JPH0219785B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a lining material for lining pipes mainly buried underground, such as gas pipes, sewer pipes, power lines, communication lines, etc., oil pipelines, etc. In particular, it relates to a resin coating having watertightness and airtightness in the lining material.

In recent years, lining has been applied to the inner surface of underground pipelines for the purpose of repairing and reinforcing aging underground pipelines as described above. An adhesive is applied to the inner surface of a shaped lining material, and this lining material is inserted into the pipe while being turned over by fluid pressure, and the lining material is bonded to the inner surface of the pipe via the adhesive. There is. This method does not require digging up the entire length of the pipe, it is sufficient to form manholes only at both ends of the pipe to be lined, and the lining work itself can be done in a short period of time. It can be constructed even in pipelines with many bends,
This is an extremely excellent method and has attracted particular attention in recent years.

Therefore, the lining material conventionally used in this construction method is the material previously applied by the applicant.
The outer surface of the cylindrical woven fabric described in Japanese Patent Application No. 54-84808 (see Japanese Unexamined Patent Publication No. 56-8229), Utility Application No. 86058 (see Japanese Utility Model Application No. 56-3619), etc. An example of this is a lining material coated with rubber or synthetic resin. This lining material has sufficient strength in the longitudinal and radial directions of the cylinder, and the adhesive can be sufficiently impregnated into the cylindrical woven fabric before inversion, so even after inversion, When the adhesive impregnated into the woven fabric layer hardens, the lining material becomes a rigid pipe, as if another pipe was formed within the conduit, which is extremely preferable.

By the way, various performances are required for such lining materials, among which the following various performances are required for the resin coating layer in particular. (1) Be flexible.

In order to ensure the flexibility of the lining material, the covering layer is required to be flexible. The hardness is preferably 95 or less on the Shore A hardness, which is a flexibility that allows the lining material to be turned over.

(2) Must have sufficient tensile strength.

(3) Must have extensibility.

(4) The coating layers should have low frictional resistance and good wear resistance.

(5) Excellent chemical resistance, solvent resistance, water resistance, and mold resistance.

(6) Must have heat resistance.

(7) The adhesive used must not deteriorate significantly.

(8) After the adhesive hardens, the adhesive and the coating layer should be able to bond well.

(9) It should be easy to mold.

When forming a coating layer on the outer surface of a cylindrical fabric,
Since extrusion molding is used, the plastic forming the coating layer is required to have good extrusion moldability.

(10) Good adhesion to cylindrical fabric by extrusion molding.

By the way, the applicants have conventionally used a thermoplastic polyester elastic resin as the synthetic resin coating of the lining material, and used a thermosetting epoxy resin adhesive as the adhesive. This thermoplastic polyester satisfies most of the above conditions and is extremely preferred as a resin for the coating of the lining material. However, the adhesion to the adhesive (epoxy resin adhesive) and the adhesion to the cylindrical fabric were not satisfactory.

Regarding the adhesion with the cylindrical fabric, when extruding and coating the resin of the coating layer, the resin is pushed into the grain of the cylindrical fabric to ensure adhesion between the cylindrical fabric and the resin coating due to the anchoring effect. is not necessarily impossible. However, when the resin is forced between the grains of the fabric, the elasticity of the cylindrical fabric decreases, which not only impairs the flexibility of the lining material, but also reduces the voids in the cylindrical fabric, causing the cylindrical fabric to become adhesive. This results in a disadvantage that the amount of impregnation is reduced, and the adhesion between the lining material and the pipe line is reduced.

The present invention has been made in view of the above circumstances, and involves applying fluid pressure to turn the lining material inside out as described above, inserting the lining material into the pipe, and attaching the lining material to the inner surface of the pipe to line the pipe. It is an object of the present invention to provide a lining material which is suitable for use in the method and which satisfies the aforementioned conditions.

Accordingly, the present invention covers the outer surface of a cylindrical fabric with a laminated film having an inner layer made of a synthetic resin mainly composed of a thermoplastic polyurethane elastic resin and an outer layer made of a synthetic resin mainly composed of a thermoplastic polyester elastic resin. This is what happens.

The present invention will be explained below with reference to the drawings. The drawing is a cross-sectional view of the lining material of the present invention, and 1 is the lining material, and the lining material 1 has a synthetic resin coating layer 3 formed on the outer surface of a cylindrical fabric 2. The coating layer 3 is made of a two-layer laminated coating, the inner and outer layers, the inner layer 4 is made of a synthetic resin whose main component is a thermoplastic polyurethane elastic resin, and the outer layer 5 is made of a synthetic resin whose main component is a thermoplastic polyester elastic resin. It is what it is.

Next, as a more specific example of the lining material 1 of the present invention, a specific configuration as a lining material used for a pipe line with a nominal diameter of 150 mm will be shown. The tubular fabric 2 is a tubular woven fabric in which warp yarns and weft yarns are woven into a tubular shape, and the warp yarns are made of 444 yarns made by twisting three 1000 denier polyester filament yarns together. The weft yarn is made by twisting 1100 denier polyester filament yarn and 20 count polyester spun yarn, and the yarn is inserted at a rate of 62 yarns per 10 cm to weave into a cylindrical shape.

The thermoplastic polyurethane elastic resin used for the inner layer of the coating layer is mainly composed of diisocyanate, polyol, and glycol. Then,
Examples of diisocyanates include 4,4'-diphenylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tridene diisocyanate, hexamethylene diisocyanate, etc., and examples of polyols include polyethylene adipate, poly 1,4-butylene adipate, Examples of the glycol include polycaprolactone and polytetramethylene glycol, and examples of the glycol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and bishydroxyethoxybenzene. Among these, especially 4,4'-
A so-called polyether type thermoplastic polyurethane elastic resin made from a combination of diphenyl diisocyanate, polytetramethylene glycol, and 1,4-butanediol has excellent properties such as mold resistance and hydrolysis resistance. desirable.

Furthermore, the thermoplastic polyurethane elastic resin has an overall -OH component of polyol and glycol,
Molar ratio of diisocyanate to -NCO component (R
Value = -NCO component/-OH component) is 1.05 to 1.3,
It is preferable to use a thermoplastic polyurethane elastic resin of the incompletely thermoplastic type. This incompletely thermoplastic type polyurethane has -NCO groups at the terminals of its molecules, and under the influence of heat, water, etc., the urethane bonds and unreacted isocyanate (-NCO groups) react, resulting in crosslinking. The tubular fabric 2
It is possible to improve the adhesion and peeling strength with.

The thermoplastic polyester elastic resin is a block copolymer in which aromatic polyester is used as a hard segment and either or both of aliphatic polyether and aliphatic polyester are used as soft segments.

The aromatic polyester of the hard segment is obtained by condensing an acid component and a glycol component, and the acid component includes terephthalic acid,
Aromatic dicarboxylic acids such as isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, etc.
Examples of the glycol component include aliphatic or alicyclic glycols having 2 to 12 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol.

The aliphatic polyether of the soft segment is preferably an alkylene oxide polymer having an average molecular weight of 400 to 6,000 and a carbon number of 2 to 10, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly hexamethylene glycol, or
Examples include block or random copolymers of ethylene glycol, propylene glycol, etc., which can be used alone or in combination.

In addition, examples of aliphatic polyesters used as the soft segment include polyethylene adipate, polytetramethylene sebacate, polyesters of dimer acid and alkylene glycol, and aliphatic copolyesters made of mixed acids and mixed glycols. These can be used alone or in combination. Furthermore, polylactones such as polyε-caprolactone and polyvalerolactone may be used.

Among these, it is most preferable to use a polyester elastic resin in which a polyester made of terephthalic acid or naphthalene dicarboxylic acid and 1,4-butanediol is used as a hard segment and polytetramethylene glycol is used as a soft segment. This resin is preferable because it is excellent in moldability during extrusion, hydrolysis resistance, water resistance, mold resistance, and the like. Furthermore, in order to reduce the coefficient of friction between the coating layers, a small amount of a lubricant such as wax, liquid paraffin, or graphite may be added to the thermoplastic polyester elastic resin.

In the lining material of the present invention, a small amount of thermoplastic polyester elastic resin may be blended into the thermoplastic polyurethane elastic resin of the inner layer of the coating layer to the extent that its properties are not impaired, and the thermoplastic polyester elastic resin of the outer layer may be blended with the thermoplastic polyester elastic resin of the inner layer of the present invention. It is also possible to use a blend of thermoplastic polyurethane elastic resin.
Thermoplastic polyurethane elastic resin and thermoplastic polyester elastic resin are resins that have very similar properties and are compatible and can be mixed with each other, and by blending them, mutual adhesiveness can be improved. is improved, and delamination between the inner layer and the outer layer is less likely to occur.

Furthermore, the lining material of the present invention is not limited to having two resin coating layers, an inner and outer layer, but can also have a three-layer structure. That is, a blend of a thermoplastic polyester elastic resin and a thermoplastic polyurethane elastic resin can also be used as the intermediate layer. By doing so, while maintaining the adhesive properties of the thermoplastic polyurethane elastic resin of the innermost layer, delamination between the polyurethane elastic resin and the polyester elastic resin becomes less likely to occur.

Further, the cylindrical fabric 2 of the lining material of the present invention is not limited to the cylindrical woven fabric as described above, but a cylindrical knitted or braided fabric can also be used.

Thus, the lining material of the present invention satisfied all of the various performances required of the lining material described above. In particular, it was very flexible compared to conventional lining materials. This is because the thermoplastic polyurethane elastic resin has a lower modulus at low elongation than the thermoplastic polyester elastic resin even if the hardness is the same.

Furthermore, the adhesion of thermoplastic polyurethane elastic resins to cylindrical fabrics is greater than that of thermoplastic polyester elastic resins, and particularly good results have been obtained with those having an R value of 1.05 to 1.3. Furthermore, when adhering a lining material to the inner surface of a pipe, thermoplastic polyurethane elastic resin exhibits several times higher adhesion with an epoxy resin adhesive than thermoplastic polyester elastic resin. This is due to the fact that thermoplastic polyurethane elastic resins are highly reactive with amines used as curing agents for epoxy resin adhesives. This means that if only a thermoplastic polyurethane elastic resin is used as the coating layer of the lining material, the thermoplastic polyurethane elastic resin will be attacked by the amine in the adhesive and cause deterioration. In the present invention, since there is a thermoplastic polyester elastic resin layer as an outer layer, such a phenomenon does not occur, and the entire coating layer does not deteriorate and pinholes do not occur.

[Brief explanation of drawings]

The drawing is a cross-sectional view of the lining material of the present invention. DESCRIPTION OF SYMBOLS 1... Lining material, 2... Cylindrical fabric, 3... Film layer, 4... Inner layer, 5... Outer layer.

Claims (1)

[Claims] 1. In a lining material for lining a conduit by inserting and pasting the lining material into a conduit while turning it over while applying fluid pressure, a thermoplastic polyurethane elastic resin is applied to the outer surface of a cylindrical fabric. What is claimed is: 1. A lining material for conduits, characterized in that it is coated with a laminated film, the inner layer being a synthetic resin whose main component is a thermoplastic polyester elastic resin, and the outer layer is a synthetic resin whose main component is a thermoplastic polyester elastic resin. 2 The thermoplastic polyurethane elastic resin has an R value (-NCO component/-OH component molar ratio) of 1.05 to 1.3.
A lining material for a pipe according to claim 1, characterized in that it is of an incompletely thermoplastic type. 3 The thermoplastic polyurethane elastic resin is a polyurethane resin containing polytetramethylene glycol, 1,4-butanediol, and 4,4' diphenylmethane diisocyanate as main components. A pipe lining material as described in Scope 1. 4. A patent claim characterized in that the thermoplastic polyester elastic resin is a block copolymer having an aromatic polyester as a hard segment and an aliphatic polyether or an aliphatic polyester, or both as a soft segment. A pipe lining material according to item 1.