KR20090083825A - Liner for repairing pipe and cold setting resin therefor - Google Patents

Abstract

A liner for pipe repair and a cold-setting resin for the liner are provided to reduce the setting time within 2~5 hours regardless of the ambient temperature by adding a proper amount of initiator and accelerant. A liner(L) for pipe repair includes non-woven fabric(P) which is impregnated in a cold-setting resin and inserted in a pipe(20) to repair a damaged part(25) of the pipe, and a cover(C) which covers the outside of the non-woven fabric. The cold-setting resin is prepared by polymerizing polymerization initiator 0.5~2.0wt.% and promoter 0.5~2.0wt.% in a mixture 100wt.%, where the mixture is made of MMA(Methylmethacrylate) monomer and anti-shrinkage agent.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pipe for repairing a pipe,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piping repair liner and a low-temperature curing resin for the same. More particularly, the present invention relates to a piping repair liner that can be cured even at a low temperature and a low-temperature curing resin for the same.

With urbanization, various pipelines such as water supply and drainage pipes and gas pipes were buried in the basement, and these pipes gradually became aged and corrosion occurred over time. It is an important issue to repair old pipes due to the leakage of water and sewage, pollution of drinking water and leakage of gas due to corrosion of piping.

In the case of excavation works to repair water pipes or gas pipes buried underground, the cost of social loss such as enormous construction cost, heavy traffic, safety accidents and environmental problems will increase. Accordingly, a non-digging type pipe maintenance method has been developed. Especially in Korea, the width of the road is narrow and the bending part is many, and there are many joints of the auxiliary facilities such as the branch pipe connection and the manhole. In addition, since the depth of the piping is deep and the working environment is poor, many non-digging piping repairing methods are advantageous because there are many sites that are used for the removal of obstacles and the like.

In a conventional unreachable pipe repairing method, a liner impregnated with a resin produced in a factory is transferred to a site using a cooling car, and then the liner is inverted in the pipe using a reversing device, and hot water and steam are introduced to expand the liner Curing method. Here, epoxy resin is mainly used as a liner resin, but when an epoxy resin is used as a liner impregnation material, a separate impregnation plant is required to impregnate the resin. Also, in order to prevent the hardening of the liner resin produced in the field, it is inconvenient to transport the liner to the sewer repair site using a cooling car maintained at about -5 ° C to 5 ° C. In addition, curing is not smoothly performed at low temperatures such as sewer pipes in sewage plant construction. Therefore, curing should be promoted by using circulating hot water or high-temperature steam in order to shorten curing time. Therefore, it is necessary to have a boiler vehicle and energy consumption due to the use of the boiler is large. In addition, there is a problem that it is difficult to construct a small area due to the enlargement of equipment such as a cooling car and a boiler vehicle.

A problem to be solved by the present invention is to provide a piping repair liner which can be easily cured at a low temperature in the field.

Another object of the present invention is to provide a low temperature curable resin for a piping repair liner.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a piping repair liner comprising: a nonwoven fabric to be inserted into the piping for repairing a damaged portion of a piping, the nonwoven fabric impregnated with a low-temperature curable resin; Cover. Here, the low-temperature curable resin is prepared by adding 0.5 to 2.0% by weight of a polymerization initiator and 0.5 to 2.0% by weight of an accelerator to 100% by weight of a mixture composed of a methyl methacrylate (MMA) monomer and a shrinkage reducing agent, .

According to another aspect of the present invention, there is provided a low temperature curable resin for a piping repair liner according to an embodiment of the present invention, which is a low temperature curable resin impregnated into a nonwoven fabric to be inserted into the piping for repairing a damaged portion of the piping, MMA) monomer and a shrinkage reducing agent in an amount of 0.5 to 2.0% by weight and a promoter in an amount of 0.5 to 2.0% by weight, based on 100% by weight of the mixture.

The details of other embodiments are included in the detailed description and drawings.

According to the piping repairing liner of the present invention and the low-temperature curing resin for the piping repair according to the present invention, it is possible to perform the construction without a separate heating device at a low temperature (about 5 ° C or less), and by adding an appropriate amount of an initiator and an accelerator, The curing time can be adjusted within about 2 ~ 5 hours, so that the curing time can be shortened compared with the existing products. Also, it has an excellent durability such as acid resistance, alkali resistance, chemical resistance and weather resistance, excellent adhesiveness, no shrinkage and deformation after curing, and excellent abrasion resistance and workability.

In addition, since the low temperature curing resin is directly impregnated into the nonwoven fabric in the field to produce the liner, the cooling car and the boiler device, which were conventionally used in the unreachable piping repair method, are unnecessary. As a result, It is possible to reduce the damage of telephone poles, roadside trees, street lamps, garden beds, and the like to the utmost.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a piping repair liner according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. Here, FIG. 1 is a perspective view of a piping in which a piping maintenance liner according to an embodiment of the present invention is installed, and FIG. 2 is a cross-sectional view taken along line II-II 'of FIG.

The unreduced piping repairing method according to an embodiment of the present invention includes the steps of inserting a liner (L) including a nonwoven fabric impregnated with a low-temperature curing resin into a pipe (20) to be repaired, And the inner side of the pipe 20 is reinforced with the liner L to repair the broken pipe 20.

Referring to FIGS. 1 and 2, a liner L is inserted into the inner side of the broken pipe 20. The liner L serves to prevent fluid such as sewage, water, and gas from flowing out of the piping 20 through the broken portion 25 of the piping 20 and to prevent foreign matter from flowing into the piping 20 . The liner L includes a nonwoven fabric P impregnated with a low temperature curable resin and a vinyl C surrounding the outside of the nonwoven fabric P. [ More specifically, the low-temperature curing resin in a liquid phase is impregnated into the double-folded nonwoven fabric (P). Here, the low-temperature curable resin is cured within about 1 to 8 hours without applying any heat at room temperature. Since methyl methacrylate (MMA) is used, the conventional method It hardens at low temperatures without being subjected to a heat curing process such as circulating hot water or high temperature steam. When the low temperature curable resin is impregnated with the vinyl (C) on the outer side of the nonwoven fabric P and then inserted into the pipe 20, the low temperature curable resin is cured to form the inner tube in the shape of the pipe 20.

The vinyl C covers the nonwoven fabric P when the air is filled in the nonwoven fabric P and the nonwoven fabric P expands. That is, the cover surrounding the nonwoven fabric P is not limited to the vinyl (C), and various materials such as polypropylene and polystyrene which can be used as the covering material of the nonwoven fabric P may be used. Particularly, it is possible to use a cover formed of a heat insulating material so that the resin can be cured even at a very low temperature depending on the construction environment.

Hereinafter, the low temperature curable resin used for the liner will be described in detail.

The low-temperature curable resin according to one embodiment of the present invention is characterized in that 100 weight% of a mixture of methyl methacrylate (MMA) monomer and a shrinkage reducing agent is added to 0.5 to 2.0 weight% of a polymerization initiator as an external proportion and 0.5 By weight to 2.0% by weight of a polymerization initiator. The process of impregnating the nonwoven fabric (P) with a low temperature curing resin will be described below. First, a mixture obtained by mixing a methyl methacrylate (MMA) monomer and a shrinkage reducing agent is prepared, and then a polymerization initiator and an accelerator are added to the mixture at a construction site to cause a polymerization reaction to produce a low-temperature curable resin. Next, the low temperature curable resin is impregnated into the nonwoven fabric P to complete the liner L. After the liner L is inserted into the sewer pipe, it is cured at a low temperature to repair the damaged portion 25 of the pipe 20.

As the polymerization initiator, for example, organic peroxides such as benzoylperoxide (BPO), redox agents, azo compounds and the like may be used. When organic peroxides are used as polymerization initiators, there is a risk of explosion when exposed to impact or high temperatures, but benzoyl peroxide is less sensitive to impact than other peroxides and can be safely used.

The accelerator serves to accelerate the polymerization reaction. For example, dimethylamine (DMA) may be used.

The shrinkage reducing agent plays a role of preventing shrinkage and controlling viscosity, and may be polymethly methacrylate (PMMA), polystyrene (PS), or unsaturated polyester (UP). Here, the polystyrene (PS) includes expanded polystyrene (EPS).

When polymethylmethacrylate (PMMA) is used as a shrinkage reducing agent, it is preferable that 100 wt% of a mixture composed of 65 to 80 wt% of methyl methacrylate (MMA) and 20 to 35 wt% of polymethyl methacrylate (PMMA) 0.5 to 2.0% by weight of benzoyl peroxide (BPO) as an external polymerization initiator and 0.5 to 2.0% by weight of dimethylamine (DMA) as a promoter are added to the mixture, followed by polymerization to obtain a low-temperature curable resin.

When polystyrene (PS) is used as a shrinkage reducing agent, 100 weight% of a mixture composed of 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polystyrene (PS) 0.5 to 2.0% by weight of peroxide (BPO) and 0.5 to 2.0% by weight of dimethylamine (DMA) as an accelerator are added, and polymerization reaction is carried out to obtain a low-temperature curable resin.

Further, polymethylmethacrylate (PMMA) and polystyrene (PS) may be added in a total amount of 65 to 80% by weight as shrinkage reducing agents.

Methyl methacrylate (MMA) is excellent in polymerization reactivity, and polymerization can be carried out by a polymerization initiator and an accelerator even at 0 ° C or lower. By controlling the composition ratio of methyl methacrylate (MMA) and the shrinkage reducing agent as described above, the viscosity of the mixture can be obtained to be about 400 to 2000 cP, which is in a state of easy impregnation.

When the content of methyl methacrylate (MMA) is less than 65% by weight, viscosity increases and workability at the time of site impregnation for repairing the sewer pipe drastically deteriorates. When the content exceeds 80% by weight, shrinkage due to curing increases, Distortion may occur. If the content of polymethylmethacrylate (PMMA) or polystyrene resin (PS) is less than 20% by weight, workability is remarkably decreased due to low viscosity. If the content exceeds 35% by weight, the viscosity is increased, May be required. If the content of benzoyl peroxide (BPO) is less than 0.5% by weight, the curing time is prolonged and uncured portions may occur. If the content of benzoyl peroxide (BPO) is more than 2.0% by weight, the curing time becomes faster and the workability decreases. If the content of dimethylamine (DMA) is less than 0.5% by weight, the reaction is delayed and the curing time becomes long. When the content of dimethylamine (DMA) exceeds 2.0% by weight, the curing time becomes faster and the workability decreases.

Further, when unsaturated polyester (UP) is used as a shrinkage reducing agent, 100 weight% of a mixture composed of 10 to 50 wt% of methyl methacrylate (MMA) and 50 to 90 wt% of unsaturated polyester (UP) 0.5 to 2.0% by weight of benzoyl peroxide (BPO) as a polymerization initiator and 0.5 to 2.0% by weight of dimethylamine (DMA) as an accelerator are added and then polymerized to obtain a low temperature curable resin.

Methyl methacrylate (MMA) is excellent in polymerization reactivity and can be used in combination with unsaturated polyester (UP). Mixing less amount than polymethyl methacrylate (PMMA) or polystyrene (PS) can be used. This is because the amount of methyl methacrylate (MMA) is decreased in order to obtain the same viscosity or strength because a commercially available unsaturated polyester (UP) is generally added with a certain amount of styrene monomer to control the viscosity and workability at the time of shipment . If the content of methyl methacrylate (MMA) is less than 10% by weight in the polymerization reaction of such a low-temperature curable resin, workability at the time of site impregnation for repairing the sewer pipe is largely deteriorated due to an increase in viscosity, And shrinkage due to curing is large. If the content of the unsaturated polyester (UP) is less than 50% by weight, the viscosity is low and the curing shrinkage largely occurs. If the content of the unsaturated polyester (UP) exceeds 90% by weight, the viscosity increases and the workability decreases.

Table 1 below shows the viscosity of the mixture according to the mixing ratio of the mixture of methyl methacrylate (MMA) and shrinkage reducing agent.

<Table 1>

Sample MMA (% by weight) Shrinkage reducing agent (% by weight) Viscosity (cP) EPS PMMA One 100 0 0 0.4 2 90 10 0 100 3 80 20 0 400 4 70 30 0 800 5 60 10 0 4703 6 90 0 10 13.5 7 80 0 20 450 8 70 0 30 1500 9 60 0 40 PMMA recording

As shown in Table 1, when mixing 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polymethyl methacrylate (PMMA), methyl methacrylate (MMA) 70 To 80% by weight and polymethyl methacrylate (PMMA) in an amount of 20 to 30% by weight, the mixture has a viscosity of 400 to 2000 cP and can easily carry out impregnation work. In the case of mixing 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polystyrene (PS), 70 to 80% by weight of methyl methacrylate (MMA) When the mixing ratio is 20 to 30% by weight, the mixture has a viscosity of 400 to 2000 cP, so that the impregnating operation can be easily performed.

0.5 to 2.0% by weight of benzoyl peroxide (BPO) as a polymerization initiator and 0.5 to 2.0% by weight of dimethylamine (DMA) as an accelerator are added to the mixture having the above mixing ratio at room temperature and at a low temperature , For example, at -5 to 20 ° C, the curing time of the low-temperature curable resin is about 2 to 5 hours. When the content of the polymerization initiator and the accelerator is less than 0.5% by weight, the curing time exceeds 10 hours. When the content of the polymerization initiator and the accelerator exceeds 2.0% by weight, the curing time is less than 1 hour.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1 is a perspective view of a piping constructed by a non-digging piping repairing method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II 'of FIG. 1; FIG.

Description of the Related Art

20: piping 25: broken portion

L: Liner P: Non-woven fabric

C: Vinyl

Claims (16)

A nonwoven fabric to be inserted into the pipe for repairing a damaged portion of a pipe, the nonwoven fabric impregnated with a low-temperature curing resin; And And a cover covering an outer side of the nonwoven fabric, The low-temperature curable resin is prepared by adding 0.5 to 2.0% by weight of a polymerization initiator and 0.5 to 2.0% by weight of an accelerator to 100% by weight of a mixture composed of a methyl methacrylate (MMA) monomer and a shrinkage reducing agent, Obtained piping repair liners. The method according to claim 1, Wherein the shrinkage reducing agent is made of polymethylmethacrylate (PMMA), polystyrene (PS), or unsaturated polyester (UP). 3. The method of claim 2, Wherein said mixture comprises 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polymethylmethacrylate (PMMA). 3. The method of claim 2, Wherein said mixture comprises 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polystyrene (PS). 3. The method of claim 2, Wherein said mixture comprises 10-50 wt% methyl methacrylate (MMA) and 50-90 wt% unsaturated polyester (UP). 3. The method of claim 2, Wherein said polystyrene (PS) comprises expanded polystyrene (EPS). The method according to claim 1, Wherein said polymerization initiator is benzoyl peroxide (BPO). The method according to claim 1, Wherein said accelerator is dimethylamine (DMA). A low-temperature curable resin impregnated in a nonwoven fabric to be inserted into the pipe for repairing a damaged portion of the pipe, A low temperature for piping repair liner obtained by adding 0.5 to 2.0% by weight of a polymerization initiator and 0.5 to 2.0% by weight of an accelerator to 100% by weight of a mixture composed of methyl methacrylate (MMA) monomer and a shrinkage reducing agent, Curable resin. 10. The method of claim 9, Wherein the shrinkage reducing agent is a low temperature curable resin for a piping repair liner made of polymethylmethacrylate (PMMA), polystyrene (PS), or unsaturated polyester (UP). 11. The method of claim 10, Wherein the mixture comprises 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polymethylmethacrylate (PMMA). 11. The method of claim 10, Wherein the mixture comprises 65 to 80% by weight of methyl methacrylate (MMA) and 20 to 35% by weight of polystyrene (PS). 11. The method of claim 10, Wherein the mixture comprises 10 to 50% by weight of methyl methacrylate (MMA) and 50 to 90% by weight of an unsaturated polyester (UP). 11. The method of claim 10, Wherein the polystyrene (PS) comprises expanded polystyrene (EPS). 10. The method of claim 9, Wherein the polymerization initiator is benzoyl peroxide (BPO). 10. The method of claim 9, The accelerator is a low temperature curable resin for a piping repair liner made of dimethylamine (DMA).

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