JP2001182869A - Heat-resistant vinyl chloride resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant vinyl chloride resin pipe which has high heat-resistant performance, which is capable of improving shock strength and mechanical strength, and which has good suppression of crack propagation. SOLUTION: The heat-resistant vinyl chloride resin pipe is formed in such a constitution that a resin pipe formed by molding vinyl chloride resin composition which is substantially composed of 100 pts.wt. of chlorinated vinyl chloride resin whose a content of chlorine is 60 to 71 wt.% and an average polymerization degree of vinyl chloride resin before chlorination is 60 to 1400, and 0.5 to 5 pts.wt. of alkyl tin mercapto compound or alkyl tin maleate compound, is extended by 1.3 to 2.5 times in a pipe circumferential direction and by 1 to 2.5 times in the pipe axial direction, in a temperature region of 120 to 170 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a heat-resistant vinyl chloride resin tube obtained by molding a vinyl chloride resin composition.

[0002]

2. Description of the Related Art A molded article of vinyl chloride resin has mechanical strength,
Utilizing excellent properties such as chemical resistance and oil resistance, for example,
It is widely used for building materials, water supply, agricultural, industrial pipes and joints, flat plates, etc., and is also used in applications requiring heat resistance.

As a method for improving the heat resistance of a vinyl chloride resin molded product, there is a method of producing a molded product using a chlorinated vinyl chloride resin composition obtained by chlorinating a vinyl chloride resin.

According to this method, it is possible to use the molded article of vinyl chloride resin, for example, as a hot water supply pipe, a fire extinguisher sprinkler pipe, an industrial pipe, an industrial board, and the like.
It has become possible to use various molded products in application fields or use environments that cannot be used with conventional vinyl chloride resin molded products.

[0005]

However, a tube formed using a chlorinated vinyl chloride resin molded article has a problem that the impact resistance and the crack propagation property are not sufficient. For example, Japanese Patent Application Laid-Open No. 10-296831 proposes a method for improving impact resistance. However, mechanical strength and heat resistance other than impact resistance are reduced, and mechanical strength and heat resistance are reduced. If it is reduced, the creep property and the water pressure resistance are reduced, so that when used as a hot water supply pipe, a fire extinguisher sprinkler piping material, or an industrial piping material, there is a problem that the use environment and the life are greatly limited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to improve heat resistance, improve impact strength and mechanical strength, and furthermore, to provide a heat resistant material which is excellent in suppressing crack propagation. An object of the present invention is to provide a polyvinyl chloride resin tube.

[0007]

That is, a first aspect of the present invention is a chlorinated chloride having a chlorine content of 60 to 71% by weight and an average degree of polymerization of the vinyl chloride resin before chlorination of 60 to 1400. Vinyl resin: 100 parts by weight, alkyltin mercapto compound or alkyltin malate compound: 0.5
A resin pipe obtained by molding a vinyl chloride resin composition consisting essentially of 1 to 5 parts by weight, in a temperature range of 120 to 170 ° C., 1.3 to 2.5 times in a pipe circumferential direction, in a pipe axial direction. The present invention provides a heat-resistant vinyl chloride resin tube which is stretched 1 to 2.5 times.

[0008] Further, the second present invention provides that the chlorine content is 6%.
0 to 71% by weight, chlorinated vinyl chloride resin having an average degree of polymerization of 60 to 1400 before chlorination: 100 parts by weight, alkyltin mercapto compound or alkyltin malate compound: 0.5 to 5 Parts by weight, chlorinated polyethylene having a chlorine content of 30 to 40% by weight:
In a temperature range of 120 to 170 ° C., a resin pipe obtained by molding a vinyl chloride resin composition consisting essentially of 20 parts by weight is 1.3 to 2.5 times in the pipe circumferential direction and in the pipe axis direction. An object of the present invention is to provide a heat-resistant vinyl chloride resin tube which is stretched by 1 to 2.5 times.

Further, the present invention provides a chlorinated vinyl chloride resin having a chlorine content of 60 to 71% by weight and an average degree of polymerization of the vinyl chloride resin before chlorination of 60 to 1400: 100 parts by weight. Molding a vinyl chloride resin composition consisting essentially of: an alkyltin mercapto compound or an alkyltin malate compound: 0.5 to 5 parts by weight, and a methacrylate resin having a weight average molecular weight of 500 to 5,000,000: 1 to 15 parts by weight. Characterized in that the obtained resin pipe is stretched 1.3 to 2.5 times in the pipe circumferential direction and 1 to 2.5 times in the pipe axis direction in a temperature range of 120 to 170 ° C. The present invention provides a vinyl chloride resin tube.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

The chlorinated vinyl chloride resin used in the present invention has a chlorine content of 60 to 71% by weight and an average degree of polymerization of the chlorinated vinyl chloride of 600 to 1400.

As the chlorination method of the vinyl chloride resin, a conventionally known water suspension method, solution chlorination method and the like are used, but the water suspension method is industrially preferable. As a method of adjusting the chlorine content to the above range, it may be adjusted at the reaction stage, or may be adjusted by blending a vinyl chloride resin having a high chlorine content and a vinyl chloride resin having a low chlorine content. Good.

The vinyl chloride resin before being chlorinated as described above includes a vinyl chloride homopolymer, a copolymer with a copolymerizable monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer, and a vinyl chloride monomer as the polymer. And a graft copolymer obtained by graft copolymerizing the above. In the present invention, these polymers may be used alone, or two or more of them may be used in combination. As the polymerization method, conventionally known bulk polymerization, solution polymerization, emulsion polymerization and the like are used, and the above-mentioned degree of polymerization is adjusted in the polymerization stage.

Examples of the copolymerizable monomer having an unsaturated bond copolymerizable with vinyl chloride include α-olefins such as ethylene, propylene and butylene; vinyl acetate;
Vinyl esters such as vinyl propionate; vinyl ethers such as butyl vinyl ether and cetyl vinyl ether; (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate, and phenyl methacrylate; styrene, α-
Aromatic vinyls such as methylstyrene; vinylidene chloride;
Vinyl halides such as vinylidene fluoride; N-phenylmaleimide and N-cyclohexylmaleimide;
Substituted maleimides and the like may be mentioned, and one or more of these may be used. The polymer for graft copolymerization of vinyl chloride is not particularly limited as long as it is a polymer for graft polymerization of vinyl chloride.
Vinyl acetate copolymer; ethylene-vinyl acetate-carbon monoxide copolymer; ethylene-ethyl acrylate copolymer;
Ethylene-butyl acrylate-carbon monoxide copolymer;
Ethylene-methyl methacrylate copolymer; ethylene-propylene copolymer; acrylonitrile-butadiene copolymer; polyurethane; chlorinated polyethylene; chlorinated polypropylene, and the like. They may be used together.

In the present invention, the chlorine content of the chlorinated vinyl chloride resin must be 60 to 71% by weight.
Preferably, it is 62 to 68% by weight. Chlorine content is 6
If it is less than 0% by weight, sufficient heat resistance cannot be obtained.
If the amount exceeds 50% by weight, the moldability becomes difficult, so the amount is limited to 60 to 71% by weight.

[0016] The chlorine content is determined by neutralization by an oxygen flask combustion method. (Based on JIS K7229)

In the present invention, the average degree of polymerization represents the average degree of polymerization of the vinyl chloride resin before chlorination and is determined by a solution viscosity method and must be 600 to 1400. Preferably it is 700-1100. When it is less than 600, when the average degree of polymerization of vinyl chloride before chlorination becomes small, elongation characteristics at the stretching temperature are deteriorated, cracks are easily generated at the time of stretch molding, and the impact strength of the molded product may be reduced. is there. On the other hand, if it is larger than 1400, the formability of the original tube before stretching may be deteriorated.

Examples of the alkyltin mercapto compound used in the present invention include dialkyltin mercapto such as dibutyltin mercapto, dioctyltin mercapto and dimethyltin mercapto; monoalkyltin mercapto such as monobutyltin mercapto, monooctyltin mercapto and monomethyltin mercapto. Mercapto is preferably used.

As the alkyltin maleate compound used in the present invention, for example, dibutyltin maleate, dibutyltin maleate polymer, dioctyltin maleate, dioctyltin maleate polymer and the like are preferably used.

The amount of the above-mentioned alkyltin mercapto compound or alkyltin malate compound to be used is 0.5 to 5 parts by weight based on 100 parts by weight of the chlorinated vinyl chloride resin. 0.5
If the amount is less than 5 parts by weight, the heat stabilizing effect may be reduced. If the amount is more than 5 parts by weight, the heat resistance may be significantly reduced.

The chlorinated polyethylene used in the second invention is a chlorinated polyethylene obtained by chlorinating polyethylene by a conventional method. When chlorinated polyethylene is blended, the molding load is reduced, the stretch formability and the impact resistance after the stretch molding are improved, and the appearance of the molded resin tube is improved.

The chlorine content of the chlorinated polyethylene is determined by neutralization by an oxygen flask combustion method. (JI
SK7229), which must be 30 to 40% by weight. If the chlorine content is less than 30% by weight, the physical properties of the resin tube are adversely affected. If the chlorine content exceeds 40% by weight, it may not contribute to the improvement of impact resistance.

The weight average molecular weight of the chlorinated polyethylene is 5
It is preferably from 0000 to 400,000, more preferably from 150,000 to 350,000. When the weight average molecular weight is less than 50,000 or more than 400,000, it may not contribute to the improvement of impact resistance. The weight average molecular weight is a value in terms of polystyrene measured by GPC.

The methacrylate ester resin used in the third aspect of the present invention improves the appearance of the resin tube and the elongation characteristics at the time of stretching, and provides stable stretch moldability during stretch molding.
The methacrylate resin is preferably polymethyl methacrylate (PMMA). Further, the methacrylate resin may be a copolymer of a methacrylate monomer and a copolymerizable monomer.

In the present invention, the weight molecular weight of the methacrylate resin is limited to 500,000 to 5,000,000. If the molecular weight is small, there is no effect on the elongation characteristic direction at the stretching temperature, and if the molecular weight is too large, the moldability (molding load, etc.) of the resin tube is deteriorated, and the tensile strength at the stretching temperature becomes large, which makes stretching molding difficult. . The weight average molecular weight is a value in terms of polystyrene measured by GPC.

The amount of the methacrylate resin is 1 to 15 parts by weight based on 100 parts by weight of the chlorinated vinyl chloride resin. If the amount is less than 1 part by weight, the effect of the methacrylate resin compounding is not exhibited, and if it exceeds 15 parts by weight,
The load at the time of molding is increased and the cost is disadvantageous.

In the chlorinated vinyl chloride resin composition used in the present invention, a polyvinyl chloride resin and di-2-ethylhexyl phthalate (DO
P), plasticizers such as 2-ethylhexyl adipate (DOA); lubricants such as polyethylene wax, ester wax, stearic acid, montanic acid wax, calcium stearate; CPE-based reinforcing agents, MBS-based reinforcing agents; Modifiers such as acrylic tougheners; pigments; antistatic agents;
Flame retardant; inorganic fillers such as calcium carbonate, talc, clay, mica and the like are added, and by a conventionally known means,
It is manufactured by mixing each component uniformly.

The above chlorinated vinyl chloride resin composition is formed into a resin tube as a raw tube by a conventionally known molding method, and then the raw tube is stretched in a temperature range of 120 to 170 ° C. Is manufactured.

The stretching method in the present invention is not particularly limited. For example, a method of stretching a raw tube at a stretching temperature of 120 ° C. to 170 ° C. in a circumferential and axial direction by a stretching die, or a method of stretching a raw tube with air or a liquid. A method for stretching in the circumferential and axial directions by heating to a temperature of 120 ° C. to 170 ° C. and pressing, 1
For example, there is a method in which a billet is stretched by solid extrusion at 20 ° C to 170 ° C.

The stretching ratio is from 1.3 to 1.3 in the circumferential direction of the tube.
It is limited to 2.5 times and the tube axis direction to 1 to 2.5 times. If the stretching ratio is small, the improvement in mechanical properties is small, and the effect of improving crack propagation is also small. If the stretch ratio is large, stretch molding becomes difficult, and the elongation of the tube is reduced, the tube becomes weak against displacement, and the tube is easily broken. In the present invention, the stretching ratio refers to a rate of change in outer diameter of a pipe (OD
₁ / OD ₀ OD ₁ : Outer diameter of tube after stretching, OD ₀ : Outer diameter of original tube before stretching), and tube length change rate (L ₁
/ L ₀ L ₁ : length of the tube after stretching, L ₀ : length of the tube before stretching).

[0031]

The present invention will be described more specifically with reference to the following examples. The present invention is not limited by these examples.

A predetermined amount of chlorinated vinyl chloride resin ("HA-05H" manufactured by Tokuyama Sekisui Kogyo Co., Ltd., average degree of polymerization before chlorination 500, chlorine content 65% by weight, "HA-24"
K ", average degree of polymerization before chlorination 700, chlorine content 67% by weight," HA-34F "average degree of polymerization before chlorination 800, chlorine content 65% by weight," HA-52K "average degree of polymerization before chlorination 1000 , Chlorine content 67% by weight, "HA-52KX
(Prototype), average degree of polymerization before chlorination 1000, chlorination degree 70.0% by weight), polyvinyl chloride resin ("TS-1000R", manufactured by Tokuyama Sekisui Industry Co., Ltd., average degree of polymerization 1000), alkyltin mercapto compound And / or alkyltin maleate compound, chlorinated polyethylene (CPE: "JMR135C" manufactured by Daiso Corporation, chlorine content 35% by weight, Showa Denko Corporation "Eraslen 202BH (S)" chlorine content 22% by weight, "Eraslen 452NA" chlorine) Content: 45% by weight), methacrylic acid ester resin ("METABLEN P" manufactured by Mitsubishi Rayon Co., Ltd.), stearic acid ("Stearic Acid Sakura" manufactured by NOF Corporation), polyethylene lubricant ("Hiwax220MP" manufactured by Mitsui Petrochemical Co., Ltd.) ) Was heated to 120 ° C. with a Henschel mixer and mixed to prepare a resin composition. Each size raw material pipe by supplying to 0mm biaxial extractor was extruded. Then, 114mm inside diameter,
It is set in a mold having a length of 2 m, the inner and outer surfaces of the original tube are heated to 120 ° C. to 170 ° C. with polyethylene glycol, and only the inner surface is pressurized by a pump.
A resin tube stretched to 5 mm was formed.

The following evaluation items were tested on the obtained resin pipes, and the results are shown in each table. "Evaluation items" Original tube formability: Observed visually and evaluated according to the following evaluation criteria. ：: No problem in molding load and appearance. ×: Thermal decomposition occurred during molding, and molded products could not be collected. Appearance after stretching: Observed visually and evaluated according to the following evaluation criteria. ：: The wall thickness accuracy is equivalent to the wall thickness accuracy of the original pipe, and the smoothness of the inner and outer surfaces is good. ：: The wall thickness precision is worse than the wall thickness accuracy of the raw pipe. ×: A thin wall portion is locally generated. Vigat softening temperature: JIS K 7206 Compliant (1K
g load) Stretching ratio: Peripheral direction Change rate of outer diameter of tube (OD ₁ / OD ₀ ,
OD ₁ : Outer diameter of pipe after stretching, OD ₀ : Before stretching, OD ₀ : Outer diameter of original pipe) Axial length change rate of pipe (L ₁ / L ₀ , L ₁ : Length of pipe after drawing) (L ₀ : length of tube before stretching) Dropping impact value: After adjusting the condition of a 25 cm short tube of a test sample at 0 ° C. for 60 minutes, the 50% breaking height when a 9 kg column-shaped heavy cone was dropped was determined. And JIS K7211. Breaking water pressure: A water pressure was applied to a short tube of 1 m at a normal temperature at a normal temperature, and the pressure at which the tube was broken was measured. Three-point weighted breaking water pressure: A short pipe of 1 m of the test piece was brought into contact with a pipe wall having a tip of 5R at a three-point uniform circumferential position in the circumferential direction, and water pressure was applied at room temperature to measure the pressure at which the pipe was broken. Fracture form: The fracture form at a three-point weighted fracture water pressure was visually observed and evaluated according to the following criteria. ：: A pinhole opens in the pipe wall at the conical contact portion, and the pipe is not broken. ×: Cracks propagate in the pipe starting from the conical contact portion, and the pipe is broken.

[Table 1] and [Table 2] are Examples and Comparative Examples relating to the first invention, [Table 3] and [Table 4] are Examples and Comparative Examples relating to the second invention, [Table 5], "Table 6" and "Table 7" show Examples and Comparative Examples according to the third invention.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7] ・ Dioctyltin mercapto: “SNT” manufactured by Sankyoki Gosei Co., Ltd.
-461K "・ Dibutyltin mercapto:" Stan "manufactured by Sankyoki Gosei Co., Ltd.
n JF-10B "Dioctyltin malate polymer:" Stann OMF "manufactured by Sankyoki Seisakusho Co., Ltd. Metablen P: @ P-570A (weight average molecular weight 25
× 10 ⁴ ), P-501A (weight average molecular weight 80 × 1)
0 ⁴ ), P-551A (weight average molecular weight 145 × 1)
0 ^4), P-530A (weight average molecular weight 310 × 1
0 ^4), P-531 (weight average molecular weight 450 × 10 ^4)}

[0035]

According to the present invention, it is possible to provide a heat-resistant vinyl chloride resin pipe which has high heat resistance, improves impact strength and mechanical strength, and is excellent in suppressing crack propagation.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) (C08L 27/24 (C08L 27/24 23:28) 23:28) B29K 27:06 B29K 27:06 B29L 23:00 B29L 23:00 F term (Reference) 3H111 AA02 BA15 BA34 DA09 DA11 DA26 DB03 DB06 DB18 DB22 EA12 4F210 AA04A AA15A AA21A AB06 AB19 AB22 AG08 AR06 QA05 QC03 QD13 QG04 QG18 4J002 BB242 BD181 BG05066 EZ046

Claims (6)

[Claims] 1. The method according to claim 1, wherein the chlorine content is 60 to 71% by weight, and the average degree of polymerization of the vinyl chloride resin before chlorination is 60 to 14%.
A chlorinated vinyl chloride resin of No. 00: 100 parts by weight, an alkyltin mercapto compound or an alkyltin malate compound: 0.5 to 5 parts by weight. , 120-170
1.3 to 2.5 times in the circumferential direction in the temperature range of
A heat-resistant vinyl chloride resin pipe stretched 1 to 2.5 times in the pipe axis direction. 2. The chlorine content is 60 to 71% by weight, and the average degree of polymerization of the vinyl chloride resin before chlorination is 60 to 14%.
Chlorinated vinyl chloride resin of 00: 100 parts by weight, alkyltin mercapto compound or alkyltin malate compound: 0.5 to 5 parts by weight, chlorinated polyethylene having a chlorine content of 30 to 40% by weight: 2 to 20 parts by weight And a resin tube obtained by molding a vinyl chloride resin composition consisting essentially of 1.3 to 2.5 times in the circumferential direction of the tube and 1 to 2 times in the axial direction in a temperature range of 120 to 170 ° C. A heat-resistant vinyl chloride resin tube stretched by a factor of 5. 3. The chlorinated polyethylene having a chlorine content of 30 to 40% by weight has a weight average molecular weight of 50,000 to 40.
3. The heat-resistant vinyl chloride resin pipe according to claim 2, wherein the pipe is 0000. 4. The vinyl chloride resin having a chlorine content of 60 to 71% by weight and having an average degree of polymerization of 60 to 14 before chlorination.
Chlorinated vinyl chloride resin of 100: 100 parts by weight, alkyl tin mercapto compound or alkyl tin maleate compound: 0.5 to 5 parts by weight, and weight average molecular weight of 50 to 50
100,000 methacrylic acid ester resin: A resin pipe obtained by molding a vinyl chloride resin composition substantially consisting of 1 to 15 parts by weight was placed in a temperature range of 120 to 170 ° C. in a circumferential direction of 1.3 to 1.3 ° C. A heat-resistant vinyl chloride resin tube stretched 2.5 times and 1 to 2.5 times in the tube axis direction. 5. The alkyltin mercapto compound is one or more alkyl selected from the group consisting of dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, monobutyltin mercapto, monooctyltin mercapto and monomethyltin mercapto. 5. The heat-resistant vinyl chloride resin tube according to claim 1, wherein the tube is a tin mercapto compound. 6. The alkyltin maleate compound is one or more alkyltin maleate compounds selected from the group consisting of dibutyltin maleate, dibutyltin maleate polymer, dioctyltin maleate, and dioctyltin maleate polymer. Claims 1 and 2,
A heat-resistant vinyl chloride resin tube according to 3, 4, or 5.