Active polymer modification of bitumen for use in roofing materials

Patent metadata

Field	Value
Publication number	US-9745473-B2
Application number	US-201615375462-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Feb 26, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A modified bitumen consisting of a polyurethane wherein the polyisocyanate or polyisocyanate-dominated polyurethane prepolymer (or prepolymers) is first reacted with the bitumen to take advantage of the bitumen's hydroxyl and amine functionality and form an isocyanate-bitumen adduct to form a weatherproofing product.

First claim

What is claimed:

1. A method for forming a manufactured roof membrane comprising:
providing 25-75 wt. % of a first component that consists of bitumen, coal tar, or combinations thereof;
2-45% wt. % of a second component that consists of polyurethane, or blend of polyurethane and rubber;
adding said second component to said first component to allowed said second component to react with hydroxyl functional groups of said first component; and,
adding additional polyol or polyol blend to the mixture of first and second components after it is determined that essentially no further isocyanates are being reacted in said mixture.

2. A method for forming a manufactured roof membrane comprising:
providing 25-75 wt. % of a first component that consists of bitumen, coal tar, or combinations thereof;
2-45% wt. % of a second component that consists of polyurethane, or blend of polyurethane and rubber;
adding said second component to said first component to allow said second component to react with hydroxyl functional groups of said first component; and,
adding additional a polyisocyanate monomer to the first component to react with hydroxyl functional groups in an asphaltene fraction, hydroxyl pendant groups, amine pendant groups, or combinations thereof in said first component after it is determined that essentially no further isocyanates are being reacted in said mixture.

3. The method as defined in claim 1 , wherein said first component is in a molten state prior to said addition of said second component.

4. A method for forming a manufactured roof membrane comprising:
providing 25-75 wt. % of a first component that consists of bitumen, coal tar, or combinations thereof, at least a portion of said first component including hydroxyl end groups;
heating said first component to a temperature of about 320° F. to 355° F.;
providing 2-45 wt. % of a second component that consists of polyurethane, or blend of polyurethane and rubber, at least a portion of said second component including isocyanate end groups, a weight percent of said first component is greater than a weight percent of said second component; and,
adding said second component to said first component after said heating step of said first component to allow said second component to react with hydroxyl functional groups of said first component.

5. The method as defined in claim 4 , including the step of adding one or more additional components selected from the group consisting of filler, processing oil, chain extender, modifier, antioxidant, and catalyst, said additional component having a weight percent of 10-66 wt. %, said additional component including chain extender.

6. The method as defined in claim 4 , wherein a weight ratio of said second component to said first component is 0.05-0.7:1.

7. The method as defined in claim 4 , wherein an equivalent ratio of a polyisocyanate compound to a polyol in the polyurethane is 1.2-8:1.

8. The method as defined in claim 5 , wherein said additional component includes a filler, said filler including one or more compounds selected from the group consisting of calcium carbonate, talc, ammonium polyphosphate, alumina trihydrate and Mg(OH) 2 .

9. The method as defined in claim 4 , wherein said second component includes said rubber, said rubber including one or more compounds selected from the group consisting of SBS, SEBS, SIS, and nitrile rubber, a weight ratio of said rubber to said polyurethane is 1:0.2-15.

10. The method as defined in claim 4 , wherein said first component includes a blend of said coal tar and said bitumen, a weight ratio of said coal tar and said bitumen is 1:0.1-10.

11. The method as defined in claim 4 , further including the step of adding a catalyst.

12. The method as defined in claim 4 , wherein said second component includes a mixture of polyisocyanate compound and polyol, a weight ratio of polyisocyanate compound to polyol is 1.2-8:1.

13. The method as defined in claim 4 , wherein said manufactured roof membrane comprises by weight percent:

Bitumen and/or coal tar
30-70%

Polyurethane
 4-20%

Filler
10-66%.

14. The method as defined in claim 4 , wherein said manufactured roof membrane comprises by weight percent:

Bitumen and/or coal tar
50-55%

Polyurethane
 8-20%

Filler
30-41%.

15. The method as defined in claim 4 , wherein said manufactured roof membrane comprises by weight percent:

Bitumen and/or coal tar
50-55%

Polyurethane
 8-20%

Filler
30-41%.

Process oil
 1-5%.

16. The method as defined in claim 4 , wherein said manufactured roof membrane comprises by weight percent:

Bitumen and/or coal tar
50-55%

Polyurethane
 8-20%

Filler
30-41%.

Process oil
 1-3%.

17. The method as defined in claim 4 , wherein said manufactured roof membrane comprises by weight percent:

Assignees

• Garland Ind Inc

Inventors

• Smith Jason D
• Mellott Ii Joseph W
• Rus Melissa
• Sokol David
• Holland Julia

Classifications

• C08L2555/84

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

• C08L2555/74

  Petrochemicals other than waxes, e.g. synthetic oils, diesel or other fuels, hydrocarbons, halogenated or otherwise functionalized hydrocarbons · CPC title

• E04D5/10

  by making use of compounded or laminated materials, e.g. metal foils or plastic films coated with bitumen · CPC title

• C08L2555/50

  Inorganic non-macromolecular ingredients · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title