JP2014080498A - Photocurable elastomer composition, sealing material, and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable elastomer composition which is capable of achieving both flexibility and low adhesiveness when cured, and to provide a sealing material using the composition and a device having the sealing material.SOLUTION: The photocurable elastomer composition of the present invention contains (A) a polymer having a (meth)acryloyl group in the molecule, (B) a monomer having a photocurable functional group in the molecule, (C) a fatty acid amide compound, and (D) a photopolymerization initiator.

Description

  The present invention relates to a photocurable elastomer composition, a sealing material, and an apparatus.

As a material of the hard coating material which is the mainstream of the sealing material, a composition containing a bisphenol A type epoxy (meth) acrylate as a main component is common. Since this composition has a strong intermolecular force and is three-dimensionally dense, it has excellent gas / water vapor barrier properties, but the cured product is very hard. Therefore, it cannot be used as a sealing material in the electrical equipment field where flexibility is required.
As a sealing material in the electrical equipment field where flexibility is required, for example, a flexible display-related sealing material or a material that may be bent like a packing, a hard disk drive (hereinafter, referred to as a hard disk drive used for a computer and a recording device). For example, a member used for high compression such as a gasket for “HDD”. Furthermore, in particular, in HDD gaskets, adherends (also called adherends) are bonded together, and then the adherends are released (peeled), and then the same adherend is used again. A property capable of bonding and sealing the adherends, so-called reworkability is also required.

  Conventionally, an elastomer composition (for example, see Patent Document 1) containing a reactive polymer having a (meth) acryloyl group at a terminal, a (meth) acrylic acid ester monomer, and a radical photopolymerization initiator is sealed. It is being considered as a material.

  However, a photocurable elastomer that can achieve both flexibility and low adhesiveness when cured has not been developed yet, and its development has been strongly desired.

JP 2007-39587 A

  Then, the objective of this invention is providing the photocurable elastomer composition which can make the softness | flexibility at the time of hardening and low adhesiveness make compatible. Moreover, the objective of this invention is providing the sealing material which can make a softness | flexibility and low adhesiveness make compatible. Furthermore, the objective of this invention is providing the apparatus which can make sealing performance and reworkability compatible.

  The photocurable elastomer composition of the present invention comprises (A) a polymer having a (meth) acryloyl group in the molecule, (B) a monomer having a photocurable functional group in the molecule, and (C) a fatty acid amide compound. And (D) a photopolymerization initiator. According to this structure, the softness | flexibility at the time of making it harden | cure and low adhesiveness can be made compatible.

In this specification, “light” in “photocurability” and “photopolymerization” means ultraviolet rays; visible rays; charged particle rays such as α rays, β rays, electron rays, electromagnetic waves such as γ rays, and high Ionizing radiation containing energetic particles, and particularly preferably ultraviolet rays. In the present specification, the “number average molecular weight” means a number average molecular weight represented by a standard polystyrene equivalent value measured by a gel permeation chromatography (GPC) method unless otherwise specified. In this specification, “liquid” means having fluidity at room temperature (25 ° C.). In the present specification, “(meth) acryloyl” means at least one of acryloyl and methacryloyl, an acryloyl group means (CH ₂ ═CHCO—), and a methacryloyl group has (CH ₂ ═C ( CH ₃ ) CO—). In the present specification, the “main skeleton” means a main skeleton that forms the main chain of the polymer. The main skeleton can be determined using, for example, NMR measurement. In this specification, “urethane skeleton” means a skeleton composed of — [OCONH] — units, and “butadiene skeleton” means (i)-[CH ₂ —CH═CH—CH ₂ ] -units (cis- 1,4 _{bonds), (ii) - [CH} 2 -CH = CH-CH 2] - units (trans-1,4 bonds), and _{(iii) - [CH 2 -CH} (CH = CH 2)] - This means a skeleton consisting of at least one selected from the group consisting of units (1,2 bonds), and “isoprene skeleton” means (i) — [CH ₂ —C (CH ₃ ) ═CH—CH ₂ ] —. unit (cis-1,4 _{bond), (ii) - [CH} 2 -C (CH 3) = CH-CH 2] - units (trans-1,4 _{bonds), (iii) - [CH} 2 -C ( _{CH 3) (CH = CH 2} )] - units (1,2-bond), and _{(iv) - [CH 2 -C} (C (CH 3) = C H ₂ )] — means a skeleton composed of at least one selected from the group consisting of units (3,4 bonds), and “isobutylene skeleton” refers to — [CH ₂ —C (CH ₃ ) ₂ ] — units. The “conjugated diene skeleton” means a skeleton derived from a conjugated diene such as a butadiene skeleton or an isoprene skeleton. In the present specification, the “cyclic hydrocarbon skeleton” includes not only aliphatic cyclic hydrocarbons but also aromatic cyclic hydrocarbons. In the present specification, the “sealing material” is a concept including a sealing material, a sealing material, a gasket, and packing. Further, in this specification, unless otherwise specified, the sealing material, the gasket, and the packing include both a fixing seal (static seal) and a motion seal.

  In the photocurable elastomer composition of the present invention, the main skeleton of the polymer preferably contains at least one selected from the group consisting of a urethane skeleton, a butadiene skeleton, an isoprene skeleton, and an isobutylene skeleton. According to this configuration, flexibility when cured can be maintained.

  In the photocurable elastomer composition of the present invention, the polymer preferably has at least two (meth) acryloyl groups in the molecule. According to this configuration, a network structure can be formed, and the compression set can be reduced.

  In the photocurable elastomer composition of the present invention, the fatty acid amide compound is preferably a primary fatty acid amide or a secondary fatty acid amide having 22 or more carbon atoms and having a carbon double bond. According to this structure, low adhesiveness can be achieved.

  In the photocurable elastomer composition of the present invention, the fatty acid amide compound preferably has a portion composed of a saturated hydrocarbon and a portion composed of an unsaturated hydrocarbon. According to this structure, low adhesiveness can be improved more.

  In the photocurable elastomer composition of the present invention, the portion consisting of the saturated hydrocarbon and the portion consisting of the unsaturated hydrocarbon are connected via an amide bond, and the portion consisting of the saturated hydrocarbon is the amide The number of carbon atoms of the portion consisting of the unsaturated hydrocarbon is the portion of the unsaturated hydrocarbon bonded to the nitrogen atom in the bond, the portion of the amide bond bonded to the carbon atom of the amide bond. More preferably, it is more than that. According to this structure, low adhesiveness can be improved more.

  In the photocurable elastomer composition of the present invention, the content of the fatty acid amide compound is 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass in total of the (A) polymer and the (B) monomer. It is preferable that According to this structure, low adhesiveness can be improved more.

  In the photocurable elastomer composition of the present invention, it is preferable that the (B) monomer further has a cyclic hydrocarbon skeleton, and the photocurable functional group is a (meth) acryloyl group. According to this structure, the gas barrier property at the time of hardening can be improved more.

  The photocurable elastomer composition of the present invention is preferably used for a sealing material.

  The sealing material of the present invention is characterized in that the photocurable elastomer composition of the present invention is used at least in part. The sealing material of the present invention can achieve both flexibility and low adhesiveness by using the photocurable elastomer composition of the present invention at least in part.

  The apparatus of the present invention is characterized by having at least a part of the sealing material of the present invention. The apparatus of the present invention has both the sealing performance and the reworkability by having the sealing material of the present invention at least in part.

  ADVANTAGE OF THE INVENTION According to this invention, the photocurable elastomer composition which can make the softness | flexibility at the time of hardening and low adhesiveness make compatible can be provided. Moreover, according to this invention, the sealing material which can make a softness | flexibility and low adhesiveness compatible can be provided. Furthermore, according to this invention, the apparatus which can make sealing performance and rework property compatible can be provided.

(Photocurable elastomer composition)
The photocurable elastomer composition of the present invention comprises at least (A) a polymer, (B) a monomer, (C) a fatty acid amide compound, and (D) a photopolymerization initiator. Accordingly, (E) a carbodiimide compound and other components are included.

<(A) Polymer>
The polymer (A) is not particularly limited as long as it has a (meth) acryloyl group in the molecule, and can be appropriately selected according to the purpose, and is a hydrogenated product (main skeleton is hydrogenated). May be. Specific examples of the polymer (A) are not particularly limited and may be appropriately selected depending on the purpose. For example, (1) a bifunctional urethane-based acrylate oligomer (for example, Light Tuck PUA- manufactured by Kyoeisha Chemical Co., Ltd.) Polymer contained in KH32M, number average molecular weight 10,000, (meth) acryloyl group at both ends), (2) methacryl-modified isoprene rubber (for example, trade name UC-102 manufactured by Kuraray Co., Ltd., number average molecular weight 17) , 000 (having two (meth) acryloyl groups in the side chain), (3) hydrogenated polybutadiene diacrylate (for example, (i) product name CN9014 (number average molecular weight 6,500, (meth) acryloyl manufactured by Sartomer) Having a group at both ends, the main skeleton is hydrogenated), (ii) Nippon Soda Co., Ltd. trade name TEAI-1000, number average (Molecular weight 2,000, (meth) acryloyl groups at both ends, main skeleton is hydrogenated)), (4) Acrylic modified butadiene rubber: (trade name L-1253, manufactured by Kuraray, number average molecular weight 7,000, (Having a (meth) acryloyl group at one end), (5) acrylic modified isoprene rubber (trade name UC-203, manufactured by Kuraray, number average molecular weight 27,000, main chain having 3 (meth) acryloyl groups in the side chain, Skeleton is non-hydrogenated). These may be used individually by 1 type and may use 2 or more types together.

  The number of (meth) acryloyl groups in the molecule of the (A) polymer is not particularly limited as long as it is 1 or more, and can be appropriately selected according to the purpose, and preferably 2 or more. When the number of (meth) acryloyl groups in the molecule of the (A) polymer is 2 or more, a network structure can be formed, and compression set can be reduced. Thereby, sealing performance is maintained and high reworkability is obtained. There is no restriction | limiting in particular as a position of the (meth) acryloyl group in the said polymer molecule, According to the objective, it can select suitably, A polymer terminal (one terminal, both terminals) may be sufficient, There may be.

  The main skeleton of the polymer (A) is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a urethane skeleton; a conjugated diene skeleton such as a butadiene skeleton and an isoprene skeleton; an isobutylene skeleton; Are preferable in terms of the properties and gas barrier properties.

The number average molecular weight of the (A) polymer is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 1,000 to 40,000, and more preferably 2,000 to 35,000. When the number average molecular weight of the (A) polymer is 1,000 or more, it is preferable from the viewpoint of flexibility, and when it is 40,000 or less, it is preferable from the viewpoint of low viscosity and easy handling.
Moreover, it is more advantageous in the point of the softness | flexibility at the time of making it harden | cure that the number average molecular weight of the said (A) polymer is in the more preferable range, and a handling point.

  The content of the polymer (A) is not particularly limited and may be appropriately adjusted depending on the application, use state, required performance, and the like. 30 mass%-70 mass% is preferable with respect to the total amount of a component. In terms of compression set when cured, the content of the polymer (A) is 30% by mass or more based on the total amount of the two components of the polymer (A) and the monomer (B) described below. Preferably, it is preferably 70% by mass or less from the viewpoint of viscosity control.

<(B) Monomer>
(B) The monomer has a function of imparting photocurability (moldability) to the photocurable elastomer composition of the present invention. The monomer (B) is not particularly limited as long as it has a photocurable functional group in the molecule, and can be appropriately selected according to the purpose. Examples of the photocurable functional group include a (meth) acryloyl group, an epoxy group, a vinyl group, a maleimide group, and a vinylidene group. There is no restriction | limiting in particular as a monomer which has the said (meth) acryloyl group in a molecule | numerator, According to the objective, it can select suitably, For example, phenoxyethyl acrylate, (meth) acryloyl morpholine, cyclohexyl (meth) acrylate , Dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, dimethylaminoethyl (meth) acrylate, dipropylene glycol mono ( (Meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate, ethyl (meth) acrylate, isoamyl (meth) acrylate, isobornyl (meth) ) Acrylate, isobutyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, isostearyl (meth) acrylate, isomyristyl (meth) acrylate, lauroxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, Methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate (For example, 2-ethylhexyl-diglycol acrylate), n-octadecyl (meth) acrylate, (meth) acrylic acid Esters of polyhydric alcohols, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a monomer having a cyclic hydrocarbon skeleton (particularly isobornyl (meth) acrylate) is preferable in terms of high gas barrier properties, and a monomer having an ethylene oxide moiety (for example, phenoxyethyl acrylate) is excellent in flexibility. Is preferable. These are preferably selected as necessary.

  The content of the (B) monomer is not particularly limited and may be appropriately adjusted according to the use, use state, required performance, etc., but the two components of the (A) polymer and the (B) monomer. 30 mass%-70 mass% is preferable with respect to the total amount. By being in such a range, the photocurable elastomer composition can exhibit excellent sealing properties.

<(C) Fatty acid amide compound>
The (C) fatty acid amide (fatty acid amide) compound is considered to function to impart low tackiness to the photocurable elastomer composition after curing, with hydrocarbons (hydrophobic groups) oriented on the surface. There is no restriction | limiting in particular as said (C) fatty acid amide, According to the objective, it can select suitably, For example, N-oleyl palmitic acid amide (compound represented by following Structural formula (1)), N-oleyl Stearic acid amide (compound represented by the following structural formula (2)), N-stearyl oleic acid amide (compound represented by the following structural formula (3)), N-stearyl erucic acid amide (the following structural formula (4) ), Purified erucic acid amide (compound represented by the following structural formula (5)), purified oleic acid amide (compound represented by the following structural formula (6)), behenic acid amide (the following structural formula) (Compound represented by (7)), erucic acid amide (compound represented by the following structural formula (8)), stearic acid amide (compound represented by the following structural formula (9)), and the like. These may be used individually by 1 type and may use 2 or more types together. In addition, as the fatty acid amide compound, a primary fatty acid amide having 22 or more carbon atoms and having a carbon double bond (for example, a compound represented by the following structural formulas (5) and (8)), or In addition, a secondary fatty acid amide having 22 or more carbon atoms and having a carbon double bond (for example, a compound represented by the following structural formulas (2) to (4)) is a low-tack expression. preferable. In addition, as the fatty acid amide compound, a compound having a portion composed of a saturated hydrocarbon and a portion composed of an unsaturated hydrocarbon (for example, a compound represented by the following structural formulas (2) to (4)) is low. More preferable in terms of adhesiveness. Furthermore, a portion consisting of a saturated hydrocarbon and a portion consisting of an unsaturated hydrocarbon are connected via an amide bond (—NHCO—), and the portion consisting of the saturated hydrocarbon is in the amide bond (—NHCO—). The portion bonded to the nitrogen atom N and composed of the unsaturated hydrocarbon is bonded to the carbon atom C in the amide bond (—NHCO—), and the portion composed of the saturated hydrocarbon is composed of the unsaturated hydrocarbon. A secondary fatty acid amide (for example, a compound represented by the following structural formula (3)) having a larger number of carbon atoms is more preferable in terms of low adhesiveness.

  There is no restriction | limiting in particular as content of the said (C) fatty acid amide compound, Although it can select suitably according to the objective, With respect to a total of 100 mass parts of the said (A) polymer and the said (B) monomer. 0.1 mass part-10 mass parts are preferable, 0.2 mass part-5 mass parts are more preferable, 0.5 mass part-3 mass parts are especially preferable. Low adhesiveness is manifested by the content of the (C) fatty acid amide being 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the (A) polymer and the (B) monomer. can do. Further, when the content of the (C) fatty acid amide compound is within the more preferable range or the particularly preferable range, it is advantageous in terms of further low tackiness.

<(D) Photopolymerization initiator>
(D) The photopolymerization initiator has a function of initiating or promoting photopolymerization or curing of the photocurable component. The (D) photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include benzoin alkyl ether photopolymerization initiators such as benzoin ethyl ether, benzoin isobutyl ether and benzoin isopropyl ether. Acetophenone-based photopolymerization initiators such as 2,2-diethoxyacetophenone, 4′-phenoxy-2,2-dichloroacetophenone; 2-hydroxy-2-methylpropiophenone, 4′-isopropyl-2-hydroxy-2 -Propiophenone photopolymerization initiators such as methylpropiophenone and 4'-dodecyl-2-hydroxy-2-methylpropiophenone; benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 1- [4- (2 -Hydroxyethoxy) -phenyl] -2-hydro Ci-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy-2 -Methyl-propionyl) -benzyl] phenyl] -2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1 -Alkylphenone photopolymerization initiators such as butanone; anthraquinone photopolymerization initiators such as 2-ethylanthraquinone and 2-chloroanthraquinone; 2,4,6-trimethylbenzoyl Acylphosphine oxide photopolymerization initiators such as phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; bis (η5-2, Titanocene photopolymerization initiators such as 4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium; α-alkylaminoketone photopolymerization Initiators; oxime ester photopolymerization initiators; oxyphenyl acetate photopolymerization initiators; cationic photopolymerization initiators; and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, 1-hydroxycyclohexyl phenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, and α-aminoalkylphenone are preferable.

  What is necessary is just to adjust suitably content of the said (D) photoinitiator according to the kind, content, etc. of a photocurable component in a photocurable elastomer composition. There is no restriction | limiting in particular as content of the said (D) photoinitiator, Although it can select suitably according to the objective, For example, the said photocurable component (For example, (A) polymer and (B) monomer) 0.1 mass part-10 mass parts are preferable with respect to a total of 100 mass parts, 0.5 mass part-5 mass parts are more preferable, and 0.5-3 mass part is especially preferable. Moreover, you may use together a well-known photosensitizer with the said photoinitiator.

<(E) Carbodiimide compound>
(E) The carbodiimide compound has a function of improving the heat hydrolysis resistance.
There is no restriction | limiting in particular as said (E) carbodiimide compound, According to the objective, it can select suitably, For example, 4,4'- dicyclohexyl methane carbodiimide, tetramethyl xylylene carbodiimide, N, N- dimethylphenyl carbodiimide, N, N′-di-2,6-diisopropylphenylcarbodiimide and the like. In addition, the (E) carbodiimide compound is preferably liquid in order to facilitate mixing and dispersion with other components, and the viscosity of the component is 0.1 to 100 Pa · s from the point of being liquid. Preferably, 0.5 to 10 Pa · s is more preferable.

<Other ingredients>
The photocurable elastomer composition of the present invention is an inorganic filler; an organic thixotropic agent; a coupling agent; an antioxidant; a light stabilizer; and stearin as necessary without departing from the spirit of the present invention. Fatty acid such as acid; Fatty acid metal salt such as calcium stearate; Fatty acid ester; Internal mold release agent such as polyolefin wax and paraffin wax; Softener such as process oil; Colorant; Leveling agent; Solvent; .

<< Inorganic filler (thixotropic agent) >>
There is no restriction | limiting in particular as an inorganic filler (thixotropic agent), According to the objective, it can select suitably, For example, a silica (SiO2), an alumina, a titania, a viscosity mineral, etc. are mentioned. Among these, silica is preferable in terms of curability and cost. The average particle diameter of the inorganic filler is more preferably 5 μm to 50 μm, more preferably 5 μm to 12 μm, from the viewpoint of imparting thickening and thixotropic properties (holding force in a state where no pressure is applied to the photocurable elastomer composition). Further preferred. When the photocurable elastomer composition of the present invention contains the inorganic filler, the content thereof may be adjusted as appropriate, and 0.1 parts by mass with respect to 100 parts by mass of the total amount of the photocurable elastomer composition. -30 mass parts is preferable, and 1-15 mass parts is more preferable.

<Method for Preparing Photocurable Elastomer Composition>
There is no restriction | limiting in particular in the preparation method of the photocurable elastomer composition of this invention, A well-known method can be used. For example, the above-mentioned (A) polymer, (B) monomer, (C) fatty acid amide compound, (D) photopolymerization initiator, (E) carbodiimide compound, and the other components are mixed into a kneader (for example, a single screw extruder). , Twin screw extruder, planetary mixer, twin screw mixer, high shear mixer, etc.).

(Seal material)
The sealing material of the present invention can be produced by using at least a part of the photocurable elastomer composition of the present invention. That is, the sealing material of the present invention is a sealing material containing at least part of a cured product obtained by irradiating the photocurable elastomer composition of the present invention with light such as ultraviolet rays. The sealing material of the present invention can achieve both flexibility (low hardness) and low adhesiveness by using at least a part of the photocurable elastomer composition of the present invention.

  Although the softness | flexibility of the sealing material of this invention can be suitably adjusted according to a use, it is preferable that the JIS-A hardness mentioned later is 70 or less, and it is more preferable that it is 50 or less.

  The low adhesiveness of the sealing material of the present invention can be appropriately adjusted depending on the application, but is preferably 35N or less, more preferably 25N or less, and more preferably 15N by the method described later in Examples. It is particularly preferred that Thereby, high reworkability is obtained.

The water vapor barrier property of the sealing material of the present invention can be appropriately adjusted according to the application, but the moisture permeability described later is preferably 20 (g / m ² · day) or less, and preferably 10 (g / m). ² · day) or less.

The helium barrier property of the sealing material of the present invention can be appropriately adjusted according to the application, but the helium barrier property (helium leak property) described later is 10 (× 10 ⁻⁷ Pa · m ³ / s) or less. Preferably, it is 5 (× 10 ⁻⁷ Pa · m ³ / s) or less.

  The sealing material of the present invention includes, for example, HDD gaskets; ink tank sealing materials; desktop computers, notebook computers, tablet computers and other various computers, mobile phones, liquid crystal display devices, organic EL displays, electronic paper, plasma displays, and the like. Various display devices, sealing materials for various electronic parts such as cameras; automotive parts, water purification devices, air purification devices, stirrers, speakers, pumps, etc .; anti-vibration devices, waterproof devices, dampers, civil engineering, architecture, etc. It can be used for applications such as sealing materials for structures; packing such as O-rings. Among these, since the sealing material of the present invention is excellent in flexibility and low adhesiveness, it can be suitably used for HDD gaskets. Furthermore, in the sealing material using the photocurable elastomer composition according to a preferred embodiment as described above at least in part, in addition to being excellent in flexibility and low adhesiveness, water vapor barrier property, helium barrier property, In addition, since the compression set is also good, it can be used particularly suitably for HDD gasket applications. The thickness of the sealing material can be appropriately adjusted depending on the application, but is usually about 0.1 mm to 2 mm.

<Method for producing member with sealing material>
A member with a sealing material can be produced by applying the photocurable elastomer composition of the present invention to an adherend and curing it by irradiation with light. As an adherend, it can select suitably according to a use, for example. In the case of a gasket, the adherend may be a metal or a hard resin. A metal adherend is preferred from the viewpoint of workability. The metal as the adherend is not particularly limited, and a conventionally known adherend can be used. For example, a cold rolled steel plate, a galvanized steel plate, an aluminum / zinc alloy plated steel plate, a stainless steel plate, an aluminum plate, an aluminum alloy plate, a magnesium plate, a magnesium alloy plate, and the like can be given. Moreover, what injection-molded magnesium can also be used. From the viewpoint of corrosion resistance, a nickel-plated metal is preferred.

  The method for applying the photocurable elastomer composition of the present invention to an adherend is not particularly limited, and a conventionally known method can be appropriately selected and used. Application is, for example, adjusting the temperature of the photocurable elastomer composition as necessary, adjusting to a desired viscosity, gravure coat, roll coat, spin coat, reverse coat, bar coat, screen coat, blade coat, air It can be performed by knife coating, dipping, dispensing, or the like. The photocurable elastomer composition of the present invention is applied to an adherend, molded as necessary, and then irradiated with light to cure the photocurable elastomer composition to obtain a member with a sealing material. .

The light that cures the photocurable elastomer composition of the present invention includes ultraviolet rays; visible rays; and charged particle beams such as α rays, β rays, electron beams, electromagnetic waves such as γ rays, and ionization including high energy particles. What is necessary is just to select suitably from radiation. Such light is preferably ultraviolet rays from the viewpoints of operability, productivity, economy, and the like. As the ultraviolet ray source, a conventionally known one can be used, and examples thereof include a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and a microwave excimer lamp. The atmosphere for irradiating ultraviolet rays may be an air atmosphere, an inert gas atmosphere such as nitrogen gas or carbon dioxide gas, or an atmosphere with a reduced oxygen concentration. As such an atmosphere, an inert gas atmosphere or an atmosphere with a reduced oxygen concentration is preferable. The irradiation atmosphere temperature may be adjusted as appropriate, and can usually be 10 ° C to 200 ° C. The irradiation time may be adjusted as appropriate, and is usually preferably 10 seconds to 60 minutes. The integrated light quantity may be adjusted as appropriate, and is usually preferably 1,000 mJ / cm ^{2 to} 20,000 mJ / cm ² .

<Method of molding HDD gasket>
For example, the photo-curable elastomer composition of the present invention is filled in a dedicated syringe, extruded by air (air) or machine, discharged from a thin needle tip, and applied to a cover plate (adhered body). By irradiating light, such as ultraviolet rays, to the photocurable elastomer composition, the photocurable elastomer composition is cured and molded.

(apparatus)
The apparatus of the present invention is characterized by having at least a part of the sealing material of the present invention.
The apparatus of the present invention is excellent in sealing performance and reworkability by having at least a part of the sealing material of the present invention.
Examples of the apparatus of the present invention include various computers such as HDDs; desktop computers, notebook computers, tablet computers, and the like; mobile phones; ink tanks; pipes; liquid crystal display devices, organic EL displays, electronic paper, and plasma displays. A camera, a speaker, an anti-vibration device, a waterproof device, a damper, a water purification device, an air purification device, an agitator, a pump, an automobile part, and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

  Each component was mix | blended with the prescription shown in Table 1-Table 3 (The value in each component represents a mass part), and the photocurable elastomer composition was prepared. And the following methods measured and evaluated about hardness (flexibility), adhesiveness, moisture permeability (water vapor barrier property), helium barrier property, and compression set. The results are shown in Tables 1 to 3.

<Flexibility (hardness)>
A photocurable elastomer composition was formed to a thickness of about 2 mm, and this was cured by light irradiation using a metal halide lamp to obtain a sheet. The light irradiation was performed under conditions of an illuminance of about 150 mW / cm ² and an integrated light amount of about 9,000 mJ / cm ^{2 in} an air atmosphere. This sheet was further baked at 120 ° C. for 4 hours in an air atmosphere. The hardness of this sheet was measured with a type A durometer in accordance with JIS K 6253. A specimen having a thickness of about 6 mm obtained by laminating three sheets having a thickness of about 2 mm was used. In addition, the smaller one is better, and 50 or less is preferable.

<Adhesiveness>
A photocurable elastomer composition is formed on a stainless steel plate (1) with a thickness of about 1 mm and a width of about 1 mm near the outer periphery of the stainless steel plate (1), and this is irradiated with light using a metal halide lamp and cured. I let you. The light irradiation was performed under conditions of an illuminance of about 150 mW / cm ² and an integrated light amount of about 9,000 mJ / cm ^{2 in} an air atmosphere. The molded body was further baked for 4 hours at 120 ° C. in an air atmosphere. This molded body was covered with another stainless steel plate (2) having a hole on the elastomer side and left standing at 85 ° C. for 20 hours in a fixed state. After returning to room temperature and allowing to stand for 30 minutes, the stainless plate (1) was pressed with a pusher through the hole at a speed of 10 mm / min, and the force when the stainless plate (2) and the elastomer were peeled was measured. In addition, the smaller the adhesiveness, the better, and 35N or less is preferable.

<Moisture permeability (water vapor barrier property)>
A photocurable elastomer composition was formed to a thickness of about 1 mm, and was cured by light irradiation using a metal halide lamp. The light irradiation was performed under conditions of an illuminance of about 150 mW / cm ² and an integrated light amount of about 9,000 mJ / cm ^{2 in} an air atmosphere. The molded body was further baked for 4 hours at 120 ° C. in an air atmosphere. About this sheet | seat, the moisture-permeable cup of A method of JISL1099 description was used, and it measured on 50 degreeC relative humidity 90% conditions based on JISZ0208. The moisture permeability is preferably as small as possible and is preferably 20 [g / m ² · day] or less.

<Helium barrier properties>
A photocurable elastomer composition is formed on a stainless steel plate (1) with a thickness of about 1 mm and a width of about 1 mm in the vicinity of the outer periphery of the stainless steel plate (1), and this is irradiated with light using a metal halide lamp and cured. It was. The light irradiation was performed under conditions of an illuminance of about 150 mW / cm ² and an integrated light amount of about 9,000 mJ / cm ^{2 in} an air atmosphere. The molded body was further baked for 4 hours at 120 ° C. in an air atmosphere. Put another stainless steel plate (2) having a hole on the elastomer side of this molded body, fix it, and inject helium gas from the hole (sealing so that gas does not leak from the injection part) The amount of helium leaked through the elastomer was defined as a helium barrier property. A smaller value indicates a higher barrier property. The helium barrier property is preferably smaller, and is preferably 10 [× 10 ⁻⁷ Pa · m ³ / s] or less.

In Tables 1 to 3, * 1 to * 23 indicate the following.
* 1 Bifunctional urethane acrylate oligomer (number average molecular weight 10,000, having (meth) acryloyl groups at both ends), isobornyl acrylate (content: 25% to 29% by weight), phenoxyethyl acrylate (containing Amount: 69% by mass to 73% by mass) and Irgacure 2959 (content: 2% by mass) or equivalent mixture: Light Tuck PUA-KH32M manufactured by Kyoeisha Chemical Co., Ltd.
* 2 Hydrogenated acrylic modified butadiene rubber: CN-9014 manufactured by Sartomer (number average molecular weight 6,500, having (meth) acryloyl groups at both ends, the main skeleton is hydrogenated)
* 3 Methacryl-modified isoprene rubber: UC-102 manufactured by Kuraray Co., Ltd. (number average molecular weight 17,000, having two (meth) acryloyl groups in the side chain)
* 4 Hydrogenated acrylic modified butadiene rubber: TEAI-1000 manufactured by Nippon Soda Co., Ltd. (number average molecular weight 2,000, (meth) acryloyl groups at both ends, the main skeleton is hydrogenated)
* 5 Acrylic modified butadiene rubber: Kuraray product name L-1253 (number average molecular weight 7,000, having (meth) acryloyl group at one end)
* 6 Methacrylic modified isoprene rubber: Kuraray product name UC-203 (number average molecular weight 27,000, 3 (meth) acryloyl groups in the side chain, main skeleton is non-hydrogenated)
* 6-2: Isoprene rubber: Kuraray product name LIR-700 (number average molecular weight 28,000, no (meth) acryloyl group)
* 7 Light acrylate EHDG-AT (2-ethylhexyl-diglycol acrylate, molecular weight 272, monofunctional acrylate monomer) manufactured by Kyoeisha Chemical Co., Ltd.
* 8 IBXA (isobornyl acrylate, molecular weight 208, monofunctional acrylate monomer) manufactured by Osaka Organic Chemical Industry Co., Ltd.
* 9 Light acrylate PO-A (phenoxyethyl acrylate, molecular weight 192, monofunctional acrylate monomer) manufactured by Kyoeisha Chemical Co., Ltd.
* 10 ACMO manufactured by Kojin Co., Ltd. (Acroyl morpholine, molecular weight 141, monofunctional acrylate monomer)
* 10-2 Kyoeisha Chemical Co., Ltd. light ester 1,4BG (1,4 butanediol dimethacrylate (without cyclic hydrocarbon skeleton), molecular weight 226, bifunctional acrylate monomer)
* 10-3 Kyoeisha Chemical Co., Ltd. light acrylate LA (lauryl acrylate (without cyclic hydrocarbon skeleton), molecular weight 240, monofunctional acrylate monomer)
* 11 N-stearyl oleic acid amide (compound represented by the structural formula (3), Nikka Amide SO manufactured by Nippon Kasei Co., Ltd.)
* 12 Erucic acid amide (compound represented by the structural formula (8), manufactured by Nippon Kasei Co., Ltd.)
* 13 Stearic acid amide (compound represented by the structural formula (9), manufactured by Nippon Kasei Co., Ltd.)
* 14 N-oleyl stearamide (compound represented by the structural formula (2), Nikka Amide OS manufactured by Nippon Kasei Co., Ltd.)
* 15 N-stearyl erucamide (compound represented by the structural formula (4), Nikka Amide SE manufactured by Nippon Kasei Co., Ltd.)
* 16 Purified erucic acid amide (compound represented by the structural formula (5), Diamond L-200 manufactured by Nippon Kasei Co., Ltd.)
* 17 Purified oleic amide (compound represented by the above structural formula (6), Nippon Kasei Co., Ltd., Diamond O-200)
* 18 Behenic acid amide (compound represented by the structural formula (7), BNT22H manufactured by Nippon Seika Co., Ltd.)
* 19 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by BASF)
* 20 α-aminoalkylphenone (Irgacure 379 manufactured by BASF)
* 21 2,4,6-trimethylbenzoylphenylphosphine oxide (Lucirin TPO manufactured by BASF)
* 22 Nisshinbo's product name "Elasto Stub H01"
* 23 Silica (Asahi Kasei Wacker Silicone, trade name: HDK N20)

  From Tables 1 to 3, (A) a polymer having a (meth) acryloyl group in the molecule, (B) a monomer having a photocurable functional group in the molecule, (C) a fatty acid amide compound, and (D) It turns out that Examples 1-37 containing a photoinitiator can improve a softness | flexibility (low hardness) and low adhesiveness.

Claims (11)

(A) a polymer having a (meth) acryloyl group in the molecule;
(B) a monomer having a photocurable functional group in the molecule;
(C) a fatty acid amide compound;
(D) A photopolymerization initiator, and a photocurable elastomer composition comprising the photopolymerization initiator.   The photocurable elastomer composition according to claim 1, wherein the polymer includes at least one selected from the group consisting of a urethane skeleton, a butadiene skeleton, an isoprene skeleton, and an isobutylene skeleton.   The photocurable elastomer composition according to claim 1, wherein the polymer has at least two (meth) acryloyl groups in the molecule.   2. The photocurable elastomer composition according to claim 1, wherein the fatty acid amide compound is a primary fatty acid amide or a secondary fatty acid amide having 22 or more carbon atoms and having a carbon double bond. object.   The photo-curable elastomer composition according to claim 1, wherein the fatty acid amide compound has a portion made of a saturated hydrocarbon and a portion made of an unsaturated hydrocarbon. The portion consisting of the saturated hydrocarbon and the portion consisting of the unsaturated hydrocarbon are connected via an amide bond,
The portion consisting of the saturated hydrocarbon is bonded to a nitrogen atom in the amide bond,
The portion consisting of the unsaturated hydrocarbon is bonded to a carbon atom in the amide bond,
6. The photocurable elastomer composition according to claim 5, wherein the number of carbon atoms in the portion made of saturated hydrocarbon is larger than the number of carbon atoms in the portion made of unsaturated hydrocarbon.   The content of the fatty acid amide compound is 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the polymer (A) and the monomer (B). The photocurable elastomer composition as described.   The photocurable elastomer composition according to claim 1, wherein the monomer has a cyclic hydrocarbon skeleton, and the photocurable functional group is a (meth) acryloyl group.   The photocurable elastomer composition according to claim 1, wherein the photocurable elastomer composition is used for a sealing material.   A sealing material comprising the photocurable elastomer composition according to claim 1 at least partially.   An apparatus comprising at least a part of the sealing material according to claim 10.