FIELD

The present invention is related to a curable epoxy resin composition; and more specifically, the present invention is related to a curable epoxy resin composition including a cashew nutshell liquid (CNSL) moiety and asphalt. The curable epoxy composition of the present invention is useful; for example, to improve the properties of asphalt concrete, asphalt waterproofing layers and coating compositions.

BACKGROUND

Asphalt, also known as bitumen, is typically a sticky, black and highly viscous liquid or a semi-solid petroleum at ambient or room temperature (e.g., about 25 °C). Asphalt has been widely used in road paving applications as the binder of aggregates to form asphalt concrete because asphalt has good adhesion properties and asphalt is relatively inexpensive. The hydrophobicity property of petroleum asphalt also makes the asphalt advantageously useful in bituminous waterproofing products and anticorrosion coating applications.

One of the disadvantages of using asphalt is that during the preparation of asphalt concrete or a bituminous waterproofing layer, a high temperature (e.g., greater than [>] 150-200 °C) has to be constantly applied to the asphalt to maintain the viscosity of the asphalt sufficiently low (e.g., less than [<] 100 mPa-s) to allow the proper handling of the asphalt during its use. In addition to high temperature, it is known to reduce the viscosity of the semi-solid asphalt by blending the asphalt with a solvent. However, during use of the asphalt and solvent blend, the solvent can evaporate into the atmosphere and emit unwanted volatile organic compounds (VOC) contained in the solvent. In road pavements and waterproofing layers applications, the operator using an asphalt composition faces the challenge of providing an asphalt composition that has sufficient: (1) adhesion to aggregates or concrete substrates, (2) strength at elevated temperatures, and (3) durability through constant environmental changes.

Epoxy resins have been widely used in extensive applications including coatings and structural adhesive industries owing to the epoxy resins' well known excellent adhesion, mechanical properties and thermal resistance. However, use of a combination of epoxy resins and asphalt materials is limited because epoxy compounds and asphalt are known to be incompatible. Many known epoxy resins and epoxy curing agents are not able to form a homogenous and continuous network with asphalt. The poor miscibility of epoxy resins in asphalt can be attributed to the dissimilarities of the epoxy resin and asphalt at a molecular level.

Still, in spite of the poor miscibility of epoxy resins in asphalt, there have been attempts by the prior art to combine an epoxy resin with asphalt to provide an asphalt/epoxy resin composition useful for pavement applications. For example,

JP2003064156A discloses an asphalt/epoxy resin composition having excellent properties such as flow resistance, abrasion resistance, and workability; wherein the asphalt/epoxy resin composition is useful for pavement. The asphalt epoxy resin composition for paving comprises asphalt, an epoxy resin, and a curing agent. The epoxy resin is a rubber- containing liquid epoxy resin; and the curing agent is a combination of a 12 to

18 carbon (C) atoms aliphatic primary amine and a polyhydric phenol resin. The asphalt/epoxy resin composition disclosed in JP2003064156A suffers from several disadvantages including for example requiring handling the disclosed epoxy resin at a high temperature.

U.S. Patent No. 4,499,215 discloses an asphalt/epoxy resin coating composition produced by mixing, under heat, asphalt with a condensation product of an asphalt and a non-thermoreactive phenol resin such as C4 -C8 alkylphenol-formaldehyde resin. The condensation asphalt/phenol product is formulated at a temperature of 160 °C using an arylsulfonic acid as a catalyst. The coating composition described in U.S. Patent No. 4,499,215 provides an excellent coating without the coating showing signs of the asphalt separating from the epoxy, or "silking" in spite of the incompatibility between the asphalt and the epoxy resin. The coating composition also includes mixing a curing agent for the epoxy resin. The asphalt/epoxy resin composition disclosed in U.S. Patent No. 4,499,215 suffers from several disadvantages including for example requiring an extra step to modify the asphalt through reaction.

WO2005000968A3 describes an asphalt/epoxy resin composition containing a solvent for road paving applications. The composition improves the wheel-rut formation resistance, flow resistance at high temperature and aggregate scattering. In preparing the asphalt-epoxy composition of WO2005000968A3, an epoxy is first mixed with asphalt at a high temperature. Then, a maleic acid modified thermoplastic elastomer is added to the mixture. The desired composition is obtained by reacting the epoxy groups of the epoxy resin with the carboxyl groups of the thermoplastic elastomer. The asphalt/epoxy resin composition disclosed in WO2005000968A3 suffers from several disadvantages including for example requiring that the disclosed composition be handled at high temperatures.

CN102173663A describes a waterborne epoxy modified emulsification bituminous concrete for steel bridge surfaces. CN102173663A further discloses preparing a waterborne epoxy modified emulsification bitumen by adding a waterborne epoxy resin, a hardener and a stabilizing agent into a bitumen emulsion. A resulting mounting material made from the above composition has high steel plate pasting strength, high flexibility and low fatigue property. The waterborne epoxy modified emulsification bitumen composition disclosed in CN102173663A suffers from several disadvantages including for example requiring extra steps for preparing an asphalt emulsion.

An article by de Araujo Barroso et al., "Application of Cashew Nut Shell Liquid in Bituminous Priming of Low- Volume Roads in Ceara, Brazil," Transportation Research Record: Journal of the Transportation Research Board, 2011, 2205(-l), pp. 130-137; discloses the potential use of a mixture produced from cashew nut shell liquid and asphalt cement as a prime coat. The purpose described in the above article is to obtain a less environmentally aggressive bituminous prime coat product. The product disclosed in the above article can satisfactorily be used as cutback asphalt. However, the reported cutback asphalt has no epoxy content to enhance the mechanical strength of the cutback asphalt. In an article by Tomoo Kiryu, "Study of Epoxy-Asphalt Compounds From

Sekiyu to Sekiyu Kagaku " (1976), 20(5), pp. 48-52, a method is described for increasing the compatibility of asphalt with epoxy resins. The method includes oxidizing straight asphalt with air for 6 hours (hr) in the presence of a cobalt-manganese (Co-Mn) catalyst to provide an oxidized asphalt with an alcoholic OH content of 3.3 groups/mol, a phenolic OH content of 0.26 groups/mol, and a carboxyl content of 0.18 groups/mol. The oxidized asphalt readily dissolves in an epoxy resin; and compositions suitable for pavement applications are produced. However, the compositions disclosed in the above article suffer from several disadvantages including for example requiring an extra reaction step to modify the asphalt.

A paper by Huang et al., Advance in Preparation and Modification Methods of Thermosetting Epoxy Asphalt Materials, from Reguxing Shuzhi (2009), 24(6), 50-54. Language: Chinese, Database: CAPLUS, describes a method to improve the compatibility of an epoxy resin and asphalt by using: (i) a maleic anhydride modified asphalt, (ii) a particular curing agent with good compatibility to asphalt, or (iii) a particular compatibilizer. The curing time of the epoxy asphalt blends disclosed in the above paper can be adjusted by adding a certain fatty acid curing agent and tertiary amine or quaternary ammonium salt as accelerants to the epoxy asphalt composites. The long chain fatty acids or anhydrides with low viscosity improve the properties of epoxy asphalt. However, the compositions disclosed in the above paper suffer from disadvantages including for example requiring the use of asphalt that must be modified with maleic anhydride.

SUMMARY

There is a need in the industry for a composition that combines an epoxy and asphalt together to form a miscible composition which exhibits a synergy of a combination of properties such as a high mechanical strength, a high temperature performance, and a high anticorrosion performance. To address the aforementioned deficiencies of the prior art and the aforementioned needs of the industry, it would be highly desirable to be able to produce a novel curable epoxy resin composition wherein the composition exhibits the required properties for various applications such as road pavements, protective coatings, and civil engineering applications.

Accordingly, one embodiment of the present invention is directed to a novel curable epoxy composition including asphalt and a CNSL moiety, wherein all of the components of the composition are compatible with each other; the temperature of handling the composition is reduced from a typical use temperature in the range of

150 °C - 200 °C to a use temperature of < about 50 °C; and the mechanical and thermal performance of the composition remains intact or is improved. Another embodiment of the present invention is directed to a process for preparing the above curable epoxy resin composition. Still another embodiment of the present invention includes a cured product produced using the above curable composition. In one preferred embodiment, the present invention includes a curable epoxy resin composition comprising a mixture of:

(A) an epoxy resin compound without a cashew nutshell liquid moiety, or an epoxy resin compound containing a cashew nutshell liquid moiety;

(B) asphalt; and

(C) a hardener compound without a cashew nutshell liquid moiety, or a hardener compound containing a cashew nutshell liquid moiety;

with the proviso that when component (A) is an epoxy resin compound without a cashew nutshell liquid moiety and component (B) is a hardener compound without a cashew nutshell liquid moiety, the curable epoxy resin composition further includes (D) a compound containing a cashew nutshell liquid moiety.

In the present invention composition, an epoxy compound and asphalt can readily combine with each other because of the presence of a compound containing a CNSL moiety, i.e., a CNSL moiety-containing compound is used to improve the compatibility between the asphalt and the epoxy resin. For example, the compound containing a CNSL moiety can be (i) an epoxy resin compound containing a CNSL moiety, (ii) a hardener compound containing a CNSL moiety, (iii) a separate and distinct compound containing a CNSL moiety different from the epoxy resin compound containing a CNSL moiety and different from the hardener compound containing a CNSL moiety; and (iv) mixtures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the present invention, the drawings show a form of the present invention which is presently preferred. However, it should be

understood that the present invention is not limited to the embodiments shown in the drawings.

Figure 1 is a photograph of a film sample showing the film homogeneity of the film sample prepared according to Comparative Example A.

Figure 2 is a photograph of a film sample showing the film homogeneity of the film sample prepared according to Example 1. Figure 3 is a photograph a film sample showing the film homogeneity of the film sample prepared according to Example 3.

DETAILED DESCRIPTION

A "homogenous and continuous network" herein means a network that is uniform at polymer level with no phase separations. "Compatibility" or "miscibility" herein means the property or capability of substances to mix in all proportions sufficient to form a homogeneous solution.

"Strength" herein means the ability of a material to withstand an applied stress.

"Good adhesion" herein, with reference to an epoxy resin system, means the ability of the epoxy resin system to bond to an applied surface of a substrate. "Durability" herein means the ability of a substrate to withstand repeated external forces or deformations.

"Mechanical performance" herein, with reference to an epoxy resin system, means the resin system's behavior under mechanical loadings. "Good thermal resistance" herein means the resin system's resistance to the effect of elevated temperatures.

"Good corrosion resistance" herein, with reference to an epoxy resin system, means the resin system's resistance to the effect of a corrosive substance.

"No solvent", "solvent-free", or "free of solvent" herein means the concentration of solvent in the formulation is essentially zero (disregarding any trace amounts of solvent).

"Ambient temperature" or "room temperature" herein means a temperature of less than about 50 °C.

"Reduced temperature" or "low temperature" herein means the temperature range lower than ambient temperature.

A broad embodiment of the present invention is directed to providing a curable epoxy resin formulation or composition including:

(A) an epoxy resin compound without a cashew nutshell liquid moiety, or an epoxy resin compound containing a cashew nutshell liquid moiety;

(B) asphalt; and

(C) a hardener compound without a cashew nutshell liquid moiety, or a hardener compound containing a cashew nutshell liquid moiety;

with the proviso that when component (A) is an epoxy resin compound without a cashew nutshell liquid moiety and component (B) is a hardener compound without a cashew nutshell liquid moiety, the curable epoxy resin composition further includes (D) a compound containing a cashew nutshell liquid moiety. Other optional additives known to the skilled artisan can be included in the curable composition such as for example a curing catalyst and other additives for various enduse applications.

Epoxy resins without a cashew nutshell liquid moiety, component (A), useful in the curable epoxy resin composition of the present invention can include a wide variety of epoxy compounds. Any epoxy compound that improves the mechanical and thermal performance of the composition is preferably used in the epoxy resin composition. For example, the epoxy compounds or polyepoxides can be aliphatic, cycloaliphatic, aromatic, hetero-cyclic and mixtures thereof. In one embodiment, epoxy compounds may contain, on the average, one or more reactive oxirane groups. Epoxy resins useful in the embodiments described herein may include for example mono-functional epoxy resins, multi- or poly- functional epoxy resins, and combinations thereof. The epoxy resins useful in the present invention and the preparation of such epoxy resins are disclosed, for example, in Lee, H. and Neville, K., Handbook of Epoxy Resins, McGraw-Hill Book Company, New York, 1967, Chapter 2, pages 2-1 to 2-27, incorporated herein by reference.

In another embodiment, commercially available epoxy resins that can be used according to the present invention may include for example DER™ 331, DEN™ 438, DER 671, DER 852, available from The Dow Chemical Company, and mixtures thereof.

Generally, the amount of epoxy resin used in the present invention may be in the range of from 0 weight percent (wt %) to about 95 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about

10 wt % to about 75 wt % in another embodiment, and from about 20 wt % to about 50 wt % in still another embodiment.

Alternatively, component (A) useful in the epoxy resin composition of the present invention can include epoxy resin compounds containing a cashew nutshell liquid (CNSL) moiety. For example, such epoxy resin compounds containing a cashew nutshell liquid moiety can include an epoxidized CNSL, an epoxy resin modified CNSL, a reaction product of epoxy resin and CNSL, and mixtures thereof.

In one embodiment, the epoxy resin compound containing a CNSL moiety can be, for example, a CNSL-modified epoxy resin. A CNSL-modified epoxy resin includes the reaction product of (i) an epoxy resin and (ii) CNSL. The epoxy resin, component (i) used to prepare the CNSL-modified epoxy resin can be, for example, one or more of the same aforementioned epoxy resins without a cashew nutshell liquid moiety as referenced above with regard to the epoxy resin component (A).

The CNSL, component (ii) used to prepare the CNSL-modified epoxy resin can be, for example, one or more compounds containing a CNSL moiety. For example, in one embodiment, the cashew nut shell liquid (CNSL) compound may comprise cardanol, a naturally occurring phenol manufactured from CNSL. Cardanol is a monohydroxyl phenol having a long hydrocarbon chain in the meta position. The cardanol useful in the present invention is one component of CNSL, an oil isolated from the shell of the cashew nut. In general, the chemical structure of cardanol is a phenol containing one hydroxyl group in the para-position, and an aliphatic side chain of from 15 carbon atoms in the meta-position. Cardanol can be illustrated, for example, by the following general chemical formula:

wherein R can be for example Ci ₅ H ₃ i_„, and n can be for example a numerical integer of 0, 2, 4, or 6. Some specific side chains, R, of cardanol can include for example -C ₁₅ H ₂₅ ,

In general, the concentration of cardanol in the CNSL may be, based on the total weight of the CNSL, about 10 wt % or more in one embodiment, about 50 wt % or more in another embodiment, or about 90 wt % or more in still another embodiment; and at the same time, about 99 wt % or less in one embodiment, about 97 wt % or less in another embodiment, or about 95 wt% or less in still another embodiment.

The CNSL may also include a concentration of cardol. Cardol can be illustrated, for example, by the following general chemical formula:

The concentration of cardol in the CNSL may be, based on the total weight of the CNSL, about 0.1 wt % or more in one embodiment, about 1 wt % or more in another embodiment, or about 5 wt % or more in still another embodiment; and at the same time, about 90 wt % or less in one embodiment, about 50 wt % or less in another embodiment, or about 10 wt % or less in still another embodiment. It is also known in the art that CNSL may include minor concentrations of other materials such as anacardic acid, oligomers of cardanol, oligomers of cardol, and mixtures thereof. Typically, the total concentration of the other materials present in the CNSL is < about 10 wt %.

In another embodiment, the epoxy resin compound containing a CNSL moiety can be, for example, a CNSL glycidyl ether. The CNSL glycidyl ether compound can be one or more of the compounds prepared and described in Kanehashi, S., et al., Preparation and Characterization of Cardanol-based Epoxy Resin for Coating at Room Temperature Curing, Journal of Applied Polymer Science, 2013. 130(4): p. 2468-2478; incorporated herein by reference. Some of the CNSL glycidyl ether compounds described in the reference above include for example monoglycidyl ether of cardanol, diglycidyl ether of cardol, or mixtures thereof.

Generally, the amount of epoxy resin containing a cashew nutshell liquid moiety used in the present invention may be in the range of from 0 wt % to about

95 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 10 wt % to about 75 wt % in another embodiment, and from about 20 wt % to about 50 wt % in still another embodiment.

Asphalt, component (B), is a dark brown to black cement- like residuum obtained from the distillation of suitable crude oils, as defined in ASTM D8-13. In Europe asphalt is called bitumen. Examples of suitable asphalt useful in the present invention may include heavy traffic asphalt such as AH-70 or AH-90 asphalt, polymer-modified asphalt such as SBS-modified asphalt or SBR-modified asphalt, or mixtures thereof.

Asphalt material as known in the art can be in the form of an emulsion. An asphalt emulsion is a suspension of minute globules of bituminous material in water or in an aqueous solution. In the present invention, an asphalt emulsion (or a bituminous emulsion) is preferably not used in the resin composition of the present invention. Coal tar as known in the art is an asphalt-like material and which is a dark brown to black cementitious material produced by destructive distillation of bituminous coal. Coal tar is also preferably not used in the resin composition of the present invention.

The asphalt useful in the present invention may have a needle penetration at 25 °C of from about 40 decimiUimeters (dmm) to about 100 dmm in one embodiment, from about 50 dmm to about 90 dmm in another embodiment, or from about 60 dmm to about 90 dmm according to the T0604-2011 method described in the JTG E20-2011 standard.

In another embodiment, suitable commercially available asphalt useful in the present invention may include, for example, Zhonghai 70# asphalt, Zhonghai 90# asphalt, Donghai 70# asphalt, and Donghai 90# asphalt (all which are available from Sinopec); AH-70# asphalt and AH-90# asphalt (both available from Shell); or mixtures thereof.

Generally, the amount of asphalt resin used in the present invention may be in the range of from about 2 wt % to about 90 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 6 wt % to about 75 wt % in another embodiment, and from about 10 wt % to about 50 wt % in still another embodiment.

The curable epoxy resin composition of the present invention is made curable by including in the composition a hardener compound. In general, the hardener (also referred to as a curing agent or crosslinking agent), component (C), can be either a hardener compound without a cashew nutshell liquid moiety or a hardener compound containing a cashew nutshell liquid moiety; and the hardener is blended with the other components (A) and (B) to prepare the curable composition of the present invention. The hardener compound without a cashew nutshell liquid moiety of the present invention may include for example, any conventional hardener known in the art useful for including in a curable epoxy resin composition. The hardener useful in the curable composition may be selected from, for example but are not limited to, anhydrides, carboxylic acids, amine compounds, phenolic compounds, or mixtures thereof. In a preferred embodiment, the hardener useful in the present invention may be selected from, for example, aminoplasts, polyisocyanates including blocked isocyanates, polyepoxides, beta-hydroxyalkylamides, polyacids, anhydrides, organometallic acid-functional materials, polyamines, polyamides, and mixtures of any of the foregoing.

Generally, the amount of hardener compound without a cashew nutshell liquid moiety used in the present invention may be in the range of from 0 wt % to about 50 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 1 wt % to about 40 wt % in another embodiment, and from about 5 wt % to about 30 wt % in still another embodiment.

Alternatively, component (C) useful in the epoxy resin composition of the present invention can include a hardener compound containing a cashew nutshell liquid moiety. For example, such hardener compound containing a cashew nutshell liquid moiety can include a phenalkamine, a CNSL-modified anhydride, and mixtures thereof.

In one embodiment, the hardener compound containing a CNSL moiety can be, for example, one or more phenalkamines. A phenalkamine is the condensation product of (i) a polyamine, (ii) CNSL, and (iii) formaldehyde, via the Mannich reaction

(aminomethylation) well known in the art.

The polyamine, component (i) used to produce a phenalkamine, can be, for example, an aliphatic ethyleneamine, a cycloaliphatic amine, an aromatic amine, or mixtures thereof. For example, the phenalkamine can be ethylenediamine (EDA), diethylenetriamine (DETA), trie thy enetetraamine (TETA), tetraethylenepentaamine (TEPA), N-aminoethylenepiperazine (AEP), isophorone diamine (IPDA), m-xylene diamine

(MXDA), or mixtures thereof. The CNSL, component (ii) used to prepare a phenalkamine can be, for example, any one or more compounds containing a CNSL moiety previously described above. For example, in one embodiment, the CNSL compound may comprise cardanol.

Formaldehyde (CH ₂ 0 or HCHO), component (iii) used to prepare a phenalkamine, is available commercially and can also be obtained as a commercial solution. In another embodiment, the hardener compound containing a CNSL moiety can be, for example, a CNSL-modified anhydride. A CNSL-modified anhydride resin is the reaction product of (i) an anhydride and (ii) CNSL. The anhydride, component (i) used to prepare the CNSL-modified anhydride, can include, for example, phthalic acid anhydride and derivatives of phthalic acid anhydride, nadic acid anhydride and derivatives of nadic acid anhydride, trimellitic acid anhydride and derivatives of trimellitic acid anhydride, pyromellitic acid anhydride and derivatives of pyromellitic acid anhydride,

benzophenonetetracarboxylic acid anhydride and derivatives benzophenonetetracarboxylic acid, dodecenylsuccinic acid anhydride and derivatives of dodecenylsuccinic acid anhydride, poly(ethyloctadecanedioic acid) anhydride and derivatives of poly(ethyloctadecanedioic acid) anhydride, and the like, or mixtures thereof. Each of the above CNSL-modified anhydride resins can be used alone or in an admixture thereof.

The CNSL, component (ii) used to prepare the CNSL-modified anhydride, can include, for example, any one or more compounds containing a CNSL moiety previously described above. For example, in one embodiment, the CNSL compound may comprise cardanol.

Generally, the amount of hardener containing a cashew nutshell liquid moiety used in the present invention may be in the range of from 0 wt % to about

50 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 1 wt % to about 40 wt % in another embodiment, and from about 5 wt % to about 30 wt % in still another embodiment.

When the curable composition of the present invention includes an epoxy resin compound without a cashew nutshell liquid moiety as component (A) (i.e., the curable composition does not include an epoxy resin compound containing a cashew nutshell liquid moiety), and the curable composition of the present invention further includes a hardener compound without a cashew nutshell liquid moiety as component (B) (i.e., the curable composition does not include a hardener compound containing a cashew nutshell liquid moiety), the curable epoxy resin composition includes, as a separate compound, a compound containing a cashew nutshell liquid moiety as component (D). In other words, it is important that the present invention curable composition include, as one of its

components, a compound containing a cashew nutshell liquid moiety. Thus, if the component (A) for the curable composition is chosen to be an epoxy resin compound without a cashew nutshell liquid moiety and the component (B) for the curable composition is chosen to be a hardener compound without a cashew nutshell liquid moiety, then the curable epoxy resin composition must include a compound containing a cashew nutshell liquid moiety as component (D).

The compound containing a cashew nutshell liquid moiety useful as component (D) in the curable epoxy resin composition can include, for example, any one or more of the compounds containing a CNSL moiety previously described above. Therefore, component (D) of the present invention can include (i) an epoxy resin compound containing a CNSL moiety described above; (ii) a hardener compound containing a CNSL moiety described above, (iii) a cashew nutshell liquid, or (iv) mixtures thereof. In one embodiment, component (D) used in the curable composition of the present invention can be one compound containing a CNSL moiety; or in another embodiment, component (D) can be a combination of two or more compounds containing a CNSL moiety.

For example, the compound containing a CNSL moiety used as component (D) in the present invention may include (i) a cashew nutshell liquid; (ii) a compound containing a cashew nutshell liquid moiety different from the epoxy resin compound containing a CNSL moiety described above; (iii) a compound containing a cashew nutshell liquid moiety different from the hardener compound containing a CNSL moiety described above; (iv) a different epoxy resin compound containing a CNSL moiety from the epoxy resins described above; (v) the same epoxy resin compound containing a CNSL moiety described above; (vi) a different hardener compound containing a CNSL moiety from the hardeners described above; (vii) the same hardener compound containing a CNSL moiety described above, and (viii) mixtures thereof.

One of the advantages of using a CNSL moiety in the curable epoxy resin composition is that the CNSL moiety solves the compatibility issue between the epoxy resin and asphalt present in the composition. Another advantage of using the CNSL moiety in the epoxy resin composition is that the temperature of handling the asphalt can be reduced from a higher temperature of about 160 °C to a lower temperature of about 50 °C or less. Thus, it is important to use a compound containing a CNSL moiety in the curable epoxy resin composition that is compatible to both an epoxy and asphalt; that increases the miscibility of the composition; and that reduces the asphalt handling temperature.

Generally, the amount of the compound containing a CNSL moiety, component (D), when used in the present invention may be in the range of from about 5 wt % to about 95 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 10 wt % to about 85 wt % in another embodiment, and from about 15 wt % to about 75 wt % in still another embodiment.

A curing catalyst may be optionally added to the curable epoxy resin composition of the present invention to speed up the curing process of epoxy resin composition. Examples of suitable catalyst useful in the curable epoxy resin composition may include tris(dimethylaminomethyl)-phenol, bis(dimethylaminomethyl)-phenol, salicylic acid, bisphenol A, and mixtures thereof.

The curable epoxy resin composition of the present invention may include other optional compounds. The optional compounds that may be added to the curable composition of the present invention may include compounds that are normally used in resin formulations known to those skilled in the art for preparing curable compositions and thermosets. For example, the other optional compounds that may be added to the curable epoxy resin composition of the present invention may include additives generally known to be useful for the preparation, storage, application, and curing of epoxy resin compositions.

For example, other optional additives known to those skilled in the art customarily used in epoxy resin compositions may be added to epoxy resin composition of the present invention including, for example, one or more of the following compounds: solvents, pigments, fillers, reactive diluents, flexibilizing agents, processing aides, toughening agents, leveling assistants, and the like, or mixtures thereof. The solvent can be selected from, for example, ketones, ethers, aromatic hydrocarbons, glycol ethers, cyclohexanone and combinations thereof.

Generally, the amount of the optional curing catalyst or other optional additives used in the present invention may be in the range of from 0 wt % to about 50 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 1 wt % to about 40 wt % in another embodiment, and from about 5 wt % to about 35 wt % in still another embodiment.

When the composition of the present invention is said to be "processable", "processable" or "processability" with reference to the composition herein means that the composition is readily and easily handled at room temperature without having to heat the composition beyond room temperature; and when the composition is cured, the composition shows essentially no signs of phase separation in the resultant cured articles made from such composition; and when the composition is cured to form a cured product, the cured product formed shows essentially no signs of defects. Advantageously, the composition of the present invention is able to be cured as a homogeneous coating film with (i) no phase separation visually observable by the naked eye, (ii) no phase migration to the surface to the film visually observable by the naked eye, and (iii) no wrinkling on the film surface visually observable by the naked eye.

Besides improving the compatibility between the asphalt and the epoxy resin, the curable epoxy resin composition of the present invention exhibits several other advantageous features including, for example, the following features:

(1) the present invention can provide a curable composition containing asphalt such that the viscosity of asphalt is reduced and the handling of asphalt can be performed at mediate or ambient temperatures without VOC concerns; (2) the epoxy resin component of the curable composition imparts good mechanical performance and thermal resistance to the cured product by forming a crosslinked network; and

(3) the CNSL moiety present in the composition aids in providing good anti- corrosion or corrosion resistance properties to the composition. Because of the above advantages, in one preferred embodiment the epoxy resin composition of the present invention is capable of being used at a relatively cold or ambient temperature (e.g., < about 50 °C) in mixed asphalt and asphalt waterproofing applications; and the resultant modified asphalt has excellent strength comparable to conventional asphalt compositions. However, the epoxy resin composition of the present invention is also capable of being used (or cured) at temperatures elevated temperatures such as > about 50 °C to about 200 °C; thus, providing flexibility/adjustability in the handling of the composition at a wider temperature range. In another preferred embodiment, the composition of the present invention contains essentially no solvent (except for unintentional contamination quantities introduced with starting raw materials) that can potentially emit into the environment. However, optionally the epoxy resin composition of the present invention can also include a solvent as one of the components in the composition; thus, providing flexibility /adju stability in formulating the composition for various enduses.

In another embodiment, the composition of the present invention can also be used in coatings applications to provide benefits such as preparing coatings formulations at a cost comparable or lower than conventional asphalt compositions. And, the composition of the present invention can also be used to produce coatings having anticorrosion performance comparable to coatings prepared from conventional asphalt compositions.

In one embodiment, the curable epoxy resin composition of the present invention is advantageously (i) processable at a temperature of from about 20 °C to about 30 °C; and (ii) substantially free of phase separation. In addition; when the curable epoxy resin composition is cured, the resultant cured product is substantially free of defects.

The process for preparing the curable epoxy resin composition of the present invention includes admixing or blending, in known mixing equipment: an epoxy resin, asphalt, a hardener, a compound containing a CNSL moiety, and optionally any other desirable additives. Any of the above-mentioned optional additives, for example a curing catalyst, may be added to the curable composition during the mixing or prior to the mixing to form the curable composition.

All of the compounds of the curable formulation are typically mixed and dispersed at a temperature enabling the preparation of an effective curable epoxy resin composition. For example, the temperature during the mixing of all components may be generally from about 100 °C to about 10 °C in one embodiment, and from about 50 °C to about 20 °C in another embodiment. Lower mixing temperatures help to minimize reaction of the epoxide and hardener in the composition to maximize the pot life of the composition.

The preparation of the curable formulation of the present invention, and/or any of the steps thereof, may be a batch or a continuous process. The mixing equipment used in the process may be any vessel and ancillary equipment well known to those skilled in the art.

Some other advantages of the curable epoxy resin composition of the present invention include: (1) no modification of asphalt by reaction is necessary to improve the compatibility between the asphalt and the epoxy compound;

(2) a homogenous film can be formed with no phase separation, phase migration to the surface or any wrinkling of film surface; (3) no solvent or a low concentration of solvent is needed in the composition.

The amount of the solvent used in the present invention may be in the range of from 0 wt % to about 30 wt % based on the total weight of the resin forming components of the composition in one embodiment, from about 1 wt % to about 20 wt % in another

embodiment, and from about 2 wt % to about 15 wt % in still another embodiment; (4) an asphalt concrete can be paved using the composition of the present invention in the form of a cold or hot mixed asphalt without using an asphalt emulsion. For example, the asphalt concrete is able to be paved in a temperature range of from about 20 °C to about 50 °C when used as a cold mixed asphalt; and from about 150 °C to about 200 °C when used as a hot mixed asphalt; and (5) no extra steps are required in the method of producing the curable composition such as a step of oxidizing the asphalt before its use.

Exemplary of another advantageous use of the curable epoxy resin compositions of the present invention is the use of the composition for preparing a composition with enhanced adhesion between the asphalt and aggregates. The adhesion can reach to grade 4 to grade 5 by following the test method of "T0616-1993 asphalt and coarse aggregate adhesion test" in "Highway engineering asphalt and asphalt mixture test procedures" (JTJ052-2000).

Another embodiment of the present invention includes a process for curing the curable epoxy resin composition described above to form a thermoset or cured composition. For example, the curable epoxy resin composition or formulation of the present invention can be cured under conventional processing conditions to form a film, a coating, or a solid. Curing the curable composition may be carried out at curing reaction conditions including a predetermined temperature and for a predetermined period of time sufficient to cure the composition. The curing conditions may be dependent on the various components used in the curable composition such as the hardener used in the formulation.

The curing reaction conditions include, for example, carrying out the reaction under a temperature, generally in the range of from about -5 °C to about 60 °C in one embodiment; from about 0 °C to about 50 °C in another embodiment; and from about 5 °C to about 25 °C in still another embodiment.

In general, the use of the curable formulation of the present invention and the curing of the composition may employ conventional equipment and methods well known to those skilled in the art. For example, to prepare asphalt concrete used in pavement applications, the curable epoxy resin composition can be applied to roads using asphalt pavers, screeds, and push rollers and the like; and the applied composition can be cured by heating the composition at the aforementioned curing temperatures.

In asphalt waterproofing layer applications, the curable epoxy resin composition can be applied, for example, as a waterproofing layer using squeegees, spray guns, and brushes and the like; and the applied composition can be cured by heating the composition at the aforementioned curing temperatures.

For coating applications, the curable epoxy resin composition can be applied to substrates, for example, using airless sprayers and air-assisted pneumatic sprayers and the like; and the applied composition can be cured by heating the composition at the aforementioned curing temperatures.

The cured product (i.e., the cross-linked product made from the curable composition) of the present invention shows several improved properties over conventional epoxy asphalt coating compositions. For example, the asphalt used in the curable composition of present invention can be petroleum asphalt or natural asphalt which are readily available in the industry.

The cured product made from the curable composition can exhibit a combination and balance of advantageous properties including for example Tg, mechanical performance, thermal performance, corrosion resistance, waterproofing performance, and the like.

For example, the cured product or composite of the present invention may advantageously have a high glass transition temperature (Tg). Generally, the cured product of the present invention can exhibit a Tg in the range of between about 0 °C and about 180 °C in one embodiment, between about 5 °C and about 140 °C in another embodiment, and between about 10 °C and about 100 °C in still another embodiment. The Tg of the cured product can be measured for example by the method described in ASTM E1356. The cured product or composite of the present invention may also

advantageously have a high tensile strength. For example, the cured product of the present invention can exhibit a tensile strength of generally up to about 40 MPa in one embodiment, from about IMPa to about 40MPa in another embodiment, from about 2 MPa to about 30 MPa in still another embodiment, and from about 5 MPa to about 20 MPa in yet another embodiment. The tensile strength of the cured product can be measured, for example, by the method described in ASTM D638.

The cured product or composite of the present invention may also advantageously have a high softening point. For example, the cured product of the present invention can exhibit a softening point temperature generally in the range of between about 10 °C and about 120 °C in one embodiment, between about 20 °C and about 90 °C in another embodiment, and between about 30 °C and about 70 °C in still another embodiment. The softening point of the cured product can be measured, for example, by the method described in ASTM D3461. The cured product or composite of the present invention may also advantageously have an excellent anticorrosion resistance. For example, the cured product of the present invention can show no signs of "blister up" for a period of time of no less than about 100 hour (hr) exposure to a salt spray environment in one embodiment, no less than about 500 hr exposure to a salt spray environment in another embodiment, no less than about 1,000 hr exposure to a salt spray environment in still another embodiment, and no less than about 1,500 hr exposure to a salt spray environment in yet another embodiment. The corrosion resistance of the cured product can be measured, for example, by the method described in ASTM B 117.

The cured product or composite of the present invention may also advantageously have an excellent waterproofing performance. For example, the cured product of the present invention generally can show water absorption of no more than about 1 % in one embodiment, no more than about 0.5 % in another embodiment, and no more than about 0.1 % in yet another embodiment. The water absorption of the cured product can be measured, for example, by the method described in ASTM D570. In general, the curable epoxy resin composition of the present invention includes a combination of components or compounds that advantageously deliver unique properties to the resulting cured product. As aforementioned, preferred embodiments of the curable epoxy resin composition of the present invention may be used to prepare asphalt concrete for pavement applications, asphalt waterproofing layers, and coatings.

EXAMPLES

The following Examples and Comparative Examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof. All parts and percentages are by weight unless otherwise indicated.

Various terms, designations and materials used in the following examples are explained herein below:

D.E.H.™ 641 is a phenalkamine hardener having an AHEW of around 125 and commercially available from The Dow Chemical Company.

D.E.H.™ 140 is a polyamide hardener having an AHEW of around 125 and commercially available from The Dow Chemical Company.

D.E.R.™ 331 is a diglycidyl ether of bisphenol A and has an EEW of from 182 to 192 and commercially available from The Dow Chemical Company. Xylene is available from Sinopharm Chemical Reagent Co., Ltd.

Asphalt 90# is available from Royal Dutch Shell China.

Test panels (101.6 millimeters [mm] x 152.4 mm x 0.81 mm steel panels) are prepared with a coating as described in the examples which follow to evaluate the coatings performances in terms of compatibility and physical properties. Viscosity

Viscosity is measured using an ARES G2 viscometer of TA Instruments equipped with an environmental chamber. Samples are filled into a gap (from 0.5 mm to 2 mm) between two 25 mm parallel stainless plates; and are tested at a shear rate of 100 radian per second (rad/s). The temperature of the environmental chamber is set up at 120 °C when evaluating the thermoplastic resin, or 25 °C when evaluating the hardener, respectively.

Epoxide Equivalent Weight (EEW)

A standard titration method was used to determine percent epoxide in the various epoxy resins. A sample was weighed (ranging from about 0.1 g to about 0.2 g) and dissolved in dichloromethane (10 mL). Tetraethylammonium bromide solution in acetic acid (30 mL) was added to the sample. The resultant solution was treated with 3 drops of crystal violet solution (0.1 % w/v in acetic acid) and was titrated with 0.1N perchloric acid in acetic acid on a Metrohm 665 Dosimat titrator (Brinkmann). Titration of a blank sample comprising dichloromethane (10 mL) and tetraethylammonium bromide solution in acetic acid (30 mL) provided correction for solvent background. General methods for this titration are found in the scientific literature, for example, in Jay, R.R., "Direct Titration of Epoxy Compounds and Aziridines", Analytical Chemistry, 36, 3, pp 667-668 (March, 1964).

Compatibility Test

Samples of formulations were blended using speed mixer 3000 revolutions per minute (rpm) for 2 minutes (min) at room temperature. The formulations were casted on steel panels with a 400 microns drawdown applicator and the resultant coated panels were conditioned at a temperature of 23 °C and relative humidity of 50 % for 7 days. The dry film thicknesses tested were in the range of 180 microns to 200 microns. Two panels were prepared for each formulation. Compatibility with asphalt was graded based on naked eye observation of cured coating film surfaces. A ranking of "0" means that a large phase separation is observed. A ranking of "1" means no phase separation is observed, but rough surfaces observed. A ranking of "2" means a completely homogeneous film is observed.

Physical Property Tests

The testing methods of physical properties used in the examples herein are listed in Table I.

Table I

Synthesis of Glycidyl Ether of CNSL (CNSLGE)

The glycidyl ether of CNSL was prepared by epoxidation reaction. A 5 L, 4-neck, glass, round bottom reactor was charged with distilled cashew nutshell liquid (750.0 g, 3.7 hydroxyl equivalent [eq.]), epichlorohydrin (1710.60 g, 18.48 moles, 5: 1 epichlorohydrin:hydroxyl eq.), isopropanol (921.1 g, 35 wt % of epichlorohydrin used), and deionized (DI) water (148.8 g, 6 wt % of epichlorohydrin used) in the indicated order. The reactor was additionally equipped with a condenser (maintained at 0 °C), a thermometer, a Claisen adaptor, an overhead nitrogen inlet (1 LPM N ₂ used), and a stirrer assembly (Teflon™ paddle, glass shaft, and variable speed motor). (Teflon fluorocarbon resin is a trademark of E.I. DuPont de Nemours.)

A controller monitored the temperature registered on the thermometer in the reactor and provided heating via the heating mantle placed under the reactor as well as cooling delivered by a pair of fans positioned on the reactor exterior. Sodium hydroxide (133.05 g, 3.33 moles) dissolved in DI water (532.2 g) for the initial addition was added to a side arm vented addition funnel, sealed with a ground glass stopper, and attached to the reactor. Stirring and heating commenced to give a 52 °C solution followed by

commencement of dropwise addition of the aqueous sodium hydroxide solution. The reaction temperature was maintained at 52 °C during the 2.25 hr aqueous sodium hydroxide addition time via cooling of the reactor exterior from the fans as needed. After 20 min of post-reaction at 52 °C, stirring and heating ceased, and the reactor contents were added to a pair of 2 L separatory funnels. The aqueous phase and a minor amount of dark colored insoluble material were drained off and discarded as waste and the remaining organic layer added back into the reactor. Stirring and heating of the 44 °C solution resumed. Sodium hydroxide

(59.13 g, 1.478 moles) dissolved in DI water (236.5 g) was added to a side arm vented addition funnel, sealed with a ground glass stopper, and then attached to the reactor.

Stirring and heating commenced to reestablish a 52 °C solution followed by commencement of dropwise addition of the aqueous sodium hydroxide solution. The reaction temperature was maintained at 52 °C during the 1 hr aqueous sodium hydroxide addition time via cooling of the reactor exterior from the fans as needed. After 20 min of post-reaction at 52 °C, stirring and heating ceased, and the reactor contents were added to a pair of 2 L separatory funnels. The aqueous phase and a minor amount of dark colored insoluble material were drained off and discarded as waste and the remaining organic layer added back into the reactor.

Stirring and heating of the 40 °C solution resumed. Sodium hydroxide (14.78 g, 0.37 moles) dissolved in DI water (59.1 g) was added to a side arm vented addition funnel, sealed with a ground glass stopper, then attached to the reactor. Stirring and heating commenced to reestablish a 52 °C solution followed by commencement of dropwise addition of the aqueous sodium hydroxide solution. The reaction temperature was maintained at 52 °C during the 15 min aqueous sodium hydroxide addition time via cooling of the reactor exterior from the fans as needed. After 20 min of post-reaction at 52 °C, stirring and heating ceased, and the reactor contents were equally split into a pair of 2 L separatory funnels. The aqueous phase was drained off and discarded as waste.

To the contents of each separatory funnel was added 400 mL of DI water and the contents were washed with the DI water by vigorously shaking the funnels. The washed product in each of the funnels was allowed to settle for < 30 min to resolve, allowing the aqueous and organic phases to re-form in the funnels; and then the aqueous phase was removed from each of the funnels and discarded as waste. Second and third washes were carried out using the aforementioned method.

Rotary evaporation of the organic phase using a maximum oil bath temperature of 110 °C to a final vacuum of 4.7 mm of Hg removed the bulk of volatiles present in the organic phase. A total of 911.52 g of amber colored, slightly hazy liquid was recovered after completion of the rotary evaporation. Epoxide titration indicated that the resultant liquid had an EEW of 387.

Synthesis of CNSL Modified Epoxy (CME) A CNSL modified epoxy (CME) was prepared by the following general procedure: 85 parts by weight D.E.R.™ 331, 12.8 parts by weight cardanol and 2.2 parts by weight cardol were mixed under a nitrogen atmosphere. After the mixture reached a temperature of 90 °C, 300 ppm of ethyl triphenyl phosphonium acetate (70 wt % methanol solution) was added as catalyst. The resultant mixture was heated to 170 °C and kept at this temperature for 3 hr. A CNSL modified epoxy was then obtained. Epoxide titration indicated that the CNSL modified epoxy had an EEW of 250. Examples 1-4 and Comparative Example A

Epoxy resin compositions of Examples 1-4 and Comparative Example A were prepared by mixing the ingredients described in Table II. Asphalt 90# was first mixed with xylene at 120 °C to form an asphalt solution with 75 weight percent of asphalt. Then the asphalt solution was mixed at room temperature with the rest of the components of each example as described in Table II.

Table II

The results obtained from the above examples as described in Table III show that good compatibility is achieved with the addition of a compound containing CNSL moiety. The results described in Table III also show that when the concentration of the CNSL moiety is increased, the homogeneity of the epoxy composition containing asphalt is improved.

The above improvement in homogeneity described in Table III can also be seen in Figure 1-3. Figure 1 (Comparative Example A) shows a film with a discontinuous film surface and phase separation, while Figure 2 (Example 1 ; similar figures were obtain from Examples 2 and 4) shows a continuous and uniform film surface. Figure 3 (Example 3) shows a rough film surface, however, the film still remains as a continuous and uniform film. With regard to Comparative Example A, an "oily" material formed on the surface of the film and penetrated through the surface of the film of Comparative Example A and the film surface was not dry; as a result, no physical performance test was able to be performed on the film of Comparative Example A. Table III