CA1147886A - Thermoplastic blends of 1-olefin polymers with styrene butadiene rubber - Google Patents
Thermoplastic blends of 1-olefin polymers with styrene butadiene rubberInfo
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- CA1147886A CA1147886A CA000305203A CA305203A CA1147886A CA 1147886 A CA1147886 A CA 1147886A CA 000305203 A CA000305203 A CA 000305203A CA 305203 A CA305203 A CA 305203A CA 1147886 A CA1147886 A CA 1147886A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L9/06—Copolymers with styrene
- C08L9/08—Latex
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
- C08L23/06—Polyethene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/10—Homopolymers or copolymers of propene
- C08L23/12—Polypropene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/16—Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/18—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
- C08L23/20—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms having four to nine carbon atoms
- C08L23/22—Copolymers of isobutene; Butyl rubber ; Homo- or copolymers of other iso-olefins
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Materials For Medical Uses (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
Thermoplastic elastomer blends of 1-olefin polymers and copolymers such as polypropylene with styrene-butadiene rubber have good physical properties such as a low brittle point, good low temperature impact resistance, minimum creep at high temperatures and good elongation. The blends can be repeatedly processed and yet maintain their good physical properties. The amount of the 1-olefin polymer or copolymer based upon the weight of the blend ranges from about 15 percent to about 48 percent with the amount of the styrene-butadiene rubber correspondingly ranging from about 85 percent to about 52 percent. The blend is mixed at a temperature at or above the melting point of the 1-olefin polymer or copolymer with two phases produced which are generally continuous. The blends which may be partially cured have excellent and un-expected ozone resistance and aging properties, as well as excellent paint adhesion.
Thermoplastic elastomer blends of 1-olefin polymers and copolymers such as polypropylene with styrene-butadiene rubber have good physical properties such as a low brittle point, good low temperature impact resistance, minimum creep at high temperatures and good elongation. The blends can be repeatedly processed and yet maintain their good physical properties. The amount of the 1-olefin polymer or copolymer based upon the weight of the blend ranges from about 15 percent to about 48 percent with the amount of the styrene-butadiene rubber correspondingly ranging from about 85 percent to about 52 percent. The blend is mixed at a temperature at or above the melting point of the 1-olefin polymer or copolymer with two phases produced which are generally continuous. The blends which may be partially cured have excellent and un-expected ozone resistance and aging properties, as well as excellent paint adhesion.
Description
~7886 BACKGROUND OF THE INVENTION
The present invention relates to the thermoplastic elastomer blends of l-olefin polymers such as polypropylene or to copolymers such as polypropylene and polyethylene, and styrene-butadiene rubber which require no curing or vulcaniza-tion whatsoever to develop elastomeric properties. Addition-ally, the invention relates to partially cured blends thereof.
Heretofore, a few specific types of thermoplastic elastomers have been known. The term "thermoplastic elastomer"
has-generally been applied to elastomers which can be readily processed and reprocessed, molded, or the like by common or conventional thermoplastic methods and which do not require vulcanization to develop the various physical properties.
Previous specific types of known thermoplastic elastomers are the thermoplastic urethanes, the thermoplastic polyesters such as the Hytrel* brand manufactured by DuPont, and the styrene block copolymers sold under the brand names of Kraton and Solprene manufactured, respectively, by Shell Oil Company and Phillips Petroleum.
Another very recent thermoplastic elastomer is a blend of polypropylene and EPDM (ethylene-propylene-non-conjugated diene monomer) as described in U.S. Patent N~s.
3,758,743, 3,806,558, and 3,862,106 to Fischer of Uniroyal, Inc. It is not surprising that blends of EPDM and polypropy-lene form a material having good mechanical properties since, due to the fact that EPDM contains a large number of monomer units in its backbone identical to those in polypropylene, there is good compatibility between these two polymers.
The blending of an incompatible rubber with a 1-olefin polymer such as polypropylene can result in a material with poor properties. Examples include polybutadiene or -* Trade mark.
iB
~14'7886 nitrile rubber blended wi~h polyp~apYl~e. ~t is, thus, sur-pris$ng that whe~ styrene~butad~ene rubber is blended wi~h a l-olefin polymer such as polypropylene, a blend having good physicai properties`results, since styrene-butadiene rubber is so different from EPDM. That is, SBR contains an aromatic group in cont~as-t to ~ almost completely al~phatic chain and, moreover, it contains a great number of unsatur~ted groups in comparison to the usual 2 to 4 percent unsaturation of the EPDM polymer.
Thus, the Fischer patents are not even suggestive of applicant's present in~e~tion.
SUMMARY OF THE INVENTION
It would be advantageous to have thermoplastic elastomer b~ends of l-olefin polymers or copolymer with styrene-butadiene rubber.
It would also be advantageous to have thermo-plastic elastomer blends, as above, whereln the blends may or may not be partially cured, have good phYSical properties without any fur~her vulcanization, and may be readily reprocessed and still retaln their good physical properties.
It woul~ further be advantageous to have thermo-plastic elastomer blends, as above, wherein the blends are mixed at or aboYe the melting temperaturé of said l-olefin polymers or copolymers.
It would additionally be advantageous to have thermoplastic elastomer blends, as above, which may be partially cured.
It would also be advantageous to have thermo-plastic elastomer blends, as above, ln which both the l-olefin polymers or copolymers and the styrene-butadiene rubber are in a continuous phase.
Finally it would be adva~tageous to have thermo-plastic elastomer blends, as above, which have exceedingly good r~
~4 - 2 -ozone resistant and aging properties, good paint adhesion, a low brittle point, good low temperature impact resistance, minimum creep at high temperatures and good elongation.
Generally, the present invention provides a thermo-plastic elastomer composition comprising a blend of a crys-talline l-olefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from the class consisting of a homo-polymer and a copolymer made from l-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend; and said blend forming a thermoplastic elastomer.
In particular, the present invention provides a thermoplastic elastomer composition, comprising, a blend of a crystalline l-olefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from the class consisting of a poly-propylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90C, the amoun~ of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend lncluding from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend; and said blend forming a thermoplastic elastomer.
Additionally, the thermoplastic elastomer composition can be partially cured to have a melt flow index of at least ~7a~6 1Ø
Thus, the present invention provides a thermoplastic elastomer composition, comprising;
a blend of a crystalline l-olefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from . the class consistinq.of a polypropylene homopolymer and a t copolymer made from a major amount by weight of propylene monomers and a minor amount.of ethylene monomers, said pro-pylene homopolymer containing up to about.l5 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, said styrene-butadiene rubber being partially cured and having a melt flow index of at least 1.0 to form a thermo-plastic elastomer.
Generally, in accordance with another aspect the present invention provides a process for making a thermoplastic elastomer blend comprising the steps of, providing a blend of a crystalline l-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from l-olefin monomérs having from 2 to about 20 carbon atoms, sald homopolymer and said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to ; about 20 parts by weight of polyisobutylene per 100 parts of said blend; and heating said blend at a temperature at or E ` - 3a -,, ~147886 above the melting point of said crystalline l-olefin polymer so that a reprocessable blend is formed.
The present invention also provides a process of making a thermoplastic elastomer blend, comprising the steps of;
providing a blend of a crystalline l-oLefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers,~said propyl-ene homopolymer containing up to about 15 percent by weight of an atactic polyprop~vlene, said homopolymer and said copolymer having a melting point of at least 90C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, .
said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend; and heating said blend at a temperature at or above the melting point of said crystalline l-olefin polymer so that a ; reprocessable blend is formed.
... ~
~ ~ - 4 -, , .
~14~886 Add~tiona~ a p~oces~s. fo~ making ~he thermo-plas~ic elastomer blend can include t~e ~dd~t~onal step o~ partial curing said blend to have a ~el~ ~low ~ndex of at least 1.0 The present invent~on further provides a process for making a thermoplastic elastomer blend, comprising the steps of, providin~ a blend of a ~rystalline l-olefin polymer and styrene-butadie~e rubber, said l-olefin polyme~ selec-ted from the class consisting of a polypropylene ho~opolymer and a copolymer made from a major amount by weight of propylene mono-mers and a mino~ amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, sald homopolymer and said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 30 percent to about 42 percent by weight based upon the total weight of said blend, said blend including from about 1 to about 5 parts by weight per 100 parts of said blend of zinc oxide, ~0 said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, heating said blend at a temperature at or above the melting point of said l-olefin polymer, and partially curing said blend to have a melt flow index greater than 1.0 so that a reprocessable blend is produced, said partial cure being obtained by utilizing a sulfur curatlve, the amount of said sulfur curative ranging from about 0.1 parts to about 1.0 parts by weight per 100 parts of said blend.
B
~147~386 P~E~;RRl~;~ E~lBODI~IE~TS
The thermoplastic elastomers of the present inventio~ relate to uncured or partlally cured blends of l-olefin polymers wi~h styrene~butadiene rubber. The l~olefin polymer can be a homopolymer or a copolymer of various l-olefin monomers ~aving from 2 to 20 carbon atoms. Examples of suitable - l-olefin monomers lnclude ethylene, propylene, l-butene, l-pentene, l-hexene, l-octene, 4-methyl~l-hexene, 4-ethyl-1-hexene, 6-methyl-~-heptene, and the like. A preferred monomer is ethylene with a highly preferred monomer being propylene. In addition to the homopolymers, the l-olefin polymer may be a copolymer made from various l-olefin monomers, It is an important aspect of the present invention that only l-olefin polymers or copolymers be utilized which have a melting point of 90C or higher. Thus, whenever Yarious l-olefin monomers are utilized in preparing a copolymér, the amount o~ each must be such that a copolymer is produced havlng a melting point of at least 90C. A preferred copolymer is made from a major amount by weight of ethylene mono-mers and a minor amount of propylene monomers. A highly preferred ; copolymer is made from a major amount by weight of monomers of propylene and a minor amount by weight of ethylene monomers.
The amount by weight of a l-olefin polymer in the total blend ranges from about 15 percent to about 48 percent with from about 30 percent to about 42 percent being preferred.
Accordingly the remaining weight of the blend is the styrene-butadiene rubber, that is, from 85 percent to about 52 percent by weight with from 58 percent to about 70 percent by weight being preferred.
~B.
~47886 The butadiene-styrene rubber is a random copolymer made from monomers of butadiene and styrene. The copolymer can be prepared in any common or conventional manner well known to the art such as through solution or emulsion polymer-ization. Additionally, the specific type of styrene-butadiene rubber may vary. For example, the butadiene portion may be largely 1,2-polybutadiene, that is, as high as 90 or even 100 percentl or largely 1,4-poly-butadiene, that it, as high as 90 or even 100 percent. The amount by weight of the butadiene may vary greatly with a range of from about 60 percent to about 90 percent by weight based upon the total copolymer being desirable, although larger or smaller amounts can be used. The number average molecular weight of the copolymer may range from about 50,000 to about 1,000,000.
Similarly, the l-olefin polymer such as the preferred polyéthylene and the highly preferred polypropylene may be prepared in any common or conventional manner so long as it is largely crystalline such as an isotactic configuration.
Generally, the melt flow index of the isotactic l-olefin polymer and especially isotactic polypropylene can range from about 0.4 to about 30 with a preferred range being from about
The present invention relates to the thermoplastic elastomer blends of l-olefin polymers such as polypropylene or to copolymers such as polypropylene and polyethylene, and styrene-butadiene rubber which require no curing or vulcaniza-tion whatsoever to develop elastomeric properties. Addition-ally, the invention relates to partially cured blends thereof.
Heretofore, a few specific types of thermoplastic elastomers have been known. The term "thermoplastic elastomer"
has-generally been applied to elastomers which can be readily processed and reprocessed, molded, or the like by common or conventional thermoplastic methods and which do not require vulcanization to develop the various physical properties.
Previous specific types of known thermoplastic elastomers are the thermoplastic urethanes, the thermoplastic polyesters such as the Hytrel* brand manufactured by DuPont, and the styrene block copolymers sold under the brand names of Kraton and Solprene manufactured, respectively, by Shell Oil Company and Phillips Petroleum.
Another very recent thermoplastic elastomer is a blend of polypropylene and EPDM (ethylene-propylene-non-conjugated diene monomer) as described in U.S. Patent N~s.
3,758,743, 3,806,558, and 3,862,106 to Fischer of Uniroyal, Inc. It is not surprising that blends of EPDM and polypropy-lene form a material having good mechanical properties since, due to the fact that EPDM contains a large number of monomer units in its backbone identical to those in polypropylene, there is good compatibility between these two polymers.
The blending of an incompatible rubber with a 1-olefin polymer such as polypropylene can result in a material with poor properties. Examples include polybutadiene or -* Trade mark.
iB
~14'7886 nitrile rubber blended wi~h polyp~apYl~e. ~t is, thus, sur-pris$ng that whe~ styrene~butad~ene rubber is blended wi~h a l-olefin polymer such as polypropylene, a blend having good physicai properties`results, since styrene-butadiene rubber is so different from EPDM. That is, SBR contains an aromatic group in cont~as-t to ~ almost completely al~phatic chain and, moreover, it contains a great number of unsatur~ted groups in comparison to the usual 2 to 4 percent unsaturation of the EPDM polymer.
Thus, the Fischer patents are not even suggestive of applicant's present in~e~tion.
SUMMARY OF THE INVENTION
It would be advantageous to have thermoplastic elastomer b~ends of l-olefin polymers or copolymer with styrene-butadiene rubber.
It would also be advantageous to have thermo-plastic elastomer blends, as above, whereln the blends may or may not be partially cured, have good phYSical properties without any fur~her vulcanization, and may be readily reprocessed and still retaln their good physical properties.
It woul~ further be advantageous to have thermo-plastic elastomer blends, as above, wherein the blends are mixed at or aboYe the melting temperaturé of said l-olefin polymers or copolymers.
It would additionally be advantageous to have thermoplastic elastomer blends, as above, which may be partially cured.
It would also be advantageous to have thermo-plastic elastomer blends, as above, ln which both the l-olefin polymers or copolymers and the styrene-butadiene rubber are in a continuous phase.
Finally it would be adva~tageous to have thermo-plastic elastomer blends, as above, which have exceedingly good r~
~4 - 2 -ozone resistant and aging properties, good paint adhesion, a low brittle point, good low temperature impact resistance, minimum creep at high temperatures and good elongation.
Generally, the present invention provides a thermo-plastic elastomer composition comprising a blend of a crys-talline l-olefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from the class consisting of a homo-polymer and a copolymer made from l-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend; and said blend forming a thermoplastic elastomer.
In particular, the present invention provides a thermoplastic elastomer composition, comprising, a blend of a crystalline l-olefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from the class consisting of a poly-propylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90C, the amoun~ of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend lncluding from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend; and said blend forming a thermoplastic elastomer.
Additionally, the thermoplastic elastomer composition can be partially cured to have a melt flow index of at least ~7a~6 1Ø
Thus, the present invention provides a thermoplastic elastomer composition, comprising;
a blend of a crystalline l-olefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from . the class consistinq.of a polypropylene homopolymer and a t copolymer made from a major amount by weight of propylene monomers and a minor amount.of ethylene monomers, said pro-pylene homopolymer containing up to about.l5 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, said styrene-butadiene rubber being partially cured and having a melt flow index of at least 1.0 to form a thermo-plastic elastomer.
Generally, in accordance with another aspect the present invention provides a process for making a thermoplastic elastomer blend comprising the steps of, providing a blend of a crystalline l-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from l-olefin monomérs having from 2 to about 20 carbon atoms, sald homopolymer and said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to ; about 20 parts by weight of polyisobutylene per 100 parts of said blend; and heating said blend at a temperature at or E ` - 3a -,, ~147886 above the melting point of said crystalline l-olefin polymer so that a reprocessable blend is formed.
The present invention also provides a process of making a thermoplastic elastomer blend, comprising the steps of;
providing a blend of a crystalline l-oLefin polymer and styrene-butadiene rubber, said l-olefin polymer selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers,~said propyl-ene homopolymer containing up to about 15 percent by weight of an atactic polyprop~vlene, said homopolymer and said copolymer having a melting point of at least 90C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, .
said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend; and heating said blend at a temperature at or above the melting point of said crystalline l-olefin polymer so that a ; reprocessable blend is formed.
... ~
~ ~ - 4 -, , .
~14~886 Add~tiona~ a p~oces~s. fo~ making ~he thermo-plas~ic elastomer blend can include t~e ~dd~t~onal step o~ partial curing said blend to have a ~el~ ~low ~ndex of at least 1.0 The present invent~on further provides a process for making a thermoplastic elastomer blend, comprising the steps of, providin~ a blend of a ~rystalline l-olefin polymer and styrene-butadie~e rubber, said l-olefin polyme~ selec-ted from the class consisting of a polypropylene ho~opolymer and a copolymer made from a major amount by weight of propylene mono-mers and a mino~ amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, sald homopolymer and said copolymer having a melting point of at least 90C, the amount of said crystalline l-olefin polymer ranging from about 30 percent to about 42 percent by weight based upon the total weight of said blend, said blend including from about 1 to about 5 parts by weight per 100 parts of said blend of zinc oxide, ~0 said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, heating said blend at a temperature at or above the melting point of said l-olefin polymer, and partially curing said blend to have a melt flow index greater than 1.0 so that a reprocessable blend is produced, said partial cure being obtained by utilizing a sulfur curatlve, the amount of said sulfur curative ranging from about 0.1 parts to about 1.0 parts by weight per 100 parts of said blend.
B
~147~386 P~E~;RRl~;~ E~lBODI~IE~TS
The thermoplastic elastomers of the present inventio~ relate to uncured or partlally cured blends of l-olefin polymers wi~h styrene~butadiene rubber. The l~olefin polymer can be a homopolymer or a copolymer of various l-olefin monomers ~aving from 2 to 20 carbon atoms. Examples of suitable - l-olefin monomers lnclude ethylene, propylene, l-butene, l-pentene, l-hexene, l-octene, 4-methyl~l-hexene, 4-ethyl-1-hexene, 6-methyl-~-heptene, and the like. A preferred monomer is ethylene with a highly preferred monomer being propylene. In addition to the homopolymers, the l-olefin polymer may be a copolymer made from various l-olefin monomers, It is an important aspect of the present invention that only l-olefin polymers or copolymers be utilized which have a melting point of 90C or higher. Thus, whenever Yarious l-olefin monomers are utilized in preparing a copolymér, the amount o~ each must be such that a copolymer is produced havlng a melting point of at least 90C. A preferred copolymer is made from a major amount by weight of ethylene mono-mers and a minor amount of propylene monomers. A highly preferred ; copolymer is made from a major amount by weight of monomers of propylene and a minor amount by weight of ethylene monomers.
The amount by weight of a l-olefin polymer in the total blend ranges from about 15 percent to about 48 percent with from about 30 percent to about 42 percent being preferred.
Accordingly the remaining weight of the blend is the styrene-butadiene rubber, that is, from 85 percent to about 52 percent by weight with from 58 percent to about 70 percent by weight being preferred.
~B.
~47886 The butadiene-styrene rubber is a random copolymer made from monomers of butadiene and styrene. The copolymer can be prepared in any common or conventional manner well known to the art such as through solution or emulsion polymer-ization. Additionally, the specific type of styrene-butadiene rubber may vary. For example, the butadiene portion may be largely 1,2-polybutadiene, that is, as high as 90 or even 100 percentl or largely 1,4-poly-butadiene, that it, as high as 90 or even 100 percent. The amount by weight of the butadiene may vary greatly with a range of from about 60 percent to about 90 percent by weight based upon the total copolymer being desirable, although larger or smaller amounts can be used. The number average molecular weight of the copolymer may range from about 50,000 to about 1,000,000.
Similarly, the l-olefin polymer such as the preferred polyéthylene and the highly preferred polypropylene may be prepared in any common or conventional manner so long as it is largely crystalline such as an isotactic configuration.
Generally, the melt flow index of the isotactic l-olefin polymer and especially isotactic polypropylene can range from about 0.4 to about 30 with a preferred range being from about
2 to about 12 according to ASTM N. D1238. Thus, an isotactic l-olefin polymer is primarily utilized, although an amount such as from 0.1 up to about 15 percent by weight based upon the total weight of the l-olefin polymer of a low crystalline - atactic configuration may be utilized. Hence, in the highly preferred embodiment, isotactic polypropylene is utilized along with small amounts of atactic polypropylene. Small amounts of the atactic configuration of a particular l-olefin polymer are not only economical but also improve flow and does not significantly reduce the various physical properties.
Generally, amounts in excess of a total of 15 percent of an B
~ - 7 -~147886 atactic configuration of a specific l-olefin polymer are undesirable since the physical properties are reduced; but, in some applications, such a blend may be acceptable and even desirable.
Regardless of the specific type of l-olefin polymer utilized, the particle size is that produced by normal and conventional polymerization techniques. Generally, the ; particle size is greater than 1.0 microns and desirably larger than 5.0 microns, although any particle size may be utilized. From a practical standpoint, large particles such as up to 2 mm may be conveniently utilized, as well as even larger particles. Of course, since the l-olefin polymer is generally blended with the styrene-butadiene rubber on a mill, large particles such as diced polypropylene may be utilized.
It has been found that the addition of from about 2 to about 20 parts of polyisobutylene per 100 parts of said blend, surprisingly, improves the texture, smoothness, and surface gloss of injection molded plaques and gives improved tensile elongation when added to a blend of a l-olefin such as polypropylene and styrene-butadiene rubber.
The blend of the l-olefin polymer and the styrene-butadiene rubber, whether or not partially cured, results in a thermoplastic elastomer. That is, the blend is considered a thermoplastic elastomer in that it can be repeatedly reprocess-ed and, if partially cured, does not require further vulcanization to develop elastomer properties. In other words, the blend can be readily and repeatedly molded, extruded, or otherwise processed since it flows at temperatures at or above the melting point of the l-olefin polymer. Generally, a partial cure is preferred in that the properties exhibit improved tensile set as well as a remarkable increase in aging properties.
B
By partial cure, it is meant that the styrene-butadiene rubber portion of the blend is crosslinked to an extent less than full cure or vulcanization. According to the concepts of the present invention, a partial cure is achieved when the melt flow index (ASTM N. D1238, condition "L", but with the exception that the load is 100 pounds) is at least 1.0 and preferably 10.0 or greater. Blends of the l-olefin polymer and styrene-butadiene rubber which are cured in excess of a partial cure and, thus, have a melt flow index below 1.0 result in vulcanized blends or thermoset elastomers which are clearly outside the scope of the present invention~
The partial cure may be obtained utilizing any conventional curing agent compound or method as set forth below. Generally, good blends of the present invention will have a melt flow index of from about 90 to about 150 with a preferred melt flow index of approximately 120.
It is a critical aspect of the present invention that the l-olefin polymer and the styrene-butadiene rubber be mixed together at a temperature equal to or greater than the melting point of the 1-olefin polymer. Due to variations in molecular weight and tacticity, the melting point will vary over a small range for the particular 1-olefin polymer. The typical polyethylene will have a melting point range of from about 127C to about 140C with a typical melting point of approximately 135C. The melting point range for the highly preferred polypropylene is from about 150C to about 175C
with a practical or typical melting point temperature of about 160C. Thus, temperatures within this range, or desirably above it, are necessary to the present invention. The actual blending or mixing may be according to any common or conven-tional mixing process and, thus, may conveniently take place on a mill, a Banbury, a Brabender, a twin screw extruder, or BI g ~47886 the like. When a partial cure is utilized, preferably, the two components are first blended and then partially cured, although the styrene-butadiene rubber can be initially, partially cured and then blended with the 1-olefin polymer.
Another method of preparation involves the addition of all dry ingredients to a styrene-butadiene rubber latex.
When the SBR latex is coagulated by standard and well known techniques, all ingredients are intimately mixed. This mixture is then mixed in any manner, as on a mill, at tempera-tures above the melting point of the polypropylene and the thermoplastic elastomer blend is formed.
If a partial cure is utilized, the curing agent can be conveniently added as well as other conventional processing aids, compounding ingredients, and the like either before or during the blending step. Moreover, the partial cure may be achieved under either static conditions or under dynamic co~ditione. Under static conditions, the partial cure can be achieved by placing a mixed blend containing the curing agent in an oven and heating to a desired temperature whereby partial cure occurs such as at a temperature of from about 65C to about 260C for approximately 5 to 30 minutes. The dynamic partial cure is achieved by working or processing the blend containing the curing agent on an open mill, in a Banbury, in an extruder, or the like, at a temperature sufficient to bring about a partial cure such as from about 65C to about 210C for approximately 5 to 20 minutes. Even if the dynamic cure occurs below the melting point of the l-olefin polymer, the dynamic blend temperature must be at a temperature above the melting point of the l-olefin polymer.
As noted, the curing agent utilized, when a partial cure is desired, may be any known or conventional-~rubber curative or method known to those skilled in the art.
B -lo_ ~78t~6 Variations from standard procedures or compounds may, of course, be utilized. Typical types of curing a~ents include the sulfur curatives such as sulfur, itself, or sulfur donors, the various peroxides. whether aromatic or aliphatic, and low dosages of irradiation. If a sulfur curative is utilized, generally from 0.01 to about 1.0 parts by weight per 100 parts of the blend is utilized with the preferred range being from about 0.1 to about 0.2 parts. Some representative examples of sulfur curatives include sulfur, tetramethyl - 10 thiorea, 2-(hexamethyleniminothio)-benzothiazole, sulfur dichloride, sulfur monochloride, alkyl phenol, disulfide, and tetramethyl thiuram disulfide. A preferred curative is sulfur, itself. Generally, it is desirable to use from about 1 to about 5 parts per 100 parts of blend of zinc oxide, conventional amounts of stearic acid and an accelerator since very good antioxidant properties are imparted to the blend.
In addition, this particular partial cure system in combina-tion with carbon black, surprisingly, gives superior paint adhesion. These unexpected results are especially noted with regard to the highly preferred l-olefin polymer of polypropy-lene.
The amount of the organic peroxides to effect a partial cure generally varies from about 0.01 to about 0.5 parts by weight per 100 parts of the blend with a preferred range being from about 0.1 to about 0.3. Once again, any conventional peroxide compound may be utilized such as the aromatic diacyl peroxides, the aliphatic diacyl peroxides, dibasic acid peroxides, ketone peroxides, alkyl peroxyesters, alkyl hydroperoxides, and the like. Specific examples include dicumyl peroxide, dibenzoyl peroxide, diacetyl peroxide, bis-2,4-dichlorobenzoyl peroxide, ditertiary-butyl peroxide, tertiary-butylcumyl peroxide, and the like, Of course, the number of the various peroxides is enormous and any of them can be utilized, with the above specific compounds merely being representative examples. A preferred peroxide curative is dicumyl peroxide and 2,5-bis(tertiary-butylperoxy)2,5-dimethylhexane.
Of course, multiple peroxide curatives, multiple sulfur curatives, as well as combinations of sulfur and peroxide curatives may be utilized as well known to those skilled in the art. Furthermore, the amount of the curative range sét forth above, naturally, represents the amount of the active compound. Thus, if a curative is utilized such as dicumyl peroxide in a solvent system, only the weight of dicumyl peroxide itself is considered. Additionally, the exact amount of a specific curative utilized to obtain a specific melt flow index will vary from one specific curative to another, depending on the general activity or efficiency of the specific curatives.
Another method of achieving the partial cure involves subjecting the blend to ionizing irradiation.
Ionizing rays include alpha rays, beta rays, gamma rays, electron beam, proton rays, neutron rays, and X-rays. In most commercial applications, an accelerated electron beam is utilized. The irradiation is desirably carried out by subjecting pellets or a thin layer of the blend to the irradiation. The irradiation may be admitted from one side or from both sides of the blend composition. The amount of irradiation, of course, will vary with the thickness of the blend composition. In any event, a desirable amount of irradiation is that which results in a partially cured blend having a melt flow index above the index number set forth above. Due to the inherent nature of the irradiation applica-tion, the cross-link density of the styrene-butadiene B _ 12 i ~147W6 copolymers will vary with the distance from the irradiated surface. This aspect is acceptable as long as an overall, partially cured system is produced~ However, too high of a dose will result in a cross-linked system which cannot be molded or extruded, that is, is not reprocessable. Generally, when the irradiation is admitted to only one side of the blend composition, the amount of irradiation may bary from about 0.1 to about 5.0 Megarads when an electron accelerator is utilized ~ and from about 0.1 to about 3.0 Megarads when the irradiation is applied to each side of the blend composition~.
In addition to the curing agents, as noted above, other rubber components, compounding agents, fillers, process-ing aids, and the like may be added in conventional amounts.
Specific types of additives include in addition to accelerators, activators, colorants, antioxidants, flame retardants, ozone resistant compounds, and various processing aids such as oil, stearic acid, and the like. Examples of fillers include carbon black, such as from about 0.1 and preferably from about 0.6 parts to about 30 to 40 parts by weight per 100 parts of the blend. Other fillers such as silica, the various clays, calcium carbonate, talc, and the like can be utilized in conventional amounts.
The blends of the present invention, whether or not partially cured, generally have good physical properties and generally consists of two continuous phases. A fe~ of the properties were completely unexpected such as the low brittle point. Other unexpected properties include minimum creep at high temperatures, good low temperature impact resistance, good elongation, good paint adhesion, and good ozone and aging resistance. Generally, the unexpected properties as set forth hereinbelow are generally achieved by the blends of the present invention regardless of the exact amount of l-olefin polymer D _ 13 _ Dj such as polypropylene and whether or not partially cured.
However, as previously noted, partially cured blends did give improved tensile set as well as improved ageing properties.
Generally, the thermoplastic elastomer blends of the present invention achieved an elongation of at least 50 percent at break and, preferably at least 200 percent. The maximum creep was less than 4 percent at 120C under a load of 0.08 MPa. The blends did not show any ozone cracking when tested according to ASTM D518. The low temperature impact at minus 30C and paint scuff resistance were good as illustrated in the examples. The brittle point of the blends is generally - below minus 20C and, preferablyl below minus 45C. I
The aspect of the ozone resistance was completely unexpected in that, as well known to those skilled in the art, copolymers of styrene and butadiene exhibit poor ozone resis-tance. Moreover, the blends also had very good flexibility properties and exhibited very good heat aging properties upon the addition of various heat resistant agents.
The exact combination of physical properties desired will depend upon the intended applications. For example, in automotive exterior applications, it is imperative that the material be able to withstand impact at low temperature. When the same material is used to make a kitchen spatula, low temperature impact is irrelevant. The thermoplastic elastomer blends of the present invention are very versatile and flexible in that changes of the composition ratio of SBR to the l-olefin polymer and especially to polypropylene and changes of compounding additives, make it possible to generate a wide range of desired physical properties. These changes will be obvious to those skilled in the art of rubber or plastics compounding.
The thermoplastic elastomer blends of the present _ 14 _ B
~478~6 invention may be utilized to produce articles as by molding, extruding, calendaring, vacuum-forming, and the like with specific articles including tubing, gaskets, toys, and house-hold articles. A desired area of use resides in various automobile parts such as flexible bumpers, dash panels, bumper filler panels, and the like.
The invention will be better understood by reference to the various examples.
' ., , ~ .
The following list identifies the various materials used in the examples.
.~
Profax 6523 PM an isotactic polypropylene with a melt flow index of 4.0, made by Hercules, Inc.
FRS-2006 a Firestone "hot" emulsion polymeriæed SBR copolymer with 23.5 percent bound styrene, ML/4/212 = 50.
.~
FRS-1502 a Firestone ~cold" emulsion polymerized SBR copolymer with 23.5 percent bound styrene, ML/4/212 ~ 45.
Stereon 750 a Firestone solution polymerized BD/
styrene copolymer with 18 to 21 percent bound styrene, ML/4/212 = 45 to 47 when oil extended with 37.5 pphr oil.
However, the examples used Stereon 750 with ho oil.
Stereon 700 a Firestone solution polymerized BD/
styrene copolymer with 18 to 21 per-cent bound styrene, ML/4/212 = 50 to 60.
! Varox peroxide 2,5-bis(tert-butylperoxy)-2,5-dimethyl ¦ hexane - made by ~niroyal.
Santocure NS an accelerator, N-t-butyl-2-benzothia-zolesulfenamide made by Monsanto Chemical Co.
Afax 500 HL-l an atactic polypropylene wi~h a vis-l cosity range of 2.5 to 5.5 Pa made by 20 ¦ Hercules, Incorporated.
¦ Vitanex L-120 polyisobutylene made by Exxon.
¦ Agerite Super- butylated bisphenol A, made by RT
¦ lite Solid Vanderbilt Company.
Irganox 565 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-l di-tert-butylanilino)-1,3,5-triazine ¦ made by Ciba-Geigy Chemical Corporatio n.
I I
I ~ , ~47886 EXAMPLE I
SBR/PP = 60/40 BY LATEX COAGULATION
Five hundred sixty grams of Profax 6523 PM poly-propylene (PP) was stirred into 2 liters of water with 0.5 ml Triton X-100 wetting agent. To this was added 3.03 liters of FRS 2006 SBR latex with 27.7 percent solids to provide 840 grams of SBR rubber. While stirring vigorously, 4 liters of methanol was added and then 10 ml H2S04 which had been - diluted with water to 150 ml. The SBR coagulated rapidly upon addition of the acid, trapping essentially all of the polypropylene. The liquid was poured off and the coagulant mass was washed several times before again being washed and sheeted on a wash mill. The SBR with trapped polypropylene powder was dried for 15 hours at 75C. The material was then blended in a twin screw extruder on which all six heat zones were held between 190C to 220C. The extrudate was chopped into pellets to be injection molded. The following properties were obtained:
Tensile at break 8.27 MPa Elongation at break 2.88 (Tested at room temperature at 2,000 percent/minute strain rate. No cracks due to ozone aging (60 pphm ozone at 37C for 14 hours.) EXAMPLE II
Profax 6523 PM in the amount of 1.2 kg. was stirred into 7.2 kg hexane cement of Stereon 750 Duradene without oil which had a 25 percent solids content to provide 1.8 kg of Stereon 750 rubber. The mixture was dried on a drum dryer which was steam heated to-about 150C. The polypropylene powder was firmly held in the sheeted rubber until the mixture was blended in a twin screw extruder on which all six ~147886 heat zones were held at 190C to 220C. The extrudate was chopped into pellets to be injection molded.
EXAMPLE III
The procedure was identical to Example II, except there were 2.1 kg Stereon 750 and 0.9 kg of Profax 6523 PM
utilized.
Examples II and III gave the following physical properties:
TENSILE AT BREAK ELONGATION AT B~EAK
EXAMPLE II10.4 MPa 170 EXAMPLE III7.94 252 EXAMPLES IV THRO~GH XIII
DRY MIXING
The styrene-butadiene rubber was sheeted out on a two roll mill at a temperature between 90-120C. The remaining ingredients (set forth in Table I) were added, and milling was continued until the additives were well dispersed in the rubber. The blend was then cut into strips so that 20 it could easily be fed into a twin screw extruder. The material was extruded at 200C into a quenching water bath and subsequently chopped into small pellets, which were then injection molded into plaques (15.2 x 10.2 x 0.2 cm). The plaques were tested for physical properties.
Table I also lists several properties of the blends.
All tests are according to ASTM standards except the paint adhesion and cold impact test which will, therefore, now be described in more detail.
PAINT A~HESION TEST
-Before painting, a test plaque was first washed with a mild alkaline solution and water rinsed. After drying, the plaque was then sprayed with Seibert Oxidermo primer and ~147886 flash dried for at least 2 minutes. A topcoat of Durethane 100 was then applied and cured for 40 minutes at 120C. The paint scuff resistance was evaluated by scratching the painted surface with the edge of a dime. For surfaces showing excellent paint adhesion, the paint could not be scraped cleanly from the surstrate. When adhesion was poor, the paint could be easily stripped off with only mild pressure exerted on the dime.
COLD IMPACT TEST
The cold impact test utilized was that General Motors requires flexible thermoplastic elastomer parts to . .
pass. For this test, the ends of a painted specimen (7.62 x 15.2 x 0.3 cm) were inserted into grooves that were cut into a base plate 7.62 cm apart. The test sample was then allowed to equilibrate at minus 30C for at least four hours. After this, the dome-like test specimen was impacted at the apex by a hemispherical dart (5 cm. diameter, 27 kg) dropped from a height of 32.2 cm. In order to pass this test, the sample must not break or crack.
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~B 21 _ ~147886 In addition to the properties given in Table I, it is noted that all samples show no ozone cracking when tested according to ASTM D518, and show less than 5 percent creep when tested 30 minutes at 120C under a stress of 0.08 MPa.
To illustrate the ready reprocessability of the blends, the blends of Example VIII were re-extruded three times before in~ection molding. Essentially, identical tensile properties were obtained when compared to the blend which had been only extruded once and then molded.
While in accordance with the patent statutes, various preferred embodiments have been illustrated and described in detail, it is to be understood that the invention is not limited thereto, the scope of the invention being measured by the scope of the attached claims.
I
~ - 22 -
Generally, amounts in excess of a total of 15 percent of an B
~ - 7 -~147886 atactic configuration of a specific l-olefin polymer are undesirable since the physical properties are reduced; but, in some applications, such a blend may be acceptable and even desirable.
Regardless of the specific type of l-olefin polymer utilized, the particle size is that produced by normal and conventional polymerization techniques. Generally, the ; particle size is greater than 1.0 microns and desirably larger than 5.0 microns, although any particle size may be utilized. From a practical standpoint, large particles such as up to 2 mm may be conveniently utilized, as well as even larger particles. Of course, since the l-olefin polymer is generally blended with the styrene-butadiene rubber on a mill, large particles such as diced polypropylene may be utilized.
It has been found that the addition of from about 2 to about 20 parts of polyisobutylene per 100 parts of said blend, surprisingly, improves the texture, smoothness, and surface gloss of injection molded plaques and gives improved tensile elongation when added to a blend of a l-olefin such as polypropylene and styrene-butadiene rubber.
The blend of the l-olefin polymer and the styrene-butadiene rubber, whether or not partially cured, results in a thermoplastic elastomer. That is, the blend is considered a thermoplastic elastomer in that it can be repeatedly reprocess-ed and, if partially cured, does not require further vulcanization to develop elastomer properties. In other words, the blend can be readily and repeatedly molded, extruded, or otherwise processed since it flows at temperatures at or above the melting point of the l-olefin polymer. Generally, a partial cure is preferred in that the properties exhibit improved tensile set as well as a remarkable increase in aging properties.
B
By partial cure, it is meant that the styrene-butadiene rubber portion of the blend is crosslinked to an extent less than full cure or vulcanization. According to the concepts of the present invention, a partial cure is achieved when the melt flow index (ASTM N. D1238, condition "L", but with the exception that the load is 100 pounds) is at least 1.0 and preferably 10.0 or greater. Blends of the l-olefin polymer and styrene-butadiene rubber which are cured in excess of a partial cure and, thus, have a melt flow index below 1.0 result in vulcanized blends or thermoset elastomers which are clearly outside the scope of the present invention~
The partial cure may be obtained utilizing any conventional curing agent compound or method as set forth below. Generally, good blends of the present invention will have a melt flow index of from about 90 to about 150 with a preferred melt flow index of approximately 120.
It is a critical aspect of the present invention that the l-olefin polymer and the styrene-butadiene rubber be mixed together at a temperature equal to or greater than the melting point of the 1-olefin polymer. Due to variations in molecular weight and tacticity, the melting point will vary over a small range for the particular 1-olefin polymer. The typical polyethylene will have a melting point range of from about 127C to about 140C with a typical melting point of approximately 135C. The melting point range for the highly preferred polypropylene is from about 150C to about 175C
with a practical or typical melting point temperature of about 160C. Thus, temperatures within this range, or desirably above it, are necessary to the present invention. The actual blending or mixing may be according to any common or conven-tional mixing process and, thus, may conveniently take place on a mill, a Banbury, a Brabender, a twin screw extruder, or BI g ~47886 the like. When a partial cure is utilized, preferably, the two components are first blended and then partially cured, although the styrene-butadiene rubber can be initially, partially cured and then blended with the 1-olefin polymer.
Another method of preparation involves the addition of all dry ingredients to a styrene-butadiene rubber latex.
When the SBR latex is coagulated by standard and well known techniques, all ingredients are intimately mixed. This mixture is then mixed in any manner, as on a mill, at tempera-tures above the melting point of the polypropylene and the thermoplastic elastomer blend is formed.
If a partial cure is utilized, the curing agent can be conveniently added as well as other conventional processing aids, compounding ingredients, and the like either before or during the blending step. Moreover, the partial cure may be achieved under either static conditions or under dynamic co~ditione. Under static conditions, the partial cure can be achieved by placing a mixed blend containing the curing agent in an oven and heating to a desired temperature whereby partial cure occurs such as at a temperature of from about 65C to about 260C for approximately 5 to 30 minutes. The dynamic partial cure is achieved by working or processing the blend containing the curing agent on an open mill, in a Banbury, in an extruder, or the like, at a temperature sufficient to bring about a partial cure such as from about 65C to about 210C for approximately 5 to 20 minutes. Even if the dynamic cure occurs below the melting point of the l-olefin polymer, the dynamic blend temperature must be at a temperature above the melting point of the l-olefin polymer.
As noted, the curing agent utilized, when a partial cure is desired, may be any known or conventional-~rubber curative or method known to those skilled in the art.
B -lo_ ~78t~6 Variations from standard procedures or compounds may, of course, be utilized. Typical types of curing a~ents include the sulfur curatives such as sulfur, itself, or sulfur donors, the various peroxides. whether aromatic or aliphatic, and low dosages of irradiation. If a sulfur curative is utilized, generally from 0.01 to about 1.0 parts by weight per 100 parts of the blend is utilized with the preferred range being from about 0.1 to about 0.2 parts. Some representative examples of sulfur curatives include sulfur, tetramethyl - 10 thiorea, 2-(hexamethyleniminothio)-benzothiazole, sulfur dichloride, sulfur monochloride, alkyl phenol, disulfide, and tetramethyl thiuram disulfide. A preferred curative is sulfur, itself. Generally, it is desirable to use from about 1 to about 5 parts per 100 parts of blend of zinc oxide, conventional amounts of stearic acid and an accelerator since very good antioxidant properties are imparted to the blend.
In addition, this particular partial cure system in combina-tion with carbon black, surprisingly, gives superior paint adhesion. These unexpected results are especially noted with regard to the highly preferred l-olefin polymer of polypropy-lene.
The amount of the organic peroxides to effect a partial cure generally varies from about 0.01 to about 0.5 parts by weight per 100 parts of the blend with a preferred range being from about 0.1 to about 0.3. Once again, any conventional peroxide compound may be utilized such as the aromatic diacyl peroxides, the aliphatic diacyl peroxides, dibasic acid peroxides, ketone peroxides, alkyl peroxyesters, alkyl hydroperoxides, and the like. Specific examples include dicumyl peroxide, dibenzoyl peroxide, diacetyl peroxide, bis-2,4-dichlorobenzoyl peroxide, ditertiary-butyl peroxide, tertiary-butylcumyl peroxide, and the like, Of course, the number of the various peroxides is enormous and any of them can be utilized, with the above specific compounds merely being representative examples. A preferred peroxide curative is dicumyl peroxide and 2,5-bis(tertiary-butylperoxy)2,5-dimethylhexane.
Of course, multiple peroxide curatives, multiple sulfur curatives, as well as combinations of sulfur and peroxide curatives may be utilized as well known to those skilled in the art. Furthermore, the amount of the curative range sét forth above, naturally, represents the amount of the active compound. Thus, if a curative is utilized such as dicumyl peroxide in a solvent system, only the weight of dicumyl peroxide itself is considered. Additionally, the exact amount of a specific curative utilized to obtain a specific melt flow index will vary from one specific curative to another, depending on the general activity or efficiency of the specific curatives.
Another method of achieving the partial cure involves subjecting the blend to ionizing irradiation.
Ionizing rays include alpha rays, beta rays, gamma rays, electron beam, proton rays, neutron rays, and X-rays. In most commercial applications, an accelerated electron beam is utilized. The irradiation is desirably carried out by subjecting pellets or a thin layer of the blend to the irradiation. The irradiation may be admitted from one side or from both sides of the blend composition. The amount of irradiation, of course, will vary with the thickness of the blend composition. In any event, a desirable amount of irradiation is that which results in a partially cured blend having a melt flow index above the index number set forth above. Due to the inherent nature of the irradiation applica-tion, the cross-link density of the styrene-butadiene B _ 12 i ~147W6 copolymers will vary with the distance from the irradiated surface. This aspect is acceptable as long as an overall, partially cured system is produced~ However, too high of a dose will result in a cross-linked system which cannot be molded or extruded, that is, is not reprocessable. Generally, when the irradiation is admitted to only one side of the blend composition, the amount of irradiation may bary from about 0.1 to about 5.0 Megarads when an electron accelerator is utilized ~ and from about 0.1 to about 3.0 Megarads when the irradiation is applied to each side of the blend composition~.
In addition to the curing agents, as noted above, other rubber components, compounding agents, fillers, process-ing aids, and the like may be added in conventional amounts.
Specific types of additives include in addition to accelerators, activators, colorants, antioxidants, flame retardants, ozone resistant compounds, and various processing aids such as oil, stearic acid, and the like. Examples of fillers include carbon black, such as from about 0.1 and preferably from about 0.6 parts to about 30 to 40 parts by weight per 100 parts of the blend. Other fillers such as silica, the various clays, calcium carbonate, talc, and the like can be utilized in conventional amounts.
The blends of the present invention, whether or not partially cured, generally have good physical properties and generally consists of two continuous phases. A fe~ of the properties were completely unexpected such as the low brittle point. Other unexpected properties include minimum creep at high temperatures, good low temperature impact resistance, good elongation, good paint adhesion, and good ozone and aging resistance. Generally, the unexpected properties as set forth hereinbelow are generally achieved by the blends of the present invention regardless of the exact amount of l-olefin polymer D _ 13 _ Dj such as polypropylene and whether or not partially cured.
However, as previously noted, partially cured blends did give improved tensile set as well as improved ageing properties.
Generally, the thermoplastic elastomer blends of the present invention achieved an elongation of at least 50 percent at break and, preferably at least 200 percent. The maximum creep was less than 4 percent at 120C under a load of 0.08 MPa. The blends did not show any ozone cracking when tested according to ASTM D518. The low temperature impact at minus 30C and paint scuff resistance were good as illustrated in the examples. The brittle point of the blends is generally - below minus 20C and, preferablyl below minus 45C. I
The aspect of the ozone resistance was completely unexpected in that, as well known to those skilled in the art, copolymers of styrene and butadiene exhibit poor ozone resis-tance. Moreover, the blends also had very good flexibility properties and exhibited very good heat aging properties upon the addition of various heat resistant agents.
The exact combination of physical properties desired will depend upon the intended applications. For example, in automotive exterior applications, it is imperative that the material be able to withstand impact at low temperature. When the same material is used to make a kitchen spatula, low temperature impact is irrelevant. The thermoplastic elastomer blends of the present invention are very versatile and flexible in that changes of the composition ratio of SBR to the l-olefin polymer and especially to polypropylene and changes of compounding additives, make it possible to generate a wide range of desired physical properties. These changes will be obvious to those skilled in the art of rubber or plastics compounding.
The thermoplastic elastomer blends of the present _ 14 _ B
~478~6 invention may be utilized to produce articles as by molding, extruding, calendaring, vacuum-forming, and the like with specific articles including tubing, gaskets, toys, and house-hold articles. A desired area of use resides in various automobile parts such as flexible bumpers, dash panels, bumper filler panels, and the like.
The invention will be better understood by reference to the various examples.
' ., , ~ .
The following list identifies the various materials used in the examples.
.~
Profax 6523 PM an isotactic polypropylene with a melt flow index of 4.0, made by Hercules, Inc.
FRS-2006 a Firestone "hot" emulsion polymeriæed SBR copolymer with 23.5 percent bound styrene, ML/4/212 = 50.
.~
FRS-1502 a Firestone ~cold" emulsion polymerized SBR copolymer with 23.5 percent bound styrene, ML/4/212 ~ 45.
Stereon 750 a Firestone solution polymerized BD/
styrene copolymer with 18 to 21 percent bound styrene, ML/4/212 = 45 to 47 when oil extended with 37.5 pphr oil.
However, the examples used Stereon 750 with ho oil.
Stereon 700 a Firestone solution polymerized BD/
styrene copolymer with 18 to 21 per-cent bound styrene, ML/4/212 = 50 to 60.
! Varox peroxide 2,5-bis(tert-butylperoxy)-2,5-dimethyl ¦ hexane - made by ~niroyal.
Santocure NS an accelerator, N-t-butyl-2-benzothia-zolesulfenamide made by Monsanto Chemical Co.
Afax 500 HL-l an atactic polypropylene wi~h a vis-l cosity range of 2.5 to 5.5 Pa made by 20 ¦ Hercules, Incorporated.
¦ Vitanex L-120 polyisobutylene made by Exxon.
¦ Agerite Super- butylated bisphenol A, made by RT
¦ lite Solid Vanderbilt Company.
Irganox 565 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-l di-tert-butylanilino)-1,3,5-triazine ¦ made by Ciba-Geigy Chemical Corporatio n.
I I
I ~ , ~47886 EXAMPLE I
SBR/PP = 60/40 BY LATEX COAGULATION
Five hundred sixty grams of Profax 6523 PM poly-propylene (PP) was stirred into 2 liters of water with 0.5 ml Triton X-100 wetting agent. To this was added 3.03 liters of FRS 2006 SBR latex with 27.7 percent solids to provide 840 grams of SBR rubber. While stirring vigorously, 4 liters of methanol was added and then 10 ml H2S04 which had been - diluted with water to 150 ml. The SBR coagulated rapidly upon addition of the acid, trapping essentially all of the polypropylene. The liquid was poured off and the coagulant mass was washed several times before again being washed and sheeted on a wash mill. The SBR with trapped polypropylene powder was dried for 15 hours at 75C. The material was then blended in a twin screw extruder on which all six heat zones were held between 190C to 220C. The extrudate was chopped into pellets to be injection molded. The following properties were obtained:
Tensile at break 8.27 MPa Elongation at break 2.88 (Tested at room temperature at 2,000 percent/minute strain rate. No cracks due to ozone aging (60 pphm ozone at 37C for 14 hours.) EXAMPLE II
Profax 6523 PM in the amount of 1.2 kg. was stirred into 7.2 kg hexane cement of Stereon 750 Duradene without oil which had a 25 percent solids content to provide 1.8 kg of Stereon 750 rubber. The mixture was dried on a drum dryer which was steam heated to-about 150C. The polypropylene powder was firmly held in the sheeted rubber until the mixture was blended in a twin screw extruder on which all six ~147886 heat zones were held at 190C to 220C. The extrudate was chopped into pellets to be injection molded.
EXAMPLE III
The procedure was identical to Example II, except there were 2.1 kg Stereon 750 and 0.9 kg of Profax 6523 PM
utilized.
Examples II and III gave the following physical properties:
TENSILE AT BREAK ELONGATION AT B~EAK
EXAMPLE II10.4 MPa 170 EXAMPLE III7.94 252 EXAMPLES IV THRO~GH XIII
DRY MIXING
The styrene-butadiene rubber was sheeted out on a two roll mill at a temperature between 90-120C. The remaining ingredients (set forth in Table I) were added, and milling was continued until the additives were well dispersed in the rubber. The blend was then cut into strips so that 20 it could easily be fed into a twin screw extruder. The material was extruded at 200C into a quenching water bath and subsequently chopped into small pellets, which were then injection molded into plaques (15.2 x 10.2 x 0.2 cm). The plaques were tested for physical properties.
Table I also lists several properties of the blends.
All tests are according to ASTM standards except the paint adhesion and cold impact test which will, therefore, now be described in more detail.
PAINT A~HESION TEST
-Before painting, a test plaque was first washed with a mild alkaline solution and water rinsed. After drying, the plaque was then sprayed with Seibert Oxidermo primer and ~147886 flash dried for at least 2 minutes. A topcoat of Durethane 100 was then applied and cured for 40 minutes at 120C. The paint scuff resistance was evaluated by scratching the painted surface with the edge of a dime. For surfaces showing excellent paint adhesion, the paint could not be scraped cleanly from the surstrate. When adhesion was poor, the paint could be easily stripped off with only mild pressure exerted on the dime.
COLD IMPACT TEST
The cold impact test utilized was that General Motors requires flexible thermoplastic elastomer parts to . .
pass. For this test, the ends of a painted specimen (7.62 x 15.2 x 0.3 cm) were inserted into grooves that were cut into a base plate 7.62 cm apart. The test sample was then allowed to equilibrate at minus 30C for at least four hours. After this, the dome-like test specimen was impacted at the apex by a hemispherical dart (5 cm. diameter, 27 kg) dropped from a height of 32.2 cm. In order to pass this test, the sample must not break or crack.
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~B 21 _ ~147886 In addition to the properties given in Table I, it is noted that all samples show no ozone cracking when tested according to ASTM D518, and show less than 5 percent creep when tested 30 minutes at 120C under a stress of 0.08 MPa.
To illustrate the ready reprocessability of the blends, the blends of Example VIII were re-extruded three times before in~ection molding. Essentially, identical tensile properties were obtained when compared to the blend which had been only extruded once and then molded.
While in accordance with the patent statutes, various preferred embodiments have been illustrated and described in detail, it is to be understood that the invention is not limited thereto, the scope of the invention being measured by the scope of the attached claims.
I
~ - 22 -
Claims (24)
1. A thermoplastic elastomer composition comprising:
a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend;
and said blend forming a thermoplastic elastomer.
a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline l-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend;
and said blend forming a thermoplastic elastomer.
2. A thermoplastic elastomer composition according to claim 1, wherein said crystalline 1-olefin polymer contains up to about 15 percent by weight of a low crystalline configu-ration.
3. A thermoplastic elastomer composition according to claim 1, wherein said 1-olefin polymer is selected from the class consisting of a homopolymer of polyethylene and a copolymer made from a major amount by weight of ethylene monomers and a minor amount of propylene monomers.
4. A thermoplastic elastomer composition, comprising a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consist-ing of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend; and said blend forming a thermoplastic elastomer.
5. A thermoplastic elastomer composition according to claim 4, wherein the amount of said crystalline poly-propylene in said blend ranges from about 30 percent to about 42 percent by weight.
6. A thermoplastic elastomer composition, comprising:
a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend;
and said styrene-butadiene rubber being partially cured and having a melt flow index of at least 1.0 to form a thermoplastic elastomer.
a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend;
and said styrene-butadiene rubber being partially cured and having a melt flow index of at least 1.0 to form a thermoplastic elastomer.
7. A thermoplastic elastomer composition according to claim 6, wherein said crystalline 1-olefin polymer contains up to about 15 percent by weight of a low crystalline con-figuration.
8. A thermoplastic elastomer composition according to claim 6, wherein said 1-olefin polymer is selected from the class consisting of a homopolymer of polyethylene and a copolymer made from a major amount by weight of ethylene monomers and a minor amount of propylene monomers.
9. A thermoplastic elastomer composition, comprising:
a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said pro-pylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, said sytrene-butadiene rubber being partially cured and having a melt flow index of at least 1.0 to form a thermo-plastic elastomer.
a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said pro-pylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer or said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, said sytrene-butadiene rubber being partially cured and having a melt flow index of at least 1.0 to form a thermo-plastic elastomer.
10. A thermoplastic elastomer composition according to claim 9, wherein the amount of said crystalline polypro-pylene in said blend ranges from about 30 percent to about 42 percent by weight.
11. A thermoplastic elastomer composition according to claim 10, wherein said partial cure is obtained utilizing a compound selected from the class consisting of a sulfur curative and an organic peroxide curative, the amount of said sulfur curative ranging from about 0.01 parts to about 1.0 parts by weight per 100 parts of said blend and wherein the amount of said organic peroxide curative ranges from about 0.01 to about 0.05 parts per 100 parts of said blend.
12. A thermoplastic elastomer composition according to claim 11, wherein said curative is a sulfur curative, and including from about 1 to about 5 parts by weight per 100 parts of said blend of zinc oxide.
13. A process of making a thermoplastic elastomer blend, comprising the steps of providing a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and copolymer made from 1-olefin monomers having from 2 to about 20 carbon atoms, said homopolymer and said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts of polyisobutylene by weight per 100 parts of said blend;
and heating said blend at a temperature at or above the melting point of said crystalline 1-olefin polymer so that a reprocessable blend is formed.
and heating said blend at a temperature at or above the melting point of said crystalline 1-olefin polymer so that a reprocessable blend is formed.
14. A process according to claim 13, wherein said crystalline 1-olefin polymer contains up to about 15 percent by weight of a low crystalline configuration.
15. A process according to claim 13, wherein said 1-olefin polymer is selected from the class consisting of a homopolymer of polyethylene and a copolymer made form a major amount by weight of ethylene monomers and a minor amount of propylene monomers.
16. A process of making a thermoplastic elastomer blend, comprising the steps of providing a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propyl-ene monomers and a minor amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer and said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend; and heating said blend at a temperature at or above the melting point of said crystalline 1-olefin polymer so that a reprocessable blend is formed.
17. A process according to claim 16, wherein the amount of said crystalline polypropylene in said blend ranges from about 30 percent to about 42 percent by weight.
18. a process for making a thermoplastic elastomer blend, comprising the steps of providing a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to about 20 carbon atoms, said homopolymer and said copolymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 15 percent to about 48 percent by weight based upon the total weight of said blend, said blend including from about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, heating said blend at a temperature at or above the melting point of said 1-olefin polymer, and partially curing said blend to have a melt flow index greater than 1.0 so that a reprocessable blend is produced.
19. A process according to claim 18, wherein said crystalline 1-olefin polymer contains up to about 15 percent by weight of a low crystalline configuration.
20. A process according to claim 18, wherein said 1-olefin polymer is selected from the class consisting of a homopolymer of polyethylene and a copolymer made from a major amount by weight of ethylene monomers and a minor amount of propylene monomers.
21. A process according to claim 18, wherein said 1-olefin polymer is selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said propylene homopolymer containing up to about 15 percent by weight of an atactic polypropylene.
22. A process according to claim 21, wherein the amount of said crystalline polypropylene in said blend ranges from about 30 percent to about 42 percent by weight.
23. A process according to claim 22, wherein said partial cure is obtained utilizing a compound selected from the class consisting of a sulfur curative and an organic peroxide curative, the amount of said sulfur curative ranging from about 0.1 parts to about 1.0 parts by weight per 100 parts of said blend and wherein the amount of said organic peroxide curative ranges from about 0.1 to about 0.5 parts per 100 parts of said blend.
24. A process for making a thermoplastic elastomer blend, comprising the steps of providing a blend of a crystalline 1-olefin polymer and styrene-butadiene rubber, said 1-olefin polymer selected from the class consisting of a polypropylene homopolymer and a copolymer made from a major amount by weight of propylene monomers and a minor amount of ethylene monomers, said propyl-ene homopolymer containing up to about 15 percent by weight of an atactic polypropylene, said homopolymer and said copol-ymer having a melting point of at least 90°C, the amount of said crystalline 1-olefin polymer ranging from about 30 percent to about 42 percent by weight based upon the total weight of said blend, said blend including from about 1 to about 5 parts by weight per 100 parts of said blend of zinc oxide, said blend including form about 2 to about 20 parts by weight of polyisobutylene per 100 parts of said blend, heating said blend at a temperature at or above the melting point of said 1-olefin polymer, and partially curing said blend to have a melt flow index greater than 1.0 so that a reprocessable blend is produced, said partial cure being obtained by utilizing a sulfur curative, the amount of said sulfur curative ranging from about 0.1 parts to about 1.0 parts by weight per 100 parts of said blend.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US80603677A | 1977-06-13 | 1977-06-13 | |
| US806,036 | 1991-12-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1147886A true CA1147886A (en) | 1983-06-07 |
Family
ID=25193160
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000305203A Expired CA1147886A (en) | 1977-06-13 | 1978-06-12 | Thermoplastic blends of 1-olefin polymers with styrene butadiene rubber |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS544943A (en) |
| AU (1) | AU520136B2 (en) |
| BE (1) | BE867934A (en) |
| CA (1) | CA1147886A (en) |
| DE (1) | DE2825697A1 (en) |
| ES (1) | ES470737A1 (en) |
| FR (1) | FR2394576A1 (en) |
| GB (1) | GB2007682A (en) |
| IT (1) | IT1112635B (en) |
| NL (1) | NL184115C (en) |
| NO (1) | NO782028L (en) |
| SE (1) | SE443147B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4419469A (en) * | 1979-01-08 | 1983-12-06 | The Firestone Tire & Rubber Company | Thermoplastic elastomer blends with bitumen |
| US4271049A (en) * | 1979-09-10 | 1981-06-02 | Monsanto Company | Elastoplastic compositions of cured diene rubber and polypropylene |
| HU197338B (en) * | 1986-10-10 | 1989-03-28 | Boer Es Cipoeipari Kutato Fejl | Process for producing improved material for shoesole workable withinjection moulding |
| JP2565563B2 (en) * | 1989-03-18 | 1996-12-18 | 株式会社日立製作所 | Liquid crystal display device manufacturing method and liquid crystal display device phase plate manufacturing method |
| CN102782036B (en) | 2009-12-29 | 2016-01-27 | 美国圣戈班性能塑料公司 | Flexible pipe and the method for the formation of this material |
| AU2013271955B2 (en) | 2012-06-06 | 2016-09-29 | Saint-Gobain Performance Plastics Corporation | Thermoplastic elastomer tubing and method to make and use same |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT205736B (en) * | 1955-10-27 | 1959-10-10 | Phillips Petroleum Co | Novel polymeric compositions and methods of making them |
| GB802460A (en) * | 1955-10-27 | 1958-10-08 | Phillips Petroleum Co | Novel polymeric compositions and process for production thereof |
| BE555836A (en) * | 1956-03-16 | |||
| US3037954A (en) * | 1958-12-15 | 1962-06-05 | Exxon Research Engineering Co | Process for preparing a vulcanized blend of crystalline polypropylene and chlorinated butyl rubber |
| US3758643A (en) * | 1971-01-20 | 1973-09-11 | Uniroyal Inc | D polyolefin plastic thermoplastic blend of partially cured monoolefin copolymer rubber an |
| US4104210A (en) * | 1975-12-17 | 1978-08-01 | Monsanto Company | Thermoplastic compositions of high unsaturation diene rubber and polyolefin resin |
-
1978
- 1978-05-31 SE SE7806346A patent/SE443147B/en not_active IP Right Cessation
- 1978-06-06 AU AU36847/78A patent/AU520136B2/en not_active Expired
- 1978-06-08 NL NLAANVRAGE7806240,A patent/NL184115C/en not_active IP Right Cessation
- 1978-06-08 BE BE188419A patent/BE867934A/en not_active IP Right Cessation
- 1978-06-09 NO NO782028A patent/NO782028L/en unknown
- 1978-06-12 FR FR7817459A patent/FR2394576A1/en active Granted
- 1978-06-12 CA CA000305203A patent/CA1147886A/en not_active Expired
- 1978-06-12 IT IT24442/78A patent/IT1112635B/en active
- 1978-06-12 GB GB7826676A patent/GB2007682A/en not_active Withdrawn
- 1978-06-12 DE DE19782825697 patent/DE2825697A1/en active Granted
- 1978-06-13 JP JP7043678A patent/JPS544943A/en active Granted
- 1978-06-13 ES ES470737A patent/ES470737A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NL184115B (en) | 1988-11-16 |
| FR2394576A1 (en) | 1979-01-12 |
| ES470737A1 (en) | 1979-09-01 |
| SE443147B (en) | 1986-02-17 |
| NO782028L (en) | 1978-12-14 |
| JPS6115093B2 (en) | 1986-04-22 |
| FR2394576B1 (en) | 1982-07-23 |
| AU520136B2 (en) | 1982-01-14 |
| IT7824442A0 (en) | 1978-06-12 |
| DE2825697A1 (en) | 1978-12-21 |
| AU3684778A (en) | 1979-12-13 |
| IT1112635B (en) | 1986-01-20 |
| DE2825697C2 (en) | 1988-07-21 |
| NL7806240A (en) | 1978-12-15 |
| SE7806346L (en) | 1978-12-14 |
| NL184115C (en) | 1989-04-17 |
| GB2007682A (en) | 1979-05-23 |
| BE867934A (en) | 1978-12-08 |
| JPS544943A (en) | 1979-01-16 |
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