JPH0525344A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition retaining the conventional mechanical strength of a vinyl chloride resin and having excellent moldability and molded product appearance by compounding the vinyl chloride resin with a stabilizer consisting of an inorganic stabilizer and/or a metal soap and a plasticizer. CONSTITUTION:The objective composition is characterized by compounding (B) a thermal stabilizer consisting of an inorganic stabilizer (e.g. lead oxide) and/or a metal soap (e.g. lithium stearate) and (C) a plasticizer (preferably dioctyl adipate) with (A) a vinyl chloride resin, the component C being compounded in an amount of 0.1-1.5 pts.wt. per 100 pts.wt. of the component A. The inorganic stabilizer and the metal soap are compounded preferably in amounts of 0.5-5 pts.wt. and 1-6 pts.wt., respectively, per 100 pts.wt. of the component A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard vinyl chloride resin composition such as a pipe or a building material which requires a certain level of heat resistance and mechanical toughness.

[0002]

2. Description of the Related Art A vinyl chloride resin has a glass transition point Tg of about 80 ° C. by itself. A plasticizer can be added to soften like rubber, and a heat stabilizer and a filler can be added to obtain a variety of products from a transparent molded product to an opaque molded product. In addition, the addition of dyes and pigments facilitates coloring, allowing the surface of a molded product to be painted or printed. Therefore, it is widely used from hard molded products such as pipes and building materials to soft molded products such as leather, agricultural vinyl and hoses.

Among these, hard molded products such as tap water, sewage,
When it is used for piping materials such as distribution lines, interior materials for buildings, outer wall materials, window frame materials, etc., it is often exposed to temperatures of about 70 ° C, so heat resistance and high tensile strength are required. There is.

In order to obtain a hard molded product having high heat resistance and high tensile strength, vinyl chloride resin is used in combination with an inorganic heat stabilizer such as tribasic lead sulfate and dibasic lead phosphite, and lead stearate. , And metal soaps having a high melting point such as calcium stearate were also compounded and extruded.

At this time, if the amount of the metallic soap is increased, the sliding effect is increased, the load on the motor during extrusion molding and kneading is reduced, and the appearance of the obtained molded product becomes smooth and good, but the tensile strength is increased. Not only that, but also a large number of air bubbles were included in the molded product due to the non-uniform kneading, which adversely affected various physical properties such as mechanical properties and heat resistance.

On the other hand, when the amount of metal soap is reduced, the load on the motor during extrusion molding and kneading increases, and the appearance of the resulting molded product deteriorates remarkably, and thermal decomposition is promoted by local overkneading and internal heat generation. It was hard to make a long run.

As described above, in order to obtain a hard molded product having high heat resistance and high tensile strength, when a vinyl chloride resin is used in combination with an inorganic heat stabilizer and metal soaps, high heat resistance is obtained. It was very difficult to obtain a balanced molded product with high tensile strength and good appearance.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention makes it easy to process without losing the conventional mechanical strength, and the appearance of the obtained molded product has a flash mark. It is an object of the present invention to provide a hard vinyl chloride resin composition having a small surface roughness and a good glossy surface.

[0009]

In order to achieve the above object, the vinyl chloride resin composition of the present invention comprises a vinyl chloride resin and an inorganic stabilizer or a metal soap or a heat stabilizer comprising both of them. 0.1 to 1.5 parts by weight of a plasticizer with respect to 100 parts by weight of the vinyl chloride resin.

The vinyl chloride resin composition of the present invention contains a vinyl chloride resin. Examples of such vinyl chloride resin include polyvinyl chloride (PVC) homopolymer, vinyl chloride (VC) -vinyl acetate copolymer, V
C-vinyl ether copolymer, ethylene vinyl chloride copolymer, propylene-VC copolymer, ethylene / vinyl acetate copolymer (EVA) -VC graft polymer, ethylene / propylene rubber (EPR) -VC graft polymer, PVC- Styrene graft polymer, PVC-methyl methacrylate (MMA) graft polymer, PVC-
Styrene / butadiene (S / B) graft polymer, P
VC-butadiene (B) graft polymer can be mentioned.

The vinyl chloride resin also contains an inorganic stabilizer or a stabilizer composed of metal soaps. Depending on the application, the inorganic stabilizer and the metallic soap may be used alone or in combination.

Examples of such inorganic stabilizers include tribasic lead sulfate, basic lead sulfite, basic lead bisulfite, dibasic lead phosphite, and lead white (PbO.2PbCO ₃ .H ₂
O), lead oxide, lead orthosilicate-silica gel coprecipitation, lead orthosilicate. These may be used alone or in combination.

The metal soaps are organic metal salts, and examples thereof include stearic acid metal salt, lauric acid metal salt, 2-ethylhexylic acid metal salt, and other acid metal salts.

Examples of the metal stearate include lithium stearate, sodium stearate, calcium stearate, strontium stearate, barium stearate, zinc stearate, cadmium stearate, lead stearate, basic lead stearate, and dibasic. Lead stearate etc. can be mentioned. Examples of the metal laurate include barium laurate, zinc laurate, cadmium laurate and the like.
Examples of the metal salt of 2-ethylhexyl acid include barium 2-ethylhexylate, zinc 2-ethylhexylate, cadmium 2-ethylhexylate, and lead 2-ethylhexylate. Examples of other acid metal salts include barium ricinoleate, tribasic lead maleate, lead naphthenate, dibasic lead phthalate, and lead salicylate. These may be used alone or in combination.

In the present invention, a small amount of a highly compatible plasticizer is used in addition to such an inorganic stabilizer or metal soap. Examples of such plasticizers include dialkyl phthalate plasticizers, dioctyl adipate (DOA), epoxidized soybean oil, dibutyl sebacate (DBS), 2-ethylhexyl diphenyl phosphate, and tricresyl phosphate (TCP).

The two alkyl groups of the dialkyl phthalate plasticizer may be the same or different from each other. When the alkyl groups are the same atomic groups, examples of the dialkyl phthalate include dioctyl phthalate among them, normal octyl phthalate (DOP), other dibutyl phthalate (DBP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP). , Dicyclohexyl phthalate and the like.
Examples of the dialkyl phthalate having different atomic groups include butylbenzyl phthalate. These plasticizers may be used alone or in combination. Among these, for example, DBP, DOP, or DOA having a higher compatibility with the vinyl chloride resin is particularly preferable to epoxidized soybean oil and the like.

In addition to the above stabilizers and plasticizers, for example, a lubricant, a filler, a colorant, a release agent, etc. may be contained within a range that does not impair the effects of the invention. Examples of such a lubricant include paraffin and stearic acid, examples of the filler include wood powder and mica, and examples of the release agent include silicone oil.

In the vinyl chloride resin composition of the present invention, 0.5 part by weight to 10 parts by weight, preferably 0.5 part by weight to 5 parts by weight of an inorganic stabilizer may be added to 100 parts by weight of vinyl chloride. I hope you are there. If the added amount of the inorganic stabilizer exceeds 10 parts by weight, plate out occurs, and if the added amount is less than 0.5 part by weight, the effect of thermal stability is poor,
Not preferable.

The amount of the metallic soap added may be appropriately selected in consideration of the degree of thermal stability required for the vinyl chloride resin composition as a whole. Usually, 1 to 10 parts by weight, preferably 1 to 6 parts by weight, may be added per 100 parts by weight of vinyl chloride. If the amount of the metallic soap added exceeds 10 parts by weight, plate-out will occur and uniform kneading will not be possible, and if it is less than 1 part by weight, the load on the motor will increase and the appearance of the resulting molded article will be impaired. .

The plasticizer is added in an amount of 100% vinyl chloride resin.
0.1 to 1.5 parts by weight is preferable with respect to parts by weight. If the amount added exceeds 1.5 parts by weight, the plasticizing effect becomes large, the mechanical properties are lowered, and the softening temperature is lowered to a large extent, which is not preferable. If the amount is less than 0.1 parts by weight, the load of the motor during the molding process is increased, the appearance of the obtained molded product is impaired, and the physical properties of the molded product are affected such as the deterioration of mechanical properties.

[0021]

As described in detail above, the vinyl chloride resin composition of the present invention has the conventional mechanical strength when molded by a screw kneader, and can be easily molded. In addition, it is possible to obtain a hard vinyl chloride resin composition having a small flash mark in the appearance of the obtained molded product, a good surface gloss, and excellent moldability. As a result, the present invention leads to a reduction in the motor load during the molding process, and a molded product with a good appearance can also be obtained.

[0022]

EXAMPLES Examples of the present invention will be described below.

The base compositions shown in Table 1 were prepared and evaluated for their melt processability and mechanical strength.

That is, in Table 1, three kinds of base compositions as shown in Base Formulation Examples 1 to 3 were prepared, and then these respective base compositions and various additives were added to 100 liters manufactured by Kawata Manufacturing Co., Ltd. A super mixer was charged with an amount equivalent to 30 kg of PVC, the temperature was raised to 150 ° C., and the mixture was dried. As a result, a vinyl chloride resin composition containing PVC in an amount corresponding to 30 kg and having a composition ratio as shown in Tables 2 and 3 according to the present invention, Examples 1 to 1
8, vinyl chloride resin compositions based on conventional compositions, Comparative Examples 1 to 7 were obtained.

Each composition thus obtained was subjected to a molding process and its processability was evaluated. The molding process was based on the following pipe extrusion molding method and pipe joint injection molding method.

The evaluation results are shown in Tables 2 and 3.

(1) Pipe Extrusion Molding Method A die for producing hard vinyl chloride pipe VP-50 (JISK-6741) (t (lip gap) = 4.5 mm) was connected to a TE-90 type extruder manufactured by Toshiba Machine. , Rotation speed 14 rpm
Each vinyl chloride-based resin composition was extruded from the screw kneader set in above to form a hard vinyl chloride pipe.

The molding barrel temperature is 170 ° C. on the hopper side,
The temperature at the front of the barrel was 185 ° C and the temperature of the die was 195 ° C. The motor load during extrusion molding was 27 Amp or less.

(Evaluation method) Appearance evaluation of pipe: According to JISK-6742, the inner surface of the pipe was evaluated by visual observation.

The inner surface is a mirror surface ⊚, the screw kneading machine mark is slightly recognized ○, the screw kneading machine mark is Δ, and the screw kneading machine mark unevenness is attached to the pipe inner surface. And the screw kneader mark on the inner surface of the pipe and the unevenness was large were evaluated as XX.

Pipe foaming: Immersed in a glycerin bath at 130 ° C. for 5 minutes, then taken out, quickly cut in an axial direction with an NT-cutter, and observed the generation state of bubbles in the cut cross section.

∘ when no bubbles are generated, small bubbles are 3 or less in a length of 5 cm, 0 or small bubbles are 3 or more in a length of 5 cm, and Δ are 5 cm. The case where large bubbles were present in the cross section of length was evaluated as x. Tensile strength: Based on JISK6742, a tensile test piece was cut out from a pipe and the tensile strength at 15 ° C was observed. It was found that the tensile strength was 500 kg / cm ² or more.

Flexible temperature (T _f ° C): JISK-67
Based on 45, the composition was heated on a 6 ″ roll at 180 ° C. for 5 minutes to obtain a sheet having a thickness of 1 mm. The obtained sheet was 1
A 100-ton press machine (manufactured by Toho Press) at 90 ° C. was preheated for 7 minutes and pressed for 5 minutes. After pressurizing and cooling, a sheet having a thickness of 1 mm was used to obtain 6.3 in accordance with JISK6745.
A test piece having a width of 5 mm and a length of 64 mm was prepared, and the softening temperature of the test piece was measured.

Needle insertion temperature: from pipe to JISK67
According to No. 42, a test piece having a width of 10 mm × 15 mm and a thickness of 2 mm was prepared, and the needle insertion temperature was measured.

(2) Injection molding method for pipe joints An Ankerberg V-15 (30z) injection molding machine manufactured by Japan Steel Works is set with a mold for an A-type socket having a nominal diameter of 25 in accordance with JIS-K6743, and the hopper side cylinder is set. The temperature is 170 ° C, the temperature at the center of the cylinder, the temperature at the front of the cylinder, and the nozzle temperature are all 190 ° C, and the metal temperature is 5 ° C.
Molding was carried out at 0 ° C., the rotation speed of the screw kneader was 45 rpm, and the injection pressure was 1200 kg / cm ² .

The motor load during extrusion molding is 7.0 Amp.
Below.

(Evaluation Method) Appearance: The presence or absence of flash in the sprue part and the glossy state of the surface were visually observed. Those with a large flash mark were evaluated as x, those with a small flash mark were evaluated as ◯, and those with a small flash mark and a good surface gloss were evaluated as ⊚.

The tensile strength, glass transition point, and needle insertion temperature were evaluated in the same manner as in the pipe extrusion molding method.

[0039]

[Table 1]

[0040]

[Table 2]

Unit: Component Weight part Motor load Amp Tensile strength kgf / cm ² Needle insertion temperature ° C Epoxidized soybean oil is trade name ADEKA Cider O-
130P was used.

[0042]

[Table 3]

In proportions 6 and 7, the motor load was so high that molding could not be performed.

From the above results, when a small amount of the plasticizer is added to the vinyl chloride resin composition, the load on the motor of the screw kneader is reduced, the appearance of the molded product is improved, and the tensile strength evaluation shows that According to this, it was also found that it will have a mechanical strength higher than the conventional one.

Claims (2)

[Claims] 1. A vinyl chloride resin and / or an inorganic stabilizer.
Alternatively, a heat stabilizer composed of metal soaps and a plasticizer may be added to 100 parts by weight of the vinyl chloride resin.
A vinyl chloride resin composition comprising 1 to 1.5 parts by weight. 2. The vinyl chloride resin composition according to claim 1, wherein the plasticizer is a dialkyl phthalate plasticizer or a dioctyl adipate plasticizer.