JPH11228642A - Production of vinyl chloride resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin that has excellent fabrication, stably produce molded products having good surfaces for hours and high impact strength by grafting vinyl chloride or the like onto a specific acrylic copolymer in the presence of a specific crosslinked acrylic copolymer. SOLUTION: In the presence of (A) 2-40 pts.wt. of a crosslinked copolymer prepared from 80-99 wt.% of radically polymerizable polymer having the glass transition point of -14-30 deg.C and 20-0.1 wt.% of a polyfunctional monomer, (B) 0.1-20 pts.wt. of an alkyl (meth)acrylate having a glass transition point of -10-180 deg.C is polymerized, then 100 pts.wt. of vinyl chloride monomer or a mainly vinyl chloride monomer-containing monomer mixture is grafted to the acrylic copolymer to give the objective resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a vinyl chloride resin.

[0002]

2. Description of the Related Art Conventionally, vinyl chloride resin has a mechanical strength,
As a material having excellent properties such as weather resistance, self-extinguishing property, and chemical resistance, it is used in a wide range of applications such as pipes, joints, plates, sheets, films, and containers. However, since a hard molded article of a vinyl chloride resin is particularly poor in impact resistance, various methods for improving impact resistance have been proposed.

[0003] In particular, for applications requiring impact resistance and weather resistance, a vinyl chloride resin in which a vinyl chloride is graft-copolymerized with a crosslinked acrylic copolymer latex has been proposed (Japanese Patent Laid-Open Publication (Kokai)). (Showa 60-255813). However, when a rubber component having the above-mentioned tackiness is mixed into a vinyl chloride resin, the rubber component adheres and accumulates on the surface of the mold during the molding process, and the surface of the molded article gradually becomes "faint" over time. And "streaks" tend to occur, and improvement in long-term moldability has been desired.

Generally, in order to improve the appearance of a molded product,
A method of adding an acrylic processing aid during molding is known, but commercially available processing aids are insufficiently dispersible in vinyl chloride resins, so that a small amount of the additive effectively improves the appearance. It is difficult to improve. Therefore, a vinyl chloride-based resin capable of stably obtaining a molded article having a good surface condition even in continuous molding for a long time has been demanded.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to stably produce a molded product having a good surface condition for a long time due to its excellent moldability. It is another object of the present invention to provide a method for producing a vinyl chloride resin in which the obtained molded article has excellent impact resistance.

[0006]

According to the method for producing a vinyl chloride resin of the present invention, the homopolymer has a glass transition temperature of -14.
A radical polymerizable monomer having an alkyl (meth) acrylate (a) having a main temperature of 0 ° C. or higher and lower than 30 ° C.
Crosslinked acrylic copolymer (A) 2 obtained by copolymerizing 99.9% by weight and 20 to 0.1% by weight of a polyfunctional monomer
Acrylic resin obtained by copolymerizing 0.1 to 20 parts by weight of an alkyl (meth) acrylate (b) having a glass transition temperature of -10 ° C or more and less than 180 ° C in the presence of ４０40 parts by weight. The copolymer (B) is characterized in that vinyl chloride alone or 100 parts by weight of a vinyl monomer containing vinyl chloride as a main component is graft-copolymerized.

The crosslinked acrylic copolymer (A) used in the present invention can be obtained by copolymerizing a radically polymerizable monomer and a polyfunctional monomer. The radical polymerizable monomer has a glass transition temperature of a homopolymer of -1.
Alkyl (meth) acrylate (a) having a temperature of 40 ° C. or higher and lower than 30 ° C. is a main component. The alkyl (meth) acrylate (a) is used for the purpose of improving the impact resistance of the vinyl chloride resin, but since the flexibility at room temperature is required, the glass transition temperature of the homopolymer is 30 ° C. Limited to Further, the glass transition temperature of a homopolymer is limited to −140 ° C. or more in consideration of the glass transition temperature of a polymer that has been conventionally industrially used.

Examples of the alkyl (meth) acrylate (a) which is a main component of the radical polymerizable monomer include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate and n-acrylate.
Butyl acrylate, isobutyl acrylate, sec
-Butyl acrylate, cumyl acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, 2-methylheptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n -Nonyl (meth) acrylate, 2-methyloctyl (meth) acrylate, 2-
Alkyl (meth) acrylates such as ethyl (meth) heptyl acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl acrylate, myristyl (meth) acrylate, palmityl methacrylate, and stearyl methacrylate; 2-hydroxyethyl acrylate; Examples thereof include 2-hydroxypropyl (meth) acrylate, which may be used alone or in combination of two or more.

The glass transition temperature of the homopolymer is -14.
The alkyl (meth) acrylate (a) having a temperature of 0 ° C. or more and less than 30 ° C. was quoted from “Polymer Data Handbook (Basic Edition)” edited by The Society of Polymer Science, published by Baifukan. The same applies to the glass transition temperatures of the following homopolymers.

The above-mentioned radical polymerizable monomer is a vinyl monomer copolymerizable with the above alkyl (meth) acrylate (a) for the purpose of improving the mechanical strength, chemical resistance and moldability of the vinyl chloride resin. May be added. Examples of the vinyl monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate,
Alkyl (meth) such as t-butyl (meth) acrylate, cumyl methacrylate, cyclohexyl methacrylate, palmityl acrylate, and stearyl acrylate
Acrylate; 2-hydroxyethyl methacrylate,
Polar group-containing vinyl monomers such as 2-acryloyloxyethyl phthalic acid; styrene, α-methylstyrene, p-
Aromatic vinyl monomers such as methylstyrene and p-chlorostyrene; unsaturated nitrile compounds such as (meth) acrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate; and these may be used alone. Two or more kinds may be used in combination.

In the above radical polymerizable monomer,
The proportion of the alkyl (meth) acrylate (a) is preferably at least 50% by weight. If the proportion is less than 50% by weight, the flexibility of the crosslinked acrylic copolymer (A) is lost, and the impact resistance of the molded article is reduced.

The above-mentioned polyfunctional monomer not only improves the impact resistance of the obtained vinyl chloride resin by crosslinking the acrylic copolymer (A), but also at the time of production and after production. The copolymer (A) is added for the purpose of preventing coalescence of the particles.

The above-mentioned polyfunctional monomers include, for example,
Di (meth) such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and trimethylolpropane di (meth) acrylate Acrylates: tri (meth) acrylates such as trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, and pentaerythritol tri (meth) acrylate.

Examples of polyfunctional monomers other than those described above include, for example, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, diallyl phthalate, diallyl malate, diallyl fumarate, diallyl succinate, triaryl Diallyl or triallyl compounds such as allyl isocyanurate; and divinyl compounds such as divinylbenzene and butadiene.

The above polyfunctional monomers may be used alone or in combination of two or more.

In the constituents of the crosslinked acrylic copolymer (A), if the proportion of the polyfunctional monomer is reduced, the shape of the crosslinked acrylic copolymer (A) is destroyed during the formation of the vinyl chloride resin. Therefore, the impact resistance does not appear, and when it is increased, the crosslinking density becomes excessive and it becomes difficult to obtain sufficient impact resistance.
0.1 to 20% by weight with respect to 9 to 80% by weight, preferably 99.7 to 92% by weight of a radical polymerizable monomer.
From 0.3 to 8% by weight.

When the proportion of the crosslinked acrylic copolymer (A) in the vinyl chloride resin obtained in the present invention decreases, the impact resistance of the molded article decreases, and when the proportion increases, the mechanical strength of the molded article decreases. Therefore, the amount is 2 to 40 parts by weight, preferably 4 to 1 part by weight, based on 100 parts by weight of vinyl chloride alone or vinyl chloride monomer containing vinyl chloride as a main component.
2 parts by weight.

The acrylic copolymer (B) used in the present invention is obtained by copolymerizing an alkyl (meth) acrylate (b) in the presence of the crosslinked acrylic copolymer (A).

The above alkyl (meth) acrylate (b)
Is used for the purpose of diffusing into and dissolving in a vinyl chloride matrix during molding to improve moldability and appearance of a molded article. To prevent the vinyl chloride resin obtained in the present invention from sticking during molding, the glass transition temperature of the homopolymer of alkyl (meth) acrylate (b) is limited to -10 ° C or higher. In addition, the glass transition temperature of a homopolymer of alkyl (meth) acrylate (b) is limited to less than 180 ° C. in consideration of the glass transition temperature of a polymer conventionally used industrially.

The above alkyl (meth) acrylate (b)
As, for example, methyl (meth) acrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate,
sec-butyl methacrylate, t-butyl (meth) acrylate, cumyl methacrylate, scrohexyl methacrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like.
They may be used alone or in combination of two or more.

When the proportion of the acrylic copolymer (B) in the vinyl chloride resin obtained in the present invention is small, the effect of improving the appearance and moldability of a molded article is not sufficient, and when it is large, moldability is poor. The amount of the alkyl (meth) acrylate (b) is 0.1 to 20 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the vinyl chloride monomer.

When the molecular weight of the acrylic copolymer (B) is small, the effect of improving the appearance and moldability of a molded article is not sufficient, and when the molecular weight is large, the moldability is poor, so that the weight average molecular weight is 50,000 to 5,000,000. And more preferably 200,000 to 2,000,000.

The acrylic copolymers (A) and (B)
The polymerization method is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method. )
In view of controlling the particle size of the latex, the emulsion polymerization method is preferred.

In the present invention, when synthesizing the acrylic copolymer, first, a radical polymerizable monomer and a polyfunctional monomer are copolymerized to form a core portion composed of a crosslinked acrylic copolymer (A). After formation, a shell portion composed of the acrylic copolymer (B) is formed by adding and polymerizing the alkyl (meth) acrylate (b) in the presence of the crosslinked acrylic copolymer (A), An acrylic copolymer having a two-layer structure having a core portion and a shell portion around the core portion is obtained.

In the above emulsion polymerization method, an emulsifying dispersant and a polymerization initiator are used. The emulsifying and dispersing agent is added for the purpose of improving the dispersion stability of the monomer used in the emulsion polymerization reaction in the emulsion and efficiently performing the polymerization, for example, an anionic surfactant and a nonionic surfactant. , Partially saponified polyvinyl alcohol, cellulosic dispersant,
Gelatin or the like is used. In particular, examples of the anionic surfactant include polyoxyethylene nonyl phenyl ether sulfate.

Examples of the polymerization initiator include water-soluble polymerization initiators such as potassium persulfate, ammonium persulfate, and hydrogen peroxide; organic peroxides such as benzoyl peroxide and lauroyl peroxide; azobisisobutyrate; Examples include azo-based polymerization initiators such as lonitrile.

In the above emulsion polymerization method, if necessary, a pH adjuster, an antioxidant and the like may be added.

The method of the emulsion polymerization is not particularly limited. For example, any method such as (1) batch polymerization, (2) monomer dropping, and (3) emulsion dropping may be employed. In order to obtain latex particles of the acrylic copolymer (B) having a two-layer structure of a core part / shell part, a monomer dropping method or an emulsion dropping method is preferable.

(1) In the batch polymerization method, for example, pure water, an emulsifying dispersant, a polymerization initiator, and a mixed monomer composed of the above-mentioned radical polymerizable monomer and polyfunctional monomer are placed in a jacketed polymerization reactor at a time. After the inside of the polymerization reactor was decompressed and oxygen was removed, nitrogen was blown and the pressure was returned to atmospheric pressure.The mixture was sufficiently emulsified by stirring under a nitrogen atmosphere. This is a method in which the temperature is raised to a temperature and a polymerization initiator is added to start a polymerization reaction.

(2) In the monomer dropping method, for example, pure water, an emulsifying dispersant and a polymerization initiator are put in a polymerization reactor with a jacket, and the inside of the polymerization reactor is depressurized to remove oxygen and then to nitrogen. In a nitrogen atmosphere in which the pressure is returned to the atmospheric pressure, the inside of the polymerization reactor is first heated to a predetermined temperature by a jacket, and the above-mentioned mixed monomer is dropped by a predetermined amount to carry out polymerization gradually.

(3) In the emulsion dripping method, for example, the above-mentioned mixed monomer, emulsifying dispersant and pure water are sufficiently emulsified by stirring to prepare an emulsifying monomer in advance, and then the pure water is introduced into a jacketed polymerization reactor. After the polymerization initiator was charged, the inside of the polymerization reactor was decompressed and oxygen was removed, and then the pressure was returned to the atmospheric pressure with nitrogen. The polymerization is carried out by elevating the temperature and dropping the above-mentioned emulsified monomer in a fixed amount. Furthermore, in the emulsion dropping method, if a method is used in which a part of the above-mentioned emulsifying monomer is added all at once in the early stage of polymerization (hereinafter referred to as a seed monomer) and then the remaining emulsifying monomer is dropped, the amount of the seed monomer can be changed. Therefore, the particle size of the produced latex can be easily controlled.

In order to form a two-layer structure composed of a core portion / shell portion on the acrylic copolymer (B) latex particles, it is preferable to use an emulsion dropping method in order to control the particle size. Specifically, first, a mixed emulsifying monomer composed of an alkyl (meth) acrylate (a) and a polyfunctional monomer is dropped in order to form a core layer, and a polymerization reaction is carried out to form a crosslinked acrylic copolymer (A). Synthesize latex particles. Next, in the presence of the above-mentioned crosslinked acrylic copolymer (A) latex particles, an emulsifying monomer of alkyl (meth) acrylate (b) for forming a shell layer is dropped, and the above crosslinked acrylic copolymer serving as a core layer is dropped. By copolymerizing with the polymer (A), a shell layer is formed on the surface of the copolymer (A) particles.

The formation of the shell layer may be carried out simultaneously with the synthesis of the core layer forming copolymer (A) particles and a series of polymerization steps, and once the core layer forming copolymer (A) particles are synthesized,
After the collection, polymerization may be performed by adding a shell layer-forming monomer again. However, in the latter case, it is preferable to newly add a polymerization initiator when forming the shell layer.

In the formation of the shell layer, it is preferable to control the polymerization temperature and to add a chain transfer agent in order to control the molecular weight of the acrylic copolymer (B).

The solid content of the acrylic copolymer (B) latex is not particularly limited, but is preferably 10 to 6 in consideration of the productivity of the latex and the stability of the polymerization reaction.
0% by weight is preferred.

The average particle diameter of the acrylic copolymer (B) latex particles is preferably 1 μm or less, since the impact resistance and tensile strength of the molded article decrease as the particle diameter increases, and the impact resistance decreases when the particle diameter is too small. Because there is
１1 μm is more preferable.

After the completion of the latex polymerization reaction, a protective colloid agent may be added to the acrylic copolymer (B) latex, if necessary, for the purpose of improving the mechanical stability of the latex. .

In the present invention, a vinyl chloride resin is obtained by graft copolymerizing a vinyl chloride monomer with the acrylic copolymer (B) latex. Although the graft copolymerization method is not particularly limited, for example, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a bulk polymerization method, and the like can be adopted, and among these, the suspension polymerization method is particularly preferable.

In the above suspension polymerization method, it is preferable to use a dispersant and an oil-soluble polymerization initiator. Further, a coagulant may be added to prevent the scale from adhering to the inner wall of the polymerization reactor during the polymerization.

The dispersant is an acrylic copolymer (B)
It is used for improving dispersion stability of latex and for efficiently performing graft copolymerization of a vinyl chloride monomer. Examples of the dispersant include poly (meth) acrylate, (meth) acrylate-alkyl acrylate copolymer, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, polyethylene glycol, polyvinyl acetate and partially saponified products thereof, gelatin,
Examples thereof include polyvinylpyrrolidone, starch, and maleic anhydride-styrene copolymer, and these may be used alone or in combination of two or more.

Examples of the radical polymerization initiator include, for example, lauroyl peroxide, t-butyl peroxypivalate, diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, t-butyl peroxy neodecanoate, α-cumene Organic peroxides such as luperoxy neodecanoate; 2,2-azobisisobutyronitrile, 2,2-azobis-2,4-
In addition to azo compounds such as dimethylvaleronitrile, redox-based polymerization initiators and the like can be mentioned.

In the above suspension polymerization method, if necessary, pH
Modifiers, antioxidants and the like.

The vinyl chloride monomer refers to a vinyl chloride monomer alone or a monomer containing vinyl chloride as a main component. In the case of a monomer containing vinyl chloride as a main component, a mixture of vinyl chloride and a monomer copolymerizable with the vinyl chloride is used. Examples of the monomer copolymerizable with vinyl chloride include, for example, a mixture of vinyl acetate, an alkyl (meth) acrylate other than the above, an alkyl vinyl ether, ethylene, vinyl fluoride, and maleimide, and these are used alone. Or two or more of them may be used in combination.

In the present invention, as a method for producing a vinyl chloride resin, for example, a polymerization reactor equipped with a stirrer and a jacket is charged with pure water, the acrylic copolymer (B) latex, a dispersant, and an oil. A soluble polymerization initiator, and
After adding a water-soluble thickener and, if necessary, a polymerization degree regulator, the air in the polymerization reactor is discharged by a vacuum pump, and further, vinyl chloride and, if necessary, polymerization under stirring conditions. After adding the degree-controlling agent, a method of heating with a jacket and graft-copolymerizing vinyl chloride may be mentioned.

The above vinyl chloride graft copolymerization reaction is carried out as follows:
It is possible to control the polymerization temperature in the polymerization reactor by adjusting the temperature with a jacket due to the exothermic reaction. After completion of the reaction, unreacted vinyl chloride is removed to obtain a slurry, which is then dehydrated and dried to obtain a vinyl chloride resin.

In the above-mentioned vinyl chloride-based resin, the degree of polymerization of the grafted vinyl chloride polymer portion is lowered, regardless of whether it is large or small.
2,000 is preferred, and more preferably 400 to 1.6.
00.

When molding the vinyl chloride resin,
If necessary, heat stabilizers, stabilizing aids, lubricants, processing aids, antioxidants, light stabilizers, fillers, pigments and the like may be added.

Examples of the heat stabilizer include dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin malate polymer, dibutyltin laurate, dibutyltin Organic tin stabilizers such as laurate polymers; lead stabilizers such as lead stearate, dibasic lead phosphite, and tribasic lead sulfate; calcium-zinc stabilizers; barium-zinc stabilizers; Cadmium stabilizers and the like can be mentioned.

Examples of the above-mentioned heat stabilizing aid include epoxidized soybean oil, epoxidized linseed oil, epoxidized tetrahydrophthalate, epoxidized polybutadiene, phosphate ester and the like. As the lubricant, for example,
Examples include montanic acid wax, paraffin wax, polyethylene wax, stearic acid, stearyl alcohol, butyl stearate and the like.

As the processing aid, for example, an acrylic processing aid which is an alkyl acrylate / alkyl methacrylate copolymer having a weight average molecular weight of 100,000 to 2,000,000 is used. For example, n-butyl acrylate / methyl methacrylate copolymer is used. Examples of the polymer include a 2-ethylhexyl acrylate / methyl methacrylate / butyl methacrylate copolymer.

Examples of the antioxidants include phenolic antioxidants. Examples of the light stabilizer include salicylic acid ester-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers; and hindered amine-based light stabilizers.

Examples of the filler include titanium oxide, calcium carbonate, talc and the like. Examples of the pigment include organic pigments such as azo-based, phthalocyanine-based, sulene-based and dye lake-based; oxide-based, molybdenum chromate-based, sulfide / selenide-based, and ferrocyanide-based inorganic pigments. No.

A plasticizer may be added to the vinyl chloride graft copolymer of the present invention for the purpose of improving the processability during molding. As the plasticizer, for example, dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate and the like are used.

The method for mixing the above-mentioned various additives with the above-mentioned vinyl chloride graft copolymer may be, for example, either a hot blend method or a cold blend method. Examples of the molding method include an extrusion molding method and an injection molding method. Any molding method, such as a calender molding method and a press molding method, can be used.

[0055]

Embodiments of the present invention will be described below. (Examples 1 to 8 and Comparative Examples 2 to 7) Preparation of Acrylic Copolymer A predetermined amount of pure water (ion-exchanged water), an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), and a core monomer For the percentages shown in the table,
n-butyl acrylate (indicated by n-BA in the table), 2
-Ethylhexyl acrylate (indicated by 2-EHA in the table), methyl methacrylate (indicated by MMA in the table) and styrene, and trimethylolpyropane triacrylate (indicated by TMPTA in the table) as a polyfunctional monomer The mixture was stirred to prepare an emulsified monomer for the core layer.

Separately, a predetermined amount of pure water (ion-exchanged water), an emulsifying dispersant (polyoxyethylene nonyl phenyl ether ammonium sulfate), and a monomer for shell, methyl methacrylate (in the table,
MMA), ethyl methacrylate (EMA in the table)
And n-butyl methacrylate (in the table, n-B
MA) was mixed and stirred to prepare an emulsion monomer for a shell layer.

On the other hand, a predetermined amount of pure water (ion-exchanged water) was charged into the polymerization reactor, and stirring was started. Next, the polymerization reactor was depressurized to deoxygenate the interior of the polymerization reactor, and then replaced by depressurization with nitrogen, and the polymerization reactor was heated to 70 ° C. Upon completion of the temperature increase, ammonium persulfate and 20% by weight of the above-mentioned emulsifying monomer for a core layer were charged all at once into a polymerization reactor as a seed monomer, and polymerization was started. Subsequently, after dropping the rest of the core layer emulsifying monomer,
The emulsifying monomer for the shell layer was dropped, and all the addition was completed for 3 hours. Further, after an aging time of 1 hour, the polymerization was terminated and the solid content concentration was about 30% by weight, and the particle size was 0.1 to 0.1%.
An acrylic copolymer latex of 2 μm was obtained.

Production of Vinyl Chloride Resin In a polymerization reactor equipped with a stirrer and a reflux condenser, pure water (ion-exchanged water), the above acrylic copolymer latex, a 3% by weight aqueous solution of partially saponified polyvinyl acetate, t- After butyl peroxy neodecanoate, and α-cumyl peroxy neodecanoate were charged at once, the air in the polymerization reaction vessel was discharged with a vacuum pump, and further, vinyl chloride was charged under stirring conditions. The polymerization was started at a polymerization temperature of 57 ° C. by controlling the jacket temperature. The completion of the reaction was confirmed by the internal pressure of the polymerization reaction vessel dropping to 6.0 kg / cm ² , and the reaction was stopped by cooling. Next, after removing unreacted vinyl chloride out of the system, the obtained slurry reaction product was dehydrated and dried to obtain a vinyl chloride resin (polymerization degree: 1,000).

Comparative Example 1 An acrylic copolymer latex was obtained in the same manner as in Example 1 except that no shell monomer was used, and then a vinyl chloride-based resin was obtained in the same manner as in Example 1. Was manufactured.

Comparative Example 8 A vinyl chloride resin was produced in the same manner as in Comparative Example 1. In the evaluation of the moldability and the appearance of the molded article described below, a resin obtained by adding 2 parts by weight of a commercially available acrylic processing aid to 100 parts by weight of a vinyl chloride resin was used.

The vinyl chloride monomer and acrylic copolymer (A) used in the production of the vinyl chloride resin
The amounts of (B) and (B) are shown in the table.

The following items were measured and evaluated for the acrylic copolymer (B) and the vinyl chloride resin obtained in the above Examples and Comparative Examples, and the results are shown in Tables 1 to 4.

(1) Weight Average Molecular Weight of Acrylic Copolymer (B) Part 1 g of a film obtained by drying the acrylic copolymer (B) latex is dissolved in 100 ml of tetrahydrofuran and filtered through a filter having a pore size of 1 μm. did. The weight average molecular weight of the uncrosslinked polyalkyl (meth) acrylate portion present in the filtrate was measured by Otsuka Electronics Co., Ltd. “light scattering photometer”.

(2) Impact resistance 100 parts by weight of the vinyl chloride resin, 0.5 part by weight of an organotin stabilizer and 1 part by weight of a montanic acid lubricant were mixed.
The resulting resin composition was kneaded with a roll kneader at a temperature of 200 ° C. for 3 minutes after wound around a roll, and then heated at a temperature of 200 ° C. and a pressure of 7
Press molding was performed at 5 kg / cm ² for 3 minutes to obtain a 3 mm thick vinyl chloride resin plate. The obtained plate was subjected to a Charpy impact test at 23 ° C. in accordance with JIS K7111, and a Charpy impact value was measured.

(3) Tensile test Using the same vinyl chloride resin plate as in (2),
A tensile test was performed at 23 ° C. in accordance with JIS K7113 to measure tensile strength.

(4) Evaluation of moldability 100 parts by weight of the vinyl chloride resin, 0.8 parts by weight of organotin stabilizer, 0.5 parts by weight of polyethylene lubricant, 0.2 parts by weight of stearic acid, and stear 0.5 parts by weight of calcium phosphate was mixed with a super mixer (Kawata, capacity 1
00 liters) and kneaded to obtain a resin composition. The obtained resin composition was supplied to a biaxial anisotropic extruder having a screw diameter of 50 mm ("BT-50" manufactured by Plastics Engineering Laboratory), and a 20-mm-diameter hard vinyl chloride tube was continuously extruded for 24 hours. In the continuous extrusion for 24 hours, the moldability of the resin is evaluated by the load on the screw of the extruder, and the load on the screw of the extruder is:
It was measured by measuring the power of a screw drive motor.

(5) Evaluation of Appearance of Molded Article In the continuous extrusion molding for 24 hours in (4), the inner and outer surfaces of the obtained rigid vinyl chloride pipe were visually observed, and from the start of molding,
The time until appearance defects such as "fading", "streaks" and "unevenness" were measured. In the continuous molding for 24 hours, those having no appearance defect at all are shown as ">2" in the table.
4 ".

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

[Table 3]

[0071]

[Table 4]

[0072]

The vinyl chloride resin of the present invention is as described above, and has an extremely excellent impact resistance, and contains stabilizers, lubricants, pigments and the like generally used in vinyl chloride resins. Thereby, molding can be performed with good fluidity, and a molded article having a good surface condition can be stably obtained in long-term continuous molding. Accordingly, the molded product is suitably used not only for pipes, outer walls, soundproof walls having irregular cross sections, etc., which require high impact resistance, but also for window frames, sashes, etc., which require good surface properties. You.

Claims (2)

[Claims] 1. The glass transition temperature of a homopolymer is -140 ° C.
The radical polymerizable monomer having an alkyl (meth) acrylate (a) as a main component having a temperature of not higher than 30 ° C.
9.9% by weight and 20 to 0.1% by weight of a polyfunctional monomer
Acrylic copolymers (A) 2 obtained by copolymerizing
In the presence of 40 parts by weight, an acrylic copolymer obtained by copolymerizing 0.1 to 20 parts by weight of an alkyl (meth) acrylate (b) having a glass transition temperature of -10 ° C or more and less than 180 ° C in the presence of 40 parts by weight. In the polymer (B), vinyl chloride alone or vinyl chloride monomer 100 containing vinyl chloride as a main component
A method for producing a vinyl chloride resin, comprising graft copolymerizing parts by weight. 2. The vinyl chloride resin according to claim 1, wherein the weight average molecular weight of the alkyl (meth) acrylate (b) copolymer portion in the acrylic copolymer (B) is 50,000 to 5,000,000. Production method.