JP2002128979A - Vinyl chloride resin, its preparation process and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinyl chloride resin which may be directly heat molded without blending various compounding agents. SOLUTION: In the vinyl chloride resin, various compounding agents required for heat molding the vinyl chloride resin is contained in the vinyl chloride resin particles by polymerizing vinyl chloride monomers in the presence of various compounding agents which are microencapsulated using a (meth)acrylic ester monomer as a capsule wall constituent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride resin which can be thermoformed as it is because various additives are contained in the resin.

[0002]

2. Description of the Related Art A vinyl chloride resin is a material excellent in mechanical strength, weather resistance, chemical resistance and the like, and is therefore widely used in building members, pipework equipment, housing materials and the like. Generally, molding of a vinyl chloride resin is performed by heat kneading and shaping by an extruder or an injection molding machine to form a molded product. Before the thermoforming, various compounding agents such as a heat stabilizer and a lubricant are added. . In order for these various compounding agents to fully exert their effects, it is necessary to uniformly penetrate the vinyl chloride resin and into the inside of the resin. For this reason, a high-speed blender or high-speed stirring mixer called a blend is used. Mixing using
A kneading process was being performed. However, this equipment for blending requires a large investment, and also requires a lot of man-hours for blending.

[0003]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a vinyl chloride resin which can be thermoformed as it is without blending various additives.

[0004]

Means for Solving the Problems The vinyl chloride resin of the present invention is a vinyl chloride resin in which various compounding agents necessary for thermoforming the vinyl chloride resin are contained in the vinyl chloride resin particles. . The gist of the present invention is to microencapsulate various compounding agents required for thermoforming vinyl chloride, and polymerize vinyl chloride monomer in the presence of the microencapsulated compounding agent when polymerizing vinyl chloride. , A compounding agent is previously contained in the vinyl chloride resin particles.

[0005] The various compounding agents used in the present invention are compounding agents used during thermoforming of vinyl chloride resin, and include, for example, heat stabilizers, heat stabilizing aids, internal lubricants, external lubricants, processing aids. , An antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a pigment and the like.

The heat stabilizer is not particularly restricted but includes, for example, dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, dibutyltin malate, dibutyltin maleate polymer, dioctyltin maleate, dioctyltin maleate polymer, dibutyltin maleate Organic tin-based stabilizers such as laurate and dibutyltin laurate polymers, lead-based stabilizers such as lead stearate, dibasic lead phosphite, and tribasic lead sulfate; calcium-zinc-based stabilizers; barium-zinc-based stabilizers Agents: barium-cadmium stabilizers and the like. These may be used alone or in combination of two or more.

[0007] The heat stabilizing aid is not particularly restricted but includes, for example, epoxidized soybean oil and phosphate esters. These may be used alone or in combination of two or more.

The external lubricant is used for the purpose of enhancing the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and includes, for example, paraffin wax, polyolefin wax, ester wax,
Examples include waxes such as montanic acid wax and higher fatty acids such as stearic acid. These may be used alone or in combination of two or more.

The above-mentioned internal lubricant is used for the purpose of accelerating the gelation of the molten resin at the time of molding, reducing the flow viscosity and preventing frictional heat generation between the resins, for example, butyl stearate,
Lauryl alcohol, stearyl alcohol, epoxy soybean oil, monoglyceride, bisamide, and the like. These may be used alone or in combination of two or more.

The processing aid is not particularly restricted but includes, for example, an acrylic processing aid containing methyl methacrylate having an average molecular weight of 100,000 to 5,000,000 as a main component.
The antioxidant is not particularly restricted but includes, for example, phenolic antioxidants. The light stabilizer is not particularly limited, and examples thereof include hindered amine light stabilizers. The ultraviolet absorber is not particularly limited, and examples thereof include salicylate-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers.

The above-mentioned filler is not particularly limited, and examples thereof include titanium oxide, calcium carbonate, talc, and mica. The pigment is not particularly limited, and includes, for example, azo-based, phthalocyanine-based, sulene-based, organic pigments such as dye lake-based, oxide-based, molybdenum chromate-based, sulfide / selenide-based, ferrocyanide-based, and the like. And inorganic pigments.

The term "microencapsulation" as used in the present invention means that the periphery of the compounding agent is covered with a polymer, and various known methods can be employed. For example, after dispersing the compounding agent in the solvent solution of the polymer, and then spray-dried,
By performing physical microencapsulation method of dropping into the polymer precipitation solvent and seed polymerization with compounding agent as the core,
There is a chemical method of coating around the compound with a polymer wall.

The composition of the polymer wall used at this time is not particularly limited as long as it is a composition capable of covering the periphery of the compounding agent with a capsule wall, but it is finally kneaded by heat and dispersed in a vinyl chloride resin to be a matrix. Therefore, in consideration of compatibility with the vinyl chloride resin, vinyl chloride or (meth) acrylate is preferred. Furthermore, (meta)
Acrylic esters, especially methyl methacrylate, can be easily microencapsulated in the above-described seed polymerization method, and have an effect of facilitating the melting of the vinyl chloride resin during the heat kneading of the vinyl chloride resin. Particularly preferred.

The compounding agent for microencapsulation is preferably in the form of fine particles of several tens μm to several μm. This is a microencapsulated compound,
This is because the vinyl chloride monomer oil droplet layer is easily impregnated during polymerization.

[0015] The above-mentioned compounding agent can be made into fine particles by a granulation and fine pulverization method in which a blend of various compounding agents is heated and melted, then cooled and solidified, and further mechanically finely pulverized.
When there is a large amount of liquid compounding agent, there is a master batch pulverizing method in which a vinyl chloride polymer is added in addition to the various compounding agents, and heat impregnation is performed, followed by mechanical pulverization.

The reason for microencapsulation in the present invention is that the heat stabilizers and lubricants required for thermoforming vinyl chloride, and other antioxidants, light stabilizers, ultraviolet absorbers, etc. When the polymerization is carried out, various additives act as radical scavengers, which inhibits the polymerization and makes it impossible to obtain a moldable resin, increases the amount of scale adhering in the polymerization vessel, or obtains a desired average particle diameter. And the chemical oxygen demand (CO 2
D) increases, and many problems occur.
Therefore, when microencapsulation is carried out as in the present invention, the above-mentioned problems can be solved because the compounding agent is covered with the polymer layer.

In the present invention, the polymerization of vinyl chloride is carried out by a usual method. For example, after charging ion-exchanged water, a dispersant, a polymerization initiator, a microencapsulation compounding agent, and other additives as necessary into a polymerization vessel, the remaining air is discharged out of the vessel by suction, and a vinyl chloride monomer is discharged. Into the vessel. Thereafter, the temperature inside the vessel is heated by a jacket while stirring, so as to reach a desired temperature. As the temperature in the vessel rises, the polymerization of vinyl chloride proceeds and generates heat. The temperature in the vessel is kept at a predetermined temperature while cooling from the jacket. After the pressure in the vessel has dropped to the specified pressure, the slurry is cooled to remove the residual vinyl chloride monomer outside the vessel to obtain a slurry. Thereafter, the slurry is dehydrated and dried to obtain a vinyl chloride resin.

The dispersant is not particularly restricted but includes, for example, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, partially saponified polyvinyl alcohol, gelatin, polyvinylpyrrolidone, sodium polyacrylate, starch, maleic anhydride-styrene copolymer and the like. Is mentioned. These may be used alone or in combination of two or more.

The polymerization initiator is not particularly restricted but includes, for example, benzoyl peroxide, di- (2-ethylhexyl) peroxydicarbonate, di-sec.
-Butyl peroxy dicarbonate, lauroyl peroxide, t-butyl peroxy pivalate, diisopropyl peroxy dicarbonate, dioctyl peroxy dicarbonate, t-butyl peroxy neodecanoate, α-cumyl peroxy neodecanoate And azobisisobutyronitrile. These may be used alone or in combination of two or more.

The vinyl chloride resin of the present invention may contain other monomers copolymerizable with vinyl chloride, if necessary. For example, vinyl esters such as vinyl acetate and vinyl propionate, α-olefins such as ethylene and propylene, vinyl ethers such as isobutyl vinyl ether and cetyl vinyl ether, ethyl (meth) acrylate, methyl (meth) acrylate, 2-
(Meth) acrylates such as ethylhexyl (meth) acrylate, aromatic vinyls such as styrene and α-methylstyrene, vinyl fluorides such as vinyl fluoride, vinylidene fluoride and vinylidene chloride, cyclohexylmaleimide and phenylmaleimide And N-substituted maleimides, and vinyl cyanide such as acrylonitrile. These may be used alone,
Two or more types may be used in combination.

In the above-mentioned polymerization of vinyl chloride, a pH adjuster, a chain transfer agent and the like may be added as required.

In the vinyl chloride resin of the present invention, since various compounding agents are contained in the resin, thermoforming can be performed as it is without the need for a general blending operation of compounding agents. Since the compounding agent is uniformly finely dispersed in the resin particles, the functions of various compounding agents can be exhibited in a small amount.

[0023]

[Preparation of blended powder]

(Preparation of Lead-Based Blended Powder) 100 parts by weight of tribasic lead sulfate, 30 parts by weight of dibasic lead phosphite, 15 parts by weight of lead stearate, and 5 parts by weight of pigment are placed in a Henschel mixer and stirred to 120 ° C. Heat and granulate. After cooling, the obtained granulated product was finely pulverized to obtain a lead-based compound powder (a) as a fine powder having an average particle diameter of 3 μm. (Preparation of tin-based compound) PVC resin (degree of polymerization 800) 50
20 parts by weight of organic tin mercapto, 10 parts by weight of organic tin malate, 10 parts by weight of calcium stearate, 5 parts by weight of glycerin monostearate, 3 parts by weight of stearic acid, and 2 parts by weight of pigment are put into a Henschel mixer and stirred. The mixture was heated to 100 ° C. and granulated. After cooling, the obtained granulated product was obtained with a fine pulverizer as a fine powder having an average particle size of 5 μm to obtain a tin-based mixed powder (b).

[Microencapsulation of Compounding Agent] (Microencapsulation of Lead-Based Compounding Powder) In a glass reactor equipped with a stirrer, 900 parts by weight of ion-exchanged water, ammonium glycol polyethylene glycol nonylphenyl ether sulfonate as an emulsifier were used. 3 parts by weight, lead-based compound powder (a) 8
0 parts by weight was added and heated to 70 ° C. in an oil bath with stirring. Next, 0.15 parts by weight of ammonium persulfate was added as a polymerization initiator, and 20 parts by weight of methyl methacrylate (hereinafter referred to as MMA) and 70 parts of ion-exchanged water were added.
An emulsion obtained by adding 0.3 parts by weight of polyethylene glycol nonylphenyl ether sulfonate ammonium salt to parts by weight and emulsifying well was added at a rate of 2 parts by weight / minute over 50 minutes. Thereafter, the polymerization reaction was completed while maintaining the temperature at 70 ° C. for 60 minutes. After cooling, the solid content was taken out by centrifugation and further dried to obtain a microencapsulated lead-based mixed powder (A). The MMA content of the obtained microencapsulated blended powder (A) was measured by gas chromatography and was found to be 20% by weight. (Microencapsulation of tin-based powder) Lead-based powder (a)
Was replaced with the tin-based mixed powder (b), and a microencapsulated tin-based mixed powder (B) was obtained in the same manner as the microencapsulated lead-based mixed powder (A). The MMA content was 20% by weight.

(Synthesis of Comparative MMA) An acrylic polymer (C) containing no compounding agent was obtained in the same manner as in the preparation of the microencapsulated compounded powder using only MMA without adding the compounded fine powder at all. Was.

(Example 1) In a polymerization vessel equipped with a stirrer and a jacket, 9000 parts by weight of pure water, 150 parts by weight of microencapsulated lead-based mixed powder (A), partially saponified polyvinyl alcohol (Kuraray Co., Ltd.) 100 parts by weight of a 3% aqueous solution of a 3% aqueous solution of hydroxypropyl methylcellulose (trade name "Metroze 60SH50" manufactured by Shin-Etsu Chemical Co., Ltd.) Peroxy neodecanoate 2 weight, α
-1 part by weight of cumyl peroxy neodecanoate is charged at once, and then the air in the polymerization reactor is discharged by a vacuum pump,
Further, 6300 parts by weight of vinyl chloride was added under stirring conditions, the mixture was stirred for 30 minutes, mixed uniformly, and then heated by a jacket to carry out polymerization while maintaining the temperature in the polymerization vessel at 57 ° C. When the pressure in the polymerization vessel dropped to 0.64 MPa, the reaction was stopped by cooling from the jacket. Thereafter, unreacted vinyl chloride monomer was removed from the vessel, and further dehydrated and dried to obtain a vinyl chloride resin having an average particle diameter of 140 μm. Scale adhesion rate at this time (the following formula)
Was 0.2% by weight. Also, 10 parts by weight of the obtained resin was mixed with tetrahydrofuran 1
The soluble component after dissolving in 00 parts by weight and filtering the insoluble component was reprecipitated in 500 parts by weight of methanol, and only the vinyl chloride resin component was taken out and dried, and then JISK-6.
The average degree of polymerization was determined to be 1,040 by 721. The chlorine content was measured by the oxygen flask method, and the content of the microencapsulated lead-based mixed powder (A) in the obtained vinyl chloride-based resin was calculated to be 2.9% by weight.
3.0 parts by weight, 2.6 parts by weight of the compounding agent component, and 0.4 parts by weight of MMA as the capsule wall component were contained per 100 parts by weight of the vinyl chloride resin.

(Example 2) In Example 1, microencapsulated tin-based powder (B) was used in place of microencapsulated lead-based powder (A), and the amount added was 360 parts by weight. The polymerization was carried out in exactly the same manner,
A 60 μm vinyl chloride resin was obtained. At this time, the scale adhesion rate was 0.3% by weight. Further, in the same manner as in Example 1, the degree of polymerization and the tin-containing microencapsulated powder (B)
Was measured, the degree of polymerization was 1040, the content was 7.0% by weight, and 7.5 parts by weight, 100 parts by weight of the vinyl chloride resin, 6.0 parts by weight of the compounding agent component, and the capsule wall component Was 1.5 parts by weight.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that the microencapsulated lead-based compound powder (A) was not added at all, and a vinyl chloride resin having an average particle diameter of 140 μm was obtained. The polymerization degree was 1,040. To 100 parts by weight of this resin, 2.6 parts by weight of the lead-based compounding powder (a) and 0.4 part by weight of the acrylic polymer (C) resin were added, and the temperature was raised to 100 ° C. while stirring with a Henschel mixer, followed by cooling. As a result, a lead-based vinyl chloride resin was obtained.

(Comparative Example 2) To 100 parts by weight of the vinyl chloride resin obtained in Comparative Example 1, 6.0 parts by weight of the tin-based compounding powder (b) and 1.5 parts by weight of the acrylic polymer (C) were added. Then, in the same manner as in Comparative Example 1, a tin-based vinyl chloride-based resin was obtained.

(Comparative Example 3) In Example 1, instead of the fine powder of the microencapsulated lead-based mixed powder, the same amount of the lead-based mixed powder (a) not microencapsulated was added and polymerized in exactly the same manner. A vinyl chloride resin was obtained. At this time, the scale adhesion rate was 12% by weight. When the degree of polymerization and the content of the lead-based compounded powder were measured in the same manner as in Example 1,
The polymerization degree is 1040, the content is per 100 parts by weight of the resin,
0.9 parts by weight.

(Comparative Example 4) In Example 2, instead of the microencapsulated tin-based compound powder (B), the same amount of a tin-based compound powder (b) not microencapsulated was added.
As a result of exactly the same polymerization, abnormal polymerization occurred, and a moldable vinyl chloride resin powder could not be obtained.

[Measurement of Physical Properties of Vinyl Chloride Resin] The physical properties of the resins obtained in Examples 1 and 2 and Comparative Examples 1, 2, and 3 were measured by the following methods. Table 1 shows the obtained results. (Molding method) Each resin was kneaded with an 8-inch roll at 190 ° C. for 3 minutes after winding, and then removed from the roll to obtain a sheet having a thickness of 1 mm. A part was used for a heat aging test, and the rest was pressed (200 ° C. preheating for 4 minutes—pressing for 4 minutes: pressure of 4.9 MPa) to prepare a plate, cut out into various test pieces, and then subjected to various tests. (Impact Resistance) A Charpy impact test at 23 ° C. was performed on a notched test piece in accordance with JIS K7111. (Tensile strength) A tensile strength test at 23 ° C. was performed according to JIS K7113. (Elongation) According to JIS K7113, the elongation was measured together with the tensile strength test at 23 ° C. (Vicat Softening Temperature) A Vicat softening temperature test was performed in accordance with JIS K7206. (Heat aging property) A heat aging property test was performed in an oven at 190 ° C. in accordance with JIS K7212, and the time until the sample turned brown was measured. The sample was performed on the sheet after the roll kneading.

[0033]

[Table 1]

[0034]

The vinyl chloride resin obtained according to the present invention comprises:
Since various compounding agents necessary for molding are contained in the vinyl chloride resin particles, they can be thermoformed as they are, and the obtained physical properties show the same or better performance than conventional compounding powders. It is suitably used for various molded products such as pipes, sheets, plates and joints obtained by calendering and injection molding.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08K 9/10 C08K 9/10 F term (reference) 4F071 AA24 AA77 AE05 AE09 AE11 AH19 BC07 4J002 BB032 BD031 CD162 DE188 EC067 EH037 EZ046 EZ076 FB282 FB286 FB287 FB288 FD058 FD066 FD090 FD172 FD177 4J011 PA69 PB06 PB20 PB22 PB24 PB25 PB33 PC02 PC07 4J026 AA45 AA48 AC09 BA10 BB01 DB03 DB12 DB15 DB23 FA03 GA06

Claims (5)

[Claims] 1. A vinyl chloride resin characterized in that various compounding agents necessary for thermoforming the vinyl chloride resin are contained in the vinyl chloride resin particles. 2. The vinyl chloride resin according to claim 1, wherein at least one selected from the various compounding agents is microencapsulated and contained in the vinyl chloride resin particles. 3. The vinyl chloride resin according to claim 2, wherein a (meth) acrylate monomer is used as a capsule wall constituent material. 4. The process for producing a vinyl chloride resin according to claim 2, wherein the vinyl chloride monomer is polymerized in the presence of various microencapsulated compounding agents. 5. A vinyl chloride resin molded article obtained by thermoforming the vinyl chloride resin according to claim 1.