Adhesive Composition for Bonding Shaped Parts Made of Plastic

Abstract

The invention relates to the field of adhesives. More particularly, it relates to an agent for bonding shaped parts made of plastic, particularly plastic pipes, comprising a PVC-C resin with a K-value of 55 and butan-2-one as a solvent, as well as to a method for materially bonding plastic pipes, and a pipe composite consisting of at least two plastic pipes.

Claims

1. An adhesive composition for adhesively bonding molded parts made of plastic material, comprising: (1) at least one PVC-C resin having a K-value 55 and a chlorine content 65%; and (2) at least one liquid organic solvent comprising butan-2-one.

2. The adhesive composition according to claim 1, wherein the at least one PVC-C resin is contained in an amount of from 10 to 25 wt. %, based on the total weight of the composition.

3. The adhesive composition according to claim 1, wherein the butan-2-one is contained in an amount of from 40 to 90 wt. %, based on the total weight of the composition.

4. The adhesive composition according to claim 1, wherein the composition further contains at least one cosolvent selected from cyclohexanone, cyclopentyl methyl ether (CPME) and 2-methyltetrahydrofuran (2-MeTHF).

5. The adhesive composition according to claim 4, wherein the at least one cosolvent is contained in an amount of up to 35 wt %, based on the total weight of the composition.

6. The adhesive composition according to claim 1, wherein the composition contains less than 0.1 wt. %, tetrahydrofuran (THF) or aliphatic cyclic hydrocarbons having two ring oxygen atoms.

7. The adhesive composition according to claim 1, wherein the composition is free of tetrahydrofuran (THF) or aliphatic cyclic hydrocarbons having two ring oxygen atoms.

8. The adhesive composition according to claim 1, wherein the composition further contains: (1) at least one calcium-, calcium-zinc- or tin-based stabilizer; and/or (2) at least one additive, based on the total weight of the composition.

9. The adhesive composition according to claim 1, comprising: (1) from 10 to 25 wt. % PVC-C resin; (2) from 50 to 85 wt. % butan-2-one; (3) optionally from 5 to 35 wt. % of further solvents selected from cyclohexanone, cyclopentyl methyl ether (CPME) and 2-methyltetrahydrofuran (2-MeTHF).

10. A pipe assembly consisting of at least two plastics pipes bonded together by cured reaction products of the adhesive of claim 1.

11. A method for bonding plastic pipe to a fitting, comprising: (a) applying the adhesive according to claim 1 to the joining surface of the fitting and/or to the joining surface of the pipe end to be connected thereby, and subsequently (b) pushing the pipes and fitting together, and subsequently (c) curing the adhesive to form a bonded pipe to fitting connection.

12. The method according to claim 11, wherein: (a) the plastic pipe is comprised of a thermoplastics material selected from PVC-U, PVC-C, ABS, ASA or ABS/ASA; and/or (b) the bonded pipe to fitting connection can withstand a pressure of 8 bar; and/or (c) the bonded pipe to fitting connection is a component of drinking water piping, service water piping and/or for pressure drainage piping.

13. A method for bonding thermoplastic polymer pipes, comprising: providing a first pipe having an end with an interior surface defining a receiving cavity; providing a second pipe having an end with an exterior surface defining an insertion part; applying the adhesive according to claim 1 to the interior surface and/or the exterior surface; disposing the insertion part into the receiving cavity so that the adhesive is disposed therebetween to form a connection; and curing the adhesive to bond the interior surface to the exterior surface.

14. The method according to claim 13, wherein: (a) the plastic pipe is comprised of a thermoplastics material selected from PVC-U, PVC-C, ABS, ASA or ABS/ASA; and/or (b) the bonded pipe to fitting connection can withstand a pressure of 8 bar; and/or (c) the bonded pipe to fitting connection is a component of drinking water piping, service water piping and/or for pressure drainage piping.

Description

EXAMPLES

[0068] The following adhesives were prepared by mixing the components while heating to 40 C.:

Formulation 1:

[0069]

TABLE-US-00001 Butan-2-one 79.00 wt. % PVC-C 20.50 wt. % Tin stabilizer <0.50 wt. %

[0070] Formulation 1 was prepared with three different PVC-C resins and tested for compressive strength of PVC-C pipes adhesively bonded thereby at 80 C. and 8 bar (according to EN ISO 9311-3:2005).

TABLE-US-00002 CPVC resin 1 CPVC resin 2 CPVC Resin K-value 52 50 57-60 Chlorine content (%) 67 68 64 Density (g/l) 620 480 228 Solubility in MEK Very good Very good Very good Compressive Passed Passed Unsatisfactory strength at 80 C. (cracks)

[0071] The results show that only the PVC-C resins according to the invention having a K-value of 55 or less have the desired compressive strength at 80 C. with appropriate solubility.