JPH0539385A - Modified thermoplastic elastomer composition having good coatability and its manufacture - Google Patents

Abstract

PURPOSE:To obtain the subject composition which can be coated with urethane without priming and to realize cost reduction, the curtailment of processing steps, etc. CONSTITUTION:(1) A modified thermoplastic elastomer composition which consists of a thermoplastic elastomer (A) obtained by kneading a crystalline polyolefin resin, an olefin polymer rubber, and an unsaturated hydroxy compound with an organic peroxide to effect the crosslinking of the olefin polymer rubber and the grafting with the unsaturated hydroxy compound at the same time and a hydroxylated polyolefin resin (B), and the manufacture of the composition. (2) A thermoplastic elastomer composition obtained by kneading a hydroxylated polyolefin resin, an olefin polymer rubber, and an unsaturated hydroxy compound with an organic peroxide to effect the crosslinking of the olefin polymer rubber and the grafting with the unsaturated hydroxy compound at the same time, and the manufacture of the composition.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Thermoplastic elastomers are used as various structural materials in a wide range of industrial fields such as automotive materials, home appliances, and construction. The present invention relates to a thermoplastic elastomer composition having excellent coatability. More specifically, the present invention relates to a modified thermoplastic elastomer composition having good coatability, which enables polyurethane coating without the need for pretreatment such as primer treatment or corona treatment, and a method for producing the same.

[0002]

2. Description of the Related Art Polyolefin thermoplastic elastomers are excellent in moldability such as injection molding and sheet molding and are used in a wide variety of fields as structural materials. These thermoplastic elastomer molded bodies may be used unpainted,
Depending on the application, the molded body often needs to be painted. Since the thermoplastic polyolefin-based elastomer is a composition mainly composed of a non-polar polymer made from polyolefin, if the coating is applied directly to it, the coating film easily peels off due to its low affinity with the coating. There's a problem.

Therefore, it is common practice to apply a so-called primer treatment of applying a material having an affinity for both the polyolefin-based thermoplastic elastomer and the paint, such as a chlorinated polyolefin, to the molded product and then applying the paint. It is being appreciated. It is also practiced to improve the surface properties by corona treatment or the like to improve the affinity with the paint and then apply the paint.

However, since the primer is expensive and contains a large amount of organic solvent, a step for recovering or removing the organic solvent is required. The problem is that this process is performed at a high temperature and takes a long time. Further, there are problems that the method of improving the surface properties such as corona treatment is limited in shape, and expensive equipment investment is required. Therefore, if a thermoplastic elastomer that does not require treatment such as primer treatment or corona treatment at the time of coating is obtained, the process can be shortened.
It will bring advantages such as reduction of capital investment.

Regarding simple polyolefin resins such as polyethylene and polypropylene, as a method for improving the coating properties of polyurethane paints, graft modification with a hydroxyl group-containing compound is not possible to improve the affinity between the polyolefin resin and polyurethane paints. As is already known, such attempts are rare in special compositions such as thermoplastic elastomers.

Japanese Patent Application Laid-Open No. 1-259090 for improving the coating properties of a special composition such as a thermoplastic elastomer.
47 is mentioned. Here, a thermoplastic elastomer composition prepared by dynamically heat-treating a mixture of a peroxide-crosslinking polyolefin-based copolymer rubber, an olefin-based plastic, and a monomer having at least one amino group with an organic peroxide is used. A method of blending a saturated carboxylic acid derivative with heating is disclosed.

Further, Japanese Patent Laid-Open Nos. 1-259048 and 1-
259049 is at least one in a thermoplastic elastomer composition obtained by dynamically heat-treating a mixture of a peroxide-crosslinked polyolefin copolymer rubber, an olefin plastic and an unsaturated carboxylic acid or a derivative thereof with an organic peroxide. A method of blending the above-mentioned amino group-containing monomer under heating is disclosed. However, in these, the coating property is not sufficiently improved, and compounds having a low boiling point and harmfulness such as allylamine, acrylamide, and diethylenetriamine are used.

In JP-A-64-85206, a peroxide-crosslinkable polyolefin copolymer rubber, an olefin plastic and an unsaturated epoxy monomer or an unsaturated hydroxy monomer are dynamically heat treated with an organic peroxide. Although the above thermoplastic elastomer composition has already been disclosed, its effect is the adhesiveness to a metal or the like, and the paintability such as whether it can be coated without a primer treatment is not shown. Further, as shown in Examples, the present inventors investigated the suitability of this composition for polyurethane coating, and as a result, sufficient coatability could not be obtained without the primer treatment.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a modified thermoplastic resin having an excellent coating property, which allows sufficient polyurethane coating without primer treatment without significantly deteriorating mechanical properties such as breaking strength and breaking elongation. Aims to develop elastomers.

[0010]

SUMMARY OF THE INVENTION The present invention provides a thermoplastic elastomer composition comprising a polyolefin resin and a partially crosslinked olefin polymer rubber, which has good coatability of a polyurethane paint, and the polyolefin resin has a hydroxyl group. The present invention provides a modified thermoplastic elastomer composition having good coatability, which comprises an olefinic resin having an olefinic resin or an olefinic resin having a hydroxyl group. Then, as a method for producing the modified thermoplastic elastomer composition, (A) a polyolefin and an olefin polymer rubber are kneaded with an organic peroxide in the presence of an unsaturated hydroxy compound to prepare an unsaturated hydroxy compound of the olefin polymer rubber. The (B) hydroxyl group is added to the modified thermoplastic elastomer obtained by graft modification and cross-linking, or by kneading with an organic peroxide in the absence of an unsaturated hydroxy compound to cross-link an olefin polymer rubber. A method for producing a modified thermoplastic elastomer composition comprising blending a polyolefin resin having the above, and a polyolefin resin having a hydroxyl group, and an olefin polymer rubber for organic peroxidation in the presence or absence of an unsaturated hydroxy compound. Kneaded together with the product to produce an olefin polymer Modified thermoplastic elastomer composition obtained by graft-modifying and cross-linking with an unsaturated hydroxy compound or kneading with an organic peroxide in the absence of an unsaturated hydroxy compound to cross-link an olefin polymer rubber. A method for manufacturing a product is provided.

The present invention will be described in detail below. As the polyolefin resin in the present invention, isotactic polypropylene, syndiotactic polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, propylene-alpha olefin block copolymer, propylene-alpha olefin random copolymer , Poly-1-butene, poly-4-methyl-1-pentene, and other polyolefins and mixtures thereof. Among these, isotactic polypropylene, syndiotactic polypropylene, propylene-alpha olefin block copolymer, propylene-alpha olefin random copolymer and mixtures thereof are preferable, and propylene-ethylene block copolymer, propylene-ethylene random copolymer. Further preferred are copolymers and those containing them.

It is also possible to replace a part of the above-mentioned polyolefin with a compound modified with an unsaturated carboxylic acid, a derivative thereof, an unsaturated hydroxy compound or the like. Examples of these compounds include maleic anhydride, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl maleimide and the like.

The ethylene content of the propylene-ethylene block copolymer and the propylene-ethylene random copolymer is preferably 20 parts by weight or less. If the ethylene content exceeds 20 parts by weight, the heat resistance will decrease. From the viewpoint of the balance between heat resistance and flexibility, the ethylene content of the propylene-ethylene block copolymer and the propylene-ethylene random copolymer is preferably 3 to 15 parts by weight, more preferably 5 to 10 parts by weight. Is.

The polyolefin resin has a lower reactivity with the unsaturated hydroxy compound than the olefin polymer rubber, and is substantially graft-modified when the mixture of the both is kneaded with the organic peroxide together with the hydroxy compound. It is said that it reacts only slightly with hydroxy compounds. Therefore, in the present invention, a mixture obtained by kneading the mixture with a hydroxy compound may have a small amount of hydroxy compound graft modification, but this is also described in the category of the polyolefin resin.

As the olefin polymer rubber, ethylene-alpha olefin copolymer rubber, butadiene rubber,
Although natural rubber, styrene-butadiene rubber, etc. can be used, ethylene-propylene copolymer rubber, ethylene-
A propylene-diene copolymer rubber is particularly preferred. Among these, those having a melt index of 1 or less are preferable from the viewpoint of the mechanical strength of the composition. The propylene content in these propylene-based rubbers is preferably 50% by weight or less from the viewpoint of crosslinking efficiency, and particularly preferably in the range of 25 to 45% by weight in consideration of flexibility as a rubber.

The definition of partial crosslinking in the present invention is that the weight of the P-xylene Soxhlet extraction residue of the composition (excluding the weight of the filler such as filler) is 90% or less of the weight of the olefin polymer rubber. There is something.

In the present invention, the mixing ratio of the polyolefin resin and the olefin polymer rubber used in the modified thermoplastic elastomer is 20% by weight or more and less than 70% by weight of the crystalline polyolefin resin in the total weight of both. It is necessary. When the content of the polyolefin resin is less than 20% by weight, heat resistance and fluidity are lowered and flow marks are easily formed, which is not preferable. Further, if it is 70% by weight or more, it lacks flexibility and loses its properties as an elastomer.

The unsaturated hydroxy compound in the present invention is a compound having an ethylenic double bond and a hydroxyl group at the same time in the same molecule, and examples thereof include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and hydroxy. Ethyl maleimide, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, triethylene glycol monoacrylate, triethylene glycol monomethacrylate,
Tetraethylene glycol monoacrylate, tetraethylene glycol monomethacrylate and other polyethylene glycol monoacrylate and monomethacrylate or dipropylene glycol monoacrylate,
Polypropylene glycol monoacrylates and monomethacrylates such as dipropylene glycol monomethacrylate, tripropylene glycol monoacrylate, tripropylene glycol monomethacrylate, tetrapropylene glycol monoacrylate, tetrapropylene glycol monomethacrylate, trimethylene glycol monoacrylate or methacrylate,
Tetramethylene glycol monoacrylate and methacrylate, ethylene glycol and propylene glycol copolymer monoacrylate and methacrylate, and further polyethylene glycol or polypropylene glycol monoallyl ethers such as diethylene glycol monoallyl ether and dipropylene glycol monoallyl ether, and these And the like.

Among these, in view of graft reactivity and balance between strength and coatability of the resulting composition, polyethylene glycol and polypropylene glycol monoacrylate or monomethacrylate having a degree of polymerization of 2 to 20, a degree of polymerization of 2 are used. To 20 in the range of trimethylene glycol monoacrylate or methacrylate, the degree of polymerization in the range of 2 to 20 in tetramethylene glycol monoacrylate and methacrylate, and the degree of the polymerization in the range of 2 to 20 ethylene glycol and propylene glycol copolymer The monoacrylates and methacrylates of are preferred.

In the present invention, the compounding amount in the case of kneading with an organic peroxide in the presence of an unsaturated hydroxy compound is 100 parts by weight in total of (a) the polyolefin resin and (b) the olefin copolymer rubber. For 0.
1 to 10 parts by weight is preferable, and a particularly preferable range is 1 to 5 parts by weight. If the compounding amount is less than 0.1 part by weight, no effect is observed, and if the compounding amount exceeds 10 parts by weight, the composition obtained becomes non-uniform, resulting in deterioration of mechanical properties and deterioration of appearance.

When kneading with an organic peroxide in the presence of an unsaturated hydroxy compound, thermoplasticity can be obtained whether the starting polyolefin resin is an unmodified polyolefin or a modified polyolefin resin having a hydroxyl group. By increasing the hydroxyl group concentration in the elastomer, the effect can be enhanced as compared with the case of kneading in the absence.

In the present invention, it is possible to add a softening agent as required to improve fluidity and flexibility. As the softening agent, any of paraffin type, naphthene type and aromatic type can be used, but from the viewpoint of stability, color tone and the like, it is preferable to use paraffin type. The amount to be blended differs depending on the purpose and cannot be determined unconditionally, but it is generally 0 for the thermoplastic elastomer composition.
Is about 200% by weight. When it is blended in an amount of 200% by weight or more, bleeding out occurs and the adhesion strength to the coating film is reduced.

Examples of organic peroxides that can be used in the present invention include dibenzoyl peroxide, p-chlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 1,3-bis (t-). Butylperoxy) isopropylbenzene, 2,5-bis (t-butylperoxy) -2,5-dimethylhexane, 2,5-bis (t-butylperoxy) -2,5-
Dimethyl-3-hexyne, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane,
Examples thereof include t-butyl peroxybenzoate, which may be diluted with an inactive substance such as a plasticizer or calcium carbonate. The compounding amount is 100 in total of (a) the crystalline polyolefin and (b) the olefin polymer rubber.
The amount is 0.05 to 3 parts by weight, preferably 0.2 to 1.5 parts by weight, based on parts by weight.

The olefin polymer rubber is partially cross-linked by kneading it with an organic peroxide, regardless of the presence or absence of an unsaturated hydroxy compound, to improve heat resistance. In addition, it is considered that when an unsaturated hydroxy compound is present, it is almost selectively graft-polymerized with an olefin polymer rubber.

Further, for the purpose of improving the crosslinking efficiency of these organic peroxides, a compound having a plurality of unsaturated bonds in one molecule can be used in combination. Examples of such compounds include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, ethylene glycol diacrylate and dimethacrylate, trimethylolpropane di- or triacrylate and di- or trimethacrylate. Can be mentioned.

The blending amount of these is different depending on the blending amount of the organic peroxide, but is usually 3 parts by weight or less with respect to 100 parts by weight of the total of (a) the crystalline polyolefin and (b) the olefin polymer rubber. ..

As the polyolefin resin having a hydroxyl group, isotactic polypropylene, syndiotactic polypropylene, high density polyethylene,
Low density polyethylene, linear low density polyethylene, propylene-alpha olefin block copolymer, propylene-alpha olefin random copolymer, poly-1
-Selected from olefin resins such as copolymers of ethylene with one or more kinds of compounds selected from polyolefins such as butene and poly-4-methyl-1-pentene, vinyl esters and unsaturated carboxylic acid derivatives One or more kinds of the resins described above are obtained by graft-modifying an unsaturated hydroxy compound in the presence of an organic peroxide or the like. The unsaturated hydroxy compound here is the same as described above, and all of them can be carried out.

Other usable polyolefin resins having a hydroxyl group other than the above are ethylene-vinyl alcohol copolymer, hydrolyzate of ethylene-vinyl ester, and copolymerization weight of ethylene and the unsaturated hydroxy compound. Examples thereof include a combination (which may contain other monomer having no hydroxyl group) and the like, and these can also be used in combination with a resin graft-modified with an unsaturated hydroxy compound.

Of these, at least one selected from isotactic polypropylene, syndiotactic polypropylene, propylene-ethylene block copolymer, propylene-ethylene random copolymer, vinyl ester and unsaturated carboxylic acid derivative. A copolymer of a compound and ethylene and a mixture thereof, which is graft-modified with the above unsaturated hydroxy compound in the presence of an organic peroxide, ethylene-vinyl alcohol copolymer, hydrolysis of ethylene-vinyl ester. Preferred are copolymers of ethylene with a compound having a hydroxyl group as described above (which may include other monomers having no hydroxyl group) and mixtures thereof.

Particularly preferred is a propylene-based polymer such as isotactic polypropylene, syndiotactic polypropylene, propylene-ethylene block copolymer or propylene-ethylene random copolymer graft-modified with an unsaturated hydroxy compound.

The ethylene content of the propylene-ethylene block copolymer and the propylene-ethylene random copolymer is preferably 20 parts by weight or less. If the ethylene content exceeds 20 parts by weight, the heat resistance will decrease. From the viewpoint of the balance between heat resistance and flexibility, the ethylene content of the propylene-ethylene block copolymer and the propylene-ethylene random copolymer is preferably 3 to 15 parts by weight, more preferably 5 to 10 parts by weight. Is.

Generally, the concentration of the hydroxyl group in the polyolefin resin having a hydroxyl group obtained by kneading the polyolefin and the hydroxy compound is such that the polyolefin and the olefin polymer rubber are kneaded together with the organic peroxide in the presence of the unsaturated hydroxy compound. The concentration is higher than that of the polyolefin resin having a hydroxyl group thus obtained, and it is necessary to have such a high concentration of the hydroxyl group-containing polyolefin resin.

In order to develop the coating film adhesion strength, the hydroxyl group concentration of the modified thermoplastic elastomer composition as a whole is 7 × 10 ⁻³ mmol / g or more, preferably 20 ×.
10 ^-3 mmol / g or more, it is necessary to 40 × 10 ^-3 mmol / g or more concentrations for particularly high coating adhesion strength development.

In the modified thermoplastic elastomer composition of the present invention, a modified thermoplastic elastomer obtained by kneading a polyolefin resin and an olefin polymer rubber with an organic peroxide in the presence or absence of an unsaturated hydroxy compound. The amount of the polyolefin resin having a hydroxyl group to be blended with
It is 1 to 30 parts by weight, preferably 5 to 15 parts by weight, relative to parts by weight. If it is less than 1 part by weight, the effect of exhibiting coating adhesion strength is not exhibited, and if it exceeds 30 parts by weight, further improvement of the effect cannot be expected and flexibility is lowered.

In order to reduce flow marks during injection molding, the weight average molecular weight of the polyolefin resin component used as a raw material for the modified thermoplastic elastomer composition is preferably 100,000 or more, particularly preferably 2
It is more than 0,000. When the molded product is partially coated, the appearance of the molding may be impaired due to the generation of flow marks, and a part having a low coating film adhesion strength may be formed, and the coating film may be peeled from the part.

Another embodiment of the present invention is to knead a polyolefin resin having a hydroxyl group and an olefin polymer rubber together with an organic peroxide in the presence or absence of an unsaturated hydroxy compound to obtain an olefin polymer rubber. It is a thermoplastic elastomer composition obtained by cross-linking. Here, as the polyolefin resin having a hydroxyl group, the olefin polymer rubber, the unsaturated hydroxy compound, and the organic peroxide, the same ones as described above can be used.

The modified thermoplastic elastomer composition is produced by preliminarily mixing (A) the polyolefin resin, the olefin polymer rubber (unsaturated hydroxy compound) and the organic peroxide with a Henschel mixer or the like. A modified thermoplastic elastomer prepared by kneading with a kneading device such as a Banbury mixer, a kneader, a single-screw extruder or a twin-screw extruder, and simultaneously performing the crosslinking reaction of the olefin copolymer rubber and the graft reaction of the unsaturated hydroxy compound. (B) A polyolefin resin having a hydroxyl group is further prepared by kneading with a kneading device such as a Banbury mixer, a kneader, a single-screw extruder or a twin-screw extruder.

In another aspect of the present invention,
A polyolefin resin having a hydroxyl group, an olefin polymer rubber (unsaturated hydroxy compound if necessary) and an organic peroxide are mixed in advance with a Henschel mixer or the like, and then Banbury mixer, kneader, single screw extruder, twin screw extruder A modified thermoplastic elastomer composition is prepared by kneading with an kneading machine such as the above, and simultaneously carrying out the crosslinking of the olefinic copolymer rubber and the graft reaction of the unsaturated hydroxy compound.

In the present invention, for the purpose of accelerating the reaction between the hydroxyl group in the composition and the urethane paint, a catalyst for the reaction between the hydroxyl group and the isocyanate group such as an organic tin compound or a tertiary amine can be added. Examples of such catalysts include dibutyltin dilaurate, dibutyltin dimaleate, organic tin compounds such as dibutyltin dioctylmalate, tetramethylethylenediamine,
N, N-dimethylbenzylamine, N, N-dimethylaniline, N, N-dialkylethanolamine, 1,4
-Diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] -7-undecene, N, N
And tertiary amines such as dimethylaminopyridine.

In the present invention, a filler such as a filler, carbon black, a pigment or the like can be added if necessary.

[0041]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples without departing from the gist thereof. The measuring method in the examples is as follows. MFR JIS K7210 (load 2.16 kg 230 ° C.) HLMFR JIS K7210 (load 21.6 kg 230 ° C.) Tensile breaking strength JIS K6301 hydroxyl group content Polyolefin resin and partially crosslinked olefin polymer rubber in modified thermoplastic elastomer composition The hydroxyl group concentration of each component was determined by extracting the polyolefin resin (propylene resin) with p-xylene using Soxhlet, cooling to room temperature, and measuring the hydroxyl group concentration of the precipitate by infrared absorption spectrum.
The hydroxyl group concentration in the rubber component was determined by determining the hydroxyl group concentration in the entire elastomer and subtracting the hydroxyl group concentration in the propylene resin from this. Test conditions As a sample, an injection-molded flat plate having a thickness of 2 mm was used. Paint is Nippon Bee Chemical Co., Ltd. 2-liquid polyurethane paint (R-27
1) was used. The peeling test was performed with a width of 10 mm and 180 degree peeling.

(Example 1) <Composition A> Polypropylene homopolymer 40 parts by weight (MFR 0.5 g / 10 min, abbreviated as PP1 hereinafter) 60 parts by weight ethylene propylene copolymer rubber (MFR 0.01 and EPR below Abbreviated) 2-hydroxyethylmethacrylate 3 parts by weight (hereinafter abbreviated as HEMA) paraffinic process oil 15 parts by weight (hereinafter abbreviated as oil) After kneading the above mixture with a Brabender mixer at 180 ° C., 2,5-bis (t) -Butylperoxy) -2,5-
Add 1 part by weight of dimethylhexane (hereinafter abbreviated as PO) 1
The mixture was kneaded for 0 minutes to produce a modified thermoplastic elastomer (composition A). <Composition B> PP1 100 parts by weight HEMA 3 parts by weight PO 0.4 parts by weight Further, the above mixture was mixed with a Brabender mixer for 180 parts.
The mixture was kneaded at 10 ° C. for 10 minutes to obtain a polypropylene resin having a hydroxyl group (composition B). 90 of the above composition A
Parts by weight and 10 parts by weight of the composition B were kneaded with a Brabender mixer at 180 ° C. for 5 minutes to obtain a modified thermoplastic elastomer composition.

Example 2 Composition B of Example 1 40 parts by weight EPR 60 parts by weight HEMA 3 parts by weight Oil 15 parts by weight The above composition was kneaded at 180 ° C. in a Brabender mixer, and then 1 part by weight of PO was added. Then, the mixture was kneaded for 10 minutes to produce a modified thermoplastic elastomer composition.

(Example 3) In Example 1, the composition A was used.
A modified thermoplastic elastomer composition was produced in the same manner as in Example 1 except that half of PP1 was changed to ethylene propylene random copolymer (MFR 0.5 ethylene content 7%, hereinafter abbreviated as PP2).

(Example 4) In Example 1, the composition A was used.
HEMA of polyethylene glycol monomethacrylate (a mixture of tetraethylene glycol monomethacrylate and pentaethylene glycol monomethacrylate)
A modified thermoplastic elastomer composition was prepared in the same manner as in Example 1 except that

Example 5 A thermoplastic elastomer composition was produced in the same manner as in Example 1 except that the HEMA of the composition A was not added in Example 1.

(Example 6) <Composition C> PP1 100 parts by weight Polyethylene glycol monomethacrylate 3 parts by weight PO 2 parts by weight The above mixture was subjected to 180 ° C. with a Brabender mixer.
The mixture was kneaded for 0 minutes to obtain a polypropylene resin having a hydroxyl group (composition C). To 5 parts by weight of this composition C,
90 parts by weight of the composition A of Example 1 and 5 parts by weight of a propylene random copolymer (MFR 0.5 g / 10 minutes, ethylene content 3% by weight) were mixed with a Brabender mixer to obtain 18 parts.
The mixture was kneaded at 0 ° C. for 5 minutes to obtain a modified thermoplastic elastomer composition.

(Example 7) A thermoplastic elastomer composition was produced in the same manner as in Example 1 except that PP2 was used instead of PP1 and polyethylene glycol monomethacrylate was used instead of HEMA in the composition A of Example 1. did.

Comparative Example 1 A thermoplastic elastomer composition was produced in the same manner as in Example 1 except that HEMA of composition A and composition B were not blended.

Comparative Example 2 A thermoplastic elastomer composition was produced in the same manner as in Example 1 except that HEMA of the composition B was not blended in Example 1.

(Comparative Example 3) In Example 1, the composition A was used.
Only the composition was prepared and the composition B was not blended.

Comparative Example 4 A modified thermoplastic elastomer composition was obtained by using PO in the composition A in Example 1 as 1.5 parts by weight, and the physical properties of the modified thermoplastic elastomer composition were measured. Table 1 shows the physical property values of Examples and Comparative Examples.

[0053]

[Table 1]

[0054]

EFFECTS OF THE INVENTION The present invention provides a modified thermoplastic elastomer composition which can be coated with urethane without primer treatment, and can omit the primer treatment step and shorten the step, and does not need to use an expensive primer. And so on. The modified thermoplastic elastomer composition of the present invention can be used in a wide range of fields such as automobile interiors, exteriors, and home appliances.

Claims (5)

[Claims] 1. A thermoplastic elastomer composition comprising a polyolefin resin and a partially crosslinked olefin polymer rubber, wherein the polyolefin resin contains a hydroxyl group-containing polyolefin resin or a hydroxyl group-containing polyolefin resin. A modified thermoplastic elastomer composition characterized by good coatability. 2. The modified thermoplastic elastomer composition with good coatability according to claim 1, wherein the concentration of hydroxyl groups is 7 × 10 ⁻³ mmol / g or more. 3. A polyolefin resin having a hydroxyl group is obtained by graft-modifying an isotactic polypropylene, a syndiotactic polypropylene, a propylene-ethylene block copolymer or a propylene-ethylene random copolymer with an unsaturated hydroxy compound. A modified thermoplastic elastomer composition having good coatability according to claim 1. 4. A polyolefin resin and an olefin polymer rubber (A) are kneaded together with an organic peroxide in the presence of an unsaturated hydroxy compound to effect graft modification and crosslinking of the olefin polymer rubber with the unsaturated hydroxy compound. (B) a polyolefin resin having a hydroxyl group in a modified thermoplastic elastomer obtained by carrying out crosslinking of an olefin polymer rubber by kneading with an organic peroxide in the absence of an unsaturated hydroxy compound. The method for producing a modified thermoplastic elastomer composition according to claim 1, which comprises blending. 5. A polyolefin resin having a hydroxyl group and an olefin polymer rubber are kneaded together with an organic peroxide in the presence of an unsaturated hydroxy compound, and graft modification and crosslinking of the olefin polymer rubber with the unsaturated hydroxy compound. Or obtained by kneading with an organic peroxide in the absence of an unsaturated hydroxy compound,
The method for producing a modified thermoplastic elastomer composition according to claim 1, which is obtained by crosslinking an olefin polymer rubber.