Reactive hot melt adhesive composition and method for use thereof

• US 3,931,077 A
• Filed: 01/04/1974
• Issued: 01/06/1976
• Est. Priority Date: 01/11/1973
• Status: Expired due to Term

• Current Assignee: Mitsui Petrochemical Industries, Ltd.
• Original Assignee: Mitsui Petrochemical Industries, Ltd.
• Inventors: Omori, Kenichi, Okamura, Masataka, Uchigaki, Taku
• Primary Examiner(s): Jacobs, Lewis T.
• Application Number:
  US05/432,844
• Time in Patent Office: 732 Days
• Field of Search: 260/24, 260/27 EV, 260/26, 260/27 R, 260/858
• US Class Current: 524/272
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/12 Polypropene
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 31/04 Homopolymers or copolymers of vinyl acetate
• CPC Class Codes: C08L 33/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 65/00 Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08L7/00 - C08L57/00, C08L61/00 take precedence; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C08L 93/00 Compositions of natural resins; Compositions of derivatives thereof of polysaccharides C08L1/00 - C08L5/00; of natural rubber C08L7/00
• CPC Class Codes: C08L 93/04 Rosin
• CPC Class Codes: C09J 175/04 Polyurethanes

Abstract

A reactive hot-melt adhesive composition useful for bonding is described comprising a reactive urethane prepolymer, a thermoplastic polymer, and a tackifier. A method for using this composition which melts at lower than hot-melt adhesive temperatures and has good pot-life is also described.

Claims

1. A reactive hot melt-type adhesive composition comprising (a) a reactive compound, (b) a thermoplastic resin and (c) a tackifier;

wherein;

a. the reactive compound is a urethane prepolymer having terminal isocyanate groups at both ends thereof and a viscosity higher than 300,000 cps at 25°

C;

resulting from the addition polymerization of at least one diisocyanate and at least one diol

b. the thermoplastic resin is an ethylene-vinylacetate co-polymer or an ethylene-acrylic acid copolymer, or an ethyleneacrylate copolymer or an atactic polypropylene or a polyethyleneterephthalate linear polymer; and

c. the tackifier is a hydrogenated abietic acid-type rosin or esters thereof having its double bonds removed by hydrogenation in whole or in part, or a terpene-phenol copolymer of a mono- or diterpene wherein the terpene has 10 carbon atoms and having a 1.0 to 3.0 molar ratio of terpene to phenol;

said adhesive composition comprising 20 - 73 wt % of said urethane prepolymer (a), 2 - 25 wt % of said thermoplastic resin (b) and 25 - 55 wt % of said tackifier (c) said composition having a viscosity ranging from 9000 cp to 2000 cp in the temperature range of 100°

- 130°

C.

2. The adhesive composition according to claim 1 wherein the urethane prepolymer is an addition polymerization product of a diisocyanate selected from the group consisting of 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate, 4,4'"'"'-diphenylmethanediisocyanate, hexamethylene diisocyanate, or 1,5-naphthylenediisocyanate or a mixture thereof;

and a diol selected from the group consisting of ethyleneglycol, propyleneglycol, 1,4-butanediol or 1,4-butinediol or polymers thereof, polytetramethyleneglycol ether or a mixture thereof.

3. The adhesive composition according to claim 1 wherein said thermoplastic resin is a thermoplastic ethylene-vinylacetate copolymer having a vinylacetate content of 5 - 70 wt.%.

4. The adhesive composition according to claim 1 wherein said thermoplastic resin is a thermoplastic ethylene-ethylacrylate copolymer having an ethylene content of 70 - 95 wt.%.

5. The adhesive composition according to claim 1 wherein said tackifier has good miscibility with the urethane prepolymer, is non-reactive, with the terminal isocyanate groups thereof, has a low viscosity at 100°

to 130°

C. and is solid at 60°

C.