Radiant energy curable acrylic urethane prepolymer resin compositions and method

• US 5,747,552 A
• Filed: 09/12/1996
• Issued: 05/05/1998
• Est. Priority Date: 04/10/1996
• Status: Expired due to Fees

• Current Assignee: HEHR International Incorporated (LCI Industries)
• Original Assignee: HEHR International Incorporated (LCI Industries)
• Inventors: Smith, Stuart B.
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): Cheng, Wu C.
• Application Number:
  US08/713,177
• Time in Patent Office: 600 Days
• Field of Search: 523/137, 522/96, 522/174, 526/301, 526/347
• US Class Current: 522/96
• CPC Class Codes: C08F 283/006 on to polymers provided for in C08G18/00 C08F283/004 takes precedence
• CPC Class Codes: C08F 283/01 on to unsaturated polyesters C08F283/004 takes precedence
• CPC Class Codes: C08F 290/067 Polyurethanes; Polyureas
• 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 18/3821 Carboxylic acids; Esters thereof with monohydroxyl compounds
• CPC Class Codes: C08G 18/4615 containing nitrogen
• CPC Class Codes: C08G 18/50 having heteroatoms other than oxygen
• CPC Class Codes: C08G 18/5024 containing primary and/or secondary amino groups
• CPC Class Codes: C08G 18/6705 Unsaturated polymers not provided for in the groups C08G18/671, C08G18/6795, C08G18/68 or C08G18/69
• CPC Class Codes: C08G 18/673 containing two or more acrylate or alkylacrylate ester groups
• CPC Class Codes: C08G 18/678 containing nitrogen
• CPC Class Codes: C08G 18/68 Unsaturated polyesters
• CPC Class Codes: C08G 18/765 alpha, alpha, alpha', alpha', -tetraalkylxylylene diisocyanate or homologues substituted on the aromatic ring
• CPC Class Codes: C08G 18/797 containing carbodiimide and/or uretone-imine groups
• CPC Class Codes: C08G 2115/06 to carbodiimide or uretone-imine groups
• CPC Class Codes: C08L 67/06 Unsaturated polyesters
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C08L 75/14 Polyurethanes having carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09D 175/16 having terminal carbon-to-carbon unsaturated bonds
• CPC Class Codes: Y10T 428/2933 Coated or with bond, impregnation or core

Abstract

An acrylic urethane prepolymer composition and an unsaturated polyester resin composition to which the prepolymer has been added. The prepolymer composition includes an acrylic urethane prepolymer prepared by the reaction of diisocyanate, like MDI, with an hydroxyl-containing acrylate monomer, such as a pentaerythritol triacrylate. The prepolymer composition contains a styrene monomer and an inhibitor, such as benzoquinone, to retard the reaction of the prepolymer and styrene monomer prior to the addition of the prepolymer composition into the polyester resin composition and a photoinitiator to promote the polymerization of the resin by exposure to radiant energy. The employment of the urethane prepolymer composition provides for the reduction in the amount of styrene monomer used in the unsaturated resin composition and also provides for improved chemical and physical properties of the photocured, unsaturated resin composition.

Claims

1. An acrylic-urethane prepolymer composition adapted for addition as an additive diluent to an unsaturated resin composition, which prepolymer composition consists essentially of:

a) an acrylic-urethane liquid prepolymer prepared by the reaction of a about a stoichiometric amount or slight excess amount of diisocyanate with a high functionality hydroxyl-containing acrylate monomer;

b) a styrene monomer;

c) an inhibitor in an amount to retard the reaction of the prepolymer and the styrene monomer; and

d) a photoinitiator in an amount to promote the radiation polymerization of the unsaturated resin composition.

2. The composition of claim 1 wherein the acrylate monomer comprises a polyhydroxy C₂ -C₆ alkyl polyacrylic acid monomer.

3. The composition of claim 2 wherein the acrylate monomer comprises a pentaerythritol triacrylate.

4. The composition of claim 1 wherein the inhibitor comprises an inhibiting amount of a quinone compound.

5. The composition of claim 1 which contains an amount of styrene monomer, which when the acrylic-urethane prepolymer composition is added to the unsaturated resin composition ranges from about 5% to 40% by weight of the unsaturated resin composition.

6. The composition of claim 1 wherein the acrylate monomer comprises a hydroxy C₂ -C₃ methacrylate or acrylate monomer.

7. The composition of claim 1 wherein the diisocyanate comprises MDI.

8. The composition of claim 5 wherein the styrene monomer comprises less than 30% by weight of the unsaturated resin composition.

9. The composition of claim 1 wherein the photoinitiator is present in an amount of from 0.01 to 5.0 percent by weight.

10. The composition of claim 1 wherein the photoinitiator is selected from the group consisting of:

benzildimethyl ketal, 60% solution of benzildimethyl ketal, mixture of benzoin normal butyl ethers, trimethylbenzophenone blend, alpha hydroxy ketone, lend of trimethylbenzophenone blend and alpha hydroxy ketone, isopropylthioxanthone, blend of isopropylthioxanthone and trimethylbenzophenone blend, ethyl 4-(dimethylamino) benzoate, and benzophenone.

11. The composition of claim 1 wherein the acrylate monomer comprises an ethyoxylated or propoxylated trimethylol propane polyacrylate.

13. The composition of claim 1 wherein the photoinitiator promotes radiant polymerization of the unsaturated resin composition on exposure to radiant energy in the range of about 250 to 450 nanometers.

14. The composition of claim 1 which includes a peroxide curing agent to promote the polymerization of the unsaturated resin composition.

15. The composition of claim 1 which includes a promoting amount of a metal carboxylate to provide with the peroxide agent on exothermic curing reaction of the unsaturated resin composition.

12. An acrylic urethane prepolymer composition adapted for addition to an unsaturated polyester resin composition and to provide polymerization of the resin composition by radiant energy, which prepolymer composition consists essentially of:

a) an acrylic urethane liquid prepolymer prepared by the reaction of a stoichiometric amount or slight excess amount of MDI with a high functionality hydroxy-containing alkyl or pentaerythritol polyacrylate;

b) from about 0% to 40% by weight of a styrene monomer;

c) a quinone inhibitor in an amount to retard the reaction of the prepolymer and the styrene monomer; and

d) a photoinitiator in an amount of from about 0.01 to 5.0 percent by weight of the prepolymer composition to provide for the polymerization of the unsaturated resin on exposure to radiant light in the range of 250 to 450 nanometers.