JPS5952904B2 - resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high nitrile thermoplastic resin composition that has excellent gas barrier properties, is thermally stable, and is thermoformable.

In general, polymers containing a high amount of nitrile monomers, or compositions containing the same, yellow or decompose when heated, making them unstable and extremely difficult to mold.

Particularly when hot molding is performed at high temperatures, for example when extrusion molding or injection molding, yellowing and decomposition are significant. For this reason, the emergence of this type of material that has sufficient gas barrier properties and does not discolor has been awaited. As a result of intensive research, the present inventors found that an organic tin compound having the general formula: 1mi~■-~-X-X'-~~L and the general formula: 0=P<0H0■ P<0R3 0R3, 0B4 They discovered that discoloration can be prevented while maintaining gas barrier properties by molding an organic phosphoric acid compound or its metal salt in combination with a resin of a specific composition, especially a resin containing a high nitrile monomer content, and completed the present invention. did.

The present invention uses 50 to 90% by weight of a nitrile monomer represented by the general formula (where R is hydrogen or an alkyl group having 1 to 2 carbon atoms) and other polymerizable monomers that can be copolymerized with the nitrile monomer. 50 to 10% by weight of the nitrile monomer, or the copolymer containing a rubbery polymer with 50 to 90% by weight of the nitrile monomer based on the total polymer.
A polymer composition containing the general formula (wherein Rl, R2
is an alkyl group having 1 to 10 carbon atoms, R and R'' are hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 10); is a thermally stable thermoplastic resin composition containing an organic phosphoric acid compound (alkyl group having 1 to 18 carbon atoms) or a metal salt thereof as an essential component.

A copolymer consisting of 50 to 90% by weight of a nitrile monomer and 50 to 10% by weight of another polymerizable monomer that can be copolymerized with the monomer, or a copolymer containing a rubbery polymer. Polymer compositions containing from 50 to 90% by weight of nitrile monomers, based on the combined weight, are used in the present invention.

Other polymerizable monomers that can be copolymerized with the nitrile monomer include styrene, vinyl toluene, vinyl aromatic compounds such as α-methylstyrene, acrylic acid alkyl esters such as methyl acrylate and ethyl acrylate, and methacryl. Polymerizable monovinylidene compounds such as methacrylic acid alkyl esters such as methyl acid and ethyl methacrylate, vinyl esters of fatty acids such as vinyl acetate, vinyl halides such as vinyl chloride, vinyl ethers such as methyl vinyl ether, and vinyl ketones such as methyl vinyl ketone. There is. Preferably, a monomer that can lower the softening temperature or improve the thermal stability is preferable in order to improve the moldability of the nitrile compound. The amount used must be at least 10% by weight, and is limited to 50% by weight because gas barrier properties are reduced. These monomers can also be used as a mixture of one or more types. Furthermore, the copolymer can contain a rubbery polymer.

Rubbery polymers include polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, butadiene-alkyl acrylate copolymer, butadiene-alkyl methacrylate copolymer, polyisoprene,
Diene polymers such as polychloroprene, rubber-like polymers having a glass transition temperature lower than room temperature such as alkyl acrylates and ethylene monovinyl acetate copolymers can be used. The amount of these rubbery polymers to be used is arbitrary, but unless the amount of nitrile monomer is less than 50% by weight based on the total polymer, gas barrier properties will be impaired. To contain a rubbery polymer, it is necessary to blend it with a nitrile copolymer, to graft a nitrile monomer in the presence of a rubbery polymer, or to add the graft copolymer to a nitrile copolymer. It can also be produced by blending.

In order to improve the impact resistance of the resulting polymer composition and obtain a composition with high gas barrier properties, it is necessary to add other materials that can be copolymerized with the nitrile monomer in the presence of the dinin rubbery polymer. It is preferable to graft-polymerize the monomers.

The organotin compound used in the method of the present invention has the general formula (j)n
(However, in the above formula, Rl and R2 are alkyl groups having 1 to 10 carbon atoms, R and R'' are hydrogen or alkyl groups having 1 to 4 carbon atoms, and n is an integer of 1 to 10.) Examples include di-n-octyltin maleate, di-n-butyltin maleate, di-n-octyltin fumarate, di-n-butyltin fumarate and condensates of 2 to 10 of these, and di-n-butyltin maleate. n-octyltin alkyl-substituted maleate, di-n-butyltin alkyl-substituted maleate, di-n-octyltin alkyl-substituted fumarate, dijn-butyltin alkyl-substituted fumarate, and condensates thereof.

In addition, the organic phosphoric acid compound has the general formula (wherein R3,
R4 is a compound (alkyl group having 1 to 18 carbon atoms), examples of which include monoethyldihydrogenphosphate, diethylhydrogenphosphate, monobutyldihydrogenphosphate, dibutylhydrogenphosphate, mono- 2-Ethylhexyl dihydrogen phosphate, di-2-ethylhexyl hydrogen phosphate, monoisodecyl dihydro, zen phosphate, diisodecyl hydrogen phosphate, monolauryl dihydrogen phosphate, dilauryl hydrogen phosphate , monooctadecyl dihydrogen phosphate, dioctadecyl hydrogen phosphate, monooleyl dihydrogen phosphate, dioleyl hydrogen phosphate, and the like.

These organic phosphorus compounds may be used as they are, or in the form of metal salts with lithium, potassium, magnesium, calcium, barium, zinc, etc.
Note that even if an organic phosphorous compound other than an organic phosphorous compound, such as an organic phosphorous compound, is used in combination with an organic tin compound, a synergistic effect cannot be obtained. Therefore, in the present invention, an organic phosphorous compound is used as the organic phosphorous compound. Adopted. The amount of the organic tin compound and the organic phosphoric acid compound or metal salt thereof used is 0.05 to 15% by weight, preferably 0.05% by weight, based on the polymer.
．． It is 1 to 5.0% by weight.

If the amount added is less than 0.05% by weight, no significant effect can be expected, and if it is added in excess of 15% by weight, the gas barrier property,
Not only does it reduce transparency and mechanical strength, but it is also economically unfavorable.

The mixing method is arbitrary, but if the stabilizer is poorly dispersed, the stabilizing effect will be small, so it is preferable to mix thoroughly.

Therefore, it is preferable to mechanically mix the polymer powder and the stabilizer and mix them under heating, or to dissolve and disperse the stabilizer into the polymer dispersion using a solvent. The present invention will be further explained below with reference to Examples.

Examples 1 to 4, Comparative Examples 1 to 9 A dispersion was obtained by emulsion graft polymerization of 65 parts of acrylonitrile and 25 parts of methyl acrylate to an aqueous dispersion of 10 parts of a conjugated diene polymer.

Various organic tin compounds, organic phosphorus compounds, or their salts shown in Table 1, assuming the solid content in the dispersion as 100, are sufficiently dispersed in water using a dispersant, and then added to the dispersion. A polymer powder mixed with a stabilizer was obtained by a recovery method. The mixture was made into pellets through a screw extruder heated to 200°C, and then injection molded into a 2.6 mm plate.

The yellowness of the plate was measured using a colorimetric colorimeter (4) Model ND-21 manufactured by Hondenshoku Kogyo Co., Ltd. in the following manner.
The degree of yellowness is determined by calculating the tristimulus values X, Y, and Z for standard light from the spectral reflection characteristic curve in the visible wavelength range (400 to 700 mμ) for a standard magnesium oxide evaporated whiteness plate.
It was calculated from the following formula.

As is clear from the results in Table 1, thermal stability can be considerably improved by using only an organotin compound, but using only an organophosphorus compound or its metal salt has no effect at all.

However, it can be seen that the combined use of an organotin compound and an organophosphoric acid ester or its metal salt produces a remarkable synergistic effect. What? As shown in Comparative Examples 8 and 9, almost no synergistic effect was observed when an organic tin compound and an organic phosphite or a metal salt thereof were used in combination. Also, Ji-n-
The product using 1.0 part of octyltin maleate alone was less yellow (lower in intensity) than Comparative Example 2, which also used 0.5 part. Example 5 The polymer obtained in Example 1 was - The mixing ratio of the zinc salts of octyltin maleate and dioctadecyl hydrogen phosphate was changed to 0.00% each based on 100 parts of the polymer.
The mixture was varied from 2 parts to 1.0 parts, mixed and molded in the same manner as in Example 1, and the degree of yellowness was examined.

Claims (1)

[Claims] 1. 50 to 90% by weight of a nitrile monomer represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (where R is hydrogen or an alkyl group having 1 to 2 carbon atoms); A copolymer consisting of 50 to 10% by weight of other polymerizable monomers that can be copolymerized, or the above copolymer containing a rubbery polymer in which 50 to 90% by weight of the nitrile monomer is contained in the total polymer. Polymer compositions containing general formulas ▲mathematical formulas, chemical formulas, tables, etc.
, where R and R' are hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is an integer from 1 to 10), and general formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ Mathematical formulas , chemical formulas, tables, etc.▼ (However, R_3 in the formula,
R_4 is an alkyl group having 1 to 18 carbon atoms) A thermally stable thermoplastic resin composition containing an organic phosphoric acid compound or a metal salt thereof.