JPH1036540A - Thermoformable sheet-like resin molded product excellent in scratch resistance and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molded product by providing the surface of a sheet-like basal form with a hard coat layer consisting of the cured product from a specific photocurable resin composition. SOLUTION: This molded product is obtained by providing the surface of a sheet-like basal form with a hard coat layer consisting of the cured product from a photocurable resin composition prepared by incorporating (B) a photopolymerization initiator and (C) an ultraviolet light absorber, etc., in (A) a monomer mixture of a polyfunctional (meth)acrylate mixture comprising (i) a polyfunctional (meth)acrylate bearing two or more (meth)acryloyloxy groups (AO groups) produced by condensation reaction between a dicarboxylic acid, a polyhydric alcohol and (meth)acrylic acid and (ii) another polyfunctional (meth)acrylate bearing two or more AO groups produced by reaction between an isocyanate of the formula (R<1> is a 1-12C aliphatic alkylene) and an active hydrogen-contg. (meth)acrylate, with each of the components (i) and (ii) having a viscosity of >=150cp at 25 deg.C, with (iii) a third polyfunctional (meth)acrylate bearing 1-2 AO group(s) with a viscosity of <150cp at 25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like resin molded article having a surface excellent in scratch resistance and capable of being thermoformed, and a method for producing the same.

[0002]

2. Description of the Related Art Polycarbonate resin, acrylic resin,
Polyolefin resins, polystyrene resins, and other resins have excellent impact resistance and transparency, and are used as highway sound insulation plates, automotive headlight lenses, helmet shields, goggles, and various equipment cover materials. ing. In particular, polycarbonate resins have transparency, impact resistance, electrical insulation, self-extinguishing properties, etc., and are widely used as industrial materials, building materials, etc., but due to their low surface hardness, scratches due to scratching etc. It has the drawback of being easily attached.

In order to improve the disadvantages of this polycarbonate resin, JP-A-53-102936 and JP-A-53-104638 disclose a compound having a plurality of (meth) acryloyloxy groups in a substrate molecule. A method is described in which a molded article having a scratch-resistant coating is obtained by applying the composition to a molded article and curing it with an active energy ray such as heat or ultraviolet rays, as disclosed in JP-A-48-26822 and JP-A-59-64.
No. 671 discloses a method in which an alkoxysilane compound is applied to a molded article and cured by heat, and attempts to form a scratch-resistant coating on the surface of the molded article are widely performed.

On the other hand, sheet-like resin molded products such as polycarbonate resin are widely used for final molding after secondary molding such as heating bending. Being sexual is very important. However, the three-dimensional cross-linked film formed on the surface of the molded product to improve the scratch resistance is hard and has an extremely low elongation compared to the polycarbonate resin or the like of the substrate, so that the three-dimensional cross-linked film has a low elongation. There is a problem that it cannot follow deformation and cracks occur.

[0005]

SUMMARY OF THE INVENTION The present inventors have studied to solve the above problems at the time of thermoforming of a sheet-like resin molded product having such a three-dimensional crosslinked film formed thereon, and as a result, have found that a specific (meth) acrylate If a photocurable resin composition using a monomer is coated on a resin sheet-like substrate and cured, a thermoformable sheet-like resin molding having a hard coat layer having excellent scratch resistance and solvent resistance It has been found that a product can be obtained, which has led to the present invention. An object of the present invention is to provide a sheet-like resin molded product having a surface excellent in scratch resistance and capable of being thermoformed.

[0006]

SUMMARY OF THE INVENTION The present invention provides a polyfunctional compound having two or more (meth) acryloyloxy groups in a molecule obtained by a condensation reaction of a dihydric carboxylic acid, a polyhydric alcohol and (meth) acrylic acid. (Meth) acrylate (a-
1) 1 to 99% by weight of a molecule having two or more (meth) acryloyloxy groups in a molecule obtained by reacting an isocyanate represented by the following general formula [1] with a (meth) acrylate having active hydrogen. Urethane (meth) acrylate (a-3) represented by the following general formula [2] having 99 to 1% by weight of a functional (meth) acrylate (a-2) and two or more (meth) acryloyloxy groups in a molecule. ) 0
(A-1), (a-2)
And (a-3) are polyfunctional (meth) acrylate mixtures (A ₁ ) having a viscosity at 25 ° C. of 150 cP or more, respectively.
80% by weight, having one or two (meth) acryloyloxy groups in the molecule and having a viscosity at 25 ° C. of 150 cP
Polyfunctional (meth) acrylate (A ₂ )
0.1 to 10 parts by weight of a photopolymerization initiator (B), 0 to 6 parts by weight of an ultraviolet absorber (C), and hindered amine-based light stability based on 100 parts by weight of a monomer mixture (A) consisting of 20% by weight. Excellent in heat-formable scratch resistance, characterized in that a hard coat layer made of a cured product of the photocurable resin composition to which 0 to 5 parts by weight of the agent (D) is added is provided on the surface of the sheet-like substrate. Sheet resin molded products,

[0007]

Embedded image

[0008]

Embedded image

Further, the photocurable resin composition is coated on one or both sides of a sheet-like substrate formed by a continuous extrusion molding method of a resin, and the light is applied in a state where a release film is adhered to the coated surface. Irradiating the coating layer to polymerize and cure the coating layer, and then peeling off the release film, thereby producing a thermoformable sheet-like resin molded article having excellent scratch resistance.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photocurable resin composition of the present invention comprises a monomer mixture (A), a photopolymerization initiator (B), an ultraviolet absorber (C) and a hindered amine light stabilizer (D).
And the monomer mixture (A) is a polyfunctional compound having two or more (meth) acryloyloxy groups in a molecule obtained by a condensation reaction of a dihydric carboxylic acid, a polyhydric alcohol and (meth) acrylic acid. (Meth) acrylate (a-
1) a polyfunctional (meth) acrylate having two or more (meth) acryloyloxy groups in a molecule obtained by reacting the isocyanate represented by the general formula [1] with a (meth) acrylate having active hydrogen (A-2) and a urethane (meth) acrylate (a-3) represented by the general formula [2] having two or more (meth) acryloyloxy groups in the molecule, and the (a-1) ),
(A-2) and (a-3) each have a viscosity at 25 ° C. of 150
Polyfunctional (meth) acrylate mixture having a cP or more (A
₁ ) and a polyfunctional (meth) acrylate (A ₂ ) having 1-2 (meth) acryloyloxy groups in the molecule and having a viscosity at 25 ° C. of less than 150 cP.

The urethane (meth) acrylate (a
-3), the ultraviolet absorber (C) and the hindered amine-based light stabilizer (D) are added as needed, and need not necessarily be included as constituent components.

Polyfunctional (meth) acrylate (a-1)
Is a main component for forming a hard coat layer having excellent scratch resistance on a sheet-like substrate, and comprises a hydroxyl group of a polyhydric alcohol and a carboxyl group of both a divalent carboxylic acid and (meth) acrylic acid. Group has two or more (meth) acryloyloxy groups in a molecule obtained by subjecting a mixture to a condensation reaction to be finally equivalent, and has a viscosity at 25 ° C of 150 cP or more. It is a saturated or unsaturated polyester poly (meth) acrylate.

Examples of the divalent carboxylic acid used in the synthesis of the polyfunctional (meth) acrylate (a-1) include aliphatic dicarboxylic acids such as succinic acid, adipic acid and sebacic acid;
Aromatic dicarboxylic acids such as tetrahydrophthalic acid, 3,6-endomethylenetetrahydrophthalic acid, other thioglycolic acid, thiodivalic acid, diglycolic acid, maleic acid, fumaric acid, itaconic acid, and chlorides thereof.
Anhydrides, esters and the like.

Further, a polyfunctional (meth) acrylate (a-
Examples of the polyhydric alcohol used in the synthesis of 1) include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol having an average molecular weight of about 300 to about 1,000, propylene glycol, dipropylene glycol. , 1,3
-Propanediol, 1,3-butanediol, 2,3
-Butanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,9
-Dihydric alcohols such as nonanediol, neopentyl glycol, 2-ethylhexyl-1,3-hexanediol, 2,2'-thiodiethanol, 1,4-cyclohexanedimethanol, trimethylolpropane, pentaglycerol, glycerol, And trihydric alcohols such as 2,2,4-butanetriol and 1,2,6-hexanetriol, and pentaerythritol and dipentaerythritol.

The polyfunctional (meth) acrylate (a-
Preferred specific examples of the combination of dihydric carboxylic acid, polyhydric alcohol and (meth) acrylic acid used in the synthesis of 1) are as follows.

Malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane /
(Meth) acrylic acid, malonic acid / glycerin / (meth)
Acrylic acid, malonic acid / pentaerythritol / (meth) acrylic acid, succinic acid / trimethylolethane /
(Meth) acrylic acid, succinic acid / trimethylolpropane / (meth) acrylic acid, succinic acid / glycerin / (meth) acrylic acid, succinic acid / pentaerythritol /
(Meth) acrylic acid, adipic acid / trimethylolethane / (meth) acrylic acid, adipic acid / trimethylolpropane / (meth) acrylic acid, adipic acid / glycerin / (meth) acrylic acid, adipic acid / pentaerythritol / ( (Meth) acrylic acid, glutaric acid / trimethylolethane / (meth) acrylic acid, glutaric acid / trimethylolpropane / (meth) acrylic acid, glutaric acid /
Glycerin / (meth) acrylic acid, glutaric acid / pentaerythritol / (meth) acrylic acid,

Sebacic acid / trimethylolethane / (meth) acrylic acid, sebacic acid / trimethylolpropane / (meth) acrylic acid, sebacic acid / glycerin / (meth) acrylic acid, sebacic acid / pentaerythritol /
(Meth) acrylic acid, fumaric acid / trimethylolethane / (meth) acrylic acid, fumaric acid / trimethylolpropane / (meth) acrylic acid, fumaric acid / glycerin /
(Meth) acrylic acid, fumaric acid / pentaerythritol / (meth) acrylic acid, itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, itaconic acid / glycerin / ( (Meth) acrylic acid, itaconic acid / pentaerythritol / (meth) acrylic acid, maleic anhydride / trimethylolethane / (meth) acrylic acid, maleic anhydride / trimethylolpropane / (meth) acrylic acid, maleic anhydride / glycerin / (Meth) acrylic acid, maleic anhydride / pentaerythritol / (meth) acrylic acid.

Polyfunctional (meth) acrylate (a-2)
Is a component that maintains the adhesiveness between the sheet-like substrate and the hard coat layer in thermoforming, the abrasion resistance, and the hardness of the hard coat layer when the sheet-like resin molded article of the present invention is obtained by the continuous production method described below. Having two or more (meth) acryloyloxy groups in the molecule obtained by reacting the isocyanate represented by the general formula [1] with a (meth) acrylate having active hydrogen, and having a viscosity at 25 ° C. Is 150
It is more than cP.

As the isocyanate represented by the general formula [1], for example, hexamethylene diisocyanate,
Diisocyanate obtained by reacting a diisocyanate such as tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, trimethylhexamethylene diisocyanate with a diol and an active hydrogen group-containing (meth) acrylate And the compounds obtained by the reaction with

The (meth) acrylate having active hydrogen is, for example, 2-hydroxyethyl (meth) acrylate.
Acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, N-methylol (meth) acrylamide, N-hydroxy ( (Meth) acrylamide, 1,2,3-propanetriol-1,3
-Dimethacrylate, 3-acryloyloxy-2-hydroxypropyl methacrylate and the like.

As the polyfunctional (meth) acrylate (a-2), isocyanate 1 represented by the above general formula [1]
Urethane (meth) acrylate obtained by reacting at least 3 moles of (meth) acrylate having an active hydrogen per molecule by a conventional method is preferably used.

The urethane (meth) acrylate (a-3) represented by the general formula [2] is a component that imparts flexibility to the hard coat layer and improves the thermoformability of the sheet-like resin molded product. , Urethane (meth) acrylate (a-3)
Examples thereof include dihydric alcohols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and polycaprolactone diol, and hexamethylene diisocyanate, phenylene diisocyanate, and 5-methylphenylene-1,3-diisocyanate. A reaction product of a polyisocyanate obtained by reacting a divalent isocyanate with a (meth) acrylate having active hydrogen is mentioned, which has two or more (meth) acryloyloxy groups in a molecule and has a viscosity at 25 ° C. It is 150 cP or more.

As the polyfunctional (meth) acrylate (A ₂ ) having 1-2 (meth) acryloyloxy groups in the molecule and having a viscosity at 25 ° C. of less than 150 cP, for example, methyl (meth) acrylate , Ethyl (meth) acrylate, butyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tetrahydrofurfuryl (meth) Acrylate,
1,4-butanediol di (meth) acrylate, 1,
6-hexanediol di (meth) acrylate, 1,9
-Nonanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate and the like.
Among them, 1,6-hexanediol diacrylate or 1,9-nonanediol diacrylate is preferred as the balance between the adhesion of the hard coat layer to the sheet-like substrate and the scratch resistance.

The monomer mixture (A) in the photocurable resin composition of the present invention is a polyfunctional (meth) acrylate (a)
-1) 1 to 99% by weight, preferably 10 to 90% by weight,
Polyfunctional (meth) acrylate (a-2) 99-1% by weight, preferably 90-10% by weight and urethane (meth)
Acrylate (a-3) consisting of 0-20% by weight polyfunctional (meth) acrylate mixture (A ₁₎ 20 to 80 wt%, preferably 30 to 70% by weight, polyfunctional (meth) acrylate (A ₂₎ 80 ~ 20% by weight, preferably 70
-30% by weight. In addition, polyfunctional (meth) acrylate (a-1), polyfunctional (meth) acrylate (a-
Each amount of 2) and urethane (meth) acrylate (a-3) indicates a range occupying in 100% by weight of the monomer mixture (A), and their total amount is 100% by weight.

The content of the polyfunctional (meth) acrylate mixture (A ₁ ) in the monomer mixture (A) is 20% by weight.
If it is less than 1, sufficient hardness cannot be imparted to the hard coat layer,
If it exceeds 80% by weight, a sheet-like resin molded product having good thermoformability cannot be obtained. When the content of the polyfunctional (meth) acrylate (A ₂ ) is less than 20% by weight, sufficient adhesion between the hard coat layer and the sheet-like substrate cannot be obtained. Sufficient hardness cannot be provided. Further, urethane (meth) acrylate (a-
3) is used as needed, but if it exceeds 20% by weight, the hardness of the hard coat layer is significantly reduced.

As the photopolymerization initiator (B) in the photocurable resin composition of the present invention, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, Benzyl, benzophenone, p-methoxybenzophenone,
2,2-diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,
4'-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, -Hydroxycyclohexylphenyl ketone, carbonyl compounds such as methylbenzoyl formate, trimethylbenzoyldiphenylphosphine oxide, acylophosphine compounds such as benzoyldiethoxyphosphine oxide,
Sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile; benzoyl peroxide; di-t
Peroxide compounds such as tert-butyl peroxide and the like can be mentioned. These are used alone or as a mixture.

In particular, the photocurable resin composition of the present invention is preferably a photocurable resin composition using a compound represented by the following general formula [3] as a photopolymerization initiator (B). By using the compound represented by the general formula [3], for example, the above-mentioned trimethylbenzoyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide, etc., sufficient curability can be obtained even with light irradiation through a release film. In addition, good curability can be obtained even when an ultraviolet absorber is present in the photocurable resin composition in order to improve weather resistance.

[0028]

Embedded image

The addition amount of the photopolymerization initiator (B) is 0.1 to 10 parts by weight based on 100 parts by weight of the monomer mixture (A). In some cases, sufficient hardness cannot be imparted to the coat layer, or the photo-curable resin composition does not cure at all. When the amount exceeds 10 parts by weight, banding of the hard coat layer becomes a problem.

The photocurable resin composition of the present invention includes:
For the purpose of shielding light and improving the weather resistance of the hard coat layer, an ultraviolet absorber (C) is added as necessary. As the ultraviolet absorber (C), for example, a benzotriazole-based, benzophenone-based, benzoate-based, or cyanoacrylate-based one is used. As specific examples of them,

For example, 2- (2'-hydroxy-5'-
tert-butylphenyl) benzotriazole, 2-
(2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-tert-butylphenyl)-
5-chlorobenzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,
2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2-hydroxybenzophenone,
-Chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2,2′- Dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,
4'-dimethoxybenzophenone, 2-hydroxy-4
-Dodecyloxybenzophenone, phenyl salicylate, p-tert-butylphenyl salicylate, 3-
Hydroxyphenyl benzoate, phenylene-1,3
-Benzoate, 2-ethylhexyl-2-cyano-
3,3′-diphenyl acrylate, ethyl-2-cyano-3,3′-diphenyl acrylate and the like can be mentioned.

The amount of the ultraviolet absorber (C) to be added is 0 to 6 parts by weight based on 100 parts by weight of the monomer mixture (A).
If the amount exceeds 6 parts by weight, the hardness of the hard coat layer is significantly reduced, and the thermoformability of the obtained sheet-like resin molded product is reduced.

Further, a hindered amine light stabilizer (D) is added to the photocurable resin composition of the present invention, if necessary, for the purpose of improving light resistance. Examples of the hindered amine light stabilizer (D) include 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethylpiperidyl) sebacate, bis (1,2) , 2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-
Tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2
2,6,6-pentamethyl-4-piperidyl) -1,
2,3,4-butanetetracarboxylate and the like. The amount of the hindered amine light stabilizer (D)
The amount is 0 to 5 parts by weight based on 100 parts by weight of the monomer mixture (A). When the amount exceeds 5 parts by weight, polymerization hardening of the coat layer is inhibited, and sufficient hardness is imparted to the hard coat layer. No, and the adhesion of the hard coat layer is reduced.

Further, the photocurable resin composition of the present invention may be used to improve the flexibility of the hard coat layer, improve the adhesion between the hard coat layer and the sheet-like substrate by reducing the amount of polymerization shrinkage, and adjust the viscosity. For the purpose, a polymer or copolymer of an alkyl acrylate and / or an alkyl methacrylate can also be added, and in order to maintain the hardness of the hard coat layer, 5 parts by weight based on 100 parts by weight of the monomer mixture (A) Is added within a range not exceeding.

Furthermore, additives such as an organic solvent, a surface smoothing agent, and a surfactant can be added to the photocurable resin composition of the present invention, if necessary.

The sheet-shaped resin molded article of the present invention has a hard coat layer made of a cured product of the photocurable resin composition on the surface of the sheet-shaped substrate. Examples of the sheet-like substrate of the sheet-like resin molded article of the present invention include a sheet-like resin molded article such as a polycarbonate resin, an acrylic resin, a transparent polyolefin resin, and a polystyrene resin.
The effect is great when the sheet-like substrate is a polycarbonate resin plate having a problem in scratch resistance. The polycarbonate resin is particularly preferably an aromatic polycarbonate resin. Further, the sheet-shaped substrate may be flat or curved.

Next, a method for producing the sheet-shaped resin molded product of the present invention will be described. The sheet-shaped resin molded product of the present invention is provided with a coating layer of the photocurable resin composition capable of forming a hard coat layer on one or both surfaces of a sheet-shaped substrate, and a light-transmitting release film on the coated surface. Is obtained by irradiating light to the coated surface to polymerize and cure the coated layer, and then peeling off the release film.

As described above, as the sheet-like substrate,
Sheet-like resin molded products such as polycarbonate resin, acrylic resin, transparent polyolefin resin, and polystyrene resin are used, and are preferably applied to a sheet-like resin molded product formed by a continuous extrusion molding method, and particularly a continuous extrusion molding method. When using the polycarbonate resin plate formed by the above, applying the above method subsequent to the formation of the polycarbonate resin plate by the continuous extrusion molding method can also produce the sheet-shaped resin molded product of the present invention continuously. It is possible and preferred.

When a hard coat layer is formed on the surface of the sheet-like substrate, the resin composition is coated on the surface of the sheet-like substrate and / or the surface of the release film and joined to form a resin on the surface of the sheet-like substrate. Although a coating layer of the composition is provided, as a method of coating the resin composition on the surface of the sheet-like substrate and / or the surface of the release film, a roller coating method, a bar coating method, a spray coating method, an air knife coating method, Any method such as a dipping method is used. The thickness of the coat layer is not particularly limited, but in order to have sufficient scratch resistance on the hard coat layer after polymerization and curing and to prevent cracks or the like from occurring after heating or bending, 1 to 20 μm
It is preferable to be within the range.

The release film used in the present invention is not particularly limited as long as it is a film that transmits light used when polymerizing and curing the uncured resin composition coat layer and does not hinder polymerization curing in the coat layer. However, it is preferable that the film has excellent solvent resistance, low oxygen permeability, and strength enough to withstand peeling and winding, and a polyethylene terephthalate film is preferably used. The thickness of the release film is 5 to 300 μm, preferably 10 to 200 μm.
m, and when the thickness of the film is less than 5 μm, the surface appearance of the hard coat layer becomes poor due to wrinkles of the film,
If it exceeds 300 μm, not only costs are increased, but also it becomes difficult to adjust the thickness of the hard coat layer.

In the present invention, the light source used to form the hard coat layer by irradiating the coated surface of the uncured resin composition with an electron beam, an infrared ray, an ultraviolet ray, and the like. Is a fluorescent chemical lamp,
Metal halide lamps, xenon lamps, high-pressure mercury lamps,
An ultra-high pressure mercury lamp, a low pressure mercury lamp, an arc lamp, or the like is used, and a light source suitable for the effective absorption wavelength of the photopolymerization initiator in the resin composition is selected. Further, as the light source, one or more light sources of the same type may be used, or different types of light sources may be used in combination.

When ultraviolet light is used as the light source, it is preferable that the ultraviolet irradiation energy be in the range of 10 to 10000 mJ / cm ² . When the ultraviolet irradiation energy is 10
If it is less than mJ / cm ² , sufficient abrasion resistance cannot be imparted to the hard coat layer, and if it exceeds 10,000 mJ / cm ² ,
Problems such as deterioration of the hard coat layer and the sheet-like substrate such as yellowing and deformation due to heat, and difficulty in peeling the release film may occur.

In the present invention, when irradiating light to the coated surface of the resin composition, the sheet-like substrate is brought into contact with the resin composition at a temperature of 30 to 70 ° C. in the first light irradiation. By heating, the uncured resin composition is impregnated in the range of 0.3 to 5 μm from the surface of the sheet-like substrate to form a swelling layer. In this state, the coating layer is polymerized and cured by light. A sheet-shaped resin molded product having a hard coat layer having excellent thermoformability as well as excellent adhesion can be obtained.

Therefore, it is preferable to heat the sheet-like substrate at the time of light irradiation in order to obtain the adhesiveness and thermal formability of the hard coat layer. The heating of the sheet-like substrate is performed by a method such as preheating the sheet-like substrate before coating the resin composition, heating the sheet-like substrate after coating the resin composition, or the like. It is sufficient that the sheet-like substrate is heated to 30 to 70 ° C. in a state where the sheet-like substrate is brought into contact with, for example, heating by an infrared heater or heat generated from a lamp in a light irradiation device can be used.

According to the present invention, the photocurable resin composition is
Since a sheet-like resin molded product having a hard coat layer can be manufactured by a method of sandwiching between a release film and a sheet-like substrate and curing in an anaerobic atmosphere created by the release film, a mold using a mold is used. There is a method of creating an anaerobic atmosphere between the substrate and the substrate, and a method of creating an anaerobic atmosphere as an inert gas atmosphere, but compared to these methods, it is necessary to manufacture a sheet-like resin molded product having a hard coat layer at a lower cost. Can be.

Further, according to the present invention, a photocurable resin composition of the present invention is coated on a curved substrate obtained by molding a resin by an appropriate method such as an injection molding method by a method such as a spraying method or a dipping method. Irradiation with light can form a hard coat layer.

Next, an example of a method of continuously producing a polycarbonate resin plate which can be thermoformed and has scratch resistance, which is a preferred application example of the present invention, will be described with reference to FIG.
In FIG. 1, a polycarbonate resin melted from a T-die 1 is extruded into a sheet, and the thickness of the sheet 2 is controlled by three rolls 3 to form a resin plate 4.
The release films 5 and 7 coated with the photocurable resin compositions 6 and 8 are bonded to both surfaces, and the thickness of the coat layer is controlled while adjusting the pressing pressure with a press roll 9.

Subsequently, the resin plate 4 having this coat layer
Then, the coat layer is polymerized and cured by irradiating light with the first light irradiators 10 and 11 to form a polycarbonate resin plate in which hard coat layers are adhered to both surfaces of the resin plate 4, and the mold is released via a press roll 12. The peelable films 13 and 14 are peeled to obtain a polycarbonate resin plate having a hard coat layer on both surfaces of the present invention. In FIG. 1, the polycarbonate resin plate is further cut through a predetermined length by passing it through the second light irradiation devices 16 and 16 in order to make polymerization hardening in the hard coat layer more complete.

The sheet-shaped resin molded article of the present invention can be subjected to heating bending with a radius of curvature of 50 to 150 mm. To bend the sheet-shaped resin molded article of the present invention into a secondary processed article, For example, using a polycarbonate resin plate having a hard coat layer according to the present invention, a mold is punched into a predetermined shape, for example, a shape of a helmet shield for a motorcycle, and the mold is placed in a heating furnace, and 150 to 200 ° C., preferably When the hard coat layer is on one side of the sheet-like substrate, the mold heated to 160 to 170 ° C. is placed in a forming die with the hard coat layer being on the outside, bent into a curved molded product, and taken out from the forming die after cooling. . The polycarbonate resin plate having the used hard coat layer does not peel off the hard coat layer from the base resin plate at the time of punching,
In addition, even if bending is performed, optical distortion does not occur,
It has characteristics as a helmet shield for motorcycles.

The sheet-like resin molded product of the present invention has excellent scratch resistance and can be thermoformed by bending with a radius of curvature of 50 to 150 mm. It is useful as a window material, a window material for a freezing showcase, a lens for a headlight of an automobile, a cover material for various devices, and the like.

Further, according to the present invention, the photocurable resin composition of the present invention is applied to a curved substrate obtained by molding a resin by an appropriate method such as an injection molding method as in the case of a lens for an automobile headlamp. Can be coated by a spraying method, a dipping method or the like, and a hard coat layer can be formed by light irradiation.

[0052]

The present invention will be described below in more detail with reference to examples. In addition, the measurement and evaluation of each physical property in the examples were based on the following methods.

<Scratch Resistance># 000 steel wool was mounted on a circular pad surface having a diameter of 25 mm, and the sample was fixed on a reciprocating friction tester table with the hard coat surface facing up. The sample was subjected to a steel wool test by placing a circular pad so that the steel wool surface was in contact with the tester and reciprocating the tester 100 times under a load of 200 g / cm ² . After the steel wool test was completed, the sample piece was washed and dried, and the haze value of the sample piece was measured as a haze value using a haze meter. Scratch resistance (%) = Haze value (%) of test piece after steel wool test-Haze value (%) of test piece before steel wool test

<Adhesion of Hard Coat Layer> 11 cuts were made on the hard coat surface of the sample with a razor blade at 1 mm intervals in each of the vertical and horizontal directions to make 100 eyes, and a cellophane tape (Nichiban (Nichiban After sticking an adhesive tape (manufactured by K.K. Co., Ltd.), the operation of peeling at a stretch in the direction of 90 ° was repeated three times, and the number (n) of the remaining eyes of the hard coat layer without peeling was n / 1.
Indicated by 00.

<Thermoformability> A sample cut into a 100 mm square was heated in a hot air oven at 160 ° C. for 10 minutes. Thereafter, the sample taken out was bent into a single curved surface using a wooden mold having a curvature of 15 mm, and the state of the hard coat surface of the sample was visually judged. ：: No crack generation ×: Crack generation

<Weather Resistance> Using a sunshine weather meter (WEL-SUN-DC type, manufactured by Suga Test Instruments Co., Ltd.), at a black panel temperature of 63 ° C., rainfall of 12 minutes, drying of 4
A weather resistance test was performed by exposing for 500 hours at a cycle of 8 minutes, and the yellowing degree (ΔYI), haze value and adhesion of the hard coat layer after the weather resistance test were evaluated.

Example 1 A cross-linked compound (hereinafter abbreviated as TAS) 20 as a polyfunctional (meth) acrylate (a-1) condensed at a molar ratio of succinic acid / trimethylolethane / acrylic acid of 1: 2: 4. A multifunctional (meth) acrylate comprising 20 parts by weight of a urethane pentaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester U-6HA, hereinafter abbreviated as U-6HA) as a polyfunctional (meth) acrylate (a-2) )
Acrylate (A ₁ ) and 60 parts by weight of 1,6-hexanediol diacrylate (manufactured by Osaka Organic Chemical Co., Ltd., viscosity 6 cP / 25 ° C., hereinafter abbreviated as C6DA) as polyfunctional (meth) acrylate (A ₂ ) And the mixture (A)
And 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TP manufactured by BASF) as a photopolymerization initiator (B) in the mixture (A).
O, hereinafter abbreviated as TPO) 3 parts by weight and benzophenone 1
A part by weight was added and dissolved by stirring to prepare a photocurable resin composition.

The polycarbonate is melt-extruded and formed into a sheet from a T-die, and is passed through three rolls to a thickness of 2 m.
m polycarbonate plate. After preheating this polycarbonate plate to 50 ° C. in a hot air drying oven, a biaxially stretched polyethylene terephthalate biaxially stretched film having a film thickness of 50 μm coated with the photocurable resin composition on the upper and lower surfaces of the polycarbonate plate (Diafoil Co., Ltd.) Made)
Are joined so that their coat surfaces are in contact with each other.
The resin composition was ironed with a rubber press roll having an IS hardness of 40 °, and the thickness of the hard coat layer was set to 8 µm. The polyethylene terephthalate biaxially stretched film was used as a release film.

Thereafter, the contact state between the coat layer and the polycarbonate plate was maintained for 50 seconds, and the output power of 120 w
/ Cm ozone-less type metal halide lamp is disposed at a distance of 210 mm with the film side up.
The coating layer was polymerized and cured by passing at a speed of 6 m / min.
Thereafter, the film was peeled off to obtain a polycarbonate plate having a hard coat layer. In addition, the temperature on the film surface is set to 40 to 100 μm from the time when the thickness of the hard coat layer is set to be 8 μm to the time when the first-stage metal halide lamp is irradiated.
43 ° C. Table 1 shows the evaluation results of the obtained polycarbonate plate having the hard coat layer.

(Examples 2, 3, 5, and 7) A polycarbonate plate having a hard coat layer was obtained in the same manner as in Example 1 except that the photocurable resin composition prepared with the composition shown in Table 1 was used. . Table 1 shows the evaluation results of the obtained polycarbonate plates. In Example 7, Tinuvin PS was used as an ultraviolet absorber (C) in the photocurable resin composition.
(Ciba Geigy, hereinafter abbreviated as TV-PS) 4 parts by weight was used.

Example 4 20 parts by weight of TAS as polyfunctional (meth) acrylate (a-1), polyfunctional (meth) acrylate
10 parts by weight of U-6HA as acrylate (a-2) and C6D as polyfunctional (meth) acrylate (A ₂ )
A of 70 parts by weight was mixed, and 3 parts by weight of TPO and 1 part by weight of benzophenone as a photopolymerization initiator (B) were added to the mixture, followed by stirring and dissolution to prepare a photocurable resin composition.

After a polycarbonate plate having a thickness of 2 mm obtained in the same manner as in Example 1 was preheated to 40 ° C. in a hot air drying oven, the upper and lower surfaces of the polycarbonate plate were coated with the photocurable resin composition. A 50 μm-thick biaxially stretched polyethylene terephthalate film is joined so that the coated surfaces thereof are in contact with each other, and the resin composition is pressed with a rubber press roll having a JIS hardness of 40 ° to form a hard coat layer having a thickness of 8 μm. Was set as follows.

Then, after maintaining the contact state between the coat layer and the polycarbonate plate for 20 seconds, an output of 120 w
/ Cm ozone-less type metal halide lamp is disposed at a distance of 210 mm with the film side up.
The coating layer was polymerized and cured by passing at a speed of 6 m / min.
Thereafter, the film was peeled off, and further irradiated with an ozone-less high-pressure mercury lamp having an output of 120 w / cm for a distance of 210 m.
m at a speed of 1.6 m / min to complete the curing of the coat layer to obtain a polycarbonate plate having a hard coat layer. In addition, the temperature on the film surface was 33 to 35 ° C. from the time when the thickness of the hard coat layer was set to be 8 μm to the time when the first stage metal halide lamp irradiation was performed. Table 1 shows the evaluation results of the obtained polycarbonate plate having the hard coat layer.

Example 6 20 parts by weight of TAS as a polyfunctional (meth) acrylate (a-1), a polyfunctional (meth) acrylate
20 parts by weight of U-6HA as the acrylate (a-2) and urethane pentaacrylate as the urethane (meth) acrylate (a-3) (Shin-Nakamura Chemical Co., Ltd.)
And NK ester U-108A (hereinafter abbreviated as U-108A), 7.5 parts by weight, and 52.5 parts by weight of C6DA as a polyfunctional (meth) acrylate (A ₂ ). As B), 3 parts by weight of TPO and 1 part by weight of benzophenone were added and dissolved by stirring to prepare a photocurable resin composition.

On the upper and lower surfaces of a polycarbonate plate having a thickness of 2 mm obtained in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film having a film thickness of 50 μm coated with the photocurable resin composition was coated. At the same time, the resin composition was pressed with a rubber press roll having a JIS hardness of 40 mm, and the thickness of the hard coat layer was set to 8 μm.

Then, after maintaining the contact state between the coat layer and the polycarbonate plate for 120 seconds, the output 120
The coating layer was polymerized and cured by passing through a w / cm ozone-less type metal halide lamp at a speed of 1.6 m / min with the film surface facing upward at a distance of 210 mm. Thereafter, the film is peeled off, and the output is 120 w / c.
m under an ozone-less high-pressure mercury lamp
It was passed at a speed of 1.6 m / min at a distance of 0 mm to complete the curing of the coat layer, and a polycarbonate plate having a hard coat layer was obtained. Note that the thickness of the hard coat layer is 8 μm.
The temperature on the film surface is 40 to 43 ° C. during the period from the setting so as to irradiate the first stage metal halide lamp.
Met. Table 1 shows the evaluation results of the obtained polycarbonate plate having the hard coat layer.

[0067]

[Table 1]

The abbreviations in Table 1 have the following meanings. M-8030: Aronix M-8030 (manufactured by Toa Gosei Chemical Industry Co., Ltd.) THFA: tetrahydroxyfurfuryl acrylate, viscosity 2.8 cP / 25 ° C. D-1173: Darocure-1173 (manufactured by Merck) V-55: Vicure -55 (manufactured by Stoffer Chemical Company)

Comparative Example 1 10 parts by weight of TAS as polyfunctional (meth) acrylate (a-1), polyfunctional (meth)
5 parts by weight of U-6HA as acrylate (a-2),
C6DA as polyfunctional (meth) acrylate (A ₂ )
85 parts by weight, and the photopolymerization initiator (B) was added to the mixture.
And 3 parts by weight of TPO and 1 part by weight of benzophenone were added and dissolved by stirring to prepare a photocurable resin composition.

After a polycarbonate plate having a thickness of 2 mm obtained in the same manner as in Example 1 was preheated to 50 ° C., the upper and lower surfaces of the polycarbonate plate were coated with the photocurable resin composition to a film thickness of 50 μm. The polyethylene terephthalate biaxially stretched film was joined so that the coated surfaces thereof were in contact with each other, and the resin composition was pressed with a rubber press roll having a JIS hardness of 40 ° to set the thickness of the hard coat layer to 8 μm.

Then, after maintaining the contact state between the coat layer and the polycarbonate plate for 50 seconds, an output of 120 w
/ Cm ozone-less type metal halide lamp is disposed at a distance of 210 mm with the film side up.
The coating layer was polymerized and cured by passing at a speed of 6 m / min.
Thereafter, the film was peeled off, and further irradiated with an ozone-less high-pressure mercury lamp having an output of 120 w / cm for a distance of 210 m.
m at a speed of 1.6 m / min to complete the curing of the coat layer to obtain a polycarbonate plate having a hard coat layer. In addition, the temperature on the film surface was 40 to 43 ° C. from the time when the thickness of the hard coat layer was set to be 8 μm to the time when the first-stage metal halide lamp irradiation was performed. Table 2 shows the evaluation results of the obtained polycarbonate plate having the hard coat layer.

(Comparative Examples 2 to 5) A polycarbonate plate having a hard coat layer was obtained in the same manner as in Example 1 except that the photocurable resin compositions prepared with the compositions shown in Table 2 were used. Table 2 shows the evaluation results of the obtained polycarbonate plates. The abbreviation DPHA in Table 2 is an abbreviation for dipentaerythritol hexaacrylate.

(Comparative Example 6) In Example 1, except that the thickness of the hard coat layer was set to be 25 μm.
A polycarbonate plate having a hard coat layer was obtained in the same manner as in Example 1. Table 2 shows the evaluation results of the obtained polycarbonate plates.

(Comparative Example 7) A polycarbonate plate having a hard coat layer was obtained in the same manner as in Example 1, except that 10 parts by weight of TV-PS was used as the ultraviolet absorbent (C). Table 2 shows the evaluation results of the obtained polycarbonate plates.

Reference Example 2 mm thick polycarbonate plate without a hard coat layer (Mitsubishi Rayon Co., Ltd.)
Table 2 shows the evaluation results of the products (Dialite).

[0076]

[Table 2]

(Example 8) The polycarbonate sheet having the hard coat layer obtained in Examples 1 and 7 and the polycarbonate sheet of the reference example were subjected to a weather resistance test, and the yellowing degree (ΔYI) after the weather resistance test was measured. Table 3 shows the evaluation results of the haze value, the haze value and the adhesion of the hard coat layer.

[0078]

[Table 3]

(Examples 9 to 11 and Comparative Examples 8 to 10) The procedure of Example 1 was repeated, except that the composition of the photocurable resin composition and the thickness of the hard coat layer were changed as shown in Table 4. In the same manner as in Example 1, a polycarbonate plate having a hard coat layer was obtained. Table 4 shows the evaluation results of the obtained polycarbonate plates. When the component (a-2) was not contained (Comparative Examples 8 to 10), the scratch resistance was reduced, the thermoformability was also reduced, and the radius of curvature was 30 irrespective of the thickness of the hard coat layer.
Even with gentle bending in mm, the thermoformability is poor.

[0080]

[Table 4]

(Examples 12 to 14, Comparative Examples 11 to 13)
Except that the thickness of the hard coat layer was set to be 8 μm and the temperature on the film surface between the irradiation of the first stage metal halide lamp was changed as shown in Table 5, the same as Example 1 was performed. Thus, a polycarbonate plate having a hard coat layer was obtained. Table 5 shows the evaluation results of the obtained polycarbonate plates. When the component (a-2) is not contained (Comparative Examples 11 to 13), the scratch resistance is reduced and the thermoformability is also reduced regardless of the temperature on the film surface.

[0082]

[Table 5]

[0083]

The sheet-like resin molded article of the present invention has a surface excellent in scratch resistance and can be thermoformed, and is subjected to secondary molding such as heating bending to obtain a final product. It is suitable for the use to be performed. In addition, such a sheet-like resin molded product can be obtained at low cost and with high productivity by a method of producing the sheet-like resin molded product under an anaerobic atmosphere using the film of the present invention.

[Brief description of the drawings]

FIG. 1 is a process chart of an example of a method for continuously producing a polycarbonate resin plate as a sheet-like resin molded product of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 T die 2 Sheet material 3 Roll 4 Resin plate 5 Release film 6 Photocurable resin composition 7 Release film 8 Photocurable resin composition 9 Press roll 10 Light irradiation device 11 Light irradiation device 12 Press roll 13 Release Film 14 Release Film 15 Light Irradiation Device 16 Light Irradiation Device 17 Resin Pool 18 Resin Pool

Claims (4)

[Claims] 1. A polyfunctional (meth) acrylate (a-1) having two or more (meth) acryloyloxy groups in a molecule obtained by a condensation reaction of a dihydric carboxylic acid, a polyhydric alcohol and (meth) acrylic acid. 1) to 99% by weight, a polyfunctional compound having two or more (meth) acryloyloxy groups in a molecule obtained by reacting an isocyanate represented by the following general formula [1] with a (meth) acrylate having active hydrogen. (Meth) acrylate (a-2) 99 to 1% by weight
And a urethane (meth) represented by the following general formula [2] having two or more (meth) acryloyloxy groups in the molecule
The acrylate (a-3) is composed of 0 to 20% by weight, and (a-1), (a-2) and (a-3) are each at 25 ° C.
20-80% by weight of a polyfunctional (meth) acrylate mixture (A ₁ ) having a viscosity of
Polyfunctional (meth) having ２2 (meth) acryloyloxy groups and having a viscosity at 25 ° C. of less than 150 cP
Acrylate (A ₂₎ 80 to 20% by weight consisting of the monomer mixture (A) 100 parts by weight of contrast, the photopolymerization initiator (B) 0.1 to 10 parts by weight, the ultraviolet absorber (C) Less than six
Thermoforming characterized by having a hard coat layer made of a cured product of a photocurable resin composition obtained by adding 0 to 5 parts by weight of a hindered amine light stabilizer (D) on the surface of a sheet-like substrate. Sheet-like resin molded product with excellent possible scratch resistance. Embedded image Embedded image 2. The photopolymerization initiator (B) has the following general formula [3]:
The sheet-shaped resin molded article according to claim 1, which is a compound represented by the formula: Embedded image 3. The heat-moldable sheet-like resin molded article having excellent scratch resistance according to claim 1, wherein the sheet-shaped substrate is a polycarbonate resin plate. 4. The photocurable resin composition according to claim 1 or 2 is coated on one or both surfaces of a sheet-like substrate formed by a continuous extrusion molding method of a resin, and a release film is formed on the coated surface. A method for producing a thermoformable, scratch-resistant, sheet-like resin molded article characterized in that a release layer is peeled off after polymerizing and curing the coat layer by irradiating light in a state in which the resin is adhered. .