Asphalt compositions and methods of making same

Patent metadata

Field	Value
Publication number	US-2018334554-A1
Application number	US-201815984127-A
Country	US
Kind code	A1
Filing date	May 18, 2018
Priority date	May 18, 2017
Publication date	Nov 22, 2018
Grant date	—

Abstract

A coupled block copolymer composition with a combination of high viscosity at manufacturing, finishing and handling conditions, low viscosity at asphalt blending conditions and suitable viscosity stability is provided for use in asphalt compositions. The composition comprises: (i) a diblock copolymer, (ii) at least a linear triblock copolymer having a peak molecular weight that is 1.5 to 3.0 times the peak molecular weight of the diblock copolymer, and (iii) at least a multiarm coupled block copolymer having a peak molecular weight that is 1.5 to 9.0 times the peak molecular weight of the diblock copolymer, and mixtures thereof. The block copolymer composition is characterized as having a melt viscosity at 110° C. or less of greater than 2.0E7 Poise and a coupling efficiency after 24 hours at 180° C. is less than 25%.

First claim

1 . A coupled block copolymer composition comprising: (i) a diblock copolymer comprising one block of a monovinylaromatic hydrocarbon and one block of a conjugated diene having a peak molecular weight from 30,000 to 78,000, each block copolymer has a vinyl content from 8 to 80 mol percent based on the number of repeat monomer units in the conjugated diene block, (ii) a linear triblock copolymer having a peak molecular weight that is 1.5 to 3.0 times the peak molecular weight of the diblock copolymer, and (iii) a multiarm coupled block copolymer having a peak molecular weight that is 1.5 to 9.0 times the peak molecular weight of the diblock copolymer,
wherein the composition has a sufficient coupling efficiency to have a melt viscosity at less than 110° C. of greater than 2.0E7 Poise; wherein the composition is prepared by coupling a diblock copolymer with a coupling agent such that the composition decouples at a temperature at or above180° C. and after 24 hours for a coupling efficiency of less than 25%.

2 . The coupled block copolymer composition of claim 1 , wherein the multiarm coupled block copolymer is present in an amount of less than 5 wt. % of total mass of the coupled block copolymer composition.

3 . The coupled block copolymer composition of claim 1 , wherein the composition is a distributed vinyl coupled block copolymer comprising uncoupled copolymers and coupled copolymers, having mixtures of copolymers having formulae S-B1-B2 and (S-B1-B2) n X, or mixtures of copolymers having formulae S-B1-B2, (S-B1-B2) n X, and any of S-B1-B1′-B2 and (S-B1-B1′-B2) n X, wherein X is residue of the coupling agent, n is an integer from 2 to 6, each of B1, B2, B 1′ and B2 is a conjugated diene block, and S is a monoalkenyl arene block.

4 . The coupled block copolymer composition of claim 1 , wherein the ratio of the diblock copolymer to the multi-arm coupled block copolymer is from 4:5 to 1:10.

5 . The coupled block copolymer composition of claim 1 , wherein both the diblock copolymer and the multi-arm coupled block copolymer have a vinyl content from 8 mol % to 60 mol % and a polystyrene content from 20 mol % to 35 mol %.

6 . The coupled block copolymer composition of claim 1 , wherein the composition has a coupling efficiency ranging from 45 to 90%.

7 . The coupled block copolymer composition of claim 1 , wherein the composition has a coupling efficiency ranging from 50 to 75%.

8 . The coupled block copolymer of claim 1 , wherein the composition is prepared by coupling a diblock copolymer with a coupling agent represented by Formula I:

wherein Y is R, OR, SR′, or X (where X═F, Cl, Br and/or I); Z is O, S, or NW″ where R, R′, and R″ are independently an alkyl group or an aryl group; and Ar is an aromatic group comprises one or more rings.

9 . The coupled block copolymer of claim 8 , wherein the coupling agent is represented by the formula:

wherein Y is R, OR, SR′, or X;
X═F, Cl, Br and/or I;
Z is O, S, or NW″;
R, R′, and R″ each independently comprises an alkyl group or aryl group.

10 . The coupled block copolymer composition of claim 9 , wherein the coupling agent is methyl benzoate (MBZ).

11 . An asphalt composition comprising: a) the coupled block copolymer composition of claim 1 ; b) an asphalt binder; and c) optionally a chemical crosslinking agent.

12 . A self-adhesive roofing composition comprising the coupled block copolymer composition of claim 1 .

13 . A bituminous emulsion comprising the asphalt composition of claim 11 .

14 . The bituminous emulsion of claim 13 , for use in any of fog seal, rejuvenator seal, scrub seal, prime coat, tack coat, chip seal, slurry seal, micro surfacing, an in-place recycling applications.

15 . The bituminous emulsion of claim 14 , for use as a pavement surface treatment for sealing and repairing roads, drive ways, parking lots and black topped surfaces.

16 . The bituminous emulsion of claim 13 , wherein the coupled block copolymer is present in an amount ranging from 1 to 9 wt. % based on the amount of asphalt in the emulsion composition.

17 . A waterproofing composition comprising the coupled block copolymer composition of claim 1 .

18 . A method for preparing a coupled block copolymer composition for use in adhesive and/or asphalt applications, the method comprising:
providing a diblock copolymer, coupling the diblock copolymer with a coupling agent to obtain a coupled block copolymer comprising:
(i) a diblock copolymer comprising one block of a monovinylaromatic hydrocarbon and one block of a conjugated diene having a peak molecular weight from 30,000 to 78,000, each block copolymer has a vinyl content from 8 to 80 mol percent based on the number of repeat monomer units in the conjugated diene block
(ii) a linear triblock copolymer having a peak molecular weight that is 1.5 to 3.0 times the peak molecular weight of the diblock copolymer, and
(iii) a multiarm coupled block copolymer having a peak molecular weight that is 1.5 to 9.0 times the peak molecular weight of the diblock copolymer,
wherein the coupled block copolymer composition has a sufficient coupling efficiency to have a melt viscosity at less than 110° C. of greater than 2.0E7 Poise; wherein the coupled block copolymer composition decouples at a temperature at or above180° C. and after 24 hours for a coupling efficiency of less than 25%.

19 . The method of claim 18 , wherein the coupled block copolymer composition has a coupling efficiency ranging from 45 to 90%.

20 . The method of claim 18 , wherein the coupled block copolymer composition has a coupling efficiency ranging from 50 to 75%.

Assignees

• Kraton Polymers Llc

Inventors

• Kluttz Robert Q
• Jellema Erica
• Dubois Donn A
• Puchalski Sebastian
• Willis Carl L
• Lubbers Christopher M

Classifications

• C08L2555/84

  Polymers comprising styrene, e.g. , polystyrene, styrene-diene copolymers or styrene-butadiene-styrene copolymers · CPC title

• C04B24/36

  Bituminous materials, e.g. tar, pitch {(C04B24/243 takes precedence)} · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C04B2103/0061

  Block (co-)polymers · CPC title