JPH0326708B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a vinyl chloride resin (hereinafter abbreviated as PVC) composition having improved properties, particularly moldability, impact resistance, dynamic heat resistance,
This relates to a PVC composition that has excellent weather resistance, transparency, heat deformation resistance, high temperature elongation, and resistance to whitening upon bending. PVC is a general-purpose polymer with excellent transparency, mechanical properties, and economic efficiency, but it has drawbacks such as a narrow molding area and low impact strength because the polymer processing temperature and thermal decomposition temperature are close to each other. . (Prior art and its problems) Various proposals have been made to improve the moldability and impact resistance of PVC, and in particular, acrylonitrile-butadiene-styrene copolymer has been proposed as a means to improve the impact resistance. It is widely practiced to combine or blend methyl methacrylate-butadiene-styrene copolymer.
However, although impact resistance is improved by adding these modifiers, moldability is not improved, and as the amount added increases, weather resistance, transparency, and resistance to whitening on bending decrease. , there is a drawback that dynamic heat resistance etc. are reduced. On the other hand, vinyl acetate-ethylene copolymer (hereinafter referred to as
Proposals have also been made to improve moldability and impact resistance by incorporating VAE resin (abbreviated as VAE resin). There are publications such as No. 55-11704. However, although the moldability and impact resistance of PVC are somewhat improved by adding VAE resin, on the other hand, the transparency and resistance to heat deformation are also reduced, and since VAE resin has adhesive properties, heating It was necessary to add VAE resin after cooling the PVC mixture containing stabilizers, plasticizers, etc. below, which resulted in poor dry blendability. Moreover,
Even when VAE resins are used in combination with other polymers, these essential drawbacks have not been sufficiently improved. (Means for Solving the Problems) Under such circumstances, the present inventors conducted intensive research on PVC compositions free from the above-mentioned drawbacks, and found that
A copolymer made of PVC, butadiene and a specific monomer, and a copolymer made by graft-polymerizing a specific monomer to a vinyl ester-ethylene copolymer (hereinafter abbreviated as VEE resin) are used in combination. It is mixed
PVC compositions have improved moldability, impact resistance, and dynamic heat resistance, as well as weather resistance, transparency,
The present inventors have discovered that they are also excellent in heat deformation resistance, high-temperature elongation, folding whitening resistance, and dry blendability, and have completed the present invention. That is, the present invention provides a copolymer obtained from (A) PVC, (B) butadiene and one or more vinyl monomers selected from styrenes, acrylonitriles, and (meth)acrylates, and (C) A PVC composition comprising a copolymer obtained by copolymerizing VEE resin with one or more vinyl monomers selected from styrenes, acrylonitriles, and (meth)acrylates under graft polymerization conditions. This is what we provide. PVC used in the present invention includes homopolymers of vinyl chloride, vinyl esters such as vinyl acetate, olefins such as ethylene, acrylic acid, methacrylic acid and their alkyl esters, and copolymerizable with vinyl chloride such as vinylidene chloride. There are copolymers with vinyl chloride containing monomers at a ratio of 30% by weight or less, but there are also copolymers with vinyl chloride added to ethylene-vinyl acetate copolymers, chlorinated polyethylene, and thermoplastic polyurethane. Graft copolymers and the like can also be used. The component (B) to be incorporated into such PVC is a polymer obtained by copolymerizing butadiene with one or more vinyl monomers selected from styrenes, acrylonitriles, and (meth)acrylates.
The styrenes referred to here include styrene and α
- Styrene derivatives such as methylstyrene and α-chlorostyrene are examples of acrylonitriles.
Acrylonitrile, methacrylonitrile, etc., and (meth)acrylates with 1 to 4 carbon atoms.
Preferred examples include alkyl (meth)acrylates having alkyl groups, particularly methyl (meth)acrylate, ethyl methacrylate, and the like. In producing the polymer of component (B), any known polymerization method may be employed, and there are no particular restrictions. Among them, butadiene alone or combination thereof with styrenes, acrylonitriles or ( 1 or 2 meth)acrylates
Polymers obtained by once polymerizing or copolymerizing the seeds and then adding and copolymerizing one or more of styrenes, acrylonitriles, or (meth)acrylates have good results for the purpose of the present invention. It is preferable to show this. Examples of the polymer of component (B) include butadiene-acrylonitrile copolymer, butadiene-methyl methacrylate copolymer, butadiene-styrene-acrylonitrile copolymer, and butadiene-styrene-methyl methacrylate copolymer (hereinafter referred to as MBS resin). ), butadiene-styrene-acrylonitrile-methyl methacrylate copolymer, butadiene-
Examples include ethyl methacrylate-acrylonitrile-styrene copolymer, butadiene-α-methylstyrene-acrylonitrile-methyl methacrylate copolymer, and butadiene-methacrylonitrile-styrene copolymer, but these are merely examples. Any polymer that falls under the above definition can be effectively used. Among these, butadiene-styrene-acrylonitrile copolymer and MBS resin are particularly preferred since they have excellent transparency. Component (C) is a copolymer obtained by copolymerizing VEE resin with one or more vinyl monomers selected from styrenes, acrylonitriles, and (meth)acrylates under graft polymerization conditions. used here
VEE resins usually have a vinyl ester content.
Among them, 35% to 80% by weight can be mentioned.
A content of up to 65% by weight is preferable because it has good compatibility with PVC, excellent transparency, quick gelation, and no decrease in heat deformation resistance. Such a VEE resin can be obtained by copolymerizing vinyl ester and ethylene, and the polymerization method may be any one of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Examples of vinyl esters include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl laurate, and vinyl versatate, each of which may be used alone or in combination of two or more, with vinyl acetate being particularly preferred. . Furthermore, as the styrenes, acrylonitriles, and (meth)acrylates, any of the same ones used in the component (B) can be preferably used, and among them, methyl methacrylate alone or a combination of methyl methacrylate and styrene can be used. The case of is particularly preferable in terms of excellent transparency. In producing the copolymer of component (C), any known polymerization means can be employed, and for example, it is carried out as follows. In other words, styrene, VEE resin in latex state,
A vinyl monomer such as acrylonitrile or (meth)acrylate is added, the monomer is absorbed into the VEE resin particles, the phase is inverted to a suspended state, and then the temperature is raised to carry out polymerization using a radical initiator. These radical initiators include benzoyl peroxide, azobisisobutyronitrile, t-butylperoxybenzoate, t-butylperoxy(2-ethylhexanoto) diisopropylperoxycarbonate, t-butylperoxypivalate,
Examples include t-butyl peroxyisopropyl carbonate, t-butyl lauryl peroxide, etc., and the amount is usually 0.1 to 100 parts by weight of the vinyl monomer.
Polymerization is carried out by adding 10 parts by weight. The polymerization temperature varies depending on the radical initiator used, but is generally 60 to 130°C, and the resulting modified VEE resin in a suspended state is separated from water, washed, and dried. In this case, use anti-blocking agents such as wax, silicone oil, silica, etc.
Calcium carbonate, magnesium oxide, and calcium stearate may also be used, and the amount added depends on the modification.
The amount is usually 0.1 to 10 parts by weight per 100 parts by weight of VEE resin. The amount of components (B) and (C) used in the present invention is usually 5 to 30 parts by weight in total, based on 100 parts by weight of PVC (A). Among these, it is preferable because it is excellent in impact resistance, moldability, dynamic heat resistance, weather resistance, heat deformation resistance, high temperature elongation, etc. Also (B)
The mixing ratio of component and (C) component is usually 3:7 by weight.
Select from the range of ~8:2. If the content of component (B) is increased beyond this blending ratio, transparency, moldability, weather resistance, and heat resistance will decrease, while if the content of component (C) is increased, impact resistance will decrease. When blending each component of the composition of the present invention, PVC (A), the above-mentioned (B) component, and (C) component are mixed using a suitable kneading device such as a Banbury mixer, heated roll, or extruder. Physically uniform kneading or other arbitrary means may be employed. Further, at the time of blending, known additives for PVC such as heat stabilizers, fillers, pigments, etc. may be blended as appropriate. (Effects of the Invention) The PVC composition of the present invention thus obtained has good dry blendability and can be easily molded by known molding means such as calendering, extrusion, and injection molding. It has excellent molding processability and dynamic heat resistance, and the resulting molded product can have excellent impact resistance, weather resistance, transparency, temperature resistance, heat deformation resistance, and whitening resistance on bending. (Examples) Next, in order to further clarify the characteristics of the present invention, examples will be given to specifically explain the features of the present invention. Note that parts and percentages in Reference Examples, Examples, and Comparative Examples are based on weight. However, light transmittance and elongation are excluded. Further, the physical property evaluation method used in this example is as follows. 1 Processability of the compound 1-1) Gellability Brabender Plastograph (PLV-151
The measurement was carried out using a mold) under the following conditions. Track the kneading torque curve of the formulation and measure the time to the first peak as gel time (GT);
If the gelation time was less than half that of the product without the addition of processing aids, it was considered to have passed. Jacket temperature: 190℃ Rotor rotation speed: 30rpm Sample filling amount: 60g 1-2) Dynamic heat resistance Measured using the same method as gelation property, and using the measurement conditions as the time to the second peak as the decomposition time (DT). If it was 22 minutes or longer, there was no practical problem and it was considered a pass. 1-3) Processing stability Further, as a measure of processing stability, the following decomposition time after gelation was calculated. The larger the time span, the longer the allowable time for stable processing of the compound, and if this time was 22 minutes or more, there would be no practical problem and it was passed. Decomposition time after gelation = DT - GT (minutes) 2 Physical properties After kneading the formulation in the example for 5 minutes at 190℃ with two rolls, use a press molding machine to make specimens suitable for the following evaluation physical properties. Each physical property was measured. 2-1) Impact resistance Charpy impact value was measured according to JIS K-6745. If the impact value is 10Kg・cm/cm ² or more, there is no practical problem and the test is considered to have passed. 2-2) Transparency A 1 mm thick press sheet was prepared from each formulation, and its light transmittance was measured. light transmittance
If it is 85% or higher, there is no practical problem, so it is considered a pass. 2-3) Resistance to heat deformation Measurement was carried out according to JIS K-6745, and if the Classyberg flexibility temperature was 60°C or higher, there would be no practical problem, so it was passed. 2-4) High temperature elongation A 1 mm thick press sheet was obtained from each compound.
A specimen was prepared according to JIS K-6745. A tensile test was conducted at a tensile speed of 50 mm/min and a measurement temperature of 100°C, and the elongation at break was 450%.
If it is above, there is no practical problem, so it was judged as passing. 2-5) Resistance to whitening on bending A press sheet with a thickness of 0.5 mm was prepared from each compound, and a tanzak-shaped specimen of 1.5 cm x 8.0 cm was prepared. This test piece was bent at 90° and those that did not turn white at the bend were considered to be acceptable. 2-6) Weather resistance Create a 1 mm thick press sheet from each compound and place it in a size in weather meter.
The state of discoloration was checked after 500 hours. Those who remained the same as before the test were considered to have passed. Reference example 1 Sodium laurate 1.5% Methyl cellulose 0.3%
4 parts of calcium phosphate and distilled water were added to 200 parts of latex of VAE resin (ethylene content: 41%) obtained by polymerization in an emulsion system containing
% aqueous dispersion with 1.0 part of benzoyl peroxide dissolved therein.
50 parts were added at room temperature and kept under stirring for 1 hour to allow the methyl methacrylate to be absorbed into the latex particles. Subsequently, the temperature was raised to 75°C and reacted for 4 hours, and the temperature was further raised to 90°C and maintained for 2 hours. When the temperature was lowered and stirring was stopped, bead-shaped precipitates with a particle size of 0.2 to 0.5 mm were obtained, which were washed with water and dried.
Parts of modified VEE resin () were obtained. Reference Example 2 The particle size was determined in the same manner as in Reference Example 1, except that 30 parts of ethyl acrylate in which 0.8 parts of benzoyl peroxide was dissolved and 10 parts of acrylonitrile were used instead of 50 parts of methyl methacrylate in which 1.0 part of benzoyl peroxide was dissolved. A bead-like precipitate of 0.1 to 0.3 mm was obtained, washed with water, dried, and modified with 225 parts.
VEE resin () was obtained. Reference example 3 Using vinyl versatile acid-ethylene copolymer (ethylene content 22%) instead of VEE resin,
Also, in the same manner as Reference Example 1 except that methyl acrylate was used instead of methyl methacrylate.
241 parts of modified VEE resin () were obtained. Examples 1 to 3 and Comparative Examples 1 to 3 100 parts of PVC with a degree of polymerization of 700, 2.6 parts of octyltin mercapto-based composite stabilizer, Ca-St/Zn-St-based stabilizer
0.8 parts, 0.15 parts of polyethylene wax, and
A mixture of MBS resin (Kane Ace B-12 manufactured by Kanebuchi Kagaku Co., Ltd.) and modified VEE resin () in the parts shown in Table 1 was applied to a Brabender plastograph to obtain a PVC composition, and then various evaluations were carried out. I did it. Separately, PVC compositions with the same blending ratio were kneaded using two rolls, press-molded, and then evaluated for physical properties. The evaluation items and their results are shown in Table-1. Examples 4 to 5 and Comparative Example 4 PVC compositions were obtained in the same manner as in Examples 1 to 3 and Comparative Example 3, respectively, except that modified VEE resin () was used instead of modified VEE resin (), and then I conducted an evaluation. The results are shown in Table-1. Examples 7 to 9 and Comparative Example 5 PVC compositions were obtained in the same manner as in Examples 1 to 3 and Comparative Example 3, respectively, except that modified VEE resin () was used instead of modified VEE resin (), and then I conducted an evaluation. The results are shown in Table-1.

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Claims (1)

[Scope of Claims] 1. A copolymer obtained from (A) a vinyl chloride resin and (B) butadiene and one or more vinyl monomers selected from styrenes, acrylonitriles, and (meth)acrylates; (C) A copolymer obtained by copolymerizing a vinyl ester-ethylene copolymer with one or more vinyl monomers selected from styrenes, acrylonitriles, and (meth)acrylates under graft polymerization conditions. A vinyl chloride resin composition characterized by: