JPH09110945A - Vinyl chloride resin and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinyl chloride resin capable of giving a molding which has sufficient impact resistance not only at ordinary temp. but at 0 deg.C or lower temps. and has a high strength at room temp. SOLUTION: This resin is obtained by graft-copolymerizing 1-30wt.% copolymer (A) with 99-70wt.% vinyl chloride. The copolymer (A) is obtained by graft- copolymerizing 30-95wt.% copolymer obtained from 100 pts.wt. one or more free radical-polymerizable monomers each giving a homopolymer having a glass transition temp. of -60 deg.C lower and 0-30 pts.wt. polyfunctional monomer with 5-70wt.% monomer mixture comprising 100 pts.wt. one or more (meth) acrylates each giving a homopolymer having a glass transition temp. of -55 deg.C or higher and 0.1-30 pts.wt. polyfunctional monomer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vinyl chloride resin having excellent impact resistance and a method for producing the same.

[0002]

2. Description of the Related Art Vinyl chloride resins have hitherto been used in many applications as materials having excellent impact resistance, weather resistance and chemical resistance. However, such a vinyl chloride resin has a drawback that it is inferior in impact resistance when used for hard materials, and various improvement methods have been proposed. Particularly, as a resin suitable for applications requiring impact resistance and weather resistance, a vinyl chloride resin obtained by graft-copolymerizing an acrylic copolymer with vinyl chloride (JP-A-60-255).
No. 813) has been proposed.

Further, in such an acrylic copolymer,
As an example of using a graft copolymer, when synthesizing such a vinyl chloride resin, the glass transition of the homopolymer to the acrylic polymer is carried out for the purpose of reducing the scale attached to the inner surface of the polymerization reactor. A method (Japanese Patent Publication No. 5-43731) using a graft-copolymerized monomer having a temperature of 80 ° C. or higher is proposed.

However, the molded article using the vinyl chloride resin obtained by such a method has improved impact resistance at room temperature as compared with ordinary hard vinyl chloride, but at a low temperature of 0 ° C. or lower. In, the impact resistance performance is remarkably reduced, and the application is limited in cold regions.

[0005]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a vinyl chloride product which has sufficient impact resistance not only at room temperature but also at a low temperature of 0 ° C. or less and has high strength at room temperature. The purpose is to provide a resin.

[0006]

Means for Solving the Problems The gist of the present invention is to produce, in the production of vinyl chloride resin, one or more radical polymerizable monomers whose homopolymer has a glass transition temperature of −60 ° C. or lower. The core copolymer (A-1) is prepared by reacting parts by weight with 0 to 30 parts by weight of a polyfunctional monomer.
30 to 95% by weight of the above core copolymer (A-1)
In addition, 100 parts by weight of one or two or more (meth) acrylates having a glass transition temperature of a homopolymer of −55 ° C. or higher and 0.1 to 30 parts by weight of a polyfunctional monomer (A-). 2) Graft copolymerization of 5 to 70% by weight to obtain a core / shell type copolymer (A), and thereafter, 1 to 30% by weight of the core / shell type copolymer (A) and vinyl chloride ( B) 99 to 70% by weight is graft-copolymerized.

The gist of the present invention also lies in the vinyl chloride resin itself obtained by the above method. Hereinafter, the present invention will be described in detail.

In the present invention, first, 100 parts by weight of one or more radical-polymerizable monomers having a glass transition temperature of the homopolymer of -60 ° C. or less and 100 parts by weight of a polyfunctional monomer are used.
~ 30 parts by weight is reacted to obtain the core copolymer (A-1).

The radical polymerizable monomer used for obtaining the core copolymer (A-1) has a homopolymer glass transition temperature of -60 ° C or lower. If it exceeds −60 ° C., rubber elasticity cannot be exhibited at a low temperature, so the range is limited.

The homopolymer has a glass transition temperature of -60.
The radical-polymerizable monomer having a temperature of ℃ or less is not particularly limited, and examples thereof include dienes such as butadiene, isoprene, 2-ethylbutadiene, and 2-propylbutadiene; alkenes such as ethylene, 1-octene, and 2-methylpropylene; n-heptyl acrylate, n-octyl acrylate, 2-methylheptyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, 2
Alkyl acrylates such as -methyloctyl acrylate, 2-ethylheptyl acrylate, n-decyl acrylate, 2-methylnonyl acrylate, 2-ethyloctyl acrylate; n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n- Examples thereof include vinyl ethers such as heptyl vinyl ether and 2-ethylhexyl vinyl ether, and 4-decylstyrene. These can be used alone or in combination of two or more kinds.

The polyfunctional monomer used for obtaining the core copolymer (A-1) crosslinks the core copolymer (A-1) to form particles of the core copolymer (A-1). It is added for the purpose of making it difficult to cause coalescence and further improving the impact resistance of the obtained vinyl chloride resin.

The polyfunctional monomer is not particularly limited, and examples thereof include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
Triethylene glycol di (meth) acrylate, 1,
Di (meth) acrylates such as 6-hexanediol di (meth) acrylate and trimethylolpropane di (meth) acrylate; trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate Tri (meth) acrylates such as (meth) acrylate; pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, diallyl phthalate, diallyl malate, diallyl fumarate, diallyl succinate, triallyl isocyanurate, etc. Diallyl compounds or triallyl compounds; divinyl compounds such as divinylbenzene and butadiene, and the like, which may be used alone or in combination of two or more kinds. Kill.

The amount of the polyfunctional monomer added to the radical-polymerizable monomer whose glass transition temperature of the homopolymer forming the core copolymer (A-1) is -60 ° C. or lower is the homopolymer. Glass transition temperature of -60 ℃
The amount of the polyfunctional monomer is 0 to 30 parts by weight with respect to 100 parts by weight of the following radically polymerizable monomer. If it exceeds 30 parts by weight, impact resistance becomes difficult to be obtained due to an increase in crosslink density, so the content is limited to the above range. Preferably 0
-5 parts by weight.

In the present invention, 30% to 95% by weight of the above core copolymer (A-1) is then added to one of the (meth) acrylates whose homopolymer has a glass transition temperature of -55 ° C or higher, or Mixed monomer (A-2) 5 consisting of 100 parts by weight of two or more kinds and 0.1 to 30 parts by weight of a polyfunctional monomer
Graft copolymerization of about 70 wt% is performed to obtain a core-shell type copolymer (A).

The mixed monomer (A-2) is (meth)
It consists of an acrylate and a polyfunctional monomer. The (meth) acrylate has a homopolymer glass transition temperature of −55 ° C. or higher. If the temperature is lower than −55 ° C., a waxy substance bleeds out on the surface of the obtained molded product of vinyl chloride resin, and the surface becomes sticky or sticky, impairing the appearance of the molded product and contaminating the contacting substance. Therefore, it is limited to the above range.

The glass transition temperature of the above homopolymer is -5.
The (meth) acrylate monomer having a temperature of 5 ° C. or higher is not particularly limited, and examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth). ) Acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-heptyl methacrylate, n-octyl methacrylate, 2 -Methylheptyl methacrylate, 2
-Ethylhexyl methacrylate, n-nonyl methacrylate, 2-methyloctyl methacrylate, 2-ethylheptyl methacrylate, n-decyl methacrylate, 2-methylnonyl methacrylate, 2-ethyloctyl methacrylate, lauryl (meth) acrylate,
Myristyl (meth) acrylate, palmityl (meth)
Alkyl (meth) acrylates such as acrylates and stearyl (meth) acrylates; polar group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylates and 2-hydroxypropyl (meth) acrylates; Alternatively, two or more kinds can be used in combination.

The polyfunctional monomer used for producing the mixed monomer (A-2) is added for the purpose of improving the impact resistance of the resulting vinyl chloride resin. The polyfunctional monomer is not particularly limited, and the same ones as those exemplified as the polyfunctional monomer used for obtaining the core copolymer (A-1) can be used.

The glass transition temperature of the above homopolymer is -55.
The addition amount of the polyfunctional monomer with respect to the (meth) acrylate monomer which is not less than 0 ° C. is 0.
It is 1 to 30 parts by weight. If the amount is less than 0.1 parts by weight, it is difficult to obtain the impact resistance of the vinyl chloride resin obtained with a decrease in the crosslinking density, and if it exceeds 30 parts by weight,
Since the impact resistance becomes difficult to be obtained due to the excessive crosslinking density, it is limited to the above range. Preferably it is 0.5 to 8 parts by weight.

In the present invention, the above core copolymer (A
-1) 30 to 95% by weight of the mixed monomer (A-
2) Graft copolymerization of 5 to 70% by weight to obtain a core-shell type copolymer (A).

When the amount of the core copolymer (A-1) is less than 30% by weight, sufficient impact resistance cannot be obtained at low temperature,
If it exceeds 95% by weight, stickiness appears on the surface of the molded product, so the content is limited to the above range.

The graft copolymerization method for obtaining the above core / shell copolymer (A) is not particularly limited.
For example, an emulsion polymerization method, a suspension polymerization method, and the like can be mentioned, but the emulsion polymerization method is preferable because the impact resistance is excellent.

The core-shell type copolymer (A) obtained by the above method is prepared by first synthesizing a core copolymer having a remarkably low glass transition temperature, and forming a shell copolymer having a high glass transition temperature on the outer portion thereof. Can be obtained. In the above emulsion polymerization method, an emulsion dispersant and a polymerization initiator can be 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. The emulsifying dispersant is not particularly limited, and examples thereof include anionic surfactants, nonionic surfactants, partially saponified polyvinyl acetate, cellulose dispersants, and gelatin.

Examples of the above-mentioned anionic surfactant include polyoxyethylene nonylphenyl ether sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name "HITENOL N-").
08 ") and the like. Examples of the polymerization initiator include water-soluble polymerization initiators such as potassium persulfate, ammonium persulfate, and hydrogen peroxide solution; organic peroxides such as benzoyl peroxide and lauroyl peroxide; azobisisobutyronitrile and the like. Azo-based initiators and the like.

In the above emulsion polymerization method, a pH adjusting agent, an antioxidant and the like may be added if necessary. The emulsion polymerization method is roughly classified into three methods, that is, a batch polymerization method and a monomer dropping method and an emulsion dropping method, depending on the difference in the monomer addition method, but it is not particularly limited. The batch polymerization method, for example, in a polymerization reactor with a jacket, pure water, an emulsifying dispersant,
In this method, a polymerization initiator and the above mixed monomer are added all at once, and the mixture is sufficiently emulsified by stirring under the conditions of removing oxygen by a nitrogen stream and pressurizing and then heating the inside of the vessel with a jacket to perform polymerization.

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 oxygen removal and pressurization under a nitrogen stream are carried out. Is heated by a jacket, and then the above mixed monomer is added dropwise in a constant amount to gradually polymerize.

The emulsion dropping method is, for example,
The mixed monomer, the emulsifying dispersant, and the pure water are sufficiently emulsified by stirring to adjust the emulsified monomer in advance, and then pure water and the polymerization initiator are put in the jacketed polymerization reactor,
Under the conditions of oxygen removal and pressurization under a nitrogen stream,
First, the inside of the vessel is heated by a jacket, and then the above-mentioned emulsified monomer is added dropwise by a fixed amount to polymerize.

In order to form the core-shell type copolymer (A), any of the above-mentioned three monomer addition methods may be used, and the method is as follows: first, the above-mentioned mixing for forming the core copolymer. Monomers or emulsified monomers are added or dropped all at once, and a polymerization reaction is performed to synthesize core particles. Subsequently, the above mixed monomer or emulsion monomer for newly forming a shell copolymer is added or dropped all at once, and copolymerized with the core particles to form a shell portion on the surface of the core particles.

The formation of the shell portion may be carried out in the same polymerization process as the synthesis of the core particles, or after the core particles are synthesized and recovered, the monomer may be added again to polymerize and form the shell portion. . However, in the latter case, it is necessary to newly add the above-mentioned polymerization initiator when the shell portion is polymerized.

The particle diameter of the core copolymer (A-1) is 0.01 to 1 μm in order to develop impact resistance.
m is preferable.

In the present invention, thereafter, 1 to 30% by weight of the core / shell copolymer (A) and 99 to 70% by weight of vinyl chloride (B) are graft-copolymerized. If the proportion of the core / shell copolymer (A) is less than 1% by weight, it becomes difficult to obtain sufficient impact resistance, and if it exceeds 30% by weight, mechanical strength such as bending strength and tensile strength is increased. Is low, and is therefore limited to the above range. Preferably 4 to
It is 20% by weight.

In the present invention, the method of graft copolymerization for obtaining the vinyl chloride resin is not particularly limited, and examples thereof include suspension polymerization method, emulsion polymerization method, solution polymerization method and bulk polymerization method. However, the suspension polymerization method is preferred in order to carry out the present invention advantageously. In the suspension polymerization method, a dispersant and an oil-soluble polymerization initiator are used.

The dispersant is added for the purpose of improving the dispersion stability of the core-shell copolymer (A) and efficiently carrying out the graft polymerization of vinyl chloride. The dispersant is not particularly limited, and examples thereof include methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, polyvinyl alcohol and partially saponified products thereof, gelatin, polyvinylpyrrolidone, starch, maleic anhydride-styrene copolymer, and the like. They can be used alone or in combination of two or more.

As the above-mentioned oil-soluble polymerization initiator, a radical polymerization initiator is preferably used because it is advantageous for graft copolymerization. The radical polymerization initiator is not particularly limited, and examples thereof include lauroyl peroxide,
t-butyl peroxypivalate, diisopropyl peroxy dicarbonate, dioctyl peroxy dicarbonate, t-butyl peroxy neodecanoate, α-
Organic peroxides such as cumyl peroxyneodecanoate; 2,2-azobisisobutyronitrile, 2,2
-Azo compounds such as azobis-2,4-dimethylvaleronitrile and the like.

Further, in the above suspension polymerization method, a pH adjusting agent, an antioxidant and the like may be added if necessary.

Specific examples of the method for producing the vinyl chloride resin of the present invention include, for example, pure water, the above core / shell copolymer (A), a dispersant, and an oil in a reaction vessel equipped with a stirrer and a jacket. Soluble polymerization initiator and water-soluble thickener,
If necessary, add a polymerization degree regulator, etc., then evacuate the air in the polymerization vessel with a vacuum pump, and further add vinyl chloride and other vinyl monomers as necessary under stirring conditions, and then add the reaction vessel. Examples include a method of heating the inside with a jacket to perform graft copolymerization of vinyl chloride.

Since the graft copolymerization of vinyl chloride is an exothermic reaction, the polymerization temperature in the reaction vessel can be controlled by changing the jacket temperature. After completion of the reaction, vinyl chloride resin can be obtained by removing unreacted vinyl chloride to form a slurry and then dehydrating and drying.

If the degree of polymerization of polyvinyl chloride in the vinyl chloride resin is small, it is difficult to obtain sufficient moldability of the molded product, and therefore, it is preferably 300 to 2000, more preferably 400 to 1400.

The vinyl chloride resin obtained by the production method of the present invention contains a heat stabilizer, a stabilizing aid, a lubricant, a processing aid, an antioxidant, a light stabilizer, and a filling agent, if necessary, during molding. Agent,
A pigment or the like may be added.

The heat stabilizer is not particularly limited and includes, for example, dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin malate polymer, dibutyltin. Organic tin stabilizers such as laurate and dibutyltin laurate polymer; lead stearate, dibasic lead phosphite,
Lead stabilizers such as tribasic lead sulfate; calcium-zinc stabilizers, barium-zinc stabilizers, barium-cadmium stabilizers and the like.

The above-mentioned stabilizing aid is not particularly limited,
Examples thereof include epoxidized soybean oil, epoxidized linseed bean oil, epoxidized tetrahydrophthalate, epoxidized polybutadiene, and phosphoric acid ester.

The lubricant is not particularly limited, and examples thereof include montanic acid wax, paraffin wax, polyethylene wax, stearic acid, stearyl alcohol, and butyl stearate.

The processing aid is not particularly limited, and examples thereof 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 above antioxidant is not particularly limited,
Examples include phenolic antioxidants. The light stabilizer is not particularly limited, for example, salicylic acid ester-based, benzophenone-based, benzotriazole-based,
Examples thereof include cyanoacrylate-based ultraviolet absorbers; hindered amine-based light stabilizers, and the like.

The filler is not particularly limited, and examples thereof include calcium carbonate and talc. The pigment is not particularly limited, and examples thereof include azo-based, phthalocyanine-based, slene-based, dye lake-based and other organic pigments, oxide-based, molybdenum chromate-based, sulfide / selenide-based, ferrocyanide-based, and the like. Examples thereof include inorganic pigments.

A plasticizer may be added to the above vinyl chloride resin for the purpose of improving the processability during molding. Examples of such a plasticizer include dibutyl phthalate and di-2-ethylhexyl. Phthalate, di-2-
Ethylhexyl adipate and the like can be mentioned.

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

[0047]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Examples 1 to 14 and Comparative Examples 1 to 9 According to the blending composition shown in Table 1, each vinyl chloride resin was obtained by the following operation procedure. (Preparation of Copolymer Latex Containing Acrylic Polymer) Pure water was added to a reaction vessel equipped with a stirrer and a reflux condenser.
After adding ammonium persulfate (APS) and replacing oxygen in the container with nitrogen, the reaction container was heated to 65 ° C. under stirring conditions.
The temperature rose. For forming the core copolymer, a predetermined amount of pure water, an emulsifying dispersant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name "Hitenol N-08"), 2-ethylhexyl acrylate (2-EHA), trimethylolpropane tri. Acrylate (TMP-A) was mixed and stirred to prepare an emulsified monomer. Separately, for forming a shell copolymer, a predetermined amount of pure water, an emulsifying dispersant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name "Hitenol N-08"), n-butyl acrylate (n-BA), TMP-A was mixed and stirred to prepare an emulsified monomer.

The emulsified monomer prepared for forming the core copolymer was dropped into the reactor whose temperature had been raised to start the polymerization. As soon as the dropping of the core copolymer monomer was completed, the dropping of the shell copolymer monomer was started. The dropping of all the emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was completed and the solid content concentration was 30% by weight.
Obtained a latex.

(Production of Vinyl Chloride Resin) Next, in a reaction vessel equipped with a stirrer and a jacket, pure water, the above latex, and partially saponified polyvinyl acetate (Kuraray Co., Ltd., trade name "Clam Poval L-8"). 3% aqueous solution (hereinafter "3
% PVA aqueous solution "), t-butylperoxyneodecanoate (BPOND), α-cumylperoxyneodecanoate (QPOND) and a flocculant are added all at once, and then the air in the polymerization vessel is blown with a vacuum pump. After discharging and further adding vinyl chloride under stirring conditions, the vinyl chloride was uniformly mixed by stirring for 30 minutes, and the polymerization was started at a polymerization temperature of 57 ° C. by controlling the jacket temperature.

When the pressure inside the reactor dropped to 7 kg / cm ² , it was confirmed that the reaction was completed, and the reaction was stopped. Then, unreacted vinyl chloride monomer was removed, and dehydration drying was performed to obtain a vinyl chloride resin having a vinyl chloride polymerization degree of 1000 in the vinyl chloride resin.

The evaluation items and evaluation methods were as shown below. (Impact resistance) An Izod impact test was conducted in accordance with JIS K7110. The measurement temperature was −10 ° C. (Tensile Strength) A tensile strength test was performed according to JIS K7113. The measurement temperature was 23 ° C. The results are shown in Table 1.

[0052]

[Table 1]

[0053]

Since the vinyl chloride resin of the present invention has the above-mentioned constitution, it has impact resistance even at a low temperature of 0 ° C. or lower,
Extremely excellent tensile strength. By incorporating the usual lubricants, stabilizers, pigments, etc. used in the molding process of vinyl chloride resin, the molding process can be performed with good fluidity, and by utilizing the above characteristics, high impact resistance and tensile strength in cold regions can be obtained. Not only for applications such as outer walls and soundproof walls that require strength,
It can be suitably used for window frames, sashes and the like that require good moldability.

Claims (2)

[Claims] 1. The homopolymer has a glass transition temperature of −60 ° C.
100 to 100 parts by weight of one or more radical-polymerizable monomers which are the following, and 30 to 95% by weight of a copolymer (A-1) consisting of 0 to 30 parts by weight of a polyfunctional monomer, Glass transition temperature is -55 ° C or higher (meta)
100 parts by weight of one or more acrylates, and
1 to 30% by weight of a copolymer (A) obtained by graft copolymerizing 5 to 70% by weight of a mixed monomer (A-2) consisting of 0.1 to 30 parts by weight of a polyfunctional monomer, and vinyl chloride (B) 9
A vinyl chloride resin characterized by being graft-copolymerized with 9 to 70% by weight. 2. The glass transition temperature of the homopolymer is −60 ° C.
The core copolymer (A-1) is obtained by reacting 100 parts by weight of one or more of the following radically polymerizable monomers with 0 to 30 parts by weight of a polyfunctional monomer, and the core copolymer is obtained. (A-1) 30 to 95% by weight, 100 parts by weight of one or more (meth) acrylates having a glass transition temperature of a homopolymer of −55 ° C. or more, and 100 parts by weight of a polyfunctional monomer. 30 parts by weight of mixed monomer (A-2) 5
To 70% by weight is graft-copolymerized to obtain a core / shell type copolymer (A), and thereafter, 1 to 30% by weight of the core / shell type copolymer (A) and vinyl chloride (B) 99. ~
A method for producing a vinyl chloride resin, which comprises graft-copolymerizing with 70% by weight.