JPH06246835A - Synthetic resin lining tube and its production - Google Patents

Abstract

PURPOSE:To obtain a synthetic resin lining tube superior in durable adhesion between the synthetic resin tube and a metallic pipe and obtain a production method therefor. CONSTITUTION:An epoxy resin adhesive is applied to the outer peripheral surface of a synthetic resin tube to serve as a first adhesive layer. On the first adhesive layer, an adhesive mainly composed of a hydrogenated butadiene- styrene block copolymer elastomer containing carboxyl group or acid anhydride group in a molecule is applied to serve as a second adhesive layer. The synthetic resin tube coated with the first and second adhesive layers is inserted into a metallic pipe. A synthetic resin lining tube is produced by reducing the metallic pipe in diameter or expanding the synthetic resin tube in diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin lining pipe obtained by adhering a synthetic resin pipe to the inner surface of a metal pipe and a method for producing the same, and in particular, by devising an adhesive, the synthetic resin pipe and the metal pipe The present invention relates to a synthetic resin lining tube having enhanced durability and adhesion with, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a synthetic resin lining pipe has been manufactured by a method called an expansion method or a contraction method. In the swelling method, an adhesive is interposed between the outer peripheral surface of the synthetic resin pipe and the inner peripheral surface of the metal pipe to expand the diameter of the synthetic resin pipe by heating and pressurizing the outer peripheral surface of the synthetic resin pipe. And the inner surface of the metal tube are adhered to each other (for example, JP-A-56-55).
227, JP-A-58-12720, JP-A-59-5
9418). On the other hand, in the diameter reduction method, the diameter of the metal pipe is reduced by a roll or the like with an adhesive agent interposed between the outer peripheral surface of the synthetic resin pipe and the inner peripheral surface of the metal pipe, whereby the outer periphery of the synthetic resin pipe is reduced. The surface and the inner peripheral surface of the metal pipe are pressure-bonded to each other.

In the conventional method for producing a synthetic resin lining pipe as described above, a polyamide-based or polyester-based adhesive (JP-A-56-55227) and a butadiene-styrene block copolymer elastomer-based hot melt are used as the adhesive. An adhesive (JP-A-58-12720), an adhesive containing a polyolefin obtained by copolymerizing an unsaturated aliphatic carboxylic acid or an anhydride thereof, and the like have been used.

[0004]

However, in the synthetic resin lining pipe obtained by the above-mentioned manufacturing method,
There is a problem that the durable adhesion between the synthetic resin pipe and the metal pipe is not sufficient. That is, when the cold cycle test was repeated for the obtained synthetic resin lining pipe,
There has been a problem that the synthetic resin pipe and the metal pipe tend to be separated at the bonded portion.

Further, among the conventional methods for manufacturing synthetic resin lining pipes, in the method of using a solvent type adhesive as an adhesive, the working environment is contaminated by the organic solvent, and many working spaces and steps are required for drying the solvent. There was also a problem that was necessary.

An object of the present invention is to solve the drawbacks of the conventional method for producing a synthetic resin lining pipe and to provide a synthetic resin lining pipe having excellent durability and adhesion between the synthetic resin pipe and the metal pipe and a method for producing the same. It is in.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors in order to improve the durable adhesion between a synthetic resin pipe and a metal pipe in a synthetic resin lining pipe, two specific types of adhesives are used in combination. Therefore, they have found that the above-mentioned durable adhesiveness is enhanced, and have completed the present invention.

According to a first aspect of the present invention, a synthetic resin pipe, a first adhesive layer formed on an outer peripheral surface of the synthetic resin pipe and made of an epoxy resin adhesive, and a first adhesive are formed. A second adhesive layer containing a hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule and formed on the agent layer; 2 is a synthetic resin lining pipe including a metal pipe in which a synthetic resin pipe is bonded to the inner surface by an adhesive layer 2.

The invention according to claim 2 relates to a method for producing the synthetic resin lining pipe according to claim 1, wherein an epoxy resin adhesive is applied to the outer peripheral surface of the synthetic resin pipe to form a first Of the hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule on the first adhesive layer. Is applied to form a second adhesive layer, and the metal pipe is lined by inserting the synthetic resin pipe in which the first and second adhesive layers are formed into the metal pipe. It is a manufacturing method of a synthetic resin lining pipe.

In the method for producing a synthetic resin lining pipe of the present invention, in order to form the first and second adhesive layers on the outer peripheral surface of the synthetic resin pipe, an epoxy adhesive and a carboxyl group or an acid anhydride group are used. Hydrogenated butadiene contained in the molecule
An adhesive containing a styrene block copolymer elastomer as a main component is used.

In the method of the present invention, the epoxy resin in the epoxy resin adhesive and the hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule are heated during heating during lining. The carboxyl group or the acid anhydride group reacts, and the first and second adhesive layers are firmly adhered.

The cured film formed by the second adhesive containing a hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule as a main component has an appropriate elasticity. Since this cured film has a completely different linear expansion coefficient between the synthetic resin tube and the metal tube, it absorbs the shrinkage stress caused by the difference in the linear expansion coefficient in the durability evaluation such as the thermal cycle test, and the synthetic resin tube and the metal tube. Does not separate from the tube. That is, the present invention is characterized in that the durable adhesiveness is particularly enhanced by forming the first and second adhesive layers using the above-mentioned specific two kinds of adhesives, respectively. The details of the configuration of the present invention will be described below.

The synthetic resin pipe usable in the present invention is, for example, a vinyl chloride resin pipe containing a mixture containing vinyl chloride resin as a main component and, if necessary, a stabilizer, a filler and a lubricant. Examples thereof include those extruded, but the present invention is not particularly limited thereto.

That is, a synthetic resin pipe made of an appropriate synthetic resin can be used depending on the use of the synthetic resin lining pipe, and may be a synthetic resin pipe in which a synthetic resin foam layer is laminated. For example, a synthetic resin pipe in which a vinyl chloride resin foam layer is laminated on the outer peripheral surface of a vinyl chloride resin pipe can be used. A synthetic resin lining pipe in which a synthetic resin pipe having such a synthetic resin foam layer is adhered to the inner surface of a metal pipe can be suitably used as a drainage pipe because the synthetic resin foam layer exhibits a sound deadening function.

In the present invention, on the outer peripheral surface of the synthetic resin pipe,
A first adhesive layer is formed by applying an epoxy resin adhesive. This first adhesive layer usually has a thickness of 10 μm to 50 μm.
It is formed with a thickness of about μm. As the epoxy resin-based adhesive, an epoxy resin as a main component, which is mixed with a curing agent for an epoxy resin is used.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin and various alicyclic epoxy resins. As the epoxy resin curing agent, an amine-based curing agent such as an aliphatic amine or an aromatic amine or an acid anhydride curing agent can be used.
It is not particularly limited to these.

On the first adhesive layer, an adhesive containing a hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in its molecule as a main component is applied. Thus, the second adhesive layer is formed. The thickness of this second adhesive layer is usually
The thickness is about 50 μm to 300 μm.

The hydrogenated butadiene-styrene block copolymer elastomer is a styrene-ethylene-butylene-styrene block copolymer elastomer in which an ethylene structure and a butylene structure are mixed between the styrene polymer blocks at both ends. It has a structure. Such a structure can be obtained, for example, by completely hydrogenating the butadiene portion of a styrene-butadiene-styrene block copolymer having a structure in which styrene polymer blocks are bonded to both ends of the butadiene polymer block.

The hydrogenated butadiene-styrene block copolymer has a two-phase structure of a styrene phase as a hard block and an ethylene-butylene phase as an elastic block. If the styrene content is low, the elastic modulus and cohesive force of the resin will be low, and problems will occur in adhesive strength and heat resistance when used as an adhesive. On the other hand, if the styrene content is too high, the elastic modulus becomes too high, resulting in loss of flexibility and deterioration of fluidity and peel strength during heating. Therefore, for use in the present invention, the styrene content needs to be 20 to 50% by weight, and more preferably 25 to 35% by weight.

When the hydrogenated butadiene-styrene block copolymer elastomer is used for producing a vinyl chloride resin lining tube, the weight average molecular weight is 40,000 to 40,000.
Those in the range of 120,000 are preferable. Examples of the carboxylic acid or acid anhydride grafted to the block copolymer include maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid, crotonic acid, maleic anhydride, and the like. Especially, maleic anhydride is preferable.

The content of the carboxyl group or acid anhydride is usually 0.01 to 30% by weight, preferably
It is 0.05 to 10% by weight. If it is less than 0.01% by weight, the improvement of the adhesive strength due to grafting is hardly seen, and sufficient adhesive strength cannot be obtained. On the other hand, even if it exceeds 30% by weight, the effect of adding the carboxyl group or the acid anhydride does not increase further.

The above-mentioned hydrogenated butadiene-styrene block copolymer elastomer is produced by mixing styrene-ethylene-butylene-styrene copolymer resin (SEBS) and unsaturated carboxylic acid or its anhydride in a molten state or a solution state. , A radical polymerization initiator or not. The method for producing the hydrogenated butadiene-styrene block copolymer elastomer is not particularly limited, but the obtained hydrogenated butadiene-styrene copolymer elastomer contains an unfavorable component such as gel or has a melt viscosity of A manufacturing method that greatly reduces the workability is not preferable.

Specific examples of the hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule as described above include:
Examples include Clayton FG1901 (manufactured by Shell Chemical Co., Ltd.), Tuftec MX077, Tuftec M1913 (all manufactured by Asahi Kasei Co., Ltd.) and the like.

In the adhesive containing the hydrogenated butadiene-styrene block copolymer elastomer as a main component,
Rosin, terpene-based resin, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, phenolic resin for the purpose of improving adhesiveness, heat resistance, adjusting melt viscosity, etc. with respect to the adhesive main component Alternatively, a tackifying resin such as coumarone indene resin can be added. One of these tackifying resins is used for 1 part by weight of the adhesive main component.
It is added as needed in the range of up to 300 parts by weight.

Further, with respect to the above adhesive main component, a filler such as calcium carbonate, barium sulfate, clay, talc or titanium oxide; a fluidity adjusting agent such as naphthene-based, aroma-based or paraffin-based oil; dioctyl phthalate ( Plasticizers such as DOP) and dibutyl phthalate (DBP); antioxidants and the like can be added as necessary.

In the manufacturing method of the present invention, the synthetic resin pipe is inserted into the metal pipe after the first and second adhesive layers are formed on the outer peripheral surface of the synthetic resin pipe. The subsequent steps are performed by a conventionally known method.

[0027]

In the invention described in claim 1, since the first adhesive layer has good adhesion to the synthetic resin, particularly the synthetic resin foam, and the epoxy resin type adhesive does not attack the surface layer of the resin. In addition, since the second adhesive layer is mainly composed of a hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule, the cured film of this adhesive has an appropriate amount. It has elasticity and absorbs the contraction stress based on the difference in linear expansion coefficient between the synthetic resin tube and the metal tube, and the contraction stress is effectively relieved. Therefore, peeling between the synthetic resin pipe and the metal pipe hardly occurs, and the durability and adhesion are excellent.

In addition, between the first and second adhesive layers, the carboxyl group or acid anhydride group in the second adhesive layer reacts with the epoxy resin in the first adhesive layer during heat curing. The first and second adhesive layers are firmly adhered. Therefore, peeling between the first and second adhesive layers hardly occurs.

[0029]

EXAMPLES The present invention will be clarified by giving Examples and Comparative Examples of the present invention.

Example 1 As an adhesive constituting the first adhesive layer, 100 parts by weight of a bisphenol A type epoxy resin (produced by Yuka Shell Epoxy Co., trade name: Epicoat 828) having an epoxy equivalent of 190 was used for the epoxy resin. An epoxy resin adhesive containing 12 parts by weight of dicyandiamide (DICY) as a curing agent was used.

As the adhesive forming the second adhesive layer,
Maleic anhydride-modified hydrogenated butadiene-styrene block copolymer elastomer having a molecular weight of about 50,000 and a styrene content of about 30% by weight (manufactured by Asahi Kasei Co., Ltd., trade name: Tuftec M1913), and a softening point of 100 as a tackifying resin. 30 parts by weight of alicyclic saturated hydrocarbon resin (trade name: Alcon P-100, manufactured by Arakawa Chemical Co., Ltd.) at ℃, and a terpene having a softening point of 145 ° C. as a tackifying resin.
Phenolic resin (Yasuhara Chemical Co., Ltd., trade name: YS
A blend of 30 parts by weight of POLYSTAR S-145) was used.

Example 2 As the adhesive constituting the first adhesive layer, the same adhesive as in Example 1 was used. As the adhesive constituting the second adhesive layer, the adhesive compounded in the same manner as in Example 1 was used except that the Alcon P-100 was 50 parts by weight and the terpene-phenol resin amount was 50 parts by weight. I was there.

Example 3 As an adhesive constituting the first adhesive layer, 100 parts by weight of Epicoat 828 used in Example 1 and 3 parts of trimellitic acid (TMA) as a curing agent for epoxy resin were used.
An epoxy resin adhesive compounded with 2 parts by weight was used. Second
The same adhesive as that used in Example 1 was used as the adhesive forming the adhesive layer.

Example 4 As an adhesive constituting the first adhesive layer, 100 parts by weight of Epicoat 828 used in Example 1 was added to triethylenetetramine (T) as a curing agent for epoxy resin.
An epoxy resin adhesive containing 12 parts by weight of ETA) was used. As the adhesive forming the second adhesive layer, the same adhesive as in Example 1 was used.

Comparative Example 1 As the adhesive, only the same adhesive as the adhesive constituting the second adhesive layer used in Example 1 was used.

COMPARATIVE EXAMPLE 2 As the adhesive, the Epicoat 828 used in Example 1 was used.
An epoxy resin adhesive containing 12 parts by weight of TETA was used with respect to 00 parts by weight. Table 1 below shows the combinations of the adhesives in Examples 1 to 4 and the compositions of the adhesives in Comparative Examples 1 and 2.

[0037]

[Table 1]

With respect to the combinations of the adhesives of Examples 1 to 4 and the adhesives of Comparative Examples 1 and 2, the adhesion strength to a vinyl chloride plate and a metal plate laminated with a vinyl chloride foam layer was measured as follows. It was evaluated by an adhesion test.

Small test piece Adhesiveness evaluation 90 ° peeling test Vinyl chloride consisting of a vinyl chloride foam layer having a thickness of 1.5 mm (expansion ratio about 3 times) and a lower layer comprising a vinyl chloride resin layer having a thickness of 1.6 mm Vinyl chloride plate (25 mm x 125 mm x thickness 3.1 mm) laminated with a foam layer, and 25 m
JIS G 314 m × 125 mm × thickness 1.6 mm
1 and a cold rolled steel sheet. Also, as an adherend to be adhered to this vinyl chloride plate or rolled steel plate, 25 mm ×
A canvas (No. 9) having a size of 125 mm and a thickness of 1.6 mm was prepared.

In the evaluation of Examples 1 to 4, first, the first and second adhesive layers were sequentially formed on the vinyl chloride foam layer surface of the vinyl chloride plate to a thickness of about 50 μm and about 100 μm, respectively. , 150 ℃ by pasting with the above canvas
Then, a pressure of ² kg / cm ² was applied for 20 minutes for adhesion to obtain a small test piece.

Next, after forming the first and second adhesive layers on the rolled steel plate in the reverse order of the case of the vinyl chloride plate, they were laminated with the canvas and 2 kg at 150 ° C. for 20 minutes.
A small test piece was obtained by applying a pressure of / cm ² for adhesion. Further, in Comparative Examples 1 and 2, an adhesive was applied to each of the vinyl chloride foam layer surface of the vinyl chloride plate and the rolled steel plate (application thickness of about 100 μm), and the adhesive was applied to the above-mentioned canvas to attach to Examples 1 to 4. Bonding was performed in the same manner to obtain a small test piece.

Then, with respect to the small test piece obtained by pasting, the tensile strength when the canvas was peeled off at an angle of 90 ° was measured according to JIS K 6854, and 9
0 ° peel strength (measurement temperature 23 ° C, tensile speed 50m
m / min). The measurement was performed on a small test piece immediately after bonding and a small test piece after being immersed in hot water at 85 ° C. for 3 days and then left under reduced pressure at 50 ° C. for 6 hours. The results of this 90 ° peel test are shown in Table 2 below.

Lining Pipe Test Next, synthetic resin lining pipes were actually prepared using the combinations of the adhesives of Examples 1 to 4 and the adhesives of Comparative Examples 1 and 2, and the initial bonded state and the thermal cycle were used. The subsequent adhesion state and the contraction state of the synthetic resin tube were evaluated.

By the two-layer extrusion method, a two-layer pipe (inner diameter: 1.6 mm thick outer layer of vinyl chloride foam layer (foaming ratio: about 3 times) and inner layer: 1.5 mm thick hard vinyl chloride resin layer) 51.1 mm) and apply an adhesive to the outer peripheral surface,
It was inserted into a 9.5 mm steel pipe, and the diameter of the steel pipe was reduced by a roll to make it adhere to the adhesive layer, followed by curing at 150 ° C. for 1 hour to produce a synthetic resin lining pipe.

In Examples 1 to 4, the first and second adhesive layers were formed on the vinyl chloride foam layer surface of the vinyl chloride synthetic resin pipe in the order of the first and second adhesive layers ( The adhesive was applied so that the first adhesive layer had a thickness of about 50 μm and the second adhesive layer had a thickness of about 150 μm. For the comparative example, the adhesive coating thickness is 200 μm.
And

Initial punching adhesion evaluation of the synthetic resin lining pipes of Examples 1 to 4 obtained as described above [standard for hard vinyl chloride lining steel pipe for water supply (JWWA K 11
According to 6), the measurement temperature was 20 ° C., the length was 2 cm, and the entire circumference was punched out. In addition, the evaluation of the adhesion state after the thermal cycle test was performed using the synthetic resin lining pipe (length 3
0 cm) is immersed in cold water at 25 ° C for 5 minutes, and at 85 ° C
The state of being immersed in hot water for 5 minutes was set as one cycle, and after repeating 700 cycles, the punching adhesion evaluation was performed in the same manner as described above, and the shrinkage rate of the synthetic resin pipe was measured. The shrinkage rate (%) of the synthetic resin pipe is calculated by [(length of the synthetic resin pipe at the beginning-length of the synthetic resin pipe after 700 cycles) / (length of the synthetic resin pipe at the beginning)] x 100 It was calculated. The evaluation results of these lining tube tests are shown in Table 2 below.

[0047]

[Table 2]

As is clear from the results in Table 2, in Comparative Example 1 in which only the adhesive containing a maleic anhydride-modified hydrogenated butadiene-styrene block copolymer elastomer as a main component was used, the small test piece adhesiveness was evaluated. Shows that the adhesive strength to the synthetic resin (synthetic resin foam) is remarkably small as compared with Examples 1 to 4, and the punching strength is not sufficient after the synthetic resin lining pipe is manufactured and the thermal cycle is repeated. And, the synthetic resin tube contracted in the axial direction. That is, it is understood that the durable adhesiveness is not sufficient. Further, in Comparative Example 2 using only the epoxy resin-based adhesive, the adhesive strength to the metal in the small test piece adhesiveness evaluation was remarkably small, and when the synthetic resin lining pipe was manufactured, the punching strength after the thermal cycle was changed. And the synthetic resin tube shrank significantly in the axial direction. That is, it is understood that the durable adhesiveness is not sufficient.

On the other hand, in the case of using the combination of the adhesives of Examples 1 to 4, a synthetic resin lining pipe was produced, and the vinyl chloride foam layer of the steel pipe and the vinyl chloride pipe was prepared even if the cooling and heating cycle was repeated. Almost no peeling was observed, and there was no axial shrinkage of the vinyl chloride pipe.

[0050]

According to the present invention, the synthetic resin pipe and the metal pipe are adhered by the first and second adhesive layers formed by using the adhesive of the above specific combination, and the second adhesive layer is formed. Since the adhesive layer is mainly composed of a hydrogenated butadiene-styrene block copolymer elastomer containing a carboxyl group or an acid anhydride group in the molecule, strain caused by the difference in linear expansion coefficient between the synthetic resin pipe and the metal pipe Can be effectively absorbed.

Further, since the first adhesive layer is formed by using an epoxy resin type adhesive, the adhesion durability to a synthetic resin pipe, particularly to a synthetic resin pipe having a synthetic resin foam layer on the outer surface thereof, is improved. Has been increased. Therefore, a synthetic resin pipe in which the durable adhesion between the synthetic resin pipe and the metal pipe is effectively enhanced is provided.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B32B 27/28 8413-4F // B29K 55:00 4F 63:00 4F B29L 9:00 4F

Claims (2)

[Claims] 1. A synthetic resin pipe, a first adhesive layer formed on an outer peripheral surface of the synthetic resin pipe and made of an epoxy resin adhesive, and a carboxyl formed on the first adhesive layer. Of a hydrogenated butadiene-styrene block copolymer elastomer containing a group or an acid anhydride group in the molecule as a main component, and the first and second adhesive layers as a synthetic resin pipe A synthetic resin lining pipe having a metal pipe bonded to the inner surface thereof. 2. An epoxy resin adhesive is applied to the outer peripheral surface of a synthetic resin tube to form a first adhesive layer, and then a carboxyl group or an acid anhydride group is formed on the first adhesive layer as a molecule. An adhesive containing a hydrogenated butadiene-styrene block copolymer elastomer contained therein as a main component is applied to form a second adhesive layer, and the first and second adhesive layers are formed in the metal tube. A method of manufacturing a synthetic resin lining pipe, characterized in that a synthetic resin lining is applied to a metal pipe by inserting the synthetic resin pipe thus prepared.