JP4293886B2 - Photocurable resin composition, photocurable sheet using the same, and method for producing molded article using the same - Google Patents

Description

The present invention relates to a photocurable sheet and a method for producing a molded product thereof. Specifically, the present invention is a photocurable sheet having excellent appearance, designability, abrasion resistance, chemical resistance and weather resistance, and having no surface tackiness, and a method for producing a molded article using the sheet. About.

  As a method of decorating the surface of a plastic product at the same time as molding, (1) a method of pre-patterning the inner surface of the mold, (2) mounting a transfer film on the inner wall surface of the mold, A method of transferring a pattern or the like to the outer surface of a molded product, (3) a method of pasting a functional sheet or printed sheet on the inner wall surface of a mold, and affixing the sheet to the surface of the molded product at the same time as molding are proposed. ing. For the method (2) or (3), after forming a weather resistance imparting sheet or printed sheet on the inner wall surface of the mold, a molded product whose surface is covered with the sheet is manufactured by injection molding a molding resin. (For example, refer to Patent Documents 1, 2, and 3).

  However, in the above technique, the decoration and functionality are imparted by a thermoplastic sheet or printing transfer, so that the surface hardness of the obtained molded product is insufficient. For example, when weather resistance is imparted to a molded product, 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. As a countermeasure, when trying to obtain a molded product having a high surface hardness, it is conceivable to use a pre-crosslinked sheet having a high surface hardness. The problem is that it is difficult to apply.

  As means for improving these drawbacks, methods of applying a hard coat treatment to the surface of a resin molded product and methods of attaching a hard coat sheet to each other have been studied. For example, on the surface of a molded resin molded product, an acrylate-based or silicone-based material for forming a cross-linked film is applied by a dip coating method, a spray coating method, or the like, and subjected to a hard coat treatment that is cured by energy such as ultraviolet rays or heat. There exist methods (see, for example, Patent Documents 4 and 5). However, in the method of performing a hard coat treatment on the surface of these resin molded products, there are problems such as difficult application due to the shape of the molded product, appearance defects due to dust during application, and low productivity.

  In addition, a method has been proposed in which a polycarbonate sheet with a hard coat treatment on one side is mounted in a mold and another resin is laminated and integrated by injection molding to improve the surface hardness of the resin (for example, a patent) References 6 and 7). However, since this method applies a hard coat treatment to the polycarbonate sheet, there is a problem that a primer or an adhesive layer made of an acrylic resin or the like is required in a separate process, and the process becomes complicated. Since a sheet having a high surface hardness is used, it is difficult to apply to a molded product having a three-dimensional shape, and there is a problem that chemical resistance is poor in terms of performance.

  Therefore, there is provided a photocurable sheet obtained by laminating a photocurable resin layer formed of a resin composition containing an acrylic resin, a compound having a reactive vinyl group, and a photopolymerization initiator and a sheet substrate (B). It has been proposed (see, for example, Patent Document 8). However, since this photocurable sheet contains a compound having a low molecular weight reactive vinyl group in the sheet before photocuring, the surface has adhesiveness, or the adhesiveness of the surface changes with time. Such a phenomenon occurs, and the storage stability in the roll state is poor. Specifically, there are problems such as sticking out and unwinding, and exudation of compounds from both ends unless stored at low temperature, and furthermore, due to its stickiness, there are problems in the printing process when used as a printing sheet. Arise.

Under the circumstances as described above, the present inventors previously made photocuring of a specific composition that realized excellent moldability before photocuring and excellent surface properties (hardness, weather resistance, etc.) after photocuring at a high level. The resin composition and the photocurable sheet comprising the composition were developed (see, for example, Patent Documents 9 and 10).
Usually, these photocurable sheets are produced by coating a mixed solution containing a photocurable resin composition and a solvent on the base sheet (B), followed by heating and drying to volatilize the solvent. Moreover, it can also be set as a photocurable decorating sheet by forming a printing layer etc. in the back surface of a base material sheet (B).
These photo-curable sheets and photo-curable decorative sheets are suitably used for automotive interior / exterior materials such as center pillars, side moldings, door moldings, console boxes, etc., but such as bumpers, spoilers, wheel caps, etc. In applications in which asphalt powder, sand, mud, and the like are often struck up, there may be a problem that the photocurable resin composition layer is peeled off from the base sheet (B).

JP-A-60-250925 Japanese Patent Publication No.59-36841 Japanese Patent Publication No. 8-2550 Japanese Patent Laid-Open No. 52-12647 Japanese Patent Publication No.56-92059 Japanese Patent Publication No. 4-21588 Japanese Patent Publication No.8-309790 Japanese Patent Publication No.7-323 JP 2002-79621 A JP 2002-80550 A

The object of the present invention is to improve the characteristics of the photocurable resin composition and the photocurable sheet proposed in Patent Documents 9 and 10, and to improve the design, wear resistance, weather resistance, chemical resistance, workability, Is to obtain a photocurable sheet or a molded product thereof having further excellent characteristics such as storage stability.

In order to solve the above-mentioned problems, the present inventors have further advanced material development research, and as a result, a photocurable resin composition comprising a specific composition containing a thermoplastic resin having a radically polymerizable unsaturated group in the side chain. Has been found to be extremely excellent as a material for a photocurable sheet and its molded product, and has led to the completion of the present invention.
That is, the present invention is a radical polymerization of a side chain obtained by using a (meth) acrylate monomer as a main component on a base sheet (B) which is a thermoplastic acrylic resin sheet having a crosslinked rubber component. Number average molecular weight (Mn) of the thermoplastic resin (a-1) in the photocurable resin composition containing the thermoplastic resin (a-1) having a polymerizable unsaturated group and the photopolymerization initiator (a-2) A layer (A) of the photocurable resin composition, wherein 5,000 to 2,500,000 and the weight average molecular weight (Mw) / number average molecular weight (Mn) is 5 or less. A photocurable sheet is provided.

Further, the present invention provides a photocurable decorative sheet in which any one or more of a printed layer, a vapor deposition layer, an adhesive layer, and a primer sheet are formed on the base sheet (B) side of the photocurable sheet. provide.

Furthermore, the present invention includes a step of inserting and arranging a photocurable sheet or a photocurable decorative sheet so that the photocurable resin composition side faces the inner wall surface of the mold, closing the mold, and A step of forming a resin molded product in which a photocurable sheet or a photocurable decorative sheet is arranged on the surface by injecting into a mold and solidifying the resin, and a photocurable resin on the surface of the molded product by light irradiation Provided is a method for producing a molded article comprising a step of photocuring the composition.
The present invention also includes a step of inserting and arranging a photocurable sheet or a photocurable decorative sheet so that the photocurable resin composition side faces the inner wall surface of the mold, the photocurable sheet or the photocurable decorative sheet. A step of preforming the sheet to follow the shape of the mold, closing the mold, injecting the molten resin into the mold, and solidifying the resin, photocurable sheet, photocurable decorative sheet or Provided is a method for producing a molded product including a step of forming a resin molded product having a photocurable decorative sheet disposed on the surface and a step of photocuring the photocurable resin composition on the surface of the molded product by light irradiation. To do.

The present invention also includes a step of inserting a photocurable sheet or a photocurable decorative sheet into a preforming mold so that the photocurable resin composition side faces the inner wall surface of the mold, a photocurable sheet Alternatively, a step of preforming a photocurable decorative sheet and causing the sheet to follow the shape of the mold, a preformed photocurable sheet or a photocurable decorative sheet, the photocurable resin composition side is the inner wall surface of the mold The step of inserting and arranging in the molding die so as to face each other, closing the molding die, injecting the molten resin into the die, solidifying the resin, the photocurable sheet or the photocurable decorative sheet is Provided is a method for producing a molded article comprising a step of forming a resin molded article disposed on the surface and a step of photocuring the photocurable resin composition on the surface of the molded article by light irradiation.
Furthermore, the present invention provides a molded product obtained by each of the above production methods.

  According to the present invention, a layer of a photocurable resin composition (A) containing a thermoplastic resin (a-1) having a photopolymerizable functional group in the side chain and a photopolymerization initiator (a-2), and a group It is a photocurable sheet comprising the material sheet (B), and the number average molecular weight (Mn) of the thermoplastic resin (a-1) is 5,000 to 2,500,000, and the weight average molecular weight (Mw) ) / Adopting a photocurable resin composition having a number average molecular weight (Mn) of 5 or less, the adhesion between the layer of the photocurable resin composition and the substrate sheet (B) is good and excellent. Various physical properties (abrasion resistance, weather resistance, chemical resistance, workability, storage stability, appearance, etc.) can be expressed, and in particular, high-level adhesion between the cured resin layer and the substrate is required. Photo-curable sheet that can be used for automobile exterior materials, such as bumpers, spoilers, wheel caps, etc. It is possible to provide.

Hereinafter, preferred embodiments of the present invention will be sequentially described.
The photocurable resin composition (A) used in the present invention includes a thermoplastic resin (a-1) having a radically polymerizable unsaturated group in the side chain, a photopolymerization initiator (a-2), and the heat The number average molecular weight (Mn) of the plastic resin (a-1) is 5,000 to 2,500,000, and the weight average molecular weight (Mw) / number average molecular weight (Mn) is within 5 or less. It is characterized by that. The number average molecular weight (Mn) of the thermoplastic resin (a-1) in the photocurable resin composition is 5,000 to 2,500,000, and the weight average molecular weight (Mw) / number average molecular weight ( By making Mn) within the range of 5 or less, the adhesiveness between the photocurable resin composition (A) layer and the base sheet (B) is good, and the surface appearance is excellent, and further excellent Various physical properties (abrasion resistance, chemical resistance, non-surface adhesiveness, processability, storage stability, etc.) can be exhibited.

  As the thermoplastic resin (a-1) having a radically polymerizable unsaturated group in the side chain, for example, a radically polymerizable unsaturated group in the polymer having a glass transition temperature of 25 to 175 ° C., preferably 30 to 150 ° C. The thing which has is mentioned. Specifically, a polymer obtained by polymerizing or copolymerizing the following compounds (1) to (8) as a polymer with a radically polymerizable unsaturated group introduced by the methods (a) to (d) described later. 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 (2) Monomers having a carboxyl group: (meth) acrylic acid, acryloyloxyethyl monosuccinate, etc. (3) Monomers having an epoxy group: glycidyl (meth) acrylate, 3,4- Epoxycyclohexylmethyl (meth) acrylate, etc. (4) Monomers having an aziridinyl group: 2-aziridinylethyl (meth) acrylate, allyl 2-aziridinylpropionate, etc.

(5) Monomer having amino group: (meth) acrylamide, diacetone acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc. (6) Monomer having sulfone group: 2-acrylamide- 2-Methylpropanesulfonic acid, etc. (7) Monomer having isocyanate group: radically polymerizable monomer having diisocyanate and active hydrogen such as equimolar adduct of 2,4-toluene diisocyanate and 2-hydroxyethyl acrylate Body adducts, 2-isocyanatoethyl (meth) acrylate, etc.

  (8) Further, in order to adjust the glass transition temperature of the above copolymer or to harmonize the physical properties of the photocurable sheet, the above compound is copolymerized with a monomer copolymerizable therewith. You can also. Examples of such copolymerizable monomers 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.

As will be described later, when the inorganic fine particles (a-7) are added to the photocurable resin composition (A) used in the present invention , the functional groups (hydroxyl groups) on the surface of the inorganic fine particles (a-7) are used. Group, carboxyl group, silanol group, etc.), a vinyl having at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, a halogenated silyl group and an alkoxysilyl group in the molecule. Since the polymerizable monomer works to further improve the physical properties such as rigidity, toughness, heat resistance and the like of the resulting photocurable resin composition, the functional group is a vinyl polymerizable monomer component capable of radical polymerization. It may be contained as a part.
Examples of the vinyl polymerizable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylic acid, vinyltrichlorosilane, vinyltrimethoxysilane, and γ- (meth) acryloyloxy. And propyltrimethoxysilane. Furthermore, from the viewpoint of improving the weather resistance of the thermoplastic resin copolymer, it is preferable to use a (meth) acrylate as a main component as a vinyl polymerizable monomer.

Next, radically polymerizable unsaturated groups are introduced into the polymer obtained as described above by the methods (i) to (d) described below.
(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 aforementioned 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 monomer having a carboxyl group is subjected to an addition reaction.
(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, a monomer having an aziridinyl group, a monomer having an isocyanate group, or An equimolar adduct of a diisocyanate compound and a hydroxyl group-containing acrylate monomer is subjected to an addition reaction.
The above reaction is preferably carried out while adding a small amount of a polymerization inhibitor such as hydroquinone and sending dry air.

  The radical polymerizable unsaturated group of the side chain of the thermoplastic resin (a-1) has a double bond equivalent (average molecular weight per one side chain radical polymerizable unsaturated group) calculated from the charged value. An average of 3000 g / mol or less is preferable from the viewpoint of improving scratch resistance and wear resistance. A more preferable range is an average of 1200 g / mol or less, and a most preferable range is an average of 800 g / mol or less. Thus, it becomes possible to improve hardened | cured material property efficiently by introduce | transducing multiple radically polymerizable unsaturated groups which participate in bridge | crosslinking in a thermoplastic resin.

When mold-molding or in-mold molding a photo-curable sheet formed using the photo-curable resin composition (A) containing the thermoplastic resin (a-1), the mold releasability is improved. From the viewpoint of the surface hardness of the molded product after photocuring, the number average molecular weight (Mn) is preferably 5,000 or more. On the other hand, it is preferable that the number average molecular weight is 2,500,000 or less from the viewpoint of ease of synthesis and appearance, and from the viewpoint of adhesion with the base sheet (B).
Moreover, the range of the weight average molecular weight (Mw) / number average molecular weight (Mn) of a thermoplastic resin (a-1) is the adhesiveness of a photocurable resin composition (A) layer and a base sheet (B). In consideration, the weight average molecular weight (Mw) / number average molecular weight (Mn) must be 5 or less. More preferably, it is 4 or less, and most preferably 3 or less. In particular, when the weight average molecular weight (Mw) / number average molecular weight (Mn) is 3 or less, for example, it can be used as a resin molded product requiring strict adhesion such as under cowling of a two-wheeled vehicle. Very high value.

  In addition, the glass transition temperature of the thermoplastic resin (a-1) is preferably adjusted to 25 to 175 ° C, and more preferably 30 to 150 ° C. From the viewpoint of mold releasability of the photocurable sheet during insert molding or in-mold molding and the surface hardness of the molded product after photocuring, the glass transition temperature is preferably 25 ° C. or higher. On the other hand, it is preferable that a glass transition temperature is 175 degrees C or less from a viewpoint of the handleability of a photocurable sheet. In consideration of the glass transition temperature of the thermoplastic resin copolymer obtained, it is preferable to use a vinyl polymerizable monomer having a high glass transition temperature as a homopolymer.

Further, considering the adhesion, the thermoplastic resin (a-1) is a thermoplastic resin having a hydroxyl group and / or a carboxylic acid group in the side chain in the presence of the compound (C) represented by the following structural formula (1). Same as (a-3), reaction of compound (a-4) having an epoxy group and a radically polymerizable unsaturated group in the same molecule, and thermoplastic resin (a-5) having an epoxy group in the side chain It is preferable to use those obtained by the reaction of a compound (a-6) having a hydroxyl group and / or carboxylic acid group and a radically polymerizable unsaturated group in the molecule.
(R ₁ R ₂ R ₃ R ₄ P) X (1)
(In the formula, R _{1 to} R ₄ are the same or different and each represents a hydrogen atom, a hydroxyl group, a halogen, a carboxyl group, a cyano group, an asino group, an alkoxy group, or an acetonyl group. Represents a chain or branched alkyl group, alkenyl group, benzyl group, aryl group or phenyl group, and X represents a hydroxyl group, a halogen or other acid group.)

The thermoplastic resin (a-3) having a hydroxyl group and / or a carboxylic acid group in the side chain is obtained by polymerizing a mixture containing monomers selected from the above (1) and (2). Yes, it may be used alone or in combination of two or more.
The compound (a-4) having an epoxy group and a radically polymerizable unsaturated group in the same molecule is the monomer shown in the above (3).
Moreover, as a thermoplastic resin (a-5) which has an epoxy group in a side chain in the same molecule, it is obtained by superposing | polymerizing the mixture containing the monomer selected from above-mentioned (3), and is independent. May be used, or two or more types may be used.
The compound (a-6) having a hydroxyl group and / or a carboxylic acid group and a radically polymerizable unsaturated group is a monomer selected from the above (1) and (2) and may be used alone. Two or more types may be used.

Although the following compound is mentioned as an example of the said compound (C), It is not limited to these.
Tetraethylphosphonium bromide, triethylbenzylphosphonium chloride, tetra-n-butylphosphonium bromide, tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium iodide, tri-n-butylmethylphosphonium iodide, tri-n-butyloctyl Phosphonium bromide, tri-n-butylhexadecylphosphonium bromide, tri-n-butylbenzylphosphonium chloride, tri-n-octylethylphosphonium bromide, tetrakishydroxymethylphosphonium sulfate, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium Iodide, ethyltriphenylphosphonium chloride, methyltriphenylphosphonium bromide , Butyltriphenylphosphonium bromide, methoxymethyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, triphenylbenzylphosphonium chloride, acetonyltriphenylphosphonium chloride, allyltriphenylphosphonium bromide, allyltriphenylphosphonium chloride, n-amyltriphenyl Phosphonium bromide,

  1H-benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate, benzotriazol-1-yloxytris (dimethylamino) phosphonium hexafluorophosphate, benzyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, bromomethyltriphenyl Phosphonium bromide, 3-bromopropyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, 4-carboxybutyltriphenylphosphonium bromide, (3-carboxypropyl) triphenylphosphonium bromide, 4-chlorobenzyltriphenylphosphonium chloride, chloro Methyltriphenylphosphonium chloride, cinnamyltriphe Le phosphonium bromide, cyclopropyl triphenyl phosphonium bromide, cyanomethyl tri -n- butyl phosphonium chloride,

  2-dimethylaminoethyltriphenylphosphonium bromide, 2- (1,3-dioxan-2-yl) ethyltriphenylphosphonium bromide, 2- (1,3-dioxolan-2-yl) ethyltriphenylphosphonium bromide, (1 , 3-Dioxolan-2-yl) methyltriphenylphosphonium bromide, 4-ethoxybenzyltriphenylphosphonium bromide, ethoxycarbonylmethyl (triphenyl) phosphonium bromide, (formylmethyl) triphenylphosphonium chloride, n-heptyltriphenylphosphonium bromide , N-hexyltriphenylphosphonium bromide, isopropyltriphenylphosphonium iodide, methoxycarbonylmethyl (triphenyl) phosphonium Romaido, (N-methyl -N- phenylamino) triphenyl phosphonium iodide, methyl triphenyl phosphonium iodide,

Phenacyltriphenylphosphonium bromide, n-propyltriphenylphosphonium bromide, n-tetradecyltriphenylphosphonium bromide, tetraethylphosphonium hexafluorophosphate, tetraethylphosphonium tetrafluoroborate, tetrakis (hydroxymethyl) phosphonium chloride, tetra-n-octyl Phosphonium bromide, tetraphenylphosphonium chloride, tetraphenylphosphonium iodide, tetraphenylphosphonium tetraphenylborate, 2- (trimethylsilyl) ethoxymethyltriphenylphosphonium chloride, (2-trimethylsilyl) ethyltriphenylphosphonium iodide, (3-trimethylsilyl- 2-propynyl) triphenyl Suho bromide, triphenyl vinyl phosphonium bromide.
Of these compounds (C), tetraethylphosphonium bromide is preferable in that the adhesion between the photocurable resin composition (A) layer and the base sheet (B) is remarkably improved. As tetraethylphosphonium bromide, commercially available PX-2B (trade name; manufactured by Nippon Chemical Industry Co., Ltd.) can be used.

As a photoinitiator (a-2) of this invention, the photoradical polymerization initiator which generates a radical by light irradiation is mentioned.
As the radical photopolymerization initiator, known compounds can be used, and are not particularly limited, but considering yellowing during curing and deterioration during weathering, such as acetophenone-based, benzophenone-based, acylphosphine oxide-based An initiator that does not contain an amino group in the molecule is preferable. For example, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl 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-trimethylpentyl Phosphine oxide and the like are preferable.

Of these, care must be taken because the temperature may be temporarily higher than the boiling point of the compound depending on the molding method. In order to increase the surface hardness of the molded product, an additive such as n-methyldiethanolamine that suppresses polymerization hardening inhibition by oxygen may be added. In addition to these photopolymerization initiators, various peroxides may be added in consideration of curing using heat during molding. When the photocurable sheet contains a peroxide, it is necessary to cure at 150 ° C. for about 30 seconds. Therefore, a peroxide having a low critical temperature, such as lauroyl peroxide, t-butylperoxy-2, etc. -Ethylhexanoate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane and the like are preferably used.
The amount of the radical photopolymerization initiator added is preferably 5% by weight or less based on the thermoplastic resin having a radically polymerizable unsaturated group in the side chain, since the residual amount after curing affects the weather resistance, particularly at the time of curing. The amount of the amino radical photopolymerization initiator related to yellowing is desirably 1% by weight or less.

  Inorganic fine particles (a-7) can be added to the photocurable resin composition (A) for the purpose of further improving scratch resistance and wear resistance. As long as the transparency of the obtained photocurable resin composition is ensured, the kind, particle diameter, and form of the inorganic fine particles (a-7) are not particularly limited. Examples of inorganic fine particles include colloidal silica, alumina, titanium oxide, tin oxide, foreign element doped tin oxide (ATO, etc.), indium oxide, foreign element doped indium oxide (ITO, etc.), cadmium oxide, antimony oxide, etc. Is mentioned. These may be used alone or in combination of two or more. Of these, colloidal silica is particularly preferable from the viewpoints of availability, price, transparency of the resulting photocurable resin composition layer, and expression of wear resistance.

Colloidal silica can be used in the form of a normal aqueous dispersion or in a form dispersed in an organic solvent, but in order to disperse uniformly and stably with the thermoplastic resin (a-1). It is preferable to use colloidal silica dispersed in an organic solvent.
Examples of such organic solvents include methanol, isopropyl alcohol, n-butanol, ethylene glycol, xylene / butanol, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl isobutyl ketone, toluene and the like. In order to uniformly disperse together with the thermoplastic resin, it is preferable to select an organic solvent capable of dissolving the thermoplastic resin.

  Colloidal silica dispersed in an organic solvent includes commercially available products dispersed in a dispersion medium such as methanol silica sol MA-ST, isopropyl alcohol silica sol IPA-ST, n-butanol silica sol NBA-ST, ethylene glycol silica sol EG. -ST, xylene / butanol silica sol XBA-ST, 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 MIBK- ST (above, trade name; manufactured by Nissan Chemical Industries, Ltd.) can be used.

The particle diameter of the inorganic fine particles (a-7) is usually preferably 200 nm or less from the viewpoint of the transparency of the resulting photocurable resin composition layer. More preferably, it is 100 nm or less, More preferably, it is 50 nm or less.
The added amount of the inorganic fine particles (a-7) is 5 to 400 weights in solid content of the inorganic fine particles with respect to 100 weight parts of the solid content of the thermoplastic resin (a-1) having a radical polymerizable unsaturated group in the side chain. The range of parts is preferable, and the range of 10 to 200 parts by weight is particularly preferable. When the addition amount of the inorganic fine particles is less than 5 parts by weight, the effect of improving the wear resistance may not be recognized. When the addition amount exceeds 400 parts by weight, the photocurable resin composition (A) In addition to a decrease in storage stability, the moldability of the resulting photocurable sheet may decrease.

Moreover, as an inorganic fine particle (a-7) used by this invention, you may use what processed the surface beforehand by the silane compound represented by following Structural formula (2). The use of 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 resulting photocurable sheet are also improved.
SiR ⁴ _a R ⁵ _b (OR ⁶ ) _c (2)
(In formula, R < ⁴ > and R < ⁵ > represents the C1-C10 hydrocarbon residue which may have an ether bond, an ester bond, an epoxy bond, or a carbon-carbon double bond, respectively, and R < ⁶ >. Represents a hydrocarbon residue having 1 to 10 carbon atoms which may have a hydrogen atom, an ether bond, an ester bond, an epoxy bond or a carbon-carbon double bond, and a and b are 0 to 3 respectively. It is an integer, and c is an integer of 1 to 4 that satisfies 4-ab.

Among the silane compounds represented by the structural formula (2), silane compounds represented by the following structural formulas (3) to (8) can be given as preferable examples.
SiR ⁷ _a R ⁸ _b (OR ⁹ ) _c (3)
SiR ⁷ _n (OCH ₂ CH ₂ OCO (R ¹⁰ ) C═CH ₂ ) _4-n (4)
CH ₂ = C (R ¹⁰ ) COO (CH ₂ ) _p SiR ¹¹ _n (OR ⁹ ) _3-n (5)
CH ₂ = CHSiR ¹¹ _n (OR ⁹ ) _3-n (6)
HS (CH ₂ ) _p SiR ¹¹ _n (OR ⁹ ) _3-n (7)

（式中、Ｒ^７及びＲ^８は、それぞれ、エーテル結合、エステル結合又はエポキシ結合を有していてもよい炭素数１〜１０の炭化水素残基を表し、Ｒ^９は水素原子又は炭素数１〜１０の炭化水素残基を表し、Ｒ¹⁰は水素原子又はメチル基を表し、Ｒ¹¹は炭素数１〜３のアルキル基又はフェニル基を表し、ａ及びｂは、それぞれ、０〜３の整数であり、ｃは４−ａ−ｂを満足する１〜４の整数であり、ｎは０〜２の整数であり、ｐは１〜６の整数である。）

(In the formula, R ⁷ and R ⁸ each represent a hydrocarbon residue having 1 to 10 carbon atoms which may have an ether bond, an ester bond or an epoxy bond, and R ⁹ is a hydrogen atom or 1 carbon atom. represents a hydrocarbon residue of the to 10, R ¹⁰ represents a hydrogen atom or a methyl group, R ¹¹ represents an alkyl group or phenyl group having 1 to 3 carbon atoms, a and b are each an integer of 0 to 3 C is an integer of 1 to 4 satisfying 4-ab, 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 (3) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltrimethoxysilane. Ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, methylethyldiethoxysilane, methylphenyldimethoxysilane, trimethylethoxysilane, methoxyethyltriethoxysilane, acetoxyethyltriethoxysilane, diethoxy Ethyldimethoxysilane, tetraacetoxysilane, methyltriacetoxysilane, tetrakis (2-methoxyethoxy) silane, γ-glycidoxypro Le trimethoxysilane, .gamma.-glycidoxypropylmethyldiethoxysilane, beta-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.
Examples of the silane compound represented by the structural formula (4) include tetrakis (acryloyloxyethoxy) silane, tetrakis (methacryloyloxyethoxy) silane, methyltris (acryloyloxyethoxy) silane, and methyltris (methacryloyloxyethoxy) silane. Can be mentioned.

Examples of the silane compound represented by the structural formula (5) include β-acryloyloxyethyldimethoxymethylsilane, γ-acryloyloxypropylmethoxydimethylsilane, γ-acryloyloxypropyltrimethoxysilane, and β-methacryloyloxyethyldimethoxy. Examples include methylsilane and γ-methacryloyloxypropyltrimethoxysilane.
Examples of the silane compound represented by the structural formula (6) include vinylmethyldimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.
Examples of the silane compound represented by the structural formula (7) include γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, and the like.
Examples of the silane compound represented by the structural formula (8) include p-vinylphenylmethyldimethoxysilane and p-vinylphenyltrimethoxysilane.

Such a silane compound is preferably used in a proportion of 0 to 3 mole parts relative to 1 mole part of the solid content of the inorganic fine particles (a-7). When the usage-amount of a silane compound exceeds 3 mol part, the abrasion resistance of the photocurable sheet obtained may fall.
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-7) to the thermoplastic resin (a-1) having a radically polymerizable unsaturated group in the side chain, the inorganic fine particles are synthesized after the thermoplastic resin (a-1) is synthesized in advance. Or any method such as a method of polymerizing a thermoplastic resin under a condition in which a vinyl polymerizable monomer constituting the thermoplastic resin (a-1) and inorganic fine particles are mixed is selected. Can do.

In the photocurable resin composition (A) used in the present invention, a thermoplastic resin (a-1) having a side chain radical polymerizable unsaturated group, a photopolymerization initiator (a-2), and inorganic fine particles (a In addition to -7), additives such as sensitizers, denaturing resins, dyes, pigments and leveling agents, repellency inhibitors, ultraviolet absorbers, light stabilizers, and oxidation stabilizers may be blended as necessary. it can.
The above sensitizer accelerates the photocuring reaction, and examples thereof include benzophenone, benzoin isopropyl ether, and thioxanthone.

The substrate sheet (B) used in the present invention is a thermoplastic acrylic resin sheet having a crosslinked rubber component in consideration of adhesion to the photocurable resin composition (A), weather resistance, transparency, and the like.

Transparent thermoplastic acrylic resin sheets having a crosslinked rubber component are disclosed in JP-A-8-323934, JP-A-9-263614, JP-A-11-147237, JP-A-2001-10474, and the like. There is a transparent thermoplastic acrylic sheet.
Commercially available transparent thermoplastic acrylic sheets include Acryprene HBX-N47, HBS-006, HBD-013 (manufactured by Mitsubishi Rayon Co., Ltd.), Technoloy S001, S003, SN101 (summer, Sumitomo Chemical Co., Ltd.) Manufactured), Sanduren SD007, SD009 (above, manufactured by Kaneka Chemical Co., Ltd.) and the like.

When the thickness of the base sheet (B) exceeds 500 μm, the rigidity is increased and it is not preferable as a sheet for insert molding or in-mold molding. Therefore, it is usually preferable that the thickness of the base sheet is 500 μm or less.
In addition, in the base sheet (B), lubricants such as polyethylene wax and paraffin wax, lubricants such as silica, spherical alumina, and scaly alumina, benzotriazole, benzophenone, and fine particles are appropriately added as necessary. Various additives such as UV absorbers such as cerium oxides, light stabilizers such as hindered amine radical scavengers, plasticizers, stabilizers, pigments and dyes may be added.

  The photocurable sheet of the present invention is a structure in which the photocurable resin composition (A) layer is laminated on the base sheet (B), and not only has excellent workability during insert molding and in-mold molding, It is a photocurable sheet capable of giving a molded product having various physical properties (particularly, weather resistance-abrasion resistance (surface hardness) -adhesion balance). As long as the excellent properties of the photocurable sheet of the present invention are not impaired between the photocurable resin composition (A) layer and the base sheet (B), one or more layers of the photocurable resin composition are further provided. It is also possible to stack physical layers. In this case, when a composition equivalent to or similar to the photocurable resin composition (A) is used as one or more layers of the photocurable resin composition to be newly introduced, the surface of the photocurable sheet after photocuring is used. The properties (particularly adhesion, weather resistance, appearance, and design) tend to be favorable, which is preferable.

As a method for producing the photocurable sheet of the present invention, for example, the photocurable resin composition (A) is sufficiently stirred and dissolved in a solvent (S) such as an organic solvent, and a gravure printing method, a screen printing method, or an offset printing is performed. Well-known printing methods such as blade coating method, rod coating method, roll doctor coating method, knife coating method, comma coating method, reverse roll coating method, transfer roll coating method, kiss roll coating method, curtain coating method, dip There is a method of coating on the substrate sheet (B) by a known coating method such as a coating method, and performing heat drying for removing the solvent (S) to obtain a laminated sheet.
When using a flammable organic solvent as the solvent (S), the dryer used for heating and drying to remove the solvent (S) is equipped with an air heating heat source using steam from the viewpoint of safety. For example, a method in which hot air in the dryer is brought into countercurrent contact and a method in which the hot air in the dryer is sprayed onto the photocurable sheet from a nozzle can be used. As the shape of the dryer, a known one such as an arch type or a flat type can be selected and used according to the purpose.

  As the solvent (S) for stirring and dissolving the photocurable resin composition (A), each component of the photocurable resin composition (A) is dissolved or uniformly dispersed, and the physical properties of the base sheet (B) are obtained. There is no particular limitation as long as it is a volatile solvent that does not have a practically serious adverse effect on (mechanical strength, transparency, etc.). Examples of such solvents include alcohol solvents such as methanol, ethanol, isopropyl alcohol, n-butanol and ethylene glycol, aromatic solvents such as xylene, toluene and benzene, aliphatic hydrocarbon solvents such as hexane and pentane, Halogenated hydrocarbon solvents such as chloroform and carbon tetrachloride, phenol solvents such as phenol and cresol, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and acetone, diethyl ether, methoxytoluene, 1,2-dimethoxyethane, 1 Ether solvents such as 1,2-dibutoxyethane, 1,1-dimethoxymethane, 1,1-dimethoxyethane, 1,4-dioxane, THF, fatty acid solvents such as formic acid, acetic acid, propionic acid, acetic anhydride, etc. Acid anhydride solvent, ethyl acetate, butyl acetate, Ester solvents such as butyl acid, nitrogen-containing solvents such as ethylamine, toluidine, dimethylformamide and dimethylacetamide, sulfur-containing solvents such as thiophene and dimethyl sulfoxide, diacetone alcohol, 2-methoxyethanol (methylcellosolve), 2-ethoxy A solvent having two or more functional groups such as ethanol (ethyl cellosolve), 2-butoxyethanol (butyl cellosolve), diethylene glycol, 2-aminoethanol, acetocyanohydrin, diethanolamine, morpholine, or various known solvents such as water is used. be able to.

Moreover, when coating the said resin liquid on the base material sheet (B) which consists of polyolefin, such as polyethylene and a polypropylene, in order to raise the adhesiveness of a base material sheet and a photocurable resin composition, (1) beforehand A primer composed of a low molecular weight polyolefin or the like is applied on the base sheet (B), or (2) the surface of the base sheet (B) is activated in advance by corona discharge or the like (this corona discharge As the step to be performed, it is preferable that immediately after being activated, the adhesiveness is high, so that it is preferably a little before coating. Furthermore, it is preferable to laminate a primer layer for the purpose of preventing the photocurable resin composition from shrinking in volume during photocuring and reducing the adhesion to the base sheet (B).
The photocurable sheet of the present invention obtained by the above method can also be used as a photocurable decorative sheet by providing a printing layer on the base sheet (B) side.

The printed layer is for decorating the surface of the molded product with patterns, characters, and the like. The decoration is arbitrary, but for example, a pattern composed of wood grain, stone grain, cloth grain, sand grain, geometric pattern, letters, full-color solid, and the like can be mentioned. 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, cellulose A colored ink containing a resin such as an ester resin, an alkyd resin, or a chlorinated polyolefin resin as a binder and an appropriate color pigment or dye as a colorant may be used.
As the ink pigments used in the printing layer, for example, the following can be used. Usually, as pigments, yellow pigments as azo pigments such as polyazo, isoindolinone and other organic pigments and yellow lead as inorganic pigments, red pigments as azo pigments such as polyazo, quinacridone and other organic pigments and petals An inorganic pigment such as phthalocyanine blue or an inorganic pigment such as cobalt blue, an organic pigment such as aniline black as a black pigment, and an inorganic pigment such as titanium dioxide as a white pigment can be used.

Various known dyes can be used as the dye of the ink used in the printing layer as long as the effects of the present invention are not impaired.
As the ink printing method, a known printing method such as an offset printing method, a gravure rotary printing method or a screen printing method, or a known coating method such as a roll coating method or a spray coating method may be used. In this case, as in the present invention, when only a polymer having a photopolymerizable functional group in the side chain is used without using any other crosslinkable compound, the surface is not sticky, and there is a trouble during printing. There are few, and a yield is favorable.
Further, as a layer for decorating the surface of the molded product, a vapor deposition layer may be provided instead of the print layer, or both the print layer and the vapor deposition layer may be provided.
The vapor deposition layer uses at least one metal selected from the group of aluminum, nickel, gold, platinum, chromium, iron, copper, indium, tin, silver, titanium, lead, zinc, or an alloy or compound thereof. It can be formed by a method such as a vacuum deposition method, a sputtering method, an ion plating method, or a plating method.

The thickness of the printing layer and the vapor deposition layer for decorating may be appropriately selected according to the degree of expansion of the sheet at the time of insert molding or in-mold molding so that a desired molded product surface appearance can be obtained.
Moreover, the photocurable sheet of the present invention is a photocurable decorative sheet in which a printed layer and / or a vapor deposition layer, an adhesive layer and, if necessary, a primer sheet are formed on the base sheet (B) side. it can. In that case, the preferable thickness range of a photocurable decorating sheet is 30-750 micrometers. When the sheet thickness is less than 30 μm, the sheet thickness on the curved surface is remarkably lowered when deep drawing is performed, and as a result, sheet physical properties such as scratch resistance and chemical resistance may be lowered. In addition, when the sheet thickness exceeds 750 μm, the shape followability to the mold may be deteriorated.

  As the adhesive layer, any synthetic resinous material can be selected and used as long as it has the property of improving the adhesion between the printed layer or vapor-deposited layer and the molding resin, or the printed layer or vapor-deposited layer and the primer sheet. . For example, when the molding resin is a polyacrylic resin, a polyacrylic resin may be used. In addition, when the molding resin is polyphenylene oxide / polystyrene resin, polycarbonate resin, styrene copolymer resin, or polystyrene blend resin, polyacrylic resin, polystyrene resin, polyamide resin having affinity with these resins Etc. may be used. Furthermore, when the molding resin is a polyolefin resin such as a polypropylene resin, heat using chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, coumarone indene resin, or blocked isocyanate A curable urethane resin or the like can be used. In addition, hydrophobic silica, an epoxy resin, a petroleum resin, or the like can be further included for the purpose of reducing the tackiness of the adhesive layer or improving the heat resistance.

  The primer sheet is formed as necessary, such as acrylic resin, polyester resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, chlorinated polypropylene resin, chlorinated polyethylene resin, etc. Known resins can be used. In addition, it is good to consist of a material compatible with molding resin for the purpose of improving adhesiveness with molding resin. In reality, the primer sheet is preferably made of the same or similar polymer material as the molding resin. In addition, the presence of the primer sheet provides the advantage of minimizing the surface defects of the injection molded product from being propagated onto the photocurable resin composition, and the presence of a printing layer or adhesive layer on the primer sheet. In this case, there is an advantage that the thickness and pattern of each layer are prevented from being disturbed by the molten resin at the time of injection molding. In that case, the primer sheet should have a thickness that absorbs surface defects of the molded resin while exhibiting a completely smooth upper surface of the photocurable resin composition, and the thickness is in the range of 50 to 700 μm. It is preferable. When the thickness of the primer sheet is less than 50 μm, it may be difficult to sufficiently absorb surface defects on the surface of the molded resin. On the other hand, when the primer sheet thickness exceeds 700 μm, the shape following property to the mold may be lowered.

Moreover, the photocurable sheet | seat of this invention can also provide a cover film further on the photocurable resin composition (A) layer on a base material sheet (B). This cover film is effective for preventing dust on the surface of the photocurable sheet, and also effective for preventing scratches on the surface of the photocurable resin composition (A) layer before irradiation with active energy rays.
The cover film adheres to the photocurable resin composition (A) layer until insert molding or in-mold molding, as will be described later, and is immediately peeled when insert molding or in-mold molding is performed. It is necessary for the resin composition (A) layer to have appropriate adhesion and good releasability. Any film can be selected and used as long as it satisfies such conditions. Examples of such a film include a polyethylene film, a polypropylene film, and a polyester film.
By the way, when the size of a molded product such as an automobile body panel or spoiler is large and the thickness of the molded product is thin, the gas generated from the molded resin may remain in the molded resin, The air may easily intervene between the molding resin and the sheet, resulting in a problem that the adhesion of the sheet to the molding resin is lowered. In such a case, the problem can be solved by providing a gas-permeable layer on the sheet surface in contact with the molding resin. Examples of such a gas-permeable layer include woven fabrics and nonwoven fabrics composed of spandex, acrylic fibers, polyethylene fibers, polyamide fibers, and the like. Moreover, you may use what consists of a foamed layer instead of a woven fabric / nonwoven fabric. Examples of the method for forming the foamed layer include a method in which a resin solution containing a known foaming agent is applied and then foamed by heating or the like to form continuous pores.

Next, an example of the manufacturing method of the molded article using said photocurable sheet and a photocurable decorating sheet is demonstrated.
First, when a cover film is provided on a photocurable sheet or a photocurable decorative sheet, the cover film is peeled off from the sheet. The cover film may be peeled off immediately before the sheet is inserted and placed in the mold, or may be peeled off long before the sheet is inserted and placed in the mold. However, the former is preferable in consideration of dust prevention and damage prevention of the photocurable resin composition (A) layer before light irradiation.
The photocurable sheet or the photocurable decorative sheet is inserted and arranged so that the photocurable resin composition (A) side faces the inner wall surface of the mold (that is, opposite to the photocurable resin composition (A) layer) The side is in contact with the molding resin). At this time, a necessary part may be intermittently sent as it is (e.g., unwinding from a roll) as a long sheet, or the sheets may be separated into sheets and fed one by one. In particular, when using a long sheet with a printing layer or vapor deposition layer for decoration, use a feeding device that has a positioning mechanism so that the registration of the layer for decoration matches the mold. Good. In addition, when the sheet is intermittently fed, if the sheet is fixed after the position of the sheet is detected by the sensor, the sheet can always be fixed at the same position, and the decorative layer is not displaced. Convenient.

  Next, if necessary, a photocurable sheet or a photocurable decorative sheet is preformed. For example, the sheet can be preliminarily formed by softening the sheet to a softening point or higher by a heating means such as a hot pack, and vacuuming the sheet through a suction hole provided in the mold so that the sheet follows the mold shape. If the sheet is preheated to a temperature lower than the thermal deformation temperature of the sheet before the sheet is inserted into the mold, the heating time to be performed after the sheet is inserted into the mold can be shortened. It becomes possible to improve productivity. Of course, it is also possible to simultaneously perform the molding of the sheet and the integration with the molding resin by the injection pressure of the molding resin, which will be described later, without preforming the sheet. At this time, the sheet can be preheated and softened in advance.

Also, using a preforming mold other than the injection mold, the sheet is formed by a known molding method such as a vacuum molding method, a pressure molding method, a pressure molding method for pressing heated rubber, or a press molding method. After preforming into a desired shape in advance, the preformed sheet may be inserted into a molding die so that the photocurable resin composition side faces the inner wall surface of the die.
Thereafter, the mold is closed, a molding resin in a molten state is injected into the cavity, and the resin is solidified to form a molded product on which the photocurable sheet or the photocurable decorative sheet is arranged.

  As the molding resin used in the present invention, any resin that can be injection molded can be used regardless of the type. Examples of such molding resins include polyethylene resins, polypropylene resins, polybutene resins, polymethylpentene resins, ethylene-propylene copolymer resins, ethylene-propylene-butene copolymer resins, and olefin thermoplastics. Olefin resin such as elastomer, polystyrene resin, ABS (acrylonitrile / butadiene / styrene copolymer) resin, AS (acrylonitrile / styrene copolymer) resin, acrylic resin, urethane resin, unsaturated polyester General-purpose thermoplastic or thermosetting resins such as epoxy resins and epoxy resins can be mentioned. Also, general engineering resins such as polyphenylene oxide / polystyrene resins, polycarbonate resins, polyacetal resins, polycarbonate-modified polyphenylene ether resins, polyethylene terephthalate resins, polysulfone resins, polyphenylene sulfide resins, polyphenylene oxide resins, polyethers Super engineering resins such as imide resins, polyimide resins, liquid crystal polyester resins, and polyallyl heat resistant resins can also be used. Further, reinforcing materials such as glass fibers and inorganic fillers (talc, calcium carbonate, silica, mica, etc.), composite resins added with modifiers such as rubber components, and various modified resins can be used. It is preferable that the shrinkage rate after molding of the molding resin is approximated to the shrinkage rate of the sheet because problems such as warpage of the molded product obtained by insert molding or in-mold molding and peeling of the sheet can be solved.

Finally, after taking out the molded product from the mold, the photocurable resin composition on the surface of the molded product is photocured by light irradiation.
Examples of light to be irradiated include electron beams, ultraviolet rays, and γ rays. Although irradiation conditions are determined according to the photocuring property of a photocurable resin composition (A) layer, irradiation amount is about 500-10,000mJ / cm < ² > normally. As a result, a molded product in which the photocurable resin composition is cured and a hard film is formed on the surface can be obtained.
Of the photocurable sheet or photocurable decorative sheet adhered to the molded product, unnecessary portions are appropriately trimmed and removed as necessary. This trimming can be performed after the sheet is inserted and arranged in the mold, before the molded product is irradiated with light, or after the light irradiation. As a trimming method, a known method such as a method of burning a sheet by irradiating a laser beam or the like, a method of producing a punching die for trimming and punching the sheet by press working, a method of removing the sheet by manually tearing it off, etc. It can be carried out.

In the above description, a manufacturing method using injection molding has been described as a manufacturing method of a molded product, but blow molding may be used instead of injection molding.
The molded product thus obtained is given a color or design at the same time as molding, and further, wear resistance, chemical resistance, weather resistance and the like are improved by light irradiation for a short time. Furthermore, the process can be shortened, the yield can be improved, and the influence on the environment can be reduced as compared with conventional spray coating after molding.
In addition, the photocurable sheet of the present invention can be used by being laminated on the surface of the adherend by laminating the adherend directly or via an adhesive layer. Examples of the adherend include flat plates, curved plates, sheets, films, and various three-dimensional articles (molded products) made of various materials. For example, the photocurable sheet of the present invention can be used for a molded product having a curved surface such as an injection molded product. The adherend laminated with the photocurable sheet of the present invention can be further subjected to secondary processing such as vacuum forming.

  Hereinafter, the present invention will be described in more detail based on examples. In the examples, “part” means “part by weight”.

[Synthesis Example 1] (Synthesis of thermoplastic resin A having a radical polymerizable unsaturated group in the side chain)
50 parts of methyl ethyl ketone was placed in a 1 L four-necked flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer, and the temperature was raised to 80 ° C. Under a nitrogen atmosphere, a mixture of 67.8 parts of methyl methacrylate, 32.2 parts of glycidyl methacrylate and 0.5 part of azobisisobutyronitrile was added dropwise over 3 hours. Thereafter, a mixture of 80 parts of methyl ethyl ketone (boiling point 79.6 ° C.) and 0.2 part of azobisisobutyronitrile was added and polymerized. After 4 hours, 44.3 parts of methyl ethyl ketone, 0.5 part of hydroquinone monomethyl ether, 2.5 parts of tetraethylphosphonium bromide (trade name; PX-2B, manufactured by Nippon Chemical Industry Co., Ltd.) and 16.2 parts of acrylic acid were added. The mixture was stirred at 80 ° C. for 30 hours while blowing air. Next, after cooling, the reaction product was taken out from the flask to obtain a solution of the thermoplastic resin A having a radical polymerizable unsaturated group in the side chain.
The polymerization rate of the monomer in the thermoplastic resin A having a radically polymerizable unsaturated group in the side chain is 99.5% or more, the polymer solid content is 40% by weight, and the number average molecular weight (Mn) is about 2.9. The weight average molecular weight (Mw) / number average molecular weight (Mn) was 2.4, the glass transition temperature was about 77 ° C., and the double bond equivalent was 518 g / mol on average.

[Synthesis Example 2] (Synthesis of thermoplastic resin B having a radical polymerizable unsaturated group in the side chain)
In the production example of Synthesis Example 1, the same operation was performed except that tetraethylphosphonium bromide was changed to triphenylphosphine (manufactured by Wako Pure Chemical Industries, Ltd.), and a thermoplastic resin having a radically polymerizable unsaturated group in the side chain A solution of B was obtained. The polymerization rate of the monomer in the obtained thermoplastic resin B is 99.5% or more, the polymer solid content is 40% by weight, the number average molecular weight (Mn) is about 60,000, and the weight average molecular weight (Mw) / number. The average molecular weight (Mn) was 12.9, the glass transition temperature was about 77 ° C., and the double bond equivalent was an average of 518 g / mol.

A) Physical property evaluation method of thermoplastic resin having radical polymerizable unsaturated group in side chain:
Mn, Mw, Mw / Mn: Measurement is performed using a photorefractive method in gel permeation chromatography. A calibration curve is created using a polystyrene standard so that the molecular weight of the sample to be measured can be interpolated as a reference for molecular weight measurement.

攪拌機、コンデンサー及び温度計を備えたフラスコに、上記表１に記載の成分を入れ、攪拌しながら湯浴の温度を７５℃に上げ、その温度で２時間反応させることにより、イソプロパノール中に分散され、表面がシラン化合物で処理されたコロイダルシリカを得た。続いて、イソプロパノールを留去した後にトルエン（沸点１１０．６℃）を添加することを繰り返し、完全にイソプロパノールをトルエンに置換することにより、トルエン中に分散され、表面がシラン化合物で処理されたコロイダルシリカＳ１を得た。コロイダルシリカＳ１が分散したトルエン溶液の固形分は６３重量％であった。 B) Preparation of surface-treated colloidal silica S1

Into a flask equipped with a stirrer, a condenser and a thermometer, the components listed in Table 1 above were placed, and the temperature of the hot water bath was raised to 75 ° C. while stirring, and the reaction was continued for 2 hours at that temperature. Thus, colloidal silica whose surface was treated with a silane compound was obtained. Subsequently, isopropanol was distilled off and toluene (boiling point 110.6 ° C.) was repeatedly added. By completely replacing isopropanol with toluene, the colloidal was dispersed in toluene and the surface was treated with a silane compound. Silica S1 was obtained. The solid content of the toluene solution in which the colloidal silica S1 was dispersed was 63% by weight.

C) Preparation of photocurable casting liquid compositions 1 to 4 Using the thermoplastic resins A and B having a photopolymerizable functional group in the synthesized side chain, the surface-treated colloidal silica S1 and the compounds of Table 2, Photocurable cast liquid compositions 1 to 4 having compositions were prepared.

[Example 1]
The photocurable casting liquid composition 1 having the composition shown in Table 2 was stirred with a propeller mixer, and coated on an acrylene HBX-N47 (Mitsubishi Rayon Co., Ltd., 125 μm) with a comma roll coater with a coating width of 600 mm. Went.
Subsequently, a tunnel-type drying furnace (width 800 mm, height 100 mm, length 8 m, divided into four drying zones (one zone length 2 m)) set to the temperature conditions shown in Table 3 below is suitable for the movement of the sheet. The solvent was volatilized by passing it through a method in which hot air was fed so as to form a flow at a speed of 3 m / min to form a photocurable resin layer having a thickness of 8 μm. Table 3 shows the residence time of each drying zone at this time.

続いて、幅５５０ｍｍにスリットして２０ｍの長さにＡＢＳ製コアにロール状に巻き取った。
これらの光硬化性シートを光硬化性樹脂組成物が金型の内壁面に向かい合うように金型内に配置し、次いで赤外線ヒーター（温度３５０℃）で１０秒間シートを予備加熱した後、さらに加熱を行いながら真空吸引することにより金型形状にシートを追従させた。なお、この金型の形状は、切頭角錐形状で、切頭面のサイズは１００ｍｍ×１００ｍｍで、底面のサイズは１０８ｍｍ×１１７ｍｍ、深さは１０ｍｍであり、切頭面の端部の曲率半径がそれぞれ３，５，７，１０ｍｍであった。その際の金型追従性を目視で評価したところ、各端部とも良好に追従していた。

Subsequently, it was slit into a width of 550 mm and wound up in a roll shape around an ABS core to a length of 20 m.
These photocurable sheets are placed in the mold so that the photocurable resin composition faces the inner wall surface of the mold, and then the sheet is preheated with an infrared heater (temperature 350 ° C.) for 10 seconds and further heated. The sheet was made to follow the mold shape by vacuum suction while performing. The shape of this mold is a truncated pyramid, 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 radius of curvature of the edge of the truncated surface is Were 3, 5, 7, and 10 mm, respectively. When the mold following property at that time was visually evaluated, each end portion followed well.

Next, in-mold molding is performed using a polycarbonate resin as a molding resin under conditions of a molding temperature of 280 to 300 ° C. and a mold temperature of 40 to 60 ° C., thereby obtaining a molded product in which the photocurable sheet is in close contact with the surface of the molded product. It was. At this time, the stain on the molding die was visually evaluated. The results are shown in Table 4.
Next, using an ultraviolet irradiation device, ultraviolet rays of about 2400 mJ / cm ² were irradiated to cure the photocurable resin composition, and the surface physical properties were evaluated. As shown in Table 4, the adhesiveness between the photocurable resin composition layer and acryloprene HBX-N47 was good, and no peripheral peeling or cross-cutting peeling was observed in the peeling test. Other surface properties were also good.
Further, after being stored in a roll state at room temperature for about 2 weeks, the adhesiveness of the surface was evaluated while winding. The results are shown in Table 4.

[Sheet property evaluation method]
1) Adhesion:
In accordance with JIS K 5400, 100 squares of 1 × 1 mm width grids were prepared with a cutter, and a Nichiban cello tape was pressure-bonded and then peeled off at an angle of 90 degrees. Further, the appearance of the film was visually evaluated after repeating the pressure-bonding and peeling of the cello tape at the same site for a total of 5 times.
○: No change in appearance △: Peeling around the grid or slight peeling of the grids x: Peeling around the grids and / or peeling of the grids is remarkable 2) Pencil hardness test:
In accordance with JIS K 5400, evaluation was performed using Uni (trade name; manufactured by Mitsubishi Pencil Co., Ltd.) as a pencil.

3) Appearance, etc .:
About the external appearance of the produced hard coat sheet or resin molded product, the presence or absence of cracks in the coating film was observed.
4) Transparency:
In accordance with ASTM D1003, the total light transmittance and haze were measured using a haze meter.

5) Scratch resistance:
# 000 steel wool was attached to a 1-inch diameter circular pad, and this pad was placed on the surface of a sample held on a reciprocating abrasion tester table, and scratched by reciprocating 100 times under a load of 1000 g. After the sample was washed with ethanol, the haze value was measured with a haze meter. The numerical value represented by (clouding value after scratching) − (clouding value before scratching) was shown as scratch resistance (%).
6) Abrasion resistance:
The haze value was measured with a haze meter after a Taber abrasion test (the test was carried out at a load of 500 g on one side, a CS-10F abrasion wheel, a rotation speed of 60 rpm, and the number of tests of 500 times). And the numerical value represented by (the haze value after the test) − (the haze value before the test) was shown as wear resistance (%).

7) Acid resistance:
The appearance after a spot test of a 47% by weight sulfuric acid aqueous solution at 40 ° C. for 3 hours was visually evaluated.
○: Good △: Thin trace X: Remarkable trace 8) Warm water resistance:
The sheet state after being immersed in warm water at 40 ° C. for 24 hours was visually evaluated.
○: Good △: Thin whitening ×: Remarkable whitening 9) Weather resistance:
A sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.) was used to visually evaluate the appearance when the exposure test was performed for 2000 hours in a cycle of 48 minutes for drying and 12 minutes for rain.
○: Good ×: Whitening or cracking

[Example 2]
A photocurable sheet was produced in the same manner as in Example 1 except that the photocurable cast liquid composition 1 of Example 1 was changed to the combination shown in Table 4, and an in-mold molded product was obtained. The results are shown in Table 4.

[Comparative Examples 1 and 2]
A photocurable sheet was produced in the same manner as in Example 1 except that the photocurable cast liquid composition 1 of Example 1 was changed to the combination shown in Table 4, and an in-mold molded product was obtained. Adhesion between the photocurable resin composition layer of the obtained photocurable sheet and acrylprene HBX-N47 is poor, and no peeling is observed in one peeling test, but when the peeling test is repeated five times, Peeling around the eyes and peeling of grid cells were observed. The results are shown in Table 4.

[Examples 3 and 4]
In the same manner as in Examples 1 and 2, each photocurable cast liquid composition was coated on acryloprene HBX-N47 to produce a photocurable sheet having a photocurable resin layer having a thickness of 10 μm.
Subsequently, using an ink composed of pigments of black, brown, and yellow, a pattern was printed on the surface of Acryprene HBX-N47 by a gravure printing method, and then a photocurable decorative sheet was obtained. Since these sheets have no surface tackiness, printability was good.
After these photocurable decorative sheets are placed in the mold so that the photocurable resin composition faces the inner wall surface of the mold, the sheet is preheated for 15 seconds with an infrared heater (temperature of 300 ° C.). Further, 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., in-mold molding is performed using acrylonitrile / butadiene / styrene copolymer resin as a molding resin, and a photocurable decorative sheet is molded. A molded product adhered to the product surface was obtained. The mold following property and mold releasability of the sheet at that time were both good.
Next, by using an ultraviolet irradiation device, the photocurable resin composition is cured by irradiating with ultraviolet rays of about 2400 mJ / cm ² , and has a high surface hardness, excellent gloss, and has a printed pattern and excellent design. I got a product.

[Examples 5 and 6]
In the same manner as in Examples 1 and 2, each photocurable cast liquid composition was coated on acryloprene HBX-N47 to produce a photocurable sheet having a photocurable resin layer having a thickness of 10 μm.
Next, a pattern was printed on the surface of Acryprene HBX-N47 by using a gravure printing method using inks composed of pigments of black, brown and yellow. Since these sheets have no surface tackiness, printability was good.
Furthermore, after forming the contact bonding layer which consists of chlorinated polypropylene resin (chlorination degree 15%) by the gravure printing method on the printing surface, the photocurable decorating sheet was obtained.
After these photocurable decorative sheets are placed in the mold so that the photocurable resin composition faces the inner wall surface of the mold, the sheet is preheated for 15 seconds with an infrared heater (temperature of 300 ° C.). Further, the sheet was made to follow the mold shape by vacuum suction while further heating.
Next, under conditions of a molding temperature of 200 to 240 ° C. and a mold temperature of 30 to 60 ° C., a polypropylene resin (containing 20% by weight of talc and 10% by weight of ethylene-propylene rubber) is used as a molding resin. Molding was performed to obtain a molded product in which the photocurable decorative sheet was in close contact with the surface of the molded product. The mold following property and mold releasability of the sheet at that time were both good.
Next, using an ultraviolet irradiation device, the photocurable resin composition is cured by irradiating with an ultraviolet ray of about 2400 mJ / cm ² , has high surface hardness and wear resistance, excellent gloss, and has a printed pattern. A molded product having excellent properties was obtained.

As described above in detail, the molded product of the present invention includes a weather strip, a bumper, a bumper guard, a side mud guard, a body panel, a spoiler, a front grill, a strut mount, a wheel cap, a center pillar, a door mirror, a center ornament, and a side molding. , Door moldings, wind moldings, windows, head lamp covers, tail lamp covers, windshield parts, automotive exterior applications, instrument panels, console boxes, meter covers, door lock pezels, steering wheels, power window switch bases, center clusters, dashboards, etc. Automotive interior applications, front panels of AV equipment and furniture products, buttons, emblems, surface cosmetics, etc., mobile phone housings, display windows, buttons, etc. Furthermore, furniture exterior materials, wall interiors, ceilings, floors and other architectural interior materials, siding exterior walls, fences, roofs, gates, windbreak boards, and other architectural exterior materials, window frames, doors, handrails, and sills , Surface cosmetic materials for furniture such as Kamoi, various optical components such as displays, lenses, mirrors, goggles and window glass, interior and exterior applications for various vehicles other than automobiles such as trains, aircrafts, ships, bottles, cosmetics It can be suitably used for various packaging containers and materials such as containers and accessory cases, and various other uses such as miscellaneous goods such as prizes and accessories. In addition, on transparent resin, a surface with good wear resistance, weather resistance and chemical resistance can be formed while taking advantage of its transparency, and windows, headlamp covers, windshield parts of automobiles, railway vehicles, airplanes, etc. Etc. can be used suitably. In addition, the number of steps can be omitted compared to the case of painting the surface of the molded product, the productivity is good, and the influence on the environment is small.

Claims (9)

On the base sheet (B), which is a thermoplastic acrylic resin sheet having a crosslinked rubber component, a radically polymerizable unsaturated group is obtained in the side chain obtained by using a (meth) acrylate monomer as a main component. In the photocurable resin composition containing the thermoplastic resin (a-1) and the photopolymerization initiator (a-2), the number average molecular weight (Mn) of the thermoplastic resin (a-1) is from 5,000 to 5,000. A photocurable sheet having a layer (A) of a photocurable resin composition having a weight average molecular weight (Mw) / number average molecular weight (Mn) of 2,500,000 and a number average molecular weight (Mn) of 5 or less . A thermoplastic resin (a-3) having a hydroxyl group and / or a carboxylic acid group in the side chain in the presence of the compound (C) represented by the following structural formula (1): A photocurable sheet, which is a thermoplastic resin obtained by reacting a compound (a-4) having an epoxy group and a radically polymerizable unsaturated group in the same molecule .
(R ₁ R ₂ R ₃ R ₄ P) X (1)
(In the formula, R _{1 to} R ₄ are the same or different and each represents a hydrogen atom, a hydroxyl group, a halogen, a carboxyl group, a cyano group, an asino group, an alkoxy group, or an acetonyl group. Represents a chain or branched alkyl group, alkenyl group, benzyl group, aryl group or phenyl group, and X represents a hydroxyl group, a halogen or other acid group.) The thermoplastic resin (a-1) is a hydroxyl group in the same molecule as the thermoplastic resin (a-5) having an epoxy group in the side chain in the presence of the compound (C) represented by the following structural formula (1). And / or a thermoplastic resin obtained by reacting a compound (a-6) having a carboxylic acid group and a radically polymerizable unsaturated group .
(R ₁ R ₂ R ₃ R ₄ P) X (1)
(In the formula, R _{1 to} R ₄ are the same or different and each represents a hydrogen atom, a hydroxyl group, a halogen, a carboxyl group, a cyano group, an asino group, an alkoxy group, or an acetonyl group. Represents a chain or branched alkyl group, alkenyl group, benzyl group, aryl group or phenyl group, and X represents a hydroxyl group, a halogen or other acid group.) The photocurable sheet according to any one of claims 1 to 3, wherein the photocurable resin composition does not substantially contain a crosslinkable compound other than (a-1) . The photocurable sheet according to any one of claims 1 to 4, wherein the photocurable resin composition contains inorganic fine particles (a-7) . The light characterized in that any one or more of a printing layer, a vapor deposition layer, an adhesive layer and a primer are formed on the base sheet (B) side of the photocurable sheet according to any one of claims 1 to 5. Curable decorative sheet. A step of inserting and arranging the photocurable sheet or photocurable decorative sheet according to any one of claims 1 to 6 so that the photocurable resin composition side faces the inner wall surface of the mold, and the mold is closed. Injecting molten resin into the mold and solidifying the resin to form a resin molded product with a photocurable sheet or photocurable decorative sheet placed on the surface and the surface of the molded product by light irradiation A method for producing a molded product comprising the step of photocuring the photocurable resin composition. A step of inserting and arranging the photocurable sheet or photocurable decorative sheet according to any one of claims 1 to 6 so that the photocurable resin composition side faces the inner wall surface of the mold, the photocurable sheet or The process of preforming a photocurable decorative sheet and following the sheet to the mold shape, closing the mold, injecting molten resin into the mold, and solidifying the resin, the photocurable sheet or photocuring Manufacturing a molded product comprising a step of forming a resin molded product having a decorative decorative sheet disposed on a surface thereof, and a step of photocuring a photocurable resin composition on the surface of the molded product by light irradiation Method. A step of inserting and arranging the photocurable sheet or photocurable decorative sheet according to any one of claims 1 to 6 in a preforming mold so that the photocurable resin composition side faces the inner wall surface of the mold. , A step of preforming a photocurable sheet or a photocurable decorative sheet and following the shape of the mold, a preformed photocurable sheet or a photocurable decorative sheet, the photocurable resin composition side A process of inserting and placing in a molding die so as to face the inner wall surface of the mold, closing the molding die, injecting molten resin into the mold, and solidifying the resin, a photocurable sheet or photocuring A method for producing a molded product comprising: a step of forming a resin molded product having a decorative decorative sheet disposed on the surface thereof; and a step of photocuring the photocurable resin composition on the surface of the molded product by light irradiation .