Methods for releasably attaching substrates using hot melt pressure sensitive adhesives
OwnerStephen Hatfieldinventor
Life of this patent
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Abstract
A hot melt pressure sensitive adhesive (HMPSA) is obtained by combining a linear A-B-A block copolymer, wherein the B component is polyisoprene and the A component is polystyrene (S-I-S), at least one compatible tackifying resin, at least one plasticizer, antioxidant(s) and stabilizer(s) and optionally a wax, wherein the A-B-A block copolymer contains 0 to 10% by weight residual A-B diblock. The HMPSA is suitable as a positioning adhesive for disposable articles like plasters, bandages, sanitary napkins, e.g. feminine napkins, adult incontinent pads or diapers. The HMPSA has a viscosity from 3,500 mPas to 25,000 mPas at 140° C. and exhibits adhesion values from 1.0 to 3.0 N/cm at coat weights of 10 to 25 grams per square meter.
Claims21
A method of releasably attaching a first substrate having a polyolefin surface to a second substrate having a cloth surface, said method comprising:
- A) coating at least a portion of said polyolefin surface with a hot melt pressure sensitive adhesive (HMPSA) comprising:
- (a) about 10 percent to about 40 percent, based on the weight of the HMPSA, of a linear A-B-A block copolymer, wherein the B component is polyisoprene and the A component is a vinylaromatic polymer;
- (b) about 40 percent to about 70 percent by weight of at least one compatible tackifying resin, based on the weight of the HMPSA;
- (c) about 10 percent to about 40 percent by weight of at least one plasticizer, based on the weight of the HMPSA;
- (d) about 0 percent to about 10 percent by weight of a wax, based upon the weight of the HMPSA;
- and
- (e) about 0.1 percent to about 2.5 percent by weight of antioxidant(s) and stabilizer(s) based upon the weight of the HMPSA;
- and
- wherein the A-B-A block copolymer contains 0 to 10% by weight residual A-B diblock;
- and
- B) applying said polyolefin surface of said first substrate having said HMPSA coated thereon to said cloth surface of said second substrate to adhere said first substrate to said second substrate, wherein said first substrate can be released from said second substrate with a transfer of adhesive of less than 1 milligram per square meter after being conditioned for 24 hours at 40° C. with 1 kg of pressure.
Dependencies are inferred from the claim text.