Modified Epoxy Resin

Abstract

The present disclosure relates to a modified epoxy resin having formula (I): wherein R is R1, R2, or a combination of R1 and R2; R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group. Z is dicyclopentadiene; R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form fused aromatic rings or fused heteroaromatic rings; n is 0 to 1, and n=0>75%; and N is 1 to 20. TIFF2022543472000031.tif62170

Description

[Technical Field]

[0001] The present disclosure relates to modified epoxy resins. More particularly, the present disclosure relates to modified epoxy resins useful as intentionally bisphenol A-free (BPA-NI) epoxy resins. [Background technology]

[0002] Cured epoxy resins have excellent mechanical and chemical properties, such as high impact strength, high abrasion resistance, good heat and chemical resistance, high resistance to alkalis, acids, oils, and organic solvents, high weather resistance, excellent adhesion to many materials, and high electrical insulating capacity, etc. Therefore, cured epoxy resins have been widely used in coating compositions, adhesives, insulating materials, casting applications, among others.

[0003] This article relates to the use of epoxy resins in coating compositions, particularly for metal containers used for packaging and storing food and beverages. Conventionally, coating compositions containing bisphenol A-type epoxy resins and epichlorohydrin have been used to coat the interior surfaces of such metal containers. However, bisphenol A is known to be extracted into food and to have adverse effects on human health. Bisphenol A is known to be an endocrine-disrupting compound that acts in the human body similarly to estrogen and may cause reproductive problems. Furthermore, epoxy resins made from bisphenol A and epichlorohydrin may result in coatings containing residual amounts of bisphenol A diglycidyl ether (BADGE). BADGE has been found to have potential carcinogenic effects.

[0004] Therefore, researchers have been working to eliminate bisphenol A from curable epoxy resin-based compositions and to prepare bisphenol A-diglycidyl ether (BADGE) and bisphenol A (BPA)-free resin compositions.

[0005] US Patent No. 7,682,674 discloses a BADGE- and BPA-free can coating composition comprising a polyvinyl chloride (PVC) polymer and an acrylic resin.

[0006] U.S. Patent Application Publication No. 2003 / 0170396 discloses a BPA-free coating composition containing an epoxy resin having a number average molecular weight of 2,500 to 30,000 and an epoxy equivalent weight of 1,500 to 20,000 g / equivalent, which is obtained by reacting a specific low-molecular-weight novolac epoxy resin with a specific low-molecular-weight novolac phenolic resin.

[0007] US Patent Application Publication No. 2004 / 0147638 describes a two-layer (core / shell) system in which the core is formed from a BPA- or BPF-based epoxy resin and the outer layer is formed from, for example, an acrylate resin. The key question here is whether the outer layer can truly completely prevent migration of BPA or bisphenol A diglycidyl ether (BADGE) into the content.

[0008] WO 2010 / 100122 proposes coating systems obtained by reaction of epoxidized vegetable oils with hydroxyl-functional compounds, such as propylene glycol, propane-1,3-diol, ethylene glycol, NPG, trimethylolpropane, diethylene glycol, etc.

[0009] WO 2012 / 091701 proposes various diols and their diglycidyl ethers, including BPA and ring-hydrogenated BPA derivatives, cyclobutane-based alicyclic diols, and diols with a furan ring as the parent structure, as replacements for BPA or BADGE for epoxy resins.

[0010] US Patent No. 9,139,690 disclosed BPA-free epoxy resin compositions based on diglycidyl ethers of substituted cycloaliphatic diols.

[0011] U.S. Patent No. 9,150,685 discloses a substitute for BPA or BADGE for epoxy resins, including a diglycidyl ether of 2-phenyl-1,3-propanediol, which is a derivative of the substance of structure (IV). This document also mentions oligomers prepared by reacting one or more diols with one or more diglycidyl ethers of 2-phenyl-1,3-propanediol. The disclosure is limited to the use of glycidyl ethers based on 2-phenyl-1,3-propanediol, or oligomers of such glycidyl ethers with 2-phenyl-1,3-propanediol. However, this patent mentions the use of at least one epoxy resin selected from the group consisting of diglycidyl ethers of bisphenol A, diglycidyl ethers of bisphenol F, diglycidyl ethers of ring-hydrogenated bisphenol A, diglycidyl ethers of ring-hydrogenated bisphenol F, cresol epoxy resins, novolac-type epoxy resins, and oligomers thereof, as one of the resin components.

[0012] WO 2016 / 193032 discloses tetrahydrofuran diglycidyl ether derivatives and curable epoxy resin compositions based thereon as alternatives to bisphenol A or bisphenol F diglycidyl ethers and epoxy resin compositions based thereon.

[0013] Since the glycidyl ethers described in the prior art are based on aliphatic and / or cycloaliphatic diols, the coating compositions disclosed in the prior art suffer from limitations such as soft coating properties, poor heat resistance, and poor chemical resistance. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] U.S. Patent No. 7,682,674 [Patent Document 2] US Patent Application Publication No. 2003 / 0170396 [Patent Document 3] US Patent Application Publication No. 2004 / 0147638 [Patent Document 4] International Publication No. 2010 / 100122 [Patent Document 5] International Publication No. 2012 / 091701 [Patent Document 6] U.S. Patent No. 9,139,690 [Patent Document 7] U.S. Patent No. 9,150,685 [Patent Document 8] International Publication No. 2016 / 193032 Summary of the Invention [Problem to be solved by the invention]

[0015] Therefore, there is a need to develop epoxy resins that exhibit stability, mechanical and thermomechanical properties equivalent to or superior to BPA-based epoxy resins, but which do not pose the health and environmental concerns associated with their use. [Means for solving the problem]

[0016] The present disclosure provides a compound of formula (I):

[0017] [ka]

[0018] (wherein R is R, R, or a combination of R and R; R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, a cycloaliphatic-atomatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene; R3 and R4 are independently either H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75%; and N is 1 to 20) The present invention relates to a modified epoxy resin having the following structure.

[0019] A method for preparing the above modified epoxy resin is also disclosed, which comprises: a. Formula II: [ka] wherein R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; and n is 0-1, with n=0>75%. and a dicyclopentadiene-phenol adduct of b. Formula (IIIa) or (IIIb): [ka] wherein R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene) and diglycidyl derivatives of The method includes a step of condensing the above. DETAILED DESCRIPTION OF THE INVENTION

[0020] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to embodiments and specific language will be used to describe the embodiments, it being understood, however, that no limitation of the scope of the disclosure by the embodiments is intended, and that such changes and further modifications in the disclosed compositions and methods, and such further applications of the principles of the disclosure in the embodiments, as would normally occur to one of ordinary skill in the art to which the present disclosure pertains, are contemplated.

[0021] It will be apparent to those skilled in the art that the foregoing summary and the following detailed description are exemplary and explanatory of the present disclosure and are not intended to be limiting of the present disclosure.

[0022] Throughout this specification, reference to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, throughout this specification, appearances of the phrases "in one embodiment," "in an embodiment," and similar language may, but do not necessarily, all refer to the same embodiment.

[0023] In its broadest scope, the present disclosure relates to modified epoxy resins useful as bisphenol non-intent (BPA-NI) epoxy resins. In particular, the present disclosure relates to modified epoxy resins having the formula (I): [ka] (wherein R is R, R, or a combination of R and R; R1 and R2 are independently an alkyl group having 1 to 32 carbon (C) atoms, a branched alkyl group having 1 to 32 carbon (C) atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene; R3 and R4 are independently either H, alkyl, branched alkyl, alkoxy, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75%; and N is 1 to 20) The present invention relates to a modified epoxy resin having the following structure.

[0024] According to one aspect, the modified epoxy resin is produced by reacting the modified epoxy resin with the epoxy resin in the presence of a reaction catalyst. a. Formula II: [ka] (R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75% and a dicyclopentadiene-phenol adduct of b. Formula (IIIa) and / or (IIIb): [ka] wherein R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene) and diglycidyl derivatives of It is a reaction product obtained by condensing

[0025] In one aspect, the diglycidyl derivative is either a single diglycidyl resin having formula (IIIa) or formula (IIIb), or a mixture of two or more diglycidyl resins, each having formula (IIIa) or (IIIb). In one embodiment, two diglycidyl resins, each having formula (IIIa), are used. In another embodiment, two diglycidyl resins, one having formula (IIIa) and the other having formula (IIIb), are used. Depending on the selection of the diglycidyl derivatives having formula (IIIa) and / or (IIIb), R in the modified epoxy resin having formula (I) can be R1, R2, or a combination of R1 and R2.

[0026] The disclosed modified epoxy resins, prepared by reaction progression to diglycidyl derivatives with dicyclopentadiene-phenol adducts of high monomer purity, find use as replacements for bisphenol A or bisphenol F diglycidyl ethers.

[0027] While aromatic rings are believed to be important for high chemical and corrosion resistance in conventional bisphenol A and bisphenol F epoxy resins, the modified epoxy resins disclosed herein have a balanced proportion of aromatic and aliphatic or alicyclic components in the oligomeric epoxy resin without relying on epoxy resins that are suspected of causing endocrine disruption.

[0028] The method of the present invention incorporates a typical combination of aromatic content, secondary hydroxyl groups, and epoxy functionality without any precursors of the disclosed resins being derived from bisphenol A. The inventors incorporated aromatic rings by reaction progression to diglycidyl derivatives of formula (IIIa) or (IIIb) with dicyclopentadiene-phenol adducts of formula (II), which are not included in or are not fully available in the diglycidyl derivatives of formula (IIIa) or (IIIb), and by controlling the hydroxyl and epoxide equivalent values ​​of the disclosed epoxy molecules, they controlled the molecular weight of the disclosed resins to be typical of conventional Type 7 or Type 9 BisA epoxy resins in terms of chemical composition and performance.

[0029] According to one aspect, the modified epoxy resins of the present disclosure have an epoxy equivalent weight (EEW) ranging from 500 to 25,000 g / eq, preferably from 1,000 to 20,000 g / eq. The modified epoxy resins have an average molecular weight ranging from 1,000 to 50,000 daltons, preferably from 2,000 to 45,000 daltons. The BPA-NI type epoxy resins disclosed in the present disclosure have epoxide equivalent weights and molecular weights equivalent to standard commercially available conventional bisphenol A-based can coating grades Type 7 and Type 9. The disclosed resins find use as coatings for metallized surfaces, such as can and coil coatings.

[0030] A method for preparing a modified epoxy resin is also disclosed, which comprises the steps of: a. Formula (II): [ka] (R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75% and a dicyclopentadiene-phenol adduct of b. Formula (IIIa) and / or (IIIb): [ka] wherein R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene) and diglycidyl derivatives of of The method includes a step of condensing the compound.

[0031] According to one embodiment, the dicyclopentadiene-phenol adduct of formula (II) and the diglycidyl derivatives of formula (IIIa) and / or (IIIb) are reacted in amounts that allow the target epoxide equivalent to be achieved. Based on the active hydrogen equivalent of the dicyclopentadiene-phenol adduct of formula (II) ("component II") and the epoxide equivalent of the diglycidyl derivatives of formula (IIIa) and / or (IIIb) ("component III"), the following standard formula known in the prior art is used:

number

[0032] According to one embodiment, the process is carried out at elevated temperatures in the range of 120° C. to 200° C., preferably in the range of 120° C. to 160° C. According to one embodiment, the process is carried out at atmospheric pressure, with or without a nitrogen purge.

[0033] According to one embodiment, the dicyclopentadiene-phenol adduct of formula (II) is prepared with high monomer purity by the Diels-Alder reaction of phenol or its formaldehyde-free derivative with 3a,4,7,7a-tetrahydro-4,7-methanoindene or dicyclopentadiene in the presence of a catalyst. According to one embodiment, the dicyclopentadiene-phenol adduct of formula II has a monomer purity of at least 75%, i.e., the concentration of the monomer with n=0 is greater than 75%. Preferably, the dicyclopentadiene-phenol adduct of formula II has a monomer purity of at least 75%. This avoids gelation during the reaction or condensation reaction.

[0034] According to one embodiment, the diglycidyl derivative of formula (IIIa) or (IIIb) is a diglycidyl epoxy resin. The epoxy resin may be a diglycidyl ether or a diglycidyl ester. The diglycidyl ethers and esters may be alicyclic, aliphatic, or aromatic in nature and are substantially free of epoxy resins with endocrine disrupting properties. The diglycidyl epoxy resins include, but are not limited to, bisphenol F diglycidyl ether type epoxy resins, resorcinol diglycidyl ether type epoxy resins, brominated bisphenol A diglycidyl ether type epoxy resins, chlorinated bisphenol A diglycidyl ether type epoxy resins, novolac diglycidyl ether type epoxy resins, orthocresol novolac diglycidyl ether type epoxy resins, polyalkylene glycol diglycidyl ether type epoxy resins, hydrogenated bisphenol A glycidyl ether type epoxy resins, and bisphenol A alkylene oxide-added diglycidyl ether type epoxy resins. Such chemicals can be extended to, but are not limited to, epoxy urethane resins, glycerin triglycidyl ether type epoxy resins, pentaerythritol glycidyl ether type epoxy resins, and (glycidyl ether phenyl)methane; or other glycidyl ethers such as diglycidyl ether ester type epoxy resins, e.g., p-oxybenzoic acid glycidyl ether type epoxy resins; or glycidyl ester type epoxies, e.g., diglycidyl phthalate type epoxy resins, diglycidyl tetrahydrophthalate type epoxy resins, diglycidyl hexahydrophthalate type epoxy resins. According to a preferred embodiment, the diglycidyl ethers and esters are aliphatic, alicyclic, or aromatic in nature, and are substantially free of bisphenol A type diglycidyl ethers, which are suspected of having endocrine disrupting properties.According to exemplary embodiments, the diglycidyl derivative of formula (IIIa) or (IIIb) is selected from the group consisting of diglycidyl ethers based on cyclohexanedimethanol, ring-alkylated bisphenol-F diglycidyl ethers, dicyclopentadiene diglycidyl ethers, aliphatic diglycidyl ethers such as ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and preferably a cycloaliphatic diglycidyl ether such as CHDMGE or a glycidyl ether based on DCPD-phenol novolac.

[0035] According to one embodiment, two or more diglycidyl derivatives of formula (IIIa) and (IIIb) are used, each having different R1 and R2. According to an exemplary embodiment, a dicyclopentadiene phenol epoxy resin, in which R1 is a dicyclopentadiene phenol adduct, and a cyclohexanedimethanol diglycidyl ether, in which R2 is dicyclohexanedimethanol, are used.

[0036] According to one embodiment, the diglycidyl derivative of formula (IIIa) or (IIIb) is prepared by reacting epichlorohydrin with an aliphatic diol, such as butanediol, neopentyl glycol, 1,6 hexanediol, etc., in the presence of a phase transfer catalyst, or by reacting epichlorohydrin with a dicyclopentadiene-phenol adduct.

[0037] According to one embodiment, the reaction to form the diglycidyl ether of formula (II) is carried out using a dicyclopentadiene-phenol adduct in the presence of a reaction catalyst. Any known reaction catalyst can be used. According to one embodiment, the catalyst is selected from the group consisting of quaternary phosphonium salts and quaternary ammonium salts. According to a preferred embodiment, the reaction catalyst is a compound of formula (IV): [ka] (wherein Y is an N or P atom; X is halogen or CH2-C(=O)-O - It is a base; Independently of each other, R5, R6, R7, and R8 are alkyl, aryl, or alicyclic groups. The quaternary onium salt catalyst has the formula:

[0038] In one embodiment, the advancement catalyst is used in an amount of about 0.2 wt.% to 2 wt.% of the total formulation. As known to those skilled in the art, the amount of catalyst can vary depending on the reaction kinetics and heat of reaction.

[0039] The present disclosure further relates to a curable epoxy resin composition, which comprises a resin component containing at least 10 to 50% of the modified epoxy resin composition, and a curing agent.

[0040] According to one embodiment, the resin component comprises the modified epoxy resin composition in an amount of at least 10% by weight based on the curable epoxy resin composition, preferably at least 25% by weight based on the curable epoxy resin composition.

[0041] According to one embodiment, the curing agent is selected from the group consisting of amino curing agents and phenolic curing agents other than those based on bisphenol A, bisphenol F, bisphenol S, and their derivatives. Reaction with the curing agent converts the polyepoxide compound into an infusible, three-dimensionally "crosslinked" thermoset material.

[0042] Examples of suitable curing agents for the curable epoxy resin compositions of the present invention include polyphenols, polycarboxylic acids, polymercaptans, polyamines, primary monoamines, sulfonamides, aminophenols, aminocarboxylic acids, and carboxylic acid anhydrides, phenolic hydroxyl group-containing carboxylic acids, sulfanilamides, and mixtures thereof. In the context of this disclosure, each polycompound (e.g., polyamine) also includes the corresponding dicompound (difunctional compound) (e.g., diamine).

[0043] Preferred curing agents for the curable epoxy resin composition of the present invention are amino curing agents and phenolic curing agents.

[0044] According to one embodiment, amino curing agents suitable for the curable epoxy resin composition of the present disclosure have at least one primary amino group or at least two secondary amino groups. Preferred amino curing agents include dicyandiamide (DICY), isophoronediamine (IPDA), diethylenetriamine (DETA), triethylenetetramine (TETA), bis(p-aminocyclohexyl)methane (PACM), methylenedianiline (e.g., 4,4'-methylenedianiline), polyetheramines such as Polyetheramine D230, diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), 2,4-toluenediamine, 2,6-toluenediamine, 2,4-diamino-1-methylcyclohexane, and 2,6-diamino-1-methylcyclohexane. toluene, 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene, 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, diaminodiphenyl oxide, 3,3',5,5'-tetramethyl-4,4'-diaminobiphenyl, and 3,3'-dimethyl-4,4'-diaminodiphenyl, and also aminoplast resins, for example condensation products of aldehydes, such as formaldehyde, acetaldehyde, crotonaldehyde or benzaldehyde, with melamine, urea or benzoguanamine, and also mixtures thereof. Particularly preferred amino curing agents for the curable compositions of the present invention are dimethyl dicykane (DMDC), dicyandiamide (DICY), isophorone diamine (IPDA), and methylene dianiline (such as 4,4'-methylene dianiline), as well as aminoplast resins such as the condensation products of aldehydes, such as formaldehyde, acetaldehyde, crotonaldehyde, or benzaldehyde, with melamine, urea, or benzoguanamine.

[0045] According to one embodiment, the modified epoxy resin and the amino curing agent are used in an approximately stoichiometric ratio with respect to the epoxide and amino functional groups. A particularly preferred ratio of epoxide groups to amino functional groups is 1:0.8 to 0.8:1.

[0046] According to one embodiment, a suitable phenolic resin for the curable epoxy resin composition of the present disclosure has at least two hydroxyl groups. The phenolic resin can be used in both a stoichiometric and a substoichiometric ratio relative to the epoxide compound. When using a substoichiometric equivalent of the phenolic resin, the reaction between the secondary hydroxyl groups of the existing epoxy resin and the epoxide groups can be promoted by the use of a suitable catalyst. According to one embodiment, suitable phenolic resins are generally novolac-type phenolic resins, resole-type phenolic resins, and condensation products of aldehydes (preferably formaldehyde and acetaldehyde) with phenol. Preferred phenols are phenol, cresol, xylenol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, cyclopentylphenol, and p-nonyl- and p-octylphenol.

[0047] According to one embodiment, the curing agent is used in an amount of about 5-25% by weight based on the resin component, preferably about 5-15% by weight based on the resin component. The resin to curing agent ratio can vary depending on the structure and functionality of the curing agent. A high resin to crosslinker ratio can result in partial cure and poor adhesion after retort testing, while a low resin to crosslinker ratio can result in brittle coatings.

[0048] According to one embodiment, the curable epoxy resin composition comprises an additive selected from the group consisting of accelerators, diluents, lubricants, surfactants, adhesion promoters, stabilizers, flexibilizers, pigments, and the like.

[0049] According to one embodiment, the accelerator is selected from the group consisting of imidazole, imidazole derivatives, and urea derivatives.

[0050] According to one embodiment, the diluent is selected from the group consisting of conventional diluents and reactive diluents. Conventional diluents include organic solvents or mixtures thereof. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), diethyl ketone, or cyclohexanone; esters of aliphatic carboxylic acids such as ethyl acetate, propyl acetate, methoxypropyl acetate, or butyl acetate; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, or propylene glycol; glycol derivatives such as ethoxyethanol, ethoxyethanol acetate, ethylene or propylene glycol monomethyl or dimethyl ether; aromatic hydrocarbons such as toluene or xylene; aliphatic hydrocarbons such as heptane; and alkanols such as methanol, ethanol, n-propanol, isopropanol, or butanol. During the curing process of the epoxy resin, these diluents evaporate from the resin composition.

[0051] The present disclosure further relates to a method for curing the curable epoxy resin composition, wherein, according to one embodiment, curing is carried out at atmospheric pressure and at a temperature below 250°C, preferably below 235°C, more preferably in the range of 40°C to 220°C.

[0052] According to one embodiment, the curing of the curable epoxy resin composition into a molded article is carried out in a mold until dimensional stability is achieved and the cured component can be removed from the mold. Subsequent operations to relieve the inherent stresses of the cured component and / or to complete the crosslinking of the curable epoxy resin composition are referred to as heat treatment (thermal conditioning). Alternatively, the heat treatment process is carried out with the aim of completing the crosslinking of the cured component before it is removed from the mold. The heat treatment operation is usually carried out at a temperature at the limit of dimensional stiffness. Heat treatment is carried out at a temperature in the range of 120°C to 220°C, preferably 150°C to 220°C. According to a related embodiment, the cured component is subjected to the heat treatment conditions for a period of 30 to 240 minutes. The period may be extended depending on the dimensions of the cured component.

[0053] According to one embodiment, when the curable epoxy resin composition is used to form a coating, the substrate to be coated is first treated with said curable epoxy resin composition, and then the curable epoxy resin composition on the substrate is cured.

[0054] According to one embodiment, application of the curable epoxy resin composition is carried out before or after forming the desired article by dipping, spraying, roller application, spread application, knife coating, etc. in the case of a liquid formulation, or by application of a powder coating material. Application can be to individual parts (e.g., can parts) or to an essentially continuous substrate, such as, for example, a steel strip roll in the case of coil coating. Suitable substrates are typically steel, tinplate (galvanized steel), or aluminum (e.g., for beverage cans). Curing of the curable epoxy resin composition after application to the substrate is carried out at temperatures ranging from 20°C to 250°C, preferably from 50°C to 220°C, and more preferably from 100°C to 220°C. According to a related embodiment, curing is carried out for a period of 0.1 to 60 minutes, preferably from 0.5 to 20 minutes, and more preferably from 1 to 10 minutes.

[0055] Specific Embodiments Formula (I): [ka] (In the formula, R is R1, R2, or a combination of R1 and R2; R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, a cycloaliphatic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene; R3 and R4 are independently either H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75%; and N is 1 to 20) A modified epoxy resin having the formula:

[0056] In the presence of a catalyst for reaction a. Formula II: [ka] (In the formula, R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75% and a dicyclopentadiene-phenol adduct of b. Formula (IIIa) or (IIIb): [ka] (In the formula, R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene) and diglycidyl derivatives of The modified epoxy resin is a reaction product obtained by condensing the following:

[0057] The above modified epoxy resin has an epoxide equivalent weight in the range of 500 to 25,000 g / equivalent.

[0058] The modified epoxy resin described above has a weight average molecular weight in the range of 1,000 to 50,000 daltons.

[0059] 1. A curable epoxy resin composition comprising: - 10 to 50% of a resin component containing at least 10 to 50% of the modified epoxy resin composition, based on the mass of the curable epoxy resin composition; - 5-25 wt / wt% hardener based on the mass of the resin component 1. A curable epoxy resin composition comprising:

[0060] The above curable epoxy resin composition, wherein the curing agent is selected from the group consisting of amino-based curing agents and phenol-based curing agents, and the curing agent is non-bisphenol.

[0061] 1. A method for preparing a modified epoxy resin, comprising the steps of: a. Formula II: [ka] (In the formula, R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75% and a dicyclopentadiene-phenol adduct of b. Formula (IIIa) or (IIIb): [ka] (In the formula, R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene) and diglycidyl derivatives of to form a compound of formula (I): [ka] (In the formula, R is R1, R2, or a combination of R1 and R2; R1 and R2 are independently an alkyl group having 1 to 32 carbon atoms, a branched alkyl group having 1 to 32 carbon atoms, an alicyclic group, a substituted alicyclic group, an aromatic group, a substituted aromatic group, a biaryl or alkyl-substituted biaryl group, a methyl-bridged aromatic group, an alicyclic-aromatic group, or an Ar-Z-Ar group; X and Y are independently O, —C(O)O—, or an amine group; Z is dicyclopentadiene; R3 and R4 are independently either H, an alkyl group, a branched alkyl group, an alkoxy group, a substituted biaryl group, or a methyl-bridged aromatic group; R4 and R3 optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75%; and N is 1 to 20) obtaining a modified epoxy resin of formula (1).

[0062] The above method, wherein the dicyclopentadiene-phenol adduct is prepared with high monomer purity by the Diels-Alder reaction of phenol or a formaldehyde-free phenol derivative with 3a,4,7,7a-tetrahydro-4,7-methanoindene or dicyclopentadiene in the presence of a catalyst.

[0063] The above method, wherein the concentration of the monomer where n=0 is at least 75%.

[0064] The reaction catalyst has the formula (IV): [ka] (In the formula, Y is an N or P atom; X is halogen or CH2-C(=O)-O - It is a base; R5, R6, R7, and R8 are independently alkyl, aryl, or alicyclic groups. The above method, wherein the catalyst is a quaternary onium salt having the formula:

[0065] The above method, wherein the catalyst is used in an amount of about 0.2 w / w% to 2 w / w% based on the total formulation. [Example]

[0066] In order to better understand the present invention, the following examples are set forth. These examples are for illustrative purposes only, and the exact compositions, preparation methods, and embodiments shown are not intended to limit the invention, and any obvious modifications will be apparent to those skilled in the art.

[0067] Example 1: Preparation of dicyclopentadiene-phenol adduct A 2,000 ml four-neck flask equipped with a stirrer, condenser, thermometer, heater, and dropping funnel was charged with 1,000 g (10.64 mol) of phenol and 10 g of boron trifluoride diethyl etherate (1.0% by mass of phenol) while maintaining the temperature at 65°C. Next, 468.8 g (3.55 mol) of dicyclopentadiene (DCPD) was added dropwise over 3 hours. The temperature was increased and maintained at 100°C for 5 hours. After completion of the reaction, the mixture was neutralized, and unreacted phenol was recovered at 160°C and 40 mbar.

[0068] 992 g of dark brown dicyclopentadiene-phenolic resin was obtained, having a softening point of 119.1° C. and a monomer content of 33.2%.

[0069] Example 2: Preparation of dicyclopentadiene-phenol adduct A flask similar to that used in Example 1 was charged with 1,000 g (10.64 mol) of phenol and 5 g of boron trifluoride diethyl etherate (0.5% by mass of phenol) while maintaining the temperature at 65°C. Then, 234.7 g (1.78 mol) of DCPD was added dropwise over 2 hours. The temperature was increased and maintained at 100°C for 5 hours. After completion of the reaction, neutralization was carried out, and unreacted phenol was recovered at 160°C and 40 mbar.

[0070] 528 g of dark brown dicyclopentadiene phenolic resin was obtained, having a softening point of 93.1° C. and a monomer content of 57.19%.

[0071] Example 3: Preparation of dicyclopentadiene-phenol adduct A flask similar to that used in Example 1 was charged with 1,000 g (6.38 mol) of phenol and 5 g of boron trifluoride diethyl etherate (0.5% by mass of phenol) while maintaining the temperature at 65°C. Then, 70.3 g (0.53 mol) of DCPD was added dropwise over 1 hour. The temperature was increased and maintained at 100°C for 5 hours. After completion of the reaction, the mixture was neutralized, and unreacted phenol was recovered at 160°C and 40 mbar.

[0072] 167.9 g of dark brown dicyclopentadiene phenol resin was obtained, having a softening point of 79.9° C. and a monomer content of 82.01%.

[0073] Table 1 shows the properties of the dicyclopentadiene-phenol adducts prepared in Examples 1 to 3.

[0074] [Table 1]

[0075] Example 4: Preparation of epoxidized dicyclopentadiene phenol A reactor equipped with a stirrer, condenser, thermometer, heater, and dropping funnel was charged with 150 g (0.94 equivalents) of dicyclopentadienephenol from Example 3, 869.5 g (9.4 moles) of epichlorohydrin, and 2.8 g of 50% sodium hydroxide. The solution was heated and held at 65° C. for 4 hours. Subsequently, 70.5 g of 50% sodium hydroxide was added over 1 hour while simultaneously removing water.

[0076] The unreacted molar excess of epichlorohydrin was removed, and toluene was added to dissolve the reaction mass. The reaction mass was repeatedly washed to remove residual caustic. The solvent was removed to give a brown solid product.

[0077] The product had an epoxy equivalent weight of 228 g / equivalent, a hydrolyzable chlorine content of less than 1000 ppm, and a softening point of 45°C.

[0078] Table 2 shows the composition and properties of the epoxidized dicyclopentadiene phenol obtained in Example 4.

[0079] [Table 2]

[0080] Example 5: Preparation of modified epoxy resin A 500 ml four-neck flask equipped with a stirrer, condenser, thermometer, and heater was charged with 70.1 g of the epoxidized dicyclopentadiene phenol from Example 4 and 38.2 g of the dicyclopentadiene-phenol adduct prepared in Example 3. The mixture was stirred and heated to 120° C. under nitrogen. 0.08 g of ethyl triphenylphosphonium acetate (ETPPAc) was then added as a catalyst for the reaction. The reaction temperature was increased to 160° C. and maintained for 9 hours.

[0081] The resulting modified epoxy resin had an epoxy equivalent of 1662 g / equivalent and a softening point of 158°C.

[0082] Example 6: Preparation of modified epoxy resin Into a reactor equipped as in Example 5, 165 g of cyclohexanedimethanol diglycidyl ether (EEW ​​131.5 g / eq) and 178.8 g of the dicyclopentadiene-phenol adduct of Example 3 (AHEW 160) were charged. The mixture was stirred and heated to 120°C under nitrogen. 0.9 g of ETPPAc was then added as a catalyst for the reaction. The reaction temperature was increased to 160°C and maintained for 7 hours.

[0083] The resulting modified epoxy resin had an epoxy equivalent of 2691 g / equivalent and a softening point of 113.6°C.

[0084] Example 7: Preparation of modified epoxy resin A reactor equipped similarly to Example 5 was charged with 48 g of cyclohexanedimethanol diglycidyl ether, 12 g of the diglycidyl ether of cyclopentadienephenol from Example 4, and 59.1 g of the dicyclopentadiene-phenol adduct from Example 3. The mixture was stirred and heated to 120°C under nitrogen. 0.3 g of ETPPAc was then added as a catalyst for the reaction. The reaction temperature was increased to 160°C and maintained for 5.30 hours.

[0085] The resulting modified epoxy resin had an epoxy equivalent of 2716 g / equivalent and a softening point of 120.7°C.

[0086] Example 8: Preparation of modified epoxy resin A reactor equipped similarly to Example 5 was charged with 60 g of biphenol diglycidyl ether (EEW ​​187.6 g / eq) and 41.6 g of the dicyclopentadiene-phenol adduct from Example 3. The mixture was stirred and heated to 120° C. under nitrogen. 0.15 g of ETPPAc was then added as a catalyst for the reaction. The reaction temperature was increased to 160° C. and maintained for 7 hours.

[0087] The resulting modified epoxy resin had an epoxy equivalent of 2511 g / equivalent and a softening point of 142.7°C.

[0088] Table 3 shows the composition and properties of the modified epoxy resin obtained in Example 4.

[0089] [Table 3]

[0090] Example 9 A reactor equipped similarly to Example 6 was charged with 57 g of the diglycidyl ether of cyclohexanedimethanol (EEW ​​159 g / eq) and 50.5 g of the dicyclopentadiene-phenol adduct of Example 3. The reactor was heated to 90° C., followed by the addition of 0.25 g of ETPPAc. The reaction mixture was heated to 160° C. and maintained at 160° C. for 7 hours.

[0091] At the end of the reaction, a brown reaction product was obtained with an EEW of 2358 g / eq and a softening point of 92.4°C.

[0092] Example 10 A reactor equipped as in Example 5 was charged with 167.5 g of the diglycidyl ether of cyclohexanedimethanol (EEW ​​137.8 g / eq) and 173.5 g of the dicyclopentadiene-phenol adduct from Example 3. The mixture was stirred and heated to 120° C. under nitrogen. 0.9 g of ETPPAc was then added as a catalyst for the reaction. The reaction temperature was increased to 160° C. and maintained for 5 hours.

[0093] The resulting modified resin had an epoxy equivalent of 2889 g / equivalent and a softening point of 110.4°C.

[0094] As shown in Table 4, the influence of the quality of the diglycidyl epoxy resin (EEW) on the quality of the modified epoxy resin was investigated by comparing the properties of the reaction products obtained in Examples 6, 9, and 10.

[0095] [Table 4]

[0096] Observation results: It was observed that the higher the purity of the diglycidyl ether, the higher the softening point of the modified epoxy resin.

[0097] Example 11: Preparation of a coating composition based on a modified epoxy resin A coating composition was prepared using the modified epoxy resin of Example 6. The components of the coating composition for coating metal surfaces and their properties are shown in Table 5.

[0098] [Table 5] [Industrial Applicability]

[0099] The modified epoxy resins of the present disclosure find use as safe, non-endocrine disrupting, difunctional epoxy resins that are intentionally bisphenol A-free (BPA-NI) and formaldehyde-free. The modified epoxy resins of the present disclosure are less likely to release endocrine disrupting compounds compared to epoxy resins based on bisphenol A, bisphenol F, bisphenol S, or any such molecules that have been proven to be endocrine disruptors.

[0100] The dicyclopentadiene-phenol adduct of formula (II) is structurally dissimilar to the endocrine disrupting hormone estradiol and does not use formaldehyde. Such structural similarity to estradiol is believed to be an important factor in the current decision of European agencies to phase out suspected endocrine disruptors such as bisphenols A and F from use in certain container coatings.

[0101] The existing range of cycloaliphatic, aliphatic, biaryl phenol glycidyl ethers of general formula (II) can be advanced with dicyclopentadiene-phenol adducts of formula (II) to obtain the modified epoxy resins of the present disclosure.

[0102] The disclosed modified epoxy resins exhibit similar performance to conventional can coating grade epoxy resins, namely Type 7 and Type 9 BPA type resins, but without the health and environmental concerns posed by the latter.

[0103] The modified epoxy resins described above exhibit good adhesion, excellent corrosion resistance, excellent retort resistance and impact resistance properties, and can be used in varnishes and coatings for metal surfaces without further modification with silane derivatives, as otherwise mentioned in the prior art. In particular, curable epoxy resin compositions comprising the modified epoxy resins of the present disclosure find use in adhesives, composites, molded articles, and coatings, more particularly, coatings for food and beverage containers.

Claims

1. 1. A coating composition for the interior surfaces of metal containers used in packaging and storing food and beverages, comprising: As an alternative to bisphenol A (BPA)-based epoxy resins, Formula (I): 【Chemistry 1】 (In the formula, R is R1, R2, or a combination of R1 and R2; R1 and R2 are independently an alicyclic group, a residue obtained by removing two hydroxyl groups from cyclohexanedimethanol, or a biarylene or alkyl-substituted biarylene group; X and Y are O; R3 and R4 are independently either H, an alkyl group, a branched alkyl group, an alkoxy group, or a substituted biaryl group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75%; and N is 1 to 20. A coating composition comprising a modified epoxy resin having the formula:

2. The modified epoxy resin is reacted with a reaction catalyst in the presence of c. Formula (II): 【Chemistry 2】 (In the formula, R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, or a substituted biaryl group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75% and a dicyclopentadiene-phenol adduct of d. Formula (IIIa) or (IIIb): 【Transformation 3】 (In the formula, R1 and R2 are independently an alicyclic group, a residue obtained by removing two hydroxyl groups from cyclohexanedimethanol, or a biarylene or alkyl-substituted biarylene group; X and Y are O. and diglycidyl derivatives of 2. The coating composition of claim 1, which is a reaction product obtained by condensing

3. The coating composition of claim 1, wherein the modified epoxy resin has an epoxide equivalent weight in the range of 500 to 25,000 g / eq.

4. The coating composition of claim 1, wherein the modified epoxy resin has a weight average molecular weight in the range of 1,000 to 50,000 Daltons.

5. 1. A bisphenol A-diglycidyl ether (BADGE)- and bisphenol A (BPA-free) curable epoxy resin composition for coating the interior surfaces of metal containers used in packaging and storing food and beverages, comprising: - 10 to 50% by weight of a resin component comprising at least 10 to 50% by weight of a modified epoxy resin as defined in claim 1, based on the weight of the curable epoxy resin composition; and - 5 to 25% by weight of hardener based on the weight of the resin component 1. A curable epoxy resin composition comprising:

6. 6. The curable epoxy resin composition of claim 5, wherein the curing agent is selected from the group consisting of amino-based curing agents and phenol-based curing agents, and the curing agent is non-bisphenol.

7. 1. A method for preparing a coating composition for the interior surfaces of metal containers used in packaging and storing food and beverages, comprising the modified epoxy resin of formula (I) as a replacement for bisphenol A (BPA)-based epoxy resins, the method comprising: In the presence of a catalyst for reaction c. Formula II: 【Chemistry 4】 (In the formula, R3 and R4 are independently H, an alkyl group, a branched alkyl group, an alkoxy group, or a substituted biaryl group; R4 and R3 may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75% and a dicyclopentadiene-phenol adduct of d. Formula (IIIa) or (IIIb): 【Transformation 5】 (In the formula, R1 and R2 are independently an alicyclic group, a residue obtained by removing two hydroxyl groups from cyclohexanedimethanol, or a biarylene or alkyl-substituted biarylene group; X and Y are independently O. and diglycidyl derivatives of to form a compound of the formula (I): 【Transformation 6】 (In the formula, R is R1, R2, or a combination of R1 and R2; R1 and R2 are independently an alicyclic group, a residue obtained by removing two hydroxyl groups from cyclohexanedimethanol, or a biarylene or alkyl-substituted biarylene group; X and Y are O; R and R are independently either H, an alkyl group, a branched alkyl group, an alkoxy group, or a substituted biaryl group; R and R may optionally form a fused aromatic ring or a fused heteroaromatic ring; n is 0 to 1, and n=0>75%; and N is 1 to 20. obtaining a modified epoxy resin of formula (1).

8. The method of claim 7, wherein the dicyclopentadiene-phenol adduct is prepared by the Diels-Alder reaction of phenol or a formaldehyde-free derivative of phenol with 3a,4,7,7a-tetrahydro-4,7-methanoindene or dicyclopentadiene in the presence of a catalyst to a high monomer purity where n=0>75%.

9. The reaction catalyst according to claim 8, wherein the reaction catalyst has the formula (IV): 【Transformation 7】 (In the formula, Y is an N or P atom; X is a halogen or CH ２ -C(=O)-O － is a group; R5, R6, R7, and R8 are independently an alkyl, aryl, or alicyclic group. The method of claim 7, wherein the catalyst is a quaternary onium salt having the formula:

10. 8. The method of claim 7, wherein the reaction promoter catalyst is used in an amount of 0.2% to 2% by weight based on the weight of the total formulation.

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