Process for the production of carbodiimide modified organic isocyanates
AssigneeBayer MaterialScience AG
InventorsJames William Rosthauser, James Thomas Garrett, Jeffrey S. Bolton
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Abstract
The present invention relates to an improved process for the production of carbodiimide modified organic isocyanate, preferably a polymethylene polyphenylisocyanate, and most preferably diphenylmethane diisocyanate. This process includes (1) neutralizing acidic impurities in an organic isocyanate, (2) partially carbodiimidizing isocyanate groups of the neutralized organic isocyanate, and (3) terminating the carbodiimidization reaction.
Claims21
A process for the preparation of liquid storable organic isocyanates containing carbodiimide and/or uretoneimine groups, comprising:
- (1) neutralizing acidic impurities in an organic isocyanate with an acid scavenger, in which the organic isocyanate comprises polymethylene polyphenylisocyanate comprising 90 to 100% by weight of diphenylmethane diisocyanate and 0 to 10% by weight of higher functional polyisocyanates of the diphenylmethane series, wherein the diphenylmethane diisocyanate comprises from 96 to 100% by weight of the 4.4′-isomer, from 0 to 1 % by weight of the 2,2′-isomer and from 0.1 to 4% by weight of the 2.4′-isomer, with the %'s by weight of the 4,4′-isomer, the 2.2′-isomer and the 2,4′-isomer totaling 100% by weight of monomeric diphenylmethane diisocyanate,
- (2) partially carbodiimidized isocyanate groups of the neutralized organic isocyanate with a phosphorous oxide catalyst and
- (3) terminating the carbodiimidization reaction by the addition of an acid comprising a silylated acid corresponding to the formula:
- X−[—Si(CH3)3]n
- wherein:
- X:
- represents the neutral acid residue obtained by removal of the acidic hydrogen atoms from an n-basic acid having a pKa value of at most 3, and
- n:
- represents an integer of 1 to 3.
A process for the preparation of liquid storable organic isocyanates containing carbodiimide and/or uretoneimine groups, comprising:
- (1) neutralizing acidic impurities in an organic isocyanate with an acid scavenger, in which the organic isocyanate comprises polymethylene polyphenylisocyanate comprising 80 to 100% by weight of diphenylmethane diisocyanate and 0 to 20% by weight of higher functional polyisocyanates of the diphenylmethane series, wherein the diphenylmethane diisocyanate comprises from 40 to 80% by weight of the 4,4′-isomer, from 0 to 8% by weight of the 2,2′-isomer and from 20 to 60% by weight of the 2,4′-isomer, with the % 's by weight of the 4,4′-isomer, the 2,2′-isomer and the 2,4′-isomer totaling 100% by weight of monomeric diphenylmethane diisocyanate, and the acid scavenger is selected from the group consisting of epoxides, sodium carbonate sodium bicarbonate calcium carbonate potassium carbonate, potassium bicarbonate and calcium hydroxide,
- (2) partially carbodiimidizing isocyanate groups of the neutralized organic isocyanate with a phosporous oxide catalyst, and
- (3) terminating the carbodiimidization reaction by the addition of an acid comprising a silylated acid corresponding to the formula:
- X−[—Si(CH3)3]n
- wherein:
- X:
- represents the neutral acid residue obtained by removal of the acidic hydrogen atoms from an n-basic acid having a pKa value of at most 3. and
- n:
- represents an integer of 1 to 3.
A process for the preparation of liquid storable organic isocyanates containing carbodiimide and/or uretoneimine groups, comprising:
- (1) neutralizing acidic impurities in an organic isocyanate with an acid scavenger, in which the acid scavenger comprises an aliphatic epoxidized oil,
- (2) partially carbodiimidizing isocyanate groups of the neutralized organic isocyanate with a phosphrorous oxide catalyst, and
- (3) terminating the carbodiimization reaction by the addition of an acid.
Dependencies are inferred from the claim text.