Stock material or miscellaneous articles – Web or sheet containing structurally defined element or...
Reexamination Certificate
1999-09-07
2001-06-12
Acquah, Samuel A. (Department: 1711)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
C525S437000, C525S444000, C524S081000
Reexamination Certificate
active
06245419
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vibration-damping resin composition and to a molded article such as a vibration-damping structural component obtained by molding it.
2. Description of the Prior Art
A fiber-reinforced plastic (FRP) using an unsaturated polyester resin has excellent mechanical strength, heat resistance, water resistance, and chemical resistance as well as high productivity and is used in housing appliances such as a bath tub and a washing bowl and in addition in automobile fields as a material for outer plies and cladding components. Recently, an unsaturated polyester sheet molding compound (hereafter, abbreviated as SMC) or a bulk molding compound (hereafter, abbreviated as BMC) has been paid much attention as a plastic material for automobile engine-related components, and has come to be used also for structural components that are required to have high heat resistance and chemical resistance, for example, cylinder head covers, oil pans, etc.
Conventionally, SMC or BMC or the like used for automobile engine-related components have been required of particularly heat resistance and chemical resistance. Recently, vibration-damping properties have been required keenly for the purpose of sound insulation. As a means for imparting vibration-damping properties, there have been proposed a method of decreasing the content of a filler or glass fiber in a molding material, and in addition, a method of adding a block copolymer that imparts vibration-damping properties as described in Japanese Patent Application Laid-open No. 2-102212, and a method of using a resin having a glass transition temperature of 60 to 120° C. as described in Japanese Patent Application Laid-open No. 8-301998.
However, the method of decreasing the content of a filler or glass fiber gives a great influence on the mechanical properties of the construction and finds a limitation in its use. Further, the method of adding a vibration damper such as a block copolymer leads to a decrease in mechanical properties or moldability although it can improve vibration damping properties by increasing the proportion of the vibration damper, so that it is difficult to obtain sufficient vibration-damping properties while ensuring sufficient moldability. Further, in the case of Japanese Patent Application Laid-open No. 8-301998, sufficient vibration-damping properties cannot be obtained particularly in low temperature regions as low as 60° C. or less.
SUMMARY OF THE INVENTION
Under such circumstances, an object of the present invention is to provide a resin composition exhibiting excellent vibration-damping properties in a use temperature region (for example, 0 to 100° C.) of automobile engine-related components and a molded article made thereof.
The present inventors have made extensive research on molding materials having heat resistance, chemical resistance, and moldability and having excellent vibration-damping properties in a temperature range of 0 to 100° C. or broader than it, and as a result, they have found the followings.
(I) An unsaturated polyester resin having a glass transition temperature of 0° C. or more and less than 60° C. (hereafter, referred to as “unsaturated polyester resin (A)”) has excellent vibration-damping properties in a room temperature range to a high temperature range, but the unsaturated polyester resin (A) has some problem in moldability.
(II) However, blending the unsaturated polyester resin (A) with another unsaturated polyester resin having good moldability gives improved moldability coupled with excellent vibration-damping properties.
(III) In particular, an unsaturated polyester resin composition comprising a blend of 10% by weight or more and less than 90% by weight, preferably 30% by weight or more and less than 80% by weight, more preferably 40% by weight or more and less than 60% by weight, based on the total weight of unsaturated polyesters, of the unsaturated polyester resin (A); and 10% by weight or more and less than 90% by weight, preferably 20% by weight or more and less than 70% by weight, more preferably 40% by weight or more and less than 60% by weight, based on the total weight of unsaturated polyesters, of an unsaturated polyester resin having a glass transition temperature of 150° C. or more and less than 200° C. (hereafter, referred to as “unsaturated polyester resin (B)”) is excellent in both vibrationdamping properties and moldability in a room temperature range to a high temperature range.
(IV) Also, an unsaturated polyester resin composition comprising a blend of 10% by weight or more and less than 95% by weight, preferably 40% by weight or more and less than 80% by weight, more preferably 50% by weight or more and less than 80% by weight, based on the total weight of unsaturated polyesters, of the unsaturated polyester resin (A); and 5% by weight or more and less than 90% by weight, preferably 20% by weight or more and less than 60% by weight, more preferably 20% by weight or more and less than 50% by weight, based on the total weight of unsaturated polyesters, of an unsaturated polyester resin having a glass transition temperature of 200° C. or more (hereafter, referred to as “unsaturated polyester resin (C)”) is excellent in both vibration-damping properties and moldability in a room temperature range to a high temperature range.
(V) Further, an unsaturated polyester resin composition comprising a blend of the unsaturated polyester resin (A), the unsaturated polyester resin (B) or the unsaturated polyester resin (C), and 3 to 30% by weight, preferably 5 to 20% by weight, more preferably 5 to 15% by weight a solid part of an elastomer having a glass transition temperature of −50° C. or more and less than 100° C. (hereafter, referred to as “elastomer (D)”) has excellent vibration-damping properties and moldability from low temperature range around 0° C., the percentages by weight being based on the total weight of a mixture of unsaturated polyester resins, elastomers and vinyl monomers contained in the composition.
(VI) Further, the glass transition temperature of the above-mentioned elastomer (D) is preferably −20° C. or more and less than 80° C., more preferably 0° C. or more and less than 50° C.
Based on these findings, intensive investigation has been made and adjustment of the glass transition temperature and proportion of the unsaturated polyester resins has led to the achievement of the present invention of a structural resin composition having an advantageous combination of properties of heat resistance, chemical resistance, moldability and vibration-damping properties over a wide temperature range.
Therefore, the present invention relates to:
(1) an unsaturated polyester resin composition having excellent vibration-damping properties, comprising an unsaturated polyester resin (A) having a glass transition temperature (Tg) of 0° C. or more and less than 60° C.;
(2) an unsaturated polyester resin composition having excellent vibration-damping properties and moldability, comprising an unsaturated polyester resin (A) having a glass transition temperature (Tg) of 0° C. or more and less than 60° C., and an unsaturated polyester resin (B) having a glass transition temperature (Tg) of 150° C. or more and less than 200° C., wherein said composition comprises 10% by weight or more and less than 90% by weight of unsaturated polyesters (a) of the unsaturated polyester resin (A) and 10% by weight or more and less than 90% by weight of unsaturated polyesters (b) of the unsaturated polyester resin (B), based on the total weight of unsaturated polyesters (a) and (b) of the unsaturated polyester resins (A) and (B), and wherein said composition optionally contains a vinyl monomer as a diluent;
(3) an unsaturated polyester resin composition having excellent vibration-damping properties and moldability, comprising an unsaturated polyester resin (A) having a glass transition temperature (Tg) of 0° C. or more and less than 60° C., and an unsaturated polyester resin (C) having a glass transition tempera
Akiyama Koichi
Hakotani Masahiro
Hamajima Kaneo
Kito Osamu
Shibata Takashi
Acquah Samuel A.
Takeda Chemical Industries Ltd.
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Resin composition having excellent vibration-damping... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Resin composition having excellent vibration-damping..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resin composition having excellent vibration-damping... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2490481