JPH0535181B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a vinyl chloride resin composition. More specifically, a conjugated diene rubbery graft copolymer obtained by graft polymerizing a specific monomer with a specific composition in multiple stages in the presence of a conjugated diene rubbery copolymer and a vinyl chloride resin are mixed. The present invention relates to a vinyl chloride-based resin composition that is excellent in transparency and impact resistance, especially impact resistance at low temperatures. "Conventional technology" Conventionally, conjugated diene-based rubbery graft copolymers, in which styrene, methyl methacrylate, acrylonitrile, etc. are graft-polymerized in the presence of a conjugated diene-based rubbery copolymer, have poor impact resistance and transparency. It is widely used in blow bottles, sheets, films, etc. as an excellent modifier for vinyl chloride resins. However, these modified materials do not have both transparency and impact resistance, and have the disadvantage that excellent transparency results in poor impact resistance, and excellent impact resistance results in poor transparency. Furthermore, it is extremely difficult to achieve both impact resistance and transparency at low temperatures, and this has been a long-standing challenge for researchers, and a great deal of effort has been made to solve it. "Problems to be Solved by the Invention" As mentioned above, the transparency of vinyl chloride resin compositions is insufficient, and there is still room for improvement in impact resistance, especially impact resistance at low temperatures. It was hot. As a result of various studies to solve this problem, the inventors of the present invention have discovered that, when carrying out graft polymerization in the presence of a conjugated diene-based rubbery copolymer, the graft polymerization is carried out in multi-stage polymerization, and that Conjugated diene rubber obtained by graft polymerization of one or more monomers selected from acrylic acid alkyl ester and methacrylic acid alkyl ester monomers such that the homopolymer has a glass transition temperature of 0°C or lower. We have discovered that the quality graft copolymer is closely related to the transparency and impact resistance of the final target vinyl chloride resin composition, especially the impact resistance at low temperatures. The present invention was completed with the aim of providing a vinyl chloride resin composition that has excellent impact resistance, especially at low temperatures. "Means for Solving Problems" That is, the present invention provides () vinyl chloride resin
70 to 99 parts by weight, ()(A) 30 to 80 parts by weight of a conjugated diene-based rubbery copolymer containing 50% by weight or more of conjugated diene, (B)(i) 19 to 79 parts by weight of methyl methacrylate, ( ii) Aromatic vinyl monomer 20-80% by weight, (iii) Vinyl cyanide monomer 0-30% by weight, (iv) Crosslinkable monomer 0-4% by weight, (v) Carbon of alkyl group The number is 2 or more,
20 to 70 parts by weight of a monomer mixture consisting of 1 to 15% by weight of one or more monomers selected from alkyl acrylates and alkyl methacrylates whose homopolymer glass transition temperature is 0 ° C. or lower. Grafting in multiple stages, and the final stage of grafting (outermost layer)
Among the monomers (B)(i) to (v) above, (a) methyl methacrylate 0 to 30% by weight, (a) aromatic vinyl monomer 5 to 40% by weight, (a) cyanide vinyl monomer
0 to 100% by weight, (a) Crosslinkable monomer 0 to 100% by weight, (a) Alkyl acrylate whose alkyl group has 2 or more carbon atoms and whose homopolymer has a glass transition temperature of 0°C or less 1 selected from esters and methacrylic acid alkyl esters
1 to 30 parts by weight of a conjugated diene-based rubbery graft copolymer to which 60 to 100% by weight of at least one monomer is grafted, and the glass transition temperature of the copolymer constituting the outermost layer exceeds 0°C; A vinyl chloride resin composition characterized by comprising: The present invention will be explained in detail below. The conjugated diene rubbery copolymer (A) according to the present invention is a conjugated diene rubbery copolymer containing 50% by weight or more, preferably 60% by weight or more of conjugated diene. If the conjugated diene is less than 50% by weight, the impact resistance of the final composition will be poor. Examples of monomers that can be copolymerized with the conjugated diene include aromatic vinyl, alkyl methacrylate, alkyl acrylate, and vinyl cyanide. Among these, aromatic vinyl monomers are preferred. Further, as the conjugated diene, butadiene, isoprene, piperylene, etc. can be used, but among these, butadiene is preferred. These conjugated diene-based rubbery copolymers may be crosslinked with crosslinkable monomers such as divinylbenzene and dimethacrylates, but the amount of these crosslinkable monomers used is 2% by weight. The following are preferred. If more than 2% by weight is added, the impact resistance of the final composition will be poor. In polymerizing the conjugated diene-based rubbery copolymer, commonly used emulsifiers, electrolytes, polymerization regulators, initiators, etc. are used. For example, examples of the emulsifier include alkali metal salts of fatty acids, alkali metal salts of fatty acid sulfate esters, and the like. Examples of the electrolyte include alkali metal salts of sulfuric acid, phosphoric acid, and hydrochloric acid. As polymerization regulators, mercapto compounds, terpenes, halides, etc. can be added as necessary. Further, as the polymerization initiator, peroxide, persulfate, or a redox catalyst made of a combination of peroxide and a reducing agent, etc. can be suitably used. Further, as a method for polymerizing the conjugated diene-based rubbery copolymer, widely known polymerization methods can be used. Examples include methods such as batch charge polymerization, continuous addition polymerization, and multi-stage polymerization. The conjugated diene-based rubbery graft copolymer according to the present invention includes (A) a conjugated diene-based rubbery copolymer of 30 to 80%;
It is obtained by graft polymerizing 20 to 70 parts by weight, preferably 35 to 60 parts by weight of the vinyl monomer (B) in the presence of 40 to 65 parts by weight, preferably 40 to 65 parts by weight. (A) If the amount of the conjugated diene rubbery copolymer is less than 30 parts by weight (if the vinyl monomer exceeds 70 parts by weight), the impact resistance of the final composition will decrease, which is not preferable. Conversely, if (A) the conjugated diene-based rubbery copolymer exceeds 80 parts by weight ((B) the vinyl monomer is less than 20 parts by weight), the compatibility decreases due to insufficient grafting amount. This reduces the clarity of the final composition. The composition of the vinyl monomer (B) to be subjected to the graft polymerization is as follows: (i) methyl methacrylate 19 to 79% by weight, preferably 28 to 68% by weight, (ii) aromatic vinyl monomer 20 to 80% by weight % preferably 30-70% by weight, (iii) vinyl cyanide monomer 0-30% by weight, preferably 0-20% by weight, (iv) crosslinkable monomer 0-4% by weight, preferably 0-20% by weight.
2% by weight, (v) 1 to 15% by weight of one or more monomers selected from alkyl acrylates and alkyl methacrylates whose homopolymer has a glass transition temperature of 0°C or lower, preferably 2 to 10% by weight. Weight%. (i) If methyl methacrylate is less than 19% by weight, the final composition will have poor transparency, and if it exceeds 79% by weight, the final composition will have poor impact resistance and transparency. (ii) If the aromatic vinyl monomer content is less than 20% by weight, the final composition will have poor transparency and impact resistance;
If it exceeds % by weight, the final composition will have poor transparency. (iii) If the vinyl cyanide monomer exceeds 30% by weight, the molded product of the final composition will be colored reddish brown, which is not preferable. (iv) When the crosslinkable monomer content is less than 4% by weight, the final composition has excellent transparency, but when it exceeds 4% by weight, the impact resistance of the final composition decreases. If the essential component (v) is less than 1% by weight of one or more monomers selected from acrylic acid alkyl esters and methacrylic acid alkyl esters whose homopolymer has a glass transition temperature of 0°C or less, the final The impact resistance of the composition at low temperatures is poor and the present invention cannot be achieved. On the other hand, if it exceeds 15% by weight, a powder with a good particle size cannot be obtained in the salting out step of the conjugated diene rubber graft copolymer, which will be discussed later, and this will cause the final composition to become stiff, and the tensile strength will decrease. This is undesirable as it causes a decline in the quality of the product. (ii) Examples of aromatic vinyl monomers include styrene, α
-Methylstyrene, p-methylstyrene, p-
Examples include tert-butylstyrene and dimethylstyrene. (iii) Examples of vinyl cyanide monomers include acrylonitrile and methacrylonitrile. (iv) As the crosslinking monomer, divinylbenzene,
dimethacrylates, divinyl adipates,
Examples include divinyl ethers. In addition, the essential component (v) acrylic acid alkyl ester and methacrylic acid alkyl ester monomer whose homopolymer has a glass transition temperature of 0°C or less is an alkyl ester having 2 or more carbon atoms, such as ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, tert-butyl acrylate, n-hexyl methacrylate, n-octyl methacrylate, n-decyl methacrylate, methacrylate Examples include lauryl acid, tetradecyl methacrylate, etc., but in the case of an acrylic acid alkyl ester, an ester of an alkyl having 2 to 10 carbon atoms is preferable, and in the case of an alkyl methacrylate ester, an ester of an alkyl having 4 to 14 carbon atoms is preferable. is preferred. Among these, n-butyl acrylate, 2-ethylhexyl acrylate, and n-acrylate, in which the glass transition temperature of the homopolymer of each monomer is -25°C or lower, are
Propyl is particularly preferred. The graft polymerization method includes multi-stage polymerization,
Preferably, the graft polymerization is carried out in three steps, and in the final step, (v) one or more monomers selected from alkyl acrylates and alkyl methacrylates whose homopolymer has a glass transition temperature of 0° C. or lower. 60-100% by weight of the mass, preferably 70-100% by weight
It is necessary to polymerize 100% by weight. If the graft polymerization is carried out in one step, the transparency of the final composition will decrease, which is not preferable. The polymerization conversion rate of the monomer in the final stage polymerization is 80% by weight or more, preferably 85% by weight or more. On the other hand, the monomer conversion rate in each step polymerization other than the final step polymerization is 50% or more, preferably 60% or more, and more preferably 80% by weight or more. In addition, the amount of one or more monomers selected from alkyl acrylates and alkyl methacrylates having a glass transition temperature of 0° C. or lower in the homopolymerized product (v) to be graft-polymerized in the final step is 60% by weight. If it is less than this, the impact resistance of the final composition at low temperatures, which is the object of the present invention, will be poor. In order to obtain a graft copolymer with excellent low-temperature impact strength and transparency, which is the object of the present invention, a preferred multi-stage polymerization is a three-stage polymerization, in which the above-mentioned (B) (i) methyl methacrylate is added in the first stage. (iii) 50-100% by weight of
0 to 100% by weight of the vinyl cyanide monomer and (iv) 0 to 100% by weight of the crosslinkable monomer are added to the above (B) in the second stage.
(i) 0 to 20% by weight of methyl methacrylate, (ii) 60 to 95% by weight of aromatic vinyl monomer, (iii) 0 to 100% by weight of vinyl cyanide monomer, (iv) Crosslinkability Monomer 0~
100% by weight, (v) the glass transition temperature of the homopolymer is 0
0 to 40% by weight of one or more monomers selected from acrylic acid alkyl esters and methacrylic acid alkyl esters at a temperature below
0 to 30% by weight of methyl methacrylate, (ii) 5 to 40% by weight of aromatic vinyl monomer, (iii) 0 to 100% by weight of vinyl cyanide monomer, (iv) crosslinkable monomer 0-100
(v) Graft polymerization of 60 to 100% by weight of one or more monomers selected from alkyl acrylates and alkyl methacrylates whose homopolymer has a glass transition temperature of 0° C. or lower. In the production of the conjugated diene-based rubbery graft copolymer, the emulsifier, polymerization regulator, initiator, etc. used in the production of the conjugated diene-based rubbery copolymer can be used. Further, the particle size of the polymer particles may be increased for the purpose of improving impact resistance, but the average particle size is preferably 0.25 μm or less. When the average particle size exceeds 0.25μ, the transparency of the final composition decreases. Examples of methods for enlarging polymer particles include adding hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, etc. before graft polymerization, or using these acids together with electrolytes such as potassium chloride, potassium sulfate, potassium phosphate, etc. The particle size of the conjugated diene-based rubbery copolymer may be increased in advance by, for example, adding an electrolyte such as potassium chloride, potassium sulfate, or potassium phosphate, or formaldehyde sulfonate prior to graft polymerization. A xylate salt or the like may be added to increase the particle size during graft polymerization of methyl methacrylate. An antioxidant such as 2,6-di-
After adding tert-butyl-4-methylphenol and the like, a powder is obtained through salting out and drying. The thus obtained conjugated diene-based rubbery graft copolymer may be mixed with a vinyl chloride-based resin depending on the desired impact resistance strength or transparency.
In order to effectively achieve the present invention, the conjugated diene-based rubbery graft copolymer is contained in 1 to 30 parts by weight, preferably 2 to 20 parts by weight, and the vinyl chloride resin is contained in 70 to 99 parts by weight, preferably 80 to 98 parts by weight. Mix parts by weight. If the amount of the conjugated diene-based rubbery graft copolymer is less than 1 part by weight, no effect of the addition will be seen and the impact resistance will be poor. On the other hand, if it exceeds 30 parts by weight, the excellent properties of the vinyl chloride resin will be lost and it will be uneconomical. The vinyl chloride resin is polyvinyl chloride, or 70% by weight or more of vinyl chloride and 30% by weight of a copolymerizable monomer such as vinyl bromide, vinylidene chloride, vinyl acetate, acrylic acid, methacrylic acid, or ethylene.
A copolymer with less than or equal to or after chlorination polyvinyl chloride, etc. can be used. The conjugated diene-based rubbery graft copolymer and the vinyl chloride-based resin are mixed in a powder state using, for example, a ribbon blender, Henschel mixer, etc.
The mixture can be mixed using a known kneader such as a mixing roll, a Banbury mixer, or an extruder, or can be molded. In addition, if necessary, a commonly used stabilizer,
Pigments, fillers, plasticizers, lubricants, processing aids, etc. may also be added. "Examples" Next, the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. Examples below,
In the comparative examples, parts mean parts by weight and % mean % by weight. Example 1 (1) Production of conjugated diene-based rubbery copolymer (Table-1
A) A mixture of 74 parts of 1,3-butadiene, 26 parts of styrene, 5 parts of potassium stearate, 0.5 parts of potassium sulfate, 0.5 parts of potassium persulfate, and 150 parts of deionized water was placed in an autoclave purged with nitrogen. The mixture was charged and polymerized at 50°C while stirring, and the polymerization was terminated at a polymerization conversion rate of 90%. The average bound styrene of the polymer was 23.5%. (2) Production of conjugated diene-based rubbery graft copolymer In a flask purged with nitrogen, 60 parts of the solid content of the conjugated diene-based rubbery copolymer latex produced in (1) above, 0.2 part of potassium sulfate, and ionized water 150
(including water in rubber latex) and raise the temperature. When the internal temperature reaches 80℃, as the first step of polymerization, add a mixture of 0.2 parts of kyumene hydroperoxide and 17 parts of methyl methacrylate and 0.05 parts of sodium formaldehyde sulfoxylate to deionized water.
A solution containing 10 parts of the solution was continuously added dropwise over 4 hours and maintained for an additional 1 hour to complete the polymerization. Next, in the second stage of polymerization, a solution of a mixed solution of 0.2 parts of kyumene hydroperoxide and 15 parts of styrene and 0.05 parts of sodium formaldehyde sulfoxylate dissolved in 10 parts of deionized water was continuously added dropwise over 4 hours. The polymerization was completed by holding for 1 hour. Then, in the third stage of polymerization, 0.1 part of kyumene hydroperoxide, 1 part of methyl methacrylate,
5 parts styrene, 2 parts n-butyl acrylate, 0.1 part potassium stearate, 0.05 part sodium formaldehyde sulfoxylate, and deionized water.
10 parts were added all at once and held for 2 hours to complete the polymerization. The polymerization conversion rate was 98%. Next, 1 part of butylated hydroxytoluene was added, followed by salting out with a 0.2% aqueous sulfuric acid solution, washing with warm water, and drying to obtain a white powder. (3) Physical property evaluation 100 parts of vinyl chloride resin with an average degree of polymerization of 700 and the above (2)
A mixture of 5 parts of the conjugated diene-based rubbery graft copolymer prepared in step 1, 3 parts of dibutyltin malate-based stabilizer, 3 parts of dioctyl phthalate, and 0.5 part of butylene glycol montanate was placed in a Sociel mixer and heated to 120°C. The mixture, which had been stirred and heated and then cooled, was kneaded with rolls at 165° C. for 6 minutes. The plate was then pressure-molded for 5 minutes using a heated press at 170°C, and the plate was used for physical property evaluation. Impact resistance was measured using a 0.5 mm thick sheet with a striking rod with a tip radius of 3/8 inch at a temperature of 23°C.
The DuPont impact strength at -10°C was measured. The Dupont impact strength calculation method is expressed as the product of the load and height (Kgcm) when 50% or more is destroyed. Transparency was determined using a 2mm thick sheet according to ASTM-
The total light transmittance and haze value using D-1003-61 were measured and evaluated. The results of Example 1 are as follows: Dupont impact strength 55 at 23°C
Kgcm, Dupont impact strength at -10°C was 40 Kgcm, total light transmittance was 89%, haze value was 2.5%, and impact resistance and transparency at room temperature and low temperature were extremely excellent. Examples 2 to 4, Comparative Examples 1 to 4 (1) of Example 1 using the monomer composition shown in Table 1
Conjugated diene-based rubbery copolymers B and C were produced using the polymerization method described above. Next, in the presence of the conjugated diene rubbery copolymer shown in Table 1, a conjugated diene rubbery copolymer was prepared using the graft polymerization method described in Example 1 (2) using the monomer amounts and composition shown in Table 2. A graft copolymer was produced. Next, physical properties were evaluated by the method described in Example 1 (3). The physical property evaluation results are shown in Table-2.

【table】

【table】

[Table] Example 5, Comparative Example 5 In the presence of the conjugated diene rubbery copolymer produced in Example 1 (1), the monomer composition of Example 1 (2) was
A conjugated diene-based rubbery graft copolymer obtained by polymerization using the graft polymerization method shown in Table 3 was used in Example 1.
Physical properties were evaluated using the method described in (3). The physical property evaluation results are shown in Table 3.

【table】

[Table] Examples 6 to 8, Comparative Examples 6 to 7 In the presence of the conjugated diene rubbery copolymer produced in Example 1 (1), the monomer described in Example 1 (2) was Among them, graft polymerization was carried out by replacing n-butyl acrylate with an acrylic acid alkyl ester monomer or a methacrylic acid alkyl ester monomer whose glass transition temperature is 0°C or lower as shown in Table 4. The physical properties of the conjugated diene-based rubbery graft copolymer obtained were evaluated by the method described in Example 1 (3). The physical property evaluation results are shown in Table-4.

【table】

[Table] As can be seen from the results of Examples 1 to 8 and Comparative Examples 1 to 8, as long as the temperature is within the range of the present invention,
It can be seen that both impact resistance and transparency at low temperatures are excellent. However, if it deviates from the scope of the present invention, it has the disadvantage that impact resistance and/or transparency at low temperatures deteriorate. "Effects of the Invention" As is clear from the above, the vinyl chloride resin composition obtained by the present invention has excellent impact resistance at room temperature and low temperature without losing the excellent properties of vinyl chloride resin. This composition also has excellent transparency. Because of this feature, it is suitable as a molding material for blow bottles, transparent sheets, transparent films, etc., and its utility value is extremely high.

Claims (1)

[Scope of Claims] 1 () 70 to 99 parts by weight of a vinyl chloride resin, () (A) 30 to 80 parts by weight of a conjugated diene rubber copolymer containing 50% by weight or more of a conjugated diene, (B) (i) Methyl methacrylate 19-79% by weight, (ii) Aromatic vinyl monomer 20-80% by weight, (iii) Vinyl cyanide monomer 0-30% by weight, (iv) Crosslinkable monomer 0 to 4% by weight, (v) the number of carbon atoms in the alkyl group is 2 or more,
20 to 70 parts by weight of a monomer mixture consisting of 1 to 15% by weight of one or more monomers selected from alkyl acrylates and alkyl methacrylates whose homopolymer glass transition temperature is 0 ° C. or lower. Grafting in multiple stages, and the final stage of grafting (outermost layer)
Among the monomers (B)(i) to (v) above, (a) methyl methacrylate 0 to 30% by weight, (a) aromatic vinyl monomer 5 to 40% by weight, (a) cyanide vinyl monomer
0 to 100% by weight, (a) Crosslinkable monomer 0 to 100% by weight, (a) Alkyl acrylate whose alkyl group has 2 or more carbon atoms and whose homopolymer has a glass transition temperature of 0°C or less 1 selected from esters and methacrylic acid alkyl esters
1 to 30 parts by weight of a conjugated diene-based rubbery graft copolymer to which 60 to 100% by weight of at least one monomer is grafted, and the glass transition temperature of the copolymer constituting the outermost layer exceeds 0°C; A vinyl chloride resin composition comprising: