JP2016124899A - Method for producing resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a resin sheet which provides cured product having high elastic modulus and free from the occurrence of interference fringe.SOLUTION: A method for producing a resin sheet with a film thickness of 100 μm to 5 mm is provided that uses an active energy ray-curable composition and sequentially performs the following steps 1 and 2, a step 1 of applying the active energy ray-curable composition onto a base material, or flowing or injecting the composition into a base material having a recessed portion, and a step 2 of irradiating the base material from any one side thereof with active energy rays which have a haze of 45% or more and which a light diffusion plate has transmitted, thereby curing the composition.SELECTED DRAWING: Figure 3

Description

The present invention relates to a method for producing a resin sheet, which can be used for an alternative use of glass in a display, a building material field, and an automobile field in which glass is conventionally used, and can be preferably used as an optical sheet, and belongs to these technical fields.
In the present specification, an acryloyl group or a methacryloyl group is represented as a (meth) acryloyl group, and an acrylate or methacrylate is represented as a (meth) acrylate.

In recent years, a touch panel integrated liquid crystal display device or a touch panel integrated organic EL display device is often applied to mobile devices such as smartphones, tablet terminals, and car navigation systems.
Conventionally, as a transparent conductive thin film of a touch panel, conductive glass in which a thin film of indium tin oxide (hereinafter referred to as ITO) is formed on glass is well known, but since the base material is glass, flexibility, If it is inferior in workability and is not preferred depending on the application, a polyethylene terephthalate sheet (glass transition temperature of about 120 ° C.) is used because of its advantages such as flexibility and workability, excellent impact resistance, and light weight. A transparent conductive sheet as a substrate is used.
On the other hand, since it is expected to contribute to reducing the thickness and weight of the touch panel, improving the transmittance, and reducing the cost of components, a cover-integrated touch panel that directly forms a touch sensor such as ITO on the cover glass, so-called OGS (One Glass) (Solution) is partially adopted. However, the OGS type has a bottleneck that the touch panel cannot be operated if the cover glass is broken.

  Therefore, so-called OPS (One Plastic Solution) in which a touch sensor such as ITO is directly formed on a cover resin having excellent impact resistance has been proposed. However, conventional acrylic resin sheets and polycarbonate resin sheets cannot be used because of insufficient heat resistance in the transparent conductive film or metal electrode formation process.

In order to improve the heat resistance of the resin sheet, a method for producing a resin sheet using an active energy ray-curable composition having a crosslinked structure has been proposed.
As an example of the manufacturing method of the said resin sheet, for example, in patent document 1, it is a photocurable composition containing the monofunctional (meth) acrylate which has an alicyclic structure, and the urethane (meth) acrylate which has an alicyclic structure, A resin sheet having a glass transition temperature of 200 ° C. or higher and a flexural modulus of 3.0 GPa or higher has been proposed.

By the way, the active energy ray-curable composition is generally used in applications where the thickness of the cured product is less than 50 μm, that is, in applications such as hard coats, paints, and adhesives, and the optical or mechanical properties of the cured product. Depends mainly on the composition of the composition and is not significantly affected by the curing conditions.
Even when the thickness is 50 μm or more, in applications where the elastic modulus of the cured product is low, such as an adhesive, the optical or mechanical properties of the cured product are not significantly affected by the curing conditions.
However, when a resin sheet having a thickness of 50 μm or more and an elastic modulus exceeding 1 GPa is produced from the active energy ray-curable composition, not only the composition but also the curing conditions are the mechanical properties and optical properties of the resin sheet. Problems with optical or mechanical properties that have a great influence on properties are often derived from residual stresses during curing, such as breakage and warping during curing, and birefringence.

As a method for solving these problems, Patent Document 2 discloses that the cumulative amount of ultraviolet irradiation in the first stage is 0.1 to 10 J / cm ² and the cumulative amount of ultraviolet irradiation in the second stage is disclosed in Patent Document 2. The manufacturing method of the resin sheet which is 1-100 J / cm < ² > is disclosed.
Also known is a method of heating after active energy ray irradiation to release residual stress.

Japanese Patent No. 5057775 JP 2014-113723 A

However, according to the study by the present inventors, the method of controlling the irradiation condition of ultraviolet rays and the method of post-heating were able to eliminate warping and breakage, but the elastic modulus of the resin sheet was insufficient. Or a new problem has arisen regarding the optical property of generating interference fringes on the surface of the cured product. Interference fringes on the surface of the cured product become a serious problem particularly in display applications.
There is no report example which specifies the phenomenon and the solution method of such interference fringes.

  The present inventors have intensively studied to find out a method for producing a resin sheet in which the obtained cured product has a high elastic modulus and no interference fringes are generated.

  As a result of intensive studies to solve the above problems, the present inventors use an active energy ray-curable composition, and generate interference fringes by irradiating active energy rays that have passed through a light diffusion plate. The present inventors have found that it is possible to obtain a resin sheet that is optically homogeneous and has a high elastic modulus, and has completed the present invention.

That is, this invention relates to the manufacturing method of the resin sheet which has a film thickness of 100 micrometers-5 mm which uses an active energy ray hardening-type composition and implements the following processes 1 and 2 sequentially.
Step 1: Applying the composition on a substrate or pouring or injecting the composition into a substrate having a recess Step 2: Haze is 45% from either side of the substrate The process of curing the composition by irradiating the active energy ray transmitted through the light diffusion plate as described above

As said composition, what contains the compound (A) which has an ethylenically unsaturated group is preferable.
Moreover, as (A) component, what contains the compound which has a 2 or more ethylenically unsaturated group is preferable, and the compound which has a 3 or more (meth) acryloyl group is more preferable. The compound having 3 or more (meth) acryloyl groups is preferably a reaction product of an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate, and having 3 or more (meth) acryloyl groups.
Moreover, as said composition, the thing containing (B) photoinitiator is preferable.

  The step 2 is preferably a method of curing the composition by irradiating active energy rays transmitted through the light diffusion plate from either side of the substrate while maintaining the peak temperature at 55 ° C. or lower.

As a manufacturing method of this invention, what includes the process 3 which heats the hardened | cured material of the composition obtained at the process 2 is preferable.
As step 3, it is preferable to implement step 3 when the reaction heat in step 2 is no longer confirmed.
Moreover, as process 3, it is preferable to heat at the temperature of 250 degrees C or less, and it is more preferable to heat at the temperature of 100-250 degreeC.

Moreover, as a bending elastic modulus of the hardened | cured material obtained, 1 GPa or more is preferable.
Moreover, as a total light transmittance of the hardened | cured material obtained, 90% or more is preferable.
Hereinafter, the present invention will be described in detail.

  According to the production method of the present invention, the obtained resin sheet has a high elastic modulus, and an optically homogeneous resin sheet can be obtained without generating interference fringes on the surface thereof.

FIG. 1 is a view showing an example of a molding die used in manufacturing a resin sheet according to the present invention. FIG. 2 is a diagram showing an example of a method of using a light diffusing plate used when manufacturing a resin sheet according to the present invention. FIG. 3 is a diagram showing an example of an active energy ray irradiation apparatus used when manufacturing a resin sheet according to the present invention.

The present invention relates to a method for producing a resin sheet having a film thickness of 100 μm to 5 mm, which uses an active energy ray-curable composition and sequentially performs the following steps 1 and 2.
Step 1: Applying the composition on a substrate or pouring or injecting the composition into a substrate having a recess Step 2: Haze is 45% from either side of the substrate The process of irradiating the active energy ray which permeate | transmitted the light diffusing plate which is the above, and hardening a composition Hereinafter, the manufacturing method of an active energy ray hardening-type composition and a resin sheet is demonstrated.

1. Active energy ray-curable composition In the production method of the present invention, an active energy ray-curable composition is used.
Examples of the compound constituting the active energy ray-curable composition include compounds that generate active species such as radical species, cation species, and anion species by irradiation with active energy rays.
Examples of compounds that generate radical species upon irradiation with active energy rays include compounds (A) having an ethylenically unsaturated group (hereinafter referred to as “component (A)”).
Examples of compounds that generate cation species upon irradiation with active energy rays include epoxy compounds, oxetane compounds, and vinyl ethers.
Examples of the compound that generates anion species upon irradiation with active energy rays include chromium amine thiocyanate, platinum acetylacetonate, pentacarbonyl metal complex, Schiff base, ferrocene, metallocene, and alkylaluminum porphyrin.

In the present invention, a composition containing the component (A) is preferable.
Examples of the ethylenically unsaturated group in the component (A) include a (meth) acryloyl group, a vinyl group, and a vinyl ether group, and a (meth) acryloyl group is preferable.
The component (A) includes a compound having one ethylenically unsaturated group [hereinafter referred to as “monofunctional unsaturated compound”] and a compound having two or more ethylenically unsaturated groups [hereinafter referred to as “polyfunctional unsaturated group”. Compound ”and the like.
In the present invention, it is more preferable that the component (A) contains a polyfunctional unsaturated compound because the resulting resin sheet has a high elastic modulus.
Hereinafter, each compound will be specifically described.

1-1. Monofunctional unsaturated compound Examples of the monofunctional unsaturated compound include compounds having one (meth) acryloyl group (hereinafter referred to as “monofunctional (meth) acrylate”).

  Specific examples of the monofunctional (meth) acrylate include isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, 1- Adamantyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate Rate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, benzyl (meth) acrylate, allyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate , О-phenylphenol EO modified (n = 1 to 4) (meth) acrylate, p-cumylphenol EO modified (n = 1 to 4) (meth) acrylate, phenyl (meth) acrylate, о-phenylphenyl (meth) ) Acrylate and p-cumylphenyl (meth) acrylate.

The monofunctional unsaturated compound may be a compound having various functional groups.
Examples of the compound having a carboxyl group include (meth) acrylic acid, a modified polycaprolactone of (meth) acrylic acid, a Michael addition type multimer of (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate and phthalic anhydride Examples include acid-containing adducts, carboxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and succinic anhydride adducts, and the like.

Examples of the compound having a hydroxyl group include (meth) acrylate having a hydroxyl group.
As the (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate and hydroxy And hydroxyalkyl (meth) acrylates such as octyl (meth) acrylate.

Examples of the compound having an amide group include N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone and (meth) acrylamide compounds.
Specific examples of (meth) acrylamide compounds include N-alkyl such as N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and Nt-butyl (meth) acrylamide. Acrylamide;
N, N-dialkylacrylamides such as N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide;
N-alkoxyalkyl such as N-hydroxyethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide ( And (meth) acryloylmorpholine.
Among these compounds, (meth) acryloylmorpholine and N-vinylformamide are preferable.

  Examples of the compound having a carbamate group include (meth) acrylate having an oxazolidone group, and specific examples thereof include 2- (2-oxo-3-oxazolidinyl) ethyl acrylate.

  Examples of the compound having an imide group include a compound having a maleimide group. Examples of the compound having a maleimide group include (meth) acrylate having a hexahydrophthalimide group and (meth) acrylate having a tetrahydrophthalimide group. Specific examples of the (meth) acrylate having a hexahydrophthalimide group include N- (meth) acryloyloxyethyl hexahydrophthalimide. Examples of (meth) acrylate having a tetrahydrophthalimide group include N- (meth) acryloyloxyethyl tetrahydrophthalimide.

1-2. Polyfunctional unsaturated compound As the polyfunctional unsaturated compound, a compound having two (meth) acryloyl groups [hereinafter referred to as "bifunctional (meth) acrylate". Hereinafter, a compound having three or more (meth) acryloyl groups is represented in the same manner as “◯ functional (meth) acrylate”. ] Is a bifunctional (meth) acrylate having an aromatic skeleton such as di (meth) acrylate of bisphenol A alkylene oxide adduct and bisphenol A di (meth) acrylate;
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, di Propylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4- Butanediol di (meth) acrylate, polybutylene glycol di (meth) acrylate, poly (1-methylbutylene glycol) di (meth) acrylate, 1 6- hexanediol di (meth) acrylate, 1,9-difunctional (meth) acrylates having an aliphatic skeleton such nonanediol di (meth) acrylate and neopentyl glycol di (meth) acrylate;
Hydroxypivalate neopentyl glycol di (meth) acrylate;
A bifunctional (meth) acrylate having an alicyclic skeleton such as dimethylol tricyclodecane di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate and spiroglycol di (meth) acrylate;
In the above, examples of the alkylene oxide adduct include ethylene oxide adduct and propylene oxide adduct.

  Examples of the polyfunctional (meth) acrylate include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate and polyether (meth) acrylate other than the above.

1-2-1. As the urethane (meth) acrylate polyfunctional (meth) acrylate, urethane (meth) acrylate [hereinafter referred to as “component (A1)”] which is a compound having a urethane bond and having two or more (meth) acryloyl groups. preferable.
Component (A1) includes a reaction product of polyol, organic polyisocyanate and hydroxyl group-containing (meth) acrylate (hereinafter referred to as “(A1-1) component”), and a reaction product of organic polyisocyanate and hydroxyl group-containing (meth) acrylate. [Hereinafter referred to as “component (A1-2)”] and the like.
Hereinafter, the component (A1-1) and the component (A1-2) will be described.

1) Component (A1-1)
The component (A1-1) is a reaction product of a polyol, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate.

As the polyol in the component (A1-1), a diol is preferable.
As the diol, a low molecular weight diol, a diol having a polyester skeleton, a diol having a polyether skeleton, and a diol having a polycarbonate skeleton are preferable.
Examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexanedimethanol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and the like.
Examples of the diol having a polyester skeleton include an esterification reaction product of a diol component such as the low molecular weight diol or polycaprolactone diol and an acid component such as dicarboxylic acid or an anhydride thereof.
Examples of the dicarboxylic acid or anhydride thereof include adipic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid and terephthalic acid, and anhydrides thereof.
Examples of the polyether diol include polyethylene glycol, polypropylene glycol, and polyetramethylene glycol.
Examples of the polycarbonate diol include a reaction product of the low molecular weight diol or / and bisphenol such as bisphenol A and a dialkyl ester carbonate such as ethylene carbonate and dibutyl ester carbonate.

Examples of organic polyisocyanates include aliphatic polyisocyanates having no alicyclic groups (hereinafter simply referred to as “aliphatic polyisocyanates”), aliphatic polyisocyanates having alicyclic groups (hereinafter referred to as “alicyclic polyisocyanates”). And polyisocyanates having aromatic rings and aromatic polyisocyanates.
Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, tetramethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate.
Examples of the alicyclic polyisocyanate include hydrogenated tolylene diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and isophorone diisocyanate trimer. .
Examples of the aromatic diisocyanate include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, 1,5-naphthalene diisocyanate, and the like.
In the present invention, the organic polyisocyanate is preferably an aliphatic polyisocyanate from the viewpoints of excellent physical properties of the cured product and little yellowing.

As the hydroxyl group-containing (meth) acrylate, a hydroxyl group-containing mono (meth) acrylate is preferable.
Examples of the hydroxyl group-containing mono (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate, and hydroxy And hydroxyalkyl (meth) acrylates such as octyl (meth) acrylate.

2) Component (A1-2)
The component (A1-2) is a reaction product of an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate, and is a compound called a urethane adduct.
Use of the component (A1-2) as the component (A) is preferable because the crosslink density is increased and the heat resistance is improved.

  In the component (A1-2), examples of the organic polyisocyanate and the hydroxyl group-containing (meth) acrylate include the compounds described above.

In the component (A1-2), a compound having a hydroxyl group and two or more (meth) acryloyl groups (hereinafter referred to as “hydroxyl group-containing polyfunctional (meth) acrylate”) is used as the hydroxyl group-containing (meth) acrylate. You can also.
As the component (A1-2), when a reaction product of the organic polyisocyanate and a hydroxyl group-containing polyfunctional (meth) acrylate (hereinafter referred to as “(A1-2-1) component”) is used, the crosslinking density is increased, It is preferable because it is excellent in heat resistance, wear resistance and scratch resistance.
As the hydroxyl group-containing polyfunctional (meth) acrylate, various compounds can be used, specifically, trimethylolpropane di (meth) acrylate, pentaerythritol di- or tri (meth) acrylate, ditrimethylolpropane di- or tri- Examples include (meth) acrylate and dipentaerythritol di, tri, tetra, or penta (meth) acrylate.
Among these, a compound having three or more (meth) acryloyl groups and one hydroxyl group is preferable in that the cured film is excellent in abrasion resistance and scratch resistance. Specifically, pentaerythritol trisitol is preferable. (Meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and the like.
Among these compounds, pentaerythritol tri (meth) acrylate is more preferable because it can prevent warpage of the resulting cured product.

In the production of the component (A1-2-1), the raw material hydroxyl group-containing polyfunctional (meth) acrylate is usually a mixture containing a hydroxyl group-containing polyfunctional (meth) acrylate and a polyfunctional (meth) acrylate having no hydroxyl group. However, what was manufactured using the said mixture can also be used as (A1-2-1) component.
Specifically, a mixture of trimethylolpropane di (meth) acrylate and trimethylolpropane tri (meth) acrylate, a mixture of ditrimethylolpropane tri (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate, and dipentaerythritol penta And a mixture of (meth) acrylate and dipentaerythritol hexa (meth) acrylate.

Another preferred compound of the component (A1-2) is a reaction product of an organic polyisocyanate having three or more isocyanate groups and a hydroxyl group-containing mono (meth) acrylate [hereinafter referred to as “(A1-2-2) component”. ].
Examples of the hydroxyl group-containing mono (meth) acrylate in the component (A1-2-2) include the same compounds as those described above.
Examples of the organic polyisocyanate having three or more isocyanate groups include the aforementioned hexamethylene diisocyanate trimer and isophorone diisocyanate trimer.
Preferable examples of the component (A1-2-2) include addition reaction products of hexamethylene diisocyanate trimer and hydroxybutyl acrylate.

Furthermore, the component (A1-2) is more preferably a compound that is a reaction product of an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate and has three or more (meth) acryloyl groups. The compound has high toughness while maintaining rigidity by an appropriate crosslinking density of the cured product.
Examples of the compound include the components (A1-2-1) and (A1-2-2) described above.

3) Method for producing component (A1)
Component (A1) is an addition reaction of polyol, organic polyisocyanate and hydroxyl group-containing (meth) acrylate in component (A1-1), and organic polyisocyanate and hydroxyl group-containing (meth) acrylate in component (A1-2) It is produced by the addition reaction of
Although this addition reaction can be performed without a catalyst, a tin-based catalyst such as dibutyltin dilaurate, an amine-based catalyst such as triethylamine, or the like may be added in order to advance the reaction efficiently.

1-2-2. Polyester (meth) acrylate Polyester (meth) acrylate includes a dehydration condensate of polyester diol and (meth) acrylic acid.
Here, examples of the polyester diol include a reaction product of a diol and a dicarboxylic acid or an anhydride thereof.
Diols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, tetramethylene glycol, hexamethylene glycol, neo Examples thereof include low molecular weight diols such as pentyl glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol and 1,6-hexanediol, and alkylene oxide adducts thereof.
Examples of the dicarboxylic acid or its anhydride include orthophthalic acid, isophthalic acid, terephthalic acid, adipic acid, succinic acid, fumaric acid, maleic acid, hexahydrophthalic acid, tetrahydrophthalic acid and trimellitic acid, and these An anhydride etc. are mentioned.

1-2-3. Epoxy (meth) acrylate Epoxy (meth) acrylate is a compound obtained by adding (meth) acrylic acid to an epoxy resin. Examples of the epoxy resin include aromatic epoxy resins and aliphatic epoxy resins.

  Specific examples of the aromatic epoxy resin include resorcinol diglycidyl ether, hydroquinone diglycidyl ether; diglycidyl ether of bisphenol A, bisphenol F, bisphenol S, bisphenol fluorene or an alkylene oxide adduct thereof; a phenol novolac type epoxy resin, and Examples thereof include novolak type epoxy resins such as cresol novolac type epoxy resins; glycidyl phthalimide; o-phthalic acid diglycidyl ester and the like.

Specific examples of the aliphatic epoxy resin include diglycidyl ethers of alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol and 1,6-hexanediol; diglycidyl ethers of polyethylene glycol and polypropylene glycol, etc. Diglycidyl ethers of polyalkylene glycols; diglycidyl ethers of neopentyl glycol, dibromoneopentyl glycol and its alkylene oxide adducts; diglycidyl ethers of hydrogenated bisphenol A and its alkylene oxide adducts; tetrahydrophthalic acid diglycidyl esters, etc. Is mentioned.
In the above, the alkylene oxide of the alkylene oxide adduct is preferably ethylene oxide or propylene oxide.

1-2-4. Polyether (meth) acrylate Polyether (meth) acrylate oligomers include polyalkylene glycol (meth) diacrylates, including polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and polytetramethylene glycol di (meta). ) Acrylate and the like.

  As the component (A), only one of the aforementioned compounds may be used, or two or more may be used in combination.

As the component (A), among the above-mentioned compounds, a trifunctional or higher (meth) acrylate is preferable because the flexural modulus of the cured product is high, and more preferably an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate. And a compound having 3 or more (meth) acryloyl groups.
When (A) component contains trifunctional or higher functional (meth) acrylate, it is preferable to include 20% by weight or more in the total amount of component (A).
Monofunctional (meth) acrylates include monofunctional (meth) acrylates having an alicyclic skeleton such as isobornyl (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, and cyclohexanedimethanol di (meth). Bifunctional (meth) acrylates having an alicyclic skeleton such as acrylate and spiroglycol di (meth) acrylate are preferred.

1-3. What is necessary is just to set the viscosity of an active energy ray hardening-type composition composition suitably according to the objective, and 50-10,000 mPa * s is preferable.
In the present invention, the viscosity means a value measured at 25 ° C. using an E-type viscometer.

The composition in the present invention preferably contains the component (A), but various components can be blended depending on the purpose.
Specifically, other components include a photopolymerization initiator (hereinafter referred to as “component (B)”), a thermal polymerization initiator (hereinafter referred to as “component (C)”), an organic solvent, a plasticizer, and a polymerization prohibition. And / or an antioxidant, a light resistance improver, and a compound having two or more mercapto groups.

(B) A component is a photoinitiator.
(B) A component is a component mix | blended when an ultraviolet-ray and visible light are used as an active energy ray. When an electron beam is used as the active energy ray, it is not always necessary to add it, but a small amount can be added as necessary in order to improve curability.

(B) As a component, when using the compound which generate | occur | produces radical seed | species by irradiation of an active energy ray, a photoradical polymerization initiator is used and the compound which generate | occur | produces a cation seed | species by irradiation of an active energy ray is used. In some cases, a photocationic polymerization initiator is used, and when a compound that generates anionic species upon irradiation with active energy rays is used, a photoanionic polymerization initiator is used.
In the present invention, it is preferable to use the component (A). In this case, it is preferable to use a radical photopolymerization initiator.

Examples of the radical photopolymerization initiator include benzyldimethyl ketal, benzyl, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-1- ON, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, oligo [2-hydroxy-2-methyl-1- [4-1- (methylvinyl) phenyl] ] Propanone, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl] -2-methylpropan-1-one, 2-methyl-1- [4- ( Methylthio)] phenyl] -2-morpholinopropane-1 ON, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) ) -Butane-1-one, Adekaoptomer N-1414 (manufactured by ADEKA), phenylglyoxylic acid methyl ester, ethyl anthraquinone, phenanthrenequinone, and other aromatic ketone compounds;
Benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4- (methylphenylthio) phenylphenylmethane, methyl-2-benzophenone, 1- [4- (4-Benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis ( Benzophenone compounds such as diethylamino) benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone and 4-methoxy-4′-dimethylaminobenzophenone ;
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl- (2,4,6-trimethylbenzoyl) phenylphosphinate and bis (2, Acylphosphine oxide compounds such as 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide;
Thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3- [3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl] oxy]- Thioxanthone compounds such as 2-hydroxypropyl-N, N, N-trimethylammonium chloride and fluorothioxanthone;
Acridone compounds such as acridone, 10-butyl-2-chloroacridone;
1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)] and ethanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] Oxime esters such as -1- (O-acetyloxime);
2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2 2,4,5-triarylimidazole such as 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer and 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer Dimer; and acridine derivatives such as 9-phenylacridine and 1,7-bis (9,9'-acridinyl) heptane.

  As the photoradical polymerization initiator, in addition to the above, a photopolymerization initiator having a molecular weight of 350 or more can be used. The photopolymerization initiator having a molecular weight of 350 or more does not cause coloring of the resin sheet obtained by the decomposed product after light irradiation, and the decomposed product is a vacuum of the transparent conductor layer when used for the production of a transparent conductive film. Since no outgas is generated at the time of film formation, a high vacuum can be reached in a short time, and it is possible to prevent the film quality of the conductor layer from deteriorating and becoming difficult to reduce resistance.

As the radical photopolymerization initiator, various compounds can be used as long as they have a molecular weight of 350 or more and can be initiated by light such as ultraviolet rays and visible rays.
Specific examples of the radical photopolymerization initiator include hydroxyketone polymers, and examples include compounds represented by the following formula (1). The said compound is also preferable at the point which is excellent in compatibility with (A) component.

In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkyl group, and n represents a 2 to 5 number.
R ² is preferably a lower alkyl group such as a methyl group, an ethyl group and a propyl group as the alkyl group.

Specific examples of the compound represented by the formula (1) include oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone.
The compound is commercially available, and for example, ESACURE KIP 150 (manufactured by Lamberti) is known. ESACURE KIP 150 is a compound represented by the above formula (1), wherein R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group, n is a 2-3 number, and [(204.3 × n + 16.0) or It is a compound having a molecular weight of (204.3 × n + 30.1)].

Examples of compounds other than the above include 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid.
The said compound is marketed and Irgacure 754 (made by BASF) is known. Irgacure 754 is a mixture of oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (2-hydroxyethoxy) ethyl ester.

(B) As a compounding ratio of a component, 0.01-10 weight part is preferable with respect to 100 weight part of total amounts of (A) component, More preferably, it is 0.1-5 weight part.
By setting the blending ratio of the component (B) to 0.01% by weight or more, the composition can be cured with an appropriate amount of ultraviolet light or visible light, and the productivity can be improved. By doing, it can be made the thing excellent in the weather resistance and transparency of hardened | cured material.

(C) component (thermal polymerization initiator) can be mix | blended with a composition as needed.
Various compounds can be used as the thermal polymerization initiator, and organic peroxides and azo initiators are preferred.

  Specific examples of the organic peroxide include 1,1-bis (t-butylperoxy) 2-methylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, , 1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, , 2-bis (4,4-di-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, dilauroyl peroxide, t-hexylperoxyisopropyl monocarbonate, t-butyl Peroxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyla Rate, t-butylperoxypivalate, t-hexylperoxypivalate, 2,5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t- Butyl peroxy 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxyacetate, 2,2-bis (t-butyl Peroxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, di-t-butylperoxyisophthalate, α, α′-bis (t-butyl) Peroxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5 Di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) Hexin-3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide Etc.

Specific examples of the azo compound include 1,1′-azobis (cyclohexane-1-carbonitrile), 2- (carbamoylazo) isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile. Azodi-t-octane, azodi-t-butane and the like.
These may be used alone or in combination of two or more. Moreover, an organic peroxide can also be made into a redox reaction by combining with a reducing agent.

(C) As a usage rate of a component, 10 weight part or less is preferable with respect to 100 weight part of total amounts of (A) component.
When the thermal polymerization initiator is used alone, it may be carried out in accordance with conventional means of normal radical thermal polymerization. In some cases, the thermal polymerization initiator is used in combination with a photopolymerization initiator and photocured for the purpose of further improving the reaction rate. Curing can also be performed.

2. The manufacturing method of a resin sheet TECHNICAL FIELD This invention relates to the manufacturing method of the resin sheet which has a film thickness of 100 micrometers-5 mm which uses an active energy ray hardening-type composition and implements the following process 1 and 2 sequentially.
Step 1: Applying the composition on a substrate or pouring or injecting the composition into a substrate having a recess Step 2: Haze is 45% from either side of the substrate The process of irradiating the active energy ray which permeate | transmitted the light diffusing plate which is the above, and hardening a composition Hereinafter, the process 1 and the process 2 are demonstrated.

2-1. Process 1
Step 1 is a step of applying or injecting the composition onto a substrate, or pouring or injecting the composition into a substrate having a recess.

1) As a base material , both a releasable base material and a base material having no releasability (hereinafter referred to as “non-releasable base material”) can be used.
Examples of the peelable substrate include metal, glass, a release-treated film, and a surface untreated film having peelability (hereinafter, collectively referred to as “release material”).
Examples of the release material include silicone-treated polyethylene terephthalate film, surface untreated polyethylene terephthalate film, surface untreated cycloolefin polymer film, and surface untreated OPP film (polypropylene).

In order to make the resin sheet obtained from the composition of the present invention have a low haze or provide surface smoothness, the surface roughness (centerline average roughness) Ra is 0.15 μm or less as a peelable substrate. It is preferable to use a base material of 0.001 to 0.100 μm. Furthermore, the haze is preferably 3.0% or less.
Specific examples of the substrate include glass, untreated surface polyethylene terephthalate film, untreated surface OPP film (polypropylene), and the like.
In the present invention, the surface roughness Ra means a value obtained by measuring the surface roughness of the film and calculating an average roughness.

  Examples of the non-releasable substrate include various plastics other than the above, cellulose acetate resins such as polyvinyl alcohol, triacetyl cellulose and diacetyl cellulose, acrylic resin, polyester, polycarbonate, polyarylate, polyethersulfone, norbornene and the like And cyclic polyolefin resins having a cyclic olefin as a monomer.

As a base material which has a space part, the base material which has a recessed part is mentioned. An example is one in which a hole having a predetermined shape with a desired film thickness is formed in the release material, and a recess is formed.
In this case, after pouring the composition into the substrate having a recess, another substrate can be stacked on the substrate having the recess.
As another example of the base material having a space portion, a material provided with a weir (spacer) on the mold release material so that the cured product has a desired film thickness (hereinafter referred to as “molding die”), and the like can also be mentioned. . In this case, another base material can be stacked on the weir.

In this case, it is necessary to use a transparent plate in which either or both of the base materials transmit active energy rays.
The transparent plate is only required to transmit active energy rays, and the material is not limited, but glass is preferable in terms of surface smoothness, rigidity, heat resistance, and chemical stability. The substrate may be curved.

FIG. 1 will be described as an example of the mold.
(A1-1) and (a1-2) in FIG. 1 show two substrates [FIG. 1: (1) in (a1-1) and (1) ′ in (a1-2)] Base material excellent in releasability [FIG. 1: (2) of (a1-1) and (2) ′ of (a1-2)] and base material for providing one weir [FIG. 1: (a1- This is an example of a mold composed of (1) (3)].
(A2) in FIG. 1 shows two substrates [FIG. 1: (1) and (1) ′ in (a2)] and a substrate for providing one weir [FIG. 1: (a2)] (3)].

  As shown in FIG. 1, the base material for providing the weir [FIG. 1: (3) in (a1-1)] preferably has a shape having a hole for injecting the composition at the top [FIG. 1: (3-1) of (a1-1)]. As a base material for providing the weir, various materials can be used, and silicone rubber can be exemplified.

As a specific example of (a1-1) and (a1-2) in FIG. 1, it is composed of two substrates as a substrate, two release-treated films, and a substrate for providing one weir. Molds that can be used.
On top of the glass (Fig. 1: (a1-1) (1)), the release-treated film [Fig. 1: (a1-1) (2)] is stacked, and a weir is provided on it. The base material (FIG. 1: (a1-1) (3)) is used as a stack weir (spacer). Furthermore, a film (FIG. 1: (2) ′ of (a1-2)) which has been subjected to release treatment is overlaid thereon, and glass [FIG. 1: (1) ′ of (a1-2)] is overlaid thereon. Use a mold.

A specific example of (a2) in FIG. 1 is a case of using a release-treated glass or metal as a base material [(1) and (1) ′ in FIG. 1: (a2)], and a cured product. Therefore, it is not necessary to use the two release processed films in (a1-1) and (a1-2) of FIG.
Examples of the release treatment in glass include fluorine treatment, silicone treatment, phosphate ester release agent, paraffin release agent, and metal oxide film treatment.
Further, when the cured product of the composition is excellent in releasability, glass that has not been subjected to release treatment can be used as the mold. An example in which the cured product of the composition is excellent in releasability includes an example in which a release agent is blended with the composition.
In the present invention, the mold shown in FIG. 1 (a2) is more preferable.

  As a shaping | molding die, a light-diffusion plate can be used as a base material of the surface where an active energy ray is irradiated. The light diffusing plate is as described in detail later.

2) In the production of the pre-treated resin sheet of the composition, it is preferable to perform defoaming treatment after blending each component in order to prevent bubbles from being contained in the cured product.
Examples of the defoaming treatment include standing, vacuum decompression, centrifugation, cyclone (automatic / revolving mixer), gas-liquid separation membrane, ultrasonic wave, pressure vibration, and defoaming with a multi-screw extruder.

3) As a coating method when the composition is applied to the coating or injection base material, it may be appropriately set according to the purpose, and a conventionally known bar coater, applicator, doctor blade, knife coater, comma coater, Examples of the coating method include a reverse roll coater, a die coater, a lip coater, a gravure coater, and a micro gravure coater.
In the case of injecting the composition into the substrate having the space, a method of injecting the composition into an injection device such as a syringe or an injection device can be used.
In this case, oxygen in the active energy ray-curable composition and / or in the mold may be injected while vacuum degassing or replacement with an inert gas such as nitrogen or argon.

What is necessary is just to set suitably as a film thickness in this case according to the target film thickness of the resin sheet mentioned later.
In particular, when used for glass replacement, preferably OPS, the thickness is preferably 100 μm to 5 mm, more preferably 200 μm to 3 mm, and particularly preferably 300 μm to 2 mm.

2-2. Process 2
Step 2 is a step of curing the composition by irradiating an active energy ray transmitted through a light diffusion plate having a haze of 45% or more from either side of the substrate.
When the haze of the light diffusing plate is less than 45%, the resulting resin sheet causes interference fringes.

1) Light Diffusing Plate As the material of the light diffusing plate, various materials can be used as long as they transmit the active energy rays.
The diffusion of active energy rays may be surface diffusion due to surface irregularities or internal diffusion inside the diffusion plate. Examples of the light diffusing plate having surface irregularities include those obtained by processing glass by physical means such as sand blasting, and those having irregularities on the surface during molding of glass or resin. Examples of the light diffusing plate by internal diffusion include a transparent resin in which fine particles having a refractive index different from that of the resin are dispersed. Examples of the transparent resin include polycarbonate, polystyrene, and polymethyl methacrylate. Examples of the fine particles include silica fine particles and polymer fine particles.
The haze of the light diffusing plate is 45% or more, preferably 50% or more, and more preferably 90% or more.
In the present invention, the haze means a value measured according to a method for obtaining haze of a JIS K-7136 plastic transparent material.
A reflective plate can be installed on the opposite surface of the light diffusing plate. According to this aspect, the efficiency of light diffusion can be improved.

A specific example of installation of the light diffusing plate used in step 2 will be described with reference to (b1), (b2) and (b3) in FIG. Note that FIG. 2 is merely an example, and various modes other than the above mode are possible.
(B1) in FIG. 2 is an example in which a light diffusing plate is used as the base material on the side where the active energy rays of the mold are irradiated. In (b1) of FIG. 2, (4) means a mold containing the composition obtained in step 1, (5) means an active energy ray irradiator, and (6) means a light diffusion plate.
(B2) of FIG. 2 is an example in which a light diffusing plate is installed on the side of the mold where the active energy ray is irradiated. In (b2) of FIG. 2, (4) means a mold containing the composition obtained in step 1, (5) means an active energy ray irradiator, and (6) means a light diffusion plate.
(B3) of FIG. 2 is an example in which a reflecting plate (7) is further provided on the opposite side of (6) the light diffusing plate in (b1) of FIG. According to this aspect, the efficiency of light diffusion can be improved.

2) Active energy ray irradiator Active energy rays include electron beams, ultraviolet rays, visible rays, and X-rays. Visible rays and ultraviolet rays are preferable because inexpensive devices can be used.
The ultraviolet irradiator is not particularly limited, and examples thereof include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a black light lamp, a UV electrodeless lamp, and an LED.
The irradiation intensity of the active energy ray may be appropriately adjusted according to the composition of the active energy ray-curable composition, particularly the ratio of the component (B) (photopolymerization initiator), the thickness of the target resin sheet, and the like.

3) In the temperature control step 2, a method of curing the composition by irradiating active energy rays from either side of the substrate while maintaining the peak temperature at 55 ° C. or lower is obtained. It is preferable because it does not cause defects or warpage and has a high elastic modulus. A preferable peak temperature is 20 to 40 ° C.
In the present invention, the target polymerization temperature is determined and managed by a method described later so as to maintain the temperature. In this case, even after reaching the set temperature, the temperature does not decrease immediately, and becomes a value higher than the set temperature. In the present invention, this value is called peak temperature.
The reaction temperature to be set is appropriately selected depending on the composition of the active energy ray-curable composition and the thickness of the target resin sheet, etc., but in order to reduce the volume change before and after the reaction, the difference from the temperature before the reaction Is desirably 50 ° C. or lower.

4) In the case of controlling the temperature in the active energy ray irradiation apparatus step 2, as a temperature control method, after irradiating the active energy ray to start the reaction, the reaction temperature during the reaction is measured and the detected temperature is set. Accordingly, there are a method of stopping / starting irradiation of active energy rays, adjusting an irradiation amount of active energy rays, and the like.
The irradiation of the active energy ray is stopped / started and the irradiation amount is adjusted appropriately by manual or computer control so that the reaction temperature is kept at the set temperature or does not greatly deviate from the set temperature. Specifically, when the reaction temperature exceeds the set temperature or shows a certain upward trend, the irradiation of the active energy ray is stopped or the dose is decreased, and the reaction temperature falls below the set value. In some cases or when it shows a certain downward trend, the active energy ray is re-irradiated or the irradiation amount is increased.

The irradiation intensity of the active energy ray may be appropriately adjusted according to the composition of the active energy ray-curable composition, particularly the ratio of the component (B) (photopolymerization initiator), the thickness of the target resin sheet, and the like. As irradiation intensity, 0.1-2000 mW / cm < ² > is preferable.
When the composition contains the component (B) at a relatively high concentration, the irradiation intensity is preferably 0.1 to 200 mW / cm ² . On the other hand, when the composition contains the component (B) at a relatively low concentration, the irradiation intensity is preferably 300 to 2000 mW / cm ² .
It is preferable to select the irradiation intensity and the control device so that the reaction temperature is within ± 20 ° C. of the set temperature, and more preferably within ± 10 ° C.

Examples of the measurement of the reaction temperature include a contact temperature measurement device using a thermocouple, a resistance temperature detector, a thermistor, and the like, and a non-contact temperature measurement device using infrared rays.
In the present invention, it is preferable to use a non-contact type radiation thermometer, more preferably an infrared thermometer, because the temperature of the reaction system having various liquid properties can be easily measured. .

  It is also possible to use a heat exchange device for the purpose of controlling the initial reaction temperature or for the purpose of efficiently removing reaction heat and shortening the active energy ray irradiation process. Examples of the heat exchange device include a device that generates an air flow such as air and nitrogen, and a jacket device that can be brought into contact with a mold and allow a heat medium to flow therethrough. The heat exchange device can also serve as a heating device described later.

A specific example of the active energy ray irradiation apparatus used when controlling the temperature in step 2 will be described with reference to (c1) and (c2) in FIG. FIG. 3 shows an example in which a light diffusing plate is installed in the mode (b1) of FIG. Note that FIG. 3 is merely an example, and various devices other than the device can be used.
In (c1) of FIG. 3, (4) is a mold containing the composition obtained in step 1, (5) is an active energy ray irradiator, (6) is a light diffusing plate, and (8) is a temperature control device. (9) is a non-contact type radiation thermometer.
The active energy ray is irradiated by the active energy ray irradiator (5), and the temperature of the mold (4) containing the composition is measured by the non-contact type radiation thermometer (9). Based on the temperature measured by the thermometer (9), the target set temperature is controlled by the temperature controller (8). Specifically, when the temperature is higher than the set temperature, the temperature control device (8) stops the active energy ray irradiation of the active energy ray irradiator (5) or the amount of irradiation is proposed. The active energy ray irradiation of the active energy ray irradiator (5) is started or the irradiation amount is increased by the control device (8).
As a cooling method of the mold (4) containing the composition, it may be just contacted with the outside air as it is, but the surface of the mold (4) that is not irradiated with active energy rays is air-cooled, or (c2) in FIG. As described above, there may be mentioned a method of cooling by installing a heat exchanger on the surface of the mold (4) that is not irradiated with active energy rays.
In the case of air cooling, it is preferable to supply an inert gas such as nitrogen gas.
Examples of the heat exchanger include those described above.

2-3. Process 3
In this invention, it is preferable to implement the process 3 which heats the hardened | cured material of the composition obtained at the process 2. FIG.
By carrying out step 3, the residual stress can be relaxed and the reaction rate can be improved.
Step 3 is preferably performed after the reaction heat is no longer confirmed in the curing step using active energy rays. If the heat of reaction is not confirmed, the reaction temperature is measured at the time of active energy ray irradiation, the temperature change is almost eliminated, and no active species are generated due to active energy ray irradiation. Means a state approaching the temperature in the active energy ray irradiation apparatus.
As a heating method, the cured product of the composition obtained in Step 2 is heated at a desired temperature and time by putting it in or contacting a heating device maintained at a desired temperature.
As a heating method, the cured product of the obtained composition may be removed from the mold or not. A method that does not remove the mold is preferable because the subsequent steps become simple.
Examples of the heating method in the case of using a thermosetting composition as the composition include a method of immersing in a heat medium bath such as heat and oil, a method using a heat press, and a method of holding in a temperature-controlled thermostat. It is done.

The heating temperature is appropriately set depending on the composition of the composition and the reaction rate after the curing step using active energy rays, but is preferably 250 ° C. or lower, more preferably 40 to 250 ° C., because it can prevent coloring and decomposition. 100-250 degreeC is further more preferable, Especially preferably, it is 60-180 degreeC.
What is necessary is just to set a heat time suitably according to the composition to be used, the target resin sheet, etc., and 3 hours or more are mentioned. The upper limit of the heating time is preferably 24 hours or less in consideration of economy.
Also, the heating temperature can be changed according to the purpose.

3. Resin sheet physical properties The resin sheet obtained in the present invention has a thickness of 100 μm to 5 mm.
In particular, when used for glass replacement, preferably OPS, the thickness is preferably 200 μm to 3 mm, more preferably 300 μm to 2 mm.

As a resin sheet obtained by this invention, the thing whose elasticity modulus in a bending test is 1 GPa or more is preferable as a physical property.
The elastic modulus is preferably 2 GPa or more, more preferably 3 GPa or more.
The elastic modulus in the bending test in the present invention means a value calculated from a stress of 0.1% and 1% in a bending test performed at a distance between supporting points of 30 mm and a bending speed of 0.2 mm / min.

Further, the resin sheet obtained in the present invention preferably has a total light transmittance of 90% or more as a physical property.
The total light transmittance is preferably 92% or more.
In addition, the total light transmittance in this invention means the light transmittance containing the diffusion component prescribed | regulated to JISK7361-1 (the test method of the total light transmittance of a plastic transparent material).

As a glass transition temperature (henceforth "Tg") of the hardened | cured material of a composition, 0-250 degreeC is preferable, More preferably, it is 20-230 degreeC. By setting Tg to 0 ° C. or higher, the resulting resin sheet is excellent in rigidity and heat resistance, and by setting it to 250 ° C. or lower, toughness can be maintained.
In the present invention, Tg means a temperature at which the tensile loss coefficient tan δ in the dynamic viscoelastic spectrum measured in the tensile mode is 1 Hz, the temperature rise temperature is 2 ° C./min, and the maximum.

4). Application of Resin Sheet The resin sheet obtained by the production method of the present invention can be used in display applications, construction materials and automobile fields where glass is conventionally used and a high flexural modulus is required, and is particularly preferably used as an optical sheet. it can.
The optical sheet formed from the composition of the present invention can be used for various optical applications. More specifically, sheets used for liquid crystal display devices such as polarizer protective films for polarizing plates, prism sheet support films and light guide films, and touch panel integrated liquid crystal display devices, various functional films (for example, hard coats) Sheets, decorative sheets, transparent conductive sheets) and base sheets with surface shapes (for example, moth-eye type antireflection sheets and sheets with a texture structure for solar cells), light resistance for outdoor use such as solar cells (weather resistance) ) Sheets, films for LED lighting / organic EL lighting, transparent heat-resistant sheets for flexible electronics, and the like.

Since the optical sheet formed from the composition of the present invention is excellent in heat resistance, it can be preferably used for the production of a transparent conductive sheet. The composition used in this application is preferably a solventless composition that does not contain an organic solvent in that outgassing during the vacuum deposition of the transparent conductive layer can be suppressed.
Furthermore, since the optical sheet of the present invention is excellent in heat resistance even if it is a thick film, it has flexibility and high strength, it can also be used as a transparent conductive sheet substrate for OPS. In this case, an optical sheet having a film thickness of 0.5 mm or more and 1.5 mm or less can be used more preferably.

The manufacturing method of a transparent conductive sheet should just follow a conventional method.
The metal oxide forming the transparent conductor layer is indium oxide, tin oxide, zinc oxide, titanium oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite. Examples thereof include oxides and titanium-niobium composite oxides. Of these, indium-tin composite oxide and indium-zinc composite oxide are preferable from the viewpoints of environmental stability and circuit processability.
As a method of forming the transparent conductor layer, a conventional method may be followed, and a method of forming by sputtering using a vacuum film forming apparatus using the metal oxide, using the optical sheet of the present invention. Etc.
More specifically, the metal oxide is used as a target material, dehydrated and degassed, and then evacuated and vacuumed, the optical sheet is brought to a predetermined temperature, and then sputtered onto the optical sheet. Examples include a method of forming a transparent conductor layer.

1. Examples 1 and 2, Comparative Examples 1 and 2, Reference Example 1
1) Production of composition As component (A), 50 parts by weight (hereinafter referred to as “parts”) of OT-1000 below, 10 parts of trimethylolpropane triacrylate [Aronix M-309 manufactured by Toagosei Co., Ltd.], 1 , 6-hexanediacrylate [Osaka Organic Chemical Co., Ltd. Biscoat # 230] and 40 parts of (B) component (photopolymerization initiator) as 2-hydroxy-2-methylpropiophenone (BASF DAROCURE 1173) ) Was stirred and mixed, and the resulting mixture was degassed under vacuum to obtain an active energy ray-curable composition.
In addition, as a method of defoaming under vacuum, a beaker containing the obtained mixture was put in a sealed bell jar and defoamed for 10 minutes by a vacuum decompression method. The temperature during defoaming was room temperature and the pressure was about 0.1 kPa.
OT-1000: a mixture of an addition reaction product of pentaerythritol triacrylate and hexamethylene diisocyanate (referred to as “adduct”) and pentaerythritol tetraacrylate (referred to as “PETeA”) [62:38 (weight ratio)], Toagosei Co., Ltd. Aronix OT-1000

2) Step 1
As a mold for producing a resin sheet, the mold shown in FIG. 1 (a2) was used, and a light diffusing plate was further used in the mode shown in FIG. 2 (b1).
The ground glass used as the diffusion plate is a float glass plate having a thickness of 3 mm, three types of ceramic abrasives having a particle size range of 125 to 106 μm, 250 to 210 μm, and 600 to 500 μm [abrasives made of alumina particles, Fuji Seisakusho Co., Ltd. Manufactured, “Fuji Random A”), and sandblasting was performed, and diffused plates having hazes of 90, 50, and 30%, respectively, were prepared. The haze of the untreated 3 mm thick float glass was 0.7%.
The light diffusion plate manufactured above, a float glass plate [100 mm × 100 mm, thickness 3 mm], and one silicone rubber plate (thickness 1.0 mm) were used. The surface in contact with the glass composition was subjected to a mold release treatment with a fluorine-based coating agent [MX031 manufactured by Surf Industry Co., Ltd.].
A silicone rubber plate [(a2) :( 3) in FIG. 1] is stacked on the smooth surface [(a2) :( 1) in FIG. 1] on the smooth surface of the light diffusion plate manufactured above (spacer). ) And a glass plate [(a2) :( 1) ′ in FIG. 1] was used as an overmolding die.
In Reference Example 1, a silicone bomb plate having a thickness of 50 μm was used as a spacer instead of the silicone rubber plate having a thickness of 1.0 mm.
The composition obtained above was injected from a hole portion of the silicone rubber plate of the mold (FIG. 1: (3-1)) with a syringe.

3) Step 2
As an active energy ray irradiator, an LED irradiator (LED365-9UV033B) manufactured by Optcord Co., Ltd., and an illuminance transmitted through the diffusion plate on the irradiation surface side is 3.6 mW / cm ² (“UIT-250 made by USHIO, light receiver” The position of the irradiation lamp was determined to be 365 nm ").
Irradiation with active energy rays was performed at 23 ° C. until the temperature of the composition during curing reached 25 ° C. or lower. The accumulated light amount until the end of the reaction was 12 J / cm ² .

4) Step 3
After ultraviolet irradiation, the cured product was heated at 150 ° C. for 16 hours in a nitrogen stream to obtain a resin sheet.
About the obtained resin sheet, the curvature, the external appearance, the reaction rate, and the bending elastic modulus were evaluated according to the following method. The results are shown in Table 1.

(1) Evaluation method
a) The haze of the haze diffusion plate was measured with NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K-7136 (how to determine the haze of a plastic transparent material).
b) Appearance The obtained resin sheet was held at various angles with respect to the illumination light source, and the presence or absence of interference fringes was evaluated.
c) Reaction rate The consumption rate of C = C bond was measured by FT-IR-ATR method. Based on the absorption of C═O stretching vibration at 1720 cm ⁻¹ , the calculation was made based on the decrease in absorption of the C = C variable vibration at 810 cm ⁻¹ before and after curing.
d) From a resin sheet having a flexural modulus of 80 mm × 80 mm and a thickness of 1 mm, five test pieces having a length of 40 (mm) × width of 10 (mm) were cut out and an Instron 5566A (distance between fulcrums of 30 mm, 0.2 mm / Second, 25 ° C., 50% RH), and the average value was defined as the flexural modulus (GPa).
e) Total light transmittance Using the obtained resin sheet, according to JIS K7361-1, Nippon Denshoku Industries Co., Ltd. NDH2000 was used, and the total light transmittance was measured.
The total light transmittances of the resin sheets obtained in Examples 1 and 2 and Comparative Examples 1 and 2 and Reference Example 1 were all 90% or more, and the description in Table 1 below was omitted.

2. In the production methods of General Examples 1 and 2, no interference fringes of the obtained resin sheet were observed, and the bending elastic modulus was 3 GPa or higher and the high bending elastic modulus.
Comparative Example 1 in which interference fringes were not observed at a thickness of 46 μm of a molded body using sandblast-untreated float glass (having 0.7%) as the diffusion plate of Reference Example 1, but the thickness was 0.9 mm. Then interference fringes occurred.
Further, interference fringes were also generated in the manufacturing method of Comparative Example 3 using a diffusion plate having a haze of 30%.

  The resin sheet obtained by this invention can be used for various uses, and can be used for the substitute use of the glass in the display in which the conventional glass is used, the building material field | area, and the motor vehicle field | area. The resin sheet obtained in the present invention can be preferably used as an optical sheet, and the optical sheet can be preferably used for the production of a transparent conductive sheet, and is preferably used for the production of a transparent conductive sheet for a touch panel. be able to.

Claims (13)

The manufacturing method of the resin sheet which has a film thickness of 100 micrometers-5 mm which implements the following process 1 and 2 sequentially using an active energy ray hardening-type composition.
Step 1: Applying the composition on a substrate or pouring or injecting the composition into a substrate having a recess Step 2: Haze is 45% from either side of the substrate The process of curing the composition by irradiating the active energy ray transmitted through the light diffusion plate as described above The manufacturing method of the resin sheet of Claim 1 in which the said composition contains the compound (A) which has an ethylenically unsaturated group. The manufacturing method of the resin sheet of Claim 1 or Claim 2 in which the said composition contains the compound which has a 2 or more ethylenically unsaturated group as (A) component. The manufacturing method of the resin sheet of Claim 3 in which the said composition contains the compound which has a 3 or more (meth) acryloyl group as (A) component. The compound having three or more (meth) acryloyl groups is a reaction product of an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate, and is a compound having three or more (meth) acryloyl groups. The manufacturing method of the resin sheet of description. The method for producing a resin sheet according to any one of claims 1 to 5, wherein the composition contains (B) a photopolymerization initiator. In the step 2, the composition is cured by irradiating an active energy ray transmitted through the light diffusion plate from either side of the substrate while maintaining the peak temperature at 55 ° C or lower. The manufacturing method of the resin sheet of any one of Claims 1. The manufacturing method of the resin sheet of any one of Claims 1-7 which implements the following process 3 after the process 2.
Process 3: The process of heating the hardened | cured material of the composition obtained at the process 2 The method for producing a resin sheet according to claim 8, wherein step 3 is performed when the reaction heat in step 2 is no longer confirmed. The manufacturing method of the resin sheet of Claim 8 or Claim 9 which heats in the temperature of 250 degrees C or less in the process 3. The manufacturing method of the resin sheet of any one of Claims 8-10 which heats in the temperature of 100-250 degreeC in the process 3. The method for producing a resin sheet according to any one of claims 1 to 11, wherein the cured product has a flexural modulus of 1 GPa or more. The method for producing a resin sheet according to any one of claims 1 to 12, wherein the cured product has a total light transmittance of 90% or more.

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