JP6037109B2 - Photocurable resin composition - Google Patents

Description

  The present invention relates to a photocurable composition that is cured in a thick film in a short time by irradiating light, and the cured product has excellent high transparency and heat-resistant transparency.

As a method for fixing optical devices in recent years, soldering and other high-temperature processes have been adopted. Therefore, sealants and adhesives for optical devices require heat-resistant transparency (the ability to maintain transparency even when heated). It has come to be.

As such a sealing agent and an adhesive for an optical device, Patent Document 1 discloses an epoxy resin composition containing an epoxy resin, an acid anhydride, and a curing accelerator. In addition, as a photocurable resin, Patent Document 2 discloses a (meth) acrylate ester having an alicyclic hydrocarbon group having 5 to 22 carbon atoms in an ester portion, a monomer having an alkylene oxide group, and a copolymer thereof. An optical adhesive containing a vinyl monomer having a boiling point of 180 ° C. or higher and a polymerization initiator is disclosed.

Japanese Patent Laid-Open No. 06-128359 Japanese Patent Laid-Open No. 11-061081

  However, in order to heat cure the epoxy resin composition described in Patent Document 1, it takes several hours at a high temperature of 150 ° C., and there is a problem in productivity. The invention disclosed in Patent Document 2 has a problem in terms of heat-resistant transparency.

In view of the above problems, an object of the present invention is to provide a photocurable composition that is cured in a short time by irradiating light, and the cured product has excellent high transparency and heat-resistant transparency.

The embodiments of the present invention overcome the above-mentioned conventional problems. That is, the present invention has the following gist.
[1] The following components (A) to (E) are contained, and the component (D) is 1 to 50 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (C). ) Component is 0.02 to 2 parts by mass, a photocurable resin composition.
(A) component: oligomer having a (meth) acryl group having a weight average molecular weight of 500 to 30,000 (B) component: compound having an isocyanuric ring structure and a (meth) acryl group (C) component: alicyclic (meth) acrylate ( The component (D): a polythiol compound having two or more thiol groups (E) component: a photo radical initiator [2] The component (D) is a compound having three or more thiol groups. Photocurable resin composition.
[3] The component (E) is 0.1 to 1 part by mass with respect to 100 parts by mass of the total amount of the components (A) to (C), according to [1] or [2] [4] The photocurable resin composition according to any one of [1] to [3], wherein the component (A) contains urethane (meth) acrylate. Product [5] The component (D) is trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane tris (3-mercaptobutyrate), trimethylol Ethanetris (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanate Nurate, pentaerythritol tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5-tris (3-mercaptobutyloxy) Any one of [1] to [4], characterized in that it is selected from the group consisting of ethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione The photocurable resin composition according to any one of [6] [1] to [5], wherein the photocurable resin composition according to any one of [1] to [5] is used for adhesives and sealants for optical devices. Photocurable resin composition

  As described above, the composition of the present invention described above can be cured into a thick film in a short time by irradiating light, and the cured product can provide a photocurable composition having excellent high transparency and heat-resistant transparency.

  Details of the invention will be described below.

<(A) component>
The component (A) used in the present invention is not limited as long as it is an oligomer having a (meth) acryl group having a weight average molecular weight of 500 to 30,000, and examples thereof include urethane (meth) acrylate. Urethane (meth) acrylate is obtained by reaction of a polyisocyanate compound, a polyol compound, and a (meth) acrylate monomer having active hydrogen. The urethane (meth) acrylate used in the present invention is preferably an aliphatic urethane (meth) acrylate because a cured product having heat-resistant transparency is obtained. In addition, in this specification, a weight average molecular weight means the weight average molecular weight of polystyrene conversion measured by gel permeation chromatography.

The polyisocyanate compound is an aliphatic polyisocyanate, an alicyclic polyisocyanate, or an aromatic polyisocyanate, and an aliphatic polyisocyanate or an alicyclic polyisocyanate is preferable from the viewpoint that a transparent cured product can be obtained.

Examples of the aliphatic isocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene. Examples include diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, 2,6-diisocyanatoethylcaproate, bis (2-isocyanatoethyl) fumarate and bis (2-isocyanatoethyl) carbonate. . These are used alone or in combination.

Examples of the alicyclic isocyanate include isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxyl. Rate and 2,5- or 2,6-norbornane diisocyanate. These are used alone or in combination.

Examples of the polyol compound include compounds having two or more active hydroxyl groups in the molecule. For example, polyether polyol, polyester polyol, polycarbonate diol, polybutadiene polyol, hydrogenated polybutadiene polyol, polylactone polyol, castor oil Polyols, hydrogenated castor oil-based polyols, polyisoprene polyols, hydrogenated polyisoprene polyols, and the like. These can be used alone or in combination.

Examples of the (meth) acrylate monomer having active hydrogen include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethylene glycol mono (meth) acrylate, and propylene glycol mono (meth) acrylate. 2-hydroxy-3-methoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, N-methylolacrylamide or methacrylamide, N-hydroxyacrylamide or methacrylamide, and the like. These can be used alone or in combination.

The method for synthesizing urethane (meth) acrylate is not particularly limited, and a known method can be used. For example, a polyisocyanate compound and a polyol compound are reacted to obtain a prepolymer, and further, an isocyanate group remaining in the obtained prepolymer and a sufficient amount of active hydrogen to react with this (meth) There is a method of synthesizing urethane (meth) acrylate by reacting with an acrylate monomer.

<(B) component>
The component (B) used in the present invention is not limited as long as it is a compound having an isocyanuric ring structure and a (meth) acryl group. For example, bis ((meth) acryloxymethyl) hydroxymethyl isocyanurate Bis ((meth) acryloxyethyl) hydroxyethyl isocyanurate, tris ((meth) acryloxymethyl) isocyanurate, tris ((meth) acryloxyethyl) isocyanurate, caprolactone modified tris ((meth) acryloxyethyl) Examples include isocyanurate. One kind can be used alone, or two or more kinds can be used in combination. Among these, tris ((meth) acryloxymethyl) isocyanurate and tris ((meth) acryloxyethyl) isocyanurate are obtained because they can provide a cured product having excellent thick film photocurability and transparency at high temperatures. Caprolactone-modified tris ((meth) acryloxyethyl) isocyanurate is particularly preferred.

(B) As a commercial item of a component, M-313, M-315, M-325 (made by Toa Gosei Co., Ltd.), A-9300, A-9300-1CL (made by Shin-Nakamura Chemical Co., Ltd.), SR368 (Made by Sartomer).

In the present invention, the blending ratio of the component (B) is not particularly limited, but is preferably 3 to 80% by mass, more preferably 3 to 80% by mass, in a total amount of 100 parts by mass of the components (A), (B) and (C). 5 to 60% by mass, particularly preferably 5 to 30% by mass. The amount of the component (B) used is preferably 3% by mass or more from the viewpoint of reactivity, and preferably 80% by mass or less from the viewpoint of curing shrinkage. )

<(C) component>
The component (C) used in the present invention is not limited as long as it is an alicyclic (meth) acrylate. For example, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclo Pentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, cyclohexyloxyethyl (meth) acrylate, t-butylcyclohexyloxyethyl (Meth) acrylate, isobornyloxyethyl (meth) acrylate, adamantyloxyethyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, cyclohexane dimethanol di (me ) Acrylates, poly ethoxylated cyclohexanedimethanol di (meth) acrylate, poly propoxylated cyclohexanedimethanol di (meth) acrylate, hydrogenated bisphenol A di (meth) acrylate. These can be used singly or in combination of two or more. Among these, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclo and the like from the viewpoint of transparency of the cured product. Pentenyloxyethyl (meth) acrylate is particularly preferred.

In the present invention, the blending ratio of the component (C) is not particularly limited, but is preferably 3 to 80% by weight, more preferably 100 parts by weight in the total amount of the components (A), (B) and (C). 5 to 60% by mass, particularly preferably 5 to 30% by mass. The amount of component (C) used is preferably 3% by mass or more from the viewpoint of handling properties, and preferably 80% by mass or less from the viewpoint of reactivity.

<(D) component>
The component (D) used in the present invention is not limited as long as it is a polythiol compound having two or more thiol groups. More preferably, it is a polythiol compound having 3 or more thiol groups. Examples of such component (D) include trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), and trimethylolpropane tris (3-mercaptobutyrate). , Trimethylol ethane tris (3-mercaptobutyrate), trimethylol ethane tris (3-mercaptobutyrate), ethylene glycol bis (3-mercaptoglycolate), butanediol bis (3-mercaptoglycolate), trimethylolpropane Tris (3-mercaptoglycolate), pentaerythritol tetrakis (3-mercaptoglycolate), tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, pentaerythritol tet Kiss (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), 1,4 -Bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H)- A trione etc. are mentioned, These compounds may be used individually, respectively, and may mix and use 2 or more types. Among these components (D), trimethylolpropane tris (3-mercaptopropionate) and trimethylolpropane tris (3-mercapto) are preferable from the viewpoint of excellent thick-film photocurability and transparency at high temperatures. Butyrate), trimethylolethanetris (3-mercaptobutyrate), trimethylolethanetris (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -Ethyl] -isocyanurate, pentaerythritol tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5- And tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione.

As a commercial item of (D) component of this invention, TMTP, PETP (made by Sakai Chemical Co., Ltd.), TEMPIC, TMMP, PEMP, PEMP-II-20P, DPMP (made by SC Organic Chemical Co., Ltd.), MTNR1, MTBD1 MTPE1 (manufactured by Showa Denko Co., Ltd.) and the like are exemplified, but not limited thereto. These compounds may be used alone or in combination of two or more.

In addition, it is preferable that the mixture ratio of (D) component is 1-50 mass parts with respect to 100 mass parts of total amounts of (A)-(C) component, More preferably, it is 3-35 mass parts. Yes, and particularly preferably 5 to 15 parts by mass. The amount of component (D) used is preferably 1 part by mass or more from the viewpoint of reactivity, and preferably 50 parts by mass or less from the viewpoint of the strength of the cured product.

<(E) component>
The radical photopolymerization initiator that is the component (E) used in the present invention is not limited as long as it is a compound that generates radicals by irradiating active energy rays such as ultraviolet rays, but the component (E) As, for example, acetophenone photo radical polymerization initiator, benzoin photo radical polymerization initiator, benzophenone photo radical polymerization initiator, thioxanthone photo radical polymerization initiator, acyl phosphine oxide photo radical polymerization initiator, etc. Of these, acetophenone photoradical polymerization initiator, acylphosphine oxide photoradical polymerization initiator, from the viewpoint of obtaining a curable composition excellent in initial transparency, non-yellowing property when heated, and excellent in thick film photocurability Is preferred. Moreover, these may be used independently and 2 or more types may be used together.

Examples of the acetophenone photoradical polymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy -2-propyl) ketone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4 -Morpholinophenyl) butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer and the like are exemplified, but not limited thereto.

Examples of the acylphosphine oxide photoradical polymerization initiator include acylphosphine oxide photoradical polymerization initiators such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethyl. Examples include, but are not limited to, benzoyl-diphenylphosphine oxide.

In the present invention, the amount of component (E) is preferably 0.02 to 2 parts by mass, more preferably 0.05 to 1 mass, per 100 parts by mass of the total amount of components (A) to (C). Part, particularly preferably 0.1 to 0.5 part by mass. If it is less than 0.1 parts by mass, the photocurability of the composition may be lowered, and if it exceeds 10 parts by mass, the transparency of the cured product may be impaired.

Furthermore, the composition of the present invention includes colorants such as pigments and dyes, calcium carbonate, talc, silica, alumina, aluminum hydroxide, inorganic fillers such as glass, and conductive materials such as silver, as long as the characteristics of the present invention are not impaired. Particles, flame retardants, organic fillers such as acrylic rubber, polymers such as polyimide resins, polyamide resins, phenoxy resins, SEBS resins, thermoplastic elastomers, plasticizers, organic solvents, antioxidants, antifoaming agents, silane cups An appropriate amount of additives such as a ring agent, a leveling agent, and a rheology control agent may be blended. By these additions, a composition excellent in resin strength, adhesive strength, flame retardancy, workability and the like and a cured product thereof can be obtained.

The present invention cures a thick film in a short time by irradiating light, and the cured product has excellent properties such as excellent high transparency and heat-resistant transparency. It can be used for various applications such as casting, painting, and coating materials.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Test methods used in Examples and Comparative Examples are as follows.
<Preparation of composition>
Each component was sampled in parts by mass shown in Tables 1 and 2 and mixed at room temperature with a planetary mixer for 30 minutes to prepare a resin composition, and various physical properties were measured as follows. Detailed adjustment amounts are shown in Tables 1 and 2, and all numerical values are expressed in parts by mass.

<(A) component>
a1: Aliphatic urethane acrylate having a molecular weight of 1300 (EBCRYL8804, manufactured by Daicel Cytec Co., Ltd.)
a2: Aliphatic urethane acrylate having a molecular weight of 5000 (EBCRYL230, manufactured by Daicel-Cytec Corporation)
<(B) component>
b1: Isocyanuric acid ethylene oxide modified triacrylate (M-315, manufactured by Toa Gosei Co., Ltd.)
b2: caprolactone-modified tris (acryloxyethyl) isocyanurate (M-325, manufactured by Toa Gosei Co., Ltd.)
<Comparison of component (b)>
b'1: Polyester tetraacrylate (M-8060, manufactured by Toa Gosei Co., Ltd.)
<(C) component>
c1: Isobornyl acrylate c2: Dicyclopentanyl acrylate <Comparison of ( c ) component>
c′1: 2-hydroxyethyl acrylate
c′2: Isooctyl acrylate <(d) component>
d1: Pentaerythritol tetrakis (3-mercaptobutyrate) (MT-PE1, manufactured by Showa Denko KK)
d2: Pentaerythritol tetrakis (3-mercaptopropionate) (PEMP, manufactured by SC Organic Chemical Co., Ltd.)
<Comparison component of component (d)>
d'1: Stearyl mercaptan <(e) component>
e1: 1-hydroxy-cyclohexyl-phenyl-ketone e2: bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide

<Initial / Transparency Test>
Each composition was stretched to a thickness of 3 mm to prepare a test piece with a smooth surface, and a cured product was produced by curing with a cumulative light quantity of 3000 mJ / cm ² . The transmittance of the cured product was measured with a spectrophotometer UV-2450 (manufactured by SHIMADZU) and evaluated based on the following evaluation criteria. The results are shown in Tables 1 and 2.
[Evaluation criteria]
○: 450 nm transmittance is 85% or more ×: 450 nm transmittance is less than 85%

<Heat resistance transparency test>
The cured product cured with an integrated light quantity of 3000 mJ / cm ² was left in an atmosphere at 200 ° C. for 1 hour, and then the same transmittance test as described above was performed, compared with the transmittance before the durability test, and evaluated based on the following evaluation criteria. . The results are shown in Tables 1 and 2.
[Evaluation criteria]
A: Change rate in transmittance at 450 nm less than 3% B: Change rate in transmittance at 450 nm 3-5%
X: Rate of change in transmittance at 450 nm is greater than 5%

<Thick film photocuring test>
Each composition was poured into a polypropylene cylinder having an inner diameter of 10 mm and a depth of 30 mm, and cured with an integrated light amount of 3000 mJ / cm ² . The cured product obtained at that time was taken out of the test tube, measured how much thick film photocured from the liquid surface, and evaluated based on the following evaluation criteria. The results are shown in Tables 1 and 2.
[Evaluation criteria]
A: 20 mm or more B: 10-20 mm
X: Less than 10 mm

  The photo-curable resin composition of the present invention is cured in a thick film in a short time by irradiating light, and the cured product has excellent high transparency and heat-resistant transparency, so that it has a thick film photo-curing property and heat-resistant transparency. It is extremely effective where it is necessary and is industrially useful because it can be applied to a wide range of fields.

Claims (6)

Contains the following components (A) to (E),
In a total amount of 100 parts by mass of the components (A), (B) and (C), the component (B) contains 3 to 80% by mass, the component (C) 3 to 80% by mass, (A) to (C The photocurable resin composition is characterized in that the component (D) is 3 to 50 parts by mass and the component (E) is 0.02 to 2 parts by mass with respect to 100 parts by mass of the total component). .
(A) component: urethane (meth) acrylate having a weight average molecular weight of 500 to 30,000 (B) component: bis ((meth) acryloxymethyl) hydroxymethyl isocyanurate, bis ((meth) acryloxyethyl) hydroxyethyl isocyanurate, At least one isocyanuric ring selected from the group consisting of tris ((meth) acryloxymethyl) isocyanurate, tris ((meth) acryloxyethyl) isocyanurate, caprolactone-modified tris ((meth) acryloxyethyl) isocyanurate structure and compound having a (meth) acrylic group component (C): isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (Meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, cyclohexyloxyethyl (meth) acrylate, t-butylcyclohexyloxyethyl (meth) acrylate, isobornyloxyethyl ( (Meth) acrylate, adamantyloxyethyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, polyethoxylated cyclohexanedimethanol di (meth) acrylate, polypropoxylated cyclohexane Jimetanoruji (meth) acrylate, at least one cycloaliphatic selected from the group consisting of hydrogenated bisphenol a di (meth) acrylate (meth Acrylate component (D): a polythiol compound having 2 or more thiol groups (E) component: photoradical initiator The said (D) component is a compound which has 3 or more of thiol groups, The photocurable resin composition of Claim 1 characterized by the above-mentioned. The said (E) component is 0.1-1 mass part with respect to 100 mass parts of total amounts of (A)-(C) component, The photocurable resin of Claim 1 or 2 characterized by the above-mentioned. Composition. The component (C) contains at least one selected from the group consisting of isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate. The photocurable resin composition of any one of -3. The component (D) is trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (3-mercaptobutyrate), trimethylolethanetris (3-mercaptobutyrate), trimethylolethanetris (3 -Mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, pentaerythritol tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptopropionate), 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione A small selection from Both light-curable resin composition according to any one of claims 1 to 4, characterized in that it comprises one. The photocurable resin composition of any one of Claims 1-5 is used for the adhesive agent and sealing agent use for optical devices, The photocurable resin composition characterized by the above-mentioned.