Blocked isocyanates

• US 5,986,033 A
• Filed: 05/04/1995
• Issued: 11/16/1999
• Est. Priority Date: 02/29/1984
• Status: Expired due to Term

• Current Assignee: Baxenden Chemicals Ltd. (Lanxess AG)
• Original Assignee: Baxenden Chemicals Ltd. (Lanxess AG)
• Inventors: Topham, Arthur, Hughes, Anthony H
• Primary Examiner(s): SERGENT, RABON A
• Application Number:
  US08/434,678
• Time in Patent Office: 1,657 Days
• Field of Search: 528/45, 528/73, 528/49, 528/59, 528/60, 528/61, 528/65
• US Class Current: 528/45
• CPC Class Codes: C07D 231/12 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/2865 Compounds having only one primary or secondary amino group; Ammonia
• CPC Class Codes: C08G 18/807 with nitrogen containing compounds
• CPC Class Codes: C08G 18/808 Monoamines
• CPC Class Codes: C09D 5/4496 characterised by the nature of the curing agents

Abstract

A blocked polyisocyanate of the formula

R--Y.sub.m

where R is an m valent aliphatic, cycloaliphatic, heterocyclic or aromatic residue;

each Y, which may be the same or different, is ##STR1## where R₁ is, or, when n is more than 1, each R₁, which may be the same or different, is an alkyl, alkenyl, aralkyl, N-substituted carbamyl, phenol, NO₂, halogen or ##STR2## group where R₂ is a C₁ -C₄ alkyl group; n is 0, 1, 2 or 3; and

m is an integer greater than 1 is useful in paint compositions.

Claims

1. In a storage-stable one-pack elastomer composition comprising an active hydrogen-containing compound and a blocked polyisocyanate of the formula:

space="preserve" listing-type="equation">R--Y.sub.m

wherein R is an m-valent aliphatic, cycloaliphatic, heterocyclic or aromatic residue, m is an integer greater than 1 and Y is a blocking group,

the improvement wherein said composition is curable by heating at 100°

C. to 120°

C. and the groups Y are each of the formula;

##STR7##

2. The composition according to claim 1 wherein the group Y is not directly bonded to an aromatic nucleus in the group R.

3. The composition according to claim 1 wherein the group Y is directly bonded to an aromatic nucleus in the group R.

4. The composition according to claim 1 wherein, in said blocked polyisocyanate, m is from 2 to 6.

5. The composition according to claim 1 wherein, in said blocked polyisocyanate, R is a hydrocarbon group optionally substituted by an alkoxy group.

6. The composition according to claim 1 wherein, in said blocked polyisocyanate, R is selected from the group of divalent radicals of formulae

7. The composition according to claim 1 wherein, in said blocked polyisocyanate, R is an aromatic residue of an isocyanate compound selected from the group consisting of ω

,ω

'"'"'-diisocyanato-1,3-dimethyl benzene,

ω

,ω

'"'"'-diisocyanato-1,4-dimethyl benzene,

ω

,ω

'"'"'-diisocyanato-diethyl benzene,

ω

,ω

'"'"'-diisocyanato-dimethyl toluene,

ω

,ω

'"'"'-diisocyanato-diethyl toluene,

1,3-bis-(2-isocyanato-prop-2-yl) benzene and

1,4-bis-(2-isocyanato-prop-2-yl) benzene.

8. The composition according to claim 7 wherein R is the residue of 1,3-bis-(2-isocyanato-prop-2-yl) benzene.

9. The composition according to claim 1 wherein, in said blocked isocyanate, R is a residue of a compound selected from the group consisting of

ethylene diisocyanate,

propylene diisocyanate,

tetramethylene diisocyanate,

hexamethylene diisocyanate,

decamethylene diisocyanate,

dodecamethylene diisocyanate, and

2,4,4-trimethylhexamethylene-1,6-diisocyanate.

10. The composition according to claim 1 wherein, in said blocked isocyanate, R is the residue of 4,4'"'"'-ethylene-bis(phenyl isocyanate).

11. The composition according to claim 1 wherein, in said blocked isocyanate, R is a residue of a compound selected from the group consisting of

ω

,ω

'"'"'-diisocyanato-1,4-dimethyl cyclohexane,

ω

,ω

'"'"'-diisocyanato-1,3-dimethyl cyclohexane,

1-methyl-2,4-diisocyanato cyclohexane,

4,4,'"'"'-methylene-bis (cyclohexyl isocyanate), and

3-isocyanato-methyl-3,5,5-trimethyl cyclohexyl isoscyanate.

12. The composition according to claim 1 wherein, in said blocked polyisocyanates, R is a residue of a polyisocyanate reaction product of an isocyanate and an active hydrogen containing compound selected from the group consisting of water, a lower molecular weight polyol having a molecular weight of less than or equal to 300 and a medium molecular weight polyol having a molecular weight greater than 300 and less than 8000.

13. The composition according to claim 12 wherein said active hydrogen-containing compound is a lower molecular weight polyol selected from the group consisting of ethylene glycol, neopentyl glycol, propylene glycol, 1,3-butylene glycol, hexamethylene glycol, cyclohexane dimethanol, hydrogenated bisphenol-A, trimethylol propane, trimethylol ethane, 1,2,6-hexane triol, glycerine, sorbitol and pentaerythritol.

14. The composition according to claim 1 wherein, in said blocked polyisocyanate, R is a residue of an isocyanurate.

15. The composition according to claim 1 wherein said blocked polyisocyanate has a biuret structure or an allophanate group.

16. The composition according to claim 1 wherein said active hydrogen-containing compound is an amine or an alcohol.

17. The composition according to claim 16 wherein said active hydrogen-containing compound is 1,4-butanediol.

18. The composition according to claim 1 further comprising a catalyst.

19. The composition according to claim 18 wherein said catalyst is dibutyl tin dilaurate or triethylene diamine.

20. The composition according to claim 1 having 0.5 to 2.0 blocked isocyanate groups per active hydrogen containing group.

21. A process for curing an elastomer composition comprising an active hydrogen-containing compound and a blocked polyisocyanate of the formula:

space="preserve" listing-type="equation">R--Y.sub.m

wherein R is an m-valent aliphatic, cycloaliphatic, heterocyclic or aromatic residue, m is an integer greater than 1 and Y is a blocking group, wherein said composition is curable by heating at 100°

C. to 120°

C. and the groups Y are each of formula;

##STR8## which process comprises heating said composition above the unblocking temperature.