KR20210002155A - Hydroxy-terminated prepolymer and latent hardener comprising the same, and epoxy resin composition comprising the hardener - Google Patents

Abstract

The present invention relates to a hydroxy-terminated prepolymer, a latent hardener comprising the same, and an epoxy resin composition comprising the hardener. More particularly, the present invention relates to: a hydroxy-terminated prepolymer prepared by making anhydrosugar alcohols react with polyisocyanates in a molar ratio within a specific range; a latent hardener that includes the same, and does not decrease the hardening rate and does not increase the hardening temperature when used for an epoxy resin; and an epoxy resin composition containing the hardener.

Description

Hydroxy-terminated prepolymer and latent hardener comprising the same, and epoxy resin composition comprising the hardener

The present invention relates to a hydroxy-terminated prepolymer and a latent curing agent comprising the same, and an epoxy resin composition comprising the curing agent, and more particularly, prepared by reacting an anhydrosugar alcohol and a polyisocyanate in a molar ratio within a specific range. The present invention relates to a hydroxy-terminated prepolymer, a latent curing agent that includes the same and does not decrease the curing rate and does not increase the curing temperature when used for an epoxy resin, and an epoxy resin composition comprising the curing agent.

Epoxy resin has excellent heat resistance, mechanical properties, electrical properties and adhesion. Epoxy resins are used for sealing materials such as wiring boards, circuit boards, circuit boards in which these are multilayered, semiconductor chips, coils, and electric circuits, taking advantage of this property. Alternatively, the epoxy resin is also used as an adhesive, paint, or resin for fiber-reinforced resin.

Epoxy resins can find a wide range of uses as thermosetting resins in many applications. These are used as a thermosetting matrix in a prepreg made of fibers contained in a thermosetting matrix. In addition, due to their toughness, flexibility, adhesion and chemical resistance, they can be used as materials for surface coating, bonding, molding and laminating, all of which are aerospace, automotive, electronics, construction, furniture, green energy and sporting goods. Various applications can be found in a wide variety of industries such as industry.

A wide range of epoxy resins can be readily used and can be used depending on their reactivity required for a particular application. For example, resins may be solid, liquid or semi-solid, and may have various reactivity depending on the application to which they are applied. The reactivity of an epoxy resin is often measured in terms of the epoxy equivalent weight, which is the molecular weight of the resin containing a single reactive epoxy group. The lower the epoxy equivalent, the higher the reactivity of the epoxy resin. Different reactivity is required for different epoxy resin applications, but depends on whether or not it is present as a matrix of fiber reinforced prepregs, adhesive coatings, structural adhesives.

Epoxy resin is a chemical unit of molecules that make up it and always has an epoxy bond. It is representatively made by polymerizing epichlorohydrin and bisphenol A. Epoxy resin is not used alone, and since it is used by adding a curing agent to change it into a thermoset material, it would be appropriate to think of it as an intermediate of ordinary resin. That is, a cured product cannot be obtained with only an epoxy resin, and a thermosetting structure can be obtained only when crosslinking points that cannot be moved by bonding with an epoxy reactor are formed. The substances that make these crosslinking points are called hardeners.

As a curing agent for an epoxy resin, a coating type or capsule type latent curing agent (hardener) has been widely used in the past (for example, a latent hardener coated with a film of Korean Patent Publication No. 10-2007-0104621, Korean Patent Publication No. 10- The latent hardener encapsulated in the core-shell structure of 2012-0046158, etc.). However, such a coated or encapsulated latent curing agent slows the curing rate and increases the curing temperature because the protective coating or shell must be broken or permeable in order for the core material (curing component) to be released into the adhesive environment or matrix. There is a problem.

The present invention provides a hydroxy-terminated prepolymer that does not decrease the curing rate and does not increase the curing temperature when used as a component for curing an epoxy resin, and a latent curing agent including the same, and an epoxy resin composition comprising the curing agent. The purpose.

In order to solve the above technical problem, the present invention is prepared by reacting anhydrosugar alcohol and polyisocyanate, wherein the reaction molar ratio of the anhydrosugar alcohol and polyisocyanate is 1.15 to 2.45 moles of anhydrosugar alcohol per mole of polyisocyanate, hydroxy -Provides terminal prepolymer.

According to another aspect of the present invention, there is provided a latent curing agent comprising the hydroxy-terminated prepolymer of the present invention.

According to another aspect of the present invention, an epoxy resin; And the latent curing agent of the present invention; there is provided an epoxy resin composition containing.

According to another aspect of the present invention, a cured product obtained by curing the epoxy resin composition of the present invention is provided.

According to another aspect of the present invention, there is provided a molded article comprising the cured product of the present invention.

The hydroxy-terminated prepolymer according to the present invention may cause a reversible reaction at a low temperature, and when it is used as a latent curing agent for an epoxy resin, the curing rate does not decrease, the curing temperature does not increase, and the epoxy resin composition has excellent strength. And a cured product thereof can be provided.

Hereinafter, the present invention will be described in detail.

The hydroxy-terminated prepolymer of the present invention is prepared by reacting anhydrosugar alcohol and polyisocyanate.

Anhydrosugar alcohol is prepared from hydrogenated sugars derived from natural products, and hydrogenated sugars (also referred to as “sugar alcohols”) refer to compounds obtained by adding hydrogen to the reducing end groups of sugars, and generally HOCH ₂ (CHOH) _n It has the formula of CH ₂ OH (where n is an integer of 2 to 5), and is classified into tetritol, pentitol, hexitol and heptitol (4, 5, 6 and 7 carbon atoms, respectively) according to the number of carbon atoms. Among them, hexitol having 6 carbon atoms includes sorbitol, mannitol, iditol, galactitol, and the like, and sorbitol and mannitol are particularly effective substances.

In the present invention, as the anhydrosugar alcohol, dianhydrohexitol, which is a dehydration product of hexitol, may be used, more preferably isosorbide (1,4-3,6-dianhydrosorbitol), isomannide (1,4-3,6-dianhydromannitol), isoidide (1,4-3,6-dianhydroiditol) or a mixture thereof may be used, most preferably isosorbide do.

In the present invention, as the polyisocyanate, for example, an aliphatic polyisocyanate, a cycloaliphatic polyisocyanate, an araliphatic polyisocyanate, an aromatic polyisocyanate, a heterocyclic polyisocyanate, or a polyisocyanate selected from a combination thereof may be used, In addition, both unmodified polyisocyanate or modified polyisocyanate may be used.

The polyisocyanate preferably contains an average of 2 to 5, preferably an average of 4 or less NCO groups. Examples of suitable polyisocyanates are 2,4'- or 4,4'-diphenylmethylene diisocyanate (MDI), xylylene diisocyanate (XDI), m- or p-tetramethylxylylene diisocyanate (TMXDI), Toluene diisocyanate (TDI), di- or tetra-alkyldiphenylmethane diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate (TODI), 1,3-phenylene diisocyanate, 1, Aromatic polyisocyanates such as 4-phenylene diisocyanate, naphthalene diisocyanate (NDI), or 4,4'-dibenzyl diisocyanate; Hydrogenated MDI (H12MDI), 1-methyl-2,4-diisocyanatocyclohexane, 1,12-diisocyanatododecane, 1,6-diisocyanato-2,2,4-trimethylhexane,1,6 -Diisocyanato-2,4,4-trimethylhexane, isophorone diisocyanate (IPDI), tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate, hexane-1, Aliphatic isocyanates such as 6-diisocyanate (HDI), ethylene diisocyanate or dimer fatty acid diisocyanate; Cycloaliphatic polyisocyanates such as dicyclohexylmethane diisocyanate or cyclohexane-1,4-diisocyanate; Or a combination of these.

The hydroxy-terminated prepolymer of the present invention is prepared by reacting 1.15 to 2.45 mol of the anhydrosugar alcohol per 1 mol of the polyisocyanate. If a prepolymer prepared by reacting less than 1.15 moles of anhydrosugar alcohol per mole of polyisocyanate is used as a curing agent for an epoxy resin, initial curing does not proceed smoothly, the curing time is greatly increased, and the curing speed is significantly reduced, and the strength of the cured product. There is a problem that becomes poor. On the contrary, if a prepolymer prepared by reacting more than 2.45 moles of anhydrosugar alcohol per mole of polyisocyanate is used as a curing agent for an epoxy resin, there is a problem that the curing time increases and the curing rate decreases, and the secondary calorific value due to the reversible reaction It may not occur, or the strength of the cured product may be poor.

More specifically, in the preparation of the hydroxy-terminated prepolymer of the present invention, the reaction molar ratio of anhydrosugar alcohol per mole of polyisocyanate is 1.2 moles or more, 1.25 moles or more, 1.3 moles or more, 1.35 moles or more, 1.4 moles or more, 1.45 moles or more, or It may be 1.5 mol or more, and may be 2.4 mol or less, 2.3 mol or less, 2.2 mol or less, 2.1 mol or less, or 2 mol or less. According to an embodiment of the present invention, the reaction molar ratio of anhydrosugar alcohol per mole of polyisocyanate may be 1.25 moles to 2 moles, more specifically 1.5 moles to 2 moles, but is not limited thereto.

There is no particular limitation on the method of preparing the hydroxy-terminated prepolymer of the present invention by reacting the polyisocyanate with an anhydrosugar alcohol, and the usual reaction conditions of the polyol and the polyisocyanate, for example, 50 to 100°C, more specifically 70 After adding anhydrosugar alcohol and polyisocyanate sufficiently vacuum-dried for 12 to 36 hours, preferably 20 to 28 hours at 90°C in a reactor, and then at a temperature of 50 to 100°C and preferably 50 to 70°C under a nitrogen atmosphere While maintaining the reaction for 0.1 to 5 hours, preferably 0.5 to 2 hours, it is possible to prepare a hydroxy-terminated prepolymer.

The number average molecular weight (Mn) of the hydroxy-terminated prepolymer of the present invention may be appropriately adjusted, for example, its lower limit may be 250 or more, 500 or more, 600 or more, 700 or more, or 1,000 or more, and its upper limit is 6,000 Hereinafter, it may be 5,500 or less, 5,000 or less, 4,000 or less, or 3,000 or less, and preferably 600 to 5,500, but is not limited thereto.

According to another aspect of the present invention, there is provided a latent curing agent comprising the hydroxy-terminated prepolymer of the present invention, preferably a latent curing agent for an epoxy resin.

In one embodiment, the latent curing agent of the present invention may consist only of the hydroxy-terminated prepolymer of the present invention.

In another embodiment, the latent curing agent of the present invention may further include an additional curing agent component in addition to the hydroxy-terminated prepolymer of the present invention within a range that can achieve the object of the present invention, and such an additional curing agent As the component, a curing agent component commonly used for an epoxy resin may be used.

Although not limited thereto, in one embodiment, anhydrosugar alcohol, anhydrosugar alcohol-alkylene glycol, or a mixture thereof may be used as the additional curing agent component. As the anhydrosugar alcohol, dianhydrohexitol, which is a dehydration product of hexitol, may be used, more preferably isosorbide may be used. In addition, the anhydrosugar alcohol-alkylene glycol may be an adduct obtained by reacting an alkylene oxide with hydroxy groups at both ends or one terminal (preferably both ends) of an anhydrosugar alcohol, and the alkylene oxide has carbon number It may be a linear 2 to 8 or a branched alkylene oxide having 3 to 8 carbon atoms, more specifically, may be ethylene oxide, propylene oxide, or a combination thereof.

According to another aspect of the present invention, an epoxy resin; And the latent curing agent of the present invention; is provided an epoxy resin composition containing.

A wide range of epoxy resins can be used in the epoxy resin composition of the present invention. Epoxy resins may be solid, liquid or semi-solid, and may have various reactivity depending on the application to which they are applied. The reactivity of an epoxy resin is often measured in terms of the epoxy equivalent weight, which is the molecular weight of the resin containing a single reactive epoxy group. The lower the epoxy equivalent, the higher the reactivity of the epoxy resin.

In one embodiment, the epoxy resin is a bisphenol A-epichlorohydrin resin, a diglycidyl ether resin of bisphenol A, an epoxy novolak resin, an alicyclic epoxy resin, an aliphatic epoxy resin, a bicyclic epoxy resin, and glycy. Dill ester type epoxy resins, brominated epoxy resins, bio-derived epoxy resins, epoxidized soybean oil, or those selected from the group consisting of a combination thereof, but are not limited thereto.

In another embodiment, the epoxy resin is a novolak type epoxy resin such as a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol type epoxy resin such as a bisphenol F type epoxy resin, N ,N-diglycidyl aniline, N,N-diglycidyl toluidine, diaminodiphenylmethane type glycidylamine, aminophenol type glycidylamine, and other aromatic glycidylamine type epoxy resins, hydroqui Non-type epoxy resin, biphenyl-type epoxy resin, stilbene-type epoxy resin, triphenolmethane-type epoxy resin, triphenolpropane-type epoxy resin, alkyl-modified triphenolmethane-type epoxy resin, triazine core-containing epoxy resin, dicyclopentadiene-modified Phenol type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, phenol aralkyl type epoxy resin having phenylene and/or biphenylene skeleton, naphthol aralkyl type epoxy resin having phenylene and/or biphenylene skeleton, etc. Aliphatic epoxy resins such as alicyclic epoxy such as aralkyl type epoxy resin, vinylcyclohexene dioxide, dicyclopentadiene oxide, alicyclic diepoxy-adipide, or combinations thereof. Not limited.

In another embodiment, the epoxy resin includes bisphenol F type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, hydroquinone type epoxy resin, naphthalene skeleton Type epoxy resin, tetraphenylolethane type epoxy resin, diphenyl phosphate (DPP) type epoxy resin, trishydroxyphenylmethane type epoxy resin, dicyclopentadienephenol type epoxy resin, bisphenol A ethylene oxide adduct diglycidyl Glycidyl ether having one epoxy group such as ether, diglycidyl ether of bisphenol A propylene oxide adduct, diglycidyl ether of bisphenol A, phenyl glycidyl ether, cresyl glycidyl ether, and these epoxies Nuclear hydrogenated epoxy resin, which is a nucleus hydrogenated product of the resin, may be selected from the group consisting of a combination thereof, but is not limited thereto.

In the epoxy resin composition of the present invention, the content ratio of the epoxy resin and the latent curing agent of the present invention is the equivalent ratio of the curing agent to the epoxy resin (equivalent of the curing agent/equivalent of the epoxy resin), for example, in the range of 0.25 to 1.75. The equivalent ratio may be in the range of 0.75 to 1.25, and more specifically, the equivalent ratio may be in the range of 0.95 to 1.05. If the equivalent of the curing agent to the equivalent of the epoxy resin is too small, there may be a problem that the mechanical strength decreases and the physical properties decrease in terms of thermal and adhesive strength.On the contrary, even when the equivalent of the curing agent to the equivalent of the epoxy resin is too large There may be a problem that physical properties are deteriorated in terms of strength, thermal and adhesive strength.

Room temperature curing of an epoxy resin usually requires a temperature of 15°C or more, and a curing time of 24 hours or more, so there are times when fast curing and low temperature curing are required.

Therefore, for the curing accelerating effect, the epoxy resin composition of the present invention may further include a curing catalyst.

Examples of the curing catalyst usable in the present invention include amine compounds (eg, tertiary amines) such as benzyldimethylamine, tris(dimethylaminomethyl)phenol, and dimethylcyclohexylamine; Imidazole compounds such as 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazole, and 1-benzyl-2-methylimidazole; Organophosphorus compounds such as triphenylphosphine and triphenyl phosphite; Quaternary phosphonium salts such as tetraphenylphosphonium bromide and tetra-n-butylphosphonium bromide; Diazabicycloalkenes such as 1,8-diazabicyclo[5.4.0]undecene-7 and organic acid salts thereof; Organometallic compounds such as zinc octylate, tin octylate, and aluminum acetylacetone complex; Quaternary ammonium salts such as tetraethylammonium bromide and tetrabutylammonium bromide; Boron compounds such as boron trifluoride and triphenylborate; Metal halides such as zinc chloride and tin chloride; Latent curing catalyst (e.g., a high melting point dispersion type latent amine adduct in which dicyandiamide, amine is added to an epoxy resin, etc.; a microcapsule type latent catalyst in which the surface of an imidazole-based, phosphorus-based, or phosphine-based accelerator is coated with a polymer. ; Amine salt-type latent catalyst; High-temperature dissociation-type thermocationic polymerization-type latent catalysts such as Lewis acid salts and Bronsted acid salts), or combinations thereof, but are not limited thereto.

In one embodiment, the curing catalyst may be selected from the group consisting of an amine compound, an imidazole compound, an organophosphorus compound, or a combination thereof.

When a curing catalyst is included in the epoxy resin composition of the present invention, the amount used may be 0.01 parts by weight to 1.0 parts by weight based on the total 100 parts by weight of the epoxy resin and the curing agent, and more specifically 0.05 parts by weight to 0.5 parts by weight. It may be, and more specifically, it may be 0.08 parts by weight to 0.2 parts by weight, but is not limited thereto. If the amount of the curing catalyst used is too small, the curing reaction of the epoxy resin may not proceed sufficiently, resulting in a problem of deteriorating mechanical and thermal properties.Conversely, if the amount of the curing catalyst is too large, the curing reaction even while the epoxy resin composition is stored. Since this progresses slowly, there may be a problem that the viscosity increases.

The epoxy resin composition of the present invention may further include one or more additive components commonly used in the epoxy resin composition, if necessary.

Such additive components include, for example, antioxidants, UV absorbers, fillers, resin modifiers, silane coupling agents, diluents, colorants, defoamers, defoamers, dispersants, viscosity modifiers, gloss modifiers, wetting agents, conductivity imparting agents, or a combination thereof. What is selected from the group consisting of can be used.

The antioxidant may be used to further improve the heat resistance stability of the resulting cured product, and is not particularly limited, for example, a phenolic antioxidant (dibutylhydroxytoluene, etc.), a sulfur-based antioxidant (mercaptopropionic acid derivative, etc.) , Phosphorus antioxidants (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, etc.) or combinations thereof may be used. The content of the antioxidant in the composition may be 0.01 to 10 parts by weight, or 0.05 to 5 parts by weight, or 0.1 to 3 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent.

Although it does not specifically limit as said UV absorber, For example, BASF Japan Ltd. benzotriazole type UV absorber typified by TINUBIN P and TINUVIN 234; Triazine UV absorbers such as TINUVIN 1577ED; A hindered amine UV absorber such as CHIMASSOLV 2020FDL, or a combination thereof, may be used. The content of the UV absorber in the composition may be 0.01 to 10 parts by weight, or 0.05 to 5 parts by weight, or 0.1 to 3 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent.

The filler is used for the main purpose of improving the mechanical properties of the cured product by mixing it with an epoxy resin or a curing agent, and in general, as the amount of addition increases, the mechanical properties are improved. As inorganic fillers, extenders such as talc, sand, silica, talc, calcium carbonate, and the like; Reinforcing fillers such as mica, quartz, and glass fiber; Some have special uses such as quartz powder, graphite, alumina, and Aerosil (the purpose of imparting thixotropic properties), and the metals contribute to the thermal expansion coefficient of aluminum, aluminum oxide, iron, iron oxide, copper, etc., wear resistance, thermal conductivity, and adhesion. There are fillers for weight reduction such as fine plastic balls (phenolic resins, urea resins, etc.) as organic materials, barium titanate, etc. that impart flame retardancy such as antimony oxide (SB ₂ O ₃ ). In addition, as a filler having reinforcing properties, various glass fibers or chemical fiber cloths can be handled as fillers in a broad sense in the manufacture of laminated products. Thixotropic (thixotropic: thixotropic means that the resin adhered or impregnated in the laminate by means of a vertical surface or immersion method is liquid when it is flowing so that it does not flow down or is lost during curing, and solid when it is stationary. It means to have), using fine particles with a large unit surface area. For example, colloidal silica (Aerosil) or bentonite-based clay is used. In one embodiment, the filler is not particularly limited, but for example, glass fiber, carbon fiber, titanium oxide, alumina, talc, mica, aluminum hydroxide, or a combination thereof may be used. The content of the filler in the composition may be 0.01 to 80 parts by weight, or 0.01 to 50 parts by weight, or 0.1 to 20 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent.

Although it does not specifically limit as said resin modifier, For example, flexibility imparting agents, such as polypropylene glycidyl ether, polymeric fatty acid polyglycidyl ether, polypropylene glycol, and urethane prepolymer, etc. are mentioned. The content of the resin modifier in the composition may be 0.01 to 80 parts by weight, or 0.01 to 50 parts by weight, or 0.1 to 20 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent.

Although it does not specifically limit as said silane coupling agent, For example, chloropropyl trimethoxysilane, vinyl trichlorosilane, γ methacryloxypropyl trimethoxy silane, γ aminopropyl triethoxy silane, etc. are mentioned. . The content of the silane coupling agent in the composition may be 0.01 to 20 parts by weight, or 0.05 to 10 parts by weight, or 0.1 to 5 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent.

The diluent is used for the main purpose of lowering the viscosity by adding it to an epoxy resin or a curing agent, and when using it, it serves to improve flowability, defoamability, improve penetration into parts, etc., or to effectively add a filler. . Diluents generally do not volatilize unlike solvents, and remain in the cured product upon curing the resin, and are classified into reactive and non-reactive diluents. Here, the reactive diluent has one or more epoxy groups and participates in the reaction to enter the cured product into a crosslinked structure, and the non-reactive diluent is only physically mixed and dispersed in the cured product. Commonly used reactive diluents include Butyl Glycidyl Ether (BGE), Phenyl Glycidyl Ether (PGE), and Aliphatic Glycidyl Ether (C12 -C14). , Modified-tert-Carboxylic Glycidyl Ester, and the like. Dibutylphthalate (DBP), DiOctylPhthalate (DOP), Nonyl-Phenol, Hysol, and the like are generally used as non-reactive diluents. In one embodiment, the diluent is not particularly limited, but, for example, n-butyl glycidyl ether, phenyl glycidyl ether, glycidyl methacrylate, vinylcyclohexene dioxide, diglycidyl aniline, What is selected from the group consisting of glycerin triglycidyl ether or a combination thereof may be used. The content of the diluent in the composition may be 0.01 to 80 parts by weight, or 0.01 to 50 parts by weight, or 0.1 to 20 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent.

Pigments or dyes are used as colorants to add color to the resin. As commonly used pigments, coloring agents such as titanium dioxide, cadmium red, shining green, carbon black, chromium green, chromium yellow, navy blue, and shining blue are used.

In addition, an antifoaming agent and a defoamer used for the purpose of removing air bubbles from the resin, a dispersing agent to increase the dispersion effect between the resin and the pigment, a wetting agent to improve the adhesion between the epoxy resin and the material, and a viscosity modifier. , A gloss control agent for controlling the gloss of a resin, an additive for improving adhesion, an additive for imparting electrical properties, and so on. Various additives can be used.

The curing method of the epoxy resin composition of the present invention is not particularly limited, and for example, a conventionally known curing apparatus such as a closed curing furnace or a tunnel furnace capable of continuous curing can be used. The heating method used for the curing is not particularly limited, but may be performed by a conventionally known method such as hot air circulation, infrared heating, and high frequency heating.

Curing temperature and curing time may be in the range of 30 seconds to 10 hours at 80 ℃ ~ 250 ℃. In one embodiment, after the foreground is 80 °C to 120 °C, 0.5 to 5 hours conditions, 120 °C to 180 °C, it may be post-cured under the conditions of 0.1 to 5 hours. In one embodiment, it may be cured under the conditions of 150 ℃ ~ 250 ℃, 30 seconds ~ 30 minutes for a short time curing.

In one embodiment, the epoxy resin composition of the present invention is divided into two or more components, for example, a component including a curing agent and a component including an epoxy resin, and preserved, and they may be combined before curing. In another embodiment, the epoxy resin composition of the present invention may be preserved as a thermosetting composition in which each component is blended, and may be provided for curing as it is. In the case of storing as a thermosetting composition, it can be stored at a low temperature (usually -40°C to 15°C).

Accordingly, according to another aspect of the present invention, a cured product obtained by curing the epoxy resin composition of the present invention is provided.

In addition, according to another aspect of the present invention, there is provided a molded article comprising the cured product of the present invention.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. However, the scope of the present invention is not limited to these.

[Example]

<Preparation of hydroxy-terminated prepolymer>

Example A1

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 29.2 g (0.2 mol, 54 parts by weight) and 4,4'-diphenylmethylene diisocyanate (MDI) sufficiently vacuum-dried at 80° C. for 24 hours , Weight average molecular weight: 250.25 g/mol) 25.0 g (0.1 mol, 46 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere, thereby hydroxy-terminated prepolymer Was prepared (ISB:MDI reaction molar ratio = 2:1).

Example A2

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 43.8 g (0.3 mol, 56 parts by weight) and toluene diisocyanate (TDI, weight average molecular weight: 174.2 g) sufficiently vacuum-dried at 80°C for 24 hours /mol) 34.8 g (0.2 mol, 44 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere to prepare a hydroxy-terminated prepolymer (ISB:TDI Reaction molar ratio = 1.5:1).

Example A3

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 58.4 g (0.4 mol, 44 parts by weight) and 4,4'-diphenylmethylene diisocyanate (MDI) sufficiently vacuum-dried at 80°C for 24 hours , Weight average molecular weight: 250.25 g/mol) 75.0 g (0.3 mol, 56 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere, thereby hydroxy-terminated prepolymer Was prepared (ISB:MDI reaction molar ratio = 1.33:1).

Example A4

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 73.1 g (0.5 mol, 51 parts by weight) and toluene diisocyanate (TDI, weight average molecular weight: 174.2 g) sufficiently vacuum-dried at 80°C for 24 hours /mol) 69.7 g (0.4 mol, 49 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere to prepare a hydroxy-terminated prepolymer (ISB:TDI Reaction molar ratio = 1.25:1).

Comparative example A1

Isosorbide (ISB, Samyang, weight average molecular weight: 146.14 g/mol) 14.6 g (0.1 mol, 85 parts by weight) and 4,4'-diphenylmethylene diisocyanate (MDI) sufficiently vacuum-dried at 80° C. for 24 hours , Weight average molecular weight: 250.25 g/mol) 2.5 g (0.01 mol, 15 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere, thereby hydroxy-terminated prepolymer Was prepared (ISB:MDI reaction molar ratio = 10:1).

Comparative example A2

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 58.5 g (0.4 mol, 70 parts by weight) and 4,4'-diphenylmethylene diisocyanate (MDI) sufficiently vacuum-dried at 80° C. for 24 hours , Weight average molecular weight: 250.25 g/mol) 25.0 g (0.1 mol, 30 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere, thereby hydroxy-terminated prepolymer Was prepared (ISB:MDI reaction molar ratio = 4:1).

Comparative example A3

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 36.535 g (0.25 mol, 59 parts by weight) and 4,4'-diphenylmethylene diisocyanate (MDI) sufficiently vacuum-dried at 80° C. for 24 hours , Weight average molecular weight: 250.25 g/mol) 25.0 g (0.1 mol, 41 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere, thereby hydroxy-terminated prepolymer Was prepared (ISB:MDI reaction molar ratio = 2.5:1).

Comparative example A4

Isosorbide (ISB, Samyang Corporation, weight average molecular weight: 146.14 g/mol) 16.08 g (0.11 mol, 39 parts by weight) and 4,4'-diphenylmethylene diisocyanate (MDI) sufficiently vacuum-dried at 80°C for 24 hours , Weight average molecular weight: 250.25 g/mol) 25.0 g (0.1 mol, 61 parts by weight) was added to a four-neck reactor, and then reacted for 1 hour while maintaining a temperature of 60° C. in a nitrogen atmosphere, thereby hydroxy-terminated prepolymer Was prepared (ISB:MDI reaction molar ratio = 1.1:1).

<Epoxy resin composition and its Hardened Manufacturing>

Example B1

Diglycidyl ether of bisphenol A (DGEBA)-based bifunctional epoxy resin (YD-128, Kukdo Chemical Co., Ltd., Epoxy equivalent weight (EEW: Epoxy equivalent weight): 187 g/eq, 1 equivalent) And the hydroxy-terminated prepolymer (hydroxy equivalent (HEW: Hydroxyl equivalent weight): 136 g/eq, 1 equivalent) prepared in Example A1 as a latent curing agent were mixed, and based on 100 parts by weight of the mixture, a curing catalyst As N,N-dimethylbutylamine (N,N-dimethylbutylamine (DMBA), Sigma Aldrich) 0.1 parts by weight was added to prepare an epoxy resin composition.

Differential scanning calorimeter analysis of the epoxy resin composition was performed using Q20, a differential scanning calorimeter (DSC) of TA instruments. Specifically, the prepared epoxy resin composition was sealed in an aluminum pan, and the temperature was raised from room temperature to 200°C at a temperature increase rate of 10°C/min under a nitrogen atmosphere of high purity. After that, differential scanning calorimetry was performed until the exothermic peak disappeared. At this time, whether or not the epoxy resin composition was cured was confirmed by the measured calorific value (Enthalpy). The measured calorific value is shown in Table 1 below.

Example B2

Instead of YD-128 as an epoxy resin, a cycloaliphatic bifunctional epoxy resin (Celloxide 2021p, Daicel, EEW: 136.5 g/eq, 1 equivalent) was used, and as a latent curing agent, instead of the hydroxy-terminated prepolymer prepared in Example A1. The hydroxy-terminated prepolymer (HEW: 131.4 g/eq, 1.05 equivalent) prepared in Example A2 was used, and 2-ethyl-4-methylimidazole (2) was used instead of N,N-dimethylbutylamine as a curing catalyst. -Epoxy resin composition was prepared in the same manner as in Example B1, except that 0.1 part by weight of ethyl-4-methylimidazole (2E4M), Sigma aldrich) was used, and then the prepared epoxy resin composition was the same as in Example B1. Differential scanning calorimetry was performed by the method, and the results are shown in Table 1 below.

Example B3

O-cresol novolac epoxy resin (YDCN-500-90P, Kukdo Chemical Co., Ltd., EEW: 206.3 g/eq, 1 equivalent) was used instead of YD-128 as an epoxy resin, and the hydrogen prepared in Example A1 as a latent curing agent Instead of the oxy-terminated prepolymer, the hydroxy-terminated prepolymer (HEW: 167 g/eq, 0.95 equivalent) prepared in Example A3 was used, and as a curing catalyst, triphenylphosphine was used instead of N,N-dimethylbutylamine. (TPP), Sigma aldrich) After preparing an epoxy resin composition in the same manner as in Example B1, except for using 0.1 parts by weight, differential scanning calorie analysis in the same manner as in Example B1 for the prepared epoxy resin composition And the results are shown in Table 1 below.

Example B4

Except for using the hydroxy-terminated prepolymer (HEW: 143 g/eq, 1 equivalent) prepared in Example A4 instead of the hydroxy-terminated prepolymer prepared in Example A1 as a latent curing agent, Example B1 and After preparing the epoxy resin composition by the same method, differential scanning calorimetry was performed on the prepared epoxy resin composition in the same manner as in Example B1, and the results are shown in Table 1 below.

Comparative example B1

An epoxy resin composition was prepared in the same manner as in Example B1, except that isosorbide (Samyang, HEW: 73 g/eq, 1 equivalent) was used instead of the hydroxy-terminated prepolymer prepared in Example A1 as a curing agent. Then, differential scanning calorimetry was performed on the prepared epoxy resin composition in the same manner as in Example B1, and the results are shown in Table 1 below.

Comparative example B2

The same method as in Example B1, except that the hydroxy-terminated prepolymer prepared in Comparative Example A1 (HEW: 95 g/eq, 1 equivalent) was used instead of the hydroxy-terminated prepolymer prepared in Example A1 as a curing agent. After preparing the epoxy resin composition, differential scanning calorimetry was performed in the same manner as in Example B1 on the prepared epoxy resin composition, and the results are shown in Table 1 below.

Comparative example B3

The same method as in Example B1, except that the hydroxy-terminated prepolymer prepared in Comparative Example A2 (HEW: 139 g/eq, 1 equivalent) was used instead of the hydroxy-terminated prepolymer prepared in Example A1 as a curing agent. After preparing the epoxy resin composition, differential scanning calorimetry was performed in the same manner as in Example B1 on the prepared epoxy resin composition, and the results are shown in Table 1 below.

Comparative example B4

The same method as in Example B1, except that the hydroxy-terminated prepolymer prepared in Comparative Example A3 (HEW: 205 g/eq, 1 equivalent) was used instead of the hydroxy-terminated prepolymer prepared in Example A1 as a curing agent. After preparing the epoxy resin composition, differential scanning calorimetry was performed in the same manner as in Example B1 on the prepared epoxy resin composition, and the results are shown in Table 1 below.

Comparative example B5

The same method as in Example B1, except that the hydroxy-terminated prepolymer prepared in Comparative Example A4 (HEW: 137 g/eq, 1 equivalent) was used instead of the hydroxy-terminated prepolymer prepared in Example A1 as a curing agent. After preparing the epoxy resin composition, differential scanning calorimetry was performed in the same manner as in Example B1 on the prepared epoxy resin composition, and the results are shown in Table 1 below.

Comparative example B6

As a curing agent, instead of the hydroxy-terminated prepolymer prepared in Example A1, a latent curing agent for an epoxy resin having a core-shell structure (LC-30, SHIN-A T&C, amine value: 121 mg KOH/g, 1 equivalent) was used. Except for those used, after preparing an epoxy resin composition in the same manner as in Example B1, differential scanning calorimetry was performed on the prepared epoxy resin composition in the same manner as in Example B1, and the results are shown in Table 1 below. Done.

<Method of measuring physical properties>

(1) calorific value

Differential scanning calorimetry analysis of the epoxy resin compositions prepared in Examples B1 to B4 and Comparative Examples B1 to B6 was performed using a differential scanning calorimeter (Q20, TA instruments). The first calorific value is generated when the terminal-hydroxy group of the latent curing agent causes a curing reaction. It is different depending on the type of epoxy resin, but is usually generated at 80℃ to 150℃, and the second calorific value is reversible urethane in the latent curing agent. This occurs when the bond causes a reversible reaction by heat and separates the hydroxy group and the NCO group, and the hydroxy group causes a curing reaction. It differs depending on the type of epoxy resin, but it is an exotherm that is generated secondarily at 100°C to 200°C.

(2) curing time

After fixing the temperature at 150°C using a differential scanning calorimeter, the time when the exothermic peak disappears from the time when the exothermic peak begins to appear was measured as the curing time.

(3) strength

The cured epoxy resin prepared in Examples B1 to B4 and Comparative Examples B1 to B6 was scratched with a syringe needle, and at this time, the degree of scratching was visually observed and indicated as follows.

○: The degree of scratching is small, so the strength is high

△: The degree of scratching is moderate, and the strength is moderate

X: There are many scratches, so the strength is weak

[Table 1]

As shown in Table 1 above, in the case of Examples B1 to B4 according to the present invention, the hydroxy-terminated prepolymer used as the latent curing agent has a reversible urethane bond, so first, the first calorific value through the terminal-hydroxy group of the prepolymer This occurred, and it was confirmed that a secondary calorific value was generated through a hydroxyl group exposed through a reversible reaction, and through this, the curing time was relatively shortened (in the case of Examples B1 and B4, the curing time was 35 minutes, but the comparative example In the case of B1 to B6, the curing time exceeded 41 minutes), the curing speed increased, and it can be seen that it is excellent in terms of strength.

However, in the case of Comparative Example B1 using isosorbide as a curing agent, as compared to Examples B1 and B4, the curing time increased and the curing rate decreased, and the strength was also at a normal level. In the case of Comparative Example B2 using the hydroxy-terminated prepolymer of Comparative Example A1 (when the anhydrosugar alcohol was very excessive relative to the polyisocyanate equivalent) as a curing agent, the secondary heat generated by the reversible reaction did not occur, and the curing time was increased. The speed decreased, and the strength was also moderate. In the case of Comparative Examples B3 and B4 using the hydroxy-terminated prepolymers of Comparative Examples A2 and A3 as curing agents, respectively, secondary calorific values were generated due to the reversible reaction, but the curing time was greatly increased, and the curing rate was significantly reduced, and the strength From the side, it can be seen that it has fallen below normal. In the case of Comparative Example B5 using the hydroxy-terminated prepolymer of Comparative Example A4 as a curing agent, there was a problem that the initial curing did not proceed, the curing time was greatly increased, the curing rate was significantly reduced, and the strength became poor. In the case of Comparative Example B6 using a latent curing agent for an epoxy resin having a core-shell structure as a curing agent, the curing time increased compared to the curing time of Example B1, resulting in a decrease in curing speed, and it was found that the curing rate was reduced to a normal level in terms of strength. I can.

Claims (11)

A hydroxy-terminated prepolymer, prepared by reacting an anhydrosugar alcohol and a polyisocyanate, wherein the reaction molar ratio of the anhydrosugar alcohol and polyisocyanate is 1.15 to 2.45 moles of anhydrosugar alcohol per mole of polyisocyanate. The hydroxy-terminated prepolymer according to claim 1, wherein the anhydrosugar alcohol is dianhydrohexitol. The hydroxy-terminated prepolymer according to claim 1, wherein the polyisocyanate is selected from aliphatic polyisocyanates, cycloaliphatic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, heterocyclic polyisocyanates, or combinations thereof. A latent curing agent comprising the hydroxy-terminated prepolymer of any one of claims 1 to 3. Epoxy resin; And
Including; the latent curing agent of claim 4;
Epoxy resin composition. The method of claim 5, wherein the epoxy resin is a bisphenol A-epichlorohydrin resin, a diglycidyl ether resin of bisphenol A, an epoxy novolak resin, an alicyclic epoxy resin, an aliphatic epoxy resin, a bicyclic epoxy resin, and glycidyl. An epoxy resin composition selected from the group consisting of an ester-type epoxy resin, a brominated epoxy resin, a bio-derived epoxy resin, an epoxidized soybean oil, or a combination thereof. The epoxy resin composition according to claim 5, wherein the equivalent ratio of the curing agent to the epoxy resin (the equivalent of the curing agent/the equivalent of the epoxy resin) is 0.95 to 1.05. The epoxy resin composition according to claim 5, further comprising a curing catalyst. The group consisting of antioxidants, UV absorbers, fillers, resin modifiers, silane coupling agents, diluents, colorants, defoaming agents, defoamers, dispersants, viscosity modifiers, gloss modifiers, wetting agents, conductivity imparting agents, or mixtures thereof. The epoxy resin composition further comprises an additive selected from. A cured product obtained by curing the epoxy resin composition of claim 5. A molded article comprising the cured product of claim 10.