JPH061899A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. which gives a molded article having a good thermal stability without detriment to heat resistance by compounding a vinyl chloride resin with dibasic lead sulfite, tribasic lead sulfate, and lead benzoate. CONSTITUTION:100 pts.wt. vinyl chloride resin is compounded with 0.3-5 pts.wt. dibasic lead sulfite, 0.3-5 pts.wt. tribasic lead sulfate, and 0.1-3 pts.wt. lead benzoate to give the title compsn., which gives a molded article having a good thermal stability without detriment to heat resistance. The compsn. can be molded by any known method, e.g. by extrusion molding or injection molding.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a vinyl chloride resin composition.

[0002]

2. Description of the Related Art Vinyl chloride resins are used during manufacturing, processing,
When used, it undergoes decomposition and deterioration mainly due to dehydrochlorination reaction due to the action of heat, light, oxygen, etc., and coloring occurs. Such enhancement of thermal stability against deterioration of vinyl chloride resin is required when molding thick-walled molded products when the inside of the molded product is exposed to high temperatures for a long time without being cooled, or for precision molded products that are difficult to fill. It is especially required when molding at high temperatures.
Conventionally, in order to improve the thermal stability of vinyl chloride resins, metal soaps such as zinc stearate and barium stearate, inorganic lead stabilizers such as dibasic lead sulfite and tribasic lead sulfate, dibutyltin maleate , An organic tin stabilizer such as dibutyltin mercaptide is used.

However, the use of metal soaps includes metal soaps such as cadmium and zinc, which are elements of Group 12 (2B) of the periodic table, and elements such as barium, calcium and magnesium, which are elements of Group 2 (2A) of the periodic table. Although the synergistic effect of stabilization can be obtained by combining with the above metal soap, the effect of improving the thermal stability was small.

Further, although the inorganic lead-based stabilizer improves the lubricity of the vinyl chloride resin and greatly improves the dynamic thermal stability at the time of molding with shearing, the static thermal stability of the material and the molded product. The effect of improving the sex is small. Although the organic tin stabilizer greatly improves the static thermal stability, it has a small effect of improving the lubricity and a small effect of improving the dynamic thermal stability.
Further, the organic tin-based stabilizer has a drawback that the softening temperature of the molded product, that is, the heat resistance is greatly reduced. Further, when both are mixed, the thermal stability becomes good, but there is a drawback in that the softening temperature is lowered due to the organic tin-based stabilizer, and the heat resistance of the molded product is largely lowered.

Therefore, in Japanese Patent Laid-Open No. 3-33144, benzoic acid and lead stearate are added to a vinyl chloride resin.
A method of adding a lead stabilizer such as dibasic lead stearate or tribasic lead maleate has been proposed. However, this vinyl chloride-based resin composition did not have much improved thermal stability, and sufficient thermal stability could not be obtained.

[0006]

SUMMARY OF THE INVENTION In view of these points, an object of the present invention is to provide a vinyl chloride resin composition having excellent heat stability without lowering the heat resistance of a molded product.

[0007]

As the vinyl chloride resin used in the present invention, a homopolymer of vinyl chloride, and another monomer or two or more monomers containing vinyl chloride as a main component and copolymerizable therewith And a graft polymer of vinyl chloride and a graft-polymerizable resin, a post-chlorinated product of these polymers, or a mixture of these polymers.

Examples of the monomer copolymerizable with vinyl chloride include α-type compounds such as ethylene, propylene and 1-butene.
Olefin, vinyl acetate, vinyl propionate, vinyl stearate and other vinyl esters, styrene, α
-Styrenes such as methyl styrene, vinyl ethers such as isobutyl vinyl ether, cetyl vinyl ether and phenyl vinyl ether, alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate, vinylidene chloride, halogen such as vinyl fluoride Vinyl chlorides, cyclohexylmaleimide,
Examples thereof include N-substituted maleimides such as phenylmaleimide.

For example, in the case of a copolymer of vinyl chloride and ethylene, when the ethylene content exceeds 15% by weight, the heat resistance of the obtained molded article decreases, so the ethylene content is preferably 15% by weight or less, More preferably 4-9
% By weight. In a copolymer of vinyl chloride and vinyl acetate, when the vinyl acetate content exceeds 5% by weight, the heat resistance of the obtained molded article decreases, so the vinyl acetate content is preferably 5% by weight or less, more preferably Is 1 to 4% by weight.

As the resin capable of graft-polymerizing vinyl chloride, ethylene-vinyl acetate copolymer, ethylene-
Acrylic ester copolymer, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene-vinyl acetate-
Carbon monoxide copolymer, ethylene-ethyl acrylate-
Examples thereof include carbon monoxide copolymer and polyurethane.

Further, the post-chlorinated vinyl chloride resin has a flowability remarkably deteriorated when the degree of chlorination thereof exceeds 72% by weight, so that it is preferably 72% by weight or less, more preferably 57%.
˜68% by weight.

The average degree of polymerization of the vinyl chloride resin is not particularly limited, but if it is less than 300, a molded product having sufficient strength cannot be obtained, and if it exceeds 1400, the molding performance is deteriorated. 1400 vinyl chloride resins are preferred. Here, the degree of polymerization is calculated from the viscosity value described in JIS K6721.

The dibasic lead sulfite and tribasic lead sulfate used in the present invention are generally well-known compounds as inorganic lead stabilizers. Although it is inferior in thermal stability to the organic tin stabilizer, it is superior in dynamic thermal stability and the heat resistance of the molded product is superior to that of the molded product to which the organic tin stabilizer is added. The ratio of both dibasic lead sulfite and tribasic lead sulfate is not particularly limited, and the suitable amount varies depending on the type of resin used, the degree of polymerization, the molding temperature, etc. When it is less than 0.3 parts by weight with respect to 100 parts by weight of the vinyl resin, the improvement in thermal stability is very small,
If it exceeds 5 parts by weight, the physical properties of the molded article, particularly impact resistance, will deteriorate and the external appearance will deteriorate, so all are 0.3 to 5 parts by weight.

When the amount of lead benzoate added is less than 0.1 parts by weight with respect to 100 parts by weight of the vinyl chloride resin, the thermal stability is hardly improved and the amount added exceeds 3 parts by weight. However, the effect of improving the thermal stability does not increase and the heat resistance of the molded article decreases, so 0.1 to 3 parts by weight, preferably 0.2 to
1 part by weight. When only lead benzoate is added,
The effect of improving thermal stability is not so great. Thermal stability is improved only when combined with dibasic lead sulfite and tribasic lead sulfate.

The vinyl chloride resin composition of the present invention comprises the above vinyl chloride resin, dibasic lead sulfite, tribasic lead sulfate,
And a lead benzoate, which is a conventionally used lubricant such as stearic acid ester, polyethylene wax, etc., metal soap, antioxidant, MBS rubber, A
A modifier such as BS rubber, a glass fiber, a filler such as calcium carbonate, a colorant and the like may be added as appropriate. In addition, lead-based metal soaps such as lead stearate and lead laurate are more stable in heat than metal soaps other than lead-based metal soaps such as zinc, calcium, aluminum, barium and lithium. The effect of addition is great in terms of improving the property.

As a method for producing a molded article from the vinyl chloride resin composition of the present invention, any conventionally known method can be adopted,
For example, an extrusion molding method, an injection molding method and the like can be mentioned.

[0017]

EXAMPLES Next, examples of the present invention will be described. Examples 1 to 5, Comparative Examples 1 to 16 Predetermined amount of vinyl chloride resin (average degree of polymerization 540) shown in Tables 1 to 4, dibasic lead sulfite (trade name N manufactured by Sakai Chemical Industry Co., Ltd.
B-200), tribasic lead sulfate (trade name TL-4000 manufactured by Sakai Chemical Industry Co., Ltd.), lead benzoate (trade name L-06 manufactured by Sakai Chemical Industry Co., Ltd.), lead stearate, calcium stearate, dibutyltin maleate ( Product name made by Sakai Chemical Industry Co., Ltd.
TN-3J), barium stearate, stearyl alcohol (Kalco 86, trade name, manufactured by Kao Corporation), and lubricant (WAX-OP, trade name, manufactured by Hoechst Co., Ltd.) are supplied to a Henschel mixer (Mitsui Miike Seisakusho) at about 60 ° C. 15
After mixing for a minute, the mixture was kneaded at 190 ° C. for 3 minutes with a two-roll roll having a diameter of 8 inches (20.3 cm) to obtain a kneaded product. After preheating this kneaded material at 190 ° C for 3 minutes, the pressure is 150 kg.
A sheet having a thickness of 1 mm was obtained by press molding at f / cm ² (14.8 MPa) for 2 minutes.

The heat resistance of the obtained sheet at 190 ° C. is 3
After preheating for 1 minute, the pressure was 150 kgf / cm ² (14.8
(MPa) for 3 minutes to form a test piece having a thickness of about 3 mm, and JIS K7206 (load 1.0 kgf
(9.8 N)), the Vicat softening temperature is measured,
The results are shown in Tables 1 to 4.

Thermal stability is as follows: outer diameter 15 mm, length 105 mm
Test tube (Nichiden Rika Glass Co., Ltd. A-Wasserman reinforced hard
Fully automatic test tube), several sheets cut into 5 mm square
Add 0.5g and 1.0g of copper powder as heat carrier,
Elementary gas inflow pipe (open in the center of the test tube) and exhaust pipe (test
Cover the exhaust pipe with a rubber stopper (opening at the top of the pipe) and adjust the pH of the exhaust pipe.
In a 100 ml beaker with meter and stirrer
Ion exchange water 50 cm ³And introduce nitrogen gas at a flow rate of 0.
5 cm³Test tube containing sample while flowing at
10 minutes in silicone oil in oil bath set to 0 ℃
The pH value of the aqueous solution in which hydrogen chloride generated by pickling is trapped
Read the change, convert it to the amount of hydrogen chloride, and display the result.
It showed in 1-4.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

The vinyl chloride resin composition of the present invention comprises
It is possible to obtain a molded product having good heat stability without lowering the heat resistance.

Claims (1)

[Claims] 1. A vinyl chloride resin 100 parts by weight, a dibasic lead sulfite 0.3 to 5 parts by weight, and a tribasic lead sulfate 0.3.
-5 parts by weight and 0.1 to 3 parts by weight of lead benzoate, a vinyl chloride resin composition.