JPS59223744A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent resistance to oils and ozone and suitable for use in the production of shoe soles in particular, containing a specified block copolymer and an acrylic copolymer. CONSTITUTION:The titled compsn. contains 100pts.wt. block copolymer having a weight-average MW of 3X10<4>-30X10<4>, contg. 20-70wt% vinyl-substd. arom. compd., e.g. styrene, and composed of a conjugated diene compd., e.g. 1,3-butadiene, and a vinyl-substd. arom. compd. and 3-100pts.wt. terpolymer or four-component copolymer composed of ethylene, vinyl acetate and an alkyl acrylate of formula I (wherein R1 is 3-8C alkyl) and/or an alkoxyalkyl acrylate of formula II(wherein R2 is 1-4C alkylene; R3 is 1-4C alkyl, alkoxyalkyl). Said block copolymer is excellent in thermal stability, low-temperature characteristics and slip resistance. By incorporating the acrylic copolymer therein, a compsn. having improved resistance to oils and ozone and suitable for use in the production of shoe soles can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a thermoplastic elastic composition, in particular a block copolymer of a conjugated diene compound and a vinyl-substituted aromatic compound, and a polyester comprising a block copolymer of a conjugated diene compound and a vinyl-substituted aromatic compound, ethylene and vinyl acetate, and an alkyl acrylate and/or an alkoxyalkyl acrylate. The present invention relates to a thermoplastic elastomer composition suitable for shoe soles having properties such as oil resistance and ozone resistance, and containing a base or a quaternary copolymer.

There have been various materials used for shoe soles, but among these materials, natural comb and styrene-butadiene rubber are expensive because they require vulcanization, and polyurethane resin cannot be used unvulcanized. It is possible, but it is expensive.

On the other hand, soft vinyl chloride resin does not have sufficient thermal stability, low-temperature properties, and slip resistance, and styrene-butanoene copolymer resin is an excellent resin without these drawbacks, but it has poor oil resistance and ozone resistance. There is a problem.

The present invention has solved these drawbacks, and is a ternary or quaternary copolymer consisting of a block copolymer of a conjugated diene compound and a vinyl-substituted aromatic compound, ethylene and vinyl acetate, and an alkyl acrylate and/or an alkoxyalkyl acrylate. The object of the present invention is to provide a thermoplastic elastomer composition containing a polymer and retaining oil resistance, ozone resistance, and rubber properties.

That is, the thermoplastic elastomer composition of the present invention has a polymerization average molecular weight iU
100 parts by weight of a block copolymer (hereinafter referred to as block copolymer) of a vinyl-substituted aromatic compound in which - is 3 x 10' to 30-104 (hereinafter referred to as a block copolymer), ethylene and vinyl acetate, and an alkyl acrylate and/or A ternary or quaternary copolymer consisting of alcogine algyl acrylate-1 (hereinafter referred to as Aku II)
In the present invention, the block copolymer is characterized by containing 3 to 100 parts by weight of A+B-Aln
-,, (A-B)n. (A-B). .

In the tsene compound block, X represents a polyfunctional compound in which n polymer chains are bonded together, and n is an integer of 2 to 4. Note that the connection between the A block and the B block may be a clear cut or a chi-ball.

The conjugated tsene compound of these block copolymers is 1.3
-butanoene, ■,3-pentanoene, ■,3-hexanoene, 1-sozolene, etc., and vinyl-substituted aromatic compounds include styrene, α-methylstyrene, vinyltoluene, etc.

It is sufficient that the block copolymer in the elastomer composition of the present invention is one in the rubber range, but it is particularly preferable that the block copolymer contains 20 to 70% by weight of a vinyl-substituted aromatic compound. . If it exceeds 70 qb, the permanent elongation will be high and the rubber properties will be significantly impaired, and if it is less than 20 qb, the rubber hardness will be insufficient.

The polymerization average molecular weight is preferably 3 x 10' to 30 x 10'; anything less than 3 x 104 results in poor pupil properties and abrasion resistance after immersion in oil of the resin composition;
If it exceeds o', the workability is extremely poor.

On the other hand, the acrylic copolymer contains 5 to 20 parts by weight of ethylene, 15 to 55 parts by weight of vinyl acetate, and an alkyl acrylate represented by the following formula (1) and/or an alkyl acrylate represented by the following formula (11). Wadereru alkoxy 7 alkyl acrylate 25-80
Parts by weight of terpolymers or quaternary copolymers are preferred.

(1) CH2=C. HCOOH-R1 (R, is an alkyl group having 3 to 8 carbon atoms) (If) CH2 = CHC00-Rz -0-R
3 (R2 is an alkylene group having 1 to 4 carbon atoms, R3 is an alkyl group or an alkoxyalkyl group having 1 to 4 carbon atoms). If the amount exceeds 100 parts by weight, the elongation, fluidity and hardness of the elastomer composition will drop significantly, making it undesirable as a rubber elastomer.

Furthermore, the elastomer composition of the present invention may contain, in addition to the block copolymer and acrylic copolymer described above, a styrene polymer, ethylene polymer, ethylene vinyl acetate copolymer, paraffinic, naphthenic or aromatic process oil. When blended with fillers such as lucium carbonate, clay, silica, and talc, colorants such as titanium dioxide and carbon, stabilizers such as metal soaps and stearic acid, lubricants, and vulcanizing agents, hardness adjustment and moldability can be improved. It is preferable to blend these in appropriate amounts depending on the purpose, as they have effects such as improving the heat deformation temperature and heat deformation temperature.

To produce the elastomer composition of the present invention, the block copolymer and acrylic copolymer are blended in predetermined amounts and mixed using a mixer such as a mixing roll, Banbury mixer, kneader, or extruder. good. In addition, in mixing, it is preferable to operate under conditions of 100 to 230 L.

As explained above, the elastomer composition of the present invention is characterized in that it contains a block copolymer and an acrylic copolymer,
Generally, the injection molding method is used for the soles of cloth shoes, work shoes that require oil resistance, athletic shoes that require abrasion resistance, and the like. It can also be used in other applications that require oil resistance and rubber-like physical properties, such as automobile bumper protectors.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto.

Examples 1 to 8 Comparative Examples 1 to 3 Polymerization average molecular weight 15 x 104, one-sided AABA type (A,
B is as described above, the same applies hereinafter) containing 60 g of getadiene
%, % styrene-butadiene block copolymer 1
00 parts by weight, and the blending amounts shown in Table 1 of acrylic copolymers <A> and <B>' produced by the following method,
0.5 weight percent of 4-methyl-2,6-tsuta-shari-ethylphenol and trinolyl phosphite were each added as antiaging agents, and the mixture was kneaded with a 6-inch test roll at a temperature of 160C.

Next, this kneaded product was press-molded at a temperature of 150C to prepare a test piece, which was punched out to be used as a measurement sample and various physical properties were measured. The results are shown in Table 1.

As shown in Table 1, styrene-butadiene block copolymer and plain rubber have excellent tensile strength and hardness, but
Oil resistance is extremely poor.

On the other hand, acrylic copolymer <A>e 3 parts by weight, 35 parts by weight,
When 75 parts by weight and 100 parts by weight were added, the oil dust moisture content decreased to 28, 18, 10, and 8.3%, respectively, indicating that the oil resistance was improved and other rubber-like physical properties were maintained. .

Furthermore, when the addition information of the acrylic copolymer <A> exceeds 100 parts by weight (125 parts by weight), the oil resistance is greatly improved.
The rubber-like physical properties such as tensile strength, elongation, hardness, and fluidity are significantly reduced and it cannot be used as a thermoplastic elastomer composition.

Moreover, Examples 5 to 8 using acrylic copolymer <B>'i
In Comparative Example 1, the oil resistance was slightly stronger compared to Examples 1 to 4 and Comparative Example 2, which used acrylic copolymer <A>, but
It can be seen that other physical properties are almost the same as those of acrylic copolymer <A>.

Polyvinyl alcohol 530 in a 40t autoclave
y and sodium acetate 21.69' fx tube and 16
．． 2 Pour an aqueous solution adjusted to K9, add 9 to 2.16 kg of vinyl acetate and 8.64 kg of 2-methoxyethyl acrylate while stirring, emulsify, and replace the ethylene monomer in the autoclave with nitrogen gas. It was press-fitted from the top. Ethylene pressure is polymerization temperature 63c155 green/C
It was adjusted to be n12. After that, I1If
An aqueous fW ammonium solution was added several times in portions, and the polymerization was stopped in about 10 hours.

the? A copolymer was obtained by removing the monomer, coagulating the copolymer emulsion with an aqueous solution of borax, and dehydrating in this order, followed by roll drying.

The yield of the copolymer was 1.4 K9, and the composition of the obtained copolymer was 18 parts by weight of vinyl acetate, 76 parts by weight of 2-methoxyethyl acrylate, and 6 parts by weight of ethylene.

Polyvinyl alcohol 530 in 401 autoclave
2. Sodium acid 21.6 f, Rongalite 3
2.4 fK, 1.081 f of ethylenenoaminetetraacetic acid, and 0.54 f of ferrous acid were added to an aqueous solution adjusted to 16.2 KfK, and without stirring, vinyl acetate 5.
After adding 0 kg of autoclave and emulsifying the autoclave, the space inside the autoclave was completely replaced with 9 gas, and then ethylene monomer was pressurized from the top. The ethylene pressure is 50 at a polymerization temperature of 55C.
The ratio was adjusted to 9/Crn2. Then n
A mixture of 25 kg of 2-methoxyethyl acrylate and 2.5 kg of 2-methoxyethyl acrylate and an aqueous solution of 100% ammonium sulfate were added dropwise from separate injection ports over a period of 80 to 10 hours to proceed with polymerization.

After the polymerization was completed, the monomer was removed, 3 ml of borax aqueous solution was added to solidify the polymer emulsion, and the polymer emulsion was dehydrated.
Dry on test roll at ~130C. The composition of the obtained copolymer was 51 parts by weight of vinyl acetate, 19 parts by weight of n-butyl acrylate, and 2 parts by weight of 2-nodoquinoethyl acrylate.
3 parts by weight, and ethylene part by weight.

Examples 9 to 12 Comparative Example 4 Polymerization average molecular weight 15xlO4, one side)? Ten-based process oil (manufactured by Idemitsu Kosan Co., Ltd., trade name NS-100125 parts by weight, the amount of the acrylic copolymer <A> used in Examples 1 to 4 shown in Table 2, and as an antiaging agent) 0.5% by weight of each of 4-methyl 2,6-notarsialigyl phenol and polynolyl phosphite was added, and kneaded for 15 minutes in a Ni-Goo (model D3-5 pressurized kneader manufactured by Moriyama Seisakusho) at a temperature of 160C. It was made into a sheet using a 6-inch test roll.

Next, the sheet was press-molded at a temperature of 150C for 10 minutes to prepare a test piece. Furthermore, the test piece was punched out and used as a measurement sample to measure various physical properties.

The results are shown in Table 2. As shown in Table 2, the results obtained using the ternary threads of the styrene-butadiene block copolymer tobroses oil and the acrylic copolymer <A> also showed that the acrylic copolymer <A> was 10 to 100 parts by weight. It can be seen that within this range, it has a function as a thermoplastic elastomer composition and its oil resistance can be significantly improved.

In order to measure the physical properties of Examples and Comparative Example 1, the following test oils were used, and test pieces of 50 mm x 50 mm x 2 mm were immersed at 25 tT for 72 hours, and the weight change rate C% before and after immersion was determined.

2. Tensile strength JIS-63013, elongation
JIS-ni-63014, permanent elongation JIS
-Ni-63015, Hardness JIS-N-6301 6° Melt Flow Index JIS-N-6870 Patent Applicant: Tun Value A Gakuen Ujin Company

Claims (1)

[Claims] 100% by weight of a block copolymer of a conjugated tene compound and a vinyl-substituted aromatic compound containing 20 to 70 vinyl-substituted aromatic compounds having a polymerization average molecular weight of 3X10' to 30X10', and ethylene and vinyl acetate. A thermoplastic elastomer composition containing 3 to 100 parts by weight of a terpolymer or quaternary copolymer comprising an alkyl acrylate and/or an alkoxyalkyl acrylate.