JP3093106B2 - Vinyl chloride resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin having excellent impact resistance and mechanical strength.

[0002]

2. Description of the Related Art Vinyl chloride resins have been used in many applications as materials having excellent mechanical strength, weather resistance, chemical resistance, etc., but have drawbacks in impact resistance.
Various improved methods have been proposed. For example, a method for producing a vinyl chloride resin excellent in impact resistance and weather resistance by graft copolymerizing vinyl chloride to an acrylic copolymer has been reported (Japanese Patent Application Laid-Open (JP-A) No. 2002-122568). No. 60-255813).

[0003]

However, the vinyl chloride resin obtained by the above-mentioned production method has a problem that the mechanical strength such as tensile strength is reduced as the impact resistance is improved.

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide a vinyl chloride resin having excellent impact resistance and mechanical strength.

[0005]

The vinyl chloride resin of the present invention can be obtained by graft copolymerizing vinyl chloride to an acrylic copolymer latex. In this case, the acrylic copolymer used in the present invention is obtained. The combined latex is (A)
It is obtained by graft-copolymerizing a mixed monomer composed of a vinyl monomer having a glass transition temperature of a homopolymer of −20 ° C. or higher and a polyfunctional monomer (B) to an acrylic copolymer.

The vinyl monomer (A) includes, for example, methyl (meth) acrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl (meth) acrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate,
t-butyl (meth) acrylate, n-hexyl methacrylate, cyclohexyl (meth) acrylate, lauryl acrylate, myristyl (meth) acrylate,
Palmityl (meth) acrylate, stearyl (meth)
Alkyl (meth) acrylates such as acrylate, 2-
Examples include polar group-containing vinyl monomers such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl methacrylate, and 2-acryloyloxyethyl phthalic acid, styrene monomers such as styrene and α-methylstyrene, and acrylonitrile. Two or more types can be used in combination.

The polyfunctional monomer (B) makes it difficult for particles to coalesce by crosslinking the polymer grafted on the acrylic copolymer, and furthermore, makes the resulting vinyl chloride resin have an impact resistance. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, diallyl phthalate, diallyl maleate, trimethylolpropane di (meth) acrylate, Trimethylolpropane-based polyfunctional (meth) acrylates such as methylolpropane tri (meth) acrylate and ethylene oxide modified trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hex (Meth) pentaerythritol-based polyfunctional (meth) acrylates such as acrylate and the like, which may be used singly or in combinations of two or more.

The glass transition temperature of the above homopolymer is -2.
If the amount of the polyfunctional monomer (B) is less than 100 ° C. with respect to 100 parts by weight of the vinyl monomer (A) at 0 ° C. or higher, it is difficult to obtain the impact resistance of the obtained vinyl chloride resin. Since it is difficult to obtain both properties and tensile strength, the amount is 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight.

When the proportion of the above-mentioned mixed monomer in the above-mentioned acrylic copolymer latex is small, the tensile strength of the obtained vinyl chloride resin is difficult to obtain, and when it is too large, it is difficult to obtain impact resistance. It is 1 to 50% by weight, preferably 5 to 25% by weight.

The acrylic copolymer used in the production of the above acrylic copolymer latex is an acrylic copolymer containing, as a main component, an alkyl (meth) acrylate having a glass transition temperature of (C) a homopolymer of less than -20 ° C. It is obtained by copolymerizing a monomer and (B) a polyfunctional monomer.

When the proportion of the acrylic copolymer in the acrylic copolymer latex is small, the impact resistance of the obtained vinyl chloride resin is difficult to obtain, and when the proportion is large, sufficient tensile strength is obtained. Is difficult to obtain, so 50 to 99% by weight, preferably 75 to 95% by weight
It is.

The above alkyl (meth) acrylate (C)
Examples include, for example, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n
-Octyl (meth) acrylate, isooctyl acrylate, n-nonyl (meth) acrylate, isononyl acrylate, n-decyl (meth) acrylate, lauryl methacrylate, and the like. These may be used alone or in combination of two or more. Can be done.

The above alkyl (meth) acrylate (C)
Is preferably 75% by weight or more, since the smaller the proportion in the acrylic monomer, the lower the impact resistance of the obtained vinyl chloride resin becomes.

The acrylic monomer may contain another vinyl monomer copolymerizable with the alkyl (meth) acrylate (C). For example, the acrylic copolymer may have a glass transition temperature. The above-mentioned vinyl monomer (A) is suitable for arbitrarily adjusting, and these can be used alone or in combination of two or more.

The proportion of the vinyl monomer (A) in the acrylic monomer is 25% by weight, because if the ratio is too large, it becomes difficult to obtain the impact resistance of the obtained vinyl chloride resin.
The following is preferred.

In the same manner as described above, the above-mentioned polyfunctional monomer (B) is used for the purpose of cross-linking the acrylic copolymer so that coalescence of particles hardly occurs and further improving the impact resistance of the obtained vinyl chloride resin. ) Are added alone or 2
More than one type can be used in combination.

The amount of the polyfunctional monomer (B) added is
When the amount is too small, it is difficult to obtain impact resistance of the obtained vinyl chloride resin, and when the amount is too large, it is difficult to obtain both impact resistance and tensile strength.
0.1 to 10 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight.
It is 2 to 8 parts by weight.

Examples of the method for obtaining the acrylic copolymer include an emulsion polymerization method and a suspension polymerization method. The emulsion polymerization method is preferred in that the resulting vinyl chloride resin has good impact resistance. preferable. In the above emulsion polymerization method, an emulsifying dispersant and a polymerization initiator are used.

The above-mentioned emulsifying dispersant is added for the purpose of improving the dispersion stability of the above-mentioned monomer composition in an emulsified liquid and efficiently conducting polymerization. For example, anionic surfactants and nonionic surfactants are added. And partially saponified polyvinyl alcohol, cellulosic dispersants, gelatin, and the like. Particularly, as anionic surfactants, sulfate salts of higher alcohols (trade name “Monogen Y” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
-100 ").

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 appropriately added as necessary.

The above-mentioned emulsion polymerization methods are roughly classified into three methods, namely, a batch polymerization method, a monomer dropping method, and an emulsion dropping method, depending on the monomer addition method, but are not particularly limited. The batch polymerization method means, for example, that pure water, an emulsifying dispersant, a polymerization initiator, and the above-mentioned mixed monomer are added all at once in a jacketed polymerization reactor, and under the conditions of oxygen removal and pressurization by a nitrogen stream, This is a method in which after sufficient emulsification by stirring, polymerization is performed by heating the inside of the vessel with a jacket. Also, the monomer dropping method, for example, put pure water, an emulsifying dispersant, a polymerization initiator in a polymerization reactor with a jacket,
Under a condition of oxygen removal and pressurization by a nitrogen gas stream, the inside of the vessel is first heated by a jacket, and then the above-mentioned mixed monomer is dropped by a predetermined amount to gradually polymerize. The emulsion dropping method is, for example, to prepare an emulsified monomer in advance by sufficiently emulsifying the above-mentioned mixed monomer, emulsifying dispersant, and pure water with stirring, and then putting pure water and a polymerization initiator into a polymerization reactor with a jacket. Under a condition of removing oxygen by a nitrogen gas stream and pressurizing, a vessel is first heated by a jacket, and then the above-mentioned emulsified monomer is dropped by a predetermined amount to carry out polymerization.

The acrylic copolymer latex is added to a jacketed polymerization reactor containing the acrylic copolymer obtained by the emulsion polymerization method, and then the calculated amounts of the vinyl monomer (A) and the polyfunctional monomer (B) are added. Is generally obtained by graft copolymerization using an emulsion polymerization method in which the inside of the vessel is heated again by a jacket, but can also be obtained by a suspension polymerization method.

When obtaining the above-mentioned acrylic copolymer latex, an emulsifying dispersant and a polymerization initiator may be appropriately added as necessary, and a pH adjuster, an antioxidant and the like may be added. As the emulsifying dispersant and the polymerization initiator, all the emulsifying dispersants and the polymerization initiator described above can be used,
These can be used alone or in combination of two or more.

The vinyl chloride resin of the present invention can be obtained by graft copolymerizing vinyl chloride to the acrylic copolymer latex obtained by the above method.

If the proportion of the acrylic copolymer latex in the vinyl chloride resin is too small, it is difficult to obtain sufficient impact resistance, and if it is too large, the mechanical strength such as tensile strength is low. -30% by weight, preferably 4-22% by weight.

When the proportion of the vinyl chloride in the vinyl chloride resin is small, it is difficult to obtain mechanical strength such as tensile strength, and when it is too large, it is difficult to obtain sufficient impact resistance. It is 70 to 99% by weight, preferably 78 to 96% by weight in the vinyl resin.

Examples of the method of graft copolymerizing vinyl chloride include an emulsion polymerization method and a suspension polymerization method. However, the vinyl chloride resin obtained by the emulsion polymerization method has a problem of poor thermal stability. Suspension polymerization is preferred.

In the above suspension polymerization method, a dispersant and an oil-soluble polymerization initiator are used. However, an oil-soluble polymerization initiator which generates a radical is preferably used because radical polymerization is advantageous in graft copolymerization. .

The dispersant is added for the purpose of improving the dispersion stability of the acrylic copolymer latex and efficiently performing the graft copolymerization of vinyl chloride. Examples of the dispersant include methylcellulose, ethylcellulose, hydroxypropylmethylcellulose and polyvinyl. Examples thereof include alcohols and partially saponified products thereof, gelatin, polyvinylpyrrolidone, starch, and maleic anhydride-styrene copolymer, and these can be used alone or in combination of two or more.

Examples of the oil-soluble polymerization initiator include, for example,
Organic peroxides such as lauroyl peroxide, t-butyl peroxypivalate, diisopropyl peroxy dicarbonate, dioctyl peroxy dicarbonate, t-butyl peroxy neodecanoate, α-cumyl peroxy neodecanoate, Examples include azo compounds such as 2,2-azobisisobutyronitrile and 2,2-azobis-2,4-dimethylvaleronitrile.

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

As a specific example of the above suspension polymerization method, for example, pure water,
Oil-soluble polymerization initiator, the acrylic graft copolymer,
Dispersant, if necessary add a polymerization degree regulator, then
A method in which the air in the polymerization vessel is discharged by a vacuum pump, vinyl chloride and other vinyl monomers are added under stirring conditions, and then the reaction vessel is heated by a jacket to carry out graft copolymerization. . Further, since the above graft copolymerization is an exothermic reaction, the temperature in the reaction vessel can be controlled by changing the jacket temperature. After completion of the reaction, unreacted vinyl chloride is removed to obtain a slurry, which is then dehydrated and dried to produce a vinyl chloride resin.

When the degree of polymerization of polyvinyl chloride in the vinyl chloride resin is small, it is difficult to obtain sufficient elongation at break and impact resistance of the molded article. Is difficult to obtain, preferably 300 to 2000, more preferably 400 to 1400
It is.

In the vinyl chloride resin of the present invention, a heat stabilizer, a stabilizing aid, a lubricant, a processing aid, an antioxidant, a light stabilizer, a filler, a pigment and the like are added as necessary at the time of molding. It is used.

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

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

As the above lubricant, for example, 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 pigment include organic pigment oxides such as azo, phthalocyanine, sulene, and dye lakes, oxides, molybdate chromate, sulfide / selenide, and ferrocyanide. And the like.

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

The method of mixing the above-mentioned additives with the above-mentioned vinyl chloride resin may be a method by hot blending or a method by cold blending. Examples of the molding method include an extrusion molding method, an injection molding method and a calendering method. Molding method, press molding method and the like.

[0046]

Embodiments of the present invention will be described below.
Hereinafter, "parts" means "parts by weight".

Examples 1 to 11 and Comparative Examples 1 to 8 According to the composition shown in Tables 1 and 2, each vinyl chloride resin was obtained by the following operation procedure. (Preparation of Acrylic Copolymer) In a reaction vessel equipped with a stirrer and a reflux condenser, pure water and an anionic surfactant (trade name “Monogen Y-100” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(Hereinafter referred to as AS), ammonium persulfate (hereinafter referred to as A
PS), n-butyl acrylate (hereinafter, referred to as BA), methyl methacrylate (hereinafter, referred to as MMA), and trimethylolpropane triacrylate (hereinafter, referred to as TMPTA), and oxygen in the container is replaced with nitrogen. Then, the temperature of the reaction vessel was raised to 65 ° C. under stirring conditions, and the mixture was heated and stirred for 5 hours to obtain an acrylic copolymer (hereinafter, referred to as a copolymer).

(Preparation of Acrylic Copolymer Latex)
Next, MM was added to the reaction vessel containing the copolymer.
A and TMPTA were added, and oxygen in the vessel was replaced with nitrogen in the same manner as described above.
C. and heated and stirred for 2 hours to obtain an acrylic copolymer latex (hereinafter referred to as latex) having a solid content of 31% by weight.

(Preparation of vinyl chloride resin)
In a reaction vessel equipped with a stirrer and jacket,
Latex, pure water, partially saponified polyvinyl alcohol
(Kuraray Co., Ltd., product name "Clampovar L-
8 ") of a 3% aqueous solution (hereinafter referred to as 3% PVAaq),
t-butyl peroxy neodecanoate (hereinafter referred to as BPO
ND) and α-cumylperoxy neodecanoe
(Hereinafter referred to as QPOND) were batch-injected. That
After that, the air in the polymerization reactor is discharged by a vacuum pump, and
After adding vinyl chloride under the conditions, stir for 30 minutes
To mix the vinyl chloride uniformly, raise the temperature to 57 ° C,
Started the match. 5 hours after the start of polymerization, the pressure in the reaction vessel
Power is 7kg / cm ^TwoAfter confirming that it has dropped to
Stopped. After the reaction, unreacted vinyl chloride was removed.
Thereafter, by dehydrating and drying, a vinyl chloride resin was obtained.

(Preparation of Vinyl Chloride Resin Test Panel) To 100 parts of the vinyl chloride resin obtained above,
3 parts of dioctyltin mercapto (trade name "ONZ-142F" manufactured by Sankyoki Gosei Co., Ltd.), montanic acid wax (trade name "WAX-O" manufactured by Hoechst Japan KK)
P "), and kneading the mixture with a roll kneader at 190 ° C. for 3 minutes, at a temperature of 195 ° C. and a pressure of 75 k
Press molding was performed at g / cm ² for 6 minutes to obtain a vinyl chloride resin test panel having a thickness of 3 mm.

The evaluation items and evaluation methods are shown below. (Impact resistance) Table 1 shows the results of an Izod impact test (hereinafter referred to as Izod) performed in accordance with JIS K7110. The unit is kg · cm / cm ² . (Tensile strength) The results of a tensile strength test performed in accordance with JIS K7113 are shown in Table 1. The unit is kg / cm ² .

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

The vinyl chloride resin of the present invention is a vinyl chloride resin having excellent impact resistance and mechanical strength because vinyl chloride is graft copolymerized with an acrylic copolymer latex. It can be suitably used for applications requiring impact resistance, such as soundproof walls, window frames, and sashes.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-27232 (JP, A) JP-A-7-330839 (JP, A) JP-A-7-157520 (JP, A) JP-A-61- 78812 (JP, A) JP-A-56-90819 (JP, A) JP-A-54-003864 (JP, A) JP-A-52-146455 (JP, A) JP-A-52-89159 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 265/04-265/06

Claims (1)

(57) [Claims] 1. A vinyl chloride resin obtained by graft copolymerizing 70 to 99% by weight of vinyl chloride with 1 to 30% by weight of an acrylic copolymer latex, wherein the acrylic copolymer latex is A) An acrylic copolymer comprising 100 parts by weight of a vinyl monomer having a glass transition temperature of -20 ° C. or higher and (B) 0.1 to 20 parts by weight of a polyfunctional monomer. 5
The acrylic copolymer is obtained by graft copolymerization to 0 to 99% by weight, and the acrylic copolymer contains (C) an alkyl (meth) acrylate having a glass transition temperature of a homopolymer of less than -20 ° C as a main component. A vinyl chloride resin, which is obtained by copolymerizing 100 parts by weight of an acrylic monomer and 0.1 to 10 parts by weight of a polyfunctional monomer (B).