US 12,054,613 B2Granted

Dual composition block copolymers

AssigneeDynasol Elastómeros, S.A. de C.V.

InventorsDaniel Abraham Elizarrarás Maya, Abel Zúñiga Calles, Gabriel Hernández Zamora, José Luis García Vidales, Jesús Eduardo Ibarra Rodríguez

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

Dual composition block copolymers made from conjugated diene and monovinyl aromatic monomers in batch organolithium initiated polymerization show advantageous performance in the production of crosslinked microcellular rubber compounds and pressure sensitive hot melt adhesives. The dual composition block copolymers are partially coupled with a coupling agent linking inner monovinyl aromatic blocks. Their un-coupled low molecular weight fraction has greater monovinyl aromatic repeating unit content than their coupled high molecular weight fraction. Crosslinked microcellular rubber articles made from the dual composition block copolymers exhibit lower density, smaller and more homogeneous cell size, higher softness and higher resiliency than prior art block copolymers. Rubber compounding of formulations comprising the dual composition block copolymers proceed at slightly lower torque and slightly lower temperature than with prior art block copolymers. Pressure sensitive hot melt adhesives formulated with the dual composition block copolymers are very well suited for labels, exhibiting higher tack and higher softening temperature than those made from prior art block copolymers.

Claims23

Dependent claims

A dual composition block copolymer, comprising block copolymer C and block copolymer U, wherein

block copolymer C comprises:
[D-(D/A)-A1]n-X;
[B-(B/A)-A1]n-X;
[(B/A)-A1]n-X;
or
[B-A1]n-X, or a mixture of the foregoing, and wherein
block copolymer U comprises:
D-(D/A)-A2 or D-(D/A)-A2 and D-(D/A)-A1;
B-(B/A)-A2 or B-(B/A)-A2 and B-(B/A)-A1;
(B/A)-A2 or (B/A)-A2 and (B/A)-A1;
or
B-A2 or B-A2 and B-A1, or a mixture of the foregoing, wherein
B is a polymer block made from only conjugated diene monomer, wherein
(B/A) is a random polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, wherein
D is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, wherein conjugated diene repeating units are in a greater molar amount than monovinyl aromatic repeating units along a whole polymer block length, wherein
(D/A) is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, wherein an end of the polymer block opposite to A1 or A2 is predominantly composed of conjugated diene repeating units, wherein a composition of the polymer block gradually changes along a length of the block until it becomes composed substantially of monovinyl aromatic repeating units at an end adjacent to A1 or A2, wherein
A1 and A2 are polymer blocks made from monovinyl aromatic monomer only, wherein polymer block A2 has a greater molecular weight than polymer block A1, wherein
X is a residue of a coupling agent, and wherein
n is an integer with a value from 2 to 30;
and wherein:
molecular weight distribution of the dual composition block copolymer exhibits at least two peaks, partially or totally resolved;
and
block copolymer C constitutes a fraction with the peak at the highest molecular weight in the molecular weight distribution, and block copolymer U constitutes a remainder of the molecular weight distribution;
and
block copolymer C accounts for from about 20 to about 80% of the molecular weight distribution;
and
total monovinyl aromatic repeating unit content of the dual composition block copolymer is from about 20 to about 50 wt %;
and
monovinyl aromatic repeating unit content in block copolymer U is at least 10 wt % higher than monovinyl aromatic repeating unit content in block copolymer C;
and
optionally, the dual composition block copolymer further comprises extender oil.

28 more elements

A dual composition block copolymer made from conjugated diene and monovinyl aromatic monomers, comprising a block copolymer C and a block copolymer U, wherein,

(a) molecular weight distribution of the dual composition block copolymer exhibits at least two peaks, partially or totally resolved;
(b) block copolymer C constitutes the fraction with a peak at the highest molecular weight in the molecular weight distribution, and block copolymer U constitutes a remainder of the molecular weight distribution;
(c) block copolymer C accounts for from about 20 to about 80% of the molecular weight distribution;
(d) total monovinyl aromatic repeating unit content of the dual composition block copolymer is from about 20 to about 50 wt %;
(e) monovinyl aromatic repeating unit content in block copolymer U is at least 10 wt % higher than monovinyl aromatic repeating unit content in block copolymer C;
(f) monovinyl aromatic repeating unit blockiness degree of the dual composition block copolymer is equal to or greater than about 77 mole % on a total monovinyl aromatic repeating unit basis;
(g) Mooney viscosity (ML 1+4 at 100° C.) of the dual composition block copolymer is from about 25 to about 70;
(h) complex dynamic shear viscosity of the dual composition block copolymer, evaluated at a frequency of 0.99 rad/s, at a temperature of 100° C. and at strain of 13.95%, is greater than about 50000 Pa-s and less than about 150000 Pa-s;
(i) complex dynamic shear viscosity of the dual composition block copolymer, evaluated at a frequency of 100 rad/s, at a temperature of 100° C. and at strain of 13.95%, is greater than about 3000 Pa-s and less than about 7000 Pa-s;
and
(j) dynamic oscillatory shear test of the dual composition block copolymer, when sweeping oscillation frequency from 0.25 to 200 rad/s, at a temperature of 100° C., and at strain of 13.95%, exhibits tan delta values of less than 0.95.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/282,111Filed 10 Dec 2019
Published: US 2021/0371642 A12 Dec 2021
Granted: 6 Aug 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

C08L 9/06
Compositions of homopolymers or copolymers of conjugated diene hydrocarbons: copolymers with styrene
C08F 297/046
Polymerising vinyl aromatic monomers and conjugated dienes: polymerising vinyl aromatic monomers and isoprene, optionally with other conjugated dienes
C08J 9/103
Azo-compounds: azodicarbonamide
C08L 53/02
Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated…:…