JP2020122130A - Elastomer composition for belts - Google Patents

Abstract

To provide a thermoplastic elastomer composition for belts that has excellent characteristics required of a belt, particularly excellent wear resistance, and a belt including the composition.SOLUTION: A thermoplastic elastomer composition for belts is obtained by dynamically heating a carbodiimide group-containing compound (A), an olefin polymer (B) having a group that reacts with a carbodiimide group, a polar rubber (C), and a crosslinker (E) that can crosslink the polar rubber (C). There is also provided a belt containing the same.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic elastomer composition for belts, which contains a crosslinkable rubber and an olefin polymer.

BACKGROUND ART Conventionally, various materials such as a rubber composition or a thermoplastic elastomer composition have been known as materials for forming power transmission belts or transportation belts of automobiles and other machines.

Patent Document 1 discloses a transmission or transportation belt in which a layer of a rubber composition containing an ethylene/α-olefin/non-conjugated polyene random copolymer rubber is adhered to a fiber base material containing polyamides. It is described that this belt has excellent strength characteristics, abrasion 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 rubber composition is disclosed. The rubber composition is excellent in rigidity, compression set, shape memory property and the like, and is also excellent in mechanical strength (tensile strength, elongation) and heat aging depending on conditions, and is caused by volatilization and separation of low molecular weight components. It is described that it can suppress fogging and stickiness, and is suitably used as a material for various belts.

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 article such as a belt molded from the thermoplastic elastomer composition retains mechanical properties comparable to those of conventional nitrile rubber and has excellent oil resistance.

Patent Document 4 discloses a heat-resistant rubber composition containing two kinds of ethylene/α-olefin/non-conjugated polyene copolymer rubbers having different intrinsic viscosities. It is described that this heat resistant rubber composition is excellent in fluidity (workability and moldability), mechanical properties, electrical properties and heat aging resistance, and can be suitably used as a material for industrial rubber products such as belts. ..

JP 2001-026688 A International Publication No. 2009/072553 JP, 2005-179456, A JP, 2005-330489, A

Various properties such as wear resistance, breaking strength, breaking elongation, hardness, and compression set resistance are generally required for the material forming the belt. In particular, wear resistance is an important property in belts.

The present invention was invented in order to solve the problems of the conventional techniques as described above. That is, an object of the present invention is to provide a thermoplastic elastomer composition for a belt, which is excellent in various properties required for the belt, and is particularly excellent in abrasion resistance, and a belt 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 belt, which is obtained by dynamically heat-treating.

[2] The thermoplastic elastomer composition for a belt according to [1], which further contains an olefin polymer (D).

[3] The belt 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. Thermoplastic elastomer composition.

[4] The thermoplastic elastomer composition for a belt 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 a belt according to [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.

[6] The thermoplastic resin for a belt 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. Elastomer composition.

[7] The thermoplastic elastomer composition for a belt 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]. A thermoplastic elastomer composition for belts.

[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 belts in any one of these.

[10] The thermoplastic elastomer composition for a belt according to any one 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 a belt according to any one of [1] to [10], which comprises 0.01 to 30 parts by mass of the carbodiimide group-containing compound (A).

[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 a belt.

[13] A belt containing the thermoplastic elastomer composition according to any one of [1] to [12].

According to the present invention, it is possible to provide a thermoplastic elastomer composition for a belt, which is excellent in various properties required for the belt, and is particularly excellent in abrasion resistance, and a belt using the composition.

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. The polar rubber (C) has excellent properties such as oil resistance to non-polar oil.

Specific examples of the polar rubber (C) include a carboxy group-containing nitrile rubber, a hydrogenated product of a carboxy group-containing nitrile rubber, a nitrile rubber, a hydrogenated product of a nitrile rubber, a carboxyl group-containing acrylic rubber, and an epoxy group-containing product. 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 nonpolar oils such as gasoline and lubricating oil is improved, which is preferable.

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 Belt]
The thermoplastic elastomer composition for a belt of the present invention contains 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, blended. The olefin polymer (D) and the crosslinking agent (E) capable of crosslinking the polar rubber (C) are dynamically heat-treated. The thermoplastic elastomer composition for a belt 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 belt of the present invention is not particularly limited in its production method as long as it is produced by a process of blending the respective components as raw materials and dynamically heat treating. Examples of the method for producing the thermoplastic elastomer composition for a belt 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 belt 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. Then, it may be prepared by dynamically heat treating. 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.

Since the thermoplastic elastomer composition for a belt 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, the resulting thermoplastic composition is Is at least a part of the above-mentioned carbodiimide group-containing compound (A) and the "group that reacts with a carbodiimide group" of the olefin polymer (B) having a group that reacts with a carbodiimide group react by melt kneading, 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 belt 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. As compared with the case where both are simply mixed, they are highly mixed and well dispersed. Therefore, the thermoplastic elastomer composition for a belt of the present invention may contain a reaction product (I) of the carbodiimide group-containing compound (A) and the olefin polymer (B) having a group that reacts with the carbodiimide group. preferable.

Further, since the thermoplastic elastomer composition for a belt of the present invention contains the polar rubber (C) and the cross-linking agent (E) capable of cross-linking the polar rubber (C) as raw materials, the belt heat-insulating composition of the present invention In the plastic elastomer composition, at least part of the polar rubber (C) forms crosslinks. That is, the thermoplastic elastomer composition for a belt 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 belt 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. There is.

Further, in the thermoplastic elastomer composition for a belt of the present invention, either the polar rubber (C), the reaction product (II) or the reaction product (III) described above may form a crosslink, 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 belt 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 belt of the present invention has a suitable elasticity by containing a crosslinked product, is excellent in chemical resistance, and further contains an olefin polymer (D) if necessary. By doing so, it has excellent moldability. Further, the thermoplastic elastomer composition for a belt 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 belt 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. In addition, the thermoplastic elastomer composition has excellent moldability, the molded article obtained from the thermoplastic elastomer has excellent elasticity, and also exhibits excellent wear resistance and oil resistance. In the thermoplastic elastomer composition for a belt of the present invention, each component, particularly the crosslinked polar rubber and the olefin polymer (D) optionally blended, are highly dispersed. It can be easily confirmed by observing the surface or cross section of the molded product obtained from the plastic elastomer composition with a microscope or the like and the dispersed particle size being sufficiently small.

In the thermoplastic elastomer composition for a belt of the present invention, a sea-island structure is observed in an image of 200 times or more, for example, about 1000 times by a scanning electron microscope (SEM), and the average particle size of the island phase is preferably 0. It is desirable that the range is 0.01 to 20 μm, and more preferably 0.01 to 10 μm.

[belt]
The belt of the present invention contains the above-mentioned thermoplastic elastomer composition of the present invention. The entire belt of the present invention may be composed of the thermoplastic elastomer composition of the present invention, or at least a part thereof may be composed of the thermoplastic elastomer composition of the present invention. For example, it may be a single-layer belt or a multi-layer belt in which at least one layer is composed of the thermoplastic elastomer composition of the present invention. The shape, size, wall thickness, etc. of the belt are not particularly limited and may be appropriately determined according to the intended use. Either an endless belt or an endless belt may be used, but it is particularly useful as an endless belt. There are various types of shapes such as a flat belt, a round belt, a V belt, a V rib belt, and a toothed belt.

The molding method for producing the belt of the present invention is not particularly limited, and a conventionally known method can be adopted. For example, the thermoplastic elastomer composition may be placed on a mold having a predetermined shape and subjected to hot press molding, or the thermoplastic elastomer composition may be wound around a core mold and heated and pressed in a mold clamping state to be molded. Alternatively, the thermoplastic elastomer composition may be extruded into a predetermined shape.

By including the thermoplastic elastomer composition of the present invention, the belt of the present invention is excellent in various properties required for the belt, and particularly excellent in abrasion resistance.

The use of the belt of the present invention is not particularly limited, and can be conventionally used for various uses such as a power transmission belt for automobiles and other machines, a transportation belt, and a heat insulation belt. The power transmission belt is useful as, for example, a belt used in a vehicle such as an automobile, a belt used in OA equipment such as a copying machine, and the transportation belt is used as a belt used in a belt conveyor, for example. It is useful.

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.

[Break strength (TB) (MPa), elongation at break (EB) (%)]
The thermoplastic elastomer composition was press-molded at 210° C. to prepare a press sheet having a length of 200 mm, a width of 200 mm, and a thickness of 2 mm, and the press sheet was punched out to prepare a dumbbell-shaped (JIS-3) test piece. Based on JIS K6251 (2010), the tensile strength (TB) and the elongation (EB) were measured at a tensile speed of 500 mm/min using this test piece.

[Compression set (CS)]
A press-formed sheet produced from a thermoplastic elastomer composition by a press-forming machine is 25% compressed using a spacer according to JIS K6262, heat-treated at 70° C. for 24 hours, and after treatment, in a constant temperature chamber at 23° C. After standing for 30 minutes, the thickness was measured and the compression set (CS) was calculated from the following formula.
CS=[(t0-t1)/(t0-t2)]×100
CS: compression set (%)
t0: Original thickness of the press-formed sheet (mm)
t1: Thickness of the press-formed sheet after being left for 30 minutes (mm)
t2: Thickness of the press-formed sheet with a compressive strain applied (mm)

[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.

[Shore A hardness]
In accordance with JIS K6253, it was measured by a Shore hardness meter (A hardness meter) using a press sheet having a thickness of 2 mm.

[Taber wear test]
According to JIS K7204, a press sheet having a thickness of 2 mm was punched into a test shape, and the wear mass (mg) was measured by using a CS-17 wear wheel under the conditions of 9.8 N, 60 rpm and 1000 times. ..

[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) that is a carbodiimide group-containing compound (Nisshinbo Chemical Co., Ltd., Carbodilite (registered trademark) HMV-15CA, carbodiimide equivalent 262 g), maleic anhydride-modified polypropylene (B-1) obtained in Production Example 1 , A part of polypropylene (D-1) (homopolypropylene, manufactured by Prime Polymer Co., Ltd., Prime Polypro (registered trademark) F113G, MFR: 3.0 g/10 min) [4.22 parts by mass (D-1) ¹⁾ ]. Was introduced into an extruder (manufactured by Nippon Steel Works, Ltd., TEX44, L/D=70) with the compounding amount (parts by mass) shown in Table 1, and the cylinder temperature was 290° C., the screw rotation speed was 760 rpm, and the discharge amount was 1.33 kg. The mixture was melt-kneaded at a rate of 1/min to obtain a composition containing a reaction product (contact product) of polycarbodiimide (A-1) and maleic anhydride-modified polypropylene (B-1) and polypropylene (D-1) (No. One-step formulation).

Then, the balance [23.00 parts by mass (D-1) ^{2) of} polypropylene (D-1), nitrile rubber (C-1) which is a polar rubber (manufactured by Nippon Zeon Co., Ltd., Nipol (registered trademark) 1042, NBR, Mooney viscosity=77.5, bound acrylonitrile amount=33.5%, SP value=about 20 (MPa) ^0.5 ), polar rubber (C1-1) having a group that reacts with a carbodiimide group (manufactured by Zeon Corporation) , Nipol (registered trademark) NX775, carboxyl group-containing NBR, Mooney viscosity = 44.0, bound acrylonitrile amount = 26.7%, SP value = about 20 (MPa) ^0.5 ), plasticizer (F-1) (corp.) ADEKA, Adeka Sizer (registered trademark) RS-107), additive (H-1) (manufactured by BASF, Irganox (registered trademark) 1010, phenolic antioxidant) and the above composition, a meshing type kneader (BB-L3200IM, manufactured by Kobe Steel, Ltd.) was introduced so that the compounding amount (parts by mass) shown in Table 1 would be obtained, and melt-kneaded at 120 rpm (second-stage compounding). 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.

<Example 2>
In Example 1, in place of the balance [23.00 parts by mass (D-1) ^{2) of} polypropylene (D-1)], polypropylene (D-2) (homopolypropylene, manufactured by Prime Polymer Co., Ltd., trade name Prime) Polypro J105) 10.50 parts by mass was used, and a thermoplastic elastomer composition was produced in the same manner as in Example 1 except that the other components were also changed to the compounding amounts (parts by mass) shown in Table 1. The physical properties were measured. The results are shown in Table 1.

<Comparative Example 1>
Thermoplastics were prepared in the same manner as in Example 1 except that the composition obtained in the first stage formulation of Example 1 was not used and the amounts of other components were changed to the formulation amounts (parts by mass) shown in Table 1. An elastomer composition was produced and the physical properties were measured. The results are shown in Table 1.

The thermoplastic elastomer compositions obtained in Examples 1 and 2 were remarkably excellent in abrasion resistance as compared with the elastomer composition obtained in Comparative Example 1, and were also excellent in other properties. The thermoplastic elastomer composition having excellent properties such as abrasion resistance is particularly suitable as a belt material.

INDUSTRIAL APPLICABILITY The thermoplastic elastomer composition for a belt of the present invention is particularly suitable as a material for a belt in various applications because it has various properties required for the belt and particularly excellent wear resistance.

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 belt obtained by dynamically heat-treating. The thermoplastic elastomer composition for belts according to claim 1, further comprising an olefin polymer (D). The thermoplastic elastomer composition for a belt according to claim 1 or 2, which 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. Stuff. The thermoplastic elastomer composition for a belt 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 a belt 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 belts 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 a belt according to claim 1, 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 thermoplastic elastomer for a belt according to claim 1, wherein the olefin polymer (B) having a group that reacts with a carbodiimide group is an olefin polymer having a side chain having a group having active hydrogen. 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 belt as described above. The thermoplastic elastomer composition for a belt according to claim 2, 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 a belt according to claim 1, wherein the carbodiimide group-containing compound (A) is blended in a range of 0.01 to 30 parts by mass. The thermoplastic resin for a belt 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. Elastomer composition. A belt containing the thermoplastic elastomer composition according to claim 1.