisocyanate and the hydroxyalkyl (meth) acrylate)), Examples thereof include unsaturated carboxylic acids (such as (meth) acrylic acid and crotonic acid) or reactive derivatives thereof (such as anhydrous (meth) acrylic acid and (meth) acrylic acid chloride). These polymeric compounds can be used alone or in combination of two or more depending on the type of functional group of the polyester-based resin.

[0037] The photocurable polyester-based resin may be crystalline (including semi-crystalline) or amorphous. In order to obtain a crystalline polyester-based resin, it is advantageous to use a dicarboxylic acid in which the carboxyl group is substituted at the symmetric position of the molecule and a diol in which the Z or hydroxyl group is substituted at the symmetric position of the molecule. Symmetric (or symmetric structure) dicarboxylic acids include, for example, linear C aliphatic dicarboxylic acids (particularly linear C aliphatic dicarboxylic acids) and

4-16 6-12

And at least one dicarboxylic acid selected from symmetric cyclic dicarboxylic acids (aromatic dicarboxylic acids such as terephthalic acid and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid). For symmetric (or symmetrical) diols, linear C

2-8 Alkylene glycol (ethylene glycol, 1,4 butanediol, 1,6 hexanediol, etc.) and symmetrical C cycloalkanediol (1,4-cyclohexanediol)

6-8

And at least one kind of diol selected from 1,4 cyclohexanedimethanol and the like.

[0038] When the proportion of the symmetric dicarboxylic acid component and the symmetric diol component increases, the crystallinity (or crystallinity) of the photocurable polyester-based resin increases. On the other hand, when the proportion of the polycarboxylic acid component having an asymmetric structure (including a dicarboxylic acid component) or the polyol component having an asymmetric structure (including a diol component) increases, the crystallinity (or crystallinity) of the photocurable polyester resin is increased. ) Decreases. Therefore, among the polycarboxylic acid component (including the dicarboxylic acid component), the proportion of the dicarboxylic acid component of the symmetry type, for example, 50 to: LOO mol%, favorable Mashiku is 70 to: L00 mole ^_0/0, more preferably is 85 to: L00 mole ⁰ / a ₀ about (including the diol component) Yogu polyol component also of the proportion of the diol component of the symmetry type, if example embodiment, 50 to: L00 mole ^_0/0, preferably is 70 to: L00 mole ^_0/0, more preferably 85 to: L00 may be about mol%.

[0039] The reaction between the polyester-based resin having a functional group and the polymerizable compound is carried out by a conventional method such as a thermal polymerization inhibitor (for example, hydroquinone, t-butyl in an inert gas atmosphere). In the presence of hydroquinone alkyl ethers such as hydroquinone), an esterification catalyst (metal catalyst, amines, etc.) is used, usually at a temperature of about 60 to 160 ° C (eg, 80 to 130 ° C). Good. If necessary, the reaction may be carried out in the presence of an organic solvent. The ratio of the reactive group of the polymerizable compound to 1 mol of the functional group of the polyester-based resin is, for example, 0.5 to 1.5 mol, preferably 0.7 to 1.3 mol, and more preferably 0. It may be about 8 to 1.2 moles. After the reaction is completed, if necessary, residual monomer and solvent can be removed to obtain a photopolymerizable polyester resin that is solid at room temperature.

[0040] The acid value of the photocurable polyester-based resin is usually about 0.1 to about LOmgKOHZg (for example, 0.3 to 5 mgKOH / g).

[0041] As the photocurable acrylic resin, an acrylic resin having a reactive group (hydroxyl group, carboxyl group, daricidyl group, etc.) and a polymerizable unsaturated group having a reactive group with respect to the reactive group. Compound (for example, vinyl fluorinate, reactive with hydroxyl group, maleic anhydride, maleic acid, (meth) acrylic acid or reactive derivative thereof ((meth) acrylic anhydride, (meth) acrylic acid chloride, etc.) , Glycidyl (meth) atalylate capable of reacting with a carboxyl group, (meth) acrylic acid capable of reacting with a glycidyl group, etc. An acrylic resin having a β-ethylene unsaturated bond) can be exemplified.

[0042] The photocurable epoxy (meth) acrylate resin includes, for example, an epoxy (meth) acrylate produced by the reaction of epoxy resin such as bisphenol-type epoxy resin and (meth) acrylic acid. Rate rosin is included.

[0043] The photocurable urethane (meth) acrylate resin includes, for example, a resin produced by a reaction between an urethane oligomer having an isocyanate group and a hydroxyalkyl (meth) acrylate, and a resin having a hydroxyl group. (The polyester-based resin, acrylic resin) and (meth) acrylate having a free isocyanate group (for example, a product of a reaction between polyisocyanate and hydroxyalkyl (meth) acrylate) It includes rosin produced by this reaction.

[0044] The concentration of the polymerizable group (such as (meth) atallyloyl group) in the photocurable resin is usually 200 to 10,000 gZeq (especially 250 to 50,000) as a polymerizable unsaturated bond equivalent (molecular weight per polymerizable group). 80 OOgZeq), for example, 300 to 7000 gZeq, preferably 350 to 5000 gZeq, more preferably about 400 to 4000 g / eq (specifically about 500 to 3000 g / eq)! / ヽ. The number average molecular weight of the light-hardening resin is, for example, about 500 to 30000, preferably <700 to 20000, more preferably <ί or 900 to 15000 (specially 1000 to 10,000). Moyo!

[0045] Among the photocurable resins, at least one type of photocurable resin selected from polyester-based resins, epoxy-based resins and urethane-based resins and having a polymerizable unsaturated bond is preferable.

[0046] The photocurable resin (non-crystalline and crystalline resin) usually has a glass transition temperature or a heat melting temperature (or melting point). The glass transition temperature (Tg) of the photocurable resin is, for example, about 40 to 70 ° C, preferably 40 to 65 ° C, more preferably 40 to 60 ° C (particularly 40 to 50 ° C). May be.

[0047] The photocurable resin is usually composed of an amorphous resin (for example, less than 10% of crystallinity) or a crystalline resin (including semi-crystalline resin) exhibiting the glass transition temperature. In order to improve coating properties such as coating properties and appearance properties such as coating surface smoothness, non-crystalline and crystalline resins may be combined. The degree of crystallinity of the crystalline resin constituting the photocurable resin may be, for example, 10 to 70%, preferably 15 to 60%, and more preferably about 20 to 50%. Further, the thermal melting temperature (or melting point) of the crystalline resin is usually about 50 to 150 ° C., for example, 55 to 130 ° C., preferably 60 to 110 ° C., more preferably 65 to 100 It may be about ° C (especially 70 to 90 ° C).

[0048] The ratio (weight ratio) of the amorphous resin and the crystalline resin constituting the photocurable resin is usually the former Z latter = about 50Z50 to 99Zl, for example, 60 to 40 to 982, preferably May be about 70-30 to 97-3, preferably about 75-25 to 96-4 (especially 80,20 to 95,5).

[0049] The photocurable resin contains a conventional radical polymerizable diluent for adjusting the polymerizability and kneadability within a range in which the photopolymerizable composition can maintain a solid state at room temperature. May be. The polymerizable diluent may be liquid or solid at room temperature (for example, about 10 to 25 ° C.).

[0050] [Polyfunctional polymerizable compound] The composition of the present invention contains at least a polyfunctional polymerizable compound having a plurality of polymerizable groups (for example, α, β-ethylene unsaturated bonds) as a polymerizable diluent. The polyfunctional polymerizable compound can adjust the polymerizability or crosslink density, melting temperature, melt viscosity and the like of the photopolymerizable composition. Since the polyfunctional polymerizable compound is highly reactive and multifunctional, the quality of the cured film is deteriorated (for example, unreacted polyfunctional polymerizable compound remains in the cured film). The hardness of the cured coating can be improved greatly. Particularly, the coating film hardness (pencil hardness) is 2 ranks or more (preferably by a polyfunctional polymerizable compound having 3 or more functions (for example, 3 to 8 functions, preferably 4 to 6 functions, more preferably 5 to 6 functions). Can be improved by 3 ranks or more, for example, pencil hardness F to 2 mm or 3 mm. For example, the hardness (pencil hardness) of a coating film formed by melt-coating a photopolymerizable composition on a base material, heating and leveling, and curing by irradiation with active light rays is, for example, It may be about the above (usually Η to 5 Η, particularly Η to 4 Η), preferably about 2 Η or more (usually 2 Η to 4 Η). The pencil hardness can be measured according to, for example, JIS K-5400 (1990), JIS K-5600-5-4, and the like.

[0051] The polyfunctional polymerizable compound is used at room temperature or room temperature (for example, about 10 to 25 ° C) as long as the photopolymerizable composition can be maintained in the form of a solid (for example, a granular form) or a viscous (particularly a solid). ), It may be liquid, semi-solid or solid, and may be usually liquid. Multifunctional polymerizable compounds often lower the glass transition temperature of a photopolymerizable composition, which often has a lower melting point (or glass transition point) than a photocurable resin. Usually, compared to solid polyfunctional polymerizable compounds, liquid polyfunctional polymerizable compounds are more effective in lowering the glass transition temperature of the photopolymerizable composition, and the glass transition temperature and melting of the photopolymerizable composition. In many cases, the temperature (and melt viscosity) can be reduced efficiently.

[0052] The polyfunctional polymerizable compound has two or more polymerizable groups (photopolymerizable groups) and has two or more functions, for example, 2 to 10 functions, preferably 3 to 8 functions, more preferably It may be about 4-6 functionalities. Examples of the polymerizable group include radical polymerizable groups such as a (meth) atallyloyl group and an alkenyl group (such as a C alkenyl group such as a bur group and a allyl group).

2-4

The polyfunctional polymerizable compound may have at least a (meth) atalyloyl group (particularly, an atalyloyl group). [0053] Polyfunctional polymerizable compounds include, for example, urethane (meth) acrylate, epoxy (meth) acrylate, reaction product of glycidyl group-containing oligomer or copolymer and (meth) acrylic acid, polyol poly (meth) acrylate. It may be a rate.

As the urethane (meth) acrylate, for example, a reaction product of an organic polyisocyanate (eg, tolylene diisocyanate or isophorone diisocyanate) and a hydroxyalkyl (meth) acrylate. Examples thereof include a reaction product of a terminal isocyanate oligomer and a hydroxyalkyl (meth) acrylate. Terminal isocyanate oligomers can be produced by the reaction of polyisocyanates with polyols (polyester diols, polyether diols, polycarbonate diols, etc.).

[0055] Examples of the epoxy (meth) acrylate include a reaction product of an epoxy compound (such as glycidyl ether of bisphenol A) and (meth) acrylic acid. Examples of the reaction product of a glycidyl group-containing oligomer or copolymer and (meth) acrylic acid include, for example, glycidyl (meth) acrylate and copolymerized bull monomers (acrylic monomers such as n-butyl methacrylate, methyl Examples thereof include a reaction product of a glycidyl group-containing copolymer and (meth) acrylic acid obtained by copolymerization with (meth) acrylate, such as meta acrylate.

[0056] Polyol poly (meth) acrylate has two or more (meth) attaroyl groups, and all or part of hydroxyl groups of polyol (polyol component, polyhydroxy component) are (meth) attaroyl. It may have a plurality of hydroxyl groups which may be substituted with a group, for example, 3 to 10, preferably 4 to 8, more preferably about 4 to 6 hydroxyl groups. Polyols constituting the poly (meth) acrylate are non-aliphatic polyols (aromatic polyols, heterocyclic polyols, etc.) or aliphatic polyols (alicyclic polyols, acyclic aliphatic polyols (eg, alkanes). Polyol, oligomer of alkane polyol, etc.)].

[0057] Representative polyol poly (meth) acrylates include, for example, aromatic polyol poly (meth) acrylates [for example, bisphenols with C alkylene oxides (bisphenols).

2-4

Enol A—C Dialkylene adducts, etc.) (di (meth) acrylate)], heterocyclic

2-4

Polyol poly (meth) acrylate [eg, polyol having an isocyanurate ring [tri Di (2-hydroxyethyl) isocyanurate and the like], alicyclic polyols poly (meth) acrylates [for example, C cycloalkanediol (1, 4

6-10

—Di (meth) acrylates of cyclohexanedimethanol, etc., di (meth) acrylates of hydrogenated bisphenol A alkylenoxide adducts, etc.], poly (meth) acrylates of alkane polyols or oligomers thereof, etc. It can be illustrated. The poly (meth) acrylate of alkane polyol or its oligomer includes an alkane polyol or its oligomer and a compound that can generate a hydroxyl group by addition [(C alkylene oxide (for example, ethylene

2-4

Oxides), latatones (eg, ε-force prolatatanes), etc.] adduct poly (meth) acrylates, some of the hydroxyl groups are etherified [alkyl (eg C alkyl) ethers]

1-12

And the like, and esterified (or acylated) alkane polyols or oligomeric poly (meth) acrylates.

[0058] Examples of the alkane polyol constituting the poly (meth) acrylate of the alkane polyol or its oligomer include C alkanediol, preferably C alkanediol.

2-12 2-10

More preferably C alkanediol (especially C alkanediol) (e.g.

2-8 2-6

Tylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, 1,3-butanediol, neopentyl glycol, hexanediol, etc.); C

3-alkanetriol, preferably C-alkanetriol, more preferably C-alkane force

12 3-10 3-8 Ntriol (especially branched C alkanetriol) (eg trimethylolpropane)

4-6

C alkanetetraol (preferably C alkanetetraol,

4-12 4-12

More preferably C alkanetetraol (particularly branched C alkanetetraol) (

4-10 5-8

Eg pentaerythritol); C alkanepentaol, preferably C al

5-15 5-12 Canpentaol, more preferably C alkanepentaol (especially branched C

5-10 5-8 Lucanpentaol (eg xylitol); C Alkanehexaol (eg

6-18

For example, sorbit etc.) is exemplified. The oligomer of the alkane polyol may be, for example, an alkane polyol 2-10 mer, preferably a 2-5 mer, more preferably a 2-3 mer, and is composed of a single or two or more polyols. May be.

[0059] Typical poly (meth) acrylates of alkane polyols or oligomers thereof include, for example, di (meta) of alkanediols or oligomers thereof (particularly dimers or trimers). ) Atarylates [eg, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1, 4 butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, 6 Xanthdiol di (meth) acrylate, di or triethylene glycol di (meth) acrylate, di or tripropylene glycol di (meth) acrylate, etc.]; alkanetriol or its oligomer (particularly dimer or trimer) Is tri (meth) acrylate [eg, trimethylol propane tri (meth) acrylate, glycerin di (meth) acrylate, ditrimethylol propane tetra (meth) acrylate, diglycerin tri to tetra (meth) acrylate, tri Glycerol tri to penta (meta ) Acrylate, etc.]; di-hexa (meth) acrylate of alkanetetraol or its oligomer (especially dimer or trimer) [for example, pentaerythritol tri-tetra (meth) acrylate, dipentaerythritol tri-hexa (Meta) Atarilate (Nippon Gyaku Co., Ltd.

RAYAD) DPHAJ, etc.), penta (meth) atarylate of dipentaerythritol monoalkyl ether (Nippon Gyaku Co., Ltd., “KARAYAD D-310”, etc.), dipentaerythritol's force prolataton adduct hexa ( (Meta) Atarylate (manufactured by Nippon Shakuyaku Co., Ltd., ": ARA YAD DCPA-20", "KARAYAD DCPA-30", "KARAYAD DCPA-60", "KARAYAD DCPA-120", etc.), alkanepentaol or Examples of such oligomers (particularly dimers or trimers) are di-hexa (meth) acrylates, etc. The polyfunctional polymerizable compound includes the melting temperature and melt viscosity of the photopolymerizable composition, the surface hardness of the cured coating film, and the like. From the viewpoint of appearance, for example, polyalkylene such as alkanediol, alkanetriol (monomer, dimer or trimer) or alkanetetraol (monomer, dimer or trimer). Poly (meth) acrylates of alcohols, etc. Among these, poly (meth) acrylates of oligomers of alkane polyols have an ether bond, which is effective for cured coatings. Polyols having an ether bond include, for example, alkanetriol dimers or trimer di- to penta (meth) acrylates, alkanetetraol dimers or trimer di-hexans. (Meth) atallylate [preferably C alkanetriol or C alkane

3-10 4-10 Triol-hexa of tetraol dimer (especially C-alkanetetraol dimer)

4-10

(Meta) atelate etc.] can be exemplified. [0061] From the viewpoint of significantly increasing the hardness while imparting flexibility to the coating film, a particularly preferred multifunctional polymerizable compound is a poly (meth) acrylate of a polyol oligomer, Includes compounds that are more than governmental. Typical tetra- or higher functional poly (meth) acrylates include alkanetriol dimers or trimers (especially alkanetriol dimers such as ditrimethylolpropane, preferably C alkanetriol dimers, and more preferred).

3-8

Preferably a branched c-alkanetriol dimer) tetra to penta (meth) atari

4-6

Rate (eg, ditrimethylolpropane tetra (meth) atalylate), alkanetetraol dimer or trimer (particularly alkanetetraol dimer such as dipentaerythritol, preferably C alkanetetraol dimer, more preferably Is

4-10

Tetra-hexa (meth) acrylate of branched chain C alkanetetraol dimer)

5-8

(For example, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, penta (meth) acrylate of dipentaerythritol monoalkyl ether, etc.). In particular, the alkanetetraol dimer tetra-hexa (meth) acrylate [eg, C alkanetetraol dimer tetra-hexyl]

4-10

Dimeric tethers of sa (meth) acrylate, preferably branched C alkanetetraol

5-8

La to hexa (meth) acrylate, more preferably branched C alkanetetraol

5-8

Dimer's hexa (meth) acrylate, etc.] are preferred!

[0062] Polyfunctional polymerizable compounds may be used alone or in combination of two or more.

[0063] The concentration of the polymerizable group of the polyfunctional polymerizable compound is usually 30 to 300 gZeq as a polymerizable unsaturated bond equivalent which may be larger than the concentration of the polymerizable group of the photocurable resin. It is preferably ί or 50 ~ 200g / eq, more preferably ί or 70 ~ 150g / eq! / ヽ.

[0064] The ratio of the polyfunctional polymerizable compound depends on the type of photocurable resin and the type and shape of the polyfunctional polymerizable compound (liquid, semi-solid, solid). The photopolymerizable composition can be selected within a range that can maintain a solid (for example, powder) form at room temperature (for example, 10 to 25 ° C.), and is usually 0 for 100 parts by weight of the photocurable resin. About 5 to 35 parts by weight, for example, 1 to 30 parts by weight, preferably 3 to 30 parts by weight (for example, 3 to 25 parts by weight), and more preferably 5 to 30 parts by weight (for example, 7 to 20 parts by weight), particularly about 8 to 15 parts by weight.

[0065] [Thermal polymerization inhibitor] The photopolymerizable composition of the present invention may usually contain a thermal polymerization inhibitor for storage stability and suppression of polymerization in the melt coating process. Thermal polymerization inhibitors include, for example, quinones [neurodroquinone (P benzoquinone, etc.), hydroquinone methyl ether, etc.], force techols (t-butylcatechol, etc.), amines (diphenylamine, diphenyl hydrazyl). Etc.), nitro compounds (nitrobenzene etc.) and the like. The amount of the thermal polymerization inhibitor used in the photopolymerizable composition may be, for example, 10 to: L0000 ppm, preferably 30 to L0000, more preferably about 50 to 5000 ppm. Yo!

[0066] [Photoinitiator]

The photopolymerizable composition usually may contain a photopolymerization initiator in addition to the photocurable resin and the polyfunctional polymerizable compound. The photopolymerization initiator can be selected according to the type of actinic rays, and may form an ultraviolet curable composition (or powder paint).

[0067] Examples of the photopolymerization initiator include ketone compounds, phosphine compounds, sulfide compounds (dibutylsulfide, diphenyldisulfide, dibenzylsulfide, decylsulfuride, tetramethylthiuram monosulfide). And the like. Of these photopolymerization initiators, ketone compounds and phosphine compounds are preferred.

[0068] Ketone compounds include acetophenone compounds (acetophenone jetyl ketal, ketoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy 2-methyl 1-phene. 1-one, 1-hydroxycyclohexyl-phenol ketone, etc.), benzophenone compounds [benzophenone, 2, 4, 6 trimethylbenzazophenone, 4, 4 '—dimethoxybenzophenone, 4-phenol penzophenone, 3, 3'-Dimethyl mono 4-methoxybenzophenone, 4, 4'-Diaminobenzophenone, 4-N, N-dimethylamino--methoxybenzophenone, methyl benzoylbenzoate, 4 Benzoyl-4 ' —Methyldiphenylsulfide, (4-Benzylbenzyl) trimethylammonium chloride, bis (4-dialkylamine) Phenol) ketones, benzoin compounds (benzoin derivatives such as benzoin and benzoin ether), benzil compounds (benzyl, benzylmethyl ketal, etc.), anthraquinone compounds (anthraquinone, 2- Methyl anthraquinone, 2-ethyl anthraquinone, etc.), thixanthone compounds (isopropyl thixanthone, jetyl thioxanthone, etc.), morpholine Compound [2 Methyl 2 morpholino (4 thiomethyl phenol) propane 1 ON, 2—Benzyl 1 2 Dimethylamino 1 1— (4-Morpholinol) 1 butane, 3, 6 Bis (2 morpholinoisobutyl) 9 Butylcarbazole, etc. ] Etc. can be illustrated.

[0069] Examples of the phosphine compounds include 2, 4, 6 trimethylbenzoyl diphosphine phosphine oxide, 2, 4, 6 trimethyl benzoyl ethoxy phosphine oxide, bis (2, 4, 6 Trimethylbenzoyl) phenylphosphine oxide, bis (2,6 dimethoxybenzoyl) -2,4,4 trimethylpentylphosphine oxide (BAPO), bis (2,4,6 trimethylbenzoyl) methylphosphine Examples thereof include xoxide, bis (2,4,6 trimethylbenzoyl) ethylphosphine oxide, bis (2,4,6 trimethylbenzoyl) n-butyl phosphate.

[0070] The photopolymerization initiators may be used alone or in combination of two or more. For example, a ketone compound and a phosphine compound may be used in combination.

[0071] The ratio of the photopolymerization initiator is, for example, from 0.1 to 10 parts by weight, preferably from 0.15 to 8 parts by weight, more preferably from 0.2 to 100 parts by weight based on 100 parts by weight of the photocurable resin. It may be about 6 parts by weight (particularly 0.3 to 5 parts by weight). Further, the ratio of the photopolymerization initiator is usually about 0.5 to 50 parts by weight, for example, 1 to 40 parts by weight, preferably 1 to 100 parts by weight of the polyfunctional polymerizable compound. It may be about -30 parts by weight, more preferably about 2-30 parts by weight (particularly 3-20 parts by weight).

[0072] The photopolymerizable composition contains a photopolymerization initiator and a sensitizer such as tertiary amines (dialkylaminobenzoic acid or esters thereof, atalidine, etc.), coumarins [3- (2 benzothiazolyl). ) 7 (Jetylamino) coumarin, etc.], quinolines [2- (2- (4 dimethylaminophenol) etul) quinoline, etc.], quinones (benzoquinone, anthraquinone, etc.), pyrenes (1--tropyrene, etc.), aromatic Group hydrocarbons (such as acenaphthene) may be included. The sensitizers may be used alone or in combination of two or more.

[0073] The photopolymerizable composition may form a paint (for example, a solid paint such as a powder paint) capable of forming a clear coating film (for example, a solid paint such as a powder paint). Form a paint.

[0074] The photopolymerizable composition usually contains a filler! This filler is usually For example, an organic powder or an inorganic powder. The filler includes a pigment in addition to a general additive called a filler, and may or may not have a concealing property. The filler has a matting function (adjusts the gloss of the coating film surface) like a matting agent that does not have to be colored like an extender pigment, which may or may not have coloring like a colored pigment. May have a function to perform!), But it does not have to have an erasing function.

[0075] The filler may be an inorganic filler or an organic filler. Examples of the filler include inorganic fillers such as My strength, kaolin clay, bentonite, and talc, and rosin powder particles (crosslinked grease powder particles such as bridge acrylic resin particles and crosslinked polystyrene resin particles). Organic fillers are exemplified. The filler can be used alone or in combination of two or more.

[0076] Examples of the pigment include extender pigments [metal oxides (silica, alumina, etc.), metal hydroxides (hydroxyaluminum, etc.), metal carbonates (calcium carbonate, magnesium carbonate, etc.), metals Sulfates [barium sulfate (especially barite powder obtained by pulverizing barite)], metal silicates (calcium silicate, aluminum silicate, etc.), glass (quartz glass, etc.); white pigments [titanium dioxide, Zinc oxide, aluminum hydroxide such as alumina white, magnesium silicate, lithbon (ZnS + BaSO), etc.], black pigment (carbon black, etc.), red face

Four

Materials (bengara, red lead, molybdenum red, cadmium red, etc.), yellow pigments (yellow iron oxide, yellow lead, lisage, cadmium yellow, chrome yellow, etc.), orange pigments (molybdate orange, etc.), blue pigments (dark blue, ultramarine blue, etc.) ), Green pigments (chrome green, etc.), purple pigments (manganese violet, etc.), metal powder pigments (aluminum powder pigments, etc.), inorganic pigments; yellow-red pigments [azo pigments (pigment yellow, pigment orange, Pigment red, Hansa Yellow, etc.), quinacridone pigments (quinatalidone red, etc.), perylene pigments (perylene maroon, etc.), blue-green pigments [phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, etc.)], etc. Examples thereof include pigments.

[0077] The pigment is a pigment having a special function, for example, an anti-corrosion pigment [metal chromate (zincartromate, strontium chromate, etc.), lead compound (lead tan, lead suboxide, basic lead chromate, Lead cyanamide, calcium lead, etc.), metal phosphates (such as zinc phosphate, aluminum phosphate, potassium phosphate), metal zinc powder, glass flake powder, etc.], antifouling pigments (such as cuprous oxide) ), Fluorescent pigments, pearl pigments and the like. The pigments can be used alone or in combination of two or more.

[0078] Examples of fillers (foaming agents) having a matting function include metal oxides (silica, alumina, etc.), metal hydroxides (hydroxyaluminum hydroxide, etc.), metal carbonates (calcium carbonate). And magnesium carbonate), colloidal caustic acid, glass and the like. The matting agents can be used alone or in combination of two or more.

[0079] The average particle diameter of the filler may be, for example, about 0.01 to 30 μm, preferably 0.01 to 20 μm, and more preferably about 0.01 to about LO m. In particular, the average particle size of the fillers other than the decoloring agent is often about 0.001 to 5111 (for example, 0.005 to 3 m), which depends on the type of filler. May be from 0.01 to 1 111 (for example, 0.05-0.5 / zm), more preferably from about 0.1 to 0.3 m. The oil absorption amount of the filler other than the decoloring agent is usually about 10 to 60 mlZl00 g, and may be, for example, about 15 to 55 mlZlOOg. Oil absorption can be measured according to JIS K5101 using Amani oil.

[0080] Further, the average particle diameter of the decoloring agent may be usually about 0.1 to 12 / zm, for example, 0.5 to 10 m, preferably 1 to 8 111, and more preferably 2 It may be about ~ 7 m. The oil absorption amount of the detergency is usually about 50 to 200 ml / lOOg, and may be, for example, about 60 to 170 ml Zl00g, preferably about 70 to 150 ml Zl00g (for example, 75 to 120 ml Zl00g).

[0081] The fillers may be used alone or in combination of two or more. For example, a matting agent and a filler other than the matting agent can be used in combination. The amount of the filler used can usually be selected from about 0 to 300 parts by weight (for example, 10 to 300 parts by weight), preferably 20 to 250 parts by weight (for example, for 100 parts by weight of the photocurable resin). 30 to 200 parts by weight), more preferably 40 to 150 parts by weight (specifically 50 to about L00 parts by weight!).

[0082] In particular, when an erasing agent is used, the amount of the erasing agent used is usually 200 parts by weight or less (for example, about 0.5 to 200 parts by weight with respect to 100 parts by weight of the photocurable resin). Preferably 5 to 180 parts by weight (eg 15 to 150 parts by weight), more preferably 30 to 120 parts by weight (eg 40 to: L 10 parts by weight), especially 50 to L00 parts by weight (for example 60 to 90 parts by weight). [0083] Further, when a combination of a decoloring agent and a filler other than the decoloring agent is used, the ratio of use thereof can be generally selected from the former Z latter = 1Z99 to 99Z1 by weight, for example, 5 / 95 to 95/5, preferably 10Z90 to 90ZlO, more preferably 15,85 to 85,15 (special 20/80 to 80/20)!ヽ.

[0084] [Additive]

The photopolymerizable composition contains various additives such as waxes, surface conditioners or leveling agents (acrylic leveling agent, bull leveling agent, silicone leveling agent, fluorine type leveling agent). Bedding agents, etc.), dispersants (non-ionic surfactants, surfactants such as ァ -on surfactants, polymer-type dispersants that may be non-ionic or オン -ionic), stable It may contain an agent (ultraviolet absorber, antioxidant, heat stabilizer, etc.), plasticizer, viscosity modifier, flame retardant, charging agent, antistatic agent and the like. Of these additives, a surface conditioner or leveling agent is useful for improving the surface smoothness of the coating film. The amount of these additive agents may be, for example, about 0.1 to 5 parts by weight, preferably about 0.2 to 3 parts by weight with respect to 100 parts by weight of the photocurable resin.

[0085] [Form]

The form of the photopolymerizable composition is not particularly limited, and if it is solid, for example, non-fibrous (spherical, ellipsoidal, polygonal, amorphous, etc.), fibrous (needle, short fiber) , Long fibers, etc.), granular or granular materials (powdered, granular, chip-shaped, pellet-shaped, block-shaped, flake-shaped, etc.), usually non-fibrous granular materials (especially It may be a chip-like or block-like granular material). In addition, since the photopolymerizable composition is used for melt coating, it is usually uniform by simply applying it to a substrate and cooling it even if it can be flattened by heating the coating film. It may be a composition that cannot form a coating film!

[0086] The maximum particle size of the photopolymerizable composition may be, for example, 30 mm or less, preferably 20 mm or less, and more preferably about 10 mm or less. The maximum particle size of the photopolymerizable composition may usually be about 0.005 mm or more. The volume average particle size of the photopolymerizable composition is not particularly limited, and is usually about 0.005 to 20 mm, for example, 0.01 to 15 mm, preferably 0.05 to: LOmm, more preferably. May be about 0.1 to 8 mm (especially 0.5 to 5 mm). In particular, the volume average particle of the photopolymerizable composition for use in melt coating The diameter is not particularly limited, and may be, for example, about 5 to: LOOO μm, preferably about 5 to 500 μm, and more preferably about 5 to 300 μm (particularly about 5 to: LOO μm)! / ヽ.

[0087] [Anti-blocking agent]

Since the photopolymerizable composition of the present invention is used for melt coating, for example, even if the particles of the photopolymerizable composition are fused (blocked), it does not become a serious problem. Therefore, it is not always necessary, but if necessary, a granular granular anti-blocking agent can be used to prevent blocking. The anti-blocking agent is usually composed of organic or inorganic fine particles (particularly inorganic fine particles).

[0088] Examples of the anti-blocking agent include metal oxides [silica, alumina, magnesia, titanium oxide, iron oxide, zinc oxide, etc.], metal carbonates (calcium carbonate, magnesium carbonate, etc.), metal sulfates (sulfuric acid). Examples include calcium, barium sulfate, etc., metal silicates (caustic acid, aluminum silicate, etc.), and kaic acids (anhydrous caustic acid, hydrous caustic acid). Of these inorganic fine particles, silicon-containing inorganic fine particles, for example, fine particles such as silica, metal silicate, and key acids [usually silica fine particles (especially anhydrous silica fine particles)] are often used. In general, silica fine particles are often used as an anti-blocking agent.

[0089] The anti-blocking agent may be hydrophilic or hydrophobic. Preferably, the surface of the blocking inhibitor is subjected to a hydrophobic treatment. The surface of the fine particles constituting the anti-blocking agent is, for example, silicone oil (such as dimethyl silicone oil), alkylsilane (such as octylsilane), silane coupling agent (such as a silane coupling agent having an alkylsilyl group such as a trimethylsilyl group), etc. To make it hydrophobic.

Among such antiblocking agents, anhydrous silica fine particles are available from Nippon Aerosil Co., Ltd. under the trade names “Aerosil R972”, “Aerosil R805”, “Aerosil R812S”, and the like. An antiblocking agent can be used individually or in combination of 2 or more types.

[0091] The average particle size of the fine particles (primary particles) constituting the antiblocking agent is usually 1 to 10 Onm, for example, 3 to 90 nm, preferably 5 to 80 nm, more preferably 8 to 70 nm (particularly 10 It may be about ~ 50nm). The fine particles constituting the anti-blocking agent have a small bulk density, and usually have a bulk density of about 20 to 200 gZL, for example, 25 to 180 gZL, preferably ί 30 to 150 g / L, and more preferably 35 to 130 g. / L (Special [40 ~: L00g / U or so May be.

[0092] The amount of the antiblocking agent used is, for example, 0.01 to 1 part by weight, preferably 0.05 to 0.8 part by weight, and more preferably 0. 0 part by weight with respect to 100 parts by weight of the photopolymerizable composition. It may be about 08 to 0.5 parts by weight (particularly 0.1 to 0.3 parts by weight). An antiblocking agent may be added to the granular material of the photopolymerizable composition. By adding an anti-blocking agent, blocking of the particles of the photopolymerizable composition can be effectively prevented, and storage stability can be improved.

[0093] It should be noted that the anti-blocking agent is released from the photopolymerizable composition and may be interposed between the photopolymerizable composition granules, or all or part of the photopolymerizable composition powder. It may be bonded (or fixed) by embedding or adhering to the surface of the granule.

[Method for producing photopolymerizable composition]

The photopolymerizable composition (particularly, the granular material of the photopolymerizable composition) is, for example, a photocurable resin and a polyfunctional polymerizable compound, and [other additives (for example, photopolymerization if necessary). And a composition containing an initiator, a filler, and the like] are melt-kneaded, cooled and solidified, pulverized, and classified if necessary. When an antiblocking agent is used, it may be mixed with a photopolymerizable composition classified to a predetermined size. Usually, after a composition containing a photocurable resin and a polyfunctional polymerizable compound is melt-kneaded and cooled and solidified, an anti-blocking agent is added to the solidified product (a granular solidified product such as a pellet), pulverized, There are many cases where classification is necessary. When the photopolymerizable composition is pulverized in the presence of an antiblocking agent, the antiblocking agent adheres to the surface of the photopolymerizable composition, so that the storage stability or blocking resistance of the force photopolymerizable composition can be improved.

[0095] The melt-kneading of the composition containing the photocurable rosin and the polyfunctional polymerizable compound (and other additives as necessary) is to polymerize or cure the photocurable rosin and the polyfunctional polymerizable compound. Usually, the melt-kneaded product is cooled and solidified in the form of particles (for example, pellets). Melt-kneading is a conventional method, for example, each component is dry-mixed with a mixer (Henschel mixer or carbon mixer, etc.) and melt-kneaded (single- or twin-screw extruder, Banbury mixer, kneader, mixing roll, etc.) ) By melt-kneading. The melt kneading temperature may be a temperature capable of suppressing the polymerization of the photocurable resin and the polyfunctional polymerizable compound, and is usually about 60 to 160 ° C, for example, 65 to 150 ° C, preferably Is 7 It may be about 0 to 130 ° C, more preferably about 75 to 120 ° C (particularly 80 to 100 ° C).

[0096] The pulverization step after cooling and solidification may be repeated if necessary! In the crushing process, a conventional crusher such as an atomizer can be used. When using a resin having a low glass transition temperature or a low melting point as a photocurable resin or a composition thereof, a solidified product (such as a pelletized solidified product) is cooled (for example, cold air, dry ice, liquid It is preferable to grind while cooling with nitrogen. The cooling temperature is, for example, 40 ° C or less (for example, 0 to 40 ° C), preferably 30 ° C or less (for example, 3 to 30 ° C), and more preferably 20 ° C or less (for example, 5 to 20 ° C). ) Degree. If necessary, after pulverization, classification using a sieve (for example, a standard sieve such as 325 mesh or 250 mesh) or a classifier to obtain a granular material of a predetermined size!

[0097] [Coating film forming method]

The photocurable composition of the present invention is useful for forming a coating film by melt coating. Such a coating film, for example, melt coats the photopolymerizable composition on a substrate, heats the formed coating film (uncured coating film), and emits actinic rays to the heated coating film. It can be formed by irradiation and curing. That is, the coating film includes a step of melt-coating the photopolymerizable composition of the present invention on a base material (for example, a porous base material) and a leveling by heating the formed coating film. It can form on the surface of a base material through the process of irradiating actinic light to a heated coating film, and making it harden | cure.

[0098] The substrate for forming the coating film may be, for example, a non-porous substrate or a porous substrate, or may be an organic substrate or an inorganic substrate. Examples of organic base materials include non-porous base materials such as non-porous plastics (non-porous organic base materials); porous materials such as wood materials, porous plastics, paper, and fabrics (woven fabrics and non-woven fabrics). Examples include base materials (porous organic base materials). Examples of the wood material include natural wood and synthetic wood [for example, MDF board (medium fiber board), particle board (PB), veneer board, etc.]. Examples of inorganic base materials include non-porous base materials (non-porous inorganic base materials) such as ceramics, glass, and metals (steel plates, aluminum, stainless steel, etc.); concrete panels, gypsum boards, porous metals, etc. Examples thereof include porous substrates (porous inorganic substrates). Examples of the porous metal include magnesium alloy fabrication, aluminum die cast, aluminum sprayed iron plate, porcelain, zinc sprayed iron plate (metallicon) and the like. The photopolymerizable composition of the present invention comprises a molten coating. Therefore, the substrate may be a conductive or electrically insulating substrate. The substrate may be a single substrate or two or more composite substrates.

[0099] In the photopolymerizable composition of the present invention, a uniform coating film can be formed on both the insulating substrate and the conductive substrate by melt coating. The substrate does not necessarily have to be heated (or preheated or preheated), but the photopolymerizable composition is melt-coated on the heated (preheated) substrate based on the appearance of the coating film to be formed. May be. Depending on the type of substrate, for example, it may be preheated to a temperature lower than the melting temperature of the photopolymerizable composition or higher than the melting temperature of the photopolymerizable composition. The heating (preheating) temperature is usually about 30 to 130 ° C, for example 35 to 120 ° C, preferably 40 to 110 ° C, more preferably 45 to 100 ° C (particularly 50 to 90 ° C). It may be a degree. If the preheating temperature is low, the appearance of the coating film may be adversely affected. If the preheating temperature is too high, the substrate may be deformed. The substrate can be heated using various heating means (for example, a heater such as a far infrared heater, a near infrared heater, a warm air heater, etc.).

[0100] The melt-coating is carried out by applying the photopolymerizable composition to the melting temperature of the photopolymerizable composition [usually about 50 to 200 ° C, such as 60 to 180 ° C, preferably 70 to 160 ° C, more preferably Can be performed by heating to 80 to 150 ° C. (especially about 90 to 140 ° C.) and melting, and coating (applying) the molten photopolymerizable composition onto a substrate. Examples of the melt coating method include a roll coater method and a thermal spraying method. From the standpoint of mass production, the roll coater method using hot rolls is preferred.

[0101] FIG. 1 shows a schematic diagram for explaining a coating state by a roll coater method. In the roll coater method, a doctor roll 2 for controlling the supply amount of the photopolymerizable composition 4 and a coater for applying the melted photopolymerizable composition 4 to a substrate (such as a porous substrate) 3 are used. A roll coater having a pair of rolls composed of tar roll 1 is used. The coater roll 1 and doctor roll 2 (especially the surface of each roll) may be made of metal or non-metal (for example, rubber such as heat-resistant silicone rubber)! / ずれ. The coater roll 1 and doctor roll 2 may be the same material or different. Using the coater roll 1 and the doctor roll 2, the molten photopolymerizable composition is coated on the substrate 3 which is conveyed in a certain direction at a predetermined speed by a conveying means 5 such as a conveyor. A coating film (uncured coating film) can be formed.

[0102] In the case of the roll coater method, the temperature of the coater roll and doctor roll may be any temperature that can maintain the molten state of the photopolymerizable composition, for example, 50 to 200 ° C, preferably 60 to 180. C, preferably 70-160. C, more preferably 80-150. It may be about C (for example, 90 to 140 ° C). When the heating temperature of each roll is low, the melt viscosity of the photopolymerizable composition becomes high, and the leveling property of the coating film tends to be lowered. When the heating temperature of each roll is too high, the stability of the photopolymerizable composition tends to decrease. The coater roll and doctor roll can be heated by, for example, a method in which an electric heater is incorporated in each roll and heating, a method in which heated oil is circulated inside each roll, and the like.

[0103] In a pair of rolls made up of a coater roll and a doctor roll, the doctor tool may be rotated, but the coater roll is rotated without rotating the doctor roll (for example, transporting the substrate). By rotating the photopolymerizable composition by melt coating in the direction, a coating film with an appropriate coating amount and a good appearance can be formed. When the surface of at least one of the coater roll and the doctor roll that can contact each other is made of an elastic material (such as rubber), the doctor roll is not attached to the coater roll. It is possible that the roll surface made of at least one elastic material is pressed and indented! /.

[0104] The coating amount of the photopolymerizable composition to a substrate (melt coating amount) is not particularly limited, can be selected from the range of about 10～300GZm ^2, for example, 20～250GZm ^2, rather preferably ί It may be about 40 to 200 g / m ² , more preferably about 60 to 180 g / m ² (specifically about 80 to 150 g / m ² ). The coating amount can be controlled by, for example, the distance between the coater roll and the doctor roll, the rotation speed, and the like. The distance between the coater roll and the doctor roll is usually about 2500 μm or less, for example, 10 to 2000 μm, preferably 50 to 1500 μm, more preferably 100 to 1000 m (particularly 200 to 500 μm). m) may be sufficient.

The coating amount may be controlled by the peripheral speed V of the coater roll. That is,

1

The coating amount can be increased by increasing the peripheral speed V of the tar roll. Coater roll The peripheral speed V can be selected according to the flow characteristics such as the melt viscosity of the photopolymerizable composition.

1

For example, it may be about 2 to 25 mZ, preferably 3 to 20 mZ, more preferably about 5 to 15 mZ (particularly about 7 to 13 mZ). The coating amount is the difference between the coater roll circumferential speed V and the conveyor speed V that transports the substrate (V -V or its absolute value)

1 2 2 1

You may control by. That is, the conveyor roll speed V

1

The speed V may be increased, and the coater roll peripheral speed V is increased with reference to the conveyor speed V.

The higher the 2 2 1, the greater the coating amount. The conveyor speed V is not particularly limited and is usually 5 to 60.

2

For example, it may be about 10 to 55 mZ, preferably about 15 to 50 mZ, and more preferably about 20 to 45 mZ (particularly about 25 to 40 mZ). Coater roll speed V

The difference between 1 and the conveyor speed V (V -V) is, for example, 5 to 30 mZ, preferably 10 to 25 m.

2 2 1

It may be about Z minutes, more preferably about 15 to 20 mZ.

[0105] The coating speed of the photopolymerizable composition on the substrate is not particularly limited, and is usually about 5 to 60 mZ, which may correspond to the conveyor speed, for example, 10 to 55 mZ, preferably It may be about 15 to 50 mZ, more preferably about 20 to 45 mZ (particularly about 25 to 40 mZ).

In the heating step, the coating film on which the photopolymerizable composition is melt-coated is heated and leveled to flatten the coating film surface. As the heating source, for example, an infrared irradiation furnace equipped with an infrared (IR) irradiation lamp, a heating furnace such as a hot air drying furnace can be used. As a heating method, a method using an infrared irradiation furnace (for example, an infrared irradiation furnace having a wavelength of about 700 ηπ! To 20 μm) or a method using a combination of the infrared irradiation furnace and a hot air drying furnace is preferable. Yes.

[0107] During the heating step, usually, the coating film may be heated to a temperature equal to or higher than the glass transition temperature (or the melting temperature) of the photopolymerizable composition. The heating temperature is about 50 to 160 ° C depending on the type of the photopolymerizable composition, for example, 55 to 150 ° C, preferably 60 to 140 ° C, more preferably 70 to 130 ° C ( In particular, it may be about 80 to 120 ° C. The heating time is usually about 1 to 10 minutes, for example, 3 to 9 minutes, preferably 5 to 8 minutes, more preferably 7 to 7 minutes (especially 10 to 5 minutes). There may be. When the heating time is short, the leveling property of the coating film tends to decrease, and when the heating time is long, the photopolymerizable composition becomes cheap. There is a tendency for qualitative properties to decrease.

[0108] According to the photopolymerizable composition of the present invention, the coating step and the leveling step are almost 100% (even when thickly coated while suppressing penetration into the porous substrate. A uniform coating film can be formed with a coating efficiency close to that of the solid component.

[0109] The coating film obtained by melt coating the photopolymerizable composition of the present invention and heating and leveling can be cured by irradiation with actinic rays. The actinic ray may be, for example, gamma ray, X-ray, ultraviolet ray, visible ray, etc., but usually ultraviolet ray is used. As the ultraviolet irradiation lamp, for example, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like can be used. The wavelength range of ultraviolet rays may be, for example, about 270 to 460 nm, preferably about 280 to 455 nm, and more preferably about 290 to 450 nm.

[0110] The actinic rays may be irradiated prior to the heating, if necessary, in addition to the irradiation after the heating (leveling) at least when the coating is heated. That is, the coating film formed by melt coating is irradiated with actinic rays to partially cure (pre-curing), and then the actinic ray-irradiated coating film (pre-curing coating film) is heated and further irradiated with actinic rays. A coating film (cured coating film) may be formed by irradiating and curing the coating film. When the cured coating film is formed through such preliminary curing, the improvement of the gloss of the coating film due to the heating process is suppressed, and the gloss of the cured coating film can be easily suppressed. Then, by adjusting the degree of this pre-curing, it is possible to form a matte coating film with adjusted gloss (degree of matting). In particular, a cured coating film with low gloss can be formed by increasing the degree of pre-curing (or actinic ray irradiation energy). It should be noted that the gloss of the cured coating film can be adjusted to some extent by using the filler (particularly, a matting agent). Therefore, the gloss of the cured coating film can be further adjusted over a wide range by combining the degree of preliminary curing and the amount of filler added.

[0111] For irradiation with actinic rays for pre-curing, the same active overhead wire as above and a light source (such as an ultraviolet ray irradiation lamp) can be used.

[0112] Value of irradiation energy (hereinafter referred to as G1) of actinic rays (for example, ultraviolet rays) in the pre-curing process (or irradiating the film before heating) (hereinafter referred to as G1) ) Can be selected within the range where the coating is not completely cured and can be pre-cured, and is usually about 1 to about LOOOmjZcm ² per unit area of the coating, for example, 5 to 800 mjZcm ² It may be adjusted within the range of 10 to 500 mj / cm ² , more preferably 30 to 300 nijZcm ² (especially 50 to 200 iuJ / cm 2)! / ,.

[0113] When pre-curing, the irradiation energy (hereinafter referred to as G2) of actinic rays (for example, ultraviolet rays) in the curing step (or irradiating the heated coating film (pre-cured coating film)) is , per unit area of the coating film, usually from about ² 100～5000MiZcm, for example, 200 ～4000NijZcm ^2, preferably 300～3000NijZcm ^2, more preferably 400 to 2500 mj / cm ² (particularly 500～2000MjZcm ²⁾ degree Even so! /.

[0114] Further, as the ratio of the irradiation energy G1 to the irradiation energy G2 (G1ZG2) is increased, a cured coating film having a lower surface gloss (for example, a cured coating film that has been more highly erased) can be formed. The ratio of G1ZG2 is usually about 1Z99 to 30Z70, where the total amount of G1 and G2 (G1 + G2) is 100, for example, 2 / 98-25 / 75, preferably 3Ζ97. It may be about 20/80, more preferably about 4/96 to 15/85 (special 5/95 to LO / 90).

[0115] The irradiation energy (unit: J) of the actinic ray corresponds to the product of the irradiation intensity [watt (unit: JZS)] of the actinic ray and the irradiation time (unit: s). For example, the irradiation energy of ultraviolet rays (irradiation energy per unit area) can be measured by, for example, “UVR-T 1” manufactured by TOPCOM.

[0116] When adjusting the gloss of the cured coating film, the surface glossiness of the cured coating film can usually be adjusted within the range of about 0.1 to 85, for example, 0.5 to 80, preferably 1 to It may be 75, more preferably 1.5 to 70 (particularly 2 to 65). The surface glossiness of the coating film can be measured under the condition of an incident angle of 60 ° based on, for example, JIS K5600 -4-7 (2004).

[0117] The coating step may be repeated, or a cycle composed of the coating step (and the preliminary curing step), the leveling step and the curing step may be repeated a plurality of times. In the present invention, it is possible to form a coating film that is uniform and thick even in one cycle.

Industrial applicability

[0118] According to the photopolymerizable composition of the present invention, it is possible to easily and efficiently form a coating film that is uniform and has a firm strength depending on the type of substrate by melt coating. So Therefore, it can be applied to the coating of various substrates. Further, the present invention is useful for adjusting the surface gloss of a cured coating film to form a cured coating film having a desired glossiness, and is suitable for obtaining, for example, a coated panel (for example, a building material panel). .

Example

[0119] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0120] (Example 1)

UV curable resin for powder coatings (Daicel UCB Co., Ltd., “U _VeCO at # 300 1”) 100 parts by weight, dipentaerythritol hexaatalylate (Nippon Yakuyaku Co., Ltd., “KAR AYAD DPHAJ) 10 parts by weight, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd., “Irugacure 819”, Ciba Specialty Chemicals Co., Ltd., “Irugacure 2959” mixture, former Z latter = 1Z1 (weight ratio )) 2 parts by weight, titanium oxide (manufactured by DuPont, “1 ^ 706”) 20 parts by weight, and surface conditioner (301 ^ 711, manufactured by “MODAFLOW POWDER—2000”) 1 part by weight After dry blending with a Henschel mixer, it was melt-kneaded with an etastruder and solidified by cooling. After cooling and solidification, the powder was finely pulverized by a pulverizer and filtered to obtain a powder coating material having an average particle size of about 20 μm or more. Dipentaerythritol hexatalylate is prepared by melt-mixing a composition obtained by previously mixing the ultraviolet curable resin and dipentaerythritol hexaterate at a ratio of the former Z latter (weight ratio) = 80Z20 on a hot plate. It was used as a pelletized solid product obtained by cooling and solidifying.

[0121] (Example 2)

A powder coating material was obtained in the same manner as in Example 1 except that 20 parts by weight of dipentaerythritol hexaatalylate was used instead of 10 parts by weight.

[0122] (Example 3)

Except for using dipentaerythritol hexaatalylate, an acrylate difunctional monomer (“KARAYAD HX-220” manufactured by Nippon Kayaku Co., Ltd.) was used in the same manner as in Example 1. A powder coating was obtained.

[0123] (Comparative Example 1)

Same as Example 1 except that dipentaerythritol hexaatalylate was used. A powder coating was obtained.

[0124] [Powder paint performance evaluation method]

Example 1 to 3 and comparison using MDF plate (base material) 3 preheated to 50 ° C using a roll coater having a pair of rolls composed of coater roll 1 and doctor roll 2 shown in Fig. 1 Each powder coating 4 produced in Example 1 was heated to 130 ° C and melt coated. In this process, the MDF plate 3 is transported at a conveyor speed of 30 m / min using the conveyor 5 as a transport means, and the coater roll 1 that rotates the doctor roll 2 is transported at a peripheral speed of 10 mZ. Rotated in the direction.

[0125] The MDF plate melt-coated with the powder coating was heated at 90-130 ° C using a mid-wavelength infrared irradiation furnace (wavelength 1-10 / ζ πι) to melt the coating film. Leveled. Next, using a high-pressure mercury lamp (wavelength 280 to 450 nm), the coating film was irradiated with ultraviolet rays for 10 seconds to 3 minutes to cure the coating film. Each powder paint manufactured in Examples 1 to 3 and Comparative Example 1 or the formed coating film (cured coating film) was evaluated by the following items.

[0126] (Surface hardness of coating film)

The surface hardness of the obtained coating film was measured based on JIS K-5400 (1990).

[0127] (Appearance of coating film)

The appearance of the obtained coating film was evaluated according to the following criteria.

[0128] ○: Flat, uniform coating is obtained

Δ: Although there is uneven color, a uniform coating can be obtained as a whole

X: Uneven color, roving stripes, etc., and uniform coating cannot be obtained.

[0129] (Storage stability of paint)

After the powder coating was stored at 20 ° C or 10 ° C for 2 weeks, the blocking state was evaluated according to the following criteria.

[0130] ○: Almost no change from the state before storage

Δ: Some blocking is observed, but can be easily loosened by hand

X: The whole is greatly blocked and difficult to loosen by hand.

[0131] (Melting temperature of paint)

Example and comparative example with a predetermined area (25cm ² ) on a hot plate set at 170 ° C 5 g of the powder coating material manufactured in 1 was put on, the temperature when the powder coating started to melt was measured, and this temperature was taken as the melting temperature.

[0132] (Melt viscosity of paint)

Using a viscosity measuring device (Piscometer, RE550H manufactured by Toki Sangyo Co., Ltd.), melt the powder paint at a temperature of 95 ° C and a rotation speed of 0.1 rpm, and measure the melt viscosity after 100 seconds. 7

The results are shown in Table 1.

[0134] [Table 1]

[0135] From Table 1, the coating material (photopolymerizable composition) of Example 1 3 is better than the coating material of Comparative Example 1 by the melt coating at a relatively low temperature, which has a lower melting temperature and melt viscosity. A coating with a beautiful appearance was formed, and the storage stability was equivalent. In addition, the paints of Examples 1 and 2 using a hexafunctional polyfunctional polymerizable compound formed a hardened coating film having a higher hardness than the paint of Comparative Example 1, and the pencil hardness of the cured paint film was 2 ranks. Improved. [0136] [Gloss adjustment method of cured coating film]

(Manufacture of powder paint)

Powder coatings A to F were produced according to the following procedure. Table 2 shows the coating compositions of powder coatings A to F.

[0137] (Powder paint A)

UV curable polyester resin (Daicel UCB Co., Ltd., Uvecoat 3001, T g = 44 ° C) 100 parts by weight, semi-crystalline resin (Daicel UBC Co., Ltd., Uvecoat 90 10) 10 Part by weight, Atalylate monomer [Nippon Kayaku Co., Ltd., Karadad DPHA (Dipentaerythritol Hexaatalylate)] 10 parts by weight, Photopolymerization initiator (Ciba Special Chemicals Co., Ltd., Irugacure 819) 1 part by weight , Polymerization initiator (Ciba Specialty Chemicals Co., Ltd., Irugacure 2959) 1 part by weight, matting agent [manufactured by Tatsumori Co., Ltd., Furex E-2 (amorphous high purity fused silica glass filler), average grain Diameter 7 m] 70 parts by weight, 20 parts by weight of titanium oxide (white pigment) and 1 part by weight of a surface conditioner (manufactured by SOLUTIA, MODAFLOW POWDER M-20 00) were dry-mixed with a Henschel mixer for 1 minute, Melt and knead with a strainer, solidify by cooling It was. The obtained solidified product was pulverized with a crusher at 5 to 20 ° C. to obtain a chip-like matte powder coating material (powder coating material A).

[0138] (Powder paint B)

Powder paint except that the photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd., Irugacure 2959) is used V, and the amount of the anti-foaming agent (Furex E-2) is 40 parts by weight. In the same manner as A, a chip-like matte powder paint (powder paint B) was obtained.

[0139] (Powder paint C)

A chip-like matting powder coating (powder coating C) was obtained in the same manner as powder coating A except that the amount of the matting agent (Fuselex E-2) was 20 parts by weight.

[0140] (Powder paint D)

A chip-like matting powder coating (powder coating D) was obtained in the same manner as powder coating A except that the amount of the matting agent (Fuselex E-2) was 1 part by weight.

[0141] (Powder paint E)

Same as powder coating A except that the amount of anti-fogging agent (Fuselex E-2) was 40 parts by weight In this way, a chip-like matting powder coating (powder coating E) was obtained.

[0142] (Powder paint F)

Detergent (Fuselex E-2) Instead of 70 parts by weight, barium sulfate (detergent) 70 parts by weight was used in the same manner as powder paint A. paint

F) was obtained.

[0143] [Table 2]

C

(Example 4)

Using a roll coater having a pair of rolls composed of a coater roll 1 and a doctor roll 2 shown in FIG. 1, the chip-shaped powder paint (powder paint A) 4 is brought to 130 ° C. The MDF plate (base material) 3 heated and heated to 50 ° C. (preheating) was melt coated. In this process, the MDF plate 3 is transported at a conveyor speed of 30 mZ using the conveyor 5 as a transport means, and the coater roll 1 without rotating the doctor roll 2 is transported in the transport direction of the MDF plate 3 at a peripheral speed of 10 mZ. Rotated.

[0145] The uncured coating film of powder coating A melt-coated on the MDF plate was irradiated with ultraviolet rays using a high-pressure mercury lamp (wavelength: 280 to 450 nm) until the irradiation energy reached lOOmjZcm ² or more. And pre-cured (pre-curing step). Next, the pre-cured coating film is heated using a mid-wavelength infrared irradiation furnace (wavelength 1 to 10 m) so that the surface temperature becomes 100 to 120 ° C. in about 3 minutes. (Heating process). Thereafter, the heated coating film was cured by irradiating with ultraviolet rays for 10 seconds to 3 minutes using a high pressure mercury lamp (wavelength: 280 to 450 nm) (curing step). Table 2 shows the ultraviolet irradiation energy (G1) in the preliminary curing process and the ultraviolet irradiation energy (G2) in the curing process. The total irradiation energy (G1 + G2) was 1500 mjZcm 2 in the pre-curing process and the curing process. The UV irradiation energy was measured using a “UVR-T1” manufactured by TOPCOM.

[0146] (Examples 5 and 6)

The UV irradiation energy (G1) in the pre-curing process was set to 90 mj / cm ² or more (Example 5) or 80 mjZcm ² or more (Example 6), respectively, as in Example 4.

[0147] (Reference Example 1)

The same procedure as in Example 4 was performed, except that pre-curing was not performed.

[0148] (Reference Example 2)

Pre-curing process Heating process The order of the curing process was the same as in Example 4 except that the heating process, the pre-curing process, and the curing process were performed.

[Example 7 ~: L 1]

Instead of powder paint A, powder paint B (Example 7), powder paint C (Example 8), powder paint D (Example 9), powder paint E (Example 10) or Powder coating F (Example 11) was used, and in Example 10, the UV irradiation energy (G1) in the pre-curing process was set to 80. The same procedure as in Example 4 was performed except that mjZcm ² or more.

[0150] [Evaluation of coating film]

Each test was carried out by the following procedures on the cured coating films formed in Examples 4 to 11 and Reference Examples 1 and 2. The results are shown in Table 3.

[0151] (Surface gloss)

The surface gloss of the cured coating film is measured at an incident angle of 60 ° based on JIS K5600-4-7 (2004) “Specular Gloss”.

[0152] (Adhesiveness)

Based on JIS K5600-5-6 (cross-cut method), the adhesion of the cured coating to the substrate is tested under the condition of a cross-cut width of 2 mm and evaluated according to the following criteria.

[0153] Classification 0: The edges of the cut are completely smooth, and there is no peeling to the eyes of any lattice

Classification 1: Small peeling of the coating film at the intersection of cuts. The cross-cut portion is not affected more than clearly 5%

Category 2: The coating is peeled along the edge of the cut and / or at the intersection. The cross-cut part is clearly affected by more than 5% but not more than 15% .Category 3: The coating is partially or completely peeled along the edges of the cut, and And various partial forces of Z or eyes are partially or completely peeled off. The cross-cut portion is clearly affected by more than 15% but not more than 35%

Classification 4: The paint film is partially or completely peeled along the edge of the cut, and Z or some eyes are partially or completely peeled off. The impact on the crosscut is not clearly greater than 35%

Category 5: When the degree of peeling exceeds Category 4.

[0154] (Scratch hardness)

The hardness of the cured coating film is tested based on JIS K5600-5-4 (pencil scratching method).

[0155] (Solvent resistance)

Leave the gauze soaked in xylene on the cured coating for 2 hours, and check the state of the cured coating for changes (abnormality) such as blistering, peeling or wrinkling. [Table 3]

O

m

In Table 3, the comparison with Reference Examples 1 and 2 shows that in Example 4, the surface gloss of the cured coating film is low due to the preliminary curing before heating. From Example 4-6, purple in pre-curing It can be seen that the greater the external irradiation energy (G1), the lower the surface gloss of the cured coating. From Examples 4 and 7, it can be seen that the photopolymerization initiator also affects the surface gloss of the cured coating film, but has a smaller effect than the precured layer (Examples 4 to 6). Examples 4 and 8: From LO, the amount of the decoloring agent also affects the surface gloss of the cured coating, but even if the amount of the decoloring agent is reduced, the surface gloss of the cured coating is not necessarily high. Therefore, it can be seen that it is difficult to adjust the surface gloss of the cured coating film depending on the amount of the decoloring agent. From Examples 4 and 11, it can be seen that the type of the matting agent also affects the surface gloss of the cured coating film, but the effect is smaller than that of the preliminary curing (Examples 4 to 6).

Claims

The scope of the claims

[1] A photopolymerizable melt-coating composition that is a solid or viscous photopolymerizable composition at room temperature, and is composed of a photocurable resin that is solid at room temperature and a polyfunctional polymerizable compound. .

2. The composition according to claim 1, which is a solid at room temperature.

[3] The composition according to claim 1, wherein the melt viscosity at the melt coating temperature is 50 to 500 Pa's.

[4] The composition according to claim 1, wherein the polyfunctional polymerizable compound is a polyfunctional polymerizable compound having a plurality of (meth) atalyloyl groups.

[5] The polyfunctional polymerizable compound is a poly (meth) acrylate of a polyol component selected from polyol monomers, dimers, and trimers, and the polyol has an alkanediol, alkanetriol, and alkanetetraol strength. The composition according to claim 1, which is at least one selected.

[6] The polyfunctional polymerizable compound is a dimer tri to hexa (meth) acrylate of a polyol, and the polyol is a C alkanetriol or a C alkanetetraol.

3-10 4-10

2. The composition of claim 1, wherein the composition is at least one selected.

[7] The composition according to claim 1, wherein the ratio of the polyfunctional polymerizable compound is 5 to 30 parts by weight with respect to 100 parts by weight of the photocurable resin.

[8] A photopolymerizable composition further comprising a photopolymerization initiator, wherein the ratio of the photopolymerization initiator is 0.5 to 50 parts by weight based on 100 parts by weight of the polyfunctional polymerizable compound. 1 composition.

[9] A photocurable resin that is solid at room temperature and a tri-hexa (meth) acrylate of a polyol component selected from dimers and trimers of alkanetriols or alkanetetraols. It is composed of a kind of polyol poly (meth) acrylate and a photopolymerization initiator, and the ratio of the poly (meth) acrylate is 8 to 25 parts by weight with respect to 100 parts by weight of the photocurable resin, The composition according to claim 1, wherein the ratio of the photopolymerization initiator is 1 to 30 parts by weight with respect to 100 parts by weight of the poly (meth) acrylate.

[10] The method for producing the composition according to claim 1, wherein the photocurable resin and the polyfunctional polymerizable compound that are solid at room temperature are melt-kneaded, cooled and solidified, and then pulverized.

[11] A coating film forming method in which the composition according to claim 1 is melt-coated on a substrate, the formed coating film is heated, and the heated coating film is irradiated with actinic rays to be cured.

12. The method of forming a coating film according to claim 11, wherein the coating film formed by melt coating is partially cured by irradiation with actinic rays and then the coating film is heated.

[13] When the total amount of irradiation energy G1 of actinic rays irradiated to the coating film before heating and irradiation energy G2 of the actinic rays irradiated to the coating film after heating is 100, G1ZG2 is 1/9 9 ~ The method for forming a coating film according to claim 12, which is 30Z70.

[14] A precuring step in which the coating film formed from the composition according to claim 1 is irradiated with actinic rays to be partially cured, a heating step in which the partially cured coating film is heated, and after the heating A method of adjusting the gloss of the cured coating film by the irradiation energy of the actinic ray in the preliminary curing process, comprising a curing process of irradiating the coating film with an actinic ray to cure.