JP5473852B2 - Process for producing olefinic thermoplastic elastomer composition - Google Patents

Description

  The present invention relates to a method for producing an olefinic thermoplastic elastomer composition by dynamically heat-treating an ethylene / α-olefin / non-conjugated polyene copolymer rubber and a polypropylene resin in an extruder in the presence of a crosslinking agent. About. More specifically, massive ethylene / α-olefin / non-conjugated polyene copolymer rubber, powdery polypropylene resin and a crosslinking agent are supplied to the extruder with a uniform composition without impairing these properties. The present invention relates to a method for producing an olefinic thermoplastic elastomer composition.

  A thermoplastic elastomer composition is obtained by dynamically heat-treating a crosslinkable ethylene / propylene / nonconjugated polyene polymer rubber and a noncrosslinkable polypropylene resin in the presence of a crosslinking agent with respect to an organic peroxide. Various methods have been proposed, and as an apparatus for dynamically performing a heat treatment, roughly classified, a closed kneader and an extruder represented by a Banbury mixer and a pressure kneader have been proposed.

  Among these, as a method of using a closed kneader such as a Banbury mixer or a pressure kneader, for example, in a closed kneader, ethylene / propylene / non-conjugated polyene polymer rubber and an organic peroxide are allowed to coexist. Dynamic heat treatment to partially cross-link the rubber and then melt-mix the polypropylene resin, or use ethylene / propylene / non-conjugated polyene polymer rubber, polypropylene resin and a crosslinking agent in a closed kneader. There is a method of heat treatment.

  However, the method of kneading and crosslinking with these closed kneaders requires a long time from the introduction of the material below the reaction start temperature of the crosslinking agent to the temperature rise above the crosslinking reaction temperature and the completion of the crosslinking reaction, Moreover, since this is repeated, not only is it not economical, but quality problems such as deterioration in quality due to deterioration of rubber and resin during heat treatment and generation of defects due to poor dispersion of crosslinked rubber in the resin are likely to occur. For this reason, most of the commercial production of olefinic thermoplastic elastomer compositions is carried out in an extruder, especially a twin screw extruder.

  By the way, in the method of producing an olefinic thermoplastic elastomer composition with an extruder, there is a problem of how the bulk ethylene / propylene / non-conjugated polyene polymer rubber which is one of raw materials is supplied to the extruder. There is. Since the ethylene / propylene / non-conjugated polyene polymer rubber is usually supplied in a mass called a bale, it is difficult to supply to the extruder as it is, and the bulk ethylene / propylene / non-conjugated polyene polymer rubber is also used. It is not easy to mix with a pellet-shaped polypropylene resin. For this reason, several methods for supplying bulk ethylene / propylene / non-conjugated polyene polymer rubber to an extruder have been proposed.

  For example, a method of melt-mixing a block of ethylene / propylene / non-conjugated polyene polymer rubber and a polypropylene resin in a closed kneader in advance, pelletizing the mixture, and supplying the pellet and the crosslinking agent to an extruder However, it is not economical, and is not preferable because the heat treatment causes deterioration of rubber and resin.

  In order to improve this, Japanese Patent Application Laid-Open No. 58-25340 proposes a method using pellet-like ethylene / propylene / non-conjugated polyene polymer rubber. However, this method also does not solve the economical problem such as the processing cost by the extruder necessary for turning the massive rubber into pellets and the quality problem of deterioration due to the shear heat generation of the rubber in the extruder. For this reason, Japanese Patent Application Laid-Open No. 2003-321553 proposes pulverizing massive rubber.

  However, these ethylene / propylene / non-conjugated polyene polymer rubber pellets and pulverized products are easy to adhere and harden together, and are therefore easily classified into polypropylene resins. It is difficult to supply.

  Furthermore, there is a problem of how to supply a molten mixture of pelletized rubber and resin, or a mixture of pelletized or pulverized rubber and pelletized resin, and a crosslinking agent to the extruder with a precise and uniform composition. . As this method, a method of supplying these pellets and pulverized products to an extruder after being coated with a cross-linking agent using a rotary blender or a Henschel mixer has been proposed. It is difficult to supply the extruder with a uniform composition.

  As improvements, a method of mixing a powdery cross-linking agent in a liquid such as oil and adhering it to the surface of pellets or pulverized products, or a method using a liquid cross-linking agent has been proposed. Due to the adhesion to the inner wall of the mixer and the stickiness of the pellets and pulverized material to which the liquid material has adhered, it is difficult to supply them to the extruder with a precise and uniform composition. In particular, it is difficult to supply a large amount of powdery additives, liquid oil, and these pellets and pulverized products to the extruder with a uniform composition.

  In order to solve the above problems and to supply a block of ethylene / propylene / non-conjugated polyene polymer rubber, a polypropylene resin and a crosslinking agent with high accuracy and a uniform composition to an extruder, these properties are required. In a maintained state, it is a good idea to supply these in a uniformly mixed mixture. However, melting and mixing the bulk ethylene / propylene / non-conjugated polyene polymer rubber, the polypropylene resin and the crosslinking agent is because the melting temperature of the polypropylene resin and the reaction start temperature of the crosslinking agent are close. When melt-kneading above the melting temperature, a reaction of the crosslinking agent occurs, and it is difficult to obtain a mixture in which the crosslinking agent is unreacted.

  Also, when the pelletized polypropylene resin is mixed with the bulk ethylene / propylene / non-conjugated polyene polymer rubber below the melting temperature of the polypropylene resin and the reaction start temperature of the crosslinking agent, the particles of the polypropylene resin are large and uniform. Since it is difficult to disperse in an extruder, it is difficult to supply the extruder with a uniform composition.

JP 58-25340 A JP 2003-321553 A

  The object of the present invention is to impair these properties of ethylene / α-olefin / non-conjugated polyene copolymer rubber, polypropylene resin and crosslinking agent in the production of an olefinic thermoplastic elastomer composition in an extruder. The object of the present invention is to provide a method for supplying an extruder with a uniform composition.

  Bulk ethylene / α-olefin / non-conjugated polyene copolymer rubber, powdered polypropylene resin and cross-linking agent are mixed in a closed kneader, and the melting temperature (t1) of the polypropylene resin and the cross-linking agent halved for one minute. The above-mentioned object is achieved by mixing at a temperature equal to or lower than the lowest one of the initial temperature (t2) or the reaction start temperature (t3) and feeding this mixture to the extruder.

  That is, the present invention relates to a method for producing a thermoplastic elastomer composition by melting and kneading an ethylene / α-olefin / non-conjugated polyene copolymer rubber and a polypropylene resin with an extruder and crosslinking with a crosslinking agent. The rubber, the powdery resin and the crosslinking agent are mixed in a closed kneader at a melting temperature (t1) of the resin and a half-life temperature (t2) of the crosslinking agent for 1 minute or a reaction start temperature (t3). And providing a method for producing a thermoplastic elastomer composition, wherein the homogeneous mixture is supplied to an extruder.

In the method of the present invention, a massive rubber can be used and the rubber, the resin and the cross-linking agent are uniformly mixed. Therefore, the rubber, the resin and the cross-linking agent can be accurately and uniformly supplied to the extruder.
According to the present invention, since the rubber and the resin are mixed at a low temperature without performing melt kneading and crosslinking of the rubber and the resin, the thermoplastic elastomer composition can be produced in a short time and continuously, and economically. A method for producing an excellent thermoplastic elastomer composition is provided.
Furthermore, the method for producing the thermoplastic elastomer composition of the present invention includes the melting temperature of the ethylene / α-olefin / non-conjugated polyene copolymer rubber and the polypropylene resin and the 1 minute half-life temperature or the reaction start temperature of the crosslinking agent. This is a method for producing a thermoplastic elastomer composition that does not cause deterioration of rubber or resin since it is mixed in advance and then supplied to an extruder.

  The present invention relates to a method for producing a thermoplastic elastomer composition by melt-kneading an ethylene / α-olefin / non-conjugated polyene copolymer rubber and a polypropylene resin with an extruder and crosslinking with a crosslinking agent. A propylene / non-conjugated polyene copolymer rubber, a powdery polypropylene resin, and a crosslinking agent are mixed in a closed kneading machine with a melting temperature (t1) of the resin and a half-life temperature of one minute (t2) of the crosslinking agent or Provided is a method for producing a thermoplastic elastomer composition, which comprises mixing at a temperature not higher than the minimum temperature among reaction initiation temperatures (t3) and supplying the mixture to an extruder.

  The ethylene / α-olefin / non-conjugated polyene copolymer rubber of the present invention is a copolymer comprising ethylene, an α-olefin and a non-conjugated polyene. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene, and propylene is particularly preferable.

  Examples of the non-conjugated polyene include 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, and the like. Chain non-conjugated dienes such as: cyclohexadiene, dicyclopentadiene, methyltetraindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene Non-conjugated dienes; 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, 1,3,7-octatriene, 1, And trienes such as 4,9-decatriene, one of which may be used alone, It may be used in combination of two or more species. In view of copolymerization reactivity and crosslinking reaction rate, 5-ethylidene-2-norbornene and / or 5-ethylidene-2-norbornene and dicyclopentadiene are preferable.

  As the ethylene / α-olefin / non-conjugated polyene copolymer rubber of the present invention, an ethylene / propylene / non-conjugated diene copolymer rubber is preferably used. The ethylene / propylene / non-conjugated diene copolymer rubber is usually called EPDM, and can be appropriately selected from those commercially available as EPDM.

The higher the Mooney viscosity (ML _{1 + 4} , 125 ° C.) of the ethylene / α-olefin / non-conjugated polyene copolymer rubber used in the present invention is 20 or more, the stronger the thermoplastic elastomer composition obtained is. There is a tendency to improve, preferably 20 to 100, but if it is too high, the mixture of the mixture in the closed kneader may be deteriorated.

  Mineral oil is preferably added to the ethylene / α-olefin / non-conjugated polyene copolymer rubber of the present invention. As the ethylene / α-olefin / non-conjugated polyene copolymer rubber with mineral oil added, oil-extended rubber with mineral oil added in advance may be used, or non-oil-extended rubber is used for sealing. Mineral oil may be blended with a kneader of the type. A mode in which mineral oil is added when mixing the polypropylene resin with the oil-extended ethylene / α-olefin / non-conjugated polyene copolymer rubber is also a preferred mode of the present invention.

  Examples of the mineral oil include aromatic process oil, naphthenic process oil, and paraffinic process oil. In view of contamination by oil, naphthenic process oil and paraffinic process oil are preferable.

As for the amount of mineral oil, when it is used by adding it in a closed kneader, it is desirable to use up to about 70 parts, preferably 10 to 50 parts with respect to 100 parts of rubber. In addition, when using an oil-extended rubber to which mineral oil has been added in advance, it can be used even if the Mooney viscosity of the ethylene / α-olefin / non-conjugated polyene copolymer rubber is high. Up to about 200 parts, preferably 30 to 150 parts can be blended with 100 parts.
The Mooney viscosity (ML _{1 + 4} , 125 ° C.) of the oil-extended rubber is preferably 20 to 100, more preferably 40 to 80.

  The ethylene / α-olefin / non-conjugated polyene copolymer rubber of the present invention is a massive rubber generally called a bale.

 The polypropylene resin of the present invention is a homopolymer of propylene or a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms. Here, the copolymer includes not only a random copolymer but also a block copolymer, a block copolymer containing a random copolymer portion, and the like. The polypropylene resin is preferably a propylene / ethylene block copolymer containing isotactic polypropylene and 10% by weight or less of ethylene.

  The powdery polypropylene-based resin of the present invention is a powdery one that passes 90% or more through a wire mesh of 10 mesh, preferably 20 mesh. The powdery polypropylene-based resin can be obtained by pulverizing the pellet-like resin, but it is economical to take out the resin after pelletization after polymerization. Since the powdery polypropylene-based resin taken out before pelletization usually does not contain a stabilizer, it is partly decomposed in the step of crosslinking with an organic peroxide, so the fluidity is improved. It can be preferably used.

  The proportion of the bulk ethylene / α-olefin / non-conjugated polyene copolymer rubber and the powdery polypropylene resin is 10 to 40% by weight, preferably 15 to 35% by weight, with 100% by weight of both. The bulk ethylene / α-olefin / non-conjugated polyene copolymer rubber is 60 to 90% by weight, preferably 65 to 85% by weight. If the amount of the polypropylene resin is too small, there is a fear that the fluidity is insufficient and a practical product cannot be obtained. Moreover, when there are too many polypropylene resin, the thermoplastic elastomer composition obtained will become hard and there exists a tendency for an elastomer-like property to become scarce.

  Examples of the crosslinking agent of the present invention include organic peroxides, polyfunctional monomers, and resin crosslinking agents. Specific examples of the organic peroxide include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3, 5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) cyclohexane, 2, Pers such as 2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, n-butyl-4,4-bis (t-butylperoxy) valerate, etc. Oxyketals: di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropyl L) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5- Dialkyl peroxides such as bis (t-butylperoxy) hexyne-3;

Acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m- Diacyl peroxides such as trioil peroxide; t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxylaurate, t- Butyl peroxybenzoate, di-t-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxymaleic acid, t-butyl peroxyisopropyl car Peroxy esters such as sulphonate, and cumylperoxy octate;
T-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl peroxide and the like The hydroperoxides can be mentioned.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2, 5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.
The added amount of the organic peroxide is 0.1 to 5 parts by weight, preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the rubber and the resin.

As the functional group of the polyfunctional monomer, a radical polymerizable functional group is preferable, and a vinyl group is particularly preferable. The number of functional groups is 2 or more, but it can also be used in combination with a monofunctional monomer, and is particularly effective when it has 3 or more functional groups. Specific examples of the polyfunctional monomer include divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate. , Ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinonedioxime, P, P′-dibenzoylquinonedioxime, phenylmaleimide, allyl methacrylate, N, N′-m -Phenylene bismaleimide, diallyl phthalate, tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. Triaryl isocyanurate is particularly preferable. These polyfunctional monomers may be used in combination.
The addition amount of the polyfunctional monomer is 0.1 to 5 parts by weight, preferably 0.2 to 2 parts by weight with respect to 100 parts by weight of the total of the rubber and the resin. The polyfunctional monomer is preferably used in combination with an organic peroxide.

  The resin cross-linking agent is a phenol-based resin cross-linking agent, and halogenated ones such as tin chloride or chlorinated polyethylene are used in combination with halogenated or non-halogenated ones. Generally, a crosslinking aid such as zinc oxide or zinc carbonate is used in combination.

  The crosslinking agent of the present invention is preferably an organic peroxide or a phenolic resin crosslinking agent. The addition amount of the resin cross-linking agent is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the total of rubber and resin. When there are too few crosslinking agents, there exists a possibility that crosslinking may be insufficient, compression set may become large, and heat resistance may be inferior. When there are too many crosslinking agents, there exists a possibility that crosslinking may progress too much and fluidity | liquidity may be lost.

The one-minute half-life temperature (t2) or reaction initiation temperature (t3) of the present invention refers to the one-minute half-life temperature of the organic peroxide used when the organic peroxide is used as a crosslinking agent. When an organic peroxide is not used as the agent, it indicates the reaction start temperature of the crosslinking agent to be used. In addition, when there are a plurality of cross-linking agents for determining the half-life temperature or reaction start temperature for 1 minute, the lowest temperature for the half-life temperature (t2) or reaction start temperature (t3) is adopted.
The reaction start temperature of the present invention is a temperature at which crosslinking of a mixture containing a resin crosslinking agent starts, and is a temperature at which the Mooney viscosity increases by 5 points from the minimum value in 10 minutes, measured according to the Mooney scorch test of JISK6300. It is.

  A closed kneader in which the can temperature is set to a temperature equal to or lower than the minimum temperature of the melting temperature (t1) of the powdered polypropylene resin and the one-minute half-life temperature (t2) or the reaction start temperature (t3) of the crosslinking agent. Then, after the bulk ethylene / α-olefin / non-conjugated polyene copolymer rubber is charged and the rubber is crushed, a powdery polypropylene resin and a crosslinking agent are charged. Thereafter, the content is maintained at a temperature equal to or lower than the minimum temperature of the melting temperature (t1) of the polypropylene resin and the one-minute half-life temperature (t2) or the reaction initiation temperature (t3) of the cross-linking agent. A resin and a crosslinking agent are mixed with rubber to obtain a rubber mixture in which the powdery resin and the crosslinking agent are mixed. The rubber mixture in which the obtained powdery resin and the crosslinking agent are mixed is supplied to an extruder.

  When the rubber mixture is supplied to the extruder, it can be continuously supplied to the target extruder using a biaxial taper extruder (for example, manufactured by Moriyama Co., Ltd.), and the resulting rubber mixture is made into pellets. The obtained rubber mixture can be transferred from a closed kneader to a two-roll roll, cut into a strip shape, and supplied to the extruder.

  There is no restriction | limiting in particular as an extruder, It can extrude on normal conditions using the extruder normally used. As the extruder, a twin screw extruder is particularly preferable.

 The closed kneader of the present invention refers to a kneader of a type that can seal a kneading system, and is a kneader that can be continuously turned back by a rotor blade or the like. Specific examples include a Banbury mixer and a pressure kneader.

In the method of the present invention, a lump of rubber can be used, and the rubber, resin, and crosslinking agent are uniformly mixed. Therefore, the rubber, resin, and crosslinking agent can be accurately and uniformly supplied to the extruder. In addition, since it is a low-temperature treatment that does not involve melt-kneading or cross-linking of rubber and resin, it can be continuously produced in a short time and is excellent in economic efficiency. Furthermore, since the treatment is performed at a melting temperature of the polypropylene-based resin and a 1 minute half-life temperature or a reaction start temperature of the crosslinking agent, crosslinking or rubber or resin deterioration does not occur.
Even when a large amount of inorganic filler or mineral oil softener is added, it can be easily mixed.

  In the production of an olefinic thermoplastic elastomer composition by dynamic heat treatment in an extruder, a blocky kneading of a block of ethylene / α-olefin / non-conjugated polyene copolymer rubber, a powdered polypropylene resin and a crosslinking agent in advance The mixture is mixed at the melting temperature (t1) of the resin and the one-minute half-life temperature (t2) of the crosslinking agent or the temperature at the lowest temperature of the reaction start temperature (t3), and the resulting powdery unmelted A rubber compound containing a mixture of resin and unreacted crosslinking agent is supplied to the extruder.

  In the rubber mixture of the present invention, an inorganic filler, various stabilizers, an anti-aging agent, a lubricant, a plasticizer, a processing aid, an antifoaming agent, an anti-scorch agent, a foaming agent, a flame retardant, and a tackifier are optionally added. Further, a required amount of a lubricant, a pigment and the like can be blended. Further, non-crosslinking rubber may be added to organic peroxides such as polyisobutylene, butyl rubber, propylene / ethylene copolymer, propylene / butene copolymer.

The present invention will be described more specifically with reference to examples and comparative examples below, but the present invention is not limited to these examples.
The raw materials and measurement methods used in the present invention are as follows.

I. Raw materials Ethylene / propylene / non-conjugated diene polymer rubber (EPDM)
(1) EPDM-1: Mooney viscosity (ML1 + 4, 125 ° C.); 51, ethylene content; 67% by weight, 40 parts by weight oil exhibition (2) EPDM-2: Mooney viscosity (ML1 + 4, 125 ° C.); 52, ethylene content 63% by weight, 100 parts by weight oil-extended (3) EPDM-3: Mooney viscosity (ML1 + 4, 125 ° C.); 47, ethylene content; 58% by weight, non-oil-extended

2. Polypropylene (1) PP-1: propylene homopolymer, melt flow rate (MFR) (measured at 230 ° C.): 9 g / 10 minutes, powdery form (20 mesh wire mesh 100% passage), melting temperature: 164 ° C.
(2) PP-2: Propylene / ethylene block copolymer, MFR (measured at 230 ° C.): 8 g / 10 minutes, powder (20 mesh wire mesh 100% passing), melting temperature: 160 ° C.
(3) PP-3: propylene / ethylene block copolymer, MFR (measured at 230 ° C.): 30 g / 10 minutes, pellet form, melting temperature: 162 ° C.
The melting temperature was in accordance with JISK7121.

3. Organic peroxide (1) Organic peroxide-1: 40% product of di (t-butylperoxy) diisopropylbenzene (Perbutyl P-40, manufactured by NOF Corporation), 1 minute half-life temperature: 175 ° C .
(2) Organic peroxide-2: 2,5-dimethyl-2,5-di (t-butyl peroxy) hexane 40% product (Perhexi 25B-40, manufactured by NOF Corporation), halved for 1 minute Phase temperature: 180 ° C.

4). Resin cross-linking agent: Tactrol 250-1 (brominated alkylphenol / formaldehyde resin, manufactured by Taoka Chemical Co., Ltd.), reaction start temperature: 120 ° C. or higher.
In Table 4, the mixture mixed with the 10 L pressure type kneader of Example 11 did not increase Mooney viscosity at 120 ° C. for 10 minutes.
5. Zinc flower: No. 1 zinc flower (manufactured by Sakai Chemical Industry Co., Ltd.)
6). Process oil: Diana process oil PW-90 (paraffinic oil, manufactured by Idemitsu Kosan Co., Ltd.)
7). Calcium carbonate: Whiteon SB (manufactured by Shiraishi Calcium Co., Ltd.)
8). Carbon black masterbatch (MB): LDPE / HAF carbon black = 60/40
9. Phenol stabilizer: Irganox 1010 (Ciba Geigy)
10. Calcium stearate: (manufactured by Sakai Chemical Industry Co., Ltd.)

II. Measuring method 1. Specific gravity Measured by an underwater substitution method of JIS K7112 A method.
2. Hardness Measured according to JIS K6253. It was expressed as JIS-A hardness.
3. Melt flow rate (MFR)
In accordance with JIS K7210, measurement was performed under the conditions of a temperature of 230 ° C. and a load of 10 kg, and displayed in units of g / 10 minutes.
4. 100% tensile stress, tensile strength and elongation Measured according to JIS K6251 (No. 3 dumbbell, 200 mm / min).
The test sheet was melted by a preheating press at 200 ° C. and cooled by a water-cooling press to prepare a sheet having a thickness of 2 mm.
5. Compression set According to JIS K6262, 25% compression was performed, and the residual strain after 22 hours was measured under the condition of 70 ° C. atmosphere.

(Production Example 1)
(Production example of the olefinic thermoplastic elastomer composition of the present invention)
Maintain the body temperature of the pressure kneader below the melting temperature of polypropylene and the reaction start temperature of the cross-linking agent, add bale-shaped EPDM and masticate for 1 minute, then polypropylene, cross-linking agent, zinc white, phenol stabilizer, steer Formulation materials selected from calcium phosphate, calcium carbonate, carbon masterbatch and process oil were added in this order and mixed for 5 minutes to discharge the mixture. The compounding materials to be used and the compounding amounts thereof are described for each example and comparative example.
The kneaders used and their operating conditions were as follows.
・ Kneader model: 10L pressurization type kneader (manufactured by Moriyama Co., Ltd.)
・ Can body temperature: 100 ° C
・ Rotor speed: 40rpm
The discharged mixture is supplied to a feeder ruder (manufactured by Moriyama Co., Ltd.) set at 100 ° C., pellets having a diameter of about 2.5 mm × a length of about 2.5 mm are supplied to a twin screw extruder, An olefinic thermoplastic elastomer composition was produced by a screw extruder. The twin screw extruder used and its operating conditions were as follows.
-Twin screw extruder: D; 50, L / D; 44, TEM50 manufactured by Toshiba Machine Co., Ltd.
・ Set temperature (℃): 150 (H), 150, 150, 160, 170, 180, 200, 210, 220, 230, 230, 230
200 (D)
・ Screw rotation speed: 250rpm
・ Screen: 40/80 mesh

(Production Example 2)
(Production example of comparative olefinic thermoplastic elastomer composition)
The pressure type kneader used in Production Example 1 was used, the can body temperature was set to 120 ° C., bale-shaped EPDM-1 was introduced at a rotor rotation speed of 50 rpm and masticated for 1 minute, and then the crosslinking described in Production Example 1 The compounding material selected from the compounding materials excluding the agent is blended in the order of polypropylene, phenol stabilizer and calcium stearate in this order, followed by the method of adding the carbon masterbatch, and after the power value of the kneader increases, it begins to descend for 30 seconds. Later, the melt-kneaded product was discharged. The compounding material to be used and its compounding amount were described for each comparative example.
The discharged melt-kneaded product was supplied to a feeder ruder (manufactured by Moriyama Co., Ltd.) set at 160 ° C. to obtain pellets.
The obtained pellets and a crosslinking agent were mixed with a Henschel mixer and supplied to a twin screw extruder, and an olefinic thermoplastic elastomer composition was produced by the twin screw extruder. The twin screw extruder was the same as that used in Production Example 1, but the operating conditions were as follows.
・ Set temperature (℃): 150 (H), 150, 150, 160, 170, 180, 200, 210, 220, 230, 230, 230
200 (D)
・ Screw rotation speed: 250rpm
・ Screen: 40/80 mesh

(Production Example 3)
(Production example of melt-crosslinked pellets)
Veiled EPDM was added to the kneader used in Production Example 1 and masticated for 30 seconds. Thereafter, polypropylene is added and kneaded. When the temperature of the contents reaches 120 ° C., a crosslinking agent is added. After the contents reach 180 ° C., the kneading is continued for 7 minutes. After the compounding material compounding material selected from the compounding materials described was added and the content indicated temperature reached 190 ° C., the molten cross-linked product was discharged. The compounding material to be used and its compounding amount were described for each comparative example.
The discharged molten crosslinked product was supplied to a feeder ruder (manufactured by Moriyama Co., Ltd.) set at 160 ° C. to obtain pellets.

(Examples 1 to 3, Comparative Examples 1 and 2)
Using the compounding materials described in Table 1 at the compounding ratios described in Table 1, mixing with the 10 L pressure type kneader described in Production Example 1 was performed. The appearance of the discharged mixture was visually observed. The observation results are shown in Table 1.

上記実施例及び比較例の結果からわかるように、粉状ＰＰは均一に混合するが、ペレット状ＰＰは均一に分散しないばかりか、添加量が多くなると混入が難しくなる。

As can be seen from the results of the above Examples and Comparative Examples, the powdery PP is mixed uniformly, but the pellet PP is not uniformly dispersed, and it becomes difficult to mix as the addition amount increases.

Example 4
Using the compounding materials described in Table 2 at the compounding ratios described in Table 2, an olefin-based thermoplastic elastomer composition was produced according to the method described in Production Example 1. The olefinic thermoplastic elastomer composition produced 15 kg, and the MFRs of about 1, 4, 7, 10, 13 and 15 kg were measured. The measurement results are shown in Table 2.

(Comparative Example 3)
Using the compounding materials described in Table 2 at the compounding ratios described in Table 2, an olefin-based thermoplastic elastomer composition was manufactured according to the method described in Production Example 2. The produced olefinic thermoplastic elastomer composition was 15 kg, and MFR was measured in the same manner as in Example 4. The measurement results are shown in Table 2.

実施例４と比較例３を対比すれば、本発明によって、得られるオレフィン系熱可塑性エラストマー組成物の溶融流動性が均一であって、バラツキが少ないことがわかる。

Comparing Example 4 and Comparative Example 3, it can be seen that the melt fluidity of the resulting olefinic thermoplastic elastomer composition is uniform and has little variation according to the present invention.

(Example 5)
Using the compounding materials described in Table 3 at the compounding ratios described in Table 3, an olefin-based thermoplastic elastomer composition was produced according to the method described in Production Example 1. The measurement results of the physical properties of the olefinic thermoplastic elastomer composition are shown in Table 3.

(Comparative Example 4)
Using the compounding materials described in Table 3 at the compounding ratios described in Table 3, a melt-crosslinked product was obtained according to the method described in Production Example 3. The physical properties of the obtained melt-crosslinked product were measured. The measurement results are shown in Table 3.

実施例５と比較例４を対比すれば、本発明が、生産性、流動性及び強度においてすぐれたオレフィン系熱可塑性エラストマー組成物の製造方法であることがわかる。

Comparing Example 5 and Comparative Example 4, it can be seen that the present invention is a method for producing an olefinic thermoplastic elastomer composition having excellent productivity, fluidity and strength.

(Examples 6 to 11)
Using the compounding materials described in Table 4 at the compounding ratios described in Table 4, an olefin-based thermoplastic elastomer composition was produced according to the method described in Production Example 1. The measurement results of the physical properties of the olefinic thermoplastic elastomer composition are shown in Table 4.

(Comparative Examples 5-6)
In Examples 6, 7 and 11, an olefin-based thermoplastic elastomer composition was produced in the same manner except that the use of the organic oxide-1 and the resin crosslinking agent and zinc white was omitted. The measurement results of the physical properties of the olefinic thermoplastic elastomer composition are shown in Table 5.

Compared to Comparative Examples 5 and 6 in which the use of a crosslinking agent and a crosslinking aid was omitted, in Examples 6, 7 and 11, the strength and compression set were improved.
Moreover, in Examples 6 and 7 using an organic peroxide, the fluidity is improved as compared with Comparative Examples 5 and 6 in which this is not used.

According to the method of the present invention, a lump of rubber can be used, and the rubber, the resin, and the crosslinking agent are mixed in a uniform composition prior to the dynamic heat treatment in the extruder. Is provided with an accurate and uniform composition to an extruder, and a method for producing a thermoplastic elastomer composition is provided.
Since the method for producing the thermoplastic elastomer composition provided by the present invention is a method of performing dynamic heat treatment after mixing the rubber and the resin at a low temperature without performing melt kneading and crosslinking of the rubber and the resin, the thermoplastic elastomer Since the composition can be produced continuously in a short time, it is an economical method.
Furthermore, the method for producing the thermoplastic elastomer composition of the present invention includes a melting temperature of the ethylene / α-olefin / nonconjugated polyene copolymer rubber and the polypropylene resin and a 1 minute half-life temperature or a reaction initiation temperature of the crosslinking agent in advance. Since it mixes and it supplies to an extruder, it is a manufacturing method of the thermoplastic elastomer composition which does not produce deterioration of rubber | gum and resin.

Claims (9)

  In a method for producing a thermoplastic elastomer composition by melting and kneading an ethylene / α-olefin / non-conjugated polyene copolymer rubber and a polypropylene resin with an extruder and crosslinking with a crosslinking agent, The polypropylene-based resin and the cross-linking agent in a closed-type kneading machine are below the melting temperature (t1) of the resin and the one-minute half-life temperature (t2) of the cross-linking agent or the reaction initiation temperature (t3). A method for producing a thermoplastic elastomer composition, comprising mixing at a temperature and feeding the resulting mixture to an extruder.   The total of the ethylene / α-olefin / non-conjugated polyene copolymer rubber and the polypropylene resin is 100% by weight, and the powdered polypropylene resin is 10 to 40% by weight, and the ethylene / α-olefin / non-conjugated polyene The method for producing a thermoplastic elastomer composition according to claim 1, wherein the copolymer rubber is 60 to 90% by weight.   The method for producing a thermoplastic elastomer composition according to claim 1 or 2, wherein the crosslinking agent is an organic peroxide.   The method for producing a thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the powdery polypropylene resin is a powdery material that passes 90% or more of a 10-mesh wire mesh.   The method for producing a thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the ethylene / α-olefin / non-conjugated polyene copolymer rubber is obtained by adding mineral oil.   The method for producing a thermoplastic elastomer composition according to claim 5, wherein the Mooney viscosity (ML1 + 4, 125 ° C) of the ethylene / α-olefin / nonconjugated polyene copolymer rubber to which mineral oil is added is 20 to 100.   The method for producing a thermoplastic elastomer composition according to any one of claims 1 to 6, wherein mineral oil is added to the closed kneader before or during the mixing.   The said mixture is continuously supplied to an extruder using a biaxial taper extrusion apparatus, The manufacturing method of the thermoplastic-elastomer composition of any one of Claims 1-7 characterized by the above-mentioned.   The method for producing a thermoplastic elastomer composition according to any one of claims 1 to 7, wherein the mixture is formed into a pellet before being supplied to an extruder.