KR102087093B1 - Coating composition - Google Patents

Abstract

The present invention relates to a coating composition excellent in mechanical strength, elongation and low temperature curability.

Description

Coating composition {COATING COMPOSITION}

The present invention relates to a coating composition.

Epoxy resins have excellent chemical resistance, excellent thermal and dynamic mechanical properties, and thus coating compositions containing the same have been applied to a wide variety of fields such as electricity, electronics, civil engineering, architecture, automobiles, plants, and ships. At this time, by appropriately adjusting and combining the type and blending ratio of the curing agent used in conjunction with the above-described main ingredient, it is possible to exhibit the physical properties required in various fields as described above.

Especially, the anticorrosive coating of a ship is mentioned as an example to which the said epoxy resin is applied. In general, ships have ship bottoms, boot toppings, outside boards, exposed decks, void spaces, cofferdams, and engine compartments. It is divided into many compartments such as cargo hold, cargo tank, water ballast tank, etc., and is coated with anticorrosive paint of different formulations according to the coating performance required for each site.

However, since the curing agent generally applied to a coating composition including the epoxy resin as a main part is hardened at a relatively high temperature such as 120 ° C. to 200 ° C., when the scale is very large such as civil engineering, construction, plant or ship, Performing curing has disadvantages in paintability and is not economically advantageous.

In order to solve the above problems, a phenolic curing accelerator that can not only impart curability at a relatively low temperature of 110 ° C. or less, but also promote reactivity between the epoxy resin and the curing agent was used. However, when using such a phenolic hardening accelerator, although low temperature hardenability improves, crosslinking density is low and there exists a limit which the elongation of a coating film and solvent resistance fall.

Therefore, there is still a need for the development of a curing accelerator to improve the curing properties as well as the crosslinking density at a relatively low temperature of 110 ° C or less.

Korean Unexamined Patent Publication No. 2014-0005231

The present invention provides a coating composition excellent in mechanical strength, elongation, and curability at low temperature (eg, 90 ° C. or lower).

The present invention provides a coating composition comprising a main portion including an epoxy resin, a curing agent portion including an amine compound, and a curing accelerator portion including an imidazole compound and a polyrotaxane compound.

The coating composition according to the present invention is not only excellent in mechanical strength and elongation, but also excellent in curing property at low temperature (for example, 90 ° C. or lower, especially room temperature), and thus can be usefully used as an anticorrosive coating for cargo tanks in ships. Can be.

1 and 2 show the polyrotaxane structure used in the present invention.

Hereinafter, the present invention will be described in detail.

The present invention provides a coating composition.

The coating composition of this invention contains a main part, a hardening | curing agent part, and a hardening accelerator part.

<Topic>

The main part included in the coating composition of the present invention includes an epoxy resin.

The epoxy resin may be included as a main component in the coating composition to improve mechanical properties such as tensile strength as well as appearance of the coating film.

The epoxy resin is a bisphenol A epoxy resin, bisphenol E epoxy resin, bisphenol F epoxy resin, glycidyl ether epoxy resin, glycidyl amine epoxy resin, resorcinol epoxy resin, phenol novolac It may be a type epoxy resin, a cresol novolak-type epoxy resin, a bisphenol novolak-type epoxy resin, or a dimer acid modified epoxy resin.

The epoxy resin may have an epoxy equivalent weight (EEW) of 110 to 180 g / eq. Epoxy equivalent of the epoxy resin is 110 g / eq. If less than that, the internal stress of the cured product may increase, thereby lowering the adhesion to the body, and the epoxy equivalent of 180 g / eq. When exceeded, the crosslinking density of hardened | cured material may fall and solvent resistance may deteriorate.

The epoxy resin has an epoxy equivalent weight of 110 g / eq. More than 150 g / eq. A first epoxy resin having a viscosity of 200 cps to 700 cps and an epoxy equivalent of 150 g / eq. Greater than 180 g / eq. Or less, and may include a second epoxy resin having a viscosity of 1,000 cps to 2,000 cps at 25 ° C. In this case, the weight ratio of the first epoxy resin and the second epoxy resin may be 1: 1 to 4: 1, for example, may be 2: 1 to 4: 1. When the weight ratio of the first epoxy resin and the second epoxy resin is outside the numerical range, the appearance and mechanical properties of the coating film may be reduced.

The first epoxy resin may include a resorcinol epoxy resin having excellent chemical resistance or chemical resistance, and the second epoxy resin may include a bisphenol-type epoxy resin or a phenol novolac-type epoxy resin. It may be included in an amount of 70 to 90% by weight based on 100% by weight of the paint composition. In particular, the coating composition of the present invention contains a high content of an epoxy resin, the imidazole compound described later can increase the crosslinking density and improve solvent resistance by inducing epoxy homopolymerization. When the main portion (epoxy resin) is less than 70% by weight based on 100% by weight of the coating composition, the crosslinking density is lowered and solvent resistance is inferior. When it is more than 90% by weight, the reaction is delayed and the drying property is very inferior. Problems may arise.

< Curing agent part >

The hardening | curing agent part contained in the coating composition of this invention contains an amine compound.

The amine compound includes an amine group which is a functional functional group, and when applied to the main body used in the present invention, increases the crosslinking density of the coating composition to improve mechanical strength of the coating film.

The amine compound is diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), hexamethylenediamine (HMDA), N- (2-amino Ethyl) -1,3-propanediamine (N ₃ -amine), N, N'-1,2-ethanediylbis-1,3-propanediamine (N ₄ -amine), dipropylenetriamine, 2,2 -Bis (3-amino-4-hydroxycyclohexyl) hexafluoropropane (2,2-bis (3-amino-4-hydroxycyclohexyl) hexafluoropropane), 3,3'-dimethyl-4,4'-diamino Dicyclohexylmethane (MACM), 4,4'-methylenebiscyclohexylamine (PACM), 1,3-bis (aminomethyl) cyclohexane (1,3-BAC), 1,4-bis (aminomethyl) Cyclohexane (1,4-BAC), cis-1,2-cyclohexanedimethanamine, trans-1,2-cyclohexanedimethanamine, bis (4-aminocyclohexyl) ether (H-ODA), N -(4-aminocyclohexyl) -1,4-cyclohexanediamine or isophorone diamine (IPDA) and the like.

Among the amine compounds, 4,4'-methylenebiscyclohexylamine (4,4'-methylenebis (cyclohexylamine)) (PACM) may be used to secure the curability at low temperature (especially at room temperature) of the coating composition of the present invention. .

The hardener part may be included in an amount of 5 to 20% by weight, for example, in an amount of 10 to 15% by weight, based on 100% by weight of the coating composition. When the content of the curing agent part is less than 5% by weight based on 100% by weight of the total coating composition, incomplete curing of the main part may occur when the curing agent part and the main part react, thereby affecting hardness and low temperature curing properties, and more than 20% by weight. In the case of, the crosslinking density decreases rapidly, resulting in poor solvent resistance.

In the coating composition of the present invention, the main portion and the curing agent portion may be added in a weight ratio of 3: 1 to 15: 1, for example, may be added in a weight ratio of 5: 1 to 10: 1. If the weight ratio of the main portion and the curing agent portion is less than 3: 1, there is a problem that the solvent resistance is deteriorated because the crosslinking density is lowered, and if the weight ratio of the main portion and the curing agent portion is greater than 15: 1, mechanical strength due to incomplete curing, etc. May cause poor physical properties.

< Curing accelerator >

The curing accelerator included in the coating composition of the present invention includes an imidazole compound and a polyrotaxane (PRX) compound.

The imidazole compound and the polyrotaxane compound used as the curing accelerator promote the curing between the main portion and the curing agent portion, optimize the crosslinking density and at the same time shorten the drying time, thereby reducing the low temperature of the main portion (eg, 90 Or lower), in particular curing at room temperature occurs efficiently.

The curing accelerator part may be included in an amount of 1.5 to 12% by weight, for example, in an amount of 2 to 8% by weight, and in an amount of 3 to 6% by weight, based on 100% by weight of the paint composition. May be included. When the content of the curing accelerator is less than 1.5% by weight based on 100% by weight of the coating composition, there is a problem in that solvent resistance is deteriorated due to a low crosslinking density between the main part and the curing agent, and when it is more than 12% by weight, the coating film is incompletely cured. The appearance and mechanical properties of the may be lowered.

In the curing accelerator, the imidazole compound and the polyrotaxane compound may be included in a weight ratio of 1: 1 to 5: 1, and for example, may be included in a weight ratio of 1.5: 1 to 3: 1. When the weight ratio of the imidazole compound and the polyrotaxane compound is less than 1: 1, the curing reaction cannot be sufficiently promoted, and when the weight ratio of the imidazole compound and the polyrotaxane compound is greater than 5: 1, the coating film Its flexibility and mechanical strength cannot be improved.

The coating composition of the present invention may exhibit excellent mechanical properties and elongation as compared to the conventional coating composition using a phenolic curing accelerator such as DMP-30 (Tris (dimethylaminomethyl) phenol) by including the curing accelerator as described above. . In particular, as will be described later, the polyrotaxane compound having a necklace-like structure includes a cyclic molecule having a hydroxyl group having excellent reactivity with epoxy on the surface, thereby increasing the crosslinking density of the epoxy resin to improve mechanical strength of the coating film. In addition to the above, the above cyclic molecules have mobility while sliding along the axial molecules, thereby providing a coating film having improved tensile strength and tensile elongation.

Imidazole compound

The imidazole compound may increase the crosslinking density and improve solvent resistance of the coating composition of the present invention by inducing epoxy homopolymerization of the epoxy resin included in the main part.

The imidazole compound is 1-methylimidazole (1MI), 2-methylimidazole (2MI), 2-ethylimidazole, 2-ethyl-4-methylimidazole (2E4MI), 2-phenyl Imidazole, 1-phenyl-2-methylimidazole, 2-heptadecylimidazole, 2- (β- (2'-methylimidazoyl- (1 ')))-ethyl-4-6- Diamino-s-triazine, 2,4-dimethylimidazole 2-undecylimidazole, 2-heptadecenyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 1- Benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-isopropylimidazole, 2-phenyl-4-benzylimidazole, 2-vinylimidazole, 1-vinyl- 2-methylimidazole, 1-propyl-2-methylimidazole, 1- (3-aminopropyl) -imidazole, butylimidazole, 1-cyanoethyl-2-methylimidazole, 1- Cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-guanaminoethyl-2-methylimidazole, 1-cyanoethyl-2- Isopropylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-aminoethyl-2-methyl Dazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimida Sol, 2-methyl-4,5-diphenylimidazole, 2,3,5-triphenylimidazole, 2-styrylimidazole, 1- (dodecylbenzyl) -2-methylimidazole , 2- (2-hydroxy-4-t-butylphenyl) -4,5-diphenylimidazole, 2- (2-methoxyphenyl) -4,5-diphenylimidazole, 2- ( 3-hydroxyphenyl) -4,5-diphenylimidazole, 2- (p-dimethyl-aminophenyl) -4,5-diphenylimidazole, 2- (2-hydroxyphenyl) -4, 5-diphenylimidazole, di (4,5-diphenyl-2-imidazole) -benzene-1,4,2-naphthyl-4,5-diphenylimidazole, 2-p-methoxy Styrylimidazole, 2-decylimidazole, 2-hexylimidazole, 1-cyanoethyl-2-undecyl-imidazole trimellitate, 1-cyanoethyl-2-phenylimidazole tri Mellitate, 2,4-diamino-6- (2'-methylimidazole- (1 '))-ethyl-s-triazine, 2,4-diamino-6- (2'ethyl-4- Methylimide -(1 '))-ethyl-s-triazine, 2,4-diamino-6- (2'-undecylimidazole- (1'))-ethyl-s-triazine, 4,4 ' -Methylene-bis- (2-ethyl-5-methylimidazole), 1-cyanoethyl-2-phenyl-4,5-di (cyanoethoxymethyl) imidazole, 1-dodecyl-2- Methyl-3-benzylimidazolinium chloride, imidazole containing polyamide, and the like. For example, the imidazole compound may be 2-ethyl-4-methylimidazole, but is not limited thereto.

The imidazole compound may be included in an amount of 1 to 8 wt%, for example, in an amount of 1 to 5 wt%, based on 100 wt% of the coating composition. When the content of the imidazole compound is less than 1% by weight, the crosslinking density is low and curing of the epoxy resin cannot be sufficiently promoted. When the content of the imidazole compound is more than 8% by weight, the physical property stability is improved by excessively reducing the curing reaction time of the epoxy resin. It can be greatly degraded.

Polyrotaxane  compound

The polyrotaxane compound is included in the coating composition of the present invention, and not only increases the initial reaction rate of the main portion and the curing agent portion, but also imparts flexible physical properties to the coated film after curing, while simultaneously increasing the mechanical strength of the coated film.

The polyrotaxane compound generally refers to a compound having a cyclic cyclic molecule penetrated through a linear axial molecule, and includes at least two cyclic molecules in the axial molecule. It is a form having a bulky block group at both ends of the axial molecule to prevent the cyclic molecule from escaping from the axial molecule. That is, the axial molecule may be in the form of a dumbbell having a bulky block group at both ends.

The cyclic molecule of the polyrotaxane compound can move freely on the axial molecule, and thus the effect of mitigating stress from the outside or remaining stress inside due to the free mobility (mobility) of the cyclic molecule in the polyrotaxane compound Can be represented.

The axial molecule is not particularly limited as long as it is a molecule having a functional group capable of penetrating into the opening of the cyclic molecule to be clathrate in the shape of a molecular necklace and reacting with the block group. The axial molecules are linear, for example, polyvinyl alcohol, polyvinylpyrrolidone, poly (meth) acrylic acid, cellulose resins (carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, etc.), polyacrylamide, Polyethylene oxide, polyvinyl acetal, polyvinyl methyl ether, polyamine, polyethyleneimine, polyethylene, polypropylene, polyisoprene, polybutadiene, polyisobutylene, polyvinyl chloride, polystyrene, acrylonitrile-styrene copolymer resin, polymethyl Methacrylate, acrylonitrile-methylacrylate copolymer resin, polycarbonate, polyurethane, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral, polytetrahydrofuran, polyaniline, acrylonitrile-butadiene-styrene copolymer resin ( ABS resin), nylon, polydimethylsiloxane, polysulfones, poly Imines, polyanhydrides, polyurea, polysulfides, polyphosphazenes, polyketones, polyphenylenes, polyhaloolefins, polyethylene glycols, polypropylene glycols, polytetramethylene glycols, poly (acrylo) Nitrile-butadiene) diol, polycaprolactonediol, polylactic acid, polyethylene adipate, polybutylene adipate, polyethylene terephthalate, polybutylene terephthalate, etc., and have functional groups capable of reacting the block groups at both ends Can be.

The weight average molecular weight (Mw) of the axis molecule may be 3,000 g / mol to 100,000 g / mol.

The cyclic molecule is not particularly limited as long as the cyclic molecule can pass through the opening. The cyclic molecule is, for example, cyclodextrin (CD), crown ether (crown ether), cryptand (cyclone), cyclocyclic amines, calixarene (cycloxarene), cyclophane (cyclophane), It may be a spherand (Spherand) or the like, and has a necklace-like structure as shown in Figure 1 by the intermolecular interactions not penetrating through the axis molecules.

In particular, the cyclodextrin is a compound having a cyclic structure in which a plurality of glucopyranose units are connected through α-1,4- bonds, and the outside of the ring is hydrophilic due to a hydroxyl group, and the inside of the ring Is hydrophobic due to the oxygen of hydrogen and ether groups. The cyclodextrin may be, for example, α-cyclodextrin of 6 glucopyranose units, β-cyclodextrin of 7 glucopyranose units, γ-cyclodextrin of 8 glucopyranose units, and the like.

The block group is not particularly limited as long as it can bind with a terminal functional group of the axial molecule, and examples thereof include dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes, anthracenes, Steroids, benzenes, and the like, and the block group may be substituted with alkyl, alkyloxy, hydroxy, halogen, cyano, sulfonyl, carboxyl, amino, aryl and the like.

In addition, the polyrotaxane compound may be in a form in which 10 to 200 cyclic molecules are penetrated and enclosed in one molecule of axial molecules, for example, in a form in which 20 to 80 cyclic molecules are encapsulated and penetrated. .

At least one of the hydroxyl groups included in one molecule of the cyclic molecule may be substituted with a tertiary amine. That is, one to four hydroxyl groups of the hydroxyl groups contained in one molecule of the cyclic molecule may be substituted with a compound containing a tertiary amine, for example, one to three hydroxyl groups as a compound containing a tertiary amine. Can be substituted. When more than four hydroxyl groups are substituted with tertiary amines in the cyclic molecule, there is a disadvantage in that the curing speed is excessively increased, so that the effect of improving the crosslinking density cannot be exerted.

For example, the polyrotaxane compound may be a compound in the form of a necklace in which α-cyclodextrin is stitched to polyethylene glycol, which is an axial molecule, and at least one hydroxyl group of the α-cyclodextrin may be substituted with a tertiary amine. .

The tertiary amine is N, N-dimethyl ethylenediamine, dimethylpropylamine, benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tri (dimethylaminomethyl) phenol, 2-2- (dimethylaminomethyl) Phenol or 2,4,6-tris (diaminomethyl) phenol, and the like, but is not limited thereto.

The polyrotaxane compound in which at least one hydroxyl group of the cyclic molecule is substituted with a tertiary amine may have an equivalent ratio of 1:20 to 1: 240 of the polyrotaxane compound and the tertiary amine, for example, 1:20. To 1:80. When the equivalent ratio is less than 1:20, the curing of the epoxy resin cannot be sufficiently promoted, and when the ratio is more than 1: 240, the curing rate is excessively increased, so that the effect of improving the crosslinking density cannot be sufficiently exhibited.

The polyrotaxane compound may have a weight average molecular weight (Mw) of 40,000 to 200,000 g / mol, for example, 50,000 to 150,000 g / mol, and a number average molecular weight (Mn) of 20,000 to 100,000 g / mol. May be, for example, 30,000 to 80,000 g / mol. The glass transition temperature (T _g ) of the polyrotaxane compound may be 10 to 25 ° C, and may be 13 to 20 ° C.

The polyrotaxane compound may be included in an amount of 0.5 to 4% by weight, for example, in an amount of 1 to 3.5% by weight, based on 100% by weight of the coating composition. When the polyrotaxane compound is included in an amount of less than 0.5% by weight based on 100% by weight of the coating composition, it is not possible to exert an excellent effect of elasticity and flexibility of the coating film, and when included in an amount of more than 4% by weight, relatively low temperature. (Especially at room temperature) it is not possible to maintain a high level of conversion and crosslinking density of the epoxy resin when cured.

<Other Ingredients>

In addition to the above components, the coating composition may further include one or more additional components, such as a silane coupling agent, a dispersant, an antifoaming agent, an antisettling agent, a pigment, a thickener, and an interfacial binder, if necessary. Such additional components may be appropriately selected depending on the type and amount used conventionally.

The coating composition of the present invention configured as described above can be cured at a relatively low temperature, that is, at 90 ° C. or lower, for example, a temperature of 5 ° C. to 90 ° C., 15 ° C. to 80 ° C., 15 ° C. to 40 ° C., or 20 It may be cured at a temperature of ℃ to 30 ℃. When the curing temperature is less than 5 ℃ hardening of the paint can not be sufficiently promoted, if it is above 90 ℃ not only the adhesion of the coating composition is poor, but cracks may occur in the coating film.

Moreover, the coating composition of this invention comprised as mentioned above has a tensile elongation of 2% or more simultaneously with the tensile strength of 13 Mpa or more. For example, it can exhibit a tensile strength of 13 to 18 Mpa, and at the same time a tensile elongation of 2 to 5%. When using the coating composition which satisfy | fills the said range, the external appearance of a coating film can also be improved.

Hereinafter, the present invention will be described in more detail with reference to Examples.

However, these examples are only for the understanding of the present invention, and the scope of the present invention in any sense is not limited to these examples.

< Production Example >

< Example  1 to 5 and Comparative example  1 to 4>

The coating compositions of Examples 1 to 5 were prepared in the compositions shown in Table 1 below, and the coating compositions of Comparative Examples 1 to 4 were prepared in the compositions shown in Table 2 below.

ingredient Example One 2 3 4 5 Epoxy
Suzy A 63.56 63.56 63.56 60.48 63.02 B 19.59 19.59 19.59 18.64 19.30 Hardener 11.85 11.85 11.85 11.28 11.28 Hardening
accelerant Imidazole compound 3.4 3.4 3.4 8.0 3.4 DMP-30 - - - - - PRX 1.6 - - - - PRX-NR1 - 1.6 - 1.6 3.0 PRX-NR4 - - 1.6 - - Total (% by weight) 100 100 100 100 100 1) Epoxy Resin A: Resorcinol Epoxy Resin, DE-703, Kukdo Finechem (Epoxy Equivalent: 120 ~ 135 g / eq., Viscosity: 300 ~ 500 cps)
2) Epoxy resin B: Phenol novolac epoxy resin, YDPN-631, Kukdo Chemical (Epoxy equivalent: 172 ~ 179 g / eq., Viscosity: 1,100 ~ 1,700 cps)
3) Curing agent: 4,4'-methylenebiscyclohexylamine (4,4'-methylenebis (cyclohexylamine)), Amicure PACM, Evonik (amine equivalent: 52.5 g / eq., Viscosity: 80 cps)
4) imidazole compounds: 2-Ethyl-4-methyl imidazole, Sigma Aldrich
5) DMP-30: Tri (dimethylaminomethyl) phenol, Ancamine K-54, Evonik (viscosity: 200 cps)
6) PRX: polyrotaxane (a structure in which an α-cyclodextrin ring is sewn onto polyethylene glycol)
7) PRX-NR1: 6) polyrotaxane in which one tertiary amine is substituted for α-cyclodextrin of polyrotaxane
8) PRX-NR4: 6) polyrotaxane in which 4 tertiary amines are substituted for α-cyclodextrin of polyrotaxane

ingredient Comparative example One 2 3 4 5 6 7 Epoxy
Suzy A 63.56 63.56 63.56 63.56 68.41 65.96 53.56 B 19.59 19.59 19.59 19.59 23.59 19.59 9.59 Hardener 11.85 11.85 11.85 11.85 3 11.85 31.85 Hardening
accelerant Imidazole compound 5.0 3.4 - 3.4 3.4 One 3.4 DMP-30 - 1.6 - - - - - PRX - - - - - - - PRX-NR1 - - 5.0 1.6 1.6 1.6 1.6 PRX-NR4 - - - - - - - Total (% by weight) 100 100 100 100 100 100 100 1) Epoxy Resin A: Resorcinol Epoxy Resin, DE-703, Kukdo Finechem (Epoxy Equivalent: 120 ~ 135 g / eq., Viscosity: 300 ~ 500 cps)
2) Epoxy resin B: Phenol novolac epoxy resin, YDPN-631, Kukdo Chemical (Epoxy equivalent: 172 ~ 179 g / eq., Viscosity: 1,100 ~ 1,700 cps)
3) Curing agent: 4,4'-methylenebiscyclohexylamine (4,4'-methylenebis (cyclohexylamine)), Amicure PACM, Evonik (amine equivalent: 52.5 g / eq., Viscosity: 80 cps)
4) imidazole compounds: 2-Ethyl-4-methyl imidazole, Sigma Aldrich
5) DMP-30: Tri (dimethylaminomethyl) phenol, Ancamine K-54, Evonik (viscosity: 200 cps)
6) PRX: polyrotaxane (a structure in which an α-cyclodextrin ring is sewn onto polyethylene glycol)
7) PRX-NR1: 6) polyrotaxane in which one tertiary amine is substituted for α-cyclodextrin of polyrotaxane
8) PRX-NR4: polyrotaxane substituted with 4 tertiary amines in α-cyclodextrin of 6) polyrotaxane

Comparative Example 4: A coating composition was prepared in the same composition as in Example 2, and curing for measuring physical properties of the cured product was performed at a temperature of 100 ° C.

< Experimental Example >

The physical properties of the coating compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 7 and the physical properties of the cured product after curing at room temperature (25 ° C.) are measured by the following methods. Indicated. However, the coating composition of Comparative Example 4 is shown in Table 4 below the results of measuring the physical properties of the cured product after curing at 100 ℃.

How to measure

1. Epoxy conversion (%)

The calorific value (Ho) before curing and the calorific value (H) after curing of the coating composition prepared in Preparation Example (Di) were measured by differential scanning calorimetry (Differential scanning calorimetry, DSC) to calculate the epoxy conversion. However, in the case of the coating composition prepared in Comparative Example 4, the calorific value after curing at 100 ° C. was measured and calculated in the same manner as in the above method. High epoxy conversion means that the epoxy ring-opening reaction takes place and the amount of unreacted epoxy remains, which means that the epoxy resin participates in the crosslinking reaction a lot. This means that the physical properties of the paint are excellent.

2. Glass Transition Temperature (T _g )

Dynamic and mechanical analyzes were performed in accordance with ASTM D4065 for glass transition temperature measurements. In the nitrogen atmosphere, while increasing the temperature at 5 ℃ / min in the analysis range of 25 ℃ to 300 ℃, the change in storage modulus, loss modulus and tan value was confirmed under the frequency = 1 Hz condition. Specimens were prepared in a rectangular shape of length × width × thickness = 35 × 13 × 3 (mm ³ ). Glass transition temperature was made into the temperature which shows the maximum value of a loss modulus / storage modulus.

3. Crosslinking density (mol / cm ³ )

The crosslinking density was calculated according to Formula 1 below using glass transition temperature and elastic modulus values according to the specification according to ASTM D4065. In Equation 1, _E'r is the storage modulus (MPa) in the rubbery region 50 ° C. higher than the glass transition temperature, d is the density of the specimen (g / cm ³ ), and R is the ideal gas constant (cm ³ · MPa). /mol.K), and T denotes the absolute temperature K of the rubbery region.

[Calculation 1]

Crosslink density (mol / cm ³ ) = (E ' _r ) / 3dRT

4. Tensile Strength

Tensile strength was measured according to the ASTM D1708-13 standard, and the tensile strength calculated at the time the specimen broke was expressed as an average of the measured values of at least five samples for each condition.

5. Tensile Elongation

Tensile elongation was measured according to ASTM D1708-13 standard. The tensile elongation was quantified by the S-S curve analysis of the tensile strain calculated at the moment when the specimen is broken, and expressed as an average value of the measured values of at least five samples for each condition.

division Example One 2 3 4 5 Epoxy Conversion Rate (%) 70.9% 88.47% 89.5% 88.3% 88.1% Crosslinking density
(mol / cm ³ ) 7.77 9.8 9.9 9.3 9.1 Glass transition temperature (℃) 113.67 114 114.6 113.2 111.1 Tensile Strength (Mpa) 16.9 14.7 14.1 14.0 13.9 Tensile Elongation (%) 2.4 3.3 3.1 2.9 3.0

division Comparative example One 2 3 4 5 6 7 Epoxy Conversion Rate (%) 48.13% 82.47% 45.6% 93.4% 32.2% 48.4% 92.7% Crosslinking density
(mol / cm ³ ) 5.20 4.59 4.8 10.3 3.4 5.1 8.4 Glass transition temperature (℃) 109.26 101.23 106.1 118 92.2 107.2 108.2 Tensile Strength (Mpa) 11.8 11.9 12.1 9.8 7.8 12.4 8.4 Tensile Elongation (%) 1.5 1.7 1.8 1.2 2 1.9 0.9

According to Table 3 and Table 4, in the case of Example 2 according to the present invention, compared with Comparative Example 2 using DMP-30 as a curing accelerator, the epoxy conversion rate is 6% higher, the crosslinking density is 113% or more higher, the tensile strength It was confirmed that the strength was 23% or higher and the tensile elongation was 94% or higher.

In addition, in Examples 1 to 5 including the polyrotaxane compound as the curing accelerator, the tensile strength was up to 43% higher and the tensile elongation was maximum compared to Comparative Examples 1 and 2 without the polyrotaxane compound. 120% improvement was confirmed.

In particular, Example 2 cured at room temperature, compared to Comparative Example 4 cured at a high temperature (100 ℃), it was confirmed that the tensile strength is improved by 50%, the tensile elongation is improved by 250%.

In addition, comparing Examples 1 to 5 and Comparative Example 5, in the case of Comparative Example 5 in which the weight ratio of the main part and the curing agent part is more than 15: 1, the epoxy conversion is significantly lowered, and thus the crosslinking density is lowered, resulting in As a result, it was confirmed that the tensile strength of the coating film fell close to 1/2 compared with the case of Examples 1 to 5.

In addition, even in Comparative Example 6 in which the weight ratio of the imidazole compound and the polyrotaxane compound was less than 1: 1, the epoxy conversion was significantly lowered and the crosslinking density was lowered. It was confirmed that the poor compared to the 5 to.

On the other hand, when Examples 1 to 5 and Comparative Example 7 are compared, the tensile strength and tensile elongation of the finally formed coating film is excellent only when the content of the epoxy resin is contained in the main part at a predetermined level or more (70 wt% or more). I could confirm it.

The results show that when polyrotaxane, in particular polyrotaxane substituted with tertiary amine, is used as a curing accelerator in the coating composition of the present invention, high crosslinking density, tensile strength and tensile elongation can be exhibited.

Although the present invention has been described in detail only with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, and such modifications and modifications belong to the appended claims.

Claims (8)

The main part containing epoxy resin,
Curing agent part containing an amine compound and
It comprises a curing accelerator comprising an imidazole compound and a polyrotaxane compound,
The paint composition comprising the main portion and the curing agent portion in a weight ratio of 3: 1 to 15: 1.
delete The method according to claim 1,
The imidazole compound is a coating composition contained in an amount of 1 to 8% by weight based on 100% by weight of the coating composition.
The method according to claim 1,
The polyrotaxane compound is contained in an amount of 0.5 to 4% by weight based on 100% by weight of the total coating composition.
The method according to claim 1,
The coating composition comprising the imidazole compound and the polyrotaxane compound in a weight ratio of 1: 1 to 5: 1.
The method according to claim 1,
The polyrotaxane compound includes a cyclic molecule having a hydroxyl group,
Coating composition in which at least one of the hydroxyl groups of the said cyclic molecule is substituted by a tertiary amine.
The method according to claim 1,
The coating composition is a coating composition cured at 5 ℃ to 90 ℃.
The method according to claim 1,
With respect to 100% by weight of the coating composition,
The main part is included in an amount of 70 to 90% by weight,
The hardener portion is included in the amount of 5 to 20% by weight,
The curing accelerator is a coating composition comprising a content of 1.5 to 12% by weight.

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