JP2001181462A - Vinyl chloride-based resin and molded form thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinyl chloride-based resin excellent in impact resistance and durability such as fatigue strength and creep characteristics, and to provide a molded form thereof. SOLUTION: This resin consists mainly of a vinyl vhloride-based polymer and contains an elastomer component. The other objective molded form obtained from this resin cannot be broken under the Charpy test at 23 deg.C (in accordance with JIS K-7111, using notched test pieces), being >=9.8 kJ/m2 in Charpy impact strength at 0 deg.C and being characterized by meeting at least one requirement selected from the group consisting of those, namely: (1) >=50,000 in the number of cycles until breakage in a tensile fatigue test (at 23 deg.C, stress: 0 to 29.4 MPa, frequency: 5 Hz), (2) >=20 h in 20% deformation time (the time needed until a test piece is 20% deformed under a tensile load of 12.7 MPa stress) in a tensile creep test (at 60 deg.C, in accordance with JIS K-7115) and (3) >=50 h in the time until breakage in an internal pressure creep test (at 60 deg.C, hoop stress: 12 MPa).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin and a molded product thereof.

[0002]

2. Description of the Related Art Vinyl chloride resin is a material excellent in mechanical strength, weather resistance, chemical resistance and the like, and is therefore widely used for building members, pipework equipment, housing materials and the like. Of these vinyl chloride resin molded articles, mechanical strength and impact resistance are often required, and durability such as fatigue strength is required as long-term performance. In general, since vinyl chloride resin has poor impact resistance, various modification methods have been proposed. For example, as a method for improving the impact resistance, a rubber-based resin such as chlorinated polyethylene (CPE), methyl methacrylate-butadiene-styrene copolymer (MBS), or acrylic rubber is added to a vinyl chloride resin to enhance the impact resistance. The method of blending as an agent is general.

However, in the case of a vinyl chloride resin composition containing an impact resistance enhancer, durability such as fatigue strength is inferior due to insufficient strength at the interface between vinyl chloride and a rubber component. On the other hand, JP-A-62-36412 discloses that a specific acrylic copolymer is graft-polymerized with vinyl chloride, and the interface between vinyl chloride and a rubber component is graft-bonded without impairing impact resistance. A technique capable of improving durability is disclosed. However, it is not always sufficient for applications requiring longer-term durability.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, the present invention provides a vinyl chloride resin having excellent impact resistance and excellent durability such as fatigue strength and creep characteristics, and a molded article thereof. To provide.

[0005]

Means for Solving the Problems The vinyl chloride resin of the present invention is a vinyl chloride resin containing a vinyl chloride polymer as a main component and an elastomer component, and a molding obtained from the vinyl chloride resin. The body was not broken by a Charpy test at 23 ° C. (based on JIS K 7111, using a notched test piece), had a Charpy impact strength at 0 ° C. of 9.8 kJ / m ² or more, and the following conditions:
(1) Tensile fatigue test (measuring temperature 23 ° C, stress 0 to 29.
The number of breaks at 4 MPa and a frequency of 5 Hz is 50,000 or more. (2) Tensile creep test (measuring temperature 60 ° C., JIS
20% deformation time (time required for the test piece to undergo 20% deformation under a tensile load of stress 12.7 MPa) is 20 hours or more, and (3) internal pressure creep test (measurement temperature 60 ° C. Hoop stress 12MPa)
Characterized by satisfying at least one condition selected from the group consisting of:

[0006] The hoop stress is a value calculated from the following equation. P = 2 · f · t _min / (D ₀ −t _min ) In the above formula, f is the hoop stress (MPa), P is the pressure in the tubular molded body (MPa), D ₀ is the outer diameter of the tubular molded body (cm), t
_min indicates the minimum thickness (cm) of the tubular molded body.

[0007] The vinyl chloride polymer may be a homopolymer of a vinyl chloride monomer, or a vinyl chloride monomer and another monomer copolymerizable with the vinyl chloride monomer. It may be a copolymer with a body. As other monomers copolymerizable with the vinyl chloride, for example, ethylene, propylene, allyl chloride, acrylic acid, methacrylic acid, acrylate, methacrylate, vinyl acetate,
Monomers such as maleic anhydride and acrylonitrile may be mentioned, and these may be used alone or in combination of two or more. The vinyl chloride polymer is not particularly limited, but preferably has an average degree of polymerization of 1500 to 6000 as measured by the method described in JIS K6721. When the average degree of polymerization is less than 1500, the durability such as fatigue strength and creep characteristics is not sufficiently exhibited, and when it exceeds 6000, molding becomes extremely difficult.

The content of the above elastomer component in the vinyl chloride resin is not particularly limited, but is preferably 4 to 2 times.
A range of 0% by weight is preferred. If the content is less than 4% by weight, impact resistance may not be sufficiently exhibited. If the content exceeds 20% by weight, durability such as fatigue strength and creep characteristics and mechanical strength may be reduced. There is.

As the elastomer component, for example,
Chlorinated polyethylene (CPE), methyl methacrylate
Butadiene-styrene copolymer (MBS), alkyl (meth) acrylate resin, and the like.

As a method for incorporating the above-mentioned elastomer component into the vinyl chloride resin, there are a method of blending the elastomer component and a method of copolymerizing, and any method may be used.

When the above copolymerization method is adopted,
As the elastomer component, an alkyl (meth) acrylate resin is suitably used. As a method of copolymerizing, a method of graft copolymerizing the above-mentioned vinyl chloride polymer with the above-mentioned alkyl (meth) acrylate resin is preferable.

The above-mentioned alkyl (meth) acrylate resin is preferably a resin mainly composed of an alkyl (meth) acrylate monomer having a glass transition temperature of a homopolymer of less than -20 ° C. Examples of the alkyl (meth) acrylate monomer include ethyl acrylate, n-propyl acrylate, isobutyl acrylate, n-butyl acrylate, sec-butyl acrylate, and n-
Hexyl acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, isooctyl acrylate, n-decyl (meth) acrylate, n-
Nonyl (meth) acrylate, isononyl acrylate, 2-acryloyloxyethyl succinic acid and the like can be mentioned. These may be used alone or in combination of two or more.

The form and structure of the alkyl (meth) acrylate resin are not particularly limited. For example, a core-shell structure in which the monomer composition of the inside (core portion) and the surface layer portion (shell portion) of the resin particles are different is targeted. It is preferable because the core portion and the shell portion can have different functions depending on the performance. As the alkyl (meth) acrylate monomer used for the core portion, in view of improving the impact resistance of the molded article, it is preferable to use a monomer having a low glass transition temperature. For example, 2-ethylhexyl acrylate is suitably used. For the shell portion, n-butyl acrylate is preferably used from the viewpoint of improving the handleability of the alkyl (meth) acrylate resin.

The above alkyl (meth) acrylate resin includes the above alkyl (meth) acrylate monomer 1
The polyfunctional monomer may be added in an amount of 0.01 to 15 parts by weight with respect to 00 parts by weight. When the addition amount of the polyfunctional monomer is less than 0.01 parts by weight based on 100 parts by weight of the alkyl (meth) acrylate monomer, the durability of the finally obtained molded product is reduced, and the amount is 15 parts by weight. If it exceeds, impact resistance is reduced.

The polyfunctional monomer is not particularly limited as long as it can be copolymerized with the alkyl (meth) acrylate monomer. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane di (meth)
Polyfunctional acrylates such as acrylate and trimethylolpropane tri (meth) acrylate; polyfunctional allyl compounds such as diallyl phthalate, diallyl maleate and triallyl isocyanurate; and unsaturated compounds such as butadiene. These may be used alone or in combination of two or more.

The method for obtaining the above alkyl (meth) acrylate resin is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method. Considering the impact resistance, the emulsion polymerization method is preferred. In the emulsion polymerization method, in order to improve the dispersion stability of the above-mentioned alkyl (meth) acrylate monomer in an emulsion and efficiently carry out the polymerization,
An emulsifying dispersant is added. The emulsifying dispersant is not particularly limited, and examples thereof include an anionic surfactant, a nonionic surfactant, a partially saponified polyvinyl alcohol, a cellulose dispersant, and gelatin.

In the emulsion polymerization method, a polymerization initiator is used. The polymerization initiator is not particularly limited, for example,
Examples thereof 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 azo initiators such as azobisisobutyronitrile. Further, if necessary, a pH adjuster, an antioxidant, and the like may be added.

The emulsion polymerization method is not particularly limited.
From the difference in the method of adding the monomer, for example, a batch polymerization method,
Examples include a monomer dropping method and an emulsion dropping method.
The batch polymerization method is, for example, in a jacketed polymerization reactor,
Pure water, an emulsifying dispersant, a polymerization initiator and a mixed monomer [the above-mentioned alkyl (meth) acrylate monomer + the above-mentioned polyfunctional monomer to be added as necessary] are added all at once,
Under a condition of removing oxygen by a nitrogen gas stream and pressurizing, the mixture is sufficiently emulsified by stirring and then heated by a jacket to polymerize.

In the monomer dropping method, for example, pure water, an emulsifying dispersant, and a polymerization initiator are charged into a jacketed polymerization reactor,
Under the conditions of oxygen removal and pressurization under a nitrogen stream,
First, after the inside of the vessel is heated by a jacket, the above-mentioned mixed monomer is dropped by a predetermined amount to gradually polymerize.

In the emulsion dropping method, for example, the above-mentioned mixed monomer, emulsifying dispersant, and pure water are sufficiently emulsified by stirring to prepare an emulsifying monomer in advance, and then pure water and a polymerization initiator are introduced into a jacketed polymerization reactor. In this method, the vessel is first heated by a jacket under the conditions of oxygen removal and pressurization under a nitrogen stream, and then the above-mentioned emulsified monomer is dropped by a predetermined amount to carry out polymerization.

In the case where the above-mentioned alkyl (meth) acrylate resin has a core-shell structure, the forming method is not particularly limited. For example, first, a mixed monomer constituting the core portion [the above-mentioned alkyl (meth) acrylate monomer + Polyfunctional monomer added as needed], a polymerization initiator is added to an emulsified monomer prepared from pure water and an emulsifier to carry out a polymerization reaction to form resin particles in a core portion, and then a shell portion is formed. Add the constituent monomer [the alkyl (meth) acrylate monomer + the polyfunctional monomer optionally added], the emulsifying monomer prepared from pure water and an emulsifier, and graft copolymerize the shell to the core And the like.

The alkyl (meth) thus obtained
In the acrylate resin, the shell part three-dimensionally covers the surface of the core part, and the copolymer forming the shell part and the copolymer forming the core part are partially covalently bonded to each other, and the shell part is formed. The part forms a three-dimensional crosslinked structure. In the above method, the graft copolymerization of the shell may be continuously performed in the same polymerization step as the polymerization of the core.

The ratio of the core part and the shell part can be adjusted by adjusting the ratio of the mixed monomer forming the core part and the mixed monomer forming the shell part in the emulsion polymerization method.

As the vinyl chloride resin of the present invention, an alkyl (meth) acrylate resin obtained by the above-mentioned method is used, and vinyl chloride or a copolymer of vinyl chloride and vinyl chloride is added to the alkyl (meth) acrylate resin. Those obtained by graft-copolymerizing a vinyl chloride polymer composed of other possible monomers are preferably used.

The method for obtaining the vinyl chloride resin is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method. Among them, the suspension polymerization method is preferred. In the suspension polymerization method, the dispersion stability of the alkyl (meth) acrylate resin is improved, and the graft copolymerization of vinyl chloride or a mixture of vinyl chloride and another monomer copolymerizable with vinyl chloride is efficiently performed. A dispersant and an oil-soluble polymerization initiator are used for this purpose.

The dispersant is not particularly restricted but includes, for example, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, polyvinyl alcohol, partially saponified polyvinyl acetate, gelatin, polyvinylpyrrolidone, starch maleic anhydride-styrene copolymer and the like. No. These may be used alone or in combination of two or more.

As the oil-soluble polymerization initiator, a radical polymerization initiator is preferably used from the viewpoint of being advantageous for graft copolymerization. The polymerization initiator used in the present invention is, for example, t
-Butyl peroxy pivalate, diisopropyl peroxy dicarbonate, t-butyl peroxy neodecanoate, α-cumyl peroxy neodecanoate, isobutyryl peroxide, α, α 'bis (neodecanoyl peroxy) Diisopropylbenzene, 1,1,3
Organic peroxides such as 3-tetramethylbutylperoxy neodecanoate; 2,2-azobis-2,4-
Examples include azo compounds such as dimethylvaleronitrile.

The preferred degree of polymerization of the vinyl chloride polymer constituting the vinyl chloride resin is in the range of 1500 to 6000. In order to obtain the above polymerization degree, it is important to control the polymerization temperature. In order to increase the degree of polymerization, it is necessary to lower the polymerization temperature. Therefore, the polymerization temperature is changed according to the desired degree of polymerization, and it is necessary to appropriately select the polymerization initiator according to the desired degree of polymerization.

In the above suspension polymerization method, if necessary, p
An H adjuster, an antioxidant and the like may be added.

In the above suspension polymerization method, specifically,
For example, in a reaction vessel equipped with a stirrer and a jacket, pure water, the alkyl (meth) acrylate resin, a dispersant,
An oil-soluble polymerization initiator and, if necessary, a polymerization regulator are charged, and then the air in the polymerization vessel is discharged by a vacuum pump, and further, under stirring conditions, vinyl chloride and, if necessary, other After the vinyl monomer is charged, the inside of the reaction vessel is heated by a jacket to carry out graft copolymerization of vinyl chloride.

Since the above-mentioned graft copolymerization of vinyl chloride is an exothermic reaction, the temperature in the reaction vessel can be controlled by changing the jacket temperature. After the completion of the reaction, the unreacted vinyl chloride is removed to form a slurry, and the slurry is dehydrated and dried to produce a vinyl chloride resin. Since the vinyl chloride resin produced by the above production method is obtained by graft copolymerizing a vinyl chloride polymer with an alkyl (meth) acrylate resin,
A vinyl chloride resin molded article having excellent impact resistance can be formed.

When the vinyl chloride resin of the present invention is molded, a heat stabilizer, a lubricant, a modifier, a processing aid, which is generally used as a molding additive for the vinyl chloride resin before molding, A filler, a coloring agent, and the like may be appropriately added.

The heat stabilizer is not particularly restricted but includes, for example, dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, 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, and barium-zinc-based stabilizers Agents, barium-cadmium stabilizers and the like. These may be used alone or in combination of two or more.

The method for mixing the above-mentioned additives with the above-mentioned vinyl chloride resin is not particularly limited, and examples thereof include a method using hot blending and a method using cold blending. The method for molding the vinyl chloride resin composition of the present invention is not particularly limited, but an extrusion molding method, a press molding method, or the like is preferable in consideration of a resin having a high degree of polymerization.

Since the vinyl chloride resin of the present invention has a high degree of polymerization, it has a high melt viscosity at the time of molding, and it is expected that gelation is difficult. Can be formed using an ordinary extruder. Further, in the case of a high degree of polymerization, the resin is once kneaded at a relatively low temperature of from the glass transition temperature of the resin to 180 ° C. to disintegrate the resin's particle hierarchical structure (eg, grain particle structure).
It is desirable to perform melt molding in the range of 80 ° C to 230 ° C.

The above-mentioned disintegration and melt molding may be performed by a batch process or a continuous process. Further, each of them may be performed in a separate process or may be performed inline. Considering molding efficiency and the like, it is more preferable to use an extruder. When using an extruder, disintegration and melt molding may be performed sequentially with one extruder, or may be performed with two sets of tandem extruders.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 [Preparation of alkyl (meth) acrylate resin] 70 parts by weight of 2-ethylhexyl acrylate, 0.1 part by weight of trimethylolpropane triacrylate (TMPTA),
0.7 parts by weight of sodium dodecylbenzenesulfonate,
200 parts by weight of pure water was mixed to prepare a monomer mixture for the core layer, and 30 parts by weight of n-butyl acrylate, TMPT
A1.5 parts by weight of A, 0.3 parts by weight of sodium dodecylbenzenesulfonate and 25 parts by weight of pure water were mixed to prepare a monomer mixture for the shell layer. Next, into a reaction vessel equipped with a stirrer and a reflux condenser, 20% by weight of the above-mentioned monomer mixture solution for the core layer was collectively charged as a seed monomer, and oxygen in the vessel was replaced with nitrogen. The vessel was heated to 70 ° C. After the temperature was raised, 0.1 part by weight of ammonium persulfate (polymerization initiator) was added to the reactor to cause a reaction, and then the remaining monomer mixture for the core layer was dropped and polymerized. As soon as the dropping of the core layer monomer mixture was completed, the shell layer monomer mixture was dropped. The dropping of all emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated to obtain an acrylic copolymer having a solid content of 30% by weight.

[Preparation of Vinyl Chloride Resin] Then, 2000 ppm of pure water, the acrylic copolymer, and partially saponified polyvinyl alcohol (Kuraray Povar L-8, manufactured by Kuraray Co., Ltd.) were placed in a reaction vessel equipped with a stirrer and a jacket. , Α
-Cumyl peroxy neodecanoate (polymerization initiator) 1
000 ppm at a time, and then the air in the polymerization vessel was discharged by a vacuum pump. After vinyl chloride was further added under stirring conditions, the mixture was stirred for 30 minutes to uniformly mix the vinyl chloride and jacket temperature. Was initiated at a polymerization temperature of 43.0 ° C. The pressure in the reactor is 0.
The completion of the reaction was confirmed by dropping to a pressure of 57 MPa. Thereafter, unreacted vinyl chloride was removed, and further dehydration drying was performed to obtain a vinyl chloride resin having an elastomer component content of 5.3% by weight.

[Measurement of Degree of Polymerization] After dissolving 500 mg of the obtained vinyl chloride resin in 100 ml of nitrobenzene,
Insoluble components were removed by filtration through a 200 mesh wire mesh.
JIS for vinyl chloride resin from which unnecessary components have been removed
The degree of polymerization was measured according to K6721.

[Production of molded article of vinyl chloride resin] Tin stabilizer (“ONZ-
142F ", 2 parts by weight, manufactured by Sankyo Co., Ltd .; 0.5 parts by weight of polyethylene wax (" HIWAX220MP ", manufactured by Mitsui Chemicals) as a lubricant;" SC100 "(manufactured by Sakai Chemicals)
After adding 0.5 parts by weight and 2.0 parts by weight of "P501A" (manufactured by Mitsubishi Rayon Co., Ltd.) as a processing aid, mixing with a Henschel mixer, using an 8-inch roll, the roll temperature was 210 ° C., and after winding, 3 parts. Kneading for 5 minutes to produce a roll sheet, and then using a hand press, at a pressure of 10 MPa,
Pressing was performed at a temperature of 220 ° C. under the conditions of a preheating time of 3 minutes and a pressurizing time of 3 minutes, to produce a plate-like molded body having a thickness of 3 mm.

[Evaluation of Physical Properties] The physical properties of the vinyl chloride resin molded article were evaluated by the following methods. The results are summarized in Table 1. (Impact resistance) In accordance with JIS K 7111, a Charpy impact test was performed at 23 ° C and 0 ° C using a notched test piece prepared by cutting the sample. (Fatigue strength) Using a No. 1 type dumbbell test piece (thickness 3 mm) described in JIS K 7113, at 23 ° C., maximum stress 2
A tensile load (29.4 MPa → 0 MPa → 29.4 MPa) was repeatedly applied under the conditions of 9.4 MPa and a frequency of 5 Hz, and the number of repetitions until breaking was measured. (Tensile creep test) Using a No. 1 type dumbbell test piece (thickness: 3 mm) described in JIS K 7115, a tensile load was applied under the conditions of 60 ° C. and stress of 29.4 MPa, and the change over time of the test piece was observed. Was measured for the time it took to deform by 20%.

Example 2 100 parts by weight of the vinyl chloride resin produced in Example 1 were 2 parts by weight of a tin-based stabilizer ("ONZ-142F", manufactured by Sankyo Co., Ltd.), and polyethylene wax ("HIWAX") was used as a lubricant.
220MP, manufactured by Mitsui Chemicals, Inc.) 0.5 parts by weight, "SC1
00 "(manufactured by Sakai Chemical Co., Ltd.) and 2.0 parts by weight of" P501A "(manufactured by Mitsubishi Rayon Co., Ltd.) as processing aids, and mixed with a Henschel mixer.
Using an extruder (manufactured by Nagata Seisakusho), extruded resin temperature 218
Extrusion molding was performed at 25 ° C. and a screw rotation speed of 25 rpm to produce a tubular molded body having an outer diameter of 20 mm and a thickness of 3 mm. The obtained molded product was evaluated for impact resistance, internal pressure creep test, fatigue strength and tensile creep test. Table 1 shows the results. (Internal pressure creep test) In a hot water bath at 60 ° C, water pressure was applied to and held in the tubular molded body so that the hoop stress became 12 MPa, and the time to breakage was measured.

Example 3 The polymerization temperature for producing a vinyl chloride resin was 39.0 ° C.
A plate-like molded body was produced in the same manner as in Example 1 except that the above conditions were adopted. The obtained molded product was evaluated for impact resistance, fatigue strength and tensile creep test. Table 1 shows the results.

Example 4 A tubular molded body was produced in the same manner as in Example 2 except that the vinyl chloride resin produced in Example 3 was used. The obtained molded product was evaluated for impact resistance, internal pressure creep test, fatigue strength and tensile creep test. Table 1 shows the results.

Example 5 The polymerization temperature at the time of producing a vinyl chloride resin was 36.0 ° C.
A plate-like molded body was produced in the same manner as in Example 1 except that the above conditions were adopted. The obtained molded product was evaluated for impact resistance, fatigue strength and tensile creep test. Table 1 shows the results.

Example 6 The polymerization temperature for producing a vinyl chloride resin was 36.0 ° C.
And the amount of the acrylic copolymer to be added was adjusted to obtain a plate-like molded body in the same manner as in Example 1 except that the content of the elastomer component was changed to a vinyl chloride-based resin having an amount of 11.0% by weight. Produced. The obtained molded product was evaluated for impact resistance, fatigue strength and tensile creep test. Table 1 shows the results.

Example 7 The polymerization temperature for producing a vinyl chloride resin was 31.5 ° C.
A plate-like molded body was produced in the same manner as in Example 1 except that isobutyl peroxide was used as a polymerization initiator. The obtained molded product was evaluated for impact resistance, fatigue strength and tensile creep test. Table 1 shows the results.

Comparative Example 1 The polymerization temperature for producing a vinyl chloride resin was 53.6 ° C.
After preparing a vinyl chloride resin in the same manner as in Example 1 except that α-cumyl peroxy neodecanoate and di-sec-butyl peroxy dicarbonate were used in combination as polymerization initiators, 100 parts by weight of a vinyl resin, 2 parts by weight of a tin-based stabilizer (“ONZ-142F”, manufactured by Sankyo Co., Ltd.), and polyethylene wax (“H
IWAX220MP ", manufactured by Mitsui Chemicals, Inc.) 0.5 parts by weight,
After adding 0.5 parts by weight of "SC100" (manufactured by Sakai Chemical Co.) and 2.0 parts by weight of "P501A" (manufactured by Mitsubishi Rayon Co., Ltd.) as a processing aid and mixing with a Henschel mixer,
Extrusion molding was performed using an LM50 extruder (manufactured by Nagata Seisakusho) at an extrusion resin temperature of 194 ° C. and a screw rotation speed of 25 rpm to produce a pipe-shaped molded product having an outer diameter of 20 mm and a thickness of 3 mm. The obtained molded product was evaluated for impact resistance, internal pressure creep test, fatigue strength and tensile creep test. Table 1 shows the results.

Comparative Example 2 A vinyl chloride resin having a degree of polymerization of 3000 ("TK" manufactured by Shin-Etsu Chemical Co., Ltd.)
-2500PE ”) in 100 parts by weight of a tin-based stabilizer (“ ON
Z-142F, Sankyoki Co., Ltd.) 2 parts by weight, polyethylene wax ("HIWAX220MP", Mitsui Chemicals) 0.5 part by weight as a lubricant, "SC100" (Sakai Chemicals) 0.5 part by weight and "P501A" as a processing aid
After adding 2.0 parts by weight (manufactured by Mitsubishi Rayon Co., Ltd.) and mixing with a Henschel mixer, using an 8 inch roll,
Roll temperature 210 ° C, kneading for 3 minutes after winding to prepare a roll sheet, and then using hand press, pressure 10MPa
a, Pressing was performed at a temperature of 220 ° C. under the conditions of a preheating time of 3 minutes and a pressurizing time of 3 minutes to produce a plate-like molded body having a thickness of 3 mm. The obtained molded product was evaluated for impact resistance, fatigue strength and tensile creep test. Table 1 shows the results.

[0051]

[Table 1]

[0052]

Since the vinyl chloride resin of the present invention is constituted as described above, by producing a molded body using the vinyl chloride resin, impact resistance, fatigue strength and tensile creep resistance can be attained. It can greatly improve the properties and the like, and is suitably used particularly in applications requiring impact resistance and durability such as building materials, plumbing equipment and housing materials.

Claims (7)

[Claims] 1. A vinyl chloride resin containing a vinyl chloride polymer as a main component and an elastomer component, and a molded product obtained from the vinyl chloride resin is subjected to a Charpy test at 23 ° C. (JIS K 7111). Not destroyed by compliant, using a notched test piece), the Charpy impact strength at 0 ° C. is 9.8 kJ / m ² or more, and the following conditions: (1) Tensile fatigue test (measuring temperature 23 ° C., stress 0 to 2)
The number of breaks at 9.4 MPa and a frequency of 5 Hz is 50,000 or more. (2) Tensile creep test (measured at 60 ° C., J
20% deformation time (time required for the test piece to undergo 20% deformation under a tensile load of stress 12.7 MPa) of 20 hours or more in accordance with IS K 7115) and (3)
Internal pressure creep test (measurement temperature 60 ° C, hoop stress 12M
A vinyl chloride resin characterized by satisfying at least one condition selected from the group consisting of a breaking time of 50 hours or more in Pa). 2. The vinyl chloride resin according to claim 1, wherein the average degree of polymerization of the vinyl chloride polymer is from 1500 to 6000. 3. The vinyl chloride polymer according to claim 1, wherein the average degree of polymerization is from 1500 to 6000, and the content of the elastomer component in the vinyl chloride resin is from 4 to 20% by weight. Vinyl chloride resin. 4. The method according to claim 1, wherein the elastomer component is an alkyl (meth) acrylate resin,
4. The vinyl chloride resin according to claim 2, wherein the vinyl chloride resin is a vinyl chloride resin obtained by graft copolymerizing a vinyl chloride polymer with an acrylate resin. 5. The vinyl chloride resin according to claim 4, wherein the alkyl (meth) acrylate resin has a core-shell structure of 2-ethylhexyl acrylate and n-butyl acrylate. 6. A molded article of a vinyl chloride resin, comprising the vinyl chloride resin according to any one of claims 1 to 5. 7. A vinyl chloride resin molded article according to claim 6, wherein the molded article is a tubular molded article.