Retarders for hardening phenolic resins
AssigneeBorden, Inc.
InventorArthur H. Gerber
Life of this patent
Estimating the term…
Abstract
There is disclosed methods and compositions for retarding the room temperature hardening of phenolic resole resins when such resins are mixed with lightburned magnesium oxide with or without an ester functional hardening agent. Compounds which act as retarders include azelaic acid, salicylamide, sulfanilic acid, glyoxal, salicylic acid, N-methylaniline, and 2,6-diethylaniline.
Claims14
A method for retarding the hardening of a mixture comprising a phenolic resole resin having a pH of about 4.5 to 9.0 and a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide which method comprises mixing said resin and hardener with a retarder selected from the group consisting of:
- azelaic acid;
- catechol;
- glyoxal;
- and salicylic acid said retarder being in a quantity sufficient to retard the hardening of the mixture in comparison with such mixture without the retarder.
A binder composition comprising a mixture of:
- a. a phenolic resole resin having a pH of about 4.5 to 9, a resin solids content of about 50% to 90% by weight of said resin, and a viscosity of about 100 to 4,000 cps at 25.degree. C;
- b. a magnesium hardening agent selected from the group consisting of magnesium hardening agent being sufficient to accelerate the hardening of said resin, said lightburned magnesium oxide having a surface area of about 10 to 200 square meters per gram;
- and
- c. a retarder selected from the group consisting of:
- azelaic acid;
- catechol;
- glyoxal;
- and salicylic acid, said retarder being in a quantity sufficient to retard the hardening of the mixture in comparison with such mixture without the retarder.
Dependencies are inferred from the claim text.