Asphalt compositions and methods of making same

Patent metadata

Field	Value
Publication number	US-10767033-B2
Application number	US-201815984127-A
Country	US
Kind code	B2
Filing date	May 18, 2018
Priority date	May 18, 2017
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

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

The invention claimed is:

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, and having a peak molecular weight from 30,000 to 78,000, and 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 ratio of (i) to (ii) in the block copolymer composition is less than 1;
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 composition is prepared in a reaction mixture consisting of a diblock copolymer, a coupling agent, a microstructure control reagent, and a solvent, wherein the diblock copolymer is coupled with the coupling agent, and wherein the coupling agent is 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 NR″ 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;
and wherein the coupled block copolymer composition, heated at 180° C. for 24 hours, decouples to a coupling efficiency of less than 20%.

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, B1′ 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 greater than 50 to 90%.

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

8. The coupled block copolymer of claim 1 , 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 NR″;
R, R′, and R″ each independently comprises an alkyl group or aryl group.

9. The coupled block copolymer composition of claim 8 , wherein the coupling agent is methyl benzoate (MBZ).

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

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

12. A bituminous emulsion comprising the asphalt composition of claim 10 .

13. The bituminous emulsion of claim 12 , 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.

14. The bituminous emulsion of claim 13 , for use as a pavement surface treatment for sealing and repairing roads, drive ways, parking lots and black topped surfaces.

15. The bituminous emulsion of claim 12 , 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.

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

17. A method for preparing a coupled block copolymer composition for use in adhesive and/or asphalt applications, the method comprising:
providing a diblock copolymer,
forming a reaction mixture consisting of the diblock copolymer, a coupling agent, a microstructure control reagent, and a solvent, and
coupling the diblock copolymer with the coupling agent; in the presence of the microstructure control reagent, 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 coupling agent is 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 NR″ 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;
wherein the ratio of (i) to (ii) in the block copolymer composition is less than 1;
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;
and wherein the coupled block copolymer composition decouples at a temperature at or above 180° C. and after 24 hours for a coupling efficiency of less than 20%.

18. The method of claim 17 , wherein the coupled block copolymer composition has a coupling efficiency ranging from greater than 50% to 90%.

19. The method of claim 17 , wherein the coupled block copolymer composition has a coupling efficiency ranging from greater than 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

• C09J109/06

  Copolymers with styrene · CPC title

• C09D109/06

  Copolymers with styrene · CPC title

• C08L2555/84

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

• C08L2205/03

  containing three or more polymers in a blend · 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