JPH07216166A - Vinyl chloride resin composition for powder molding - Google Patents

Abstract

PURPOSE:To obtain a resin composition which can give a molding improved in thermal aging resistance especially residual elongation in which a molding made from a vinyl chloride resin composition for powder molding is defective and improved in hygroscopicity and dispersibility. CONSTITUTION:This resin composition comprises 100 pts.wt. vinyl chloride resin and 0.1-5 pts.wt. mixture of calcium carbonate with a perchlorate ion- containing hydrotalcite compound obtained by adding calcium perchlorate to an aqueous slurry containing a hydrotalcite compound in a ratio of 0.05-1.0mol of the calcium perchlorate to 1mol of the carbonate ions of the hydrotalcite.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vinyl chloride resin composition for powder molding. More specifically, it relates to a vinyl chloride resin composition for powder molding, which can provide a molded article having excellent aging resistance.

[0002]

2. Description of the Related Art In recent years, covering materials such as crash pads, console boxes, headrests, armrests, meter covers, door trims, etc., which are automobile interior materials, are lightweight, have a soft feeling, and have a high-class texture. Those with a stitch pattern have become more and more demanded. A powder molding method is one of the molding methods that satisfies these requirements. As the powder molding method, a fluidized dipping method, an electrostatic coating method, a powder spraying method, a powder rotational molding method, and a powder slush molding method are generally used. A powder rotomolding method or a powder slush molding method is particularly suitable as a covering material for automobile interior materials. The powder rotation molding method or powder slush molding method is 180 ° C.
Molding in which the mold maintained at the above temperature and the powder supply box are integrated, the powder is welded to the inner surface of the mold by rotation, rocking or jetting, and the unfused powder is automatically or forcibly recovered in the powder supply box. Is the law. Since the powder molding method has no kneading step, the mechanical properties, particularly the elongation residual rate after heat aging, are poor. Therefore, it is necessary to select various additives having good dispersibility or those having a small amount of volatile components that cause foaming.

In producing a vinyl chloride resin composition for powder molding, a vinyl chloride resin and a plasticizer, stabilizer, pigment, etc. are dry blended by using a blender with a heating jacket or a high-speed rotary mixer. The method is known. It is also known to add an inorganic filler such as finely divided vinyl chloride resin, finely divided calcium carbonate, or silica in the cooling step after dry blending in order to improve powder fluidity. When the covering material obtained by the powder molding method is used as an automobile interior material, urethane is often injected and foamed. Therefore, the covering material is required to have high resistance to the amine contained in the urethane. It can be made to have excellent amine resistance by adding a perchlorate metal salt or a perchlorate ion type hydrotalcite compound ion-exchanged with an aqueous solution of perchloric acid to a vinyl chloride resin composition for powder molding. Has been proposed (Japanese Patent Laid-Open No. 62-270645).

[0004]

The present inventors have presumed that the heat aging property is affected by the water content in the powder resin composition. Therefore, as a result of examining the hygroscopicity of the stabilizer, the conventionally proposed metal perchlorate has a very high hygroscopicity, and the perchlorate ion-type hydrotalcite compounds ion-exchanged with the aqueous solution of perchloric acid also absorb the moisture. I knew that it was very good. Further, the latter has a drawback that the dispersibility is poor even if it is pulverized by applying strong energy because the cohesiveness at the time of drying is strong. An object of the present invention is to improve the heat aging property, which is a drawback of the molded product obtained from the vinyl chloride resin composition for powder molding, and particularly to improve the elongation residual ratio. Still another object of the present invention is to provide a vinyl chloride resin composition for powder molding, which gives a molded article having improved hygroscopicity and dispersibility.

[0005]

The present invention comprises 100 parts by weight of vinyl chloride resin and 0.1 to 5 parts by weight of the following mixed product, which is a vinyl chloride resin for powder molding. A composition is provided. The mixed product is 0.05 to 1.0 mol, preferably 0.4 to 1 mol, relative to 1 mol of carbonate radical of the aqueous slurry containing the hydrotalcite compound.
It is a mixed product of calcium carbonate and a perchlorate ion-containing hydrotalcite compound obtained by adding calcium perchlorate at a ratio of 0.8 mol. The present invention further provides a vinyl chloride resin composition for powder molding, which comprises a dry powder of the above mixed product and a vinyl chloride resin.

The vinyl chloride resin composition for powder molding of the present invention is prepared by dry blending the vinyl chloride resin with a plasticizer, a stabilizer, a pigment and the like using a blender equipped with a heating jacket or a high speed rotary mixer. Manufactured. The perchlorate ion-containing hydrotalcite compound is represented by the formula (1) M 2 ⁺ _1-x Al _x (OH) ₂ (CO ₃ ) _{x / 2} · mH ₂ O (1) [wherein M is Mg. , At least one divalent metal selected from Ca, Ni, Cu and Zn, and x and m each represent a number in the following range: 0 <x <0.5, 0 ≦ m
≤2. ) To an aqueous slurry containing 1 mol of the hydrotalcite compound, calcium perchlorate is added.
It is added at a ratio of 05 to 1.0 mol, preferably 0.4 to 0.8 mol. The pH during addition is preferably maintained at 5 or higher. According to the present invention, 0.05 to 1 mol of calcium carbonate is mixed and present with respect to 1 mol of the hydrotalcite compound. It is preferable that the concentration of the hydrotalcite compound in the aqueous slurry of the hydrotalcite compound is about 10% from the viewpoint of achieving uniform mixing.

The mixed product obtained as described above is
It is a mixture of perchlorate ion-containing hydrotalcite compounds and calcium carbonate. This was confirmed by the diffraction X-ray measurement. In addition, calcium perchlorate was substantially absent in this mixture. The calcium perchlorate used in the present invention is obtained by reacting a commercially available aqueous solution of perchloric acid with calcium hydroxide, calcium oxide, calcium carbonate and the like in a normal equivalent amount. However, if the calcium content is 0.9 equivalent or more, the hygroscopicity and cohesiveness are not adversely affected. In the present invention, the mixed product is preferably used as a dry powder, but it may be used in a liquid form or a paste form.

The conventional perchlorate ion-containing hydrotalcite compounds ion-exchanged with an aqueous perchloric acid solution have an ion exchange pH in the low range of 1.5 to 2.5. Therefore, it was confirmed by elution of magnesium that the crystals of the hydrotalcite-type compound were dissolved simultaneously with the ion exchange. Therefore, the perchlorate ion-containing hydrotalcite compound obtained by ion exchange with the perchloric acid aqueous solution has high hygroscopicity due to the presence of magnesium perchlorate or the crystal defect of the hydrotalcite compound, It also has the drawback of high cohesiveness.

In producing a perchlorate ion-containing hydrotalcite compound, a hydrotalcite compound surface-treated with a surfactant may be used. Examples of the surfactant include alkali metal salts of stearic acid and oleic acid, higher alkyl sulfonic acid alkali metal salts such as laurylbenzene sulfonic acid alkali metal salt, and the like. The reaction temperature may be heated to 50 ° C. or higher to accelerate the reaction. Examples of the vinyl chloride resin used in the present invention are as follows. Suspension polymerization method, vinyl chloride polymer produced by bulk polymerization method or emulsion polymerization method, copolymer of vinyl chloride and ethylene, propylene, vinyl acetate, etc., ethylene-vinyl acetate copolymer and vinyl chloride Graft copolymers, or mixtures of two or more of these. The above vinyl chloride resin is an example, and the present invention is not limited to these examples.

The stabilizer used in the present invention has been conventionally used in addition to a mixture of a calcium perchlorate ion-containing hydrotalcite compound ion-exchanged with calcium perchlorate and calcium carbonate. A stabilizer can also be used in combination. Examples of such stabilizers include metal salts of organic acids such as carboxylic acids and phenols, and organic phosphite compounds. As the metal of the metal salt, Li, N
Examples include a, K, Mg, Ca, Zn, Sn and the like.
Various conventionally known plasticizers can be used as the plasticizer.
Examples of these are as follows. Phthalic acid esters such as diisodecyl phthalate, dialkyl phthalate having 9 to 11 carbon atoms, tri-n-octyl trimellitate, tri-2-ethylhexyl trimellitate, tridecyl trimellitate, carbon atom number 7
Trimellitic acid triesters such as alkyl trimellitate, which is an alkyl group of 1 to 11, epoxy plasticizers, polyester plasticizers and the like. Hereinafter, the present invention will be described in more detail based on examples. In the following examples,% and parts mean% by weight and parts by weight, respectively, unless otherwise specified.

Synthesis Examples 1 to 3 Mixtures of perchlorate ion type hydrotalcite compounds and calcium carbonate were prepared by the following method. To 10 liters of an aqueous slurry containing 10% hydrotalcite compounds at a temperature of 30 ° C., a 40% aqueous calcium perchlorate solution (at a temperature of 30 ° C.) was added at a compounding ratio shown in Table 1,
Stirring was continued for a minute. The obtained slurry was dried at 105 ° C. for 2 hours. The dried product was crushed in a mortar and the crushed product passed through a 200-mesh sieve was used as a sample. The obtained sample was placed in a thermo-hygrostat at a temperature of 30 ° C. and a relative humidity of 75%, and the moisture absorption amount after 70 hours was measured. The measurement results are shown in Table 1.

Comparative Synthesis Examples 1-2 A 40% aqueous solution of perchloric acid (temperature 30 ° C.) was added to 10 liters of a 10% aqueous hydrotalcite compound slurry (temperature 30 ° C.) at a compounding ratio shown in Table 1. And then 30
Stirring was continued for a minute. The obtained slurry was dried at 105 ° C. for 2 hours. The dried product was crushed in a mortar and the crushed product passed through a 200-mesh sieve was used as a sample. The obtained sample was placed in a thermo-hygrostat at a temperature of 30 ° C. and a relative humidity of 75%, and the moisture absorption amount after 70 hours was measured. The measurement results are shown in Table 1.

Table 1 Calcium perchlorate Hygroscopic amount Addition amount (mol) (%) Synthesis example 1 0.4 4.5 2 0.6 5.0 5.0 3 0.8 6.5 6.5 Perchloric acid aqueous solution (mol) Comparison Synthesis example 1 1.2 18.5 2 1.6 23.0 Note: The amount of addition (mol) of calcium perchlorate is the value based on 1 mol of the hydrotalcite compound, and the amount of moisture absorption is the amount after absorption of moisture relative to the original weight. Displayed by weight.

Examples 1 to 5 and Comparative Examples 1 to 2 100 parts of a straight vinyl chloride resin having an average degree of polymerization of 800 obtained by the suspension polymerization method was placed in a super mixer having a volume of 20 liters, and then a plasticizer and the like were added. The compounding agents were added in the following compounding ratio with stirring while heating. When the plasticizer was absorbed by the resin, the heating was stopped and the mixture was cooled to 50 ° C or lower with water. Then, in order to improve the fluidity, a fine-grain vinyl chloride resin for paste having an average degree of polymerization of 1600 obtained by an emulsion polymerization method was uniformly dispersed to obtain a powdered vinyl chloride resin composition. In addition, the compounding amounts of the samples obtained in the synthesis examples or the comparative synthesis examples are shown in Table 2. Suspension polymerization vinyl chloride resin (P = 800) 100 parts Emulsion polymerization vinyl chloride resin (P = 1600) 10 parts Plasticizer (trioctyl trimellitate) 50 parts Epoxidized linseed oil 8 parts Phosphite (“MARK1500”, Asahi) Denka Co., Ltd.) 0.1 part Zinc stearate 0.2 part Stabilizer Variable Note: As the stabilizer, the samples obtained in Synthesis Examples and Comparative Synthesis Examples or barium perchlorate were used.

Moisture absorption test: The obtained powder molding resin composition was placed in a thermo-hygrostat at a temperature of 30 ° C. and a relative humidity of 75%.
A moisture absorption test was conducted. Aging test: heated in an oven at 250 ° C for 30 minutes 2
00x300mm, 3mm thick mirror-finished mold,
Resin composition for powder molding 3 prepared in Examples or Comparative Examples
It was sprinkled with 00 g and welded for 10 seconds. Then, the unwelded powder was brushed off, and then heated and melted in a 250 ° C. oven for 30 seconds. After cooling with water, the molded sheet was peeled off, and semi-rigid urethane foam was joined with a thickness of 10 mm, and then JIS K7
A No. 2 type test piece of the 113 plastic tensile test method was prepared. The obtained test piece was subjected to an aging test in a gear oven at 120 ° C. for 200 hours. The tensile test before and after the aging test was performed according to JIS K7113 to 200
It was carried out at a pulling speed of mm / min. The test results are shown in Table 2.

Table 2 Stabilizer addition amount Hygroscopic amount Elongation (%) Dispersibility (Part) (%) Before aging After aging Example 1 Synthesis example 1 1.0 0.04 231 220 Excellent 2 Synthesis example 2 1.0 0.05 233 236 Excellent 3 Synthesis example 3 1.0 0.08 230 227 Excellent 4 Synthesis example 2 0.5 0. 04 238 234 Excellent 5 Synthetic example 2 3.0 0.10 225 220 Good Comparative example 1 Comparative synthetic example 1 1.0 0.16 223 195 Yes 2 Comparative synthetic example 2 1.0 0.20 222 182 Yes 3 Perchlorine Barium acid 0.5 0.20 235 202 Excellent Note: The dispersibility was evaluated by the number of spots visible in 100 mm ^{2 of} the molded sheet. Excellent: 0 to 1, Good: 2 to 4, Fair: 5 to 7

[0017]

INDUSTRIAL APPLICABILITY According to the present invention, by adding a perchlorate ion-containing hydrotalcite compound having good dispersibility and low hygroscopicity, it is possible to provide a powder compact having excellent aging resistance. A vinyl chloride resin composition for use is provided.

Claims (2)

[Claims] 1. A vinyl chloride resin of 100 parts by weight,
0.1 to 5 parts by weight of the following mixed product, a vinyl chloride resin composition for powder molding, wherein the mixed product is 1 mol of a carbonate group of an aqueous slurry containing a hydrotalcite compound. Against 0.05-1.0
A mixed product of calcium carbonate and a perchlorate ion-containing hydrotalcite compound obtained by adding calcium perchlorate in a molar ratio. 2. The vinyl chloride resin composition for powder molding according to claim 1, wherein the mixed product is a dry powder.