JP2003268198A - Epoxy resin composition for precision molding part and molded product with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for precision molding parts with improved moldability and dimensional stability. <P>SOLUTION: The epoxy resin composition comprises an epoxy resin, a curing agent, a filler and a silicon a compound shown by a molecular structure of formula (I) (wherein R<SP>1</SP>-R<SP>4</SP>are each voluntarily selected from methyl and phenyl groups, m and n are integers). The filler is contained in the epoxy resin composition at 80 wt.% or above. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition for molding precision parts, and a precision part obtained by molding using the epoxy resin composition.

[0002]

2. Description of the Related Art Recent developments in the fields of electronics and information and communication have been remarkable, and they are used in these fields to make devices lighter, thinner, shorter, smaller and more functional, and to increase the capacity and speed of information. Extremely high dimensional accuracy is now required for precision parts. For example, in the field of optical information communication, optical connectors for connecting optical fibers are required to have dimensional accuracy on the order of submicrons.

Conventionally, inorganic materials such as metal materials and ceramics have been used as constituent materials for the above-mentioned precision parts. However, precision parts manufactured from these metal materials and inorganic materials have a small dimensional change, but require cutting and polishing at the time of manufacturing, and these processing require highly skilled technology and expensive manufacturing equipment. However, there is a problem that a complicated process is required, which makes not only mass production difficult but also the cost of precision parts increases significantly.

On the other hand, for the purpose of manufacturing a large amount of various equipment parts at low cost, a technique of molding a resin material such as a thermoplastic resin or a thermosetting resin by injection molding is widely known. Attempts have been made to improve the dimensional stability by adding a large amount of inorganic filler to the molding material (Japanese Patent Laid-Open No. 8-225656), but these resin molded products are liable to cause sink marks or warpage during molding, It did not meet the required performance as a precision part requiring dimensional stability. In addition, when a large amount of inorganic filler is compounded, mold releasability is deteriorated due to a decrease in molding shrinkage, productivity is decreased, and a molded product is deformed during mold release.

[0005]

The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a resin composition for molding precision parts which is excellent in moldability and dimensional stability and a precision resin composition which is excellent in dimensional stability. It is to provide parts.

[0006]

In order to solve the above problems, the present invention mainly has the following configuration. That is,
An epoxy resin composition containing an epoxy resin (A), a curing agent (B), a filler (C) and a silicone compound (D) having a molecular structure represented by the formula (I), wherein the filler ( The epoxy resin composition for precision parts molding is characterized in that 80% by weight or more of C) is contained in the epoxy resin composition.

[0007]

[Chemical 2]

(In the formula, R ^{1 to} R ⁴ are arbitrarily selected from a methyl group and a phenyl group, and m and n are integers.)

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The constitution of the present invention will be described in detail below.

The epoxy resin (A) in the present invention is
It is a compound having two or more epoxy groups in one molecule, and the molecular weight and the molecular structure are not particularly limited.

Specific examples of the epoxy resin (A) used in the present invention include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol type epoxy resins such as tetramethylbisphenol F type epoxy resins, and cresol novolac type epoxy resins. Resin, phenol novolac type epoxy resin, 4,4'-bis (2,
3-epoxypropoxy) biphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'
Biphenyl skeleton-containing epoxy resin such as tetramethylbiphenyl, naphthalene such as 1,5-di (2,3-epoxypropoxy) naphthalene, 1,6-di (2,3-epoxypropoxy) naphthalene, and naphtholaralkyl-type epoxy resin Backbone-containing epoxy resin, 3-t-butyl-2,4'-dihydroxy-3 ', 5', 6-trimethylstilbene diglycidyl ether, 3-t-butyl-4,4'-dihydroxy-3 ', 5 , 5'-Diglycidyl ether of trimethylstilbene, 4,4'-
Diglycidyl ether of dihydroxy-3,3 ', 5,5'-tetramethylstilbene, 4,4'-dihydroxy-3,3'-di-t-butyl-6,6'-dimethylstilbene diglycidyl ether, etc. Examples of the stilbene type epoxy resin, dicyclopentadiene type epoxy resin, phenol aralkyl type epoxy resin, triphenolmethane type epoxy resin, triazine skeleton-containing epoxy resin, and the like, which may be used alone or in combination of two or more kinds. I don't care.

The curing agent (B) in the present invention is not particularly limited as long as it can react with the epoxy resin (A) to cure it.

Specific examples of the curing agent (B) used in the present invention include imidazole compounds such as 2-phenylimidazole, acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride and succinic anhydride. Compounds, amine compounds such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and triethylenetetramine, bisphenol F, bisphenol A, phenol novolac resin, cresol novolac resin,
Dicyclopentadiene modified phenol resin, phenol aralkyl resin, terpene modified phenol resin, tris (hydroxyphenyl) methane, 1,1,2-tris (hydroxyphenyl) ethane, 1,1,3-tris (hydroxyphenyl) propane, tri Examples thereof include phenol compounds such as phenol methane type resins, and these may be used alone or in combination of two or more kinds. The amount of these curing agents (B) compounded is 1 to 2 with respect to 100 parts by weight of the epoxy resin (A) from the viewpoint of mechanical properties and the like.
It is preferably in the range of 00 parts by weight, or the amount such that the number of curing functional groups of the curing agent is in the range of 0.5 to 2 with respect to the number of epoxy groups of the epoxy resin (A). Among the above curing agents (B), a phenol compound is particularly preferably used from the viewpoint of moldability.

Further, in the present invention, the epoxy resin (A)
A curing catalyst may be used to accelerate the curing reaction of the curing agent (B). The curing catalyst is not particularly limited as long as it accelerates the curing reaction, and for example, 2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-
Methylimidazole, 2-phenylimidazole, 2-
Imidazole compounds such as phenyl-4-methylimidazole and 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzylmethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) ) Phenols, tertiary amine compounds such as 1,8-diazabicyclo (5,4,0) undecene-7 and salts thereof, zirconium tetramethoxide, zirconium tetrapropoxide, tetrakis (acetylacetonato) zirconium, tri (acetyl) Acetonato) aluminum and other organometallic compounds and salts thereof, triphenylphosphine, trimethylphosphine, triethylphosphine,
Organic phosphine compounds such as tributylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine and salts thereof, 1,8-diazabicyclo (5,4,0) undecene-7.tetraphenylborate, tetraphenyl Examples thereof include phosphonium / tetraphenylborate and an adduct of triphenylphosphine and p-benzoquinone.

Two or more kinds of these curing catalysts may be used in combination, and the compounding amount thereof is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin (A).

Further, in order to improve the dispersibility of the curing catalyst in the epoxy resin composition, the curing catalyst can be used in advance by mixing it with an epoxy resin, a curing agent and other compounding agents.

The filler (C) in the present invention means an inorganic filler, and the composition, shape, crystallinity and the like are not particularly limited.

Specific examples of the filler (C) used in the present invention include crystalline silica, amorphous silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, mica, kaolin, talc, calcium silicate. , Potassium titanate, titanium oxide, antimony oxide, silicon nitride, graphite, carbon fiber, glass fiber, carbon nanotube and the like, and these may be used in combination of two or more kinds, spherical, crushed, fibrous, needle. Items having various shapes such as shapes can be used not only alone but also in combination. Further, the particle diameter of the filler (C) is not particularly limited, but those having an average particle diameter of 1 to 100 μ are preferably used.

The content of the filler (C) in the epoxy resin composition for molding precision parts of the present invention is 80% by weight or more,
It is more preferably 83% by weight or more. If the content of the filler (C) is less than 80% by weight, the linear expansion coefficient and the molding shrinkage of the molded product will not be sufficiently small, and a precision component excellent in dimensional stability cannot be obtained.

The silicone compound (D) in the present invention is a compound having a molecular structure represented by the following chemical formula (I).

[0021]

[Chemical 3]

(In the formula, R ^{1 to} R ⁴ are arbitrarily selected from a methyl group and a phenyl group, and m and n are integers.) The molecular weight of the silicone compound (D) is not particularly limited, and the above formula (I It may have only a repeating structure of (4), a crosslinked structure or a branched structure, and may be a modified silicone or a copolymer bonded to an organic polymer or an organic compound.

The silicone compound (D) is an epoxy group,
It is preferable to contain at least one functional group selected from a hydroxyl group, an alkoxy group, an amino group, a carboxyl group and a mercapto group in one molecule. The functional group may be bound to either the side chain or the terminal of the main chain, and when it has a plurality of functional groups, it may be bound in any combination. When it has a plurality of functional groups, it may have two or more types of functional groups. By containing a functional group, dispersibility of the silicone compound in the epoxy resin composition is improved, and moldability and dimensional stability are further improved.

The addition amount of the silicone compound (D) is preferably 0.0 with respect to the whole epoxy resin composition.
It is 1 to 10% by weight, and more preferably 0.05 to 2% by weight.

The epoxy resin composition for molding precision parts of the present invention preferably contains a coupling agent. As the coupling agent, a known silane coupling agent,
A titanate-based coupling agent, an aluminum-based coupling agent, or the like can be used. Specific examples thereof include γ-glycidoxypropyltrimethoxysilane, γ
-Glycidoxypropylmethyldiethoxysilane, N-
(2-aminoethyl) γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-
Silane coupling agents such as ureidopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane, titanate couplings such as isopropyl tris (dioctyl pyrophosphate) titanate and tetraisopropyl bis (dioctyl phosphite) titanate. Agents, and aluminum-based coupling agents such as acetoalkoxyaluminum diisopropylate. These may be used alone or in combination of two or more kinds.

The coupling agent may be surface-treated on the filler (C) in advance, but it may be added only to the epoxy resin composition.

Further, these coupling agents are preferably added in an amount of 0.1 to 3% by weight with respect to the filler (C).

The epoxy resin composition for molding precision parts of the present invention may optionally contain the following various additives. That is, flame retardants such as halogenated compounds such as halogenated epoxy resins and phosphorus compounds, flame retardant aids such as diantimony trioxide, diantimony tetroxide and diantimony pentoxide, coloring of carbon black, iron oxide, titanium oxide, etc. Agent, silicone rubber, styrene block copolymer, olefin polymer, modified nitrile rubber, modified polybutadiene rubber and other elastomers, polystyrene and other thermoplastic resins, long chain fatty acids, long chain fatty acid metal salts, long chain fatty acid A release agent such as an ester, an amide of a long chain fatty acid, paraffin wax, polyethylene wax, or oxidized polyethylene wax can be optionally added.

The method for producing the epoxy resin composition for molding precision parts of the present invention is not particularly limited, and a known method can be used, but it is preferably produced by melt kneading. For example, it is produced by melt-kneading using a kneading method such as a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder and a cokneader.

The epoxy resin composition of the present invention is a resin composition for molding precision parts. Here, as the precision parts, for example, various gears, cases, connectors, sockets, optical pickups, terminal plates, plugs, substrates, bases,
Plates, housings, adapters, bearings, hard disk drive (HDD) sliders, HD
Computer parts such as D motor hub and HDD arm, OA equipment parts such as facsimiles and copiers, mobile equipment parts such as mobile phones and portable audio equipment, microscopes,
Optical equipment parts such as cameras, watches, various measuring equipment, precision machine parts such as various machine tools, semiconductor manufacturing equipment parts such as wafer polishing plates, semiconductor equipment parts such as semiconductor mounting boards, optical connectors, optical modules Examples include optical communication parts such as packages. Preferably, the molding shrinkage during molding is 0.3% or less,
Moreover, it is a component having a linear expansion coefficient of 12 × 10 ^-6 ° C ^-1 or less.

By providing the composition of the present invention for the molding of these precision parts, it is possible to obtain precision parts having a high molding yield and high dimensional accuracy.

The precision component of the present invention can be obtained by molding the above epoxy resin composition. Here, as the molding method, compression molding, injection molding, extrusion molding, cast molding,
A general plastic molding method such as transfer molding can be applied. In particular, transfer molding and injection molding are preferably used in terms of productivity and quality of molded products.

The molding conditions are not particularly limited, but in transfer molding, the mold temperature is 150 to 200.
C., injection pressure 7 to 30 MPa, injection time 5 to 20 seconds, and curing time 30 to 180 seconds are preferable. In injection molding, the mold temperature is 150 to 200 ° C, and the screw temperature is 80 to
120 ° C, injection time 5 to 20 seconds, curing time 30 to 180
Seconds are preferred.

After molding, if necessary, 100 to 20
It is preferable to carry out the post-curing treatment in the range of 0 ° C. for dimensional stability and mechanical properties.

Specific examples of the precision parts of the present invention include the above-mentioned parts. In particular, various microscopes, optical measuring devices, sample tables such as precision measuring instruments, wafer polishing plates, various optical fiber connectors, optical parts, etc. Optical fiber connecting parts such as connector ferrules, optical connector sleeves, optical fiber connecting V-grooves, and optical module packages are preferable.

[0036]

EXAMPLES The present invention will be specifically described below with reference to production examples, examples and comparative examples of formulations. In addition, the evaluation method of the obtained epoxy resin composition is as follows.

Gelation time: The resin composition was cured on a hot plate at 175 ° C., and the curing time was measured.

Spiral flow: A resin composition is tableted and a low-pressure transfer molding machine equipped with a spiral flow measuring mold according to EMMI-1-66 is used to mold temperature 175 ° C., molding pressure 10 MPa, curing time. Molding was performed for 90 seconds and the flow length was measured.

Molding of various test pieces: The resin composition was tabletted and molded using a low-pressure transfer molding machine equipped with various molds at a mold temperature of 175 ° C., a molding pressure of 10 MPa, and a curing time of 90 seconds. The various molded products (test pieces) thus obtained were post-cured at 175 ° C. for 4 hours and then subjected to the test.

Linear expansion coefficient: 6 mm × 6 mm × 12 mmh
25 by thermomechanical analysis (TMA) using the test piece of
C. to 275.degree. C. was heated at a temperature rising rate of 10.degree.

Molding shrinkage ratio: Measured according to JIS K6911.

Bending strength at room temperature: Measured according to JIS K6911.

Mold release load: upper surface 9 mmφ, lower surface 10 mm
A frustum-conical test piece having a size of φ and a height of 20 mm was molded, and the force of pulling out from the mold was measured with a push-pull gauge. The measured value was an average value of 10 times.

Dimensional stability [square plate]: 100 mm × 100
Five square plates of mm × 3 mm (thickness) were molded, post-cured under the above conditions, and then the outer shape was measured with a three-dimensional measuring device (BH504 manufactured by Mitutoyo). The variation in outer dimension was set to the largest value from the design values, and the warp amount was measured on the diagonal line of the square plate and was the average value of five sheets.

Appearance of molded product [square plate]: visually observing the above-mentioned square plates, good products with no problems (○), bad products with stains in an acceptable range (△), products with sink marks or chips Bad (x)
And ○ and △ are passed.

Dimensional stability [connector]: JIS C59
81. Multi-core optical fiber connector (CNF12SPM)
Tens of 126C10-4) were molded and post-cured under the above conditions, and then the optical fiber insertion hole position was measured by an image measuring device equipped with a CCD camera. The hole position variation is ◯ if the positional deviation amount of each optical fiber insertion hole center (positional deviation amount with respect to the measured center with respect to the set center) is all within 1 μm, and if there is a hole of 1 to 3 μm, Δ is 3 μm or more. If there is, it is marked as x. ○ means pass.

Void [connector]: Nondestructive inspection was performed on the above-mentioned 10 multi-fiber optical fiber connectors using a soft X-ray apparatus, and the total number of internal voids was counted.

Dimensional stability [Ferrule]: 10 ferrules shown in FIG. 1 were molded, post-cured under the above conditions, and then the diameter (φD) and hole diameter (φd) were mounted on a CCD camera. It was measured with a measuring instrument. When all the diameters, hole diameters and hole center positions are within 1 μm in the amount of deviation from the setting, it is indicated as ◯, when there is an object of 1 to 3 μm, Δ: when there is an object of 3 μm or more. ○ means pass.

[Production Example 1] Bisphenol A type epoxy resin (Epicoat 8 manufactured by Japan Epoxy Resins Co., Ltd.)
28 ") 100 g and both end carboxyl group-modified silicone (" X-22-162A "manufactured by Shin-Etsu Chemical Co., Ltd.) 20
0 g was mixed with stirring in a three-neck glass flask and heated to 120 ° C. Next, 1 g of triphenylphosphine was added and reacted for 1 hour to obtain a silicone modified with epoxy resin having epoxy equivalent of 1300 at both ends.

[Examples 1 to 14 and Comparative Examples 1 to 3] The compounds shown in Table 1 were weighed in the compounding ratio shown in Table 2 and mixed with stirring using a mixer. The blending ratio in Table 2 is% by weight
Represents Then, the mixture is fed to a twin-screw extruder to 90 ° C.
It was melt-kneaded. The obtained molten mixture was passed through a cooling roll to form a sheet, cooled, and ground with a grinder to obtain an epoxy resin composition. The evaluation results are shown in Table 2.

[0051]

[Table 1]

[0052]

[Table 2]

From Table 2, the compositions of the present invention of Examples 1 to 14 have small linear expansion coefficient and molding shrinkage, and small mold release load at the time of molding, so that precision parts excellent in dimensional stability can be molded. . The molded products of Examples 1 to 14 were excellent in external dimension stability, small warpage, and good appearance. Especially, in the multi-fiber optical fiber connector which is an optical fiber connecting part,
The variation in the position of the hole that connects the optical fiber is extremely small, and since there are no voids, the connection loss of the optical signal can be made extremely small, and the ferrule has the same dimensional stability as the molded product made of zirconia ceramics. Was.

On the other hand, in Comparative Examples 1 to 3 which do not contain the silicone compound (D), although the linear expansion coefficient and the molding shrinkage rate are small, the mold release load is high, so that it is impossible to force the mold during release. As a result, the dimensional stability of the molded part was poor, the warpage was large, and the appearance and sink marks occurred. In addition, in the multi-fiber optical fiber connector, there are large variations in the positions of the holes that connect the optical fibers, and many voids are generated. The dimensional stability of the ferrule was also poor.

Further, in Comparative Example 4 in which the content of the filler (C) was small, the mold releasability was not a problem, but the linear expansion coefficient and the molding shrinkage ratio were large, so that the dimensional stability of each molded product was poor.

[0056]

Industrial Applicability According to the present invention, an epoxy resin composition for molding precision parts having excellent moldability and dimensional stability can be obtained, and a precision part having high dimensional stability, particularly an optical fiber connection part with a small optical connection loss can be obtained. To be

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the shape of a ferrule for measuring dimensional stability.

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Claims (4)

[Claims] 1. An epoxy resin composition comprising an epoxy resin (A), a curing agent (B), a filler (C) and a silicone compound (D) having a molecular structure represented by the formula (I). An epoxy resin composition for precision part molding, wherein the filler (C) is contained in the epoxy resin composition in an amount of 80% by weight or more. [Chemical 1] (In the formula, R ^{1 to} R ⁴ are arbitrarily selected from a methyl group and a phenyl group, and m and n represent integers.) 2. A silicone compound (D) is an epoxy group,
The epoxy resin composition for precision part molding according to claim 1, wherein at least one functional group selected from a hydroxyl group, an alkoxy group, an amino group, a carboxyl group, and a mercapto group is contained in one molecule. 3. A precision part obtained by molding the epoxy resin composition for molding a precision part according to claim 1 or 2. 4. An optical fiber connection part obtained by molding the epoxy resin composition for molding precision parts according to claim 1 or 2.