JPS6342938B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl chloride resin composition for molded articles having a good matte state. Recently, matte molded products have been attracting attention because of their luxurious appearance. Conventionally, as a method for obtaining such a matte molded body, a method has been adopted in which irregularities are mechanically imparted to the surface of the molded body by a so-called embossing method during processing. Recently, vinyl chloride resins (hereinafter referred to as
A method has been proposed to obtain a matte molded product by using PVC. However, in the former mechanical method, it is necessary to install an embossing device, which increases the cost and makes it difficult to obtain a fine matte molded product. Furthermore, the latter method using crosslinked PVC has the drawbacks of high cost due to the use of a crosslinking agent, and that the crosslinking agent impairs the thermal stability of the molded product. The present inventors have improved upon these drawbacks and achieved a PVC resin composition with good matte properties. That is, in the present invention, (A) the average particle diameter (direct light) is 3 to
80μ, preferably 5-50μ, porosity (unit,
(cc/100g of resin, hereinafter the same) is 10 to 80 parts by weight of PVC with a porosity of 10 or less, preferably 5 or less, and (B) 100 parts by weight of PVC with a porosity of 15 or more, preferably 20 or more. . The amount of porosity in the present invention is 0.17 μm in pore size determined by mercury intrusion method per 100 g of resin.
(1000psi) to 5.9μ (20psi) in cc/100g PVC. Further, the matte state of the molded product was observed with the naked eye. To explain the present invention in detail, the object of the matte molded article can be achieved by having minute PVC particles with insufficient gelation present on the surface of the molded article.
Therefore, by using resins with extremely different gelation rates during processing and molding, a matte molded product can be obtained. Next, the matte state depends on the size of the ungelled PVC particles present on the surface of the molded product.
The size of the unevenness is determined, and therefore the matte state is also determined. In the present invention, the PVC used in (A) is a resin that gels slowly, and the PVC used in (B) is a resin that gels quickly. The particle size of the PVC used in (A) is related to the unevenness of the surface of the molded object; the smaller the particle size, the finer the matte state of the molded object, and the larger the particle size, the coarser the texture. However, if the particle size is less than 3μ, the matting effect of the molded object cannot be obtained, and the particle size may be too small.
If the thickness exceeds 80μ, the surface condition will be more like the presence of foreign matter than matte, which is not preferable. The preferred particle size is 5 to 50μ. The matte state of the molded product is also related to the amount of (A) used; if it is too low, there will be no matting effect, and if it is too large, the physical properties such as tensile strength and elongation of the molded product will be extremely reduced, which is not desirable. . The preferred amount used is 10 to 80 parts by weight. Next, regarding the porosity of PVC used in (A), the smaller the porosity, the more
Gelation rate slows down. In order to create a gelling rate difference with the PVC used in (B) and obtain a matte molded product, the porosity of the PVC used in Calendar (A) should be 10 or less.
Preferably it is 5 or less. Various methods are known to control the porosity of vinyl chloride resin, but
The most common method is a two-stage polymerization method. That is,
When vinyl chloride is polymerized to a normal degree, and vinyl chloride is added to the polymer, the porosity becomes smaller. The smaller the ratio of the first-stage monomer and the larger the ratio of the second-stage monomer, the smaller the porosity becomes. The PVC used in (B) gels quickly and forms a continuous phase in the molded product. this
PVC can be molded using general processing and molding machines under normal extrusion conditions. The PVC (B) has a porosity of 15 or more, preferably 20 or more. Generally, commercially available PVC falls within this range. In the present invention, known components such as stabilizers, lubricants, plasticizers, reinforcing agents, pigments, fillers, etc. that are used during processing and molding of PVC resins may be used, and the amounts used may be in conventional amounts. In addition, in the PVC used in (A) and (B) of the present invention,
There is no problem even if other monomer components that copolymerize with vinyl chloride are included. However, in this case the vinyl chloride component should be the predominant amount (by weight). Examples of the present invention are shown below, but these are not intended to limit the present invention in any way. Reference example: In a polymerization vessel with an internal volume of 150 mm equipped with a stirring blade, 70 kg of ion-exchanged water, 25 g of partially saponified polyvinyl acetate,
After preparing 20g of dimethylvaleronitrile and degassing,
50 kg of vinyl chloride was charged and polymerized at 65°C for a predetermined time. Next, add a predetermined amount of vinyl chloride, and add 65
Polyvinyl chloride (PVC) with different porosity was obtained by polymerization at ℃ for a predetermined period of time. These are shown in the table below.

[Table] Examples 1 to 5, Reference Example 1, Comparative Example 1 Average degree of polymerization to 100 parts by weight of PVC (B resin) with average degree of polymerization 1000, porosity 20.5, and average particle size 130μ
700 with different average particle size and porosity
A sheet with a thickness of 0.7 mm was made using a 50 mm extruder from a mixture consisting of 50 parts by weight of PVC (Resin A), 3 parts by weight of a tin-based stabilizer, and 0.7 parts by weight of low molecular weight polyethylene.
The matte state was observed. The results are shown in Table 1.

[Table] From Table 1, PVC with good matte condition has a porosity of 10 or less, preferably 5 or less, and an average particle size of 3.
~80μ, preferably 5-50μ. Examples 6 to 10, Reference Example 2, Comparative Example 2 Average degree of polymerization 1300, porosity 26, average particle diameter
100 parts by weight of 130μ PVC (B resin), average degree of polymerization
750, the porosity is 3 and the average particle size is different.
PVC (A resin) 40 parts by weight, lead stearate 1.5 parts by weight, calcium stearate 0.5 parts by weight, G-2
- 40 mm from a blend of 70 parts by weight of ethylhexyl phthalate and 0.02 parts by weight of carbon black
Create a circular extrudate with a diameter of 5 mm using an extruder,
Table 2 shows the results of observing the matte state of the surface.

[Table] *A resin is not used.
** Ranks for matte condition are the same as in Table 1.
From Table 2, it can be seen that even in the case of a soft type, a molded article with good matting effect can be obtained according to the present invention. Examples 11 to 14, Reference Example 3, Comparative Example 3 Average degree of polymerization 680, porosity 20, average particle size
100 parts by weight of PVC (B) of 150 μ, PVC (A) with an average degree of polymerization of 680, porosity of 4, average particle size of 15 μ, 10 parts by weight of Kane Ace B-22 (manufactured by Kanebuchi Kagaku Kogyo Co., Ltd.), tin-based stable A bottle was molded using a 50 mm blow bottle molding machine from a blend consisting of 3 parts by weight of agent, 0.8 part by weight of ester wax, and 0.005 part by weight of blue pigment, and the matte state of the molded product was observed. The results are shown in Table 3.

[Table] * The rank of matte condition is the same as in Table 1.
Table 3 shows that the matte state of the molded article changes depending on the amount of resin (A) used.

Claims (1)

[Scope of Claims] 1 (A) A vinyl chloride resin with an average particle diameter of 3 to 80μ and a porosity (unit, cc/100g of resin) of 10 or less
10 to 80 parts by weight, and (B) 100 parts by weight of a vinyl chloride resin having a porosity of 15 or more. 2. The vinyl chloride resin composition according to claim 1, wherein the vinyl chloride resin (A) has an average particle diameter of 5 to 50 μm and a porosity of 5 or less.