JP2014031453A - Ultraviolet-curable resin composition for optical laminate, cured product and optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet-curable resin composition which is cured by irradiation with ultraviolet rays, has a performance of stably maintaining heat resistance, light resistance and moisture resistance, that is, optically excellent qualities for a long period of time, and is excellent in heat shock resistance and an impact absorbing property; a cured product of the same; and an optical laminate comprising a cured product obtained by curing the ultraviolet-curable resin composition.SOLUTION: Provided is an ultraviolet-curable resin composition for an optical laminate comprising: a glass having a thickness of 300 μm or less and a transparent plastic material having a larger thickness than the glass, which are bonded together by an ultraviolet-curable resin composition. The resin composition comprises (A) a polymer having a number average molecular weight Mn of 10000 or more and a polydispersity d of 1.5 or less, and having two or more (meth)acrylate groups; and (B) a photopolymerization initiator.

Description

  The present invention includes buildings, automobiles, agricultural greenhouses, flat panel displays such as liquid crystal displays and organic EL displays, mobile phones, smartphones, tablet information terminals, solar cells, lithium ion batteries, digital signage, touch panels, electronic paper, etc. Glass materials used in device glass substrates and glass covers used in device cover glasses and pharmaceutical packages such as organic EL lighting. More specifically, glass excellent in optical properties, light weight, heat shock resistance, and shock absorption. The present invention relates to an optical laminate using

  Glass plate is excellent in light resistance, chemical resistance and scratch resistance, and is transparent and excellent in daylighting, so it can be used for windows for general buildings and high-rise buildings, lighting from roofs, covering materials for agricultural greenhouses, automobiles, etc. , Windows for vehicles such as trains, flat panel displays such as liquid crystal displays and organic EL displays, devices such as mobile phones, smartphones, tablet information terminals, solar cells, lithium-ion batteries, digital signage, touch panels, and electronic paper Widely used in glass substrates.

  However, glass is a brittle material and has a problem of being easily damaged by being weak against physical impact. It is also known that it can be easily damaged by thermal shock and cold shock.

  In order to solve this problem, many laminates in which a transparent plastic is laminated on a glass plate have been proposed. Transparent plastics are common with glass, which is an inorganic material, in terms of transparency, but have the advantage of being more resistant to physical impact than glass, but are inferior in chemical resistance, light resistance, and scratch resistance than glass. Have the disadvantages. For example, Patent Document 1 below proposes a laminated glass (glass laminate) configured by sequentially laminating glass / polyvinyl butyral / polycarbonate / polyvinyl butyral / glass. In Patent Document 1, glass that is vulnerable to physical impact is supported by a transparent plastic to prevent breakage and scattering of the glass plate, and by sandwiching the transparent plastic with a glass plate having excellent light resistance and scratch resistance, It prevents the plastics from being exposed to the outside environment, and each has the advantages of glass plates and transparent plastics. In flat panel displays such as liquid crystal display panels, when a shock is applied, a transparent protection consisting of a display panel and an acrylic plate or glass plate that protects the display panel so that the shock is not transmitted to the display panel A certain gap is provided between the plates.

  Further, glass is a substance that has a high density and tends to increase in weight. A glass plate used for construction or the like generally has a thickness of 2 to 10 mm. When the glass plate becomes large, the weight of the glass plate becomes large. When the glass is heavy, when the glass plate is used as a window material for high-rise buildings or as a covering material for agricultural greenhouses, it has a high rank as a material for pillars, beams, trunks, and hazes from the viewpoint of earthquake resistance. There is a problem that it is necessary to use a thing and the cost becomes high. In addition, when a glass plate is used as a window material for a vehicle such as an automobile, if the weight of the glass plate is large, the fuel efficiency of the vehicle deteriorates, increasing the amount of carbon dioxide generated, which may cause environmental problems. .

  On the other hand, since the invention described in Patent Document 1 described above replaces a part of the glass plate with polycarbonate, in the case of the same size, the entire laminated glass described in Patent Document 1 is more preferable than the glass plate. The weight is lighter.

  However, in the Example of patent document 1, the glass plate of 0.5 mm or more is used for the glass plate currently used for the laminated glass, and in the laminated glass which uses two glass plates, the whole laminated glass is used. In terms of thickness, only a glass plate has a thickness of 1 mm. For example, when a 2 mm laminated glass is used as an alternative to a 2 mm glass plate, 1 mm, which is half the total thickness of the laminated glass, is occupied by the same glass plate, which is sufficient to reduce the weight. I can't say that. Moreover, since the used polyvinyl butyral is inferior in transparency and flexibility, the obtained laminate cannot be said to have sufficient optical properties, heat cycle resistance, and impact resistance.

JP-A-6-915

  The present invention has been made in view of the circumstances as described above. The object of the present invention is to attach a glass having a thickness of 300 μm or less and a transparent plastic thicker than the glass by an ultraviolet curable resin composition. Ultraviolet rays with excellent heat resistance and shock absorption in heat resistance, light resistance, moisture resistance, that is, the ability to stably maintain optically superior quality over a long period of time in the combined optical laminate It is providing the optical laminated body which has a curable resin composition, its hardened | cured material, and the hardened | cured material obtained by hardening | curing such a resin composition.

  That is, the ultraviolet curable resin composition for an optical laminate of the present invention is for an optical laminate in which a glass having a thickness of 300 μm or less and a transparent plastic thicker than the glass are bonded together by the ultraviolet curable resin composition. An ultraviolet curable resin composition, wherein the resin composition has (A) two or more (meth) acrylate groups having a number average molecular weight Mn of 10,000 or more and a dispersity d of 1.5 or less. It contains a polymer and (B) a photopolymerization initiator.

The (A) preferably contains a polyether polymer.
The (A) preferably contains a conjugated diene polymer.

  The present invention is a cured product obtained by curing the ultraviolet curable resin composition for an optical laminate of the present invention as described above by ultraviolet irradiation, an optical laminate having the cured product, and a transparent plastic. Also includes an optical laminate in which is polymethylmethacrylate.

  The ultraviolet curable resin composition for optical laminates of the present invention is cured by ultraviolet irradiation, and has heat resistance, light resistance, moisture resistance, that is, the ability to stably maintain optically superior quality over a long period of time, heat resistance A cured product having excellent shock resistance and shock absorption can be provided. Therefore, it is suitable as a transparent polymer material used for the optical laminate.

The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and is not limited to these contents.

<Ultraviolet curable resin composition for optical laminate>
First, the ultraviolet curable resin composition for an optical laminate of the present invention will be described.

The ultraviolet curable resin composition for optical laminates of the present invention (hereinafter sometimes simply referred to as “resin composition”) is composed of a glass having a thickness of 300 μm or less and a transparent plastic thicker than the glass. In the optical laminate bonded with the resin composition, as a main component, (A) two or more (meth) acrylate groups having a number average molecular weight Mn of 10,000 or more and a dispersity d of 1.5 or less. Containing a polymer (hereinafter sometimes referred to as the compound (A)) and (B) a photopolymerization initiator.
[Compound (A)]
Although it does not specifically limit as a compound (A), For example, it has polyether group (a-1) whose number average molecular weight Mn is 10000 or more and dispersity d is 1.5 or less, and an isocyanate group. Polyether polymers obtained by reaction with (meth) acrylate (a-2) or (meth) acrylate (a-3) having a carboxyl group such as (meth) acrylic acid, and further, for example, butadiene, isoprene, etc. A conjugated diene-based prepolymer obtained by anionic polymerization of a conjugated diene compound is reacted with a dibasic unsaturated acid anhydride, and then a part of the acid anhydride residue in the obtained prepolymer, Alternatively, a conjugated diene polymer obtained by reacting all of them with a hydroxyl group-containing (meth) acrylate, and further, for example, a living anion Poly (meth) acrylate polymer obtained by reacting a poly (meth) acrylate prepolymer having a reactive functional group obtained by polymerization with a (meth) acrylate having a functional group that reacts with the prepolymer Is mentioned. Of these, polyether polymers and conjugated diene polymers are preferred, polyether polymers are more preferred, and polyether polyols (a-1) and isocyanate groups are preferred because they are simple to produce and excellent in various performances. A polyether polymer obtained from the (meth) acrylate (a-2) having is particularly preferred.
The compound (A) has two or more (meth) acrylates having a number average molecular weight Mn of 10,000 or more and a dispersity d (synonymous with a molecular weight distribution (Mw / Mn) described later) of 1.5 or less. Although it will not specifically limit if it is a polymer which has group, The above-mentioned polyether type polymer, conjugated diene type polymer, poly (meth) acrylate type polymer, etc. are used suitably.
The viscosity at 25 ° C. of the compound (A) is preferably 500,000 mPa · s or less, more preferably 350,000 mPa · s or less, further preferably 200000 mPa · s or less, and particularly preferably 100000 mPa · s or less, depending on the polymer used. Moreover, 1000 mPa * s or more is preferable, 2000 mPa * s or more is more preferable, 3000 mPa * s or more is further more preferable. When converted to a number average molecular weight, it is preferably 10,000 or more, more preferably 13,000 or more, further preferably 15,000 or more, particularly preferably 18,000 or more, preferably 300,000 or less, more preferably 100,000 or less, further preferably 50,000 or less, and further 30,000 or less. Is particularly preferred. When the viscosity at 25 ° C. exceeds 500,000 mPa · s (when the number average molecular weight exceeds 300,000), the resulting resin composition tends to have a high viscosity and poor workability.
The molecular weight distribution (Mw / Mn) of the compound (A) is preferably 1.50 or less, more preferably 1.35 or less, further preferably 1.20 or less, and most preferably 1.10 or less. When the molecular weight distribution (Mw / Mn) is large, the viscosity of the resulting resin composition tends to be high and the workability tends to be poor, and the elongation of the cured product of the resulting resin composition tends to be small and the impact resistance tends to be poor. .
As content of (A) polymer compound in a resin composition, it is suitable that it is 20-99.9 mass% with respect to 100 mass% of resin compositions. More preferably, it is 25-80 mass%, More preferably, it is 30-70 mass%, Most preferably, it is 35-60 mass%. By being in the above numerical range, the elongation of the cured product is increased and the impact resistance is improved.
[Polyether polymer]
The polyether polymer which is one of the preferred forms of the compound (A) includes, for example, a polyether polyol (a-1) having a number average molecular weight Mn of 10,000 or more and a dispersity d of 1.5 or less, and an isocyanate. It can be obtained by reaction with (meth) acrylate (a-2) having a nate group or (meth) acrylate (a-3) having a carboxyl group.
The polyether polyol (a-1) has a number average molecular weight Mn of 10,000 or more and a dispersity d of 1.5 or less, and the compound has a repeating unit represented by the following general formula (1). And it will not specifically limit if it has two or more hydroxyl groups.

Formula (1): —R—O—
R preferably has a linear and / or branched alkylene group having 1 to 14 carbon atoms, specifically, —CH ₂ O—, —CH ₂ CH ₂ O—, —CH ₂ CH (CH _{3) O -, - CH 2} CH (C 2 H 5) O-, CH 2 C (CH 3) 2 O -, - CH 2 CH 2 CH 2 CH 2 O -, - COCH 2 CH 2 CH 2 CH 2 CH ₂ O—, —CH ₂ C (CH ₃ ) ₂ CH ₂ O— and the like are mentioned, among which —CH ₂ CH ₂ O—, —CH ₂ CH (CH ₃ ) O— are preferred, CH ₂ CH (CH ₃ ) O— is particularly preferred.
The repeating unit contained in these polyether polyols (a-1) may consist of only one type of repeating unit, or may consist of two or more types of repeating units. Moreover, repeating units other than the said structure may be contained in these polyether polyol (a-1). The content ratio of the general formula (1) in the polyether polyol (a-1) is preferably 80% by mass (% by weight) or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more. . When the content ratio of the general formula (1) is 80% by mass or more, it is obtained by reacting with (meth) acrylate (a-2) having an isocyanate group or (meth) acrylate (a-3) having a carboxyl group. As a result, a resin composition excellent in workability can be obtained.
Examples of the polyether polyol (a-1) include polyethylene glycol which is a diol of ethylene oxide alone, polypropylene glycol which is a diol of propylene oxide alone, and a diol of random and / or block copolymerization of ethylene oxide and propylene oxide. Polyethylene propylene glycol, bisphenol A diol obtained by adding ethylene oxide and / or propylene oxide to bisphenol A, glycerin triol obtained by adding ethylene oxide and / or propylene oxide to glycerin, ethylene oxide and / or propylene oxide added to trimethylolpropane Trimethylolpropane triol, ethylenediamine and ethylene oxide and / or propylene Ethylenediamine-based tetraol with addition of xoxide, sorbitol-based polyol with addition of ethylene oxide and / or propylene oxide to sorbitol, sucrose-based polyol with addition of ethylene oxide and / or propylene oxide to sucrose, ethylene oxide and / or sucrose and glycerin There are polyether polyols to which propylene oxide is added. Among them, polypropylene glycol, trimethylolpropane triol to which propylene oxide is added, and glycerin triol to which propylene oxide is added are preferable, and polypropylene glycol is more preferable.
As a commercially available polyether polyol (a-1), the brand name "Preminol" by Asahi Glass Co., Ltd. is mentioned, for example.
As for the molecular weight of the polyether polyol (a-1), the number average molecular weight Mn is preferably 10,000 to 50,000, more preferably 10,000 to 30,000, and particularly preferably 10,000 to 25,000. If the number average molecular weight Mn is less than 10,000, the cured product of the resulting resin composition is hard (hardness is high), or the elongation percentage is small, and a tendency to be inferior in impact resistance is seen. When the molecular weight Mn exceeds 50,000, the viscosity of the resulting resin composition becomes too high, and the workability tends to be inferior.
The molecular weight distribution (Mw / Mn) of the polyether polyol (a-1) is preferably 1.5 or less, more preferably 1.4 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less. When the molecular weight distribution (Mw / Mn) is large, the viscosity of the resulting resin composition is high and the workability is poor, the cured product of the resulting resin composition is hard (hardness is high), or the elongation rate tends to be small. It can be seen.
The number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) in this specification are all tetrahydrofuran (THF) as a mobile phase, temperature 40 ° C., flow rate 0.3 mL. Using a Tosoh column TSK-gel SuperHM-H and one TSK-gel SuperH2000, the gel permeation chromatography (GPC) apparatus manufactured by Tosoh HLC-8220GPC is used. It is a converted value.
The (meth) acrylate (a-2) having an isocyanate group is not particularly limited as long as it has an isocyanate group and a (meth) acrylate group, but 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, 1,1-bis (acryloyloxymethyl) ethyl isocyanate and the like are preferable, and 2-acryloyloxyethyl isocyanate is more preferable.
The (meth) acrylate (a-3) having a carboxyl group is not particularly limited as long as it has a carboxyl group and a (meth) acrylate group, but methacrylic acid, acrylic acid, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid and the like are preferred, and methacrylic acid and acrylic acid are more preferred as a method for producing a polyether-based polymer. Urethane reaction of polyether polyol (a-1) and isocyanate group-containing (meth) acrylate (a-2) in the presence, or polyether polyol (a-1) and carboxyl group (meth) It can be obtained by conducting an esterification reaction with acrylate (a-3). That.
Examples of the urethanization reaction catalyst include amines such as triethylamine and benzylmethylamine, dilaurate compounds such as dibutyltin dilaurate and dioctyltin dilaurate, copper naphthenate, cobalt naphthenate, and zinc naphthenate. . The amount of the catalyst added is preferably about 0.001 to 1% by mass, particularly preferably about 0.01 to 0.5% by mass, based on the entire reaction mixture. The reaction temperature is usually 10 to 100 ° C, particularly preferably 30 to 80 ° C. In order to prevent gelation due to radical polymerization during the reaction, it is preferable to add a known polymerization inhibitor. As the polymerization inhibitor, for example, hydroquinone, methoquinone, p-methoxyphenol, p-benzoquinone and the like can be preferably used, and preferably 0.001 to 3% by mass with respect to the entire reaction mixture, 0.01 to 1 More preferably, it is mass%.
As the esterification reaction catalyst, for example, a catalyst that functions as a Lewis acid is preferable. For example, a Ti compound (for example, Ti (OBu) ₄ , Ti (O—Pr) _4, etc.), a Sn compound (for example, tin octylate, Dibutyltin oxide, dibutyltin dilaurate, monobutyltin hydroxybutyl oxide, stannous chloride, stannic chloride, etc.), protonic acids (eg, sulfuric acid, paratoluenesulfonic acid, methanesulfonic acid, etc.), among others, reactive From the viewpoints of chemical toxicity and availability, Ti (OBu) ₄ , Ti (O—Pr) ₄ , tin octylate, dibutyltin oxide, dibutyltin dilaurate, monobutyltin hydroxybutyl oxide, and methanesulfonic acid are preferred. The said catalyst may be used independently and may use 2 or more types together in the range which does not impair the effect of this invention. The amount of the catalyst used is preferably about 0.001 to 5% by mass, particularly preferably about 0.01 to 1% by mass, based on the entire reaction mixture. The reaction temperature is preferably 80 to 250 ° C, more preferably 90 to 230 ° C, and still more preferably 100 to 210 ° C. By setting it as the said range, since the synthesis | combination by a suitable reaction rate is attained and coloring of the polyester acrylate obtained becomes small, it is preferable. In order to prevent gelation due to radical polymerization during the reaction, it is preferable to add a known polymerization inhibitor. As the polymerization inhibitor, for example, hydroquinone, methoquinone, p-methoxyphenol, p-benzoquinone and the like can be preferably used, and preferably 0.001 to 3% by mass with respect to the entire reaction mixture, 0.01 to 1 More preferably, it is mass%.
The reaction ratio between the polyether polyol (a-1) and the (meth) acrylate (a-2) having an isocyanate group or the (meth) acrylate (a-3) having a carboxyl group is determined by the polyether polyol (a -1) with respect to 1 equivalent of a hydroxyl group, an isocyanate group having an isocyanate group (a-2) or an (meth) acrylate (a-3) having a carboxyl group This is preferably determined such that the carboxyl group contained is 0.40 to 1.05 equivalent, more preferably 0.60 to 1.05 equivalent, and even more preferably 0.80 to 1.05 equivalent. When the amount is less than 0.40 equivalent, the elongation rate of the cured product of the resulting resin composition is reduced and the impact resistance is inferior, and when it exceeds 1.05 equivalent, it remains (a-2) or ( Since a-3) tends to cause a decrease in heat resistance and light resistance, it is not preferable.
The proportion of the polyether polyol (a-1) in the polyether polymer is preferably 90% by mass or more, more preferably 93% by mass or more, particularly preferably 95% by mass or more, and most preferably 97% by mass or more. When the amount is less than 90% by mass, the heat resistance, light resistance, and moisture resistance tend to be inferior, and the resulting resin composition has a high viscosity and poor workability.
The viscosity of the polyether polymer at 25 ° C. is preferably 1000 to 10000 mPa · s, more preferably 1000 to 50000 mPa · s, and particularly preferably 1000 to 30000 mPa · s. When the viscosity at 25 ° C. exceeds 100000 mPa · s, the resulting resin composition tends to have a high viscosity and poor workability.
The number average molecular weight Mn of the polyether polymer is preferably 10,000 to 80,000, more preferably 10,000 to 50,000, and particularly preferably 10,000 to 30,000. If the number average molecular weight Mn is less than 10,000, the cured product of the resulting resin composition is hard (hardness is high), or the elongation percentage is small, and a tendency to be inferior in impact resistance is seen. When the molecular weight Mn exceeds 80000, the viscosity of the resulting resin composition becomes too high, which tends to be inferior in workability.
The molecular weight distribution (Mw / Mn) of the polyether polymer is preferably 1.5 or less, more preferably 1.4 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less. When the molecular weight distribution (Mw / Mn) is large, the viscosity of the resulting resin composition is high and the workability is poor, the cured product of the resulting resin composition is hard (hardness is high), or the elongation rate tends to be small. It can be seen.
[Conjugated diene polymer]
The conjugated diene polymer, which is one of the preferred forms of the compound (A), can be synthesized by various methods. For example, the conjugated diene prepolymer is first synthesized, and then the conjugated diene prepolymer is converted into two. After reacting the basic unsaturated acid anhydride, it is obtained by subsequently reacting a part or all of the acid anhydride group in the obtained prepolymer with a (meth) acrylate having a hydroxyl group. As another method for obtaining a conjugated diene polymer, a method in which a conjugated diene prepolymer having a hydroxyl group and a (meth) acrylate having a hydroxyl group are reacted via a diisocyanate compound such as a 2,4-tolylene diisocyanate compound. And a method of reacting a conjugated diene prepolymer having a carboxyl group with a (meth) acrylate having a glycidyl group, a method of reacting a conjugated diene prepolymer having a hydroxyl group and a (meth) acrylate having an acid halide group, etc. Is mentioned. Among them, a conjugated diene polymer is prepared by first synthesizing a conjugated diene prepolymer, then reacting the conjugated diene polymer with a dibasic unsaturated acid anhydride, and then continuing with acid anhydride in the obtained polymer. It is preferably obtained by reacting a part or all of the physical group with a (meth) acrylate having a hydroxyl group.
Examples of the conjugated diene compound constituting the conjugated diene prepolymer include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenylbutadiene, 2-phenylbutadiene, 1,1-diphenylbutadiene, 1 2,2-diphenylbutadiene, 2,3-diphenylbutadiene, and the like. The conjugated diene polymer may be composed of one kind of these conjugated diene compounds or may be composed of two or more kinds. As the conjugated diene prepolymer, polybutadiene, polyisoprene, or a copolymer of a mixture of isoprene and butadiene is particularly preferable.
Conjugated diene prepolymers are prepared by using the above conjugated diene compounds such as butadiene and isoprene as initiators such as sodium naphthalene complex, n-butyllithium, s-butyllithium, methyllithium, ethyllithium, and alkyllithium such as pentyllithium. It can also be produced by anionic polymerization, or by radical polymerization using an azobisnitrile compound such as azobisisobutyronitrile and a peroxide such as benzoyl peroxide as an initiator. These polymerization reactions are usually performed under the conditions of a polymerization temperature of −80 ° C. to 150 ° C. and a polymerization time of 1 to 100 hours in the presence of an aliphatic or aromatic hydrocarbon solvent such as hexane, heptane, toluene, and xylene. Can be done.
Next, an acid anhydride group is introduced by reacting the conjugated diene prepolymer obtained by the above-described method with a dibasic unsaturated acid anhydride. In this reaction, for example, a conjugated diene-based prepolymer and a dibasic unsaturated acid anhydride are present in the presence of a solvent inert to a reaction such as an aliphatic or aromatic hydrocarbon solvent such as hexane, heptane, toluene, or xylene. Under stirring or in the absence, it can usually be carried out with stirring in the range of room temperature to 200 ° C. for 1 to 100 hours.

As the dibasic unsaturated acid anhydride, for example, maleic anhydride can be used. The amount of the dibasic unsaturated acid anhydride used is such that the final conjugated diene-based prepolymer can have two or more (meth) acrylate groups as an average per molecule. The upper limit is not particularly limited as long as the group can be introduced into the conjugated diene prepolymer, but usually 0.1 to 100 mass relative to 100 mass parts (parts by weight) of the conjugated diene prepolymer. Is preferably in the range of 0.5 to 50 parts by mass. The amount of the acid anhydride group introduced into the conjugated diene prepolymer is preferably controlled in the range of usually 2 to 20 as an average per molecule by reacting under the above conditions. It is more preferable to control within the range of -10. The amount of the acid anhydride group introduced into the conjugated diene prepolymer by the above reaction can be quantified by an analytical means such as NMR or neutralization titration.
Furthermore, a conjugated diene polymer can be obtained by reacting part or all of the acid anhydride groups introduced into the conjugated diene prepolymer with a (meth) acrylate having a hydroxyl group. This reaction is usually performed at room temperature to 200 ° C. for 1 to 100 hours in the presence or absence of an inert solvent such as aliphatic or aromatic hydrocarbon solvents such as hexane, heptane, toluene and xylene. This can be done by stirring.
Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, pentaerythritol tri (meth) acrylate, Examples include dipentaerythritol monohydroxy (meth) acrylate. Among these, from the viewpoints of price and availability, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate are preferable.
The amount of (meth) acrylate having a hydroxyl group should be such that the number of (meth) acrylate groups in the conjugated diene-based prepolymer has two or more per molecule, preferably 2 to 10, more preferably From the viewpoint of preferably 2-5, it is usually preferable that the conjugated diene polymer is in the range of 0.01 to 1.5 mole times the acid anhydride group as an average per molecule. The range of 0.1 to 1 mol times is more preferable.
When the conjugated diene polymer has less than 2 acrylate groups as an average per molecule, the resulting UV curable resin composition has insufficient curability, whereas when it exceeds 10, the resulting resin composition There is a tendency that the elongation percentage of the cured product becomes small and the shock absorption is inferior.
The number average molecular weight Mn of the conjugated diene polymer is preferably in the range of 10,000 to 50,000, more preferably in the range of 10,000 to 30,000, and more preferably in the range of 10,000 to 25,000. When the number average molecular weight is less than 10,000, the elongation percentage of the cured product of the resin composition to be obtained tends to be small and the impact resistance is inferior. On the other hand, if the number average molecular weight exceeds 50,000, the viscosity of the resulting conjugated diene polymer is increased, and the workability tends to be lowered.
The molecular weight distribution (Mw / Mn) of the conjugated diene polymer is preferably 1.5 or less, more preferably 1.45 or less, and particularly preferably 1.35 or less. When the molecular weight distribution (Mw / Mn) is large, the viscosity of the resulting resin composition is high and the workability is poor, the cured product of the resulting resin composition is hard (hardness is high), or the elongation rate tends to be small. It can be seen.
The viscosity at 25 ° C. of the conjugated diene polymer is preferably 10,000 to 500,000 mPa · s, more preferably 10,000 to 400,000 mPa · s, and particularly preferably 10,000 to 350,000 mPa · s. When the viscosity at 25 ° C. exceeds 500,000 mPa · s, the resulting resin composition tends to have high viscosity and poor workability.
[Poly (meth) acrylate polymer]
A poly (meth) acrylate polymer which is one of the preferred forms of the compound (A) is reacted with a poly (meth) acrylate prepolymer having a reactive functional group obtained by living anionic polymerization. It can be obtained by reacting a (meth) acrylate having a functional group.
As the living anionic polymerization method in the poly (meth) acrylate-based prepolymer having a reactive functional group, a known method can be used. For example, molecular weight distribution is achieved by conducting anionic polymerization of a known methacrylate using tert-butyl lithium at −78 ° C. in toluene in the presence of an organoaluminum compound such as trialkylaluminum and dialkyl (diphenylamino) aluminum. A narrow polymethacrylate polymer (Japanese Patent Publication No. 7-57766), known anionic polymerization of methacrylate using an organic lithium compound such as tert-butyllithium in a hydrocarbon solvent, one or more bulky In the presence of specific organoaluminum compounds having various groups (eg, triisobutylaluminum, diisobutyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum, etc.) (Japanese Patent Laid-Open No. 5-5009) , Using tert-butyllithium A method in which anionic polymerization of a known methacrylate or acrylate is carried out in toluene in the presence of methylbis (2,6-di-tert-butylphenoxy) aluminum or ethylbis (2,6-di-tert-butylphenoxy) aluminum (high Proceedings of Molecular Society (Polymer Preprints, Japan), 46, 7, 1081-1082 (1997) and 47, 2, 179 (1998)), α-Lithioiso Anionic polymerization of a known methacrylate or acrylate using an organolithium compound such as ethyl butyrate or tert-butyllithium is conducted in a hydrocarbon solvent such as toluene, an organoaluminum compound such as trialkylaluminum and an ester compound, an ether compound or an organic compound. Method carried out in the presence of a quaternary salt (Macromolecules, Vol. 31, pages 573-577 (1 1998) and international application WO 98/23651), a method of anionic polymerization in the presence of a specific polymerization initiator compound and a specific organoaluminum compound (Japanese Patent Laid-Open No. 2002-88109). It is done.
Examples of the reactive functional group contained in the poly (meth) acrylate prepolymer having a reactive functional group include a carboxyl group, an amino group, a cyano group, a hydroxyl group, an amide group, and a glycidyl group.
When the poly (meth) acrylate-based polymer has less than two (meth) acrylate groups as an average per molecule, the curability of the resulting ultraviolet curable resin composition becomes insufficient, whereas when it exceeds ten, The elongation percentage of the cured product of the resulting resin composition becomes small, and a tendency to be inferior in impact resistance is seen.
The number average molecular weight Mn of the poly (meth) acrylate polymer is preferably in the range of 10,000 to 50,000, more preferably in the range of 10,000 to 40,000, and more preferably in the range of 10,000 to 25,000. When the number average molecular weight is less than 10,000, the elongation percentage of the cured product of the resin composition to be obtained tends to be small and the impact resistance is inferior. On the other hand, if the number average molecular weight exceeds 50,000, the resulting poly (meth) acrylate polymer will have a high viscosity, and workability will tend to be reduced, which is not preferable.
[(B) Photopolymerization initiator]
Although the resin composition of this invention contains (B) photoinitiator as an essential component, there exists an effect that it can be hardened rapidly by light irradiation by containing a photoinitiator.

(B) Examples of the photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2- Hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- ( 4-morpholinophenyl) butanone, oligo {2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone}, 2-hydroxy-1- {4- [4- (2-hydroxy- Acetophenones such as 2-methylpionyl) benzyl] phenyl} -2-methylpropan-1-one; Benzoins such as in, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3, 3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyl) Benzophenones such as (oxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthate Thioxanthones such as 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4-dimethyl-9H-thioxanthone-9-one mesochloride, Oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] ethyl ester, oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] ethyl ester, bis (2,4,4 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the like. Among them, acetophenones, oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] ethyl ester, oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] ethyl ester, 2 , 4,6-Trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide are preferred.
As content of (B) photoinitiator in a resin composition, it is suitable that it is 0.1-10 mass% with respect to 100 mass% of resin compositions. When the content is 0.1% by mass or more, the resin composition can be sufficiently cured, and when the content is 10% by mass or less, generation of odor and coloring of the cured product can be sufficiently suppressed. More preferably, it is 0.3-5 mass%, More preferably, it is 0.5-3 mass%.
[(C) Plasticizer]
The optical ultraviolet resin curable resin composition of the present invention may contain (C) a plasticizer as necessary. (C) A plasticizer refers to a compound having no radical polymerizability, specifically a compound having no (meth) acrylate group, such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate. , Diisononyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, etc .; di-n-butyl adipate, diisobutyl adipate, dibutoxyethyl adipate, di-n -Adipates such as octyl adipate, diisooctyl adipate, diisononyl adipate, bis-2-ethylhexyl adipate, diisodecyl adipate; dibutyl sebacate, geo Sebacic acid esters such as tilsebacate and di-2-ethylhexyl sebacate; azelaic acid esters such as dihexyl azelate and dioctyl azelate; citric acids such as triethyl citrate, acetyl triethyl citrate and tri-n-butyl citrate Esters; glycolic acid esters such as methylphthalyl ethyl glycolate and ethyl phthalyl ethyl glycolate; trioctyl trimellitate, tri-n-octyl-n-decyl trimellitate, trialkyl trimellitic acid (C4- Trimellitic acid esters such as C11); ricinoleic acid esters such as methyl acetyl ricinoleate, butyl acetyl ricinolate and glycerin monoricinoleate; maleic acid esters such as di-n-butyl malate; monobutyl itacone Itaconic acid esters such as butyl oleate; Phosphoric acid esters such as tricresyl phosphate, trioctyl phosphate, triphenyl phosphate, and trixylenyl phosphate; and esters such as benzoic acid esters In addition, the above-mentioned polyether polyols (a-1) such as polyethylene glycol, polypropylene glycol, ethylene oxide and propylene oxide copolymer; trade name “Adeka Carpol” manufactured by Adeka Company, product name “New” manufactured by Sanyo Kasei Co., Ltd. Polyether monools such as “Paul”, etc .; 50HB series mainly composed of propylene oxide and ethylene oxide, polyolefin resins such as polyethylene, polypropylene, polystyrene, etc .; polymethyl methacrylate, polyacryl (Meth) acrylic polymers having no polymerizable functional group or double bond in the side chain such as acid; polyester resins such as polyethylene terephthalate; polyamide resins such as nylon 6 and 6, polyisoprene, polybutadiene, polybutene, etc. A rubber-based polymer; thermoplastic elastomer, terpene resin, terpene phenol resin, modified terpene resin, hydrogenated terpene resin, rosin ester resin, and the like can be used.

  The (C) plasticizer is appropriately selected according to the compatibility with the compound (A), the viscosity of the composition, etc. Among them, the polyether polyol (a-1) and the polyether monool are particularly preferable. A rosin ester resin is preferred. When these compounds are used as plasticizers, they can be preferably used from the viewpoint that flexibility and adhesion can be improved without deteriorating optical properties and transparency durability of the cured product.

  The above (C) plasticizer preferably has a color tone (Hazen) of 200 or less, more preferably 150 or less, and still more preferably so as not to affect the optical properties (particularly light transmittance) of the cured product. It is preferable to select one of 100 or less, most preferably 50 or less.

The (C) plasticizer is preferably blended in a proportion of 0 to 80% by mass of the entire resin composition excluding the photopolymerization initiator, more preferably 10 to 70% by mass, and even more preferably 20 to 60% by mass. %, Most preferably 30 to 60% by mass. By increasing the blending ratio of the (C) plasticizer in the resin composition, it is possible to reduce the curing shrinkage rate of the resulting resin composition, and it is possible to suppress a decrease in image forming performance of the display device. Moreover, the softness | flexibility of hardened | cured material can also be improved and shock-absorbing property also improves. On the other hand, when the blending amount of the plasticizer (C) exceeds 80% by mass, the plasticizer tends to be exuded on the surface of the cured product, and adheres to adherends such as display panels and protective plates. This is not preferable because it causes a decrease in performance.
[Other polymerizable components]
In the present invention, in addition to the above-described essential components (A) and (B) and the optional component (C), if necessary, a component that can be co-cured with the essential component (A) (other polymerizable components) ) May contain one or more of the following (meth) acrylate compounds and unsaturated compounds.
Although it does not specifically limit as a (meth) acrylate type compound, Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t- Butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, unde (Meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, isomyristyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl Alkyl (meth) acrylates such as (meth) acrylate, nonadecyl (meth) acrylate, eicodecyl (meth) acrylate, n-lauryl (meth) acrylate, isobornyl (meth) acrylate, (meth) acryloylmorpholine, cyclohexyl (meth) Acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, pheny (Meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) Acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, neopentyl glycol mono (Meth) acrylate, the above hydroxyl group-containing (meth) acrylic acid ester compound added with cyclic ester compound such as ε-caprolactone, alkyl glycidyl ether, allyl glycidyl ether, Compounds obtained by addition reaction of glycidyl group-containing compounds such as gil (meth) acrylate and (meth) acrylic acid, tricyclodecane dimethanol di (meth) acrylate, 1,6 hexanediol di (meth) acrylate, bisphenol A Bifunctional (meth) acrylates such as those reacted with (meth) acrylic acid; trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Trifunctional or higher functional (meth) acrylates such as acrylate and dipentaerythritol hexa (meth) acrylate, and various (meth) modified by adding ethylene oxide and / or propylene oxide to the above (meth) acrylate Chlorates, methoxy-polyethylene glycol (meth) acrylate, ethoxy-polyethylene glycol (meth) acrylate, butoxy-polyethylene glycol (meth) acrylate, phenoxy-diethylene glycol (meth) acrylate, phenoxy-triethylene glycol (meth) acrylate, etc. (Meth) acrylate, methoxy-polypropylene glycol (meth) acrylate, ethoxy-polypropylene glycol (meth) acrylate, butoxy-polypropylene glycol (meth) acrylate, phenoxy-dipropylene with terminally alkylated ethylene glycol or polymer thereof One end of glycol (meth) acrylate, phenoxy-tripropylene glycol (meth) acrylate, etc. Amino group-containing (meth) acrylate such as (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like with alkylated propylene glycol or a polymer thereof, (meth) acrylic acid, 2-acrylic acid Carboxyl group-containing (meth) acrylate such as leuoxyethyl succinic acid, compound obtained by reaction of polyether polyol such as polypropylene glycol and (meth) acrylate (a-2) having isocyanate group, urethane (meth) acrylate And reactive oligomers having (meth) acrylate such as epoxy resin, polyester (meth) acrylate resin, and epoxy (meth) acrylate resin.

  The unsaturated compound is not particularly limited, but styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; vinyl esters such as vinyl acetate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether. Allyl compounds such as allyl alcohol, allyl glycidyl ether, ethylene glycol monoallyl ether and propylene glycol monoallyl ether; N-substituted maleimides such as N-phenylmaleimide, N-cyclohexylmaleimide and N-isopropylmaleimide; N- N-vinyl compounds such as vinylpyrrolidone, N-vinylcaprolactam, N-vinyl-N-methylformamide, N-vinylimidazole, N-vinylacetamide, 2- (vinyl) (meth) acrylate Siethyl, 3-vinyloxyethyl (meth) acrylate, 2-vinyloxypropyl (meth) acrylate, 1-methyl-2-vinyloxyethyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, (meth) acrylic acid 6 -Vinyloxyhexyl, (meth) acrylic acid 4-vinyloxycyclohexyl, (meth) acrylic acid 4-vinyloxymethylcyclohexylmethyl, (meth) acrylic acid 2- (2-vinyloxyethoxy) ethyl, (meth) acrylic acid 2- (2-vinyloxyisopropoxy) propyl, 2- (2- (2-vinyloxyethoxy) ethoxy) ethyl (meth) acrylate, diallyl isophthaldiphenate, diallyl phthalate diallyl, triallyl cyanurate, triallyl isocyanurate Allyl ester monomers such as tri Vinyl ether monomers such as tylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, hydroxybutyl vinyl ether, dodecyl vinyl ether; trimethylolpropane diallyl ether, pentaerythritol triallyl ether, allyl glycidyl ether, allyl ether of methylol melamine, adipine of glycerin diallyl ether Allyl ether monomers such as allyl ethers of acid esters, allyl acetals, methylol glyoxalureins; Maleate ester monomers such as diethyl maleate and dibutyl maleate; Fumarate monomers such as dibutyl fumarate and dioctyl fumarate Is mentioned.

The content of other polymerizable components is preferably blended at a rate of 0 to 50% by mass of the entire resin composition, more preferably 3 to 50% by mass, still more preferably 5 to 40% by mass, and most preferably 5 to 35% by mass. By using a (meth) acrylate compound and / or a vinyl compound, the viscosity and workability of the resulting resin composition can be adjusted. Furthermore, physical properties such as heat resistance, light resistance, and transparency can be adjusted. On the other hand, if the use ratio exceeds 50% by mass, the curing shrinkage rate increases, which is not preferable.
[Other ingredients]
Furthermore, the ultraviolet curable resin composition of the present invention includes a thermosetting catalyst, an ultraviolet absorber, a polymerization inhibitor, a leveling agent, a thickener, a thickener, and a thixotropy imparting agent as long as the effects of the present invention are not impaired. Further, a defoaming agent or the like may be included.

  Specific examples of the thermosetting catalyst include benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy octoate, t- Organic peroxides such as butyl peroxybenzoate, cumene hydroperoxide, cyclohexanone peroxide, dicumyl peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate; azobisisobutyronitrile, 2-phenylazo- Examples include azo compounds such as 2,4-dimethyl-4-methoxyvaleronitrile, but are not particularly limited. These thermosetting catalysts may be used alone or in combination of two or more. The addition amount of the curing catalyst with respect to the monomer component is not particularly limited.

A commercially available ultraviolet absorber may be used. For example, salicylic acid esters such as benzotriazoles, benzoates, cyanoacrylates, benzophenones, phenyl salicylate, pt-butylphenyl salicylate, p-octylphenyl salicylate; TINUVIN PS99-2, 109 382-2, 400, 405, 460, 477 DW, 470, 900, 928, 1130, 5236 (above, product name of BASF), Adeka Stub LA-52, 57, 62 (above, product name of Asahi Denka Co., Ltd.) ), And a reactive ultraviolet absorber having (meth) acrylate such as 2- [3- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] ethyl methacrylate. It is preferable that the usage-amount of a ultraviolet absorber shall be 0.05-10 mass% in a resin composition, More preferably, it is 0.1-8 mass%, Most preferably, it is 0.2-5 mass%.
The other components as described above are preferably 0 to 30% by mass in the resin composition, more preferably 0 to 20% by mass, and particularly preferably 0 to 10% by mass.

(Preparation of resin composition)
The resin composition of the present invention can be prepared by mixing the above components and is usually in the form of a viscous liquid. Specifically, the viscosity is 200 to 10000 mPa · s, preferably 200 to 8000 mPa · s, more preferably 300 to 6000 mPa · s, particularly preferably 500 to 8000 mPa · s, and most preferably 500 to 6000 mPa · s. When the viscosity is too high, handling properties such as workability are lowered. The viscosity of the resin composition can be calculated using a B-type viscometer (model “RB80L” manufactured by Toki Sangyo Co., Ltd.) under a temperature of 25 ° C.

  The resin composition of the present invention is preferably solventless. This is because the diluting solvent needs to be volatilized after injection, and the residual solvent can cause a decrease in the photopolymerization speed, and can cause a decrease in the optical properties and durability of the resulting cured product.

  Therefore, when the resin composition is obtained in a state containing a solvent, it is preferable to remove the solvent by reduced pressure, distillation or the like.

<Hardened product>
The resin composition of the present invention having the above composition can be cured by ultraviolet irradiation. The term “curing” as used herein means a state having no fluidity, but is preferably in the form of a sheet or film.
The wavelength of the ultraviolet rays used may be in the range of 150 to 450 nm. Examples of the light source that emits such a wavelength include sunlight, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a gallium lamp, a xenon lamp, a flash type xenon lamp, and a carbon arc lamp. The irradiation integrated light amount is preferably in the range of 0.5 to ¹⁰ J / cm ² , more preferably 1 to 8 J / cm ² , and still more preferably ^{2 to} 7 J / cm ² .

  The cured product of the present invention may be obtained by using both curing by light irradiation and curing by heating. In this case, infrared light, far infrared light, hot air, high-frequency heating, or the like may be used together with the light source described above. The heating temperature may be appropriately adjusted according to the decomposition temperature of the thermosetting catalyst, the type of base material used, and the like, and is not particularly limited, but is preferably 50 to 150 ° C, more preferably 50 to 100 ° C. More preferably, it exists in the range of 60-90 degreeC. The heating time may be appropriately adjusted according to the decomposition temperature or coating thickness of the thermosetting catalyst, and is not particularly limited, but is preferably 1 minute to 12 hours, more preferably 10 minutes to 6 hours, Preferably, it is within the range of 10 minutes to 3 hours.

  The cured product of the present invention may be obtained by using both curing by light irradiation and curing by electron beam irradiation. In this case, the acceleration voltage is preferably 0 to 500 kV, more preferably 20 to 300 kV, and even more preferably 30 to 200 kV. The irradiation amount is preferably in the range of 2 to 500 kGy, more preferably 3 to 300 kGy, and still more preferably 4 to 200 kGy.

  The cured product of the present invention has a cure shrinkage of 5% or less, more preferably 4% or less, further preferably 3% or less, and most preferably 2% or less. By setting the curing shrinkage rate to 5% or less, warping of the optical laminate can be prevented. In addition, the value obtained by the specific gravity measurement described in the below-mentioned Example is employ | adopted for hardening shrinkage.

  The cured product of the present invention has a C hardness of 60 or less, more preferably 50 or less, further preferably 40 or less, and most preferably 30 or less. When the C hardness is 60 or less, the impact resistance is improved. For the C hardness, a value obtained using an ASKER durometer C-type hardness meter based on JIS K7312 in an atmosphere of 25 ° C. is adopted.

  The cured product of the present invention preferably has an elongation of 100% or more, more preferably 150% or more, still more preferably 200% or more, and most preferably 250% or more. By setting the elongation rate to 100% or more, the impact resistance is improved. In addition, the value obtained by the tensile test on the conditions described in the below-mentioned Example is employ | adopted for elongation rate.

The cured product of the present invention preferably has a light transmittance of 400 nm at a thickness of 0.3 mm of 89% or more, more preferably 90% or more, and still more preferably 91% or more. By setting the light transmittance to 89% or more, it is possible to prevent the transparency of the optical laminate from being lowered. The light transmittance at 400 nm is a value measured using a spectrophotometer.
The cured product of the present invention preferably has a turbidity at a thickness of 0.3 mm of 0.5% or less, more preferably 0.4 or less, and still more preferably 0.3. By setting the turbidity to 0.5 or less, it is possible to prevent a decrease in transparency of the optical laminate. In addition, the value measured based on JISK7136 is employ | adopted for turbidity.
<Optical laminate>
The ultraviolet curable resin composition for an optical laminate of the present invention from which the cured product as described above is obtained is a flat panel display such as a building, an automobile, an agricultural greenhouse, a liquid crystal display or an organic EL display, a mobile phone, a smartphone, Glass and transparent plastic used for tablet information terminals, solar cells, lithium-ion batteries, digital signage, touch panels, glass substrates for devices such as electronic paper, and cover glasses and pharmaceutical packages for devices such as organic EL lighting Can be used for bonding. That is, the optical layered body of the present invention only needs to contain at least a glass having a thickness of 300 μm or less and a transparent plastic thicker than the glass. For example, a glass having a thickness of 300 μm or less and a transparent plastic thicker than the glass Further, one or more functional layers may be provided between the two.
As the glass having a thickness of 300 μm or less, silicate glass is used, preferably silica glass, borosilicate glass, soda lime glass, and aluminosilicate glass, and most preferably non-alkali glass. Glass is generally excellent in light resistance, but when an alkali component is contained in the glass, if the glass is continuously used in a situation where it has been exposed to the external environment for a long period of time, cations drop off on the surface, A so-called soda blowing phenomenon may occur, resulting in a rough structure, and the translucency of the glass may be deteriorated. Here, the alkali-free glass is a glass that does not substantially contain an alkali component (alkali metal oxide), and specifically, a glass having a weight ratio of the alkali component of 1000 ppm or less. It is. The weight ratio of the alkali component of the glass used in the present invention is preferably 500 ppm or less, more preferably 300 ppm or less.

As the glass, the same kind of glass material may be used, or different kinds of glass materials may be used. For example, when using it for architectural windows, use non-alkali glass with excellent light resistance for the glass exposed to the outside environment, and use soda lime glass for the glass on the inside environment such as indoors. You can also
The glass thickness is 300 μm or less, and the thickness of the transparent plastic is larger than the thickness of the glass. Thereby, since the ratio which glass accounts in an optical laminated body reduces, the weight reduction of an optical laminated body can be achieved. The thickness of the glass is preferably 20 μm to 200 μm, and most preferably 50 μm to 100 μm. Thereby, the thickness of glass can be made thinner and the optical laminated body can be reduced in weight more efficiently. When the thickness of the glass is less than 20 μm, the strength of the glass tends to be insufficient, and when a flying object hits the optical laminate, the glass is easily damaged. Further, the glass may have the same thickness or different thicknesses.

The density of the glass is preferably low. Thereby, weight reduction of an optical laminated body can be achieved. Specifically, the density of the glass is preferably 2.6 g / cm ³ or less, and more preferably 2.5 g / cm ³ or less.

  The higher Young's modulus of the glass is preferable. Thereby, even if the thickness of the glass is reduced to 300 μm or less, it becomes difficult to bend due to its own weight. The Young's modulus of the glass is preferably 50 GPa or more, more preferably 60 GPa or more, and most preferably 70 GPa or more.

The glass has a higher Vickers hardness. Thereby, an optical laminated body with higher scratch resistance can be obtained. The Vickers hardness of the glass is preferably 400 or more, more preferably 500 or more, and most preferably 550 or more.
The transparent plastic is not particularly limited as long as it is a transparent plastic. For example, polyethylene, polyvinyl chloride, polyethylene terephthalate, polyvinylidene chloride, polypropylene, polyvinyl alcohol, polyester, polystyrene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene -Vinyl alcohol copolymer, ethylene-methacrylic acid copolymer, polymethyl methacrylate, polycarbonate and the like can be used. In particular, polymethyl methacrylate and polycarbonate are preferably used because of excellent transparency and impact resistance.

The thickness of the transparent plastic can be appropriately set and selected from the thickness of the glass to be used, the target thickness of the optical laminate, etc., but is preferably equal to or greater than the thickness of the glass. It is more preferable that it is not less than 100 times and not more than 100 times. Thereby, since the ratio for which a transparent plastic accounts in an optical laminated body increases, the whole weight can further be reduced. When the thickness of the glass is different, it is preferably at least 3 times the thickness of the thickest glass. Furthermore, the thickness of the transparent plastic is more preferably 10 times or more of the glass thickness, further preferably 15 times or more, and most preferably 20 times or more. The upper limit is more preferably 100 times or less, still more preferably 80 times or less, and most preferably 50 times or less.
The method for bonding the glass and the transparent plastic is not particularly limited, and a known method can be appropriately selected and used. For example, the ultraviolet curable resin composition for optical laminates of the present invention may be applied to glass, covered with a transparent plastic, and then irradiated with ultraviolet rays. The resin composition may be preliminarily formed into a sheet shape, bonded to glass or transparent plastic, and then bonded to one member.
The optical layered body of the present invention includes at least a three-layer structure composed of glass / transparent adhesive layer (cured product of resin composition) / transparent plastic. More preferably, it is a five-layer structure composed of glass / transparent adhesive layer / transparent plastic / transparent adhesive layer / glass. Since glass is not laminated in the middle by this structure, the amount of high-density glass used can be minimized, and the overall weight can be more effectively reduced. Glass and transparent plastic may be alternately laminated via a transparent adhesive layer, but are not limited to this form.
The thickness of the transparent adhesive layer (cured product of the resin composition) in the optical layered body of the present invention can be appropriately set depending on the desired heat cycle resistance and impact resistance absorption, but is preferably 50 μm or more, and preferably 100 μm or more. More preferably, 150 μm or more is further preferable, 200 μm or more is most preferable, 2000 μm or less is preferable, 1000 μm or less is more preferable, 700 μm or less is further preferable, and 500 μm or less is most preferable.

  As described above, the optical laminate in which the cured product of the ultraviolet curable resin composition for an optical laminate of the present invention is interposed is based on the characteristics of the resin composition of the present invention, and has, for example, excellent shock absorption. Furthermore, since excellent transparency can be maintained against environmental changes such as high temperature, high humidity, and light, it has high durability.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to description of a following example.

  In the examples, “part” means a weight basis unless otherwise specified.

〔Evaluation method〕
(1) Composition viscosity The resin composition was measured using a B-type viscometer (model “RB80L”, manufactured by Toki Sangyo Co., Ltd.) under the condition of a temperature of 25 ° C.

(2) Curing shrinkage (%)
The specific gravity of the resin composition and the specific gravity of the cured product obtained by curing the resin composition at 25 ° C. were measured and obtained from the following calculation.

Curing shrinkage (%) = (cured product specific gravity−resin composition specific gravity) / cured product specific gravity × 100
(3) Hardness value Based on JIS K7312, the hardness of a sheet-like test piece (width 17 mm × length 45 mm × thickness 4 mm) obtained by curing the resin composition using an ASKER durometer C-type hardness meter Was measured. The value after 15 seconds from the start of measurement was taken as the hardness value.

(4) Growth rate (%)
Using a sheet-like test piece (width 4 mm × length 20 mm × thickness 1 mm) obtained by curing the resin composition, a tensile test is performed at an atmospheric temperature of 25 ° C. and a tensile speed of 0.1 mm / s. The elongation was calculated according to the following formula. In the formula, L is the displacement length until breakage, and L ₀ is the length of the sheet before the test.

Elongation rate (%) = L / L ₀ × 100
(5) Light transmittance (%)
Using a sheet-like test piece (width 50 mm × length 50 mm × thickness 0.3 mm) obtained by curing the resin composition, the light transmittance at 400 nm was measured using a spectrophotometer (form “UV-3100”, (Manufactured by Shimadzu Corporation).

(6) Turbidity (%)
It measured based on JISK7136 using the sheet-like test piece (width 50mm x length 50mm x thickness 0.3mm) obtained by hardening | curing a resin composition.
(7) Heat resistance A test piece (width 50 mm × length 70 mm × thickness 1 mm) sandwiched between glass plates obtained by curing the resin composition was heated in an oven at 100 ° C. for 500 hours. The discoloration after heating was visually confirmed and evaluated in the following three stages. A glass plate having a thickness of 3 mm was used.

○: No discoloration is observed Δ: Slight discoloration ×: Large discoloration (8) Light resistance Test piece sandwiched between glass plates obtained by curing the resin composition (width 50 mm × length 70 mm × 1 mm thick) was irradiated with light at 500 MJ / m ² using a metering weather meter (model “M6T”, manufactured by Suga Test Instruments Co., Ltd., irradiation intensity 0.5 kW / m ² ). The discoloration after irradiation was visually confirmed and evaluated in the following three stages. A glass plate having a thickness of 3 mm was used.
○: No discoloration was observed Δ: Slight discoloration ×: Large discoloration (9) Moisture resistance A sheet-shaped test piece (width 50 mm × length 70 mm × thickness 1 mm) obtained by curing the resin composition After maintaining for 100 hours in a thermo-hygrostat (temperature 80 ° C., humidity 90% RH), the turbidity of the sheet was visually confirmed and evaluated in the following three stages.

○: No turbidity Δ: Slightly turbid ×: Turbidity (10) Resistance to heat shock The optical laminate comprising the obtained glass plate / cured product of the composition / polymethylmethacrylate plate was −40 ° C. for 30 minutes, A heat shock test is performed with 5 levels of evaluation at 100, 200, 400, 500, and 5 cycles, with 30 minutes at 60 ° C., and / or a polymethylmethacrylate plate and / or an interface between the glass plate and the cured product. The presence or absence of peeling at the interface of the cured product of the composition was confirmed and evaluated according to the following criteria.

S: No peeling at 500 cycles A: Hagging occurred at 500 cycles B: Hagging occurred at 400 cycles C: Hagging occurred at 200 cycles D: 100 cycles (11) Impact absorption at the time When a 100 g steel ball was dropped from the glass plate side onto the optical laminate composed of the obtained glass plate / cured product of the composition / polymethylmethacrylate plate The height at which the glass plate was damaged was determined and evaluated in the following four stages.

○: 300 mm or more Δ: 200 mm or more and less than 300 mm ×: less than 200 mm Production Example 1 (synthesis of PPG-N-1)
In a reactor equipped with a thermometer, a cooler, a gas introduction pipe, and a stirrer, the number average molecular weight Mn is 11000 (molecular weight distribution (Mw / Mn) = 1.08) as the polyether polyol (a-1). 300 g of polypropylene glycol (manufactured by Asahi Glass Co., Ltd., product number: Preminol S4011), 0.15 g of methoquinone and 0.15 g of dibutyltin dilaurate were charged, and the mixture was heated to 70 ° C. while stirring. Next, as an acrylate (a-2) having an isocyanate group, 7.7 g of 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK, product number Karenz AOI) (1.0 equivalent to the hydroxyl group in the polyether polyol) Was added dropwise over 2 hours. After completion of the dropping, the temperature was maintained at 80 ° C. for 3 hours to complete the reaction, and a polyether polymer (referred to as “PPG-N-1”) having an average of two acrylate groups in the molecule was obtained. The isocyanate reaction rate determined by infrared spectroscopy was 98%. Moreover, the viscosity in 25 degreeC was 4900 mPa * s. Further, by GPC measurement, the number average molecular weight (Mn) was 11300, and the molecular weight distribution (Mw / Mn) was 1.08.
Production Example 2 (Synthesis of PPG-N-2)
Polyether glycol (a-1) having a number average molecular weight Mn of 15000 (molecular weight distribution (Mw / Mn) = 1.09), 300 g of polypropylene glycol (product number: Preminol S4015, manufactured by Asahi Glass Co., Ltd.), 2-acryloyloxyethyl isocyanate Except for using 5.3 g of Naruto (manufactured by Showa Denko KK, product number Karenz AOI) (1.0 equivalent to the hydroxyl group in the polyether polyol), an average of 2 acrylates in the molecule in the same manner as in Production Example 1. A polyether-based polymer having a group (referred to as “PPG-N-2”) was obtained. The isocyanate reaction rate determined by infrared spectroscopy was 99%. Moreover, the viscosity in 25 degreeC was 9900 mPa * s. Further, by GPC measurement, the number average molecular weight (Mn) was 15300, and the molecular weight distribution (Mw / Mn) was 1.09.
Production Example 3 (Synthesis of PPG-A-1)
In a reactor equipped with a thermometer, a cooler, a gas introduction pipe, and a stirrer, the number average molecular weight Mn is 15000 (molecular weight distribution (Mw / Mn) = 1.09) as the polyether polyol (a-1). 300 g of polypropylene glycol (manufactured by Asahi Glass Co., Ltd., product number: Preminol S4015), 0.15 g of methoquinone, 0.5 g of paratoluenesulfonic acid, 12.3 g of acrylic acid (1.0 equivalent to the hydroxyl group in the polyether polyol), The mixture was heated to 150 ° C. while stirring. Next, when the acid value became 0.5 KOH mg / g or less, the reaction was terminated, and a polyether polymer (referred to as “PPG-A-1”) having an average of two acrylate groups in the molecule was obtained. It was. Moreover, the viscosity in 25 degreeC was 9100 mPa * s. Further, by GPC measurement, the number average molecular weight (Mn) was 15200, and the molecular weight distribution (Mw / Mn) was 1.09.
Production Example 4 (Synthesis of IP-A)
Prepare a reactor equipped with a thermometer, cooler, gas inlet tube, and stirrer, charge isoprene monomer in n-hexane, charge initiator n-butyllithium, anion at reaction temperature -50 ° C By polymerization, a conjugated diene prepolymer having a number average molecular weight Mn of 30,500 was obtained. By adding 1.5 parts by mass of maleic anhydride to 100 parts by mass of this conjugated diene-based prepolymer and reacting at 180 ° C. for 15 hours, a conjugated diene-based prepolymer having three acid anhydride groups as an average per molecule. Got. Next, 7.5 parts by mass of 2-hydroxyethyl acrylate is added to 100 parts by mass of this conjugated diene prepolymer and reacted at 120 ° C. for 10 hours to have 3 acrylate groups as an average per molecule. A conjugated diene polymer (referred to as “IP-A”) was synthesized. The viscosity of the conjugated diene polymer at 25 ° C. was 290000 mPa · s. Furthermore, by GPC measurement, the number average molecular weight (Mn) was 31000, and the molecular weight distribution (Mw / Mn) was 1.34.
Production Example 5 (Synthesis of A-1)
2.0 g of 1,1-diphenylethylene was added to a 500 ml Schlenk tube containing a magnetic stirrer, and the internal atmosphere was replaced with nitrogen. To this, 190 ml of toluene and 7.7 ml of a cyclohexane solution of sec-butyllithium having a concentration of 1.3M were added, and the mixture was reacted at room temperature for 2 days with stirring, and 1,1-diphenyl-3-methylpentyl having a concentration of 0.05M. A toluene solution of lithium (DPMPLi) was obtained. Next, 3 ml of a toluene solution containing 0.20 mmol of diisobutyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum, 30.0 g of methyl methacrylate and 0.5 g of 2-hydroxypropyl methacrylate were added in a nitrogen atmosphere. A mixture of both was prepared by stirring for 10 minutes at room temperature. Next, a magnetic stirrer was placed in a 200 ml Schlenk tube with a three-way cock, and the atmosphere in the container was replaced with nitrogen. To this, 20 ml of toluene and 4 ml of a toluene solution of DPMPLi (DPMPLi content: 0.20 mmol) were added and cooled to −25 ° C. Subsequently, a mixture of diisobutyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum, methyl methacrylate, and 2-hydroxypropyl metallate was added, and polymerization was performed at −25 ° C. with stirring for 1 hour. A part of the obtained reaction mixture was sampled and analyzed by GC (gas chromatography). As a result, it was found that the polymerization rate of methacrylate was 100%. The obtained polymer had a number average molecular weight Mn of 24,000 and a molecular weight distribution (Mw / Mn) of 1.08. In this way, a poly (meth) acrylate prepolymer containing a hydroxyl group was obtained. Next, the obtained hydroxyl group-containing poly (meth) acrylate-based prepolymer was added dropwise to methanol for precipitation, and after drying, only the polymer was taken out.
Next, 100 parts by mass of toluene, 0.15 g of methoquinone, and 0.15 g of dibutyltin dilaurate are charged with respect to 100 parts by mass of this polymer, and the mixture is heated to 70 ° C. while stirring, and 2-acryloyloxyethyl isocyanate is added. 1.6 g (1.0 equivalent to the hydroxyl group in the polymer) (manufactured by Showa Denko KK, product number Karenz AOI) was added dropwise over 2 hours. After completion of the dropping, the temperature is maintained at 80 ° C. for 3 hours to complete the reaction, and a poly (meth) acrylate polymer (referred to as “A-1”) having an average of two or more acrylate groups in the molecule is obtained. It was. The isocyanate reaction rate determined by infrared spectroscopy was 98%. According to GPC measurement, the number average molecular weight (Mn) was 24500, and the molecular weight distribution (Mw / Mn) was 1.08.
Production Example 6 (Synthesis of PPG-N-3)
As the polyether polyol (a-1), a polyether triol having a number average molecular weight Mn of 15000 (molecular weight distribution (Mw / Mn) = 1.08) and having propylene oxide added to glycerin (manufactured by Asahi Glass Co., Ltd., part number preminol) 300 g of S3015) and 8.0 g of 2-acryloyloxyethyl isocyanate (product number Karenz AOI, manufactured by Showa Denko KK) as an acrylate (a-2) having an isocyanate group (1.0 to the hydroxyl group in the polyether triol) Except for using the equivalent weight), a polyether polymer (referred to as “PPG-N-3”) having an average of three acrylate groups in the molecule was obtained in the same manner as in Production Example 1. The isocyanate reaction rate determined by infrared spectroscopy was 99%. Moreover, the viscosity in 25 degreeC was 6300 mPa * s. Further, by GPC measurement, the number average molecular weight (Mn) was 15600, and the molecular weight distribution (Mw / Mn) was 1.08.
Production Example 7 (Synthesis of PPG-N-4)
300 g of polypropylene glycol (manufactured by Asahi Glass Co., product number Preminol 4004) having a number average molecular weight Mn of 4000 (molecular weight distribution (Mw / Mn) = 1.08), which is a polyether polyol, an acrylate having an isocyanate group (a-2) In the same manner as in Production Example 1, except that 21.2 g of 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK, product number Karenz AOI) (1.0 equivalent to the hydroxyl group in the polyether polyol) was used, A polyether polymer (referred to as “PPG-N-4”) having an average of two acrylate groups therein was obtained. The isocyanate reaction rate determined by infrared spectroscopy was 98%. Moreover, the viscosity in 25 degreeC was 1000 mPa * s. Further, by GPC measurement, the number average molecular weight (Mn) was 4300, and the molecular weight distribution (Mw / Mn) was 1.08.
Production Example 8 (A-2 synthesis)
In a reactor equipped with a thermometer, a cooler, a gas introduction tube, and a stirrer, 100 g of butyl acrylate, 100 g of 2-ethylhexyl silylate, 10 g of acrylic acid, 0.5 g of chain transfer agent n-dodecyl mercaptan, toluene as a solvent After charging 500 parts, the inside of the reactor was replaced with nitrogen gas. Next, while stirring the above mixture, the temperature was raised to 85 ° C., and as a polymerization initiator, 1 part of 2,2′-azobismethylbutyronitrile was dissolved in 300 g of toluene over 5 hours. The solution was added dropwise to carry out a polymerization reaction. After maintaining the reaction temperature at 95 ° C. for 3 hours, add 0.3 g of methoquinone, 1.0 g of zinc octenoate and 3 g of glycidyl acrylate as an esterification catalyst, and hold at 100 ° C. for 10 hours to complete the reaction. It was. Subsequently, toluene was distilled off under reduced pressure to obtain a poly (meth) acrylic polymer (referred to as “A-2”) having two or more colorless transparent viscous liquid acrylates. The viscosity of this polymer at 25 ° C. was 250,000 mPa · s. The number average molecular weight Mn of the obtained acrylic polymer was 38000, and the molecular weight distribution (Mw / Mn) was 5.60.
Production Example 9 (UA-1 synthesis)
Polypropylene glycol (manufactured by Asahi Glass Co., Ltd.) having a number average molecular weight Mn of 4000 (molecular weight distribution (Mw / Mn) = 1.08) in a reactor equipped with a thermometer, a cooler, a gas introduction pipe, a dropping line and a stirrer Preminol 4004) 150 g, methoquinone 0.05 g, and dibutyltin dilaurate 0.05 g were added, and the temperature was raised to 80 ° C. After a fixed temperature, 17 g of hexamethylene diisocyanate was added dropwise over 1 hour, and after completion of the addition, a temperature of 80 ° C. was maintained for 5 hours. Next, a mixture of 34 g Plaxel FA2D (manufactured by Daicel Chemical Industries, ε-caprolactone 2-mol adduct of 2-hydroxyethyl acrylate) and 0.01 g of methoquinone was added dropwise over 2 hours. After completion of the dropwise addition, a temperature of 80 ° C. was maintained for 15 hours to obtain urethane acrylate (referred to as “UA-1”) having an average of two acrylates. The viscosity of UA-1 obtained at 25 ° C. was 550000 mPa · s. Furthermore, by GPC measurement, the number average molecular weight (Mn) was 10500, and the molecular weight distribution (Mw / Mn) was 4.60.
Example 1
[Preparation of UV curable resin composition for optical laminate, production of cured product and optical laminate]
50 parts of a polyether polymer (PPG-N-1) having an acrylate synthesized in Production Example 1, 45 parts of polypropylene glycol (trade name “P-3000”, manufactured by Adeka), 5 parts of 4-hydroxyethyl acrylate, light An ultraviolet curable resin composition for an optical laminate (hereinafter referred to as a composition) was prepared by mixing 1 part of a polymerization initiator (manufactured by BASF, product number Irgacure 184). Next, the viscosity of the composition was measured by the above method. Next, the obtained composition was dropped on a glass plate having a predetermined size in which silicone spacers having a predetermined thickness were arranged on four sides, and the glass plate was filled. Next, a glass plate of the same size was put on the top. Next, cured by 3J / cm ² irradiation by a high pressure mercury lamp, a test piece having a laminated structure of the cured product / glass plate glass plate / composition or a test specimen to separate the cured product from the glass plate Created. The prepared test pieces were evaluated for curing shrinkage, hardness value, elongation, light transmittance, turbidity, heat resistance, light resistance, and moisture resistance based on the above evaluation measurement method.
Next, the obtained composition was applied onto a non-alkali glass plate having a density of 2.46 g / cm ³ , a Young's modulus of 73 GPa, and a Vickers hardness of 610, a length of 300 mm, a width of 200 mm, and a thickness of 200 μm. A 300 mm long, 200 mm wide, 3 mm thick polymethylmethacrylate plate was bonded to it, adjusted to a composition thickness of 400 μm, and then irradiated with ³ J / cm ² light with a high pressure mercury lamp from the glass plate side. Was cured to obtain an optical laminate comprising glass / cured product / polymethyl methacrylate. The obtained optical layered product was evaluated for heat shock resistance and shock absorption resistance based on the evaluation measurement method. The evaluation results are shown in Table 1.

Examples 2-8, Comparative Examples 1-3
In the same manner as in Example 1, the components were mixed and stirred at the ratios shown in Table 1 to obtain compositions (2) to (8) and comparative compositions (1) to (3). Then, it replaced with the composition (1) in Example 1, and obtained the test piece like Example 1 except having used each of these compositions. The obtained composition and test piece were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Abbreviations in Table 1 are as follows.
DIDA: Diisodecyl adipate (Brand name “Vinizer 50”, manufactured by Kao Corporation)
M30: Polypropylene glycol monomethyl ether (trade name “M-30”, manufactured by Adeka)
IB-A: Isobornyl acrylate KE311: Rosin ester plasticizer (trade name “Pine Crystal KE-311”, manufactured by Arakawa Chemical Co., Ltd.)

From the results of Examples and Comparative Examples described above, the ultraviolet curable resin composition for an optical laminate of the present invention has (A) a number average molecular weight Mn of 10,000 or more and a dispersity d of 1.5 or less, Furthermore, the cured product and the optical laminate obtained by curing the composition have a transparency, heat resistance, a polymer having two or more acrylate groups, and (B) a photopolymerization initiator. It has been confirmed that it has an advantageous effect in that various properties such as light resistance, moisture resistance, heat shock resistance, and shock absorption properties can be exhibited simultaneously in a well-balanced manner.

  The ultraviolet curable resin composition for optical laminates of the present invention can retain optical characteristics against environmental changes such as light, heat and moisture, and also has heat shock resistance, shock absorption resistance, etc. Therefore, it is suitable as an ultraviolet curable resin composition used between glass and transparent plastic.

Claims (6)

An ultraviolet curable resin composition for an optical laminate in which a glass having a thickness of 300 μm or less and a transparent plastic thicker than the glass are bonded together by an ultraviolet curable resin composition, wherein the resin composition is (A ) Number average molecular weight Mn is 10,000 or more and dispersity d is 1.5 or less,
An ultraviolet curable resin composition for an optical laminate, comprising a polymer (B) photopolymerization initiator having two or more (meth) acrylate groups. The ultraviolet curable resin composition for an optical laminate according to claim 1, wherein the (A) contains a polyether polymer. The ultraviolet curable resin composition for an optical laminate according to claim 1 or 2, wherein (A) contains a conjugated diene polymer. Hardened | cured material obtained by hardening | curing the ultraviolet curable resin composition for optical laminated bodies in any one of Claims 1-3 by ultraviolet irradiation. The optical laminated body which has the hardened | cured material of the ultraviolet curable resin composition for optical laminated bodies in any one of Claims 1-3. The optical laminate according to claim 5, wherein the transparent plastic is a polymethyl methacrylate type.