KR20220136188A - Optical resin composition and optical resin sheet - Google Patents

Abstract

Provided is an optical resin composition which is excellent in adhesive force, holding power, and bending resistance while maintaining good transparency in the form of an optical resin sheet. The optical resin composition contains an acrylic polymer (A) and a crosslinking agent component (B). The acrylic polymer (A) is obtained by copolymerizing a crosslinkable functional group-containing monomer and a (meth)acrylate ester monomer in which the number of carbon atoms at an ester group terminal is 1 or more and 18 or less. The acrylic polymer (A) has a glass transition temperature Tg of -10.0 ℃ or lower. The crosslinking agent component (B) contains an aliphatic or alicyclic polyisocyanate having a weight average molecular weight of 2,100 or more and 200,000 or less.

Description

Optical resin composition and optical resin sheet {OPTICAL RESIN COMPOSITION AND OPTICAL RESIN SHEET}

The present invention relates to an optical resin composition and an optical resin sheet.

In recent years, optical members such as pressure-sensitive adhesives, adhesives, and films for displays have become not only transparent and have an adhesive strength above a certain level, but also have high weather resistance, with the increase in image quality, touch panelization, flexibility in displays, and diversification of use places. , high transparency, strong adhesion, high heat-and-moisture resistance, bending resistance, reworkability, and control of electrical properties are required. In particular, the performance requested|required of the adhesive and adhesive agent which joins optical members together by flexible-ization and foldable-ization of a display is becoming more advanced. Specifically, while maintaining transparency, performance, such as strong adhesive force, high cohesive force (high holding force), and bending resistance, is calculated|required.

For example, Patent Document 1 discloses an acrylic polymer having a specific structure, and a pressure-sensitive adhesive composition containing an organic polyisocyanate-based crosslinking agent or an epoxy-based crosslinking agent. According to the said pressure-sensitive adhesive composition, it is disclosed that a film excellent in stress dispersibility can be provided.

Japanese Patent Laid-Open No. 2017-132872

However, it is calculated|required that it is excellent in adhesive force, holding power, and bending resistance, maintaining transparency rather than the technique of patent document 1 etc. In particular, in recent years, foldable displays have been released, and bending resistance has become an important performance.

The present invention has been made in view of the above circumstances, and while maintaining good transparency when used as an optical resin sheet, an optical resin composition excellent in adhesive force, holding power and bending resistance, and an optical resin composition using the optical resin composition A resin sheet is provided.

That is, this invention includes the following aspects.

(1) An optical resin composition comprising an acrylic polymer (A) and a crosslinking agent component (B),

The acrylic polymer (A) is formed by copolymerizing a crosslinkable functional group-containing monomer and a (meth)acrylic acid ester monomer having 1 to 18 carbon atoms at the terminal of the ester group,

The glass transition temperature Tg of the acrylic polymer (A) is -10.0 ° C. or less,

The said crosslinking agent component (B) is an optical resin composition containing the aliphatic or alicyclic polyisocyanate whose weight average molecular weights are 2100 or more and 200000 or less.

(2) The optical resin composition as described in (1) whose average number of isocyanate groups of the said crosslinking agent component (B) is 2.0 or more and 6.5 or less.

(3) The optical resin composition as described in (1) or (2) whose content of the said crosslinking agent component (B) is 0.01 mass part or more and 5.0 mass parts or less with respect to 100 mass parts of said acrylic polymer (A).

(4) The optical resin composition according to any one of (1) to (3), wherein the acrylic polymer (A) has a weight average molecular weight of 5.0×10 ⁵ or more and 5.0×10 ⁶ or less.

(5) The optical resin composition according to any one of (1) to (4), wherein the crosslinkable functional group is at least one selected from the group consisting of a hydroxyl group, an epoxy group, a carboxy group and a vinyl group.

(6) In any one of (1) to (5), wherein the content of the structural unit derived from the (meth)acrylic acid ester monomer is 0.01% by mass or more and 99.99% by mass or less with respect to the total mass of the acrylic polymer (A) The described optical resin composition.

(7) The aliphatic or cycloaliphatic polyisocyanate includes at least one diisocyanate (b1) selected from the group consisting of aliphatic diisocyanate and alicyclic diisocyanate, and a bifunctional polyol (b2) having a number average molecular weight of 1500 or more. and a polyisocyanate derived from a trifunctional or higher polyol (b3) having a number average molecular weight of 500 or more,

Any one of (1) to (6), wherein the ratio NCO/OH of the molar amount of the isocyanate group of the diisocyanate (b1) to the total molar amount of the hydroxyl groups of the polyol (b2) and the polyol (b3) is 3 or more and 30 or less The optical resin composition as described in one.

(8) the mass ratio (b3)/(b2) of the polyol (b3) to the polyol (b2) is 0.1/99.9 or more and 99.9/0.1 or less, and

With respect to 100 mass parts of said diisocyanate (b1),

The content of the polyol (b2) is 0.1 parts by mass or more and 250 parts by mass or less,

The optical resin composition as described in (7) whose content of the said polyol (b3) is 0.1 mass part or more and 190 mass parts or less.

(9) the polyol (b2) and the polyol (b3) are at least one polyol selected from the group consisting of polyester polyol, polyether polyol, epoxy polyol, polyolefin polyol and polycarbonate polyol, (7) or The optical resin composition according to (8).

(10) The optical resin composition in any one of (1)-(9) whose isocyanate group content rate of the said crosslinking agent component (B) is 1 mass % or more and 10 mass % or less.

(11) The optical resin composition according to any one of (1) to (10), further comprising 0.01 parts by mass or more and 0.5 parts by mass or less of a silane coupling agent (C) with respect to 100 parts by mass of the acrylic polymer (A). .

(12) The crosslinking agent component (B) is an isocyanate compound other than the aliphatic or cycloaliphatic polyisocyanate, a carbodiimide compound, an oxazoline compound, a polyfunctional acrylic acid ester monomer, a peroxide, a titanium coupling agent, a zirconium compound, a metal aluminum chelate , The optical resin composition according to any one of (1) to (11), comprising at least one selected from the group consisting of a hydrazide compound, an epoxy-based crosslinking agent, a thermal acid generator, and a photoacid generator.

(13) Coating the crosslinking agent component (B) on glass, and after storage for 168 hours at 23 ° C. and 65% humidity environment, a cured film with a film thickness of 40 µm formed under a 23 ° C environment has a König hardness of 60 times or less, (1) The optical resin composition according to any one of to (12).

(14) An optical resin sheet formed by curing the optical resin composition according to any one of (1) to (13) with heat or light.

(15) The optical resin sheet according to (14), wherein the thickness of the optical resin sheet is 1 µm or more and 1000 µm or less.

(16) The optical resin composition is coated on a polyethylene terephthalate film having a thickness of 25 μm, dried at 125° C. for 3 minutes to cure, and then stored for 7 days at 23° C. and 50% RH environment, the polyethylene terephthalate An optical resin sheet having a thickness of 70 μm, a width of 20 mm and a length of 100 mm, having a film on one side, is bonded to the SUS304BA plate as an adherend, and compressed once with a 2 kg roller and cured at 23° C. for 30 minutes, then at 23° C., 300 mm/ The optical resin sheet as described in (14) or (15) whose 180 degree peel adhesive force measured at the speed of a minute is 2.0 N/20 mm or more and 65 N/20 mm or less.

(17) The optical resin composition was coated on a polyethylene terephthalate film having a thickness of 25 μm, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH environment for 7 days, the polyethylene terephthalate An optical resin sheet having a thickness of 70 μm, a width of 25 mm and a length of 130 mm, having a film on one side, is attached to the SUS304BA plate as an adherend so that the ranges of 25 mm in width and 25 mm in length overlap, and one reciprocating compression with a 2 kg roller is performed at 23 ° C. After curing for 1 hour and further curing at 40° C. for 30 minutes, a 500 g weight is suspended at the lower end of the optical resin sheet under a 40° C. environment for 1 hour, and then the optical resin when returned to a 23° C. environment. The optical resin sheet according to any one of (14) to (16), wherein the sheet shift amount is 2 mm/hour or less.

(18) The optical resin composition is coated on a polyethylene terephthalate film having a thickness of 38 μm and is subjected to peeling treatment, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. (14) to (14)-( 17) The optical resin sheet as described in any one of.

(19) The optical resin composition is coated on a peeling-treated polyethylene terephthalate film having a thickness of 38 μm, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. A 70-micrometer-thick optical resin sheet obtained by peeling from the peeling-treated polyethylene terephthalate film was stored for 7 days at 23°C and 50% RH, then wrapped in a mesh-like sheet, immersed in ethyl acetate at 23°C for 1 week, and taken out. The optical resin sheet in any one of (14)-(18) whose gel fraction computed by drying at 120 degreeC for 2 hours after drying is 40.0 mass % or more and 99.9 mass % or less.

(20) The optical resin composition is coated on a peel-treated polyethylene terephthalate film having a thickness of 38 μm, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. An optical resin sheet having a thickness of 70 μm obtained by peeling from a peeling-treated polyethylene terephthalate film was laminated to a thickness of 210 μm, cut to a width of 10 mm and a length of 40 mm, and set on a tensile tester so that the distance between the chucks was 10 mm The optical resin sheet according to any one of (14) to (19), wherein the Young's modulus in a tensile test conducted at a speed of 300 mm/min in a 23°C environment is 0.40 N/mm 2 or less.

According to the optical resin composition of the said aspect, the optical resin composition excellent in adhesive force, holding power, and bending resistance can be provided, maintaining favorable transparency when it is set as an optical resin sheet. The resin sheet for optics of the said aspect is made by hardening the said resin composition for optics, transparency is favorable, and is excellent in adhesive force, holding power, and bending resistance.

In addition, in this specification, "polyol" means the compound which has two or more hydroxyl groups (-OH) in 1 molecule.

In addition, in this specification, "polyisocyanate" means a reaction product in which a plurality of monomer compounds having two or more isocyanate groups (-NCO) are bonded.

In addition, in this specification, unless otherwise indicated, "(meth)acryl" shall contain methacryl and acryl, and "(meth)acrylate" shall contain a methacrylate and an acrylate.

≪Resin composition for optical use≫

The optical resin composition of this embodiment contains an acrylic polymer (A) and a crosslinking agent component (B).

The acrylic polymer (A) is a polymer obtained by copolymerizing a crosslinkable functional group-containing monomer and a (meth)acrylic acid ester monomer having 1 to 18 carbon atoms at the terminal of the ester group.

The acrylic polymer (A) has a glass transition temperature Tg of -75.0°C or more and -10.0°C or less, preferably -74.0°C or more and -20.0°C or less, more preferably -73.0°C or more and -30.0°C or less, and -72.0°C or more. It is more preferable that it is -40.0 degrees C or less, -71.0 degrees C or more and -50.0 degrees C or less are especially preferable, and -71.0 degrees C or more and -50.0 degrees C or less are the most preferable. When the glass transition temperature Tg of an acrylic polymer (A) is in the said range, there exists a tendency excellent in the adhesive force and bending resistance when it is set as the resin sheet for optics.

The glass transition temperature of the acrylic polymer (A) is, for example, the organic solvent and moisture in the solution in which the acrylic polymer (A) is dissolved or dispersed under reduced pressure, then vacuum dried, using a differential scanning calorimetry (DSC) measuring device Thus, a value measured under the condition of a temperature increase rate of 5°C/min can be used as the glass transition temperature.

The said crosslinking agent component (B) contains the aliphatic or alicyclic polyisocyanate whose weight average molecular weights are 2100 or more and 200000 or less.

When the resin composition for optics of this embodiment has the said structure, the resin sheet for optics excellent in adhesive force, holding power, and bending resistance is obtained, maintaining transparency favorably. In addition, as shown in Examples to be described later, the bending resistance is evaluated by the elastic modulus, the maximum stress, and the elongation modulus for simplification of evaluation, and the elastic modulus (Young's modulus) of the layer formed by curing the optical resin composition is low, , the elongation rate is large, and it can be expressed by a large maximum stress. That is, it is considered that it is easy to follow the deformation|transformation by bending, it is easy to relieve a stress, and the thing which is hard to break (large maximum stress) is excellent in bending resistance. The preferable range of Young's modulus is mentioned later.

<Acrylic polymer (A)>

The acrylic polymer (A) is a polymer obtained by copolymerizing a crosslinkable functional group-containing monomer (a1) and a (meth)acrylic acid ester monomer (a2) having 1 to 18 carbon atoms at the terminal of the ester group.

The crosslinkable functional group-containing monomer (a1) has a polymerizable functional group and a crosslinkable functional group capable of forming a crosslinked structure with the crosslinking agent component (B). As a polymerizable functional group, a vinyl group etc. are mentioned, for example. Examples of the crosslinkable functional group include a hydroxyl group, a thiol group, an amino group, an amide group, an epoxy group, a carboxy group, and a vinyl group. Among them, a hydroxyl group, an epoxy group or a carboxy group is preferable, and a hydroxyl group is more preferable. A crosslinkable functional group can also be provided by modification, after polymerizing an acrylic acid ester.

The acrylic polymer (A) may contain only one type of structural unit derived from the crosslinkable functional group-containing monomer (a1) and the structural unit derived from the (meth)acrylic acid ester monomer (a2), respectively, or a combination of two or more types. there may be That is, the acrylic polymer (A) may be formed by copolymerizing one each of the crosslinkable functional group-containing monomer (a1) and (meth)acrylic acid ester monomer (a2), and the crosslinkable functional group-containing monomer (a1) and (meth) ) The acrylic acid ester monomer (a2) may be copolymerized by combining two or more types, respectively. Moreover, although the (meth)acrylic acid ester monomer (a2) may have a crosslinkable functional group and does not need to have it, it is preferable not to have it.

The acrylic polymer (A) is, in addition to the structural unit derived from the crosslinkable functional group-containing monomer (a1) and the structural unit derived from the (meth)acrylic acid ester monomer (a2), other polymerizable monomers (a3) (hereinafter, It may further include a structural unit derived from "other polymerizable monomers (a3)" in some cases simply. That is, the acrylic polymer (A) is prepared by copolymerizing one or more crosslinkable functional group-containing monomers (a1), one or more (meth)acrylic acid ester monomers (a2), and one or more other polymerizable monomers (a3). may be done. In addition, another polymerizable monomer (a3) may have a crosslinkable functional group, and does not need to have it.

As the crosslinkable functional group-containing monomer (a1), a polymerizable (meth)acrylic monomer having a crosslinkable functional group is preferable.

As a polymerizable (meth)acrylic-type monomer which has a crosslinkable functional group, what is shown to the following (i)-(viii) is mentioned, for example. These may be used individually by 1 type, and may be used in combination of 2 or more type.

(i) Acrylic acid-2-hydroxyethyl, acrylic acid-2-hydroxypropyl, acrylic acid-2-hydroxybutyl, acrylic acid-4-hydroxylbutyl, acrylic acid-6-hydroxyhexyl, acrylic acid-8-hydroxyoctyl Acrylic acid esters having a hydroxyl group, such as.

(ii) methacrylic acid-2-hydroxyethyl, methacrylic acid-2-hydroxypropyl, methacrylic acid-2-hydroxybutyl, methacrylic acid-4-hydroxylbutyl, methacrylic acid-6-hydroxy Methacrylic acid esters having a hydroxyl group, such as hydroxyhexyl and methacrylic acid-8-hydroxyoctyl.

(iii) (meth)acrylic acid esters having a polyvalent hydroxyl group such as acrylic acid monoester or methacrylic acid monoester of glycerin, acrylic acid monoester or methacrylic acid monoester of trimethylolpropane;

(iv) unsaturated carboxylic acids such as acrylic acid and methacrylic acid.

(v) Unsaturated amides such as (meth)acrylamide.

(vi) (meth)acrylic acid esters having an amino group, such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate.

(vii) (meth)acrylic acid esters having an epoxy group such as glycidyl methacrylate.

(viii) (meth)acrylic acid esters having a carboxyl group, such as acrylic acid-2-carboxyethyl and methacrylic acid-2-carboxyethyl.

When the polymerizable (meth)acrylic monomer having a crosslinkable functional group is a (meth)acrylic acid ester monomer having a crosslinkable functional group, the number of carbon atoms in the ester portion is preferably 1 or more and 18 or less, more preferably 1 or more and 12 or less, It is more preferable that they are 1 or more and 10 or less, It is especially preferable that they are 1 or more and 8 or less, It is most preferable that they are 2 or more and 8 or less.

Carbon number of the ester group terminal in a (meth)acrylic acid ester monomer (a2) is 1 or more and 18 or less.

As the (meth)acrylic acid ester monomer (a2), for example, (meth)methyl acrylate, (meth)ethyl acrylate, (meth)acrylic acid propyl, (meth)acrylic acid isopropyl, (meth)acrylic acid-n-butyl, (meth)acrylic acid ) acrylic acid isobutyl, (meth)acrylic acid-sec-butyl, (meth)acrylic acid-tert-butyl, (meth)acrylic acid pentyl, (meth)acrylic acid isopentyl, (meth)acrylic acid hexyl, (meth)acrylic acid-2-ethyl Hexyl, (meth) acrylate heptyl, (meth) acrylate octyl, (meth) acrylate isooctyl, (meth) acrylate nonyl, (meth) acrylate isononyl, (meth) acrylate decyl, (meth) acrylate isodecyl, (meth) acrylate ) Undecyl acrylate, (meth) acrylate dodecyl ((meth) acrylic acid lauryl), (meth) acrylic acid tridecyl, (meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylate (Meth) such as heptadecyl acrylate, (meth) stearyl (meth) acrylate, isostearyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate ) and acrylic acid esters. These may be used independently and may be used in combination of 2 or more type.

As another polymerizable monomer (a3), what is shown to the following (i)-(iv) is mentioned, for example. These may be used by 1 type, and may be used in combination of 2 or more type.

(i) Unsaturated carboxylic acids, such as maleic acid and itaconic acid.

(ii) A monomer having an epoxy group, such as 1,2-epoxy-4-vinylcyclohexane, allyl glycidyl ether, and 4-hydroxybutyl acrylate glycidyl ether.

(iii) unsaturated amides such as N-methylolacrylamide, diacetoneacrylamide and dimethylaminopropylacrylamide.

(iv) vinyl acetate, (meth)acrylonitrile, styrene, vinyltoluene, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine.

Further, as other monomers copolymerizable with the crosslinkable functional group-containing monomer (a1) and the (meth)acrylic acid ester monomer (a2), Japanese Patent Laid-Open Nos. 1-261409 (Reference 1) and Japanese Patent Laid-Open Nos. 3-006273 You may use the polymerizable ultraviolet-stable monomer disclosed by the publication (Reference 2) etc.

Specific examples of the polymerizable UV-stable monomer include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2, 2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 2-hydroxy-4- (3-meth Cryloxy-2-hydroxypropoxy) benzophenone etc. are mentioned.

For example, the acryl-type polymer (A) can be obtained by carrying out solution polymerization of the said monomer component in presence of radical polymerization initiators, such as a well-known peroxide and an azo compound, and diluting with an organic solvent etc. as needed.

In the case of obtaining the aqueous-based acrylic polymer (A), it can be prepared by solution polymerization of an olefinically unsaturated compound, and a known method such as conversion into an aqueous layer or emulsion polymerization. In that case, water solubility or water dispersibility can be imparted by neutralizing an acidic moiety such as a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid or a sulfonic acid-containing monomer with an amine or ammonia.

It is preferable that content of the structural unit derived from a crosslinkable functional group containing monomer (a1) is 0.01 mass % or more and 25 mass % or less with respect to the total mass of acrylic polymer (A), It is more preferable that they are 0.02 mass % or more and 23 mass % or less. And, it is more preferable that they are 0.03 mass % or more and 21 mass % or less, and it is especially preferable that they are 0.04 mass % or more and 20 mass % or less. When content of the structural unit derived from a crosslinkable functional group containing monomer (a1) is in the said numerical range, there exists a tendency for the adhesive force and cohesion force (holding force) to be more excellent when it is set as an optical resin sheet.

The content of the structural unit derived from the (meth)acrylic acid ester monomer (a2) is preferably 0.01 mass% or more and 99.99 mass% or less with respect to the total mass of the acrylic polymer (A), more preferably 10 mass% or more and 99.99 mass% or less It is preferable, and it is more preferable that they are 50 mass % or more and 99.99 mass % or less, It is especially preferable that they are 80 mass % or more and 99.99 mass % or less. When content of the structural unit derived from a (meth)acrylic acid ester monomer (a2) is in the said numerical range, there exists a tendency for the adhesive force and cohesive force (holding force) to be more excellent when it is set as an optical resin sheet.

The content of the structural unit derived from the crosslinkable functional group-containing monomer (a1) and the content of the structural unit derived from the (meth)acrylic acid ester monomer (a1) are, for example, used in the production of the acrylic polymer (A), It can calculate from the compounding quantity of each crosslinkable functional group containing monomer (a1) and (meth)acrylic acid ester monomer (a2). Moreover, it can also calculate from the composition ratio calculated by combining, for example, ¹ H-NMR spectrum, ¹² C-NMR spectrum, IR spectrum, and mass spectrum analysis.

The weight average molecular weight Mw(A) of the acrylic polymer (A) is preferably 5.0×10 ⁵ or more and 5.0×10 ⁶ , more preferably 6.0×10 ⁵ or more and 2.5×10 ⁶ or less, and 6.5×10 ⁵ or more and 2.0× 10 ⁶ is more preferable, and 7.0×10 ⁵ or more and 1.9×10 ⁶ or less are particularly preferable. When the weight average molecular weight Mw(A) of the acrylic polymer (A) is within the above range, the adhesive force, cohesive force (holding holding force), and moisture-and-heat resistance durability when it is set as an optical resin sheet tend to be more excellent. The weight average molecular weight Mw (A) of the acrylic polymer (A) can be measured, for example, by using the method described in Examples described later.

<Crosslinking agent component (B)>

A crosslinking agent component (B) contains the aliphatic or alicyclic polyisocyanate whose weight average molecular weights are 2100 or more and 200000 or less.

The weight average molecular weight Mw(b) of the aliphatic or alicyclic polyisocyanate is 2100 or more and 200000 or less, preferably 2500 or more and 150000 or less, more preferably 2800 or more and 100000 or less, still more preferably 3000 or more and 80000 or less, and 3200 or more and 70000 or less. It is especially preferable that it is the following. When the weight average molecular weight Mw (b) of the aliphatic or alicyclic polyisocyanate is within the above numerical range, the elastic modulus (Young's modulus) is lower, the elongation rate is higher, and the breaking strength is higher with respect to the optical resin sheet obtained. have.

Mw(b) of an aliphatic or alicyclic polyisocyanate is a polystyrene standard weight average molecular weight by GPC measurement.

2.0 or more and 6.5 or less are preferable, as for the average number of isocyanate groups of aliphatic or alicyclic polyisocyanate, 2.3 or more and 6.3 or less are more preferable, 2.4 or more and 6.1 or less are still more preferable, 2.5 or more and 6.0 or less are especially preferable. When the average number of isocyanate groups in the aliphatic or cycloaliphatic polyisocyanate is within the above numerical range, the acrylic polymer (A) and the crosslinking agent component (B) form a crosslinked network more effectively, and the resulting optical resin sheet has a higher elongation, Moreover, breaking strength can be made higher.

The average number of isocyanate groups (fn) of aliphatic or alicyclic polyisocyanate is computable using the following formula. In the following formulae, "Mn" represents the number average molecular weight of the aliphatic or alicyclic polyisocyanate, and "NCO%" represents the isocyanate group content of the aliphatic or alicyclic polyisocyanate. The number average molecular weight Mn of the aliphatic or alicyclic polyisocyanate is a polystyrene standard weight average molecular weight by GPC measurement. The measuring method of NCO% is mentioned later.

[fn]=[Mn]×[NCO%]/4200

The aliphatic or alicyclic polyisocyanate (b) comprises at least one diisocyanate (b1) selected from the group consisting of aliphatic diisocyanate and alicyclic diisocyanate, and a bifunctional polyol (b2) having a number average molecular weight of 1500 or more; , a polyisocyanate derived from a trifunctional or higher polyol (b3) having a number average molecular weight of 500 or more.

The ratio NCO/OH of the molar amount of isocyanate groups in the diisocyanate (b1) to the total molar amount of hydroxyl groups in the polyol (b2) and the polyol (b3) is preferably 3 or more and 30 or less, and more preferably 4 or more and 25 or less. It is preferable, it is more preferable that they are 5 or more and 22 or less, It is especially preferable that they are 6 or more and 20 or less. When the NCO/OH is within the above numerical range, the crosslinking agent component (B) can be synthesized without gelation, and with respect to the optical resin sheet obtained, the elastic modulus is lower, the elongation rate is higher, and the breaking strength is higher. can

The aliphatic or alicyclic polyisocyanate (b) may be a polyisocyanate having all of the structural units derived from diisocyanate, polyol (b2) and polyol (b3) in one molecule, diisocyanate, polyol (b2) and The mixture of polyisocyanate which has a structural unit derived from at least 1 type or more selected from the group which consists of polyol (b3) may be sufficient.

The aliphatic or alicyclic polyisocyanate (b) is at least one selected from the group consisting of an allophanate structure, a uretdione structure, an iminooxadiazinedione structure, an isocyanurate structure, a urea structure, a urethane structure, and a biuret structure. It may have more than one structure. Among them, it is preferable to have at least one structure selected from the group consisting of a urethane structure, an allophanate structure, a biuret structure, a urea structure, and an isocyanurate group, and it is more preferable to include a urethane structure.

[Diisocyanate (b1)]

Diisocyanate (b1) is at least 1 sort(s) chosen from the group which consists of aliphatic diisocyanate and alicyclic diisocyanate.

Although it is not limited to the following as an aliphatic diisocyanate, For example, 1, 4- diisocyanatobutane, 1, 5- diisocyanatopentane, ethyl (2,6- diisocyanato) hexanoate, 1,6 -diisocyanatohexane (hereinafter sometimes abbreviated as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4; 4-trimethyl-1,6-diisocyanatohexane etc. are mentioned. These aliphatic diisocyanates may be used individually by 1 type, and may be used in combination of 2 or more type.

Although not limited to the following as alicyclic diisocyanate, For example, 1,3- or 1, 4-bis (isocyanatomethyl) cyclohexane (Hereinafter, it may abbreviate as "hydrogenated XDI"); 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl 1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter sometimes abbreviated as “IPDI”) ), 4-4'-diisocyanato-dicyclohexylmethane (hereinafter sometimes abbreviated as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylnorbornane, etc. can These alicyclic diisocyanates may be used individually by 1 type, and may be used in combination of 2 or more type.

Any of these aliphatic diisocyanate and alicyclic diisocyanate may be used independently and may be used in combination of 2 or more types of aliphatic diisocyanate and alicyclic diisocyanate.

Further, from the viewpoint of flexibility, the mass ratio of the alicyclic polyisocyanate to the aliphatic diisocyanate is preferably 0/100 or more and 30/70 or less, and more preferably 0/100 or more and 20/80 or less.

Especially, as diisocyanate, HDI, IPDI, hydrogenated XDI, or hydrogenated MDI is preferable, HDI or IPDI is more preferable, HDI is still more preferable.

In addition to the diisocyanate mentioned above, you may further use the isocyanate monomer shown below for manufacture of a polyisocyanate.

(1) diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, tolylene diisocyanate (TDI), xylylene diisocyanate, m-tetramethylxylylene diisocyanate (TMXDI), etc. of aromatic diisocyanates.

(2) 4-isocyanatomethyl-1,8-octamethylene diisocyanate (hereinafter sometimes referred to as “NTI”), 1,3,6-hexamethylene triisocyanate (hereinafter referred to as “HTI”) In some cases), bis(2-isocyanatoethyl)2-isocyanatoglutarate (hereinafter sometimes referred to as “GTI”), lysine triisocyanate (hereinafter sometimes referred to as “LTI”) triisocyanates, such as.

[Polyol (b2) and Polyol (b3)]

The polyol (b2) has a number average molecular weight of 1500 or more and is a bifunctional polyol (diol).

The polyol (b3) has a number average molecular weight of 500 or more, and is a polyol having a trifunctional or higher function.

The number average molecular weight of a polyol (b2) is 1500 or more, and 1800 or more are preferable. When the number average molecular weight of a polyol (b2) is more than the said lower limit, the hardness of the cured film formed by hardening only a polyisocyanate is low, and a softness|flexibility becomes a favorable thing.

On the other hand, the upper limit of the number average molecular weight of the polyol (b2) is not particularly limited, but can be, for example, 12000, preferably 11000, more preferably 10000, still more preferably 8000. and more preferably set to 6000, particularly preferably set to 5000, and most preferably set to 4200.

The number average molecular weight Mn of the polyol (b2) is, for example, a polystyrene standard number average molecular weight by GPC measurement. In addition, when using in mixture of 2 or more types of polyol (b2), the number average molecular weight of the mixture is computed.

The number average molecular weight of a polyol (b3) is 500 or more, and it is preferable that it is 800 or more. When the number average molecular weight of a polyol (b3) is more than the said lower limit, the hardness of the cured film formed by hardening|curing only a polyisocyanate is low, and a softness|flexibility becomes favorable.

On the other hand, although it does not specifically limit about the upper limit of the number average molecular weight of a polyol (b3), For example, it can be set as 3000, and it is preferable to set it as 2200.

The number average molecular weight Mn of the polyol (b3) is, for example, a polystyrene standard number average molecular weight by GPC measurement. In addition, when using in mixture of 2 or more types of polyol (b3), the number average molecular weight of the mixture is computed.

The polyol (b2) is preferably at least one bifunctional polyol (diol) selected from the group consisting of polyester polyol, polyether polyol, epoxy polyol, polyolefin polyol and polycarbonate polyol, It is more preferable that it is a polyester polyol.

As a bifunctional polyester polyol, the polyester polyol of any of the following (1) or (2), etc. are mentioned, for example.

(1) A polyester polyol obtained by a condensation reaction of a dibasic acid alone or a mixture of two or more types and a dihydric alcohol alone or a mixture of two or more types.

(2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone with a dihydric alcohol.

Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid. .

Examples of the dihydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, and cyclohexanediol.

Especially, as a bifunctional polyester polyol, a bifunctional polycaprolactone polyol is preferable.

As a commercially available bifunctional polycaprolactone polyol, for example, the brand names "Flaxel 210" (number average molecular weight 1000) manufactured by Daicel Corporation, "Flaxel 220" (number average molecular weight 2000), "Flaxel 230" ( number average molecular weight 3000), "flaxel 240" (number average molecular weight 4000), etc. are mentioned.

The polyol (b3) may be a trifunctional or more functional polyol, preferably a trifunctional or more and 10 functional or less polyol, more preferably a trifunctional or more and 7 functional or less polyol, and still more preferably a trifunctional or more and pentafunctional or less polyol, , a trifunctional or more and tetrafunctional or less polyol is particularly preferable, and a trifunctional polyol (triol) is most preferable.

The trifunctional polyol (triol) is preferably at least one trifunctional polyol (triol) selected from the group consisting of polyester polyol, polyether polyol, epoxy polyol, polyolefin polyol and polycarbonate polyol. And, it is more preferable that it is a trifunctional polyester polyol.

As a trifunctional polyester polyol, the polyester polyol of any of the following (1) or (2), etc. are mentioned, for example.

(1) A polyester polyol obtained by a condensation reaction of a dibasic acid alone or a mixture of two or more types and a trihydric alcohol alone or a mixture of two or more types.

(2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone with a trihydric alcohol.

Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid. .

As said trihydric alcohol, trimethylol propane, glycerol, pentaerythritol, 2-methylol propanediol, ethoxylated trimethylol propane etc. are mentioned, for example.

Especially, as trifunctional polyester polyol, trifunctional polycaprolactone polyol is preferable.

Commercially available trifunctional polycaprolactone polyols include, for example, Daicel's brand names "Flaxel 305" (number average molecular weight 550), "Flaxel 308" (number average molecular weight 850), "Flaxel 309" ( number average molecular weight 900), "flaxel 312" (number average molecular weight 1250), "flaxel 320" (number average molecular weight 2000), etc. are mentioned.

In the aliphatic or alicyclic polyisocyanate (b), the mass ratio of the polyol (b2) to the polyol (b3) (mass ratio of (b2)/(b3)) is preferably 0.1/99.9 or more and 99.9/0.1 or less, and 1/ 99 or more and 99/1 or less are more preferable, 3/97 or more and 90/10 or less are still more preferable, 3/97 or more and 85/15 or less are particularly preferable, and 5/95 or more and 80/20 or less are the most preferable.

When the mass ratio of (b2)/(b3) is more than the said lower limit, the hardness of the cured film formed by hardening|curing polyisocyanate independent is low, and a softness|flexibility becomes more favorable. Moreover, the optical resin sheet which was more excellent in adhesive force and flexibility is obtained. On the other hand, when the mass ratio of (b2)/(b3) is below the said upper limit, the resin sheet for optics which was more excellent in adhesive force, softness|flexibility, and cohesion force becomes more favorable.

The mass ratio of (b2)/(b3) is computable from the compounding quantity of each polyol at the time of manufacture of a polyisocyanate, for example.

In the aliphatic or alicyclic polyisocyanate (b), the content (charge) of the polyol (b2) is usually 0.1 parts by mass or more and 250 parts by mass or less, and 0.1 parts by mass or more and 210 parts by mass or less with respect to 100 parts by mass of the diisocyanate. It is preferably 0.1 parts by mass or more and 170 parts by mass or less, more preferably 0.5 parts by mass or more and 100 parts by mass or less, still more preferably 1 part by mass or more and 50 parts by mass or less, 1.5 parts by mass or more and 45 parts by mass or less It is still more preferable that they are parts or less, and it is especially preferable that they are 1.7 mass parts or more and 42 mass parts or less.

When content of a polyol (b2) is more than the said lower limit, the hardness of the cured film formed by hardening|curing polyisocyanate independent is low, and a softness|flexibility becomes a more favorable thing. Moreover, the resin sheet for optics which was more excellent in adhesive force, sclerosis|hardenability, and bending resistance is obtained. On the other hand, when content of polyol (b2) is below the said upper limit, a liquid state can be maintained without gelatinizing at the time of manufacture of a polyisocyanate, and the softness|flexibility at the time of setting it as an optical resin sheet becomes a thing more favorable.

Content of a polyol (b2) is computable from the compounding quantity of the diisocyanate and polyol (b2) at the time of manufacture of a polyisocyanate, for example.

In the aliphatic or alicyclic polyisocyanate (b), the content (charge) of the polyol (b3) is usually 0.1 parts by mass or more and 190 parts by mass or less, and 1 part by mass or more and 140 parts by mass or less with respect to 100 parts by mass of the diisocyanate. Preferably, it is more preferable that they are 1 mass part or more and 90 mass parts or less, It is more preferable that they are 2 mass parts or more and 80 mass parts or less, It is still more preferable that they are 5 mass parts or more and 70 mass parts or less, 7 mass parts or more and 65 mass parts It is more preferable that they are below, and it is especially preferable that they are 10 mass parts or more and 60 mass parts or less.

When the content of the polyol (b3) is equal to or less than the upper limit, the liquid state can be maintained without gelation during the production of the polyisocyanate, and the curability and flexibility when an optical resin sheet is obtained are more favorable. On the other hand, when content of a polyol (b3) is more than the said lower limit, the hardness of the cured film formed by hardening|curing polyisocyanate independent is low, and a softness|flexibility becomes a more favorable thing. Moreover, the resin sheet for optics which is more excellent in adhesive force and sclerosis|hardenability is obtained.

Content of polyol (b3) is computable from the compounding quantity of diisocyanate and polyol (b3) at the time of manufacture of a polyisocyanate, for example.

[Other crosslinking agent components]

The crosslinking agent component (B), in addition to the aliphatic or alicyclic polyisocyanate (b), is an isocyanate compound other than the aliphatic or alicyclic polyisocyanate (b), a carbodiimide compound, an oxazoline compound, a polyfunctional acrylic acid ester monomer; At least one other crosslinking agent component (b') selected from the group consisting of a peroxide, a titanium coupling agent, a zirconium compound, a metal aluminum chelate, a hydrazide compound, an epoxy-based crosslinking agent, a thermal acid generator, and a photoacid generator.

The content of the aliphatic or alicyclic polyisocyanate (b) in the crosslinking agent component (B) is preferably 50 mass% or more, more preferably 70 mass% or more, and 90 mass% or more with respect to the total mass of the crosslinking agent component (B). It is more preferable, and it is especially preferable that it is 100 mass %. When content of the aliphatic or alicyclic polyisocyanate (b) in a crosslinking agent component (B) is more than the said lower limit, the effect which the optical resin composition of this embodiment exhibits can fully exhibit.

As an isocyanate compound other than an aliphatic or alicyclic polyisocyanate (b), the aliphatic or alicyclic diisocyanate monomer illustrated in the said diisocyanate (b1) is mentioned, for example. Moreover, the aromatic diisocyanate and triisocyanate illustrated in the said diisocyanate (b1), polyisocyanate derived from them, etc. are mentioned.

As a carbodiimide compound, it can obtain by making isocyanate groups of a polyisocyanate compound decarbon dioxide-react, for example. As a commercial item of a carbodiimide compound, For example, carbodilite V-02, carbodilite V-02-L2, carbodilite V-04, carbodilite E-01, carbodilite E-02 (all are Nissan). Shinbo Corporation make, brand name), etc. are mentioned.

As an oxazoline compound, the polymer compound which has at least two oxazoline groups in a side chain, the compound of the monomer which has at least two oxazoline groups in 1 molecule, etc. are mentioned.

Examples of the polyfunctional acrylic acid ester monomer include tripentaerythritol acrylate, trimethylolpropane triacrylate, a condensate of pentaerythritol and acrylic acid, and 1,6-hexanediol diacrylate. The polyfunctional acrylic acid ester monomer as used herein contains two or more vinyl groups, and is distinguished from the crosslinkable functional group-containing monomer.

Examples of the peroxide include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexine. -3, di-tert-butyl peroxide, tert-butylcumyl peroxide, di(2-tert-butylperoxy isopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy) Hexane, dicumyl peroxide, di-tert-butylperoxyisophthalate, tert-butylperoxybenzoate, 2,2-bis(tert-butylperoxy)butane, 2,2-bis(tert-butylperoxy) Octane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, trimethylsilyltriphenylsilylperoxide, etc. are mentioned.

Examples of the titanium coupling agent include isopropyltriisostearoyltitanate, isopropyltris(dioctylpyrophosphate)titanate, isopropyltri(N-aminoethyl-aminoethyl)titanate, tetraoctylbis( Di-tridecylphosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(di-tridecyl)phosphite titanate, bis(octylpyrophosphate)oxyacetate titanate, bis (dioctylpyrophosphate)ethylene titanate, isopropyltrioctanoyltitanate, isopropyldimethacrylic isostearoyltitanate, isopropyltridodecylbenzenesulfonyltitanate, isopropylisostearoyldiaryl Titanate, isopropyl tri(dioctyl sulfate) titanate, isopropyl tricumyl phenyl titanate, tetraisopropylbis (dioctyl phosphite) titanate, etc. are mentioned.

Examples of the zirconium compound include zirconium tetraacetylacetonate, zirconyl 2-ethylhexanoate, and zirconyl naphthenate.

As a metal aluminum chelate, aluminum triacetylacetone etc. are mentioned, for example.

Examples of the hydrazide compound include aliphatic carboxylic acid hydrazide, alicyclic carboxylic acid hydrazide, and aromatic carboxylic acid hydrazide.

As aliphatic carboxylic acid hydrazide and alicyclic carboxylic acid hydrazide, for example, lauric acid hydrazide, palmitic acid hydrazide, stearic acid hydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecane Saturated or unsaturated fatty acid hydrazide, such as diacid dihydrazide, eiic acid diacid dihydrazide, and sorbic acid hydrazide; oxy fatty acid hydrazide such as α-oxybutyric acid hydrazide and glyceric acid hydrazide; 7,11-octadecadiene-1,18-dicarbohydrazide, 1,3-bis(hydrazinocarbonoethyl)-5-isopropylhydantoin), tris(hydrazinocarbonylethyl)isocyanurate and the like.

Examples of the aromatic carboxylic acid hydrazide include 1-naphthoic acid hydrazide, 2-naphthoic acid hydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide and 2,6-naphthoic acid dihydrazide. and the like.

As an epoxy-type crosslinking agent, the brand name "TETRAD-C", "TETRAD-X" etc. which are polyfunctional epoxy resins by a Mitsubishi Gas Chemical company are mentioned, for example.

Examples of the thermal acid generator include a salt formed from a strong acid and a base, such as an onium salt having a function of generating an acid by heat, and an imide sulfonate.

Examples of the onium salt include diaryl iodonium salts such as aryldiazonium salts and diphenyliodonium salts; di(alkylaryl)iodonium salts such as di(tert-butylphenyl)iodonium salt; trialkylsulfonium salts such as trimethylsulfonium salts; dialkyl monoarylsulfonium salts such as dimethylphenylsulfonium salt; diaryl monoalkyl iodonium salts, such as a diphenylmethyl sulfonium salt; A triarylsulfonium salt etc. are mentioned.

Moreover, as a salt formed from a strong acid and a base, besides the onium salt mentioned above, the salt formed from the following strong acid and a base, for example, a pyridinium salt can also be used. Examples of the strong acid include arylsulfonic acids such as p-toluenesulfonic acid and benzenesulfonic acid; perfluoroalkylsulfonic acids such as camphorsulfonic acid, trifluoromethanesulfonic acid, and nonafluorobutanesulfonic acid; and alkylsulfonic acids such as methanesulfonic acid, ethanesulfonic acid and butanesulfonic acid. Examples of the base include pyridine; alkylpyridines such as 2,4,6-trimethylpyridine; N-alkylpyridines such as 2-chloro-N-methylpyridine; Halogenated -N-alkylpyridine etc. are mentioned.

Examples of the imide sulfonate include naphthoylimide sulfonate and phthalimide sulfonate, but it is not limited as long as it is a compound that generates an acid by heat.

As the photoacid generator, one that generates an acid capable of cationic polymerization by irradiation with ultraviolet rays is used, and the reaction further proceeds by applying heat. Examples of the photo-acid generator include an anion component such as SbF ₆ -, PF ₆ -, BF ₄ -, AsF ₆ -, (C ₆ F ₅ ) ₄ -, PF ₄ (CF ₂ CF ₃ ) ₂ -; Onium salts (such as diazonium salts, sulfonium salts, iodonium salts, selenium salts, pyridinium salts, ferrocenium salts, and phosphonium salts) containing a cationic component are mentioned. These may be used independently and may use 2 or more types together. Specific examples thereof include aromatic sulfonium salts, aromatic iodonium salts, aromatic phosphonium salts, and aromatic sulfoxonium salts.

[Method for producing the crosslinking agent component (B)]

When a crosslinking agent component (B) is an aliphatic or alicyclic polyisocyanate (b), it is obtained by making the said diisocyanate (b1), a polyol (b2), and a polyol (b3) react. Hereinafter, the polyol (b2) and the polyol (b3) are collectively referred to as a polyol in some cases.

Polyol (b2) and polyol (b3) can be used individually or as a mixture, respectively. When using as a mixture, you may mix before making it react with diisocyanate, and after making each polyol react with diisocyanate independently and setting it as a polyisocyanate, you may mix.

That is, as a manufacturing method of a polyisocyanate, For example, a diisocyanate, a polyol (b2), and a polyol (b3) are made to react simultaneously, The method of obtaining a polyisocyanate; a method for obtaining polyisocyanate by mixing diisocyanate and polyol (b2) reacted with diisocyanate and polyol (b3) reacted; The method of further reacting a polyol which remained after making diisocyanate and a polyol (b2) or a polyol (b3) react, and obtaining polyisocyanate, etc. are mentioned.

The blending amount of the polyol (b2) and the polyol (b3) is preferably blended so that the mass ratio of the polyol (b2) to the polyol (b3) falls within the above range.

In the reaction, the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyol (b2) and the polyol (b3) (molar ratio of isocyanate group/hydroxyl group) is preferably 3 or more and 30 or less, more preferably 4 or more and 25 or less, It is more preferable that they are 5 or more and 22 or less, and it is especially preferable that they are 6 or more and 20 or less. When the NCO/OH is within the above numerical range, the crosslinking agent component (B) can be synthesized without gelation, and with respect to the optical resin sheet obtained, the elastic modulus is lower, the elongation rate is higher, and the breaking strength is higher. can

Reaction of polyol and diisocyanate is performed as follows. Reaction temperature is usually room temperature (about 23 degreeC) or more and 200 degrees C or less, and 60 degrees C or more and 130 degrees C or less are preferable. When the reaction temperature is equal to or higher than the lower limit, the reaction time becomes shorter. On the other hand, when the reaction temperature is equal to or lower than the upper limit, the increase in the viscosity of the polyisocyanate due to undesirable side reactions can be more avoided, and the coloration of the produced polyisocyanate can also be avoided. have.

Reaction may be performed without a solvent, and may be performed using an inert arbitrary solvent for an isocyanate group. Moreover, in order to accelerate|stimulate reaction of an isocyanate group and a hydroxyl group, you may use a well-known catalyst if necessary.

[Physical properties of the crosslinking agent component (B)]

It is preferable that the isocyanate group content rate (NCO group content rate) of the crosslinking agent component (B) is 1 mass % or more and 10 mass % or less with respect to the total mass of the crosslinking agent component (B) in the state which does not contain a solvent or diisocyanate substantially. It is more preferable that they are 2 mass % or more and 9 mass % or less, It is still more preferable that they are 2.5 mass % or more and 8.5 mass % or less, It is especially preferable that they are 2.7 mass % or more and 8.2 mass % or less.

The NCO group content rate can be calculated|required, for example by making the isocyanate group in a crosslinking agent component (B) react with an excess amine (dibutylamine etc.), and back titration of the remaining amine with acids, such as hydrochloric acid.

After coating only the above-mentioned crosslinking agent component (B) on glass, and storing for 168 hours in 23 degreeC, 65% humidity environment, 23 degreeC environment of the cured film with a film thickness of 40 micrometers formed by the reaction of the said polyisocyanate composition with the water|moisture content in a film|membrane. The König hardness under the condition is 60 or less, preferably 57 or less, more preferably 55 or less, and still more preferably 54 or less. When the König hardness is below the upper limit, the hardness is low and the flexibility is more excellent.

[Content of the crosslinking agent component (B)]

The content of the crosslinking agent component (B) is preferably 0.01 parts by mass or more and 5.00 parts by mass or less, more preferably 0.03 parts by mass or more and 4.00 parts by mass or less, 0.05 parts by mass or more and 3.50 parts by mass with respect to 100 parts by mass of the acrylic polymer (A). It is more preferable that they are parts or less, and it is especially preferable that they are 0.07 mass parts or more and 3.00 mass parts or less. When content of a crosslinking agent component (B) is in the said numerical range, sclerosis|hardenability at the time of setting it as an optical resin sheet is more excellent, and there exists a tendency which is more excellent in bending resistance, adhesive force, and holding power. Content of a crosslinking agent component (B) is computable from the compounding quantity of the crosslinking agent component (B) used at the time of manufacture of the resin composition for optics, for example.

[Isocyanate group/crosslinkable functional group]

The molar ratio of the isocyanate group of the crosslinking agent component (B) to the crosslinkable functional group (especially hydroxyl group) of the acrylic polymer (A) contained in the optical resin composition of the present embodiment (the molar ratio of isocyanate group/crosslinkable functional group) is necessary Although it is determined by the physical property of the optical resin sheet used as , it is 0.01 or more and 50 or less normally.

<Other ingredients>

The resin composition for optics of this embodiment can further contain 0.01 mass part or more and 0.5 mass part or less of a silane coupling agent (C) with respect to 100 mass parts of acrylic polymers (A). The optical resin composition of this embodiment improves the adhesive force of the optical resin sheet obtained more by including the silane coupling agent (C) in the quantity within the said numerical range, and floatation at the to-be-adhered body interface at the time of heating and humidification, Peeling can be suppressed more.

The silane coupling agent (C) is not limited to the following, for example, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltri Methoxysilane, ureidopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2-(3 ,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3- Mercaptopropyltrimethoxysilane, 3-isocyanate propyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, etc. are mentioned.

It is preferable that they are 0.01 mass part or more and 0.5 mass part or less with respect to 100 mass parts of acrylic polymers (A), and, as for content of a silane coupling agent (C), it is more preferable that they are 0.05 mass part or more and 0.4 mass part or less.

The resin composition for optics of this embodiment may further contain another additive.

Other additives include, for example, curing catalysts, solvents, pigments (such as constitutional pigments, colored pigments, metallic pigments), tackifying resins, photopolymerization initiators, ultraviolet absorbers, light stabilizers, radical stabilizers, and suppression of coloring during baking. anti-yellowing agents, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners, film forming aids, and the like.

As said curing catalyst, a basic compound may be sufficient and a Lewis acidic compound may be sufficient.

Examples of the basic compound include metal hydroxide, metal alkoxide, metal carboxylate, metal acetylacetylnate, hydroxide of onium salt, onium carboxylate, halide of onium salt, metal salt of active methylene compound, active methylene Onium salts of the system compounds, aminosilanes, amines, phosphines, and the like are exemplified. As said onium salt, an ammonium salt, a phosphonium salt, or a sulfonium salt is suitable.

As said Lewis acidic compound, an organic tin compound, an organic zinc compound, an organic titanium compound, an organic zirconium compound, etc. are mentioned, for example.

Examples of the solvent include 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and propylene glycol monoethyl ether. Methyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether (DPDM), propylene Glycol dimethyl ether, methyl ethyl ketone, acetone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol, iso-propanol, 1-propanol, iso-butanol, 1-butanol, tert-butanol, 2-ethyl hexane ol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, toluene, xylene, pentane, iso-pentane, hexane, iso-hexane, cyclohexane, solvent naphtha, mineral spirit, etc. are mentioned. These solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

In addition, pigments (substance pigments, colored pigments, metallic pigments, etc.), ultraviolet absorbers, light stabilizers, radical stabilizers, anti-yellowing agents for suppressing coloring during baking, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners and film forming agents As an adjuvant, a well-known thing can be appropriately selected and used.

<Method for producing optical resin composition>

The optical resin composition can be manufactured by a conventionally well-known method. For example, a melt-kneading method using a general mixer such as a Banbury mixer, a single screw extruder, a twin screw extruder, a kneader, and a multi screw extruder, after dissolving or dispersing and mixing each component, after coating on the base film by a coater, etc. , a method of removing the solvent by heating, etc. are used.

≪Resin sheet for optics≫

The resin sheet for optics of this embodiment is made by hardening|curing the above-mentioned resin composition for optics with a heat|fever or light.

The resin sheet for optics of this embodiment has favorable transparency and is excellent in adhesive force, holding|maintenance force, and bending resistance.

Although the thickness of the optical resin sheet of this embodiment can be suitably determined according to the use used, it is preferable that it is 1 micrometer or more and 1000 micrometers or less, It is more preferable that it is 3 micrometers or more and 900 micrometers or less, It is 5 micrometers or more and 800 micrometers or less It is more preferable, and it is especially preferable that they are 7 micrometers or more and 700 micrometers or less.

The resin sheet for optics of this embodiment can be manufactured by, for example, coating the above-mentioned resin composition for optics on a base material, drying as needed, and hardening after that.

Although it does not specifically limit as a base material, For example, Paper, such as fine paper, coated paper, cast-coated paper, thermal paper, inkjet paper; Cloths, such as a woven fabric and a nonwoven fabric; Polyvinyl chloride, synthetic paper, polyethylene terephthalate (PET), polypropylene, polyethylene, cellulose triacetate, cellulose diacetate, polystyrene, polycarbonate, nylon, polyvinyl alcohol, ethylene-vinyl acetate copolymer, polyimide, etc. resin film; porous resin films, such as a porous polypropylene film; vapor deposition film obtained by metal vapor deposition of aluminum or the like on PET or polyolefin; Metal foil etc. are illustrated. As a base material, the thing by which the peeling process was given to the surface may be sufficient.

As a method of coating the optical resin composition on a base material, the method of apply|coating using an applicator, a roll coater, a knife coater, a gravure coater, etc. is mentioned, for example. When drying after the said coating, for example, put the obtained laminated body in a dryer etc., for example, at a temperature of 50 degreeC or more and 150 degrees C or less, the heat drying method of 1 minute or more and 30 minutes or less is mentioned. Or, as another drying method, natural drying, hot air drying, infrared drying etc. are mentioned, for example.

As heating temperature at the time of hardening, it can be 70 degreeC or more and 150 degrees C or less, can be 75 degreeC or more and 145 degrees C or less, and can be 80 degreeC or more and 140 degrees C or less.

The optical resin sheet of this embodiment coats the said optical resin composition on a 25-micrometer-thick polyethylene terephthalate film, and after drying and hardening at 125 degreeC for 3 minutes, 23 degreeC, 50%RH environment for 7 days An optical resin sheet having a thickness of 70 μm, a width of 20 mm, and a length of 100 mm, having the stored polyethylene terephthalate film on one side, is bonded to a SUS304BA plate as an adherend, and compressed once with a 2 kg roller and cured at 23° C. for 30 minutes. Then, it is preferable that the 180 degree peel adhesive force measured at 23 ° C. and a speed of 300 mm/min is 2.0N/20mm or more and 65N/20mm or less, more preferably 4.0N/20mm or more and 63N/20mm or less, 5.0N/20mm or more It is more preferable that they are 61 N/20 mm or less, and it is especially preferable that they are 6.0 N/20 mm or more and 58 N/20 mm or less. When 180 degree peel adhesive force is more than the said lower limit, adhesive force is more excellent.

The optical resin sheet of this embodiment coats the said optical resin composition on a 25-micrometer-thick polyethylene terephthalate film, and after drying and hardening at 125 degreeC for 3 minutes, 23 degreeC, 50%RH environment for 7 days An optical resin sheet having a thickness of 70 µm, a width of 25 mm and a length of 130 mm, having the stored polyethylene terephthalate film on one side, is attached to the SUS304BA plate as an adherend so that the ranges of 25 mm in the width direction and 25 mm in the longitudinal direction overlap, and 2 kg One reciprocating compression with a roller, cured at 23°C for 1 hour, and further cured at 40°C for 30 minutes, a 500g weight is suspended at the bottom of the optical resin sheet under a 40°C environment for 1 hour, and then at 23°C environment It is preferable that the shift amount of the said optical resin sheet when returning to below is 2 (mm/hour) or less, It is more preferable that it is 1 (mm/hour) or less, It is more preferable that it is 0.5 (mm/hour) or less, It is 0.3 (mm/hour) or less is particularly preferable. When the shift amount is equal to or less than the upper limit, the holding force (cohesive force) is more excellent.

In addition, the lower limit of the shift|offset|difference amount is so preferable that it is small, for example, it can be set as 0.0 (mm/hour).

The optical resin sheet of this embodiment coats the said optical resin composition on a 38-micrometer-thick peeling-processed polyethylene terephthalate film, and after drying and hardening at 125 degreeC for 3 minutes, 23 degreeC, 50%RH environment The optical resin sheet having a thickness of 70 μm, obtained by peeling from the polyethylene terephthalate film subjected to the peeling treatment, was stored under the condition for 7 days and affixed on a glass having a haze value of 0.1%, and the haze value measured by a haze meter was 2.0% It is preferable that it is less than, it is more preferable that it is 1.0 % or less, It is still more preferable that it is 0.9 % or less, It is especially preferable that it is 0.8 % or less. When a haze value is below the said upper limit, transparency is more excellent.

In addition, although it is so preferable that the lower limit of a haze value is small, it can be set as 0.1 %, for example.

The optical resin sheet of this embodiment coats the said optical resin composition on a 38-micrometer-thick peeling-processed polyethylene terephthalate film, and after drying and hardening at 125 degreeC for 3 minutes, 23 degreeC, 50%RH environment The optical resin sheet having a thickness of 70 μm, obtained by peeling from the polyethylene terephthalate film subjected to the peeling treatment, was stored for 7 days under It is preferable that the gel fraction calculated by drying at 120 degreeC for 2 hours after being immersed at °C for 1 week and taking out is preferably 40.0 mass% or more and 99.9 mass% or less, more preferably 55.0 mass% or more and 99.9 mass% or less, 58.0 mass% It is more preferable that they are 99.9 mass % or more, and it is especially preferable that they are 62.0 mass % or more and 99.9 mass % or less. When a gel fraction is more than the said lower limit, it is more excellent in sclerosis|hardenability, cohesive force, and heat-and-moisture durability.

In addition, the gel fraction here is the percentage of the mass of the said optical resin sheet dried after immersion in ethyl acetate with respect to the mass of the said optical resin sheet before immersion in ethyl acetate.

The optical resin sheet of this embodiment coats the said optical resin composition on a 38-micrometer-thick peeling-processed polyethylene terephthalate film, and after drying and hardening at 125 degreeC for 3 minutes, 23 degreeC, 50%RH environment After storage for 7 days under the condition, the optical resin sheet having a thickness of 70 μm obtained by peeling from the polyethylene terephthalate film subjected to the peeling treatment was laminated to a thickness of 210 μm, cut to a width of 10 mm and a length of 40 mm, and the distance between the chucks was It is set in a tensile tester so that it becomes 10 mm, and the Young's modulus in a tensile test conducted at a speed of 300 mm/min in an environment of 23° C. is preferably 0.40 N/mm 2 or less, more preferably 0.30 N/mm 2 or less, and 0.25 N/ It is more preferable that it is mm<2> or less, and it is especially preferable that it is 0.20 N/mm<2> or less. When Young's modulus is below the said upper limit, it is more excellent in softness|flexibility, adhesive force, and bending resistance.

Moreover, although it is so preferable that the lower limit of Young's modulus is small, it can be set as 0.01 N/mm<2>, for example, and can be set as 0.02 N/mm<2>.

The resin sheet for optics of this embodiment has favorable transparency as mentioned above, and since it is excellent in adhesive force, holding|maintenance force, and bending resistance, it is used suitably as an optical transparent adhesive sheet (OCA), for example.

<Example>

Hereinafter, although an Example demonstrates this invention, this invention is not limited to the following Example.

[Physical Property 1]

(Glass Transition Temperature Tg)

The glass transition temperature of the acrylic polymer (A) is, after blowing the organic solvent and moisture in the solution of the acrylic polymer (A) under reduced pressure, vacuum-dried, using a differential scanning calorimetry (DSC) measuring device, a temperature increase rate of 5 ° C. / The value measured under the condition of minutes was used as the glass transition temperature.

[Physical Properties 2]

(number average molecular weight and weight average molecular weight)

The number average molecular weight and the weight average molecular weight are the number average molecular weight and the weight average molecular weight based on polystyrene by gel permeation chromatography (GPC) measurement using the following apparatus.

(Measuring conditions)

Device: Tosoh Co., Ltd., HLC-802A

Column: Tosoh Corporation, G1000HXL x 1

G2000HXL×1

G3000HXL×1

Carrier: tetrahydrofuran

Detection method: differential refractometer

[Physical Properties 3]

(isocyanate group content)

First, 2 g or more and 3 g or less of the measurement sample were precisely weighed (Wg) in the flask. Next, 20 mL of toluene was added to dissolve the measurement sample. Next, 20 mL of a toluene solution of 2N di-n-butylamine was added and mixed, and then left to stand at room temperature for 15 minutes. Next, 70 mL of isopropyl alcohol was added and mixed. Next, this solution was titrated to the indicator with 1 N hydrochloric acid solution (factor F). The obtained titration value was defined as V2mL. Next, the titrated value obtained without the sample was designated as V1ml. Next, the isocyanate group content (NCO%) (mass %) of the crosslinking agent component (B) was computed from the following formula.

"Isocyanate group content (mass %)" = (V1-V2) x F x 42/(W x 1000) x 100

[Physical Properties 4]

(average number of isocyanate functional groups)

The average number of isocyanate functional groups (average number of NCOs) of the crosslinking agent component (B) was calculated|required with the following formula. In addition, in formula, "Mn" means a number average molecular weight, and the value measured in the said "physical property 2" was used. "NCO%" used the value calculated in the said "physical property 3".

“Average number of isocyanate functional groups” = (Mn×NCO%×0.01)/42

[Preparation of cured film of crosslinking agent component (B)]

About each crosslinking agent component (B), it coated on glass using the applicator, and obtained the cured film with a film thickness of 40 micrometers after storage for 168 hours in 23 degreeC and 65% humidity environment.

[Physical Properties 5]

(Konig longitude)

For each cured film, the König hardness (times) was measured in an environment of 23° C. with a König hardness tester (Pendulum hardness tester manufactured by BYK Gardner).

<Evaluation method>

[Production of optical resin sheet 1]

Each optical resin composition was coated on a 25-micrometer-thick polyethylene terephthalate (PET) film by an applicator so that the thickness after drying might be set to 70 micrometers, and it dried at 125 degreeC for 3 minutes. Then, it stored for 7 days in 23 degreeC and 50%RH environment, and for the object for 180 degree peel adhesive force measurement and the object for holding force measurement, the optical resin sheet 1 provided with PET film on single side|surface was obtained.

[Production of optical resin sheet 2]

Each optical resin composition was coated on a PET film having a thickness of 38 µm and subjected to a peeling treatment so that the thickness after drying was 70 µm with an applicator, and dried at 125°C for 3 minutes. Then, it stored for 7 days under 23 degreeC, 50%RH environment, and for the object for a gel fraction measurement, the object for haze measurement, and the object for a tensile test, the optical resin sheet 2 provided with the PET film by which the peeling process was carried out on one side was obtained. The peel-treated PET film was peeled off and provided for each evaluation.

[Evaluation 1]

(180 degree peel adhesion)

The optical resin sheet 1 obtained by the said "preparation of the optical resin sheet 1" was cut|disconnected to 20 mm in width and 100 mm in length, and the test piece was obtained. Next, the test piece is affixed to the SUS304BA plate as an adherend, and a 2 kg roller is reciprocated to press the test piece to the SUS304BA plate, and after curing at 23° C. for 30 minutes, using a tensile tester at a speed of 300 mm/min 180 degrees peel adhesive force was measured.

The thing 2.0N/20mm or more evaluated that adhesive force was favorable.

[Evaluation 2]

(holding capacity)

The optical resin sheet 1 obtained by the said "preparation of the optical resin sheet 1" was cut|disconnected to 25 mm in width and 130 mm in length, and the test piece was obtained. Next, the test piece was affixed to a SUS304BA plate as an adherend so that a range of 25 mm in width and 25 mm in length overlapped, and it was compressed one reciprocally with a 2 kg roller, cured at 23° C. for 30 minutes, and cured at 40° C. for 1 hour. Thereafter, a 500 g weight was suspended at the lower end of the test piece in a 40 degreeC environment for 1 hour, and the amount of shift (mm/hour) of the test piece when returning to a 23 degreeC environment was measured.

The smaller the amount of misalignment, the better the holding force (cohesive force) tends to be, and those with a misalignment of 0.5 (mm/hour) or less were evaluated as having good holding capacity (cohesive force).

[Evaluation 3]

(Heize)

The optical resin sheet 2 obtained in the said "preparation of the optical resin sheet 2" was laminated|attached on the glass whose haze value is 0.1 %, it peeled from the polyethylene terephthalate film by which the peeling process was carried out, and it was set as the test piece. Next, with respect to the test piece, using a haze meter (HMG-2DP) manufactured by Suga Shikenki, among the two surfaces of the test piece, the side on which the peeling-treated polyethylene terephthalate film was peeled was placed at the light source to measure the haze. measured.

Transparency was evaluated as favorable about the thing whose haze value is 1.0 % or less.

[Evaluation 4]

(Gel fraction)

About 0.1 g or more and 0.2 g or less of the optical resin sheet 2 obtained by peeling the peeling-treated PET film obtained in the above "Production of the optical resin sheet 2" was collected, wrapped in a mesh-like sheet, and immersed in ethyl acetate for 1 week. Then, it was dried at 120° C. for 2 hours. Next, the gel fraction (mass %) was computed using the following formula.

With respect to a gel fraction of 60 mass % or more, sclerosis|hardenability evaluated that it was favorable.

(Gel fraction)

= (mass of sample after adding to ethyl acetate and drying) / (mass of sample before adding in ethyl acetate) x 100

[Evaluation 5]

(Tensile test: Young's modulus, elongation, maximum stress and strain energy indicators)

The optical resin sheet 1 obtained by peeling the peeling-processed PET film obtained in the said "production of the optical resin sheet 1" was laminated|stacked so that thickness might be set to 210 micrometers, and it cut|disconnected to 10 mm width and 40 mm length. Thereafter, the tensile tester was set so that the distance between the chucks was 10 mm, and the Young's modulus, elongation rate, and maximum stress were measured at a speed of 300 mm/min using the tensile tester in an environment of 23°C. Next, from the obtained elongation rate and maximum stress, the strain energy index was calculated by the following formula.

A Young's modulus of 0.25 N/mm 2 or less and a strain energy index of 2.00 or more were evaluated as good in bending resistance.

(Strain energy index) = {(Elongation (%))/100) × (Maximum stress)} × 1/2

<Synthesis of acrylic polymer (A)>

[Synthesis Example 1-1]

(Synthesis of acrylic polymer A-1)

97 parts by mass of 2-ethylhexyl acrylate (2EHA) and 3 parts by mass of 4-hydroxybutyl acrylate (4HBA) were put into a four-neck flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube and a cooling tube, and the solvent 140 mass parts of ethyl acetate was injected|thrown-in as this. Next, 0.15 mass parts of 2,2'- azobisisobutyronitrile (AIBN) was thrown in as a polymerization initiator, stirring in nitrogen gas atmosphere, and reaction was performed at 63 degreeC for 8 hours. It cooled after reaction and obtained the acrylic polymer A-1 with a solid content concentration of 42.0 mass %.

[Synthesis Examples 1-2 to 1-14]

(Synthesis of acrylic polymers A-1 to A-14)

Each acrylic polymer was synthesized using the same method as in Synthesis Example 1-1, except that the mixing ratio of each monomer was as described in Tables 1 to 2.

The composition and physical properties of each synthesized acrylic polymer are shown in Tables 1 to 2 below. In addition, in Tables 1-2, the abbreviation of a monomer shows the following compounds.

(Crosslinkable functional group-containing monomer (a1))

4HBA: 4-hydroxybutyl acrylate

HEA: hydroxyethyl acrylate

AA: acrylic acid

((meth)acrylic acid ester monomer (a2))

2EHA: 2-ethylhexyl acrylate

MEA: methoxyethyl acrylate

iOA: isooctyl acrylate

iNA: isononyl acrylate

EA: ethyl acrylate

MA: methyl acrylate

BezA: benzyl acrylate

BA: butyl acrylate

PEA: Phenoxyethyl acrylate

(Other polymerizable monomers (a3))

NVP: N-vinyl-2-pyrrolidone

<Synthesis of crosslinking agent component (B)>

[Synthesis Example 2-1]

(Synthesis of polyisocyanate component B-1)

In a four-neck flask equipped with a thermometer, a stirring blade and a reflux cooling tube, under a nitrogen stream, 100 parts by mass of HDI: was put, and a bifunctional polycaprolactone polyol (manufactured by Daicel, trade name "Flaxel 220", number average molecular weight) 2000) (hereinafter referred to as "polyol b2-1" or simply "b2-1" in some cases): 4.7 parts by mass and trifunctional polycaprolactone polyol (manufactured by Daicel, trade name "Flaxel 308", water Average molecular weight 850) (hereinafter sometimes referred to as “polyol b3-1” or simply “b3-1”): 33 parts by mass (molar ratio of isocyanate groups of HDI to hydroxyl groups of polyol b2-1 and polyol b3-1) The reaction was stopped when the temperature in the reactor was maintained at 90°C and maintained for 110 minutes or longer, while stirring the amount to be 10.0), when the yield reached 40% by mass. After filtering the reaction liquid, unreacted HDI was removed by the thin film distillation apparatus, and polyisocyanate component B-1 was obtained.

[Synthesis Examples 2-2 to 2-6]

(Synthesis of polyisocyanate components B-2 to B-6)

Each polyisocyanate component was synthesize|combined using the method similar to Synthesis Example 2-1 except having carried out the kind of raw material and compounding ratio as Table 3 was used.

[Synthesis Example 2-7]

(Synthesis of polyisocyanate component B-7)

In a four-neck flask equipped with a thermometer, a stirring blade and a reflux cooling tube, under a nitrogen stream, HDI: 100 parts by mass and trimethylolpropane (hereinafter referred to as "polyol b3-3" or simply "b3-3" may be ): 8.9 parts by mass was added, and the temperature in the reactor was maintained at 75° C. for 5 hours under stirring to perform urethanation reaction. After filtering the reaction liquid, unreacted HDI was removed using the thin film evaporation can, and isocyanurate-type polyisocyanate (Hereinafter, it may call "polyisocyanate component B-7") was obtained.

[Synthesis Example 2-8]

(Synthesis of polyisocyanate component B-8)

In a four-neck flask equipped with a thermometer, a stirring blade and a reflux cooling tube, under a nitrogen stream, 100 parts by mass of HDI was put, and the temperature in the reactor was maintained at 62° C. under stirring, and trimethylbenzylammonium hydroxide: 0.095 parts by mass was added and reacted for 4 hours. Then, when the conversion ratio became 38 mass %, phosphoric acid:0.02 mass part was added and reaction was stopped. After filtering the reaction liquid, unreacted HDI was removed using the thin film evaporation can, and isocyanurate-type polyisocyanate (Hereinafter, it may call "polyisocyanate component B-8") was obtained.

[Synthesis Example 2-9]

(Synthesis of polyisocyanate component B-9)

In a four-necked flask equipped with a thermometer, a stirring blade and a reflux cooling tube, under a nitrogen stream, 100 parts by mass of HDI was put, and polyol b3-1: 30 parts by mass (of the isocyanate group of HDI relative to the hydroxyl group of polyol b3-1) The molar ratio becomes 11.4) while stirring, the temperature in the reactor was maintained at 95° C. and maintained for 80 minutes. Reaction was stopped when the yield reached 39 mass %. After filtering the reaction liquid, unreacted HDI was removed by the thin film distillation apparatus, and polyisocyanate component B-9 was obtained.

[Synthesis Example 2-10]

(Synthesis of polyisocyanate component B-10)

In a four-neck flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI was put under a nitrogen stream, and a trifunctional polycaprolactone polyol (hereinafter referred to as "polyester polyol b3-3" may be called ) (manufactured by Daicel, trade name "Flaxel 305", number average molecular weight 550) 22.0 parts by mass (an amount in which the molar ratio of the isocyanate group of HDI to the hydroxyl group of the polyol becomes 9.9) while stirring the temperature in the reactor to 90 ° C. and maintained for 75 minutes. When the yield reached 33 mass%, the reaction was stopped. After filtering the reaction liquid, unreacted HDI was removed by the thin film distillation apparatus, and polyisocyanate component B-10 was obtained.

The composition and physical properties of each synthesized polyisocyanate component are shown in Table 3 below. In addition, in Table 3, a polyol is the following compound.

(polyol (b2))

b2-1: bifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "Flaxel 220", number average molecular weight 2000

(polyol (b2'))

b2'-1: polyether polyol, Asahi Glass Co., Ltd. product, brand name "Excenol2020", number average molecular weight 2000

(polyol (b3))

b3-1: trifunctional polycaprolactone polyol, manufactured by Daicel, trade name "Flaxel 308", number average molecular weight 850

b3-2: trifunctional polycaprolactone polyol, manufactured by Daicel, trade name "Flaxel 312", number average molecular weight 1250

b3-3: trifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "Flaxel 305", number average molecular weight 550

(polyol (b3'))

b3'-1: trimethylolpropane (TMP)

<Production of optical resin composition>

[Example 1]

(Preparation of optical resin composition O-a1)

Acrylic polymer A-1: with respect to 100 mass parts, polyisocyanate component B-1: 0.5 mass part, silane coupling agent (3-glycidoxypropyl trimethoxysilane, Shin-Etsu Chemical Co., Ltd. make, product name "KBM-" 403"): 0.1 mass part and ethyl acetate were added, and the 30 mass % solid content resin composition O-a1 for optics was obtained.

[Examples 2 to 14 and Comparative Examples 1 to 5]

(Preparation of optical resin compositions O-a2 to O-a14 and O-b1 to O-b5)

Each optical resin composition was prepared in the same manner as in Example 1, except that the types and blending ratios of the acrylic polymer (A) and the crosslinking agent component (B) were as described in Tables 4 to 6.

The composition and evaluation result of each optical resin composition are shown in Tables 4-6.

From Tables 4 to 6, the glass transition temperature Tg is -69.7 ° C. or more and -58.0 ° C. or less, and the crosslinkable functional group-containing monomer and the (meth) acrylic acid ester monomer having the carbon number at the end of the ester group in a specific numerical range are copolymerized, An acrylic polymer (A) comprising an aliphatic polyisocyanate having a weight average molecular weight of 4180 or more and 32700 or less and an average number of isocyanate groups of 3.8 or more and 5.0 or less as the crosslinking agent component (B), Optical resin compositions O-a1 to O In the optical resin sheet using -a14 (Examples 1-14), transparency was favorable and it was excellent in adhesive force, holding power, and bending resistance.

On the other hand, with respect to 100 parts by mass of the acrylic polymer (A), an optical resin composition O-b1 containing 0.5 parts by mass of each polyisocyanate component B-7 to B-9 having a weight average molecular weight of less than 1400 as a crosslinking agent component (B); In the optical resin sheets using O-b3, O-b4, and O-b5 (Comparative Examples 1, 3, 4 and 5), transparency, holding force, and adhesive force were good, but bending resistance was poor.

Further, based on 100 parts by mass of the acrylic polymer (A), an optical resin composition O-b2 (Comparative Example 2) containing 0.05 parts by mass of a polyisocyanate component B-7 having a weight average molecular weight of less than 1400 as a crosslinking agent component (B) was prepared. In the used optical resin sheet, although transparency and adhesive force were favorable, holding force and bending resistance were inferior.

ADVANTAGE OF THE INVENTION According to the resin composition for optics of this embodiment, the optical resin composition excellent in adhesive force, holding power, and bending resistance can be provided, maintaining favorable transparency when it is set as an optical resin sheet. The resin sheet for optics of the said aspect is made by hardening the said resin composition for optics, transparency is favorable, and is excellent in adhesive force, holding power, and bending resistance.

Claims (20)

As an optical resin composition comprising an acrylic polymer (A) and a crosslinking agent component (B),
The acrylic polymer (A) is formed by copolymerizing a crosslinkable functional group-containing monomer and a (meth)acrylic acid ester monomer having 1 to 18 carbon atoms at the terminal of the ester group,
The glass transition temperature Tg of the acrylic polymer (A) is -10.0 ° C. or less,
The said crosslinking agent component (B) is an optical resin composition containing the aliphatic or alicyclic polyisocyanate whose weight average molecular weights are 2100 or more and 200000 or less. The optical resin composition according to claim 1, wherein the average number of isocyanate groups in the crosslinking agent component (B) is 2.0 or more and 6.5 or less. The optical resin composition according to claim 1 or 2, wherein the content of the crosslinking agent component (B) is 0.01 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the acrylic polymer (A). The optical resin composition according to claim 1 or 2, wherein the acrylic polymer (A) has a weight average molecular weight of 5.0×10 ⁵ or more and 5.0×10 ⁶ or less. The optical resin composition according to claim 1 or 2, wherein the crosslinkable functional group is at least one selected from the group consisting of a hydroxyl group, an epoxy group, a carboxy group, and a vinyl group. The optical resin composition of Claim 1 or 2 whose content of the structural unit derived from the said (meth)acrylic acid ester monomer is 0.01 mass % or more and 99.99 mass % or less with respect to the total mass of the said acrylic polymer (A). The aliphatic or alicyclic polyisocyanate according to claim 1 or 2, wherein the aliphatic or cycloaliphatic polyisocyanate comprises at least one diisocyanate (b1) selected from the group consisting of aliphatic diisocyanate and alicyclic diisocyanate, and a number average molecular weight of 1500 or more. a polyisocyanate derived from a bifunctional polyol (b2) and a trifunctional or higher polyol (b3) having a number average molecular weight of 500 or more;
The optical resin composition wherein the ratio NCO/OH of the molar amount of the isocyanate group of the diisocyanate (b1) to the total molar amount of the hydroxyl groups of the polyol (b2) and the polyol (b3) is 3 or more and 30 or less. The mass ratio (b3)/(b2) of the polyol (b3) to the polyol (b2) is 0.1/99.9 or more and 99.9/0.1 or less, and
With respect to 100 mass parts of said diisocyanate (b1),
The content of the polyol (b2) is 0.1 parts by mass or more and 250 parts by mass or less,
The optical resin composition whose content of the said polyol (b3) is 0.1 mass part or more and 190 mass parts or less. The optical use according to claim 7, wherein the polyol (b2) and the polyol (b3) are at least one polyol selected from the group consisting of polyester polyol, polyether polyol, epoxy polyol, polyolefin polyol, and polycarbonate polyol. resin composition. The optical resin composition of Claim 1 or 2 whose content rate of the isocyanate group of the said crosslinking agent component (B) is 1 mass % or more and 10 mass % or less. The optical resin composition according to claim 1 or 2, further comprising 0.01 parts by mass or more and 0.5 parts by mass or less of a silane coupling agent (C) with respect to 100 parts by mass of the acrylic polymer (A). The said crosslinking agent component (B) is an isocyanate compound other than the said aliphatic or alicyclic polyisocyanate, a carbodiimide compound, an oxazoline compound, a polyfunctional acrylic acid ester monomer, a peroxide, and a titanium coupling agent according to claim 1 or 2 , A zirconium compound, a metal aluminum chelate, a hydrazide compound, an epoxy-based crosslinking agent, an optical resin composition comprising at least one selected from the group consisting of a thermal acid generator and a photoacid generator. The Könich hardness of a cured film with a film thickness of 40 μm formed after coating the crosslinking agent component (B) on glass for 168 hours at 23° C. and 65% humidity environment under 23° C. environment according to claim 1 or 2 60 or less optical resin composition. An optical resin sheet formed by curing the optical resin composition according to claim 1 or 2 by heat or light. The optical resin sheet according to claim 14, wherein the optical resin sheet has a thickness of 1 µm or more and 1000 µm or less. The method of claim 14, wherein the optical resin composition is coated on a polyethylene terephthalate film having a thickness of 25 μm, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. An optical resin sheet having a thickness of 70 μm, a width of 20 mm, and a length of 100 mm, having a polyethylene terephthalate film on one side, is bonded to a SUS304BA plate as an adherend, and compressed once with a 2 kg roller, after curing at 23° C. for 30 minutes, at 23° C. , An optical resin sheet having a 180-degree peel adhesive strength of 2.0N/20mm or more and 65N/20mm or less, measured at a speed of 300mm/min. The method of claim 14, wherein the optical resin composition is coated on a polyethylene terephthalate film having a thickness of 25 μm, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. An optical resin sheet having a thickness of 70 μm, a width of 25 mm and a length of 130 mm, having a polyethylene terephthalate film on one side, is attached to the SUS304BA plate as an adherend so that the ranges of 25 mm in width and 25 mm in length overlap, and one reciprocating compression with a 2 kg roller is performed. After curing at 23° C. for 1 hour, and further curing at 40° C. for 30 minutes, a 500 g weight is suspended at the lower end of the optical resin sheet for 1 hour under a 40° C. environment, and then returned to a 23° C. environment. The optical resin sheet whose shift amount of the optical resin sheet is 2 mm/hour or less. [Claim 15] The method of claim 14, wherein the optical resin composition is coated on a polyethylene terephthalate film having a thickness of 38 μm and subjected to peeling treatment, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. and affixing a 70 µm-thick optical resin sheet obtained by peeling from the peeling-treated polyethylene terephthalate film on a glass having a haze value of 0.1%, and having a haze value of 2.0% or less as measured by a haze meter. Sheet. [Claim 15] The method of claim 14, wherein the optical resin composition is coated on a polyethylene terephthalate film having a thickness of 38 μm and subjected to peeling treatment, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. Then, a 70 μm-thick optical resin sheet obtained by peeling from the peeling-treated polyethylene terephthalate film was stored at 23° C. and 50% RH for 7 days, then wrapped in a mesh-like sheet, in ethyl acetate at 23° C. for 1 week. The optical resin sheet whose gel fraction computed by drying at 120 degreeC for 2 hours after being immersed and taking out is 40.0 mass % or more and 99.9 mass % or less. [Claim 15] The method of claim 14, wherein the optical resin composition is coated on a polyethylene terephthalate film having a thickness of 38 μm and subjected to peeling treatment, dried at 125° C. for 3 minutes to cure, and then stored at 23° C. and 50% RH for 7 days. Then, a 70 μm thick optical resin sheet obtained by peeling from the peeling-treated polyethylene terephthalate film is laminated to a thickness of 210 μm, cut to a width of 10 mm and a length of 40 mm, and then tensioned so that the distance between the chucks is 10 mm The optical resin sheet set in the testing machine and whose Young's modulus in the tensile test performed at the speed|rate of 300 mm/min in 23 degreeC environment is 0.40 N/mm<2> or less.