JP3068728B2 - Vinyl chloride resin composition - Google Patents

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 which gives a molded article having good workability and excellent impact resistance.

[0002]

2. Description of the Related Art In many vinyl chloride resins, the higher the average degree of polymerization in a hard compound, the better the physical properties such as tensile strength and heat resistance, and the addition of an impact resistance modifier has a large effect even in a small amount. It is known to be obtained. However, as the degree of polymerization increases, the processability decreases, and the fluidity and surface smoothness required for high-speed molding such as calendar molding, extrusion molding, injection molding, and blow molding are lacking. There is a method of increasing the processing temperature as a method of compensating for the lack of such fluidity and surface smoothness, but when the average polymerization degree of the vinyl chloride resin is high in a hard compounding system, satisfactory fluidity and surface smoothness are obtained. When the temperature condition is increased to a state where the resin can be obtained, the resin itself is deteriorated by heat, and the physical properties that the resin originally should have cannot be exhibited. In addition, when a resin having a low degree of polymerization is used to improve moldability, the fluidity and surface smoothness are improved, but the impact resistance is reduced, so that a larger amount of the modifier must be kneaded. As a result, physical properties such as heat resistance and tensile strength may be reduced.

[0003]

For these reasons, a method of adding a processing aid is used to improve the processability of a vinyl chloride resin, and a rubber-based heavyweight is used as an impact modifier to improve the impact resistance. A method of adding a small amount of coalescence has been generally adopted. It has been thought that these methods improve processability and fluidity under mild processing conditions, and can also improve impact properties due to rubber-based additives. However, Japanese Patent Application Laid-Open No. 50-88170 discloses a copolymer of methyl methacrylate and / or acrylonitrile, styrene and alkyl acrylate, acrylonitrile-butadiene-styrene resin in 90 to 99 parts by weight of a vinyl chloride graft polymer.
It describes a resin composition obtained by adding 1 to 10 parts by weight of at least one polymer material among chlorinated polyethylenes. According to this, improvement in impact resistance is recognized, but fluidity and surface smoothness are described. Sex has not improved. Similarly, JP
In -142661, the average degree of polymerization of vinyl chloride is 400 to 15.
It is considered to be good up to 00, and although the impact resistance of this composition is high, the fluidity and surface smoothness are not improved. Further, the descriptions in JP-B-48-57846 and JP-A-60-179443 are the same. Accordingly, an object of the present invention is to provide a vinyl chloride resin composition which is excellent in physical properties such as impact resistance and tensile strength and gives a molded article having good surface smoothness.

[0004]

The present inventors have intensively studied how to simultaneously satisfy the above-mentioned contradictory properties of workability (particularly surface smoothness) and physical properties (particularly impact resistance and tensile strength). As a result, a vinyl chloride-based resin, Latte
Methacrylate-butadiene-styrene (hereinafter referred to as MBS) resin or acrylonitrile-butadiene-styrene (hereinafter referred to as AB) obtained from polybutadiene latex or styrene-butadiene rubber (hereinafter referred to as SBR) latex having an average particle diameter of 0.08 μm or less.
S) and an acrylonitrile-styrene (hereinafter, referred to as AS) copolymer were found to provide excellent workability and physical properties, thereby completing the present invention. That is, the vinyl chloride resin composition according to the present invention comprises: A) 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 700 to 2500, and B) graft polymerization of a polybutadiene latex or SBR latex having an average particle size of latex of 0.08 μm or less. MBS resin or ABS resin 4 to 15
Parts by weight and C) 1 to 10 parts by weight of an AS copolymer having a weight ratio of acrylonitrile to styrene of 10:90 to 35:65.

Hereinafter, the present invention will be described in detail. In the vinyl chloride resin composition of the present invention, the vinyl chloride resin used as the component A has an average degree of polymerization of 700 to 2500, preferably 1000 to 1700. This average degree of polymerization is 700
If less, the impact strength, heat resistance, etc. are inferior, and 2500
If the temperature exceeds the above, the workability is poor unless the temperature of the molten resin is increased during the molding process. Due to the high temperature, thermal deterioration is remarkable and the inherent properties of the resin are impaired. Examples of the vinyl chloride resin include polyvinyl chloride resin, a copolymer of a vinyl monomer containing at least 50% by weight of vinyl chloride and a copolymerizable vinyl monomer, and chlorinated polyvinyl chloride. Of these, polyvinyl chloride resin is particularly preferred. Examples of the copolymerizable vinyl monomer include α-olefins such as ethylene and propylene; acrylic acids such as acrylic acid, methyl acrylate and ethyl acrylate or esters thereof; and methacrylic acids such as methacrylic acid and methyl methacrylate. Acids or esters thereof; maleic acid or esters thereof; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as lauryl vinyl ether and isobutyl vinyl ether; maleic anhydride; vinylidene chloride; maleimide; Used in combination above.

The MBS resin or ABS resin used as the B component in the resin composition of the present invention is a latex
Is a graft polymer of polybutadiene latex or SBR latex having an average particle size of 0.08 μm or less. The MBS resin or ABS resin obtained from the latex having such an average particle diameter is used in a vinyl chloride resin composition to form
Existing at the interface of the primary particles (1-2 μm) of VC,
It has the function of retaining primary particles. As a result, it is possible to improve not only the impact resistance but also the tensile strength which is a contradictory physical property. The moldability of such a vinyl chloride resin composition is remarkably improved, for example, when it is extruded to have excellent surface smoothness and can be finely extruded. On the other hand, if the average particle diameter of the latex is larger than 0.08 μm, the impact resistance is improved, but it is difficult to retain the primary particles of PVC, and the tensile strength decreases. Regarding processability, the average particle size of latex is 0.08
If it is less than μm, it is easy to hold the primary particles of PVC, so that it can be molded with a wide processing temperature range. However, if it exceeds 0.08 μm, it becomes difficult to hold the primary particles and the processing temperature range becomes narrow.

The MBS resin or the ABS resin preferably contains 40 to 80% by weight of butadiene. If it exceeds 80% by weight, the impact resistance is good, but it causes a reduction in fluidity and tensile strength. If it is less than 40% by weight, the impact resistance cannot be improved. This MBS resin or ABS resin is used in a proportion of 4 to 15 parts by weight with respect to 100 parts by weight of the vinyl chloride resin, but if the amount is less than 4 parts by weight, the effect of improving impact resistance cannot be obtained. If the amount exceeds 15 parts by weight, various properties such as heat resistance, tensile strength, and workability deteriorate, which is not preferable.

[0008] AS as C component in the present resin composition
The copolymer had a weight ratio of acrylonitrile to styrene of 1
0:90 to 35:65, preferably 20:80 to 30:70. Acrylonitrile in this copolymer is 10
If the amount is less than 35% by weight, the compatibility with the resin may be reduced to cause separation, and if the amount is more than 35% by weight, the fluidity may be reduced. This AS copolymer is a vinyl chloride resin.
It is used in an amount of 1 to 10 parts by weight, particularly 3 to 10 parts by weight based on 00 parts by weight.
The effect of improving heat resistance cannot be obtained, and if it exceeds 10 parts by weight, impact resistance and workability may be reduced.

In the resin composition of the present invention, in addition to the above three resin components, if necessary, a stabilizer, a stabilizing aid, a lubricant, an inorganic filler, a plasticizer, a coloring agent, an ultraviolet absorber, Various additives such as antioxidants can be added.
The stabilizer is not particularly limited as long as it is blended with a general vinyl chloride resin, and laurate, malate,
Organotin stabilizers such as mercaptides, Ca, Ba,
Examples thereof include metal soap stabilizers such as Pb, and lead stabilizers such as tribasic lead sulfate, lead silicate, and dibasic lead phosphite. These may be used alone or in combination of two or more. Epoxy compounds and the like as stabilizing aids, pure hydrocarbons such as paraffin wax and polyethylene wax, fatty acids such as palmitic acid and stearic acid, aliphatic alcohols such as stearyl alcohol, fatty acids and alcohols as lubricants And partial esters of fatty acids and polyhydric alcohols. Calcium carbonate as inorganic filler,
Titanium oxide, talc, etc. are mentioned. Of these, calcium carbonate is preferable, and heavy calcium carbonate or light calcium carbonate may be used. However, when importance is placed on impact resistance, it is preferable to add a large amount of light calcium carbonate. .

[0010] The vinyl chloride resin composition of the present invention comprising these components is mixed using a conventional means such as a high-speed mixer to form a powder or pellets, and is subjected to calender molding, extrusion molding, injection molding, blow molding. It can be formed into a molded product having a desired shape by molding.

[0011]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to the description of the examples. Examples 1 to 6 and Comparative Examples 1 to 16 To each of the resin components of the formulations shown in Tables 1 and 2, 1 part by weight of a stabilizer, 0.7 part by weight of a stabilizing aid, 6 parts by weight of an inorganic filler and 0.5 part by weight of a lubricant The resulting mixture was kneaded at 170 ° C. for 5 minutes using a 6-inch roll to prepare a 0.8 mm thick sheet. Using the kneaded material and the sheet, impact resistance, heat resistance, tensile strength and surface smoothness were tested by the following methods, and the results are shown in each table.

The details of the components used and the test method are as follows. (Components)-Polyvinyl chloride resin (abbreviated as PVC in the table): TK-600 (Shin-Etsu Chemical Co., Ltd., trade name, polyvinyl chloride, average degree of polymerization 600) TK-800 (Same before, average polymerization) Degree 800) TK-1000 (（, 〃1000) TK-1300 (〃, 〃1300) TK-2500P (〃, 〃3000) ・ MBS resin (abbreviated as MBS in the table): MBS-: graft polymerization type, butadiene Content: 60% by weight, latex particle size: 0.2 μm. MBS-: Same as above, butadiene content: 60% by weight, latex particle diameter: 0.05 μm. ABS resin (abbreviated as ABS in the table): ABS-: Same as above, butadiene content: 65% by weight, latex particle diameter: 0.2 μm. ABS-: Same as above, butadiene content: 60% by weight, latex particle diameter: 0.08 μm.

AS copolymer (abbreviated as AS in the table): AS−: acrylonitrile: styrene = 23: 77 (weight ratio) AS−: 〃 = 5: 95 (weight ratio) AS−: 〃 = 40: 60 (weight ratio)-Stabilizer: T-17MJ (Katsuda Kakosha, trade name, organic tin stabilizer)-Stabilizing aid: calcium stearate-Inorganic filler: Shirahama CCR (Shiraishi calcium company, trade name, carbonic acid) Calcium) ・ Lubricant: AC-6A (manufactured by Allied Chemical Company, trade name, polyethylene wax)

(Test method)-Impact resistance test: The above-mentioned four sheets having a thickness of 0.8 mm were stacked and pressed, and a sheet having a thickness of 3 mm was measured based on JIS K-7110. 80 kg · cm / cm ² or more was accepted.・ Heat resistance test: The above-mentioned four sheets having a thickness of 0.8 mm were overlapped and pressed to obtain a sheet having a thickness of 3 mm, and the Vicat softening point (° C.) was measured based on JIS K-7206. C or higher was considered as a pass. -Tensile strength test: Two sheets of the above-mentioned 0.8 mm in thickness are stacked and pressed to obtain a sheet of 1 mm in thickness, which is measured based on JIS K-7113, and has a yield value of 470 kgf / cm ^2.
The above was passed. In each of the above tests, a sheet having a thickness of 3 mm was pressed with 6 minutes of preheating and 4 minutes of pressing, and a sheet having a thickness of 1 mm was pressed with 5 minutes of preheating and 3 minutes of pressing.

Surface smoothness: The above-mentioned kneaded material was extruded into a sheet by a 20 mmφ extruder, and the surface of the molded product was observed and evaluated according to the following four criteria. ◎ ‥ Both sides of the sheet are glossy and smooth with no gloss on the surface. Those at this stage were accepted. ○ ‥ The surface is slippery, but one of the two ends has a pinch. △ ‥ The surface is slippery, but there are splinters at both ends. × ‥ The surface is rough and not shiny, and there are burrs at both ends.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

According to the vinyl chloride resin composition of the present invention, it is possible to obtain a molded article having excellent physical properties such as impact resistance and tensile strength and good surface smoothness.

Continuation of the front page (56) References JP-A-61-97345 (JP, A) JP-A-4-292648 (JP, A) JP-A-58-13650 (JP, A) JP-A-63-191852 (JP) , A) JP-A-3-134404 (JP, A) JP-A-63-191851 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 27/04-27/08

Claims (1)

(57) [Claims] A) 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 700 to 2500, and B) an average particle diameter of latex of 0.08.
4 to 15 parts by weight of methyl methacrylate-butadiene-styrene resin or acrylonitrile-butadiene-styrene resin obtained by graft polymerization of polybutadiene or styrene-butadiene rubber latex having a particle size of 1 μm or less, and C) the weight ratio of acrylonitrile to styrene is 1
A vinyl chloride resin composition comprising 1 to 10 parts by weight of an acrylonitrile-styrene copolymer having a ratio of 0:90 to 35:65.