JP2020122129A - Thermoplastic elastomer composition for tube or hose - Google Patents

Abstract

To provide a thermoplastic elastomer composition for tube or hose that has excellent characteristics required of a tube or hose, particularly excellent fuel permeation resistance, fuel resistance, and ozone resistance, and does not require a crosslinking step during molding, and a tube or hose including the composition.SOLUTION: A thermoplastic elastomer composition for tube or hose is obtained by dynamically heating a carbodiimide group-containing compound (A), an olefin polymer having a group that reacts with a carbodiimide group (B), a polar rubber (C), and a crosslinker that can crosslink the polar rubber (C) (E). There is also provided a tube or hose containing the same.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic elastomer composition for tubes or hoses containing a crosslinkable rubber and an olefin polymer.

BACKGROUND ART Conventionally, various materials such as a rubber composition such as nitrile rubber or a thermoplastic elastomer composition are known as materials for forming tubes or hoses for various applications such as automobiles, water supply, and gas. ..

Patent Document 1 discloses a hose for automobile, water supply or gas in which ethylene/α-olefin/non-conjugated polyene random copolymer rubber is laminated on a fiber base material containing polyamides as an ozone protective layer. It is described that this hose has excellent strength characteristics, wear resistance and compression set resistance.

Patent Document 2 contains an ethylene/α-offine/non-conjugated polyene copolymer (A), a polyolefin resin (B) and/or an ethylene/α-olefin copolymer having 3 to 20 carbon atoms (C). A molded product such as a tire tube or a hose obtained by using the rubber composition is disclosed. This molded product has excellent rigidity, compression set, shape memory property, etc., mechanical strength (tensile strength, elongation) and heat aging resistance depending on conditions, and fogging caused by volatilization and separation of low molecular weight components. It is also described that stickiness can be suppressed.

Patent Document 3 discloses a thermoplastic elastomer composition containing a thermoplastic elastomer having a side chain containing a carbonyl-containing group and a nitrogen-containing heterocycle. It is described that a molded product such as a hose molded from this thermoplastic elastomer composition retains mechanical properties comparable to those of conventional nitrile rubber and has excellent oil resistance.

JP 2001-026688 A International Publication No. 2009/072553 JP, 2005-179456, A

Various properties such as elasticity, oil resistance, chemical resistance, and moldability are generally required for the material forming the tube or hose. In particular, in tubes or hoses used for specific applications such as automobile applications, fuel permeation resistance, fuel resistance, and ozone resistance are particularly required. Furthermore, it is important to eliminate the cross-linking step during molding from the viewpoint of simplifying the tube or hose manufacturing process.

The present invention was invented in order to solve the problems of the conventional techniques as described above. That is, the object of the present invention is to improve the various properties required for tubes or hoses, and also to be particularly excellent in fuel permeation resistance, fuel resistance, ozone resistance, and heat for tubes or hoses that do not require a crosslinking step during molding. It is intended to provide a plastic elastomer composition and a tube or hose using the composition.

As a result of intensive studies to achieve the above object, the present inventors have found that a specific thermoplastic elastomer containing a polar rubber having crosslinks and, if necessary, an olefin polymer, is highly dispersed with each other. It has been found that the use of the composition is very effective, and the present invention has been completed. That is, the present invention is specified by the following matters.

[1] Carbodiimide group-containing compound (A),
An olefin polymer (B) having a group that reacts with a carbodiimide group,
Polar rubber (C) and cross-linking agent (E) capable of cross-linking polar rubber (C)
A thermoplastic elastomer composition for a tube or hose, which is obtained by dynamically heat-treating.

[2] The thermoplastic elastomer composition for belts for tubes or hoses according to [1], which further contains an olefin polymer (D).

[3] The tube according to [1] or [2], containing a reaction product (I) of a carbodiimide group-containing compound (A) and an olefin polymer (B) having a group that reacts with a carbodiimide group. Or a thermoplastic elastomer composition for hoses.

[4] The thermoplastic elastomer composition for tubes or hoses according to any one of [1] to [3], wherein the polar rubber (C) contains a polar rubber (C1) having a group that reacts with a carbodiimide group.

[5] The thermoplastic elastomer composition for tubes or hoses according to [4], wherein the polar rubber (C1) having a group that reacts with a carbodiimide group is a polar rubber having a group having active hydrogen in its side chain.

[6] A tube or hose according to [4] or [5], containing a reaction product (II) of a carbodiimide group-containing compound (A) and a polar rubber (C1) having a group that reacts with a carbodiimide group. Thermoplastic elastomer composition.

[7] The thermoplastic elastomer composition for tubes or hoses according to any one of [1] to [6], wherein the carbodiimide group-containing compound (A) is a polycarbodiimide having a repeating unit represented by the following general formula.
^{-N = C = N-R 1} -
(In the formula, R ¹ represents a divalent organic group.)

[8] The olefin-based polymer (B) having a group that reacts with a carbodiimide group is the olefin-based polymer having a group having active hydrogen in a side chain, as described in any of [1] to [7]. Thermoplastic elastomer composition for tubes or hoses.

[9] The olefin polymer (B) having a group that reacts with a carbodiimide group is a graft copolymer of a polyolefin and a compound (b) having a group that reacts with a carbodiimide group, [1] to [8]. ] The thermoplastic elastomer composition for tubes or hoses in any one of these.

[10] The thermoplastic elastomer composition for tubes or hoses according to any of [2] to [9], wherein the olefin polymer (D) is a propylene polymer.

[11] With respect to a total of 100 parts by mass of the olefin polymer (B) having a group that reacts with a carbodiimide group, the polar rubber (C), and the olefin polymer (D) optionally blended,
The thermoplastic elastomer composition for tubes or hoses according to any one of [1] to [10], wherein the carbodiimide group-containing compound (A) is blended in the range of 0.01 to 30 parts by mass.

[12] The sea-island structure is observed in an image of 200 times or more by a scanning electron microscope (SEM), and the average particle diameter of the island phase is 0.01 to 20 μm, [1] to [11] The thermoplastic elastomer composition for tubes or hoses.

[13] A tube or hose containing the thermoplastic elastomer composition according to any one of [1] to [11].

ADVANTAGE OF THE INVENTION According to the present invention, the thermoplastic properties for tubes or hoses which are excellent in various properties required for tubes or hoses, particularly excellent in fuel permeation resistance, fuel resistance, and ozone resistance, and which do not require a crosslinking step at the time of molding An elastomer composition and a tube or hose using the composition can be provided.

The thermoplastic elastomer composition of the present invention can crosslink a carbodiimide group-containing compound (A), an olefin polymer (B) having a group that reacts with a carbodiimide group, a polar rubber (C), and the polar rubber (C). A composition obtained by dynamically heat-treating a different crosslinking agent (E).

[Carbodiimide group-containing compound (A)]
The carbodiimide group-containing compound (A) used in the present invention is not particularly limited as long as it is a compound having a carbodiimide group represented by -N=C=N-, but is preferably the following general formula. It is a polycarbodiimide having the repeating unit shown.
^{-N = C = N-R 1} -
(In the formula, R ¹ represents a divalent organic group.)

The method for synthesizing polycarbodiimide is not particularly limited, but polycarbodiimide can be synthesized, for example, by reacting an organic polyisocyanate in the presence of a catalyst that promotes a carbodiimidization reaction of an isocyanate group.

When the carbodiimide group-containing compound (A) is polycarbodiimide, the polystyrene-equivalent number average molecular weight (Mn) determined by gel permeation chromatography (GPC) is usually 400 to 500,000, preferably 1,000 to 10 1,000, more preferably 2,000 to 4,000. When the number average molecular weight (Mn) is within this range, each component in the composition exhibits good compatibility, and the thermoplastic elastomer composition obtained has rubber elasticity and oil resistance, and is also excellent in moldability. It becomes a thing.

The carbodiimide group-containing compound (A) may be used alone or in combination of two or more. For example, polycarbodiimide alone may be used, polycarbodiimide and monocarbodiimide may be used in combination, or monocarbodiimide alone may be used. In the present invention, the carbodiimide group-containing compound (A) preferably contains polycarbodiimide.

As the carbodiimide group-containing compound (A), a commercially available carbodiimide group-containing compound can be used as it is. Examples of commercially available carbodiimide group-containing compounds include Carbodilite (registered trademark) HMV-8CA, HMV-15CA, and LA1 manufactured by Nisshinbo Chemical Inc.

The carbodiimide group content in the carbodiimide group-containing compound (A) and in the obtained reaction product or thermoplastic elastomer composition can be measured by ¹³ C-NMR, IR, titration method or the like, and is grasped as a carbodiimide equivalent. It is possible. It is possible to observe a peak at 130 to 142 ppm by ¹³ C-NMR and 2130 to 2140 cm ⁻¹ by IR.

[Olefin-based polymer (B) having a group that reacts with a carbodiimide group]
The olefin-based polymer (B) having a group that reacts with a carbodiimide group used in the present invention is not particularly limited, but a compound (b) having a group that reacts with a carbodiimide group can be used to produce a carbodiimide group. It can be obtained by introducing into the polyolefin a group that reacts with. Here, the “group having reactivity with a carbodiimide group” includes, for example, a group having active hydrogen, or a group easily converted to a group having active hydrogen by water or the like.

As a method for introducing a group that reacts with a carbodiimide group into a polyolefin, a known method can be adopted. For example, a compound (b) having a group that reacts with a carbodiimide group is graft-copolymerized on a polyolefin main chain. And a method of radically copolymerizing the compound (b) having a group that reacts with a carbodiimide group and an olefin. Of these, graft copolymerization is preferred.

The case where the olefin polymer (B) having a group that reacts with a carbodiimide group is obtained by graft copolymerization and the case where it is obtained by radical copolymerization will be specifically described below.

(Graft copolymerization)
The olefin polymer (B) having a group that reacts with a carbodiimide group in its side chain is a compound having a group that reacts with a carbodiimide group with respect to an unmodified polyolefin (hereinafter, also referred to as a polyolefin main chain) that becomes a main chain ( It can be obtained by graft-copolymerizing b).

<Unmodified polyolefin (polyolefin main chain)>
The unmodified polyolefin used as the polyolefin main chain is, for example, a polymer containing an aliphatic α-olefin having 2 to 20 carbon atoms, a cyclic olefin, or a non-conjugated diene as a main component, and preferably having 2 to 10 carbon atoms. It is a polymer containing α-olefin, more preferably 2 to 8 α-olefin as a main component. These olefins may be used alone or in combination of two or more. In the present invention, a homopolymer or copolymer of ethylene, propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, tetracyclododecene, norbornene. Coalescence can be preferably used. Further, these can be used in both the isotactic structure and the syndiotactic structure, and there is no particular limitation in stereoregularity.

In the thermoplastic elastomer composition of the present invention, the carbodiimide group-containing compound (A) as a raw material is an olefin polymer (B) having a group that reacts with a carbodiimide group [and a polar rubber (C) described later is a carbodiimide group). A polar rubber (C1) having a group capable of reacting with the polar rubber (C1)] is reacted with the polar rubber (C1) by melt-kneading, and the resulting reaction product acts as a compatibilizer to give a polar rubber (C). It is considered that the compatibility with the olefin polymer (D) is improved. The thermoplastic elastomer composition of the present invention preferably contains a reaction product (I) of a carbodiimide group-containing compound (A) and an olefin polymer (B) having a group that reacts with a carbodiimide group.

Here, the effect of improving the compatibility by the reaction product (I) becomes more remarkable when the reaction product (I) has a main chain similar to that of the olefin polymer (D). The main chain of the olefin polymer (B) having a group that reacts with a carbodiimide group, which is the main chain of (I), and the structure of the main chain of the olefin polymer (D) are similar to each other. More preferable.

For example, when the olefin-based polymer (D) described later is a propylene-based polymer, a propylene-based polymer such as a propylene homopolymer or a copolymer of propylene and another α-olefin is used as the polyolefin main chain. A polymer can be preferably selected and used.

The density of the polyolefin used for the graft copolymerization, that is, the density of the polyolefin main chain before introducing the group that reacts with carbodiimide is usually 0.8 to 1.2 g/cm ³ , preferably 0.90 to 1.1 g/cm. ³ and more preferably 0.925 to 1.0 g/cm ³ .

The melt flow rate (MFR) of the polyolefin main chain according to ASTM D1238 at 190° C. or 230° C. under a load of 2.16 kg is usually 0.01 to 500 g/10 minutes, preferably 0.05 to 200 g/10 minutes, and further preferably It is 0.1 to 100 g/10 minutes. When the density and MFR are within this range, the density and MFR of the graft copolymer after modification are also about the same, and therefore handling is easy.

The crystallinity of the polyolefin main chain is usually 2% or more, preferably 5% or more, more preferably 10% or more. When the crystallinity is within this range, the graft copolymer after modification is excellent in handleability.

The number average molecular weight (Mn) of the polyolefin main chain used for graft copolymerization measured by gel permeation chromatography (GPC) is preferably 5,000 to 500,000, more preferably 10,000 to 100,000. .. When the average molecular weight (Mn) is within this range, the handleability is excellent. The number average molecular weight of ethylene-based polyolefin can be calculated in terms of polyethylene when the amount of comonomer is 10 mol% or less and in terms of ethylene-propylene when the amount of comonomer is 10 mol% or more (based on ethylene content of 70 mol%). It is possible.

The above-mentioned polyolefin main chain can be produced by any conventionally known method, for example, polymerization can be performed using a titanium-based catalyst, a vanadium-based catalyst, a metallocene catalyst, or the like. The polyolefin used for the graft modification may be in the form of resin or elastomer, both isotactic structure and syndiotactic structure can be used, and stereoregularity is not particularly limited. It is also possible to use a commercially available resin as it is.

In the present invention, the unmodified polyolefin serving as the polyolefin main chain may have properties similar to those of the olefin polymer (D) described later, or may be of a completely different type, but with high compatibility. When it is required, it is preferable that the density, monomer constitution, stereoregularity, structural unit sequence such as random/block, etc. are similar to those of the olefin polymer (D). Is preferred. Further, the unmodified polyolefin serving as the polyolefin main chain is more preferably a polyolefin resin having thermoplasticity.

<Compound (b) Having Group Reactive with Carbodiimide Group>
Examples of the compound (b) having a group that reacts with a carbodiimide group include compounds having a group having active hydrogen that is reactive with a carbodiimide group, and specific examples include carboxylic acid, carboxylic anhydride, amine, Examples thereof include compounds having a group derived from alcohol, thiol and the like. That is, in the present invention, as an olefin polymer (B) having a group that reacts with a carbodiimide group, for example, as a group that reacts with a carbodiimide group, a carboxylic acid anhydride group, a carboxy group (-COOH), a hydroxy group (-OH). A polyolefin having a group such as a thiol group (-SH) is preferably used.

As the compound (b) having a group that reacts with a carbodiimide group, among the above, a compound having a group derived from an unsaturated carboxylic acid such as a carboxylic acid or a carboxylic acid anhydride is preferably used. / Or its derivative is used preferably. In addition to the compound having a group having active hydrogen, a compound having a group which can be easily converted into a group having active hydrogen by water or the like can be preferably used, and specifically, has an epoxy group or a glycidyl group. Compounds. In the present invention, the compound (b) having a group capable of reacting with a carbodiimide group may be used alone or in combination of two or more.

When an unsaturated carboxylic acid and/or a derivative thereof is used as the compound (b) having a group that reacts with a carbodiimide group, the compound (b) includes an unsaturated compound having one or more carboxy groups and one or more carboxylic acid anhydride groups. Examples of the unsaturated group include a vinyl group, a vinylene group, an unsaturated cyclic hydrocarbon group, and the like. Specific compounds (b) include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, bicyclo[2,2,1]. Unsaturated carboxylic acids such as hept-2-ene-5,6-dicarboxylic acid, or their acid anhydrides or their derivatives (for example, acid halides, amides, imides, esters, etc.) can be mentioned. Specific examples of the acid anhydrides or derivatives include malenyl chloride, maleenyl imide, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo[2,2,1]hept-2-ene- 5,6-dicarboxylic acid anhydride, dimethyl maleate, monomethyl maleate, diethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citracone, dimethyl tetrahydrophthalate, bicyclo[2,2,1]hept-2- Examples thereof include dimethyl ene-5,6-dicarboxylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, aminoethyl methacrylate and aminopropyl methacrylate.

When the unsaturated carboxylic acid and/or its derivative is used as the compound (b) having a group that reacts with a carbodiimide group, it can be used alone or in combination of two or more. it can. Among these, maleic anhydride, (meth)acrylic acid, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic anhydride , Hydroxyethyl (meth)acrylate, glycidyl methacrylate and aminopropyl methacrylate are preferred. Further, it is a dicarboxylic acid anhydride such as maleic anhydride, itaconic acid anhydride, citraconic acid anhydride, tetrahydrophthalic acid anhydride, or bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic acid anhydride. Is particularly preferable.

<Graft copolymerization method>
Examples of the method for obtaining the olefin polymer (B) having a group that reacts with a carbodiimide group used in the present invention by graft copolymerization (graft modification) include, for example, the above-mentioned polyolefin (polyolefin main chain) to be the main chain. In addition, a method of graft-copolymerizing the compound (b) having a group that reacts with a carbodiimide group in the presence of a radical initiator can be mentioned. Such graft copolymerization may be carried out together with the compound (b), if necessary, in the presence of other ethylenically unsaturated monomers and the like.

The method of graft-copolymerizing the compound (b) having a group that reacts with a carbodiimide group on the polyolefin main chain is not particularly limited, and a conventionally known graft polymerization method such as a solution method or a melt-kneading method can be adopted.

(Radical copolymerization)
In the case of radical copolymerization, it is possible to employ the same olefin as the above-mentioned olefin for forming the polyolefin main chain, and as the compound (b) having a group that reacts with a carbodiimide group, It is possible to employ the same one as described above in the section of graft copolymerization.

The method for copolymerizing the olefin and the compound (b) having a group that reacts with a carbodiimide group is not particularly limited, and a conventionally known radical copolymerization method can be adopted.

(Characteristics of Olefin Polymer (B) Having Group Reacting with Carbodiimide Group)
The olefin polymer (B) having a group that reacts with a carbodiimide group used in the present invention is usually at least partly contained in the thermoplastic elastomer composition obtained by being used together with the carbodiimide group-containing compound (A). It reacts with the carbodiimide group-containing compound (A) to form a reaction product (I). The thermoplastic elastomer composition according to the present invention exhibits a form in which the constituent components are highly dispersed and has excellent mechanical properties because the reaction product (I) is compatible with the thermoplastic elastomer composition. It is considered that this is partly due to the fact that it acts as an agent.

The content of the compound (b) having a group reactive with a carbodiimide group (content of a portion derived from the compound (b)) in the olefin polymer (B) having a group reactive with a carbodiimide group is usually 0. 0.1 to 10% by mass, preferably 0.1 to 3.0% by mass, and more preferably 0.1 to 2.0% by mass. When the content of the compound (b) is within the above range, a reaction with the carbodiimide group-containing compound (A) is likely to occur, which is preferable.

Further, in the present invention, when the content of the compound (b) having a group reactive with a carbodiimide group in the olefin polymer (B) having a group reactive with a carbodiimide group is within the above range, a carbodiimide group-containing compound A binding portion of the reaction product (I) between the (A) and the olefin polymer (B) having a group that reacts with a carbodiimide group is formed, and acts as a compatibilizer in the resulting thermoplastic elastomer composition. Is preferable because

In order to prevent gelation due to cross-linking, the lower the number average molecular weight of the olefin polymer (B) having a group that reacts with a carbodiimide group is, It is preferable that the molar ratio of (the number of moles)/(the number of moles of the olefin polymer (B) having a group that reacts with a carbodiimide group) is small. That is, when the compound (b) is present in a state close to the singular number, instead of the plural number, on the main chain of the olefin polymer (B) having a group that reacts with the carbodiimide group, This means that when the carbodiimide group (N=C=N) of the compound (A) reacts with the compound (b) part, gelation due to crosslinking hardly occurs.

In the present invention, by controlling the number average molecular weight (Mn) of the olefin polymer (B) having a group reactive with a carbodiimide group and the content of the compound (b) having a group reactive with a carbodiimide group. Even when the reaction product (I) with the carbodiimide group-containing compound (A) is formed during the production of the thermoplastic elastomer composition, gelation due to cross-linking is unlikely to occur and the production stability can be maintained. In the obtained thermoplastic elastomer composition, the reaction product (I) can sufficiently exhibit the performance as a compatibilizer.

In the present invention, the olefin polymer (B) having a group that reacts with a carbodiimide group preferably satisfies the following formula (1).
0.1<Mn/[(100-M)*f/M]<6 (1)
(In formula (1),
f: Formula weight (g/mol) of the compound (b) having a group that reacts with a carbodiimide group
M: Content of compound (b) having a group that reacts with a carbodiimide group (content of a portion derived from compound (b)) (mass %)
Mn: The number average molecular weight of the olefin polymer (B) having a group that reacts with a carbodiimide group. )

Further, from the viewpoint of production stability that gelation due to cross-linking does not occur, it is more preferably in the range satisfying the following formula (2), and most preferably in the range satisfying formula (3).
0.3<Mn/[(100-M)*f/M]<4 (2)
0.5<Mn/[(100-M)*f/M]<2.8 (3)

When the relationship between the number average molecular weight (Mn) of the olefin polymer (B) having a group that reacts with a carbodiimide group and the compound (b) having a group that reacts with a carbodiimide group is within the above range, the carbodiimide group-containing compound (A ) And an olefin-based polymer (B) having a group that reacts with a carbodiimide group, a carbodiimide group-containing compound (A) is added when a reaction product (I) is produced or when a thermoplastic elastomer composition is produced. It is possible to suppress the gelation due to the cross-linking resulting from the stable production.

Further, in the present invention, when the olefin-based polymer (B) having a group that reacts with a carbodiimide group is obtained by graft polymerization, the polyolefin serving as the graft main chain has an ethylene content such as linear low density polyethylene. When the amount of the resin is large, it tends to be easily crosslinked as compared with a resin having a large amount of α-olefin copolymerization such as an ethylene/butene copolymer. Therefore, when a resin having a high ethylene content is used as the graft main chain, the compound (b) having a group that reacts with a carbodiimide group is present on the molecular chain of the polyolefin in a number close to a singular number, that is, The lower the number in the calculation formula, the more the gelation due to crosslinking can be suppressed.

The number average molecular weight can be determined by a general molecular weight measuring method for polymers such as GPC method, light scattering method, low angle light scattering photometric method, vapor pressure osmotic pressure method, and membrane osmotic pressure method.

The melt flow rate (MFR) at 190° C. or 230° C. of the olefin polymer (B) having a group which reacts with a carbodiimide group at a load of 2.16 kg according to ASTM D1238 at 190° C. or 230° C. is the polar rubber (C) constituting the thermoplastic elastomer composition. ) And the characteristics of the olefin polymer (D), but usually 0.01 to 500 g/10 min, preferably 0.05 to 300 g/10 min. Within the above range, the compatibility between the polar rubber (C) and the olefin polymer (D) in the resulting thermoplastic elastomer composition is more excellent, which is preferable.

The density of the olefin polymer (B) having a group reactive with a carbodiimide group is generally 0.8~1.2g / cm ^3, preferably 0.8~1.1g / cm ^3, more preferably 0.8 Is about 1.0 g/cm ³ .

Among the olefin-based polymers (B) having a group that reacts with a carbodiimide group in such a range, polyethylene, polypropylene, polybutene 1, poly-4-methylpentene-1, and the copolymerization of these with α-olefin A maleic anhydride graft copolymer of a crystalline polyolefin such as a coalesced product is preferable, and a maleic anhydride graft copolymer of polyethylene or polypropylene is more preferable, although it depends on an object of compatibilization, and a maleic anhydride graft copolymer of polypropylene is preferable. Coalescence is more preferred.

The density of the olefin polymer (B) having a group that reacts with a carbodiimide group is not particularly limited, but may be the density of the olefin polymer (D) constituting the thermoplastic elastomer composition, if necessary. It is more preferable that the density is close to, the density close to that of the polar rubber (C), or the density between the density of the polar rubber (C) and the density of the olefin polymer (D).

As the olefin-based polymer (B) having a group that reacts with such a carbodiimide group, one appropriately prepared by the above-mentioned graft copolymerization or radical copolymerization may be used, or a commercially available one may be used. .. Examples of the commercially available polyolefin having a group that reacts with a carbodiimide group include Admer (registered trademark) manufactured by Mitsui Chemicals, Inc., Orevac (registered trademark) manufactured by Arkema, and Polybond (registered trademark) manufactured by Additive.

[Polar rubber (C)]
As the polar rubber (C), rubbers having polarity can be used without particular limitation. In addition to carbon (C) and hydrogen (H), nitrogen (N) and oxygen (O) are included in the molecular structure. A rubber having a polar group containing atoms such as sulfur, sulfur (S), halogen (F, Cl, Br, etc.) and phosphorus (P) is preferable, and a rubber having a polar group in the side chain is more preferable. Since the polar rubber (C) has excellent properties such as oil resistance to non-polar oil, it is particularly useful as a material for tubes or hoses for transferring non-polar oil such as gasoline and lubricating oil.

Specific examples of the polar rubber (C) include carboxy group-containing nitrile rubber, hydrogenated product of carboxy group-containing nitrile rubber, nitrile rubber, hydrogenated product of nitrile rubber, carboxy group-containing acrylic rubber, epoxy group-containing Examples thereof include acrylic rubber, acrylic rubber, carboxy group-containing epichlorohydrin rubber, epichlorohydrin rubber, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, polysulfide rubber, fluororubber and hydrogenated ethylenically unsaturated nitrile-conjugated diene rubber. Various rubbers commercially available as polar rubbers can also be used in the present invention. Among these, nitrile rubber and carboxy group-containing nitrile rubber are preferable from the viewpoint of properties such as oil resistance to nonpolar oils such as gasoline and lubricating oil.

The polar rubber (C) preferably has a number average molecular weight of 5,000 to 2,000,000, more preferably 10,000 to 500,000. Depending on the use of the rubber composition, if the number average molecular weight is equal to or more than the lower limit, desired rubber strength physical properties are easily obtained, and if it is equal to or less than the upper limit, desired molding processability is obtained. It is preferable because it is easy.

Further, the Mooney viscosity (ML ₁₊₄ , 100° C.) of the polar rubber (C) is preferably 10 to 200, more preferably 20 to 150. When the Mooney viscosity is at least the lower limit value, the desired rubber strength physical properties are easily obtained, and when it is at most the upper limit value, the handleability in the uncrosslinked state is good and the desired processability and moldability are obtained. It is preferable because it is easy.

The solubility parameter (SP value) of the polar rubber (C) is usually 16.5 to 30 (MPa) ^0.5 , preferably 17 to 29 (MPa) ^0.5 , and more preferably 17.5 to 28 (MPa) ^0.5 . When the SP value is relatively high as described above, the oil resistance to non-polar oil such as gasoline and lubricating oil is improved, and the material of the tube or hose for transferring non-polar oil such as gasoline and lubricating oil, gasoline and It is useful as a material for a tube or hose for transferring a gas in which mist of non-polar oil such as lubricating oil may be mixed.

The polar rubber (C) may be used alone or in combination of two or more.

The polar rubber (C) used in the present invention is not particularly limited, but at least a part thereof is preferably an amorphous elastic copolymer which can be crosslinked by using a crosslinking agent.

(Polar rubber (C1) having a group that reacts with a carbodiimide group)
In the thermoplastic elastomer composition of the present invention, it is also preferable that the polar rubber (C) contains a polar rubber (C1) having a group that reacts with a carbodiimide group. In the present invention, the entire polar rubber (C) may be a polar rubber (C1) having a group that reacts with a carbodiimide group, or a part of the polar rubber (C) has a group that reacts with a carbodiimide group. It may be a polar rubber (C1). Here, as the "group having reactivity with a carbodiimide group", as mentioned above, for example, a group having active hydrogen, or a group easily converted into a group having active hydrogen by water or the like can be mentioned.

The polar rubber (C1) having a group that reacts with a carbodiimide group reacts with a carbodiimide group such as a carboxylic acid anhydride group, a carboxy group (-COOH), a hydroxy group (-OH), and a thiol group (-SH). Examples thereof include polar rubbers having a group in the side chain and the like, and particularly polar rubbers containing a carboxy group.

Preferable examples of the polar rubber (C1) include a carboxy group-containing nitrile rubber, a hydrogenated product of a carboxy group-containing nitrile rubber, a carboxy group-containing acrylic rubber, an epoxy group-containing acrylic rubber, and a carboxy group-containing epichlorohydrin rubber.

The polar rubber (C1) having a group that reacts with a carbodiimide group may be used alone or in combination of two or more.

When the polar rubber (C) constituting the thermoplastic elastomer composition of the present invention contains the polar rubber (C1) having a group that reacts with a carbodiimide group, it depends on the manufacturing process such as the order of melt kneading. The resulting thermoplastic elastomer composition contains the reaction product (II) of the carbodiimide group-containing compound (A) and the polar rubber (C1) having a group that reacts with the carbodiimide group. It is preferable that the thermoplastic elastomer composition contains the reaction product (II) because the compatibility of each component in the thermoplastic elastomer composition is further improved.

[Olefin-based polymer (D)]
The olefin polymer (D) constituting the thermoplastic elastomer composition of the present invention, if necessary, is a polymer or copolymer mainly having a structural unit derived from an olefin and has reactivity with a carbodiimide group. Substantially free of groups. “Substantially free of a group having reactivity with a carbodiimide group” means that it does not actually react with the carbodiimide group of the carbodiimide group-containing compound (A) in the state of being prepared as the thermoplastic elastomer composition of the present invention. It means that no contribution is made to the action and effect of the present invention even if the group is contained in a very small amount.

Examples of the olefin-based polymer (D) are the same as those described in the section of the polyolefin main chain, which is the main chain of the olefin-based polymer (B) having a group that reacts with the carbodiimide group. .. That is, the olefin polymer (D) used in the present invention is a polymer or copolymer containing an aliphatic α-olefin having 2 to 20 carbon atoms, a cyclic olefin, or a non-conjugated diene as a main component, and preferably It is a polymer or copolymer mainly composed of an α-olefin having 2 to 10 carbon atoms, and more preferably an α-olefin having 2 to 8 carbon atoms. These olefins as monomers may be used alone or in combination of two or more. The comonomer content is usually 50 mol% or less, preferably 40 mol% or less, and more preferably 30 mol% or less.

In the present invention, the olefin polymer (D) is usually a polyolefin resin having thermoplasticity.

In the present invention, as the olefin polymer (D), ethylene, propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, tetracyclododecene. A homopolymer or copolymer of norbornene can be preferably used. Further, these can be used in both the isotactic structure and the syndiotactic structure, and there is no particular limitation in stereoregularity. The above-mentioned polyolefin can be produced by any conventionally known method, for example, polymerization can be performed using a titanium-based catalyst, a vanadium-based catalyst, a metallocene catalyst, or the like.

In the present invention, the olefin polymer (D) is preferably a polypropylene polymer, and as the polypropylene polymer, a homopolymer of propylene, a copolymer of propylene and another α-olefin, or the like. The propylene-based polymer can be preferably selected and used. When the olefin polymer (D) is a polypropylene polymer, the melt flow rate (MFR) measured at 2.16 kgf and 230° C. according to ASTM D1238 is 0.01 to 500 g/10 minutes, preferably 0. The range is from 0.05 to 200 g/10 minutes, and more preferably from 0.1 to 100 g/10 minutes.

[Crosslinking agent (E)]
The crosslinking agent (E) according to the present invention is a crosslinking agent capable of crosslinking the polar rubber (C) described above. As the cross-linking agent (E), various known cross-linking agents generally used in cross-linking rubber can be used. Specifically, for example, organic peroxides, phenol resins, sulfur compounds, hydrosilicone compounds, amino resins, quinones or their derivatives, amine compounds, azo compounds, epoxy compounds, thiourea compounds, thiazole compounds. Examples of the crosslinking agent include compounds, triazine compounds and isocyanates. Of these, crosslinking agents such as organic peroxides, phenolic resins and sulfur compounds are preferable.

Examples of organic peroxides include dicumyl peroxide, di-tert-butyl peroxide, 2,5-di-(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-di-(tert-butylperoxy). Hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)- 3,3,5-Trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert. -Butyl peroxy isopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butyl cumyl peroxide, etc. are mentioned.

Among these, 2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di- (Tert-Butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4 Bifunctional organic peroxides such as 4,4-bis(tert-butylperoxy)valerate are preferable, and above all, 2,5-di-(tert-butylperoxy)hexane and 2,5-dimethyl-2,5- Most preferred is di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3.

When an organic peroxide is used as the crosslinking agent (E), it is preferable to use a crosslinking auxiliary together. Examples of such a crosslinking aid include quinonedioxime-based crosslinking aids such as sulfur and p-quinonedioxime; acrylic-based crosslinking aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; diallyl phthalate and triallyl. Allyl-based cross-linking aids such as isocyanurate; Other maleimide-based cross-linking aids; divinylbenzene; zinc oxide (for example, ZnO#1 and 2 types of zinc oxide, manufactured by Hakusui Tech Co., Ltd.), and metal oxides such as magnesium oxide. To be The amount of the crosslinking aid compounded is usually 0.01 to 10 mol, preferably 0.1 to 7 mol, and more preferably 0.5 to 5 mol, based on 1 mol of the organic peroxide.

Examples of the phenol resin-based cross-linking agent include a resole resin obtained by condensing an alkyl-substituted or unsubstituted phenol with an aldehyde (preferably formaldehyde) in the presence of an alkali catalyst. The alkyl group of the alkyl-substituted phenol is preferably an alkyl group having 1 to about 10 carbon atoms. Further preferred are dimethylolphenols or phenolic resins substituted with alkyl groups having 1 to about 10 carbon atoms in the p-position. Crosslinking with a phenolic resin-based crosslinking agent is described in, for example, US Pat. No. 4,311,628, US Pat. No. 2,972,600, and US Pat. No. 3,287,440.

The phenol resin-based cross-linking agent is also available as a commercial product. Examples of commercially available products include Takki roll 201, Takki roll 250-I, Takki roll 250-III manufactured by Taoka Chemical Co., Ltd.; SP1045, SP1055, SP1056 manufactured by SI Group; Shonor CRM manufactured by Showa Denko KK; Arakawa Chemical Co., Ltd. Tamanor 531; Sumitomo Bakelite Co., Ltd. Sumilite Resin PR; Gunei Chemical Industry Co., Ltd. cash register top and the like (all the above are trade names). These can be used in combination of two or more. Among them, Takkiroll 250-III (brominated alkylphenol formaldehyde resin) manufactured by Taoka Chemical Co., Ltd. and SP1055 (brominated alkylphenol formaldehyde resin) manufactured by SI Group are preferable.

Moreover, when using a phenol resin type crosslinking agent as a crosslinking agent (E), it is preferable to use a crosslinking auxiliary together. Examples of such a crosslinking aid include metal halides such as stannous chloride and ferric chloride, halogen-containing polymers such as chloroprene rubber and halogenated butyl rubber, and zinc oxide (for example, ZnO#1 and zinc oxide 2 Seed, manufactured by Hakusui Tech Co., Ltd.), and metal oxides such as magnesium oxide.

Examples of the sulfur-based compound (vulcanizing agent) include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dithiocarbamate.

When a sulfur compound is used as the crosslinking agent (E), it is preferable to use a vulcanization accelerator together. Examples of such a vulcanization accelerator include N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N,N′-diisopropyl-2-benzothiazole sulfenamide, 2-mercaptobenzothiazole (for example, Sunceller M (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), 2-(4-morpholinodithio) benzthiazole (for example, Nocceller MDB-P (trade name; Ouchi Shinko Kagaku) Industrial Co., Ltd.)), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole and dibenzothiazyl disulfide (for example, Sancellar DM (commercial product). Name: Sanshin Chemical Industry Co., Ltd.)) and other thiazole vulcanization accelerators; guanidine vulcanization accelerators such as diphenylguanidine, triphenylguanidine and diorsotolylguanidine; acetaldehyde aniline condensate and butyraldehyde aniline. Aldehydeamine-based vulcanization accelerators such as condensates; 2-mercaptoimidazoline- and other imidazoline-based vulcanization accelerators; thiourea-based vulcanization accelerators such as diethylthiourea and dibutylthiourea; tetramethylthiuram monosulfide (for example, Sancellar TS ( (Trade name; Sanshin Chemical Industry Co., Ltd.)), tetramethylthiuram disulfide (for example, Sancella TT (trade name; Sanshin Chemical Industry Co., Ltd.)), tetraethylthiuram disulfide (for example, Sancella TET (trade name; Sanshin) Chemical Industry Co., Ltd.)), tetrabutyl thiuram disulfide (for example, Sancellar TBT (trade name; Sanshin Chemical Industry Co., Ltd.)) and dipentamethylene thiuram tetrasulfide (for example, Sancella TRA (trade name; Sanshin Chemical Industry Co., Ltd.) ) Etc.; zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate (for example, Sancella PZ, Sancella BZ and Sancella EZ (trade name; Sanshin Chemical Industry Co., Ltd.) )) and dithioate vulcanization accelerators such as tellurium diethyldithiocarbamate; ethylene thiourea (for example, Sancellar BUR (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.), Sanseller 22-C (trade name; Sanshin Chemical Industry) )) and thiourea-based vulcanization accelerators such as N,N'-diethylthiourea; Zanthate-based vulcanization accelerators such as zinc loxatate; and zinc white (for example, META-Z102 (trade name; zinc oxide manufactured by Inoue Lime Industry Co., Ltd.)) and the like.

When a sulfur compound is used as the crosslinking agent (E), it is also preferable to use a vulcanization aid. Examples of the vulcanization aid include zinc oxide (for example, ZnO#1/zinc oxide type 2, manufactured by Hakusui Tech Co., Ltd.), magnesium oxide and the like.

In the thermoplastic elastomer composition of the present invention, as the cross-linking agent (E), an organic peroxide cross-linking agent or a phenol resin cross-linking agent is preferably used among these cross-linking agents.

The thermoplastic elastomer composition of the present invention contains the above-mentioned polar rubber (C) and a cross-linking agent (E) capable of cross-linking the polar rubber (C) as a raw material to dynamically heat-treat the raw material. Become. In the thermoplastic elastomer composition, at least a part of the polar rubber (C) usually forms a crosslinked structure. That is, the thermoplastic elastomer composition of the present invention usually contains a crosslinked product of the polar rubber (C). Since the thermoplastic elastomer composition of the present invention contains a crosslinked polar rubber which is a crosslinked product of polar rubber, it has suitable elasticity and is also excellent in chemical resistance.

Further, in the thermoplastic elastomer composition of the present invention, the polar rubber (C), the reaction product (II) or the olefin polymer having a group reactive with the carbodiimide group-containing compound (A) and the carbodiimide group ( Either of the three-component reaction product (III) of B) and the polar rubber (C) may form a crosslink, and the reaction product (II) or the reaction product (III) and the polar product The rubber (C) may have crosslinks with each other. In the thermoplastic elastomer composition of the present invention, when two or more kinds of components have cross-links with each other, the respective components of the thermoplastic elastomer composition have better compatibility and separation is less likely to occur. preferable.

[Other ingredients]
The thermoplastic elastomer composition of the present invention comprises the above-mentioned carbodiimide group-containing compound (A), an olefin polymer (B) having a group that reacts with a carbodiimide group, a polar rubber (C), an olefin polymer (D) and Components other than the cross-linking agent (E) may be contained as raw materials within a range that does not impair the object of the present invention.

That is, the thermoplastic elastomer composition of the present invention can be blended with other resins, elastomers and the like within a range that does not impair the object of the present invention. Further, in the thermoplastic elastomer composition of the present invention, known plasticizers (F) and cross-linking aids (G), as well as softening agents, tackifiers, and anti-aging agents are included in the range not impairing the object of the present invention. , Processing aids, adhesion promoters, inorganic fillers, inorganic fibers such as glass fibers, acrylic fibers, PET fibers, PEN fibers, kenaf, plant fibers and other organic fibers, organic fillers, heat stabilizers, weather stabilizers, Additives (H) such as antistatic agents, colorants, lubricants, flame retardants, anti-blooming agents, reinforcing agents, activators, hygroscopic agents, colorants, and thickeners can also be added.

Of these, the thermoplastic elastomer composition of the present invention preferably contains a plasticizer (F) and/or a crosslinking aid (G). The plasticizer (F) is not particularly limited, and known plasticizers can be used. For example, phthalate ester plasticizers such as dibutyl phthalate and dioctyl phthalate; dioctyl adipate, dibutyl sebacate and the like. Aliphatic dibasic acid ester plasticizer; trimellitic acid ester plasticizer such as tridecyl trimellitate; Aliphatic dibasic acid ether ester plasticizer such as dibutoxyethoxyethyl adipate; Ether ester plasticizer; Polyester Plasticizers; phosphate ester plasticizers; epoxy plasticizers such as epoxidized soybean oil and epoxidized linseed oil; petroleum oils such as process oils, lubricating oils, aromatic oils, naphthene oils, paraffin oils, liquid paraffin, and vaseline Coal tars such as coal tar and coal tar pitch; fatty oils such as castor oil, linseed oil, rapeseed oil, soybean oil and coconut oil; waxes such as tall oil, beeswax and lanolin; ricinoleic acid, palmitin Acids, stearic acid, fatty acids such as calcium stearate or metal salts thereof; petroleum resins, chromanindene resins, synthetic polymeric substances such as atactic polypropylene; other microchlorin wax, sub (factice), liquid polybutadiene, modified liquid polybutadiene, liquid Thiocol and the like are listed, and among these, various ester types such as phthalate ester plasticizers, aliphatic dibasic acid ether ester plasticizers, ether ester plasticizers, etc. from the viewpoint of affinity with polar rubber (C). Plasticizers are preferred. The cross-linking aid (G) is not particularly limited, and examples thereof include the cross-linking aid described above in the section of the cross-linking agent (E).

These other components may be blended from the beginning as a raw material during the production of the thermoplastic elastomer composition, or may be added at the stage of dynamically heat treating the raw material, so that the thermoplastic elastomer composition is It may be added after it is obtained.

[Blending ratio of each component]
The thermoplastic elastomer composition of the present invention is not particularly limited, but an olefin polymer (B) having a group that reacts with a carbodiimide group, a polar rubber (C), and an olefin compounded as necessary. The carbodiimide group-containing compound (A) is usually 0.01 to 30 parts by mass, preferably 0.01 to 20 parts by mass, and more preferably 0.01 to 100 parts by mass with respect to the total amount of 100 parts by mass of the polymer (D). It is preferably obtained by using in the range of 15 parts by mass.

Further, the thermoplastic elastomer composition of the present invention includes a carbodiimide group-containing compound (A), an olefin polymer (B) having a group reactive with the carbodiimide group, the polar rubber (C), and the olefin polymer ( In 100% by mass of the total of D), the carbodiimide group-containing compound (A) has a group that reacts with the carbodiimide group in an amount of usually 0.01 to 30% by mass, preferably 0.01 to 20% by mass. The olefin polymer (B) is usually contained in an amount of 0.05 to 70% by mass, preferably 0.1 to 60% by mass, and the polar rubber (C) is usually contained in an amount of 10 to 95% by mass, preferably 20 to 90% by mass. In a preferred embodiment, the olefin polymer (D) is used as a raw material in a proportion of usually 0 to 85% by mass, preferably 2 to 85% by mass, and more preferably 4 to 70% by mass. ..

Furthermore, the thermoplastic elastomer composition of the present invention is based on a total of 100 parts by mass of the olefin polymer (B) having a group that reacts with a carbodiimide group, and the olefin polymer (D) optionally blended. The carbodiimide group-containing compound (A) is usually added in an amount of 0.01 to 30 parts by mass, preferably 0.03 to 25 parts by mass.

The thermoplastic elastomer composition of the present invention is a total of a polar rubber (C), an olefin polymer (B) having a group that reacts with a carbodiimide group, and an olefin polymer (D) optionally blended. It is desirable that the mass ratio (C):[(B)+(D)] of the above is usually 1:99 to 99:1, preferably 5:95 to 95:5.

When the thermoplastic elastomer composition of the present invention contains the olefin polymer (D), the mixing ratio of the polar rubber (C) and the olefin polymer (D) in the thermoplastic elastomer composition is Although not particularly limited, it is desirable that the mass ratio (C):(D) of the raw materials is usually 1:99 to 99:1, preferably 5:95 to 95:5. In the thermoplastic elastomer composition of the present invention, for example, the polar rubber (C) and the olefin polymer (D) have a mass ratio (C):(D) of the raw materials of 51:49 to 99:1. It may be contained at a ratio, or may be contained at a ratio satisfying 30:70 to 70:30.

In the thermoplastic elastomer composition of the present invention, although depending on the types of the polar rubber (C) and the cross-linking agent (E), the cross-linking agent (E) is usually 0 per 100 parts by mass of the polar rubber (C). It is desirable to contain 0.01 to 15 parts by mass, preferably 0.05 to 10 parts by mass.

Further, when the thermoplastic elastomer composition of the present invention contains a plasticizer (F), the plasticizer (F) is usually added in an amount of 1 to 150 parts by weight, preferably 3 parts by weight, relative to 100 parts by weight of the polar rubber (C). It is desirable to contain -100 parts by mass.

[Thermoplastic Elastomer Composition for Tube or Hose]
The thermoplastic elastomer composition for a tube or hose of the present invention comprises the above-mentioned carbodiimide group-containing compound (A), an olefin polymer (B) having a group that reacts with a carbodiimide group, a polar rubber (C), and if necessary. The olefin polymer (D) and the crosslinking agent (E) that can crosslink the polar rubber (C) are dynamically heat-treated. The thermoplastic elastomer composition for a tube or hose of the present invention may contain the above-mentioned other components, if necessary. The mixing ratio of each component in the thermoplastic elastomer composition of the present invention is not particularly limited and is preferably as described above.

The thermoplastic elastomer composition for a tube or hose of the present invention is not particularly limited in its production method as long as it is produced through a step of blending raw material components and dynamically heat treating. Examples of the method for producing the thermoplastic elastomer composition for a tube or hose of the present invention include a method of melt-kneading each component all at once or sequentially. That is, the thermoplastic elastomer composition for a tube or hose of the present invention may be prepared by blending the components as raw materials at once and dynamically heat-treating the components, and the components may be sequentially added in any order. It may be prepared by adding it to and heat treating dynamically. The method of dynamically performing heat treatment is not particularly limited, but melt kneading is preferable.

Specifically, for example, a method of dry-blending each component that is a raw material of the thermoplastic elastomer composition and then melt-kneading with a uniaxial or biaxial extruder, a Banbury mixer, a roll, various kneaders, and the like can be mentioned. .. Regarding the melting and kneading temperature, it is preferable to adopt a temperature at which each component melts, and it is preferable to adopt a temperature higher than the melting point of the component having the highest melting point among the raw materials to be subjected to melt kneading, but usually 130 to 400 C., preferably 160 to 280.degree. C. in the temperature range.

The thermoplastic elastomer composition for tubes or hoses of the present invention contains the carbodiimide group-containing compound (A) as a raw material and the compound (B) containing a group that reacts with a carbodiimide group, and thus is obtained as a thermoplastic composition. Among them, the above-mentioned carbodiimide group-containing compound (A) and the "group which reacts with a carbodiimide group" of the olefin polymer (B) having a group which reacts with a carbodiimide group react at least partially by melt kneading. However, it is considered that a reaction product (I) may be formed between the carbodiimide group-containing compound (A) and the olefin polymer (B) having a group that reacts with the carbodiimide group. This reaction product (I) has a carbodiimide group as well as a polyolefin chain derived from the olefin polymer (B) having a group that reacts with a carbodiimide group. Since such a reaction product (I) has a carbodiimide group which is a polar group, it has excellent compatibility with the polar rubber (C), and since it has a polyolefin chain, an olefin that is blended as necessary. The compatibility with the system polymer (D) is also excellent. Therefore, when the thermoplastic elastomer composition for a tube or hose of the present invention contains the olefin polymer (D), the polar rubber (C) and the olefin polymer (D) are contained in the thermoplastic elastomer composition. And are highly mixed and well dispersed as compared with the case where both are simply mixed. Therefore, the thermoplastic elastomer composition for a tube or hose of the present invention contains the reaction product (I) of the carbodiimide group-containing compound (A) and the olefin polymer (B) having a group that reacts with the carbodiimide group. It is preferable.

Further, the thermoplastic elastomer composition for a tube or hose of the present invention contains a polar rubber (C) and a cross-linking agent (E) capable of cross-linking the polar rubber (C) as raw materials, and therefore the tube of the present invention Alternatively, in the thermoplastic elastomer composition for hoses, at least part of the polar rubber (C) forms crosslinks. That is, the thermoplastic elastomer composition for a tube or hose of the present invention usually contains a crosslinked polar rubber which is a crosslinked product of the polar rubber (C). In the thermoplastic elastomer composition for a tube or hose of the present invention, the crosslinked polar rubber which is a crosslinked product of the polar rubber (C) and the olefin polymer (D) optionally blended are highly dispersed. doing.

Further, in the thermoplastic elastomer composition for a tube or hose of the present invention, any one of the above-mentioned polar rubber (C), reaction product (II) or reaction product (III) may form a crosslink. Further, the reaction product (II) or the reaction product (III) and the polar rubber (C) may have cross-links with each other. That is, the thermoplastic elastomer composition for a tube or hose of the present invention may contain a crosslinked product in which two or more kinds of these components are crosslinked with each other.

Such a thermoplastic elastomer composition for a tube or hose of the present invention has suitable elasticity by containing a crosslinked product, has excellent chemical resistance, and, if necessary, an olefin polymer (D). By containing, it has excellent moldability. Further, the thermoplastic elastomer composition for a tube or hose of the present invention is preferable because each component constituting the composition is highly dispersed and separation is unlikely to occur. This means that the reaction product (I), the reaction product (II), etc. are produced in the thermoplastic elastomer composition part to act as a compatibilizer, or at least a part of the raw material forms a crosslink. It is thought that this is due to the fact that they are intertwined with each other.

In the thermoplastic elastomer composition for a tube or hose of the present invention, the crosslinked polar rubber which is a crosslinked product of the polar rubber (C) and the olefin polymer (D) optionally blended are highly dispersed. The thermoplastic elastomer composition has excellent moldability, and the molded product obtained from the thermoplastic elastomer has excellent elasticity, and also exhibits excellent fuel resistance, fuel permeation resistance, and ozone resistance. .. Further, the thermoplastic elastomer composition for a tube or hose of the present invention has excellent moldability because it contains the olefin polymer (D) component in a highly dispersed state. In the thermoplastic elastomer composition for a tube or hose of the present invention, the fact that the respective components, particularly the crosslinked polar rubber and the olefin polymer (D) are highly dispersed, can be determined, for example, from the thermoplastic elastomer composition. It can be easily confirmed by observing the surface or cross section of the obtained molded body with a microscope or the like and the dispersed particle size being sufficiently small.

In the thermoplastic elastomer composition for a tube or hose of the present invention, a sea-island structure is observed in an image with a scanning electron microscope (SEM) of 200 times or more, for example, about 1000 times, and the average particle size of the island phase is preferably. Is preferably 0.01 to 20 μm, and more preferably 0.01 to 10 μm.

[Tube or hose]
The tube or hose of the present invention contains the above-mentioned thermoplastic elastomer composition of the present invention. The tube or hose of the present invention may be wholly made of the thermoplastic elastomer composition of the present invention, or at least a part thereof may be made of the thermoplastic elastomer composition of the present invention. .. For example, it may be a single-layer tube or a single-layer hose, or may be a multi-layer tube or a multi-layer hose in which at least one layer is composed of the thermoplastic elastomer composition of the present invention. The size or wall thickness of the tube or hose is not particularly limited, and may be appropriately determined according to the application to be used.

The aforementioned multilayer tube or hose may include a fuel barrier layer. The position of the fuel barrier layer is not particularly limited and may be any of the inner layer, the intermediate layer and the outer layer. When a fuel barrier layer is included, the ratio (%) of the thickness of the barrier layer to the total thickness, which is the total thickness of the layers of the multilayer tube or hose, is usually 0.1 to 40, preferably 0.3 to 24. It is desirable to be in the range. The above-mentioned fuel barrier layer is not particularly limited as long as it is a material having a low fuel permeation coefficient. For example, a known material as a fuel barrier layer such as fluororesin, fluororubber, polyamide, polyester, EVOH, and PPS. Can be used.

The tube or hose of the present invention can also include a reinforcement layer. The position of the reinforcing layer is not particularly limited and may be any of the inner layer, the intermediate layer and the outer layer. The material of the reinforcing layer is not particularly limited, and any material known as a reinforcing layer for tubes or hoses can be used. For example, when the fibers used for the reinforcing layer are used, the type of the fibers is not particularly limited, and for example, known fibers such as polyester, polyamide, and aramid used for the application can be used.

The tube or hose described in the present invention may include an adhesive or an adhesive layer depending on the layer structure. The type of adhesive used for the adhesive layer is not particularly limited, and any known adhesive layer for tubes or hoses can be used.

The molding method for producing the tube or hose of the present invention is not particularly limited, and a conventionally known method can be adopted. For example, a thermoplastic elastomer composition extruded from an extruder can be further extruded into a cylindrical shape through a die, cooled and solidified to obtain a tube- or hose-shaped molded article.

The tube or hose of the present invention, by including the thermoplastic elastomer composition of the present invention, is excellent in various properties required for the tube or hose, and is particularly excellent in fuel permeation resistance, fuel resistance, and ozone resistance. No cross-linking step is required during molding.

The application of the tube or hose of the present invention is not particularly limited, and it can be used for various applications such as automobiles, water supply, and gas. However, since it is particularly excellent in fuel permeation resistance, fuel resistance, and ozone resistance, a tube or hose for transferring non-polar oil such as gasoline and lubricating oil, non-polar oil such as gasoline and lubricating oil, etc. It is useful as a tube or hose for transferring gas that may be mixed with mist.

For example, fuel hoses such as PCV hoses, fuel hoses, filler hoses, vent hoses, and evaporation hoses, air hoses such as air hoses, turbo hoses, recirculation lines, high-pressure hoses used for hydraulic systems for power steering, and returns. Examples include PS hoses such as hoses and suction hoses, vacuum brake hoses, and some hydraulic brake hoses.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

<Measurement and evaluation method>
In the following examples and comparative examples, each property was measured or evaluated as follows.

[Number average molecular weight (Mn)]
The number average molecular weight (Mn) was measured by gel permeation chromatography (GPC). It was measured as follows using a gel permeation chromatograph Alliance GPC-2000 type manufactured by Waters. The separation column used two TSKgel GMH6-HT and two TSKgel GMH6-HTL, the column size was 7.5 mm in diameter and 300 mm in length, and the column temperature was 140° C. and the mobile phase was o. -Using dichlorobenzene (Wako Pure Chemical Industries, Ltd.) and BHT (Takeda Yakuhin) 0.025 mass% as an antioxidant, moving at 1.0 ml/min, the sample concentration is 15 mg/10 mL, and the sample injection amount is 500 micro The liter was used and a differential refractometer was used as a detector. As the standard polystyrene, those having a molecular weight of Mw<1000 and Mw>4×10 ⁶ were manufactured by Tosoh Corporation, and those having a molecular weight of 1000≦Mw≦4×10 ⁶ were manufactured by Pressure Chemical. In the case of maleic anhydride-modified polypropylene, it was calculated in terms of polypropylene.

[Particle size]
An image obtained by enlarging a sample obtained by dyeing a resin component with ruthenium tetroxide to 500 to 3000 times with a scanning electron microscope (measuring device: JSM-7001F manufactured by JEOL Ltd.) was analyzed.

The analysis was performed by binarization processing using image analysis software ImageJ. The area occupied by the polypropylene resin and the polar rubber particles in this image was specified.

The area of each of the occupying regions of the specified particles was calculated by image analysis. Then, the diameter of a true circle having the same area as the area was obtained, and the arithmetic average of the values obtained for the respective occupied areas was used as the measured value of the average particle diameter of the particles. That is, for the particle diameter of each particle, the area S of each particle was obtained, and using S, (4S/π) ^0.5 was taken as the particle diameter of each particle.

[Fuel immersion test]
In the fuel immersion test, a test piece cut into a size of 30 mm×30 mm from a press sheet having a thickness of 2 mm was subjected to Fuel C (isooctane/toluene=50/50 mass%) or CE20 (ethanol/isooctane/toluene=20/40/40 mass%). Each was immersed for 72 hours at a temperature of 40° C., and the volume change rate (%) was calculated from the volume before and after the test.

[Fuel permeation test (cup method)]
About 10 ml of Fuel C (isooctane/toluene=50/50 mass%) or CE20 (ethanol/isooctane/toluene=20/40/40 mass%) was put in a 30 mmφ SUS special cup (permeation area 7.07 cm ² ), A test piece prepared from a press sheet having a thickness of 2 mm was sealed with a lid. Hold the same amount of Fuel C or CE20 with a lid made of aluminum instead of the press sheet together with a blank compensating cup, and keep it in a nitrogen atmosphere kept at a temperature of 40°C ± 2°C and a humidity of 0% RH for a regular period. The weight change was measured (once/day). The test was continuously conducted for 144 hours or more, and the numerical value obtained by subtracting the numerical value of the blank correction cup was determined as the weight change amount at each time. The obtained amount of change in weight was plotted against time, and the transmittance (g/(m ² ·24h)) was calculated from the slope/permeation area of the straight line. Further, the permeation coefficient (g·mm/(m ² ·24h)) was determined from the actual measurement value (mm) of the thickness of the press sheet used for the measurement×permeability.

[Static ozone deterioration test]
The static ozone deterioration test is based on JIS K 6259 static ozone deterioration test, and a test piece (JIS K 6251 standard dumbbell-shaped No. 1 type) punched out from a press sheet having a thickness of 2 mm is used at a temperature of 40±2° C. In a 50±5 pphm atmosphere, a state in which a strain of 20% was applied was maintained, and the state of crack generation on the surface was periodically observed. The test lasted up to 72 hours.

[Production Example 1]
<Production of maleic anhydride modified polypropylene (B-1)>
100 parts by mass of polypropylene (Prime Polymer Co., Ltd., Prime Polypro (registered trademark) F327), 1 part by mass of maleic anhydride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 2,5-dimethyl-2,5-bis( tert-butylperoxy)hexyne-3 (NOF CORPORATION, Perhexin (registered trademark) 25B) (0.25 parts by mass) is mixed, and a twin-screw kneader (manufactured by Japan Steel Works, Ltd., TEX-30, L/) is mixed. D=40, using a vacuum vent), a cylinder temperature of 220° C., a screw rotation speed of 200 rpm, and a discharge rate of 80 g/min were extruded to obtain a maleic anhydride-modified polypropylene (B-1). The obtained maleic anhydride-modified polypropylene (B-1) was dissolved in xylene, and then the obtained xylene solution was poured into acetone for reprecipitation and purification, and the grafted amount of maleic anhydride was measured by IR. The result was 0.7% by mass. The number average molecular weight (Mn) was Mn 28,000 as measured by GPC.

<Example 1>
Polycarbodiimide (A-1) which is a carbodiimide group-containing compound (manufactured by Nisshinbo Chemical Co., Ltd., Carbodilite (registered trademark) HMV-15CA, carbodiimide equivalent 262 g), and maleic anhydride-modified polypropylene (B-1) obtained in Production Example 1 ), polypropylene (D-1) (homopolypropylene, made by Prime Polymer Co., Ltd., Prime Polypro (registered trademark) F113G, MFR: 3.0 g/10 min) at the blending amount (mass part) shown in Table 1 (extruder). TEX44, L/D=70) manufactured by Japan Steel Works, Ltd., melted and kneaded at a cylinder temperature of 290° C., a screw rotation speed of 760 rpm, and a discharge rate of 1.33 kg/min, and anhydrous with polycarbodiimide (A-1). A composition containing a reaction product (contact product) with the maleic acid-modified polypropylene (B-1) and the polypropylene (D-1) was obtained (first stage blending).

Next, polypropylene (D-2) (homopolypropylene, Prime Polymer Co., Ltd., Prime Polypro (registered trademark) J105), nitrile rubber (C-1) which is a polar rubber (Nihon Zeon Co., Ltd., Nipol (registered trademark)) 1042, NBR, Mooney viscosity=77.5, amount of bound acrylonitrile=33.5%, SP value=about 20 (MPa) ^0.5 ), polar rubber having a group that reacts with a carbodiimide group (C1-1) (Nippon Zeon Corporation) Nipol (registered trademark) NX775, NBR containing carboxyl group, Mooney viscosity = 44.0, bound acrylonitrile amount = 26.7%, SP value = about 20 (MPa) ^0.5 ), plasticizer (F-1) ( ADEKA Corporation, Adeka Sizer (registered trademark) RS-107), additive (H-1) (BASF, Irganox (registered trademark) 1010, phenolic antioxidant), additive (H-2) ( Ouchi Shinko Chemical Industry Co., Ltd., Nocrac 224), Additive (H-3) (Ouchi Shinko Chemical Industry Co., Ltd., Nocrac MMB), Carbon Black (I) (Tokai Carbon Co., Ltd., trade name SIST S) ) And the above composition were introduced into an intermeshing kneader (BB-L3200IM, manufactured by Kobe Steel, Ltd.) so that the compounding amount (parts by mass) shown in Table 1 was reached, and melt-kneaded at 120 rpm (No. Two-stage formulation). After that, a crosslinking agent (E-1) (manufactured by NOF CORPORATION, Perhexa (registered trademark) 25B, organic peroxide-based crosslinking agent) and a crosslinking aid (G-1) (manufactured by NS Styrene Monomer Co., Ltd., divinylbenzene). Dynamic crosslinking was carried out at 100 to 250° C. in the presence of a system crosslinking aid (trade name DVB-810) (third stage compounding) to obtain a thermoplastic elastomer composition. The obtained thermoplastic elastomer composition was about 3 kg/batch.

A molded body sample made of the obtained thermoplastic elastomer composition was observed by SEM (measuring device: JSM-7001F, manufactured by JEOL Ltd., magnification 1000 times) to measure the average particle diameter. Further, the obtained thermoplastic elastomer composition was press-molded at 210° C. to a thickness of 2 mm and punched into various test shapes as samples, and the physical properties were measured by the above-mentioned test methods. The results are shown in Table 1.

<Comparative Example 1>
The composition obtained in the first stage formulation of Example 1 was not used, and the polar rubber (C1-1) and polypropylene (D-2) having a group that reacts with a carbodiimide group were not used, and the nitrile rubber (C -1) and each of the other components in the blending amounts (parts by mass) shown in Table 1 using an intermeshing kneader and a roll to prepare an unvulcanized rubber composition, and using a hot press. And held at 180° C. for 10 minutes to be crosslinked to obtain a crosslinked rubber sheet. Physical properties were evaluated using the obtained crosslinked rubber sheet. The results are shown in Table 1.

The molded article made of the thermoplastic elastomer composition obtained in Example 1 has better fuel resistance, fuel permeation resistance, and ozone resistance than the molded article made of the elastomer composition obtained in Comparative Example 1. Was excellent. Further, if the thermoplastic elastomer composition obtained in Example 1 is used, a molding step can be shortened because a cross-linking step is not required when molding a tube or a hose.

The thermoplastic elastomer composition for tubes or hoses of the present invention is excellent in various properties required for tubes or hoses, particularly excellent in fuel permeation resistance, fuel resistance, ozone resistance, and requires a crosslinking step during molding. Therefore, it is particularly suitable as a material for tubes or hoses in various applications. Further, since it is thermoplastic, it can be processed even after forming a tube or a hose, and can be easily processed even when it is necessary to bend it into a complicated shape such as an automobile application. Further, even if it does not contain a halogen-based polymer such as PVC, since it has excellent ozone resistance, it is possible to provide a tube and a hose made of a non-halogen material.

Claims (13)

Carbodiimide group-containing compound (A),
An olefin polymer (B) having a group that reacts with a carbodiimide group,
Polar rubber (C) and cross-linking agent (E) capable of cross-linking polar rubber (C)
A thermoplastic elastomer composition for a tube or hose, which is obtained by dynamically heat-treating. The thermoplastic elastomer composition for belts for tubes or hoses according to claim 1, further comprising an olefin polymer (D). Thermoplastic for tubes or hoses according to claim 1 or 2, containing a reaction product (I) of a carbodiimide group-containing compound (A) and an olefin polymer (B) having a group that reacts with a carbodiimide group. Elastomer composition. The thermoplastic elastomer composition for tubes or hoses according to claim 1, wherein the polar rubber (C) contains a polar rubber (C1) having a group that reacts with a carbodiimide group. The thermoplastic elastomer composition for tubes or hoses according to claim 4, wherein the polar rubber (C1) having a group that reacts with a carbodiimide group is a polar rubber having a side chain having a group having active hydrogen. The thermoplastic elastomer composition for tubes or hoses according to claim 4 or 5, containing a reaction product (II) of a carbodiimide group-containing compound (A) and a polar rubber (C1) having a group that reacts with a carbodiimide group. .. The thermoplastic elastomer composition for tubes or hoses according to any one of claims 1 to 6, wherein the carbodiimide group-containing compound (A) is a polycarbodiimide having a repeating unit represented by the following general formula.
^{-N = C = N-R 1} -
(In the formula, R ¹ represents a divalent organic group.) The heat for tubes or hoses according to any one of claims 1 to 7, wherein the olefin polymer (B) having a group that reacts with a carbodiimide group is an olefin polymer having a group having active hydrogen in a side chain. Plastic elastomer composition. The olefin polymer (B) having a group that reacts with a carbodiimide group is a graft copolymer of a polyolefin and a compound (b) having a group that reacts with a carbodiimide group. A thermoplastic elastomer composition for a tube or hose as described above. The thermoplastic elastomer composition for tubes or hoses according to any one of claims 2 to 9, wherein the olefin polymer (D) is a propylene polymer. With respect to a total of 100 parts by mass of the olefin polymer (B) having a group that reacts with a carbodiimide group, the polar rubber (C), and the olefin polymer (D) optionally blended,
The thermoplastic elastomer composition for tubes or hoses according to any one of claims 1 to 10, wherein the carbodiimide group-containing compound (A) is blended in the range of 0.01 to 30 parts by mass. The tube or hose according to any one of claims 1 to 11, wherein a sea-island structure is observed in a 200 times or more image by a scanning electron microscope (SEM), and an average particle size of the island phase is 0.01 to 20 µm. Thermoplastic elastomer composition. A tube or hose containing the thermoplastic elastomer composition according to claim 1.