JP2008088354A - Resin composition and cast molding method - Google Patents

Abstract

Provided is a photocurable resin composition that is suitable for a cast molding method, can be instantly cured, exhibits an appropriate elastic modulus and excellent elongation, and is excellent in hydrolysis resistance.
(1) (A) a urethane (meth) acrylate oligomer having a polyester skeleton in the molecule and having a molecular weight in the range of 5,000 to 100,000, (B) a monofunctional (meth) acrylate, , (C) a hindered amine compound, the compounding ratio of the component (A) and the component (B) is in the range of 5:95 to 95: 5 by mass ratio, and the component (C) is the component (A) and ( B) A resin composition containing 0.01 to 10 parts by mass with respect to 100 parts by mass of the total component.
[Selection figure] None

Description

The present invention relates to a photocurable resin composition and a cured product that can be cured by irradiation with energy rays such as ultraviolet rays and visible rays (hereinafter, also simply referred to as “light irradiation”). The present invention relates to a photocurable resin composition and a cured product thereof, which exhibit an appropriate elastic modulus and excellent elongation, and also have excellent hydrolysis resistance. Further, the resin composition is capable of transmitting energy rays. It is related to a casting method characterized in that it is injected into the mold prepared in step (b) and cured by irradiation with energy rays such as ultraviolet rays and visible rays from the outside of the mold to form a molded body.

In general, a composition that imparts so-called rubber properties such as flexibility, stretchability, and elasticity is called an elastomer, which is superior in flexibility and elongation compared to other polymer materials, and has an appropriate elastic modulus. As shown, automobile members such as tires, sealing members for structures such as civil engineering and construction, packing members such as O-rings, acoustic members such as speakers, sheet members such as key sheets for mobile phones, vibration-proof materials, various types It is applied as a mechanism member.

As elastomers (hereinafter denoted by symbol R), natural rubber, modified natural rubber, grafted natural rubber, cyclized natural rubber, chlorinated natural rubber, styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, carboxylated nitrile rubber , Acrylonitrile-vinyl chloride rubber, acrylonitrile-EPDM rubber blend, butyl rubber, brominated butyl rubber, chlorinated butyl rubber, ethylene-vinyl acetate rubber, acrylic rubber, ethylene-acrylic rubber, chlorosulfonated polyethylene, chlorinated polyethylene, epichlorohydrin rubber, epichlorohydrin- Rubber materials such as ethylene oxide rubber, methyl silicone rubber, vinyl-methyl silicone rubber, phenyl-methyl silicone rubber, fluorosilicone rubber, polystyrene-based thermoplastics Lastomer, Polyvinyl chloride thermoplastic elastomer, Polyolefin thermoplastic elastomer, Polyurethane thermoplastic elastomer, Polyester thermoplastic elastomer, Polyamide thermoplastic elastomer, Vinyl chloride thermoplastic elastomer, Fluoro rubber thermoplastic elastomer, Chlorination Thermoplastic elastomer materials such as polyethylene-based elastomers are known.

In general, as a method for obtaining a molded body of elastomer (R), a kneading step for sufficiently kneading an elastomer raw material containing a curing agent and other additives, and a kneaded dough for a vacuum forming method, a pressure forming method, an upper die After a curing process (vulcanizing process) in which the lower mold is molded by a heating mold and an injection molding process using a molding mold (hereinafter referred to as an upper and lower mold), vulcanized or cured by heating and pressing. The desired molded body is obtained.

However, in the vacuum forming method, the pressure forming method, the heat pressing method using the upper and lower molds, etc., it is necessary to raise the mold temperature to near the melting point of the material, and enormous energy is required for heating. Moreover, since it is necessary to cool and take out the metal mold, it takes a long time for the molding cycle.

In the injection molding method, the melted resin is cooled immediately after coming into contact with a mold having a temperature difference, and the fluidity is extremely reduced. Therefore, it is difficult to obtain a thin molded body, and heating, injection, holding pressure, etc. This makes the equipment expensive. Further, since the thermoplastic material is heated to near the melting point, the heating energy is enormous.

In the above-mentioned vacuum forming method, pressure forming method, heating and press forming method using upper and lower molds, etc., the molding material is formed by molding a planar material that is substantially larger than the target part size, and then cutting out the part part for use. A lot of waste is generated, which is not preferable environmentally and economically.

The above-mentioned constituent materials of vacuum forming method, pressure forming method, and heat forming by upper and lower molds are generally materials of uniform thickness, so after forming, each part has the same thickness, and from the same material each part It is difficult to change the thickness.

In addition, the thickness produced industrially is limited, and it is usually difficult to obtain materials with other thicknesses. A method of changing the thickness by a process such as stretching at the time of molding has also been proposed, but problems such as increased internal stress distortion after molding occur.

As means for solving the problems of the molding method as described above, an energy ray-curable liquid substance is injected or filled into a mold made of a material capable of transmitting energy rays as described in Patent Documents 1 to 3, Examples thereof include a photo-curing cast molding method in which a cured product is formed by irradiation with energy rays such as ultraviolet rays and visible rays.
Japanese Patent No. 3140478 Japanese Patent No. 3197907 JP 2004-357020 A

In particular, the molding method described in Patent Document 3 can obtain a molded body without destroying the mold by using an upper mold and a lower mold, and can repeatedly produce a molded body with the same mold.

More specifically, at least one of a pair of molds composed of an upper mold and a lower mold is formed of a material that transmits light, and a resin that can be cured by light irradiation is set to close the mold, This is a method of irradiating light from the outside of the mold to transmit and curing the resin to obtain a cured body of the desired shape. By this method, a molded body of any thickness can be easily and inexpensively produced with less energy and fewer man-hours. It becomes possible to do.

However, there is no known resin composition having moldability suitable for the above-mentioned photo-curing cast molding method, and the obtained cured product satisfies an appropriate elastic modulus and elongation required for conventional elastomers. Patent Documents 4 to 6 are disclosed as photocurable elastomers or resin compositions exhibiting rubber elasticity, but the sealing resin compositions described in Patent Document 4 and Patent Document 5 are also disclosed in Patent Document 6. The resin composition for optical three-dimensional modeling described above did not satisfy the moldability required for the above-mentioned photo-curing cast molding and the appropriate elastic modulus and extensibility required for the elastomer.
Japanese translation of PCT publication No. 2002-501109 Special table 2003-505525 JP 2000-290328 A

The present invention has been made in view of the state of the art, and relates to a photocurable resin composition and a cured body that can be cured by irradiation with light such as ultraviolet rays and visible light, and more specifically, can be instantaneously cured by irradiation with light. The present invention provides a photo-curable resin composition and a cured product thereof, which exhibit an appropriate elastic modulus and excellent elongation, and are further excellent in hydrolysis resistance, and are capable of transmitting energy rays through the resin composition. A casting molding method is characterized in that it is injected into a mold made of a material and cured by irradiating energy rays such as ultraviolet rays and visible light from the outside of the mold to form a molded body. is there.

（式中、Ｒ^１は炭素数１〜３０の直鎖もしくは分岐もしくは環状のアルキル基、または、炭素数１〜３０の直鎖もしくは分岐もしくは環状のアルコキシ基もしくはポリアルコキシ基であり、Ｒ^２は炭素数１〜１０の直鎖もしくは分岐もしくは環状のアルキル基、または、ベンゼン環、ナフタレン環、アントラセン環、又はフルオレン環から選ばれる芳香環を含む基であり、ｍは重合度を表す。）
（Ｂ）単官能（メタ）アクリレート、
さらに、
（Ｃ）下記化式〔２〕で表される基を有するヒンダードアミン化合物

を含有し、（Ａ）成分と（Ｂ）成分の配合比が、質量比で５：９５〜９５：５の範囲であり、（Ｃ）成分が（Ａ）成分と（Ｂ）成分の合量１００質量部に対して、０．０１〜１０質量部含有する樹脂組成物であることを特徴とする樹脂組成物である。 (1) (A) a urethane (meth) acrylate oligomer having a polyester skeleton represented by the following chemical formula [1] in the molecule and having a molecular weight in the range of 5,000 to 100,000.

(Wherein R ¹ is a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, or a linear, branched or cyclic alkoxy group or polyalkoxy group having 1 to 30 carbon atoms, and R ² is C 1-10 linear or branched or cyclic alkyl group, or a group containing an aromatic ring selected from a benzene ring, naphthalene ring, anthracene ring, or fluorene ring, and m represents the degree of polymerization.)
(B) monofunctional (meth) acrylate,
further,
(C) A hindered amine compound having a group represented by the following chemical formula [2]

The mixing ratio of the component (A) and the component (B) is in the range of 5:95 to 95: 5 by mass ratio, and the component (C) is the total amount of the components (A) and (B). It is a resin composition containing 0.01 to 10 parts by mass with respect to 100 parts by mass.

（式中、Ｒ^３は水素原子またはメチル基であり、Ｒ^４は、炭素数１〜２２である直鎖もしくは分岐アルキル基、シクロヘキシル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたシクロヘキシル基、フェニル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたフェニル基、ジシクロペンタニル基、ジシクロペンテニル基、ボルニル基、イソボルニル基、アダマンチル基、メチルアダマンチル基、又はアリル基である。）

（式中、Ｒ^３は水素原子またはメチル基であり、Ｒ^５は、炭素数１〜４である直鎖もしくは分岐アルキル基、Ｒ^６は、炭素数１〜４である直鎖もしくは分岐アルキル基、シクロヘキシル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたシクロヘキシル基、フェニル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたフェニル基、ジシクロペンタニル基、ジシクロペンテニル基、ボルニル基、イソボルニル基、アダマンチル基、メチルアダマンチル基、又はアリル基であり、ｎは１〜１２の整数である。） (2) The resin composition according to (1), wherein the (B) monofunctional (meth) acrylate is a monofunctional (meth) acrylate represented by the following chemical formula [3] or [4]: is there.

(In the formula, R ³ is a hydrogen atom or a methyl group, and R ⁴ is substituted with a linear or branched alkyl group having 1 to 22 carbon atoms, a cyclohexyl group, or a linear or branched alkyl group having 1 to 4 carbon atoms. Cyclohexyl group, phenyl group, phenyl group substituted by a linear or branched alkyl group having 1 to 4 carbon atoms, dicyclopentanyl group, dicyclopentenyl group, bornyl group, isobornyl group, adamantyl group, methyladamantyl group Or an allyl group.)

(Wherein R ³ is a hydrogen atom or a methyl group, R ⁵ is a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁶ is a linear or branched alkyl group having 1 to 4 carbon atoms. A cyclohexyl group, a cyclohexyl group substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, a phenyl group, a phenyl group substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, a dicyclopentanyl group A dicyclopentenyl group, a bornyl group, an isobornyl group, an adamantyl group, a methyladamantyl group, or an allyl group, and n is an integer of 1 to 12.)

(3) The resin composition as described in (1), which contains a photopolymerization initiator as the component (D).

(4) The resin composition according to (3), wherein the photopolymerization initiator (D) is an acylphosphine oxide compound.

(5) A cured product comprising the resin composition according to any one of (1) to (4).

(6) The cured product of (5) having a tensile modulus of 1 to 100 MPa and a tensile fracture elongation of 200% or more.

(7) The resin composition according to any one of (1) to (4) is injected into a mold made of a material capable of transmitting energy rays, and cured by irradiating energy rays from the outside of the mold. And forming a molded body.

The resin composition of the present invention is cured in an extremely short time by irradiation with light such as ultraviolet rays or visible light, and the cured product exhibits an appropriate elastic modulus and excellent elongation, and further has excellent hydrolysis resistance. Because it has, automotive members such as tires, sealing members for structures such as civil engineering and construction, packing members such as O-rings, acoustic members such as speakers, sheet members such as key sheets for mobile phones, members, vibration isolation It can be suitably used for materials and various mechanism members. The resin composition of the present invention can also be applied to structural sealants for civil engineering and construction, and adhesives for metals, magnets, ceramics, glass, and plastics.

As used herein, the term “molecular weight” means weight average molecular weight unless otherwise specified.

As used herein, the term “Tg” means glass transition temperature unless otherwise specified.

The term “alkyl” as used herein refers to straight chain, branched and cyclic saturated hydrocarbon groups, unless otherwise specified.

The term “viscosity” as used herein means “absolute viscosity” unless otherwise specified, and is defined as a proportional coefficient between a flow velocity gradient and a shear stress generated against the gradient, and is generally B type. It can be measured with a viscometer such as a viscometer, an E-type viscometer, a rheometer, etc. In the present invention, it is shown with a value measured with an E-type viscometer.

The resin composition of the present invention is a photocurable resin composition that is irradiated with light to form a cured product. The light here refers to energy rays typified by ultraviolet rays and visible rays.

In achieving the object of the present invention, the resin composition contains a urethane (meth) acrylate oligomer having a specific composition and a monofunctional (meth) acrylate monomer.

As a urethane (meth) acrylate oligomer used in the resin composition of the present invention, a monofunctional (meth) acrylate is a polyester polyol urethane (meth) acrylate oligomer having a polyester skeleton represented by the following chemical formula [5] in the molecule. And a specific hindered amine compound can be used to obtain a cured product that exhibits rapid curing, an appropriate elastic modulus and excellent elongation, and has a low curing shrinkage, heat resistance, chemical resistance, and UV resistance. It is preferable because a cured product excellent in the above can be obtained.

（式中、Ｒ^１は炭素数１〜３０の直鎖もしくは分岐もしくは環状のアルキル基、または、炭素数１〜３０の直鎖もしくは分岐もしくは環状のアルコキシ基もしくはポリアルコキシ基であり、Ｒ^２は炭素数１〜１０の直鎖もしくは分岐もしくは環状のアルキル基、または、ベンゼン環、ナフタレン環、アントラセン環、又はフルオレン環から選ばれる芳香環を含む基であり、ｍは重合度を表す。） The polyester polyol urethane (meth) acrylate oligomer used in the resin composition of the present invention is a polyester polyol compound having a polyester skeleton represented by the following chemical formula [6] in the molecule (hereinafter referred to as “X”). And a urethane (meth) acrylate oligomer obtained by reacting an organic polyisocyanate compound (hereinafter represented by “Y”) and hydroxy (meth) acrylate (hereinafter represented by “Z”).

(Wherein R ¹ is a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, or a linear, branched or cyclic alkoxy group or polyalkoxy group having 1 to 30 carbon atoms, and R ² is C 1-10 linear or branched or cyclic alkyl group, or a group containing an aromatic ring selected from a benzene ring, naphthalene ring, anthracene ring, or fluorene ring, and m represents the degree of polymerization.)

Specific examples of the polyester polyol compound (X) include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, 1,4-butanediol, and polybutylene. Glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5 -Pentanediol, 2,2-butylethyl-1,3-propanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, polytetramethylene glycol, etc. And at least one alcohol selected from the group consisting of maleic acid, fumaric acid, itaconic acid, adipic acid, phthalic acid, terephthalic acid and isophthalic acid, or one or more acid anhydrides thereof. The polyester polyol which is a condensate is mentioned.

The molecular weight of the polyester polyol is preferably 200 to 100,000, more preferably 500 to 50,000, and still more preferably 1,000 to 10,000. If the molecular weight is 200 or more, suitable elongation can be obtained, and if it is within 100,000, an appropriate elastic modulus can be obtained, and the curability is not lowered, which is preferable.

Examples of the organic polyisocyanate compound (Y) include aromatic, aliphatic, cycloaliphatic, and alicyclic polyisocyanates. Specific examples include tolylene diisocyanate (TDI) and diphenylmethane diisocyanate. (MDI), hydrogenated diphenylmethane diisocyanate (H-MDI), polyphenylmethane polyisocyanate (crude MDI), modified diphenylmethane diisocyanate (modified MDI), hydrogenated xylylene diisocyanate (H-XDI), xylylene diisocyanate (XDI) ), Hexamethylene diisocyanate (HMDI), trimethylhexamethylene diisocyanate (TMXDI), tetramethylxylylene diisocyanate (m-TMXDI), isophorone diisocyanate (IPDI), nor Polyisocyanates such as runene diisocyanate (NBDI) and 1,3-bis (isocyanatomethyl) cyclohexane (H6XDI) or trimer compounds of these polyisocyanates, reaction products of these polyisocyanates and polyols, etc. are preferably used. Of these, hydrogenated xylylene diisocyanate (H-XDI) and isophorone diisocyanate (IPDI) are preferred because of excellent light resistance. The molecular weight of the polyisocyanate compound (Y) is preferably 500 or less. If it is 500 or less, the reactivity with a diol will not fall.

Examples of the hydroxy (meth) acrylate (Z) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyethyl acryloyl phosphate, and 4-butyl. Hydroxy (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, glycerin di (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, caprolactone modified 2-hydroxyethyl (Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, etc. Of these 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate is preferably used.

In the urethane (meth) acrylate oligomer, the number of (meth) acryloyl groups in the molecule is 1 or more and 6 or less, more preferably 2 or more and 4 or less (meth) acryloyl groups at the end or side chain of the molecule. What has is preferable. When there is no (meth) acryloyl group, it cannot be copolymerized with the monofunctional (meth) acrylate as the component (B), and when it is more than 6, the resulting cured product becomes too hard and has excellent elongation. It may not be obtained.

The molecular weight of the urethane (meth) acrylate oligomer is preferably 5,000 or more and 100,000 or less, more preferably 10,000 or more and 80,000 or less. If the molecular weight is 5,000 or more, the resulting cured product is not too hard, and exhibits excellent elongation without increasing the cure shrinkage, and if it is 100,000 or less, the curability is poor. It shows a suitable elastic modulus without any problem.

The Tg of a cured product obtained by polymerizing a urethane (meth) acrylate oligomer alone is preferably 0 ° C. or lower. More preferably, Tg is −10 ° C. or lower, particularly preferably −20 ° C. or lower. When Tg is 0 ° C. or lower, the obtained cured product exhibits excellent elongation. In addition, about Tg of the resin composition of this invention, it measures by well-known methods, such as DSC and dynamic viscoelasticity, for example.

（式中、Ｒ^３は水素原子またはメチル基であり、Ｒ^４は、炭素数１〜２２である直鎖もしくは分岐アルキル基、シクロヘキシル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたシクロヘキシル基、フェニル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたフェニル基、ジシクロペンタニル基、ジシクロペンテニル基、ボルニル基、イソボルニル基、アダマンチル基、メチルアダマンチル基、又はアリル基である。）

（式中、Ｒ^３は水素原子またはメチル基であり、Ｒ^５は、炭素数１〜４である直鎖もしくは分岐アルキル基、Ｒ^６は、炭素数１〜４である直鎖もしくは分岐アルキル基、シクロヘキシル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたシクロヘキシル基、フェニル基、炭素数１〜４の直鎖もしくは分岐アルキル基により置換されたフェニル基、ジシクロペンタニル基、ジシクロペンテニル基、ボルニル基、イソボルニル基、アダマンチル基、メチルアダマンチル基、又はアリル基であり、ｎは１〜１２の整数である。） The monofunctional (meth) acrylate as the component (B) is not particularly limited as long as it contains one (meth) acryloyl group in the molecule, but is represented by the following formula [7] or [8]. A resin composition containing a monofunctional (meth) acrylate is particularly preferable because a cured product having an appropriate elastic modulus and excellent elongation can be obtained.

(In the formula, R ³ is a hydrogen atom or a methyl group, and R ⁴ is substituted with a linear or branched alkyl group having 1 to 22 carbon atoms, a cyclohexyl group, or a linear or branched alkyl group having 1 to 4 carbon atoms. Cyclohexyl group, phenyl group, phenyl group substituted by a linear or branched alkyl group having 1 to 4 carbon atoms, dicyclopentanyl group, dicyclopentenyl group, bornyl group, isobornyl group, adamantyl group, methyladamantyl group Or an allyl group.)

(Wherein R ³ is a hydrogen atom or a methyl group, R ⁵ is a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁶ is a linear or branched alkyl group having 1 to 4 carbon atoms. A cyclohexyl group, a cyclohexyl group substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, a phenyl group, a phenyl group substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, a dicyclopentanyl group A dicyclopentenyl group, a bornyl group, an isobornyl group, an adamantyl group, a methyladamantyl group, or an allyl group, and n is an integer of 1 to 12.)

Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meta ) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tridecyl (meth) acrylate, behenyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl ( (Meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meta) Acrylate, methoxytetraethylene (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, phenoxyhexaethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate , Methoxytripropylene glycol (meth) acrylate, cyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (Meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate 2-methyl-2-adamantyl (meth) acrylate, allyl (meth) acrylate and the like. Of acrylate and methacrylate, methacrylate shows more preferable elastic modulus and elongation.

(B) The monofunctional (meth) acrylate preferably contains at least one monofunctional (meth) acrylate having a homopolymer Tg of 20 ° C. or higher. More preferably, Tg is 50 ° C. or more, and particularly preferably 80 ° C. or more. When Tg is 20 ° C. or higher, the obtained cured product exhibits an appropriate elastic modulus and does not deteriorate the curability.

In the resin composition of the present invention, the blending ratio of the component (A) and the component (B) is in the range of 5:95 to 95: 5, preferably in the range of 10:90 to 80:20, particularly preferably in mass ratio. When it exists in the range of 20: 80-70: 30, the hardening body obtained by light irradiation can obtain the resin composition which shows quick hardening, moderate elastic modulus, and the outstanding elongation.

When the present inventor contains a polyester polyol-based urethane (meth) acrylate in the above blending ratio, it contains a lot of ester bonds in the molecule. Therefore, when used under conditions of high temperature and high humidity, the molecular weight due to hydrolysis of ester bonds As a result of finding out that the mechanical properties accompanying the decrease in the quality are not sufficient and conducting various studies to improve this, in addition to the resin composition containing the components (A) and (B), (C) By containing a hindered amine compound having a group represented by the chemical formula [9], it is cured in a very short time by light irradiation, and the cured product exhibits an appropriate elastic modulus and excellent elongation, and further is resistant to hydrolysis. It came to achieve the objective of this invention of obtaining the resin composition excellent in property.

The hindered amine compound as component (C) is a compound having a group represented by the chemical formula [9]. As a specific example,
Bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate,
Bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate,
4-benzoyloxy-2,2,6,6-tetramethylpiperidine,
1,2,2,6,6-pentamethyl-4-piperidinyl- (meth) acrylate,
2,2,6,6-tetramethyl-4-piperidinyl- (meth) acrylate,
1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionyloxy] -2,2,6,6-tetramethylpiperidine,
Bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [3,5-di-tert-butyl-4-hydroxyphenylmethyl] butyl malonate,
Decanoic acid bis [2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl] ester, reaction product of 1,1-dimethylethylhydroxyperoxide and octane,
N, N ', N ", N"'-tetrakis- [4,6-bis- [butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino] -triazine- 2-yl] -4,7-diazadecane-1,10-diamine,
Dibutylamine, 1,3,5-triazine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) -1,6-hexamethylenediamine and N- (2,2,6 , 6-tetramethyl-4-piperidyl) butylamine polycondensate,
Poly [[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl ) Imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]],
Polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol,
2,2,4,4-tetramethyl-7-oxa-3,20-diazadispiro- [5 · 1 · 11 · 2] -heneicosane-21-one,
β-alanine, N,-(2,2,6,6-tetramethyl-4-piperidinyl) -dodecyl ester / tetradecyl ester,
N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione, 2,2,4,4-tetramethyl-7-oxa-3 , 20-diazadispiro [5,1,11,2] heneicosan-21-one,
2,2,4,4-tetramethyl-21-oxa-3,20-diazadicyclo- [5,1,11,2] -heneicosane-20-propanoic acid dodecyl ester / tetradecyl ester,
Propannic acid, [(4-methoxyphenyl) -methylene] -bis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester,
Higher fatty acid esters of 2,2,6,6-tetramethyl-4-piperidinol,
1,3-benzenedicarboxamide, N, N′-bis (2,2,6,6-tetramethyl-4-piperidinyl),
1,2,3,4-butanetetracarboxylic acid tetrakis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester,
A tetraester of a mixture of 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piperidinyl and tridecyl;
Tetraester of a mixture of 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinyl and tridecyl;
1,2,3,4-butanetetracarboxylic acid tetramethyl ester and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-2,4,8, A reaction product with 10-tetraoxaspiro [5.5] undecane-3,9-diethanol,
1,2,3,4-butanetetracarboxylic acid tetramethyl ester and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-2,4,8, A reaction product with 10-tetraoxaspiro [5.5] undecane-3,9-diethanol,
1,2,3,4-butanetetracarboxylic acid polymer 2,2-bis (hydroxymethyl) -1,3-propanediol and 3-hydroxy-2,2-dimethylpropanal,
1,2,2,6,6-pentamethyl-4-piperidinyl ester,
1,2,3,4-butanetetracarboxylic acid tetramethyl ester 1,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-2,4,8,10- Tetraoxaspiro [5.5] undecane-3,9-diethanol,
Etc.

The content ratio of the component (C) in the resin composition of the present invention is obtained when the composition contains 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). The resulting cured product has particularly excellent hydrolysis resistance. If it is 0.01 mass part or more, the outstanding hydrolysis resistance can be provided, and if it is 10 mass parts or less, curability will not be lowered.

In the resin composition of the present invention, it is preferable to contain a photopolymerization initiator as component (D). As the photopolymerization initiator, benzoin-based, benzophenone-based, acetophenone-based, acylphosphine oxide-based, thioxanthone-based , Metallocene-based, quinone-based, boron-based ultraviolet polymerization initiators and visible light polymerization initiators.

Specific examples of the photopolymerization initiator include, for example, benzophenone, 4-phenylbenzophenone, benzoylbenzoic acid, 2,2-diethoxyacetophenone, bisdiethylaminobenzophenone, benzyl, benzoin, benzoylisopropyl ether, benzyldimethyl ketal, 1-hydroxy Cyclohexyl phenyl ketone, thioxanthone, 1- (4-isopropylphenyl) 2-hydroxy-2-methylpropan-1-one, 1- (4- (2-hydroxyethoxy) -phenyl) -2-hydroxy-2-methyl- 1-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, camphorquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzo L) -Phenylphosphine oxide, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) Examples include -1-butanone-1, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, among which curable with visible light and particularly excellent in reactivity 2 , 4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, etc. Acylphosphine oxide compounds are preferred.

Furthermore, in the resin composition of the present invention, a rubber composition can be blended in order to impart excellent vibration fatigue durability.

Examples of the rubber composition include the elastomer (R) described above, and among these, (meth) acrylic acid ester compounds, vinyl compounds, and olefin hydrocarbons are particularly preferable from the viewpoint of compatibility with the resin composition. A rubber composition that is a copolymer comprising a monomer selected from the group consisting of compounds is preferred.

In the present invention, if necessary, pigments (titanium white, cyanine blue, watching red, bengara, carbon black, aniline black, manganese blue, iron black, ultramarine blue are used as long as the effects of the present invention are not impaired. , Hansa Red, Chrome Yellow, Chrome Green, etc.), inorganic fillers (calcium carbonate, kaolin, clay, talc, mica, barium sulfate, lithopone, gypsum, zinc stearate, perlite, quartz, quartz glass, fused silica, spherical Silica powder such as silica, etc., oxides such as spherical alumina, crushed alumina, magnesium oxide, beryllium oxide and titanium oxide, nitrides such as boron nitride, silicon nitride and aluminum nitride, carbides such as silicon carbide, water Hydroxides such as aluminum oxide and magnesium hydroxide, , Silver, iron, aluminum, nickel, titanium and other metals and alloys, diamond, carbon and other carbon-based materials), thermoplastic resins and thermosetting resins (nylon-6, nylon-6,6, etc. polyamides) Resin, vinyl chloride resin, nitrocellulose resin, vinylidene chloride resin, acrylic resin, acrylamide resin, styrene resin, vinyl ester resin, polyester resin, fluorine resin, acrylic rubber, urethane rubber, etc. Various elastomer resins, methyl methacrylate-butadiene-styrene graft copolymers and graft copolymers such as acrylonitrile-butadiene-styrene graft copolymers), reinforcing agents (glass fibers, carbon fibers, etc.), anti-sagging agents (Hydrogenated castor oil, fine particulate succinic anhydride, etc.), matting agents (fine silica, para Inwakkusu etc.), it is also possible to blend the abrasive (zinc stearate).

In addition to the above components, phenolic antioxidants, quinone antioxidants, phosphorus antioxidants, amine antioxidants, lactone antioxidants, sulfur antioxidants and other antioxidants, It is also possible to use an ultraviolet absorber, an antifoaming agent, a flame retardant, an antistatic agent, a plasticizer, a thermal polymerization initiator, a silane coupling agent, an adhesion imparting agent and the like in combination.

By irradiating energy rays such as light to the resin composition of the present invention obtained as described above, it cures in a short time, and has an appropriate elastic modulus and excellent elongation required for conventional elastomer resins. The cured product shown can be obtained.

The cured product of the resin composition of the present invention has a tensile elastic modulus of 1 to 100 MPa, particularly preferably 3 to 70 MPa, when a tensile test measurement is performed according to JIS K7113 (plastic tensile test method). The tensile elongation at break is 200% or more. When the tensile elastic modulus of the cured body is 1 MPa or more, there is no problem that the obtained cured body is too soft to maintain the target shape. Moreover, if the tensile elastic modulus of the cured body is 100 MPa or less and the tensile fracture elongation is 200% or more, excellent vibration fatigue durability can be obtained.

Further, when molding the cured product of the resin composition of the present invention, various methods can be adopted as the means, and the following two methods are particularly preferable. (1) At least one of a set of molds including an upper mold and a lower mold is formed of a material that transmits energy rays such as light, and a predetermined amount of the resin composition before curing is disposed. Next, the upper mold and the lower mold are pressure-bonded, the mold is closed, the energy beam is irradiated from the outside of the mold made of a material that transmits the energy beam, and the resin is cured to obtain a desired cured body, or ( 2) At least one of a pair of molds consisting of an upper mold and a lower mold is formed of a material that transmits energy rays, and then the upper mold and the lower mold are pressure-bonded, and the mold is closed. A predetermined amount of the resin composition before curing is injected from an injection port formed in advance. And the method of irradiating light from the outer side of the type | mold which consists of a material which permeate | transmits an energy ray, and hardening a resin and obtaining the target hardening body.

Examples of materials used for the mold that transmits energy rays include glass materials such as quartz, quartz glass, borosilicate glass, and soda glass, acrylic resin, polycarbonate resin, polystyrene resin, polyester resin, polyethylene resin, polypropylene resin, and fluorine resin. And resin materials such as cellulose resin, styrene-butadiene copolymer, methyl methacrylate-styrene copolymer, silicone resin, and polycycloolefin resin. Among them, an acrylic resin such as polymethyl methacrylate is particularly preferable because it is excellent in transparency, durability, and can be manufactured at low cost, and the excellent moldability exhibited by the resin composition of the present invention by using the acrylic resin. It can be maximized.

Energy ray sources include halogen lamps, metal halide lamps, high power metal halide lamps (containing indium, etc.), low pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, xenon lamps, xenon excimer lamps, xenon flash lamps, etc. .

Since the radiation wavelength and energy distribution are different, the energy ray source (hereinafter simply referred to as a light source) is selected depending on, for example, the reaction wavelength of the photopolymerization initiator. Natural light (sunlight) can also be a reaction initiation light source.

The light source can be directly irradiated, focused with a reflecting mirror or the like, or focused with a fiber or the like, and a low wavelength cut filter, a heat ray cut filter, a cold mirror, or the like can also be used.

Moreover, when shape | molding the hardening body of the resin composition of this invention with said shaping | molding method, it is preferable that the cure shrinkage rate of a resin composition is 0%-5%. This is because if it is less than 0% (represents expansion due to curing) or exceeds 5%, a difference between the dimension of the mold and the dimension of the cured body will occur, making it difficult to obtain a cured body of the desired shape.

Moreover, it is preferable that the viscosity of a resin composition is 100-100,000 mPa * s at 25 degreeC, Most preferably, it is 3,000-90,000 mPa * s. If it is less than 100 mPa · s, liquid leakage from the mold may occur, and a molded product of the desired shape may not be obtained. If it exceeds 100,000 mPa · s, it is difficult to fill the mold. This is because the cured product having the desired shape may not be obtained.

<Examples 1 to 14 and Comparative Examples 1 to 3>
Each type of component shown in Tables 1-2 was mixed with the composition shown in the table to prepare a photocurable resin composition. In addition, the following compounds were selected for each component described in Tables 1-2.

(A) The following was used as a urethane (meth) acrylate oligomer. In addition, the molecular weight as described below is a weight average molecular weight in terms of standard polystyrene measured by gel permeation chromatography (GPC) (solvent: tetrahydrofuran (THF)).
(A1) Polyester polyol-based urethane acrylate (1) (manufactured by Nippon Synthetic Chemical Industry “UV-3000B” molecular weight: 18,000)
(A2) Polyester polyol urethane acrylate (2) (“KHP-11” molecular weight: 25,000, manufactured by Negami Kogyo Co., Ltd.)
(A3) Polyester polyol urethane acrylate (3) (“KHP-17” molecular weight: 40,000 manufactured by Negami Kogyo Co., Ltd.)
(A4) Polyester polyol urethane acrylate (4) (“SD-7” molecular weight: 3,500, manufactured by Negami Kogyo Co., Ltd.)

The following (b1) to (b4) were used as the monofunctional (meth) acrylate of the component (B).
(B1) Dicyclopentanyl methacrylate (“Fancryl FA-513M” manufactured by Hitachi Chemical Co., Ltd.)
(B2) n-Butyl methacrylate (“Light Ester NB” manufactured by Kyoeisha Chemical Co., Ltd.)
(B3) Phenoxyethyl methacrylate (“Light Ester PO” manufactured by Kyoeisha Chemical Co., Ltd.)
(B4) 4-Hydroxybutyl methacrylate (“Eye ester HOB” manufactured by Kyoeisha Chemical Co., Ltd.)

As the hindered amine compound of component (C), the following (c1) to (c8) were used.
(C1) Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (“Sanol LS-770” manufactured by Sankyo Lifetech Co., Ltd.)
(C2) Bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (“Sanol LS-765” manufactured by Sankyo Lifetech Co., Ltd.)
(C3) 1,2,2,6,6-pentamethyl-4-piperidinyl- (meth) acrylate (“Sanol LS-3410” manufactured by Sankyo Lifetech Co., Ltd.)
(C4) 1,2,3,4-butanetetracarboxylic acid tetrakis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester (“Adeka Stub LA-52” manufactured by Adeka)
(C5) Tetraester of a mixture of 1,2,3,4-butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinyl and tridecyl ("Adeka Stub LA-62" manufactured by Adeka)
(C6) Tetraester of a mixture of 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinyl and tridecyl (“ADEKA STAB LA-67” manufactured by Adeka)
(C7) 1,2,3,4-butanetetracarboxylic acid tetramethyl ester and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-2,4 , 8,10-tetraoxaspiro [5.5] undecane-3,9-diethanol (“Adeka Stab LA-63P” manufactured by Adeka)
(C8) 2,2,4,4-tetramethyl-21-oxa-3,20-diazadicyclo- [5,1,11,2] -heneicosane-20-propanoic acid dodecyl ester / tetradecyl ester (Clariant Japan Ltd.) "Hostabin N24")

As the photopolymerization initiator of component (D),
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (“IRGACURE819” manufactured by Ciba Specialty Chemicals) was used.

Various physical properties were measured as follows.

[Light irradiation conditions]
At the time of light irradiation, a belt conveyor type ultraviolet curing device manufactured by Fusion equipped with an electrodeless discharge lamp (D bulb) is used, and the total irradiation amount to the resin composition is 4,000 mJ / cm ² (365 nm). And cured.

[Adjustment of cured specimen]
A set of molds consisting of an acrylic resin plate of 200 mm × 200 mm × 5 mm thickness as the upper mold and a lower mold that imitates a concave portion of the desired shape at the center of one side of the acrylic resin plate having the same shape as the upper mold The required amount of the resin composition before curing was dropped onto the lower mold recess. Next, the upper mold was put on the lower mold, and was pressure-bonded and closed. The light was irradiated from the outside of the upper mold under the irradiation conditions described above, and the resin was cured to obtain a desired cured body test piece.

(Resin tensile test)
(1) In accordance with the initial JIS K7113 (plastic tensile test method), a 2 (1/2) dumbbell shape (distance between gauge points 12 mm) and a 1 mm thick test piece were adjusted under the above conditions, and the temperature was 23 ° C. In a 50% humidity environment, the measurement was performed at a tensile speed of 50 mm / min. Each value of tensile fracture strength, tensile elastic modulus, and tensile fracture elongation was determined according to JIS K7113.

(2) High temperature and humidity test
A test piece prepared under the same conditions as in (1) was exposed to an environment of a temperature of 60 ° C. and a humidity of 90% for 10 days. The test specimen after exposure was measured at a tensile speed of 50 mm / min in the same environment as in (1), and the resin physical property retention ratio (resin physical property retention ratio (%)) = {(resin physical property after high temperature and high humidity exposure) / (Initial resin properties)} × 100.

Tables 1 and 2 collectively show the results of the resin tensile test and the high-temperature and high-humidity test of the cured product of the obtained resin composition.

The resin composition of the present invention is instantly cured by irradiation with light such as ultraviolet rays or visible light, and the cured product has characteristics such as an appropriate elastic modulus and excellent elongation, and further excellent hydrolysis resistance. Therefore, automobile members such as tires, sealing members for structures such as civil engineering and construction, packing members such as O-rings, acoustic members such as speakers, sheet members such as key sheets for mobile phones, members, vibration-proof materials, The resin composition of the present invention can be suitably used for various mechanism members and the like, and can also be applied to structural sealants for civil engineering and construction, and adhesives for metals, magnets, ceramics, glass and plastics. Very useful on the industry.

Claims (7)

(A) a urethane (meth) acrylate oligomer having a polyester skeleton represented by the following chemical formula [1] in the molecule and having a molecular weight in the range of 5,000 to 100,000;

(Wherein R ¹ is a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, or a linear, branched or cyclic alkoxy group or polyalkoxy group having 1 to 30 carbon atoms, and R ² is C 1-10 linear or branched or cyclic alkyl group, or a group containing an aromatic ring selected from a benzene ring, naphthalene ring, anthracene ring, or fluorene ring, and m represents the degree of polymerization.)
(B) monofunctional (meth) acrylate,
further,
(C) A hindered amine compound having a group represented by the following chemical formula [2]

The mixing ratio of the component (A) and the component (B) is in the range of 5:95 to 95: 5 by mass ratio, and the component (C) is the total amount of the components (A) and (B). The resin composition which contains 0.01-10 mass parts with respect to 100 mass parts. (B) The monofunctional (meth) acrylate is a monofunctional (meth) acrylate represented by the following chemical formula [3] or [4].

(In the formula, R ³ is a hydrogen atom or a methyl group, and R ⁴ is substituted with a linear or branched alkyl group having 1 to 22 carbon atoms, a cyclohexyl group, or a linear or branched alkyl group having 1 to 4 carbon atoms. Cyclohexyl group, phenyl group, phenyl group substituted by a linear or branched alkyl group having 1 to 4 carbon atoms, dicyclopentanyl group, dicyclopentenyl group, bornyl group, isobornyl group, adamantyl group, methyladamantyl group Or an allyl group.)

(Wherein R ³ is a hydrogen atom or a methyl group, R ⁵ is a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁶ is a linear or branched alkyl group having 1 to 4 carbon atoms. A cyclohexyl group, a cyclohexyl group substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, a phenyl group, a phenyl group substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, a dicyclopentanyl group A dicyclopentenyl group, a bornyl group, an isobornyl group, an adamantyl group, a methyladamantyl group, or an allyl group, and n is an integer of 1 to 12.) (D) The resin composition of Claim 1 or Claim 2 containing a photoinitiator as a component. (D) The resin composition according to claim 3, wherein the photopolymerization initiator is an acylphosphine oxide compound. The hardening body which consists of a resin composition as described in any one of Claims 1-4. The cured product according to claim 5, wherein the tensile elastic modulus is 1 to 100 MPa, and the tensile fracture elongation is 200% or more. The resin composition according to any one of claims 1 to 4 is injected into a mold made of a material capable of transmitting energy rays, and cured by irradiation with energy rays from the outside of the mold, and then molded. A casting method characterized by forming a body.