Impregnation sealant for electronic components

Patent metadata

Field	Value
Publication number	US-11725128-B2
Application number	US-202016904300-A
Country	US
Kind code	B2
Filing date	Jun 17, 2020
Priority date	Dec 19, 2017
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

The present invention relates to an anaerobically curable impregnation sealant composition and methods thereof containing a (meth)acrylic monofunctional monomer with a hydrophobic moiety, a (meth)acrylic monofunctional monomer with a hydroxyl group, a modified polyester urethane methacrylate resin having a weight average molecular weight of from about 8000 to about 18000 g/mol, and triallylisocyanurate, triallylcyanurate, or derivatives thereof, or a combination thereof. The present invention particularly relates to a sealant composition for impregnation to plastic and metal substrates that also provides resistance to thermal cycling.

First claim

What is claimed:

1. An anaerobically curable impregnation sealant composition comprising:
(a) at least two (meth)acrylic monofunctional monomers containing a C 4 -C 20 alkyl hydrophobic moiety, wherein (a) comprises lauryl (meth)acrylate and trimethylcyclohexyl (meth)acrylate;
(b) at least one (meth)acrylic monofunctional monomer containing a hydroxyl group;
(c) at least one modified polyester urethane methacrylate resin having a weight average molecular weight of from about 8000 to about 18000 g/mol and a glass transition temperature of less than ˜20° C., present in an amount ranging from about 10 to 30 wt. % based on total weight of the composition, wherein the amount of (c) is selected such that viscosity of the composition is suitable for impregnation; and
(d) triallylisocyanurate, triallylcyanurate, or derivatives thereof, or a combination thereof, present in an amount of about 5 to 15 wt. % based on total weight of the composition.

2. The composition of claim 1 , wherein (a) the (meth)acrylic monofunctional monomers containing the hydrophobic moiety further comprises one or more monomers having C 6 -C 12 alkyl groups.

3. The composition of claim 1 , wherein (a) the (meth)acrylic monofunctional monomer containing the hydrophobic moiety further comprises monomer selected from the group consisting of 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and combinations thereof.

4. The composition of claim 1 , wherein (b) is a hydroxyalkyl(meth)acrylate having from C 1 to C 10 carbon atoms in the alkyl group.

5. The composition of claim 1 , wherein (b) is selected from the group consisting of hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), and combinations thereof.

6. The composition of claim 1 , wherein (c) wherein the polyester urethane methacrylate resin has a weight average molecular weight of from 12000 to 18000 g/mol.

7. The composition of claim 1 , wherein (d) is triallylisocyanurate or a derivative thereof.

8. The composition of claim 1 , wherein (d) is triallylcyanurate or a derivative thereof.

9. The composition of claim 1 , wherein (d) is included in the composition in an amount of about 10 wt. % based on the total weight of the composition.

10. The composition of claim 6 wherein (c) the modified polyester urethane methacrylate resin has a glass transition temperature less than −30° C.

11. The composition of claim 6 , wherein (c) the modified polyester urethane methacrylate resin has a glass transition temperature less than −40° C.

12. The composition of claim 1 , wherein (c) the modified polyester urethane methacrylate resin is a reaction product between polyester diol and toluene diisocyanate.

13. The composition of claim 1 , wherein a reaction weight ratio of equivalents of (meth)acrylate monomers containing a hydroxyl group to (meth)acrylate monomers containing a hydrophobic moiety is about 1:1 to about 1:6.

14. The composition of claim 1 , wherein a reaction weight ratio of equivalents of the modified polyester urethane (meth)acrylate resin to (meth)acrylic monomers containing a hydrophobic moiety and (meth)acrylic monofunctional monomers containing a hydroxyl group is about 1:0.5 to about 1:6.

15. The composition of claim 1 further comprising (f) at least one catalyst capable of initiating free-radical cure of the composition.

16. The composition of claim 1 further comprising (e) a polyfunctional monomer.

17. The composition of claim 1 , wherein (c) has a glass transition temperature less than −40° C.; (d) is included in the composition in an amount of about 10 wt. % based on the total weight of the composition and viscosity of the uncured sealant composition is less than 50 mPa·s.

18. An anaerobically curable impregnation sealant composition comprising:
(a) at least two (meth)acrylic monofunctional monomers containing a hydrophobic moiety, wherein (a) comprises lauryl (meth)acrylate and trimethylcyclohexyl (meth)acrylate;
(b) at least one (meth)acrylic monofunctional monomer containing a hydroxyl group, and is present in an amount from about 3 to about 45 wt. % based on total weight of the composition;
(c) at least one modified polyester urethane methacrylate resin having a weight average molecular weight of from about 8000 to about 18000 g/mol, a glass transition temperature of less than −40° C., and present in an amount ranging from about 10 to 30 wt. % based on total weight of the composition; and
(d) triallylisocyanurate, triallylcyanurate, or derivatives thereof, or a combination thereof; and
wherein (c) the at least one modified polyester urethane methacrylate resin comprises the reaction product of reactants:
(i) a polyester diol,
(ii) toluene diisocyanate, and
(iii) a polymerizable methacrylate acid ester;

wherein viscosity of uncured sealant composition is less than 100 mPa·s.

19. The composition of claim 18 , wherein said (i) polyester diol is poly(3-methyl-1,5-pentanediol adipate).

20. The composition of claim 18 , wherein said (i) polyester diol is a reaction product of neopentyl glycol and a diol adipate, the diol adipate containing at least 3 carbons.

21. The composition of claim 18 , wherein (a) the hydrophobic moiety includes monomers containing a C 4 -C 20 alkyl groups; and wherein equivalent weight of the polyester diol to the toluene diisocyanate is in a ratio of about 1.0 to 4.0 parts diol to about 1.0 to 4.0 parts diisocyanate.

22. The composition of claim 21 , wherein equivalent weight of the polyester diol to the toluene diisocyanate is in a ratio of about 1.0 parts diol to about 2.0 parts diisocyanate.

23. The composition of claim 18 , wherein
(a) the at least two (meth)acrylic monofunctional monomers containing a hydrophobic moiety are present in a total amount of about 20 to 60 wt. % based on the total weight of the sealant composition;
(b) the at least one (meth)acrylic monofunctional monomer containing a hydroxyl group is present in an amount of about 5 to about 33 wt. % based on total weight of the composition;
(c) the at least one modified polyester urethane methacrylate resin has a molecular weight of 12000 to about 18000 g/mol, and is present in an amount of about 10 to 30 wt. % based on total weight of the composition; and
(d) the triallylisocyanurate, triallylcyanurate, or derivatives thereof, or a combination thereof, is present in an amount of about 5 to 15 wt. % based on total weight of the composition.

24. A method of manufacturing an anaerobically curable composition comprising:
step a) providing (a) at least two (meth)acrylic monofunctional monomers containing a C 4 -C 20 alkyl hydrophobic moiety and (b) at least one (meth)acrylic monofunctional monomer containing a hydroxyl group, wherein (a) comprises lauryl (meth)acrylate and trimethylcyclohexyl (meth)acrylate; and
step b) combining said monomers with (c) at least one modified polyester urethane methacrylate resin having a weight average molecular weight of from about 8000 to about 18000 g/mol, and (d) triallylisocyanurate, triallylcyanurate, or derivatives thereof, or a combination thereof; wherein a reaction weight ratio of equivalents of the modified polyester urethane methacrylate resin to (meth)acrylic monomers containing a hydrophobic moiety and (meth)acrylic monofunctional monomers containing a hydroxyl group is about 1:0.5 to about 1:6.

25. The method of claim 24 , wherein (a) the (meth)ac

Assignees

• Henkel Ag & Co Kgaa

Inventors

• O'Dwyer Patrick
• Clarke Greg
• Wrobel Peter Joseph

Classifications

• C09K3/1021 Primary

  Polyurethanes or derivatives thereof · CPC title

• C08K5/34924

  containing cyanurate groups; Tautomers thereof · CPC title

• C08F220/281

  and containing only one oxygen, e.g. furfuryl (meth)acrylate or 2-methoxyethyl (meth)acrylate · CPC title

• C08F220/301

  and one oxygen in the alcohol moiety · CPC title

• C08F220/346

  and further oxygen · CPC title