JPH0649307A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To provide a vinyl chloride resin compsn. which has a high flowability and hence an excellent moldability and gives a molded article excellent in impact strength, tensile strength, heat resistance, weatherability, and surface smoothness. CONSTITUTION:The resin compsn. comprises 100 pts.wt. vinyl chloride resin having an average degree of polymn. of 700-2,500, 4-15 pts.wt. chlorinated polyethylene, 0.5-8 pts.wt. styrene-hydrogenated isoprene copolymer, and 1-10 pts.wt. acrylonitrile-styrene copolymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention provides a vinyl chloride resin composition which is easy to process due to its high fluidity and which can be used to obtain a molded article having excellent impact resistance, tensile strength, heat resistance, weather resistance and surface smoothness. To do.

[0002]

2. Description of the Related Art Generally, in many vinyl chloride resins, the one having a higher average degree of polymerization in a hard compound is capable of obtaining a molded article having improved physical properties such as tensile strength and heat resistance, and addition of an impact resistance modifier. It is known that a great 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 is lowered, and the surface smoothness of the resulting molded product is lacking. There is a method of increasing the processing temperature as a measure for compensating for such a decrease in fluidity and the resulting lack of surface smoothness of the molded article, but it is satisfactory when the average degree of polymerization is high in a hard compounding vinyl chloride resin. If the temperature is raised to a state where fluidity is obtained (200 ° C with a die), the resin itself will deteriorate due to heat, and the physical properties that the resin should have will not be exhibited. Further, when a resin having a low degree of polymerization is used to improve molding processability, the fluidity is improved but the impact resistance is lowered,
In addition, a large amount of impact modifier must be added,
As a result, the ratio of the rubber component increases, and the physical properties such as heat resistance and tensile strength also deteriorate.

For these reasons, a method of adding a processing aid or a lubricant is used to improve the processability of the vinyl chloride resin, and a butadiene rubber is added to improve the impact resistance of a molded product obtained from the resin. The method has been generally adopted. It is considered that, if these methods are used in combination, the workability, particularly the fluidity, is improved under milder processing conditions, and the impact resistance is improved because of the butadiene rubber.
However, in compounds such as polybutadiene having a carbon-carbon double bond in the molecule, the double bond portion is easily oxidized when receiving energy such as heat and light in the presence of oxygen. When the number of oxidized portions increases, the color gradually changes from white to yellow, brown, and then black, and the physical properties are fragile and easily cracked and easily torn. Therefore,
In a molded article using an impact resistance modifier containing this as a main component, such a reaction is likely to occur in the inside (especially in the surface layer), which may cause color deterioration.

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

[0005]

Therefore, the object of the present invention is that it has a high fluidity and is easy to process, and the molded articles obtained from this are excellent in impact resistance, tensile strength, heat resistance, weather resistance and surface smoothness. A vinyl chloride resin composition is provided.

[0006]

The inventors of the present invention have the above-mentioned contradictory properties of processability as a resin (particularly fluidity and surface smoothness) and physical properties of molded articles obtained therefrom (particularly impact resistance and impact resistance). As a result of diligently studying how to simultaneously satisfy the (tensile strength), impact resistance was improved by adding chlorinated polyethylene to vinyl chloride resin, and
Addition of hydrogenated isoprene (hereinafter referred to as SEP) copolymer improves flowability and surface smoothness, and addition of acrylonitrile-styrene (hereinafter referred to as AS) copolymer can improve tensile strength, and further vinyl chloride. Chlorinated polyethylene, SEP copolymer, AS
Each of the components of the copolymer is a thermoplastic resin whose main chain is a saturated type, and it is difficult for the main chain to be cleaved by oxidation, so that during processing or long-term use without the use of UV absorbers or antioxidants. The present invention was completed by finding that the color change of the molded article in (1) hardly occurs.

The vinyl chloride resin composition according to the present invention is
A) 100 parts by weight of vinyl chloride resin having an average degree of polymerization of 700 to 2500, B) 4 to 15 parts by weight of chlorinated polyethylene, and C) SEP.
Copolymer 0.5 to 8 parts by weight and D) AS Copolymer 1 to 10
More preferably, the chlorinated polyethylene as the component B has a chlorine content of 25 to 50% by weight, and the styrene-hydrogenated isoprene copolymer as the component C is hydrogenated with the polystyrene phase. A diblock or triblock copolymer with a polyisoprene phase, wherein styrene and hydrogenated isoprene are mixed in a weight ratio of 10:90.
It is contained at a ratio of about 60:40, and the AS copolymer as the component D contains 10 to 35% by weight of acrylonitrile.

The present invention will be described in detail below. 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, and if it exceeds 2500, the workability is poor unless the temperature of the molten resin during molding is raised, and the resulting high temperature causes significant thermal deterioration, resulting in significant resin deterioration. The original physical properties of will be lost. This vinyl chloride resin includes polyvinyl chloride resin, vinyl chloride-
Examples thereof include maleimide copolymers, vinyl chloride copolymers such as ethylene-vinyl chloride copolymers, and chlorinated polyvinyl chloride. Among these, polyvinyl chloride resins are particularly preferable.

The chlorinated polyethylene used as the component B in the resin composition of the present invention is a thermoplastic resin obtained by chlorinating high density polyethylene, and preferably has a chlorine content of 25 to 50% by weight. If it is less than 25% by weight, the rubber elasticity is poor and the impact resistance is poor, and if it exceeds 50% by weight, it becomes too soft and the heat resistance and tensile strength are lowered. This chlorinated polyethylene is 4 to 15 parts by weight, preferably 5 to 5 parts by weight with respect to 100 parts by weight of the vinyl chloride resin.
It is used in a proportion of 13 parts by weight, but if it 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 deteriorated. Absent.

The SEP copolymer used as the C component in the present resin composition has a polystyrene phase S in which the polystyrene end block and the hydrogenated polyisoprene middle block are incompatible with each other to form a two-phase structure. Diblock (S with hydrogenated polyisoprene phase EP)
-EP) or triblock (S-EP-S) copolymer is preferable. Of these, 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 point (T _g ) of polystyrene, the domains soften and become fluidized under shear. When this is cooled, the domains are recreated and the process is completely reversible.

The weight ratio of styrene to hydrogenated isoprene in the SEP copolymer is from 10:90 to 60:40, especially
It 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 compounding amount of the SEP copolymer in the present 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, whereby the copolymer is a vinyl chloride resin. Flow unit of resin (particle size about 1-2 μm)
And contributes to a marked improvement in fluidity and smoothness of the surface of the molded product. On the contrary, if the addition amount is less than 0.5 parts by weight, not only these improvements are not observed but also the workability is deteriorated, and if it exceeds 8 parts by weight, physical properties such as heat resistance and tensile strength are deteriorated.

The AS copolymer as the component D preferably has a weight ratio of acrylonitrile and styrene of 10:90 to 35:65, particularly 20:80 to 25:75. If the amount of acrylonitrile in this copolymer is less than 10% by weight, the compatibility with the resin may decrease and separation may occur, while if it exceeds 35% by weight, the fluidity may decrease. 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 it 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 are deteriorated.

The vinyl chloride resin composition of the present invention contains, in addition to the above-mentioned four types of resin components, a stabilizer, a stabilizing aid, a lubricant, an inorganic filler, a plasticizer, a colorant, if necessary.
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 mixed with a general vinyl chloride resin, and laurate-based, malate-based, mercaptide-based organotin stabilizers, Ca, Ba, Pb and other metals. There are soap stabilizers and the like, and they are used alone or in combination of two or more kinds. Examples of the stabilizing aid include epoxy compounds, ultraviolet absorbers, antioxidants and the like. As a lubricant, a pure hydrocarbon type such as paraffin wax and polyethylene wax, a fatty acid type such as palmitic acid and stearic acid, an aliphatic alcohol type such as stearyl alcohol, an ester type of fatty acid and alcohol, and a portion of fatty acid and polyhydric alcohol Ester type etc. are mentioned. Calcium carbonate is preferred as the inorganic filler,
It can be used regardless of whether it is heavy calcium carbonate or light calcium carbonate. When importance is attached to impact resistance, it is preferable to add a large amount of light calcium carbonate.

The vinyl chloride resin composition of the present invention thus obtained is mixed by a conventional means such as a high-speed mixer to obtain powder or pellets, and calender molding, extrusion molding, injection molding, A molded product 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 1-5 and Comparative Examples 1-12. In addition to the resin components of the formulations shown in Tables 1 and 2, 1 part by weight of an organic tin stabilizer T-17MJ (manufactured by Katsuta Kako Co., Ltd.), 0.7 parts by weight of calcium stearate as a stabilizing aid, and white luster CCR (as an inorganic filler) 6 parts by weight of calcium carbonate from Shiraishi Calcium Co., Ltd. and 0.5 part by weight of lubricant AC-6A (polyethylene wax from Allied Chemicals Co., Ltd.) were added and mixed, and each mixture was heated at 170 ° C. using a 6 inch roll.
The fluidity and surface smoothness of the mixture kneaded for 5 minutes were tested. A sheet having a thickness of 0.8 mm was prepared from this kneaded product and subjected to impact resistance, heat resistance and tensile strength tests. These results are also shown in each table. Furthermore, Example 1
The yellowing degree test was performed using the 0.8 mm-thick sheets obtained in Comparative Examples 10 to 12, and the results are shown in Table 3. In Comparative Examples 10 to 12, a mixed example of ABS and SBR is shown as a material having excellent physical properties but poor weather resistance. The details of the components used in each of the above tests and each test method are as follows.

(Components used in the test) Polyvinyl chloride resin (PVC in the table): TK-700 (Shin-Etsu Chemical Co., Ltd., polyvinyl chloride, average degree of polymerization 700) TK-1000 (〃, 〃 , 〃 1000) TK-1700 (〃, 〃, 〃 1700) TK-2500P (〃, 〃, 〃 3000) ・ Chlorinated polyethylene (Cl-PE in the table): Eraslen 301A (Showa Denko KK, chlorinated Polyethylene, chlorine content rate: 30
weight%)

SEP copolymer (SEP in the table): Septon 1001 (Kuraray Co., Ltd. diblock copolymer, styrene content: 35% by weight, hydrogenated isoprene content: 65
Viscosity of solution of 20% by weight of toluene and 20% by weight of toluene at 30 ° C: 61 cps
) Septon 2002 (trade name, triblock copolymer, manufactured by Kuraray Co., Ltd., styrene content: 30% by weight, hydrogenated isoprene content: 70% by weight, toluene 20% by weight solution viscosity at 30 ° C .: 1.5 cps) Septon 2006 (Kuraray Co., Ltd., trade name, triblock copolymer, styrene content: 35% by weight, hydrogenated isoprene content: 65% by weight, toluene 20% by weight solution viscosity at 30 ° C .: 780 cps)

AS copolymer (denoted by AS in the table): CEVIAN FD [manufactured by Daicel Chemical Industries, Ltd., acrylonitrile: styrene (weight ratio) = 23: 77] ・ Acrylonitrile / butadiene / styrene copolymer resin (in the table) ABS-4): G-4 (Ube Cycon, graft polymerization type, butadiene content: 65% by weight) -Styrene-butadiene rubber (SBR in the table): TRKX-139S [Shell Chemical Co., styrene- Butadiene
Styrene / block copolymer, styrene: butadiene (weight ratio) = 40: 60, melt index at ²⁰⁰ ° C., 5 kg / cm ² : 50 g / 10 min]

(Test method) Fluidity: Measured with 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 extrudate was observed with a Koka type flow tester and evaluated according to the following criteria. (Evaluation Criteria) 1 ... The entire surface is rough to the extent that it can be visually judged and has no gloss. 2 ... The surface is not visible, but it is rough and not glossy. 3: Part of the surface is rough and not glossy. 4: Most of the surface is slippery and glossy. 5: The entire surface is smooth and glossy.

Impact resistance: The above-mentioned four 0.8 mm-thick sheets were superposed and pressed by preheating for 6 minutes and pressurization for 4 minutes to give a sheet having a thickness of 3 mm, which was measured according to JIS K-7110. .・ Heat resistance: A sheet with a thickness of 3 mm was used in the same manner as above, and JI
It was measured based on S K-7206. -Tensile strength: The above-mentioned four 0.8 mm-thick sheets were superposed and pressed by preheating for 5 minutes and pressurization for 3 minutes to form a sheet having a thickness of 1 mm, which was measured according to JIS K-7113.

-Yellowness: A 0.8 mm thick sheet of sunshine weatherometer WEL-SUN-HC (manufactured by Suga Test Instruments Co., Ltd.)
, 100 hours, 300 hours, 500 hours and
After irradiation for 1000 hours, take out and use tristimulus value X by color difference meter Z-1001DP (manufactured by Nippon Denshoku Industries Co., Ltd.) based on JIS Z-8730.
Y and Z are measured, and from these values, L ^* , a ^* , b
^Ask for ^* . L ^* = 116 (Y / 116) ¹ / 3−16 a ^* = 500 [(X / 98) ¹ / 3− (Y / 100) ^1/3 ] b ^* = 200 [(Y / 100) ^1/3 -(Z / 118.1) ^1/3 ] On the other hand, the standard L ₀ , a ₀ , and b ₀ are calculated using X ₀ = 94.6, Y ₀ = 92.7, and Z ₀ = 111.4 as the standard stimulus values. Next, the differences ΔL = L ^* −L ₀ , Δa = a ^* −a ₀ , Δb = b between the L ^* , a ^* , b ^* and the standard L ₀ , a ₀ , b ₀ , respectively.
^* −b ₀ is calculated and ΔE = [(ΔL) ² + (Δ
The color difference is calculated as a) ² + (Δb) ² ] ^1/2 .

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

[0025]

EFFECTS OF THE INVENTION The vinyl chloride resin composition according to 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. .

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Claims (4)

Reference number P041143 [Claims] 1. A) 100 parts by weight of vinyl chloride resin having an average degree of polymerization of 700 to 2500, B) 4 to 15 parts by weight of chlorinated polyethylene, C) styrene-hydrogenated isoprene copolymer 0.5 to
A vinyl chloride resin composition comprising 8 parts by weight and D) 1 to 10 parts by weight of an acrylonitrile / styrene copolymer. 2. The chlorinated polyethylene has a chlorine content of 25 to 50.
The vinyl chloride resin composition according to claim 1, wherein the vinyl chloride resin composition is in a weight percentage. 3. A styrene-hydrogenated isoprene copolymer is a diblock or triblock copolymer of a polystyrene phase and a hydrogenated polyisoprene phase,
Weight ratio of styrene and hydrogenated isoprene 10: 90-6
The vinyl chloride resin composition according to claim 1, which is contained at a ratio of 0:40. 4. An acrylonitrile-styrene copolymer,
The vinyl chloride resin composition according to claim 1, which contains 10 to 35% by weight of acrylonitrile.