Epoxy casting resin formulation

Patent metadata

Field	Value
Publication number	US-11732155-B2
Application number	US-201716485871-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Mar 16, 2017
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

The present disclosure provides a curable casting resin precursor, comprising (a) a first part (A) comprising: (a1) at least one epoxy resin; (b) a second part (B) comprising: (b1) at least one first amine-based epoxy curing agent; (b2) optionally, at least one second amine-based epoxy curing agent; (b3) at least one mineral filler; (b4) at least one phenolic lipid; wherein part (A) and/or part (B) comprise at least one triphenylmethane dye. The curable casting resin precursor is suited for encapsulating metal parts such as cable joints and the like.

First claim

The invention claimed is:

1. A curable casting resin precursor, comprising
(a) a first part (A) comprising:
(a1) at least one epoxy resin;

(b) a second part (B) comprising:
(b1) at least one first amine-based epoxy curing agent selected from a phenalkamine,
the phenalkamine being a reaction product of cardanol, formaldehyde and an amine, and
the phenalkamine being present in an amount of 10 to 45 wt % with respect to the weight of the second part (B);

(b2) optionally, at least one second amine-based epoxy curing agent, if present, the at least one second amine-based epoxy curing agent being present in an amount of 1.5 to 10 wt % with respect to the weight of the second part (B);
(b3) at least one mineral filler;
(b4) at least one phenolic lipid; and

at least one triphenylmethane dye,
wherein the at least one triphenylmethane dye is within the first part (A) and/or the second part (B).

2. The curable casting resin precursor according to claim 1 , wherein the at least one epoxy resin is based on bisphenol A epoxy resin, bisphenol F epoxy resin, and mixtures thereof.

3. The curable casting resin precursor according to claim 1 , wherein the at least one phenolic lipid is selected from alkylcatechols, alkylphenols, alkylresorcinols and anacardic acids.

4. The curable casting resin precursor according to claim 3 , wherein the at least one phenolic lipid is an alkylphenol selected from propylphenol, butylphenol, amylphenol, octylphenol, nonylphenol, dodecylphenol, and a cardanol-based compound.

5. The curable casting resin precursor according to claim 1 , wherein at least one second amine-based epoxy curing agent is a polyether amido amine.

6. The curable casting resin precursor according to claim 1 , wherein the at least one mineral filler is selected from the group of filler materials comprising inorganic oxides, inorganic hydroxides, inorganic oxyhydroxides and metal nitrides.

7. The curable casting resin precursor according to claim 1 , wherein the at least one triphenylmethane dye is selected from 4-[[4-(diethyl-amino)phenyl]-(4-diethylazaniumylidenecyclohexa-2,5-dien-1-ylidene)methyl]-6-hydroxybenzene-1,3-di sulfonate acid and its calcium, potassium or sodium salts or Bromothymol Blue (4,4′-(1,1-Dioxido-3H-2,1-benzoxathiole-3,3-diyl)bis(2-bromo-6-isopropyl-3-methylphenol)).

8. The curable casting resin precursor according to claim 1 , comprising:
(a) a first part (A) comprising:
(a1) at least one epoxy resin in an amount of from 60 to 100 wt.-%,based on the total weight of part (A);

(b) a second part (B) comprising:
(b3) at least one mineral filler in an amount of from 40 to 80 wt.-%, based on the total weight of part (B);
(b4) at least one phenolic lipid in an amount of from 1 to 30 wt.-%, based on the total weight of part (B).

9. The curable casting resin precursor according to claim 1 , which exhibits a first colour change after mixing of the first part (A) and the second part (B).

10. The curable casting resin precursor according to claim 9 , which exhibits a second colour change upon curing.

11. A curable casting resin composition, obtained from combining the first part (A) and the second part (B) of the curable casting resin precursor according to claim 1 .

12. A method of encapsulating metal parts, the method comprising the following steps:
providing a curable casting resin precursor according to any claim 1 ,
combining the first part (A) and the second part (B) of the curable casting resin precursor to form a curable casting resin composition;
providing at least one metal part;
applying the curable casting resin composition to at least part of the at least one metal part; and
allowing the curable casting resin composition to cure.

13. The curable casting resin precursor according to claim 1 , wherein the at least one mineral filler is selected from aluminum hydroxide, silica, aluminum oxide calcium carbonate, silicon nitride, boron nitride, aluminum nitride, silicon carbide, and glass bubbles.

14. The curable casting resin precursor according to claim 8 , the first part (A) further comprising:
(a4) at least one triphenylmethane dye in an amount of from 0.01 to 2 wt.-%, based on the total weight of the first part (A).

15. The curable casting resin precursor according to claim 8 , the first part (A) further comprising:
(a2) at least one phenolic lipid in an amount of from 5 to 30 wt.-%, based on the total weight of the first part (A).

16. The curable casting resin precursor according to claim 8 , the first part (A) further comprising:
(a3) at least one reactive diluent in an amount of from 1 to 20 wt.-%, based on the total weight of the first part (A).

17. The curable casting resin precursor according to claim 8 , the second part (B) further comprising:
(b5) at least one triphenylmethane dye in an amount of from 0.01 to 2 wt.-%, based on the total weight of the second part (B).

18. The method of claim 12 , further comprising providing a cast around at least part of the at least one metal part and applying the curable casting resin into the cast.

Assignees

• 3M Innovative Properties Company

Inventors

• Muth Mathis A
• Petry Michael
• Jung Adrian T

Classifications

• C09D163/00 Primary

  Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins · CPC title

• B29C39/003

  characterised by the choice of material · CPC title

• B29C39/18

  incorporating preformed parts or layers, e.g. casting around inserts or for coating articles {(B29C39/206 takes precedence)} · CPC title

• C09D7/41

  Organic pigments; Organic dyes · CPC title

• C09D7/61

  inorganic · CPC title