NZ625110B2 - Asphalt compositions having improved properties and related coatings and methods - Google Patents

Abstract

Disclosed is a composition to coat a substrate comprising: an asphalt material; a polyol; and a polymer that is not a polyol (e.g., styrene butadiene styrene (SBS)). The polyol has a molecular weight of about 1000 to about 5000 and/or the polyol is present in an amount no greater than about 30% by weight of the total composition. Also disclosed are methods of improving the processability of an asphalt material comprising combining together an asphalt material, a polyol and a polymer that is not a polyol, wherein the resultant composition exhibits improved process ability as compared to an asphalt composition that does not contain a polyol. eight of the total composition. Also disclosed are methods of improving the processability of an asphalt material comprising combining together an asphalt material, a polyol and a polymer that is not a polyol, wherein the resultant composition exhibits improved process ability as compared to an asphalt composition that does not contain a polyol.

Description

[Annotation] sak TITLE OF THE INVENTION Asphalt Compositions Having Improved Properties And Related Coatings and Methods CROSS—REFERENCE TO RELATED ATION

[0002] This application claims the benefit under 35 U.S.C. §119(e) to US. Provisional Patent Application No. 61/565,215, filed November 30, 2011, entitled “Asphalt CompositiOns Having Improved Properties and Related Coatings and Methods,” the entire disclosure ofwhich is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0003] Asphalt or n is a mixture of s hydrocarbons and contains varying amounts of paraffinic, naphthenic, and aromatic hydrocarbons. It has properties which make it useful in a number of applications including as a surface application to a road bed or road surface, a sealing nd, a coating material, a waterproofing material. It may also be used to protect building structures or components of building structures, and as a caulking or waterproofing material.

Neat n generally has little or no elasticity. Thus, asphalt processing is difficult and resultant coatings or pavement layers comprised of bitumen are brittle at low temperatures and soft at higher atures. us ts have been developed reduced eness and" an attempt to modify the bitumen and provide it with elasticity, increased processabilityr Such attempts include ng the bitumen with amounts of various polymers, most commonly SBS. The objective ofusing polymers as bitumen additives is to alter the viscoelastic properties of bitumen, in particular to extend the city range and to improve the elastic restoration. These materials are commonly ed to as “polymer modified bitumens” (PMBs).

[0005] The process of preparing PMBs requires heating and shear mixing of the polymer and the bitumen which give the high Viscosity of the bitumen, requires application of significant shear rates, relatively high temperatures in the reactors, and longer processing times.

While PMBs have been considered an improvement over neat bitumens, the end ts still lack sufficient flexibility, particularly at lower temperatures (such as those associated present during most road maintenance operations). Moreover, the lties with the processing ofPMB remain a challenge. 0812178_1):SAK According to a first aspect of the present invention there is provided a composition to coat a substrate comprising a hot melt blend of: a. an asphalt material up to about 85% by weight of the total composition wherein the asphalt material is a de-asphaltized grade asphalt; b. a polymer that is not a polyol selected from the group of a natural rubber, a synthetic rubber, a thermoplastic rubber, a styrene butadiene styrene (SBS), an ethylene vinyl acetate (EVA), a setting polymer, an acrylic polymer, a polyurethane polymer, a styrenated-acrylic polymer, a styrene/butadiene mer, an EPDM mer, atactic polypropylene and es thereof; and c. a polyol selected from the group of a polyether polyol, a natural polyol, a polyester polyol and mixtures thereof; wherein the polyol has a molecular weight of about 1000 to about 5000 and the polyol is present in an amount no greater than about 30% by weight of the total composition.

According to a second aspect of the present ion there is provided a composition to coat a substrate comprising a hot melt blend of: a. an asphalt material up to about 85% by weight of the total composition wherein the asphalt material is a de-asphaltized grade asphalt; b. a polymer that is not a polyol selected from the group of a natural rubber, a synthetic rubber, a thermoplastic rubber, a styrene butadiene styrene (SBS), an ne vinyl acetate (EVA), a thermosetting r, an acrylic polymer, a ethane polymer, a styrenated-acrylic polymer, a styrene/butadiene copolymer, an EPDM copolymer, atactic polypropylene and mixtures thereof; and c. a polyolselected from the group consisting of rythritol, ethylene glycol, glycerin, polyethylene glycol, polypropylene , and poly(tetramethylene ether) glycol, polypropylene glycol, polyethylene nonyl phenol and any mixtures thereof; wherein the polyol is t in an amount no greater than about 30% by weight of the total composition.

AH26(10812178_1):SAK According to a third aspect of the present invention there is provided a coated article comprising a substrate coated with a coating layer of the composition of the first or second aspect of the invention.

According to a fourth aspect of the present ion there is provided a method of improving flexibility at temperatures below 0°C of a cured asphalt coating comprising g a hot melt blend of the composition of the first or second aspect of the invention and applying the composition to a substrate and curing, to form a coating layer, wherein the coating layer exhibits improved ility as compared to an asphalt composition that does not contain a polyol.

According to a fifth aspect of the present invention there is provided a road bed or road surface comprising a coating layer formed from the asphalt coating ition of the first or second aspect of the invention.

According to a sixth aspect of the present invention there is ed a building material comprising a coating layer formed from the asphalt coating composition of the first or second aspect of the invention.

AH26(10812178_1):SAK [Annotation] sak DETAILED DESCRIPTION OF THE INVENTION The above-described drawbacks are sed by the ion, which formed from the compositions, and encompasses compositions, coating layers and ts substrates or surfaces, particularly roadbeds and building materials, that are coated with the coating layer. Also included within the scope of the invention are methods of increasing the flexibility, for example, at temperatures below about 0°C, of an asphalt coating and methods of increasing the sability of asphalt—containing compositions. Once formed and cured, the coating layer provides to the substrate or surface waterproofing properties and protection from physical damage.

[0012] It has been found that a composition containing an asphalt material, a polymer and a polyol exhibits improved processability and improved flexibility when cured, which in turn s in increased durability and reduced delamination ofthe asphalt composition coating, properties that may be particularly desirable when the material is used in road beds ageously, it or to coat other building and infrastructure materials and components. has been discovered that these properties are achieved through relatively minimal loading of polymer and polyol as compared to the amount of t and other materials in the composition, ng the costs of the l material and of processing.

The composition ofthe invention includes an asphalt or bituminous material that when cured. The asphalt material may include any may form a flexible barrier or coating known or to be developed in the art. It may be added to the ition in the form of a pre—mixed asphalt composition or as neat t. Any asphalt may be selected; it may be preferred that the asphalt has a low oil content. For e, the composition ofthe invention may include a de-asphaltized “DA" grade asphalt. As is understood in the art, DA grade asphalt originates from ght-run” asphalt that is formed from the distillation bottoms in crude oil refining. The DA asphalt is produced by solvent ting remaining oil from straight—run asphalt.

Depending on the processing method(s) chosen to e the composition and/or to coat the substrate, the asphalt selected as the barrier—forming material may be of a penetration grade (“pen grade”) at 25°C, when tested according to ASTM method D 5, of about 0.5 to about 30, alternatively about 1 to about 20, or about 3 to about 15 (all at 25°C).

Similarly, it may be desirable to that the selected asphalt has a softening point of about 62°C to about 95°C. .

The asphalt content may be varied in an inverse manner with respect to the other that the components along similar guideline, i.e., the asphalt content must not be so high [Annotation] sak composition cannot be processed, nor so low that it cannot e a film or layer in the desired application. As an example, the total t in the composition may be an amount ofabout 85wt% to about 15wt% or about 70wt% to about 50wt% of the composition or about 60wt% to about 65wt% ofthe composition.

The composition also ns a polymer, copolymer or polymer blend (hereinafter, referred to tively as “polymer’for “polymers”) that is not a polyol. Any polymer that fits this definition and is capable of altering the asphalt’s viscoelastic properties, however entally, may be used. For example, the selected polymer may be capable of increasing the bitumen’s plasticity range, i.e., the difference between the material’s ing point and its e point, of improving the material’s elastic restoration, and/or of increasing the material’s ductility. a natural rubber, a synthetic , a . Suitable polymer(s) may include thermoplastic rubber, a styrene butadiene styrene (SBS), an ethylene vinyl acetate (EVA), a thermosetting r, a plastic polymer, an acrylic polymer, a polyurethane polymer, a styrenated-acrylic polymer, a duroplastic resin, a styrene/butadiene copolymer, based on an EPDM copolymer, atactic polypropylene and es thereof. Polymers (meth)acrylic acid esters, particularly polymers of alkylmethacrylic acid esters (PAMAs) may also be used. Other polymers include those described in, for example, German Patent No. 25 09 473, Japan Patent No. 52—141,829, and PCT application No. 88/07 067, the contents of each of which are incorporated herein by reference.

The r may be added directly to the composition. Alternatively, pre-made asphalt/polymer blends (“polymer modified bitumens”) may be used. Polymer-modified bitumens ble cially include CARABIT (styrene-butadiene modified, available from Shell Chemical), OLEXOBIT (EPDM modified, available from British Petroleum), STYREL (styrene—butadiene modified, available from Elf). Other suitable polymer modified bitumen include, for example, those disclosed in US. Pat. No. 2,420,082, U.S.

Pat. No. 2,848,429, Ger. AS 12 40 773, and 23 31 727, the contents of each of which are incorporated herein by reference.

The polymer may be present in the composition in any amount sufficient to modify the bitumen’s properties, as desired. For example, it may be present in the - composition in an amount ofno r than about 50%, no greater than about 40%, no greater than about 30%, no greater than about 20%, no greater than about 15%, no greater than about 10%, no greater than about 7%, no greater than about 5%, and/or no greater than about 3% by weight of the total composition.

[Annotation] sak In one embodiment, the polymer is present in an amount of about 3.5% to about % by weight of the total composition, or about 5% to about 12% by weight of the total composition.

The composition also includes a polyol. The polyol may be any known or to be developed in the art, although it may be preferred that the polyol is in a liquid state at room about 7000, or temperature and/or that the polyol has a molecular weight of about 500 to about 1000 to about 5000. Suitable s may include a monomeric polyol, a polyether polyol, a natural polyol, a polyester polyol, rythritol, ethylene glycol, glycerin, polyethylene glycol, polypropylene glycol, and poly(tetramethylene ether) glycol, opylene glycol, polyethylene nonyl phenol, and hydroxyl-terminated polybutadiene and mixture thereof. Polyols may be obtained from, for example, ter Co. Dow Chemicals, Huntsman, Bayer, BASF, SKC etc.

It has been discovered that one may achieve a composition that has the desired processing and end product lity, by which is easier to compound and cost effective when the polyol is included in the composition in an amount ofno greater than about 30% by weight of the of the total composition. It some circumstances, it may be desirable that the polyol is included in an amount ofno greater than 25%, no greater than 20%, no r than 17%, no greater than 15%, no greater than 10%, no greater than 7%, no greater than %, no greater than 3%, no greater than 2%, and/or no greater than 1% by weight of the total composition (priOr to curing).

In an embodiment, the ition does not contain (that is, specifically omits) and/or is substantially free of one or both of a plasticizer and a surface active agent (surfactant). Additionally, or alternately, the ition does not contain an aromatic oil (i.e., it is substantially free of aromatic oils). However, in some embodiments, these materials may be present, as well as other additives and components.

For example, the composition may e emulsifiers. Suitable fiers may include sodium pyrophosphate (tetrasodium pyrophosphate) and natural or synthetic organic emulsifiers such as tall oil resin, rosins, wood—derived resins, either chemically d or unreacted. Examples may include, for example, the wood resin sold as VINSOL®, d from a pine wood resin material and UNITOL®, a tall oil resin having --COOH functionality.

In one embodiment, the composition may include a mixture ofwood resin and tall oil resin in a weight ratio ofwood resin to tall oil resin of about 14:1 to about 27.5:1. In those ments which include wood resins and/or tall oil emulsifiers it may be desirable [Annotation] sak to include a dilute aqueous hydroxide solution, such as an hydroxide of ium, sodium, lithium, and/or organic amines.

Another additive that may be included is talc, limestone, carbon, silica or glass fibers, depending on the end us of the materials. Any talc may be used, although tale of mesh values of about 200 to about 400 may be preferred. Therefore, any materials having similar functionality may also be used, such as, for e, precipitated silica, especially with high BET surface areas.

Other additives may include fillers (such as fibers, balls or nanotubes, ground or particularized polymers, etc.), clays and other minerals (ground or otherwise particularized), pebbles, fiberglass, wood pulp, ground rubber, amidoamines, neamines, such as, e.g, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, aminoethylpiperazine, adhesives, anti—strippers, dispersants, resins. Any additive or combination of additives may be used. However, in some embodiments it may be desirable to exclude any additive that has a plasticizer function, a surface active agent function, and/or an oil.

[0028] Other additives that may be orated into the composition include, for example, pigments and colorants, opaciflers, scents, biocidal agents, izing agents, desiccants and stabilizers.

The hot-melt blend may be prepared using typical melting process. Polyol may be added in the premix stage, preferably, or in letdown stage. For example, One may first combine the polyol and asphalt (or use a commercial t-polyol blend), then combine the asphalt-polyol blend with the remaining components. Alternatively, the components in a horizontal tank with agitation or may be ed simultaneously. Mixing may occur in a vertical mixing tank. Mixing may be mechanical and chemical/heat facilitated. For example, a precursor blend may be prepared by mechanical mixing or compounding. The while under heat) to form the composition, precursor blend may then be melt mixed (mixed which itself may then be applied to a ate to form a coating or layer as bed below. As is known to a person of skill in the art, care must be taken in preparing such es with particular attention paid to the flash point of the materials involved and the temperature at which the process is carried out and all safeguards and precautions must observed.

The composition is prepared and applied to a substrate or surface to form a g layer. The substrate may be of any material to which one wishes to apply a coating.

Illustration examples are a road bed, asphalt slab, metal substrate, partial metal substrate, iron, steel, metal alloys (nickel, iron, chromium, etc), concrete, ceramic, plastic, or polymer.

[Annotation] sak The substrate may be in any format, including vessels, pipes, slabs, boards, tiles, and may The coating possess any geometry, e.g., te, planar, corrugated planar, spherical, etc. layer may be continuous or discontinuous. If the substrate takes the format of a pipe, either the interior e ofthe pipe, the exterior surface of the pipe, or both, may be coated.

[0031] The composition is applied to the substrate and cured, thereby forming a coating layer. Application may be accomplished by any means in the art.

The compositions of the invention (1, 2 & 3) were prepared by incorporating the components as shown below in Table 1 (all amounts ‘shown are percent by Weight of the total composition): Table 1 [— Component 1 Styrene-Butadiene-Styrene polymer Limestone (pulverized) Polyol [CARPOL GP 3008] a polyol her TOTAL A comparative ition (c1) was also prepared containing: asphalt in an amount of 68.1 wt%, Styrene-Butadiene-Styrene polymer in an amount of 6.83 wt%, limestone (pulverized) in an amount of 25.05 wt %, and no polyol component.

[0034] Each composition 1, 2 & 3 exhibits improved processability relative to the ative ition cl.

Example II The compositions of the invention (4, 5 & 6) were prepared by incorporating the components as shown below in Table 2 (all amounts shown are percent by weight ofthe total composition): [Annotation] sak Asphalt Styrene-Butadiene—Styrene polymer 1 (a liner SBS polymer) Styrene-Butadiene—Styrene polymer 1 (a radial SBS r) TOTAL A comparative composition (02) was also prepared containing: t in an amount of 78.76wt%, Styrene-Butadiene—Styrene polymer 1 in an amount of 5.74wt%, Styrene-Butadiene—Styrene polymer 2 in an amount of 9.96 by weight, oil in amount of 5.54 % by weight, and no polyol (0%).

Each composition 4, 5, and 6 exhibits improved processability relative to the comparative ition c2.

Example III

[0038] The ingredients of Table 1 are heated and mechanically compounded together.

The resultant blend is poured into a lined box in a shape resembling a brick. The boxes are closed and packaged. Several bricks are delivered to a road construction project. The bricks are loaded in a hot melt mixer (melter), heated to approximately, 375°F to 400°F and mixed for about 10 to 15 minutes, until ity (qualitatively assessed) les a thick roadbed and permitted to cure. syrup. The composition is them coated onto the It will be appreciated by those skilled in the art that changes could be made to the embodiments bed above without departing» from the broad inventive concept thereof. It is tood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

WE

Claims (13)

CLAIM :

1. A composition to coat a substrate comprising a hot melt blend of: a. an asphalt material up to about 85% by weight of the total composition wherein the asphalt material is a de-asphaltized grade t; b. a polymer that is not a polyol selected from the group of a natural rubber, a synthetic rubber, a thermoplastic , a styrene butadiene styrene (SBS), an ethylene vinyl acetate (EVA), a thermosetting polymer, an acrylic r, a polyurethane polymer, a styrenated-acrylic polymer, a styrene/butadiene mer, an EPDM copolymer, atactic polypropylene and mixtures thereof; and c. a polyol selected from the group of a polyether polyol, a l polyol, a ter polyol and mixtures thereof; wherein the polyol has a molecular weight of about 1000 to about 5000 and the polyol is present in an amount no greater than about 30% by weight of the total composition.

2. A composition to coat a substrate comprising a hot melt blend of: a. an asphalt material up to about 85% by weight of the total composition wherein the asphalt material is a de-asphaltized grade asphalt; b. a polymer that is not a polyol selected from the group of a natural rubber, a synthetic rubber, a thermoplastic rubber, a styrene butadiene styrene (SBS), an ethylene vinyl e (EVA), a thermosetting polymer, an acrylic polymer, a polyurethane polymer, a styrenated-acrylic polymer, a styrene/butadiene copolymer, an EPDM copolymer, c polypropylene and mixtures thereof; and c. a polyolselected from the group consisting of pentaerythritol, ne , glycerin, polyethylene glycol, polypropylene glycol, and poly(tetramethylene ether) glycol, polypropylene glycol, polyethylene nonyl phenol and any mixtures thereof; AH26(10812178_1):SAK wherein the polyol is present in an amount no greater than about 30% by weight of the total composition.

3. The composition of claim 1 or claim 2, wherein the polyol is t in an amount no greater than about 10% by weight of the total composition.

4. The composition of any one of claims 1 to 3, wherein the polymer is present in the ition in an amount of no greater than about 40% by weight.

5. The composition of any one of claims 1 to 4, n the polymer is a styrene butadiene styrene polymer.

6. The composition of any one of claims 1 to 5, r comprising a filler.

7. The composition of claim 6, wherein the filler is selected from the group of bentonite, laponite, saponite, nite, montmorillonite, and a titanate compound.

8. The composition of any one of claims 1 to 7 wherein the substrate is selected from the group of a road bed and a ng material.

9. A composition as defined in claim 1 or claim 2 and substantially as herein described with reference to Table 1 or Table 2.

10. A coated article comprising a substrate coated with a coating layer of the composition of any one of claims 1 to 9.

11. A method of improving flexibility at temperatures below 0°C of a cured asphalt coating comprising forming a hot melt blend of the composition of any one of claims 1 to 9 and applying the composition to a substrate and curing, to form a g layer, wherein the coating layer exhibits improved flexibility as compared to an asphalt composition that does not contain a polyol. AH26(10812178_1):SAK

12. A road bed or road surface sing a coating layer formed from the asphalt coating composition of any one of claims 1 to 9.

13. A building material comprising a coating layer formed from the asphalt coating composition of any one of claims 1 to 9. Henry Company LLC By the Attorneys for the Applicant SPRUSON & FERGUSON Per: AH26(10812178_1):SAK