TW201704229A - Diglycidyl ethers of tetrahydrofuran diglycol derivatives and oligomers thereof as curable epoxy resins - Google Patents

Abstract

Cured epoxy resins are widespread on account of their outstanding mechanical and chemical properties. It is common to use epoxy resin based on bisphenol A diglycidyl ether or bisphenol F diglycidyl ether, but for many sectors these are problematic because of their endocrine effect. The present invention relates to tetrahydrofuran diglycol diglycidyl ether derivates and to curable epoxy resin compositions based thereon, as alternatives to the bisphenol A or bisphenol F diglycidyl ethers and to the epoxy resin compositions based thereon.

Description

Diglycidyl ether derivative of tetrahydrofuran ethylene glycol as a curable epoxy resin and oligomer thereof

This invention relates to tetrahydrofuran ethylene glycol diglycidyl ether derivatives, to their preparation and to their use in the manufacture of adhesives, composites, shaped articles, 3D printed parts or coatings. The present invention further relates to a curable epoxy resin composition comprising a curing component and a resin component, the resin component comprising at least one tetrahydrofuran ethylene glycol diglycidyl ether derivative as a polyepoxide or based thereon Polymer, and also relates to a method for curing such a composition and an epoxy resin obtained by curing such a composition.

Epoxy resins are conventional names for oligomeric compounds having an average of more than one epoxy group per molecule, which are converted to heat by reaction with a suitable curing agent (hardener) or by polymerization of epoxy groups. Solid or cured epoxy resin. Cured epoxy resin due to its outstanding mechanical and chemical properties, such as high impact strength, high wear resistance, good heat resistance and chemical resistance, more specifically high levels of alkali, acid, oil and organic solvents It is widely distributed with high resistance to weathering and high weather resistance, excellent adhesion to a large number of materials and high electrical insulation. It acts as a matrix for the fiber composite and is typically an electrical laminate, a structural adhesive, a cast resin, a coating, The main component of 3D printing resin and powder coating. 3D printing resins are typically photographic formulations used in stereolithography or photopolymer spray applications.

Most commercially available (uncured) epoxy resins are coupled by coupling epichlorohydrin to compounds having at least two reactive hydrogen atoms, such as polyphenols, monoamines and diamines, aminophenols, heterocyclic imines And decylamine, aliphatic diol or polyol or dimer fatty acid to prepare. An epoxy resin derived from epichlorohydrin is referred to as a glycidyl group-based resin. In general, bisphenol A diglycidyl ether or bisphenol F diglycidyl ether or a corresponding oligomer is used as the epoxy resin.

In particular, there are strict requirements for the coating of containers for storing foods and beverages. The coating thus strongly resists acidic or savoury foods (such as tomatoes) or beverages so that the metal does not corrode, which in turn may cause contamination of the contents. In addition, the coating must not affect the flavor or appearance of the food. Since the manufacture of the container typically involves further shaping of the already coated container, the coating must be flexible. Many inclusions, such as food, are not sterilized until they are in the can; the coating therefore needs to withstand heating at 121 ° C for at least 2 hours without damage and without component migration.

The use of epoxy resins based on bisphenol A or bisphenol F diglycidyl ether in an increasing number of industries is increasingly being considered problematic due to the endocrine effect of the corresponding diol.

In order to solve this problem, various proposals have been made: US 2012/0116048 discloses a polymer containing no bisphenol A (BPA) and bisphenol F (BPF), which polymer also contains a hydroxy ether bridge in addition to the ester bond, From a double based on an open chain aliphatic diol such as neopentyl glycol (NPG), based on a single cycloaliphatic diol such as 1,4-cyclohexanedimethanol or based on an aromatic diol such as resorcinol Made of epoxy compound. However, empirically, the aliphatic and cycloaliphatic diols produce coatings that are extremely soft and have low temperature and chemical resistance.

WO 2012/089657 discloses a BPA-free formulation comprising a film-forming resin and an adhesion promoter. The resin is, for example, an epoxidized resin prepared from NPG, ethylene glycol, propylene glycol or dipropylene glycol, 1,4-butanediol or diglycidyl ether of 1,6-hexanediol. Here, the same limitations on the properties of the coating are contemplated as in the previous examples.

WO 2010/100122 proposes a reaction obtainable by reacting an epoxidized vegetable oil with a hydroxy-functional compound such as propylene glycol, propane-1,3-diol, ethylene glycol, NPG, trimethylolpropane, diethylene glycol or the like. Coating system.

US 2004/0147638 describes a 2-layer (core/shell) system in which the core is formed from an epoxy resin based on BPA or BPF and the outer layer is formed, for example, from an acrylate resin. The key question here is whether the outer layer is truly capable of completely preventing the migration of BPA or bisphenol A diglycidyl ether (BADGE) into the inclusions.

WO 2012/091701 proposes various diols and diglycidyl ethers thereof as substitutes for BPA or BADGE for epoxy resins, including BPA and derivatives of cyclic hydrogenated BPA, cyclobutane-based alicyclic diols and a diol which is a furan ring of its parent structure.

The object on which the invention is based is to provide an epoxy resin system, in particular as an at least partial replacement for BADGE in a corresponding epoxy resin system, in particular a monomer and/or oligomeric second in a coating for a container. Glycidyl ether compound.

Accordingly, the present invention relates to a tetrahydrofuran ethylene glycol diglycidyl ether derivative of the following formula I (THF DGE derivative)

Wherein R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 4 C atoms, a halogen atom (F, Cl, Br, I) or a nitro group, preferably a hydrogen atom or having 1 to 4 C The alkyl group of the atom, R3 is a hydrogen atom or a glycidyl group, and n is from 0 to 100, preferably from 0 to 30.

In the case where the THF DGE derivative of the formula I has 2 or more R3 groups (n = 2 to 100), R2 is in each case independent of any other hydrogen atom or glycidyl group.

For the purposes of the present invention, alkyl groups have from 1 to 20 C atoms. It can be linear, branched or cyclic. It is preferably free of substituents having a hetero atom. A hetero atom is all atoms except C and H atoms.

A specific example of the invention relates to an oligoTHF DGE derivative of formula I wherein n is from 1 to 100, preferably from 1 to 30. For the purposes of the present invention, the oligous THF DGE derivatives of formula I also include mixtures of different polysubstituted THF DGE derivatives having different n and R3 (hydrogen or glycidyl groups).

A specific example of the invention relates to a monomeric THF DGE of formula I with n=0 derivative.

A specific example of the invention is a mixture of a monomer of formula I and an oligomeric THF DGE derivative.

A specific example of the invention relates to a tetrahydrofuranethylene glycol diglycidyl ether derivative of formula I, wherein R1 and R2 are each a hydrogen atom, n is from 0 to 100, preferably from 0 to 30, and R3 is as defined above (Different diglycidyl ether of monomer or oligomeric tetrahydrofuran ethylene glycol and monomer or oligo diglycidyl ether, respectively).

A preferred embodiment of the invention is a monomeric tetrahydrofuran ethylene glycol diglycidyl ether (THF DGE) corresponding to formula I, wherein R1 and R2 are each a hydrogen atom and n is 0, and also corresponds to a lower formula I PolyTHF DGE, wherein R1 and R2 are each a hydrogen atom, n is from 1 to 100, preferably from 1 to 30, and R3 is a hydrogen atom or a glycidyl group (independently of each other), and is also a monomeric THF DGE and oligomerization Mixture of THF DGE.

The invention further relates to a process for the preparation of a THF DGE derivative of the formula I, which comprises reacting a corresponding tetrahydrofuran ethylene glycol derivative (THF derivative) of the following formula II with epichlorohydrin Wherein R1 and R2 have the same definitions as for the THF DGE derivative of formula I.

The reaction typically produces a mixture of monomer and oligomeric THF DGE derivatives. The more excess the epichlorohydrin used, the greater the fraction of the monomeric THF DGE derivative. By those skilled in the art Separation techniques known, such as, for example, chromatography, extraction or distillation methods, can separate monomeric THF DGE derivatives from oligomeric THF DGE derivatives.

In a particular embodiment, from 1 to 20 equivalents, preferably from 2 to 10 equivalents of epichlorohydrin are used to prepare the THF DGE derivative of formula I. The reaction is typically carried out at a temperature ranging from -10 ° C to 120 ° C, preferably from 20 ° C to 60 ° C. To accelerate the reaction, a base such as an inorganic salt or an alcohol solution or a base of a dispersion such as LiOH, NaOH, KOH, Ca(OH) ₂ or Ba(OH) _{2 may be added} . In addition, a suitable catalyst such as a tertiary amine can be used.

In another specific embodiment, in accordance with the present invention, in the presence of a Lewis acid catalyst, preferably in the presence of tin (IV) chloride or a boron trifluoride adduct (such as boron trifluoride etherate) The THF derivative of the formula II is reacted with 0.9 to 20, preferably 1 to 10 equivalents of epichlorohydrin at a temperature ranging from 20 ° C to 180 ° C, preferably from 70 ° C to 150 ° C, to obtain a corresponding a THF DGE derivative of formula I. The reaction mixture is then blended with a base (eg, a dilute solution of sodium hydroxide) and heated for a further period of time (eg, 1 to 5 hours) (eg, under reflux). The product can then be separated by phase separation and a washing step with water.

The invention further relates to a process for the preparation of oligomers based on THF DGE derivatives by reacting a monomeric THF DGE derivative of formula I with a diol (chain elongation). This is achieved by reacting a monomeric THF DGE derivative of formula I (n = 0) or two or more mixtures of THF DGE derivatives of formula I wherein n is predominantly 0 with one or more diols To be done. The mixture of the two or more THF DGE derivatives of formula I preferably comprises a monomeric THF DGE derivative (n = 0) to the extent of at least 60% by weight. For this purpose, it is preferred to use from 0.01 to 0.95, more preferably from 0.05 to 0.8, more specifically from 0.1 to 0.4 equivalents of the diol, based on the THF DGE derivative used. Preferably, a substoichiometric amount of one or more diols is used to The resulting THF DGE derivative-based oligomer has an average of more than one, preferably more than 1.5, and more preferably more than 1.9, epoxy groups per molecule. The reaction is typically carried out at a temperature in the range of from 50 ° C to 200 ° C, preferably from 60 ° C to 160 ° C. Suitable diols are generally aromatic, cycloaliphatic or aliphatic dihydroxy compounds, examples being furan dimethanol, cyclohydrogenated bisphenol A, cyclic hydrogenated bisphenol F, neopentyl glycol, bisphenol A, bisphenol F or Bisphenol S is preferably furan dimethanol, cyclohydrogenated bisphenol A or cyclic hydrogenated bisphenol F.

Accordingly, the present invention also provides oligomers based on THF DGE derivatives which can be made by making the monomeric THF DGE derivative of formula I (n = 0) or two or more different n, wherein n is predominant A mixture of THF DGE derivatives of formula I of 0 is obtained by reaction with one or more diols. The mixture of the two or more THF DGE derivatives of formula I preferably comprises a monomeric THF DGE derivative (n = 0) to the extent of at least 60% by weight. In a particular embodiment, one or more of the diols used are inconsistent with the THF derivative of formula II corresponding to the THF DGE derivative of formula I, and as a result, a total of THF based DGE derivatives are obtained. Oligomer.

In a particular embodiment, the invention relates to a process for the preparation of an oligomer based on a THF DGE derivative, starting from a monomeric THF DGE derivative of formula I, wherein the monomeric THF of formula I A DGE derivative (n = 0) or a mixture of two or more THF DGE derivatives of formula I having a different n, wherein n is predominantly 0, is reacted with the corresponding THF derivative of formula II. The mixture of the two or more THF DGE derivatives of formula I preferably comprises a monomeric THF DGE derivative (n = 0) to the extent of at least 60% by weight. For this purpose, it is preferred to use from 0.01 to 0.95, more specifically from 0.1 to 0.4 equivalents of the THF derivative of the formula II, based on the THF DGE derivative of the formula I used. Preferably, a substoichiometric amount of the THF derivative of formula II is used to produce an average of more than one, preferably more than 1.5, per molecule of the resulting THF DGE derivative-based oligomer. More preferably, more than 1.9 epoxy groups. The reaction is typically carried out at a temperature in the range of from 50 ° C to 200 ° C, preferably from 60 ° C to 160 ° C.

A particular preparation of a higher molecular weight oligomeric THF DGE derivative of formula I can also be carried out in a similar manner starting from an oligomeric THF DGE derivative of formula I having a lower degree of polymerization.

The present invention also relates to a curable epoxy resin composition comprising a curing component comprising at least one curing agent; and a resin component comprising at least one polyepoxide based on a THF DGE derivative selected from the group consisting of THF DGE derivatives of formula I (monomer and/or oligomeric) and co-oligomers based on THF DGE derivatives.

The present invention preferably relates to a curable epoxy resin composition comprising a curing component comprising at least one curing agent; and a resin component comprising at least one polyepoxide based on a THF DGE derivative selected from the group consisting of Compound: THF DGE derivative of formula I (monomer and/or oligomerization).

In a specific embodiment, the invention relates to a curable epoxy resin composition comprising a curing component comprising at least one curing agent; and a resin component comprising at least one oligomeric THF DGE of formula I Derivatives (n = 1 to 100, preferably 1 to 30), the epoxide equivalent weight (EEW) of the oligomeric THF DGE derivatives of formula I used is on average between 130 and 3000 g/mol, more specifically 140 Between 1000g/mol.

In a specific embodiment, the curable epoxy resin composition of the present invention contains less than 40% by weight, more preferably less than 10% by weight, very preferably less than 5% by weight, still more preferably less than 1% by weight, based on the total resin component. a compound based on bisphenol A or F. The curable epoxy resin composition of the present invention is preferably free of compounds based on bisphenol A or F. For the purposes of the present invention, based on double The compounds of phenol A or F are bisphenol A and F itself, diglycidyl ethers thereof and oligomers or polymers based thereon.

In a specific embodiment of the curable epoxy resin composition of the present invention, the polyepoxide based on the THF DGE derivative accounts for at least 40% by weight, preferably at least 60% by weight, based on the total resin component. More specifically, the fraction of at least 80% by weight.

In a particular embodiment, the curable epoxy resin composition of the present invention is a photographic formulation and may also comprise an acrylate component, similar to a typical blend formulation typically used in 3D printing applications as described, for example, in US Pat. No. 5,476,748. Acrylate component.

Since the compound of the formula I according to the invention is suitable for reducing other epoxy resins in the resin component and in the curable composition, in particular based on BADGE, bisphenol F diglycidyl ether, tetraglycidyl methylene diphenylamine, cresol The viscosity of epoxy resin of novolac or triglycidylaminophenol, so it is also suitable as a reactive diluent, more specifically, based on BADGE, bisphenol F diglycidyl ether, tetraglycidyl A reactive diluent for an epoxy resin of methylene bisaniline, cresol, novolac or triglycidylaminophenol. The addition of the compound of the formula I according to the invention as a reactive diluent has the advantageous effect of making the glass transition temperature relatively slightly lower.

Accordingly, in a specific embodiment, the present invention relates to a curable composition comprising a cured component comprising at least one curing agent; and a resin component comprising at least one group selected from the group consisting of Polyepoxide of THF DGE derivative: THF DGE derivative (monomer) of formula I, and at least one epoxy resin selected from the group consisting of bisphenol A diglycidyl ether, bisphenol F II Glycidyl ether (BFDGE), diglycidyl ether of cyclic hydrogenated bisphenol A, diglycidyl ether of cyclohydrogenated bisphenol F, tetraglycidyl methylene diphenylamine, cresol epoxy resin, novolac epoxy resin And triglycidylaminophenol and its oligomerization Things. Here, at least one polyepoxide based on the THF DGE derivative accounts for preferably up to 30% by weight based on the resin component of the curable composition (epoxy resin and polyepoxide based on THF DGE derivative). More preferably, it is a fraction of 25% by weight, more particularly 1 to 20% by weight, especially 2 to 20% by weight, very particularly 5 to 15% by weight.

Accordingly, the present invention also relates to a resin component comprising at least one THF DGE derivative-based polyepoxide selected from the group consisting of: a THF DGE derivative of the formula I (monomer), and at least one selected from the group consisting of The following composition of epoxy resin: bisphenol A diglycidyl ether, bisphenol F diglycidyl ether (BFDGE), cyclohydrogenated bisphenol A diglycidyl ether, cyclohydrogenated bisphenol F diglycidyl Ether, tetraglycidyl methylene bisaniline, cresol epoxy resin, novolak epoxy resin and triglycidylamino phenol and oligomers thereof. Here, at least one polyepoxide based on the THF DGE derivative accounts for preferably up to 30% by weight based on the resin component of the curable composition (epoxy resin and polyepoxide based on THF DGE derivative). More preferably, it is a fraction of 25% by weight, more particularly 1 to 20% by weight, especially 2 to 20% by weight, very particularly 5 to 15% by weight.

In a preferred embodiment of the curable epoxy resin composition of the present invention, the total resin component accounts for at least 10% by weight, more specifically at least 25% by weight, based on the total curable epoxy resin composition.

For the purposes of the present invention, all of the epoxides of the curable epoxy resin composition and only the epoxide are distributed to the resin component. For the purposes of the present invention, epoxides have at least one epoxy group and thus include, for example, compounds corresponding to reactive diluents.

The epoxide of the resin component preferably contains at least 1.1, more preferably at least 1.5, and more specifically at least 1.9 epoxy groups per molecule.

For the purposes of the present invention, the curing agent is a compound suitable for use in the crosslinking of the THF DGE derivative-based polyepoxide of the present invention.

The reaction with the curing agent can be used to convert the polyepoxide into an infusible three-dimensional "crosslinked" thermoset material.

In the curing of epoxy resins, a distinction is made between the two types of curing. In the first case, the curing agent has at least two functional groups capable of reacting with the oxiranyl group and/or hydroxyl group of the polyepoxide to form a covalent bond (addition polymerization). During the curing process, a polymer network is subsequently formed, which consists of units derived from polyepoxide and units derived from curing agent molecules, which are covalently bonded to each other and can be cured by means of a curing agent and The relative amount of functional groups in the epoxide controls the degree of crosslinking. In the second case, a compound which causes homopolymerization of the polyepoxides with each other is used. Such compounds are also commonly referred to as initiators or catalysts. The homopolymerization-inducing catalyst is a Lewis base (anionic homopolymerization; an anionic curing catalyst) or a Lewis acid (cationic homopolymerization; cationic curing catalyst). It causes an ether bridge to form between the epoxides. It is assumed that the catalyst reacts with the first epoxy group, together with ring opening to form a reactive hydroxyl group, which in turn reacts with another epoxy group to form an ether bridge, thus creating a new reactive hydroxyl group. Due to this reaction mechanism, the use of substoichiometric amounts of such catalysts is sufficient for curing. Imidazole is an example of a catalyst which induces anion homopolymerization of an epoxide. Boron trifluoride is an example of a catalyst that triggers cationic homopolymerization. Further, a mixture of different curing agents entering the addition polymerization reaction, a mixture of a curing agent for inducing homopolymerization, a curing agent for performing addition polymerization, and a curing agent for inducing homopolymerization can be used for curing. Polyepoxide.

Capable of entering the polyaddition with the oxirane group of polyepoxide (epoxy resin) Suitable functional groups in the reaction are, for example, an amine group, a hydroxyl group, a thiol and derivatives thereof, an isocyanate and a carboxyl group and/or a derivative thereof such as an acid anhydride. Therefore, curing agents for epoxy resins typically include aliphatic, cycloaliphatic, and aromatic polyamines; carboxylic anhydrides, polyamidoamines, amine based resins (such as formaldehyde condensation products of melamine), urea, benzo A guanamine or phenolic resin such as a novolak. Oligomeric or polymeric, acrylate-based curing agents and epoxy vinyl ester resins having hydroxyl functional groups or glycidyl functional groups in the side chain are also used. Those skilled in the art are aware of their use of fast or slow acting curing agents. For example, for a stable storage one-component formulation, it will use a very slow acting curing agent (or a curing agent that only works at relatively high temperatures). Optionally, a curing agent which is released in active form only under the conditions of use will be used, examples being ketimines or aldimines. It is known that a curing agent has a structure which is linear or only slightly crosslinked. Such curing agents are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, Fifth Edition (on CD-ROM), 1997, Wiley-VCH, "Epoxy Resins", which is incorporated herein by reference in its entirety.

Examples of suitable curing agents for use in the curable epoxy resin composition of the present invention include polyphenols, polycarboxylic acids, polythiols, polyamines, primary monoamines, sulfonamides, aminophenols, aminocarboxylic acids A carboxylic acid anhydride, a phenolic hydroxyl group-containing carboxylic acid, an amine benzenesulfonamide, and a mixture thereof. In the context of the present invention, the corresponding polycompound (e.g., polyamine) also includes the corresponding di compound (e.g., diamine).

Preferred curing agents for use in the curable epoxy resin composition of the present invention are amine-based hardeners and phenolic resins.

In a specific embodiment, the curable epoxy resin composition of the present invention comprises an amine-based hardener as a curing agent. Amine-based hardeners suitable for addition polymerization are compounds having at least two secondary or at least one primary amine groups. The linkage of the amine group of the amine-based hardener to the epoxy group of the polyepoxide forms a polymer derived from the amine-based hardener and the polymer Epoxide. The amine based hardener is therefore typically used in a ratio to the stoichiometric amount of epoxide. If, for example, the amine-based hardener has two primary amine groups and can thus be coupled with up to four epoxy groups, a crosslinked structure can be formed.

The amine-based hardener of the curable epoxy resin composition of the present invention has at least one primary amine group or two secondary amine groups. Starting from a polyepoxide having at least two epoxy groups, curing can be achieved by addition polymerization (chain elongation) using an amine compound having at least two amine functional groups. The functionality of the amino compound herein corresponds to the number of NH bonds. Thus the functionality of the primary amine group is 2 and the functionality of the secondary amine group is 1. The linkage of the amine group of the amine-based hardener to the epoxy group of the polyepoxide produces a polymer from the amine-based hardener and the polyepoxide, and the epoxy groups are reacted to form a free OH group. It is preferred to use an amine-based hardener having a functionality of at least 3 (e.g., at least 3 secondary amine groups or at least one primary and one secondary amine group), more specifically two primary amine groups (functionality 4) Amino hardener.

Preferred amine-based hardeners are dimethyl dicyano (DMDC), dicyandiamide (DICY), isophorone diamine (IPDA), di-ethyltriamine (DETA), and tri-ethyl Tetraamine (TETA), bis(p-aminocyclohexyl)methane (PACM), methylene bisaniline (eg 4,4'-methylene bisaniline), polyether amine (eg polyether amine D230), two Aminodiphenylmethane (DDM), diaminodiphenyl hydrazine (DDS), 2,4-toluenediamine, 2,6-toluenediamine, 2,4-diamino-1-methylcyclohexane Alkane, 2,6-diamino-1-methylcyclohexane, 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyl Toluene, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, diaminodiphenyl oxide, 3,3',5,5'-tetramethyl-4 , 4'-diaminobiphenyl and 3,3'-dimethyl-4,4'-diaminodiphenyl, and amine based plastic resins such as aldehydes such as formaldehyde, acetaldehyde, crotonaldehyde, or a condensation product of benzaldehyde with melamine, urea or benzoguanamine, and mixtures thereof. For use in the present invention Particularly preferred amine-based hardeners for curing compositions are dimethyl dicyano (DMDC), dicyandiamide (DICY), isophorone diamine (IPDA), and methylene bisanilide (eg, 4, 4'- Methylene bisaniline) and amine based plastic resins, such as aldehydes, such as formaldehyde, acetaldehyde, crotonaldehyde or benzaldehyde and condensation products of melamine, urea or benzoguanamine.

In the case of the curable epoxy resin composition of the present invention, it is preferred to use a polyepoxide and an amine-based hardener in a ratio of a substantially stoichiometric amount with respect to the epoxide and the amine functional group. A particularly suitable ratio of epoxy groups to amine functional groups is from 1:0.8 to 0.8:1.

In a specific embodiment, the curable epoxy resin composition of the present invention comprises a phenolic resin as a curing agent. The phenolic resin suitable for the addition polymerization reaction has at least two hydroxyl groups. The bonding of the hydroxyl group of the phenolic resin to the epoxy group of the polyepoxide forms a polymer, and the units of the polymer are derived from a phenolic resin and a polyepoxide. The phenolic resin can be generally used in a ratio to the stoichiometric amount of the epoxide and the ratio of the substoichiometric amount. When a substoichiometric amount of the phenolic resin is used, the reaction of the secondary hydroxyl group of the existing epoxy resin with the epoxy group is promoted by using a suitable catalyst.

Examples of suitable phenolic resins are the condensation products of novolaks, phenolic resole phenolic resins, aldehydes (preferably formaldehyde and acetaldehyde) and phenols in general. Preferred phenols are phenol, cresol, xylenol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, cyclopentylphenol, and p-nonyl and p-octylphenol.

The curable epoxy resin composition of the present invention may also contain an accelerator for curing. Suitable curing accelerators are, for example, imidazole or imidazole derivatives or urea derivatives (uron) such as 1,1-dimethyl-3-phenylurea (fenuron). It has also been described that tertiary amines such as triethanolamine, benzyldimethylamine, 2,4,6-glycol (dimethylaminomethyl)phenol and tetramethylhydrazine are used for curing. Accelerator (US 4,948,700). It is known that the curing of an epoxy resin by DICY can be accelerated, for example, by adding a non-grass.

Curable epoxy resins can be formulated as photographic formulations commonly used in stereolithography or photopolymer spray applications. In particular, such photosensitive epoxy resins may also contain certain amounts of acrylate components as described, for example, in U.S. Patent 5,476,748 and are commonly used in 3D printing applications.

The curable epoxy resin composition of the present invention may also comprise a diluent.

For the purposes of the present invention, the diluent is a conventional diluent or a reactive diluent. The addition of a diluent to the curable epoxy resin composition typically reduces the viscosity of the composition.

The conventional diluent is usually an organic solvent or a mixture thereof, and examples are 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; etc.; glycol derivatives such as ethoxylate Ethanol, ethoxyethanol acetate, ethylene glycol 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 , or isopropanol or butanol. During the curing of the epoxy resin, it evaporates from the resin composition. This can result in a reduction (shrinkage) or formation of voids that are undesirable for the volume of the resin, and thus can adversely affect the mechanical properties of the cured material, such as fracture resistance, or even surface characteristics.

The reactive diluent is a low molecular weight substance having a functional group compared to a conventional solvent, usually an oxiranyl group capable of reacting with a hydroxyl group of a resin and/or a functional group of a curing agent. The reaction forms a covalent bond. In the sense of the present invention, the reactive diluent is an aliphatic or cycloaliphatic compound. It does not evaporate during the curing process, but is covalently bonded to the resin matrix during the formation of the resin matrix during the curing process. Examples of suitable reactive diluents are monofunctional Or polyfunctional ethylene oxide. Examples of monofunctional reactive diluents are glycidyl ethers of aliphatic and cycloaliphatic monohydroxy compounds generally having 2 to 20 C atoms, such as ethylhexyl glycidyl ether, and usually having 2 to 20 C atoms. A glycidyl ester of an aliphatic or cycloaliphatic monocarboxylic acid. In particular, examples of polyfunctional reactive diluents are glycidyl ethers of polyfunctional alcohols generally having from 2 to 20 C atoms, and typically containing from 1.5 to 4 glycidyl groups on average, such as 1,4-butane Alcohol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diethylene glycol diglycidyl ether or trimethylolpropane or a glycidyl ether of pentaerythritol. The reactive diluent has so far improved the viscosity characteristics of the epoxy resin composition, but in most cases it weakens the hardness of the cured resin and produces relatively low solvent resistance. Reactive diluents are also known to reduce the reactivity of the epoxy resin composition formulated therewith, resulting in longer curing times.

The curable epoxy resin composition of the present invention may also include a filler such as a pigment. Suitable fillers are metal oxides such as titanium dioxide, zinc oxide and iron oxide or hydroxides, sulfates, carbonates and silicates of such or other metals, examples being calcium carbonate, aluminum oxide and aluminum niobate. Other suitable fillers are, for example, cerium oxide, aerosol or precipitated cerium oxide and carbon black, talc, barite or other non-toxic pigments. Mixtures of such fillers can also be used. The weight fraction of the filler in the coating, as well as its particle size and particle hardness, as well as its aspect ratio, will be selected by those skilled in the art in accordance with the requirements of the application.

The curable epoxy resin composition of the present invention may further comprise an additive according to requirements, examples being an antifoaming agent, a dispersing agent, a wetting agent, an emulsifier, a thickener, a biocide, a cosolvent, a base, a corrosion inhibitor, Flame retardant, mold release agent and / or wax.

The curable epoxy resin composition of the present invention may also comprise reinforcing fibers such as glass fibers or carbon fibers. Such fibers may, for example, be short staple pieces having a length of a few millimeters to a few centimeters. Or in the form of continuous fibers, fiber windings or woven fabrics.

The invention further relates to a method for preparing a cured epoxy resin comprising curing of a curable epoxy resin composition.

Curing can occur at atmospheric pressure and at a temperature of less than 250 ° C, more specifically less than 235 ° C, preferably less than 220 ° C, more specifically in the range of 40 ° C to 220 ° C.

The curing of the curable epoxy resin composition to the shaped article is typically carried out in a mold until dimensional stability has been achieved and the workpiece can be removed from the mold. Subsequent operations for removing the intrinsic stress in the workpiece and/or for completing the crosslinking of the curable epoxy resin are referred to as heat regulation. In principle, it is also possible to carry out a heat conditioning process before the workpiece is removed from the mold, for example for the purpose of completing the crosslinking. The heat adjustment operation is typically carried out at a temperature at the limit of dimensional stiffness (Menges et al., "Werkstoffkunde Kunststoffe" (2002), Hanser-Verlag, 5th edition, page 136). The heat adjustment is typically carried out at a temperature of from 120 ° C to 220 ° C, preferably from 150 ° C to 220 ° C. The cured workpiece is typically exposed to heat conditioning conditions for a period of 30 to 240 minutes. Depending on the size of the workpiece, a longer heat adjustment time may also be suitable.

In curing the curable epoxy resin composition to form a coating, the substrate to be coated is first treated with a curable epoxy resin composition, followed by curing the curable epoxy resin composition on the substrate.

It can be treated before or after shaping the desired article by dipping, spraying, rolling, spreading, knife coating or the like (in the case of a liquid formulation) or by applying a powder coating Curable epoxy resin composition. The coating can be performed on individual sheets (e.g., can portions) or on substantially continuous substrates to strip the steel rolls, for example, in the case of coil coating. suitable The substrate is typically a substrate of steel, tinplate (galvanized steel) or aluminum (for example for beverage cans). The curing of the curable epoxy resin composition after application to the substrate is typically carried out at a temperature ranging from 20 ° C to 250 ° C, preferably from 50 ° C to 220 ° C, more preferably from 100 ° C to 220 ° C. The time is typically from 0.1 to 60 min, preferably from 0.5 to 20 min, more preferably from 1 to 10 min.

A comprehensive description of common types of metal packages and their production, metals and alloys used, and coating techniques are provided in PKT Oldring and U. Nehring: Packaging Materials, 7th Metal Packaging for Foodstuffs, ILSI Report, 2007, by way of citation Incorporated herein.

The invention further relates to a cured epoxy resin obtained by curing the curable epoxy resin composition of the invention, and more particularly to a coating form on a metal substrate.

The invention further relates to the use of a compound of the formula I according to the invention and a curable epoxy resin composition according to the invention for the manufacture of adhesives, composites, shaped bodies and coatings, more particularly coatings, It is better on the container, more specifically on the container for storing food.

The invention further relates to the use of the compounds of the formula I according to the invention as reactive diluents, more particularly as reactive diluents for epoxy resins based on BADGE or BFDGE. The compounds of the formula I according to the invention are suitable for reducing the viscosity of resin components and other epoxy resins in curable compositions, in particular epoxy resins based on BADGE or BFDGE. The addition of the compound of the formula I according to the invention as a reactive diluent has the advantageous effect of making the glass transition temperature relatively slightly lower.

The differential amount can be used according to, for example, the standard DIN EN ISO 6721 by means of Dynamic Mechanical Analysis (DMA) or according to, for example, the standard DIN 53765 A heat meter (DSC) is used to determine the glass transition temperature (Tg). In the case of DMA, the cuboid sample is subjected to a torsional load at a certain applied frequency with a specified deformation. Here, the temperature is ramped up by a defined ramp and the storage modulus and loss modulus are recorded at fixed time intervals. The former indicates the stiffness of the viscoelastic material. The latter is proportional to the energy consumed in the material. The phase shift between dynamic stress and dynamic deformation is characterized by the phase angle δ. The glass transition temperature can be determined by a variety of methods: as the maximum of the tan δ curve, as the maximum of the loss modulus or by means of a tangential method suitable for storing the modulus. When the glass transition temperature was measured using a differential calorimeter, a very small amount of sample (about 10 mg) was heated in aluminum crucible and the heat flux was measured relative to the reference crucible. Repeat this cycle three times. Glass transfer was determined based on the average from the second and third measurements. The Tg phase of the heat flux curve can be determined by a half-width method or by a midpoint temperature method via a turning point.

The term "pot life" refers to a parameter typically utilized to compare the reactivity of different resin/curing agent and/or resin/curing agent mixture combinations. The pot life measurement is a method of characterizing the reactivity of a lamination system by means of temperature measurement. Depending on the application, deviations in the parameters (quantity, test conditions, and measurement methods) have been determined. The pot life is determined as follows: 100 g of the curable composition comprising the epoxy resin and the curing agent or curing agent mixture is placed in a container (typically a paper cup). The temperature sensor was immersed in this curable composition and measured at specific time intervals and the temperature recorded. Once the curable composition is cured, the measurement is ended and the time to reach the maximum temperature is confirmed. If the reactivity of the curable composition is too low, this measurement is carried out at a high temperature. The test temperature must also be specified at all times when the pot life is specified.

The gel time (also referred to as gel time) according to DIN 16 945 indicates a reference point during the period between the addition of the curing agent to the reaction mixture and the conversion of the reactive resin composition from a liquid state to a gel state. At this temperature plays a crucial role, and therefore the needle is found in each case Gel time for the specified temperature. With dynamic mechanical methods, especially rotational viscosity measurements, a smaller number of samples can be examined semi-isothermally and their overall viscosity or stiffness distribution recorded. According to the standard ASTM D 4473, the intersection point between the storage modulus G' and the loss modulus G" (where the value of the damping tan δ is 1) is the gel point, and a curing agent is added to the reaction mixture until the gel point is reached. The time period is the gel time. The gel time thus determined can be considered as a measure of the cure rate.

The invention will now be illustrated by the following non-limiting examples.

Example 1

Preparation of monomeric THF DGE

Tetrahydrofuran ethylene glycol (0.8 mol, 105.8 g) was heated to 90 ° C and blended with BF ₃ etherate (8 mmol, 0.54 g). Epichlorohydrin (1.6 mol, 148 g) was then added dropwise in portions, during which time the temperature should not exceed 140 °C or fall below 85 °C. After the end of the addition, stirring was carried out at 90 ° C until no more measurable epoxide content was present. The reaction mixture was cooled to room temperature, a 25% strength sodium hydroxide solution (1.6 mol, 258 g) was added, and the mixture was heated once to boiling. After cooling, the phases were separated and the organic phase was washed repeatedly with water and dried under reduced pressure. This gave the product in 52% yield. The resulting epoxy resin had an epoxide equivalent weight (EEW) of 198 g/eq (and monomeric diglycidyl ether, the product also included dimers, trimers, and higher molecular weight diglycidyl ethers). . The monomer THF DGE can be purified by distillation to remove the oligomer.

Example 2

Preparation of cured epoxy resin from monomeric THF DGE

THF DGE from Example 1 (EEW 198 g/eq) was mixed with a stoichiometric amount of amine curing agent immediately after preparation and without further purification. The curing agent used is IPDA. For comparison, a stoichiometric amount of a mixture of bisphenol A based epoxy resin (BADGE; Epilox A19-03 from Leuna Harze, EEW 182 g/eq) and IPDA was prepared. The mixture was incubated at 23 ° C or 75 ° C.

Rheology measurements for the study of reactive distribution were performed at various temperatures on a shear rate controlled plate/plate rheometer (MCR 301 from Anton Paar) with a plate diameter of 15 mm and a groove pitch of 0.25 mm.

The gel time was measured on the above rheometer under rotational shaking at 23 ° C and 75 ° C. The gelation time was obtained at the intersection of the loss modulus (G") and the storage modulus (G'). The average initial viscosity (η _o ) during the 2 to 5 minute period after preparation of the mixture was measured at 23 ° C and 75 ° C, The time until the viscosity of 10 000 mPa*s was reached (t ₁₀₀₀₀ ) was also measured.

The glass transition temperature (Tg) was measured according to ASTM D 3418 during the second run by means of Differential Scanning Calorimetry (DSC) analysis of the curing reaction. The temperature distribution for the measurement operation is as follows: 0 ° C → 5 K / min 180 ° C → 30 min 180 ° C → 20 K / min 0 ° C → 20 K / min 220 ° C.

The measurement results are compiled in Table 1 below.

Measurements showed a much lower glass transition temperature by THF DGE based resin, indicating improved flexibility. Further, it was found that, in the case of curing, the initial viscosity was remarkably lowered and the reactivity was also lowered.

Claims (19)

A tetrahydrofuran ethylene glycol diglycidyl ether derivative of formula I Wherein R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 4 C atoms, a halogen atom (F, Cl, Br, I) or a nitro group, and R 3 is a hydrogen atom or a glycidyl group, and n is 0 to 100. A tetrahydrofuranethylene glycol diglycidyl ether derivative according to claim 1, wherein R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 4 C atoms, and R3 is a hydrogen atom or a glycidyl group. And n is 0 to 30. A tetrahydrofuran ethylene glycol diglycidyl ether derivative according to claim 2, wherein each of R1 and R2 is a hydrogen atom. A process for the preparation of a tetrahydrofuran ethylene glycol diglycidyl ether derivative according to any one of claims 1 to 3, which comprises reacting a tetrahydrofuran ethylene glycol derivative of the formula II with epichlorohydrin reaction Wherein R1 and R2 have the same definitions for the tetrahydrofuranethylene glycol diglycidyl ether derivative. A method for preparing an oligomer based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative, wherein tetrahydrofuran ethylene glycol condensed water according to any one of claims 1 to 3, wherein n is 0 a glycerol ether derivative or a mixture of two or more tetrahydrofuran ethylene glycol diglycidyl ether derivatives having a different n, wherein n is mainly 0, as in any one of claims 1 to 3, Or a variety of diol reactions. An oligomer based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative which can be obtained by using any of the tetrahydrofuran ethylene glycol diglycidide according to any one of claims 1 to 3 wherein n is 0. An ether derivative or two or more of tetrahydrofuran ethylene glycol diglycidyl ether derivatives having one or more of two, wherein n is mainly 0, as in any one of claims 1 to 3. The alcohol reaction is obtained. An oligomer based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative according to claim 6 wherein the one or more diols and the tetrahydrofuran ethane corresponding to the tetrahydrofuran ethylene glycol diglycidyl ether derivative The alcohol derivatives are inconsistent. A curable epoxy resin composition comprising a curing component comprising at least one curing agent, and a resin component comprising at least one selected from the group consisting of tetrahydrofuran ethylene glycol diglycidyl ether Polyepoxide of tetrahydrofuran ethylene glycol diglycidyl ether derivative according to any one of claims 1 to 3 An oligomer based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative as claimed in claim 7 of the patent application. The curable epoxy resin composition of claim 8, wherein the resin component comprises at least one polyepoxide based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative selected from the group consisting of: The tetrahydrofuran ethylene glycol diglycidyl ether derivative according to any one of the first to third aspects of the patent. The curable epoxy resin composition according to claim 8 or 9, wherein the at least one curing agent is selected from the group consisting of an amine curing agent and a phenol resin. The curable epoxy resin composition according to any one of claims 8 to 10, wherein the polyepoxy resin based on the tetrahydrofuran ethylene glycol diglycidyl ether derivative is based on the total resin component The total amount of the compound accounts for at least 40% by weight. The curable epoxy resin composition according to any one of claims 8 to 11, wherein the curable epoxy resin composition comprises a fraction of less than 40% by weight based on the total resin component A compound based on bisphenol A or F. The curable epoxy resin composition according to any one of claims 9 to 10, wherein the resin component comprises at least one epoxy resin selected from the group consisting of bisphenol A diglycidyl Diether, diglycidyl ether of bisphenol F, diglycidyl ether of cyclic hydrogenated bisphenol A, diglycidyl ether of cyclohydrogenated bisphenol F, tetraglycidyl methylene bisaniline, cresol epoxy resin, phenolic aldehyde Varnish epoxy resin and triglycidylaminophenol and oligomers thereof. The curable epoxy resin composition of claim 13, wherein the polyepoxides based on the tetrahydrofuranethylene glycol diglycidyl ether derivative account for a total of 30% by weight. A method for producing a cured epoxy resin, the method comprising curing the curable epoxy resin composition according to any one of claims 8 to 14. A cured epoxy resin obtainable by curing the curable epoxy resin composition according to any one of claims 8 to 14. A resin component comprising at least one polyepoxide based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative selected from the group consisting of: tetrahydrofuran according to any one of claims 1 to 3. An ethylene glycol diglycidyl ether derivative, and at least one epoxy resin selected from the group consisting of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and cyclic hydrogenated bisphenol A Glycerol ether, diglycidyl ether of cyclohydrogenated bisphenol F, tetraglycidyl methylene bisaniline, cresol epoxy resin, novolak epoxy resin, and triglycidylamino phenol and oligomers thereof. A use of a curable epoxy resin composition according to any one of claims 8 to 12 for the manufacture of an adhesive, composite, molding or coating. Use of a polyepoxide based on a tetrahydrofuran ethylene glycol diglycidyl ether derivative as a reactive diluent, which is selected from the group consisting of tetrahydrofuran ethylene glycol dihydrates according to any one of claims 1 to 3. A group consisting of glycerol ether derivatives.