JP2000219790A - Vinyl chloride polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer composition which can give a molding having excellent toughness in a breaking mode such as the propagation of a craze after a long-term use and having good appearance by selecting a composition having a structure derived by dispersing particulate polymer having a specified particle diameter in a vinyl chloride polymer having a specified degree of polymerization in a specified ratio. SOLUTION: This composition is prepared by dispersing a particulate polymer (B) having a mean particle diameter of 0.1-20 μm in a vinyl chloride polymer (A) having a degree of polymerization of 600-3,000, and wherein 1-70 pts.wt. component B is present per 100 pts.wt. component A. It is desirable that component B is a vinyl chloride polymer. It is desirable that the content of tetrahydrofuran insolubles of component B is higher than that of component A and that the content of tetrahydrofuran insolubles of component B is at least 20 wt.%, and that of component A is at most 5 wt.%. It is desirable that the degree of polymerization of component B is larger than that of component A and is 1,500-4,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride polymer composition suitably used for applications requiring long-term durability such as pipes.

[0002]

2. Description of the Related Art Vinyl chloride polymers and their compositions are:
It has been widely used in the fields of pipes, window frames, flat plates, sheets, etc. by extrusion molding because of its excellent rigidity, weather resistance, flame retardancy, etc., and its low cost and high productivity. . Among these, in application fields requiring excellent impact resistance, such as window frames and pipes, the impact resistance has been improved by adding a rubber component.

[0003] Methods for improving the impact resistance include, for example, JP-A-60-255813 and JP-A-61-4361.
No. 0 discloses a method of graft copolymerizing vinyl chloride with an acrylic copolymer rubber. According to such a method, the impact resistance is improved without impairing the weather resistance.

However, in the application of pipes and the like, even if the impact resistance is improved as described above, a molded product that satisfies the required level cannot always be obtained. In these applications, the long-term durability of the pipe, such as crack propagation during long-term use due to cracks generated during use or construction, becomes a problem. It is considered effective to improve the toughness of the molded article to improve the long-term durability, but this is not always realized by the above-described improvement in impact resistance.

[0005] The impact resistance represents the absorbed energy at the time of destruction when the molded body is deformed at high speed in a short time, and is usually evaluated by a Charpy test or the like. The more plastically deformable material (ductile material), the better the impact resistance. However, even if the plasticity of the molded body is increased and the impact resistance is improved, the long-term durability is not necessarily improved. That is, the above-described improvement of the characteristics by the addition of the rubber component is not always effective in improving the long-term durability. This is because the impact resistance indicates toughness corresponding to a fracture mode in which a high-speed deformation is performed in a short period of time, and is different from the toughness in a long-term durability fracture mode such as crack propagation during long-term use. Therefore, the improvement of the long-term durability of a molded article is a different subject from the conventional improvement of impact resistance, and requires a different viewpoint.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a long-term durability of a molded article, specifically, a toughness in a fracture mode such as a crack propagation property in a long-time use. An object of the present invention is to provide a vinyl chloride-based polymer composition having excellent properties and a good appearance of a molded article.

[0007]

As described above, in order to improve long-term durability, it is effective to form a molded article having a structure in which cracks are unlikely to develop. The present inventors have found that in realizing such a molded product, it is effective to use a fracture toughness value as an index indicating toughness in a fracture mode such as crack growth during long-term use. The fracture toughness value is to evaluate the difficulty of crack growth due to stress concentration near the notch when a load is applied to a molded body for a long time. For example, when evaluating by a three-point bending test, From the maximum stress at which fracture occurs, the fracture toughness value K _c
Is calculated. In the case of evaluating by a creep test, the fracture toughness value _Kc is calculated from the magnitude of the load required to break in a certain time. Therefore, the magnitude of the stress required for breaking is important for the fracture toughness value, and a rigid material, rather than a ductile material, exhibits a high fracture toughness value.

On the other hand, as a characteristic value indicating the toughness of a molded article, impact resistance evaluated by a Charpy test or the like has been conventionally used. The impact resistance indicates the absorbed energy at the time of breaking when the molded body is deformed at high speed in a short time. Therefore, the ease of plastic deformation of the material is important for impact resistance. For example, a method of adding a rubber component is often employed as a technique for improving the impact resistance of a vinyl chloride polymer. In this case, the impact resistance improves as the rubber component increases. However, when the plasticity of the polymer is increased by increasing the amount of the rubber component, the absorbed energy at the time of fracture is increased, but it is stretched by a small load and fractured, so that the fracture toughness value is reduced. That is, although both the fracture toughness value and the impact resistance are common in that they represent the toughness of the molded article, they show the toughness for different fracture modes, and the improvement methods are different. The present inventors have found that it is effective to increase the fracture toughness value in order to improve the long-term durability of a molded article, and have completed the present invention. Specifically, a small amount of a rubber component is added to a vinyl chloride-based monomer in a finely dispersed state, and the stress required for breaking is increased to improve the fracture toughness value.

As a technique for improving a vinyl chloride resin composition using the fracture toughness value as a strength guide, Japanese Patent Application Laid-Open No. Hei 9-137 discloses a technique.
No. 022 discloses that a vinyl chloride-based polymer composition containing a high and low average degree of polymerization of a vinyl chloride-based polymer suppresses an increase in torque during extrusion molding, and obtains a molded product. Methods for improving fracture toughness values are disclosed. However, obtains energy released rate G _c obtained by performing a Charpy test in the art, it is evaluating fracture toughness by the G _c value. In other words, this technology improves the durability in the short-time and high-speed fracture mode, and improves the long-term durability of the molded product, specifically, the toughness in the fracture mode such as crack growth during long-term use. Is to solve a different problem. In the above technique, the effect of improving the crack growth after long-term use cannot always be sufficiently obtained.

The present invention comprises the following inventions.

(1) A vinyl chloride polymer (A) having an average degree of polymerization of 600 to 3000 contains an average particle size of 0.1 to 20 μm.
Wherein the content of the polymer (B) is from 1 to 70 parts by weight based on 100 parts by weight of the vinyl chloride-based polymer (A). -Based polymer composition.

(2) The vinyl chloride polymer composition according to (1), wherein the polymer (B) is a vinyl chloride polymer.

(3) The vinyl chloride polymer according to (1) or (2), wherein the tetrahydrofuran insoluble content of the polymer (B) is larger than the tetrahydrofuran insoluble content of the vinyl chloride polymer (A). Coalescing composition.

(4) The polymer (B) has a tetrahydrofuran-insoluble content of 20% by weight or more (1).
The vinyl chloride polymer composition according to any one of (1) to (3).

(5) The vinyl chloride polymer composition according to (4), wherein the tetrahydrofuran insoluble content of the polymer (A) is 5% by weight or less.

(6) The vinyl chloride polymer according to any one of (1) to (5), wherein the polymerization degree of the polymer (B) is larger than that of the vinyl chloride polymer (A). Coalescing composition.

(7) The vinyl chloride polymer composition according to any one of (1) to (6), wherein the polymerization degree of the polymer (B) is from 1500 to 4000.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the present invention, the vinyl chloride polymer is a homopolymer of vinyl chloride, or
It refers to a copolymer of vinyl chloride and another vinyl monomer copolymerizable with vinyl chloride.

The vinyl monomer copolymerizable with vinyl chloride can be used without any particular limitation as long as it is generally known to be copolymerized with vinyl chloride, and examples thereof include vinyl acetate and vinyl propionate. Vinyl esters of carboxylic acids and vinyl alcohols; alkyl vinyl ethers such as methyl vinyl ether and cetyl vinyl ether;
Α-monoolefin monomers such as ethylene and propylene; alkyl acrylates such as methyl acrylate and butyl acrylate; alkyl methacrylates such as methyl methacrylate and butyl methacrylate;
Unsaturated nitriles such as acrylonitrile; vinylidenes such as vinylidene chloride;

The average degree of polymerization of the vinyl chloride polymer (A) is from 600 to 3,000. When the average degree of polymerization is less than 600, the surface appearance of the molded article is good, but the fracture toughness value of the obtained molded article is lowered, which is not preferable. On the other hand, if the average degree of polymerization exceeds 3,000, moldability may deteriorate. The average degree of polymerization of the vinyl chloride polymer (A) is 70
When it is in the range of 0 or more and 2000 or less, not only a molded product having a high fracture toughness value is obtained, but also the surface appearance of the molded product is good, and the load on the molding machine at the time of molding is small.

The powder properties of the vinyl chloride polymer (A), such as bulk specific gravity and average particle size, are not particularly limited, but should be 0.40 to 0.65 for bulk specific gravity and 80 to 250 μm for average particle size. Is preferred. By doing so, the transportability and gelling property of the powder in the molding machine at the time of molding are improved.

The method for producing the vinyl chloride polymer (A) may be any of a suspension polymerization method, an emulsion polymerization method, a solution polymerization method and a bulk polymerization method, and is not particularly limited.
Those produced by a suspension polymerization method are preferred. This is because there are few residual monomers, and the various physical properties of the powder such as the bulk specific gravity of the vinyl chloride polymer (A) are improved.

The suspension polymerization method of a vinyl chloride polymer is well known, and a vinyl chloride monomer or a vinyl chloride monomer and another polymerizable vinyl monomer are used in the presence of a dispersant and a polymerization initiator. Below, it is polymerized in an aqueous medium. Thus, a slurry containing the vinyl chloride polymer can be obtained by the suspension polymerization method.

Examples of the dispersant used in the polymerization include known suspending agents, for example, water-soluble cellulose ethers such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose; partially saponified polyvinyl having different degrees of saponification and polymerization. Alcohol; Modified partially saponified polyvinyl alcohol into which hydrophobic group, hydrophilic group, etc. are introduced; Acrylic acid polymer; Water-soluble inorganic salt; Water-soluble polymer such as gelatin; Sorbitan monolaurate, Sorbitan monostearate, Glycerin monostearate And water-soluble emulsifiers such as polyoxyethylene glycerol oleate and sodium laurate. These dispersants may be used alone or in combination of two or more. It may be used in combination.

The vinyl chloride polymer composition of the present invention has an average particle size of 0.1 to 20 μm in the vinyl chloride polymer (A).
m of the polymer (B) is dispersed, and the content of the polymer (B) is 1 to 70 parts by weight based on 100 parts by weight of the vinyl chloride polymer (A). Since the particulate polymer (B) is dispersed at an appropriate ratio, the interface between the polymer (B) and the vinyl chloride-based polymer (A) when a stress is applied to the molded article of the composition. Peeling occurs as a stress concentration point, and the breaking energy is absorbed. This allows
The fracture toughness value is improved, and the long-term durability of the molded body, specifically, the toughness in a fracture mode such as crack growth after long-term use is improved.

As described above, the periphery of the polymer (B)
Since the polymer (B) functions as a site for absorbing breaking energy, the polymer (B) preferably maintains a particulate form in the matrix of the vinyl chloride polymer (A) even after molding.
This further improves the fracture toughness value.

As described above, in order to effectively make the peripheral portion of the polymer (B) function as a breaking energy absorption site and to improve the fracture toughness, the average particle size of the polymer (B) and the polymer It is important to set the mixing ratio of (B) and the vinyl chloride polymer (A) to an appropriate value.

In the present invention, the average particle size of the vinyl chloride polymer (B) is set to 0.1 to 20 μm or less. If the average particle size exceeds 20 μm, the effect of improving the fracture toughness cannot be sufficiently obtained. Further, the smoothness of the surface of the molded product is also reduced, which is not preferable. Further, when the average particle size is 0.1 to 15 μm, a better fracture toughness value is obtained, and the smoothness of the surface of the molded product is improved.

In the present invention, the content of the polymer (B) with respect to 100 parts by weight of the vinyl chloride polymer (A) is as follows:
1 to 70 parts by weight, preferably 10 to 60 parts by weight.
By setting the weight ratio to the above value, the periphery of the polymer (B) effectively functions as a breaking energy absorption site, and the fracture toughness value is improved.

As described above, the fracture toughness value can be improved by setting the average particle size and the weight ratio of the polymer (B) to appropriate values. It is necessary to appropriately adjust the properties of the coalesced (B) or the vinyl chloride polymer (A) so that the periphery of the polymer (B) can sufficiently absorb the breaking energy.

The following means are effective as such means. The tetrahydrofuran insoluble content of the polymer (B) is made larger than the tetrahydrofuran insoluble content of the vinyl chloride polymer (A). The degree of polymerization of the polymer (B) is determined using the vinyl chloride polymer (A).
Greater than the degree of polymerization.

By employing such a means, the stress concentration coefficient at the peripheral portion of the polymer (B) becomes larger, so that a larger breaking energy can be absorbed.

Here, the tetrahydrofuran-insoluble content of the polymer (B) is preferably at least 20% by weight, more preferably at least 50% by weight. Further, it is preferable that the content of the polymer (A) insoluble in tetrahydrofuran is 5% by weight or less. By doing so, the effect of further improving the fracture toughness value and improving the roll adhesiveness during the forming process can be obtained.

The polymerization degree of the polymer (B) is preferably 1500 or more and 4000 or less, more preferably 200 or less.
It is set to 0 or more and 4000 or less. Thereby, the fracture toughness value is further improved.

Here, if the polymer (B) is a vinyl chloride polymer, the elastic modulus of the polymer (B) is almost the same as the elastic modulus of the vinyl chloride polymer (A). By adjusting the tetrahydrofuran insoluble content, the elastic modulus can be easily increased to a value higher than that of the vinyl chloride polymer (A). Thereby, the peripheral portion of the polymer (B) can sufficiently absorb the fracture energy, and the fracture toughness value can be further improved. Furthermore, in this case, since the polymer (B) and the vinyl chloride-based polymer (A) are composed of the same material, the appearance and moldability of the molded article are improved.
In addition, the adhesiveness of the roll during molding is improved. As described above, the vinyl chloride polymer refers to a homopolymer of vinyl chloride or a copolymer of vinyl chloride and another vinyl monomer copolymerizable with vinyl chloride.

Hereinafter, the polymerization method when the polymer (B) is a vinyl chloride polymer will be described.

In this case, the polymer (B) is prepared by a suspension polymerization method,
It is manufactured by a known polymerization method such as an emulsion polymerization method, a solution polymerization method, and a bulk polymerization method. Any method may be used, and there is no particular limitation. However, in consideration of the average particle size of the polymer (B), those produced by an emulsion polymerization method, a fine suspension polymerization method, or the like are preferable.

Emulsion polymerization of vinyl chloride polymers is well known, and an aqueous medium is prepared by using an anionic surfactant or an anionic surfactant and a nonionic surfactant in the presence of a polymerization initiator. It is a method of emulsifying the monomer in it and conducting polymerization, but in order to adjust the particle size, lipophilic substances such as higher alcohols such as lauryl alcohol and cetyl alcohol and nonionic surfactants such as sorbitan trialkyl ester May be added.

The polymerization initiator used for the emulsion polymerization of the polymer (B) is not particularly limited and may be a known one, for example, a water-soluble polymerization initiator such as potassium persulfate, ammonium persulfate, hydrogen peroxide or the like. It can be used in combination with a water-soluble reducing agent and an organic peroxide.

Examples of the anionic surfactant or nonionic surfactant used in the emulsion polymerization of the polymer (B) include alkyl sulfate salts such as sodium lauryl sulfate and sodium mythyl sulfate; sodium dodecylbenzenesulfonate and dodecylbenzenesulfone. Alkyl aryl sulfonates such as potassium silicate; sulfosuccinates such as dioctyl sulfosuccinate; anionic surfactants such as polyoxyethylene alkyl sulfate; fatty acid salts such as ammonium laurate; sorbitan such as sorbitan monooleate Esters; Nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, and polyoxyethylene alkyl esters; cetyl pyridi Umukurorido include such cationic surfactants such as, may be used in combination one or two or more kinds.

As another conventional production method of the polymer (B), a fine suspension polymerization method is well known. In the presence of an oil-soluble polymerization initiator, a surfactant is added before starting the polymerization. This is a method of performing polymerization after adjusting the particle diameter of monomer oil droplets and homogenously dispersing them.

The oil-soluble polymerization initiator used in the fine suspension polymerization of the polymer (B) is dissolved in vinyl chloride or a mixture of monomers copolymerizable with vinyl chloride and has an appropriate half-life at the polymerization temperature. There is no particular limitation as long as it has, and known ones may be used, for example, sialic peroxides such as dibenzoyl peroxide, peroxydicarbonates such as diisopropylperoxydicarbonate,
Peroxyesters such as t-butylperoxypivalate, organic peroxides such as acetylcyclohexylsulfonyl peroxide, and azo compounds such as 2,2'-azobisisobutyronitrile can be used.

The surfactant used for the fine suspension polymerization of the polymer (B) is not particularly limited and may be a known surfactant.
The surfactants used in the emulsion polymerization can be used in the same manner.

By using a crosslinking agent at the time of emulsion polymerization or fine suspension polymerization of the polymer (B), a crosslinked structure is formed, and the tetrahydrofuran-insoluble content can be increased to 20% by weight or more or 50% by weight or more. . Thereby, the fracture toughness value of the molded article can be further improved as described above, which is more preferable.

The crosslinking agent to be added may be a known one and is not particularly limited. Examples thereof include diallyl phthalate,
Diallyl esters of saturated or unsaturated dibasic acids such as diallyl terephthalate and diallyl maleate; divinyl ethers such as divinyl ether and diallyl ether;
Acrylic esters or methacrylic esters of polyhydric alcohols such as ethylene glycol dimethacrylate and diethylene glycol diacrylate; allyl compounds of cyanuric acid or isocyanuric acid such as triallyl cyanurate; bismethacryloyloxyethylene phthalate; 1,3,5- Examples include polyfunctional monomers having two or more ethylenic double bonds in the molecule such as triacryloylhexahydrotriazine, and the above polyfunctional monomers are used alone or in combination of two or more. It doesn't matter.

As described above, it is essential that the composition of the present invention contains a vinyl chloride polymer having an average particle size of 0.1 to 20 μm, but other stabilizers, lubricants and impact modifiers Processing aids, inorganic fillers, organic fillers, coloring agents, plasticizers and the like can be used without any limitation.

The method for producing the composition of the present invention is not particularly limited. For example, a composition in which a predetermined amount of a vinyl chloride polymer (A) and a polymer (B) are blended, and various additives are blended as necessary. Henschel mixer, raisers, planetary mixer, and other various mixers may be uniformly mixed, even at the temperature at the time of mixing, there is no particular limitation, even if the so-called cold blending at room temperature,
Further, the so-called hot blending in a temperature range of 60 to 140 ° C. may be performed.

When the polymer (B) is produced by emulsion polymerization or fine suspension polymerization, the surfactant adhering to the surface of the obtained polymer particles is removed in advance by using alcohol such as ethanol or water. , Or a mixture thereof to remove the surfactant is more preferable because the resulting molded article has a further improved fracture toughness value.

[0050]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

For the vinyl chloride polymer compositions obtained in the following Examples 1 to 6 and Comparative Examples 1 to 5, the tetrahydrofuran insoluble content of the vinyl chloride polymer used was measured.
The measurement of the degree of polymerization and the average particle size, the evaluation of the appearance of a molded article of the composition, and the fracture toughness test of the molded article were performed.

1. Method for measuring tetrahydrofuran insoluble content of vinyl chloride-based polymer 50 g of vinyl chloride-based polymer was added to tetrahydrofuran 100
After stirring for 24 hours at room temperature,
Centrifugation at 10,000 rpm for 1 minute,
The tetrahydrofuran insoluble content of the vinyl chloride polymer was measured by the ratio of the weight of the insoluble matter obtained by vacuum drying to the weight of the resin sample.

2. Method for measuring average degree of polymerization of vinyl chloride polymer The viscosity was calculated by measuring the viscosity of a vinyl chloride polymer solution using nitrobenzene as a solvent according to JIS-K6721.

3. Method for Measuring Average Particle Diameter of Vinyl Chloride Polymer A sample obtained by uniformly dispersing a vinyl chloride polymer in a mixed solution of water and a surfactant is subjected to a laser light scattering particle size distribution analyzer (manufactured by Nikkiso Co., Ltd .: The average particle size was measured using a Microtrac particle size analyzer. Here, the average particle size is
It is a volume average particle diameter, and was defined as a particle diameter of particles corresponding to a cumulative frequency of 50% in the particle diameter distribution of the particles.

4. Production method of molded article A mercapto tin stabilizer (manufactured by Nitto Kasei Corporation: TVS-89) was added to 100 parts by weight of a predetermined vinyl chloride polymer mixture.
40) 3 parts by weight were blended and mixed with a Henschel mixer at room temperature for 3 minutes. The obtained vinyl chloride polymer composition was kneaded with a roll at a temperature of 185 ° C. for 5 minutes to prepare a roll kneaded sheet. The obtained roll kneaded sheet was heated at a temperature of 19
Press molding was performed at 5 ° C. under a pressure of 150 kg / cm 2 for 20 minutes to produce a molded body.

5. Evaluation of Surface Appearance of Molded Article The appearance of the molded article was evaluated by visual evaluation of the appearance of the kneaded sheet obtained at the time of the roll forming.

6. Fracture toughness test method Using the molded article obtained by the above method, ASTM D-5
According to 045-95, the fracture toughness value (Kc) was measured by a three-point bending test using a flat plate having a notch inserted on one side.

Example 1 An average degree of polymerization of 10 was used as the vinyl chloride polymer (A) component.
20, 50 parts by weight of a vinyl chloride polymer (manufactured by Ocean PVC Co., Ltd .: TH-1000) produced by a suspension polymerization method having an average particle size of 150 μm, and a polymer (B) component containing less than 1% of a tetrahydrofuran-insoluble component; 50 parts by weight of a vinyl chloride polymer (Ryuron paste 761 manufactured by Tosoh Corporation) having an average degree of polymerization of 2100 and an average particle size of 1.5 μm manufactured by an emulsion polymerization method were mixed to prepare a vinyl chloride polymer composition. .

The surface appearance at the time of molding was smooth, and the fracture toughness of the obtained molded product was high and good. The roll adhesion during molding was also good.

Example 2 As a vinyl chloride polymer (A) component, an average degree of polymerization of 10
20, 50 parts by weight of a vinyl chloride polymer (manufactured by Ocean PVC Co., Ltd .: TH-1000) produced by a suspension polymerization method having an average particle size of 150 μm, and a polymer (B) component containing less than 1% of a tetrahydrofuran-insoluble component; 50 parts by weight of a vinyl chloride polymer (Ryuron paste 810, manufactured by Tosoh Corporation) having an average degree of polymerization of 1650 and an average particle diameter of 1.5 μm were mixed to prepare a vinyl chloride polymer composition. .

The surface appearance at the time of molding was smooth, and the fracture toughness value of the obtained molded article was high and good. The roll adhesion during molding was also good.

Example 3 An average degree of polymerization of 10 was used as the vinyl chloride polymer (A) component.
20, 50 parts by weight of a vinyl chloride polymer (TH-1000, manufactured by Taiyo Vinyl Co., Ltd.) produced by a suspension polymerization method having an average particle diameter of 150 μm, and as a polymer (B) component, tetrahydrofuran insoluble content 85%, average 50 parts by weight of a vinyl chloride polymer (Ryuron paste C-38, manufactured by Tosoh Corporation) having a particle size of 1.5 μm manufactured by an emulsion polymerization method was mixed to prepare a vinyl chloride polymer composition.

The surface appearance at the time of molding was smooth, and the obtained molded article had good and high fracture toughness. The roll adhesion during molding was also very good.

Example 4 An average degree of polymerization of 13 was used as the vinyl chloride polymer (A) component.
70 parts by weight of a vinyl chloride polymer (TH-1300 manufactured by Ocean PVC Co., Ltd.) produced by a suspension polymerization method having an average particle diameter of 150 μm, and a polymer (B) component having a tetrahydrofuran-insoluble content of 85% and an average A vinyl chloride polymer (Ryuron paste C-38, manufactured by Tosoh Corporation) having a particle size of 1.5 μm manufactured by an emulsion polymerization method, which was stirred in ethanol at 70 ° C. for 2 hours and washed. 30 parts by weight of the coalesced were mixed to prepare a vinyl chloride polymer composition.

The surface appearance at the time of molding was smooth, and the fracture toughness value of the obtained molded product was high and good. The roll adhesion during molding was also very good.

Example 5 An average degree of polymerization of 17 was used as the vinyl chloride polymer (A) component.
50, 95 parts by weight of a vinyl chloride polymer (manufactured by Taiyo Vinyl Co., Ltd .: TH-1700) produced by a suspension polymerization method having an average particle size of 140 μm, and as a polymer (B) component, less than 1% of a tetrahydrofuran-insoluble content, 5 parts by weight of a vinyl chloride polymer (manufactured by Tosoh Corporation: Ryuron Paste 725) produced by an emulsion polymerization method having an average degree of polymerization of 1050 and an average particle size of 1.5 μm were mixed to prepare a vinyl chloride polymer composition. .

The surface appearance at the time of molding was smooth, and the fracture toughness value of the obtained molded product was high and good. The roll adhesion during molding was also good.

Example 6 The average degree of polymerization was 17 as the vinyl chloride polymer (A) component.
50, 30 parts by weight of a vinyl chloride polymer (TH-1700, manufactured by Ocean PVC Co., Ltd.) produced by a suspension polymerization method having an average particle size of 140 μm, and as a polymer (B) component, less than 1% of a tetrahydrofuran-insoluble content, 70 parts by weight of a vinyl chloride polymer (Ryuron paste 725, manufactured by Tosoh Corporation) having an average degree of polymerization of 1050 and an average particle size of 1.5 μm were mixed to prepare a vinyl chloride polymer composition. .

The surface appearance at the time of molding was smooth, and the obtained molded article had good and high fracture toughness. The roll adhesion during molding was also good.

Comparative Example 1 An average degree of polymerization of 10 was used as the vinyl chloride polymer (A) component.
20, 99.5 parts by weight of a vinyl chloride polymer (manufactured by Taiyo PVC Co., Ltd .: TH-1000) produced by a suspension polymerization method having an average particle size of 150 μm, and 1% of a tetrahydrofuran-insoluble content as a polymer (B) component 0.5, average polymerization degree of 1050, average particle size of 1.5 μm, manufactured by an emulsion polymerization method, and 0.5 of a vinyl chloride polymer (manufactured by Tosoh Corporation: Ryuron Paste 725)
The parts by weight were mixed to prepare a vinyl chloride polymer composition.

The surface appearance during molding was not smooth, and the fracture toughness of the obtained molded article was low, which was not preferable. Roll adhesion during molding was also poor.

Comparative Example 2 An average degree of polymerization of 10 was used as the vinyl chloride polymer (A) component.
20, 10 parts by weight of a vinyl chloride polymer (TH-1000 manufactured by Ocean PVC Co., Ltd.) produced by a suspension polymerization method having an average particle size of 150 μm, and a polymer (B) component having a tetrahydrofuran-insoluble content of 85% and an average content of 85% 90 parts by weight of a vinyl chloride polymer (Ryuron paste C-38, manufactured by Tosoh Corporation) having a particle size of 1.5 μm and manufactured by an emulsion polymerization method was mixed to prepare a vinyl chloride polymer composition.

Although the surface appearance at the time of molding was smooth, the resulting molded article had a low fracture toughness, which was not preferable.

Comparative Example 3 As the vinyl chloride polymer (A) component, an average degree of polymerization of 51 was used.
0, a vinyl chloride polymer (TH-500, manufactured by Taiyo PVC Co., Ltd.) produced by a suspension polymerization method having an average particle size of 150 μm
20 parts by weight, as a polymer (B) component, 20% by weight of a vinyl chloride polymer (manufactured by Tosoh Corporation: Ryuron Paste C-38) produced by an emulsion polymerization method having a tetrahydrofuran-insoluble content of 85% and an average particle size of 1.5 μm. Were mixed to prepare a vinyl chloride polymer composition.

Although the surface appearance at the time of molding was smooth, the resulting molded article had a low fracture toughness value, which was not preferable.

Comparative Example 4 An average degree of polymerization of 10 was used as the vinyl chloride polymer (A) component.
20, 50 parts by weight of a vinyl chloride polymer (manufactured by Ocean PVC Co., Ltd .: TH-1000) produced by a suspension polymerization method having an average particle size of 150 μm, and a polymer (B) component containing less than 1% of a tetrahydrofuran-insoluble component; Average degree of polymerization 1010, average particle size 5
50 parts by weight of a vinyl chloride polymer produced by a 6 μm suspension polymerization method were mixed to prepare a vinyl chloride polymer composition. Here, the polymer (B) component was produced by the following method.

In a stainless steel polymerization machine, 100 parts by weight of a vinyl chloride monomer, 150 parts by weight of deionized water, 0.05 part by weight of t-butyl neodecaneate as an initiator, and a viscosity of 22 parts
CPS, a methoxyl group content of 22% by weight, a hydroxypropoxyl group content of 8% by weight, and 0.6 parts by weight of a water-soluble cellulose ether were charged at a temperature of 57 ° C. When the pressure reached 2.0 kg / cm2G, the mixture was filtered to recover the unreacted vinyl chloride monomer to obtain a vinyl chloride polymer slurry. The slurry thus obtained was stirred and dehydrated at 50 ° C. for 30 minutes, and further fluid-dried at 70 ° C. for 2 hours to obtain a polymer (B) component.

The surface appearance of the composition at the time of molding was not smooth, and the fracture toughness value of the obtained molded article was low, which was not preferable. Roll adhesion during molding was also poor.

Comparative Example 5 The average degree of polymerization was 13 as the vinyl chloride polymer (A) component.
00, 50 parts by weight of a vinyl chloride polymer (manufactured by Taiyo Vinyl Co., Ltd .: TH-1300) produced by a suspension polymerization method having an average particle size of 150 μm, and as a polymer (B) component, less than 1% of a tetrahydrofuran-insoluble content, Average degree of polymerization 690, average particle size 14
50 parts by weight of a vinyl chloride polymer (manufactured by Taiyo PVC Co., Ltd .: TH-700) produced by a suspension polymerization method of 0 μm was mixed to prepare a vinyl chloride polymer composition.

The surface appearance at the time of molding was not smooth, and the obtained molded article had low fracture toughness, which was not preferable. Roll adhesion during molding was also poor.

[0081]

[Table 1]

[0082]

[Table 2]

[0083]

As described above, according to the present invention, it is possible to obtain a vinyl chloride polymer having good surface appearance during molding and excellent fracture toughness of a molded article.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koji Mori 1-8 Kasumi, Yokkaichi-shi, Mie Taiyo PVC Co., Ltd. In-house F-term (reference)

Claims (7)

[Claims] 1. A vinyl chloride polymer (A) having an average degree of polymerization of 600 to 3000 and a particulate polymer (B) having an average particle size of 0.1 to 20 μm dispersed therein. A vinyl chloride polymer composition, wherein the content of the polymer (B) is 1 to 70 parts by weight based on 100 parts by weight of the combined (A). 2. The vinyl chloride polymer composition according to claim 1, wherein the polymer (B) is a vinyl chloride polymer. 3. The vinyl chloride polymer composition according to claim 1, wherein the tetrahydrofuran insoluble content of the polymer (B) is larger than the tetrahydrofuran insoluble content of the vinyl chloride polymer (A). . 4. The vinyl chloride polymer composition according to claim 1, wherein the tetrahydrofuran insoluble content of the polymer (B) is 20% by weight or more. 5. The vinyl chloride polymer composition according to claim 4, wherein the tetrahydrofuran-insoluble content of the polymer (A) is 5% by weight or less. 6. The vinyl chloride polymer composition according to claim 1, wherein the polymerization degree of the polymer (B) is larger than the polymerization degree of the vinyl chloride polymer (A). . 7. The polymerization degree of the polymer (B) is from 1500 to 4
The vinyl chloride polymer composition according to any one of claims 1 to 6, wherein the composition is not more than 000.