JP5114940B2 - Process for producing olefinic thermoplastic elastomer - Google Patents

Description

  The present invention relates to a method for producing an olefinic thermoplastic elastomer.

  Thermoplastic elastomers do not require a vulcanization process and can be processed with a molding machine for processing ordinary thermoplastic resins. Used in Among thermoplastic elastomers, olefinic thermoplastic elastomer obtained by kneading olefinic copolymer rubber obtained by polymerizing ethylene, α-olefin having 3 to 20 carbon atoms and non-conjugated polyene and olefinic resin Is widely used as an environmentally friendly material that is lightweight and recyclable and does not contain chlorine.

  As a method for producing an olefinic thermoplastic elastomer, a method is known in which an olefinic copolymer rubber and an olefinic resin are kneaded by a closed kneader exemplified by a Banbury mixer. However, since this method uses a batch kneader such as a Banbury mixer, there is a problem in that productivity is poor and the method is not efficient.

  As a method for solving such a problem, a method of kneading an olefin copolymer rubber and an olefin resin with a twin screw extruder is known. For example, in Patent Document 1, a rubber mixture composed of 100 parts by weight of an olefin copolymer rubber and 3 to 10 parts by weight of a volatile organic solvent is introduced into an extruder from a supply part of a multistage vent type extruder and is inert. A method for producing a rubber composition is described in which a polyolefin resin is introduced into the extruder from another supply section in a gas atmosphere, and the rubber mixture and the polyolefin resin are kneaded and desolvated.

JP 2006-37115 A

  However, when the olefin copolymer rubber, the volatile organic solvent and the olefin resin are kneaded in an extruder at the above ratio, heat is remarkably generated in the extruder, and the olefin copolymer rubber deteriorates. There was a problem of doing.

  An object of this invention is to provide the method of manufacturing an olefin type thermoplastic elastomer efficiently, suppressing the heat_generation | fever in a manufacturing process and suppressing deterioration of an olefin type copolymer rubber.

  That is, the present invention relates to 100 parts by weight of an olefin copolymer rubber (A) obtained by polymerizing ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene, and the olefin copolymer rubber (A). A mixture obtained by mixing 11 to 50 parts by weight of the volatile organic solvent (B), 5 to 150 parts by weight of the olefin resin (C), and 1 to 300 parts by weight of the mineral oil softener (D) with respect to 100 parts by weight, This is a method for producing an olefinic thermoplastic elastomer by removing the volatile organic solvent (B) while kneading in an extruder.

  According to the method for producing an olefinic thermoplastic elastomer of the present invention, an olefinic thermoplastic elastomer can be produced efficiently while suppressing heat generation in the production process and suppressing deterioration of the olefinic copolymer rubber.

  In the present invention, an olefin copolymer rubber (A) obtained by polymerizing ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene is used. The olefin copolymer rubber (A) in the present invention is an ethylene / α-olefin / non-conjugated polyene copolymer rubber having an A hardness of JIS K-6253 of 98 or less. Hereinafter, the term “ethylene unit” in the present invention means a structural unit derived from a monomer present in a rubber or resin obtained by polymerization.

  Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene and the like; and combinations of two or more thereof can be exemplified. Among these, from the viewpoint of availability, propylene or 1-butene is preferable, and propylene is more preferable.

  Examples of the non-conjugated polyene include 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene. Chain non-conjugated dienes such as: cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2- Cyclic non-conjugated dienes such as norbornene and 6-chloromethyl-5-isopropenyl-2-norbornene; 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2 -Propenyl-2,2-norbornadiene, 4-ethylidene-8-me It can be exemplified triene such as Le 1,7 Nanojien. Of these, 5-ethylidene-2-norbornene or dicyclopentadiene is preferable.

  When the total of ethylene units, α-olefin units having 3 to 20 carbon atoms, and non-conjugated polyene units contained in the olefin copolymer rubber (A) is 100% by weight, the olefin copolymer rubber ( The amount of ethylene units contained in A) is usually 30 to 90% by weight, preferably 40 to 80% by weight, and the amount of α-olefin units having 3 to 20 carbon atoms is usually 5 to 70% by weight, Preferably it is 15 to 60% by weight. The amount of the non-conjugated polyene unit contained in the olefin copolymer rubber (A) is usually 0.1 to 30% by weight, preferably 0.1 to 20% by weight (the total of these three types of monomer units is 100% by weight). Specific examples of the olefin copolymer rubber (A) include ethylene / propylene / 5-ethylidene-2-norbornene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 1,4- Examples include hexadiene copolymer, and ethylene / propylene / 5-vinyl-2-norbornene copolymer; and combinations of two or more thereof. Among them, ethylene / propylene / 5-ethylene content of 40 to 80% by weight, propylene unit content of 15 to 55% by weight, and 5-ethylidene-2-norbornene unit content of 2 to 10% by weight Ethylidene-2-norbornene copolymer is preferred.

  The olefin copolymer rubber (A) can be obtained by polymerization by a known method. Examples of the polymerization method include a polymerization method in an inert solvent such as hexane, heptane, toluene, and xylene using a polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst.

The Mooney viscosity (ML _{1 + 4} 100 ° C.) of the olefin copolymer rubber (A) is preferably 10 to 350, more preferably 30 to 300. The olefinic thermoplastic elastomer obtained using the olefinic copolymer rubber (A) having a Mooney viscosity in the above range gives a molded product having excellent mechanical strength and a very good appearance when molded. be able to.

  The volatile organic solvent (B) in the present invention specifically includes aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, kerosene and their halogen derivatives, cyclohexane, methylcyclopentane, methylcyclohexane. And alicyclic hydrocarbons and their halogen derivatives, aromatic hydrocarbons such as benzene, toluene and xylene, and halogen derivatives such as chlorobenzene and the like. These solvents may be used alone or in combination. The volatile organic solvent (B) may be a solvent used when the olefin copolymer rubber (A) is polymerized in the solution polymerization method. The volatile organic solvent (B) may contain a monomer used when the olefin copolymer rubber (A) is polymerized.

  The olefin-based resin (C) in the present invention is a resin obtained by polymerizing ethylene and / or α-olefin, for example, an ethylene-based resin containing 70% by weight or more of an ethylene unit or a propylene unit of 50% by weight. The propylene-type resin containing the above is mentioned.

  The propylene resin used as the olefin resin (C) in the present invention is a propylene homopolymer containing 50 to 100% by weight, preferably 80 to 100% by weight of propylene units, or propylene and ethylene and / or Or a random copolymer or a block copolymer with an α-olefin having 4 to 10 carbon atoms (for example, 1-butene, 1-hexene, 1-pentene, 1-octene and 4-methyl-1-pentene). Can be mentioned. Examples of the copolymer include an ethylene / propylene copolymer, a propylene / 1-butene copolymer, a propylene / 1-hexene copolymer, a propylene / 1-octene copolymer, and a propylene / ethylene / 1-butene copolymer. An ethylene / propylene / 1-hexene copolymer can be exemplified. As the olefin resin (C), it is preferable to use a propylene homopolymer, an ethylene / propylene copolymer or a propylene / 1-butene copolymer.

The case where the block copolymer is used in the case of using propylene and ethylene means a polymer produced by a production method comprising the following steps.
(1) A step of homopolymerizing propylene to produce polypropylene;
(2) A step of copolymerizing propylene and ethylene in the presence of the polypropylene.
Or (1) a step of homopolymerizing propylene to produce polypropylene;
(2) A step of removing unreacted propylene monomer and polymerizing by adding ethylene in the presence of the polypropylene.
In the former case, the resulting polymer is substantially a mixture of the polypropylene produced in step (1) and the propylene-ethylene copolymer produced in step (2).

  When the olefin resin (C) used in the present invention is a propylene resin, the propylene resin has a melt flow rate measured at a temperature of 230 ° C. under a load of 21.18 N according to JIS K6758 of 0.1 to 0.1. It is preferably 300 g / 10 minutes, and more preferably 0.5 to 200 g / 10 minutes.

  The ethylene resin used as the olefin resin (C) in the present invention includes (1) a homopolymer of ethylene or (2) ethylene and 3 to 3 carbon atoms, containing 70 to 100% by weight of ethylene units. 10 α-olefins (eg propylene, 1-butene, 1-pentene, 4-methyl-1-pentene and 1-hexene) and / or monomers having polar groups and carbon-carbon double bonds (eg , Vinyl acetate, acrylic acid ester and methacrylic acid ester). Preferred ethylene resins include high density polyethylene, low density polyethylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-pentene copolymer, ethylene / 4-methyl-1-pentene copolymer. Examples thereof include a polymer and an ethylene / 1-hexene copolymer.

  When the olefin-based resin (C) used in the present invention is an ethylene-based resin, the ethylene-based resin has a melt flow rate measured at a temperature of 190 ° C. under a load of 21.18 N according to JIS K6760. 300 g / 10 min is preferable, and 0.1 to 200 g / 10 min is more preferable.

  The olefin resin (C) used in the present invention can be obtained by polymerization by a known method. As the polymerization method, (1) polymerization in an inert solvent such as hexane, heptane, toluene, xylene using a polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst; (2) a liquid monomer (3) a method of polymerizing gaseous monomers (gas phase polymerization method); and (4) a combination thereof. The three-dimensional structure of the olefin resin (C) is not particularly limited, and examples of the three-dimensional structure include an isotactic structure, a syndiotactic structure, and a structure in which both of these structures are mixed. Among these, a propylene-based resin having an isotactic structure as a main structure is preferable.

  As the mineral oil softening agent (D) in the present invention, the high molecular weight of petroleum having an average molecular weight of 300 to 1500 and a pour point of 0 ° C. or less, such as aroma mineral oil, naphthenic mineral oil, and paraffin mineral oil. A boiling fraction can be illustrated. Among these, paraffinic mineral oil is preferable. The mineral oil softener (D) may be previously contained in the olefin copolymer rubber. In the rubber field, the olefin copolymer rubber containing a mineral oil softener is generally called an oil-extended rubber, and the mineral oil softener is called an extender oil.

  As a method for obtaining an olefin copolymer rubber containing a mineral oil softener, (1) a method of kneading them mechanically using a roll or a Banbury mixer, (2) an olefin copolymer A method of adding a mineral oil softening agent to the solution of the olefin copolymer rubber obtained in the production process of the combined rubber (A) and then removing the solvent by a method such as steam stripping can be exemplified.

  The present invention relates to 100 parts by weight of the olefin copolymer rubber (A), 11 to 50 parts by weight of volatile organic solvent (B), 100 parts by weight of the olefin copolymer rubber (A), olefin The volatile organic solvent (B) is removed while kneading a mixture obtained by mixing 5 to 150 parts by weight of the resin (C) and 1 to 300 parts by weight of the mineral oil softening agent (D) in an extruder to remove the olefin. This is a method for producing a thermoplastic elastomer. In the production process, the olefin copolymer rubber (A), the volatile organic solvent (B), the olefin resin (C) and the mineral oil softener (D) are kneaded in the above ratio in an extruder. The olefinic thermoplastic elastomer can be efficiently produced while suppressing the heat generation and suppressing the deterioration of the olefinic copolymer rubber. The ratio of the volatile organic solvent (B) to 100 parts by weight of the olefin copolymer rubber (A) is preferably 15 parts by weight or more, and more preferably 20 parts by weight or more. The ratio of the olefin resin (C) to 100 parts by weight of the olefin copolymer rubber (A) is preferably 10 to 140 parts by weight, and more preferably 15 to 120 parts by weight. The ratio of the mineral oil softener (D) to 100 parts by weight of the olefin copolymer rubber (A) is 5 to 200 parts by weight from the viewpoint of the balance between flexibility and tackiness of the resulting olefin thermoplastic elastomer. It is preferable.

  In the present invention, components other than the olefin copolymer rubber (A), the volatile organic solvent (B), the olefin resin (C) and the mineral oil softener (D), for example, inorganic materials such as talc and calcium carbonate. Fillers; additives such as flame retardants, plasticizers, antistatic agents, heat and light resistance stabilizers, anti-aging agents, and mold release agents; or pigments may be used in combination. These may be blended in olefin copolymer rubber (A) or olefin resin (C), olefin copolymer rubber (A), volatile organic solvent (B) olefin resin ( C) and the mineral oil softener (D) may be added separately when kneading in an extruder.

  One extruder may be used in the present invention, and a plurality of extruders may be connected and used. The extruder used when kneading the olefin copolymer rubber (A), the volatile organic solvent (B), the olefin resin (C) and the mineral oil softening agent (D) uses the volatile organic solvent (B). It should be a vented extruder having one or more vents for discharge, preferably two or more. The extruder used when kneading the olefin copolymer rubber (A), the volatile organic solvent (B), the olefin resin (C) and the mineral oil softener (D) is a twin screw extruder. It is preferable. Examples of the twin screw extruder include those in which the rotational directions of the two screws are the same direction, those in different directions, those in which the two screws are completely or partially engaged, and those in which they are not engaged. However, among these, those in which the screw rotation direction is the same direction and the two screws are completely or partially engaged are preferable.

  In the present invention, it is not necessary to supply the olefin copolymer rubber (A), the volatile organic solvent (B), the olefin resin (C) and the mineral oil softener (D) to the extruder at the same time. When kneading these in 100 parts by weight of the olefin copolymer rubber (A) and 100 parts by weight of the olefin copolymer rubber (A), 11 to 50 weights of the volatile organic solvent (B). Parts, olefin resin (C) 5 to 150 parts by weight, mineral oil softener (D) 1 to 300 parts by weight. While kneading the mixture at such a ratio, by removing the volatile organic solvent (B) from the vent of the extruder, the heat generation is suppressed and deterioration of the olefin copolymer rubber is suppressed efficiently. Olefin-based thermoplastic elastomers can be produced.

  As a method for producing an olefinic thermoplastic elastomer using one extruder, an olefinic copolymer rubber (A), a volatile organic solvent (B), an olefinic resin (C) and a mineral oil softener ( D) is supplied to the extruder from one supply port and kneaded while using a method for removing the volatile organic solvent (B) from the vent or a vented extruder having a plurality of supply ports. Polymer rubber (A), volatile organic solvent (B), and mineral oil softener (D) are supplied to the extruder from the upstream supply port, and olefin resin (C) is supplied from the downstream supply port. And a method of removing the volatile organic solvent (B) from the vent while kneading. The olefin resin (C) may be divided and supplied from two or more supply ports. In the latter method, as illustrated in FIG. 2, a dispersion in which the olefin copolymer rubber (A) polymerized in the polymerization tank (12) is dispersed in a polymerization solvent is used as an olefin copolymer rubber ( A) After adjusting so that it may become 11-50 weight part of polymerization solvents with respect to 100 weight part, it supplies directly to an extruder (13), and also mineral oil softener (D) and olefin resin (C) are extruder. You may supply to (13). In such a case, the polymerization solvent becomes the volatile organic solvent (B). While kneading these with an extruder (13), the volatile organic solvent (B) can be removed from the vents (16), (17) and (18) to obtain an elastomer.

  As a method for producing an olefinic thermoplastic elastomer using two extruders, the olefinic copolymer rubber (A) and the volatile organic solvent (B) are supplied to and mixed with the first extruder. , While supplying the second extruder to which the first extruder is connected, further supplying the mineral oil softener (D) and the olefin resin (C) to the second extruder and kneading, The method of removing a volatile organic solvent (B) from a vent is mentioned. The mineral oil softener (D) may be supplied to the first extruder. When two connected extruders are used, an extruder without a vent is used as the first extruder. As the second extruder, a vent type extruder having a vent on the downstream side from the supply port of the olefin resin (C) is used. Thus, also when using two extruders, the dispersion liquid in which the olefin copolymer rubber (A) polymerized in the polymerization tank is dispersed in the polymerization solvent is used as the olefin copolymer rubber (A). You may supply to a 1st extruder directly, after adjusting a ratio with a polymerization solvent so that it may become 11-50 weight part of polymerization solvents with respect to 100 weight part of olefin copolymer rubber (A).

  In the case of producing an olefinic thermoplastic elastomer using three extruders, an extruder in which the first extruder and the second extruder are respectively connected to the third extruder is used. The first extruder is supplied with an olefin copolymer rubber (A), a volatile organic solvent (B), and a mineral oil softener (D). The olefin resin (C) is supplied to the second extruder. While these are joined and kneaded in the third extruder, the volatile organic solvent (B) can be removed from the vent to obtain an olefin-based thermoplastic elastomer. In this case, an extruder without a vent is used as the first extruder, and a vented extruder is used as the third extruder. The second extruder may or may not have a vent. Thus, also when using three extruders, the dispersion liquid in which the olefin copolymer rubber (A) polymerized in the polymerization tank is dispersed in the polymerization solvent is used as the olefin copolymer rubber (A). After adjusting the ratio with the polymerization solvent to be 11 to 50 parts by weight of the polymerization solvent with respect to 100 parts by weight of the olefin copolymer rubber (A), it can be directly supplied to the first extruder.

  In the present invention, it is preferable to produce an olefinic thermoplastic elastomer using two connected extruders. The case of using two extruders will be described in detail with reference to FIG. FIG. 3 shows an apparatus in which a first extruder and a second extruder are connected. Further, the olefin copolymer rubber (A) and the volatile organic solvent (B) are directly fed from the polymerization tank (19) of the olefin copolymer rubber through a concentration adjusting step (not shown) directly to the first extruder. (20) can be supplied. In the first extruder, the olefin copolymer rubber (A) and the volatile organic solvent (B) are kneaded. Thereafter, the mixture is supplied to the second extruder (21) and further kneaded with the mineral oil softener (D) supplied from the supply pump (22) and the olefin resin (C) supplied from the supply port (23). . By removing the volatile organic solvent (B) from the vents (24), (25) and (26), an olefin-based thermoplastic elastomer can be obtained.

  The olefinic thermoplastic elastomer produced by the production method of the present invention is a bumper part, roof molding, side molding, body panel, side shield, glass run channel, instrument panel skin, door skin, ceiling skin, weatherstrip material, hose. And automotive parts such as steering wheels; electrical parts such as wire coverings, connectors, and cap plugs; footwear such as soles and sandals; such as swimming fins, underwater glasses, golf club grips, and baseball bat grips Leisure goods; used for gaskets, various gaskets and sheets for civil engineering and construction, waterproof cloth, garden hoses, belts, and industrial miscellaneous goods such as industrial packing.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to these.
(1) As the raw material olefin copolymer rubber (A), a veiled esprene 553 (manufactured by Sumitomo Chemical Co., Ltd.) crushed with a rubber crusher was used (hereinafter referred to as EPDM). The EPDM is ethylene-propylene having an ethylene unit content of 58.0% by weight, a propylene unit content of 37.5% by weight, and a 5-ethylidene-2-norbornene unit content of 4.5% by weight. -5-ethylidene-2-norbornene copolymer rubber.
As the olefin resin (C), Nobrene U501E1 (manufactured by Sumitomo Chemical Co., Ltd.) was used (hereinafter referred to as PP). The PP is a propylene homopolymer having a melt flow rate of 130 g / 10 min measured at 230 ° C., a load of 21.18 N, and a melting point of 160 ° C.
As the volatile organic solvent (B), a mixed solvent in which hexane and 5-ethylidene-2-norbornene were mixed at a weight ratio of hexane: 5-ethylidene-2-norbornene = 15: 1 (hereinafter referred to as mixed solvent and Called).
As mineral oil softener (D), PW-100 (made by Idemitsu Kosan Co., Ltd.) was used (hereinafter referred to as softener). The softener is a paraffinic mineral oil having an average molecular weight of 545 and a pour point of −12.5 ° C.
(2) Apparatus The olefin type thermoplastic elastomer was manufactured using the apparatus with which the 1st extruder and the 2nd extruder as shown in FIG. 1 were connected. The first extruder was a twin-screw extruder having a trade name of TEX65XCT manufactured by Nippon Steel, Ltd., and had a cylinder inner diameter of 69 mm and a ratio of the cylinder length to the cylinder inner diameter (L / D) of 31.5. Further, a cooling water pipe was provided inside the cylinder, and a heater for controlling the temperature was provided outside the cylinder. The second extruder was a twin screw extruder having a trade name of TEX30α manufactured by Nippon Steel Works, and had a cylinder inner diameter of 32 mm and a ratio of the cylinder length to the cylinder inner diameter (L / D) of 42. Further, a cooling water pipe was provided inside the cylinder, and a heater for controlling the temperature was provided outside the cylinder.

[Example 1]
EPDM and PP were continuously fed from the feed port (3) of the first extruder (1) using a weight type feeder at a feed rate of 20 kg / hr for EPDM and 8.6 kg / hr for PP, respectively. Further, the mixed solvent was continuously supplied from the supply pump (4) of the first extruder at a supply rate of 4 kg / hr and the softener was supplied from the supply pump (5) at a supply rate of 6.8 kg / hr. The screw speed of the first extruder (1) was set to 50 rpm, and the cylinder temperature was set to 130 ° C. In the first extruder (1), EPDM, PP, a mixed solvent, and a softening agent were continuously fed to the second extruder (2) through the feed port (10). The second extruder (2) was set to a screw rotation speed of 300 rpm and a cylinder temperature of 180 ° C. In the second extruder (2), while mixing EPDM, PP, mixed solvent and softener, the mixed solvent is removed from the vent (6), vent (7), vent (8) and vent (9). The kneaded material was cut with a pelletizer attached to the two extruder to obtain a pellet-shaped olefinic thermoplastic elastomer. Table 1 shows the temperature of the elastomer measured by a thermometer provided at the position (11) of the second extruder.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that the supply rate of the mixed solvent was changed to 2 kg / hr. The results are shown in Table 1.

実施例１と比較例１を対比すると、実施例１のほうが、第２押出機出口温度が低いことがわかる。このことから、実施例１では、オレフィン系共重合体ゴム（Ａ）の劣化が抑制されているといえる。

When Example 1 and Comparative Example 1 are compared, it can be seen that Example 1 has a lower outlet temperature of the second extruder. From this, in Example 1, it can be said that deterioration of the olefin copolymer rubber (A) is suppressed.

It is the schematic of the vent type twin-screw extruder used in the Example and comparative example of this invention. It is the schematic of the other extruder used by this invention. It is the schematic of the other extruder used by this invention.

Explanation of symbols

1: First extruder 2: Second extruder 3: Feed port 4: Feed pump 5: Feed pump 6: Vent 7: Vent 8: Vent 9: Vent 10: Feed port 11: Second extruder resin temperature measurement position 12: Olefin copolymer rubber polymerization tank 13: Extruder 14: Supply pump 15: Olefin resin (C) supply port 16: Vent 17: Vent 18: Vent 19: Olefin copolymer rubber polymerization tank 20: No. 1 extruder 21: second extruder 22: supply pump 23: olefin resin (C) supply port 24: vent 25: vent 26: vent

Claims (2)

100 parts by weight of an olefin copolymer rubber (A) obtained by polymerizing ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene, and 100 parts by weight of the olefin copolymer rubber (A) A mixture obtained by mixing 11 to 50 parts by weight of the volatile organic solvent (B), 5 to 150 parts by weight of the olefin resin (C), and 1 to 300 parts by weight of the mineral oil softening agent (D) is kneaded in an extruder. And removing the volatile organic solvent (B) while producing an olefin-based thermoplastic elastomer. The method for producing an olefinic thermoplastic elastomer according to claim 1, wherein the olefinic resin (C) is a propylene resin.

Images