Claims
- 1. A method for joining polyolefin piping elements at least one of whose surfaces to be joined have a gel fraction of at least 20% by weight, which comprises applying an adhesive comprising a water curable polyolefin having a melt index of 0.1 to 20 to one or both of the above surfaces, said adhesive being applied in a melted state, and placing both of the surfaces in contact with each other and water curing the adhesive to obtain a bond which will withstand an internal water pressure which is at least as high as the rupture pressure of the polyolefin piping element.
- 2. A method of claim 1, which comprises in turn a step to apply said adhesive heated at a temperature of at least T.sub.o, and a step to heat both of said surfaces at a temperature of at least (T.sub.o +20).degree.C., and a step to join both of said surfaces, wherein T.sub.o being a melting point (.degree.C.) of said water curable polyolefin.
- 3. A method of claim 2, wherein both of said surfaces are heated at a temperature of at least T.sub.o .degree.C. in advance said step to apply said adhesive.
- 4. A method of claim 1, 2, or 3, wherein heating both of said surfaces are conducted by contacting with a metallic heater held at a high temperature.
- 5. A method of claim 2, wherein said two polyolefin elements are two cured polyolefin pipes.
- 6. A method of claim 2, wherein said two polyolefin elements are a cured polyolefin pipe and a cured polyolefin joint.
- 7. A method of claim 5, wherein said two cured polyolefin pipes are two water cured polyethylene pipes.
- 8. A method of claim 6, wherein said cured polyolefin pipe is a water cured polyethylene pipe and said cured polyolefin joint is a water cured polyethylene joint.
- 9. A method of claim 6, wherein before said step to join, the outer surface of said cured polyolefin pipe and the inner surface of said cured polyolefin joint are heated at a temperature of from (T.sub.o +50).degree.C. to (T.sub.o +180).degree.C.
- 10. A method of claim 2, wherein heating both of said surfaces are conducted by contacting with a metallic heater held at a high temperature.
- 11. A method of claim 3, wherein heating both of said surfaces are conducted by contacting with a metallic heater held at a high temperature.
Priority Claims (4)
Number |
Date |
Country |
Kind |
56-211628 |
Dec 1981 |
JPX |
|
57-73920 |
Apr 1982 |
JPX |
|
57-93382 |
May 1982 |
JPX |
|
57-93749 |
May 1982 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 451,392, filed Dec. 20, 1982, now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (3)
Number |
Date |
Country |
51-101081 |
Sep 1976 |
JPX |
54-149741 |
Nov 1979 |
JPX |
865806 |
Apr 1961 |
GBX |
Non-Patent Literature Citations (1)
Entry |
H. G. Scott et al., Modern Plastics, pp. 82-87, of Mar. 1973. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
451392 |
Dec 1982 |
|