Polyacrylated polyurethanes and gaskets having sealants thereof

• US 4,145,509 A
• Filed: 04/21/1978
• Issued: 03/20/1979
• Est. Priority Date: 04/21/1978
• Status: Expired due to Term

• Current Assignee: Dana Corporation (Dana, Inc.)
• Original Assignee: Dana Corporation (Dana, Inc.)
• Inventors: Bhatia, Yog R.
• Primary Examiner(s): Cockeram, H.S.
• Application Number:
  US05/898,921
• Time in Patent Office: 333 Days
• Field of Search: 260/859 R, 260/77.5 CR, 428/425, 528/75, 528/50, 277/138-166
• US Class Current: 428/425.8
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: Y10S 277/944 Elastomer or plastic
• CPC Class Codes: Y10T 428/31605 Next to free metal
• CPC Class Codes: Y10T 428/31609 Particulate metal or metal compound-containing

Abstract

An improved gasket is disclosed having a novel sealant comprising the reaction product of a monoacrylated, terminated, active hydrogen-containing hydrocarboxy reactant an aromatic diisocyanate, and a polyacrylated terminated hydrocarboxy reactant. The active hydrogen of the monoacrylated reactant reacts with at least one isocyanate radical of the aromatic diisocyanate to form an isocyanate linkage, and the reaction product of the monoacrylated and diisocyanate reactant is further reacted with the polyacrylated terminated reactant in widely varying mole ratios. The resulting gaskets have improved temperature resistance, compressibility, film hardness, elongation, flexibility, and organic solvent resistance.

Claims

1. As a composition of matter, the reaction product of (a) a monoacrylated terminated, active hydrogen-containing hydrocarboxy reactant, (b) an aromatic diisocyanate, and (c) a polyacrylated terminated hydrocarboxy reactant, the active hydrogen of reactant (a) reacting with at least one isocyanate radical of reactant (b) to form an isocyanate linkage, the reaction product of reactants (a) and (b) being reacted with reactant (c) in a molar ratio, respectively, of from 1:

25 to 25;

1, said reactant (c) serving primarily as a cross-linking agent to bond together linear chains formed by the reaction of (a) and (b).

2. The composition of matter of claim 1 in which said monoacrylated hydrocarboxy reactant has an alkyl or alkenyl linear stem and a molecular weight of up to about 8,000.

3. The composition of matter of claim 1 in which said monoacrylated hydrocarboxy reactant has the formula:

##STR5## in which R is hydrogen or methyl, and n is a whole number from 1 to 8.

4. The composition of matter of claim 1 in which the aromatic diisocyanate moiety in said first-mentioned reaction product is selected from the group consisting of:

##STR6## ##STR7## in which R is hydrogen or methyl, R₁ is (C₂ H₄ O)_n, and n is a whole number from 1 to 8.

5. The composition of matter of claim 1 in which said polyacrylated terminated, hydrocarboxy reactant is diacrylated and selected from the group consisting of an alkylene glycol diacrylate, alkylene glycol dimethacrylate, a polyalkylene glycol diacrylate, and a polyalkylene glycol dimethacrylate, in which said alkylene group contains 4 to 8 carbon atoms.

6. The composition of matter of claim 1 in which said aromatic diisocyanate in the reaction product formed by reactants (a) and (b) has one isocyanate radical reacted with said active hydrogen of reactant (a) and the other isocyanate radical reacted with a carboxyl radical of an organic acid to form an ester group, said ester group having a molecular weight of about 500 to about 6,000.

7. The composition of matter of claim 6 in which said esterified isocyanate radical has the formula:

##STR8## in which x is a whole number from 2 to 4, y is a whole number from 2 to 12, and n is a number sufficient to provide a molecular weight from about 500 to about 6,000 for said esterified isocyanate radical.

8. A gasket comprising a base sheet and a sealant thereon comprising the reaction product of (a) a monoacrylated terminated, active hydrogen-containing hydrocarboxy reactant, (b) an aromatic diisocyanate, and (c) a polyacrylated terminated hydrocarboxy reactant, the active hydrogen of reactant (a) reacting with at least one diisocyanate radical of reactant (b) to form an isocyanate linkage, the reaction product of reactants (a) and (b) being reacted with reactant (c) in a molar ratio, respectively, of from 1:

25 to 25;

1, said gasket having a compressibility at 1,000 psi of about 2% to about 20%, a film hardness by pencil test of 6B to 4H, an elongation of about 2% to about 100%, and a flexibility by mandrel test of from 1/8 inch to one inch without failure.

9. The gasket of claim 8 in which said first-mentioned reaction product is of (a) a monoacrylated terminated hydrocarboxy reactant having the formula:

##STR9## in which R is hydrogen or methyl, and n is a whole number from 1 to 8, (b) an aromatic diisocyanate selected from the group consisting of phenylene diisocyanate and toluylene diisocyanate, and (c) a diacrylated terminated, hydrocarboxy reactant selected from the group consisting of an alkylene glycol diacrylate, an alkylene glycol dimethacrylate, a polyalkylene glycol diacrylate, and a polyalkylene glycol dimethacrylate in which said alkylene group contains from 4 to 8 carbon atoms, the hydrogen of reactant (a) reacting with at least one isocyanate radical of reactant (b) to form an isocyanate linkage, and the reaction product of (a) and (b) being reacted with reactant (c) in a molar ratio, respectively, of 1;

25 to 25;

1.

10. The composition of matter of claim 9 in which said monoacrylated hydrocarboxy reactant is monoacrylated ethylene glycol, said aromatic diisocyanate is toluylene diisocyanate, and said diacrylated hydrocarboxy reactant is diacrylated tetraethylene glycol.

11. The gasket of claim 8 in which said base sheet is metallic and said first-mentioned reaction product contains from about 1% to about 40% by weight of metallic powder, and said gasket having temperature resistance up to 500°

F., a compressibility at 1000 psi. of about 5% to about 20%, a film hardness by pencil test of 6B to 4H, an elongation of about 5% to about 25%, and a flexibility by mandrel test of from 1/8 inch to 1/4 inch without failure.

12. A process for preparing an improved gasket comprising placing on sheet material defining a base sheet of said gasket a reaction mixture from a solventless system, said mixture including (a) a monoacrylated terminated, active hydrogen-containing hydrocarboxy reactant, (b) an aromatic diisocyanate, and (c) a polyacrylated terminated, hydrocarboxy reactant, reacting the active hydrogen of reactant (a) with at least one isocyanate radical of reactant (b) to form an isocyanate linkage, and reacting the reaction product of reactants (a) and (b) with reactant (c) in a molar ratio, respectively, of 1:

25 to 25;

1, said improved gasket having a temperature resistance up to 500°

F., a compressibility at 1000 psi. of about 2% to about 20%, a film hardness by pencil test of 6B to 4H, an elongation of about 2% to about 100%, and a flexibility by mandrel test of from 1/8 inch to one inch without failure.

13. The process of claim 12 in which said monoacrylated hydrocarboxy reactant has the formula:

##STR10## in which R is hydrogen or methyl, and n is a whole number from 1 to 8, said aromatic diisocyanate is selected from the group consisting of phenylene diisocyanate and toluylene diisocyanate, and said polyacrylated hydrocarboxy reactant is diacrylated and selected from the group consisting of an alkylene glycol diacrylate, an alkylene glycol dimethacrylate, a polyalkylene glycol diacrylate, and a polyalkylene glycol dimethacrylate, in which said alkylene group contains 4 to 8 carbon atoms.

14. The process of claim 12 in which said reaction is generated by heat.

15. The process of claim 12 including a peroxide catalyst in said reaction mixture, and catalyzing said reaction by the peroxide catalyst.

16. The process of claim 12 in which said monoacrylated hydrocarboxy reactant has an alkyl or alkenyl linear stem and a molecular weight of up to about 8000.

17. The process of claim 12 in which said monoacrylated hydrocarboxy reactant has the formula:

##STR11## in which R is hydrogen or methyl, and n is a whole number from 1 to 8.

18. The process of claim 12 in which said polacrylated terminated, hydrocarboxy reactant is diacrylated and selected from the group consisting of an alkylene glycol diacrylate, alkylene glycol dimethacrylate, a polyalkylene glycol diacrylate, and a polyalkylene glycol dimethyacrylate, in which said alkylene group contains 4 to 8 carbon atoms.

19. The process of claim 12 in which said aromatic diisocyanate in the reaction product formed by reactants (a) and (b) has one isocyanate radical rected with said active hydrogen of reactant (b) and the other isocyanate radical reacted with a carboxyl radical of an organic acid to form an ester group, said ester group having a molecular weight of about 500 to about 6,000.