JP7271168B2 - Vinyl chloride resin composition for rehabilitating pipe, and rehabilitating pipe - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vinyl chloride resin composition for rehabilitating pipes and rehabilitating pipes.

BACKGROUND ART In recent years, as one of the methods for repairing an existing pipe that has deteriorated, a lining method is known in which a synthetic resin pipe is inserted inside the existing pipe to line the inner surface. For example, in the technique described in Patent Document 1, a rehabilitated pipe (also referred to as a lining pipe) made of thermoplastic synthetic resin whose outer diameter is smaller than its inner diameter is inserted into the existing pipe to be repaired in a heated and softened state. After that, steam is introduced into the rehabilitated pipe to apply internal pressure to expand the rehabilitated pipe in the radial direction and bring it into close contact with the inner surface of the existing pipe. The cooling medium is used to solidify the rehabilitating pipe.

Conventionally, hard vinyl chloride resins have been used as materials for constructing such rehabilitated pipes. Patent Documents 2 to 4 disclose vinyl chloride resin compositions used for rehabilitation pipes.

In Patent Document 2, a mixture of 40 to 60% by weight of a polyvinyl chloride resin having an average degree of polymerization of 400 to 600 and 60 to 40% by weight of a polyvinyl chloride resin having an average degree of polymerization of 1050 to 1350 is the main component, and the mixture A resin composition is disclosed in which 3 to 25 parts by weight of an MMA-based and/or MBS-based modifier is blended with 100 parts by weight.

Patent Document 3 discloses a resin composition containing a vinyl chloride resin and a compound (thermoplastic elastomer, plasticizer, antioxidant) having a glass transition point, melting point, or dropping point lower than the glass transition point of the vinyl chloride resin. things are disclosed.

Patent Document 4 discloses a resin composition containing a composite vinyl chloride resin having an average degree of polymerization of 400 to 2500 obtained by graft copolymerizing a vinyl chloride monomer or a vinyl chloride monomer and other copolymerizable monomers to an acrylic copolymer. things are disclosed.

Further, Patent Document 5 discloses a rigid vinyl chloride resin pipe obtained by melt-extrusion molding a vinyl chloride resin composition into a tubular shape. The vinyl chloride resin composition used in the technique described in Patent Document 5 is vinyl chloride having a polymerization degree of 800 to 2000 obtained by graft copolymerizing vinyl chloride to an acrylic copolymer by suspension polymerization. Contains system resin.

Japanese Patent Application Laid-Open No. 1-295828 (published on November 29, 1989) Japanese Patent Application Laid-Open No. 3-275335 (published on December 6, 1991) Japanese Patent Application Laid-Open No. 2003-73518 (published on March 12, 2003) Japanese Patent Application Laid-Open No. 2002-249634 (published on September 6, 2002) Japanese Patent Application Laid-Open No. 10-231410 (published on September 2, 1998)

However, the polyvinyl chloride resin compositions disclosed in Patent Documents 2 to 5 have the following problems.

First, although the resin composition disclosed in Patent Document 2 exhibits excellent expansion workability, polyvinyl chloride resins having an average degree of polymerization of 400 to 600 do not have versatility. Therefore, the cost of the resin composition increases.

Moreover, the compounds (thermoplastic elastomer, plasticizer, antioxidant) contained in the resin composition disclosed in Patent Document 3 are more expensive than polyvinyl chloride resin. Compositions obtained by blending these compounds with polyvinyl chloride resins are viscous and adherent, resulting in poor moldability. For this reason, problems tend to arise in the mass production of rehabilitating pipes by extrusion molding.

Although the vinyl chloride resin obtained by graft copolymerizing vinyl chloride to the acrylic copolymer by suspension polymerization disclosed in Patent Document 4 or 5 is excellent in product performance, expansion workability, etc. , are more expensive than general vinyl chloride resins.

Therefore, the techniques described in Patent Documents 2 to 5 have room for improvement in terms of compatibility between the cost required for manufacturing the rehabilitating pipe and the extrusion moldability and expansion workability.

An object of one aspect of the present invention is to realize a vinyl chloride-based resin composition for a rehabilitating pipe and a rehabilitating pipe that are economically efficient and have excellent extrusion moldability and expansion workability.

In order to solve the above problems, the vinyl chloride resin composition for rehabilitating pipes according to aspect 1 of the present invention comprises a first polyvinyl chloride resin having an average degree of polymerization of 1000 to 1100 and a polyvinyl chloride resin having an average degree of polymerization of 750 to 850. 2, or a main resin component consisting of the first polyvinyl chloride resin, a stabilizer other than lead, and an MMA-based modifier and an MBS-based modifier. 3 to 25 parts by weight of one or more modifiers selected from the group consisting of modifiers and CPE modifiers are blended with 100 parts by weight of the main resin component.

Further, in the vinyl chloride resin composition for rehabilitating pipes according to aspect 2 of the present invention, in aspect 1, the main resin components are 50 to 100% by weight of the first polyvinyl chloride resin and 0 to 50% by weight of the first polyvinyl chloride resin. and the second polyvinyl chloride resin.

Further, in the vinyl chloride resin composition for rehabilitating pipes according to aspect 3 of the present invention, in aspect 1 or 2, the stabilizer is a group consisting of an organic tin stabilizer, a metal soap stabilizer, and an inorganic stabilizer. at least one stabilizer selected from

Further, in the vinyl chloride resin composition for rehabilitating pipes according to aspect 4 of the present invention, in any one aspect of aspects 1 to 3, the stabilizer is 0.5 to 5 parts per 100 parts by weight of the mixture. .0 parts by weight.

Further, a rehabilitating pipe according to aspect 5 of the present invention is inserted into an existing pipe and is composed of the vinyl chloride resin composition for rehabilitating pipe according to any one of aspects 1 to 4.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to realize a vinyl chloride-based resin composition for rehabilitating pipes, which is economical and has excellent extrusion moldability and expansion workability.

It is a front view which shows schematic structure of the apparatus used for a ring diameter expansion test.

[Embodiment 1]
An embodiment of the present invention will be described below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less".

As a result of intensive studies, the present inventors have found that the main resin component is a combination of polyvinyl chloride resins with a highly versatile average degree of polymerization, and the modifier in the vinyl chloride resin composition is a specific modifier. The present inventors have found that it is possible to manufacture a rehabilitating pipe excellent in economic efficiency and expansion workability by setting the compounding amount of the agent within a specific range, and have arrived at the basic concept of the present invention.

The vinyl chloride-based resin composition for rehabilitating pipes according to the present embodiment (hereinafter sometimes simply referred to as a vinyl chloride-based resin composition) comprises a first polyvinyl chloride resin having an average polymerization degree of 1000 to 1100, and an average polymerization degree of 750 to 850 containing a mixture with a second polyvinyl chloride resin or a main resin component consisting of the first polyvinyl chloride resin and a non-lead-based stabilizer, the main resin component 100 3 to 25 parts by weight of MMA-based and/or MBS-based modifiers are blended with respect to parts by weight.

(main resin component)
The first and second polyvinyl chloride resins, which are the main resin components of the vinyl chloride resin composition, have different ranges of average degree of polymerization. The average degree of polymerization of the first polyvinyl chloride resin is 1000-1100, and the average degree of polymerization of the second polyvinyl chloride resin is 750-850. The "average degree of polymerization" is the average measured in accordance with JIS K 6720-2 "Plastics-Vinyl chloride homopolymers and copolymers (PVC)-Part 2: How to make test pieces and how to determine various properties" means the degree of polymerization.

A polyvinyl chloride resin having such an average degree of polymerization is used for general pipe materials (pipes, joints, etc.). Therefore, the first and second polyvinyl chloride resins are versatile and economical materials. In the present embodiment, such economical polyvinyl chloride resin is used as the main resin component to realize a rehabilitating pipe with excellent extrusion moldability and expansion workability.

The reason for setting the range of the average degree of polymerization for each of the first and second polyvinyl chloride resins as described above is that a commercially available polyvinyl chloride resin for general use is used. Generally commercially available polyvinyl chloride resins have average degrees of polymerization of 1050, 800 and 700 (all types have a range of average degree of polymerization of about ±50). By using such a versatile polyvinyl chloride resin as a material, an economical vinyl chloride resin composition can be realized.

The mixing ratio of the first and second polyvinyl chloride resins in the main resin component is not particularly limited. Preferably, said main resin component comprises 50 to 100% by weight, particularly preferably 60 to 80% by weight, of said first polyvinyl chloride resin and 0 to 50% by weight, particularly preferably 20 to 40% by weight of said and a second polyvinyl chloride resin. The main resin component may consist only of the first polyvinyl chloride resin. When the mixing ratio of the first polyvinyl chloride resin is less than 50% by weight, the mixing ratio of the second polyvinyl chloride resin exceeds 50% by weight. As a result, the strength of the product becomes insufficient, which is not preferable.

(stabilizer)
The stabilizer is added to the vinyl chloride resin composition to ensure thermal stability during molding and thermal expansion of the rehabilitating pipe. As the stabilizer, a non-lead material with a relatively low glass transition point is used in order to adjust the softness (modulus of elasticity) of the vinyl chloride resin composition.

When a lead-based stabilizer is added to a vinyl chloride-based resin composition, there are the following problems. First, lead-based stabilizers are mostly inorganic materials and have no effect of lowering the glass transition point of vinyl chloride-based resins. Next, when the vinyl chloride resin composition is used as a material for rehabilitating pipes constituting, for example, sewage drainage pipes, the lead-based stabilizer reacts with sulfuric acid gas generated from sewage drainage to produce lead sulfide. Then, this lead sulfide contaminates the rehabilitating pipe and turns it black.

The stabilizer used in the present embodiment is not particularly limited as long as it is a stabilizer other than lead-based stabilizers. Preferably, the stabilizer is at least one stabilizer selected from the group consisting of organotin stabilizers, metallic soap stabilizers, and inorganic stabilizers. Examples of stabilizers include organic tin stabilizers such as dimethyltin mercapto, dibutyltin malate, dioctyltin laurate, and dioctyltin mercapto; metal soap stabilizers such as calcium stearate, zinc stearate, and barium stearate; hydrotalcite. and inorganic stabilizers such as zeolite. These stabilizers may be used alone, or two or more of them may be used in combination.

The amount of the stabilizer in the vinyl chloride resin composition is appropriately set according to the composition of the main resin component, the type of stabilizer, etc., so as to ensure the necessary thermal stability during molding and thermal expansion of the rehabilitating pipe. It is possible. For example, when an organic tin-based stabilizer is used as the stabilizer, the stabilizer is preferably 0.5 to 5.0 parts by weight, more preferably 1.0 part by weight, per 100 parts by weight of the main resin component. Contains ~4.0 parts by weight. By blending the stabilizer within the above range, it is possible to secure the necessary thermal stability during molding and thermal expansion of the rehabilitating pipe. When the amount of the stabilizer is less than 0.5 parts by weight with respect to 100 parts by weight of the main resin component, the thermal stability during molding is insufficient, which is undesirable. Further, if the amount of the stabilizer exceeds 5.0 parts by weight with respect to 100 parts by weight of the main resin component, the strength of the product will be insufficient, which is not preferable.

In addition to the stabilizer, the vinyl chloride resin composition may contain a stabilizing aid. Stabilizing aids used in the present embodiment include, for example, epoxidized soybean oil, epoxidized linseed oil, phosphate esters, and the like. These stabilizing aids may be used alone, or two or more of them may be used in combination. The amount of the stabilizing aid in the vinyl chloride resin composition can be appropriately set according to the type of the stabilizer and the like so as to assist the thermal stability of the stabilizer.

(Modifier)
Modifiers are essential in vinyl chloride resin compositions mainly for improving elongation and strength of polyvinyl chloride resins. The modifier used in the present embodiment is one or more modifiers selected from the group consisting of MMA-based modifiers, MBS-based modifiers, and CPE-based modifiers. That is, it is one of MMA, MBS, and CPE modifiers, or a combination of two or more of them.

The MMA-based modifier is a multi-component resin obtained by graft-polymerizing monomers such as methyl methacrylate, styrene, and acrylonitrile to a copolymer rubber mainly composed of acrylic acid ester. The MBS modifier is a butadiene/styrene/methyl methacrylate copolymer. CPE-based modifiers are polymers of chlorinated polyethylene. The degree of chlorination of chlorinated polyethylene can be adjusted according to the required performance. Elongation and strength of the polyvinyl chloride resin are improved by blending at least one modifier selected from the MMA, MBS and CPE modifiers into the vinyl chloride resin composition. MBS-based modifiers are insufficient in improving the weather resistance of reclaimed pipes. Therefore, preferably, the modifier used in this embodiment includes MMA-based and CPE-based modifiers.

EVA-based and ABS-based modifiers are known as conventionally known modifiers. Compared to MMA, MBS, or CPE modifiers, many of these modifiers are viscous and sticky. The effect of improving the elongation of the product cannot be expected or is insufficient.

Further, in the present embodiment, one or more modifiers selected from the group consisting of MMA-based modifiers, MBS-based modifiers, and CPE-based modifiers are included in 100 parts by weight of the main resin component. 3 to 25 parts by weight are blended with respect to When the amount of the modifier compounded relative to 100 parts by weight of the main resin component is less than 3 parts by weight, the practical strength of the rehabilitated pipe is insufficient, the elongation of the rehabilitated pipe at the expansion work temperature is insufficient, and the expansion workability. decreases. Further, when the amount of the modifier compounded exceeds 25 parts by weight with respect to 100 parts by weight of the main resin component, extrusion moldability is deteriorated. The amount of the modifier compounded with respect to 100 parts by weight of the main resin component is preferably 3 to 25 parts by weight, particularly preferably 5 to 20 parts by weight.

(Other additives)
If necessary, the vinyl chloride resin composition according to the present embodiment contains fillers, pigments, lubricants, processing aids, light stabilizers, ultraviolet absorbers, fillers, coloring agents, antioxidants (antiaging agents). agents), antistatic agents, flame retardants, and the like. The method and order of addition of these additives are not particularly limited, and may be any method or any order.

Examples of the filler include inorganic fillers such as calcium carbonate, talc, clay and silica. These fillers may be used alone or in combination of two or more.

Examples of the pigment include organic pigments such as azo-based, phthalocyanine-based, threne-based, and dye lake-based pigments; and inorganic pigments such as molybdenum chromate-based and ferrocyanide-based pigments. These pigments may be used alone or in combination of two or more.

Examples of the lubricant include fatty acids such as stearic acid; fatty acid ester materials such as butyl stearate; olefin waxes such as polyethylene and polyethylene oxide; and hydrocarbon waxes such as paraffin. These lubricants may be used alone, or two or more of them may be used in combination.

Examples of the processing aid include homopolymers or copolymers of (meth)acrylate monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; and a copolymer with a vinyl monomer such as styrene, vinyltoluene, acrylonitrile, and the like. These processing aids may be used alone, or two or more of them may be used in combination.

Examples of the light stabilizer include hindered amine light stabilizers. These light stabilizers may be used alone, or two or more of them may be used in combination.

Examples of the ultraviolet absorber include salicylate-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers. These ultraviolet absorbers may be used alone, or two or more of them may be used in combination.

Moreover, titanium oxide etc. are mentioned as said filler.

Moreover, the amount of these additives to be added is not particularly limited, and may be in accordance with the conventional method for manufacturing rehabilitating pipes. For example, the lubricant is 0.1 to 2.5 parts by weight per 100 parts by weight of the main resin component, and the filler or coloring agent is added to 100 parts by weight of the main resin component, if necessary. 5.0 parts by weight or less.

As described above, the vinyl chloride resin composition according to this embodiment has the following features.

(a) a mixture of a first polyvinyl chloride resin having an average degree of polymerization of 1000 to 1100 and a second polyvinyl chloride resin having an average degree of polymerization of 750 to 850, or from the first polyvinyl chloride resin and a non-lead-based stabilizer.

(b) 3 to 25 parts by weight of an MMA-based and/or MBS-based modifier is blended with 100 parts by weight of the main resin component;

First, the main resin component as in the above feature (a) is highly versatile and therefore economical. Then, as in the feature (b), 3 to 25 parts by weight of an MMA-based and/or MBS-based modifier is blended with respect to 100 parts by weight of the main resin component, thereby improving extrusion moldability. And the expansion workability at the construction temperature (70 to 100° C.) is excellent. As described above, according to the present embodiment, it is possible to realize a vinyl chloride-based resin composition for rehabilitating pipes that is economical and has excellent extrusion moldability and expansion workability.

(expansion workability)
Since the vinyl chloride-based resin composition according to the present embodiment has the composition and properties described above, it has excellent expansion workability and satisfies the evaluation criteria for expansion workability. There are no particular limitations on the evaluation criteria for expansive workability, and conventionally known criteria can be applied. The vinyl chloride-based resin composition according to the present embodiment is a molded tube molded by a tube extrusion molding method, and the following 1. ~3. It is preferable to satisfy at least one of the evaluation criteria of, particularly preferably, the following 1. ~3. It is particularly preferable to satisfy all of the evaluation criteria of

1. The elongation rate of the formed tube is 100% or more, preferably 140% or more, in a ring diameter expansion test described later.

2. According to an elastic modulus (80° C.) measurement test described later, the elastic modulus at 80° C. of the molded tube is 1000 MPa or less, preferably 500 MPa or less.

3. The elongation percentage of the test piece of the molded tube is 20% or less, preferably 17% or less in a tensile creep test at 90°C, which will be described later.

(rehabilitation pipe)
A rehabilitating pipe according to the present embodiment is inserted into an existing pipe and is made of the vinyl chloride resin composition described above. More specifically, the rehabilitated pipe is inserted into the existing pipe and heated so as to adhere to the inner surface of the existing pipe.

Such a reclaimed pipe is produced by melt-kneading the vinyl chloride-based resin composition described above using an extruder, performing extrusion molding, and molding into a tubular body having a desired cross-sectional shape. The cross-sectional shape of the rehabilitated pipe is not particularly limited as long as it can be inserted into the existing pipe to be rehabilitated (repaired) and can be brought into close contact with the inner surface of the existing pipe by heating.

The present invention is not limited to the above-described embodiments, and can be modified in various ways within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in the embodiments is also included in the technical scope of the present invention.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Evaluation method for rehabilitating pipe>
(1) Extrusion Moldability The outer and inner surfaces of the reclaimed pipe obtained by extrusion molding were observed to visually confirm the presence or absence of burnt streaks, undulations, and the like. The inner and outer surfaces of the rehabilitated pipe were evaluated based on the appearance regulations of Japan Sewage Works Association Standard JSWAS K1-2010 "Rigid vinyl chloride pipe for sewerage".

(2) Expansion workability Passing all of the following tests A to C was judged as "◯", and failing at least one of the following tests A to C was judged as "x".

A. Ring diameter expansion test The obtained rehabilitated pipe was cut into a ring shape with a width of 15 mm, heated to a temperature of 90°C, and then placed in a test apparatus for expanding the ring diameter as shown in Fig. 1 . Specifically, the rehabilitating pipe sample is placed so that the eight cylindrical bodies in the test apparatus shown in FIG. 1 are in contact with the inner surface of the ring-shaped rehabilitating pipe sample. After that, the cylindrical body is moved to the outer surface side of the rehabilitated pipe, and the ring of the rehabilitated pipe sample is enlarged in the circumferential direction into an octagonal shape. Then, the elongation rate of the rehabilitated pipe sample was measured when the ring of the rehabilitated pipe sample was broken. When the elongation percentage of the rehabilitating pipe sample was 100% or more when it was broken, it was determined to be acceptable.

B. Measurement Test of Elastic Modulus (80° C.) A dumbbell-shaped specimen having a width of 10 mm, a length of 50 mm, and a thickness of 1 mm was cut out from the obtained rehabilitated pipe. Then, the storage elastic modulus of each cut dumbbell-shaped test piece was measured for each temperature using a dynamic viscoelasticity measuring tester. The dynamic viscoelasticity measurement tester used was DMA7100 manufactured by Hitachi High-Tech Science, under the conditions of set temperature = 30 ° C. → 130 ° C. (heating rate = 5 ° C./min), frequency = 1 Hz, amplitude width = 10 μm. , the storage elastic modulus at each temperature was measured. Among the elastic moduli measured, the elastic modulus at 80° C. was used as the criterion. A sample having an elastic modulus of 1000 MPa or less at 80° C. was determined to be acceptable.

C. Tensile Creep Test at 90° C. A test piece having a width of 10 mm, a length of 100 mm and a thickness of 2.5 mm was cut out from the obtained rehabilitated pipe. The cut test piece was subjected to a tensile creep test in accordance with JISK7115 “Plastics—Determination of creep properties—Part 1: Tensile creep” to measure the elongation of the test piece. The test conditions were test temperature: 90° C.±1.5° C. (in water), tensile stress: 0.5 MPa, test time=240 hours. Then, when the elongation percentage of the test piece was 20% or less, it was determined to be acceptable.

(3) Black discoloration during sulfurization A sample having a width of 15 mm and a length of 30 mm was cut out from the obtained regenerated pipe. Then, the sample was immersed in a mercaptotin-based stabilizer and allowed to stand at room temperature for 24 hours in a closed beaker. The presence or absence of discoloration (blackening) of the sample after being left for 24 hours was visually evaluated. A case where black discoloration was not observed was evaluated as "good", and a case where black discoloration was observed was evaluated as "poor".

[Example 1]
A polyvinyl chloride resin having an average degree of polymerization of 1050 was used as the main resin component. Per 100 parts by weight of the main resin component, 4.00 parts by weight of an organic tin-based stabilizer (contents: octyl tin, methyl tin, thermal stabilization aid) as a stabilizer, and an MMA-based modifier ( 10.00 parts by weight of product name "Kane Ace FM Series" (manufactured by Kaneka Corporation), which is also called an acrylic impact modifier, 3.00 parts by weight of product name "Metabrene P551" (manufactured by Mitsubishi Rayon Co., Ltd.) as a processing aid, and as a lubricant Ester-based lubricant (trade name “Rikester SL-02”, manufactured by Riken Vitamin) and ethylene-based lubricant (trade name “Hiwax220MP”, manufactured by Mitsui Chemicals) 0.40 parts by weight, white pigment and filler as other additives agent (trade name “μ-POWDER 3S”, manufactured by Shiraishi Calcium Co., Ltd.) was blended at a rate of 1.20 parts by weight to prepare a vinyl chloride resin composition.

The obtained vinyl chloride resin composition was extruded by a tube extrusion molding method to prepare a rehabilitating tube (test tube) having an outer diameter of 185±1.0 mm and a wall thickness of 8.6±0.6 mm.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Example 2]
Chlorination was performed in the same manner as in Example 1, except that a mixture of 25 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 800 and 75 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 1050 was used as the main resin component. A vinyl resin composition was prepared, and a rehabilitating pipe was produced using the vinyl chloride resin composition.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Example 3]
Chlorination was performed in the same manner as in Example 1, except that a mixture of 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 800 and 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 1050 was used as the main resin component. A vinyl resin composition was prepared, and a rehabilitating pipe was produced using the vinyl chloride resin composition.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Example 4]
As the main resin component, a mixture of 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 800 and 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 1050 was used; A vinyl chloride resin composition was prepared in the same manner as in Example 1, except that 20.00 parts by weight of the impact modifier was added, and a rehabilitating pipe was produced using the vinyl chloride resin composition.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Comparative Example 1]
100 parts by weight of polyvinyl chloride resin with an average degree of polymerization of 1300 was used as the main resin component, and a lead-based composite one-pack stabilizer (tribasic sulfuric acid) was used instead of 4.00 parts by weight of an organic tin stabilizer as a stabilizer. 9.00 parts by weight of a mixture of lead and lead stearate) is added to 100 parts by weight of the main resin component, and 0.4 parts by weight of chlorinated polyethylene is added as a content of the lubricant to 100 parts by weight of the main resin component. A vinyl chloride resin composition was prepared in the same manner as in Example 1, except that the formulation of the lubricant was finely adjusted, and a rehabilitating pipe was produced using the vinyl chloride resin composition.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Comparative Example 2]
A vinyl chloride resin composition was prepared in the same manner as in Comparative Example 1, except that 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 700 was used as the main resin component. A rehabilitated pipe was produced using

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Comparative Example 3]
A vinyl chloride resin composition was prepared in the same manner as in Example 1, except that 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 800 was used as the main resin component. was used to produce a rehabilitated pipe.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Comparative Example 4]
As the main resin component, a mixture of 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 800 and 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 1050 was used; A vinyl chloride resin composition was prepared in the same manner as in Example 1, except that 2.00 parts by weight of the impact modifier was added, and a rehabilitating pipe was produced using the vinyl chloride resin composition.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

[Comparative Example 5]
As the main resin component, a mixture of 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 800 and 50 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 1050 was used; A vinyl chloride resin composition was prepared in the same manner as in Example 1, except that 30.00 parts by weight of an impact modifier was added, and a rehabilitating pipe was produced using the vinyl chloride resin composition.

The obtained reclaimed pipe was evaluated for extrusion moldability, expansion workability, and blackening during sulfurization. The results were as shown in Table 1.

From the results of Examples 1 to 4 in Table 1, in the vinyl chloride resin composition, (a) the main resin component is a first polyvinyl chloride resin having an average polymerization degree of 1000 to 1100 and an average polymerization degree of 750 to 850. consisting of a mixture with a second polyvinyl chloride resin or consisting of the first polyvinyl chloride resin, and (b) 3 to 25 parts by weight of MMA based on 100 parts by weight of the main resin component It was found that the extrudability and expansion workability were good if the and/or MBS-based modifier was blended. Furthermore, it was found that black discoloration during sulfurization was suppressed by blending an organic tin-based stabilizer, which is a stabilizer other than a lead-based stabilizer.

As shown in Table 1, Comparative Example 1 using 100 parts by weight of polyvinyl chloride resin with an average degree of polymerization of 1300 as the main resin component, and 100 parts by weight of polyvinyl chloride resin with an average degree of polymerization of 700 as the main resin component. In Comparative Example 2 and Comparative Example 3 using 100 parts by weight of polyvinyl chloride resin having an average polymerization degree of 800 as the main resin component, a ring diameter expansion test, an elastic modulus (80 ° C.) measurement test, a tensile creep at 90 ° C. It failed in at least one of the tests and had poor expansion workability. Moreover, in Comparative Examples 1 and 2 in particular, not only expansion workability but also extrusion moldability were not good. In addition, in Comparative Examples 1 and 2 in which a lead-based stabilizer was used in place of the organotin-based stabilizer, black discoloration during sulfurization was confirmed.

In Comparative Examples 4 and 5, a mixture of a polyvinyl chloride resin with an average degree of polymerization of 800 and a polyvinyl chloride resin with an average degree of polymerization of 1050 is used as the main resin component. However, in Comparative Example 4, 2.00 parts by weight of the acrylic impact modifier was added to 100 parts by weight of the main resin component, and in Comparative Example 5, the acrylic impact modifier was added to 100 parts by weight of the main resin component. 30.00 parts by weight is blended. In other words, in Comparative Examples 4 and 5, the amount of the acrylic impact modifier blended with respect to 100 parts by weight of the main resin component is outside the range of 3 to 25 parts by weight. In such Comparative Examples 4 and 5, both extrusion moldability and expansion workability cannot be satisfied.

INDUSTRIAL APPLICABILITY The present invention can be used in the civil engineering and construction industries, etc., where repair of existing pipes is required.

Claims (4)

a main resin component consisting of a mixture of a first polyvinyl chloride resin having an average degree of polymerization of 1000 to 1100 and a second polyvinyl chloride resin having an average degree of polymerization of 750 to 850;
Stabilizers other than lead-based,
One or more modifiers selected from the group consisting of MMA-based modifiers, MBS-based modifiers, and CPE-based modifiers, in an amount of 3 to 25 parts by weight per 100 parts by weight of the main resin component is compounded,
The main resin component is
50 to 80 % by weight of the first polyvinyl chloride resin;
20 to 50% by weight of the second polyvinyl chloride resin, and a vinyl chloride resin composition for rehabilitating pipes. 2. The vinyl chloride resin for rehabilitating pipes according to claim 1, wherein said stabilizer is at least one stabilizer selected from the group consisting of organic tin stabilizers, metal soap stabilizers, and inorganic stabilizers. Composition. 3. The vinyl chloride resin composition for rehabilitating pipes according to claim 1, wherein said stabilizer is contained in an amount of 0.5 to 5.0 parts by weight with respect to 100 parts by weight of said main resin component. A rehabilitating pipe inserted into an existing pipe and made of the vinyl chloride resin composition for rehabilitating pipe according to any one of claims 1 to 3.

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