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
2002-04-23
2004-09-07
Peng, Kuo-Liang (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...
C528S421000, C528S418000, C528S012000, C528S038000, C525S523000, C549S512000, C556S458000
Reexamination Certificate
active
06787614
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thermosetting resin composition such as an epoxy resin, and a process for producing the same.
2. Description of the Related Art
Epoxy resins that are one of thermosetting resins are widely employed in uses for electronic materials and coating compositions owing to its excellent moldability, adhesive properties and insulation reliability. Among them, the uses in the electronic materials widely range over laminate sheets and resist inks for printed wiring boards, sealing materials and die bonding materials for semiconductors, and under-filing materials. Recently, as information terminal electronic devices such as personal computers and mobile phones come into wide use, there is remarkable progress in the miniaturization of various electronic parts and the realization of their high performance. For the purpose, mounting parts such as the printed wiring boards and packages mounted thereon need to be thinner and smaller than before and also need to realize high reliability which can endure the high-density mounting.
Under such circumstances, also for the epoxy resins to be used in these electronic parts, enhanced thermal resistance and adhesive properties are required.
Hitherto, the employment of polyfunctional epoxy resins typified by novolak-type and a curing agent is a general method for enhancing the thermal resistance of epoxy resins. However, since their cured products have a high crosslinking density, they inconveniently become hard and brittle. Such hard and brittle resins tend to exhibit the decreased thermal resistance and reduced adhesive properties to a metal after moisture absorption.
On the other hand, as a measure for enhancing the adhesive properties of the epoxy resins, there is a usual way of reducing a crosslinking density of the cured resin products and increasing an elongation of the products. However, when the crosslinking density is reduced, the glass transition temperature (hereinafter, referred to as Tg) also decreases. Therefore, there arises a problem that mechanical properties at a high temperature are deteriorated. Moreover, there is a possibility that the reliability of a wired board is adversely affected. This tendency results in a very serious problem in the current situation that electronic parts become thin and highly dense and the number of reflow times for solder jointing is increasing.
Furthermore, material development or the like based on the consideration of a future global environment, e.g., a solder containing no lead, has been promoted. Thereby, it has been expected that electronic materials be increasingly exposed to a high temperature atmosphere.
Therefore, the epoxy resins are required to possess both of a high thermal resistance and a high toughness. In order to satisfy these requirements, it is important that they have a high Tg and exhibit some degree of low elasticity at a high temperature region.
As a representative method for enhancing the adhesive properties without deteriorating thermal resistance, there is a method of modifying the resins with a thermosetting resin or the like. One example includes a modification by adding a thermally resistant thermoplastic resin having a high toughness to a highly crosslinked thermally resistant hard and brittle epoxy resin. However, as represented by super engineering plastics, a thermoplastic resin excellent in thermal resistance has a high softening point and also has a very high melt viscosity. Therefore, even when an epoxy resin is well modified, the resulting modified epoxy resin has a high melt viscosity. Thus, there arises a problem that moldability is remarkably deteriorated as compared with the conventional epoxy resins generally molded by heating and pressing. Moreover, thermoplastic resins generally have a low polarity and low adhesive properties to a metal and, as a result, the adhesive properties of the modified epoxy resin also decrease in most cases. Additionally, there is a tendency of decrease of elastic modulus at room temperature, so that handleability and rigidity tend to decrease.
In recent years, as one of modification methods for the epoxy resins, blends with an inorganic compound are reported in Japanese Patent Application Laid-Open Nos. 100107/1996, 298405/1998, and 92623/1999. However, all these method comprises adding a hard gelated product having a high elastic modulus into a thermosetting resin by sol-gel method or the like, whereby a high thermal resistance is realized but toughness in a high temperature region decreases.
As mentioned above, an epoxy resin composition with excellent toughness at high temperatures without deterioration in its excellent thermal resistance and moldability has been desired.
SUMMARY OF THE INVENTION
An embodiment of the present invention is a thermosetting resin composition. wherein the storage modulus of a cured product at 25° C. is 1.0 Gpa or more, and the storage modulus thereof at 200° C. is 100 MPa or less.
Furthermore, another embodiment of the invention is a thermosetting resin composition comprising an epoxy resin and a curing agent as essential components, wherein the storage modulus of the cured product at 200° C. is 100 MPa or less.
Moreover, the glass transition temperature of the cured product is preferably 170° C. or higher.
Moreover, the resin composition preferably comprises a silicone polymer containing a bifunctional siloxane unit represented by the formula R
2
SiO
2/2
(wherein R is the same or a different organic group) in the molecule.
Moreover, the resin composition preferably contains 2 parts by weight or more of the silicone polymer with respect to 100 parts by weight of the epoxy resin
Furthermore, another embodiment of the present invention is a thermosetting resin composition comprising, as essential components, (a) an epoxy resin, (b) a curing agent, and (c) a silicone polymer containing a bifunctional siloxane unit represented by the formula R
2
SiO
2/2
(wherein R is the same or a different organic group) in the molecule.
Moreover, the curing agent (b) is preferably a phenol resin.
Moreover, the silicone polymer (c) may contain a bifunctional slioxane unit represented by the formula R
2
SiO
2/2
(wherein R is the same or a different organic group) and a trifunctional siloxane unit represented by the formula RSiO
3/2
(wherein R is the same or a different organic group) in the molecule.
Moreover, the silicone polymer (c) may contain a bifunctional siloxane unit represented by the formula R
2
SiO
2/2
(wherein R is the same or a different organic group) and a tetrafunctional siloxane unit represented by the formula SiO
4/2
in the molecule.
Moreover, the silicone polymer (c) may contain a bifunctional siloxane unit represented by the formula R
2
SiO
2/2
(wherein R is the same or a different organic group), a trifunctional siloxane unit represented by the formula RsiO
3/2
(wherein R is the same or a different organic group), and a tetrafunctional siloxane unit represented by the formula SiO
4/2
in the molecule.
Moreover, the silicone polymer (c) preferably contains the above bifunctional siloxane unit in the molecule in an amount of 10 mol % or more of the total silicone polymer.
Moreover, an average polymerization degree of the silicone polymer (c) is preferably from 2 to 2000.
Moreover, a blend amount of the silicone polymer (c) is preferably 2% by weight or more with respect to the epoxy resin.
Moreover, at least one end of the silicone polymer (c) is preferably a silanol group or an alkoxy group.
Moreover, the resin composition further preferably comprises a coupling agent.
Moreover, the silicone polymer (c) may contain a monomer of a bifunctional silane compound, a trifunctional silane compound, or a tetrafunctional silane compound.
Moreover, the silicone polymer (c) may contain a homo-type oligomer of one compound selected from a bifunctional silane compound, a trifunctional silane compound and a tetrafunctional silane compound, or a composite-type oligomer of two or more compounds thereof.
Furthermore, another
Baba Hideo
Miyauchi Kazuhiro
Takano Nozomu
Greenblum & Bernstein P.L.C.
Hitachi Chemical Co. Ltd.
Peng Kuo-Liang
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