JP3480022B2 - Thermoplastic elastomer composition - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic elastomer resin composition having excellent compression set resistance.

[0002]

2. Description of the Related Art Conventionally, as a thermoplastic polyolefin-based elastomer, one mainly composed of polypropylene and ethylene / propylene-based rubber as a crosslinked rubber component is widely known. In addition to the above, there were those using acrylonitrile-butadiene rubber, butyl rubber, and further natural rubber as the crosslinked rubber component. However, none of these materials are satisfactory in terms of compression set resistance, and at present, the substitution in the field of crosslinked rubber has not progressed.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic elastomer resin composition having excellent compression set resistance characteristics.

[0004]

The present inventors have completed the present invention as a result of intensive studies in view of the above-mentioned present situation. The present invention provides a polypropylene-based resin (1), A
It is composed of a kryl ester copolymer rubber (2), an oil (3) and a vinyl aromatic resin-conjugated diene resin block copolymer (4), and is one of the conjugated diene resin parts in the block copolymer (4). , 2 bond is 30 mol% or more, and a thermoplastic elastomer resin composition and a method for producing the same. The details of the present invention will be described below.

Polypropylene resin used in the present invention
As (1), for example, polypropylene homopolymer,
Propylene / ethylene block copolymer, propylene /
Butene-1 random copolymer, propylene / ethylene /
Butene-1 random copolymer and propylene / ethylene
Examples thereof include random copolymers. Of these, ethylene
The ethylene content of the copolymer containing is not particularly limited, and
The polypropylene resin is a single type or a mixture of two or more types.
You may use it. This polypropylene resin
(1) is mixedAcrylic ester copolymer rubber
(2) 3 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight
Below, moreover, 5 parts by weight or more and 30 parts by weight or less may be blended.
desired. An error which is obtained when the compounding amount is less than 3 parts by weight.
The molding processability of the storm composition may be significantly reduced.
It Further, when it exceeds 50 parts by weight, the elastomer composition
The surface hardness may be extremely high and the rubber properties may be impaired.
There is.

Acrylic ester copolymer in the present invention
Rubber (2) is used. Heat resistance of the elastomer composition,
It is preferable when oil resistance and ozone resistance are required.

In addition,Acrylic ester copolymer rubber
(2) is a cross-linking point with a non-conjugated diene component as a copolymerization component.
It is preferable to use the one that has
The resulting elastomer composition has excellent thermal stability.
It The non-conjugated diene component used at this time is not particularly limited.
I do not receive it, but for example 1,3-butadiene, 1,4-pen
Tadiene, 1,4-hexadiene, 6-methyl-1,5
-Heptadiene, 5-methylene-2-norbornene, 5
-Alkynyl-2-norbornene, 2,5-norbornadi
Ene, 1,5-cyclooctadiene, 2-alkyl-
Such as 2,5-norbonadiene and dicyclopentadiene
Examples include monomers.

The oil (3) used in the present invention is not particularly limited. For example, paraffin type process oil,
Any oil such as naphthenic oil, aroma process oil, ester plasticizer and ether plasticizer can be used. Also, two or more kinds of oil may be used at the same time. For example, it is preferable to use, as the oil (3), a blend of a paraffinic process oil and a polyester plasticizer. The amount of the oil (3) used is the acrylic ester copolymer rubber (2) 10
It is desirable to add 3 parts by weight or more and 120 parts by weight or less, preferably 3 parts by weight or more and 100 parts by weight or less, and further 3 parts by weight or more and 50 parts by weight or less with respect to 0 parts by weight. 120
If it exceeds the weight part, the oil may bleed,
If the amount is less than 3 parts by weight, the molding processability of the obtained elastomer composition may be significantly deteriorated.

The vinyl aromatic resin-conjugated diene resin block copolymer (4) used in the present invention is A-
B diblock copolymer, A-B-A or A-B-
C triblock copolymer, which may be used alone or as a blend of two or more kinds. Further, it is necessary to use a vinyl aromatic resin for the A block and a conjugated diene resin for the B block which form these block copolymers. When there is a C block having a structure different from that of the A and B block portions, the structure is not particularly limited, and any resin may be used. Further, it may be a block copolymer having a completely different structure at the boundary between the A block and the B block, or may be a Taber block copolymer having a disordered structure at the block boundary. However, the ratio of 1,2 bonds in the conjugated diene resin portion in the block copolymer (4) used in the present invention needs to be 30 mol% or more. Further, the conjugated diene resin portion may be hydrogenated. When the ratio of 1,2 bonds in the conjugated diene resin portion in the block copolymer (4) is less than 30 mol%, the block copolymer (4) and the polypropylene resin (1)
And the resulting elastomer composition has poor strength properties. Incidentally, the compatibility of the polypropylene resin (1) and the block copolymer (4) can be easily evaluated by the temperature dispersion of dynamic viscoelasticity, and if the compatibility is good, both can be evaluated. The loss tangent (tan δ) derived from the glass transition temperature of the blend has a single peak, and when the compatibility is poor, it has a double peak.

Examples of the vinyl aromatic resin portion in the block copolymer (4) include polymers of styrene and α-methylstyrene. Of these, polystyrene is preferably used from the viewpoint of cost performance, and the proportion of the vinyl aromatic resin portion in the block copolymer (4) is preferably 20 mol% or less. If this ratio exceeds 20%, the strength characteristics of the resulting elastomer composition may deteriorate. On the other hand, examples of the conjugated diene resin portion in the block copolymer (4) include polymers such as butadiene and isoprene.

The vinyl aromatic resin-conjugated diene resin block copolymer (4) described above is commercially available (eg, Nippon Synthetic Rubber Co., Ltd., trade name Dynaron 1320).
P etc.).

In the thermoplastic elastomer composition of the present invention, the vinyl aromatic resin-conjugated diene resin block copolymer (4) is used in an amount of 30 to 200 parts by weight per 100 parts by weight of the polypropylene resin (1). The following is preferable. If it is less than 30 parts by weight, the effect of improving compression set may be poor, and if it exceeds 200 parts by weight, defective molding may occur.

The thermoplastic elastomer resin composition of the present invention is prepared by mixing the above-mentioned raw materials to obtain an acrylic ester copolymer rubber.
Beam (2) is obtained by carrying out the crosslinking, effect crosslinking accession Riruesuteru copolymer rubber (2) melting of a polypropylene resin (1), while applying shear for the purpose of especially improving the strength properties process It is desirable to manufacture through.

The thermoplastic elastomer resin composition of the present invention is preferably produced so that the vinyl aromatic resin-conjugated diene resin block copolymer (4) does not cause cross-linking. When the block copolymer (4) forms a crosslinked product, the molding processability of the resulting elastomer composition may be significantly reduced. In order to prevent the block copolymer (4) from being crosslinked, for example, acrylic ester
The copolymer rubber (2) contains a non-conjugated diene as a copolymerization component, and crosslinking with a peroxide gives priority to acrylic ester copolymerization.
Method for producing polymer rubber (2), acrylic
Examples include a method in which the block copolymer (4) is mixed and kneaded after the crosslinking of the ester copolymer rubber (2) is completed.

In the present inventionAcrylic ester copolymer rubber
The crosslinking agent used for the crosslinking of (2) is not particularly limited,
Reduces manufacturing time by using organic peroxides
It is preferable because it is possible. Organic peracid used here
Compounds include hydroperoxide, diacyl peroxide
Oxide, ketone peroxide, peroxyester
And dialkyl peroxides, etc., examples
For example, t-butyl hydroperoxide, cumene hydrate
Loperoxai, diisopropylbenzene hydropa
-Oxide, 2,5-dimethylhexane-2,5-di
Hydroperoxide, 2,5-dimethyl-2,5-
Di (t-butylperoxy) hexyne-3, dicumylpa
-Oxide, di-t-butyl peroxide, n-bu
Cyl-4,4-bis (t-butylperoxy) hexa
Amine, t-butylperoxybenzoate, benzoylpa
-Examples include oxides. These can be alone or mixed
Used in combination. The amount of organic peroxide used is
Used in inventionAcrylic ester copolymer rubber(2)
0.1 to 10 parts by weight is preferable per 100 parts by weight.
If the amount is less than 0.1 part by weight, the thermoplastic elastomer obtained is
The compression set deteriorates, and if it exceeds 10 parts by weight, the thermoplastic
The liquidity of the lastomer may be impaired.

Further, acrylic ester copolymer rubber (2)
It is effective to use a co-crosslinking agent together with a crosslinking agent to crosslink, because the crosslinking effect is improved. As a co-crosslinking agent,
For example, P.quinone dioxime, P.P dibenzoylquinone dioxime, lauryl methacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane tri Methacrylate,
Diaryl fumarate, diaryl phthalate, tetraaryloxyethane, triaryl cyanurate, maleimide, phenyl maleimide N.I. Examples thereof include N'.m-phenylene bismaleimide, maleic anhydride, itaconic acid, divinylbenzene, vinyltoluene and 1,2-polybutadiene. The amount of these co-crosslinking agents used is
The amount is preferably 5 parts by weight or less per 100 parts by weight of the acrylic ester copolymer rubber (2), and if this amount exceeds 5 parts by weight, the processability of the obtained elastomer composition may be deteriorated. It is also possible to use a crosslinking aid, a crosslinking retarder, a crosslinking accelerator, etc. in combination for the purpose of controlling the crosslinking rate.

Acrylic ester cross-linked in this way
The degree of crosslinking of the rubber copolymer rubber (2) is not particularly limited, but it is preferable to perform crosslinking so that the gel content is 90% or more from the viewpoint of improving the compression set of the obtained elastomer composition. .

Further, the thermoplastic elastomer resin composition of the present invention includes a polypropylene resin (1) and an acrylic ester.
A compatibilizer may be added for the purpose of improving the interfacial adhesion with the tercopolymer rubber (2). In particular, when an acrylic ester copolymer rubber is used, it is desirable to add a compatibilizing agent in order to further improve the compatibility with the polypropylene resin (1). As the compatibilizing agent, in particular (a) a carboxyl group or an acid is used. 100 parts by weight of modified polyolefin containing 0.01 to 15% by weight of anhydride group, (b) 1 to 500 parts by weight of acrylic acid ester copolymer elastomer containing 0.01 to 5% by weight of carboxyl group, and (c) The metal salt is converted into the carboxyl group of (a) or the acid anhydride group of 0.
The elastomer-modified polyolefin contained in an amount of 1 to 30 equivalents is preferably used because it is inexpensive, has a great effect of improving physical properties, and is easy to synthesize.

In the thermoplastic elastomer resin composition of the present invention, calcium carbonate, mica, talc,
Silica, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, serisanite, zeolite, nepheline sinite, attapulgite, wollastonite, ferrite, calcium silicate,
Inorganic fillers such as magnesium carbonate, dolomite, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass beads, glass powder, glass balloons, quartz, quartz glass and glass fibers It is also possible to add organic or inorganic pigments. In addition, release agents, anti-blocking agents, slip agents, antistatic agents, lubricants, heat stabilizers, light stabilizers,
UV absorber, weather resistance stabilizer, foaming agent, defoaming agent, rust preventive agent,
A fungicide, an ion trapping agent, a crystal nucleating agent, a clarifying agent, a flame retardant, a flame retardant aid, and the like may be added if necessary. Further, the thermoplastic elastomer resin composition of the present invention can be used by blending it with another resin, and in this case, a compatibilizing agent can be used together as the third component. In particular, blending the thermoplastic elastomer resin composition of the present invention with low-density polyethylene or ultra-low-density polyethylene is preferable because extrusion moldability is improved.

The thermoplastic elastomer resin composition of the present invention thus obtained is blended with a reinforcing filler, an inorganic filler and the like, and is subjected to injection molding, extrusion molding, inflation molding, calender molding and press molding. It can be molded into various molded products, films, sheets, tubes and the like. The molded product thus obtained has excellent compression set resistance and heat resistance, and is suitable for automobile interior materials.

[0021]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

In the examples, the compression set was measured in accordance with JIS K6301 at 70 ° C. after 22 hours.

The 1,2-bond content of the vinyl aromatic resin-conjugated diene resin block copolymer is 13N carbon.
It was identified by MR.

Example 1 Acrylic ester copolymer rubber (RV-2540 manufactured by Nisshin Chemical Industry Co., Ltd.) containing a non-conjugated diene as a copolymerization component 1
00 parts by weight, HAF carbon 60 parts by weight, polyester plasticizer (Adeka Sizer PN- manufactured by Asahi Denka Co., Ltd.)
170 (molecular weight: about 1100)) 10 parts by weight, paraffinic process oil (Diana Process Oil PW-90 manufactured by Idemitsu Kosan Co., Ltd.) 10 parts by weight, antioxidant (NAUIGARD445 manufactured by Uniroyal Chemical Co., Ltd.) 2 parts by weight Parts and 1 part by weight of stearic acid were sufficiently kneaded with a roll kneader to obtain an acrylic rubber compound. Next, 85 g of this acrylic rubber compound and polypropylene resin (Tosoh Polypro J5100A manufactured by Tosoh Corporation) 7.
5 g was put into a Brabender mixer having an internal volume of 100 cc and a temperature of 180 ° C., and kneaded at a rotation speed of 140 rpm for 5 minutes. Then, this was taken out and the peroxide (C-13 manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 1.5 with a water-cooled roll forming machine.
g, Vulcanization aid (Sumifine BM manufactured by Sumitomo Chemical Co., Ltd.)
Kneaded well with 0.75 g. The material thus obtained is again charged into a Brabender mixer at a temperature of 180 ° C.,
Acrylic rubber was peroxide-crosslinked while melt-kneading at a rotation speed of 140 rpm, and after 5 minutes, it was taken out from the mixer. A hydrogenated styrene-butadiene block copolymer having a butene-1 structural unit content of 46 mol%, an ethylene structural unit content of 50 mol% and a styrene content of 4 mol% (Dynalon 1320P manufactured by Nippon Synthetic Rubber Co., Ltd.) )
7.5 g was added, and the mixture was kneaded for 5 minutes by a roll forming machine whose surface temperature was set to 180 ° C.

The roll sheet thus obtained was designated JISK6301.
According to the procedure described above, a sample for compression set was press-molded to obtain the desired composition, and the compression set was measured. The results are shown in Table 1.

Example 2 A target composition was obtained in the same manner as in Example 1 except that the polypropylene resin was 10 g and the hydrogenated styrene-butadiene block copolymer was 5 g, and the compression set was measured. The results are shown in Table 1.

[0027]

[0028]

[0029]

Comparative Example 1 A composition was obtained in the same manner as in Example 1 except that the polypropylene resin was 15 g and the hydrogenated styrene-butadiene block copolymer was not used, and the compression set was measured. The results are shown in Table 1.

Comparative Example 2 A composition was obtained in the same manner as in Example 3 except that the polypropylene resin was 35 parts by weight and the hydrogenated styrene-butadiene block copolymer was not used, and the compression set was measured. It was The results are shown in Table 1.

Comparative Example 3 Hydrogenated styrene-butadiene block copolymer having a butene-1 structural unit content of 21 mol%, an ethylene structural unit content of 74 mol% and a styrene content of 5 mol% (Clayton G1657 manufactured by Shell Chemical Co.). A composition was obtained in the same manner as in Example 1 except that was used, and the compression set was measured. The results are shown in Table 1.

[0033]

[Table 1]

[0034]

As described above, the composition of the present invention is a material having excellent compression set resistance.

Claims (3)

(57) [Claims] 1. A polypropylene resin (1), an acrylic resin
Stell copolymer rubber (2), oil (3) and vinyl aromatic resin-conjugated diene resin block copolymer (4)
And a ratio of 1,2 bonds in the conjugated diene resin portion in the block copolymer (4) is 30 mol% or more, a thermoplastic elastomer resin composition. 2. Polypropylene resin (1), acrylic resin
The thermoplastic elastomer resin composition according to claim 1, further comprising a step of melt-mixing the stell copolymer rubber (2) and crosslinking the acrylic ester copolymer rubber (2) while applying shear. Manufacturing method. 3. An automobile interior material obtained by molding the thermoplastic elastomer resin composition according to claim 1.