US 6,103,814 A · Styrenic block copolymer based hot-melt adhesives, their use for disposable soft goods, and tackifying resins contained therein

Abstract

Disclosed are hot-melt adhesive compositions suitable for the manufacture of soft goods. They have a melt viscosity of 60,000 mPa.s or less at a temperature of 120.degree. C. and include: (a) 50 to 150 parts by weight of a styrenic block copolymer or mixtures and/or modified and/or hydrogenated derivatives thereof; (b) 20 to 450 parts by weight of a tackifying resin which, when incorporated into a reference composition, leads to the following properties: a tan .delta. value of 3.5 or less, wherein tan .delta. is defined as the ratio between the loss modulus and the storage modulus of said composition and an elastic retention on spandex fibers (300%) or natural latex rubber (200%) after 4 h at 40.degree. C. of 70% or more; and a crossover temperature of 95.degree. C. or less. Further disclosed are novel partially hydrogenated hydrocarbon resins which are useful as tackifying resins and have the following properties: (a) a R&B softening point (R&B) of 50.degree. C. to 150.degree. C.; (b) a mixed methylcyclohexane aniline cloudpoint (MMAP) of 10.degree. C. to 75.degree. C.; (c) a Di-Acetone Alcohol cloudpoint (DACP) of 35.degree. C. or less; (d) a molecular weight (Mz) of 10,000 Dalton or less; and (e) a UV absorbance at 268 nm ranging from 2.0 to 5.0.

Claims33

Dependent claims

A hot-melt adhesive composition which comprises:

(a) about 50 to about 150 parts by weight of a styrenic block copolymer;
(b) about 20 to about 450 parts by weight of a tackifying resin which, when incorporated into a reference composition consisting of 100 parts by weight of a styrene-isoprene-styrene copolymer having a styrene content of about 20 to 30% by weight, 250 parts by weight of said tackifying resin, 50 parts by weight of a paraffinic/napthenic (70/30 weight/weight) extender oil and 2 parts by weight of a stabilizer consisting essentially of pentaerythrityl-tetrakis[3-(3,5-di-tert.butyl-4-hydroxyphenyl)-propionate] , leads to the following properties of said reference composition:
a melt viscosity of about 60,000 mPa.s or less at a temperature of about 120.degree. C.;
a tan .delta. value of about 3.5 or less, wherein tan .delta. is defined as the ratio between the loss modulus (G") and the storage modulus (G') of said composition;
an elastic retention on natural latex rubber (200%) after 4 h at about 40.degree. C. of about 70% or more;
and
a crossover temperature between G' and G" (tan .delta.=1) of about 95.degree. C. or less,
wherein G" and G' of said composition are determined on a Rheometrics Mechanical Spectrometer (RDS-II) using 8 mm circular shaped parallel plates with a 2 mm gap distance over a temperature range from about -60.degree. C. up to about 140.degree. C. and a frequency of 10 radians/sec.

5 more elements

Dependencies are inferred from the claim text.

Styrenic block copolymer based hot-melt adhesives, their use for disposable soft goods, and tackifying resins contained therein

Life of this patent

Styrenic block copolymer based hot-melt adhesives, their use for disposable soft goods, and tackifying resins contained therein

Life of this patent

Abstract

Claims33