JP3115948B2 - Vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a vinyl chloride resin composition which is easy to process because of its high fluidity, and provides a molded article excellent in impact resistance, tensile strength, heat resistance, weather resistance and surface smoothness. Is what you do.

[0002]

2. Description of the Related Art In many vinyl chloride resins, a higher average degree of polymerization in a hard compound generally results in a molded article having improved physical properties such as tensile strength and heat resistance. It is known that a large effect can be obtained even with a small amount. However, as the degree of polymerization increases, calender molding, extrusion molding, injection molding, blow molding, vacuum molding,
The fluidity required for other high-speed molding decreases, and the resulting molded article lacks surface smoothness. As a countermeasure, there is a method of increasing the processing temperature.However, when the average polymerization degree of the vinyl chloride resin is high in a hard compounding system, if the temperature condition is increased to a state where satisfactory fluidity is obtained, the resin itself is heated by heat. It deteriorates, 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 the moldability, the flowability is improved but the impact resistance is reduced.Therefore, a large amount of an impact resistance modifier must be used. As a result, physical properties such as heat resistance and tensile strength were reduced.

[0003] For these reasons, a method of adding a processing aid or a lubricant is used to improve the processability of a vinyl chloride resin, and a butadiene rubber is added to improve the impact resistance of a molded product obtained therefrom. The method has been generally adopted. Then, it was considered that when these methods were used in combination, the processability, especially the fluidity, was improved under milder processing conditions, and the impact resistance was also improved because of the butadiene rubber.
However, since butadiene rubber is susceptible to oxidative deterioration due to heat, light, etc., molded products using an impact resistance modifier containing it as a main component have mechanical properties such as color deterioration, impact resistance, and tensile strength. Decreased.

On the other hand, Japanese Patent Application Laid-Open No. 50-88170 discloses that a copolymer comprising methyl methacrylate and / or acrylonitrile, styrene and an alkyl acrylate in 90 to 99 parts by weight of a vinyl chloride graft polymer, acrylonitrile butadiene. Styrene copolymer resin, at least one polymer of chlorinated polyethylene 1-10
It describes a resin composition obtained by adding parts by weight, and according to this, although the impact resistance of the molded article is improved,
The fluidity of the resin and the resulting surface smoothness of the molded article are not improved. Similarly, JP-A-50-142661 discloses that the average degree of polymerization of vinyl chloride is preferably up to 400 to 1500,
Although the impact resistance of the molded article obtained from this composition is high, the fluidity of the resin and the resulting surface smoothness of the molded article are not improved. Furthermore, JP-B-48-57846 and JP-A-60-57846
The description in both publications of 179443 is the same.

[0005]

Accordingly, an object of the present invention is to process easily due to high fluidity, and a molded product obtained therefrom is excellent in impact resistance, tensile strength, heat resistance, weather resistance and surface smoothness. A vinyl chloride resin composition is provided.

[0006]

Means for Solving the Problems The present inventors have studied the processability (particularly fluidity and surface smoothness) of a resin, which is the above contradictory properties, and the physical properties (particularly impact resistance) of a molded article obtained therefrom. As a result of intensive study on how to simultaneously satisfy the tensile strength), impact resistance was improved by adding an acrylic rubber / graft copolymer modifier to vinyl chloride resin, and styrene / hydrogenated isoprene (hereinafter SEP
To improve fluidity and surface smoothness by adding a copolymer, and to improve tensile strength by adding an acrylonitrile / styrene (hereinafter, referred to as AS) copolymer;
Acrylic rubber / graft copolymer impact resistance modifier used in combination with vinyl chloride resin, SEP copolymer, AS
Each component of the copolymer is a thermoplastic resin whose main chain is a saturated type, and the main chain is hardly cut by oxidation.Therefore, during processing or long-term use without using an ultraviolet absorber or antioxidant It was found that almost no color change of the molded article occurred in the above, and the present invention was completed.

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, B) 4 to 15 parts by weight of an acrylic rubber / graft copolymer impact modifier, C) 0.5 to 8 parts by weight of a SEP copolymer and D) 1 to 10 parts by weight of an AS copolymer,
More preferably, the acrylic rubber / graft copolymer type impact modifier as the B component is a graft copolymer of an acrylic rubber and an AS copolymer, and contains 40 to 80% by weight of an acrylic rubber, The styrene / hydrogenated isoprene copolymer as the C component is a diblock or triblock copolymer of a polystyrene phase and a hydrogenated polyisoprene phase, and styrene and hydrogenated isoprene are present in a weight component ratio of 10:90 to 60:40, and the AS copolymer as the D component contains 10 to 35% by weight of acrylonitrile.

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. If it is less than 700, the impact strength and heat resistance are inferior.If it is more than 2500, the processability is poor unless the molten resin temperature during molding is raised. Physical properties of the original will be impaired. This vinyl chloride resin includes polyvinyl chloride resin, vinyl chloride-
Examples thereof include a vinyl chloride copolymer such as a maleimide copolymer and an ethylene-vinyl chloride copolymer, and chlorinated polyvinyl chloride. Among them, a polyvinyl chloride resin is particularly preferable.

In the resin composition of the present invention, the acrylic rubber / graft copolymer-based impact modifier used as the component B comprises an acrylic rubber composed of a polymer of an alkyl acrylate and an AS copolymer. 40-80% by weight of acrylic rubber, especially 50%, obtained by graft copolymerization
KM-334 as a commercial product.
(Made by Rohm and Haas), DURASTRENGTH 200 (ATO
Chem.), S-2001 (Mitsubishi Rayon), HIA-28
(Made by Kureha Chemical Co., Ltd.). The amount of the impact modifier in the present resin composition is the same as that of the vinyl chloride resin.
4 to 15 parts by weight, preferably 5 to 13 parts by weight, per 100 parts by weight. If the amount is less than 4 parts by weight, the effect of improving impact resistance cannot be obtained, and if it exceeds 15 parts by weight, various physical properties such as heat resistance, tensile strength and workability are undesirably reduced.

The SEP copolymer used as the component C in the present resin composition is composed of a polystyrene phase S in which the polystyrene end block and the hydrogenated polyisoprene intermediate block are incompatible with each other to form a two-phase structure. Diblock (S) having a hydrogenated polyisoprene phase EP
(EP) or a triblock (S.EP.S) copolymer. Among them, the polystyrene phase S forms a physical crosslinking point (domain) and plays a role of a crosslinking point of the vulcanized rubber. The hydrogenated polyisoprene phase EP imparts rubber elasticity to the product. When the SEP copolymer is heated above the glass transition temperature (T _g ) of polystyrene, the domains soften and flow under shear. Upon cooling, the domains are reproduced again, and this process is completely reversible.

The weight ratio of styrene to hydrogenated isoprene in the SEP copolymer is from 10:90 to 60:40,
The ratio is preferably 30:70 to 50:50. Also, this SE
From the viewpoint of fluidity during processing, the P copolymer preferably has a toluene solution of 20% by weight and a solution viscosity at 30 ° C. of 1,000 cps or less. The amount of the SEP copolymer in the resin composition is 0.5 to 8 parts by weight, preferably 1 to 7 parts by weight, based on 100 parts by weight of the vinyl chloride resin. Resin flow unit (particle size about 1-2 μm)
And contributes to remarkable improvement in fluidity and smoothness of the surface of the molded article. On the other hand, if the amount is less than 0.5 part by weight, not only these improvements are not observed, but also the processability is reduced, and if it exceeds 8 parts by weight, physical properties such as heat resistance and tensile strength are also reduced.

The AS copolymer as the D component preferably has a weight ratio of acrylonitrile to styrene of 10:90 to 35:65, particularly preferably 20:80 to 25:75. If the amount of acrylonitrile in the copolymer is less than 10% by weight, the compatibility with the resin may be reduced to cause separation, and if it exceeds 35% by weight, the fluidity may be reduced. The AS copolymer is used in an amount of 1 to 10 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the vinyl chloride resin.
If the amount is less than 10 parts by weight, the effect of improving tensile strength cannot be obtained, and if it exceeds 10 parts by weight, impact resistance and workability deteriorate.

The vinyl chloride resin composition of the present invention may further comprise, if necessary, a stabilizer, a stabilizing aid, a lubricant, an inorganic filler, a plasticizer, a coloring agent, in addition to the above four resin components.
An ultraviolet absorber, an antioxidant and the like can be added and mixed. The stabilizer used in this resin is not particularly limited as long as it is blended with a general vinyl chloride resin, and organic tin stabilizers such as laurate, malate, and mercaptides, and metals such as Ca, Ba, and Pb are used. There are soap stabilizers and the like, used alone or in combination of two or more. Examples of the stabilizing aid include an epoxy compound, an ultraviolet absorber, and an antioxidant. Lubricants include pure hydrocarbons such as paraffin wax and polyethylene wax, fatty acids such as palmitic acid and stearic acid, aliphatic alcohols such as stearyl alcohol, esters of fatty acids and alcohols, and parts of fatty acids and polyhydric alcohols. Ester type and the like can be mentioned. As the inorganic filler, calcium carbonate is preferable,
It can be used for both heavy calcium carbonate and light calcium carbonate. When emphasizing impact resistance, it is preferable to add a large amount of light calcium carbonate.

The thus-obtained vinyl chloride resin composition of the present invention is mixed using a conventional means such as a high-speed mixer, and powdered or pelletized, and is subjected to calendering, extrusion, injection molding, A molded article having a desired shape can be obtained by a molding method such as blow molding.

[0015]

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 these descriptions. Examples 1 to 5 and Comparative Examples 1 to 12. To each of the resin components of the formulations shown in Tables 1 and 2, 1 part by weight of a stabilizer described below, 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 were further added and mixed. The mixture was kneaded for 5 minutes at 170 ° C. using a 6-inch roll, and then tested for fluidity and surface smoothness. Further, a sheet having a thickness of 0.8 mm was prepared from the kneaded material, and each test of impact resistance, heat resistance, and tensile strength was performed. These results are shown in each table. Further, using the sheets having a thickness of 0.8 mm obtained in Examples 1 to 5 and Comparative Examples 10 to 12, a test for the degree of yellowing was carried out, and the results are shown in Table 3. The components used in each of the above tests and the details of each test method are as follows.

(Components used in the test) Polyvinyl chloride resin (referred to as PVC in the table): TK-700 (trade name, polyvinyl chloride, average degree of polymerization 700, manufactured by Shin-Etsu Chemical Co., Ltd.) TK-1000 ( 〃, 〃, 〃, 〃 1000) TK-1700 (〃, 〃, 〃, 〃 1700) TK-3000 (〃, 〃, 〃, 〃 3000) acrylic rubber graft copolymer impact modifier ( AG in the table): DURASTRENGTH 200 (manufactured by ATO Chem., Trade name, acrylic rubber content: 60% by weight, AS copolymer content: 40% by weight)

SEP copolymer (hereinafter referred to as SEP): Septon 1001 (trade name, manufactured by Kuraray Co., diblock copolymer, styrene content: 35% by weight, hydrogenated isoprene content: 65% by weight, Viscosity of a 20% by weight solution of toluene at 30 ° C .: 61 cps) Septon 2002 (trade name, manufactured by Kuraray Co., Ltd., triblock copolymer, styrene content: 30% by weight, hydrogenated isoprene content: 70% by weight, toluene 20) Viscosity at 30 ° C. of 1.5 wt% solution: Septon 2006 (trade name, manufactured by Kuraray Co., Ltd., triblock copolymer, styrene content: 35 wt%, hydrogenated isoprene content: 65 wt%, toluene 20 wt) % Solution viscosity at 30 ° C: 780 cps)

AS copolymer (referred to as AS in the table): CEVI
AN FD [manufactured by Daicel Chemical Industries, Ltd., trade name, acrylonitrile: styrene (weight ratio) = 23:77] • Acrylonitrile / butadiene / styrene copolymer resin (ABS in the table): G-4 (manufactured by Ube Sycon) , Trade name, graft polymerization type, butadiene content: 65% by weight)-butadiene-styrene rubber (referred to as SBR in the table): TR
KX-139S [Shell Chemical Co., trade name, styrene: butadiene (weight ratio) = 40:60]

Stabilizer: T-17MJ (trade name, organic tin stabilizer, manufactured by Katsuta Kako Co., Ltd.) Stabilizing aid: calcium stearate Inorganic filler: Shirahama CCR (trade name, calcium carbonate, manufactured by Shiraishi Calcium Co., Ltd.)・ Lubricant: AC-6A (manufactured by Allied Chemical Company, trade name, polyethylene wax)

(Test Method) Fluidity: Measured using a Koka type flow tester (trade name, manufactured by Shimadzu Corporation) at a load of 100 kg and 200 kg at 200 ° C. Surface smoothness: The surface of the extruded product was observed with a Koka type flow tester and evaluated according to the following criteria. (Evaluation Criteria) 1) The whole surface is rough to the extent that it can be visually judged and has no gloss. 2) The whole surface is not rough enough to be visible, but rough and glossy. 3 ‥ Part of the surface is rough and glossless. 4 ‥ Most of the surface is smooth and shiny. 5 ‥ The whole surface is smooth and shiny.

Impact resistance: The above-mentioned four sheets having a thickness of 0.8 mm were superposed, pressed for 6 minutes in preheating and four minutes in pressure to form a sheet having a thickness of 3 mm, and measured in accordance with JIS K-7110. .・ Heat resistance: Same as above, 3mm thick sheet, JI
It was measured based on SK-7206. Tensile strength: Four sheets having a thickness of 0.8 mm described above were superimposed, pressed with 5 minutes of preheating and 3 minutes of pressing to form a 1 mm thick sheet, and measured based on JIS K-7113.・ Yellowness: Put a 0.8mm thick sheet into Sunshine Weatherometer (Suga Test Instruments Co., Ltd., trade name)
Take out after irradiation for 100 hours, 300 hours, 500 hours and 1000 hours, measure the color difference ΔE with a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd.) based on JIS Z-8730, and determine the yellowing degree (the larger the color difference ΔE, High degree of yellowing).

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

[0025]

The vinyl chloride resin composition of the present invention has high fluidity and is easy to process, and the resulting molded article has excellent impact resistance, tensile strength, heat resistance, weather resistance and surface smoothness. .

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-251554 (JP, A) JP-A-51-92856 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 27/06 C08L 51/04 C08L 53/02 C08L 25/12

Claims (4)

(57) [Claims] 1. A) 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 700 to 2500, B) 4 to 15 parts by weight of an acrylic rubber / graft copolymer type impact modifier, C) styrene / hydrogenated isoprene A vinyl chloride resin composition comprising 0.5 to 8 parts by weight of a copolymer and 1 to 10 parts by weight of an acrylonitrile / styrene copolymer. 2. The acrylic rubber / graft copolymer-based impact modifier is a graft copolymer of an acrylic rubber and an acrylonitrile / styrene copolymer, and contains 40 to 80% by weight of the acrylic rubber. The vinyl chloride resin composition according to claim 1. 3. The styrene / hydrogenated isoprene copolymer is a diblock or triblock copolymer of a polystyrene phase and a hydrogenated polyisoprene phase,
Styrene and hydrogenated isoprene in a weight ratio of 10: 90-6
The vinyl chloride resin composition according to claim 1, which is contained in a ratio of 0:40. 4. An acrylonitrile / styrene copolymer,
2. The vinyl chloride resin composition according to claim 1, which contains 10 to 35% by weight of acrylonitrile.