US-12624156-B2 - Processes for forming epoxy resin compositions and separation processes

US12624156B2US 12624156 B2US12624156 B2US 12624156B2US-12624156-B2

Abstract

Embodiments of the present disclosure generally relate to processes for forming epoxy resin compositions and processes for separating substrates from complex mixtures. In an embodiment, a process for making an epoxy resin composition is provided and includes: reacting a mixture comprising a substrate, an epihalohydrin, and a catalyst to form a first composition comprising a halohydrin reaction product; introducing an alkaline reagent with the first composition to form a second composition comprising an epoxy resin product; introducing a liquid epoxy resin with the second composition to form a resin mixture; and removing unreacted epihalohydrin from the resin mixture to form the epoxy resin composition. In another embodiment, a process for separating a substrate from a substrate source is provided and includes: introducing an epihalohydrin with the substrate source comprising the substrate, the substrate comprising at least one hydroxyl group, and separating the epihalohydrin and the substrate from the substrate source.

Inventors

Nicola Majella BOYLE
Jimmy Antonius Van Rijn
Maria SANTANA MARTIN

Assignees

Westlake Epoxy Inc.

Dates

Publication Date: 20260512
Application Date: 20230404

Claims (20)

1 . A process for forming an epoxy resin composition, the process comprising: reacting a mixture comprising a substrate comprising at least one hydroxyl group, an epihalohydrin, and a catalyst to form a first composition comprising a halohydrin reaction product; introducing an alkaline reagent with the first composition to form a second composition comprising an epoxy resin product, a residual halohydrin reaction product, and a salt; introducing a liquid epoxy resin with the second composition to form a liquid resin mixture; and removing unreacted epihalohydrin from the liquid resin mixture to form the epoxy resin composition.
2 . The process of claim 1 , wherein, after the removing unreacted epihalohydrin from the liquid resin mixture, the process further comprises: converting at least a portion of any residual halohydrin reaction product in the liquid resin mixture to an epoxy resin.
3 . The process of claim 1 , wherein the substrate comprising the at least one hydroxyl group comprises an alcohol of biological origin, an alcohol present in a resin waste stream, an alcohol present in a resin recycle stream, or combinations thereof.
4 . The process of claim 3 , wherein the substrate comprises a polyhydric phenol.
5 . The process of claim 3 , wherein the substrate comprises an aliphatic hydroxyl.
6 . The process of claim 1 , wherein the substrate comprises a polyhydric phenol, an aliphatic alcohol, or combinations thereof.
7 . The process of claim 1 , wherein the catalyst is selected from the group consisting of an alkali metal hydroxide, an alkali earth metal hydroxide, an ammonium salt, a phosphonium salt, a sulfonium salt, a lithium salt, and combinations thereof.
8 . The process of claim 1 , wherein: the catalyst is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, tetramethyl ammonium chloride, tetrabutyl ammonium chloride, tetrabutyl ammonium bromide, and combinations thereof; and the alkaline reagent is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, and combinations thereof, the catalyst and the alkaline reagent being the same or different.
9 . The process of claim 8 , wherein the catalyst and the alkaline reagent are different.
10 . The process of claim 1 , wherein the epihalohydrin comprises epichlorohydrin.
11 . The process of claim 1 , wherein the liquid epoxy resin has a viscosity that is about 15 Pa·s or less at 25° C.
12 . A process for making a liquid epoxy resin composition, the process comprising: reacting a mixture comprising an alcohol of biological origin, an epihalohydrin, and a catalyst to form a first composition comprising a halohydrin reaction product; introducing an alkaline reagent with the first composition to form a second composition comprising a glycidated product, residual halohydrin reaction product, and a salt; introducing a liquid epoxy resin with the second composition to form a liquid resin mixture; removing unreacted epihalohydrin from the liquid resin mixture; separating the salt from the liquid resin mixture; and after the separating the salt from the liquid resin mixture, forming the liquid epoxy resin composition by: converting at least a portion of the residual halohydrin reaction product in the liquid resin mixture to an epoxy resin; performing a liquid-liquid separation of the liquid resin mixture; or combinations thereof.
13 . The process of claim 12 , wherein: the catalyst is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, tetramethyl ammonium chloride, tetrabutyl ammonium chloride, tetrabutyl ammonium bromide, and combinations thereof; and the alkaline reagent is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, and combinations thereof, the catalyst and the alkaline reagent being the same or different.
14 . The process of claim 13 , wherein the catalyst and the alkaline reagent are different.
15 . The process of claim 12 , wherein the alcohol of biological origin comprises a phenol, an aliphatic hydroxyl, or combinations thereof.
16 . The process of claim 12 , wherein the alcohol of biological origin comprises a lignin selected from the group consisting of technical lignin, Kraft lignin, organosolv lignin, hydrolysis lignin, or combinations thereof.
17 . The process of claim 12 , wherein the epihalohydrin is epichlorohydrin.
18 . The process of claim 12 , wherein the mixture comprises: a molar ratio of epoxy group of the epihalohydrin to hydroxyl group of the alcohol of biological origin that is from about 1:1 to about 50:1; and a molar ratio of catalyst to hydroxyl group of the alcohol of biological origin that is from about 0.01:1 to about 0.15:1.
19 . A process for converting a substrate to a liquid epoxy resin composition, the process comprising: reacting a mixture comprising the substrate, an epihalohydrin, and a catalyst to form a first composition comprising a halohydrin reaction product and a salt, the substrate comprising an alcohol of biological origin, an alcohol present in a resin waste stream, an alcohol present in a resin recycle stream, or combinations thereof; introducing an alkaline reagent with the first composition to form a second composition comprising a glycidated product, residual halohydrin reaction product, and a salt; introducing a liquid epoxy resin with the second composition to form a liquid resin mixture, the liquid epoxy resin having a viscosity that is about 15 Pa·s or less at 25° C.; removing unreacted epihalohydrin from the liquid resin mixture; and separating the salt from the liquid resin mixture to form the liquid epoxy resin composition.
20 . The process of claim 19 , wherein the substrate is derived from a substrate source by: introducing the substrate source with an epihalohydrin and separating the substrate and the epihalohydrin from the substrate source; or introducing the substrate source with an epihalohydrin and an acid, and separating the substrate and the epihalohydrin from the substrate source.

Description

FIELD Embodiments of the present disclosure generally relate to processes for forming epoxy resin compositions and processes for separating substrates from complex mixtures. BACKGROUND The synthesis of epoxy resins, such as liquid epoxy resin (LER) compositions and solid epoxy resin (SER) compositions, involves a reaction carried out in two steps to convert a hydroxyl-containing substrate (for example, a phenolic substrate) or an amine-containing substrate to a product mixture comprising a glycidated product using, for example, epichlorohydrin (ECH). The product mixture is discharged from the reactor and transferred to a separate reactor for work up. The work-up process is carried out on the product mixture to remove salt formed during glycidation, remove excess ECH, and to convert a halohydrin reaction product to the desired glycidation product. Problems arise when the conventional work-up process is applied to unconventional substrates, such as alcohols (for example phenols) of biological origin, alcohols present in an epoxy resin recycle stream, and alcohols present in a phenolic resin recycle stream. For example, when glycidation is performed on an unconventional substrate, the resulting product mixture is, for example, insoluble in solvents used for the work-up process. Further, the product mixture is too viscous to be discharged or removed from the glycidation reactor and transferred to the reactor for performing the work-up process. Even if the product mixture is not transferred to a different reactor, the halohydrin reaction product present in the product mixture cannot undergo conversion to the desired glycidyl ether as the halohydrin reaction product is not soluble in solvents used for the conversion. In addition, the unconventional substrates often come from waste streams that are not purified or are crude raw materials. For example, alcohols of biological origin may come from a lignin waste stream and alcohols present in an epoxy resin or phenolic resin may come from recycled epoxy resins and phenolic resins, respectively. In each case, the hydroxyl-containing substrates to be converted to desired glycidyl ethers are present in complex compositions. Conventionally, the waste streams are purified by some form of fractionation or depolymerization, after which glycidation is attempted. Both fractionation and depolymerization utilize solvents that are not carried forward to downstream glycidation processes and instead are recycled or discarded. Beyond solvents, such additional steps can increase process complexity and cost, making use of waste streams for glycidation not commercially attractive. Therefore, there is a need for new and improved processes for forming epoxy resin compositions. There is also a need for new and improved processes for separating substrates from raw materials and recycle streams. SUMMARY Embodiments of the present disclosure generally relate to processes for forming epoxy resin compositions. Unlike conventional technologies, embodiments described herein can be utilized to form epoxy resin compositions from, for example, bio-based substrates (alcohols of biological origin), as well as alcohols present in resin recycle streams (such as epoxy resin waste streams and phenolic resin waste streams), or combinations thereof. Embodiments of the present disclosure also relate to processes for separating substrates, such as substrates used for glycidation reactions, from complex mixtures such as raw materials, waste streams, or recycle streams, among other complex mixtures. Unlike conventional technologies for separating glycidation substrates (alcohols) from complex mixtures, embodiments described herein enable reduced resin production costs, by, for example, using an epihalohydrin as a solvent for the extraction. In an embodiment, a process for forming an epoxy resin composition is provided. The process includes reacting a mixture comprising a substrate comprising at least one hydroxyl group, an epihalohydrin, and a catalyst to form a first composition comprising a halohydrin reaction product. The process further includes introducing an alkaline reagent with the first composition to form a second composition comprising an epoxy resin product, a residual halohydrin reaction product, and a salt. The process further includes introducing a liquid epoxy resin with the second composition to form a liquid resin mixture; and removing unreacted epihalohydrin from the liquid resin mixture to form the epoxy resin composition. In another embodiment, a process for making a liquid epoxy resin composition is provided. The process includes reacting a mixture comprising an alcohol of biological origin, an epihalohydrin, and a catalyst to form a first composition comprising a halohydrin reaction product. The process further includes introducing an alkaline reagent with the first composition to form a second composition comprising a glycidated product, residual halohydrin reaction product, and a salt