JP2006316089A - Resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition that can be finely dispersed in a thermosetting resin constituting a matrix resin such as an epoxy resin or a polyimide resin to raise the glass transition temperature of the thermosetting resin and can perform functions of relaxing internal stresses and external stresses in the temperature range below the glass transition temperature without exerting influences on the thermosetting resin. <P>SOLUTION: The resin composition comprises a polyrotaxane and the thermosetting resin. Preferably, the thermosetting resin in the resin composition is an epoxy resin or a polyimide. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin composition, and particularly to a resin composition suitable for packaging electronic and electric parts.

Various thermosetting resins are used for packaging electronic and electrical components. Among them, epoxy resins have excellent mechanical properties, electrical properties, heat resistance, adhesiveness, moldability, etc. It is the most extensive and used in large quantities. Electronic component packages are becoming thinner and smaller, as represented by ICs, but conventional epoxy resin compositions have the disadvantage that they tend to crack when subjected to a thermal cycle. there were. This is caused by an internal stress generated in the package during the thermal cycle. In addition, cracks are also likely to occur due to external mechanical stress or direct external thermal stimulation accompanying solder processing. To solve these drawbacks, structural solutions include, for example, lowering the linear expansion coefficient of the package material, absorbing stress due to the height of the connection terminals being increased, and a buffer layer (low Measures such as stress absorption by elastic body are taken. On the other hand, measures to impart crack resistance to the packaging material itself are also being studied. For example, an epoxy resin containing a curing agent is blended with silicone fine rubber particles coated with polyorganosilsesquioxane resin as an additive. A thermosetting resin composition has been proposed (Patent Document 1). However, such an additive may adversely affect the performance of the epoxy resin, such as a decrease in mechanical strength such as elastic modulus.
Japanese Patent Laid-Open No. 8-85753

  The present invention has been made against the background of the above-described prior art. The thermosetting resin is finely dispersed in the thermosetting resin without affecting the matrix resin such as epoxy resin or polyimide resin. An object of the present invention is to provide a resin composition capable of increasing the glass transition temperature and exhibiting the function of relieving internal and external stresses in a temperature range below the glass transition temperature.

The present invention relates to a resin composition comprising a polyrotaxane and a thermosetting resin.
Here, examples of the thermosetting resin include epoxy resin, polyimide, phenol resin, urea resin, melamine resin, unsaturated polyester, alkyd resin, and the like.
In addition, the polyrotaxane includes a polyalkylene glycol as an axis molecule, cyclodextrin is fitted into the polyrotaxane, and the polyalkylene glycol is blocked with a blocking group so that the cyclodextrin molecule is not detached from the polyalkylene glycol molecule. Those in which both ends of the molecule are sealed are preferred.

  According to the present invention, by adding a polyrotaxane to a thermosetting resin such as an epoxy resin or a polyimide resin, it is possible to effectively absorb and relax internal stresses during the thermosetting and cooling cycles of these thermosetting resins. In addition, the mechanical strength and the glass transition temperature can be maintained or improved.

  Examples of the thermosetting resin used in the present invention include an epoxy resin, a polyimide resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester, an alkyd resin, and the like, and an epoxy resin is particularly preferable.

  Among these, the epoxy resin used in the present invention includes a compound having at least one, preferably at least two epoxy groups in one molecule, and the molecular structure, molecular weight and the like are not particularly limited. Examples of such an epoxy compound include 2,2′-bis (4-hydroxyphenyl) propane or diglycidyl ether of this halide, butadiene diepoxide, vinylcyclohexene dioxide, diglycidyl ether of resorcin, 1,4 -Bis (2,3-epoxypropoxy) benzene, 4,4'-bis (2,3-epoxypropoxy) diphenyl ether, 1,4-bis (2,3-epoxypropoxy) cyclohexene, bis (3,4-epoxy) -6-methylcyclohexylmethyl) adipate, 1,2-dioxybenzene or resorcinol, epoxy glycidyl ether or polyglycidyl ester obtained by condensation of polyphenol or polyhydric alcohol and epichlorohydrin, novolac type phenol Lumpur resin (or halogenated novolac type phenolic resin) and epichlorohydrin and epoxy novolac obtained by condensing, epoxidized epoxidized polyolefins by peroxides method, such as epoxidized polybutadiene.

  In addition, a monoepoxy compound may be used in combination with an epoxy compound having at least two epoxy groups in one molecule as appropriate. Examples of the monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, and ethyl. Examples thereof include glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, octylene oxide and dodecene oxide. Moreover, the epoxy resin to be used is not necessarily limited to only one type, and two or more types can be used in combination.

In the present invention, various conventionally known curing agents for epoxy resins can be used together with the epoxy resin. Examples thereof include diethylenetriamine, triethylenetetramine, diethylaminopropylamine, N-aminoethylpiperazine, bis (4-amino-3-methylcyclohexyl) methane, metaxylyleneamine, menthanediamine, 3,9-bis (3 -Aminopropyl) -2,4,8,10-tetraoxaspiro (5,5) undecane and other amine compounds; 2-ethyl-4-methylimidazole, 1,8-diazabicyclo [5,4,0] unde Imidazole compounds such as -7-cene; epoxy resins-modified aliphatic polyamines such as diethylenetriamine adducts, amine-ethylene oxide adducts, cyanoethylated polyamines; bisphenol A, trimethylolallyloxyphenol, low-polymerization phenol novolac resins, Xylated or butylated phenolic resin or “Super Beckcite” 1001 [manufactured by Nippon Reichhold Chemical Co., Ltd.], “Hitanol” 4010 (manufactured by Hitachi, Ltd.), Scado form L 9 (manufactured by Scado Zwoll, the Netherlands), Phenol resins known under trade names such as Methylon 75108 (manufactured by General Electric, USA); “Beckamine” P.138 (manufactured by Nippon Reichhold Chemical Co., Ltd.), “Melan” (manufactured by Hitachi, Ltd.) , “U-Van” 10R (manufactured by Toyo Koatsu Kogyo Co., Ltd.), etc., carbon resins; amino resins such as melamine resins and aniline resins; formula HS (C ₂ H ₄ OCH ₂ OC ₂ H _{4 SS) n C 2 H 4} OCH 2 OC 2 H 4 SH (n = polysulfide resin having at least two mercapto groups in one molecule as represented by an integer from 1 to 10); phthalic anhydride, hexahydro Phthalic acid, tetrahydrophthalic anhydride, none Examples thereof include water pyromellitic acid, methyl nadic acid, dodecyl succinic anhydride, organic acid such as chlorendic anhydride or anhydride thereof.

Among the curing agents described above, the phenol resin, the organic acid anhydride, and the imidazole compound effectively accelerate the curing reaction, give good molding workability to the composition of the present invention, such as IC and LSI. It is desirable to give excellent mechanical properties when used for resin sealing.
The above-described curing agents are not necessarily limited to one type in use, and two or more types may be used in combination according to the curing performance of the curing agents.
The amount of the curing agent to be used varies depending on its specific type, but is usually in the range of 0.1 to 20 parts by weight, preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the epoxy resin. It is. If the amount of the curing agent used is less than 0.1 parts by weight, it is difficult to cure the composition of the present invention satisfactorily. On the other hand, if it exceeds 20 parts by weight, it is economically disadvantageous and the epoxy resin is diluted. Accordingly, it takes a long time to cure, and further, the physical properties of the cured product are lowered.

  The polyimide resin is generally obtained by synthesizing a polyamic acid by an addition reaction between a dianhydride and a diamine, and then causing a ring-closing reaction with elimination of water by a heat reaction treatment. The polyimide resin belonging to this category is not particularly limited and can be used in the present invention.

The polyimide resin used in the present invention is preferably a polyimide soluble in an organic solvent (hereinafter referred to as “soluble polyimide”).
The polyimide soluble in the solvent used in the present invention can be produced, for example, by subjecting at least one tetracarboxylic dianhydride and at least one diamine to a polyaddition condensation reaction.
Examples of such a soluble polyimide include at least one aromatic tetracarboxylic dianhydride and the following general formula (1), (2) or (3) [in the general formulas (1) to (3), X ¹ ~ X ⁶ may be the same or different, -O-, -S-, -SO _2- , -CO-, -CONH-,-(CH ₂ ) _n
-(Where n is an integer of 1 to 4) or -C (R ¹ ) (R ² )-(where R ¹ and R ² may be the same or different and are alkyls of 1 to 5 carbon atoms) Group, a C1-C5 fluoroalkyl group or a halogen atom.), And Ar ^{1 to} Ar ³ may be the same or different and represent a divalent aromatic group. In] or (4) [Formula (4), R ³ represents an alkyl group or an alkoxy group having 1 to 5 carbon atoms of 1 to 5 carbon atoms, m is an integer of 1 to 4. A polyimide soluble in a phenol-based solvent produced by a polyaddition condensation reaction with at least one aromatic diamine selected from the group of compounds represented by the formula:

Particularly preferred soluble polyimides in the present invention are polyimides produced by the following copolyaddition condensation reaction (a) or (b).
(A) Two or more aromatic tetracarboxylic dianhydrides and one or more aromatic diamines selected from the group of compounds represented by the general formula (1), (2) or (3) Copolyaddition condensation reaction.
(B) 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride alone and selected from the group of compounds represented by the above general formula (1), (2), (3) or (4) Copolyaddition condensation reaction with two or more aromatic diamines.

Examples of the aromatic tetracarboxylic dianhydride used in the copolyaddition condensation reaction of (i) above include pyromellitic dianhydride and the following general formula (5), (6) or (7) [general formula ( 5), (6) and (7), Y ^{1 to} Y ⁶ may be the same or different and are each a single bond, —O—, —SO ₂ —, —CO— or —C (R ⁴ ) (R ⁵ )-(Wherein R ⁴ and R ⁵ may be the same or different and each represents an alkyl group having 1 to 5 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, or a halogen atom). ,
Ar ^{4 to} Ar ⁶ may be the same or different and each represents a divalent aromatic group. An aromatic tetracarboxylic dianhydride selected from the group of compounds represented by

  Specific examples of the aromatic tetracarboxylic dianhydride represented by the general formula (5) include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyl). Phenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) Examples include methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, and the like. .

  Specific examples of the aromatic tetracarboxylic dianhydride represented by the general formula (6) include 1,3-phenylene bis trimellitate dianhydride, 1,4-phenylene bis trimellitate dianhydride, 2, 7-naphthalene bis trimellitate dianhydride, 1,5-naphthalene bis trimellitate dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,3-bis (3,4 -Dicarboxyphenoxy) benzene dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 3,3'-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 2,7-bis (3,4-dicarboxyphenoxy) naphthalene dianhydride, 1,5-bis (3,4-dicarboxyphenoxy) naphthalene dianhydride, etc. Can.

  Specific examples of the aromatic tetracarboxylic dianhydride represented by the general formula (7) include 2,2-bis (4-hydroxyphenyl) propane bistrimellitate dianhydride, 2,2-bis (4 -Hydroxyphenyl) hexafluoropropane bistrimellitic dianhydride, bis (4-hydroxyphenyl) ether bistrimellitate dianhydride, bis (4-hydroxyphenyl) furphone bistrimellitate dianhydride, bis (4-hydroxy Phenyl) ketone bistrimellitate dianhydride, 2,2-bis (3,4-dicarboxyphenoxy) propane dianhydride, 2,2-bis (3,4-dicarboxyphenoxy) hexafluoropropane dianhydride, etc. Can be mentioned.

  Among the aromatic diamines used in the copolyaddition condensation reaction of (i) above, specific examples of the aromatic diamine represented by the general formula (1) include 4,4′-diaminodiphenyl ether, 3 , 4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone 3,3′-diaminobenzophenone, 4,4′-diaminobenzanilide, 3,3′-diaminobenzanilide, 4,4′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 2,2-bis (4 -Aminophenyl) propane, 2,2-bis (3-aminophenyl) propane, 2,2-bis 4-aminophenyl) hexafluoropropane, 2,2-bis (3-aminophenyl) hexafluoropropane and the like.

  Specific examples of the aromatic diamine represented by the general formula (2) include 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis. (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, 3 , 3′-bis (3-aminophenoxy) biphenyl, 3,3′-bis (4-aminophenoxy) biphenyl, 2,7-bis (3-aminophenoxy) naphthalene, 1,5-bis (3-aminophenoxy) ) Naphthalene, 2,7-bis (4-aminophenoxy) naphthalene, 1,5-bis (4-aminophenoxy) naphthalene, and the like.

  Specific examples of the aromatic diamine represented by the general formula (3) include bis (4- (3-aminophenoxy) phenyl) ether, bis (4- (4-aminophenoxy) phenyl) ether, and bis (4 -(3-aminophenoxy) phenyl) sulfide, bis (4- (4-aminophenoxy) phenyl) sulfide, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl ) Sulfone, bis (4- (3-aminophenoxy) phenyl) ketone, bis (4- (4-aminophenoxy) phenyl) ketone, bis (4- (3-aminophenoxy) phenyl) methane, bis (4- ( 4-aminophenoxy) phenyl) methane, 2,2-bis (4-aminophenoxyphenyl) propane, 2,2-bis (3- Mino phenoxyphenyl) propane, 2,2-bis (4-aminophenoxy) hexafluoropropane, 2,2-bis (3-aminophenoxy phenyl) hexafluoropropane and the like.

  A preferred combination of two or more aromatic tetracarboxylic dianhydrides and one or more aromatic diamines used in the copolyaddition condensation reaction of (a) described above is pyromellitic dianhydride and One or more aromatic tetracarboxylic dianhydrides selected from the group of compounds represented by the general formula (5), (6) or (7), and the general formula (1), (2) or ( A combination with one or more aromatic diamines selected from the group of compounds represented by 3). Specific examples of the combination include pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4′-diaminodiphenyl ether, pyromellitic dianhydride / bis (3,4 -Dicarboxyphenyl) sulfone dianhydride / 4,4'-diaminodiphenyl ether / 4,4'-diaminodiphenylmethane, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4, 4'-diaminodiphenylsulfone, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4'-diaminodiphenylsulfone / 4,4'-diaminodiphenylmethane, pyromellitic acid Anhydride / Bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4′-diaminobenzo Enone, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4′-diaminobenzophenone / 4,4′-diaminodiphenylmethane, pyromellitic dianhydride / bis (3 , 4-Dicarboxyphenyl) sulfone dianhydride / 4,4′-diaminodiphenylmethane, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4′-diaminodiphenylmethane / 2,2-bis (4-aminophenyl) propane, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 2,2-bis (4-aminophenyl) propane, pyromellitic Acid dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 2,2-bis (4-aminophenyl) Safluoropropane, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4′-diaminodiphenylmethane / 2,2-bis (4-aminophenyl) hexafluoropropane, pyro Mellitic acid dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 2,2-bis (4-aminophenoxyphenyl) propane, pyromellitic dianhydride / bis (3,4-dicarboxy) Phenyl) sulfone dianhydride / 4,4′-diaminodiphenyl ether / 2,2-bis (4-aminophenoxyphenyl) propane, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 4,4'-diaminodiphenylmethane / 2,2-bis (4-aminophenoxyphenyl) propane, pyro Mellitic dianhydride / 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride / 4,4′-diaminodiphenylmethane, pyromellitic dianhydride / 3,3 ′, 4,4′-benzophenone Tetracarboxylic dianhydride / 4,4′-diaminodiphenylmethane / 4,4′-diaminodiphenyl ether, pyromellitic dianhydride / 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride / 4, 4'-diaminodiphenylmethane / 4,4'-diaminodiphenylsulfone, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) sulfone dianhydride / 3,3 ', 4,4'-benzophenone tetracarboxylic Acid dianhydride / 4,4'-diaminodiphenylmethane, pyromellitic dianhydride / bis (3,4-dicarboxyphenyl) Lufone dianhydride / 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride / 4,4′-diaminodiphenylmethane / 4,4′-diaminodiphenyl ether, pyromellitic dianhydride / 3,3 ′ , 4,4′-biphenyltetracarboxylic dianhydride / 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride / 4,4′-diaminodiphenylmethane, pyromellitic dianhydride / 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride / 3,3', 4,4'-benzophenonetetracarboxylic dianhydride / 4,4'-diaminodiphenylmethane / 4,4'-diaminodiphenyl ether, pyro Mellitic dianhydride / 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride / 4,4′-diaminodiphenylmethane / 2 -Bis (4-aminophenoxyphenyl) propane, pyromellitic dianhydride / 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride / 3,3', 4,4'-benzophenone tetracarboxylic acid And dianhydride / 4,4′-diaminodiphenylmethane / 4,4′-diaminodiphenyl ether / 2,2-bis (4-aminophenoxyphenyl) propane.

  Next, in the copolyaddition condensation reaction of (b) above, the aromatic tetracarboxylic dianhydride is a kind of aromatic tetracarboxylic dianhydride represented by the general formula (5) 3 , 3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is used alone, and as the aromatic diamine, the compound represented by the above general formula (1), (2) or (3) or the above general Two or more selected from the group of compounds represented by formula (4) are used. Specific examples of the aromatic diamine represented by the general formula (1), (2) or (3) used in the copolyaddition condensation reaction of (b) above include the copolyaddition condensation of (a) above. The compounds exemplified for the reaction can be mentioned, and specific examples of the aromatic diamine represented by the general formula (4) include 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diamino. Toluene, 2-methoxy-1,3-phenylenediamine, 2-methoxy-1,4-phenylenediamine, 4-methoxy-1,3-phenylenediamine, 6-methoxy-1,3-phenylenediamine, etc. it can.

  Specific examples of two or more aromatic diamines used in combination with 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride used in the copolyaddition condensation reaction of (b) above. 4,4′-diaminodiphenyl ether / 4,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl ether / 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether / 2,2-bis (4 -Aminophenyl) propane, 4,4'-diaminodiphenyl ether / 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-diaminodiphenylsulfone / 4,4'-diaminodiphenylmethane, 4,4 ' -Diaminodiphenylsulfone / 2,2-bis (4-aminophenyl) propane, 4,4'-diamino Phenylsulfone / 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4′-diaminodiphenylmethane / 2,2-bis (4-aminophenyl) propane, 4,4′-diaminodiphenylmethane / 2,2 -Bis (4-aminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) propane / 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-diaminodiphenyl ether / 4, 4'-diaminodiphenylsulfone / 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether / 4,4'-diaminodiphenylsulfone / 2,2-bis (4-aminophenyl) propane, 4,4'- Diaminodiphenyl ether / 4,4′-diaminodiphenylsulfone / 2 -Bis (4-aminophenyl) hexafluoropropane, 4,4'-diaminodiphenylsulfone / 4,4'-diaminodiphenylmethane / 2,2-bis (4-aminophenyl) propane, 4,4'-diaminodiphenylsulfone / 4,4′-diaminodiphenylmethane / 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4′-diaminodiphenylmethane / 2,2-bis (4-aminophenyl) propane / 2,2-bis (4-aminophenyl) hexafluoropropane, 2,4-diaminotoluene / 2,6-diaminotoluene, 2,4-diaminotoluene / 2-methoxy-1,3-phenylenediamine, 2,6-diaminotoluene / 2 -Methoxy-1,3-phenylenediamine and the like can be mentioned.

  In the copolyaddition condensation reaction of the above (a) and (b), as long as the obtained polyimide is soluble in a phenol solvent, it is represented by pyromellitic acid and the general formula (5), (6) or (7). Aromatic tetracarboxylic dianhydrides other than aromatic tetracarboxylic dianhydrides selected from the group of compounds represented by formula (1), (2), (3) or (4) One or more aromatic diamines other than the aromatic diamine selected from the group of the above can be used, and an aliphatic or alicyclic tetracarboxylic dianhydride, aliphatic or aliphatic, depending on the use of the resin composition One or more alicyclic diamines may be used in combination.

In the production of the soluble polyimide, (1) at least one aromatic tetracarboxylic dianhydride and at least one aromatic diamine as described above are used, for example, dimethylformamide, dimethylacetamide, N-methylpyrrolidone. A polyamic acid is synthesized by polyaddition in such an amide solvent, and then the polyamic acid is dehydrated and cyclized by a thermal imidization method or a chemical imidization method, or (2) at least one as described above Reaction of a kind of aromatic tetracarboxylic dianhydride and at least one kind of aromatic diamine by heating in a phenolic solvent such as o-cresol, m-cresol, p-cresol, p-chlorophenol. The one-step method for producing polyimide can be adopted, but the one-step method (2) is preferred. Arbitrariness.
The logarithmic viscosity [η _inh ] (measured with an Ubbelohde viscometer in m-cresol at 30 ° C. and a concentration of 0.5 g / dl) of the soluble polyimide thus obtained is usually 0.1 to 10.0 dl / g, preferably 0.3 to 3.0 dl / g, and the glass transition point (Tg; measured at a heating rate of 4 ° C./min and 1 Hz by dynamic viscoelasticity test) is usually 100 to 400 ° C. The temperature is preferably 200 to 350 ° C.

The resin composition of the present invention is a composition to which polyrotaxane is added as a material that relieves internal stress during thermosetting of the above thermosetting resin.
Here, rotaxane refers to a molecule in which a ring-shaped molecule is embedded in a dumbbell-shaped shaft molecule. By using a polymer such as polyethylene glycol as the shaft molecule, a plurality of ring-shaped molecules such as cyclodextrin are confined. This is called polyrotaxane.

As the polyrotaxane in the resin composition of the present invention, a chain polymer molecule having a terminal functional group serving as a shaft molecule is included in a ring-like molecule in a skewered manner, and the cyclodextrin molecule has the terminal functional group Examples thereof include compounds in which the above-mentioned terminal functional group is chemically modified with a blocking group that is bulky enough not to be removed from the chain polymer molecule.
The ring-shaped molecule used in the polyrotaxane can be used without any limitation as long as a chain polymer molecule can be passed through the ring. Preferred examples of the cyclic molecule include cyclodextrins, crown ethers, cryptands, macrocyclic amines, calixarenes, and cyclophanes. Cyclodextrins are particularly preferred because they have the property of easily forming an inclusion compound with an organic compound. Cyclodextrins are compounds in which a plurality of glucoses are linked in a cyclic manner with α-1,4-linkages. Among them, compounds formed with 6, 7, and 8 glucoses are α-, β-, And γ-cyclodextrin and more preferably used. In addition, modified dextrins in which at least one of the hydroxyl groups of these cyclodextrins is substituted with another organic group are more preferably used because of their improved solubility in solvents.

As the chain polymer molecule having a terminal functional group, any molecule having a reactive group capable of binding a blocking group at the terminal can be used without any limitation. The terminal functional groups preferably used here include hydroxyl group, amino group, carboxyl group, acid chloride group, phenol group, isocyanate group, vinyl group, acrylic group, methacryl group, styryl group, active ester group, thiol group, and lactone. Examples thereof include a cyclic group, a cyclic / chain acid anhydride group, a carbonate group, a silane group, a silanol group, and an alkoxysilyl group, and particularly preferably a hydroxyl group, an amino group, and a carboxyl group. It is also suitably used that a plurality of these terminal functional groups coexist in one molecule. The chain polymer molecule can be used without any limitation as long as it is a chain polymer molecule that can form a structure in which a penetrating ring-like molecule cannot be removed. The chain polymer molecules preferably used include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol; polybutadiene diol, polyisoprene diol, polyisobutylene diol, poly (acrylonitrile-butadiene) diol, hydrogenated polybutadiene. Terminal hydroxyl group polyolefins such as diol, polyethylene diol and polypropylene diol; Polycaprolactone diol, Polylactic acid, Polyethylene adipate, Polybutylene adipate, Polyesters such as polyethylene terephthalate, Polybutylene terephthalate; Terminal functionality such as terminal silanol type polydimethylsiloxane Polysiloxanes: terminal amino group polyethylene glycol, terminal amino group poly Propylene glycol, terminal amino group chain polymer such as the terminal amino groups polybutadiene; and the like above-mentioned functional group polyfunctional chain polymer molecules, three or more functionalities with in one molecule three or more can be mentioned.
The chain polymer having a terminal functional group preferably has a molecular weight of 2,000 to 1,000,000, preferably 10,000 to 500,000. When the molecular weight is less than 2,000, there is an effect of restricting the mobility due to the terminal blocking group, and the stress relaxation effect is not sufficiently exhibited. On the other hand, when the molecular weight exceeds 1,000,000, the solubility of the rotaxane in the matrix resin is lowered, and the workability is also lowered.

  The bulky blocking group can be used without any limitation as long as it is a sufficiently bulky group that binds to the terminal by reacting with the above-described terminal functional group and cannot remove the ring-shaped molecule. Particularly preferred blocking groups include 2,4-dinitrophenyl group, trityl group, dansyl group, 2,4,6-trinitrophenyl group, triisopropylsilyl group, naphthalene derivative group, anthracene derivative group, and the like. . Prior to the reaction between the chain polymer having a terminal functional group and the blocking group, it is also preferable to convert the terminal functional group of the chain polymer into a more reactive functional group. For example, a terminal amino group polyethylene glycol is synthesized by reacting a hydroxyl group terminal of polyethylene glycol with carbonyldiimidazole and subsequently reacting with ethylenediamine. Hereinafter, “polyethylene glycol” and “polypropylene glycol” include cases where these molecular terminals are modified by chemical modification.

The ratio between the ring-shaped molecule and the shaft molecule of the polyrotaxane used in the present invention is an important factor that strongly influences the stress relaxation characteristics of the resin composition of the present invention. The number of ring molecules fitted into the axis molecule is determined by the length of the axis molecule and the width of one ring molecule. In general, the ratio between the ring-shaped molecule and the axial molecule of this polyrotaxane is called “filling rate”. For example, in the case of a polyrotaxane comprising α-cyclodextrin (α-CD) and polyethylene glycol (PEG), the following formula It is expressed by (3).

¹ H-NMR integrated intensity ratio: R = (C ₁ -H integrated intensity of α-CD) / (Integrated intensity of PEG-H)
(1)
Number of α-CD added to PEG: N = R x (4/6) x (degree of polymerization of PEG) (2)
Filling rate (%): FR = N × 100 / (degree of polymerization of PEG / 2) (3)

The filling rate represented by the above: FR can take a value in the range of 0 to 100 (%), but when the stress relaxation property of the resin composition of the present invention is expressed, preferably 1 to 30%, more preferably Is in the range of 2-20%, more preferably 3-10%. If the filling rate is less than 1%, the effect of immobilization by the multipoint bond between the cyclodextrin molecule and the matrix and the improvement of mechanical strength retention are small. On the other hand, if the filling rate exceeds 30%, the mobility of the shaft molecule is limited. Thus, a sufficient stress relaxation effect is not exhibited.

In a specific embodiment of the polyrotaxane used in the present invention, the ring-shaped molecule is preferably cyclodextrin, and the chain polymer molecule having the terminal functional group is preferably a polyalkylene glycol, and the hydroxyl group of the polyalkylene glycol A polyrotaxane is prepared by modifying the terminal end to an amino group and blocking the terminal end of the amino group with a bulky group such as a 2,4-dinitrophenyl group.
For example, by reacting a terminal amino group-modified polyalkylene glycol incorporating cyclodextrin with 2,4-dinitrophenyl fluoride, the terminal end of the molecular axis is 2,4-dinitrophenyl group as the bulky blocking group. An end-capped polyrotaxane consisting of α-cyclodextrin and polyethylene glycol is prepared.

  Note that β-cyclodextrin and γ-cyclodextrin can form a polyrotaxane from polypropylene glycol in the same manner as described above. These polyrotaxanes are also prepared by chemically modifying the end of polypropylene glycol incorporating cyclodextrin with a bulky blocking group, as in the case of the polyrotaxane comprising α-cyclodextrin and polyethylene glycol.

  Polyrotaxane and β- or γ-cyclodextrin from α-cyclodextrin (α-CD) and polyethylene glycol [PEG, for example, poly (ethylene glycol) bisamine (PEG-BA) as amino-modified at both ends of the molecule]] The production method of polyrotaxane from (β- or γ-CD) and amino group-modified polypropylene glycol (PPG-BA) will be described in more detail.

  For example, with respect to 1 mol of α-, β- or γ-CD, both are stirred and mixed in an aqueous medium so as to be 2 mol or more as an alkylene glycol unit (unit) of PEG or PPG. The reaction is carried out in the temperature range of 90 ° C. for about 10 minutes to 1 hour. It is not preferable to use PEG or PPG in a larger amount than necessary because of high cost. In particular, when PPG is used, it may be in a dispersed state rather than a dissolved state, and therefore it is preferable to stir while irradiating with ultrasonic waves. Then, it cools to the temperature of 0-10 degreeC as needed, and the produced precipitate is solid-liquid-separated from a reaction mixture. As this solid-liquid separation method, filtration, centrifugation, membrane separation using an ultrafiltration membrane, etc. are common.

  Next, as a typical chemical modification method of the end of the shaft molecule with a blocking group, an inclusion compound of α-CD and PEG-BA and 2,4-dinitrophenyl fluoride [2,4-dinitrofluorobenzene (DNFB) ] Will be described.

  For example, DNFB is added to a solution of the above polymer compound dissolved in a solvent such as dimethylformamide, and the mixture is stirred for 30 minutes to 5 hours, for example, near normal temperature. The reaction mixture is dissolved in dimethyl sulfoxide, poured into water, and the resulting precipitate is recovered by washing with water and methanol three times each. For further purification, the dissolution / precipitation process is repeated using the above dimethyl sulfoxide / water system.

  Instead of the above 2,4-dinitrophenyl fluoride, for example, trityl bromide, dansyl chloride, 2,4,6-trinitrophenyl fluoride, 9-anthraldehyde, 9-anthracene carboxylic acid, etc. may be used. it can.

  After the inclusion of a polymer compound such as polyethylene glycol or polypropylene glycol in a skewered manner using a cyclodextrin as a ring molecule and a cyclodextrin as a ring molecule, both ends of the polymer compound are chemically modified with a bulky blocking group. When blocked, the bulky blocking group prevents the cyclodextrin molecule as a ring-shaped molecule from detaching from the chain of the polymer compound, and the polyrotaxane obtained even when heated or contacted with a solvent becomes a ring molecule and a shaft molecule. No detachment.

The polyrotaxane as described above forms a dispersion domain at the molecular level in the matrix resin (thermosetting resin), ensures a free motion mode at a low temperature, and coexists with the mechanical property retention mechanism of the matrix resin. Can do.
The resin composition of the present invention is a composition of a polyrotaxane and a thermosetting resin (such as an epoxy resin) having a high glass transition temperature (Tg), while the polyrotaxane is in a uniform and finely dispersed state of a flexible material, It is possible to increase the Tg and storage elastic modulus of the resulting composition and to ensure the molecular mobility of the stress relaxation component.

The resin composition of the present invention is obtained by finely dispersing polyrotaxane in a thermosetting resin that is a matrix resin.
Here, the difference between the effect of adding a general stress relaxation material having a transition temperature lower than the glass transition temperature (Tg) of the matrix resin and the effect of the polyrotaxane used in the present invention is shown below.




General molecular dispersion system Phase separation system Transparency of the polyrotaxane of the present invention Maintenance Opaque Transparent Storage elastic modulus Significant decrease Maintenance to decrease Increase Matrix Tg Decrease Unchanged Increase

Thus, the superiority of the polyrotaxane lies in the expression of the aggregation effect at the molecular level, the formation of a cross-linked structure by multipoint bonding between the matrix and the ring-shaped molecule, and the accompanying contribution to improving the thermal and mechanical properties.

The reason why the glass transition temperature (Tg) and storage modulus of the matrix resin are increased by adding polyrotaxane is
(1) Chain transfer reaction that occurs for cyclodextrin molecules during ring-opening polymerization of epoxy groups and formation of chemical bonds with the accompanying matrix (2) Effect of dispersion of rotaxane molecules having multiple cyclodextrin molecules at the molecular level (3) It is considered that the crosslink density is increased by multipoint crosslinking.
The functions of (1) to (3) are not limited to cyclodextrins, and even when other cyclic molecules are used, they have or impart reactive groups capable of binding to the matrix resin on the molecules. Can be expressed in the same manner.
The external stress applied to the molded product obtained from the resin composition is a mechanical stress accompanied by deformation of the matrix due to heat and impact, but this stress is alleviated by adding the polyrotaxane of the present invention. There is a function.
That is, the stress relaxation function that converts heat and strain energy into molecular motion by free movement of the molecular chain of the polyrotaxane's axial molecular chain within the free volume formed by the ring-shaped molecular group bound by the matrix resin. work. Specifically, the stress relaxation mechanism is expressed by free movement of unbound polyethylene glycol molecular chains in a free volume formed by a plurality of cyclodextrin molecules in the polyrotaxane molecule.

  In the resin composition of the present invention, the amount of the polyrotaxane added to the thermosetting resin such as epoxy resin or polyimide resin used as the matrix resin is 1 to 20 parts by weight, preferably 5 parts per 100 parts by weight of the thermosetting resin. ~ 15 parts by weight. If the amount is less than 1 part by weight, the stress relaxation effect by the polyrotaxane is not sufficient, while if it exceeds 20 parts by weight, aggregation of the polyrotaxane molecules starts and it is difficult to form an effective dispersion state.

  In addition to the above-mentioned thermosetting resin, its curing agent, and polyrotaxane component, the resin composition of the present invention includes various additives generally used in thermosetting resin compositions depending on the application and purpose. Can be blended as needed. Examples of such additives include inorganic fillers such as fumed silica, fused silica, crystalline silica, and alumina, flame retardants such as antimony oxide, halogen compounds, and phosphorus compounds, higher fatty acid metal salts, and ester waxes. Examples thereof include internal mold release agents, silane coupling agents, pigments, and dyes.

  The resin composition of this invention can be prepared by knead | mixing each required component uniformly using mixing apparatuses, such as a roll and a kneader. Or it can adjust also by removing a solvent, after melt | dissolving in an organic solvent uniformly as needed.

Example
Next, examples of the present invention will be given. In addition, the part in an example shows a weight part and% shows weight%.
In the examples, the cyclodextrin filling rate, stress relaxation test, and thermal analysis were measured as follows.

Filling ratio: Polyrotaxane was dissolved in deuterated dimethyl sulfoxide, and NMR spectrum was measured using 400 MHz ¹ H-NMR manufactured by Varian. In the obtained spectrum, the integrated intensity of the peak based on α-cyclodextrin C ₁ -H around 4.8 ppm and the peak based on hydrogen in the ethylene glycol unit around 3.5 ppm was determined. The cyclodextrin filling factor was calculated using the following formula.
¹ H-NMR integrated intensity ratio: R = (C ₁ -H integrated intensity of α-CD) / (Integrated intensity of PEG-H)
Number of α-CD added to PEG: N = R x (4/6) x (Polymerization degree of PEG)
Filling rate (%): FR = N × 100 / (degree of polymerization of PEG / 2)

Stress relaxation test (dynamic viscoelasticity measurement): SDM 5600 manufactured by Seiko Instruments Inc.
Dynamic viscoelasticity was measured using DMS200. Using different frequencies of 0.5, 1, 2, 5, and 10 Hz, the rate of temperature rise is 2 ° C./min, and the storage elastic modulus, loss elastic modulus and Loss tangent Tanδ was measured. The tensile mode was used for the measurement. The cross-sectional area of the sample piece was measured using a thickness gauge, about 3 mm 2, and the distance between chucks was 2 cm. The measurement was performed in an air atmosphere.

  Thermal analysis: Differential scanning calorimetry was performed using EXTAR SI I-6200 manufactured by Seiko Instruments Inc. The sample is sealed in an aluminum pan with a diameter of 5 mm, heated to room temperature to 200 ° C. at a heating rate of 5 ° C./min under a nitrogen stream (20 ml / min), then rapidly cooled with liquid nitrogen, and then raised again. Measurement was performed by heating from -100 ° C to 200 ° C at a temperature rate of 5 ° C / min.

Reference example 1
1.9 g of α-cyclodextrin is added to 1 g of terminal amino group polyethylene glycol (Wako Pure Chemicals Reagent PEG-2000) having an average molecular weight of 2,000, dissolved in distilled water, mixed, and mixed at 80 ° C. for 1 hour. Stir to obtain a clear solution. Next, this transparent solution was cooled overnight in a refrigerator (5 ° C.) to obtain a white gel. The white gel was volatilized and removed under reduced pressure using an evaporator. The obtained white solid product was dissolved in 20 ml of dimethylformamide, 2 ml of 2,4-dinitrophenyl fluoride was added thereto as an end-capping agent, and the mixture was stirred at room temperature for 2 hours. To the resulting reaction mixture, 50 ml of dimethyl sulfoxide was added and dissolved to obtain a transparent solution. Next, this clear solution was transferred to a separatory funnel, and 300 ml of distilled water was added thereto to produce a yellow precipitate. This yellow precipitate was washed with 300 ml of distilled water three times and further with 300 ml of methanol three times. The yellow precipitated product was separated by centrifugation (7,000 rpm, 10-15 minutes). The separated yellow product was dried under reduced pressure at 80 ° C. for 24 hours to obtain a polyrotaxane. The polyrotaxane synthesized in this manner was a polyrotaxane containing 3.9 α-cyclodextrins per axial molecule and having a packing rate of 17.7%. The results are shown in Table 1.

Reference example 2
5 g of polyethylene glycol having an average molecular weight of 20,000 (Wako Pure Chemicals Reagent PEG-20,000) was dissolved in 50 ml of dry methylene chloride. To this solution, 2 g of N, N′-carbonyldiimidazole was added and dissolved, and stirred at room temperature for 12 hours. 300 ml of diethyl ether was added to the resulting solution to obtain a white precipitate. The white precipitate was separated by centrifugation (7,000 rpm, 5 minutes). The separated white precipitate was washed twice with 300 ml of diethyl ether to synthesize imidazolylcarbonyloxy group-modified PEG-20,000 at the end. 3.45 g of the obtained product was dissolved in 50 ml of methylene chloride, and 10 ml of ethylenediamine was added dropwise while stirring this solution at room temperature, and then stirred for 2 hours. 300 ml of diethyl ether was added to the resulting solution to obtain a white precipitate. The white precipitate was dissolved in 100 ml of distilled water and purified using a dialysis tube (fraction molecular weight 12,000). Finally, water was removed from the purified aqueous solution by evaporation using an evaporator to obtain terminal amino group-modified PEG-20,00 (yield 2.6 g). A polyrotaxane was obtained in the same manner as in Reference Example 1 from the terminal amino group-modified PEG-20,000 and DNFB thus obtained. The results are also shown in Table 1.

Reference example 3
In the same manner as in Reference Example 2, a polyrotaxane was obtained using an average molecular weight of 35,000 (Fluka reagent PEG-35,000). The results are also shown in Table 1.

Example 1
0.1 g of the polyrotaxane obtained in Reference Examples 1 to 3 was dissolved in 1 g of dimethyl sulfoxide (DMSO), and a base epoxy resin raw material (Dainippon Ink, novolak epoxy resin EPICLON) was dissolved in this solution.
N-730-A) 1 g was added to obtain a homogeneous solution. Next, 0.02 g of 2-ethyl-4-methylimidazole was dissolved in 0.2 ml of 1-methyl-pyrrolidone (NMP) and added to the above solution. This solution was poured into a strip-shaped casting frame and cured by heating at 140 ° C. for 3 hours. In order to volatilize and remove the solvent (DMSO and NMP) from the cured product, it was heated at 220 ° C. for 2 hours. By the above operation, a cured film having a thickness of about 0.5 mm was prepared. The dynamic viscoelasticity of the cured film was measured with a dynamic viscoelasticity measuring device (DMA). The results measured at 10 Hz are shown in FIG.
From FIG. 1 (a) and (b), the new dispersion peak was seen by the temperature range of 50-100 degreeC by addition of the polyrotaxane. The above new dispersion peak does not appear when PEG or α-CD alone is added.
It can also be seen that the addition of polyrotaxane increases the storage modulus. Furthermore, it can be seen that the addition of polyrotaxane improves the glass transition temperature of the matrix epoxy resin.

Example 2
Using the polyrotaxane obtained in Reference Example 2, the amount of addition to the base epoxy resin raw material was changed, and the stress relaxation effect was examined in the same manner as in Example 1. The results measured at 10 Hz are shown in FIG.
2 (a) and 2 (b), it can be seen that the amount of polyrotaxane added is in the range of 5% to 20%, and the storage elastic modulus and the dispersion peak at 50 to 100 ° C. are higher than those of the base epoxy resin of Reference 1. . Further, as the addition amount of polyrotaxane increases from 5% to 10%, the storage elastic modulus also increases the dispersion peak over 50-100 ° C., but as the addition of polyrotaxane increases from 10% to 20%, It can be seen that the glass transition temperature is further increased while the storage modulus is slightly decreased.

Comparative Example 1
A resin composition comprising 1 g of the base epoxy resin raw material used in Example 1 and 0.1 g of a mixture composed of 0.0677 g of polyethylene glycol having an average molecular weight of 20,000 blocked with DNFB and 0.0323 g of α-cyclodextrin. Was used and the stress relaxation effect was examined in the same manner as in Example 1. The results measured at 10 Hz are shown in FIG.

  From Table 4 and FIGS. 3 (a) and (b), no dispersion peak at 50 to 100 ° C. is observed in the system in which PEG-20,000 and α-CD whose ends are capped with DNFG are added separately. Moreover, it turns out that the molecular motion mode over 50-100 degreeC does not exist in the polyethyleneglycol simply disperse | distributed in the epoxy resin.

Example 3
The thermal analysis of the resin composition prepared in Example 1 was measured using a scanning calorimeter (DSC) suggesting. The results are shown in FIG. In any resin composition containing a polyrotaxane, thermal transition is observed at around 60 ° C. On the other hand, no such thermal transition is observed in the reference. In addition, the polyrotaxane, α-cyclodextrin, and PEG-20,000 obtained in Reference Example 2 were subjected to thermal analysis in the same manner. The results are shown in FIG. As a result, it can be seen that PEG-20,000 exhibits a clear melting point peak at about 60 ° C. On the other hand, it can be seen that neither polyrotaxane nor α-cyclodextrin shows a thermal transition in the temperature range of 50 to 100 ° C.
From this, it can be seen that polyrotaxane alone has lost the molecular motion mode of PEG alone, that is, has lost the crystal structure of PEG.
Further, the resin composition (epoxy resin / polyrotaxane complex) of the present invention expresses some PEG chain motion mode, that is, a new molecular motion mode of PEG chain in the interaction between the polyrotaxane and the matrix. It is presumed that it has occurred.

The polyrotaxane used in the present invention is less cohesive than conventional silicone rubber fine particles and has excellent dispersibility in a thermosetting resin such as a base epoxy resin. Therefore, the thermosetting resin composition of the present invention Is less susceptible to cracking during thermosetting and cooling and cooling cycles, gives a molded article having excellent impact resistance, and is extremely suitable as a packaging material.

In the data obtained by Example 1, it is the effect of the molecular weight of polyethylene glycol which is an axial molecular component of polyrotaxane, (a) shows the storage elastic modulus and loss elastic modulus results of DMA, and (b) shows the loss tangent result. Indicates. In the data obtained by Example 2, it is an effect of the addition amount of a polyrotaxane, (a) shows the storage elastic modulus and loss elastic modulus result of DMA, (b) shows loss tangent. The data obtained in Comparative Example 1 shows the effect of the (PEG-DNFB + α-CD) mixture addition system, (a) shows the storage elastic modulus and loss elastic modulus results of DMA, and (b) shows the loss tangent. . It is the data obtained by Example 3, and is the thermal analysis result by DSC of the resin composition film obtained in Example 1. It is the data obtained by Example 3, and is the thermal analysis result by DSC of raw material PEG-20,000, (alpha) -CD, and the produced | generated polyrotaxane.

Claims (3)

  A resin composition comprising polyrotaxane in a thermosetting resin.   The resin composition according to claim 1, wherein the thermosetting resin is an epoxy resin or a polyimide. The polyrotaxane has a polyalkylene glycol as an axis molecule, cyclodextrin is fitted into the polyrotaxane, and both ends of the polyalkylene glycol molecule are blocked with a blocking group so that the cyclodextrin molecule is not detached from the polyalkylene glycol molecule. The resin composition according to claim 1, wherein is sealed.

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