JP2022063030A - Resin composition, dynamic-crosslinking resin composition, method for producing resin composition, and extrusion-molded product and method for producing the same - Google Patents

Abstract

To provide a resin composition that prevents the formation of resin scum (drool) around a die outlet during extrusion molding, a dynamic-crosslinking resin composition, a method for producing a resin composition, and an extrusion-molded product and a method for producing the same.SOLUTION: A resin composition contains an ethylene/vinyl acetate copolymer, an α olefin polymer, a fluororubber, and a crosslinker. In the resin composition, it is preferable that the content of the α olefin polymer is 15-65 pts.mass and the content of the crosslinker is 1-8 pts.mass relative to the ethylene/vinyl acetate copolymer 100 pts.mass. In the resin composition, it is preferable that the content of the fluororubber is 0.01-1 mass% relative to the total mass of the ethylene/vinyl acetate copolymer, the α olefin polymer, the fluororubber, and the crosslinker.SELECTED DRAWING: None

Description

The present invention relates to a resin composition, a dynamically crosslinked resin composition, a method for producing a resin composition, and an extruded product and a method for producing the same.

Conventionally, a resin composition containing a dynamically crosslinked thermoplastic elastomer (Thermo-plastic Vulcanizates; abbreviated as TPV) has been used as a raw material for a surface layer material of a rubber member for an automobile or a resin member. From the viewpoint of enhancing the slidability of the resin member, a silicone compound such as silicone oil may be added to the resin composition and used. For example, Patent Document 1 discloses a sliding material in which a silicone compound is added in a high content to a dynamically crosslinked olefin-based thermoplastic elastomer.

Japanese Patent No. 5167128

When the resin member was extruded using TPV of an ethylene / vinyl acetate copolymer and an α-olefin polymer, the present inventors generated resin residue (eyes) around the outlet of the die, and the resin residue was molded. I faced the problem of getting mixed in or sticking to the product.

INDUSTRIAL APPLICABILITY The present invention relates to a resin composition, a dynamically crosslinked resin composition, a method for producing a resin composition, and an extruded product and its production, which can suppress the generation of resin residue (rheum) around the die outlet during extrusion molding. Provide a method.

[1] A resin composition containing an ethylene / vinyl acetate copolymer, an α-olefin polymer, a fluororubber, and a cross-linking agent.
[2] The content of the α-olefin polymer is 15 to 65 parts by mass and the content of the cross-linking agent is 1 to 8 parts by mass with respect to 100 parts by mass of the ethylene / vinyl acetate copolymer. ,
The resin composition according to [1].
[3] The content of the fluororubber is 0.01 to 1% by mass with respect to the total mass of the ethylene / vinyl acetate copolymer, the α-olefin polymer, the fluororubber, and the cross-linking agent [1]. ] Or [2].
[4] The resin composition according to any one of [1] to [3] is formed, and at least a part of the ethylene / vinyl acetate copolymer and the α-olefin polymer is dynamically crosslinked. Dynamically crosslinked resin composition.
[5] A resin composition containing the dynamically crosslinked resin composition according to [4], the ethylene / vinyl acetate copolymer, the α-olefin polymer, and a thermoplastic elastomer other than the fluororubber. ..
[6] The resin composition according to [5], further comprising a silicone compound.
[7] An extruded product formed from the dynamically crosslinked resin composition according to [4] or the resin composition according to [5] or [6].
[8] While kneading the resin composition according to any one of [1] to [3], at least one of the ethylene / vinyl acetate copolymer and the α-olefin polymer contained in the resin composition. A dynamically crosslinked resin composition is obtained by cross-linking the portions, and heat other than the ethylene / vinyl acetate copolymer, the α-olefin polymer, and the fluororubber is added to the dynamically crosslinked resin composition. A method for producing a resin composition, which comprises kneading a plastic elastomer and a silicone compound to obtain a resin composition.
[9] A method for producing an extruded product, which comprises subjecting the resin composition obtained by the production method according to [8] to an extrusion molding machine equipped with a die to obtain an extruded product.

According to the dynamically cross-linked resin composition and the resin composition of the present invention, it is possible to suppress the occurrence of eyelids around the die outlet during extrusion molding, so that the eyelids may be mixed or adhered to the molded product. It can prevent and produce high quality extruded products.

A photograph showing how the resin composition of an example is extruded from a die of an extruder. A photograph showing how the resin composition of a comparative example is extruded from a die of an extruder.

<< Resin composition (1) >>
The first aspect of the present invention is a component (A) which is an ethylene / vinyl acetate copolymer, a component (B) which is an α-olefin polymer, a component (C) which is a fluororubber, and a component which is a cross-linking agent. (D) is a resin composition containing.

Hereinafter, the lower limit value and the upper limit value of the numerical value range indicated by "-" shall be included in the numerical value range.

<EVA; component (A)>
The content of the component (A) in the resin composition of this embodiment is, for example, 50 to 90% by mass with respect to the total mass of the component (A), the component (B), the component (C) and the component (D). Preferably, 60 to 80% by mass is more preferable, and 65 to 75% by mass is further preferable.
Within the above-mentioned suitable range, a resin composition having a low ShoreA hardness and an excellent elongation rate can be obtained.

The content ratio of the vinyl acetate unit in the component (A) can be, for example, 1 to 90% by mass, preferably 10 to 80% by mass, and 20 to 60% by mass with respect to the total mass of the component (A). More preferably, 25 to 45% by mass is further preferable.
Within the above-mentioned suitable range, a resin composition having a low ShoreA hardness and an excellent elongation rate can be obtained.

EVA, which is the component (A), may be a partially saponified partially saponified product.

The melt flow rate (MFR) of the component (A) at 190 ° C. and 2.16 kg is not particularly limited, and is, for example, preferably 1 to 60 g / 10 minutes, more preferably 1 to 40 g / 10 minutes, and 1 to 20 g. / 10 minutes is more preferred. Here, the MFR of the component (A) is a value measured according to JIS K7210.
Within the above-mentioned suitable range, a resin composition having a low ShoreA hardness and an excellent elongation rate can be obtained.
The component (A) contained in the resin composition of this embodiment may be one kind or two or more kinds.

<Α-olefin copolymer; component (B)>
The content of the component (B) in the resin composition of this embodiment is preferably, for example, 15 to 65 parts by mass, more preferably 25 to 55 parts by mass, and 35 to 45 parts by mass with respect to 100 parts by mass of the component (A). Parts by mass are more preferred.
Within the above-mentioned suitable range, a resin composition having a low ShoreA hardness and an excellent elongation rate can be obtained.

As the component (B), for example, a homopolymer of an α-olefin such as a propylene homopolymer or an ethylene homopolymer may be used, or a copolymer with a monomer other than the α-olefin may be used. Here, the other monomer is not particularly limited as long as it is other than vinyl acetate and a fluorine-containing monomer, and is, for example, (meth) acrylic acid, (meth) acrylic acid ester, vinyl alcohol, unsaturated carboxylic acid, vinyl ester. , Styrene and the like.
From the viewpoint of sufficiently suppressing the occurrence of rheumatism during extrusion molding of the resin composition according to the present invention, the component (B) is preferably an α-olefin homopolymer, more preferably a propylene homopolymer.
The component (B) contained in the resin composition of this embodiment may be one kind or two or more kinds.

<Fluororubber; component (C)>
The content of the component (C) in the resin composition of this embodiment is, for example, 0.01 to 1 mass with respect to the total mass of the component (A), the component (B), the component (C) and the component (D). % Is preferable, 0.05 to 0.5% by mass is more preferable, and 0.1 to 0.3% by mass is further preferable.
Within the above-mentioned suitable range, it is possible to sufficiently suppress the occurrence of rheumatism at the die outlet during extrusion molding.

Examples of the component (C) include vinylidene fluoride (VdF) / hexafluoropropylene (HFP) -based fluororubber, VdF / HFP / tetrafluoroethylene (TFE) -based fluororubber, TFE / propylene-based fluororubber, and TFE / propylene. / VdF-based fluororubber, ethylene / HFP-based fluororubber, ethylene / HFP / VdF-based fluororubber, ethylene / HFP / TFE-based fluororubber, VdF / TFE / perfluoroalkyl vinyl ether (PAVE) -based fluororubber, VdF / CTFE-based Fluororubber and the like can be mentioned.
Among these, from vinylidene fluoride (VdF) / hexafluoropropylene (HFP) -based fluororubber, VdF / HFP / tetrafluoroethylene (TFE) -based fluororubber, VdF / TFE / perfluoroalkyl vinyl ether (PAVE) -based fluororubber. It is preferable that the fluororubber is at least one selected from the above group.
The proportion of fluorine atoms in the fluororubber as the component (C) is preferably 60% by mass or more, more preferably 65% by mass or more, and further preferably 70% by mass or more.
A moiety that can be crosslinked by a peroxide may be introduced into the fluororubber as the component (C). Examples of such a site include an iodine atom, a bromine atom and the like.
The component (C) contained in the resin composition of this embodiment may be one kind or two or more kinds.

<Crosslinking agent; component (D)>
The content of the component (D) in the resin composition of this embodiment is preferably, for example, 1 to 8 parts by mass, more preferably 1.5 to 6 parts by mass, based on 100 parts by mass of the component (A). Up to 4 parts by mass is more preferable.
The content of the component (D) is preferably, for example, 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, and 1 to 3% by mass with respect to the total mass of the resin composition. Is more preferable.
Within the above-mentioned suitable range, the dynamic cross-linking of the component (A) and the component (B) can be sufficiently performed.

The component (D) is not particularly limited as long as it can crosslink at least a part of the component (A) and the component (B) to form a crosslinked body. Examples thereof include organic peroxides, hydrosilylation agents (and hydrosilylation catalysts), phenolic resin curing agents, sulfur, sulfur-containing compounds, organic polyvalent amines, metal oxides and the like. Above all, it is preferable to use an organic peroxide. The organic peroxide can cause radical cross-linking based on hydrogen extraction from a hydrocarbon moiety such as a methyl group or a methylene group of the component (A) and the component (B).

As the organic peroxide, peroxyketal, dialkyl peroxide, peroxyester, diacyl peroxide, peroxydicarbonate and the like are suitable.
Specifically, 1,1-di (t-hexylperoxy) cyclohexane, 1,1-di (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1-di (t-butylper). Oxy) cyclohexane, n-butyl-4,4-di (t-butylperoxy) valerate, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di (2) -T-Butylperoxyisopropyl) benzene, t-butylcumyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) ) Hexane-3,2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-hexylperoxybenzoate, t-butylperoxy-3-methylbenzoate, diisopropylperoxydicarbonate, di ( Examples thereof include 4-t-butylcyclohexyl) peroxydicarbonate and 1,6-bis (t-butylperoxycarbonyloxy) hexane.
The component (D) contained in the resin composition of this embodiment may be one kind or two or more kinds.

≪Dynamic crosslink type resin composition≫
The second aspect of the present invention is formed by the resin composition of the first aspect, and at least a part of the ethylene / vinyl acetate copolymer which is the component (A) and the α-olefin polymer which is the component (B). Is a dynamically crosslinked resin composition.
In the dynamically crosslinked rubber composition of this embodiment, the components (A) may be crosslinked with each other, the components (B) may be crosslinked with each other, and the component (A) and the component (B) may be crosslinked. It may be cross-linked.

The detailed structures of the dynamically crosslinked component (A) and the component (B) have not been elucidated, but it is presumed to have a structure similar to that of a generally known dynamically crosslinked elastomer. That is, it is presumed that either one of the component (A) and the component (B) forms a domain, the remaining one forms a matrix, and the domain is dispersed in the matrix.
The distribution of the fluororubber component (C) contained in the dynamically crosslinked resin composition has not been clarified, but the component (C) is a rubber in the process of being discharged from the die during extrusion molding of the rubber composition described later. It is conceivable that the uneven distribution on the surface of the composition reduces the friction between the die outlet and the rubber composition and suppresses the occurrence of rheumatism. In order for this mechanism to work, the component (C) is freely distributed in the matrix in a state where it can be unevenly distributed on the surface of the dynamically cross-linked resin composition and the resin composition, rather than being fixed to the domain by dynamic cross-linking. It is considered more convenient to be dispersed.

[Dynamic cross-linking method]
As a method for obtaining the dynamically crosslinked resin composition of the present embodiment by dynamically cross-linking the resin composition of the first aspect, the component (A), the component (B), the component (C) and the component (D) are used. Is not particularly limited as long as it is a method in which at least a part of the component (A) and the component (B) can be crosslinked while kneading them with the raw material, and a known dynamic cross-linking method for producing a TPV is adopted. can do. For example, the raw material can be kneaded with a twin-screw extruder and heated as necessary to be dynamically crosslinked. The dynamically crosslinked composition formed by dynamic crosslinking can be obtained, for example, in the form of pellets.

The degree of dynamic cross-linking can be controlled by the blending amount of the cross-linking agent in the raw material. When the blending amount of the cross-linking agent is within the above-mentioned preferable range, a part of the component (A) and the component (B) forms a cross-linked body, the rest constitutes a matrix, and the domain composed of the cross-linked body is the matrix. A dynamically crosslinked composition dispersed therein can be easily obtained.

The degree of dynamic cross-linking in the dynamically cross-linked resin composition of this embodiment can be evaluated by measuring the residual ratio of the composition by hot xylene reflux. The residual ratio mainly reflects the content of the crosslinked body and the degree of crosslinking in the dynamically crosslinked resin composition. That is, the larger the residual ratio, the higher the crosslinked body content and the higher the degree of crosslinking.
The residual ratio is preferably 10 to 90% by mass with respect to the total mass of the dynamically crosslinked resin composition. Within this range, a dynamically crosslinked rubber composition having more durability can be obtained.

[Measurement method of residual ratio by reflux of hot xylene]
Approximately 3 g of a sample of the dynamically crosslinked resin composition is weighed to obtain the correct weight (W1). The sample is placed in a cylindrical filter paper, set in a Soxhlet extractor, and reflux-extracted with xylene for 6 hours. After extraction, the filter paper containing the sample is taken out and placed on a hot plate at 120 ° C. for 5 hours to sufficiently evaporate xylene, allow to cool, and then measure the exact weight (W2) of the sample. The heating time for evaporation is appropriately adjusted so that a time is secured so that xylene evaporates and the sample weight is sufficiently stabilized. For example, when the heating time is 5 hours, the rate of change of "residual ratio% due to thermal xylene reflux" between 5 hours heating and 5 hours (10 hours in total) is + 5% to -8%. If it is in the range of, it is judged that the heating time of 5 hours is appropriate. When the rate of change is large, the heating time is extended so that the rate of change is in the range of + 5% to -8% as compared with the first heating for 5 hours. Assuming that the weight of an inorganic component such as a filler insoluble in hot xylene is W3, the "residue ratio due to reflux of hot xylene" is calculated as 100 × (W2-W3) / W1.

<< Resin composition (2) >>
A third aspect of the present invention is the dynamically crosslinked resin composition of the second aspect, and a component (E) which is a thermoplastic elastomer other than the component (A), the component (B) and the component (C). And, a resin composition comprising.

<Thermoplastic elastomer; component (E)>
When the resin composition of this embodiment contains the component (E), the characteristics of the entire resin composition can be widely adjusted.
The type of the component (E) contained in the resin composition of this embodiment may be one type or two or more types.

The content of the component (E) in the resin composition of this embodiment can be, for example, 5 to 95% by mass with respect to the total mass of the dynamically crosslinked resin composition and the component (E), and is 20 to 20 to 90% by mass is preferable, 40 to 85% by mass is more preferable, and 60 to 80% by mass is further preferable.
Within the above range, the effect of suppressing the rheumatism of the dynamically crosslinked resin composition can be sufficiently obtained while utilizing the rubber (elasticity) characteristics of the component (E).

As the component (E), the ShoreA hardness defined by JIS K 6253 is preferably 20 to 90, more preferably 25 to 70, and even more preferably 30 to 50.
When the ShoreA hardness is in the above range, durability and elasticity as a surface layer material of a rubber member for an automobile or a resin member can be easily obtained.

Specific components (E) include, for example, an olefin polymer obtained by polymerizing a conjugated diene, a hydrogenated product in which a part of the unsaturated bond of the conjugated diene polymer or the copolymer of the conjugated diene remains, and α-olefin. Examples thereof include a conjugated diene copolymer, an α-olefin and a non-conjugated diene copolymer, and a dicyclopentadiene-based polymer.

Specific examples of the component (E) include ethylene / propylene / diene rubber (EPDM), ethylene / propylene rubber (EPM), butadiene rubber (BR), styrene / butadiene rubber (SBR), and styrene / butadiene / styrene rubber (SBS). , Isoprene rubber (IR), natural rubber, styrene / isoprene rubber (SIR), styrene / isoprene block copolymer (SIS), acrylonitrile-butadiene rubber (NBR), butyl rubber (isobutylene / isoprene rubber) (IIR), 1, Examples thereof include 2-polybutadiene and hydrogenated products thereof.
Further, as the hydrogenated rubber component, for example, styrene / butadiene / butylene / styrene copolymer (SBBS), styrene / ethylene / butylene / styrene block copolymer (SEBS), hydrogenated styrene / butadiene rubber (HSBR). ), Styrene / ethylene / propylene / styrene block copolymer (SEPS), styrene / (ethylene / ethylene / propylene) / styrene block copolymer (SEEPS), styrene / ethylene / butylene / ethylene block copolymer (SEBC) , Styrene crystals, (ethylene, butylene), ethylene crystal copolymers (CEBC), and the like.

Of the above, elastomers having α-olefins such as EPDM and EPM as a monomer unit are preferable.

<Silicone compound; component (F)>
It is preferable that the resin composition of this embodiment contains a component (F) which is a silicone compound. The component (F) is a compound other than the components (A) to (E).
The component (F) contained in the resin composition of this embodiment may be one kind or two or more kinds.

As described above, it is presumed that the dynamically crosslinked resin composition of the second aspect contained in the resin composition of this aspect has a structure in which domains are dispersed in the matrix. It is considered that a minute gap is created between the matrix and the domain due to the difference in physical characteristics between the two. The component (F) enters this gap, and the component (F) is dispersed in the matrix together with the domain, and the bleed-out of the component (F) is suppressed.

The content of the component (F) in the resin composition of this embodiment is preferably 1 to 20 parts by mass, preferably 2 to 15 parts by mass, with the total of the components (A) to (E) being 100 parts by mass. It is preferable, and 3 to 10 parts by mass is more preferable.
Within the above-mentioned suitable range, the slidability of the resin composition of this embodiment becomes good.

Examples of the component (F) include silicone oil, silicone gum (rubber), and a silicone-based copolymer.
As silicone oil or silicone gum (rubber), dimethyl silicone, diphenyl silicone, methyl phenyl silicone, and those silicones having a vinyl group of 5 mol% or less, hydrogen polysiloxane, alkyl modification, higher fatty acid ester modification, fluorine modification, Examples thereof include modified silicone oils such as polyether modification, amino modification, alcohol modification, epoxy modification and carboxy modification. Among them, chain dimethylpolysiloxane (dimethylsilicone oil / gum) having a vinyl group content of less than 1 mol% and a number average molecular weight of 102 to 108, chain methylhydrogenpolysiloxane, and methylhydrogenpoly having an alkylene group. Siloxane, methylphenyl silicone oil and gum are preferred because they are superior in durability.

The silicone-based copolymer is a copolymer of the above-mentioned silicone oil or silicone gum (rubber) with another resin. Examples of the silicone-based copolymer include a silicone-acrylic copolymer "Charine" (manufactured by Shin-Etsu Chemical Co., Ltd., trade name) and a silicone-acrylic copolymer "X-22-8171" (manufactured by Shin-Etsu Chemical Co., Ltd., trade name). (Commercial name), a partially crosslinked product of dimethyl-vinylpolysiloxane having a vinyl group content of 0 to 1 mol% and EPDM, SBS, or SIS having an unsaturated group content of 0 to 5% by weight. In addition, these are pellets made into master batches with resin, "X-22-2101", "X-22-2147" (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), "BY27-001S" (Toray Dow Corning Co., Ltd.). (Product name) and “BY27-201” (manufactured by Toray Dow Corning, trade name), which is a pellet partially graft-polymerized with a resin.

The component (F) preferably has a viscosity of 10 mPa · s or more, which is selected from the group consisting of silicone oil, silicone gum, and a silicone copolymer containing 40% by mass or more of silicone. By using such a component (F), durability is improved. In addition, the component (F) does not come out during molding or use, and the appearance tends to be improved. The viscosity of the component (F) is preferably 10 to 1011 mPa · s, more preferably 102 to 107 mPa · s.
As the silicone oil, silicone gum and silicone copolymer having a viscosity of 10 mPa · s or more, those having a molecular weight of about 100 to 2000000, preferably about 4000 to 1500,000 can be applied.

Among the components (F), silicone oil having a molecular weight of 1000 to 150,000 is preferable because the slidability of the resin composition is improved.

[Other additives]
The resin composition of this embodiment may contain other additives. Other additives include, for example, pigments, reinforcing agents such as silica and carbon black, antioxidants, weather resistance improving agents, lubricants, antibacterial agents, flame retardants, paraffin-based softeners, processing aids, etc. Examples thereof include lubricants and lubricants such as fluorine-based lubricants. From the viewpoint of facilitating these kneading, it is preferable to knead at the same time as the component (E) or the component (F).
In the resin composition of this embodiment, the total of the components (A) to (F) may be 100 parts by mass, and the blending amount of the other additives may be, for example, 0.1 to 10 parts by mass.

<Physical characteristics of resin composition>
The following physical properties of the resin composition of this embodiment are values measured in accordance with JIS standards as in Examples described later.

(ShoreA hardness)
The ShoreA hardness of the resin composition of this embodiment is preferably 40 to 80, more preferably 50 to 75, and even more preferably 60 to 70.
Within the above range, it is possible to obtain a balanced rigidity, elasticity and airtightness suitable as a surface layer material of a rubber member for airtightness, which is particularly airtight between a door and a body among rubber members for automobiles.

(Tensile strength)
The tensile strength (unit: MPa) of the resin composition of this embodiment is preferably 1.0 or more, more preferably 1.5 or more, still more preferably 2.0 or more. The upper limit is not particularly limited, and for example, 10 or less is a guide.
Within the above range, it is possible to obtain balanced rigidity, elasticity and airtightness suitable as a surface layer material of a rubber member that is airtight between a door and a body among resin members for automobiles.

(Growth rate)
The elongation rate of the resin composition of this embodiment is preferably 200% or more, more preferably 250% or more, still more preferably 300% or more. The upper limit is not particularly limited, and for example, 500% or less is a guide.
Within the above range, it is possible to obtain a balanced rigidity, elasticity and airtightness suitable as a surface layer material of a rubber member for airtightness, which is particularly airtight between a door and a body among rubber members for automobiles.

≪Manufacturing method of resin composition≫
The fourth aspect of the present invention is the dynamic of the second aspect by kneading the resin composition (1) of the first aspect and cross-linking at least a part of the component (A) and the component (B). Obtaining a crosslinked resin composition and obtaining a resin composition (2) by kneading the component (E) and the component (F) into the dynamically crosslinked resin composition. It is a method for producing the resin composition of the third aspect including.

The method for obtaining the dynamically crosslinked resin composition from the resin composition (1) is as described above. The method of mixing the dynamically crosslinked resin composition with other raw materials is not particularly limited, and a general method of kneading the resin composition can be adopted. Examples thereof include a twin-screw extruder, a single-screw extruder, a kneader, a kneader such as a Banbury mixer, and the like. The resin composition (2) formed by mixing can be obtained, for example, in the form of pellets.

≪Extruded product≫
A fifth aspect of the present invention is an extruded article formed by the dynamically crosslinked resin composition of the second aspect or the resin composition of the third aspect.
Since the extruded product of this embodiment is excellent in durability, slidability, etc., it is suitable as a surface layer material for a rubber member for an automobile or a resin member, and in particular, a surface layer material (slide) for a rubber member that is airtight between a door and a body. Suitable as a moving material).
The extruded product of this embodiment may be any molded product other than the rubber member for automobiles.

≪Manufacturing method of extruded products≫
A sixth aspect of the present invention comprises subjecting the resin composition (2) obtained by the production method of the fourth aspect to an extrusion molding machine equipped with a die (die) to obtain an extrusion molded product. It is a manufacturing method.
The conditions for extrusion molding may be the same as those for extrusion molding of known elastomer compositions.
In this embodiment, since the resin composition of the third aspect is used as a raw material, the occurrence of rheumatism when extruded from the die is suppressed.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

The details of the raw materials shown in Table 1 are as follows.
"FKM": Binary type fluororubber (vinylidene fluoride-6-propylene fluoride copolymer) manufactured by Daikin Industries, Ltd.
"EVA": Lanxess, ethylene / vinyl acetate copolymer (vinyl acetate ratio 40%)
"PP": Nippon Polypro Co., Ltd., Polypropylene "Crossing agent": Organic oxide "TPE": JSR Co., Ltd., Thermoplastic elastomer (specific name: Olefin-based thermoplastic elastomer), ShoreA hardness = 35 (15s)
"Silicone": Shin-Etsu Chemical Co., Ltd., dimethyl silicone, molecular weight: 20,000 to 80,000

<Preparation of resin composition>
EVA, PP, a cross-linking agent, and FKM were charged into a twin-screw extruder in the amounts (parts by mass) shown in Table 1 and subjected to dynamic cross-linking while kneading. Then, while charging the amount (mass part) of TPE shown in Table 1 into the twin-screw extruder and kneading it, the amount (mass) shown in Table 1 is used from the middle part of the twin-screw extruder using a metering pump. The silicone oil (part) was injected and kneaded to obtain the desired resin composition (2), which was subsequently extruded from the die into a strand shape.
At the time of the above extrusion, it was confirmed whether or not the strands rubbed around the outlet of the die and resin residue (rheumatism) was generated. The results are shown in Table 1.
The blanks in the table indicate that the material is not added.

For the resin composition (2) obtained in each of the above examples, ShoreA hardness, tensile strength, and elongation were measured in accordance with the following JIS standards. The results are shown in Table 1.
-Hardness; JIS K 6253
-Tensile strength; JIS K 6251
・ Growth; JIS K 6251

Since the resin compositions (2) of Examples 1 to 7 contained fluororubber, no rheumatism was generated when extruded from the die (see the photograph in FIG. 1).
Since the resin composition of Comparative Example 1 did not contain fluororubber, rheumatism was generated when it was extruded from the die (see the photograph in FIG. 2).

From the above results, it is clear that the resin composition (2) of the third aspect of the present invention is suitable for extrusion molding. Further, it can be seen that the resin composition (1) of the first aspect and the dynamically crosslinked resin composition of the second aspect of the present invention are useful as raw materials for the resin composition (2) of the third aspect.

Claims (9)

A resin composition containing an ethylene / vinyl acetate copolymer, an α-olefin polymer, a fluororubber, and a cross-linking agent. With respect to 100 parts by mass of the ethylene / vinyl acetate copolymer
The content of the α-olefin polymer is 15 to 65 parts by mass, and the content is 15 to 65 parts by mass.
The content of the cross-linking agent is 1 to 8 parts by mass.
The resin composition according to claim 1. With respect to the total mass of the ethylene / vinyl acetate copolymer, the α-olefin polymer, the fluororubber, and the cross-linking agent.
The content of the fluororubber is 0.01 to 1% by mass.
The resin composition according to claim 1 or 2. A dynamically crosslinked resin formed by the resin composition according to any one of claims 1 to 3, wherein at least a part of the ethylene / vinyl acetate copolymer and the α-olefin polymer is dynamically crosslinked. Composition. The dynamically crosslinked resin composition according to claim 4,
A resin composition comprising the ethylene / vinyl acetate copolymer, the α-olefin polymer, and a thermoplastic elastomer other than the fluororubber. The resin composition according to claim 5, further comprising a silicone compound. An extruded product formed from the dynamically crosslinked resin composition according to claim 4 or the resin composition according to claim 5 or 6. While kneading the resin composition according to any one of claims 1 to 3, at least a part of the ethylene / vinyl acetate copolymer and the α-olefin polymer contained in the resin composition is crosslinked. To obtain a dynamically crosslinked resin composition by
A resin composition is obtained by kneading the ethylene / vinyl acetate copolymer, the α-olefin polymer, a thermoplastic elastomer other than the fluororubber, and a silicone compound into the dynamically crosslinked resin composition. A method for producing a resin composition, including the above. A method for producing an extruded product, which comprises subjecting the resin composition obtained by the production method according to claim 8 to an extrusion molding machine equipped with a die to obtain an extruded product.

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