Anaerobically curable compositions
An anaerobically curable composition in dry to touch is provided, which is formed from: (a) a liquid anaerobically curable component; (b) a thermoplastic polyurethane (“TPU”) component in an amount of about 10% to about 35%, for example from about 20% to about 30%, by weight based on the total weight of the composition; and (c) a curing component for curing the liquid anaerobically curable component.
1 . An anaerobically curable composition in dry to touch form, the anaerobically curable composition formed from:
(a) a liquid anaerobically curable component;
(b) a thermoplastic polyurethane (“TPU”) component present in an amount of from about 10% to about 35% by weight, based on the total weight of the anaerobically curable composition, wherein the TPU component comprises:
(i) polyester segments, based on at least one of a greater than C 10 diol or a greater than C 10 dicarboxylic acid, or
(ii) a (co)polyester of dodecanedioic acid and 1,6-hexanediol, said (co)polyester having a melting point of about 70° C., and with an OH number from about 27 to about 34 mg KOH/g (as measured according to standard procedure DIN 53240-2); and
(c) a curing component for curing the liquid anaerobically curable component, wherein the curing component comprises a peroxide in liquid form free of encapsulation; and
(d) a solvent present in an amount less than 1% by weight, based on the total weight of composition,
wherein the TPU component has a mass average molar mass M w from about 50,000 to about 100,000, and
wherein the TPU is soluble in the composition.
2 . A composition according to claim 1 , wherein the TPU component is present in an amount of from 20% to 30% by weight, based on the total weight of the composition.
3 . A composition according to claim 1 , wherein the TPU component comprises a modified TPU which includes one or more (meth)acrylate end groups.
4 . A composition according to claim 1 wherein the liquid anaerobically curable component is present in an amount of from about 60% to about 85%, by weight based on the total weight of the composition.
5 . A composition according to claim 1 wherein the liquid anaerobically curable component is present in an amount of from 65% to 80%, by weight based on the total weight of the composition.
6 . A composition according to claim 1 wherein the liquid anaerobically curable component comprises at least one acrylate or methacrylate ester group.
7 . A composition according to claim 1 wherein the curing component is present in an amount of from about 0.1 to about 10%, by weight based on the total weight of the composition.
8 . A composition according to claim 1 wherein the curing component is present in an amount of from about 1 to about 5% by weight based on the total weight of the composition.
9 . A composition according to claim 1 wherein the curing component is present in an amount of about 5% by weight based on the total weight of the composition.
10 . A composition according to claim 1 wherein the TPU component has a mass average molar mass M w from about 55,000 to about 75,000.
11 . A composition according to claim 1 wherein the TPU component comprises polyester segments, based on at least one of a greater than C 10 diol or a greater than C 10 dicarboxylic acid.
12 . A composition according to claim 1 wherein the TPU component has a glass transition temperature of from about −60° C. to about 0° C., and a melting point of from about 30° C. to about 100° C. as measured by differential scanning calorimetry in accordance with ISO11357.
13 . A composition according to claim 1 wherein the TPU component has a glass transition temperature of from about −55° C. to about −20° C.
14 . A composition according to claim 1 wherein the TPU component has a glass transition temperature of from about −50° C. to about −30° C.
15 . A method of applying a composition according to claim 1 to a substrate comprising the steps of:
(i) providing a composition;
(ii) heating the composition to a flowable form; and
(iii) applying the composition to the substrate.
16 . A method of providing a threadlocking composition to a thread of a threaded article to be thread locked, the method comprising:
(i) providing the composition of claim 1 ;
(ii) applying the composition to a thread of the threaded article by heating the composition to a flowable liquid form; and
(iii) optionally passively or actively cooling the composition to provide a solid tack-free form.
17 . A method of threadlocking two threaded articles, the method comprising:
(a) providing the composition of claim 1 ;
(b) applying the composition to a thread of at least one of the two threaded articles; and
(c) threading the two threaded articles together to initiate anaerobic cure of the composition, thereby chemically bonding the two threaded articles.
18 . A bolt or a nut, to which the composition of claim 1 has been applied.
19 . An assembly comprising two substrates bonded together by a cured form of a composition according to claim 1 .
20 . The composition of claim 1 , wherein the TPU has a solubility value at 65° C. of at least 40% by weight, based on the total weight of the anaerobically curable composition.
21 . An anaerobically curable composition in dry to touch form, the anaerobically curable composition formed from:
(a) a liquid anaerobically curable component;
(b) a thermoplastic polyurethane (“TPU”) component present in an amount of from about 20% to about 30% by weight, based on the total weight of the anaerobically curable composition, wherein the TPU component comprises:
(i) polyester segments, based on at least one of a greater than C 10 diol or a greater than C 10 dicarboxylic acid, or
(ii) a (co)polyester of dodecanedioic acid and 1,6-hexanediol, said (co)polyester having a melting point of about 70° C., and with an OH number from about 27 to about 34 mg KOH/g (as measured according to standard procedure DIN 53240-2); and
(c) a curing component for curing the liquid anaerobically curable component, wherein the curing component comprises a peroxide in liquid form free of encapsulation; and
(d) a solvent present in an amount less than 1% by weight, based on the total weight of composition,
wherein the TPU component has a mass average molar mass M w from about 55,000 to about 75,000, and
wherein the TPU is soluble in the composition.