JP2001055477A - Vinyl chloride-based resin composition for powder molding use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition improved in low-temperature characteristics and to be used in powder molding such as powder rotational molding or powder slash molding. SOLUTION: This resin composition is obtained by dryblending a vinyl chloride resin with a plasticizer and also by including a metal perchlorate or perchloric acid-treated hydrotalcite and a polymer of acrylic alkyl group-contg. polysiloxane compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition having improved low-temperature characteristics and used for powder molding such as powder rotation molding and powder slush molding.

[0002]

2. Description of the Related Art A vinyl chloride resin composition for powder molding is mainly composed of a powdery vinyl chloride resin obtained by a suspension polymerization method or the like and a drive land of a plasticizer. Accordingly, for example, stabilizers, pigments, lubricants,
Various additives such as fillers are blended. The main use of the vinyl chloride resin composition for powder molding is as an automobile interior material molded product, and the interior material is usually used as a laminate by injecting and foaming a urethane resin. When a urethane resin is injected and foamed into a vinyl chloride resin molded product, the amine compound in the foamed urethane resin causes an undesirable phenomenon of deterioration and deterioration of the vinyl chloride resin molded product,
In particular, this phenomenon is significantly accelerated in the presence of heat and light. In order to prevent the deterioration and deterioration of molded products due to the amine compound, that is, as a measure against amine resistance, in recent years,
A method of blending a metal salt of perchloric acid into a vinyl chloride resin composition has been adopted, and it has been found that perchloric acid-treated hydrotalcite can be used for the same purpose.

[0003] Among the interior materials, recently, the instrument panel has an airbag integrated structure in consideration of the occupant's safety, and low temperature (0 to -35 ° C) characteristics are required. Became. That is, depending on the material of the instrument panel, the temperature may be low (0 to −35 ° C.).
In the state where the airbag is deployed and destroyed due to collision or the like, there is a danger that the fragments of the molded product may be exposed to the human body, and improvement thereof has been desired.

[0004]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies to develop a vinyl chloride resin composition which does not become hard and brittle under the conditions of air bag deployment at low temperatures. As a result, perchloric acid was added to the vinyl chloride resin. The present inventors have found that the above objects can be achieved by using and blending a polymer of a metal salt or a hydrochlorite treated with perchloric acid and a polysiloxane compound containing an alkyl acrylate group, thereby completing the present invention.

[0005]

SUMMARY OF THE INVENTION The gist of the present invention is a resin composition for powder molding in which a plasticizer is dry-blended with a vinyl chloride resin, wherein perchloric acid is contained in the composition. A vinyl chloride resin composition for powder molding, comprising a polymer of a metal salt or a hydrochlorite treated with perchloric acid and a polymer of an alkyl acrylate-containing polysiloxane compound.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The vinyl chloride resin as a resin component of the present invention may be a commercially available vinyl chloride resin as it is. Specifically, a vinyl chloride homopolymer, a copolymer of a vinyl chloride monomer with ethylene, vinyl acetate, or the like as a main component, produced by a suspension polymerization method, is used according to the intended use. These vinyl chloride resins are porous and can be so-called dry-blended, which absorbs the plasticizer when mixed with the plasticizer.

The plasticizer used in the composition of the present invention is not particularly limited as long as it is generally used for vinyl chloride resins. For example, dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), etc. Phthalate plasticizer, trioctyl trimellitate (T
OTM), trimellitate plasticizers such as tridecyl trimellitate, phosphate plasticizers such as tricresyl phosphate and trioctyl phosphate, and aliphatic dibasic ester plasticizers such as dioctyl adipate and diisodecyl adipate Agents, epoxy plasticizers, polyester plasticizers and the like. Among these, it is particularly desirable to use a plasticizer having low volatility at the time of heating, such as a trimellitic acid ester plasticizer or a polyester plasticizer. These plasticizers are used alone or as a mixture of two or more.

[0008] The amount of the plasticizer is limited to the amount that the vinyl chloride resin is still present in the form of powder when the plasticizer is mixed with the vinyl chloride resin powder. It is suitable that the amount is in the range of 20 to 100 parts by weight, preferably 50 to 80 parts by weight, based on 100 parts by weight of the resin.

The amount of metal salt of perchloric acid or hydrotalcite treated with perchloric acid, which is one of the essential components of the composition of the present invention, is 0.5 parts per 100 parts by weight of the vinyl chloride resin.
A range of 10 to 10 parts by weight, preferably a range of 1 to 7 parts by weight, particularly preferably a range of 2 to 5 parts by weight is appropriate. If the amount is less than the lower limit, the effect of preventing deterioration and deterioration of the molded article due to the amine compound is not sufficient. If the amount exceeds the upper limit, it reacts with the amine compound and blows out to the surface of the molded article. As the metal salt of perchloric acid, for example,
Barium perchlorate, sodium perchlorate, magnesium perchlorate, tin perchlorate and the like can be mentioned. Further, the perchloric acid-treated hydrotalcite has the following formula: Mg _x Zn _y Al ₂ (OH) _z (CO ₃ ) · mH ₂ O (where x, y and z are the following three conditional expressions) A satisfying number: 0 ≦ (y / x) <10 2 ≦ x + y <20 z = 2 (x + y) +4 m is a real number.) Hydrous basicity of magnesium or aluminum, natural or synthetic To a hydrotalcite that is a carbonate, a concentrated aqueous solution of perchloric acid is added and stirred, or hydrotalcite is added to a dilute aqueous solution of perchloric acid and stirred, and then, if necessary, filtered, dehydrated or dehydrated. It is prepared by drying. A plurality of metal salts of perchloric acid may be used in combination, or a metal salt of perchloric acid such as tin perchlorate may be used in combination with perchloric acid-treated hydrotalcite.

The amount of the polymer of the alkyl acrylate-containing polysiloxane compound, which is another essential component of the composition of the present invention, is based on 100 parts by weight of the vinyl chloride resin.
2 to 50 parts by weight, preferably 10 to 30 parts by weight,
Particularly preferably, the amount is in the range of 15 to 25 parts by weight. If the amount is less than the lower limit, the improvement in low-temperature properties is insufficient, and if the amount exceeds the upper limit, poor dispersion occurs, which is not preferable. The polymer of the alkyl acrylate-containing polysiloxane compound is an alkyl acrylate-containing polysiloxane compound in which at least one of the silicon atoms constituting the polysiloxane chain is bonded to the carbon atom constituting the alkyl group of the alkyl acrylate. There is no particular limitation as long as it is polymerized. The polymer may be a copolymer with another vinyl monomer. As this type of polymer, for example, a copolymer of methyl methacrylate and an alkyl acrylate-containing polydimethylsiloxane is the most common and commercially available, but is not limited thereto.

The composition of the present invention may also contain various known additives as required according to the purpose of use of the composition, such as lubricants, antioxidants, fillers, foaming agents, coloring agents, ultraviolet absorbers, and charging agents. Inhibitors, flame retardants, and the like can be added to the extent that the physical properties of the composition are not reduced.

To prepare the composition of the present invention, a vinyl chloride resin, a plasticizer, a metal salt of perchloric acid or perchloric acid-treated hydrotalcite, a copolymer of methyl methacrylate, an alkyl acrylate and dimethylsiloxane are used. And, if necessary, the above-mentioned various additives are mixed, dry-blended under heating, and the plasticizer is completely absorbed by the vinyl chloride resin. To uniformly mix and dry blend these components, for example,
What is necessary is just to put into a mixer, such as a Henschel mixer, a ribbon blender, and a planetary mixer, and to fully stir.

The vinyl chloride resin composition of the present invention thus obtained is used for the purpose of improving its powder flowability.
A powder flow improver may be added. Examples of the powder fluidity improver include a vinyl chloride resin having an average particle diameter of 10 μm or less, preferably 5 μm or less, a so-called vinyl chloride paste resin, produced by an emulsion polymerization method or a fine suspension polymerization method. Fine inorganic fillers such as calcium carbonate can be mentioned, and it is preferable to use at least one of these.

The amount of the powder fluidity improver is not particularly limited, but is usually 5 to 30 parts by weight, preferably 8 to 15 parts by weight, per 100 parts by weight of the vinyl chloride resin. desirable. The powder fluidity improver needs to be added to the vinyl chloride resin composition for powder molding obtained by dry blending, and the plasticizer is added to the vinyl chloride resin produced by the suspension polymerization method. If added before it is not completely absorbed, the effect of improving the fluidity of the composition will not be sufficiently exhibited.

The vinyl chloride resin composition for powder molding of the present invention is a molded article having a desired shape obtained by a powder rotational molding method or a powder slush molding method, for example, urethane for instrument panel, door trim, console box skin, etc. It has a high utility value as a molded article composited with a resin, that is, a molding material for automobile interior parts.

[0016]

EXAMPLES Next, the vinyl chloride resin composition for powder molding of the present invention will be described in detail in Examples, but the present invention is limited to the following Examples unless departing from the gist thereof. is not.

Examples 1 to 3 and Comparative Example 1 In a Henschel mixer, 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 900 produced by the suspension polymerization method, 70 parts by weight of trioctyl trimellitate, and epoxidized linseed oil 5 Parts by weight, initial coloring inhibitor (manufactured by Asahi Denka Co., trade name: Ma
rk1500) 1 part by weight, stearic acid 0.2 part by weight,
0.2 parts by weight of zinc stearate, hydrochlorite treated with perchloric acid (Kyowa Chemical Co., Ltd., trade name Alkamizer 5)
5 parts by weight and an amount (parts by weight) of a copolymer of methyl methacrylate and an alkyl acrylate group-containing polydimethylsiloxane compound (manufactured by Mitsubishi Rayon Co., Ltd., trade name: Metablen S2001) shown in Table 1 were added. And dry blending.

When the temperature of the blend reaches 125 ° C., cooling is started, and after cooling to 50 ° C., the average degree of polymerization is 1
A vinyl chloride resin composition for powder molding was manufactured by uniformly dispersing 10 parts by weight of a vinyl chloride paste resin having an average particle size of 500 or less and 5 μm or less.

0.2 kg of the vinyl chloride resin composition for powder molding produced in this manner is charged into a mold heated to 240 ° C., and the mold is rotated three times to uniformly disperse the composition on the mold surface. After adhering, and then discharging the unmelted excess composition,
The mold was again allowed to stand still at a temperature of 240 ° C. for 90 seconds and melted by heating. When the molten resin formed a continuous thin layer uniformly on the mold surface, the cooling of the mold was started. When the mold temperature reaches 50 ° C., the outer dimensions are 220 mm × 120 mm × 7
A 0 mm, 1 mm thick box formed article was peeled off.

The low-temperature characteristics of the molded articles obtained in the above Examples and Comparative Examples were measured and evaluated as follows. Table 1 shows the results. [Embrittlement temperature] A strip-shaped test piece (length 3) cut out from a sheet-like portion of a molded product
2 mm x width 6.3 mm x thickness 1 mm) using JIS K
The embrittlement temperature was measured according to 6301. The embrittlement temperature measured in this way is preferably −35 ° C. or lower. [-35 ° C. elongation] Using a No. 2 dumbbell-shaped test piece (length 25 mm × width 6 mm × thickness 1 mm) cut out from the sheet-like portion of the molded article, J
The elongation was measured according to IS K7113. That is, the test piece was left in an atmosphere of -35 ° C for one hour,
A tensile test was performed at 35 ° C. and a tensile speed of 200 mm / min using a DCS-2000 type tester manufactured by Shimadzu Corporation, and the elongation at break was read. The larger the -35 ° C. elongation measured as described above, the better, but 100%
The above is preferred.

[0021]

[Table 1]

As apparent from Table 1, the vinyl chloride resin composition for powder molding of the present invention has improved low-temperature characteristics.

[0023]

The vinyl chloride resin composition for powder molding of the present invention contains a metal salt of perchloric acid or a polymer of hydrotalcite treated with perchloric acid and a polysiloxane compound containing an alkyl acrylate group. Thereby, extremely excellent low-temperature characteristics are exhibited.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 83/07 C08L 83/07

Claims (6)

[Claims] 1. A resin composition for powder molding obtained by dry blending a vinyl chloride resin with a plasticizer, wherein the composition contains a metal salt of perchloric acid or hydrotalcite treated with perchloric acid and acrylic acid. A vinyl chloride resin composition for powder molding, comprising a polymer of an alkyl group-containing polysiloxane compound. 2. The plasticizer is a trimellitic ester plasticizer and / or a polyester plasticizer.
The vinyl chloride resin composition for powder molding according to the above. 3. The content of the metal salt of perchloric acid or hydrotalcite treated with perchloric acid is in the range of 0.5 to 10 parts by weight per 100 parts by weight of the vinyl chloride resin. Item 3. A vinyl chloride resin composition for powder molding according to Item 2. 4. The method according to claim 1, wherein the content of the polymer of the alkyl acrylate group-containing polysiloxane compound is in the range of 2 to 50 parts by weight per 100 parts by weight of the vinyl chloride resin. Item 10. The vinyl chloride resin composition for powder molding according to item 8. 5. The powder flowability improver according to any one of claims 1 to 4, further comprising a powder flow improver 5 per 100 parts by weight of the vinyl chloride resin.
A vinyl chloride resin composition for powder molding, characterized in that 30 parts by weight are uniformly dispersed. 6. The vinyl chloride resin for powder molding according to claim 5, wherein the powder fluidity improver is a vinyl chloride resin having an average particle diameter of 10 μm or less produced by an emulsion polymerization method or a fine suspension polymerization method. Resin composition.