Damping-imparting composition having high impact durability at low temperature

1. A thermally curable composition, comprising:

Component (a) comprised of:

(a1) a solid rubber in an amount of between 2.5% and 8% by mass;

(a2) an olefinic double bond-containing polymer which is liquid or pasty at 22° C., has a styrene content in a range of 10% to 60% by mass and has a glass transition temperature of −30° C. to 20° C., wherein (a2) is present in a positive amount of less than 5% by mass;

(a3) a hydrocarbon resin present in an amount of 5% to 20% by mass, in total with component (a2); and

(a4) a liquid polydiene different from (a2) in an amount of at least 15% by mass;

based on a total mass of the composition; and

Component (b) a vulcanization system comprised of at least one substance selected from the group consisting of:

(b1) sulfur and one or more accelerator(s);

(b2) a peroxidic vulcanization system or a disulfidic vulcanization system; and

(b3) quinones, quinone dioximes or dinitrosobenzene.

2. The composition according to claim 1 , wherein the olefinic double bond-containing polymer which is liquid or pasty at 22° C. (a2) is a copolymer of a diene and has a glass transition temperature of −30° C. to 15° C.

3. The composition according to claim 1 , wherein the olefinic double bond-containing polymer which is liquid or pasty at 22° C. (a2) has a mass average molecular weight of 1,000 to 50,000.

4. The composition according to claim 1 , wherein the olefinic double bond-containing polymer which is liquid or pasty at 22° C. (a2) comprises a diene fraction, and wherein the vinyl fraction in the diene fraction is present in an amount in a range of 20 to 98 mol. %.

5. The composition according to claim 1 , comprising, as the vulcanization system (b):

0.05% to 6.5% by mass of sulfur; and

0.25% to 20% by mass of the one or more accelerator(s);

based on the total mass of the composition.

6. The composition according to claim 1 , further comprising 10% to 45% by mass of a filler (c), based on the total mass of the composition.

7. The composition according to claim 1 , further comprising 0.2% to 6% by mass a blowing agent (d), based on the total mass of the composition.

8. The composition according to claim 1 , further comprising 2% to 40% by mass of a plasticizer (e), based on the total mass of the composition.

9. The composition according to claim 1 , which exhibits a viscosity capable of being pumped with a pump at a temperature in a range of 15 to 60° C.

10. The composition according to claim 1 , having an after curing loss factor tanδ (50 Hz) of at least 0.5 as measured by a DMA method at a temperature in a range of −20 to 0° C.

11. A thermally curable composition that is a pumpable composition at a temperature in a range of 15 to 60° C., comprising:

as a component (a):

(a1) a solid rubber in an amount of between 2.5% and 8% by mass,

(a2) an olefinic double bond-containing polymer which is liquid or pasty at 22° C., has a styrene content in a range of 10% to 60% by mass and has a glass transition temperature of −30° C. to 20° C. in an amount of less than 5% by mass,

(a3) a hydrocarbon resin in an amount of, in total with said component (a2), 5% by mass or more and 20% by mass or less, and

(a4) a liquid polydiene different from (a2) in an amount of 15% by mass or more,

based on the total mass of the composition; and

as a vulcanization system (b):

at least one substance selected from the group consisting of the following (b1) to (b3):

(b1) sulfur and one or more accelerator(s),

(b2) peroxide vulcanization system or disulfide vulcanization system, and

(b3) quinones, quinone dioximes or dinitrosobenzene;

wherein after curing, the loss factor tanδ (50 Hz) measured by a DMA method is 0.5 or more at a temperature in the range of −20 to 0° C.

12. An acoustically attenuating material comprising the thermally curable composition of claim 1 , cured to thereby form a thermoset composition.

13. An article of manufacture comprising the acoustically attenuating material of claim 12 .

14. The article of manufacture of claim 13 , wherein the acoustically attenuating material is an undercoating, adhesive or sealant in a vehicle, railway car or machinery.

15. A process for applying the composition according to claim 1 , wherein the composition is injected by a pump to a point of application at a temperature in a range of 15 to 60° C., and is deposited in a liquid or pasty state onto a substrate.