JP2002096337A - Method for manufacturing plastic sheet having high dimensional stability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the internal strain remaining in a plastic sheet to ensure dimensional stability, in a method for manufacturing the plastic sheet by irradiating a photosetting resin composition with active energy beam to polymerize and cure the same. SOLUTION: In the method for manufacturing the plastic sheet by irradiating the photosetting resin composition, injected in a cavity, with active energy to polymerize and cure the same, a light path correction mask having a plurality of screens, which are vertical to the length direction of an active energy beam source, at an equal interval is arranged between the active energy beam source and the cavity. The height (b) of the screens of the light path correction mask, the pitch (a) of them and the distance (d) between the active energy beam source and the cavity satisfy formulae: b>=2a and b>=d/2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a plastic sheet having high dimensional stability. Specifically, the present invention relates to an improvement in a method for producing a plastic sheet by irradiating a photocurable resin composition with an active energy ray and polymerizing and curing the same. The plastic sheet obtained by the present invention has a small dimensional change after heating or hot water washing step during panel production, for display for organic EL display panel, for touch panel, etc., for storage and recording of optical discs and the like, for solar cell panel And the like, particularly low birefringence optical members, particularly suitable for liquid crystal display panels.

[0002]

2. Description of the Related Art A conventionally used liquid crystal display panel (sometimes called a cell) uses a glass plate as a substrate. In such a panel, the glass has low density and mechanical strength. Because there is a limit to improving
It cannot respond to the demand for thinner and thinner products. Further, problems have been pointed out from the viewpoints of moldability and workability regarding the improvement of productivity, and attention has been paid to panels using plastic as a substrate.

[0003]

However, when a plastic substrate is used in place of glass, the conventionally used plastic substrate cannot be used after a heating or hot water washing step in manufacturing a panel. Dimensional change due to degassing, dehydration, moisture absorption, etc. is large, and even if the panel is manufactured completely as designed, display failure occurs after manufacturing.

In particular, when manufacturing a panel for performing color display, this dimensional change poses a serious problem. Normally, color display includes R (red), G called color filters.
A substrate on which (green), B (blue) and black matrix (black) are formed, and a substrate without these pixels called a counter substrate are required. After patterning the transparent electrode on this color filter and patterning the transparent electrode on the opposing substrate, they are treated together with an alignment film and then pasted together via a sealing material, and liquid crystal is injected between the substrates for display. The panel is completed. If the substrate undergoes dimensional deformation after this paneling process, the following problems occur.

(1) Stress distortion occurs on the whole or a part of the panel, and the durability is reduced. (2) The bonded substrate warps, the cell gap changes, and the display quality deteriorates. Therefore, when manufacturing a liquid crystal display panel, a plastic substrate having high dimensional stability which improves the above problem is indispensable.

[0006]

In view of such circumstances, the present inventors have studied in detail the dimensional change of the substrate after the panel forming process. The paneling process mainly includes the following two processes. (1) Heat treatment performed at the time of ink drying when forming pixels, formation of a transparent electrode, sintering of an alignment film, and the like. (2) Warm water performed after pixel formation, after transparent electrode patterning, or after alignment film processing. Cleaning Process As a result of these processes, the substrate once undergoes dimensional contraction or dimensional expansion due to volatilization or water absorption of the internal gas. Thereafter, the substrate is stored under normal temperature and normal humidity conditions (for example, 23 ° C., 50% R).
H, one week), the dimension changed by the resulting dimensional contraction or dimensional expansion approaches the initial value.

[0007] However, when there is some stress or structural non-uniformity in the substrate surface due to the stretching operation or the like, the above-mentioned non-uniform internal gas volatilization or water absorption dehydration in the heating process or the hot water cleaning process is a cause. As a result, it was found that the dimensions changed due to the resulting shrinkage or expansion did not return to the initial values after a certain period of time after the treatment, or that the dimensions continuously changed irregularly.

The inventor of the present invention has analyzed the dimensional change behavior of the substrate and found that, as a plastic sheet for a liquid crystal display panel, a photocurable resin composition was irradiated with active energy rays to polymerize and cure the plastic sheet. In manufacturing, it is possible to reduce the internal strain remaining in the sheet by making the irradiation of active energy rays uniform, to secure dimensional stability, and to use a specific polymerizable composition as such a plastic sheet. It has been found that a product obtained by polymerizing and curing a product is preferable, and the present invention has been completed.

That is, the gist of the present invention is to provide a method for producing a plastic sheet by irradiating the photocurable resin composition injected into the cavity with an active energy ray and polymerizing and curing the active energy ray light source and the cavity. An optical path correction mask provided with a plurality of equally spaced partitions perpendicular to the longitudinal direction of the active energy ray light source, and the height (b) of the partition of the optical path correction mask, its pitch (a), And a distance (d) between the active energy ray light source and the cavity satisfies the following formula (1).

[0010]

B ≧ 2a and b ≧ d / 2 (1) (where a, b and d represent the pitch of the screen, the height of the screen, and the distance between the active energy ray light source and the cavity, respectively)

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The method for producing a plastic sheet of the present invention is a method for producing a plastic sheet by irradiating a photocurable resin composition injected into a cavity with an active energy ray and polymerizing and curing the plastic sheet. An optical path correction mask having a plurality of equally spaced partitions perpendicular to the longitudinal direction of the active energy ray light source is disposed therebetween, and the height of the partition of the optical path correction mask (b), its pitch (a),
And the distance between the active energy ray light source and the cavity (d)
Satisfies the following expression (1).

[0012]

B ≧ 2a and b ≧ d / 2 (1) (where a, b, and d represent the pitch of the screen, the height of the screen, and the distance between the active energy ray light source and the cavity, respectively) The plastic sheet produced according to the present invention is not particularly limited as long as it is obtained by polymerizing and curing a polymerizable monomer having two or more polymerizable functional groups in a molecule. A system resin is preferable, and a specific photocurable composition described later is particularly preferable.

Hereinafter, the specific photocurable composition, a plastic sheet obtained by polymerizing and curing the composition (hereinafter, sometimes referred to as a photocurable resin layer or a photocurable resin sheet), and a plastic laminate using the sheet. Describe the body. (Photocurable composition) The photocurable composition used in the present invention contains components A, B and C.

Here, the term "contains" means, in addition to the components A, B and C, unless the purpose of the present invention is impaired.
It means that small amounts of auxiliary components may be contained. In addition, "(meth) acryl" and "(meth) acrylate" are generic names of acryl or methacryl and acrylate or methacrylate, respectively.

<Component A: alicyclic skeleton bis (meth) acrylate> Component A is a bis (meth) acrylate having an alicyclic hydrocarbon skeleton represented by the formula (I) (an alicyclic skeleton bis (meth) acrylate). A) acrylate or bis (meth) acrylate).

[0016]

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(Where R¹And R^TwoAre independent
Represents a hydrogen atom or a methyl group, and m represents 1 or 2.
And n represents 0 or 1, and p and q are each independently
0, 1 or 2) Specific examples of the alicyclic skeleton bis (meth) acrylate of the formula (I)
Examples include, for example, bis (hydroxy) tricyclo
[5.2.1.0^2,6] Decane diacrylate, bis
(Hydroxy) tricyclo [5.2.1.0^2,6 ] Big
Dimethacrylate, bis (hydroxy) tricyclo
[5.2.1.0^2,6] Decane = acrylate methacrylate
And mixtures thereof, bis (hydroxy) penta
Cyclo [6.5.1.1^3,6. 0^2,7. 0^9,13] Penta
Decane = diacrylate, bis (hydroxy) pentane
Black [6.5.1.1^3,6. 0^2,7. 0^9,13] Pentade
Can = dimethacrylate, bis (hydroxy) pentasi
Black [6.5.1.1^3,6. 0 ^2,7. 0^9,13] Pentade
Can = acrylate methacrylate and mixtures thereof
Product, bis (hydroxymethyl) tricyclo [5.2.
1.0^2,6] Decane diacrylate, bis (hydroxy
Cimethyl) tricyclo [5.2.1.0^2,6] Decane =
Dimethacrylate, bis (hydroxymethyl) trisic
B [5.2.1.0^{2, 6}] Decane = Acrylate Methac
Acrylates and mixtures thereof, bis (hydroxymethyl
Le) pentacyclo [6.5.1.1^3,6. 0^2,7. 0
^9,13] Pentadecane diacrylate, bis (hydroxy
Cimethyl) pentacyclo [6.5.1.1^{3, 6}.
0^2,7. 0^9,13] Pentadecane dimethacrylate, bi
S (hydroxymethyl) pentacyclo [6.5.1.1
^3,6. 0^2,7. 0^9,13] Pentadecane = acrylate
Tacrylates and their mixtures, bis (hydroxy
Tyl) tricyclo [5.2.1.0^2,6] Decane-Gia
Acrylate, bis (hydroxyethyl) tricyclo
[5.2.1.0^2,6] Decane dimethacrylate, bi
Tris (hydroxyethyl) tricyclo [5.2.1.0
^2,6] Decane = acrylate methacrylate and these
Of bis (hydroxyethyl) pentacyclo
[6.5.1.1^3,6. 0^2,7. 0^9,13] Pentadecane
= Diacrylate, bis (hydroxyethyl) pentane
Black [6.5.1.1^3,6. 0^2,7. 0^9,13] Pentade
Can = dimethacrylate, bis (hydroxyethyl) pe
Nantacyclo [6.5.1.1 ^3,6. 0^2,7. 0^9,13]
Nantadecane acrylate methacrylate and these
Mixtures and the like.

Among these, bis (hydroxymethyl) to
Licyclo [5.2.1.0^2,6] Decane-diak relay
G, bis (hydroxymethyl) tricyclo [5.2.
1.0 ^2,6] Decane dimethacrylate, bis (hydro
Xymethyl) tricyclo [5.2.1.0^2,6] Decane
= Acrylate methacrylate and mixtures thereof are preferred
Good.

These tricyclodecane compounds and pentacyclodecane compounds may be used in combination of two or more in the group and / or between the groups. The proportion of bis (meth) acrylate in the photocurable composition used in the present invention is 70 to 99 parts by weight based on 100 parts by weight of the total of the components A and B (hereinafter, sometimes referred to as all acrylate components). , Preferably 80 to 98 parts by weight, more preferably 88 to 97 parts by weight, particularly preferably 92 to 96 parts by weight.

The method for producing bis (meth) acrylate is not particularly limited, and a general ester synthesis method (edited by The Chemical Society of Japan, New Experimental Chemistry Course, 14, Synthesis and Reaction of Organic Compounds (II)) (Maruzen, 1977), and the like. Typical production methods include (i) an alicyclic skeleton diol represented by the formula (1) (hereinafter, a diol of the formula (1)) Or abbreviated as diol) and (meth) acrylic acid by an esterification reaction (JP-A-62-225508).

[0021]

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Wherein m is 1 or 2 and n is 0 or 1. Specific examples of the compound of the formula (1) include:
For example, bis (hydroxymethyl) tricyclo [5.2.
1.0 ^2,6 ] decane, bis (hydroxymethyl) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadecane. Among them, bis (hydroxymethyl) tricyclodecane is commercially available as “TCD alcohol DM (trade name of Hoechst)”.

(Ii) a method by a transesterification reaction between a diol and a (meth) acrylate, (iii) a method by a reaction between a diol and a (meth) acrylic halide,
And the like. Among these, the methods (i) and (ii) are practical and preferred.

In the esterification reaction between the diol and (meth) acrylic acid in (i), usually 2.0 to 2.6 mol of (meth) acrylic acid is used per 1 mol of the diol, and a catalyst such as , Sulfuric acid, hydrochloric acid, phosphoric acid, boron fluoride, p
Using toluene sulfonic acid, benzene sulfonic acid, cationic ion exchange resin, etc., usually toluene, benzene,
The reaction is performed in the presence of a solvent such as heptane or hexane while distilling off water produced by the reaction. In addition, the transesterification reaction between the diol of (ii) and the (meth) acrylate ester,
Generally, 2.0 to 10.0 mol of methyl (meth) acrylate is used per 1 mol of the diol, and as a catalyst, for example, sulfuric acid, P-toluenesulfonic acid, tetrabutyl titanate, tetraisopropyl titanate , Potassium butoxide or the like, usually in the presence of a solvent such as toluene, benzene, heptane or hexane while distilling off methanol produced by the reaction.

In the reaction, for example, hydroquinone, hydroquinone monomethyl ether, phenothiazine, copper salt and the like can be used as a polymerization inhibitor. In these reactions, the progress of the reaction was analyzed by high performance liquid chromatography, gas chromatography, etc.
%, The unreacted diol, (meth) acrylic acid, catalyst, polymerization inhibitor, solvent, etc. are removed from the reaction mixture to obtain bis (meth) acrylate and mono (meth) acrylate. And a mixture with

As for those having a proper mixing ratio, components A and B of the photocurable composition used in the present invention are used.
It is convenient and preferable because it can be used as a raw material of a mixture with the above. <Component B: alicyclic skeleton mono (meth) acrylate> Component B is a mono (meth) acrylate having an alicyclic hydrocarbon skeleton represented by the formula (II) (alicyclic skeleton mono (meth) acrylate or Mono (meth) acrylate).

[0027]

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(Where R^ThreeRepresents a hydrogen atom or a methyl group
M represents 1 or 2, n represents 0 or 1, r and
s independently represents 0, 1 or 2) Specific examples of the alicyclic skeleton mono (meth) acrylate of the formula (II)
Examples include, for example, bis (hydroxy) tricyclo
[5.2.1.0^2,6] Decane = monoacrylate, bi
S (hydroxy) tricyclo [5.2.1.0^2,6]
Can = monomethacrylate and mixtures thereof, bis
(Hydroxy) pentacyclo [6.5.1.1 ^3,6. 0
^2,7. 0^9,13] Pentadecane monoacrylate, bis
(Hydroxy) pentacyclo [6.5.1.1^3,6. 0
^2,7. 0^9,13Pentadecane monomethacrylate and
These mixtures, bis (hydroxymethyl) tricyclo
[5.2.1.0^2,6] Decane = monoacrylate, bi
S (hydroxymethyl) tricyclo [5.2.1.0
^2,6] Decane = monomethacrylate and mixtures thereof
Product, bis (hydroxymethyl) pentacyclo [6.5.
1.1^3,6. 0^2,7. 0^9,13] Pentadecane = Monoac
Relate, bis (hydroxymethyl) pentacyclo
[6.5.1.1^3,6. 0^2,7. 0^9,13] Pentadecane
= Monomethacrylate and mixtures thereof, bis (hydr
Roxyethyl) tricyclo [5.2.1.0^2,6] Big
= Monoacrylate, bis (hydroxyethyl) tri
Cyclo [5.2.1.0^2,6] Decane = Monomethacryle
And their mixtures, bis (hydroxyethyl) paper
Nantacyclo [6.5.1.1^3,6. 0^2,7. 0^9,13]
Nantadecane = monoacrylate, bis (hydroxyethyl
Le) pentacyclo [6.5.1.1^3,6. 0^2,7. 0
^9,13] Pentadecane monomethacrylate and these
Mixtures and the like.

Among these, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = monoacrylate and bis (hydroxymethyl) tricyclo [5.2.
1.0 ^2,6 ] decane = monomethacrylate and mixtures thereof are preferred. Two or more of these tricyclodecane compounds and pentacyclodecane compounds may be used in groups and / or between groups.

The proportion of the mono (meth) acrylate in the photocurable composition used in the present invention is 1% of the total acrylate component.
1 to 30 parts by weight, preferably 2-2 to 100 parts by weight
0 parts by weight, more preferably 3 to 12 parts by weight, particularly preferably 4 to 8 parts by weight. If the proportion of the mono (meth) acrylate is too small, the effect of improving the mechanical strength of the cured resin will not be obtained, and if it is too large, the heat resistance of the cured resin will be reduced.

For such a mono (meth) acrylate, in the method for synthesizing the bis (meth) acrylate of the formula (I), for example, the method of (i) or (iii), the amount of (meth) acrylic acid per 1 mol of diol is determined. Half 1 to 1.3
It can be synthesized by conducting the reaction under the condition that a half ester is formed, for example, by making the amount of the (meth) acrylic halide half the amount of 1 mole.

However, when the bis (meth) acrylate of the formula (I) is synthesized, for example, by the method (i), the reaction is stopped halfway as described above, so that the mono (meth) acrylate Since a mixture of bis (meth) acrylate containing a desired amount is obtained and can be used as it is as a raw material of the photocurable composition used in the present invention, it is usually necessary to separately synthesize mono (meth) acrylate. Does not reach.

<Component C: At least Bifunctional Mercapto Compound> The mercapto compound used in the photocurable composition used in the present invention is at least a difunctional, preferably trifunctional or higher, mercapto compound (hereinafter referred to as polyfunctional compound). A functional mercapto compound). Specific examples of the at least bifunctional mercapto compound include, for example, compounds represented by the general formulas (III), (IV) and (V) and 2,2-bis (2-hydroxy-3-mercaptopropoxyphenyl) Propane, 1,10-decanedithiol, dimercaptotriethylene disulfide,
Dimercapto compounds synthesized by the reaction of a diglycidyl compound such as polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether with hydrogen sulfide, and the like.

[0034]

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(Wherein, R ⁴ represents a methylene group or an ethylene group, R ⁵ represents a hydrocarbon residue having 2 to 15 carbon atoms which may contain ether oxygen, and a represents an integer of 2 to 6) In the formula (III), R ⁵ is a hydrocarbon residue having 2 to 15 carbon atoms which may contain an ether oxygen. Specific examples thereof include, for example, a pentaerythritol residue and a dipentaerythritol residue. , A trimethylolpropane residue, an ethylene glycol residue, a diethylene glycol residue, a triethylene glycol residue, a butanediol residue, and the like.

The mercapto compound of the formula (III) is
And thioerythritol tetrakis (β-thiopropionate), pentaerythritol tetrakis (thioglycolate), and trimethylolpropane tris (β -Thiopropionate), trimethylolpropane tris (thioglycolate), ethylene glycol bis (β-thiopropionate), ethylene glycol bis (thioglycolate), diethylene glycol bis (β-thiopropionate), diethylene glycol Bis (thioglycolate), triethylene glycol bis (β-thiopropionate), triethylene glycol (thioglycolate), butanediol bis (β-thiopropionate), butanediol bis (thio Rikoreto), dipentaerythritol hexakis (beta-thiopropionate), dipentaerythritol hexakis (thioglycolate), and the like.

[0037]

Embedded image

(Wherein X is HS— (CH ₂ ) _b —CO—
_{(OCH 2 CH 2) d -} (CH 2) c - shows the. However,
b and c each independently represent an integer of 1 to 8,
d represents 0, 1 or 2) The compound of the formula (IV) is an isocyanate containing an ω-thiol group. Specific examples of the compound of the formula (IV) include, for example, tris [2- (β-thiopropionyloxy) ethyl] isocyanurate, tris (2-thioglyconyloxyethyl) isocyanurate, tris [2- (β- Thioglyconyloxyethoxy) ethyl] isocyanurate, tris (2-thioglyconyloxyethoxy) ethyl] isocyanurate, tris [3- (β-thiopropionyloxy) propyl] isocyanurate, tris (3-thioglyconyloxy Propyl) isocyanurate and the like.

[0039]

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(Wherein R ⁶ and R ⁷ each independently represent an alkylene group, e and f each independently represent 0 or 1, and g represents 1 or 2) The compound V) is a thiol group-containing hydrocarbon. Specific examples of the compound of the formula (V) include, for example, benzenedimercaptan, xylylenedimercaptan, 4,4'-dimercaptodiphenylsulfide and the like.

Among these at least bifunctional mercapto compounds, compounds represented by the formulas (III), (IV) and (V) are preferable. Among these compounds, trifunctional or higher functional mercapto compounds are preferred. More preferred are tetrafunctional mercapto compounds. The compounding ratio of the at least bifunctional mercapto compound in the photocurable composition used in the present invention is 1 to 15 parts by weight, preferably 4 to 12 parts by weight based on 100 parts by weight of all acrylate components.

If the proportion of the mercapto compound is too small,
The birefringence of the cured resin increases, and if it is too large, the heat resistance of the cured resin decreases. The composition obtained by removing the alicyclic skeleton mono (meth) acrylate of the component B from the photocurable composition used in the present invention can be solved if it has only two problems of low birefringence and high heat resistance. It is possible to That is, a resin having low birefringence and high heat resistance can be obtained by photopolymerizing and curing a composition comprising the alicyclic skeleton bis (meth) acrylate of the component A and the polyfunctional mercapto compound of the component C. The reason for blending the polyfunctional mercapto compound is that the thiol group in the mercapto compound acts as a chain transfer agent, and the polymerization cure proceeds slowly and uniformly, thereby greatly reducing the birefringence in the cured product. In addition, by using a polyfunctional mercapto compound having two or more thiol groups in the molecule, heat resistance when the mercaptan compound enters the three-dimensional network structure formed from the bis (meth) acrylate compound of the component A Can be solved without impairing the birefringence.

However, both component A and component C are polyfunctional, and the resulting cured product has a highly crosslinked polymer structure, and thus has a problem of poor mechanical strength such as impact resistance. This problem is solved by blending the alicyclic skeleton mono (meth) acrylate of the component B at a specific ratio. That is, the component B, which is monofunctional and does not contribute to crosslinking, enters the highly crosslinked polymer,
The crosslink density is moderately controlled. As a result, the mechanical strength such as impact resistance is improved, and the problem of production yield such as cracking of the product during molding can be solved.

It is important that the compound B does not cause an increase in birefringence of the cured product, a decrease in heat resistance or a deterioration in water absorption when the component B is blended.
Is a (meth) acrylate having an alicyclic skeleton similar to that of the component A, so that the polymerization rates of the two are almost equal, and birefringence does not change at all because no phase separation occurs. As for the heat resistance and the water absorption, the cured products obtained from the components A and B have the same characteristics, and thus maintain sufficient performance as a low birefringence optical member for a liquid crystal display without deteriorating the performance. .

<Radical polymerization initiator> A radical polymerization initiator used for copolymerization of the photocurable composition used in the present invention (hereinafter sometimes referred to as a photopolymerization initiator or a photoinitiator).
Is not particularly limited as long as radicals are generated by active energy rays such as ultraviolet rays. Specific examples thereof include a compound represented by the general formula (VI), an acetophenone-based photoinitiator, and a benzophenone-based photoinitiator.

[0046]

Embedded image

(Wherein, R ⁸ represents a methyl group, a methoxy group or a chlorine atom, n represents a number of 2 or 3, and R represents a phenyl group or a methoxy group). Specific examples include, for example, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2,6-dichlorobenzoyldiphenyl Phosphine oxide, 2,6-
Acyl phosphine oxides such as dimethoxybenzoyl diphenyl phosphine oxide and acyl phosphinic esters can be mentioned.

Specific examples of the acetophenone compound include, for example, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4-diphenoxydichloroacetophenone, diethoxydiacetphenone. , 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, and the like.

Specific examples of the benzophenone-based compound include, for example, benzophenone, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, diphenoxybenzophenone, and the like. Can be. Among these, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, trimethylbenzoylphenylphosphinic acid methyl ester, 1-hydroxycyclohexylphenylketone, benzophenone, and diphenoxybenzophenone are preferable, and 2,4,4
6-trimethylbenzoyldiphenylphosphine oxide and benzophenone are particularly preferred.

These photopolymerization initiators may be used in combination of two or more. The amount of the photopolymerization initiator added depends on the amount of the monomer 1
0.01 to 1 part by weight, preferably 0.1 to 100 parts by weight.
02 to 0.3 parts by weight. If the amount of the photopolymerization initiator is too large, the polymerization proceeds rapidly, causing not only an increase in birefringence but also a deterioration in hue. If the amount is too small, the composition cannot be cured sufficiently.

<Auxiliary Component> The low birefringence material used in the present invention is obtained by polymerizing and curing a composition containing components A, B and C, and this composition may contain a small amount of an auxiliary component. This is as described above. Therefore, the resin for a plastic sheet used in the present invention is produced by mixing and copolymerizing other radically polymerizable monomers in an amount of up to about 30 parts by weight with respect to 100 parts by weight of the composition before curing. Is also possible. Other monomers used at that time include, for example, methyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, methacryloyloxymethyltetracyclodecane, methacryloyloxymethyltetracyclododecene, ethylene Glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexenediol di (meth) acrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, bisphenol A acrylate methacrylate and mixtures thereof, bisphenol A bis [( [Oxyethyl) ether] = diacrylate, bisphenol A bis [(oxyethyl) ether] = dimethacrylate,
Bisphenol A bis [(oxyethyl) ether] =
Acrylate methacrylate and mixtures thereof, tetrabromobisphenol A bis [(oxyethyl) ether] = diacrylate, tetrabromobisphenol A bis [(oxyethyl) ether] = dimethacrylate, tetrabromobisphenol A bis [(oxyethyl) ether] = acrylate Methacrylates and mixtures thereof, bisphenol A bis [(dioxyethyl) ether] = diacrylate, bisphenol A bis [(dioxyethyl) ether] = dimethacrylate, bisphenol A bis [(dioxyethyl) ether] = acrylate methacrylate and mixtures thereof, bisphenol A bis [(polyoxyethyl) ether] = diacrylate, bisphenol A bis [(polyoxyethyl) ether ] = Dimethacrylate, bisphenol A bis [(polyoxyethylene) ether] =
Acrylate methacrylate, 2,2'-bis [4-
(Β-methacryloyloxyethoxy) cyclohexyl] propane, (meth) acrylate compounds such as 1,4-bis (methacryloyloxymethyl) cyclohexane, trimethylolpropanetri (meth) acrylate, styrene, chlorostyrene, divinylbenzene, α
Nucleus and / or side chain substituted and unsubstituted styrene such as -methylstyrene.

Among these other monomers, methacryloyloxymethylcyclododecane and 2,2-bis [4-
(Β-methacryloyloxyethoxy) phenyl] propane, 2,2-bis [4- (β-methacryloyloxyethoxy) cyclohexyl] propane, 1,4-bis (methacryloyloxymethyl) cyclohexane, and mixtures thereof are particularly preferred.

Other auxiliary components include antioxidants, ultraviolet absorbers, dyes and pigments, and fillers. The UV absorbers that may be added as desired are not particularly limited, but benzophenone-based and triazole-based UV absorbers are preferred, and these may be used alone or in combination with two or more. The above may be used in combination.

Specific examples thereof include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, and 2,2 '. Benzophenone-based compounds such as -dihydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone;
-(2'-hydroxy-5-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-ditert-butylphenyl) benzotriazole,
-(2'-hydroxy-3'-tert-butyl-
Benzotriazole-based compounds such as 5'-methylphenyl) benzotriazole can be mentioned.

The ratio of these ultraviolet absorbers is 0.01 to 100 parts by weight of the diethylenically unsaturated monomer.
0.2 parts by weight, preferably 0.03 to 0.1 parts by weight. If the blending ratio of the ultraviolet absorber is too large, the cured product will not be sufficiently cured, or the obtained cured product will have poor internal homogeneity. On the other hand, if the amount is too small, a desired ultraviolet ray cut property cannot be obtained.

(Production of Plastic Sheet) <Polymerization of Photocurable Composition> In the present invention, the photocurable resin composition injected into the cavity is irradiated with an active energy ray in the presence of a radical polymerization initiator. By doing so, it can be easily polymerized and cured (sometimes referred to as copolymerization, photopolymerization, photopolymerization curing or photocuring).

The active energy ray is not particularly limited as long as it acts on the radical polymerization initiator to generate a radical. For example, an electron beam, ultraviolet light, or the like can be used. Among these, it is preferable to irradiate ultraviolet rays of 200 to 400 nm in the range of 0.1 to 200 j in consideration of the types and amounts of the resin and the polymerization initiator. If the irradiation is extremely small, the polymerization is incomplete, and the heat resistance and mechanical properties of the cured product are not sufficiently exhibited. Conversely, if the irradiation is excessive, the cured product is deteriorated by light such as yellowing, which is preferable. Absent.

(Cavity) In the present invention, two opposing flat plates (hereinafter referred to as "molds") capable of passing active energy are used, a cavity is formed by a spacer or the like, and a peripheral portion is sealed. Called cavity. The material of the molding die is preferably made of glass in consideration of the surface smoothness of the sheet after curing, and has sufficient transmittance of active energy rays to cure the photocurable resin, and is easily formed by heat or the like. What is necessary is just a thing which does not change a shape. Further, plastics such as an acrylic plate which can obtain surface smoothness equivalent to that of glass can be used.

If the in-plane thickness accuracy of the mold is high and the variation in the in-plane permeability is small, the curing reaction becomes uniform.
A plastic sheet having better dimensional stability can be obtained. The preferable in-plane thickness accuracy is within ± 3%, and the range of the in-plane transmittance is preferably within ± 1%. Further, if necessary, a coating of a release agent or the like or a release layer may be provided on the molding die, and a treatment for easily removing the cured photocurable resin sheet from the molding die may be performed. The release agent to be used, the release layer, its application method and the like are not particularly limited, but a substance having a sufficient transmittance of active energy rays to cure the photocurable resin,
It is a substance which does not easily change its state of formation due to active energy rays for curing the photocurable resin or heat generated at the time of curing, and may be any substance capable of obtaining a flatness comparable to a glass surface.

The spacers and the like for forming the cavities are not particularly limited, as long as a sheet having a desired thickness and thickness accuracy can be obtained. For example, a plate or bar made of rubber or metal such as silicon rubber, or a plate or bar made of resin such as Teflon (registered trademark) may be used. The spacer accuracy is set to be within ± 5% of the thickness, more preferably, within ± 3%. If the accuracy is lower than this, the dimensional stability of the obtained plastic sheet decreases, which is not preferable.

(Optical Path Correction Mask) The present invention is characterized in that an optical path correction mask having a specific structure is used when the photocurable composition is cured by irradiation with active energy rays. By using the optical path correction mask, it is possible to suppress minute internal distortion locally remaining in the obtained plastic sheet, etc., so that the dimensional stability of the plastic sheet can be significantly improved. it can.

The optical path correction mask is provided with an outer frame and a plurality of partitions at equal intervals which are parallel to each other, so that the active energy ray does not leak outside the outer frame at a position between the light source and the cavity. The material is not particularly limited as long as it is arranged, but the material is preferably a steel material or the like that does not deform due to active energy rays or heat generated from an active energy ray light source. Further, a material coated with a black heat-resistant paint or the like is preferably used so that the active energy ray is not reflected on the surface. When the active energy rays are reflected, the active energy rays applied to the cavity become partially non-uniform, and the dimensional stability of the plastic sheet deteriorates.

The height b of the partition is usually two times the pitch a of the partition.
Twice as long, preferably four times as long, and the distance d between the active energy ray source and the cavity
Is usually at least half, preferably at least two-thirds. That is, b ≧ 2a and b ≧ d / 2, preferably b ≧ 4a and b ≧ 2d / 3. If the height of the partition is lower than 2a or d / 2, the dimensional stability of the obtained plastic sheet is undesirably reduced.

Although the theoretical basis is not necessarily elucidated, the energy is attenuated by air molecules when the active energy ray travels in the air, so that when the height of the partition is smaller than a certain value, the light source The degree of polymerization of the photocurable composition at the center of the cavity, where relatively short light from the lamp is irradiated, is higher than at the periphery of the cavity, and as a result, between the center and the periphery. It is presumed that local and minute internal distortion occurs, leading to a decrease in dimensional stability.

The screen has a thickness of 5 mm or less, preferably 2 m
m and the distance from the portion closest to the cavity of the screen to the cavity is at least 1 cm or more, preferably 5 cm or more. If the screen is too thick, or if the distance between the screen and the cavity is too small, there will be portions where the dose of active energy rays is low, polymerization will be uneven, and the dimensional stability of the resulting plastic sheet will be impaired. Therefore, it is not preferable.

It is preferable that the active energy ray is irradiated from both sides of the cavity because the photocurable composition is uniformly polymerized. In addition, the center line of two rod-shaped active energy ray light source lamps of the same length arranged in parallel is passed through the cavity at a constant speed in the direction perpendicular to the center line, and from the back and front of the cavity When curing the photocurable composition so that the same amount of active energy rays are irradiated at the same time,
It is more preferable because the polymerization proceeds extremely uniformly. Furthermore, it is even more preferable that the width of the cavity in the traveling direction is smaller than the length of the lamp of the active energy ray light source, especially since the polymerization around the cavity becomes uniform.

The shape of the active energy ray irradiation lamp is not particularly limited, and may be spherical (ball lamp), rod shape, circular shape (circle line), planar shape, etc., but the rod shape and planar shape are preferable. The lamp shape that provides the best effect of the present invention is a rod shape. The number of the lamps may be at least one when irradiating from one side, and at least one on each side when irradiating from both sides.

A preferred embodiment of the present invention is a method of irradiating active energy rays from both sides of the cavity. In this case, it is preferable to install two or more lamps on each side. By adopting such a lamp arrangement, it is preferable that the irradiation intensity can be controlled more uniformly and irradiation can be controlled more gently, such as irradiating the cavity with active energy rays.

When two or more lamps are installed on each side, it is preferable that the optical path correction mask is arranged on each lamp. However, when the distance between the lamps is small, the optical path correction masks are integrated. Thus, the screen can be formed in a lattice-like structure. Also, when a light source having a planar structure is used, the active energy rays applied to the cavity can be made uniform by using an optical path correction mask having a lattice-shaped screen according to the above method.

The irradiation with active energy rays may be performed in one step, but in order to obtain a sheet having good surface properties, it is preferable to perform the irradiation in a plurality of steps and at least two steps. When the irradiation is performed in two stages, the first stage requires 15% or less, preferably 10%, of the required amount of hardening of the active energy ray.
Irradiation is carried out below, particularly preferably 7% or less, so that the photocurable resin in the cavity has a self-retaining property, that is,
Gel is formed so that the resin does not leak even if the spacer is removed. In addition, in this specification, the hardening | requirement amount of an active energy source shall point out the irradiation amount required to make 80% of the ethylenic carbon-carbon double bond of the resin composition in a cavity disappear. The rate of disappearance of the ethylenic carbon-carbon double bond by irradiation with active energy rays is as follows:
It is calculated by the following equation.

Elimination = (1−K / M) × 100 (%) M = A _M / B _M A _M : Peak area of double bond in infrared absorption before irradiation with active energy ray B _M : Active energy ray C- in infrared absorption before irradiation
H bond peak area _{K = A K / B K A} K: the peak area of the double bond in the infrared absorption after irradiation with an active energy ray B _K: C-in infrared absorption after active energy ray irradiation
The peak area of the H bond is 1658.5 to 1591 cm.
^-1 and the peak of CH bond is 3210-280.
Appears at 9.8 cm ^-1 .

If the amount of active energy ray irradiation in the first stage exceeds 15% of the required curing amount, curing shrinkage occurs, and the resin in the cavity is peeled off from the face plate, and defects are easily generated on the surface of the resulting resin sheet. . In addition, there is also a problem that the gelled resin firmly adheres to the spacer, making it difficult to remove the spacer. Preferably, the means for keeping the distance between the face plates constant when the irradiation amount is 10% or less of the required curing amount is released. Conversely, if the amount of active energy ray irradiation is too small, gelation is insufficient, and when the tightening of the face plate of the mold is released, the resin in the cavity easily leaks from the gap of the mold. In addition, the adhesive force between the gelled resin and the face plate is weak, and an accident may occur in which the resin peels off from the face plate due to an impact when the tightening of the face plate of the mold is released.

Then, in the second step, 9
Irradiation is performed so that 5 to 100% of the reaction is completed, thereby completing the polymerization. The atmosphere for irradiating the active energy ray may be any of ordinary air or an inert gas atmosphere. The temperature at the time of irradiation is usually the first stage: room temperature to 100 ° C.,
The second stage: normal temperature to 300 ° C., and the irradiation time is usually the first stage: 1 second to 1 minute, and the second stage: 10 seconds to 10 minutes.

As a light source for an active energy ray, a chemical lamp, a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp and the like are used. For the purpose of quickly completing the curing, thermal polymerization may be used in combination. That is, the composition and the whole mold are simultaneously irradiated with light at 30 to
Heat in the range of 300 ° C. In this case, a radical polymerization initiator may be added in order to complete the polymerization better, but excessive use causes an increase in birefringence and a deterioration in hue. Specific examples of the thermal polymerization initiator include benzoyl peroxide, diisopropyl peroxy carbonate, t-butyl peroxy (2-ethylhexanoate), and the amount used is 1 part by weight or less based on 100 parts by weight of the monomer. Is preferred.

Further, in the present invention, the completion of the polymerization reaction and the internal strain generated during the polymerization can be reduced by heating the cured product after performing the radical polymerization by light irradiation. The heating temperature is appropriately selected according to the composition of the cured product and the glass transition temperature. However, since excessive heating causes deterioration in the hue of the cured product, a temperature near or below the glass transition temperature is desirable.

The plastic sheet obtained as described above is an optical member having low birefringence. The plastic sheet of the present invention has a birefringence of 10 nm or less, preferably 5 nm or less, more preferably 2 nm or less, particularly preferably 1 nm or less. <Gas Barrier Film> A gas barrier film can be formed on the surface of the cured product used in the present invention by various methods, and can be used as an optical member with a gas barrier.

Known gas barrier films can be used. For example, an inorganic oxide film or a gas barrier resin layer such as polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, and vinylidene chloride may be mentioned, but an inorganic oxide film is preferable. Inorganic oxides are oxides of metals, nonmetals, and submetals. Specific examples include aluminum oxide, zinc oxide, antimony oxide, indium oxide, calcium oxide, cadmium oxide, silver oxide, gold oxide, and chromium oxide. , Silicon oxide, cobalt oxide, zirconium oxide, tin oxide, titanium oxide, iron oxide, copper oxide, nickel oxide, platinum oxide, palladium oxide, bismuth oxide, magnesium oxide, manganese oxide, molybdenum oxide, vanadium oxide, barium oxide, etc. Among them, silicon oxide is particularly preferable. In addition, a small amount of metal,
Non-metals, sub-metals or hydroxides thereof, and carbon or fluorine may be appropriately contained in order to improve flexibility.

As a method of forming a gas barrier film, a method of coating a resin or the like and a method of forming a vapor deposition film made of an inorganic oxide can be mentioned. As a method for forming the deposited film, a conventionally known method such as a vacuum deposition method, a vacuum sputtering method, an ion plating method, and a CVD method can be used. The thickness of the above gas barrier film is not particularly limited, and varies depending on the type of the constituent components of the gas barrier film.For example, in the case of silicon oxide, in consideration of oxygen gas barrier properties and water vapor gas barrier properties, and further economics, The film thickness is 5-50n
m is preferred. In order to obtain more advanced oxygen gas barrier properties and water vapor barrier properties, the thickness of the film may be increased.
When the thickness is 0 nm or more, cracks are easily formed due to film stress generated during film formation. If the thickness of the film is less than 5 nm, the gas barrier properties are insufficient.

<Hardened film> The hardened film in the present invention is a resin film for improving the adhesion between the conductive film and the substrate when laminating the conductive film on the plastic sheet and further protecting the gas barrier film. This film is composed of an acrylate-based photocurable monomer and an isocyanate group-containing compound, preferably an isocyanate group-containing acrylate compound, more preferably an isocyanate group-containing silane coupling agent, and a hydroxyl group containing a hydroxyl group and three or more acryloyl groups in the molecule. A compound obtained by reacting with a polyfunctional acrylate,
Can be obtained by polymerizing and curing a photocurable composition containing
Here, "comprising" means not more than 50 parts by weight of 100 parts by weight of the total composition of a polymer or the like that does not inhibit polymerization and curing by irradiation with active energy rays other than the acrylate-based photocurable monomer and the isocyanate group-containing compound. Means that they may be used together.

As the acrylate-based photocurable monomer, for example, diethylene glycol diacrylate,
Diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,
3-butylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate,
Polypropylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate,
Diethylene glycol diacrylate, bis (oxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane diacrylate, bis (oxymethyl) tricyclo [5.2.
1.0 ^2,6 ] decane dimethacrylate, bis (oxymethyl) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0
^9,13 ] pentadecane dimethacrylate, bis (oxymethyl) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0
^9,13 ] pentadecane dimethacrylate, 2,2-bis (4- (acryloxydiethoxy) phenyl) propane, 2,2-bis (4- (methacryloxydiethoxy) phenyl) propane, tricyclo [5.2. 1.0
^2,6 ] decane-3,8-diyldimethyldiacrylate, tricyclo [5.2.1.0 ^2,6 ] decane-3,8
-Diyldimethyldimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropaneethoxytriacrylate, trimethylolpropaneethoxytrimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethanetrimethacrylate, tetramethylolmethanetetraacrylate , Tetramethylol methane tetramethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, ditrimethylolpropane tetraacrylate, ditrimethylolpropane tetramethacrylate, dipentaerythritol hexaac Rate, dipentaerythritol hexa methacrylate, tris (2-hydroxyethyl) isocyanate triacrylate, tris (2-hydroxyethyl) isocyanurate trimethacrylate, and the like.

Examples of the isocyanate group-containing compound include acrylic isocyanate, methyl isocyanate,
Isopropyl isocyanate, t-butyl isocyanate, cyclohexyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, octadecyl isocyanate, (meth) acryloyl isocyanate, 2- (meth) acryloyloxyethyl isocyanate, 3-isopropenyl isocyanate, dimethyl (M-isopropenyl) benzyl isocyanate, xylylene diisocyanate, 1,2-diisocyanateethane, 1,3-diisocyanatepropane, 1,2-
Diisocyanate propane, 1,4-diisocyanate butane, 1,5-diisocyanate butane, 1,5-diisocyanate pentane, 1,6-hexamethylene diisocyanate, bis (3-isocyanatopropyl) ether, bis (3-isocyanatepropyl) sulfide, Bis (6-isocyanatohexyl) sulfide,
1,7-diisocyanate heptane, 1,5-diisocyanate-2,2-dimethylpentane, 2,6-diisocyanate-3-methoxyhexane, 1,8-diisocyanatooctane, 1,5-diisocyanate-2,
2,4-trimethylpentane, 1,9-diisocyanatononane, 1,10-diisocyanatodecane, 1,1
1-diisocyanate undecane, 1,12-diisocyanatododecane, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4-dicyclohexylmethane diisocyanate, 3,3'-dicyclohexylmethane diisocyanate, lysine isocyanate, tolylene diisocyanate Isocyanate, isophorone diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-bis (α, α-dimethylisocyanatomethyl) benzene, 1,3-bis (isocyanatomethyl) cyclohexane, trimethylhexa Methylene diisocyanate and the like can be mentioned.

Examples of the isocyanate group-containing acrylate include known diisocyanates and known hydroxy acrylates such as 2-hydroxyethyl acrylate,
It is obtained by reacting 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl diacrylate, 1,4-cyclohexane dimethanol monoacrylate, 2-hydroxy-3-phenoxypropyl acrylate, pentaerythritol triacrylate and the like. Although a compound etc. are mentioned, Preferably, the adduct of 5-isocyanate-1- (isocyanatomethyl) -1,3,3-trimethylcyclohexane and 2-hydroxyethyl acrylate, 2- (5-isocyanate-1,3,3) 3-trimethyl-cyclohexylmethylcarbamoyloxy) -ethyl acrylate, 2
-(3-isocyanatomethyl-3,5,5-trimethyl-cyclohexylcarbamoyloxy) -ethyl acrylate, 2- (4'-isocyanato-4-diphenylmethanecarbamoyloxy) -ethyl acrylate,
2- (5-isocyanate-1-carbamoyloxy)
-Ethyl acrylate, 4- (5-isocyanate-
1,3,3-trimethyl-cyclohexylmethylcarbamoyloxy) -butyl acrylate, 4- (3-isocyanatomethyl-3,5,5-trimethyl-cyclohexylcarbamoyloxy) -butyl acrylate,
-(4'-isocyanato-4-diphenylmethanecarbamoyloxy) -butyl acrylate, 4- (5-isocyanate-1-carbamoyloxy) -butyl acrylate, 2-methacryloyloxyethyl isocyanate and the like. The isocyanate group-containing silane coupling agent represented by the general formula is used.

[0083]

Embedded image

(Wherein R ¹ and R ² are the same or different monovalent hydrocarbon groups, preferably R ¹ and R ² are lower alkyl groups such as methyl, ethyl and propyl. R ³
Is a divalent hydrocarbon group having 2 to 8 carbon atoms. a is an integer of 2 to 3, b is an integer of 0 to 1, and c is an integer equal to 4-ab.) Specific examples of the isocyanate group-containing silane coupling agent include 3-isocyanatopropyltrimethoxysilane. , 2-isocyanatoethyltrimethoxysilane, 3-
Isocyanatopropyltriethoxysilane, 2-isocyanatoethyltriethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 2-isocyanatoethylmethyldimethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, 2-isocyanatoethylmethyl Diethoxysilane and the like can be mentioned. Next, examples of the hydroxyl group-containing polyfunctional acrylate having a hydroxyl group and three or more acryloyl groups in a molecule include pentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and mixtures thereof.

The reaction between the isocyanate group-containing silane coupling agent and the hydroxyl group-containing polyfunctional acrylate is carried out by mixing the respective compounds at a ratio of -NCO / -OH group ≤1, and
It is obtained by stirring at 0 ° C. for 1 to 20 hours. These photocurable compositions contain an isocyanate group-containing compound in an amount of 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, and still more preferably 10 to 20 parts by weight, based on 50 to 99 parts by weight of an acrylate-based photocurable monomer. By blending parts by weight, a balance of physical properties as a cured film can be obtained. The adhesion between the photocurable resin sheet and the cured film can be obtained without the isocyanate group-containing compound, but the addition of the isocyanate group can further improve the adhesion between the gas barrier film and the transparent conductive film. That is, a strong bond is formed by the reaction between the hydroxyl group and the isocyanate group on these inorganic films, and both the performance as an anchor function on the conductive film side and the performance as a protective layer on the gas barrier film side are exhibited. If the amount of the isocyanate group-containing compound is too small, the adhesion on the gas barrier film side will decrease, and if it is too large, the chemical resistance will decrease.

Some examples of other polymers that can be used in combination are as follows. Polymethyl acrylate, polybutyl acrylate, polyethylene glycol, polyhydroxyethyl acrylate. Also,
Known additives such as an antioxidant, an ultraviolet absorber, a leveling agent, a thermal polymerization inhibitor, a silane coupling agent and the like may be added to these active energy ray-curable compositions. It is preferable that the composition is usually diluted with a volatile solvent and applied. The solvent and the degree of dilution are not particularly limited, but are required not to impair the surface properties of the object to be used during use. Further, the stability of the composition,
The solvent should be determined in consideration of wettability to the substrate, volatility, and the like. Further, the solvent may be used not only as one kind but also as a mixture of two or more kinds. Examples of the solvent include alcohols, esters, ethers, ketones, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, and aprotic polar solvents.

These photocurable compositions are cured by a known radical polymerization in which a photopolymerization initiator that generates a radical by active energy rays such as ultraviolet rays is added. Examples of the polymerization initiator used at that time include benzophenone, benzoylmethyl ether, benzoylisopropyl ether, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2,6-dimethylbenzoylphenylphosphine oxide and the like.
Preferred initiators are 1-hydroxycyclohexylphenyl ketone, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoylphenylphosphine oxide. Two or more of these photopolymerization initiators may be used in combination.

The addition amount of the photopolymerization initiator is 1 to 30 parts by weight, preferably 10 parts by weight, per 100 parts by weight of the photocurable composition.
-20 parts by weight. If the amount of the photoinitiator is too large,
The polymerization progresses rapidly, causing not only an increase in birefringence, but also a deterioration in hue. If the amount is too small, the composition cannot be cured sufficiently. The dip coating method is optimal for forming a cured film. That is, the photocurable resin sheet with a gas barrier may be dipped in the photocurable composition for forming a cured film, pulled up, and then cured by irradiation with active energy rays. At this time, preheating may be performed after application and before curing. If the photocurable composition has been diluted with a solvent, the solvent must be removed in this preheating step. The thickness of the cured film is not particularly limited, but is usually 0.1 to 50 μm, preferably 0.3 to 10 μm from the viewpoint of maintaining the adhesive strength and hardness. The thickness of the cured film can be controlled by the pulling speed during dip coating and the degree of dilution of the solvent.

The amount of the active energy ray to be irradiated is arbitrary as long as the photopolymerization initiator generates a radical.
UV radiation of 200 to 400 nm is 0.1 to 100 J / cm.
² , preferably in the range of 1 to 30 J / cm ² .
Specific examples of the lamp used include a metal halide lamp and a high-pressure mercury lamp. <Conductive Film> Various transparent conductive films can be preferably formed on the surface of the cured product used in the present invention by various methods, and can be used as an optical member with a transparent electrode.
There is no particular limitation on the transparent conductive film that can be formed on the surface of the cured product. For example, as a conductive material that forms this conductive film,
Indium oxide, tin oxide, gold, silver, copper, nickel and the like can be mentioned, and these can be used alone or in combination of two or more. Of these, usually indium oxide 99
Indium tin oxide (hereinafter, referred to as "ITO") composed of a mixture of 90% and 1-10% of tin oxide is preferable in terms of balance between transparency and conductivity. The method for forming the transparent conductive film can be performed by using a conventionally known vacuum evaporation method, sputtering method, ion plating method, chemical vapor deposition method, or the like. Of these, the sputtering method is preferred from the viewpoint of adhesion. The thickness of the above transparent conductive film is
The range of 500 to 2000 ° is preferable from the viewpoint of the balance between transparency and conductivity.

(Structure of Laminate) The plastic laminate of the present invention comprises a photocurable resin layer (A) having at least one surface provided with a gas barrier layer (B) (laminate 1). One obtained by further providing a cured film (C) on one surface (laminate 2) and one obtained by further providing a conductive film on at least one surface of the laminate 1 or 2.

FIGS. 1 and 2 show specific examples of the laminate 1.
And specific examples of the laminate 2 are shown in FIGS. 3 to 7. The thickness of the photocurable resin layer (A), for example, the plastic sheet substrate is usually 0.05 to 3 m.
m, preferably in the range of 0.1 to 1.5 mm. (Properties of the laminate) The plastic laminate of the present invention
It is preferable that the light transmittance at a wavelength of light of 0 nm is 80% or more. If the light transmittance is less than 80%, the screen becomes dark, so that it is difficult to use it as a liquid crystal display panel. The birefringence of the plastic laminate is usually 10
nm or less, preferably 5 nm or less, more preferably 2 nm or less, and particularly preferably 1 nm or less. If it is larger than 20 nm, when the display panel is used, color unevenness of the display screen tends to occur.

The thickness of the plastic laminate is set at 0.1.
It is preferably from 0.5 to 3 mm. If it is less than 0.05 mm, the sheet tends to bend due to its own weight, and the conventional liquid crystal device manufacturing process tends to be unusable. On the other hand, if it exceeds 3 mm, the weight becomes the same as that of a conventional 0.7 to 1.5 mm glass substrate. However, it is out of the purpose of weight reduction. As an application example of the plastic laminate of the present invention, for example, when the plastic laminate is used as a substrate for a liquid crystal display device, a liquid crystal is usually sandwiched between two plastic laminates. That is, a structure is adopted in which a liquid crystal layer is sandwiched between a substrate having an insulating film, if necessary, and an alignment film provided thereon on a conductive film of a plastic laminate. Further, a polarizing plate is provided outside the substrate holding the liquid crystal layer. In addition, in the case of an electroluminescence display element, a structure is generally exemplified in which a light-emitting layer, an insulating layer, and a back electrode are sequentially formed on a plastic laminate of the present invention, and the whole is covered with a gas barrier layer. In this case, zinc sulfide, cadmium sulfide, zinc selenide or the like is used for the light emitting layer, yttrium oxide, thallium oxide, silicon nitride or the like is used for the insulating layer, and aluminum or the like is used for the back electrode.

The plastic sheet obtained by the present invention has not only transparency but also high heat resistance and high mechanical strength, and has a display substrate such as liquid crystal or organic EL, an optical disk substrate, a solar cell substrate, various lenses, prisms, optical filters, It can be used for many optical applications such as optical communication materials.

[0094]

EXAMPLES The contents and effects of the present invention will be more specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. The plastic sheet and the plastic laminate obtained in the examples and comparative examples were evaluated by the following methods.

(1) Light transmittance: The light transmittance at 500 nm was measured on a test piece having a thickness of 0.5 mm. (2) Birefringence: Measured at 25 ° C. using a birefringence measuring device (manufactured by Oak) with a 0.5 mm thick test piece. (3) Heat resistance: Using a rectangular test piece of 3 mm × 30 mm × 0.5 mm, the glass transition temperature Tg was measured by a pulling method TM.
A was measured with a weight of 2 g at A.

(4) Dimensional change in standing test after heating:
Fine cross-shaped markings are applied to the four corners of a 100 mm × 100 mm × 0.5 mm thick test piece so that the distance between adjacent markings is about 80 mm. The specimen was heated in an oven at 150 ° C. for 3 hours, then at 23 ° C., 5
After leaving to cool in a constant temperature and humidity room of 0% RH for one week, the distance between each marking is accurately measured (accuracy ± 1 μm). Thereafter, during a heating standing test in which the sample is left in a constant temperature and humidity room at 23 ° C. and 50% RH for 8 weeks, the distance between the markings is similarly measured every week. The dimensional change and dimensional stability were evaluated based on the following formula.

Distance between markings after heating and before standing test:
a (μm) Distance between markings n weeks after the start of test: b
_{n (μm) (n = 1,2} , ..., 8) dimensional change _{c n (%) = (a} -b n) × 100 / a dimensionally stable C (%) = | (the maximum value of c _n) - (minimum value of c _n) | (5) dimensional change in shelf test after immersion in hot water: 1
Fine cross-shaped markings are applied to the four corners of a test piece having a thickness of 00 mm x 100 mm x 0.5 mm so that the distance between adjacent markings is about 80 mm. 4
Immerse in hot water at 0 ° C for 1 hour, remove moisture on the surface with absorbent paper, leave in a constant temperature and humidity room at 23 ° C and 50% RH for 1 week, and accurately (accuracy ± 1 µm) between each marking Measure the distance of. Thereafter, the same distance between the respective markings is measured every week during the standing test after immersion in warm water, which is again left in a constant temperature and humidity room at 23 ° C. and 50% RH for 8 weeks. The dimensional change and dimensional stability were evaluated based on the following formula.

Distance between markings before immersion in hot water and before standing test: d (μm) Distance between markings after n weeks from the start of test: e
_{n (μm) (n = 1,2} , ..., 8) dimensional change _{f n (%) = (d} -e n) × 100 / d dimensional stability F (%) = | (the maximum value of e _n) - (minimum value of e _n) | (6) gas barrier measurement: 0.5mm thick 23 ° C. at Okishitoran Co. oxygen Mocon instrument at the test piece was measured oxygen permeability under conditions of 80% humidity.

(7) Hardness of cured film: JIS K540
According to 0, the pencil hardness of the cured film was measured. Example 1 (Production of plastic sheet) bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = dimethacrylate 94 parts, bis (hydroxymethyl) tricyclo [5.2.1.0 ^{2, 6} ] Decane monomethacrylate 6 parts acrylate composition, pentaerythritol tetrakis (β-thiopropionate) 6 parts, photoinitiator 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF's “Lucillin TPO”) ")
After uniformly mixing 0.1 part of benzophenone and 0.1 part of benzophenone, the composition was defoamed to obtain a composition. This composition was poured into an optically polished glass mold (thickness accuracy: ± 2%) using a 0.5 mm thick (thickness accuracy: ± 3%) silicon plate as a spacer, and was placed 40 cm above and below the glass surface. As shown in FIG. 8, an optical path correction mask was attached to metal halide lamps having an output of 80 W / cm and arranged in parallel at the same length, and irradiated with ultraviolet rays for 5 minutes. Demold after UV irradiation,
The cured product was obtained by heating at 160 ° C. for 1 hour. The light transmittance of the cured product is 92%, the birefringence is 0.4 nm, and the heat resistance is 190.
° C.

(Deposition of Gas Barrier Film) Obtained 0.5 m
On one surface of the cured product having a thickness of m, a film of SiOx was formed to a thickness of 300 ° by a sputtering apparatus (Tokuda Seisakusho; Model CFS-4ES).
The oxygen permeability of the obtained plastic laminate is 1 cc / m.
Was ² · 24h · atm. (Formation of cured film) On the SiOx surface of the obtained plastic sheet with a gas barrier film, 20 parts of bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = diacrylate and 2,4,4 After spin-coating a composition consisting of 2 parts of 6-trimethylbenzoyldiphenylphosphine oxide and 78 parts of propylene glycol monomethyl ether acetate as a solvent, the solvent is dried by heating at 100 ° C. for 5 minutes to form a metal halide lamp having an output of 80 W / cm. For 5 minutes. The pencil hardness of the obtained cured film was 4H, and the film thickness was 2 μm. Further, the maximum value of the absolute value of the dimensional change and the dimensional stability in the standing test after heating and the standing test after immersion in warm water were as shown in Table 1.

Example 2 Bis (oxymethyl) tricyclo [5.2.1.0
^2,6 ] decane = dimethacrylate 92 parts, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = monomethacrylate 8 parts, except that an acrylate composition was used in the same manner as in Example 1. A cured product was obtained. The light transmittance of the cured product is 92%, the birefringence is 0.4 nm, the heat resistance is 195 ° C., and the maximum absolute value of dimensional change in the standing test after heating and the standing test after immersion in warm water, and the dimensional stability are shown in Table 1.
As shown in FIG.

Example 3 bis (oxymethyl) tricyclo [5.2.1.0
^2,6 ] decane = dimethacrylate 92 parts, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = monomethacrylate 8 parts except that an acrylate composition was used in the same manner as in Example 2. A cured product was obtained. The thickness accuracy of the cured product is ± 4%, the light transmittance is 92%, and the birefringence is 1
nm, the heat resistance was 190 ° C., the maximum value of the absolute value of the dimensional change in the standing test after heating and the standing test after immersion in warm water, and the dimensional stability were as shown in Table 1.

Comparative Example 1 The maximum absolute value of the dimensional change and the dimensional stability of a commercially available 0.5 mm-thick polycarbonate plastic sheet (thickness accuracy: ± 4%) in a standing test after heating and a standing test after immersion in warm water were as follows: As shown in Table 1. This sheet has a light transmittance of 90%, a birefringence of 10 nm, and a heat resistance of 140.
° C.

Comparative Example 2 A cured product was obtained in the same manner as in Example 1 except that the optical path correcting slit was not used. The light transmittance of the cured product is 92%, the birefringence is 0.4 nm, the heat resistance is 190 ° C, and the maximum absolute value of the dimensional change and the dimensional stability in the standing test after heating and the standing test after immersion in warm water are shown in the table. As shown in FIG.

Comparative Example 3 A cured product was obtained in the same manner as in Example 1 except that the optical path correction mask shown in FIG. 9 was mounted as shown in FIG. The light transmittance of the cured product is 92%, the birefringence is 0.4 nm, the heat resistance is 190 ° C., the maximum absolute value of the dimensional change in the standing test after heating and the standing test after immersion in warm water, and the dimensional stability are shown in Table 1.
As shown in FIG.

[0106]

[Table 1]

[0107]

According to the present invention, when a photocurable resin composition is irradiated with an active energy ray and polymerized and cured to produce a plastic sheet, the irradiation of the active energy ray is made uniform to obtain a plastic sheet. The remaining internal distortion can be reduced, and dimensional stability can be ensured.

[Brief description of the drawings]

FIG. 1 shows one embodiment of the plastic laminate of the present invention.

FIG. 2 shows one embodiment of the plastic laminate of the present invention.

FIG. 3 shows one embodiment of the plastic laminate of the present invention.

FIG. 4 shows one embodiment of the plastic laminate of the present invention.

FIG. 5 shows one embodiment of the plastic laminate of the present invention.

FIG. 6 shows one embodiment of the plastic laminate of the present invention.

FIG. 7 shows one embodiment of the plastic laminate of the present invention.

FIG. 8 shows an optical path correction mask used in the first embodiment.

FIG. 9 shows an optical path correction mask used in Comparative Example 3.

[Explanation of symbols]

 A low birefringent plate B gas barrier film C cured film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 5/18 CEY C08J 5/18 CEY // (C08F 220/20 (C08F 220/20 220: 28) 220 : 28) B29K 33:04 B29K 33:04 105: 24 105: 24 B29L 7:00 B29L 7:00 C08L 33:08 C08L 33:08 33:10 33:10 F term (reference) 4F071 AA33 AA86 AF31Y AF54Y AF61Y AH12 AH19 BB12 BC01 BC12 4F204 AA43 AG01 AR06 AR12 EA03 EB01 EE03 EE07 EF01 EF27 EK17 EK18 EW01 EW34 4J011 GB08 QA03 QA12 QA34 QA45 TA08 TA10 UA01 UA03 VA05 WA10 4J100 CA08Q27 CA03 DA03 CA03 DA03

Claims (10)

[Claims] 1. A method for producing a plastic sheet by irradiating a photocurable resin composition injected into a cavity with an active energy ray and polymerizing and curing the same to form an active energy ray between an active energy ray light source and the cavity. An optical path correction mask provided with a plurality of equally spaced partitions perpendicular to the length direction of the light source, and a height (b) of the partition of the optical path correction mask, its pitch (a), and an active energy ray light source; A method for producing a plastic sheet, wherein a distance (d) from a cavity satisfies the following expression (1). B ≧ 2a and b ≧ d / 2 (1) (where a, b and d represent the pitch of the screen, the height of the screen, and the distance between the active energy ray light source and the cavity, respectively) 2. The method of irradiating the photocurable resin composition with an active energy ray is performed by arranging two parallel rod-shaped active energy ray light source lamps of the same length, which are arranged in parallel, with respect to the intermediate line. 2. A method according to claim 1, wherein the width of the cavity in the traveling direction is smaller than the length of the active energy ray light source lamp.
The method described in. 3. The method according to claim 1, wherein the plastic sheet is in air for 150 hours.
After heating for 3 hours at 23 ° C. in 50% RH air,
The method according to claim 1, wherein a dimensional change after the test is within ± 0.01% in a heating test left for 1 hour. 4. In a hot water test in which a plastic sheet is immersed in warm water at 40 ° C. for 1 hour and then left at 50 ° C. in air at 23 ° C. for 1 week, the dimensional change after the test is ±
The method according to any one of claims 1 to 3, wherein the content is within 0.01%. 5. The plastic sheet has a thickness of 0.05 to 0.05.
5. The method according to claim 1, which is in the range of 3 mm. 6. The method according to claim 1, wherein the glass transition temperature of the plastic sheet is 150 ° C. or higher. 7. The method according to claim 1, wherein the plastic sheet has a birefringence of 5 nm or less. 8. The plastic sheet according to claim 1, wherein the plastic sheet is obtained by polymerizing and curing a polymerizable composition containing a polymerizable monomer having two or more polymerizable functional groups in a molecule. Method. 9. A polymerizable composition comprising the following components A, B and C (however, the proportion of each component is represented by 100 parts by weight of the sum of the components A and B). 8
The method described in. Component A: alicyclic skeleton bis (meth) acrylate represented by the general formula (I): 70 to 99 parts by weight (Wherein, R ¹ and R ² each independently represent a hydrogen atom or a methyl group, m represents 1 or 2, n represents 0 or 1, p and q each independently represent 0, 1, or 2) Component B: alicyclic skeleton mono (meth) acrylate represented by the general formula (II): 1 to 30 parts by weight (Wherein, R ³ represents a hydrogen atom or a methyl group, m represents 1 or 2, n represents 0 or 1, r and s each independently represent 0, 1 or 2) C: at least bifunctional mercapto compound: 1 to
15 parts by weight 10. The method according to claim 1, wherein the plastic sheet is for a liquid crystal display panel.