Polyvinyl chloride resin composition

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polyvinyl chloride resin composition having an excellent impact resistance, particularly a falling weight impact resistance, stress-whitening resistance, and optical characteristics.
2. Description of the Related Art
Polyvinyl chloride resin has excellent chemical and physical properties, and therefore, is widely used in many fields. Nevertheless, polyvinyl chloride resin per se has a drawback of an inferior impact resistance, and a large number of proposals have been made for an elimination of this drawback.
For example, Japanese Patent Publication (Kokoku) No. 42-20847 proposes a polyvinyl chloride resin composition comprising 30 parts by weight or less of a graft copolymer and 70 parts or more by weight of a polyvinyl chloride resin, wherein said graft copolymer is obtained by graft polymerizing 80 to 30 parts by weight of the monomers as the total of 40 to 80% by weight of a methacrylic acid ester and 60 to 20% by weight of styrene onto 20 to 70 parts by weight of a polymer composed mainly of 1,3-butadiene, said graft polymerization being conducted by first graft polymerizing the methacrylic acid ester and then graft copolymerizing styrene.
Japanese Patent Publication (Kokoku) 47-23648 proposes a polyvinyl chloride resin composition comprising a graft copolymer and a vinyl chloride resin, wherein said graft copolymer is obtained by graft polymerizing first methyl methacrylate in the presence of an elastomer and then graft polymerizing styrene.
Also, Japanese Patent Publication (Kokoku) No. 57-26536 proposes a polyvinyl chloride resin composition comprising 3 to 40 parts by weight of a graft copolymer and 97 to 60 parts by weight of a polyvinyl chloride resin, wherein said graft copolymer is obtained by graft polymerizing 65 to 25 parts by weight of monomer group comprising methyl methacrylate, an alkyl acrylate and styrene and optionally a polyfunctional crosslinking agent in the presence of 35 to 75 parts by weight of a 1,3-butadiene type elastomer, said graft polymerization being conducted by graft polymerizing in the first stage 50 to 90% by weight of the total amount of a major amount of methyl methacrylate and a minor amount of an alkyl acrylate and optionally a polyfunctional crosslinking agent having an allyl group, in the presence of 35 to 75 parts by weight of a 1,3-butadiene type elastomer, and then graft polymerizing styrene in the second stage, and further, graft polymerizing 10 to 50% by weight of the total amount of methyl methacrylate and an alkyl acrylate.
Further, Japanese Patent Publication (Kokoku) No. 2-19145 proposes a polyvinyl chloride resin composition comprising 2 to 40% by weight of a graft copolymer and 60 to 98% by weight of a polyvinyl chloride resin, wherein said graft copolymer is obtained by graft polymerizing 30 to 15 parts by weight of a monomer mixture comprising an alkyl methacrylate and an aromatic vinyl or a monomer mixture comprising an alkyl methacrylate, an aromatic vinyl and an unsaturated nitrile onto 70 to 85 parts by weight of a highly crosslinked butadiene rubber with a particle size of 600 to 3000 .ANG., a total crosslinking agent in an amount of 1 to 10% by weight and a degree of swelling of 7 or less, said graft polymerization being conducted by one stage or multi stage.
In the polyvinyl chloride resin composition proposed in Japanese Patent Publication (Kokoku) No. 42-20847 or 47-23648, however, an ungelled product is liable to remain under extrusion conditions of a low degree of mixing, whereby, for example, a large generation of fish eyes occurs when formed into a sheet, the optical characteristics are poor, the stress-whitening resistance is poor, and the dart falling weight impact strength is too poor. Also, since styrene as the final graft component is polymerized during the preparation of the graft copolymer used, a styrene having a slow polymerization rate often is left, and consequently, remains in the graft copolymer powder and causes an objectionable odor to arise, and thus has a drawback in that the use of such a polyvinyl chloride resin composition is limited.
In the polyvinyl chloride resin composition proposed in Japanese Patent Publication (Kokoku) No. 57-26536, however, although the optical characteristics such as a total light transmittance and haze value are good, a product having a satisfactory stress-whitening resistance and falling weight impact strength cannot be obtained.
Further, in the polyvinyl chloride resin composition proposed in Japanese Patent Publication (Kokoku) No. 2-19145, although the impact resistance is excellent, the optical characteristics such as a total light transmittance and haze value are poor, and further, the stress-whitening resistance is not satisfactory.
SUMMARY OF THE INVENTION
Accordingly, the objects of the present invention are to eliminate the above-mentioned disadvantages of the prior art and to provide a polyvinyl chloride resin composition having an excellent impact resistance, particularly a falling weight impact resistance, and an excellent stress-whitening resistance and optical characteristics.
Other objects and advantages of the present invention will be apparent from the following description.
In accordance with the present invention, there is provided a polyvinyl chloride resin composition having an excellent falling weight impact resistance, stress-whitening resistance and optical characteristics, comprising 100 parts by weight of a polyvinyl chloride resin and 2 to 40 parts by weight of a multi-stage copolymer obtained by polymerizing a resin component formable monomer in the range of from more than 30 parts by weight to 50 parts by weight, said resin component formable monomer being composed of a ratio of 25 to 55% by weight of methyl methacrylate, 2 to 15% by weight of an alkyl acrylate (alkyl group having 1 to 8 carbon atoms) and 30 to 60% by weight of an aromatic vinyl monomer in the presence of from 50 parts by weight to less than 70 parts by weight of a butadiene elastomer having a glass transition temperature of from -40.degree. C. to 5.degree. C. obtained by copolymerization of a monomer mixture of 70 to 90% by weight of butadiene, 10 to 30% by weight of an aromatic vinyl monomer and a polyfunctional monomer added in an amount corresponding to 3 to 10 parts by weight per 100 parts by weight of total amount of said butadiene and aromatic vinyl monomer, wherein a polymerization of the resin component formable monomer is conducted by polymerizing in the first stage methyl methacrylate in an amount corresponding to 45 to 85% by weight of the total amount of methyl methacrylate and the alkyl acrylate in an amount within the range specified above, subsequently polymerizing in the second stage the aromatic vinyl monomer in an amount within the range specified above in the presence of the polymer obtained in the previous stage, and further polymerizing in the third stage the remainder of methyl methacrylate in the presence of the polymers obtained in the polymerizations in the first and second stages.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the present invention, the above-mentioned object can be accomplished by formulating a multi-stage copolymer with a polyvinyl chloride resin, said multi-stage copolymer being obtained by using a highly crosslinked butadiene elastomer as the rubber component at a ratio within a specific range, and polymerizing resin component formable monomers at a special composition ratio in 3 stages in the presence of the above-mentioned rubber component.
As the polyvinyl chloride resin to be used in the present invention, polyvinyl chloride or a copolymer of 70% by weight or more of vinyl chloride and 30% by weight or less of another monomer copolymerizable therewith can be used. Examples of other copolymerizable monomers include vinyl bromide, vinylidene chloride, vinyl acetate, acrylic acid, methacrylic acid, and ethylene.
The average degree of polymerization of the polyvinyl chloride resin to be used in the present invention is not particularly limited, but preferably, such a resin having an average degree of polymerization of 600 to 1,000, more preferably 650 to 900, is used.
The multi-stage copolymer to be used in the present invention is obtained by polymerizing, in 3 stages, methyl methacrylate, an alkyl acrylate and an aromatic vinyl monomer, which are resin component formable monomers, at a specific ratio in the presence of a butadiene elastomer.
The butadiene elastomer component constituting the above-mentioned multi-stage copolymer has a glass transition temperature of from -40.degree. C. to 5.degree. C. and is obtained by copolymerizing a monomer mixture comprising 70 to 90% by weight of butadiene, 10 to 30% by weight of an aromatic vinyl monomer and a polyfunctional monomer added in an amount corresponding to 3 to 10 parts by weight per 100 parts by weight of the total amount of said butadiene and aromatic vinyl monomer. As the butadiene component, 1,3-butadiene is preferred, and as the aromatic vinyl monomer, styrene, .alpha.-methylstyrene, vinyl toluene, and ring-substituted styrene are exemplified, and these can be used alone or in combination. Of these, styrene is preferable. Further, as the polyfunctional monomer, there are included divinylbenzene, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, triethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate, and among these, divinylbenzene and 1,3-butylene glycol dimethacrylate are most preferred.
The composition ratio of butadiene and the aromatic vinyl monomer, which are the constituents of the butadiene elastomer, is within the range as specified above; when it is outside this range, the object of the present invention cannot be fully achieved. The amount of polyfunctional monomer used corresponds to 3 to 10 parts by weight of the above-mentioned range, preferably 3 to 8 parts by weight, whereby the butadiene elastomer can be highly crosslinked and the glass transition temperature can also be kept within the temperature range as specified above, thus improving the falling weight impact resistance, stress-whitening resistance and optical characteristics of the resin composition finally obtained.
The ratio of the butadiene elastomer in the multi-stage copolymer must be 50 parts by weight or more but less than 70 parts by weight to 100 parts by weight of the multi-stage copolymer. When the ratio of the butadiene elastomer is less than 50 parts by weight, the improvement of the falling weight resistance and stress-whitening resistance is not sufficient, and when it is 70 parts by weight or more, the moldability and stress-whitening resistance of the resin composition finally obtained become poorer, and thus the molded products obtained do not have satisfactory surface characteristics.
In the presence of from 50 parts by weight to less than 70 parts by weight of the butadiene elastomer with such a constitution, resin component formable monomers in the range of from more than 30 parts by weight to 50 parts by weight, said resin component formable monomers at a ratio of 25 to 55% by weight of methyl methacrylate, 2 to 15% by weight of an alkyl acrylate (alkyl group having 1 to 8 carbon atoms), and 30 to 60% by weight of an aromatic vinyl monomer (total 100 parts by weight of the butadiene elastomer and resin component formable monomers) are polymerized, and in the practice of the present invention, during the polymerization of the resin component formable monomers, in the first stage methyl methacrylate in an amount corresponding to 45 to 85% by weight of the total amount of methyl methacrylate and the alkyl acrylate in an amount within the range specified above are polymerized, then in the second stage, the aromatic vinyl monomer in an amount specified above is polymerized in the presence of the polymer obtained in the previous stage, and thereafter, in the third stage, only the remainder of methyl methacrylate is polymerized in the presence of the polymers obtained by the first and second polymerizations, to thereby obtain a multi-stage copolymer.
The combined use of methyl methacrylate and an alkyl acrylate in the first stage polymerization improves the flowability of the multi-stage copolymer and prevents the formation of an ungelled product when formulated with a polyvinyl chloride resin, and further, markedly improves the falling weight impact strength of the molded product. The amount of methyl methacrylate must correspond to 45 to 85% by weight of the total amount of methyl methacrylate, preferably 50 to 70% by weight. The use of an amount outside this range reduces the effect of a combined use thereof with an alkyl acrylate, lowers the improvement of the flowability when polymerized into a multi-stage copolymer and when the copolymer is formulated with a polvinyl chloride resin, causes difficulties in the prevention of the formation of ungelled products, and impairs the surface appearance of the molded product. Further, the falling weight impact strength becomes poorer. For this polymerization in the first stage, the relative use ratio of methyl methacrylate and the alkyl acrylate preferably has a relation of a major amount of methyl methacrylate to a minor amount of the alkyl acrylate.
The alkyl acrylate is used only in the polymerization in the first stage, and the amount thereof used is within 2 to 15% by weight of the total amount of the resin component formable monomers. When the amount of the alkyl acrylate used is outside this range, the effect of a combined use thereof with methyl methacrylate will be reduced, the improvement of the flowability when polymerized into a multi-stage copolymer is lowered, and even though it may be formulated with a polyvinyl chloride resin, it becomes difficult to fully prevent a formation of ungelled products, and thus the surface appearance of the molded product is impaired. Further, the falling weight impact strength is unsatisfactory.
The polymerization of an aromatic vinyl monomer in the second stage contributes to an improvement of the surface appearance of the product molded from the resin composition when the resulting multi-stage copolymer is formulated with a polyvinyl chloride resin.
In the polymerization in the third stage, it is important to polymerize only the remainder of methyl methacrylate, which contributes to an improvement of the stress-whitening resistance of the product molded from the resin composition, when the multi-stage copolymer obtained from such a polymerization is formulated with a polyvinyl chloride resin.
When another monomer such as an alkyl acrylate is used in combination during this polymerization in the third stage, the improvement will be lowered.
As the aromatic vinyl monomer which serves as the resin component formable monomer, the aromatic vinyl monomer constituting the above-mentioned butadiene elastomer can be used, and preferably styrene is used.
As the alkyl acrylate, those having an alkyl group having 1 to 8 carbon atoms can be used, and specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate, and these can be used alone or in a combination of two or more kinds thereof. Of these alkyl acrylates, preferably ethyl acrylate and n-butyl acrylate are used.
As the polymerization initiator used when preparing the above-mentioned multi-stage copolymer, there can be employed persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate; organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide, and diisopropylbenzene hydroperoxide; and azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile. Alternatively, the above-mentioned compound can be combined with compounds such as sulfites, hydrogen sulfites, thiosulfates, transition metal salts, sodium formaldehyde sulfoxylate, and dextrose, to be used as the redox system initiator.
An emulsion polymerization is preferred as the polymerization method, and the polymerization is preferably carried out at a temperature of about 40.degree. C. to 80.degree. C., depending on the kind of polymerization initiator used. Known emulsifiers can be used as the emulsifier.
The multi-stage copolymer latex obtained is coagulated by using a coagulant including acids such as sulfuric acid, hydrochloric acid, and phosphoric acid, and/or salts such as calcium chloride and sodium chloride, with or without an addition of an appropriate antioxidant or additives, solidified by heat treatment, followed by dehydration and washing and drying, to be formed into a powdery multi-stage copolymer.
In the present invention, as described above, a polyvinyl chloride resin composition having excellent characteristics, which is the object of the present invention, was obtained for the first time by formulating a multi-stage copolymer with a polyvinyl chloride resin. Said copolymer is obtained by satisfying the combination of using a highly crosslinked butadiene elastomer, polymerizing specific amounts of methyl methacrylate and an alkyl acrylate as the resin formable monomers in the first stage in the presence of the butadiene elastomer, polymerizing only a specific amount of an aromatic vinyl monomer in the second stage, and polymerizing only a specific amount of the remainder of methyl methacrylate in the third stage.
The polyvinyl chloride resin composition of the present invention is obtained by mixing the above-mentioned multi-stage copolymer and polyvinyl chloride resin, in powdery form, by using, for example, a ribbon blender or Henschel mixer, and kneading the resultant mixture by a known kneader or extruder. The method of mixing the polyvinyl chloride resin and the multi-stage copolymer is not limited to such a powder blend, and a polyvinyl chloride resin slurry and a multi-stage copolymer latex may be mixed and formed into a powder via coagulation, solidification, washing, and drying, etc. During the mixing according to these various methods, known stabilizers, plasticizers, processing aids, and colorants can be added, if necessary.
The polyvinyl chloride resin composition of the present invention comprises 100 parts by weight of a polyvinyl chloride resin and 2 to 40 parts of the multi-stage copolymer formulated therewith. When the amount of the multi-stage copolymer is less than 2 parts by weight, the addition has little effect, and when an amount exceeds 40 parts by weight, other excellent inherent characteristics of the polyvinyl chloride resin are liable to be lost.
EXAMPLES
The present invention will now be further illustrated in detail by, but is by no means limited to, the following Examples, wherein "parts" are all by weight unless otherwise noted.
The various characteristics in the Examples and Comparative Examples shown below were measured by the following methods.
(1) Particle Size of Butadiene Elastomer
The average particle size of the butadiene elastomer latex was determined by a transmission electron microscope (JEM-100S, produced by JEOL LTD.
(2) Glass Transition Temperature
The multi-stage copolymer was pressed at 170.degree. C. and 30 kg/cm.sup.2, and the tan.delta. determined by using a DYNAMIC MECHANICAL ANALYZER (DMA 982) produced by E. I. du Pont de Nemours and Co., and the peak value of the lower temperature of the two peaks was determined as the glass transition temperature of the butadiene elastomer.
(3) Transparency (Total Light Transmittance, Haze Value)
The formulated resin composition was kneaded at 180.degree. C. for 5 minutes, by 8 inch rolls, and then pressed at 190.degree. C. under a load of 50 kg/cm.sup.2 for 10 minutes, and using the obtained sample plate having a thickness of 4 mm, an evaluation was conducted based on ASTM-D1003-61.
(4) Falling Weight Impact Strength (Dart Impact at 50% of Breaking Height)
The formulated resin composition was molded into a film having a thickness of 0.10 mm at a resin temperature of 190.degree. C., by an extrusion molding machine with a screw diameter of 40 mm, and was evaluated based on JIS (Japan Industrial Standard)-K7211 by using a 500 g dart weight, and the height at which 50% of the film was broken was determined to be the 50% breaking height.
(5) Stress-Whitening Resistance
The formulated resin composition was formed into a sheet having a thickness of 0.5 mm at a resin temperature of 190.degree. C., by an extrusion molding machine with a screw diameter of 40 mm, and by using a dart with a 1 cm tip diameter of the du Pont impact tester, a dart was permitted to fall from a height of 30 cm under a 500 g load to deform the sheet, and the degree of whitening at the deformed portion was evaluated by the visual assessment.
A . . . Not whitened
B . . . Slightly whitened
C . . . Whitened.
EXAMPLE 1
(1) Synthesis of Butadiene Elastomer (A-1)
______________________________________1,3-Butadiene 75 partsStyrene (St) 25 partsDivinylbenzene (DVB) 7 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into a autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A-1). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -15.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-1)
A multi-stage copolymer (B-1) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-1) 65 parts(as solids)St 15 partsMethyl methacrylate (MMA) 17 partsEthyl acrylate (EA) 3 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite (sodium formaldehye 0.5 partsulfoxylate)Deionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-1), potassium oleate, Rongalite and deionized water were charged into a flask charged with nitrogen, the inner temperature thereof was maintained at 70.degree. C., and in the first stage, a mixture of 11 parts of MMA, 3 parts of EA, and 0.28 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 15 parts of St and 0.3 part of cumene hydroperoxide was continuously added dropwise over one hour, and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 6 parts of MMA and 0.12 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thus complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of butylated hydroxytoluene (BHT) was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
The respective components of 100 parts of a polyvinyl chloride resin with an average polymerization degree of 700, 3 parts of dioctyltin mercaptide as the stabilizer, 2 parts of Metablene.RTM.P-550 (produced by Mitsubishi Rayon Co., Ltd.) as the lubricant, 1 part of Metablene.RTM.P-710 (produced by Mitsubishi Rayon Co., Ltd.) as the lubricant, and 10 parts of the multi-stage copolymer powder obtained in the above (2) were mixed by a Henschel mixer till 110.degree. C. for 10 minutes, to obtain a polyvinyl chloride resin composition.
Then, the physical properties of the composition obtained were measured, and the results are shown in Table 1.
EXAMPLE 2
(1) Synthesis of Butadiene Elastomer (A-2)
______________________________________Bd 80 partsSt 20 partsDVB 5 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours, to prepare a butadiene elastomer (A-2). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -23.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-2)
A multi-stage copolymer (B-2) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-2) 60 parts(as a solid)St 16 partsMMA 20 partsEA 4 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.8 partRongalite 0.6 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-2), potassium oleate, Rongalite and deionized water were charged into a flask charged with nitrogen and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 14 parts of MMA, 4 parts of EA and 0.36 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 16 parts of St and 0.32 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 6 parts of MMA and 0.12 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein one hour, to thus complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, an aqueous solution of sulfuric acid in a concentration of 0.2% by weight was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Example 1, except that the multi-stage copolymer (B-2) was used in place of the multi-stage copolymer powder (B-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 1.
EXAMPLE 3
(1) Synthesis of Butadiene Elastomer (A-3)
______________________________________Bd 80 partsSt 20 partsDVB 6 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A-3). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -20.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-3)
A multi-stage copolymer (B-3) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-3) 65 parts(as a solid)St 15 partsMMA 17 partsEA 3 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-3), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 13 parts of MMA, 3 parts of EA, and 0.32 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 15 parts of St and 0.3 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 4 parts of MMA and 0.08 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thus complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thereby obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Example 1, except that the multi-stage copolymer (B-3) was used in place of the multi-stage copolymer powder (B-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 1.
EXAMPLE 4
(1) Synthesis of Butadiene Elastomer (A-4)
______________________________________Bd 85 partsSt 15 partsDVB 8 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A-4). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -26.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-4)
A multi-stage copolymer (B-4) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-4) 63 parts(as solids)St 18 partsMMA 15 partsEA 4 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.74 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-4), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 12 parts of MMA, 4 parts of EA, and 0.32 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 18 parts of St and 0.36 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 3 parts of MMA and 0.06 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Example 1 except that the multi-stage copolymer (B-4) was used in place of the multi-stage copolymer powder (B-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 1.
EXAMPLE 5
(1) Synthesis of Butadiene Elastomer (A-5)
______________________________________Bd 85 partsSt 15 partsDVB 4 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A-5). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -33.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-5)
A multi-stage copolymer (B-5) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-5) 65 parts(as solids)St 20 partsMMA 10 partsEA 5 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-5), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 6 parts of MMA, 5 parts of EA and 0.22 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 20 parts of St and 0.4 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 4 parts of MMA and 0.08 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Example 1, except that the multi-stage copolymer (B-5) was used in place of the multi-stage copolymer powder (B-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 1.
EXAMPLE 6
(1) Synthesis of Butadiene Elastomer (A-6)
______________________________________Bd 80 partsSt 20 parts1,3-Butylene glycol dimethacrylate 5 parts(1,3-BD)Diisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A-6). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -25.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-6)
A multi-stage copolymer (B-6) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-6) 60 parts(as solids)St 23 partsMMA 14 partsEA 3 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.8 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-6), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 10 parts of MMA, 3 parts of EA and 0.26 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 23 parts of St and 0.46 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 4 parts of MMA and 0.08 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Example 1 except that the multi-stage copolymer (B-6) was used in place of the multi-stage copolymer powder (B-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 1.
EXAMPLE 7
(1) Synthesis of Butadiene Elastomer (A-7)
______________________________________Bd 75 partsSt 25 parts1,3-BD 8 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A-7). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -15.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B-7)
A multi-stage copolymer (B-7) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A-7) 65 parts(as solids)St 15 partsMMA 16 partsEA 4 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A-7), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 11 parts of MMA, 4 parts of EA and 0.3 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 15 parts of St and 0.3 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 5 parts of MMA and 0.1 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride type resin composition was prepared under the same conditions as in Example 1 except that the multi-stage copolymer (B-7) was used in place of the multi-stage copolymer powder (B-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 1.
COMPARATIVE EXAMPLE 1
(1) Synthesis of Butadiene Elastomer (A'-1)
______________________________________Bd 75 partsSt 25 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-1). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -28.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-1)
A multi-stage copolymer (B'-1) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-1) 65 parts(as solids)St 16 partsMMA 14 partsEA 5 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-1), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 10 parts of MMA, 3 parts of EA, and 0.26 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 16 parts of St and 0.32 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 4 parts of MMA, 2 parts of EA, and 0.12 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of butylated hydroxytoluene (BHT) was added to the multi-stage copolymer later, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
The respective components of 100 parts of a polyvinyl chloride resin with an average polymerization degree of 700, 3 parts of dioctyltin mercaptide as the stabilizer, 2 parts of Metablene.RTM.P-550 (produced by Mitsubishi Rayon Co., Ltd.) as the lubricant, 1 part of Metablene.RTM.P-710 (produced by Mitsubishi Rayon Co., Ltd.) as the lubricant, and 10 parts of the multi-stage copolymer powder obtained in the above (2) were mixed by a Henschel mixer till 110.degree. C. for 10 minutes, to thus obtain a polyvinyl chloride resin composition.
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 2
(1) Synthesis of Butadiene Elastomer (A'-2)
______________________________________Bd 75 partsSt 25 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-2). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -28.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-2)
A multi-stage copolymer (B'-2) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-2) 65 parts(as solids)St 15 partsMMA 20 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-2), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof was maintained at 70.degree. C., and in the first stage, a mixture of 10 parts of MMA, 15 parts of St, and 0.50 part of cumene hydroperoxide was dropwise added over one hour and held therein for 2 hours.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 10 parts of MMA and 0.2 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Comparative Example 1, except that the multi-stage copolymer (B'-2) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 3
(1) Synthesis of Butadiene Elastomer (A'-3)
______________________________________Bd 90 partsSt 10 partsDVB 1 partDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-3). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -43.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-3)
A multi-stage copolymer (B'-3) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-3) 60 parts(as a solid)St 25 partsMMA 15 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.8 partRongalite 0.6 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-3), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 15 parts of MMA and 0.30 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour. Then, in the presence of the polymer obtained in the previous stage, in the second stage a mixture of 25 parts of St and 0.5 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex. After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water dried, to thus obtain a multi-stage copolymer powder.
(3 ) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-3) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 4
(1) Synthesis of Butadiene Elastomer (A'-4)
______________________________________Bd 85 partsSt 15 partsDVB 1 partDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-4). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -38.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-4)
A multi-stage copolymer (B'-4) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-4) 60 parts(as solds)St 23 partsMMA 15 partsEA 2 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.8 partRongalite 0.6 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-4), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 10 parts of MMA, 2 parts of EA and 0.24 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 23 parts of St and 0.46 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 5 parts of MMA and 0.10 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-4) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 5
(1) Synthesis of Butadiene Elastomer (A'-5)
______________________________________Bd 80 partsSt 20 partsDVB 5 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-5). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -25.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-5)
A multi-stage copolymer (B'-5) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-5) 80 parts(as solids)St 8 partsMMA 12 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.4 partRongalite 0.3 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene type elastomer (A'-5), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 9 parts of MMA and 0.18 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 8 parts of St and 0.16 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 3 parts of MMA and 0.6 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of polyvinyl chloride resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-5) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 6
(1) Synthesis of Butadiene Elastomer (A'-6)
______________________________________Bd 75 partsSt 25 partsDVB 6 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-6). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -17.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-6)
A multi-stage copolymer (B'-6) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-6) 65 parts(as solids)St 15 partsMMA 14 partsEA 6 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-6), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 11 parts of MMA, 3 parts of EA and 0.28 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 15 parts of St and 0.3 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 3 parts of MMA, 3 parts of EA and 0.12 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride type resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-6) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 7
(1) Synthesis of Butadiene Elastomer (A'-7)
______________________________________Bd 75 partsSt 25 partsDVB 8 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-7). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -13.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-7)
A multi-stage copolymer (B'-7) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-7) 65 parts(as solids)St 14 partsMMA 21 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.7 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-7), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 6 parts of MMA, 14 parts of St and 0.40 part of cumene hydroperoxide was dropwise added over one hour and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 15 parts of MMA and 0.30 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for 2 hours, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-7) was used in place of the multi-stage copolymer powder (B'-7).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 8
(1) Synthesis of Butadiene Elastomer (A'-8)
______________________________________Bd 80 partsSt 20 parts1,3-BD 1 partDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene type elastomer (A'-8). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -32.degree. C.)
(2) Synthesis of Multi-State Copolymer (B'-8)
A multi-stage copolymer (B'-8) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-8) 65 parts(as solids)St 16 partsMMA 15 partsEA 4 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.8 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the components of the above composition, the butadiene elastomer (A'-8), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen, and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 10 parts of MMA, 4 parts of EA and 0.28 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 16 parts of St and 0.32 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 5 parts of MMA and 0.1 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-8) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 9
(1) Synthesis of Butadiene Elastomer (A'-9)
______________________________________Bd 75 partsSt 25 parts1,3-BD 5 partsDiisopropylbenzene hydroperoxide 0.2 partSodium pyrophosphate 0.5 partFerrous sulfate 0.01 partDextrose 1 partPotassium oleate 2 partsDeionized water 200 parts______________________________________
The respective components of the above composition were charged into an autoclave, and the reaction was carried out under stirring at 50.degree. C. for 12 hours to prepare a butadiene elastomer (A'-9). (Conversion 98%, average particle size 0.08.mu., glass transition temperature -21.degree. C.)
(2) Synthesis of Multi-Stage Copolymer (B'-9)
A multi-stage copolymer (B'-9) was prepared by using the components of the following composition.
______________________________________Butadiene elastomer (A'-9) 65 parts(as a solid)St 17 partsMMA 10 partsEA 8 partsPotassium oleate 1.2 partsCumene hydroperoxide 0.8 partRongalite 0.5 partDeionized water (as a whole) 200 parts______________________________________
Of the component of the above composition, the butadiene elastomer (A'-9), potassium oleate, Rongalite, and deionized water were charged into a flask charged with nitrogen and the inner temperature thereof maintained at 70.degree. C., and in the first stage, a mixture of 8 parts of MMA, 8 parts of EA, and 0.32 part of cumene hydroperoxide was dropwise added over 20 minutes and held therein for 1 hour.
Then, in the presence of the polymer obtained in the previous stage, in the second stage, a mixture of 17 parts of St and 0.34 part of cumene hydroperoxide was continuously added dropwise over one hour and held therein for 2 hours.
Thereafter, in the presence of the polymers obtained in the first stage and the second stage, in the third stage, a mixture of 2 parts of MMA and 0.04 part of cumene hydroperoxide was added dropwise over 50 minutes and held therein for one hour, to thereby complete the polymerization to obtain a multi-stage copolymer latex.
After 0.5 part of BHT was added to the multi-stage copolymer latex, a 0.2 wt % aqueous sulfuric acid solution was added to coagulate the copolymer, followed by a solidification by a heat treatment at 90.degree. C. Then, the coagulated product was washed with warm water and dried, to thus obtain a multi-stage copolymer powder.
(3) Preparation of Polyvinyl Chloride Resin Composition
A polyvinyl chloride type resin composition was prepared under the same conditions as in Comparative Example 1 except that the multi-stage copolymer (B'-9) was used in place of the multi-stage copolymer powder (B'-1).
The physical properties of the composition obtained were measured, and the results are shown in Table 2.
TABLE 1__________________________________________________________________________Multi-stage copolymer Content of Composition ratio of resinComposition ratio of Glass butadiene formable monomers (parts)butadiene elastomer temperature elastomer First Second ThirdBd St DVB 1,3-BD of butadiene in multi-stage stage stage stage (%) (%) (parts) (parts) elastomer (.degree.C.) copolymer (parts) MMA EA St MMA__________________________________________________________________________Example 1 75 25 7 0 -15 65 11 3 15 6Example 2 80 20 5 0 -23 60 14 4 16 6Example 3 80 20 6 0 -20 65 13 3 15 4Example 4 85 15 8 0 -26 63 12 4 18 3Example 5 85 15 4 0 -33 65 6 5 20 4Example 6 80 20 0 5 -25 60 10 3 23 4Example 7 75 25 0 8 -15 65 11 4 15 5__________________________________________________________________________ Physical properties of compositionComposition ratio of Fallingpolyvinyl chloride Transparency weight strengthresin composition Haze Stress (dart impact Polyvinyl chloride Multi-stage Total light value whitening 50% breaking resin (parts) copolymer (parts) transmittance (%) (%) resistance height) (cm)__________________________________________________________________________Example 1 100 10 84.9 5.0 A 124Example 2 100 10 84.7 5.4 A 103Example 3 100 10 84.9 3.6 A 112Example 4 100 10 84.8 4.3 A 118Example 5 100 10 85.0 5.2 A 132Example 6 100 10 84.0 5.6 A 100Example 7 100 10 84.3 4.9 A 115__________________________________________________________________________
TABLE 2__________________________________________________________________________ Multi-stage copolymer Content of Composition ratio of Glass butadiene Composition ratio of resin butadiene elastomer temperature elastomer formable monomers (parts) Bd St DVB 1,3-BD of butadiene in multi-stage First Second Third (%) (%) (parts) (parts) elastomer (.degree.C.) copolymer (parts) stage stage stage__________________________________________________________________________Comparative 75 25 0 0 -28 65 MMA EA St MMA EAExample 1 10 3 16 4 2Comparative 75 25 0 0 -28 65 MMA St MMA --Example 2 10 15 10Comparative 90 10 1 0 -43 60 MMA St --Example 3 15 25Comparative 85 15 1 0 -38 60 MMA EA St MMAExample 4 10 2 23 5Comparative 80 20 5 0 -25 80 MMA St MMAExample 5 9 8 3Comparative 75 25 6 0 -17 65 MMA EA St MMA EAExample 6 11 3 15 3 3Comparative 75 25 8 0 -13 65 MMA St MMA --Example 7 6 14 15Comparative 80 20 0 1 -32 65 MMA EA St MMAExample 8 10 4 16 5Comparative 75 25 0 5 -21 65 MMA EA St MMAExample 9 8 8 17 2__________________________________________________________________________ Physical properties of composition Composition ratio of Falling polyvinyl chloride weight strength resin composition Transparency Stress (dart impact Polyvinyl chloride Multi-stage Total light Haze whitening 50% breaking resin (parts) copolymer (parts) transmittance (%) value (%) resistance height)__________________________________________________________________________ (cm)Comparative 100 10 83.9 6.9 C 64Example 1Comparative 100 10 82.5 7.2 B-C 63Example 2Comparative 100 10 80.1 11.6 C 71Example 3Comparative 100 10 82.7 6.8 C 69Example 4Comparative 100 10 76.3 12.4 C 114Example 5Comparative 100 10 84.1 5.8 C 101Example 6Comparative 100 10 83.3 6.1 B 98Example 7Comparative 100 10 83.0 6.5 C 66Example 8Comparative 100 10 81.5 7.1 B-C 87Example 9__________________________________________________________________________
The present invention exhibits a superior feature in that a polyvinyl resin composition having an excellent falling weight impact resistance, stress whitening resistance and optical characteristics can be obtained, for the first time, by formulating into a polyvinyl chloride resin a multi-stage copolymer obtained by a combination of using a highly crosslinked butadiene elastomer, polymerizing combined monomers in specific amounts of methyl methacrylate and alkyl acrylate as the resin component formable monomers in the first stage in the presence of the butadiene elastomer, polymerizing only a specific amount of an aromatic vinyl monomer in the second stage, and polymerizing only a specific amount of the remainder of methyl methacrylate in the third stage.

Number	Name	Date
3886235	Tanaka et al.	May 1975
3971835	Myers et al.	Jul 1976
4362845	Kamata et al.	Dec 1982
4657976	Ott et al.	Apr 1987

Number	Date	Country
0163939	Dec 1985	EPX
0278788	Aug 1988	EPX
0347726	Dec 1989	EPX
2090606	Jul 1982	GBX

Polyvinyl chloride resin composition

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