Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
1999-03-12
2001-07-03
Tucker, Philip (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S526000, C523S427000, C257S793000
Reexamination Certificate
active
06255409
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an epoxy resin composition which is useful for adhesives, paints and electric/electronic materials(e.g. insulation materials, laminated plate, etc.), particularly useful for encapsulating electric devices.
2. Description of the Related Art
Recently, for encapsulating semiconductors such as LSI, IC, transistor and the like, transfer mold of an economically useful epoxy resin composition is conducted.
Particularly, surface mounting of LSI is recently conducted, and direct immersion into a solder bath is increasing. Since an encapsulating material is exposed to a high temperature of above 200° C. in this treatment, moisture absorbed in the encapsulating material expands, crack is formed in the material, and peeling occurs at interface with a die pat.
Therefore, the epoxy resin encapsulant is required to have properties of low moisture absorption, high crack resistance and improved adhesion. Further, for a purpose of obtaining a low moisture absorption property, an epoxy resin of low viscosity in which a filler can be filled in high concentration is desired. Currently, an encapsulating material in which glycidyl ether of o-cresol novolak is used as a polyfunctional epoxy resin and phenol novolak is used as a curing agent is mainly used, however, when the encapsulating material absorbs moisture in storage, the above-described problems occur. Therefore, for avoiding these problems, the encapsulating material is wrapped for preventing moisture absorption in practical use.
On the other hand, a biphenyl type epoxy resin in current use has a lower viscosity and can contain a filler in higher concentration than a polyfunctional epoxy resin, since the biphenyl epoxy resin is a bifunctional epoxy resin and has a low molecular weight. Therefore, moisture absorption depending on the biphenyl type epoxy resin can be reduced as whole package and strength thereof can be increased, consequently, excellent crack resistance can be obtained as compared with an epoxy resin in the form of a glycidyl ether of o-cresol novolak. However, the biphenyl type epoxy resin has problem that molding property of a cured article thereof is low as compared with the polyfunctional epoxy resin.
Furthermore, the softening point of an amorphous epoxy resin having a low melt viscosity is generally low, and there have been problems of blocking at the time of storage to deteriorate the workability. Therefore, the amorphous resin is stored generally with cooling in a refrigerator, and the productive efficiency is bad and not economical.
There has been a proposal of using a bisphenol compound of &agr;-methylstilbene as an encapsulating material (for example, JP-A-6-345849). However, the epoxy compound disclosed there is not sufficient in moldability etc.
An object of the present invention is to provide an epoxy resin composition which has an excellent moldability (low viscosity and can be filled with filler with high density) and high softening point, and hardly causes blocking during storage.
SUMMARY OF THE INVENTION
The present invention is as follows.
[1] An epoxy resin composition comprising (A) a bifunctional crystalline epoxy compound, (B) an amorphous trisphenolmethane type epoxy compound having three or more of epoxy groups in a molecule, and (C) an epoxy curing agent having phenolic hydroxyl groups.
[2] An epoxy resin composition comprising (A) a bifunctional crystalline epoxy compound, and (B) an amorphous trisphenolmethane type epoxy compound having three or more of epoxy groups in a molecule, wherein the whole or a part of epoxy compound (A) is dispersed in epoxy compound (B) as crystallites.
The epoxy compound (A) used for the present invention is a bifunctional crystalline epoxy compound, and suitably a compound represented by the general formula (1).
Here, X represents —N═N—, —CH═C(R
9
)—, —O—CO—, —CH═C) (CN)—, —C≡C—, —CH═CH—CO— or a single bond. R
1
, to R
9
represent each independently an acyclic or cyclic alkyl group having 1-6 carbon atoms, a hydrogen atom or a halogen atom. More suitably, X is —CH═C(R
9
)—.
Concrete examples of substituents R
1
-R
9
of the epoxy compound represented by the general formula (1) include methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, cyclohexyl group, phenyl group, tolyl group, xylyl group (each isomer is included), chlorine atom, bromine atom, etc.
In the general formula (1), glycidyl ether of stilbene bisphenol whose X is —CH═C (R
9
)— can be obtained by a known method of glycidyl etherification of a stilbene bisphenol.
As for a producing method of stilbene bisphenol compound used as a raw material for epoxy compound, a reference (von Rolf H. Sieber, Liebigs Ann. Chem. 730, 31-46 (1969)) discloses a preparation method and physical properties of the compound, such as 4,4′-dihydroxystilbene, 4,4′-dihydroxy-3,3′-dimethylstilbene and 4,4′-dihydroxy-3,3′,5,5′-tetramethylstilbene.
On the other hand, bisphenol compound of &agr;-methylstilbene is also known, and for example, METHODEN DER ORGANISCHEN CHEMIE (HOUBEN-WEYL) BAND IV/1c Phenol Teil2 P1034 describes a preparation method of 4,4′-dihydroxy-&agr;-methylstilbene from phenol and chloroacetone as starting materials.
Concrete examples of stilbene phenol used as a raw material include: 4,4′-dihydroxy-3-methylstilbene, 4,4′-dihydroxy-3-ethylstilbene, 4,4′-dihydroxy-3-propylstilbene, 4,4′-dihydroxy-3-amylstilbene, 4,4′-dihydroxy-3-hexylstilbene, 4,4′-dihydroxy-2,3-dimethylstilbene, 4,4′-dihydroxy-2,6-dimethylstilbene, 4,4′-dihydroxy-2,3′-dimethylstilbene, 4,4′-dihydroxy-3,3′,5-trimethylstilbene, 4,4′-dihydroxy-2′,3,5-trimethylstilbene, 4,4′-dihydroxy-2′,3,3′,5-tetramethylstilbene, 4,4′-dihydroxy-2′,3,5,6′-tetramethylstilbene, 3-t-butyl-4,4′-dihydroxy-3′-methylstilbene, 3-t-butyl-4,4′-dihydroxy-5,3′-dimethylstilbene, 3-t-butyl-4,4′-dihydroxy-3′,6-dimethylstilbene, 3-t-butyl-4,4′-dihydroxy-5-ethyl-3′-methylstilbene, 3-t-butyl-4,4′-dihydroxy-3′-methyl-5-propylstilbene, 3-t-butyl-4,4′-dihydroxy-5-butyl-3′-methylstilbene, 3-t-butyl-4,4′-dihydroxy-5-amyl-3′-methylstilbene, 3-t-butyl-4,4′-dihydroxy-5-hexyl-3′-methylstilbene, 3-t-butyl-4,4′-dihydroxy-5-cyclohexyl-3′-methylstilbene, 3-t-butyl-4,4′-dihydroxy-3′,5,5′-trimethylstilbene, 3-t-butyl-2,4′-dihydroxy-3′,5′,6-trimethylstilbene, 3-t-butyl-4,4′-dihydroxy-3′,5′,6-trimethylstilbene, 3-t-butyl-4,4′-dihydroxy-3′,5,-dimethyl-5′-propylstilbene, 3-t-butyl-4,4′-dihydroxy-3′,6,-dimethyl-5′-propylstilbene, 4,4′-dihydroxy-3,3′-dimethylstilbene, 3,3′-diethyl-4,4′-dihydroxystilbene, 4,4′-dihydroxy-3,3′-dipropylstilbene, 3,3′-diamyl-4,4′-dihydroxystilbene, 3,3′-dihexyl-4,4′-dihydroxystilbene, 3,3′-dicyclo hexyl-4,4′-dihydroxystilbene, 2,2′-dihydroxy-3,3′, 5,5′-tetramethylstilbene, 4,4′-dihydroxy-3,3′,5,5′-tetramethylstilbene, 4,4′-dihydroxy-3,3′-di-t-butylstilbene, 4,4′-dihydroxy-3,3′-di-t-butyl-5,5′-dimethylstilbene, 4,4′-dihydroxy-3,3′-di-t-butyl-6,6′-dimethylstilbene, 2,2′-dihydroxy-3,3′-di-t-butyl-6,6′-dimethylstilbene, 2,4′-dihydroxy-3,3′-di-t-butyl-6,6′-dimethylstilbene and 4,4′-dihydroxy-3,3′,5,5′-tetra-t-butylstilbene. Isomers thereof having a substituent at a different position are also included.
Examples of &agr;-methylstilbene include those having a methyl group on a carbon atom of carbon-carbon double bond of the above described stilbene compounds.
In view of easiness of preparation, performance and price of raw material, preferable stilbenes are: 2,2&prime
Hirano Yasuhiro
Matsuoka Yoshiki
Nakajima Nobuyuki
Pillsbury & Winthrop LLP
Sumitomo Chemical Co,. Ltd.
Tucker Philip
LandOfFree
Epoxy resin composition and resin-encapsulated semiconductor... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Epoxy resin composition and resin-encapsulated semiconductor..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Epoxy resin composition and resin-encapsulated semiconductor... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2435472