KR20210083067A - Latent curing agent, and one-pack type epoxy resin composition comprising the same - Google Patents

Abstract

A latent curing agent can be obtained by addition polymerization of an amino-based compound and at least one epoxy selected from a group consisting of hydrogenated bisphenol A (HBPA)-based epoxy, isocyanate-modified epoxy, and core-shell rubber dispersed epoxy. Room temperature stability and impact adhesion can be improved through the latent curing agent of the present invention.

Description

Latent curing agent, and one-component epoxy resin composition comprising the same

The present invention relates to a latent curing agent and a one-component epoxy resin composition comprising the same.

Epoxy resins are used in various fields such as coatings, adhesives, and casting agents due to their excellent curing properties.

A typical epoxy resin composition using an epoxy resin may include a two-component epoxy resin composition in which two liquids of an epoxy resin and a curing agent are mixed when used. However, while the two-component epoxy resin composition has the advantage of being able to be cured at room temperature, the epoxy resin and the curing agent must be stored separately, and each must be weighed and mixed as needed, so storage or handling is cumbersome and work efficiency is avoided. The downside is that you can't.

In order to solve the disadvantages of the two-component epoxy resin composition, a one-component epoxy resin composition using a latent curing agent in which a curing reaction does not occur under general conditions and a curing reaction occurs by light irradiation or heating has been developed. A typical latent curing agent of the one-component epoxy resin composition includes an amine-based curing agent, and may be used in combination with an imidazole-based compound (see Japanese Patent Publication No. 3060452). However, the one-component epoxy resin composition using these amine-based curing agents has a problem in that those having excellent storage stability have a high curing temperature and slow reaction rate, and conversely, those having a fast reaction rate have poor storage stability. Therefore, there is a demand for a latent curing agent capable of providing a one-part epoxy resin composition having both good reaction rate and storage stability.

Accordingly, the present application is to provide a latent curing agent that has excellent reaction rate and storage stability, and can improve impact adhesion, which is an essential property of an adhesive material for automobile structures, and a one-component epoxy resin composition including the same.

However, the problems to be solved by the present application are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

Hydrogenated Bisphenol A (HBPA)-based epoxy, isocyanate-modified epoxy, and at least one epoxy selected from the group consisting of a core-shell rubber dispersion epoxy; and a latent curing agent obtained by addition polymerization of an amino-based compound.

The present invention is a Hydrogenated Bisphenol A (HBPA)-based epoxy; core-shell rubber dispersion epoxy; and a latent curing agent obtained by addition polymerization of an amino-based compound.

The present invention is an isocyanate-modified epoxy; core-shell rubber dispersion epoxy; and a latent curing agent obtained by addition polymerization of an amino-based compound.

Another aspect of the present application provides a one-component epoxy resin composition comprising the latent curing agent and an epoxy compound.

Another aspect of the present application provides an adhesive for automobile structures including the epoxy resin composition.

The one-component epoxy resin composition can be stored at room temperature for 150 days or more through the latent curing agent according to the present application. That is, it has excellent room temperature stability. In addition, it was confirmed that when the one-component epoxy resin composition according to the present application was cured, shear adhesion, T-peel adhesion, and impact adhesion were equivalent to or higher than those of the prior art.

Hereinafter, various embodiments of the present document are described. The examples and terms used therein are not intended to limit the technology described in this document to specific embodiments, and should be understood to include various modifications, equivalents, and/or substitutions of the embodiments.

One aspect of the present application provides a latent curing agent obtained by an addition polymerization reaction of an epoxy and an amino-based compound.

The epoxy may be at least one of Hydrogenated Bisphenol A (HBPA)-based epoxy, isocyanate-modified epoxy, and core-shell rubber dispersion epoxy.

The amino-based compound may be an imidazole-based compound. Specifically, the amino compound is 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 1,5-dimethylimidazole, 2-butyl-5-chloro-1H-imi Dazole-4-carboaldehyde, vinylimidazole, climbazole, 1,1-carbonyldiimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-ethylimidazole, 1 It may be at least one selected from the group consisting of -benzyl-2-methylimidazole and 2-butylimidazole.

Alternatively, the amino-based compound may be an amine-based compound. Specifically, the amino-based compound is 2-aminoterephthalic acid, 4-aminophthalic acid, 4-aminoisophthalic acid, 5-aminoisophthalic acid, 2,5-diaminoterephthalic acid, and 2,diamino-4,4'-stilbene. It may be any one selected from the group consisting of dicarboxylic acids.

However, the embodiment is not limited thereto, and various amino-based compounds capable of causing an addition polymerization reaction with the epoxy may be used. Preferably, the amino-based compound may be 2-methylimidazole.

The latent curing agent of the present invention can be obtained through addition polymerization using a solvent. In this case, the solvents that can be used include alcohols such as xylene, water, methanol, ethanol, and isopropanol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, and aromatic hydrocarbons such as toluene and xylene. can

Meanwhile, specifically, according to an embodiment of the present invention, the latent curing agent may be obtained by addition polymerization of HBPA-based epoxy, core-shell rubber dispersed epoxy, and amino-based compound. In this case, the weight ratio of HBPA-based epoxy: core-shell rubber dispersed epoxy: amino-based compound may be 4 to 6: 3 to 5: 1-3. Preferably, the weight ratio of HBPA-based epoxy: core-shell rubber dispersed epoxy: amino-based compound may be 5: 4: 2. Through this weight ratio, room temperature stability and impact adhesion can be improved.

Meanwhile, according to another embodiment of the present invention, the latent curing agent is obtained by addition polymerization of m-xylylenediamine (MXDA), isocyanate-modified epoxy, core-shell rubber dispersion epoxy, and amino-based compounds. can get

In this case, the weight ratio of MXDA: isocyanate-modified epoxy: core-shell rubber dispersed epoxy: amino-based compound may be polymerized in a weight ratio of 1 to 5: 23 to 27: 18 to 22: 5 to 9. Preferably, the weight ratio of MXDA: isocyanate-modified epoxy: core-shell rubber dispersed epoxy: amino-based compound may be 3:25:20:7. Through this weight ratio, room temperature stability and impact adhesion can be improved.

To prepare the latent curing agent of the present invention, stirring the amino at 90 to 110 ℃; Epoxy input; reacting at 90 to 110° C. for 2 to 4 hours; The step of recovering the solvent may be performed by reducing the pressure at 30 torr or less.

The latent curing agent of the present invention can be used after pulverization to obtain particles of a desired diameter. In this case, the particle diameter may be 0.03 μm to 300 μm.

The latent curing agent of the present invention can improve room temperature stability through Hydrogenated Bisphenol A (HBPA)-based isocyanate-modified epoxy. In addition, the impact adhesion can be increased through the core-shell rubber dispersion epoxy, and the latent curing agent of the present invention can be used as an adhesive material for automobile structures.

Another aspect of the present application relates to a one-component epoxy resin composition comprising the latent curing agent and an epoxy compound.

Examples of the epoxy compound include compounds having two or more epoxy groups in the molecule. Specifically, bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, tetramethylbisphenol A, diarylbisphenol A, hydroquinone, catechol, resorcinol, cresol, tetrabromobisphenol A, trihydroxybiphenyl , benzophenone, bisresorcinol, bisphenol hexafluoroacetone, tetramethylbisphenol A, tetramethylbisphenol F, tris(hydroxyphenyl)methane, bixylenol, phenol novolac, cresol novolac, etc. Glycidyl ether obtained by reacting chlorohydrin or aliphatic polyhydric alcohol such as glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, polyethylene glycol, and polypropylene glycol and epichlorohydrin Polyglycidyl ether obtained by the reaction or glycidyl ether ester obtained by reacting epichlorohydrin with hydroxycarboxylic acid such as p-oxybenzoic acid or β-oxynaphthoic acid or phthalic acid, methylphthalic acid, isophthalic acid, terephthalic acid , tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylenehexahydrophthalic acid, trimellitic acid, polyglycidyl esters obtained from polycarboxylic acids such as polymerized fatty acids or aminophenols, glycidyl obtained from aminoalkylphenols Glycidylaminoglycidyl ester or aniline obtained from cydylaminoglycidyl ether or aminobenzoic acid, toluidine, tribromoaniline, xylylenediamine, diaminocyclohexane, bisaminomethylcyclohexane, 4,4 Alicyclic epoxy such as '-diaminodiphenylmethane, glycidylamine obtained from 4,4'-diaminodiphenylsulfone, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylic acid ester, etc. Well-known epoxy resins, such as a resin and an epoxidized polyolefin, can be used.

On the other hand, in the one-component epoxy resin composition of the present invention, the latent curing agent may be included in an amount of 0.3 to 50 parts by weight based on 100 parts by weight of the epoxy compound. If the amount of the curing agent used is less than 0.3 parts by weight, the curability is not sufficient, while if it exceeds 50 parts by weight, the performance of the cured product may be deteriorated. Preferably, in the one-part epoxy resin composition of the present invention, the latent curing agent may be included in an amount of 10 to 12.5 parts by weight based on 100 parts by weight of the epoxy compound.

In the one-component epoxy resin composition of the present invention, in addition to the latent curing agent of the present invention, known curing agents such as phenol compounds, acid anhydrides, dicyandiamide, hydrazide compounds, thiol compounds, guanamines, melamines, and imidazole compounds; A hardening accelerator, such as a tertiary amine, can be used together. In addition, other additives may be further included as needed. Examples of such additives include inorganic fillers such as alumina, silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, talc, bentonite, barium carbonate, and aerosil; flow regulators such as acrylic oligomers and silicone; coupling agents such as silane coupling agents; phosphoric acid esters; Phosphorus-containing epoxy compounds, flame retardants such as nitrogen-containing phenolic resins, nylon microparticles, polystyrene microparticles, crosslinked rubber particles, acrylic core shell particles, rubber core shell particles, silicone microparticles, ethylene-acrylic acid copolymer microparticles, etc. Physical property improving agents, carboxyl-terminated liquid acrylic Resin modifiers, such as an oligomer, a pigment, etc. are mentioned.

Another aspect of the present application relates to an adhesive for automobile structures, including the epoxy resin composition.

In one embodiment of the present application, the structural adhesive may be in the form of a tape or paste, but may not be limited thereto.

Hereinafter, the present application will be described in more detail using examples, but the following examples are only illustrative to help the understanding of the present application, and the content of the present application is not limited to the following examples.

< Example : Preparation of latent curing agent>

The epoxy curing agent resin compositions of Examples 1 to 2 and Comparative Examples 1 to 4 were prepared by polymerization according to the formulation shown in Table 1 below.

Item Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 DETA 100 MXDA 30 100 100 2MI 100 70 100 YD-128 300 YDF-170 300 ST-4100DX60 250 100 KD-2011X60 250 KDAD-7101 200 200 200 200 Xylene 100 100 100 polymerization method solvent solvent bulk bulk bulk solvent recipe Amino stirring, 100℃ / Epoxy input (exothermic) / 100℃, 3 hours reaction / 20torr or less pressure reduction solvent recovery (in case of solvent reaction)

DETA: Diethylenetriamine

MXDA: m-xylylenediamine

2MI: 2-methylimidazole

YD-128: Bisphenol A type epoxy resin (manufactured by Kukdo Chemical)

YDF-170: Bisphenol F-type liquid epoxy resin (manufactured by Kukdo Chemical)

ST-4100DX60: Hydrogenated Bisphenol A (HBPA) Epoxy (Manufacturer: Kukdo Chemical)

KD-2011X60: Isocyanate-modified epoxy resin (Manufacturer: Kukdo Chemical)

KDAD-7101: Core-shell rubber dispersion epoxy (Manufacturer: Kukdo Chemical)

<Experimental example: adhesion evaluation>

The curing agent and the epoxy compound according to Examples 1 to 2 and Comparative Examples 1 to 4 were mixed and cured to evaluate shear adhesion, T-peel adhesion and impact adhesion.

The experimental results are shown in Table 2 below. In addition, the range of physical properties for the measurement items, test methods and specifications are shown in Table 3 below.

Item Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 room temperature storage
(50um particle) more than 150 days more than 150 days 20 days - 70 days 50 days combination hardener 10 10 5 - 10 6 YD-128 40 KR-450 20 UME-330 20 Curing conditions 100°C for 10 minutes Properties shear adhesion
(MPa, 23℃) 25 or more 25 or more 20 - 25 or more 15 T-peel adhesion
(N/25mm, 23℃) 250 or more 250 or more 250 or more 250 or more 250 or more impact adhesion
(N/mm, 23℃) 20 or more 20 or more 10 20 or more 20 or more

YD-128: Bisphenol A type epoxy resin (manufactured by Kukdo Chemical)

KR-450: CTBN (carboxyl-terminated butadiene acrylonitrile rubber) modified bisphenol A epoxy resin (manufactured by Kukdo Chemical)

UME-330: Urethane-modified liquid epoxy resin (manufactured by Kukdo Chemical)

Test Items physical properties range Test methods and specifications shear adhesion
force (Mpa, 23 ℃) CR grater > 25Mpa MS 715-60, Section 4.2 impact adhesion
(N/ mm, 23 °C ) CR grater > 22N/mm MS 715-60, Section 4.3 T-peel adhesion
(T-peel strength)
(N/25mm, 23 ℃ ) CR grater > 180 (N/25mm) MS 715-60, Section 4.6

Referring to Table 2, it can be seen that in Examples 1 and 2, room temperature storage is possible for 150 days or more, so that room temperature stability is remarkably improved compared to Comparative Examples. In addition, it was confirmed that the shear adhesive force and the impact adhesive force were equivalent to or higher than those of the comparative example. It was confirmed that the T-peel adhesion also exhibited the same level as the comparative example.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present application is indicated by the claims described below rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims, and their equivalent concepts should be construed as being included in the scope of the present application. .

Claims (7)

Hydrogenated Bisphenol A (HBPA)-based epoxy, isocyanate-modified epoxy, and at least one epoxy selected from the group consisting of a core-shell rubber dispersion epoxy; and
A latent curing agent obtained by addition polymerization of an amino-based compound. Hydrogenated Bisphenol A (HBPA) based epoxies;
core-shell rubber dispersion epoxy; and
A latent curing agent obtained by addition polymerization of an amino-based compound. isocyanate-modified epoxy;
core-shell rubber dispersion epoxy; and
A latent curing agent obtained by addition polymerization of an amino-based compound. 4. The method according to any one of claims 1 to 3,
The amino-based compound is 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 1,5-dimethylimidazole, 2-butyl-5-chloro-1H-imidazole- 4-Carboaldehyde, vinylimidazole, climbazole, 1,1-carbonyldiimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-ethylimidazole, 1-benzyl A latent curing agent, characterized in that at least one selected from the group consisting of -2-methylimidazole and 2-butylimidazole. 4. The method according to any one of claims 1 to 3,
The amino-based compound is 2-aminoterephthalic acid, 4-aminophthalic acid, 4-aminoisophthalic acid, 5-aminoisophthalic acid, 2,5-diaminoterephthalic acid, and 2,diamino-4,4'-stilbendicar. A latent curing agent, characterized in that at least one selected from the group consisting of acids. 3. The method of claim 2,
A latent curing agent, characterized in that the weight ratio of HBPA-based epoxy: core-shell rubber dispersion epoxy: amino-based compound is 4 to 6: 3 to 5: 1-3. A latent curing agent according to any one of claims 1 to 3; and
A one-component epoxy resin composition comprising an epoxy compound.