SEALANT MATERIAL

Abstract

A sealant material for sealing joints between male and female mating parts comprising: (a) an elongate flexible thread suitable for wrapping around at least one of the parts, and (b) a joint sealing composition comprising an anaerobically curable composition in solid form,
the flexible thread being coated with the anaerobically curable composition. This provides a reactive composition on the thread for sealing joints.

Claims

2-24. (canceled)

25. An article of manufacture comprising an anaerobically curable joint sealing composition in solid form packaged in a dispenser from which the anaerobically curable joint sealing composition in solid form can be supplied for direct application to a joint to be sealed.

26. A method of applying an anaerobically curable joint sealing composition in solid form to an elongate flexible thread comprising the steps of: (a) melting the anaerobically curable joint sealing composition in solid form; and (b) applying the anaerobically curable joint sealing composition in melted form to the elongate flexible thread.

27. A method according to claim 26 wherein the application of the curable composition in melted form to the elongate flexible thread is achieved by drawing the elongate flexible thread through a mass of the curable composition in melted form.

28. A method according to claim 26 wherein the method forms a sealant material.

29. A method of sealing joints between male and female mating parts by: (a) providing an anaerobically curable joint sealing composition in solid form comprising: (i) an elongate flexible thread suitable for wrapping around at least one of the parts, and (ii) a joint sealing composition comprising an anaerobically curable composition in solid form, the flexible thread being coated with the anaerobically curable composition; (b) winding the sealant material about at least one of the parts; and (c) mating the parts so as to seal a joint with the sealant material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0148] Embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings in which:

[0149] FIG. 1 is a drawing of a test assembly used in the Experimental section below;

[0150] FIG. 2 is a schematic representation of a vessel and method of applying a composition to an elongate flexible thread;

[0151] FIG. 3 shows average break torque results for Example 2;

[0152] FIG. 4 shows average break torque results for Example 3; and

[0153] FIG. 5 shows comparative average break torque results for Example 4.

DETAILED DESCRIPTION

[0154] An example of an composition that may be considered a basis for formulating (100%) solid anaerobic formulations are given below in Table 1:

TABLE-US-00001 TABLE 1 Solid Anaerobic formulation Component Wt % Resin 25-50 Monomer 45-70 Cure System 4-6 Total 100

[0155] A key prerequisite of the resins and monomers used is that they are in general solids at RT (room temperature) and have a melting point of <100° C.

[0156] General examples of types of materials that could be used are given below in Table 2.

TABLE-US-00002 TABLE 2 Examples of types of resins, monomer and initiators that can be used to prepare (100%) solid anaerobic formulation. Resins Monomers Initiators Long chain (Meth) Short chain Peroxides acrylated Polyurethane (Meth)acrylated resins (MW > 2,000 g/mol) PU resin with mp 50-80° C. Novolac Vinyl esters (Meth)acrylate Encapsulated monomers with peroxides mp 50-80° C. Encapsulated (meth)acrylate monomers

Preparation

[0157] The raw materials are formulated together at a temperature just above the melting point of the individual components. When the formulation has a homogeneuos appearance, it is allowed to cool to room temperature. At this point, it is a solid.

Example 1

[0158] Example of Resin Synthesis:

Charged Dynacoll 7380 (90.89 g), Butylated hydroxytoluene (0.03 g), 4-methoxyphenol (0.03 g) and phosphoric acid (0.007 g) to the reaction vessel and mixed while heating to 120° C. Allowed temperature to decrease and mixed for 20 minutes at 100° C. Added DBTDL (0.037 g) with mixing and then slowly added the toluene diisocyanate (6.28 g) into the vessel, maintaining the temperature at 100° C. throughout the reaction. Continued mixing for 2-3 hours or until wt % Isocyanate (NCO) reached equilibrium. Titrated for remaining NCO. Added 90% of the required HEMA (−2.5 g) based on titre. Added dibutyltin dilaurate (0.037 g). Allowed to react for 3 hours and monitored the NCO consumption via titration. Where the % NCO remaining is >0.2% charged the calculated 2nd addition of HEMA. Stopped the reaction when NCO content is <0.2%.

[0159] Once a suitable resin has been prepared, the raw materials are formulated together at a temperature just above the melting point of the individual components. When the formulation has a homogeneous appearance it is poured into a vessel as shown in FIG. 2. The yarn is then pulled through the molten adhesive formulation which is coated/absorbed onto the cord. Excess adhesive formulation is removed by the act of passing the yarn through another small aperture in the container. The coated yarn is then allowed to cool to room temperature producing an anaerobic coated/impregnated yarn.

[0160] An appropriate yarn can be a single strand or multifilament yarn comprised of polyamide or polypropylene.

Example 2: Formulation

[0161] The following composition was prepared as in Example 1

TABLE-US-00003 Material % Di-functional methacrylated polyurethane 25.0 resin from partially crystalline polyol 2-Methacryloxyethylphenylurethane 35.0 RRT600 35.0 Saccharin 0.2 Acetyl Phenyl Hydrazine 0.2 Maleic Acid 0.2 PEG 200 dimethacrylate 1.4 BPO microcaps 4.0 100 Melt temperature 70° C.

Thread-Locking:

[0162] The above formulation was coated onto a Nylon 6,6 yarn of 950 dtex as shown in FIG. 2 and described above to yield approximately 1 g anaerobic formulation per 1 g thread. Thread-locking capabilities were examined using standard nut and bolt assemblies. The cord was applied to the male threads in accordance with DIN 267-27 and once applied did not exceed the thread height. Break torques were determined in accordance with ISO10964. The results of these tests are set out in FIG. 3.

Thread-Sealing:

[0163] Pipes and fittings with cut threads in accordance with ISO 7-1 were used. The test specimens used have the following characteristics:

[0164] Tapered thread nipple, made of steel, length 250 mm

[0165] Reducer brushing, made of malleable iron, zinc coated, parallel threads

[0166] Bushing, made of malleable iron, zinc coated, parallel threads

[0167] Stopper, made of malleable iron, zinc coated, tapered threads

[0168] The reactive cord was applied to the male threads of the components such that there was a coating of one cord per thread. The thread-sealing capabilities were then tested according to EN 751-1 (for curing compounds). The following tests were carried out sequentially.

[0169] The test assembly 1 used is shown in FIG. 1 below and includes a pressure connection 2.

[0170] The reactive cord was applied to the male threads 3 of the test joints 4, 5 and 6 so that there is one chord per thread. The test pieces were assembled as shown in FIG. 1 using a torque wrench to apply an input torque of 150 Nm. The samples were room temperature tested.

[0171] The parts and in particular the joints were then tested according to Standard EN751-1 Screening Test sequentially as follows.

[0172] Test 1: Internal Pressure Test after Assembly

The specimens were tested between 30-60 minutes after the assembly. The pipes were immersed in a water bath at about 23° C. 7.5 bar 7.5±3 bar (0.75 MPa±0.3 MPa) of compressed air was used to pressurize the test piece. Gas leakage was determined by the appearance of bubbles during an immersion period of 5 minutes, ignoring those noted during the first 15 seconds of immersion.

[0173] Test 2: Hot Water Resistance Test

The test assemblies were half filled with tap water and the reducing bushing was closed by a R½″ plug sealed with Teflon tape. 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.

[0174] Test 3: Temperature Cycling Test

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 5 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. The results are as follows:

TABLE-US-00004 Joint 1 Joint 2 Joint 3 (reference (reference (reference Test numeral numeral numeral No. 4 in FIG. 1) 5 in FIG. 1) 6 in FIG. 1) 1 No leaks No leaks No leaks 2 No leaks No leaks No leaks 3 No leaks No leaks No leaks

Example 3

[0175] The following composition was prepared as in Example 1:

TABLE-US-00005 Material wt % Di-functional methacrylated polyurethane 50.0 resin from partially crystalline polyol 2-Methacryloxyethylphenylurethane 34.0 RRT600 10.0 Saccharin 0.2 Acetyl Phenyl Hydrazine 0.2 Maleic Acid 0.2 PEG 200 dimethacrylate 1.4 Cumene hydroperoxide 4.0 100 Melt temperature 70° C.

Thread-Locking:

[0176] The above formulation was coated onto a Nylon 6,6 yarn of 950 dtex as shown in FIG. 2 and described above to yield approximately 1 g anaerobic formulation per 1 g thread. Thread-locking capabilities were examined using standard nut and bolt assemblies. The cord was applied to the male threads in accordance with DIN 267-27 and once applied did not exceed the thread height. Break torques were determined in accordance with ISO10964. The results of these tests are set out in FIG. 4.

Thread-Sealing Performance:

[0177] The procedure described above for Example 2 was repeated with the formulation of the present example and gave the following results:

TABLE-US-00006 Joint 1 Joint 2 Joint 3 (reference (reference (reference Test numeral numeral numeral No. 4 in FIG. 1) 5 in FIG. 1) 6 in FIG. 1) 1 No leaks No leaks No leaks 2 No leaks No leaks No leaks 3 No leaks No leaks No leaks

Example 4: Flexible PUMA Resin Based Formulation Vs Crystalline PUMA Resin Based Formulation

[0178]

TABLE-US-00007 Flexible Resin Crystalline Resin from partially from highly crystalline crystalline polyol polyol Material (wt. %) (wt. %) Di-functional methacrylated PU resin 50.0 50.0 2-Methacryloxyethylphenylurethane 34.0 34.0 RRT600 10.0 10.0 Anaerobic liquid cure system 2.0 2.0 Cumene hydroperoxide 4.0 4.0 100 100 Melt temperature 70° C. 70° C.

Thread-Locking:

[0179] The above formulations were coated onto a Nylon 6,6 yarn of 950 dtex as shown in FIG. 2 and described above to yield approximately 1 g anaerobic formulation per 1 g thread. Thread-locking capabilities were examined using standard nut and bolt assemblies. The cord was applied to the male threads in accordance with DIN 267-27 and once applied did not exceed the thread height. Break torques were determined in accordance with ISO10964. The results of these tests are set out in FIG. 5.

[0180] It is clear from the foregoing experimental work that the sealant materials of the present invention clearly provide advantages compared to other compositions and have been carefully formulated for optimum properties.

[0181] 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.

[0182] 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.