Curative Free Joint Sealant

Abstract

A curative free sealant composition for sealing joints between male and female parts, the sealant composition comprising a solid resin component, a solid (meth)acrylate polyurethane component, and an ethoxylated bisphenol-A (meth)acrylate component.

Claims

1. A curative free sealant composition for sealing joints between male and female parts, the sealant composition comprising: (a) a solid resin component, (b) a solid (meth)acrylate polyurethane component, (c) an ethoxylated bisphenol-A (meth)acrylate component.

2. The composition of claim 1 wherein the composition consists of: (a) a solid resin component, (b) a solid (meth)acrylate polyurethane component, (c) an ethoxylated bisphenol-A (meth)acrylate component.

3. The composition of claim 1 wherein the composition is free of cure inducing components.

4. The composition of claim 1 wherein the composition is free from cure accelerators.

5. The composition according to claim 1 wherein the solid resin component has a molecular weight of about 2,000 g/mol or higher.

6. The composition according to claim 1 wherein the solid resin component has a melting temperature range from about 55° C. to about 80° C. and a resolidification temperature range of from 25° C. to 55° C. as measured by differential scanning calorimetry according to ISO 11357-1:2016.

7. The composition according to claim 1 wherein the composition has a melting point of from about 15° C. to about 100° C.

8. The composition according to claim 1 wherein the solid (meth)acrylate polyurethane component has a melting point in the range of from about 30° C. to about 100° C.

9. The composition according to claim 1 wherein the composition has a re-solidification point in the range from about 10° C. to about 50° C.

10. The composition according to claim 1 wherein the solid resin component is present in an amount of from about 10 to about 60% by weight based on the total weight of the composition, based on the total weight of the composition.

11. The composition according to claim 1 wherein the solid (meth)acrylate polyurethane component is present in an amount of from about 10% to about 45% by weight based on the total weight of the composition.

12. The composition according to claim 1 wherein the solid (meth)acrylate polyurethane component has a molecular weight of about 1,000 g/mol or lower.

13. The composition according to claim 1 wherein the ethoxylated bisphenol-A (meth)acrylate component is present in an amount of from about 10% to about 40% by weight based on the total weight of the composition.

14. The composition according to claim 1 wherein the composition is solvent-free comprising less than 1% solvent by weight based on the total weight of composition and wherein the solvent is organic solvent or water.

15. The composition according to claim 1 wherein the composition is provided in solid form.

16. A method of sealing joints between male and female mating parts by: (a) providing a composition according to claim 1; (b) applying the composition to at least one mating part by melting; and (c) subsequently, and optionally after active or passive cooling, joining the mating parts so as form a joint between the male and female mating parts wherein the joint between the male and female mating parts is sealed.

17. The method according to claim 16 comprising the steps of heating the mating part of an article to be sealed to a temperature sufficient to melt the composition.

18. The method according to claim 16 wherein at least one of the female mating part or the male mating part or both mating parts are formed from a metal.

19. A system comprising a sealed joint wherein the joint is sealed by the method according to claim 16, optionally wherein the sealed joint permits the passage of fluid or gas through the male and female mating parts.

20. A sealed joint comprising a male mating part and a female mating part and the composition according to claim 1.

21. The sealed joint according to claim 20 wherein at the male mating part or the female mating part or both are formed from a metal.

22. The sealed joint according to claim 20 wherein the joint remains sealed when exposed to internal pressure of 0.8 MPa for 5 minutes as measured in accordance with British Standard BS EN 751-2.

23. The sealed joint according to claim 20 wherein the joint remains sealed when exposed to internal pressure of 0.8 MPa for 5 minutes after the mating parts are turned back as measured in accordance with British Standard BS EN 751-2, optionally wherein the joint remains sealed when exposed to internal pressure of 0.8 MPa for 5 minutes after the mating parts are turned back up to 72 hours as measured in accordance with British Standard BS EN 751-2.

24. The sealed joint according to claim 20 wherein the joint remains sealed when exposed to internal pressure of 0.8 MPa for 5 minutes after the sealed joint is exposed to a temperature of 130° C. for 168 hours as measured in accordance with British Standard BS EN 751-2.

25. The sealed joint according to claim 20 wherein the joint remains sealed when exposed to internal pressure of 0.8 MPa for 5 minutes after the sealed joint is temperature cycled as measured in accordance with British Standard BS EN 751-2 wherein the sealed joint has been: (a) heated to 100° C. for 22 hours and cooled to 20° C. for 2 hours, (b) repeated (a) 5 times, (c) subsequently cooled to −20° C. for 4 hours, and (d) heated to 20° C. for 2 hours.

Description

DETAILED DESCRIPTION

[0073] A curative free sealant composition for sealing joints according to the present invention were prepared as set out in the following Experimental section.

Experimental

[0074] An example of a composition that may be considered a basis for formulating (100%) curative free sealant compositions are given below in table 1:

TABLE-US-00001 Wt % (based on total weight of the Component composition) Solid Resin 10-60 Solid (meth)acrylate 25-45 Ethoxylated bisphenol-A 10-40 (meth)acrylate Total 100

[0075] A key prerequisite of the resins and solid (meth)acrylate used is that they are in general solids at room temperature and have a melting point of <100° C.

Preparation

[0076] The raw materials are formulated together at a temperature just above the melting point of the individual components. When the formulation has a homogenous appearance, it is allowed to cool to room temperature. At this point it is solid.

EXAMPLES

[0077] The following compositions were prepared wherein the solid resin is Dynacoll 7380 and the solid (meth)acrylate is 2-Methacryloxyethyl phenyl urethane:

TABLE-US-00002 Material Ethoxylated Dynacoll 2-Methacryloxyethyl bisphenol-A 7380 phenyl urethane (meth)acrylate Sample Wt % (based on total weight of the composition) Test 1 33.3 33.3 33.3 Test 2 30 30 40 Test 3 40 40 20 Test 4 45 45 10 Test 5 36 36 28 Comparative test 1 15 15 70 Comparative test 2 25 25 50

Shore a Hardness Testing

[0078] Test samples 1, 3-5 and the comparative test specimens were tested for Shore A hardness using a Durometer. The test samples achieved a Shore A hardness above 5. The comparative samples were too soft to measure.

Joint Sealing

[0079] The sealant composition was heated until molten and applied to a male pipe. The coated pipes were left overnight before assembly of the male and female pipes.

Test 1: Internal Pressure Test after Assembly

[0080] The specimens were tested between 30-60 minutes after the assembly following the testing method of BS EN 751-2. The pipes were immersed in a water bath at about 23° C. Compressed air at a pressure of 8 bar (0.8 MPa)±1 bar (0.1 MPa) was used to pressurise the test specimen. Gas leakage was determined by the appearance of bubbles during an immersion period of 5 minutes, ignoring those bubbles noted during the first 15 seconds of immersion.

Test 2: Turn Back Test

[0081] The test assemblies were turned back by 45°. 10 minutes and 72 hours after turn back the internal pressure test for leaks was repeated with compressed air.

Test 3: Hot Water Resistance Test

[0082] The test assemblies were half filled with tap water and closed with a plug seal. The assemblies were placed in an oven at 130° C. in a horizontal position for 168 hours. After this period of time, the assemblies were cooled to room temperature for 2 hours, the plug was removed and the water drained. The internal pressure test for leaks was repeated with compressed air.

Test 4: Temperature Cycling Test

[0083] The test assemblies were placed into a temperature chamber at 150° C. for 22 hours and then cooled down to 20° C. for 2 hours. The temperature cycling test was repeated times. The specimens were then cooled down to −20° C. for 4 hours and warmed to 20° C. for 2 hours. The internal pressure test for leaks was repeated with compressed air.

[0084] The following compositions were prepared wherein the solid resin is a urethane methacrylate end capped crystalline polyol and the solid (meth)acrylate is 2-Methacryloxyethyl phenyl urethane:

TABLE-US-00003 Material Urethane methacrylate end capped 2-Methacryloxy- Ethoxylated crystalline ethyl phenyl bisphenol-A polyol urethane (meth)acrylate Sample Wt %(based on total weight of the composition) Test 6 33.3 33.3 33.3

Comparative Example 3

[0085] The following composition was prepared wherein a curable component (Loctite 577 which comprises the an anaerobic curative system) was included:

TABLE-US-00004 Material 2-Methacryloxy- Ethoxylated Loctite Dynacoll ethyl phenyl bisphenol-A 577 7380 urethane (meth)acrylate Sample Wt % (based on total weight of the composition) Comparative 35 40 15 10 test 3

[0086] The results are as follows:

TABLE-US-00005 Internal Turn Hot water Temperature pressure back resistance cycling Shore A Sample test test test test hardness Test 1 Passed Passed Passed Passed  6.2 Test 2 Passed Passed Passed Passed — Test 3 Passed Passed Passed Passed 46.4 Test 4 Passed Passed Passed Passed 48.2 Test 5 Passed Passed Passed Passed 77.4 Test 6 Passed Passed Passed Passed — Comparative Failed NA NA NA Too soft to test 1 measure Comparative Failed NA NA NA Too soft to test 2 measure Comparative Passed Failed Passed Failed Too soft to test 3 measure

Differential Scanning Calorimetry (DSC)

[0087] Differential Scanning calorimetry (DSC) can show the physical characteristics of the functionalised resins by determining their heat flux responses to changes in thermal conditions. Samples were analysed using a Perkin Elmer DSC 6000. Samples to be analysed were placed in amounts of 10-15 mg in aluminium pans and placed on a sample holder within the furnace. Samples were heated from −30° C. to 100° C. at a rate of 10° C. per minute and then cooled to −20° C. at a rate of 10° C./min to determine the melting and resolidifcation temperature range according to ISO 11357-1:2016. Samples were prepared as above. The samples were prepared as below.

TABLE-US-00006 2-Methacryloxy- Ethoxylated Polyester ethyl phenyl bisphenol-A Polyester polyol urethane (meth)acrylate Sample polyol used (Wt %) (Wt %) (Wt %) Example 7 Dynacoll 7360 40 30 30 Example 8 Dynacoll 7362 40 30 30 Example 9 Dynacoll 7380 40 30 30 Example 10 Dynacoll 7381 40 30 30 Example 11 Dynacoll 7250 & 20:20 30 30 7380 blend blend Example 12 Dynacoll 7360 & 20:20 30 30 7380 blend blend Comparative Dynacoll 7130 40 30 30 example 4 Comparative Dynacoll 7150 40 30 30 example 5 Comparative Dynacoll 7250 40 30 30 example 6 Comparative Dynacoll 7390 40 30 30 example 7 Comparative Dynacoll 7250 & 20:20 30 30 example 8 7390 blend blend

[0088] The crystalline polyol in examples 7 to 12 and comparative examples 4 to 8 were tested to determine the melting and resolidifcation temperature range according to ISO 11357-1:2016. Where possible a composition was formulated and tested to determine the melting and resolidifcation temperature range according to ISO 11357-1:2016 and an Internal pressure test after assembly was performed. The results are shown below.

TABLE-US-00007 Polyester polyol Composition Melting Resolidifcation Melting Resolidifcation Internal range range range range pressure (° C.) (° C.) (° C.) (° C.) test Example 7 57-67 26-38 15-30 & 30-45 NA Passed Example 8 56-66 25-36 15-30 & 31-45 33-41 Passed Example 9 70-80 45-55 48-60 23-32 Passed Example 10 70-80 36-49 33-54 12-24 Passed Example 11 — — 51-54 28-36 Passed Example 12 — — 25-35 & 50-70 29-37 Passed Comparative 27-42 No NA NA NA example 4 resolidification Comparative 59-66 No NA NA NA example 5 resolidification Comparative  2-14 No NA NA Failed example 6 resolidification Comparative 110-120 60-75 NA NA NA example 7 Comparative NA NA NA NA NA example 8

[0089] The crystalline polyester polyols in examples 7 to 10 have a melting temperature range from 55° C. to 80° C. and a resolidification temperature range of from 25° C. to 55° C. Compositions prepared using these crystalline polyester polyols pass an internal pressure test.

[0090] The amorphous and semi-crystalline polyester polyols in comparative examples 4 to 7 do not have both a melting temperature range from 55° C. to 80° C. and a resolidification temperature range of from 25° C. to 55° C. For example comparative examples 4 and 5 while having a melting temperature range from 55° C. to 80° C. do not resolidify. These amorphous or semi-crystalline polyols did not mix with the other components to form a composition. In Comparative example 6 the semi-crystalline polyol did not resolidify, however it was possible to formulate a composition but this composition did not pass the internal pressure test.

[0091] Blends of crystalline polyols have a melting temperature range from 55° C. to 80° C. and a resolidification temperature range of from 25° C. to 55° C. can be blended with polyols which may not have a resolidification temperature range to form a composition which passes an instant seal test, for comparative example 8. Blends of polyols in which none of the polyols have a resolidification temperature range do not form a composition which passes the instant seal test.

[0092] The words “comprises/comprising” and the words “having/including” when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0093] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.