JP2003183448A - Thermoplastic elastomer composition for tube or hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition for tubes or holes for foods, medical treatment, automobiles, and industrial applications which excels in kinking, extrusion moldability, and multi-layer extrusion moldability. <P>SOLUTION: The thermoplastic elastomer composition for tubes or holes for foods, medical treatment, automobiles, and industrial applications which excels in kinking, extrusion moldability, and multi-layer extrusion moldability is obtained by subjecting a composition comprising (a) 100 pts.wt. olefin based copolymer rubber and (b) 15-150. pts.wt. peroxide decomposable olefin based resin to melt kneading treatment. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition for a tube or a hose, and more particularly to a thermoplastic elastomer composition for a tube or a hose which is excellent in kink property, extrusion moldability and multilayer extrusion moldability in a thin molded product. And food, medical, automotive, industrial tube or hose components.

[0002]

2. Description of the Related Art In recent years, a thermoplastic elastomer, which is a soft material having rubber elasticity and which does not require a vulcanization step and has the same moldability and recyclability as a thermoplastic resin, has been used in automobile parts, home electric appliance parts, It is widely used in the fields of wire coating, medical parts, footwear, and sundries.

Among thermoplastic elastomers, polystyrene-based thermoplastic elastomers such as styrene-butadiene block polymer (SBS) and styrene-isoprene block polymer (SIS), which are block copolymers of aromatic vinyl compound-conjugated diene compound, are It is highly flexible, has good rubber elasticity at room temperature, and the thermoplastic elastomer composition obtained from them has excellent processability and is widely used as a substitute for vulcanized rubber.

Further, the elastomer composition obtained by hydrogenating the intramolecular double bond of the block copolymer of styrene and the conjugated diene in these elastomers is an elastomer having improved heat aging resistance (heat stability) and weather resistance. Is widely used as a

However, thermoplastic elastomer compositions using these hydrogenated block copolymers still have rubber-like properties such as oil resistance, heat-pressurization deformation rate (compression set) and rubber elasticity at high temperatures. There is a problem, and in order to improve this point, a cross-linked product obtained by cross-linking the composition containing the hydrogenated derivative of the block copolymer has been proposed (for example, JP-A-59-6236, JP-A-63-57662, JP-B-3-49927, JP-B-3-11291 and JP-B-6-136.
No. 28).

Further, the crosslinked composition of the hydrogenated block copolymer disclosed in the above publication has a problem that the compression set is still insufficient at high temperature, especially at 100 ° C., and the mechanical strength is apt to decrease. However, at present, it has not reached the performance level conventionally required for vulcanized rubber applications. Further, in extrusion molding, the melt tension at a high temperature is low, so that the shape retention is deteriorated, and in injection molding, the molding cycle becomes long, and there are many problems on the molding surface.

Furthermore, any of the compositions disclosed in the above publications, especially when used as a food, medical, automobile, industrial hose or tube, is a thin-walled molded product (for example, an inner diameter of 5 mm,
In the case of a tube with an outer diameter of about 8 mm, the kink property (remarkable when the wall thickness is 1.8 mm or less) (hard to break when bending or twisting),
At present, it is inferior in extrusion moldability and multilayer extrusion moldability.

[0008]

In view of the above problems, the present invention is a thermoplastic elastomer composition for food, medical, automobile, industrial hose and tube members, which is excellent in kink property, extrusion moldability and multilayer extrusion moldability. The purpose is to provide.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the inventors of the present invention melt-knead a specific amount of a specific olefin copolymer rubber and a peroxide-decomposable olefin resin. The present invention was found to be excellent in kink property, extrusion moldability, and multilayer extrusion moldability by the treatment, and completed the present invention.

That is, the first aspect of the present invention is (a)
A thermoplastic elastomer for tubes or hoses, which is obtained by melt-kneading a composition containing 100 parts by weight of an olefin copolymer rubber and (b) 15 to 150 parts by weight of a peroxide decomposing olefin resin. It is a composition.

The second invention of the present invention is that (a) the olefin copolymer rubber has a polyethylene crystallinity of 20% by weight or less and an ethylene content of 40 by DSC measurement.
The thermoplastic elastomer composition for tubes or hoses according to the first invention, wherein the thermoplastic elastomer composition is about 70% by weight.

The third invention of the present invention further comprises:
(C) A first or second aspect, which is obtained by subjecting a composition containing 0.01 to 3 parts by weight of an organic peroxide to a melt-kneading treatment.
A thermoplastic elastomer composition for a tube or hose according to the invention.

The fourth invention of the present invention further comprises:
(D) A thermoplastic elastomer composition for tubes or hoses according to the third invention, which is obtained by melt-kneading a composition containing 0.01 to 10 parts by weight of an ester crosslinking aid. .

The fifth invention of the present invention is the tube according to the fourth invention, wherein the (d) ester-based crosslinking aid is a polyfunctional acrylate compound or a polyfunctional methacrylate compound. Alternatively, it is a thermoplastic elastomer composition for hoses.

The sixth aspect of the present invention further includes:
(E) The thermoplastic elastomer composition for tubes or hoses according to any one of the first to fifth inventions, which contains 1 to 150 parts by weight of an inorganic filler.

The seventh invention of the present invention further comprises:
(F) 1 to 100 parts by weight of a conjugated diene-based copolymer and / or a hydrogenated conjugated diene-based copolymer, and heat for tubes or hoses according to any one of the first to sixth aspects of the invention. It is a plastic elastomer composition.

The eighth invention of the present invention further comprises:
(G) The thermoplastic elastomer composition for tubes or hoses according to any one of the first to seventh inventions, which contains 1 to 100 parts by weight of a non-aromatic softening agent for rubber.

The ninth invention of the present invention is a tube and hose member obtained by molding the thermoplastic elastomer composition for a tube or hose according to any one of the first to eighth inventions.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The components constituting the present invention, the production method, and the use are described in detail below.

1. Component (1) Olefin Copolymer Rubber Component (a) of Thermoplastic Elastomer Composition Olefin Copolymer Rubber Component (a) Used in Thermoplastic Elastomer Composition for Tube or Hose of the Present Invention
Examples thereof include an elastomer obtained by copolymerizing α-olefins such as ethylene, propylene, 1-butene and 1-pentene, and an olefin copolymer rubber obtained by copolymerizing these with a non-conjugated diene.

The non-conjugated dienes include dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene,
Examples thereof include methylene norbornene and 5-ethylidene-2-norbornene.

Specific examples of such olefinic copolymer rubbers include ethylene-propylene copolymer rubber, ethylene-propylene-non-conjugated diene copolymer rubber, ethylene-1-butene copolymer rubber, Ethylene-1
Examples thereof include ethylene-based copolymer rubbers such as butene-non-conjugated diene copolymer rubber and ethylene-propylene-1-butene copolymer rubber.

The ethylene content in the ethylene copolymer rubber is preferably 40 to 70% by weight, more preferably 45 to 65% by weight. Ethylene content is 40
If it is less than 10% by weight, mechanical properties and heat resistance will be significantly deteriorated, and if it exceeds 70% by weight, flexibility will be lost and at the same time rubber elasticity will be remarkable and kink property will be deteriorated.

Further, olefin copolymer rubber (a)
The crystallinity of polyethylene measured by DSC is preferably 20% by weight or less, more preferably 15% by weight or less, and further preferably 1% by weight or less. If the crystallinity exceeds 20% by weight, the flexibility of the resulting thermoplastic elastomer composition for tubes or hoses is lowered, and the hardness of the thermoplastic elastomer composition becomes too high, resulting in loss of flexibility and rubber feel. I can't get the product.

Here, the crystallinity is a value measured by the following measuring method. (I) The sample is put in an aluminum pan of which the weight is known, and dried for 24 hours under a pressure of 100 Pa or less before enclosing. (Ii) After drying, immediately measure the weight of the entire sample container, and seal under pressure. (Iii) The sample container is set in the DSC sample holder, and the temperature is raised to 230 ° C. at a temperature rising rate of 10 ° C./min. (Iv) Hold at 230 ° C. for 60 minutes to completely melt or relax the sample. (V) Cool to 30 ° C. at the same rate (10 ° C./min) as the temperature rising rate. (Vi) The crystallinity is evaluated from the heat of crystallization (ΔHc), assuming that the crystal perfection generated in the isothermal crystallization process is constant regardless of the crystal formation time. (Vii) Crystallinity of HDPE (HJ560: Nippon Polychem, specific gravity 0.964) is 100 crystallization heat (ΔHc).
As the heat of crystallization of the olefin-based copolymer rubber (a) (Δ
Hc) is stated in% by weight.

(2) Peroxide-decomposing olefin resin component (b) The peroxide-decomposing olefin resin component (b) used in the thermoplastic elastomer composition for a tube or hose of the present invention is the thermoplastic elastomer composition obtained. It improves the rubber dispersion of the product and the appearance of the molded product, and has the effect of adjusting the hardness and the shrinkage ratio. The component (b) is an olefin-based polymer or copolymer that is thermally decomposed by heat treatment in the presence of peroxide to appropriately reduce the molecular weight and increases the fluidity at the time of melting. Tactic polypropylene and propylene and other α-olefins such as ethylene,
Examples thereof include copolymers with 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like.

The melting point of the homopolymer portion of the olefinic copolymer as measured by DSC is preferably Tm of 15
0 to 167 ° C., ΔHm in the range of 25 to 83 mJ / mg. The crystallinity can be estimated from Tm and ΔHm measured by DSC. When Tm and ΔHm are out of the above ranges, the obtained thermoplastic elastomer composition has oil resistance or 1
Rubber elasticity at 00 ° C or higher is not improved.

Further, the melt flow rate of component (b) (MFR, ASTM D-1238, L condition, 230
C) is preferably 0.1 to 200 g / 10 minutes, more preferably 0.5 to 100 g / 10 minutes. If the MFR is less than 0.1 g / 10 minutes, the moldability of the obtained thermoplastic elastomer composition will deteriorate, and if it exceeds 200 g / 10 minutes, the mechanical strength of the obtained thermoplastic elastomer composition will decrease.

The blending amount of the component (b) is 100 parts of the component (a).
The amount is 15 to 150 parts by weight, preferably 40 to 100 parts by weight, based on parts by weight. When the blending amount is less than 15 parts by weight, the moldability of the obtained thermoplastic elastomer composition is deteriorated, and peeling, deformation and flow marks easily occur in the molded product. If it exceeds 150 parts by weight, the hardness of the thermoplastic elastomer composition becomes too high and the flexibility is lost, so that a product having a rubber-like feel cannot be obtained.

(3) Organic peroxide component (c) In the thermoplastic elastomer composition for a tube or hose of the present invention, an organic peroxide component (c) can be blended, if necessary. The component (c) generates a radical and causes the radical to react in a chain,
It has a function to crosslink the component (a), and at the same time decomposes the component (b) to increase the fluidity of the composition at the time of melt-kneading and to improve the dispersion of the rubber component.

Examples of the component (c) include dicumyl peroxide, di-tert-butyl peroxide, 2,
5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t
ert-Butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy)-
3,3,5-trimethylcyclohexane, n-butyl-
4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, ter
t-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, ter
Examples thereof include t-butyl cumyl peroxide. Of these, 2,5-dimethyl-2,5-di- (ter) is preferable from the viewpoint of odor, coloring, and scorch safety.
t-butylperoxy) hexane, 2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexyne-3 is particularly preferred.

The blending amount of the component (c), when blended, is
It is preferably 0.01 to 3 parts by weight, and more preferably 0.01 to 1 part by weight, relative to 100 parts by weight of the component (a). If the blending amount is less than 0.01 part by weight, the effect of addition cannot be seen. On the other hand, if it exceeds 3 parts by weight, moldability becomes poor.

(4) Ester-based cross-linking aid component (d) In the thermoplastic elastomer composition for a tube or hose of the present invention, an ester-based cross-linking aid component (d) can be added, if necessary. . The component (d) has the effect of causing a uniform and efficient crosslinking reaction during the crosslinking treatment with the organic peroxide (c).

Examples of the component (d) include triallyl cyanurate, ethylene glycol dimethacrylate,
Diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate having 9 to 14 repeating units of ethylene glycol, trimethylolpropane trimethacrylate, allyl methacrylate, 2-methyl-1,8-octane Polyfunctional methacrylate compounds such as diol dimethacrylate, 1,9-nonanediol dimethacrylate,
Compounded with polyfunctional acrylate compounds such as polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate and propylene glycol diacrylate, and polyfunctional vinyl compounds such as vinyl butyrate or vinyl stearate. can do. These are either alone or 2
A combination of more than one type may be used. Among the above-mentioned crosslinking aids, a polyfunctional acrylate compound or a polyfunctional methacrylate compound is preferable, and triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate is particularly preferable. The compound is easy to handle, has a solubilizing effect on the organic peroxide, and acts as a dispersion aid for the organic peroxide, so that crosslinking by heat treatment is performed uniformly and effectively, and the hardness and rubber elasticity are improved. A well-balanced thermoplastic elastomer can be obtained.

The blending amount of the component (d) is as follows.
The amount is preferably 0.01 to 10 parts by weight, more preferably 0.02 to 2 parts by weight, based on 100 parts by weight of the component (a). If the blending amount is less than 0.01 part by weight, the effect of addition cannot be seen. On the other hand, when it exceeds 10 parts by weight, moldability becomes poor.

(5) Inorganic filler component (e) In the thermoplastic elastomer composition for a tube or hose of the present invention, an inorganic filler component (e) can be blended, if necessary. The component (e) has an effect of improving some physical properties such as compression set of a molded article obtained from the thermoplastic elastomer composition, and also has an economic advantage by increasing the amount.

As the component (e), chlorite, wollastonite, calcium carbonate, talc, silica, diatomaceous earth, barium sulfate, magnesium carbonate, magnesium hydroxide,
Examples thereof include mica, clay, titanium oxide, carbon black, glass fiber, hollow glass balloon, carbon fiber, calcium titanate fiber, natural silicic acid and synthetic silicic acid (white carbon). Of these, wollastonite, chlorite, calcium carbonate, talc and mica are particularly preferable, and wollastonite and mica are even more preferable.

The blending amount of the component (e) is as follows.
The amount is preferably 1 to 150 parts by weight, more preferably 20 to 110 parts by weight, relative to 100 parts by weight of the component (a).
If the blending amount exceeds 150 parts by weight, the mechanical strength of the obtained elastomer composition is remarkably lowered, and the hardness becomes high, so that the flexibility is lost and a product having a rubber-like feel cannot be obtained.

(6) Conjugated diene-based copolymer and / or hydrogenated conjugated diene-based copolymer component (f) In the thermoplastic elastomer composition for a tube or hose of the present invention, a conjugated diene-based copolymer is optionally used. A copolymer and / or a hydrogenated conjugated diene-based copolymer component (f) can be blended. The component (f) is a copolymer obtained by hydrogenating or partially hydrogenating a conjugated diene-based copolymer and a conjugated diene-based portion in the conjugated polymer, and the following (f-1) to (F-3) component is mentioned.

(F-1) Aromatic vinyl compound-conjugated diene compound random copolymer and / or hydrogenated product thereof The aromatic vinyl compound-conjugated diene compound random copolymer used in the present invention includes a conjugated diene compound and A random copolymer with an aromatic vinyl compound, having a number average molecular weight of preferably 5,000 to 1,000,000, more preferably 10,000 to 350,000, and a polydispersity (Mw). / Mn) is 10 or less, and the content of vinyl bonds such as 1,2 bonds or 3,4 bonds in the conjugated diene portion is 5% or more, preferably 20 to 90%. If it is less than 5%, the resulting molded article will have a hard feel and will not meet the purpose of the present invention. Here, the content of the aromatic vinyl compound constituting the component (f-1) is
It is 50% by weight or less, preferably 5 to 35% by weight.
If it exceeds 50% by weight, the resulting molded article has a hard feel and does not meet the purpose of the present invention.

Examples of the aromatic vinyl compound in the component (f-1) include styrene, t-butylstyrene,
α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminoethylstyrene, vinyltoluene, p-
One kind or two or more kinds can be selected from tertiary butyl styrene and the like, and styrene is preferable among them. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3.
One or more selected from butadiene and the like, and among them, butadiene, isoprene and combinations thereof are preferable.

The aromatic vinyl compound and the conjugated diene compound are randomly bonded to each other, and Corsov [I. M. Ko
Lthoff, J. et al. Polymer Sci. , Vol
1p. 429 (1946)], it is preferable that the content of the block-shaped aromatic vinyl compound is 10% by weight or less, preferably 5% by weight or less in the total aromatic vinyl compound. Further, the hydrogenated product of the copolymer contains at least 90% of the aliphatic double bonds based on the conjugated diene compound.
Is preferably hydrogenated.

Specific examples of the component (f-1) include styrene / butadiene random copolymer (SBR) and hydrogenated styrene / butadiene random copolymer (HSBR). In the present invention, SBR, HS
BR may be used alone or in combination of two or more.

(F-2) The aromatic vinyl compound-conjugated diene compound block copolymer and / or its hydrogenated component (f-2) is at least 2 parts of the polymer block A mainly containing an aromatic vinyl compound. And a hydrogenated block copolymer obtained by hydrogenating the block copolymer, which comprises at least one polymer block B mainly composed of a conjugated diene compound. For example,
A block copolymer of an aromatic vinyl compound-conjugated diene compound having a structure such as ABA, BABAA, ABABA, and a hydrogenated block copolymer thereof. is there.

The above (hydrogenated) block copolymer (hereinafter,
The (hydrogenated) block copolymer means a block copolymer and / or a hydrogenated block copolymer. ) Is an aromatic vinyl compound in an amount of 5 to 60% by weight, preferably 20.
-50% by weight.

The polymer block A mainly containing an aromatic vinyl compound is preferably composed of only the aromatic vinyl compound, or 50% by weight or more, preferably 70% by weight or more (hydrogenated). ) A copolymer block with a conjugated diene compound (hereinafter, the (hydrogenated) conjugated diene compound means a conjugated diene compound and / or a hydrogenated conjugated diene compound).

The polymer block B based on the (hydrogenated) conjugated diene compound preferably consists only of the (hydrogenated) conjugated diene compound or 50 weight parts of the (hydrogenated) conjugated diene compound. % Or more, preferably 70% by weight or more and a copolymer block of an aromatic vinyl compound.

In each of the polymer block A mainly containing the aromatic vinyl compound and the polymer block B mainly containing the (hydrogenated) conjugated diene compound,
The distribution of the aromatic vinyl compound or the (hydrogenated) conjugated diene compound in the molecular chain is random, tapered (in which the monomer component increases or decreases along the molecular chain), partially blocked, or any of these. It may be a combination.

When there are two or more polymer blocks A mainly composed of an aromatic vinyl compound or polymer blocks B mainly composed of a (hydrogenated) conjugated diene compound, each of them has the same structure. It may have a different structure.

As the aromatic vinyl compound constituting the (hydrogenated) block copolymer, for example, one or more selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene and the like. Among them, styrene is preferable. As the conjugated diene compound, for example, one kind or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and the like. Among them, butadiene,
Isoprene and combinations thereof are preferred.

The micro bond in the polymer block B mainly composed of the conjugated diene compound can be arbitrarily selected.
In the butadiene block, the 1,2-microstructure has a lower limit of 1% or more, preferably 5% or more, more preferably 10% or more, and an upper limit of 95% or less, preferably 80% or less, more preferably 75% or less. is there.

The hydrogenation rate in the hydrogenated block copolymer of the component (f-2) can be arbitrarily selected, and the heat deterioration resistance and the like are improved while maintaining the characteristics of the unhydrogenated block copolymer. In this case, the lower limit of the aliphatic double bond based on the conjugated diene is 3% or more, preferably 5% or more, more preferably 7 or more, even more preferably 9% or more, and the upper limit is 85%.
Less than 80%, preferably less than 80%, more preferably less than 75%, even more preferably less than 60%. In addition, the 1,2-vinyl bond after hydrogenation is 0.5 to 1
It is preferably 2%, more preferably less than 10%, further preferably 5% or less, still more preferably 3% or less.

Further, in order to improve the heat deterioration resistance and the weather resistance, it is recommended to hydrogenate 80% or more, preferably 90% or more. In the polyisoprene block, 70 to 100% by weight of the isoprene compound is 1,
Those having a 4-microstructure and having at least 90% of the aliphatic double bonds based on the isoprene compound hydrogenated are preferred.

The weight average molecular weight of the hydrogenated block copolymer used in the present invention having the above structure is preferably 5,
000 to 1,500,000, more preferably 1
50,000-550,000, more preferably 50.0
The range is from 00 to 400,000. Molecular weight distribution (ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) (Mw
/ Mn)) is preferably 10 or less, more preferably 5 or less, and more preferably 2 or less. The molecular structure of the hydrogenated block copolymer may be linear, branched, radial or any combination thereof. The molecular weight in the present invention is a value determined by GPC based on polystyrene having a known molecular weight. Therefore,
The value is a relative value, not an absolute value, and may vary by about ± 30% depending on each condition of the GPC such as the reference sample, the device, and the data processing method.

The solution viscosity of the block copolymer (5% toluene solution, 77 ° F., ASTM D-2196) is preferably 5 to 500 cps, more preferably 20.
~ 300 cps.

A number of methods have been proposed as a method for producing these block copolymers. As a typical method, for example, a method described in Japanese Patent Publication No. 40-23798, a lithium catalyst or It can be obtained by block polymerization using a Ziegler type catalyst in an inert solvent. A hydrogenated block copolymer is obtained by hydrogenating the block copolymer obtained by the above method in the presence of a hydrogenation catalyst in an inert solvent.

Specific examples of the (hydrogenated) block copolymer include styrene-butadiene-styrene copolymer (S
BS), styrene-isoprene-styrene copolymer (S
IS), styrene-ethylene-butene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene copolymer (SEEP)
S), partially hydrogenated styrene-butadiene-styrene copolymer (SBBS) and the like. In the present invention, the (hydrogenated) block copolymer may be used alone or in combination of two or more kinds.

(F-3) Conjugated diene compound block copolymer and / or hydrogenated product thereof The conjugated diene compound block copolymer and / or its hydrogenated product used in the present invention is, for example, butadiene block copolymer. A block copolymer having a crystalline ethylene block and an amorphous ethylene-butene block obtained by hydrogenating a block copolymer of butadiene and a copolymer (C
EBC) and the like. In the present invention, the conjugated diene compound block copolymer and / or its hydrogenated product may be used alone or in combination of two or more kinds.

The blending amount of the component (f) is as follows.
It is 1 to 100 parts by weight, preferably 1 to 40 parts by weight, relative to 100 parts by weight of the component (a). If the compounding amount is less than 1 part by weight, there is no improvement effect, and if it exceeds 100 parts by weight, rubber elasticity is exhibited and kink property is deteriorated.

(7) Softener component for non-aromatic rubber (g) In the thermoplastic elastomer composition for a tube or hose of the present invention, a softener component for non-aromatic rubber (g), if necessary. Can be blended. As the component (g), a non-aromatic mineral oil or a liquid or low molecular weight synthetic softening agent can be mentioned. The mineral oil softener used for rubber is a mixture of a combination of aromatic rings, naphthene rings and paraffin chains,
Paraffin chains have more than 50% of the total number of carbons are called paraffins, those with 30-40% naphthene ring carbons are called naphthenes, and those with 30% or more aromatic carbons are called aromatics. Are distinguished.

The mineral oil type softener for rubber used as the component (g) of the present invention is classified into paraffin type and naphthene type softeners. The aromatic softening agent is not preferable because the component (a) becomes soluble due to its use, the crosslinking reaction is inhibited, and the physical properties of the obtained composition cannot be improved. As the component (g), a paraffinic one is preferable, and a paraffinic one having a small amount of an aromatic ring component is particularly suitable. Examples of liquid or low molecular weight synthetic softening agents include polybutene, hydrogenated polybutene, and low molecular weight polyisobutylene.

The properties of these non-aromatic softeners for rubber are such that the dynamic viscosity at 37.8 ° C. is 20 to 50,000 c.
St, dynamic viscosity at 100 ° C. is 5 to 1500 cS
t, pour point is −10 to −15 ° C., flash point (COC) is 1
It is preferably 70 to 300 ° C. Further, those having a weight average molecular weight of 100 to 2,000 are preferable.

When compounding the component (g),
It is 1 to 100 parts by weight, preferably 1 to 20 parts by weight, relative to 100 parts by weight of the component (a). If the blending amount is less than 1 part by weight, there is no improvement effect, and if the blending amount exceeds 100 parts by weight, the softening agent easily bleeds out from the resulting thermoplastic elastomer composition, and peeling, deformation, and flow marks easily occur in the molded product. .

(8) Other components (h) In the thermoplastic elastomer composition for tubes or hoses of the present invention, in addition to the above components, various antiblocking agents and sealing properties may be added, if desired. Improver, heat stabilizer, antioxidant, light stabilizer, UV absorber,
It is also possible to contain a lubricant, a crystal nucleating agent, a coloring agent and the like. Here, examples of the antioxidant include 2,6-di-tert-p-butyl-p-cresol, 2,6-di-tert-butylphenol, and 2,4-dimethyl-6.
-Tert-butylphenol, 4,4-dihydroxydiphenyl, tris (2-methyl-4-hydroxy-5)
Examples thereof include phenolic antioxidants such as -tert-butylphenyl) butane, phosphite antioxidants, and thioether antioxidants. Of these, phenol-based antioxidants and phosphite-based antioxidants are particularly preferable.
The antioxidant is 100 in total of the above components (a) to (g).
The amount is preferably 0 to 3.0 parts by weight, particularly preferably 0.1 to 1.0 parts by weight, based on parts by weight.

2. Production of Thermoplastic Elastomer Composition The thermoplastic elastomer composition for a tube or hose of the present invention contains the above-mentioned components (a) to (b), or if necessary, the components (c) to (g), Can be manufactured by melt-kneading at the same time or in any order.

The melt-kneading method is not particularly limited, and a generally known method can be used. For example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer or various kneaders can be used. For example, a moderate L / D twin-screw extruder,
The above operation can be continuously performed by using a Banbury mixer, a pressure kneader or the like. Here, the temperature of the melt-kneading is preferably 160 to 220 ° C.

The thermoplastic elastomer composition of the present invention obtained as described above is excellent in kink property, extrudability and multi-layer extrusion moldability. Here, the kink property means bending and resistance to bending during twisting, for example, fixing both ends of a tube obtained by extrusion to a jig of a tensile tester,
It can be evaluated by a value represented by a kink property test in which the material is compressed at a constant speed and the state of the shape deformation that occurs at that time is observed.

3. Use of Thermoplastic Elastomer Composition When the thermoplastic elastomer composition of the present invention is molded into a tube or hose by extrusion molding or the like, it has excellent kink properties and extrusion moldability, so that excellent hose and tube members can be obtained. In particular, it can be used as a hose or tube member for foods, medical care, automobiles, and industry, and a hose or tube not treated with an organic peroxide can be used for medical purposes.

[0069]

EXAMPLES The present invention will be specifically described with reference to the following examples and comparative examples, but the present invention is not limited to these examples. The measuring methods of physical properties and samples used in the present invention are shown below.

1. Physical Property Measuring Method (1) Specific Gravity: Measurement was carried out in accordance with JIS K7112. (2) Hardness: According to JIS K 6253, a 6.3 mm thick press sheet was used as a test piece. (3) Tensile strength: Based on JIS K 6251, a test piece was a 1 mm thick press sheet punched into a No. 3 mold with a dumbbell and used. The pulling speed was 500 mm / min. (4) 100% elongation stress: Based on JIS K 6251, a test piece was a 1 mm thick press sheet punched into a No. 3 mold with a dumbbell and used. The pulling speed was 500 mm / min. (5) Elongation at break: Based on JIS K 6251, a test piece was a 1 mm thick press sheet punched into a No. 3 mold with a dumbbell and used. The pulling speed was 500 mm / min. (6) Compression set (CS%): JIS K 6262
The test piece used was a 6.3 mm thick press sheet. It was measured at 100 ° C. for 22 hours under the condition of 25% deformation. (7) Extrudability: inner diameter 5 mm, outer diameter 8 mm, wall thickness 1.
Using a 40 mm extruder (YE40 manufactured by Yamaguchi Seisakusho Co., Ltd.) for a 5 mm tube, a cylinder temperature of 160 to 1
80 ° C, die head and crosshead temperature 185 ° C,
Full flight screw, screw rotation speed 40 rpm
Molding, observe drawdown, surface appearance and shape,
The following criteria evaluated. ◯: Good Δ: Good appearance with some greas and drawdowns X: Poor (8) Kink property: Tube 200 mm obtained in (7)
Both ends were set in a jig of a tensile tester at a jig interval of 200 mm, compressed at a compression rate of 100 mm / min, and visually checked for the presence or absence of kinks, and evaluated according to the following criteria. ◯: Good (no kink even with a jig interval of 0 mm) ×: Bad (kink occurs)

2. Sample (1) Olefin-based copolymer rubber (a) used in Examples and Comparative Examples: Nordel
IP 4520 (EPDM; Dupont Dow
(Elastomers) ethylene content: 50% by weight, crystallinity: 1% by weight or less (2) peroxide decomposition type polypropylene component (b): PP-BC8 (trademark; manufactured by Nippon Polychem Co., Ltd.), crystallinity: Tm166 ° C, △ Hm82mJ / m
g, MFR 1.8 g / 10 min (3) Organic peroxide component (c): Perhexa 25B (trademark; manufactured by NOF CORPORATION) (4) Crosslinking aid component (d): TMPT (Trimeth)
yol Propane Trimethacryl
ate; Shin-Nakamura Chemical Co., Ltd.) Molecular weight: 338 (5) Calcium carbonate component (e-1): NS400 (trademark; Sankyo Seiko Co., Ltd.) (6) Wollastonite component (e-2): NYGLOS
8 (trademark; manufactured by NYCO Minerals, Inc.), average fiber length 136 μm, average particle size 8 μm (7) Chlorite component (e-3): C
R330 (trademark; manufactured by Sankyo Seiko Co., Ltd.) (8) SBS block copolymer component (f): VECTO
R2518 (trademark; manufactured by DEXCO POLYMERS) Styrene content: 30 wt% Solution viscosity 75 cps (5% toluene solution, 77 ° F, A
STM D-2196) (9) Softener component (g): Diana Process Oil P
W-90 (trademark; manufactured by Idemitsu Kosan Co., Ltd.) (10) Hindered phenol / phosphite / lactone-based composite antioxidant component (h): HP2215 (trademark; manufactured by Ciba Specialty Chemicals)

Examples 1 to 5 and Comparative Examples 1 and 2 Using the components in the amounts shown in Table 1, they were charged into a twin-screw extruder having an L / D of 47, a kneading temperature of 180 ° C. and a screw rotation speed of 3
The mixture was melt-kneaded at 50 rpm and pelletized. next,
The obtained pellets were injection-molded to prepare test pieces, which were then subjected to respective tests. The evaluation results are shown in Table 1.

[0073]

[Table 1]

As is clear from Table 1, Examples 1 to 5
Is the thermoplastic elastomer composition of the present invention. Regardless of the presence or absence of the optional components (c) to (g), all the thermoplastic elastomer compositions showed good properties.

On the other hand, in Comparative Examples 1 and 2, the compounding amount of the component (b) was out of the range of the present invention. When the amount of the component (b) is small, mechanical properties are deteriorated, and kink property and moldability are deteriorated. If there is a large amount of component (b), it becomes too hard and kink,
Extrudability deteriorates.

[0076]

EFFECT OF THE INVENTION The thermoplastic elastomer composition of the present invention is excellent in kink property, extrusion moldability and multi-layer extrusion moldability, and therefore can be used for food, medical, automobile, industrial tube and hose members.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 15/00 C08L 15/00 91/00 91/00 F16L 11/06 F16L 11/06 F term (reference) 3H111 AA02 BA12 BA34 CB02 DA20 DA26 DB19 DB21 EA04 4J002 AC08Y AC11Y AE05Z BB05W BB12X BB14X BB15W BB15X BB17W BP01Y DA038 DE078 DE138 DE238 DJ 008 DJ048 FA02 FD048 FA02 FD048 FA086 FA086 FA086 FA086 FA086

Claims (9)

[Claims] 1. (a) Olefin-based copolymer rubber 100
A thermoplastic elastomer composition for a tube or a hose, which is obtained by melt-kneading a composition containing 15 parts by weight of (b) a peroxide-decomposable olefin resin (b) in an amount of 15 to 150 parts by weight. 2. The (a) olefin-based copolymer rubber is D
The thermoplastic elastomer composition for tubes or hoses according to claim 1, wherein the crystallinity of polyethylene by SC measurement is 20% by weight or less and the ethylene content is 40 to 70% by weight. 3. (c) Organic peroxide 0.01 to
The thermoplastic elastomer composition for tubes or hoses according to claim 1 or 2, which is obtained by melt-kneading a composition containing 3 parts by weight. 4. The (d) ester-based cross-linking aid 0.
The thermoplastic elastomer composition for tubes or hoses according to claim 3, which is obtained by melt-kneading a composition containing 01 to 10 parts by weight. 5. The thermoplastic elastomer composition for tubes or hoses according to claim 4, wherein the ester-type crosslinking aid (d) is a polyfunctional acrylate compound or a polyfunctional methacrylate compound. 6. The thermoplastic elastomer composition for tubes or hoses according to any one of claims 1 to 5, further comprising (e) 1 to 150 parts by weight of an inorganic filler. 7. The composition according to claim 1, further comprising (f) 1 to 100 parts by weight of a conjugated diene-based copolymer and / or a hydrogenated conjugated diene-based copolymer. The thermoplastic elastomer composition for tubes or hoses according to. 8. The composition according to claim 1, further comprising (g) 1 to 100 parts by weight of a non-aromatic softening agent for rubber.
The thermoplastic elastomer composition for tubes or hoses according to any one of items 1 to 7. 9. A tube and a hose member obtained by molding and processing the thermoplastic elastomer composition for a tube or a hose according to claim 1.