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
1999-04-30
2003-11-11
Short, Patricia A. (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...
C525S064000, C525S066000, C525S071000, C525S074000, C525S078000, C525S087000, C525S093000, C525S098000, C524S504000, C524S505000
Reexamination Certificate
active
06646047
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a thermoplastic elastomeric resin composition and a process for the preparation thereof.
The present composition may be added as a softening agent to a thermoplastic elastomer such as polyester type resins, polyolefine type resins, plyurethane type resins, vinyl aromatic type resins and polyamide type resins.
PRIOR ART
Thermoplastic elastomeric resins which are rubber-like materials, do not need a vulcanization process and have thermoplastic resin-like molding processability are attracting attention in the fields of auto parts, parts for electric appliances, electric wire insulation, footwears and general goods.
Various types of such thermoplastic elastomeric resins have been developed and put on sale, such as polyolefine type, polyurethane type, polyester type, polystyrene type, polyvinyl chloride type and polyamide type.
Among those, polystyrene type thermoplastic elastomeric resins such as styrene-butadiene block copolymers (SBS) and styrene-isoprene block copolymers (SIS) and hydrogenated resins thereof have high softness and good rubber elasticity at normal temperature. Further, thermoplastic elastomeric resin compositions obtained from these show good processability.
However, these polymers have problems in resistance to weathering as they have double bonds in conjugated diene blocks in molecule.
To overcome the problems, the double bonds in block copolymers of styrene and conjugated diene are hydrogenated to give elastomeric resins with improved thermal stability.
Several thermoplastic elastomeric resin compositions of such hydrogenated ones have been proposed, for instance, in Japanese Patent Application Laid-Open (hereinafter refereed to as JP Laid-Open) Nos. 50-14742/1975 and 52-26551/1977. As modification of these, JP Laid-Open Nos. 58-13203211983, 58-145751/1983, 59-53548/1984 and 62-48757 disclose compositions comprising a hydrogenated styrene-conjugated diene block copolymer, a hydrocarbon and an alpha-olefin polymeric resin, and a process for the preparation thereof.
Unfortunately, the thermoplastic elastomeric resin compositions of the prior art comprising such hydrogenated block copolymers have a drawback in rubber properties, such as deformation under heat and pressure (compression set) and rubber elasticity at a high temperature.
To solve such a drawback, there have been proposed a cross-linking composition in which a silane compound is added to a composition containing such a hydrogenated block copolymer, and cross-linked one obtained by cross-linking a composition containing such a hydrogenated block copolymer in the presence of an organic peroxide, for instance, in JP Laid-Open Nos. 59-6236/1984 and 63-57662/1987, Japanese Patent Publication Nos. 3-49927/1991,3-11291/1991 and 6-13628/1994.
However, such proposed cross-linked compositions of the hydrogenated block copolymer are unsatisfactory in compression set at a high temperature, particularly at 100° C. and, moreover, tensile properties deteriorate considerably at 80° C. or more. Further, such compositions do not meet the levels of properties required in the fields of vulcanized rubber. Particularly, good processability cannot be attained, and the mechanical strength is low.
To solve such drawbacks, in JP Laid-Open No. 4-20549/1992, there is desclosed a polymer in which a component composed of carboxylic acid derivatives and/or epoxy derivatives is copolymerized with or graft polymerized to such a block copolymer, or in which other polymers are graft or block bonded to such a block copolymer, and, further, a polyamide type polymer and/or polyester type polymer are added to a composition of a hydrogenated block copolymer, and crosslinked in the presence of an organic peroxide.
However, the crosslinked composition of the hydrogenated block copolymer desclosed has problems. That is, compression set at a high temperature, particularly at 100° C. or more is high and tensile properties are poor. Further, balance between compression set and hardness is bad.
In addition, in the case of blending polyamide type polymer, polyester type polymer and/or polyurethane type polymer, hardness is not less than HSA 85, which is little different from that of polyamide type polymer, polyester type polymer or polyurethane type polymer.
In JP Laid-Open Nos. 1-139241/1989 and 3-100045/1991, there is desclosed a melting blended substance of a thermoplastic elastic body selected from hydrogenated SBS block copolymers, olefin type elastomers, diene type elastomers, urethane type elastomers and plasticized polyvinyl chlorides and a polyester type thermoplastic elastomer or a polyether block amide.
However, this composition is poor in balance between compression set and hardness and shows unsufficient compatibility, so that the abrasion resistance is bad.
Further, JP Laid-Open No. 5-214209/1993 discloses a composition in which a modified polystyrene type resin and/or a modified polyolefin type resin having an epoxy, acid anhydride or oxazoline group is added to a composition containing a hydrogenated derivative of a block copolymer and a polyester typer resin, whereby the composition is improved in compatibility and excellent in softness, heat resistance and chemical resistance. JP Publication No. 5-75016/1993 (i.e., Laid Open No. 1-230660/1998) discloses a composition which comprises a hydrogenated derivative of a block copolymer and a hydrogenated derivative having a carboxylic acid group or a derivative group thereof together with a polyolefin resin and a thermoplastic polyester. JP Laid-Open Nos. 3-234745/1991, 3-234755/1991, 5-171003/1993 and 7-126474/1995 disclose a composition which comprises a hydrogenated derivative of a block copolymer and a hydrogenated derivative having a carboxylic acid group or a derivative group thereof together with a thermoplastic polyurethane. JP Laid-Open No. 2-97554/1990 discloses a composition which comprises a hydrogenated derivative of a block copolymer and a hydrogenated derivative having an epoxy group or a derivative group thereof together with a thermoplastic polyurethane.
However, those components have drawbacks. That is, compression set at a high temperature, particularly at 100° C. or more is high and tensile properties are poor. In addition, balance between the compression set and hardness is bad.
Although, the aforesaid compositions are excellent in initial chemical resistance, they swell extremely and cannot maintain its form in long time dipping or dipping at 100° C. or more, because such treatment as crosslinking is not carried out on a soft segment of the hydrogenated block copolymer.
SUMMARY OF THE INVENTION
A purpose of the invention is to provide a process for the preparation of a thermoplastic elastomeric resin composition which is soft and excellent in heat deformation resistance, mechanical strength, moldability, processability, particularly, oil resistance and stain resistance.
Another purpose of the invention is to provide such a thermoplastic elastomeric resin composition.
Thus, the invention provides a process for the preparation of a thermoplastic elastomeric resin composition comprising melt kneading
(a) 100 parts by weight of a block copolymer consisting of at least two polymeric blocks (A) composed mainly of a vinyl aromatic compound and at least one polymeric block (B) composed mainly of a conjugated diene compound, and/or a hydrogenated block copolymer obtained by hydrogenating said block copolymer,
(b) 20 to 300 parts by weight of a non-aromatic softening agent for rubber,
(c) 1 to 150 parts by weight of a peroxide-crosslinking type olefinic resin and/or a copolymeric rubber containing said resin, and
(d) 10 to 150 parts by weight of a peroxide-decomposing type olefinic resin and/or a copolymer containing said resin,
characterized in that the process comprises a step of heat-processing component (a), component (b), at least a part of component (c), at least a part of component (d) and at least a part of 1.0 to 1,200 parts by weight of component (e) in the presence of an organic peroxide to cause crosslinkin
Sawai Tetsuya
Tamura Akihiro
Tasaka Michihisa
Pitney Hardin Kipp & Szuch LLP
Riken Technos Corporation
Short Patricia A.
LandOfFree
Thermoplastic elastomeric resin composition and a process... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermoplastic elastomeric resin composition and a process..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoplastic elastomeric resin composition and a process... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3134605