JPH11106443A - Production of vinyl chloride graft resin and copolymer latex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process for a vinyl chloride graft resin that gives moldings of excellent mechanical strength and shock resistance. SOLUTION: In the production process for a vinyl chloride graft resin by grafting 99-70 wt.% of vinyl chloride monomer onto 1-30 wt.% of an acrylic copolymer latex, the acrylic copolymer latex is polymerized in a cylindrical polymerization tank in which the lower paddle blades 2 has a sweepback angle of 30-60 deg. at its top edges, the upper paddle blades 3 are set above the lower paddle blades 2 with a crossing angle of 30-90 deg. leading from the lower paddle blades 2 in the rotation direction and has the parts extending downward at its top edges and at least one of baffle plates 5 are arranged along the side wall face of the polymerization tank parallel to the rotary shaft axis extending from the upper part down to the lover part at a certain angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a vinyl chloride graft resin and a copolymer latex.

[0002]

2. Description of the Related Art Vinyl chloride resins are originally used in many applications as materials having excellent properties in mechanical strength, weather resistance and chemical resistance. However, when used for hard materials, they have a disadvantage of poor impact resistance, and various improvement methods have been proposed. In particular, for the use of hard vinyl chloride resins which require long-term weather resistance and impact resistance, for example, Japanese Patent Application Laid-Open No. 60-25813 discloses an acrylic copolymer comprising an alkyl (meth) acrylate and a polyfunctional monomer. A vinyl chloride-based graft resin in which vinyl chloride is graft-copolymerized with the coalescence is disclosed. However, a resin having sufficient impact resistance as a hard molded product has not been obtained.

[0003] When the above-mentioned elastic component is mixed into a vinyl chloride resin, the resulting composition generally has an improved impact resistance with an increase in the amount of the elastic component mixed therein. There is a tendency for mechanical strength such as strength and flexural modulus to decrease, and there is an industrial demand for improving mechanical strength while maintaining impact resistance. In addition, there is an industrial demand for a vinyl chloride-based resin capable of stably obtaining a molded product having a good surface condition even in long-term continuous molding.

As an example for improving the bending elastic modulus,
JP-A-61-195106 proposes a method of graft copolymerizing vinyl chloride to an acrylic copolymer of an alkyl (meth) acrylate, styrene and a polyfunctional monomer. However, although this method improves the mechanical strength of the vinyl chloride resin somewhat,
The glass transition temperature of a homopolymer such as styrene is about 100
C. is used as the copolymerization component, the flexibility of the elastic component is lost with an increase in the amount of styrene added, and the impact resistance of the obtained vinyl chloride resin tends to decrease. Therefore, at present, a resin having a sufficient balance between impact resistance and mechanical strength has not been obtained.

[0005] Further, it is desired that the latex of the copolymer used for various applications has high functionality. As a means for this purpose, research and development of particles having a hetero-phase structure have been carried out in order to introduce opposing functions into the particles. Have been done. Representative examples of the hetero-phase structure particles include core-shell type latex. For example, in Japanese Patent Publication No. 55-33765,
A latex obtained by performing a normal polymerization reaction is used as a seed particle, and a monomer different from the monomer used for the seed particle is newly added and graft copolymerization is performed on the seed particle. There has been proposed a method for producing a core-shell type latex having a shell portion of a heterogeneous polymer formed on the surface.

However, depending on the degree of polymerization of the seed particles and the polymer formed in the subsequent process or the affinity of the polymerization system for the solvent, the polymer formed in the subsequent process may be present inside the particles, or the core layer may be formed by the shell layer. A latex is obtained which is not completely covered and in which the polymer of the core layer is exposed on the surface. Also, if the affinity between the seed particles and the polymer formed in the subsequent process is good, phase mixing occurs,
If the intended heterophasic structure is not obtained or polymerization is carried out using a conventional polymerization apparatus with poor monomer dispersibility, the monomer added in the process of thickening the particles is not supplied to the seed particles and new particles are formed independently. However, there is still a problem that the intended core-shell structure cannot be obtained. Therefore,
There has been a demand for a method for stably producing a latex having a uniform and complete core-shell structure irrespective of the type of monomer used for the core-shell.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to obtain a vinyl chloride graft resin capable of obtaining a molded article having excellent impact resistance as compared with conventional vinyl chloride resins. And a method for producing a copolymer latex.

[0008]

The invention according to claim 1 (hereinafter referred to as the first invention) comprises 1 to 30% by weight of an acrylic copolymer latex containing vinyl chloride alone or vinyl chloride as a main component. In the method for producing a vinyl chloride graft resin obtained by graft copolymerizing 99 to 70% by weight of a vinyl chloride monomer, the acrylic copolymer latex has a glass transition temperature of a homopolymer of −140 ° C. or higher and 30 ° C. or higher.
(Meth) acrylate monomer (A)
To 100% by weight, and a radical polymerizable monomer (B) 0 copolymerizable with the (meth) acrylate monomer (A).
~ 100% by weight of the mixed monomer and 0.1 ~ 30% by weight of the polyfunctional monomer, and are obtained by copolymerizing the acrylic copolymer latex. A rotatable rotating shaft is vertically installed at the center of the polymerization tank, and a lower stage paddle blade disposed on the bottom of the polymerization tank close to the bottom wall of the polymerization tank has a retreat of 30 to 60 degrees at the tip. The upper paddle wing has an angle of 30 to 90 degrees ahead of the lower paddle wing in the rotation direction, and has a portion extending downward at the tip thereof. In addition, polymerization is performed using a polymerization tank in which at least one or more baffles are provided at intervals on the side wall surface of the polymerization tank from the upper part to the lower part along the direction of the rotation axis.

The invention according to claim 2 (hereinafter referred to as the second invention) is characterized in that, in the copolymerization of the acrylic copolymer latex, the power for stirring the polymerization tank is 0.2 to 2.5 kW / m.
It is characterized by ³ .

A third aspect of the invention (hereinafter referred to as a third aspect of the invention) is characterized in that the acrylic copolymer latex of the first aspect is changed to the following acrylic copolymer latex. The glass transition temperature of the homopolymer is -1
A copolymer obtained by copolymerizing a (meth) acrylate monomer (C) having a temperature of 40 ° C. or more and less than 30 ° C. and a polyfunctional monomer has a homopolymer having a glass transition temperature of 30 ° C. or more and 1
An acrylic copolymer latex obtained by graft copolymerizing a mixed monomer comprising a radical polymerizable monomer (D) having a temperature of 80 ° C. or lower and a polyfunctional monomer.

The invention according to a fourth aspect (hereinafter referred to as the fourth invention) is characterized in that the acrylic copolymer latex according to the first aspect is changed to the following acrylic copolymer latex. The glass transition temperature of the homopolymer is 30
The glass transition temperature of the homopolymer is −140 ° C. to 3 ° C. for the copolymer obtained by copolymerizing the radical polymerizable monomer (D) having a temperature of not lower than 180 ° C. and a polyfunctional monomer.
(Meth) acrylate monomer (C) having a temperature of less than 0 ° C,
And an acrylic copolymer latex obtained by graft copolymerizing a mixed monomer comprising a polyfunctional monomer and a polyfunctional monomer.

The invention according to claim 5 (hereinafter referred to as the fifth invention) provides a polymer obtained by copolymerizing 100 parts by weight of a radical polymerizable monomer and 0.1 to 30 parts by weight of a polyfunctional monomer. When graft copolymerizing a radical polymerizable monomer of a type different from the radical polymerizable monomer, copolymerization is performed using the polymerization tank according to claim 1.

Hereinafter, the manufacturing methods of the first and second inventions will be described. The vinyl chloride graft resin obtained in the first and second inventions is obtained by graft copolymerization of vinyl chloride alone or a vinyl chloride monomer containing vinyl chloride as a main component with an acrylic copolymer latex.

The (meth) acrylate monomer (A), which is a main component of the acrylic copolymer latex, is used for the purpose of improving the impact resistance of a vinyl chloride resin.
The glass transition temperature of the homopolymer is required to be less than 30 ° C. in order to require flexibility at room temperature, and the type is not particularly limited as long as it is less than 30 ° C. -140 in view of glass transition temperature
C. or higher is preferred.

The above (meth) acrylate monomer (A)
Examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl (meth) acrylate, isobutyl acrylate, sec-butyl acrylate, cumyl acrylate, n-hexyl (meth) acrylate, and 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-ethyl (meth) heptyl acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl acrylate, myristyl (meth) acrylate, palmityl ( Alkyl (meth) acrylates such as meth) acrylate and stearyl (meth) acrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, and the like; these may be used alone, or two or more kinds may be used. You may use together.

The glass transition temperature of the homopolymer of the (meth) acrylate monomer (A) having a glass transition temperature of -140 ° C. or more and less than 30 ° C. is described in “High Temperature” published by Baifukan, edited by The Society of Polymer Science, Japan. Based on “Molecular Data Handbook (Basic Edition)”.

The above (meth) acrylate monomer (A)
The radical polymerizable monomer (B) which can be copolymerized with (B) is added for the purpose of improving the mechanical strength, chemical resistance and moldability of the vinyl chloride resin, and the kind thereof is not particularly limited. For example, methyl methacrylate, ethyl Methacrylate, n
-Alkyl (meth) acrylates such as propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl (meth) acrylate, cumyl methacrylate, cyclohexyl methacrylate, palmityl acrylate, stearyl acrylate; 2-hydroxyethyl methacrylate; Polar group-containing vinyl monomers such as 2-acryloyloxyethyl phthalic acid; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene and p-chlorostyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; Examples thereof include vinyl esters such as vinyl and vinyl propionate, and these may be used alone or in combination of two or more.

The amount of the copolymerizable radical polymerizable monomer (B) added to the (meth) acrylate monomer (A) constituting the acrylic copolymer latex is as follows:
If the amount is too large, the flexibility of the latex is lost, and the grafting efficiency of a vinyl monomer containing vinyl chloride as a main component is lowered to lower the impact resistance, so that (meth) acrylate monomer (A) 51 to 100% by weight is used. To the copolymerizable radical polymerizable monomer (B) is preferably added in an amount of 0 to 49% by weight.

The above-mentioned polyfunctional monomer not only crosslinks the acrylic copolymer latex and improves the impact resistance of the vinyl chloride resin, but also promotes the coalescence of the copolymer latex particles during and after production. It is added for the purpose of making it difficult to wake up.

Examples of the polyfunctional monomer include, for example,
Di (meth) acrylate, tri (meth) acrylate and the like are used. Examples of the di (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, Examples include 1,6-hexanediol di (meth) acrylate and trimethylolpropane di (meth) acrylate. Examples of the tri (meth) acrylate include trimethylolpropane tri (meth) acrylate and ethylene oxide-modified trimethylolpropane. Tri (meth) acrylate, pentaerythritol tri (meth) acrylate and the like can be mentioned.

Further, other polyfunctional monomers other than those described above may be used. For example, pentaeristol tetra (meth) acrylate, dipentaeristol hexa (meth) acrylate, diallyl phthalate, diallyl maleate, diallyl fumarate And diallyl compounds such as diallyl succinate and triallyl isocyanurate; divinyl compounds such as divinylbenzene and butadiene; these may be used alone;
More than one species may be used in combination.

The above (meth) acrylate monomer (A)
The amount of the polyfunctional monomer added to the mixed monomer of the copolymerizable radical polymerizable monomer (B) and the copolymerizable radical polymerizable monomer (B) decreases when the particles are coalesced at the time of production and the core layer copolymer and the shell layer copolymer are reduced. Phase impact occurs and the impact resistance of the vinyl chloride resin decreases, and if it increases, it becomes difficult to obtain impact resistance due to excessive crosslinking density.
0.1 to 30 parts by weight is preferable with respect to 00 parts by weight,
0.3 to 10 parts by weight is more preferable.

As shown in FIG. 1, the polymerization tank used in the first invention has a rotatable rotary shaft 1 suspended from the center of a cylindrical polymerization tank 6, and the rotary shaft 1 is attached to the bottom of the polymerization tank. A lower paddle blade 2 arranged at the bottom of the tank in close proximity to the wall surface has 30
Has a receding angle α of ６０60 degrees, and the upper paddle blade 3 has a crossing angle β of 30 to 90 degrees ahead of the lower paddle blade 2 in the rotational direction above the lower paddle blade 2, And a portion 4 extending downward at the tip, and a polymerization tank 6
A polymerization tank characterized in that at least one or more baffle plates 5 are provided at intervals on the side wall surface from top to bottom along the direction of the rotation axis 1. The baffle 5 is
It is also possible to add cooling capacity by passing cooling water. Further, a jacket for heat exchange may be provided inside the polymerization tank.

In the second invention, when the polymerization is carried out in the polymerization tank, if the stirring power is too small, the monomer concentration of the polymerization system becomes non-uniform, and some of the particles are enlarged to form aggregates. In addition, the crosslinking point density in the latex becomes non-uniform, and the impact resistance of the vinyl chloride resin is reduced. On the other hand, if the particle size is too large, an excessive shearing force is applied to the generated polymer particles, and the particles are coalesced to generate aggregates. Therefore, the stirring power is preferably 0.2 to 2.5 kW / m ³ .

Next, the manufacturing method of the third invention will be described. The vinyl chloride graft resin obtained in the third invention is:
As in the first invention, the acrylic copolymer latex
It is obtained by graft copolymerization of vinyl chloride alone or a vinyl chloride monomer containing vinyl chloride as a main component. Further, the acrylic copolymer latex is used as a copolymer of a (meth) acrylate monomer (C) having a glass transition temperature of a homopolymer of −140 ° C. or more and less than 30 ° C. and a polyfunctional monomer. It is obtained by graft copolymerizing a mixed monomer comprising a radically polymerizable monomer (D) having a glass transition temperature of 30 ° C or higher and 180 ° C or lower and a polyfunctional monomer.

As the acrylic copolymer latex, the homopolymer has a glass transition temperature of -140 ° C. or higher and 30 or higher.
A copolymer composed of at least one kind of (meth) acrylate monomer (C) having a temperature lower than 100 ° C. and a polyfunctional monomer and having excellent flexibility at room temperature is used as a core layer, and a homopolymer glass is formed in a shell layer. At least one of the radically polymerizable monomers (D) having a transition temperature of 30 ° C or higher and 180 ° C or lower.
Latex having a two-layer structure formed of a copolymer having a high glass transition temperature and composed of a type and a polyfunctional monomer is used.

In the above-mentioned copolymer for forming the core layer, the (meth) acrylate monomer (C) used for the homopolymer has a glass transition temperature of less than 30 ° C. because it requires flexibility at room temperature. Although it is necessary, the type is not particularly limited as long as it is lower than 30 ° C., but in view of the glass transition temperature of a polymer generally used industrially, −140 is preferred.
C. or higher is preferred.

The above (meth) acrylate monomer (C)
As the (meth) acrylate monomer (A)
And the same.

In the copolymer forming the shell layer, the radical polymerizable monomer (D) used for the homopolymer is required to have low tackiness at a high temperature during molding, so that the homopolymer glass The transition temperature needs to be 30 ° C. or higher, and the type is not particularly limited as long as the temperature is 30 ° C. or higher, but is preferably 180 ° C. or lower in view of the glass transition temperature of a polymer generally used industrially.

Examples of the radical polymerizable monomer (D) include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl (meth) acrylate,
Alkyl (meth) acrylates such as cumyl methacrylate, cyclohexyl methacrylate, palmityl acrylate and stearyl acrylate; vinyl monomers containing polar groups such as 2-hydroxyethyl methacrylate, 2-acryloyloxyethyl phthalic acid, and vinylidene chloride; styrene, α-methyl Aromatic vinyl monomers such as styrene, p-methylstyrene, and p-chlorostyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate; These can be used in combination.

The glass transition temperature of the homopolymer of the radical polymerizable monomer (D) was determined according to "Polymer Data Handbook (Basic Edition)" published by Baifukan and edited by the Society of Polymer Science, Japan.

In the above-mentioned core layer copolymer, the amount of the polyfunctional monomer to be added is determined for the same reason as in the first invention.
The amount is preferably from 0.1 to 30 parts by weight, more preferably from 0.2 to 5 parts by weight, based on 100 parts by weight of the (meth) acrylate monomer (C).

In the above shell layer copolymer, the amount of the polyfunctional monomer is 0.3 to 30 parts by weight based on 100 parts by weight of the radical polymerizable monomer (D) for the same reason as in the first invention. Parts by weight, more preferably 0.5 to 8 parts by weight.

Examples of the polyfunctional monomer used in the core layer and the shell layer include the polyfunctional monomer used in the first invention.

If the weight fraction of the shell layer copolymer with respect to the core layer copolymer forming the acrylic copolymer latex is small, a molded article having a good surface condition cannot be obtained stably, and if the weight fraction is large, it is difficult to obtain a molded article. 5 to 60% by weight is preferable because impact strength is reduced.

In the third invention as well, in the production of the acrylic copolymer latex, a latex having a uniform core-shell structure can be obtained by performing polymerization using the polymerization tank described above. It is possible to obtain a latex having a uniform particle size distribution and a vinyl chloride-based graft resin capable of stably obtaining a molded product having a good surface condition even in continuous molding for a long period of time.

The polymerization tank has the same structure as in the first invention, and the stirring power is the same as in the second invention.

Next, the manufacturing method of the fourth invention will be described. The vinyl chloride graft resin obtained in the fourth invention is:
As in the first invention, the acrylic copolymer latex
It is obtained by graft copolymerization of vinyl chloride alone or a vinyl chloride monomer containing vinyl chloride as a main component. Further, the acrylic copolymer latex is a homopolymer obtained by adding a homopolymer to a copolymer comprising a radical polymerizable monomer (D) having a glass transition temperature of 30 ° C. or more and 180 ° C. or less and a polyfunctional monomer. Has a glass transition temperature of -140.
It is obtained by graft copolymerizing a mixed monomer comprising a (meth) acrylate monomer (C) having a temperature of not lower than 30 ° C. and lower than 30 ° C. and a polyfunctional monomer.

As the radical polymerizable monomer (D), the (meth) acrylate monomer (C) and the polyfunctional monomer constituting the acrylic copolymer, the same components as in the third invention are used.

In the above acrylic copolymer, a copolymer comprising a radically polymerizable monomer (D) and a polyfunctional monomer is used as a core layer and comprises a (meth) acrylate monomer (C) and a polyfunctional monomer. It has a two-layer structure in which the copolymer is a shell layer.

In the fourth invention, the core layer and the shell layer 2
Although the layer structure is formed from a copolymer opposite to that of the third invention, the use of this acrylic copolymer latex improves the mechanical strength without impairing the impact resistance of the vinyl chloride resin. Can be.

In the above-mentioned core layer copolymer, the amount of the polyfunctional monomer to be added is determined for the same reason as in the third invention.
For 100 parts by weight of the radical polymerizable monomer (D),
0.1 to 30 parts by weight is preferable, and 0.3 to 5 parts by weight is more preferable.

In the above shell layer copolymer, the amount of the polyfunctional monomer is 0.1 to 30 parts by weight based on 100 parts by weight of the (meth) acrylate monomer (C) for the same reason as in the third invention. Parts by weight are preferred, and 0.3 to 8
Parts by weight are more preferred.

If the weight fraction of the shell layer copolymer with respect to the core layer copolymer forming the acrylic copolymer latex is too small, sufficient tensile strength of the vinyl chloride resin cannot be obtained, and if it is large, the impact resistance will be high. 5-7
0% by weight is preferred.

Also in the fourth invention, in the production of the acrylic copolymer latex, the polymerization is carried out by using the above-mentioned polymerization tank having the specific stirring blades.
A latex having a uniform core-shell structure is obtained,
A latex having a uniform particle size and a narrow particle size distribution can be obtained, and a vinyl chloride graft resin stably exhibiting high mechanical strength and impact resistance can be produced.

The above-mentioned polymerization tank having a specific stirring blade is defined as
It has the same configuration as that of the first invention, and the stirring power is also the same as that of the second invention.

In the production methods of the first to fourth inventions, the method for obtaining the acrylic copolymer latex is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method. Emulsion polymerization is preferred from the viewpoints of impact resistance and control of latex particle size.

In the above emulsion polymerization method, an emulsifying dispersant and a polymerization initiator are used. The emulsifying dispersant is added for the purpose of improving the dispersion stability of the mixed monomer in the emulsion and efficiently performing the polymerization. For example, an anionic surfactant, a nonionic surfactant, and a partially saponified polyether are used. Examples include vinyl acetate, cellulose dispersants, and gelatin. Particularly preferred are, for example, anionic surfactants such as polyoxyethylene nonylphenyl ether sulfate.

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

In the emulsion polymerization method, a pH adjuster, an antioxidant and the like may be added as required.

The emulsion polymerization method includes a batch polymerization method, a monomer dropping method, and an emulsion dropping method depending on the difference in the monomer addition method, but is not particularly limited.
The batch polymerization method is, for example, collectively adding pure water, an emulsifying dispersant, a mixed monomer comprising the acrylic monomer and the polyfunctional monomer into a jacketed polymerization reactor, and removing oxygen and pressurizing by a nitrogen stream. Under these conditions, the emulsion is sufficiently emulsified by stirring, the inside of the vessel is heated to a predetermined temperature by a jacket, and then a polymerization initiator is added to carry out polymerization.

In the monomer dropping method, for example, pure water, an emulsifying dispersant, and a polymerization initiator are charged into a polymerization reactor equipped with a jacket, and the reaction is first carried out under a condition of oxygen removal and pressurization under a nitrogen stream. Is brought to a predetermined temperature by means of a jacket, and then the above-mentioned mixed monomer is added dropwise in a fixed amount to gradually polymerize.

The emulsion dripping method is, 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 pure water and a polymerization initiator are put into a jacketed polymerization reactor,
Under the conditions of oxygen removal and pressurization under a nitrogen stream,
First, after the inside of the vessel is heated to a predetermined temperature by a jacket, polymerization is carried out by dropping the above-mentioned emulsified monomer by a predetermined amount. Further, in the emulsion dropping method, if a method of adding a part of the above-mentioned emulsified monomer at a time in the early stage of polymerization (hereinafter referred to as a seed monomer) and then dropping the remaining emulsified monomer is used, by changing the amount of the seed monomer, The particle size of the produced latex can be easily controlled.

The resin solid content of the latex obtained after the polymerization reaction of the acrylic copolymer latex is not particularly limited. However, in consideration of the productivity of the latex and the stability of the polymerization reaction, it is preferably 10 to 60%. % By weight is preferred.

As the average particle diameter of the acrylic copolymer latex increases, both the impact resistance and tensile strength of the molded article decrease, and as the average particle diameter decreases, the impact resistance slightly decreases.
10-1000 nm is preferred.

The above acrylic copolymer latex includes:
For the purpose of improving the mechanical stability of the latex emulsion, a protective colloid agent may be added as needed after the completion of the latex polymerization reaction.

In the first to fourth inventions, when the proportion of the acrylic copolymer latex in the vinyl chloride graft resin is small, it is difficult to obtain sufficient impact resistance, and when it is large, the bending strength and tensile strength are large. Etc., the mechanical strength of the vinyl chloride-based graft resin is limited to 1 to 30% by weight, preferably 4 to 20% by weight.
It is.

The method for graft copolymerizing vinyl chloride alone or a vinyl chloride monomer containing vinyl chloride as a main component with the acrylic copolymer latex is not particularly limited. For example, a suspension polymerization method, Examples thereof include an emulsion polymerization method, a solution polymerization method, and a bulk polymerization method. In order to carry out the present invention advantageously, a suspension polymerization method is preferable.

The monomer containing vinyl chloride as a main component is
It means a mixture of 50% by weight or more of vinyl chloride and a copolymerizable vinyl monomer, and the copolymerizable monomer is a commonly known vinyl monomer, for example, vinyl acetate, alkyl (meth) acrylate , Alkyl vinyl ether, ethylene, vinyl fluoride, maleimide and the like, and at least one of them can be used.

When graft copolymerizing vinyl chloride,
A coagulant may be added to the acrylic copolymer latex for the purpose of reducing the scale adhering in the polymerization tank during the polymerization.

In the above suspension polymerization method, a dispersant and an oil-soluble polymerization initiator are used. As a dispersant used for suspension polymerization,
The acrylic copolymer latex is added for the purpose of improving the dispersion stability of the latex and efficiently performing graft polymerization of vinyl chloride. For example, poly (meth) acrylate, (meth) acrylate-alkyl acrylate copolymer is added. Polymers, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, polyethylene glycol, polyvinyl acetate and partially saponified products thereof, gelatin, polyvinylpyrrolidone, starch, maleic anhydride-styrene copolymer and the like, which are used alone Well,
Two or more kinds may be used in combination.

Among the above oil-soluble polymerization initiators, radical polymerization initiators are preferably used because they are advantageous for graft copolymerization. Examples thereof include lauroyl peroxide, t-butylperoxypivalate, and diisopropylperoxydioxide. Organic peroxides such as carbonate, dioctyl peroxy dicarbonate, t-butyl peroxy neodecanoate, α-cumyl peroxy neodecanoate, 2,2-azobisisobutyronitrile, 2,2
And azo compounds such as -azobis-2,4-dimethylvaleronitrile.

In the above suspension polymerization method, a pH adjuster, an antioxidant and the like may be added as required.

The method for producing the first to fourth invention resins is, for example, that pure water,
The acrylic copolymer latex, dispersant, oil-soluble polymerization initiator and water-soluble thickener, the polymerization degree regulator is charged if necessary, and then the air in the polymerization vessel is discharged by a vacuum pump, After charging vinyl chloride and, if necessary, other vinyl monomers under stirring conditions, a method in which the inside of the reaction vessel is heated with a jacket to carry out graft copolymerization of vinyl chloride.

Since the above graft copolymerization of vinyl chloride is an exothermic reaction, the temperature in the reaction vessel, that is, the polymerization temperature can be controlled by changing the jacket temperature.
After the completion of the reaction, unreacted vinyl chloride is removed to form a slurry, which is then dehydrated and dried to produce a vinyl chloride graft resin.

If the degree of polymerization of polyvinyl chloride in the vinyl chloride graft resin is too small, it is difficult to obtain sufficient moldability of the molded article. Therefore, the average degree of polymerization is preferably 300 to 2,000, more preferably 400 to 2,000. 1600
It is.

The vinyl chloride graft resin obtained by the production method of the first to fourth inventions may be used, if necessary, at the time of molding, as a heat stabilizer, a stabilizing aid, a lubricant, a processing aid, an antioxidant, Light stabilizers, fillers, pigments and the like may be added and used.

Examples of the heat stabilizer include dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, dibutyltin maleate, dibutyltin maleate polymer, dioctyltin malate, dioctyltin maleate 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 stabilizer, barium-zinc stabilizer, barium- Cadmium stabilizers and the like can be mentioned.

Examples of the above stabilizing aid include epoxidized soybean oil, epoxidized linseed oil epoxidized tetrahydrophthalate, epoxidized polybutadiene, phosphate ester and the like.

Examples of the above lubricant include montanic acid wax, paraffin wax, polyethylene wax,
Stearic acid, stearyl alcohol, butyl stearate and the like can be mentioned.

Examples of the processing aid include 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, and specific examples thereof include n-butyl acrylate / Methyl methacrylate copolymer, 2-ethylhexyl acrylate / methyl methacrylate / butyl methacrylate copolymer and the like can be mentioned.

The antioxidants include, for example, phenolic antioxidants.

Examples of the light stabilizer include a salicylic acid ester-based, benzophenone-based, benzotriazole-based, cyanoacrylate-based ultraviolet absorber, and a hindered amine-based light stabilizer. Examples of the filler include calcium carbonate and talc.

Examples of the above-mentioned pigments include organic pigments such as azo-based, phthalocyanine-based, sulene-based and dye lake-based pigments.
Oxide-based, molybdenum chromate-based, sulfide / selenide-based, ferrocyanide-based inorganic pigments and the like can be mentioned.

Further, a plasticizer may be added to the vinyl chloride graft resin for the purpose of improving the processability at the time of molding. For example, dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl Adipate and the like.

The method for mixing the above additives with the above vinyl chloride graft resin may be a method using hot blending or a method using cold blending. Examples of the molding method include extrusion molding, injection molding, and injection molding. A calender molding method, a press molding method and the like can be mentioned.

Next, a method for producing the copolymer latex of the fifth invention will be described. The copolymer latex obtained in the fifth invention is a polymer obtained by copolymerizing 100 parts by weight of a radical polymerizable monomer and 0.1 to 30 parts by weight of a polyfunctional monomer, and a polymer different from the radical polymerizable monomer. A method for producing a copolymer latex having a core-shell type two-layer structure, wherein the radical polymerization polymerizable monomer is graft-copolymerized using the polymerization tank according to claim 1.

The radical polymerizable monomers constituting the core layer copolymer and the shell layer copolymer are not particularly limited in type unless they have completely the same composition.
Depending on the properties expected of the latex, one type or two or more types may be used in combination. As the radical polymerizable monomer, the (meth) acrylate monomers (A) and (C) and the radical polymerizable monomer (D)
The same components as described above are used.

Examples of the radical polymerizable monomer further include polar group-containing vinyl monomers such as 2-acryloyloxyethylphthalic acid, acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, and maleic anhydride; ethylene and the like. Olefins; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene and p-chlorostyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate; Diene monomers such as butadiene; and vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride.

The radical polymerizable monomer forming the core layer copolymer is provided with a crosslinked structure in the core layer to prevent swelling of the shell layer monomer into the core layer during graft polymerization of the shell layer. A polyfunctional monomer is added for the purpose of suppressing the mixing and phase transition of both shell phases. Therefore, in order to obtain a latex having a complete core-shell structure, addition of a polyfunctional monomer to the core layer is an essential element.

The polyfunctional monomer includes the first
The polyfunctional monomer used in the present invention can be exemplified.

The amount of the polyfunctional monomer to be added to the radical polymerizable monomer forming the core layer copolymer is not particularly limited, but if the amount is small, phase mixing of the core layer copolymer and the shell layer copolymer occurs. And it is difficult to obtain a complete core-shell structure. If the amount is too large, the originally intended properties provided by the radically polymerizable monomer are lost due to excessive crosslinking density. Reactive monomer 0.1-3
0 parts by weight is preferable, and 0.3 to 10 parts by weight is more preferable.

A polyfunctional monomer may be added to the radical polymerizable monomer forming the shell layer copolymer for the purpose of improving the physical properties and polymerization stability of the latex. Examples of the polyfunctional monomer to be added to the radical polymerizable monomer forming the shell layer copolymer include those similar to the above polyfunctional monomer.

The weight fraction of the shell layer copolymer in the copolymer latex is not particularly limited, but if it is small, the thickness of the shell layer becomes thin and it becomes difficult to obtain a complete core-shell structure. If it is too much, the properties of the core layer are lost, so the content is preferably 5 to 95% by weight.

Also in the fifth invention, in the production of the copolymer latex, the polymerization is carried out using the polymerization tank, whereby the dispersibility of the added monomer in the polymerization system is increased, and the polymerization is carried out in the polymerization process of the shell layer. The formation of new particles by the added monomer alone is suppressed, and a copolymer latex having a uniform core-shell structure and a uniform particle size can be obtained.

For the same reason as in the second invention, the polymerization is carried out with stirring power of 0.1 to 1.8 kW / m ^3, whereby the crosslink point density in the particles is uniform, the gel fraction is high, and A latex with a narrow size distribution is obtained.

In the production method of the fifth invention, the method for obtaining the above copolymer latex is not particularly limited, and includes the same method as in the first invention, and an emulsion polymerization method is preferred.

In the third to fifth inventions, any of the above three monomer addition methods may be used to form the core layer copolymer and the shell layer copolymer. The above-mentioned mixed monomer or emulsified monomer for forming a coalescence is added or dropped at a time, and a polymerization reaction is carried out to synthesize core layer latex particles. Subsequently, the above mixed monomer or emulsified monomer for newly forming a shell layer copolymer is added or dropped at a time, and copolymerization with the core layer particles is performed to form a shell layer on the surface of the core layer particles. Things.

The formation of the shell layer may be performed in the same polymerization step as the formation of the core layer, or the core layer may be synthesized and
After recovery, a monomer may be added again to polymerize and form the shell layer. However, in the latter case, it is preferable to newly add the polymerization initiator again at the time of polymerization of the shell layer.

It is preferable.

The above emulsion polymerization is carried out in the same manner as in the first invention. The same emulsifying dispersant and polymerization initiator as used in the first invention are used. Further, as in the first invention, a pH adjuster and an antioxidant may be added.

In the third to fifth inventions, any of the three monomer addition methods mentioned in the first invention may be used to form the core layer copolymer and the shell layer copolymer. First, the above-mentioned mixed monomer or emulsified monomer for forming the core layer copolymer is added or dropped at once, and a polymerization reaction is carried out to synthesize core layer latex particles. Subsequently, the above mixed monomer or emulsified monomer for newly forming a shell layer copolymer is added or dropped at a time, and copolymerization with the core layer particles is performed to form a shell layer on the surface of the core layer particles. Things.

The formation of the shell layer may be carried out in the same polymerization step as the formation of the core layer, or the synthesis of the core layer may be carried out.
After recovery, a monomer may be added again to polymerize and form the shell layer. However, in the latter case, it is preferable to newly add the polymerization initiator again at the time of polymerization of the shell layer.

The resin solid content of the latex obtained after the polymerization reaction of the copolymer latex is not particularly limited. However, in view of the productivity of the latex and the stability of the polymerization reaction, 10 to 60% by weight is considered. Is preferred.

The average particle size of the copolymer latex is as follows:
Although not particularly limited, the thickness is preferably from 10 to 1000 nm in order to stably perform polymerization while maintaining the dispersion stability of the latex.

A protective colloid agent may be added to the copolymer latex after the end of the latex polymerization reaction, if necessary, for the purpose of improving the mechanical stability of the latex emulsion.

[0097]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1, 4 to 9, Comparative Examples 4 to 8) (Preparation of Copolymer Latex Containing Acrylic Polymer) According to the composition tables of Tables 1 and 2, a predetermined amount of pure water and an emulsifying dispersant ( Polyoxyethylene nonylphenyl ether ammonium sulfate), mixed monomer [n-butyl acrylate (hereinafter referred to as n-BA), 2-ethylhexyl acrylate (hereinafter referred to as 2-EHA), methyl methacrylate (hereinafter referred to as MMA), or styrene ] And a polyfunctional monomer [trimethylolpropane triacrylate (hereinafter referred to as TMPTA)] was mixed and stirred to prepare an emulsified monomer.

On the other hand, pure water was charged into a polymerization tank having an internal volume of 22 m ³ shown in FIG. 1 and oxygen in the container was replaced with nitrogen. Then, the temperature of the polymerization tank was raised to 70 ° C. The polymerization tank has a stirring power of 1.0 to 1.2 kW / m ³ from the start of the temperature increase to the end of the polymerization.
And stirred. Ammonium persulfate (hereinafter referred to as APS) and 20% by weight of the emulsified monomer were collectively charged as a seed monomer into the polymerization tank in which the temperature was raised, and polymerization was started. Subsequently, the remainder of the emulsified monomer was added dropwise.
The dripping of all the emulsified monomers was completed in 3 hours, and then 1
After a ripening period of time, the polymerization was terminated to obtain an acrylic polymer latex (hereinafter referred to as latex) having a solid content of about 30% by weight. The final filling rate of the produced latex in the polymerization tank was about 90% by volume.

(Preparation of vinyl chloride graft resin) Then, pure water,
The above latex, a 3% aqueous solution of partially saponified polyvinyl acetate, t-butyl peroxy neodecanoate, and α-cumyl peroxy neodecanoate were added all at once.
The air in the reactor was discharged by a vacuum pump, and vinyl chloride was further added under stirring conditions, and then polymerization was started at a polymerization temperature of 57 ° C by controlling the jacket temperature. After about 5 hours, the pressure in the reactor was reduced to 6.0 kg / cm ² to confirm the completion of the reaction and stopped. Thereafter, unreacted vinyl chloride monomer was removed, and further dehydration drying was performed to obtain a vinyl chloride graft resin having an average degree of polymerization of about 1,000.

Example 2 A vinyl chloride graft resin was obtained in the same manner as in Example 1 according to the composition table shown in Table 1. However,
The only difference is that, during the polymerization, stirring was performed with a stirring power of 0.4 to 0.5 kW / m ³ .

Example 3 A vinyl chloride graft resin was obtained in the same manner as in Example 1 according to the composition table shown in Table 1. However,
During the polymerization, the only difference is that the stirring was carried out with a stirring power of 1.8 to 2.0 kW / m ³ .

Comparative Example 1 A vinyl chloride graft resin was obtained in the same manner as in Example 1 according to the composition table shown in Table 2. However,
The only difference is that the polymerization was carried out using a polymerization tank having an internal volume of 19 m ³ shown in FIG. The polymerization tank 6 shown in FIG. 2 is different from the polymerization tank of FIG. 1 in the configuration of the paddle blades 7, and two paddle blades 7 of three blades are provided apart from the bottom wall surface.

Comparative Example 2 A vinyl chloride graft resin was obtained in the same manner as in Example 1 according to the composition table shown in Table 2. However,
The only difference is that, during the polymerization, stirring was carried out with a stirring power of 0.10 to 0.12 kW / m ³ .

Comparative Example 3 According to the composition table in Table 2, a vinyl chloride resin was obtained in the same manner as in Example 1. However, during polymerization,
The only difference is that the stirring was performed with a stirring power of 2.8 to 2.9 kW / m ³ .

(Examples 10 to 13 and Comparative Examples 12 and 13) (Preparation of Copolymer Latex Containing Acrylic Polymer) According to the composition table of Table 3, first, a predetermined amount of a core layer copolymer was formed. Pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), n-BA and / or 2-EHA and TMPTA were mixed and stirred to prepare an emulsifying monomer. Separately, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonyl phenyl ether ammonium sulfate), MMA and / or styrene and T
MPTA was mixed and stirred to prepare an emulsion monomer.

On the other hand, pure water was put into a polymerization tank having an internal volume of 22 m ³ shown in FIG. 1 and oxygen in the vessel was replaced with nitrogen. Then, the temperature of the polymerization tank was raised to 70 ° C. under stirring. 25% by weight of the above-mentioned emulsified monomer prepared for forming the APS and the core layer copolymer was collectively charged as a seed monomer into the polymerization tank in which the temperature was raised, and polymerization was started. Subsequently, the rest of the emulsified monomer prepared for forming the core layer copolymer was dropped. As soon as the dropping of the monomer for the core layer copolymer was completed, the dropping of the monomer for the shell layer copolymer was started. After the dropping of all emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated to obtain an acrylic polymer latex (hereinafter referred to as a latex) having a solid content of about 30% by weight. Was. The final filling rate of the produced latex in the polymerization tank was about 90% by volume.

(Preparation of vinyl chloride graft resin) Next, a vinyl chloride graft resin having an average degree of polymerization of about 1000 was obtained in the same manner as in Example 1 except that the above latex was used.

Comparative Example 9 According to the composition table in Table 3, a vinyl chloride graft resin was synthesized in the same manner as in Example 10. The only difference is that the polymerization was carried out using a polymerization tank having an internal volume of 19 m ³ shown in FIG.

Comparative Example 10 A vinyl chloride graft resin was synthesized in the same manner as in Example 10 according to the composition table shown in Table 3.
The only difference is that the polymerization was performed without the core layer monomer.

(Comparative Example 11) A vinyl chloride graft resin was synthesized in the same manner as in Example 10 according to the composition table in Table 3.
The only difference is that the polymerization was performed without the shell layer monomer.

(Examples 14 to 17, Comparative Examples 17 and 18) (Preparation of Copolymer Latex Containing Acrylic Polymer) According to the composition table in Table 4, a predetermined amount of pure water was used for forming a core layer copolymer. , Emulsifying dispersant (polyoxyethylene nonyl phenyl ether ammonium sulfate), M
Mixing and stirring TMPTA with MA and / or styrene,
An emulsion monomer was prepared. Separately, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), n-BA, 2-EHA and TMPTA are mixed and stirred for forming a shell layer copolymer, and the emulsified monomer is mixed. Was prepared.

On the other hand, except that the above-mentioned core layer monomer and shell layer monomer were used in the polymerization tank having an internal volume of 22 m ³ shown in FIG. 1, the solid content concentration was about 30% by weight. An acrylic polymer latex (hereinafter referred to as latex) was obtained. The final filling rate of the produced latex in the polymerization tank was about 90% by volume.

(Preparation of vinyl chloride graft resin) Next, a vinyl chloride graft resin having an average degree of polymerization of about 1000 was obtained in the same manner as in Example 1 except that the above latex was used.

(Comparative Example 14) A vinyl chloride graft resin was synthesized in the same manner as in Example 14 according to the composition table in Table 4.
The only difference is that the polymerization was carried out using a polymerization tank having an internal volume of 19 m ³ shown in FIG.

Comparative Example 15 A vinyl chloride graft resin was synthesized in the same manner as in Example 14 according to the composition table shown in Table 4.
The only difference is that the polymerization was performed without the core layer monomer.

(Comparative Example 16) A vinyl chloride graft resin was synthesized in the same manner as in Example 14, according to the composition table shown in Table 4.
The only difference is that the polymerization was performed without the shell layer monomer.

(Examples 18 to 21, Comparative Examples 21 to 23) (Preparation of Copolymer Latex) According to the composition tables of Tables 5 and 6, a predetermined amount of pure water and emulsified dispersion were used for forming a core layer copolymer. An emulsifying monomer was prepared by mixing and stirring the agent (polyoxyethylene nonylphenyl ether ammonium sulfate) and the core layer monomer. Separately, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), and a shell layer monomer were mixed and stirred to prepare an emulsion monomer for forming a shell layer copolymer.

On the other hand, pure water was placed in a polymerization tank having an internal volume of 22 m ³ shown in FIG. 1, oxygen in the vessel was replaced with nitrogen, and then the temperature of the polymerization tank was raised to 70 ° C. under stirring. 25% by weight of the above-mentioned emulsified monomer prepared for forming the APS and the core layer copolymer was collectively charged as a seed monomer into the polymerization tank in which the temperature was raised, and polymerization was started. Subsequently, the rest of the emulsified monomer prepared for forming the core layer copolymer was dropped. As soon as the dropping of the monomer for the core layer copolymer was completed, the dropping of the monomer for the shell layer copolymer was started. Dropping of all the emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated to obtain a copolymer latex (hereinafter referred to as latex) having a solid content of about 30% by weight. .

(Preparation of Vinyl Chloride Resin) Next, the above latex was mixed with a vinyl chloride resin having an average degree of polymerization of about 1000 according to the composition tables in Tables 5 and 6.

(Comparative Examples 19 and 20) According to the composition table in Table 6, a vinyl chloride graft resin was synthesized in the same manner as in Example 18. The only difference is that the polymerization was carried out using a polymerization tank having an internal volume of 19 m ³ shown in FIG.

The evaluation items and evaluation methods were carried out by the following methods.

[Latex particle diameter and standard deviation] The median diameter measured by a laser diffraction particle size distribution meter (manufactured by Horiba, Ltd.) is shown. The standard deviation was determined from the particle size distribution obtained by the measurement. [Aggregate fraction] Latex 1 obtained in Examples and Comparative Examples
00 g was filtered through a 300 mesh, and the dry weight of the aggregate remaining on the mesh was measured (referred to as w ₁ g). Next, the latex that passed through the 300 mesh was dried and the dry weight was measured (w ₂ g). The amount of aggregate generated during the polymerization was determined according to the following equation. Aggregate fraction (%) = [w ₁ / (w ₁ + w ₂ )] × 100

[Gel Fraction] The latexes obtained in Examples and Comparative Examples were dried, and about 1 g of the dried solid matter was accurately weighed (referred to as w ₃ g) and immersed in 300 ml of toluene for 48 hours. Thereafter, the mixture was filtered through a mesh of 300, the dry weight of the gel remaining on the mesh was measured (w ₄ g), and the gel fraction was determined according to the following equation.
Gel fraction (%) = (w ₄ / w ₃ ) × 100

[Charpy impact value] JIS K7111
A Charpy impact test was performed in accordance with. The sample was prepared by mixing a resin composition obtained by mixing 0.5 parts of an organic tin stabilizer and 1.0 part of a montanic acid lubricant with respect to 100 parts by weight of a vinyl chloride-based graft resin, and then kneading the roll at 200 ° C. for 3 minutes, 20
It was prepared from a 3 mm thick press plate obtained by press molding at 0 ° C. for 3 minutes. The measurement temperature is 23 ° C.

[Tensile strength] A tensile strength test was performed according to JIS K7113. The same sample as the press plate used in the above Charpy impact test was used as the sample. The measurement temperature is 23 ° C.

[Evaluation of Appearance of Molded Article] Examples 10 to 13
Vinyl chloride graft resin 1 obtained in Comparative Examples 9 to 13
0.8 parts by weight of an organic tin stabilizer, 0.5 parts by weight of a polyethylene lubricant, 0.2 parts by weight of stearic acid, 0.5 parts by weight of calcium stearate, and 3.0 parts by weight of an acrylic processing aid per 00 parts by weight Add the supermixer (100
L, manufactured by Kawata Corporation) to obtain a vinyl chloride resin composition. The obtained vinyl chloride resin composition was treated with a diameter of 5
The mixture was supplied to a 0 mm biaxially different direction extruder (trade name "BT-50" manufactured by Plastics Engineering Laboratory Co., Ltd.), and a 20 mm diameter vinyl chloride resin tube was continuously molded for 24 hours. The inner and outer surfaces of the obtained rigid PVC pipe were visually observed, and 2
When the surface condition of the tube was good over 4 hours, it was evaluated as ○, and when appearance defects such as blur, streak and unevenness occurred were evaluated as ×.

[Observation of latex core-shell structure]
An aqueous solution of a salt was added to the latex obtained in Examples 18 to 21 and Comparative Examples 19 to 23 for coagulation, followed by dehydration, washing and drying to obtain a resin. After embedding the obtained resin in an epoxy resin and dyeing it with osmium oxide or ruthenium oxide, a sample slice of about 80 nm was cut with an ultramicrotome, and the latex particle cross-sectional structure was observed with a transmission electron microscope. Examples 18 and 19 and Comparative Examples 18 and 19
In Example 2, butadiene in the core layer was preferentially dyed.
In 0, 21 and Comparative Examples 20 to 22, butyl acrylate of the shell layer is preferentially dyed. As a result of the observation, those in which a complete core-shell structure was formed were evaluated as ○, phase mixed,
A sample having an imperfect core-shell structure such as uneven distribution of two layers was evaluated as x.

[0129]

[Table 1]

[0130]

[Table 2]

[0131]

[Table 3]

[0132]

[Table 4]

[0133]

[Table 5]

[0134]

[Table 6]

[0135]

The method for producing the vinyl chloride graft resin of the present invention is as described above, and the obtained vinyl chloride resin has a good balance of both impact resistance and tensile strength. By blending ordinary lubricants, stabilizers, etc. used in molding, molding can be performed with good fluidity, and building materials and irregular cross-sections that require high impact resistance and tensile strength by utilizing the above characteristics It is suitably used not only for applications such as a soundproof wall having the above, but also for window frames, sashes and the like which require good formability. Further, the copolymer latex of the present invention is used for applications other than the above-mentioned vinyl chloride-based graft resin, such as plastic modifiers, paints, adhesives, adhesives for tires, binders for tire cords, coated papers, textile processing applications, and the like. Can be applied.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a polymerization tank used in Examples.

FIG. 2 is a partially cutaway perspective view of a polymerization tank having two-stage paddle blades used in Comparative Examples 1, 2, 6, 11, and 16.

[Explanation of symbols]

1 rotating shaft of stirring blade, 2 lower paddle blade, 3 upper paddle blade, 4 extended flat plate section, 5 baffle plate, 6 polymerization tank, 7 2-stage paddle blade, receding angle of α lower paddle blade tip, β upper paddle blade and lower stage Crossing angle with paddle wing

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshinobu Suenaga 4560 Kaiseicho, Shinnanyo-shi, Yamaguchi Prefecture Inside (72) Inventor Yasuhiro Kawaguchi 4560 Kaiseicho, Shinnanyo-shi, Yamaguchi Tokuyama Sekisui Industry Co., Ltd. 72) Inventor Seiji Tawaraya 4560 Kaiseicho, Shinnanyo City, Yamaguchi Prefecture Tokuyama Sekisui Industry Co., Ltd.

Claims (5)

[Claims] 1. Acrylic copolymer latex 1 to 30
In a method for producing a vinyl chloride graft resin in which 99 to 70% by weight of vinyl chloride alone or vinyl chloride as a main component is graft-copolymerized, the acrylic copolymer latex is A (meth) acrylate monomer (A) having a glass transition temperature of −140 ° C. or more and less than 30 ° C. and 51 to 100% by weight, and a radical polymerizable polymerizable with the (meth) acrylate monomer (A). 0 to 49% by weight of monomer (B)
100 parts by weight of a mixed monomer and 0.1 of a polyfunctional monomer.
When the acrylic copolymer latex is copolymerized, a rotatable rotating shaft is vertically provided at the center of the cylindrical polymerization tank, A lower paddle wing arranged on the bottom of the polymerization tank close to the bottom wall of the polymerization tank on the rotation axis has a receding angle of 30 to 60 degrees at the tip,
An upper portion of the lower paddle blade has a crossing angle of 30 to 90 degrees ahead of the lower paddle blade in the rotation direction with respect to the lower paddle blade, and has a portion extending downward at the tip thereof, and a polymerization tank. A method for producing a vinyl chloride-based graft resin, comprising polymerizing using a polymerization tank in which at least one or more baffles extending along the direction of the rotation axis from the upper side to the lower side are spaced apart from each other on the side wall surface. . 2. In the copolymerization of the acrylic copolymer latex, a stirring power of a polymerization tank is set to 0.2 to 2.5 kW.
/ M ^{3. The} method for producing a vinyl chloride graft resin according to claim 1, wherein 3. A method for producing a vinyl chloride graft resin, wherein the acrylic copolymer latex according to claim 1 is changed to the following acrylic copolymer latex. Glass transition temperature of homopolymer is -140 ° C or higher 3
(Meth) acrylate monomer (C) having a temperature of less than 0 ° C,
And a copolymer obtained by copolymerizing a polyfunctional monomer and a radical polymerizable monomer (D) having a homopolymer having a glass transition temperature of 30 ° C. or more and 180 ° C. or less, and a mixed monomer comprising a polyfunctional monomer. Acrylic copolymer latex obtained by graft copolymerization. 4. A method for producing a vinyl chloride graft resin, wherein the acrylic copolymer latex according to claim 1 is changed to the following acrylic copolymer latex. The glass transition temperature of the homopolymer is 30 ° C. or more and 180
(Meth) acrylate monomer having a glass transition temperature of −140 ° C. or more and less than 30 ° C. to a copolymer obtained by copolymerizing a radical polymerizable monomer (D) having a temperature of not more than 100 ° C. and a polyfunctional monomer. (C) and an acrylic copolymer latex obtained by graft copolymerizing a mixed monomer comprising a polyfunctional monomer. 5. A polymer obtained by copolymerizing 100 parts by weight of a radical polymerizable monomer and 0.1 to 30 parts by weight of a polyfunctional monomer is grafted with a radical polymerizable monomer different from the radical polymerizable monomer. A process for producing a copolymer latex having a core-shell type two-layer structure, wherein the copolymerization is carried out using the polymerization tank according to claim 1.