JP2002292807A - Photosetting sheet and method for manufacturing molded product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosetting laminated sheet excellent in abrasion resistance, weatherability and chemical resistance, capable of being advantageously used in the production of a molded product having good design effect, having no stickiness and excellent in processability and storage stability. SOLUTION: In the photosetting sheet containing a base material sheet (C) and two layers comprising a photosetting resin composition laminated on the base material sheet (C), the outermost layer among two layers comprising the photosetting resin composition comprises a photosetting resin composition (A) containing an acrylic resin (a-1) having a radical polymerizable unsaturated group in its side chain and a photopolymerization initiator (a-2) and not substantially containing a crosslinkable compound other than the acrylic resin (a-1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable sheet having excellent appearance, design, abrasion resistance, chemical resistance and weather resistance and having no tackiness, and production of a molded article using the same. Method,
And a molded article obtained by the production method.

[0002]

2. Description of the Related Art As a method of decorating the surface of a plastic product at the same time as molding, (1) a method in which a pattern is previously applied to the inner surface of a mold, (2) a transfer film is mounted on the inner wall surface of the mold, and molding At the same time, the method of transferring the pattern of the film to the outer surface of the molded product, (3) the method of pasting a functional sheet or a printed sheet on the inner wall surface of the mold, and simultaneously attaching the sheet to the surface of the molded product at the same time as molding. Proposed.
For the method (2) or (3), for example, JP-A-60-250925, JP-B-59-36841, and JP-B-8-2550 disclose a weather-resistant sheet or a printed sheet in a mold. There has been proposed a method of manufacturing a molded article whose surface is covered with a re-seat by injection molding a molding resin after forming it on a wall surface.

[0003] However, in the above-mentioned technique, the decoration and the imparting of functionality are performed by transfer of a thermoplastic sheet or printing, so that the molded product obtained has insufficient surface hardness. For example, when imparting weather resistance to a molded article, a high weather resistance sheet made of polyvinylidene fluoride (PVDF) or the like may be used, but there is a problem that sufficient surface hardness cannot be obtained. On the other hand, in order to obtain a molded product having a high surface hardness, it is necessary to use a crosslinked sheet having a high surface hardness in advance. However, it is difficult to apply such a sheet to a three-dimensional molded article.

[0004]

SUMMARY OF THE INVENTION Therefore, Japanese Patent Publication No. 7-3
As shown in JP-A No. 23, an acrylic resin, a compound having a reactive vinyl group and a photocurable resin layer formed of a resin composition containing a photopolymerization initiator and a sheet substrate are laminated. A photocurable sheet has been proposed.
However, in this method, the sheet before photo-curing contains a compound having a low-molecular-weight reactive vinyl group, so that there is a phenomenon that the surface has tackiness or the surface tackiness changes with time. Occurs, and the storage stability in the roll state is poor. Specifically, there have been problems such as sticking and unwinding, and unless stored at a low temperature, compounds exuding from both ends. Furthermore, due to the adhesiveness, a problem has occurred in a printing process when used as a printing sheet.

[0005] In order to address this problem, the present inventors have previously developed a base sheet in which a composition containing an acrylic resin having a radically polymerizable unsaturated group in a side chain and a photopolymerization initiator is laminated. Proposed a photocurable sheet having no tackiness (Japanese Patent Application No. 2000-203809, Japanese Patent Application No. 2000-2).
03849), the inventors of the present invention have conducted intensive studies with the aim of achieving higher hardness and better weather resistance, and as a result, the present invention has been achieved.

That is, an object of the present invention is to provide a non-adhesive, non-adhesive, processable and highly wear-resistant, weather- and chemical-resistant product which can be advantageously used for producing molded products having good design. An object of the present invention is to provide a photocurable laminated sheet excellent in storage stability.

[0007]

In order to solve the above problems, the present invention provides a base sheet (C) and two layers of a photocurable resin composition laminated on the base sheet (C). In the photocurable sheet containing (a), the outermost layer of the two layers of the photocurable resin composition has an acrylic resin (a-1) having a radical polymerizable unsaturated group in a side chain and a photopolymerization initiator (a). -2)
, A photocurable sheet which is a layer of the photocurable resin composition (A) substantially free of a crosslinkable compound other than (a-1), a photocurable decorative sheet using the same, and light A sheet for curable insert molding is provided.

The present invention also provides a method for producing an insert molded product using the photocurable sheet, the photocurable decorative sheet or the photocurable insert molding sheet, and an insert molded product obtained by the method. I do.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. The photocurable sheet of the present invention includes a base sheet (C) and two layers of the photocurable resin composition laminated on the base sheet (C), and includes two layers of the photocurable resin composition. The outermost layer of the product layer contains an acrylic resin (a-1) having a radically polymerizable unsaturated group in a side chain and a photopolymerization initiator (a-2), and has a crosslinkability other than the above (a-1). A photocurable sheet which is a layer of the photocurable resin composition (A) substantially free of a compound. In the photocurable sheet of the present invention having such a configuration, extremely good abrasion resistance is obtained. In addition, the photocurable sheet of the present invention has a structure in which a radical polymerizable unsaturated group is introduced into a polymer side chain, whereby a crosslinking reaction proceeds between polymer side chains. There is no need to include a low-molecular-weight crosslinkable compound, and therefore, there is an advantage that a sheet having no stickiness and having excellent storage stability can be obtained.

The acrylic resin (a-1) having a radically polymerizable unsaturated group in the side chain is, for example, a polymer having a glass transition temperature of 25 to 170 ° C., preferably 30 to 150 ° C. Those having a saturated group are exemplified. Specifically, as a polymer, the following compounds (1) to (8) are polymerized or copolymerized,
Those obtained by introducing a radically polymerizable unsaturated group by the methods (a) to (d) described below can be used.

(1) Monomers having a hydroxyl group: N-methylolacrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2
-Hydroxy-3-phenoxypropyl (meth) acrylate, etc. (2) Monomer having carboxyl group: (meth) acrylic acid, acryloyloxyethyl monosuccinate, etc. (3) Monomer having epoxy group: glycidyl (meth) )
Acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, etc. (4) Monomer having an aziridinyl group: 2-aziridinylethyl (meth) acrylate, allyl 2-aziridinylpropionate, etc. (5) Amino group Monomer having: (meth) acrylamide, diacetone acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth)
(6) Monomer having a sulfone group: 2-acrylamido-2-methylpropanesulfonic acid, etc. (7) Monomer having an isocyanate group: equimolar of 2,4-toluene diisocyanate and 2-hydroxyethyl acrylate Such as an adduct, an adduct of a diisocyanate and a radical polymerizable monomer having active hydrogen, 2-isocyanateethyl (meth) acrylate, etc. (8) Further, the glass transition temperature of the above copolymer is adjusted, In order to harmonize the physical properties of the photocurable sheet, the above compound may be copolymerized with a monomer copolymerizable therewith. Examples of such a copolymerizable monomer include (meth) acrylates such as methyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and isobornyl (meth) acrylate, N-phenylmaleimide, and cyclohexylmaleimide. And imide derivatives such as N-butylmaleimide, olefinic monomers such as butadiene, and aromatic vinyl compounds such as styrene and α-methylstyrene.

Next, a radical polymerizable unsaturated group is introduced into the side chain of the polymer obtained as described above by the following methods (a) to (d). (A) In the case of a polymer or copolymer of a monomer having a hydroxyl group, a monomer having a carboxyl group such as (meth) acrylic acid is subjected to a condensation reaction. (B) In the case of a polymer or copolymer of a monomer having a carboxyl group or a sulfone group, the above-mentioned monomer having a hydroxyl group is subjected to a condensation reaction.

(C) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or a monomer having a carboxyl group is subjected to an addition reaction. Let it. (D) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group or a monomer having an aziridinyl group, a monomer having an isocyanate group, or An equimolar adduct of the diisocyanate compound and the hydroxyl group-containing acrylate monomer is subjected to an addition reaction.

The above reaction is preferably carried out while adding a trace amount of a polymerization inhibitor such as hydroquinone and sending dry air. The amount of the radical polymerizable unsaturated group in the side chain of the acrylic resin (a-1) before photocuring is determined by the double bond equivalent (average molecular weight per one side chain radical polymerizable unsaturated group) from the charged value. It is preferable that the calculated value is an average of 1200 g / mol or less from the viewpoint of improving scratch resistance and abrasion resistance.
A more preferable range of the double bond equivalent is an average of 600 g /
mol or less, most preferably an average of 350 g / mo.
1 or less. The lower limit is preferably 1 g / mol or more.

As described above, by introducing a plurality of functional groups involved in crosslinking into the acrylic resin, the cured physical properties can be efficiently improved without causing tackiness even during long-term storage or heat molding described later. It can be improved. The molecular weight of the acrylic resin (a-1) before light curing is
The range of 5,000 to 2,500,000 is preferable,
The range of from 000 to 1,000,000 is more preferred. When insert molding a photocurable sheet formed using the photocurable resin composition (A) containing the acrylic resin (a-1) as the outermost layer, the photocurable sheet is precured at the time of molding and photocured into a molding die. The molecular weight is 5, from the viewpoint that the conductive sheet becomes difficult to stick and the surface hardness of the insert molded product after photo-curing.
It is preferably at least 000. On the other hand, from the viewpoint of ease of synthesis and appearance, and from the viewpoint of developing adhesion to the photocurable resin composition layer on the base sheet (C), the molecular weight is 2,5.
It is preferably not more than 00,000.

The acrylic resin (a-1) before light curing
The glass transition temperature is preferably adjusted to 25 to 175 ° C, more preferably 30 to 150 ° C. The glass transition temperature is preferably 25 ° C. or more from the viewpoints of mold releasability of the photocurable sheet during insert molding and surface hardness of the insert molded product after photocuring. On the other hand, from the viewpoint of handleability of the photocurable sheet, the glass transition temperature is preferably 175 ° C or lower.

In consideration of the glass transition temperature of the obtained acrylic resin copolymer, it is preferable to use a vinyl polymerizable monomer which has a high glass transition temperature as a homopolymer. Further, as described later, as one component of the photocurable resin composition (A), inorganic fine particles (a-
When 3) is used, a group capable of reacting with a functional group on the surface of the inorganic fine particles (a-3), for example, at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a silyl halide group and an alkoxysilyl group. The vinyl polymerizable monomer having a kind of functional group in the molecule functions to further improve the physical properties such as rigidity, toughness, and heat resistance of the obtained photocurable resin composition (A). May be contained as a part of a radical polymerizable vinyl polymerizable monomer component.

Examples of the vinyl polymerizable monomer containing such a reactive group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylic acid, vinyl Trichlorosilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyldimethoxymethylsilane and the like.

The photopolymerization initiator (a-2) used in the present invention includes a photoradical polymerization initiator which generates radicals upon irradiation with light. As the photopolymerization initiator, known compounds can be used, and although not particularly limited, in consideration of yellowing during curing and deterioration during weathering, molecules such as acetophenone, benzophenone, and acylphosphine oxide are used. An initiator having no amino group therein is preferred. For example, 1- (4-dodecylphenyl) -2-
Hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2
(6-Dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide is preferred. It should be noted that some of these may temporarily reach a temperature higher than the boiling point of the compound depending on the molding method. In order to increase the surface hardness of the molded article, an oxygen polymerization-inhibited hardening inhibitor such as n-methyldiethanolamine may be added. In addition to these photopolymerization initiators, various peroxides may be added in consideration of curing using heat during molding. When a peroxide is contained in the photocurable sheet, it is necessary to cure the photocurable sheet at 150 ° C. for about 30 seconds. Therefore, peroxides having a low critical temperature, for example, lauroyl peroxide and t-butylperoxy-2 -Ethylhexanoate, 1,1-bis (t-butylperoxy)-
3,3,5-trimethylcyclohexane and the like are preferably used.

The amount of the photopolymerization initiator (a-2) added is 100 parts by mass of the acrylic resin (a-1) having a radically polymerizable unsaturated group in the side chain, since the residual amount after curing affects weather resistance. 0.1 to 5 parts by mass per part by weight, and in particular, the amino-based radical photopolymerization initiator associated with yellowing during curing is 1
It is desirably less than parts by mass. In the photocurable resin composition (A) used in the present invention, in addition to the acrylic resin (a-1) and the photopolymerization initiator (a-2), which are essential components, a sensitizer, Modifier resins, dyes, pigments, and additives such as leveling agents, repelling inhibitors, ultraviolet absorbers, light stabilizers, and oxidation stabilizers can be added.

The above-mentioned sensitizer accelerates the curing reaction, and examples thereof include benzophenone, benzoin isopropyl ether, and thioxanthone. However, the photocurable resin composition (A) should not substantially contain a crosslinkable compound other than the acrylic resin (a-1). In particular, it should substantially not contain a liquid crosslinkable monomer or oligomer at 40 ° C. or a low molecular weight crosslinkable monomer or oligomer having a molecular weight of 2000 or less. When containing a liquid crosslinkable monomer or oligomer at 40 ° C. or a low molecular weight crosslinkable monomer or oligomer having a molecular weight of 2000 or less,
It becomes tacky during long-term storage or heat molding, causing problems such as problems in the printing process and contamination of the mold during insert molding. More preferably, it should be substantially free of crosslinkable monomers or oligomers that are liquid at 50 ° C.
More preferably, it should be substantially free of crosslinkable monomers or oligomers that are liquid at 60 ° C.

In the photocurable sheet of the present invention, since the photocurable resin composition (A) as described above is laminated so as to be the outermost layer, the surface of the photocurable sheet has no tackiness. Also, the phenomenon that the surface tackiness changes with time does not occur, and the storage stability in a roll state is improved. Further, the photocurable resin composition (A) constituting the outermost layer of the photocurable sheet of the present invention contains an inorganic material especially for the purpose of improving the abrasion resistance, abrasion resistance, and surface hardness of the cured product layer. Fine particles (a-3) may be added.

Inorganic fine particles (a-3) used in the present invention
Is not particularly limited as long as the obtained cured layer of the photocurable resin composition (A) becomes transparent. Examples of the inorganic fine particles include colloidal silica, alumina,
Titanium oxide, tin oxide, tin oxide doped with different elements (AT
O), indium oxide, different element-doped indium oxide (such as ITO), cadmium oxide, and antimony oxide. These may be used alone or in combination of two or more. Among them, colloidal silica is particularly preferable from the viewpoint of availability, price, and transparency and abrasion resistance of the obtained photocurable resin composition layer.

The colloidal silica can be used usually in the form of an aqueous dispersion or a form dispersed in an organic solvent. However, in order to disperse uniformly and stably with the acrylic resin as the component (a-1), It is preferable to use colloidal silica dispersed in an organic solvent. Such organic solvents include methanol, isopropyl alcohol, n-butanol, ethylene glycol, xylene /
Examples thereof include butanol, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl isobutyl ketone, and toluene. Above all, acrylic resin (a-
In order to disperse uniformly with 1), it is preferable to select an organic solvent that can dissolve the acrylic resin (a-1).

As the colloidal silica dispersed in an organic solvent, commercially available products dispersed in a dispersion medium, for example, methanol silica sol MA-ST, isopropyl alcohol silica sol IPA-ST, n-butanol silica sol NBA-ST, Ethylene glycol silica sol E
G-ST, xylene / butanol silica sol XBA-S
T, ethyl cellosolve silica sol ETC-ST, butyl cellosolve silica sol BTC-ST, dimethylformamide silica sol DBF-ST, dimethylacetamide silica sol DMAC-ST, methyl ethyl ketone silica sol MEK-ST, methyl isobutyl ketone silica sol M
IBK-ST (trade name, manufactured by Nissan Chemical Industries, Ltd.) can be used.

The particle size of the inorganic fine particles (a-3) is usually preferably 200 nm or less from the viewpoint of the transparency of the obtained photocurable resin composition (A) layer. It is more preferably 100 nm or less, and further preferably 50 nm or less. The lower limit of the particle diameter is preferably 1 nm or more. The amount of addition of the inorganic fine particles (a-3) depends on the amount of the acrylic resin (a-
1) 5 to 4 parts by weight of inorganic fine particles per 100 parts by mass
The range of 00 parts by mass is preferable, and the range of 10 to 200 parts by mass is particularly preferable. When the addition amount of the inorganic fine particles is less than 5 parts by mass, the effect of improving the abrasion resistance may not be observed, and when the addition amount exceeds 400 parts by mass, the photocurable resin composition (A Not only does the storage stability of ()) decrease, but also the moldability of the resulting photocurable sheet may decrease.

The inorganic fine particles (a) used in the present invention
As -3), a material whose surface has been previously treated with a silane compound represented by the following structural formula (1) may be used. The use of the surface-treated inorganic fine particles is preferable because the storage stability of the photocurable resin composition (A) is further improved, and the surface hardness and weather resistance of the obtained photocurable sheet are also improved.

SiR ¹ _a R ² _b (OR ³ ) _c (1) (wherein, R ¹ and R ² each have an ether bond, an ester bond, an epoxy bond, or a carbon-carbon double bond. R ³ represents a hydrogen atom or an ether bond, an ester bond, an epoxy bond or a carbon-carbon double bond which may have a carbon-carbon double bond. Represents a hydrocarbon residue, a
And b are each an integer of 0 to 3, and c is 4-
ab is an integer of 1-4 that satisfies ab) Among the silane compounds represented by the structural formula (1),
The silane compounds represented by the following structural formulas (2) to (7) are preferred.

SiR ⁴ _a R ⁵ _b (OR ⁶ ) _c (2) SiR ⁴ _n (OCH ₂ CH ₂ OCO (R ⁷ ) C = CH ₂ ) _4-n (3) CH ₂ ＣC (R ⁷ ) COO _{^{(CH 2) p SiR 8 n}} (OR 6) 3-n (4) CH 2 = CHSiR 8 n (OR 6) 3-n (5) HS (CH 2) p SiR 8 n (OR 6) 3-n (6)

[0030]

Embedded image

(Wherein R ⁴ and R ⁵ are each
Represents a hydrocarbon residue having 1 to 10 carbon atoms which may have an ether bond, an ester bond or an epoxy bond;
⁶ represents a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, R ⁷ represents a hydrogen atom or a methyl group, R ⁸ represents an alkyl group or a phenyl group having 1 to 3 carbon atoms, and a and b represent Is an integer of 0 to 3, respectively, and c is 4-a-
b is an integer of 1 to 4 that satisfies b, n is an integer of 0 to 2 and p is an integer of 1 to 6) Examples of the silane compound represented by the structural formula (2) include tetra Methoxysilane, tetraethoxysilane,
Tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,
Phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, methylethyldiethoxysilane, methylphenyldimethoxysilane, trimethylethoxysilane, methoxyethyltriethoxysilane, acetoxyethyltriethoxysilane, diethoxyethyldimethoxysilane , Tetraacetoxysilane, methyltriacetoxysilane, tetrakis (2-methoxyethoxy) silane, γ
-Glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,
4-epoxycyclohexyl) ethyltrimethoxysilane and the like.

Examples of the silane compound represented by the structural formula (3) include tetrakis (acryloyloxyethoxy) silane, tetrakis (methacryloyloxyethoxy) silane, methyltris (acryloyloxyethoxy) silane, and methyltris (methacryloyloxyethoxy) silane. Examples include silane. As the silane compound represented by the structural formula (4), for example, β-acryloyloxyethyldimethoxymethylsilane, γ-acryloyloxypropylmethoxydimethylsilane, γ-acryloyloxypropyltrimethoxysilane, β-methacryloyloxyethyldimethoxy Methylsilane, γ
-Methacryloyloxypropyltrimethoxysilane and the like.

Examples of the silane compound represented by the structural formula (5) include vinyl methyl dimethoxy silane, vinyl trimethoxy silane, and vinyl triethoxy silane. Examples of the silane compound represented by the structural formula (6) include γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, and the like.

Examples of the silane compound represented by the structural formula (7) include p-vinylphenylmethyldimethoxysilane and p-vinylphenyltrimethoxysilane. Such a silane compound is composed of inorganic fine particles (a-
It is preferable to use 0 to 3 parts by mole with respect to 1 part by solid of 3). When the use amount of the silane compound exceeds 3 mol parts, the abrasion resistance of the obtained photocurable sheet may decrease.

The inorganic fine particles surface-treated with the silane compound can be obtained by heating and stirring the silane compound and the inorganic fine particles in the presence of a small amount of water. As a method of adding the inorganic fine particles (a-3) to the acrylic resin (a-1) having a radically polymerizable unsaturated group in a side chain, the acrylic resin (a-1) is synthesized in advance, and then the inorganic fine particles are mixed. Or an arbitrary method such as a method of polymerizing the acrylic resin (a-1) under conditions in which the vinyl polymerizable monomer constituting the acrylic resin (a-1) and the inorganic fine particles are mixed. can do.

In the photocurable sheet of the present invention, two layers of the photocurable resin composition are laminated on the base sheet (C), and the two layers of the photocurable resin composition are laminated. The outermost layer is the layer of the photocurable resin composition (A). The photocurable resin composition (B) layer between the substrate sheet (C) and the outermost layer of the photocurable resin composition (A) is a base sheet (C)
And has sufficient adhesion to the photocurable resin composition (A) layer to such an extent that there is no practical problem, and the workability and storage stability of the photocurable sheet of the present invention, and after photocuring. There is no particular limitation as long as the appearance, design, abrasion resistance, chemical resistance and weather resistance of the sheet are not impaired.

By introducing the photocurable resin composition (B) layer, the photocurable resin composition of the present invention can be used even in a combination of the base sheet (C) and the photocurable resin composition (A) layer, which originally have poor adhesion. This has the advantage that it can be used for a flexible sheet. In particular, when a resin composition (A) having an extremely hard surface hardness after photocuring is used, the difference in the coefficient of thermal expansion between the base material sheet (C) and the cured product layer of the photocurable resin composition (A) is large. The hardness of the cured layer of the photocurable resin composition (B) is adjusted (generally, the base sheet (C) and the photocurable resin composition ( By adjusting the composition in the middle of the cured product layer A), there is also an advantage that a decrease in weather resistance can be prevented.

When a composition which is the same as or similar to the photocurable resin composition (A) is used as the photocurable resin composition (B), the surface properties of the photocurable sheet after photocuring (particularly, adhesion , Weather resistance, appearance, and design) tend to be good. From this, the photocurable resin composition (B) is an acrylic resin having a radical polymerizable unsaturated group in the side chain (b-
It is preferable to include 1) and the photopolymerization initiator (b-2) as essential components. Further, considering the handling and workability when producing the photocurable sheet of the present invention, it is suitable that the surface of the photocurable resin composition (B) layer also has no tackiness. More preferably, the curable resin composition (B) does not substantially contain a crosslinkable compound other than (b-1).

The acrylic resin (b-1) having a radically polymerizable unsaturated group in the side chain and the photopolymerization initiator (b-2) in the photocurable resin composition (B) include the above-mentioned acrylic resin (B). What was mentioned with respect to a-1) and the photoinitiator (a-2) can be used. Inorganic fine particles (b-3) can be used as one component of the photocurable resin composition (B). In that case, as the inorganic fine particles (b-3),
What was mentioned with respect to the above-mentioned inorganic fine particles (a-3) can be used.

The acrylic resin (b-1), the photopolymerization initiator (b-2) and the inorganic fine particles (b-3) in the photocurable resin composition (B) are combined with the photocurable resin composition (A). The acrylic resin (a-1), the photopolymerization initiator (a-2) and the inorganic fine particles (a-3) need not necessarily have the same composition, and the physical properties and light irradiation of the photocurable sheet before light irradiation. It may be appropriately selected within the above-mentioned range in consideration of the physical properties of the later insert molded product.

As the base sheet (C), regardless of whether it is transparent or opaque, a suitable one is selected depending on the method of use. For example, ABS (acrylonitrile / butadiene / styrene copolymer) Resin, AS
(Acrylonitrile / styrene copolymer) resins, vinyl chloride resins, polyolefin resins, polyolefin resins such as polypropylene, fluorine resins, cellophane resins, cellulose resins, polyurethane resins, polyamide resins such as nylon, Examples of the sheet include a polyester resin, a polycarbonate resin, a polyvinyl alcohol resin, an ethylene vinyl alcohol resin, and a soft acrylic resin. In addition, a composite of these sheets, a laminate, or the like can also be used. Among them, a thermoplastic resin sheet having an elongation of 100% or more when heated at 100 ° C. is preferable because the followability to a mold shape during insert molding is improved. Considering the adhesion to the photocurable resin composition (B), weather resistance, transparency, etc.,
More preferably, it is a thermoplastic acrylic resin sheet having a crosslinked rubber component. A transparent thermoplastic acrylic resin sheet having a crosslinked rubber component is disclosed in JP-A-9-26361.
There is a transparent thermoplastic acrylic sheet obtained by extrusion-molding an acrylic resin having a multilayer structure, as disclosed in Japanese Patent Application Laid-Open Publication No. 4 (1999) -174, etc.

In the base sheet (C), lubricating agents such as polyethylene wax and paraffin wax, lubricating agents such as silica, spherical alumina and flaky alumina, benzotriazole, benzophenone system,
UV absorbers such as fine particle cerium oxide, light stabilizers such as hindered amine radical scavengers, plasticizers, stabilizers,
Various additives such as a coloring agent may be added.

The photocurable sheet of the present invention is a laminated sheet in which a photocurable resin composition (B) layer and a photocurable resin composition (A) layer are laminated in this order on a base sheet (C). With such a laminated structure, not only is it excellent in workability during insert molding, but also in various physical properties (especially, weather resistance-abrasion resistance (surface hardness) -adhesion balance). It is possible to provide an insert molded product. Further, between the photocurable resin composition (A) layer and the photocurable resin composition (B) layer, one or more layers are further provided as long as the excellent properties of the photocurable sheet of the present invention are not impaired. Can be laminated. In this case, when one or more layers of the photocurable resin composition to be newly introduced are the same or similar to the photocurable resin composition (A) and the photocurable resin composition (B), Surface properties of the photocurable sheet after photocuring (especially,
Adhesion, weather resistance, appearance, and design) tend to be good, which is preferable.

The method for producing the photocurable sheet of the present invention includes, for example, an acrylic resin (b-1) having a radically polymerizable unsaturated group in a side chain, a photopolymerization initiator (b-2), and further necessary. Accordingly, the photocurable resin composition (B) containing colloidal silica (b-3) and other additives is sufficiently stirred and dissolved in an organic solvent or the like, and dipping, flow coating, spraying, bar coating, Coating on a substrate sheet (C) by a known method such as a gravure coating method, a roll coating method, a blade coating method, an air knife coating method, etc., and drying for removing the solvent. Photocurable resin containing an acrylic resin (a-1) having an unsaturated group, a photopolymerization initiator (a-2), and optionally colloidal silica (a-3) and other additives The product (A) is sufficiently stirred and dissolved in an organic solvent or the like, and similarly coated on the photocurable resin composition (B) layer on the base sheet (C) by a well-known method, to remove the solvent. There is a method of drying to form a laminated sheet.

At this time, before forming the photocurable resin composition (A) layer, the dried photocurable resin composition (B) layer is irradiated with light using an ultraviolet irradiation lamp or the like. The photocurable resin composition (B) layer can also be photocured (completely cured or semi-cured). However, from the viewpoint of improving the adhesion between the photocurable resin composition (A) layer and the photocurable resin composition (B) layer, or improving the workability of the obtained photocurable laminated sheet, The photocurable sheet obtained by laminating the photocurable resin composition (A) layer and the photocurable resin composition (B) layer in an uncured state is insert-molded as described later and then irradiated with light to obtain a photocurable resin. A method of simultaneously photocuring the resin composition (A) layer and the photocurable resin composition (B) layer is preferred.

When coating the photocurable resin composition (B) solution on the base sheet (C) made of polyolefin such as polyethylene or polypropylene, the base sheet and the photocurable resin composition ( In order to increase the adhesion to B), (1) a primer composed of a low molecular weight polyolefin or the like is applied on the base sheet (C) in advance,
Or (2) the base material sheet (C) in advance by corona discharge or the like
The surface is preferably activated (this corona discharge step is preferably immediately before the coating, since the adhesion is high immediately after the activation). Furthermore, it is also possible to laminate a primer layer for the purpose of preventing the photocurable resin composition (B) from contracting in volume upon photocuring, thereby preventing the adhesion to the base sheet (C) from being reduced.

The photocurable sheet of the present invention can be made into a photocurable decorative sheet by providing a printed layer on the substrate sheet (C) side. The printing layer is used to decorate the surface of the insert molded product with patterns, characters, and the like. The decoration is
Although arbitrary, for example, a pattern composed of a wood grain, a stone grain, a cloth grain, a sand grain, a geometric pattern, a character, a solid surface, and the like can be used.
Materials for the printing layer include polyvinyl resins such as vinyl chloride / vinyl acetate copolymers, polyamide resins, polyester resins, polyacrylic resins, polyurethane resins, polyvinyl acetal resins, polyester urethane resins, and cellulose. It is preferable to use a colored ink containing a resin such as an ester resin, an alkyd resin, or a chlorinated polyolefin resin as a binder and a pigment or dye of an appropriate color as a colorant.

As the pigment of the ink used in the printing layer, for example, the following can be used. Usually, as pigments, azo pigments such as polyazo, organic pigments such as isoindolinone and inorganic pigments such as graphite are used as yellow pigments, azo pigments such as polyazo, organic pigments such as quinacridone and red pigments are used as red pigments. Inorganic pigments such as phthalocyanine blue and inorganic pigments such as cobalt blue as blue pigments, organic pigments such as aniline black as black pigments,
As the white pigment, an inorganic pigment such as titanium dioxide can be used.

As the dye of the ink used in the printing layer, various known dyes can be used as long as the effects of the present invention are not impaired. Further, as a printing method of the ink, a known printing method such as an offset printing method, a gravure rotary printing method, a screen printing method, or a known coating method such as a roll coating method or a spray coating method is preferably used. In this case, as in the present invention, instead of using a low-molecular reactive vinyl compound, when using a photocurable resin composition having a configuration in which polymers are crosslinked, there is no stickiness on the surface and printing is not performed. There are few troubles at the time and the yield is good.

Further, as a layer for decorating the surface of the insert molded product, a vapor deposition layer may be provided instead of the printing layer, or both the printing layer and the vapor deposition layer may be provided. The deposited layers are aluminum, nickel, gold, platinum, chromium, iron,
Using at least one metal selected from the group of copper, indium, tin, silver, titanium, lead, zinc, or the like, or an alloy or compound thereof, a vacuum deposition method, a sputtering method, an ion plating method, a plating method, or the like. The method can be used.

The printing layer and the vapor deposition layer for these decorations are:
The thickness may be appropriately selected according to the degree of elongation during insert molding so that a desired surface appearance of the insert molded article is obtained. In addition, the photocurable sheet of the present invention can be a photocurable insert molding sheet in which a printing layer, an adhesive layer, and a primer sheet as required are sequentially formed on the base sheet side. In that case, the preferable thickness range of the sheet for photocurable insert molding is 30 to 75.
0 μm. When the sheet thickness is less than 30 μm,
When deep drawing is performed, the sheet thickness on a curved surface is significantly reduced, and as a result, sheet properties such as abrasion resistance and chemical resistance may be reduced. The sheet thickness is 750μ.
If it exceeds m, the shape followability to the mold may be reduced.

As the adhesive layer, any synthetic resinous material may be used as long as it has a property of enhancing the adhesiveness between the printing layer or the vapor-deposited layer and the molding resin, or between the printed layer or the vapor-deposited layer and the primer sheet. be able to. For example, when the molding resin is a polyacrylic resin, it is preferable to use a polyacrylic resin. When the molding resin is a polyphenylene oxide / polystyrene resin, a polycarbonate resin, a styrene copolymer resin, or a polystyrene blend resin, a polyacryl resin, a polystyrene resin, or a polyamide resin having an affinity for these resins. Etc. may be used. Furthermore, when the molding resin is a polyolefin resin such as a polypropylene resin, a chlorinated polyolefin resin, a chlorinated ethylene-vinyl acetate copolymer resin, a cyclized rubber, a coumarone indene resin, and a heat using block isocyanate. A curable urethane resin or the like can be used. Note that hydrophobic silica, an epoxy resin, a petroleum resin, and the like can be further contained for the purpose of reducing the adhesiveness of the adhesive layer and improving the heat resistance.

The primer sheet is formed as needed, and a known resin such as a urethane resin can be used as the material. In addition, it is preferable to use a material compatible with the molding resin for the purpose of enhancing the adhesion to the molding resin. In practice, the primer sheet is preferably made of a polymer material similar to the molding resin. Also, the presence of the primer sheet offers the advantage of minimizing the propagation of surface defects of the injection molded article onto the surface of the photocurable resin composition. In that case, the primer sheet needs to have a thickness enough to absorb surface defects of the molding resin while exhibiting a completely smooth upper surface of the photocurable resin composition.

Further, the photocurable sheet of the present invention is formed on the photocurable resin composition (A) layer formed on the photocurable resin composition (B) layer on the base sheet (C). In addition, a cover film may be further provided. This cover film is effective in preventing dust on the surface of the photocurable sheet, and also effective in preventing the surface of the photocurable resin composition (A) layer from being damaged before irradiation with active energy rays.

The cover film adheres to the photocurable resin composition (A) layer before insert molding as described later, and is immediately peeled off during insert molding.
It is necessary to have appropriate adhesion to the photocurable resin composition (A) layer and good releasability. If the film satisfies such conditions, any film can be selected and used. Examples of such a film include a polyethylene-based film, a polypropylene-based film, and a polyester-based film.

When a molded product such as an automobile body panel or a spoiler has a large size and a small thickness, a gas generated from the molded resin may remain in the molded resin, or the metal may be damaged. The air in the mold is likely to be interposed between the molding resin and the sheet, which may cause a problem that the adhesiveness of the sheet to the molding resin is reduced. In such a case, the problem can be solved by providing a layer having gas permeability on the sheet surface in contact with the molding resin. Examples of such a gas-permeable layer include a woven or non-woven fabric made of spandex, acrylic fiber, polyethylene fiber, polyamide fiber, or the like. Instead of a woven / non-woven fabric, a foamed layer may be used. Examples of the method for forming the foamed layer include a method in which a known resin solution containing a foaming agent is applied and then foamed by heating or the like to form continuous pores.

Next, a method for producing an insert molded product using the photocurable sheet, the photocurable decorative sheet, or the photocurable insert molding sheet will be described. In the present invention, a step (1) of inserting and arranging the photocurable sheet, the photocurable decorative sheet or the sheet for photocurable insert molding so that the photocurable resin composition side faces the inner wall surface of the mold. Close the mold, inject the molten resin into the mold, and solidify the resin to form a photo-curable sheet, a photo-curable decorative sheet, or a photo-curable insert-molding sheet on the surface of the resin molding. A production method including a step (3) of forming an article and a step (4) of photocuring the photocurable resin composition on the surface of the molded article by irradiating light; Step (1) of inserting and disposing a decorative sheet or a photocurable insert molding sheet such that the photocurable resin composition side faces the inner wall surface of the mold, a photocurable sheet, a photocurable decorative sheet, or photocurable Sex Insa (2) a step of preforming a sheet for molding to make the sheet follow the shape of the mold, closing the mold, injecting a molten resin into the mold, and solidifying the resin to form a photocurable sheet, Step (3) of forming a resin molded product having a curable decorative sheet or a photocurable insert molding sheet disposed on the surface, and light-curing the photocurable resin composition on the molded product surface by irradiating light. An insert molded product can be obtained by a manufacturing method including the step (4).

The above steps (1) to (4) do not necessarily have to be performed in that order.
(3) → (4) and step (1) → (2) → (3) →
It is preferable to perform in the order of (4). When a cover film is provided on a photocurable sheet, a photocurable decorative sheet, or a photocurable insert molding sheet, the cover film is first peeled off from the sheet. The cover film may be peeled off immediately before the sheet is inserted and arranged in the mold, or may be peeled off far before the sheet is inserted and arranged in the mold. However, the former is preferred in consideration of dust prevention and damage prevention of the photocurable resin composition (A) layer before light irradiation.

A photo-curable sheet, a photo-curable decorative sheet or a photo-curable insert molding sheet is inserted and arranged such that the photo-curable resin composition (A) side faces the inner wall surface of the mold (ie, light A state in which the opposite side of the curable resin composition (A) layer is in contact with the molding resin). At this time, a necessary portion may be intermittently fed as a long sheet (while unwinding from a roll), or the sheet may be made into a single sheet and fed one by one. In particular, when using a long sheet having a printed layer or a vapor deposition layer for decoration, use a feeding device having a positioning mechanism so that the register of the layer for decoration and the mold coincide. Good to do. In addition, when the sheet is intermittently fed, if the sheet is fixed after detecting the position of the sheet with the sensor, the sheet can always be fixed at the same position, and the misalignment of the layer for decoration can be prevented. This is convenient because it does not occur.

Then, if necessary, a photocurable sheet,
A light-curable decorative sheet or a light-curable insert molding sheet is preformed. For example, the sheet can be softened to a temperature higher than its softening point by a heating means such as a hot pack, and vacuum-sucked through a suction hole provided in the mold so that the sheet can be preformed by following the shape of the mold. If the sheet is preheated to a temperature lower than the thermal deformation temperature of the sheet before the sheet is inserted and arranged in the mold, the heating time after the sheet is inserted and arranged in the mold can be reduced. , It is possible to improve productivity. In addition, using a three-dimensional processing molding die different from the injection molding die, the sheet is formed by a known molding method such as a vacuum molding method, a pressure molding method, a press molding method for pressing heated rubber, and a press molding method. May be preformed into a desired shape in advance.
Of course, without preforming the sheet, the molding of the sheet and the integration with the molding resin can be performed simultaneously by the injection pressure of the molding resin described later. At this time, the sheet can be preheated and softened in advance.

Thereafter, the mold is closed, the molten molding resin is injected into the cavity, and the resin is solidified to form a photocurable sheet, a photocurable decorative sheet or a photocurable insert molding sheet. A resin molded body disposed on the surface is formed. As the molding resin used in the present invention, any type of resin that can be injection-molded can be used regardless of the type. As such a molding resin, for example, polyethylene-based resin, polypropylene-based resin, polybutene-based resin,
Olefin resins such as polymethylpentene resin, ethylene-propylene copolymer resin, ethylene-propylene-butene copolymer resin, olefin thermoplastic elastomer, polystyrene resin, ABS (acrylonitrile / butadiene / styrene copolymer) ) -Based resin, AS
General-purpose thermoplastic or thermosetting resins such as (acrylonitrile / styrene copolymer) resin, acrylic resin, urethane resin, unsaturated polyester resin, epoxy resin and the like can be mentioned. In addition, general-purpose engineering resins such as polyphenylene oxide / polystyrene resin, polycarbonate resin, polyacetal resin, polycarbonate-modified polyphenylene ether resin, polyethylene terephthalate resin, polysulfone resin, polyphenylene sulfide resin, polyphenylene oxide resin, polyether A super engineering resin such as an imide resin, a polyimide resin, a liquid crystal polyester resin, and a polyallyl heat resistant resin can also be used. Further, a reinforcing resin such as glass fiber or an inorganic filler (such as talc, calcium carbonate, silica, and mica), a composite resin to which a modifier such as a rubber component is added, and various modified resins can be used. In addition, by approximating the shrinkage ratio of the molding resin after molding to the shrinkage ratio of the sheet,
This is preferable because problems such as warpage of the insert molded product and peeling of the sheet can be solved.

Finally, after the insert molded product is taken out of the mold, the photocurable resin composition on the surface of the molded product is photocured by light irradiation. The irradiation light may include an electron beam, ultraviolet light, γ-ray, and the like. Irradiation conditions are determined according to the photocurable properties of the photocurable resin composition (A) layer and the photocurable resin composition (B) layer, and the irradiation amount is usually about 500 to 2,000 mJ / cm ^2. It is. Thereby, the photocurable resin composition (A) and the photocurable resin composition (B) are cured by light irradiation, and an insert molded article having a hard film formed on the surface can be obtained.

Unnecessary portions of the photocurable sheet, the photocurable decorative sheet or the photocurable insert molding sheet adhered to the insert molded product are trimmed and removed as necessary. This trimming can be performed after the sheet is inserted and arranged in the mold, before light irradiation on the insert molded product, or after light irradiation. As a trimming method, a known method such as a method of irradiating a sheet by irradiating a laser beam or the like, a method of manufacturing a punching die for trimming and punching the sheet by press working, a method of manually removing the sheet by tearing the sheet, or the like is used. It can be carried out.

Although the production method using injection molding has been described as a method for producing an insert molded product, it is also possible to use blow molding instead of injection molding. Further, the photocurable insert molding sheet of the present invention,
Alternatively, when a molded article decorated with a photocurable decorative sheet or a photocurable insert molding sheet is mainly used outdoors, an ultraviolet absorber or a light stabilizer can be added to the sheet. As the ultraviolet absorber, an organic substance such as benzotriazole, benzophenone, and salicylate, or an inorganic substance such as zinc oxide, cerium oxide, and titanium oxide having a particle diameter of 0.2 μm or less can be used. As the light stabilizer, bis (2,2,2)
Radical scavengers such as hindered amine radical scavengers such as 6,6-tetramethyl-4-piperidinyl) sebacate and piperidine radical scavengers can be used.

The molded product thus obtained is given a color or a design at the same time as the molding, and furthermore, by short-time light irradiation, the abrasion resistance, chemical resistance, weather resistance and the like are improved. Furthermore, compared with the conventional spray coating after molding, the process can be shortened, the yield can be improved, and the influence on the environment can be reduced. Further, the photocurable sheet of the present invention has already been used. It can also be used by laminating directly onto an injection molded resin or via an adhesive layer and laminating it on the surface of an injection molded product.

[0066]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. In the examples, “parts” means “parts by mass”. Synthesis Example 1 (Synthesis of acrylic resin I as component (a-1) or (b-1)) In a 1-L four-necked flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer, methyl ethyl ketone (hereinafter, MEK) was added. 50 parts), and the temperature was raised to 80 ° C. In a nitrogen atmosphere, a mixture of 19 parts of methyl methacrylate (hereinafter abbreviated as MMA), 81 parts of glycidyl methacrylate (hereinafter abbreviated as GMA), and 0.5 part of azobisisobutyronitrile (hereinafter abbreviated as AIBN) was added to 3 parts.
It was dropped over time. Then, MEK80 part and AIBN
0.2 parts of the mixture was added and polymerized. 4 hours later, ME
K50 parts, hydroquinone monomethyl ether (hereinafter, referred to as
0.5 part of MEHQ), 2.5 parts of triphenylphosphine, and acrylic acid (hereinafter abbreviated as AA) 4
0.6 part was added, and the mixture was stirred at 80 ° C. for 30 hours while blowing air. Thereafter, after cooling, the reaction product was taken out of the flask to obtain a solution of an acrylic resin I having a radically polymerizable unsaturated group in a side chain.

The polymerization rate of the monomer in the acrylic resin I is 99.5% or more, the solid content of the polymer is about 44% by mass, the number average molecular weight is about 54,000, and the glass transition temperature is about 4%.
At 1 ° C, the double bond equivalent was 249 g / mol on average. Synthesis Example 2 (Synthesis of acrylic resin II as component (a-1) or (b-1)) MEK50 was placed in a 1-L four-necked flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer.
And heated to 80 ° C. GMA1 under nitrogen atmosphere
A mixture of 00 parts and 0.5 parts of AIBN was added dropwise over 3 hours. Thereafter, a mixture of 80 parts of MEK and 0.2 parts of AIBN was added and polymerized. 4 hours later, MEK 50 parts, ME
0.5 part of HQ, 2.5 parts of triphenylphosphine and 50.1 parts of AA are added, and the mixture is blown at 80 ° C. while blowing air.
For 30 hours. Thereafter, after cooling, the reaction product was taken out of the flask to obtain a solution of an acrylic resin II having a radically polymerizable unsaturated group in a side chain.

The polymerization rate of the monomer in the acrylic resin II is 99.5% or more, the polymer solid content is about 46% by mass, the number average molecular weight is about 500000, the glass transition temperature is about 32 ° C. Heavy bond equivalents averaged 216 g / mol. Synthesis Example 3 (Synthesis of acrylic resin III as component (a-1) or (b-1)) MEK5 was placed in a 1-L four-necked flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer.
0 parts were added and the temperature was raised to 80 ° C. MMA under nitrogen atmosphere
A mixture of 67.8 parts, 32.2 parts of GMA and 0.5 part of AIBN was added dropwise over 3 hours. Thereafter, a mixture of 80 parts of MEK and 0.2 parts of AIBN was added and polymerized. After 4 hours, 50 parts of MEK, 0.5 parts of MEHQ, 2.5 parts of triphenylphosphine and 16.1 parts of AA were added, and the mixture was stirred at 80 ° C for 30 hours while blowing air. afterwards,
After cooling, the reaction product was taken out of the flask to obtain a solution of an acrylic resin III having a radically polymerizable unsaturated group in a side chain.

The conversion of the monomer in the acrylic resin III is 99.5% or more, and the solid content of the polymer is about 40%.
% By mass, number average molecular weight was about 60,000, glass transition temperature was about 77 ° C., and double bond equivalent was 519 g / mol on average. Synthesis Example 4 (Synthesis of acrylic resin IV as component (a-1) or (b-1)) MEK50 was placed in a 1-L four-necked flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer.
And heated to 80 ° C. MMA2 under nitrogen atmosphere
0.4 parts, 2-hydroxyethyl methacrylate
A mixture of 6 parts and 0.5 part of AIBN was added dropwise over 3 hours. Thereafter, a mixture of 80 parts of MEK and 0.2 parts of AIBN was added and polymerized for 4 hours. Then, after lowering the temperature to 60 ° C., 50 parts of MEK, 0.5 part of MEHQ, 0.05 parts of dibutyltin dilaurate, and 93.9 of 2-methacryloyloxyethyl isocyanate (trade name Karenz MOI, manufactured by Showa Denko KK). The mixture was stirred at 60 ° C. for 30 hours while blowing air. Then, after cooling,
The reaction product was taken out of the flask to obtain a solution of an acrylic resin IV having a radically polymerizable unsaturated group in a side chain.

The polymerization rate of the monomer in the acrylic resin IV is 99.5% or more, the solid content of the polymer is about 52% by mass, the number average molecular weight is about 32,000, the glass transition temperature is about 31 ° C. Heavy bond equivalents averaged 320 g / mol. Synthesis Example 5 (Synthesis of acrylic resin V as component (a-1) or (b-1)) A 1 L four-necked flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer was placed under a nitrogen atmosphere. , 3,4-epoxycyclohexylmethyl methacrylate (100 parts), MEK (60 parts) and AIBN (0.3 part) were added, the temperature of the hot water bath was raised to 75 ° C. while stirring, and polymerization was carried out at that temperature for 2 hours. Then, 0.7 parts of AIBN
After adding 5 times at regular intervals, the temperature inside the flask was raised to the boiling point of the solvent, and polymerization was continued at that temperature for 2 hours. Thereafter, after the temperature in the flask became 50 ° C. or lower, 90 parts of MEK was added, and the polymerization reaction product was taken out of the flask to obtain a solution of acrylic resin V.

The polymerization rate of the monomer in the acrylic resin V is 99.5% or more, the polymer solid content is about 40% by mass, the number average molecular weight is about 30,000, and the glass transition temperature is about 73 ° C.
Met. Example 1 of surface treatment of colloidal silica (Preparation of surface-treated colloidal silica S1)

[0072]

[Table 1]

Note) Numerical values are mol parts in terms of solid content. 1) MEK-ST: MEK-dispersed colloidal silica sol (manufactured by Nissan Chemical Industries, Ltd.), silica particle diameter = 15 nm 2) KBM503: γ-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), molecular weight = 248 The components shown in Table 1 were placed in a flask equipped with a stirrer, a condenser and a thermometer, and the temperature of the hot water bath was raised to 75 ° C. with stirring, and the mixture was allowed to react at that temperature for 2 hours. As a result, colloidal silica S1 whose surface was treated with a silane compound was obtained.

Example 2 of surface treatment of colloidal silica (Preparation of surface-treated colloidal silica S2)

[0075]

[Table 2]

Note) Numerical values are molar parts in terms of solid content. 1) IPA-ST: isopropanol-dispersed colloidal silica sol (manufactured by Nissan Chemical Industries, Ltd.), silica particle diameter = 1
5 nm 2) KBM503: γ-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), molecular weight = 248 A flask equipped with a stirrer, a condenser and a thermometer was charged with the components shown in Table 2 above and stirred. The temperature of the hot water bath was raised to 75 ° C. while reacting at that temperature for 2 hours to obtain colloidal silica dispersed in isopropanol and the surface of which was treated with a silane compound. continue,
By repeating the addition of toluene after distilling off isopropanol, and completely replacing isopropanol with toluene, colloidal silica S2 dispersed in toluene and having a surface treated with a silane compound was obtained.

Examples 1 to 6 and Comparative Examples 1 to 7 Using the acrylic resins I to V and the surface-treated colloidal silicas S1 and S2 synthesized by the above-described methods, photocurable resins for the outermost layer and the inner layer were used. The solution, respectively,
It was prepared to have the compositions shown in Tables 3 and 4.

[0078]

[Table 3]

Note) Numerical values are parts by weight in terms of solid content. 1) trimethylolpropane triacrylate 2) 1-hydroxycyclohexyl phenyl ketone 3) triphenylsulfonium hexafluoroantimonate

[0080]

[Table 4]

Note) Numerical values are parts by weight in terms of solid content. 1) Trimethylolpropane triacrylate 2) 1-Hydroxycyclohexylphenyl ketone 3) Triphenylsulfonium hexafluoroantimonate The composition solutions for the inner layer prepared in Examples and Comparative Examples were each stirred with a propeller type mixer, The sheet contains a crosslinked rubber component, is applied on a transparent soft acrylic sheet having a thickness of 125 μm, and has a coating width of 350 mm, and is then dried using a hot air drier to form a photocurable resin layer (inner layer) having a thickness of 8 μm. did. Next, the composition solutions for the outermost layer prepared in Examples and Comparative Examples were each stirred with a propeller-type mixer, and applied on the previously formed photocurable resin layer (inner layer) with a coating width of 350 mm. It dried using the hot-air dryer, and formed the photocurable resin layer (outermost layer) of 8 micrometers in thickness, and produced the photocurable sheet. Then, width 300
It was slit in mm and wound up in a roll shape around an ABS core to a length of 20 m. When the elongation at break of only the transparent soft acrylic sheet was measured by Tensilon, the elongation at break when heated at 100 ° C. was 260%.

After storage in a roll at room temperature for about 2 weeks, the surface was evaluated for adhesiveness while being unwound. The results are shown in Tables 5 and 6. The photocurable sheet is placed in a mold so that the outermost layer of the photocurable resin composition faces the inner wall surface of the mold.
After preheating the sheet at 10 ° C. for 10 seconds, the sheet was made to follow the mold by vacuum suction while further heating. In addition, the shape of this mold is a truncated pyramid shape,
The size of the truncated surface is 100 mm × 100 mm, the size of the bottom surface is 108 mm × 117 mm, the depth is 10 mm, and the radii of curvature of the ends of the truncated surface are 3, 5, 7, 1 respectively.
0 mm. The followability of the mold at that time was visually evaluated, and it was found that each end portion followed well.

Then, under conditions of a molding temperature of 280 ° C. to 300 ° C. and a mold temperature of 40 ° C. to 60 ° C., insert molding is performed using a polycarbonate resin as a molding resin. The obtained insert molded product was obtained. Dirt on the molding die at this time was visually evaluated. The results are shown in Tables 5 and 6. Next, ultraviolet light of about 700 mJ / cm ² was irradiated using an ultraviolet irradiation device to cure the photocurable resin compositions of the outermost layer and the inner layer, and the surface properties were evaluated. The results are shown in Tables 5 and 6.

Evaluation Method of Physical Properties of Insert Molded Product Acid resistance: A 47 mass% sulfuric acid aqueous solution was spot-tested at 40 ° C. for 3 hours, and the appearance was visually evaluated. ：: good Δ: thin trace ×: significant trace Warm water resistance: The surface state of the molded product after immersion in hot water of 80 ° C. for 24 hours was visually evaluated.

：: good Δ: light whitening X: remarkable whitening Transparency: Total light transmittance and haze were measured using a haze meter according to ASTM D1003.

Abrasion resistance: Taber abrasion test (500 on one side)
g load, using CS-10F wear wheel, rotation speed 60 rpm
m, the number of tests was 500, and the haze value was measured with a haze meter. The numerical value represented by (haze value after test)-(haze value before test) was shown as abrasion resistance (%). Weather resistance: Using a sunshine weather meter (manufactured by Suga Test Instruments), a cycle of drying for 48 minutes and raining for 12 minutes results in 150.
The appearance at the time of exposure test for 0 hours and 2000 hours was visually evaluated.

：: good ×: whitened or cracked

[0088]

[Table 5]

1) ○: no adhesiveness, Δ: adhesiveness, ×: large adhesiveness,
Unwinding not possible 2) ○: no dirt, Δ: slight dirt, ×: large dirt 3) The molded products of Examples 1 to 7 obtained by insert-molding only a soft acrylic film having no photocurable resin layer The abrasion resistance was 50%.

[0090]

[Table 6]

1) ○: no adhesiveness, Δ: adhesiveness, ×: large adhesiveness,
Unwinding is not possible 2) ○: No dirt, Δ: Slight dirt, ×: Large dirt 3) For the molded products of Comparative Examples 1 to 7, which were formed by insert molding only a soft acrylic film having no photocurable resin layer. The abrasion resistance was 50%. Example 7 In the same manner as in Example 1, on the transparent soft acrylic sheet (containing a crosslinked rubber component, 125 μm in thickness) as a base sheet, inner layer 2, inner layer 1, each having the composition shown in Table 7, were prepared.
The three outermost layers were sequentially laminated in this order to produce a photocurable sheet.

Using the obtained photocurable sheet, Example 1
Insert molding was performed in the same manner as described above, and various physical properties were evaluated. Table 5 shows the results.

[0093]

[Table 7]

Note) Numerical values are parts by weight in terms of solid content. 1) 1-Hydroxycyclohexyl phenyl ketone Examples 8 to 13 Each of the composition solutions for the inner layer prepared in Examples 1 to 6 was stirred with a propeller type mixer, containing a crosslinked rubber component as a base sheet, and having a thickness of 200 µm. It was applied on a transparent soft acrylic sheet with a coating width of 350 mm, and then dried using a hot air drier to form a 15 μm-thick photocurable resin layer (inner layer). Next, each of the composition solutions for the outermost layer prepared in Examples 1 to 6 was stirred with a propeller type mixer, and a coating width of 3 was applied on the photocurable resin layer (inner layer) formed earlier.
It was applied with a thickness of 50 mm, and then dried using a hot air drier to form a 15 μm-thick photocurable resin layer (outermost layer), thereby producing a photocurable sheet. Then, width 300mm
And wound up in a roll shape around an ABS core to a length of 20 m. When the elongation at break of only the transparent soft acrylic sheet was measured by Tensilon, the elongation at break when heated at 100 ° C. was 400%.

Next, a pattern is printed by a gravure printing method on the transparent soft acrylic sheet surface of each photocurable insert molding sheet using an ink composed of black, brown, and yellow pigments, and then the photocurable insert molding is performed. Sheet was obtained. Since the sheets of Examples 8 to 13 have no tackiness,
The printability was good. The thickness of the sheet was 233 μm.

The sheet for photocurable insert molding was
The photocurable resin composition is placed in the mold so as to face the inner wall surface of the mold, and then heated to a temperature of 300 by an infrared heater.
After preheating the sheet at 15 ° C. for 15 seconds, the sheet was made to follow the mold shape by vacuum suction while further heating. Next, under conditions of a molding temperature of 220 to 250 ° C. and a mold temperature of 40 to 60 ° C., insert molding is performed using an acrylonitrile / butadiene / styrene copolymer resin as a molding resin to form a photocurable insert molding sheet. An insert molded product closely contacting the product surface was obtained.

Then, using an ultraviolet irradiation device, about 70
The photocurable resin compositions of the outermost layer and the inner layer were cured by irradiating ultraviolet rays of 0 mJ / cm ² to obtain a molded article having high surface hardness, excellent gloss, and excellent design because of having a printed pattern. Examples 14 to 19 Each of the composition solutions for the inner layer prepared in Examples 1 to 6 was stirred with a propeller type mixer, and coated on a 200 μm-thick transparent soft acrylic sheet containing a crosslinked rubber component as a base sheet. It was applied with a width of 350 mm and then dried using a hot-air drier to form a 15 μm-thick photocurable resin layer (inner layer). Next, each of the composition solutions for the outermost layer prepared in Examples 1 to 6 was stirred with a propeller type mixer, and a coating width of 3 was applied on the photocurable resin layer (inner layer) formed earlier.
It was applied with a thickness of 50 mm, and then dried using a hot air drier to form a 15 μm-thick photocurable resin layer (outermost layer), thereby producing a photocurable sheet. Then, width 300mm
And wound up in a roll shape around an ABS core to a length of 20 m. When the elongation at break of only the transparent soft acrylic sheet was measured by Tensilon, the elongation at break when heated at 100 ° C. was 400%.

Next, a pattern was printed on the surface of the transparent soft acrylic sheet by a gravure printing method using an ink composed of black, brown, and yellow pigments. Since this sheet had no tackiness, the printability was good. Furthermore, an adhesive layer made of chlorinated polypropylene resin (chlorination degree 15%)
After being formed on the printing surface by gravure printing, a photocurable insert molding sheet was obtained. Sheet thickness is 25
It was 5 μm.

The sheet for photocurable insert molding was
The photocurable resin composition is placed in the mold so as to face the inner wall surface of the mold.
After preheating the sheet for 5 seconds, the sheet was made to follow the mold by vacuum suction while further heating. Next, a molding temperature of 200 to 240 ° C and a mold temperature of 30 to
Under the condition of 60 ° C., a polypropylene resin (containing 20% by mass of talc, ethylene-propylene rubber
(% By mass) was used as a molding resin to obtain an insert molded product in which the photocurable insert molding sheet was in close contact with the surface of the molded product.

Then, using an ultraviolet irradiation device, about 70
The photocurable resin composition is cured by irradiating ultraviolet rays of 0 mJ / cm ² , and has high surface hardness and abrasion resistance, excellent gloss,
A molded article having a printed pattern and excellent in design was obtained.

[0101]

As described above, according to the present invention,
A non-adhesive photocurable printing sheet capable of printing colors or designs can be easily obtained, and by using it at the same time as injection molding, the design of colors or designs on the resin molded product can be obtained. With good appearance, abrasion resistance,
A surface with weather and chemical resistance can be formed, instrument panels, console boxes, meter covers, door lock pezels, steering wheels, power window switch bases, center clusters, dashboards and other automotive interior materials, weather strips, bumpers, Bumper guard, side mudguard,
Windows, head lamp covers, body panels, spoilers, front grills, strut mounts, wheel caps, center pillars, door mirrors, center ornaments, side moldings, door moldings, wind moldings, etc.
Automotive exterior materials such as tail lamp covers and windshield parts,
Applications such as front panels, buttons, emblems, surface cosmetics for AV equipment and home appliances, housings for mobile phones, etc.
Applications such as display windows and buttons, as well as exterior materials for furniture,
Architectural interior materials such as walls, ceilings, floors, etc., exterior walls such as sidings, fences, roofs, gates, architectural exterior materials such as gable boards, window frames, doors, handrails, sills, Kamoi, etc. Cosmetic materials, various displays, lenses, mirrors, goggles, window glass and other optical members, or trains, aircraft, ships and other vehicles other than automobiles, interior / exterior materials,
It can be suitably used for various packaging containers and materials such as bottles, cosmetic containers and accessories, and other various uses such as miscellaneous goods such as prizes and accessories. In addition, a surface having good abrasion resistance, weather resistance and chemical resistance can be formed on the transparent resin while utilizing its transparency, and it can be used for automobiles, railway vehicles,
It can be suitably used for windows of airplanes, headlamp covers, windshield parts and the like. Further, the number of steps can be reduced, the productivity is good, and the influence on the environment is small as compared with the case where the surface of the molded article is painted.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // C08F 299/00 C08F 299/00 B29K 105: 20 B29K 105: 20 B29L 9:00 B29L 9:00 (72) Invention Person Yoko Kadono 20-1 Miyuki-cho, Otake City, Hiroshima Prefecture F-term in Central Research Laboratory, Mitsubishi Rayon Co., Ltd. CA30B CA30C DE01B DE01C EH362 EH66E GB07 GB32. BA04 BA06 BA07 BA08 BA26 CA18 CB10 CC03 CC05 CC06 CD01 CD04

Claims (13)

[Claims] 1. A base sheet (C) and a base sheet (C)
In the photocurable sheet including the two layers of the photocurable resin composition laminated thereon, the outermost layer of the two layers of the photocurable resin composition has the following photocurable resin composition (A A) a photo-curable sheet, Photocurable resin composition (A): Crosslinking other than (a-1), including acrylic resin (a-1) having a radical polymerizable unsaturated group in a side chain and photopolymerization initiator (a-2). A photocurable resin composition containing substantially no curable compound. 2. The photocurable sheet according to claim 1, wherein the photocurable resin composition (A) further contains inorganic fine particles (a-3). 3. The photocurable sheet according to claim 1, wherein the inorganic fine particles (a-3) are colloidal silica. 4. The photocurable resin composition layer in contact with the base sheet (C) is a layer of the following photocurable resin composition (B).
The photocurable sheet according to claim 1. Photocurable resin composition (B): a photocurable resin composition containing an acrylic resin (b-1) having a radically polymerizable unsaturated group in a side chain and a photopolymerization initiator (b-2). 5. The photocurable resin composition (B) is substantially free of a crosslinkable compound other than the acrylic resin (b-1) having a radically polymerizable unsaturated group in a side chain. The photocurable sheet according to any one of the above. 6. The photocurable sheet according to claim 1, wherein the photocurable resin composition (B) further contains inorganic fine particles (b-3). 7. The photocurable sheet according to claim 1, wherein the inorganic fine particles (b-3) are colloidal silica. 8. A photocurable decorative sheet comprising a printed layer and / or a vapor deposited layer applied to the substrate sheet (C) side of the photocurable sheet according to claim 1. 9. Photocurable insert molding comprising a printed layer and / or a vapor deposited layer and an adhesive layer formed on the substrate sheet (C) side of the photocurable sheet according to claim 1. Sheet. 10. A photocurable composition comprising a print layer and / or a vapor deposited layer, an adhesive layer and a primer sheet formed on the substrate sheet (C) side of the photocurable sheet according to claim 1. Insert molding sheet. 11. The photocurable sheet, the photocurable decorative sheet or the photocurable insert molding sheet according to any one of claims 1 to 10, wherein the photocurable resin composition side is attached to an inner wall surface of a mold. Step (1) of inserting and arranging to face each other,
Close the mold, inject the molten resin into the mold, and solidify the resin to form a resin molded product on the surface of which a photocurable sheet, a photocurable decorative sheet, or a photocurable insert molding sheet is disposed. And a step (4) of photocuring the photocurable resin composition on the surface of the molded article by light irradiation. 12. The photocurable sheet, the photocurable decorative sheet or the photocurable insert molding sheet according to any one of claims 1 to 10, wherein the photocurable resin composition side is provided on an inner wall surface of a mold. Step (1) of inserting and arranging to face each other,
Step (2) of preforming a photocurable sheet, a photocurable decorative sheet, or a photocurable insert molding sheet to make the sheet follow the shape of the mold, closing the mold and placing the molten resin in the mold Injecting and solidifying the resin to form a resin molded product having a photocurable sheet, a photocurable decorative sheet or a photocurable insert molding sheet disposed on the surface (3), and irradiating light A method for producing an insert molded product, comprising a step (4) of photocuring the photocurable resin composition on the surface of the molded product according to (4). 13. An insert molded article obtained by the method according to claim 11.