Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
305 words
A viscoelastic hot melt pressure-sensitive adhesive consisting essentially of: (a) about 35 to about 55% by weight of a rubbery block copolymer which comprises a rubbery polyisoprene midblock portion and a plurality of end blocks comprising a crystalline poly(vinylarene); (b) about 25 to 45% by weight of a terpene tackifying resin generally compatible with and generally associated with said midblock portion; (c) about 10 to about 30% by weight of an aromatic, essentially hydrocarbon resin having a glass transition temperature and a softening point above about 115° C., said essentially hydrocarbon resin being generally compatible with said end blocks of said rubbery block copolymer; the proportions of said components (a), (b), and (c) being selected to provide the following pressure-sensitive adhesive and rheological properties: (i) a tensile strength at 500% elongation, determined at 20°-25° C., of at least 50 pounds per square inch; (ii) a 180° peel resistance, according to PSTC-1, determined at 20°-25° C. 24 hours after formation of the pressure-sensitive adhesive bond, of at least about 1500 grams per 25.4 mm-width; (iii) a dead load deformation, tested at room temperature, 37.8° C., 43.3° C., and 48.9° C. for 3 hours under 1500 g/cm 2 , of less than 100%, where dead load deformation=the increased length minus the original length divided by the original length of a sample at least 25 mm in length; (iv) the following loss modulus, storage modulus, and loss tangent values at 0.01 and 0.25 Hz throughout the temperature range of 25°-50° C.: ______________________________________
0.01 Hz 0.25 Hz
______________________________________
loss modulus 5-100 0-100
10.sup.4 dynes/cm.sup.2
storage modulus,
65-225 75-200
10.sup.4 dynes/cm.sup.2
loss tangent 0.03-1.0 0.08-1.0
______________________________________ wherein the said values remain generally within the following limits, throughout said temperature range, at 0.25 Hz: ______________________________________
loss modulus ±70 × 10.sup.4
dynes/cm.sup.2
storage Modulus ±40 × 10.sup.4
dynes/cm.sup.2
loss tangent ±0.6.
______________________________________
Claim 2
Dependent Claim
305 words
A viscoelastic hot melt pressure-sensitive adhesive consisting essentially of: (a) about 35 to about 55% by weight of a rubbery block copolymer which comprises a rubbery polyisoprene midblock portion and a plurality of end blocks comprising a crystalline poly(vinylarene); (b) about 25 to 45% by weight of a terpene tackifying resin generally compatible with and generally associated with said midblock portion; (c) about 10 to about 30% by weight of an aromatic, essentially hydrocarbon resin having a glass transition temperature and a softening point above about 115° C., said essentially hydrocarbon resin being generally compatible with said end blocks of said rubbery block copolymer; the proportions of said components (a), (b), and (c) being selected to provide the following pressure-sensitive adhesive and rheological properties: (i) a tensile strength at 500% elongation, determined at 20°-25° C., of at least 50 pounds per square inch; (ii) a 180° peel resistance, according to PSTC-1, determined at 20°-25° C. 24 hours after formation of the pressure-sensitive adhesive bond, of at least about 1500 grams per 25.4 mm-width; (iii) a dead load deformation, tested at room temperature, 37.8° C., 43.3° C., and 48.9° C. for 3 hours under 1500 g/cm 2 , of less than 100%, where dead load deformation=the increased length minus the original length divided by the original length of a sample at least 25 mm in length; (iv) the following loss modulus, storage modulus, and loss tangent values at 0.01 and 0.25 Hz throughout the temperature range of 25°-50° C.: ______________________________________
0.01 Hz 0.25 Hz
______________________________________
loss modulus 5-100 0-100
10.sup.4 dynes/cm.sup.2
storage modulus,
65-225 75-200
10.sup.4 dynes/cm.sup.2
loss tangent 0.03-1.0 0.08-1.0
______________________________________ wherein the said values remain generally within the following limits, throughout said temperature range, at 0.25 Hz: ______________________________________
loss modulus ±70 × 10.sup.4
dynes/cm.sup.2
storage Modulus ±40 × 10.sup.4
dynes/cm.sup.2
loss tangent ±0.6.
______________________________________
Claim 3
Dependent Claim
181 words
A viscoelastic hot melt pressure-sensitive adhesive according to claim 1, wherein said adhesive consists essentially of: up to 85 parts by weight, per 100 parts by weight of said block copolymer, of said terpene tackifying resin, said tackifying resin having been synthetically derived from a mixed olefin feedstock; up to 65 parts by weight, per 100 parts by weight of said block copolymer, of said essentially hydrocarbon resin, said essentially hydrocarbon resin having a softening point of at least about 140° C.; 0-5% by weight of substantially inert extenders, fillers, pigments, and antioxidants; the foregoing proportions being selected to provide the following loss modulus, storage modulus, loss tangent, storage compliance, and loss compliance values, throughout the temperature range of 25°-50° C., at 0.01 Hz: ______________________________________
loss modulus, 10.sup.4 dynes/cm.sup.2
5-25
storage modulus, 10.sup.4 dynes/cm.sup.2
75-200
loss tangent 0.05-0.3
storage compliance, 10.sup.-8 cm.sup.2 /dyne
40-100
loss compliance, 10.sup.-8 cm.sup.2 /dyne
2-20
______________________________________ and the following storage compliance and loss compliance values, throughout said temperature range at 0.25 Hz: ______________________________________
storage compliance, 10.sup.-8 cm.sup.2 /dyne
40-100
loss compliance, 10.sup.-8 cm.sup.2 /dyne
5-40.
______________________________________
Claim 4
Dependent Claim
21 words
A viscoelastic hot melt pressure sensitive adhesive according to claim 2, wherein said aromatic, essentially hydrocarbon resin is a coumarone-indene resin.