| CPC C08G 18/4829 (2013.01) [B32B 7/12 (2013.01); B32B 27/08 (2013.01); B32B 27/32 (2013.01); B32B 27/34 (2013.01); B32B 27/40 (2013.01); B32B 37/1284 (2013.01); B32B 37/16 (2013.01); C08G 18/12 (2013.01); C08G 18/3206 (2013.01); C08G 18/36 (2013.01); C08G 18/4804 (2013.01); C08G 18/4812 (2013.01); C08G 18/4833 (2013.01); C08G 18/4858 (2013.01); C08G 18/6644 (2013.01); C08G 18/6696 (2013.01); C08G 18/724 (2013.01); C08G 18/7621 (2013.01); C08G 18/7671 (2013.01); C08G 18/7685 (2013.01); C08G 18/792 (2013.01); C09J 5/00 (2013.01); C09J 175/04 (2013.01); C09J 175/08 (2013.01); C09J 175/14 (2013.01); B32B 37/0053 (2013.01); B32B 2255/10 (2013.01); B32B 2255/205 (2013.01); B32B 2305/72 (2013.01); B32B 2375/00 (2013.01); B32B 2439/70 (2013.01); B32B 2439/80 (2013.01); B32B 2553/00 (2013.01); C08G 2170/00 (2013.01); C09J 2475/00 (2013.01)] | 20 Claims |
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1. A polyurethane 2-component adhesive composition comprising:
(a) a resin component including at least one NCO-terminated polyurethane prepolymer prepared from a reaction mixture comprising at least 40 wt. % of a diphenylmethane diisocyanate (MDI) and one or more polyether diols, wherein the MDI is 4,4′-diphenylmethane diisocyanate or a mixture of 4,4′-diphenylmethane diisocyanate and 2,4′-diphenylmethane diisocyanate, and
(b) a curing component comprising a mixture of polyols, wherein the mixture of polyols comprises:
i) 3.0 to 7.0 wt. %, relative to the total weight of the curing component, of a first polyol, the first polyol being an aliphatic alcohol selected from the group consisting of ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, glycerol, trimethylolpropane, and pentaerythritol,
ii) 25 to 40 wt. %, relative to the total weight of the curing component, of a second polyol, the second polyol being a triol, to which an alkylene oxide is added and which has a weight average molecular weight Mw of at least 400 g/mol and less than 700 g/mol, and
iii) 20 to 65 wt. %, relative to the total weight of the curing component, of castor oil, to which an alkylene oxide is added,
wherein:
the 2-component adhesive composition has a polyester content of less than 10 wt. %, based on the total weight of the 2-component adhesive composition, and
the 2-component adhesive composition does not contain a solid particulate filler in which at least 90% of filler particles of the solid particulate filler have a particle size of 4 μm or less and a Mohs hardness of 3 or less.
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