Polyethylene modified asphalt compositions

Abstract

A polymer modified bituminous composition for roofing applications that comprises polyethylene as the primary modifier.

Description

TECHNICAL FIELD OF THE INVENTION

[0001] This invention relates to bituminous roofing. More particularly, the present invention relates to modified asphalt composition for use in roofing materials. BACKGROUND OF THE INVENTION

[0002] It is well known to use asphalt compositions to manufacture waterproofing materials, such as roofing membranes, shingles or underlayments. The purpose of such materials is to offer protection against the elements. Because of its good weatherability and hydrophobic nature, asphalt has been used in waterproofing applications for several centuries.

[0003] Roofing materials must possess key mechanical and chemical characteristics, such as pliability, resistance to cracking at low temperatures, high puncture resistance, good strength and elongation (to withstand stresses and potential building movements), resistance to flow at elevated temperatures, and thermal and dimensional stability, etc. Most importantly, a roofing material must have minimal susceptibilit...

Examples

example i

[0028] Examples of preferred embodiments of the inventive formulation appear in Table III below. The LDPE used in these examples has a density of less than 0.93 g / cm3 and the HDPE used in these examples has a melt flow index of 7.

TABLE IIIWarmColdIngredientsUnitapplication blendapplication blendLow density polyethylene%5.06.0High density polyethylene%5.01.5Plastification Agent%02.5Filler%35.035.0Asphalt%55.055.0

The formulation is prepared by loading all the ingredients in an external mixer and mixing the resultant mixture at temperatures ranging from 180° C. and 210° C. for 4 hours to 6 hours. The resultant formulation should have a viscosity between 2,000 and 20,000 cP at 180° C., a softening point temperature greater than 120° C., and a needle penetration value of greater than 100 dmm at 60° C.

[0029] Various tests were conducted on the polyethylene modified asphaltic blends described in Table II using ASTM test methods and standards commonly used in the art to determine suitab...

TECHNICAL FIELD OF THE INVENTION

[0001] This invention relates to bituminous roofing. More particularly, the present invention relates to modified asphalt composition for use in roofing materials. BACKGROUND OF THE INVENTION

[0002] It is well known to use asphalt compositions to manufacture waterproofing materials, such as roofing membranes, shingles or underlayments. The purpose of such materials is to offer protection against the elements. Because of its good weatherability and hydrophobic nature, asphalt has been used in waterproofing applications for several centuries.

[0003] Roofing materials must possess key mechanical and chemical characteristics, such as pliability, resistance to cracking at low temperatures, high puncture resistance, good strength and elongation (to withstand stresses and potential building movements), resistance to flow at elevated temperatures, and thermal and dimensional stability, etc. Most importantly, a roofing material must have minimal susceptibilit...

Examples

example i

[0028] Examples of preferred embodiments of the inventive formulation appear in Table III below. The LDPE used in these examples has a density of less than 0.93 g / cm3 and the HDPE used in these examples has a melt flow index of 7.

TABLE IIIWarmColdIngredientsUnitapplication blendapplication blendLow density polyethylene%5.06.0High density polyethylene%5.01.5Plastification Agent%02.5Filler%35.035.0Asphalt%55.055.0

The formulation is prepared by loading all the ingredients in an external mixer and mixing the resultant mixture at temperatures ranging from 180° C. and 210° C. for 4 hours to 6 hours. The resultant formulation should have a viscosity between 2,000 and 20,000 cP at 180° C., a softening point temperature greater than 120° C., and a needle penetration value of greater than 100 dmm at 60° C.

[0029] Various tests were conducted on the polyethylene modified asphaltic blends described in Table II using ASTM test methods and standards commonly used in the art to determine suitab...