Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/20—Arrangements for storing inflatable members in their non-use or deflated condition; Arrangement or mounting of air bag modules or components
  • B60R21/215—Arrangements for storing inflatable members in their non-use or deflated condition; Arrangement or mounting of air bag modules or components characterised by the covers for the inflatable member
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/23—Inflatable members
  • B60R21/235—Inflatable members characterised by their material
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L15/00—Compositions of rubber derivatives
• • 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
  • C08L23/08—Copolymers of ethene
• • 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

Definitions

• the present invention relates to an olefinic thermoplastic elastomer composition and its use.
• Olefin-based thermoplastic elastomers are lightweight, easy to recycle, and do not generate toxic gas when incinerated, so that they are an alternative to vulcanized rubber especially from the viewpoint of energy saving and resource saving, and in recent years environmental protection. Widely used as automobile parts, industrial machine parts, electric/electronic parts, building materials, etc. An example of such an automobile part is an airbag cover of an automobile airbag system.
• the airbag cover of the airbag system for automobiles has rigidity suitable for each application such as driver's seat and passenger's seat, and the tear line part (provided to tear the airbag cover when the airbag is deployed. It is required that the airbag cover has a high tensile elongation at break other than the thin portion of the airbag cover) so as not to be cleaved, and the elongation at low temperature is excellent so as to withstand use in cold regions.
• thermoplastic elastomer composition for an airbag cover is one containing an ethylene/butene copolymer and block polypropylene.
• Patent Document 1 describes a thermoplastic elastomer composition for an airbag cover, which includes a polypropylene resin (for example, a propylene/ethylene block copolymer), an ethylene/butene copolymer rubber, and an ethylene/propylene copolymer rubber. Has been done.
• JP-A-10-273001 (for example, claim 1, Tables 1 to 3)
• An object of the present invention is to provide a thermoplastic elastomer composition having good low temperature tensile elongation.
• the gist of the present invention is as follows. (1) At least one of 30 to 60 parts by mass of a propylene polymer (A) and 32 to 65 parts by mass of an ethylene/ ⁇ -olefin copolymer (B) composed of ethylene and an ⁇ -olefin having 4 to 20 carbon atoms. A thermoplastic elastomer composition containing 1 to 20 parts by mass of a rubber (C) whose parts are cross-linked (the total amount of components (A), (B) and (C) is 100 parts by mass). (2) The intrinsic viscosity [ ⁇ ] measured in decalin at 135° C.
• n-decane in the propylene-based polymer (A) is 0.5 to 4.0 dl/g.
• thermoplastic elastomer molded body obtained by molding the thermoplastic elastomer composition according to any one of (1) to (4) above.
• thermoplastic elastomer composition of the present invention is excellent in elongation at break at low temperature.
• thermoplastic elastomer composition of the present invention will be specifically described below.
• thermoplastic elastomer composition of the present invention comprises a propylene-based polymer (A), an ethylene/ ⁇ -olefin copolymer (B) composed of ethylene and an ⁇ -olefin having 4 to 20 carbon atoms, and at least a part of which is crosslinked. Rubber (C).
• the thermoplastic elastomer composition of the present invention may contain only one type or two or more types of propylene polymer (A).
• the propylene polymer (A) has a melt flow rate (MFR) measured according to ASTM D1238 at 230° C. and a load of 2.16 kg of usually 5 to 150 g/10 minutes, preferably 10 to 100 g/10 minutes. Is.
• MFR melt flow rate
• a thermoplastic elastomer composition can be easily injection-molded, and a molded product excellent in dimensional stability and impact strength can be obtained.
• the propylene-based polymer (A) may be a propylene homopolymer (polypropylene) or a copolymer of propylene and ⁇ -olefin.
• the propylene/ ⁇ -olefin copolymer may be a random copolymer or a block copolymer.
• Examples of ⁇ -olefins copolymerized with propylene include ethylene and ⁇ -olefins having 4 to 12 carbon atoms.
• the amount of constituent units derived from propylene is preferably 60 to 99.5 mol %.
• the amount of the propylene-derived structural unit is more preferably 80 to 99 mol%, further preferably 90 to 98.5 mol%, and particularly preferably 95 to 98 mol%.
• the total of the amount of the propylene-derived constitutional unit and the amount of the ethylene-derived constitutional unit is 100 mol %.
• the propylene-based polymer is a copolymer of propylene and an ⁇ -olefin having 4 to 12 carbon atoms
• examples of the ⁇ -olefin having 4 to 12 carbon atoms include 1-butene, 1-pentene and 3 Linear or branched ⁇ -olefins such as -methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene Is included.
• the propylene/ ⁇ -olefin copolymer may contain an olefin having a carbon number other than 4 to 12, and for example, a small amount of a structural unit derived from ethylene or the like (for example, in all the structural units of the propylene-based copolymer, 10 mol% or less) may be included.
• the propylene/ ⁇ -olefin copolymer may contain only one type of ⁇ -olefin, or may contain two or more types of ⁇ -olefin.
• the propylene-based polymer (A) preferably contains block polypropylene from the viewpoint of elongation at break at low temperature.
• the block polypropylene is preferably a propylene/ethylene block copolymer, for example, a polymer having a propylene homopolymer block and an ethylene/propylene random copolymer block.
• the propylene homopolymer block is a component insoluble in n-decane
• the ethylene/propylene random copolymer block is a component soluble in n-decane. Therefore, these can be clearly distinguished or separated in the propylene/ethylene block copolymer.
• the intrinsic viscosity [ ⁇ ] measured in decalin at 135° C. in a portion soluble in room temperature n-decane in the propylene polymer (A) is preferably 0.5 to It is 4.0 dl/g, and more preferably 0.7 to 4.0 dl/g.
• the propylene/ethylene block copolymer can be appropriately produced by a known method. For example, it can be produced by homopolymerizing propylene in the first step and then copolymerizing propylene and ethylene.
• the propylene/ethylene block copolymer although referred to as a block copolymer, is considered to be a complicated composition composed of polypropylene, polyethylene, and ethylene propylene rubber (EPR) (Takashi Inoue, Sho Ichihara). Next, Polymer New Material One Point 12 Polymer Alloy, Kyoritsu Shuppan, p.62 (1988)).
• the density of the propylene polymer (A) used in the present invention is usually 0.90 to 0.92 g/cm 3 , preferably 0.90 to 0.91.
• the density is the density measured according to ASTM D1505.
• the initial flexural modulus of the propylene polymer (A) measured according to ASTM D790 is preferably 700 to 2000 MPa.
• the ethylene/ ⁇ -olefin copolymer (B) used in the present invention is an ethylene/ ⁇ -olefin copolymer composed of ethylene and an ⁇ -olefin having 4 to 20 carbon atoms, and has impact resistance of the thermoplastic elastomer composition. It is a component for improving the tensile elongation and is not crosslinked.
• the melt flow rate (MFR) is preferably 0.1 to 50 g/10 minutes, more preferably from the viewpoint of impact resistance and tensile elongation. It is 0.2 to 40 g/10 minutes.
• MFR is a value measured according to ASTM D1238, and the measurement conditions are 190° C. and 2.16 kg load.
• the melt flow rate of the ethylene/ ⁇ -olefin copolymer (B) is adjusted to be within a desired range by appropriately adjusting the degree of polymerization when polymerizing ethylene and ⁇ -olefin as raw materials. Is possible.
• Examples of the ethylene/ ⁇ -olefin copolymer (B) include ethylene/butene copolymer, ethylene/octene copolymer and ethylene/hexene copolymer.
• the ethylene/ ⁇ -olefin copolymer (B) preferably contains an ethylene/butene copolymer and an ethylene/octene copolymer from the viewpoint of impact resistance and tensile elongation, and the ethylene/butene copolymer and ethylene -It is more preferable that the octene copolymer alone is used.
• the mass ratio of the ethylene/butene copolymer and the ethylene/octene copolymer is preferably 5:95 to 95:5, more preferably 10:90 to 90:10.
• the ethylene/ ⁇ -olefin copolymer (B) As a method for producing the ethylene/ ⁇ -olefin copolymer (B), a known polymerization method using an olefin polymerization catalyst is used.
• the ethylene/ ⁇ -olefin copolymer (B) is, for example, a solution polymerization method, a slurry polymerization method, a high pressure ionic polymerization method, a gas polymerization method using a Ziegler-Natta catalyst, a complex catalyst such as a metallocene complex or a nonmetallocene complex. It is preferably produced by a phase polymerization method, a bulk polymerization method using a radical initiator, a solution polymerization method, or the like. Above all, it is particularly preferable to use a method of polymerizing a monomer using a Ziegler-Natta catalyst or a complex catalyst, or a method of polymerizing a monomer in the presence of a metalloc
• the at least partially crosslinked rubber (C) used in the present invention is not particularly limited, but a peroxide crosslinked olefin-based copolymer rubber is preferable.
• the peroxide-crosslinking olefin-based copolymer rubber is, for example, an amorphous random elastic rubber containing olefin as a main component such as ethylene/propylene copolymer rubber, ethylene/propylene/non-conjugated diene rubber, and ethylene/butadiene copolymer rubber.
• the above-mentioned ⁇ -olefin is usually an ⁇ -olefin having 3 to 20 carbon atoms, specifically, propylene, 1-butene, 1-pentene, 4-methylpentene-1,1-hexene, 1-heptene.
• propylene, 1-butene, 4-methylpentene-1,1-hexene and 1-octene are preferable, and propylene is particularly preferable.
• These ⁇ -olefins may be used alone or in combination of two or more.
• non-conjugated polyene examples include 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5 -Chain non-conjugated dienes such as dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadiene, 4-ethylidene-1,7-undecadiene; Methyl tetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene Cyclic non-conjugated dienes such as 5-vinyl-2-norbornene,
• the intrinsic viscosity [ ⁇ ] of the ethylene/ ⁇ -olefin/non-conjugated polyene copolymer rubber measured in decalin at 135° C. is usually 0.6 to 6.5 dl/g, preferably 0.8 to 6. It is 0 dl/g, and more preferably 0.9 to 5.5 dl/g.
• the iodine value of the ethylene/ ⁇ -olefin/non-conjugated polyene copolymer rubber is usually 2 to 50 g/100 g, preferably 5 to 40 g/100 g, more preferably 7 to 30 g/100 g.
• the Mooney viscosity ML 1+4 (100° C.) of the copolymer rubber is usually 10 to 300, preferably 30 to 250.
• the rubber used in the present invention in addition to the olefin copolymer rubber, other rubbers such as styrene-butadiene rubber (SBR), nitrile rubber (NBR), natural rubber (NR), butyl rubber (IIR), etc.
• SBR styrene-butadiene rubber
• NBR nitrile rubber
• NR natural rubber
• IIR butyl rubber
• examples include diene rubber, SEBS, polyisobutylene, and the like.
• thermoplastic elastomer composition of the present invention may contain a plasticizer (softening agent) (D), if necessary.
• plasticizer (D) a plasticizer usually used for rubber can be used.
• petroleum-based plasticizers such as process oils, lubricating oils, paraffin oils, liquid paraffin, petroleum asphalt, and petrolatum
• coal tar-based plasticizers such as coal tar and coal tar pitch
• castor oil, linseed oil, rapeseed oil a plasticizer usually used for rubber.
• Fat oil plasticizers such as soybean oil and coconut oil; tall oil; sub (factis); waxes such as beeswax, carnauba wax and lanolin; ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate, laurin Fatty acids and fatty acid salts such as zinc acid; naphthenic acid; pine oil, rosin or its derivatives; synthetic polymer substances such as terpene resin, petroleum resin, atactic polypropylene, coumarone indene resin; dioctyl phthalate, dioctyl adipate, dioctyl sebacate Ester plasticizers such as; microcrystalline wax, liquid polybutadiene, modified liquid polybutazine, liquid thiocol, hydrocarbon synthetic lubricating oil, and the like.
• petroleum-based plasticizers particularly process oils such as paraffin-based process oils and naphthene-based process oils are preferably used.
• the blending amount of the plasticizer is preferably 0 part by mass or more and 10 parts by mass or less from the viewpoint of bleeding suppression and coating adhesion.
• the propylene polymer (A) and the at least partially crosslinked rubber (C) may be present in a completely or partially crosslinked polyolefin-based thermoplastic elastomer.
• thermoplastic elastomer for example, (1) A mixture of (a) peroxide-crosslinking olefin-based copolymer rubber and (b) peroxide-decomposing olefin-based plastic (propylene-based polymer (A)), or (a) peroxide-crosslinking olefin-based copolymer Polymer rubber, (b) peroxide decomposing type olefin-based plastic (propylene polymer (A)), and (c) peroxide non-crosslinking rubber-like substance and/or (d) petroleum plasticizer, if necessary A partially crosslinked thermoplastic elastomer obtained by dynamically heat treating a mixture consisting of: (2) (a) Peroxide-crosslinking olefin-based copolymer rubber, (b) Peroxide-decomposing olefin-based plastic (propylene-based polymer (A)), and
• the above-mentioned (c) peroxide non-crosslinking rubber-like substance is a mixture with a peroxide such as polyisobutylene, butyl rubber, atactic polypropylene, propylene/ ⁇ -olefin copolymer rubber having a propylene content of 50 mol% or more.
• a peroxide such as polyisobutylene, butyl rubber, atactic polypropylene, propylene/ ⁇ -olefin copolymer rubber having a propylene content of 50 mol% or more.
• it means a hydrocarbon rubber-like substance that does not crosslink even when kneaded under heating and does not deteriorate in fluidity.
• a mass compounding ratio ((b)/(a) of (b) olefin-based plastic (propylene polymer (A)) and (a) olefin-based copolymer rubber. )) is usually in the range of 90/10 to 10/90, preferably 70/30 to 15/85.
• the other rubber is 100 in total of the peroxide-decomposing olefin plastic (propylene polymer (A)) and the rubber.
• the amount is usually 40 parts by mass or less, preferably 5 to 20 parts by mass with respect to parts by mass.
• the olefin thermoplastic elastomer preferably used in the present invention is crystalline polypropylene (propylene polymer (A)) and ethylene/ ⁇ -olefin copolymer rubber or ethylene/ ⁇ -olefin/non-conjugated polyene copolymer rubber. Which is present in a partially crosslinked state in the olefin-based thermoplastic elastomer, and has a mass compounding ratio of crystalline polypropylene (propylene polymer (A)) and rubber (crystalline polypropylene (propylene-based polymer)). It is an olefinic thermoplastic elastomer having a polymer (A))/rubber) in the range of 70/30 to 3/97.
• organic peroxide examples include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2, 5-di-(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n -Butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl Examples thereof include peroxides and tert-buty
• 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-di-(tert-butyl) are preferable in terms of odor and scorch stability.
• the organic peroxide is usually 0.01 to 5 parts by mass, preferably 0.05 to 100 parts by mass of the total amount of the crystalline polyolefin (the propylene polymer (A) in the olefinic thermoplastic elastomer) and the rubber. It is used in a proportion of ⁇ 3 parts by mass.
• Divinylbenzene is easy to handle, has good compatibility with the crystalline polyolefin and the rubber, which are the main components of the above-mentioned substance to be crosslinked, and has the action of solubilizing the organic peroxide, and is a dispersant for the organic peroxide.
• an olefinic thermoplastic elastomer having a uniform cross-linking effect by heat treatment and a good balance of fluidity and physical properties can be obtained.
• the olefin-based thermoplastic elastomer used in the present invention is produced by using a phenol resin-based cross-linking agent as a cross-linking agent, a propylene-based polymer (A) and an uncross-linked rubber (C), such as ethylene/ ⁇ -olefin/ It is preferable to dynamically crosslink the non-conjugated polyene copolymer with a phenol resin crosslinking agent.
• “dynamic crosslinking” means crosslinking while applying a shearing force to the mixture.
• the phenol resin-based cross-linking agent a halogenated phenol resin-based cross-linking agent can be mentioned.
• the phenol resin-based cross-linking agent is a resol resin and is produced by condensation of an alkyl-substituted phenol or an unsubstituted phenol with an aldehyde in an alkaline medium, preferably with formaldehyde, or a condensation of difunctional phenol dialcohols. Is also preferable.
• the alkyl-substituted phenol is preferably a substituted alkyl group having 1 to about 10 carbon atoms.
• the phenol resin-based curable resin is typically a heat-crosslinkable resin, and is also called a phenol resin-based crosslinking agent or a phenol resin.
• phenol resin-based cured resin examples include compounds represented by the following general formula (I).
• Q is a divalent group selected from the group consisting of —CH 2 — and —CH 2 —O—CH 2 —, m is 0 or a positive integer of 1 to 20, and R′ is Is an organic group.
• Q is a divalent group —CH 2 —O—CH 2 —
• m is 0 or a positive integer from 1 to 10
• R′ is an organic group having less than 20 carbon atoms. More preferably, m is 0 or a positive integer of 1 to 5 and R'is an organic group having 4 to 12 carbon atoms.
• Specific examples thereof include an alkylphenol formaldehyde resin, a methylolated alkylphenol resin, and a halogenated alkylphenol resin.
• a halogenated alkylphenol resin is preferable, and a terminal hydroxyl group is more preferably brominated.
• An example of a phenolic resin-based cured resin whose terminal is brominated is represented by the following general formula (II).
• n is an integer of 0 to 10 and R is a saturated hydrocarbon group of 1 to 15 carbon atoms.
• Examples of the product of the phenol-based curable resin include Takkyrol (registered trademark) 201 (alkylphenol formaldehyde resin, manufactured by Taoka Chemical Industry Co., Ltd.), Takkyrol (registered trademark) 250-I (brominated alkylphenol having a bromination rate of 4%).
• Formaldehyde resin manufactured by Taoka Chemical Co., Ltd., Takkyrol (registered trademark) 250-III (brominated alkylphenol formaldehyde resin, manufactured by Taoka Chemical Co., Ltd.), PR-4507 (Gunei Chemical Co., Ltd.)
• Vulkaresat 510E manufactured by Hoechst
• Vulkaresat 532E manufactured by Hoechst
• VulkaresenE manufactured by Hoechst
• Vulkaresen 105E manufactured by Hoechst Co.
• Vulkaresen 130E manufactured by Hoechst
• Vulkaresen 130E manufactured by Hoechst
• Vulkaresen 130E manufactured by Hoechst
• Vulkaresen 130E manufactured by Hoechst
• Vulkaresen 130E manufactured by Hoechst
• Vulkaresen 130E manufactured by Hoechst
• Vulkaresen 130E manufactured by Hoechst
• Examples include SP1055F (manufactured by Schenectady Chem., brominated alkylphenol formaldehyde resin), Schenectady SP1056 (manufactured by Schenectady Chem.), CRM-0803 (manufactured by Showa Union Synthetic Co., Ltd.), and Vulkadur A (manufactured by Bayer).
• halogenated phenol resin-based cross-linking agents are preferable, and brominated alkylphenol formaldehyde resins such as Tackyroll (registered trademark) 250-I, Tackyroll (registered trademark) 250-III, and Schenectady SP1055F can be more preferably used.
• thermoplastic vulcanizate with a phenol resin
• crosslinking of the thermoplastic vulcanizate with a phenol resin are described in US Pat. No. 4,311,628, US Pat. No. 2,972,600 and US Pat. No. 3,287,440. Although described, these techniques can also be used in the present invention.
• U.S. Pat. No. 4,311,628 discloses a phenolic curative system consisting of a phenolic curing resin and a cure activator.
• the basic component of the system is either the condensation of a substituted phenol (eg halogen-substituted phenol, C 1 -C 2 alkyl-substituted phenol) or an unsubstituted phenol with an aldehyde, preferably formaldehyde, in an alkaline medium, or a bifunctional phenol.
• a phenol resin cross-linking agent produced by condensation of dialcohols (preferably dimethylolphenols substituted at the para position with a C 5 -C 10 alkyl group).
• Halogenated alkyl-substituted phenolic resin-based crosslinkers prepared by halogenation of alkyl-substituted phenolic resin-based crosslinkers are particularly suitable.
• a phenol resin-based cross-linking agent comprising a methylol phenol curable resin, a halogen donor and a metal compound is particularly recommended, and the details are described in US Pat. Nos. 3,287,440 and 3,709,840. Has been done.
• the non-halogenated phenolic resin-based crosslinker is used at the same time as the halogen donor, preferably with a hydrogen halide scavenger.
• halogenated phenolic resin-based cross-linking agents preferably brominated phenolic resin-based cross-linking agents containing 2 to 10% by weight of bromine
• halogen donors such as iron oxides, titanium oxides, oxides.
• hydrogen halide scavengers such as metal oxides such as magnesium, magnesium silicate, silicon dioxide and zinc oxide, preferably zinc oxide.
• hydrogen halide scavengers such as zinc oxide are usually used in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the phenol resin crosslinking agent.
• halogen donors are, for example, stannous chloride, ferric chloride, or halogen donating heavy compounds such as chlorinated paraffins, chlorinated polyethylenes, chlorosulfonated polyethylenes and polychlorobutadienes (neoprene rubber).
• a phenolic resin-based crosslinker and includes metal oxides and halogen donors, Are used alone or in combination.
• vulcanization accelerator means any substance that substantially increases the crosslinking efficiency of a phenolic resin-based crosslinker, and includes metal oxides and halogen donors, Are used alone or in combination. For more details on phenolic vulcanizing agents, see “Vulcanization and Vulcanizing Agents" (W. Hoffman, Palmerton Publishing Company).
• Suitable phenolic resin-based crosslinkers and brominated phenolic resin-based crosslinkers are commercially available, for example such crosslinkers are available from Schenectady Chemicals, Inc. under the trade names "SP-1045”, “CRJ-352”. ,”SP-1055F” and “SP-1056". Similar functionally equivalent phenolic resin crosslinkers can also be obtained from other suppliers.
• the phenolic resin-based cross-linking agent is a suitable vulcanizing agent from the viewpoint of preventing fogging because it produces few decomposition products.
• the phenolic resin-based crosslinker is used in an amount sufficient to achieve essentially complete vulcanization of the rubber.
• the phenol resin-based cross-linking agent is usually used in an amount of 0.1 to 20 parts by mass, preferably 1 to 10 parts by mass, based on 100 parts by mass of the ethylene/ ⁇ -olefin/non-conjugated polyene copolymer rubber.
• amount of the phenol resin-based cross-linking agent to be in the above range, a composition having excellent moldability can be obtained, and the obtained molded article has high strength and excellent oil resistance, It has heat resistance and mechanical properties.
• auxiliary agent divinylbenzene is preferable. Divinylbenzene is easy to handle, has good compatibility with the crystalline olefin polymer and the ethylene/ ⁇ -olefin/non-conjugated polyene copolymer rubber contained as the main components in the thermoplastic elastomer composition, and is phenol It has a function of solubilizing the resin-based cross-linking agent and acts as a dispersant for the phenol resin-based cross-linking agent, so that the cross-linking effect by heat treatment is uniform, and a thermoplastic elastomer composition having a good balance of fluidity and physical properties is obtained.
• the auxiliary is used in an amount of usually 2 parts by mass or less, preferably 0.3 to 1 part by mass, based on 100 parts by mass of the ethylene/ ⁇ -olefin/non-conjugated polyene copolymer rubber.
• a dispersion accelerator may be used to accelerate the decomposition of the phenol resin crosslinking agent.
• tertiary amines such as triethylamine, tributylamine, 2,4,6-tri(dimethylamino)phenol; aluminum, cobalt, vanadium, copper, calcium, zirconium, manganese, magnesium, lead, mercury, etc.
• naphthenic acid salts of naphthenic acid and various metals for example, Pb, Co, Mn, Ca, Cu, Ni, Fe, Zn, and rare earths).
• the above-mentioned crosslinking aid or polyfunctional vinyl monomer is used in a proportion of 0.01 to 5 parts by weight, and particularly 0.05 to 3 parts by weight, based on 100 parts by weight of the whole article to be crosslinked. Is preferred.
• the cross-linking reaction proceeds too fast when the blending amount of the organic peroxide is large, so that the obtained thermoplastic elastomer has a fluidity.
• the content of the organic peroxide is small, the cross-linking aid and the polyfunctional vinyl monomer remain as unreacted monomers in the thermoplastic elastomer, and the thermoplastic elastomer does not undergo heat treatment during molding. Physical properties may change due to history. Therefore, the cross-linking aid and the polyfunctional vinyl monomer should not be blended in excess.
• “Dynamic heat treatment” means kneading each of the above components in a molten state.
• a conventionally known kneading device such as an open type mixing roll, a non-open type Banbury mixer, an extruder, a kneader, or a continuous mixer can be used.
• a non-open type kneading device is preferable, and kneading is preferably performed in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas.
• the kneading is preferably performed at a temperature at which the half-life of the organic peroxide used is less than 1 minute.
• the kneading temperature is usually 150 to 280° C., preferably 170 to 270° C.
• the kneading time is usually 0.5 to 20 minutes, preferably 1 to 10 minutes.
• the shear force applied is typically a shear rate, 10 ⁇ 50,000sec -1, is preferably determined in the range of 100 ⁇ 10,000sec -1.
• the completely crosslinked olefinic thermoplastic elastomer is prepared by changing the conditions such as the amount of the organic peroxide used and the kneading time according to the method for preparing the olefinic thermoplastic elastomer described in (1) and (2) above. can do.
• the olefinic thermoplastic elastomer used in the present invention preferably has a type A hardness (instantaneous value) of 60 or more in accordance with JIS K6253.
• the type A hardness (instantaneous value) is usually 1 to 98, preferably 60 to 98, more preferably 70 to 98, and particularly preferably 80 to 98.
• the olefinic thermoplastic elastomer used in the present invention has a melt flow rate (MFR: ASTM D1238, 230° C., load 2.16 kg) measured at 230° C. and a load 2.16 kg, usually 0.1 to 100 g/10 min, preferably Is in the range of 1 to 100 g/10 minutes.
• MFR melt flow rate
• thermoplastic elastomer composition of the present invention is a rubber in which 30 to 60 parts by mass of a propylene polymer (A) and 32 to 65 parts by mass of an ethylene/ ⁇ -olefin copolymer (B) are at least partially crosslinked. (C) 1 to 20 parts by mass (the total amount of components (A), (B) and (C) is 100 parts by mass), preferably 32 to 60 parts by mass of the propylene polymer (A).
• the amount is 100 parts by mass), and more preferably at least part of 35 to 60 parts by mass of the propylene polymer (A) and 34 to 58 parts by mass of the ethylene/ ⁇ -olefin copolymer (B).
• 1 to 12 parts by mass of crosslinked rubber (C) (the total amount of components (A), (B) and (C) is 100 parts by mass).
• the ratio of the propylene-based polymer (A) is less than 30 parts by mass, sufficient rigidity cannot be obtained and molding becomes difficult. On the other hand, when it exceeds 60 parts by mass, the rigidity becomes too high and sufficient resistance is obtained. Impact and tensile elongation cannot be obtained. If the ratio of the ethylene/ ⁇ -olefin copolymer (B) is less than 32 parts by mass, the rigidity becomes too high and sufficient impact resistance and tensile elongation cannot be obtained, while if it exceeds 65 parts by mass. However, sufficient rigidity cannot be obtained and molding becomes difficult. When the ratio of the crosslinked rubber (C) is less than 1 part by mass, sufficient tensile elongation at low temperature cannot be obtained, while when it exceeds 20 parts by mass, sufficient rigidity cannot be obtained and molding becomes difficult. ..
• the gel fraction of the thermoplastic elastomer composition is preferably 0.5 to 16.0 mass%, more preferably 1.0 to 12.0 mass% from the viewpoint of tensile elongation.
• thermoplastic elastomer composition of the present invention preferably has a Shore D hardness (after 5 seconds) according to ISO7619 of 32 to 55 from the viewpoint of the rigidity of the molded product.
• thermoplastic elastomer composition of the present invention comprises a propylene polymer (A), an ethylene/ ⁇ -olefin copolymer (B) and at least a partially crosslinked rubber (C), a plasticizer if necessary, Furthermore, it can be manufactured by adopting a method of granulating or pulverizing after melt-kneading other components.
• the thermoplastic elastomer composition of the present invention comprises a part of the propylene polymer (A), an uncrosslinked rubber (C), an organic peroxide, and, if necessary, other components. Is dynamically heat-treated to prepare an olefin-based thermoplastic elastomer containing at least partially crosslinked rubber (C), and then the remaining propylene-based polymer (A) and, if necessary, It is preferable to manufacture by a method of granulating or pulverizing after melt-kneading other components.
• a mixing roll As a kneading device, a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader), a single-screw or twin-screw extruder, etc. can be used, but a non-open type device is preferable.
• an intensive mixer for example, a Banbury mixer, a kneader
• a single-screw or twin-screw extruder etc.
• a non-open type device is preferable.
• thermoplastic elastomer composition of the present invention can be molded by various known molding methods, specifically, various molding methods such as extrusion molding, press molding, injection molding, calender molding, and hollow molding building. Can be Further, a molded product such as a sheet obtained by the above-mentioned molding method can be subjected to secondary processing by thermoforming or the like.
• thermoplastic elastomer molded article of the present invention is not particularly limited, but for example, various known applications such as automobile parts, civil engineering/construction material products, electric/electronic parts, hygiene products, films/sheets, etc. It is suitable.
• the automobile parts that can be used for the thermoplastic elastomer molded article of the present invention include automobile interior parts and automobile exterior parts, for example, weather strip materials, bumper moldings, side moldings, air spoilers, deflectors, mudguards, air duct hoses, wires. Harness grommets, rack and pinion boots, suspension cover boots, glass guides, inner belt line seals, corner moldings, glass encapsulation, hood seals, glass run channels, secondary seals, various packings, hoses, airbag covers, etc.
• the thermoplastic elastomer composition of the present invention is particularly preferable for automobile parts such as an airbag cover, an air spoiler, a deflector, and a mudguard because it has excellent elongation at break at low temperature.
• thermoplastic elastomer molded article of the present invention examples include, for example, ground improvement sheets, water plates, civil engineering materials and construction materials such as noise prevention, various civil engineering/construction gaskets and sheets, waterproofing. Materials, jointing materials, window frames for construction, etc. can be exemplified.
• thermoplastic elastomer molded body of the present invention examples include electric/electronic parts such as electric wire coating materials, connectors, caps and plugs.
• thermoplastic elastomer molded article of the present invention examples include sanitary products such as sanitary products, disposable diapers, and grips for toothbrushes.
• thermoplastic elastomer molded article of the present invention examples include, for example, infusion bags, medical containers, automobile interior/exterior materials, beverage bottles, costume cases, food packaging materials, food containers, retort containers, pipes, transparent. Examples include bases and sealants.
• thermoplastic elastomer molded article of the present invention can be used include, for example, footwear such as shoe soles and sandals, swimming fins, underwater glasses, leisure products such as golf club grips, baseball bat grips, gaskets, and waterproof cloth. , Belts, garden hoses, anti-slip tape for stairs, anti-slip tape for distribution pallets, and the like.
• thermoplastic elastomer molding of the present invention is not limited to the above-mentioned uses, but may be used for various uses.
• MFR Melt flow rate
• a condenser was attached to the eggplant-shaped flask, and while operating the rotor, the flask was heated in an oil bath at 135° C. for 120 minutes to dissolve the sample in n-decane.
• the solution in the beaker was stirred with a stirrer and allowed to cool to room temperature (25° C.) (8 hours or more), and then the precipitate was removed. It was filtered with a wire net.
• the obtained filtrate was further filtered with a filter paper and then poured into 2,000 ml of methanol contained in a 3,000 ml beaker, and this liquid was stirred at room temperature (25°C) with a stirrer for 2 hours. I left it over.
• the obtained precipitate was collected by filtration with a wire mesh, air-dried for 5 hours or more, and then dried at 100° C. for 240 to 270 minutes by a vacuum dryer to recover an n-decane-soluble portion at 25° C.
• the temperature was raised from 30°C to 200°C at 320°C/min, and kept at 230°C for 10 minutes, and then from 230°C.
• the melting point is determined from the endothermic curve when the temperature is lowered to 30° C. at 10° C./min, the temperature is kept at 30° C. for another minute, and then the temperature is raised at 10° C./min.
• Tm melting point
• the phrase “melting point is not observed” means that the heat of fusion ( ⁇ H) is less than 1 J/g.
• -(B-1) Ethylene/1-butene copolymer This product is a commercial product, consisting of ethylene and 1-butene, having an ethylene content of 69% by mass and a melt flow rate (ASTM D1238, 190°C, 2.16 kg). (Load) is 0.5 g/10 minutes, and a melting point peak is not substantially observed by DSC.
• -(B-2) Ethylene/1-octene copolymer This product is a commercial product, is composed of ethylene and 1-octene, has an ethylene content of 55% by mass, and has a melt flow rate (ASTM D1238, 190°C, 2.16 kg). It is a copolymer having a load of 0.5 g/10 minutes and a melting point of 55° C. by DSC.
• This product is a commercial product, has an ethylene unit content of 78 mol%, an iodine value of 13 g/100 g, and an intrinsic viscosity [ ⁇ ] of 3.4 dl/g measured in decalin at 135° C., relative to 100 parts by mass of rubber.
• Thermoplastic elastomer ( ⁇ -1) Oil-extended ethylene/propylene/5-ethylidene-2-norbornene copolymer rubber (C-1) 50 parts by mass, block polypropylene (PP-1) 50 parts by mass, and organic peroxide (Perhexa 25B, NOF Corporation) as a crosslinking agent. 0.3 parts by mass, divinylbenzene 0.3 parts by mass as a crosslinking aid, and a phenolic antioxidant (Irganox 1010, manufactured by BASF Co., Ltd.) 0.1 parts by mass as an antioxidant. Were thoroughly mixed with a Henschel mixer, and extrusion kneaded under the following conditions.
• the melt flow rate (230° C., 2.16 kg load) of the partially or completely crosslinked thermoplastic elastomer ( ⁇ -1) obtained by the above step was 25 g/10 minutes, and the durometer hardness D was 39. ..
• thermoplastic elastomer composition was evaluated according to the method described above. The results are shown in Table 1.
• thermoplastic elastomer composition of the present invention is excellent in elongation at break at low temperature.

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