TW201710361A - Free radical curable composition, plastic sheet, plastic sheet reel and molded product having excellent optical properties, surface hardness, and impact resistance to improve EL display - Google Patents

Abstract

The present invention Is to provide a free radical curable composition for forming a plastic sheet having excellent optical properties, surface hardness, and impact resistance, and is easy for winding, which is a molded product formed through 3-dimentional molding as a final cured product. The present invention Is to provide a free radical curable composition, comprising the following ingredients (A),(B),(C), and (D). (A) comprises polyfunctional urethane (meth)acrylate having an alicyclic structure; (B) comprises polyfunctional (meth)acrylate having an alicyclic structure (but does not contain the ingredient (A) mentioned above; (C) comprises (meth)arcylate resin having an alicyclic structure and the molecular weight is from 50 thousands to 700 thousands; (D) a polymerization initiator.

Description

Free radical curable composition, plastic sheet, plastic sheet reel and formed product

The present invention relates to a radical hardening composition for forming a plastic sheet, and more particularly to a radical hardening composition for forming a plastic sheet, which is easily formed to wind a plastic sheet. The plastic sheet roll is further provided with a molded article excellent in optical characteristics, surface hardness, and impact resistance of the molded product to be the final cured product.

Conventionally, in the case of a substrate for a display, glass is often used as a substrate. For example, the protective sheet is generally made of a chemically strengthened glass substrate having a thickness of about 0.5 to 2 mm. Further, the touch panel substrate is generally made of a glass substrate having a thickness of about 0.2 to 1.1 mm. Further, a liquid crystal display or an organic electroluminescence (organic EL) display generally uses a glass substrate having a thickness of about 0.2 to 0.7 mm.

On the other hand, in recent years, consideration has been given to the viewpoint of light weight and safety, and in order to manufacture a flexible display, a plastic substrate has also been used. In fact, polymethyl methacrylate (PMMA), polycarbonate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or resin sheets are used. Hard coated film substrate. For such a plastic substrate, optical properties such as light transmittance and birefringence need not be said, and mechanical properties such as heat resistance, coefficient of linear expansion, mechanical properties such as surface hardness or flexural modulus, water absorption or specific gravity, and High processing suitability such as chemical resistance and solvent resistance.

In order to satisfy these characteristics, many resins have been proposed regardless of thermoplasticity or thermosetting property. In particular, a substrate in which a sheet formed of such resins is subjected to a hard coating treatment to improve the surface hardness has been proposed, but the current situation is that the surface hardness exceeding the glass is not obtained.

Further, in recent years, a molded body obtained by photohardening a specific photopolymerizable composition can also be seen. For example, it has been revealed that a resin having a high pencil hardness can be obtained from a photopolymerizable composition composed of a polyfunctional urethane (meth) acrylate having an alicyclic structure and a polyfunctional (meth) acrylate having an alicyclic structure. A molded body (for example, refer to Patent Document 1), and a polyfunctional urethane (meth) acrylate having an alicyclic structure, a polyfunctional urethane (meth) acrylate having an alicyclic structure, and A photopolymerizable composition comprising a polyfunctional (meth) acrylate having an alicyclic structure can obtain a resin molded article having excellent optical properties and thermomechanical properties (for example, see Patent Document 2).

The techniques disclosed in Patent Documents 1 and 2 can obtain a plastic sheet having a high surface hardness, but these are formed by injection molding a photocurable composition between two glass sheets by a batch type to manufacture a plastic. Tablets and get a flat plastic sheet. Therefore, the three-dimensional forming process cannot be further performed on the obtained plastic sheet. The "three-dimensional forming process" means a method of forming a three-dimensional molded article from a conventional plastic sheet in which only a flat molded product can be obtained, or in a direction other than the plane, for example, can be formed in a substantially vertical direction.

Furthermore, in recent years, consideration has been given to the consideration of lightweighting and designing, and the demand for three-dimensional forming of plastic sheets is increasing. Moreover, in the manufacture of plastic sheets, methods have also been studied in a continuous rather than batch process. For example, it is also conceivable to apply a photocurable composition to the support film and irradiate the active energy ray. However, when the photocurable composition is used as described above, since the viscosity of the photocurable composition is low, the coating property is poor and cannot be performed. Get good plastic sheets, especially thick film plastic sheets. Further, the plastic sheet obtained by applying the photocurable composition alone and irradiating the active energy ray and hardening does not have flexibility to be stored in a roll state, and the three-dimensional forming process cannot be performed.

For example, Patent Document 3 describes a method in which, when a plastic sheet is continuously produced, when it is wound around a reel and conveyed between reels, the support sheet is further peeled off without cracking or cracking. The plastic sheet is a method in which the bending elastic modulus of the designated portion of the both end portions is lower than the bending elastic modulus of the designated portion of the central portion in the width direction of the plastic sheet. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. 2007-193

[Problems to be Solved by the Invention] However, the technique of Patent Document 3 only considers the hardening of the end portion of the plastic sheet, and it is difficult to obtain an optically and mechanically uniform sheet. Further, the reaction rate of at least a part of the plastic sheet exceeds 80%, and it is difficult to use the plastic sheet for subsequent three-dimensional forming processing.

Accordingly, the present invention is directed to such a background and aims to provide a radical hardening composition for forming a plastic sheet which is easy to form a plastic sheet reel which is obtained by winding a plastic sheet, and further obtained A molded article excellent in optical characteristics, surface hardness, and impact resistance of a molded article obtained by stereoscopically forming a cured product. Further, it is also intended to provide a plastic sheet, a plastic sheet reel, and a molded article obtained by stereolithography using the radical curable composition. [Means for solving the problem]

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a polyfunctional urethane (meth) acrylate having an alicyclic structure, a polyfunctional (meth) acrylate having an alicyclic structure, and The radically curable composition of the polymerization initiator further contains a (meth)acrylic resin having an alicyclic structure having a molecular weight which is not too high and has a moderate molecular weight, and can increase the viscosity of the radical curable composition. Therefore, it is easy to continuously form a plastic sheet roll obtained by winding a plastic sheet obtained by hardening, and further, it is also thickened, and has optical characteristics of a molded product obtained by stereoscopically forming a final cured product. The present invention has been completed by an effect of excellent surface hardness and impact resistance.

That is, the gist of the present invention is the following <1> to <9>. <1> A radical curable composition comprising the following components (A), (B), (C), and (D). (A) Polyfunctional urethane (meth) acrylate having an alicyclic structure (B) A polyfunctional (meth) acrylate having an alicyclic structure (however, the aforementioned component (A) is not included.) (C a (meth)acrylic resin (D) polymerization initiator having an alicyclic structure having a weight average molecular weight of 50,000 to 700,000, and a radical curable composition according to <1>, wherein the alicyclic ring has an alicyclic ring The content of the (meth)acrylic resin (C) of the structure relative to the polyfunctional urethane (meth) acrylate (A) having an alicyclic structure and the polyfunctional (methyl) having an alicyclic structure The total amount of the acrylate (B) is from 1 to 30 parts by weight per 100 parts by weight. <3> The radically curable composition of <1> or <2>, wherein the (meth)acrylic resin (C) having an alicyclic structure is a mono(meth)acrylate having an alicyclic structure (c1) a homopolymer. <4> The radical curable composition according to any one of <1> to <3>, further comprising the following component (E). (E) A compound containing a mercapto group. The radical curable composition according to any one of <1> to <4>, which has a viscosity at 23 ° C of 100 to 20,000 mPa·s.

<6> A plastic sheet obtained by hardening a radical curable composition according to any one of <1> to <5>; characterized in that the reaction rate of (meth)acryl fluorenyl group is 50% The above is less than 75%. <7> A plastic sheet such as <6>, which has a thickness of 50 to 10,000 μm. <8> A plastic sheet reel which is wound with a plastic sheet such as <6> or <7>. <9> A molded article obtained by molding a plastic sheet such as <6> or <7> or a plastic sheet wound from a plastic sheet roll such as <8>; characterized by: (methyl The reaction rate of the acrylonitrile group is 75% or more. [Effects of the Invention]

The radically curable composition of the present invention can form a plastic sheet having a desired film thickness by containing the components (A) to (D), and can easily form a wound plastic sheet roll, and further, it can be obtained. A molded article having excellent optical properties, surface hardness, and impact resistance of the molded product of the final cured product. Further, by adjusting the content of the component (C), the viscosity of the radical curable composition can be increased, and the impact resistance of the molded article of the final cured product can be adjusted.

The invention will be described in detail below. In the present invention, "(meth)acrylate" is a generic term for acrylate and methacrylate, and "(meth)acrylic acid" is a generic term for acrylic acid and methacrylic acid. Further, the term "multifunctional" as used herein means having two or more (meth)acryl fluorenyl groups in the molecule.

<Description of Radical Curing Composition> The radical curable composition of the present invention contains the following components (A), (B), (C) and (D). (A) Polyfunctional urethane (meth) acrylate having an alicyclic structure (B) A polyfunctional (meth) acrylate having an alicyclic structure (however, the aforementioned component (A) is not included.) (C (meth)acrylic resin (D) polymerization initiator having an alicyclic structure and having a weight average molecular weight of 50,000 to 700,000

(Polyfunctional amine ethyl acrylate (meth) acrylate having an alicyclic structure: component (A)) The component (A) is an urethane containing two or more (meth) acrylonitrile groups in the molecule ( Methyl) acrylate. Since it is multi-functional, the hardening speed is improved, and the plastic sheet can be obtained with good productivity. Further, by the radical polymerization reaction by heat or light, a crosslinked resin can be formed, and a plastic sheet having a high surface hardness can be obtained. Further, since the component (A) has an urethane group in the molecule, a flexible plastic sheet excellent in mechanical strength such as flexural modulus and impact resistance can be obtained by hydrogen bonding. The improvement in surface hardness can be exhibited, in particular, by using a tetrafunctional or higher urethane (meth) acrylate. Further, the polyfunctional urethane (meth) acrylate (A) has an alicyclic structure in the molecule, and the alicyclic structure can reduce the water absorption of the plastic sheet.

The number average molecular weight of the component (A) is preferably from 200 to 5,000. 400 to 3,000 is better, and 500 to 1,000 is especially preferred. When the number average molecular weight is too small, the hardening shrinkage tends to increase and birefringence tends to occur. On the other hand, if it is too large, crosslinkability will fall and heat resistance will fall.

A polyfunctional urethane (meth) acrylate having an alicyclic structure of the component (A), which can be obtained by using a catalyst such as dibutyltin dilaurate or the like, and a polyisocyanate compound having an alicyclic structure, and It is obtained by reacting a hydroxyl group (meth) acrylate.

Specific examples of the polyisocyanate compound having an alicyclic structure include, for example, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and 1,4-double. (Isocyanatomethyl)cyclohexane, hydrogenated dimethylenedi-isocyanate, hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate terpolymer compound, and the like. Among them, isophorone diisocyanate is preferred in view of good light resistance.

Specific examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. , 2-hydroxy-3-(methyl)propene oxime (meth)acrylate, neopentyl tris(meth)acrylate, dipentaerythritol penta(meth)acrylate, tris(A) Base) dipentaerythritol acrylate and the like. Among them, in terms of surface hardness, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and neopentyl glycol tri(meth)acrylate are preferred. Tetrakilyl tris(meth)acrylate is particularly preferred.

a polyfunctional urethane (meth) acrylate (A) having an alicyclic structure obtained by a reaction of a polyisocyanate compound having an alicyclic structure and a hydroxyl group-containing (meth) acrylate, in a free radical The curable composition may be used in combination of two or more kinds. In the above-mentioned reactants, acrylate is preferred in view of the curing rate, and tetrafunctional or higher is more preferable from the viewpoint of heat resistance, and the following formulas (1) to (4) are considered in terms of surface hardness. A tetrafunctional or higher urethane (meth) acrylate having an alicyclic structure is particularly preferred.

【化1】

[Chemical 2]

[化3]

In the formula (3), R _{1 is} each independently hydrogen or methyl.

【化4】

(Polyfunctional (meth) acrylate having an alicyclic structure: component (B)) Component (B) is also a polyfunctional (meth) acrylate, so that a plastic sheet having high heat resistance can be obtained. Compared with the ethyl carbamate (meth) acrylate of the component (A), the heat resistance is improved, but only the monomer is too much to form a glass like crosslinked resin. brittle. Therefore, it is preferred to blend and copolymerize the ethyl urethane (meth) acrylate of the component (A) with the polyfunctional (meth) acrylate of the component (B) in a specific ratio. Thereby, a plastic sheet having good surface hardness, heat resistance, and flexibility can be obtained. When the number of functional groups of the component (B) is too large, the balance between heat resistance and flexibility tends to be unbalanced. Therefore, the component (B) is preferably a bifunctional one, and further preferably a methacrylate. Further, the component (B) also has an alicyclic structure, and the alicyclic structure can also reduce the saturated water absorption rate of the plastic sheet.

The polyfunctional (meth) acrylate having an alicyclic structure of the component (B) (however, the component (A) is not included.), for example, bis(hydroxy)tricyclo[5.2.1.0 ^2,6 ]decane can be cited. Di(meth)acrylate, bis(hydroxymethyl)tricyclo[5.2.1.0 ^2,6 ]decane di(meth)acrylate, bis(hydroxy)tricyclo[5.2.1.0 ^2,6 ]decane Acrylate methacrylate, bis(hydroxymethyl)tricyclo[5.2.1.0 ^2,6 ]decane acrylate methacrylate, bis(hydroxy)pentacyclic ring [6.5.1.1 ^3,6 .0 ^2,7 .0 ^9,13 ] pentadecane di(meth) acrylate, bis(hydroxymethyl) pentacycle [6.5.1.1 ^3,6 .0 ^2,7 .0 ^9,13 ] pentadecane di(methyl) Acrylate, bis(hydroxy)pentacyclic [6.5.1.1 ^3,6 .0 ^2,7 .0 ^9,13 ] pentadecyl acrylate methacrylate, bis(hydroxymethyl) pentacycle [6.5.1.1 ^3,6 .0 ^2,7 .0 ^9,13 ] pentadecyl acrylate methacrylate, 2,2-bis[4-(β-methacryloxyethoxy)cyclohexyl]propane, 1,3-bis(methacryloxymethyl)cyclohexane, 1,3-bis(methacryloxyethyloxymethyl)cyclohexane, 1,4-bis(methacrylic)醯oxymethyl)cyclohexane, 1,4-bis(methacryloxyloxy) Bifunctional (meth) acrylate such as ethyloxymethyl)cyclohexane; 1,3,5-paraxyl (methacryloxymethyl)cyclohexane, 1,3,5-para (methyl) a trifunctional (meth) acrylate such as acryloxyethyloxymethyl)cyclohexane, and among these, in view of flexibility, a bifunctional (meth) acrylate is preferred; heat resistance is considered. In terms of aspect, it is preferred to be a bifunctional methacrylate. Further, in view of optical properties, it is preferred that at least one selected from the group consisting of the following general formulas (5), (6) and (7) is a bifunctional (meth) acrylate, wherein Bifunctional methacrylate is particularly preferred.

【化5】

In the formula (5), R _{2 is} each independently a carbon number of 1 to 6, preferably a carbon number of 1 to 3 and an alkylene group which may further contain an ether bond, and each of R _{3 is} independently hydrogen or a methyl group, and a is 1 or 2, b is 0 or 1.

【化6】

In the formula (6), R _{4 is} each independently a carbon number of 1 to 6, preferably a carbon number of 1 to 3 and an alkylene group which may further contain an ether bond, and each of R _{5 is} independently hydrogen or a methyl group.

【化7】

In the formula (7), R _{6 is} each independently hydrogen or a methyl group, and each of R _{7 is} independently a carbon number of 1 to 6, preferably a carbon number of 1 to 3 and an alkyl group which may have an ether bond, R ₈ Each is independently hydrogen or methyl.

The blending ratio of the component (A) to the component (B) is preferably (A): (B) = 10:90 to 50:50 (weight ratio) is preferred. When the amount of the component (A) is too small, the surface hardness tends to decrease. On the other hand, if the component (B) is too small, the solubility tends to be lowered. The blending ratio is preferably in the range of 15:85 to 45:55 (weight ratio) and more preferably 20:80 to 40:60 (weight ratio).

((meth)acrylic resin having an alicyclic structure: component (C) having a weight average molecular weight of 50,000 to 700,000) (meth)acrylic resin having an alicyclic structure of component (C), The viscosity of the base-hardening composition is increased, and examples thereof include poly(isobornyl (meth)acrylate), poly(adamantyl (meth)acrylate), and poly((meth)acrylate norbornene ester). a homopolymer of mono(meth)acrylate (c1) having an alicyclic structure such as poly(dicyclopentyl (meth)acrylate) or poly(dicyclopentylmethanol and (meth)acrylate Condensation composition) and the like, wherein, in terms of compatibility, it is preferred to use a homopolymer of mono(meth)acrylate (c1) having an alicyclic structure, and poly(dicyclopentyl (meth)acrylate ), poly((adamantyl (meth) acrylate), etc. are particularly preferred.

The (meth)acrylic resin (C) having an alicyclic structure has a weight average molecular weight of 50,000 to 700,000, preferably 100,000 to 700,000, and more preferably 300,000 to 650,000. When the weight average molecular weight is too small, the amount of the (meth)acrylic resin (C) to be blended is required to be, for example, 30% by weight or more in order to achieve high viscosity suitable for continuous coating, so that impact resistance is lowered. The tendency is too large, and the solubility is poor and the productivity is lowered. Further, the above weight average molecular weight means a weight average molecular weight (Mw) in terms of standard polystyrene measured by GPC (gel permeation chromatography).

The (meth)acrylic resin (C) can be produced by a polymerization method such as irradiation with an active energy ray, in addition to a solution polymerization method, and in particular, a polymerization method by ultraviolet irradiation can be considered in consideration of molecular weight control. It is better.

The content of the (meth)acrylic resin (C) having an alicyclic structure is considered to be a thick film formation property due to high viscosity, and the total amount of the component (A) and the component (B) is preferably 100 parts by weight. It is preferably from 1 to 30 parts by weight, particularly preferably from 2 to 18 parts by weight, more preferably from 2 to 15 parts by weight, still more preferably from 3 to 12 parts by weight. When the content is too small, the viscosity is insufficient and the thickness of the film tends to be difficult. When the content is too large, the viscosity tends to be too high and the productivity tends to be lowered.

(Polymerization Initiator: Component (D)) The radically curable composition of the present invention contains a polymerization initiator (D). Examples of the polymerization initiator include a photopolymerization initiator (D1) and a thermal polymerization initiator (Dh). In particular, in the present invention, it is preferred to contain a photopolymerization initiator (D1) in view of the fact that the hardening reaction is effectively carried out or the productivity is good.

Examples of the photopolymerization initiator (D1) include benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, and 2,6-di. Methyl benzhydryl diphenylphosphine oxide, 2,4,6-trimethylbenzimidyl diphenylphosphine oxide, and the like. Among these, a radical-cleaving type photopolymerization initiator such as 1-hydroxycyclohexyl phenyl ketone or 2,4,6-trimethylbenzimidyl diphenyl phosphine oxide is preferred. These photopolymerization initiators (Dl) may be used singly or in combination of two or more.

As the thermal polymerization initiator (Dh), a known compound can be used. For example, hydrogen peroxide, tributyl hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide or the like can be cited; a dialkyl peroxide such as a base peroxide or a dicumyl peroxide; a peroxy ester such as a third butyl peroxybenzoate or a third butyl peroxy(2-ethylhexanoate); a peracid such as a perylene peroxide such as a mercapto peroxide or a peroxycarbonate such as a diisopropyl peroxide or a peroxy ketal or a ketone peroxide. These thermal polymerization initiators (Dh) may be used singly or in combination of two or more. The photopolymerization initiator (D1) and the thermal polymerization initiator (Dh) can also be used.

The content of the polymerization initiator (D) is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 4 parts by weight, more preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the total of the component (A) and the component (B). . If the content is too large, the phase difference of the plastic sheet increases, and the light transmittance at 400 nm tends to decrease. On the other hand, if the amount is too small, the polymerization rate is lowered and the polymerization is not sufficiently carried out.

(Compound containing a mercapto group: component (E)) Further, in the present invention, in view of increasing the crosslinking density, it is preferred to include a compound (E) having a mercapto group. Examples of the mercapto group-containing compound (E) include neodymium thioacetate pentaerythritol ester, neopentyl thiopropionate neopentyl glycol ester, and decyl (3-sulfanylbutyric acid) pentaerythritol ester. 1,3,5-non-(2-(3-sulfanyl butanoyloxy)ethyl) (1,3,5-tris(2-(3-sulfanyl butanoyloxy)ethyl).

Further, in order to improve the storage stability of the radical curable composition, it is preferred to use a thiol group-containing compound (E1) having a fluorenyl group of a second order. Examples of the mercapto group-containing compound (E1) include a bifunctional mercaptan such as 1,4-bis(3-mercaptobutoxy)butane; and 1,3,5-para (2-(3-sulfuric acid); Alkylbutenyloxy)ethyl ester, ginseng-[(3-mercaptopropyloxy)-ethyl-]-isocyanurate, trimethylolpropane ginseng (3-mercaptopropionate), Trifunctional thiol such as dipentaerythritol tert-(3-mercaptopropionate), trimethylolpropane ginseng (3-mercaptobutyrate), trimethylolethane ginate (3-mercaptobutyrate) a tetrafunctional thiol or the like such as cerium (3-sulfanylbutyric acid) neopentyl glycol ester.

The thiol group of the compound 1 molecule is preferably 2 to 6 and 2 to 4 in terms of the curability of the radical curable composition. Further, it is preferred that all of the mercapto group-containing compounds in which all of the mercapto groups are a mercapto group. The molecular weight of the mercapto group-containing compound (E) is usually from 250 to 800, and preferably from 300 to 600. When the molecular weight is too small, the viscosity of the radical curable composition tends to be low, and if it is too large, the viscosity of the radical curable composition tends to be high.

The thiol group-containing compound (E) is preferably used in an amount of 10 parts by weight or less based on 100 parts by weight of the total of the component (A) and the component (B), more preferably 5 parts by weight or less, and 4 parts by weight. The following is especially good. When the amount of use is too large, the heat resistance and rigidity of the obtained plastic sheet and molded article tend to be lowered.

In the present invention, the curable composition may contain a small amount of auxiliary components in a range that does not impair the physical properties of the plastic sheet or the molded article of the present invention. For example, a monomer having an ethylenically unsaturated bond other than the component (A) and the component (B), a polymerization inhibitor, an antioxidant, a UV absorber, an antifoaming agent, a leveling agent, a bluing agent, and dyeing Pigments, fillers, etc. Further, when curing by active energy ray irradiation or hardening by heating, it is preferred to use a photopolymerization initiator (D1) and a thermal polymerization initiator (Dh).

Examples of the monomer having an ethylenically unsaturated bond other than the component (A) and the component (B) include methyl methacrylate, 2-hydroxyethyl (meth)acrylate, and phenyl (meth)acrylate. Benzyl acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, norbornene (meth)acrylate, bicyclo(meth)acrylate a monofunctional (meth) acrylate such as a mono(meth)acrylate having an alicyclic structure such as a condensation composition of amyl ester, dicyclopentylmethanol and (meth) acrylate; ethylene glycol di(meth)acrylate Ester, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, di(meth)acrylate of polyethylene glycol of tetraethylene glycol or higher, di(methyl) 1,3-butylene glycol acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2-hydroxy1,3-di(methyl) propylene a polyfunctional (meth) acrylate such as methoxypropane, 2,2-bis[4-(methyl)propenyloxyphenyl]propane or trimethylolpropane tri(meth)acrylate; Amine, methacrylamide, propylene (meth)acrylic acid derivatives such as nitrile and methacrylonitrile; styrene compounds such as styrene, chlorostyrene, divinylbenzene, and α-methylstyrene.

The content of the monomer having an ethylenically unsaturated bond other than the component (A) and the component (B) is preferably 30 parts by weight or less, and preferably 20 parts by weight based on 100 parts by weight or less of the total of the component (A) and the component (B). It is more preferably less than 10 parts by weight. When the content is too large, the heat resistance of the plastic sheet or the molded article tends to decrease.

As the antioxidant, for example, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, 2, 6-di-tert-butyl-4-t-butylphenol, 2,6-di-t-butyl-4-hydroxymethylphenol, n-octadecyl-β-(4'-hydroxy-3',5 '-Di-tert-butylphenyl)propionate, 2,6-di-t-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-t-butyl 4-hydroxybenzylphosphonate-diethyl ester, 2,4-bis(n-octylsulfo)-6-(4-hydroxy-3',5'-di-t-butylanilino)-1, 3,5-three , 4,4-methylene-bis(2,6-di-t-butylphenol), 1,6-hexanediol bis[3-(3,5-di-t-butyl-4-hydroxyphenyl) Propionate], bis(3,5-di-t-butyl-4-hydroxybenzyl) sulfide, 4,4'-di-thiobis(2,6-di-t-butylphenol), 4 , 4'-tris-thiobis(2,6-di-t-butylphenol), 2,2-thiodiethylidene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl) Propionate], N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propanyl] hydrazine, (3,5-di-t-butyl- 4-hydroxybenzyl)monoethylphosphonate, 1,3,5-trimethyl-2,4,6-gin (3,5-di-t-butyl-4-hydroxybenzyl)benzene, ginseng (3,5-di-t-butyl-4-hydroxyphenyl)isocyanurate, ginseng (3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3 ,5-parametric-2[3(3,5-di-t-butyl-4-hydroxyphenyl)propanoxy]ethyl isocyanate, hydrazine [methylene-3-(3',5'-di a compound such as a third butyl-4-hydroxyphenyl)propionate]methane, 3,5-di-t-butyl-4-hydroxybenzylphosphite-diethyl ester, which may be used alone , Can also be used two or more types Merger. Among these, in view of the fact that the hue suppression effect is large, 肆[methylene-3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate]methane is particularly preferable.

The content ratio of the antioxidant is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.5 part by weight, per 100 parts by weight of the total of the component (A) and the component (B). If the amount of the antioxidant is too small, the light resistance of the plastic sheet tends to decrease, and if it is too large, the light transmittance tends to decrease.

The radical curable composition of the present invention can be produced by a method known in the art. For example, by blending the components (A), (B), (C) and (D), it is preferred to further incorporate the component (E), optionally as an auxiliary component, and at a temperature of usually 20 to 50 ° C. It is produced by stirring and mixing until uniform. Thus, the radical curable composition of the present invention can be obtained.

The radical curable composition of the present invention preferably has a viscosity at 23 ° C of 100 to 20,000 mPa·s, more preferably 400 to 10,000 mPa·s, and particularly preferably 800 to 6,000 mPa·s. When the viscosity is too low, the thick film formability tends to decrease, and if it is too high, the productivity tends to decrease. As a method of adjusting the viscosity, the types, blending amounts, and the like of the components (A), (B), and (C) can be appropriately controlled. Further, the viscosity of the composition at this time was a cone-plate type viscometer (TPE-100 manufactured by Toki Sangyo Co., Ltd.), and a Peltier Plate temperature: 23 ° C, using a conical rotor: 3 The value measured under the condition of ° × R14.

<Manufacturing method of the plastic sheet [I], the molded product [II]> The plastic sheet [I] of the present invention using the radical curable composition, and a molded article obtained by further molding the same [ The manufacturing method of II] will be described.

The plastic sheet [I] of the present invention can be obtained by heating or irradiating the radical photocurable composition with an active energy ray to obtain a reaction rate of usually 50% or more and less than 75% for curing.

The plastic sheet [I] can be injected into a cavity by a batch-type photo-forming method which is generally implemented, that is, a mold for making two transparent glasses by interposing a spacer for controlling the thickness. The radical curable composition is obtained by heating or irradiating an active energy ray to be hardened and demolded, and in view of productivity and long runability, it is preferable to use a roll-to-roll (Roll-to) The continuous light forming method of -Roll is preferred. This continuous photoforming method can be carried out as follows.

For example, the above-mentioned radical hardenable composition layer may be formed on the support film to have a desired film thickness using an applicator having a clearance capable of providing a necessary coating film thickness to be formed so that the support film contacts the upper portion thereof. The laminate is arranged to be heated or irradiated with an active energy ray to cure the radical curable composition, and if necessary, the support film is peeled off from both sides of the cured resin layer (plastic sheet). And get the plastic sheet [I]. The conveying direction of the support film in this step may be any one of a horizontal direction, a direction perpendicular to the horizontal direction, and an angled angle from the horizontal direction. From the viewpoint of manufacturing efficiency, a method in which the film surface is horizontal and continuously formed while being transported in the horizontal direction is preferable.

Further, in order to produce a plastic sheet having higher flexibility, for example, the following irradiation step may be sequentially performed to perform hardening: in the thickness direction of the laminate having the radically curable composition layer on the support film (α) Supporting the opposite side of the film (α) to be exposed to oxygen, irradiating the active energy ray from the side of the support film (α); and arranging the support film (β) to contact the oxygen exposed surface of the radically curable composition layer The active energy ray is irradiated from the side of the support film (β).

The layer structure of the laminate may be, for example, a three-layer structure of a support film/curable composition/support film, a support film/curable composition/support film/curable composition/support film, a five-layer structure, and the like. . In view of the fact that the hardening step described later is carried out with good efficiency, it is preferable to support the three-layer structure of the film/curable composition/support film.

Further, in the present invention, by winding the obtained plastic sheet [I] on a branch pipe, a plastic sheet roll which is a roll body of the plastic sheet [I] can be obtained.

The support film is not limited as long as it does not inhibit the curing by radical polymerization, and in view of the fact that the curing is not caused by oxygen, it is preferable that the support film is a gas barrier resin film.

When the thickness of the gas barrier resin film is 20 μm, and the oxygen permeability is 200 cc/m ² ·day·atm or less in an environment of 20 ° C under dry conditions, oxygen barrier is not considered. Further, it is preferable to carry out good hardening (i.e., radical polymerization), and it is effective to harden, preferably 100 cc/m ² ·day·atm or less, and more preferably 40 cc/m ² ·day·atm or less. If the enthalpy is too high, the curing may not be performed due to oxygen inhibition, and the degree of polymerization and the conversion ratio tend to be lowered. Further, the lower limit is usually 0.01 cc/m ² ·day·atm.

The measurement of the oxygen permeability was carried out by measuring with an oxygen permeability meter in accordance with the measurement method shown in JIS K 7126-2:2006.

Further, in the present invention, in consideration of heat generated during radical curing, a support film excellent in heat resistance is preferable, and a glass transition temperature of a resin constituting the support film is usually 0 ° C or more, and particularly preferably 30 ° C or more. More preferably 50 ° C or more. If the glass transition temperature is too low, there is a possibility that it melts and breaks when heated. Further, the upper limit of the glass transition temperature is usually 400 °C.

The thickness of the support film used in the present invention is usually 200 μm or less, more preferably 10 to 100 μm, and particularly preferably 15 to 50 μm. If the thickness is too thick, the light transmittance may be lowered or the weight of the rolled product may become excessively large. If the thickness is too thin, the film may be broken during work or may be impaired in safety.

Examples of the support film include a polyester resin film such as a polyethylene terephthalate film; a nylon resin film such as nylon 6, biaxially stretched nylon; and an acrylic acid acrylic resin such as modified polyacrylonitrile. A vinyl alcohol-based resin film such as a polyvinyl alcohol-based resin film or an ethylene-vinyl alcohol-based resin film, or such a uniaxially stretched or biaxially stretched vinyl alcohol-based resin film, etc., in view of extremely low oxygen permeability, ethylene The alcohol resin film is particularly preferable, and the biaxially stretched vinyl alcohol resin film is more preferable.

The vinyl alcohol resin film is formed by forming a vinyl alcohol resin, and the vinyl alcohol resin may be a vinyl alcohol unit obtained by saponifying a vinyl ester unit, and the average degree of saponification is preferably 90 mol% or more. Preferably, 95% or more is more preferably 95% or more.

The vinyl alcohol-based resin of the vinyl alcohol-based resin film may, for example, be a polyvinyl alcohol-based resin (hereinafter sometimes abbreviated as a PVA-based resin) or an ethylene-vinyl alcohol-based copolymer (hereinafter sometimes abbreviated as EVOH). Further, examples of the PVA-based resin include PVA and modified PVA obtained by separately polymerizing vinyl acetate and saponifying it. Examples of the modified PVA include a copolymerized modified product and a post-modified product. Among the above, in particular, in view of heat resistance, a biaxially stretched PVA-based resin film is preferred.

The external haze of the above-mentioned support film is obtained by subtracting the internal mist from the full haze of the object measured in accordance with JIS K 7361-1:1997 and using a haze meter "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd. The internal haze is obtained by previously only inserting liquid paraffin between two glass plates and measuring the haze (Hz1), then sandwiching the film which wets the surface with liquid paraffin and measuring the fog. The degree (Hz2) is a value calculated by taking the difference. The value is usually 0.4 or less, preferably 0.4 to 0.01, and particularly preferably 0.2 to 0.01. When the external haze is too large, the obtained plastic sheet [I] tends to have a large haze value of the molded article [II] obtained by three-dimensional molding.

The above radical curable composition is usually hardened by active energy ray irradiation or heat (that is, radical polymerization). In the case of curing by active energy ray irradiation, when the curable composition is irradiated with an active energy ray, ultraviolet light having a normal wavelength of 200 to 400 nm is used, and photo-curing is performed at an irradiation amount of usually 0.1 to 0.8 J/cm ² . A more preferable range of the amount of irradiation light is 0.1 to 0.7 J/cm ² , and particularly preferably 0.15 to 0.5 J/cm ² . When the amount of the irradiation light is too large, the curing is excessive, and the three-dimensional forming process in the subsequent step tends to be difficult. When the amount is too small, the polymerization tends to be insufficient. The active energy ray illuminance is generally ^{10 ~ 2,000mW / cm 2, 50} ~ 1,000mW / cm 2 particularly preferred. If the illuminance is too small, the productivity tends to decrease. On the contrary, if the illuminance is too large, the control of the degree of hardening tends to be difficult.

The active energy ray source may be a user who is usually photohardened, and examples thereof include a metal halide lamp, a high pressure mercury lamp, an electrodeless mercury lamp, and an LED-UV. In order to prevent the polymerization from being out of control due to the infrared rays generated by the light source, the lamp can use a filter that shields infrared rays, a mirror that does not reflect infrared rays, and the like.

When heat hardening is performed, the heat treatment temperature is usually from 30 to 140 °C. The heat treatment time is usually from 0.1 second to 30 minutes. When the heat treatment temperature is too low, the curing rate is slow, and if the temperature is too high, it is considered that undesired side reactions and excessive hardening occur. Further, if the heat treatment time is too long, the curing will be excessive, and the three-dimensional forming process in the subsequent step tends to be difficult. If the heat treatment time is too short, the curing tends to be insufficient.

After the hardening (i.e., radical polymerization), the support film can be peeled off from both sides of the obtained plastic sheet [I] to remove only the plastic sheet [I]. The obtained plastic sheet [I] can be directly supplied to a desired forming process, or can be temporarily wound around a branch pipe and stored as a plastic sheet roll.

Alternatively, the support film may be peeled off and wound around the branch pipe to form a plastic film roll, and in order to prevent adhesion, scratches due to friction, etc., a polyolefin film such as polyethylene or polypropylene, or polyethylene terephthalate may be used. A polyester film such as ethylene glycol, a release paper or the like is wound together as a spacer.

Regarding the above-mentioned branch pipe, for example, those having a diameter of usually 3 to 12 inches, preferably 3 to 6 inches, are more preferable.

The plastic sheet [I] of the present invention obtained as described above is obtained by heating or active energy ray irradiation of the radical curable composition, so that the reaction rate of the (meth) acrylonitrile group is usually 50% or more. Hardening is performed at 75%, preferably 55 to 70%, and particularly preferably 60 to 70%. If the reaction rate is too low, the film thickness tends to change during storage. If the reaction rate is too high, the subsequent three-dimensional forming process tends to be difficult.

Further, the reaction rate can be measured as shown below. In other words, the test piece having a length of 50 mm and a width of 50 mm was freeze-pulverized, and then measured by a solid NMR probe using "AVANCE DPX-400" manufactured by BRUKER® BIOSPIN. The measurement was carried out under the conditions of an observation core ¹³ C, a rotation speed of 5,000 Hz, and room temperature. The carbonyl carbon in the unpolymerized (meth) acrylonitrile group was detected on the high magnetic field side (166 ppm), and the polymerized carbonyl carbon was detected on the low magnetic field side (176 ppm). The reaction rate (%) was calculated from the peak area of the above.

Further, the plastic sheet [I] of the present invention preferably has a thickness of 50 to 10,000 μm, more preferably 100 to 5,000 μm, more preferably 400 to 3,000 μm, and particularly preferably 500 to 1,000 μm. If the thickness is too small, the subsequent three-dimensional forming process tends to be difficult, and if it is too thick, the roll tends to become difficult.

In the plastic sheet [I] of the present invention, in view of high brightness of the display, the light transmittance is usually 80% or more, particularly preferably 85% or more, and more preferably 90% or more. Further, in general, the upper limit of the light transmittance is 99%.

The plastic sheet [I] of the present invention has a surface pencil hardness of usually 10 B or more and a hardness of 8 B or more, more preferably 7 B or more, and 2 B or less, 4 B or less, measured according to JIS K 5600-5-4:1999. Very good. If the pencil hardness is too low, the shape of the plastic sheet tends to be difficult to maintain. If it is too high, the subsequent three-dimensional forming process tends to be difficult.

In the plastic sheet [I] of the present invention, in view of high definition of the display, the full haze is usually 3% or less, more preferably 2% or less, and even more preferably 1.5% or less. Further, the external haze is usually 0.5% or less, more preferably 0.3% or less, and even more preferably 0.15% or less.

In addition, the external haze means that the internal haze is subtracted from the full haze of the object measured according to JIS K 7361-1:1997 and using a haze meter "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd. The obtained haze (the internal haze is obtained by previously only inserting liquid paraffin between two glass plates and measuring the haze (Hz1), and then sandwiching a film coated with liquid paraffin on the surface and measuring the haze (Hz2) ), take the difference calculated by the difference.).

In the present invention, after the plastic sheet [I] or the plastic sheet [I] rolled out from the plastic sheet roll is formed, the reaction rate is usually 75% or more by heating or active energy ray irradiation. Hardening is performed to form a shaped product [II].

The above-mentioned plastic sheet [I] of the present invention is a formable sheet because it is not completely cured, and in order to have a desired design, it can be subjected to a forming process in accordance with the relevant design, and then usually by heating or active energy ray. The coating is further subjected to hardening to form a molded product [II].

A well-known molding method can be used for the said shaping|molding process. For example, a mold forming method such as press molding, vacuum forming, or compressed air molding; a method of cutting out an arbitrary shape by a cutter, a cutter, or the like can be mentioned. In particular, it is possible to obtain only a flat molded product from the conventional plastic sheet, and in the present invention, it is possible to obtain a three-dimensional molded product formed in a direction other than the plane, for example, in a substantially vertical direction. Therefore, it is preferable to form a molded article which is formed by applying an arbitrary design or the like in a direction other than the plane with respect to the plane, for example, in a substantially vertical direction.

The plastic sheet [I] formed into a desired shape by a forming process is usually further cured by active energy ray irradiation or heat to form a molded article [II] of the present invention. When the active energy ray is hardened, it is preferable to use ultraviolet light having a normal wavelength of 200 to 400 nm for the active energy ray irradiation, and photohardening is preferably performed at a normal irradiation amount of 0.5 to 40 J/cm ² . A more preferable range of the amount of irradiation light is 5 to 35 J/cm ² , and particularly preferably 10 to 30 J/cm ² . If the amount of the irradiation light is too large, the productivity tends to be lowered, and if the amount is too small, the surface hardness tends to decrease. The active energy ray illuminance is generally ^{10 ~ 2,000mW / cm 2, 50} ~ 1,000mW / cm 2 particularly preferred. If the illuminance is too small, there is a tendency for productivity to decrease. On the contrary, if it is too large, yellowing tends to occur.

Further, the active energy ray source may be a user who is usually photohardened. For example, a metal halide lamp, a high pressure mercury lamp, an electrodeless mercury lamp, or an LED-UV may be mentioned as described above. In order to prevent the polymerization from being out of control due to the infrared rays generated by the light source, the lamp can use a filter that shields infrared rays, a mirror that does not reflect infrared rays, and the like.

Further, in order to further increase the degree of polymerization, or to release stress strain, heat treatment may be performed. In this case, it is preferred to carry out heat treatment at 50 to 250 ° C under atmospheric pressure or under vacuum.

When the hardening by heating is performed, the heat treatment temperature is usually from 30 to 140 °C. The heat treatment time is usually from 0.1 second to 10 hours. If the heat treatment temperature is too low, the curing tends to be insufficient. When the heat treatment time is too short, the curing tends to be insufficient, and if it is too long, productivity may be lowered and undesired side reactions may occur.

The molded article [II] of the present invention obtained by curing with an active energy ray has a reaction rate of usually 75% or more and is cured, and is preferably 80% or more, and particularly preferably 85% or more. When the reaction rate is too low, the surface hardness of the molded article tends to be insufficient.

Further, the reaction rate can be measured by the same method as described above.

Further, the molded article [II] of the present invention has a thickness of usually 50 to 10,000 μm, preferably 100 to 5,000 μm, more preferably 400 to 3,000 μm, and particularly preferably 500 to 1,000 μm. If the thickness is too small, the mechanical properties tend to be lowered, and if the thickness is too thick, the optical characteristics tend to be lowered.

In the molded article [II] of the present invention, in view of high brightness of the display, the light transmittance is usually 80% or more, particularly preferably 85% or more, and more preferably 90% or more. Further, in general, the upper limit of the light transmittance is 99%.

The molded article [II] of the present invention has a surface pencil hardness of 750 g or less, which is measured in accordance with JIS K 5600-5-4: 1999, and is usually 2H or more, more preferably 3H or more, and still more preferably 4H or more. If the pencil hardness is too low, the plastic sheet may be easily scratched, and the quality of the display tends to be lowered.

In the molded article [II] of the present invention, the total haze is 3% or less, particularly preferably 2% or less, and more preferably 1.5% or less, in view of high definition of the display. Further, the external haze is usually 0.5% or less, more preferably 0.3% or less, and even more preferably 0.15% or less. Further, the external haze means a crucible measured by the same measurement method as the above-mentioned plastic sheet [I].

Thus, in the present invention, a plastic sheet having a desired film thickness can be formed, and a wound plastic sheet roll can be easily formed, and further, optical properties, surface hardness, and impact resistance of a molded product which is a final cured product can be obtained. Excellent shape. Therefore, it is useful for applications such as a protective plate for a display, a photocopier, a three-dimensional part around a display unit such as a car or a home appliance. [Examples]

The present invention will be specifically described by the following examples, but the present invention is not limited to the following examples as long as the invention is not exceeded. In addition, in the examples, "parts" and "%" mean the basis of weight. The measurement method of each physical property is as follows.

(1) Pencil hardness The pencil hardness of the plastic sheet was measured in accordance with JIS K 5600-5-4:1999. Further, the load was measured at 50 g or 750 g.

(2) Full haze (%) According to JIS K 7361-1:1997, the measurement was carried out using a haze meter "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd.

(3) Light transmittance (%) The total light transmittance (%) was measured using a haze meter "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd.

(4) Saturated water absorption ratio (%) Using a test piece of 50 mm × 50 mm size, the saturated water absorption ratio (%) was calculated from the weight increase after immersion in water at 23 ° C for 20 days.

(5) Impact resistance (falling ball test) The maximum enthalpy (Y) of the height at which the ball was dropped and not broken was determined in accordance with JISR3206 in the tempered glass as follows. In other words, the test piece having a length of 50 mm and a width of 50 mm was allowed to stand in an environment of 23 ° C and 50% RH for 48 hours, and then a ball of 16 g and a diameter of 16 mmφ was used by using a ball drop tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) as shown in FIG. Tested from a specified height and impacted on a cylindrical table with a diameter of 32 mm The center of the surface of the piece. The specified height is increased by 5 cm, and the same operation is performed on the six test pieces at each height, and the maximum value (cm) of the heights of four or more unbroken is used as the maximum value of the height at which the ball is not broken or broken (Y ).

Further, the blending component was prepared as follows. [Polyfunctional amine ethyl acrylate (meth) acrylate (A) having an alicyclic structure] (A-1): a 6-functional group having an alicyclic structure (formula (1)) obtained by the method shown below Ethyl acrylate acrylate In a flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 192.0 g (0.86 mol) of isophorone diisocyanate and neopentyl methacrylate [trimethyl acrylate] a mixture of a tetraol ester and a neopentyl glycol tetraacrylate (hydroxyl price: 120 mgKOH/g)] 808.0 g (1.73 mol), and 0.01 g of hydroquinone methyl ether as a polymerization inhibitor, and a second laurel as a reaction catalyst 0.01 g of dibutyltin acid was allowed to react at 60 ° C for 8 hours, and when the residual isocyanate group became 0.3% or less, the reaction was terminated to obtain a hexafunctional urethane acrylate having an alicyclic structure (formula (1)).

【化8】

[Polyfunctional (meth) acrylate (B) having an alicyclic structure] (B-1): bis(hydroxymethyl)tricyclo[5.2.1.0 ^2,6 ]decane dimethacrylate (Xinzhongcun) Chemical Industry (Stock) Company "DCP")

[(meth)acrylic resin (C) having an alicyclic structure] (C-1): 0.05 parts of 1-hydroxycyclohexyl phenyl ketone which is doped with 100 parts of dicyclopentanyl acrylate as a photopolymerization initiator And the monomer composition obtained by adding 0.05 parts of neodymidine thiopropionate to the defoaming treatment, and sealing it in a container of the biaxially stretched polyvinyl alcohol film to prevent the bubbles from entering, and adjusting the thickness to 0.5 mm. A glass plate of 2.8 mm was placed on the upper portion of the container, and the metal halide lamp was irradiated from above with a wavelength of 360 nm of illuminance of 50 mW/cm ² and an amount of irradiation of 20 J/cm ² . Thereafter, only the cured product was taken out from the container in which the polyvinyl alcohol film was biaxially stretched, and pulverization was performed by a pulverizer. A (meth)acrylic resin powder having a monomer reaction rate of 87% and a weight average molecular weight (Mw) of 630,000 was obtained.

(C-2): a monomer obtained by blending 100 parts of dicyclopentyl acrylate with 0.1 part of 1-hydroxycyclohexyl phenyl ketone and 1 part of decyl thiopropionate After the composition was defoamed, it was sealed in a container of a biaxially stretched polyvinyl alcohol film to prevent air bubbles from entering, and the thickness was adjusted to 0.5 mm, and then a 2.8 mm glass plate was placed on the upper portion of the container so that the wavelength of 360 nm became 50 mW. / cm ² of illumination and 20J / cm ² of light quantity irradiated from above of the embodiment using a metal halide lamp. Thereafter, only the cured product was taken out from the container in which the polyvinyl alcohol film was biaxially stretched, and pulverization was performed by a pulverizer. A (meth)acrylic resin powder having a monomer reaction rate of 90% and a weight average molecular weight (Mw) of 50,000 was obtained.

(C'-1): a monomer composition obtained by dispersing 100 parts of 1-hydroxycyclohexyl phenyl ketone which is a photopolymerization initiator in 100 parts of dicyclopentanyl acrylate, is subjected to defoaming treatment, and is sealed in a double A container for stretching a polyvinyl alcohol film to prevent air bubbles from entering, and adjusting the thickness to 0.5 mm, a glass plate of 2.8 mm was placed on the upper portion of the container so that the wavelength of 360 nm became an illumination of 50 mW/cm ² and 20 J/cm ² . The amount of light to be irradiated is irradiated from above with a metal halide lamp. Thereafter, only the cured product was taken out from the container in which the polyvinyl alcohol film was biaxially stretched, and pulverization was performed by a pulverizer. A (meth)acrylic resin powder having a monomer reaction rate of 83% and a weight average molecular weight (Mw) of 1.3 million was obtained.

[Polymerization Initiator (D)] (D-1): 1-Hydroxycyclohexyl phenyl ketone

[Alkyl group-containing compound (E)] (E-1): 肆(3-sulfanylbutyric acid) pentaerythritol ester ("Karenz MT PE-1" manufactured by Showa Denko Co., Ltd.)

<Examples 1 to 5 and Comparative Example 1> [Preparation of radically curable composition] Each component was mixed as shown in Table 1, and stirred at 60 ° C until homogeneous, and then filtered by a filter of 42 μm to obtain a radical. Polymeric composition. In addition, the viscosity of the composition at this time was a cone-plate type viscometer (trade name "TPE-100", manufactured by Toki Sangyo Co., Ltd.), and the temperature of the Peltier plate was 23 ° C, and a conical rotor was used: The measurement was carried out under the conditions of ° × R14.

[Preparation of Plastic Sheet and Plastic Sheet Reel in Examples 1, 2 and Comparative Example 1] On a 38 μm-thick polyethylene terephthalate film continuously conveyed in the horizontal direction, a smear having a gap of 880 μm was used. The machine continuously forms a coating film of the radical polymerizable composition. A 38 μm thick polyethylene terephthalate film was additionally attached to the coating film, and the metal halide lamp was used to measure the ultraviolet light at a wavelength of 360 nm from the 38 μm thick polyethylene terephthalate film. The apparatus was irradiated with ultraviolet rays so that the irradiation intensity became 50 mW/cm ² and the exposure amount was 250 mJ/cm ² , and the conveyance was performed at the same time. Thereafter, a polyethylene terephthalate film/plastic sheet/polyethylene terephthalate film laminate was wound around a branch pipe to obtain a rolled composition (plastic film roll). The physical properties of the plastic sheet were measured in a state in which the support films on both sides were peeled off.

[Preparation of plastic sheet and plastic sheet reel in Examples 3 to 5] On a 38 μm-thick polyethylene terephthalate film continuously conveyed in the horizontal direction, a spreader having a gap of 880 μm was continuously formed. A coating film of the radical curable composition. From the side of the 38 μm thick polyethylene terephthalate film (α), a UV-LED (365 nm) lamp was used and a 360 nm wavelength ultraviolet measuring instrument was used to make the irradiation intensity 1500 mW/cm ² and the amount of irradiation light 200 mJ. Ultraviolet irradiation was carried out in a manner of /cm ² while conveying. A 38 μm thick polyethylene terephthalate film (β) was placed in contact with the oxygen exposed face of the radical curable composition layer from the 38 μm thick polyethylene terephthalate film (β ) side by using a UV-LED lamp and the 360nm wavelength ultraviolet meter, so that the irradiation intensity is 200mW / cm ² and the irradiation light amount becomes 100mJ / cm ² of ultraviolet rays irradiated while being conveyed. Thereafter, a polyethylene terephthalate film (α)/plastic sheet/polyethylene terephthalate film (β) laminate is wound around a branch pipe to obtain a roll-shaped composition (plastic film roll) ). The physical properties of the plastic sheet were measured in a state in which the base film on both sides was peeled off.

The physical properties of the obtained plastic sheets were evaluated, and the results are shown in Table 2. Further, the plastic sheet obtained in the examples was designated as [I], and the plastic sheet obtained in the comparative example was designated as [I'].

[Production of a molded product] A certain amount was cut out from the above-mentioned plastic sheet roll. The plastic sheet was irradiated with ultraviolet rays at 360 nm and hardened so that the illuminance became about 5,000 mW/cm ² and the amount of irradiation light was 20 J/cm ² to obtain a molded product model. Thereafter, the support film was peeled off, and only the molded product model was placed in a vacuum dryer at 200 ° C and under a vacuum of 0.1 Torr (that is, about 13.332 Pa) to be in contact with the metal frame around the dryer for 6 hr. Annealing. The physical properties of the obtained molded product model were evaluated, and the results are shown in Table 2.

Further, although the molded product model is not formed to impart designability in a direction perpendicular to the plane of the plastic sheet, the surface of the plastic sheet [I] or [I'] is free from irregularities and impurities when imparting design properties. Whether or not the design property does not affect the physical properties of the molded product is equivalent to that of the molded article obtained by designing and molding. The molded article obtained in the examples was designated as [II], and the molded article obtained in the comparative example was designated as [II']. The evaluation results of the examples and comparative examples are shown in Table 2.

【Table 1】 Note 1) () is a blending component.

【Table 2】

From the above results, it is known that radical sclerosis is formed by a polyfunctional urethane (meth) acrylate having an alicyclic structure, a polyfunctional (meth) acrylate having an alicyclic structure, and a polymerization initiator. The composition further contains a (meth)acrylic resin having an alicyclic structure such as a molecular weight of 50,000 to 700,000, and Examples 1 to 5 increase the viscosity of the radical curable composition. Therefore, it is easy to form a plastic sheet obtained by hardening, and a uniform film thickness can be ensured. Further, a molded article excellent in optical characteristics, surface hardness, and impact resistance of the molded article to be finally cured can be obtained, and the saturated water absorption rate is also as low as 1%. Further, it can be seen that in the impact resistance of the molded product, the heights of the cracks due to the falling of the rigid ball were not higher than those of Comparative Example 1 by 5 to 10 cm, and Examples 1 to 5 were able to withstand more. Dropped in the high position. Moreover, it is possible to withstand the drop test from a higher position, and it can be said that it can withstand more drop counts when evaluated at the same height, and it is considered that, for example, the molded article of the present invention is used for a member for display. When it is used in a touch panel substrate of a mobile phone or the like, it can withstand even if the number of drops is increased. [Industrial use]

The plastic sheet obtained by using the radical curable composition of the present invention and the molded article obtained by further curing it can be used for various optical materials and electronic materials. For example, various display members such as a liquid crystal substrate, an organic/inorganic EL substrate, an electronic paper substrate, a light guide plate, a phase difference plate, and a touch panel can be used; including a disc substrate, a film for a disc, and a memory for a recording. Applications: Energy applications such as thin-film battery substrates and solar cell substrates; optical communication applications such as optical waveguides; and further use in various optical films such as functional films, antireflection films, and optical multilayer films. Among them, in particular, it is expected as a protective panel for a display and a capacitive touch panel substrate.

no

Fig. 1 is a view for explaining a ball drop test performed in the present invention.

no

Claims (9)

A radical hardening composition comprising the following components (A), (B), (C) and (D); (A) a polyfunctional amine ethyl formate (meth) acrylate having an alicyclic structure; a polyfunctional (meth) acrylate having an alicyclic structure (however, excluding the aforementioned component (A)); (C) a (meth)acrylic acid having an alicyclic structure having a weight average molecular weight of 50,000 to 700,000 Resin; (D) Polymerization initiator. The radically curable composition of claim 1, wherein the content of the (meth)acrylic resin (C) having an alicyclic structure is relative to the polyfunctional urethane having an alicyclic structure The total amount of 100 parts by weight of the (meth) acrylate (A) and the polyfunctional (meth) acrylate (B) having an alicyclic structure is 1 to 30 parts by weight. The radically curable composition according to claim 1 or 2, wherein the (meth)acrylic resin (C) having an alicyclic structure is a mono(meth)acrylate having an alicyclic structure (c1) a homopolymer. The radical curable composition of claim 1 or 2 further contains the following component (E); (E) a thiol group-containing compound. The radical curable composition of claim 1 or 2, which has a viscosity at 23 ° C of 100 to 20,000 mPa·s. A plastic sheet obtained by hardening a radical curable composition according to any one of claims 1 to 5; characterized in that the reaction rate of the (meth) acrylonitrile group is 50% or more. Up to 75%. For example, the plastic sheet of claim 6 has a thickness of 50 to 10,000 μm. A plastic sheet reel wound with a plastic sheet as claimed in claim 6 or 7. A molded article obtained by forming a plastic sheet as claimed in claim 6 or 7 or a plastic sheet which is rolled out from a plastic sheet reel according to claim 8 of the patent application; The reaction rate of the propylene group is 75% or more.