KR20190093406A - Acrylic polyol resin composition and coating composition using the same - Google Patents

Abstract

The present invention relates to an acrylic polyol resin composition comprising: a monomer mixture containing at least three of a nonfunctional (meth) acrylate monomer, a nonionic-based hydrophilic reactive monomer, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and an unsaturated monomer; a reactive silane; an epoxy-based reactive compound; a high boiling point plasticizer; and a solvent. An aqueous acrylic polyol resin composition according to the present invention exhibits excellent storage stability.

Description

ACRYLIC POLYOL RESIN COMPOSITION AND COATING COMPOSITION USING THE SAME

The present invention relates to a water dispersion acrylic polyol resin composition and a urethane coating composition comprising the same.

Recently, the demand for eco-friendly paints is increasing according to regulations on volatile organic compounds (VOC) at home and abroad, and the development of water dispersible paints using water as the main solvent rather than oil-based paints is being actively performed. In particular, in the case of industrial urethane topcoats such as heavy equipment, ships, railway cars, etc., excellent gloss and appearance and water resistance, solvent resistance, weather resistance, adhesion, corrosion resistance, strength, and the like must be satisfied. To this end, it is required to develop a water-dispersible acrylic polyol resin that can be applied to industrial coatings while having similar coating properties to oil-based paints. In addition, such acrylic polyol resins require excellent storage stability that does not occur during storage after dispersion.

As a prior art, Korean Patent Laid-Open Publication No. 10-2014-0115397 discloses an epoxy-based dilution monomer, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, a nonionic acrylate monomer, a (meth) acrylic acid ester monomer, and an unsaturated monomer. And a water dispersible two-component acrylic polyol resin composition comprising a reactive silane. Acrylic polyol resin composition disclosed in the prior art has the effect of lowering the viscosity when the molecular weight increases by using an epoxy-based reactive diluent monomer.

However, when a certain amount or more of the epoxy-type reactive diluent monomer is used, a phenomenon occurs in which the strength of the coating film decreases, and the amount of use thereof is limited. On the other hand, when increasing molecular weight further, the problem that the viscosity of resin rises excessively arises. Viscosity can be lowered by increasing the amount of solvent used, but storage stability is poor after dispersion, and thus there is a limit in improving coating properties such as water resistance through high molecular weight resin.

Republic of Korea Patent Publication No. 10-2014-0115397

The present invention provides a water dispersion two-component acrylic polyol resin composition having excellent storage stability after water dispersion. In addition, the present invention is applied to a urethane top coat, and provides an acrylic polyol resin composition having excellent overall coating film properties such as gloss, appearance, water resistance, solvent resistance, weather resistance, adhesion, corrosion resistance, and strength.

Moreover, this invention provides the urethane coating composition containing the acrylic polyol resin composition mentioned above and an isocyanate hardening | curing agent.

The present invention is a mixed monomer containing three or more of non-functional (meth) acrylate monomers, nonionic hydrophilic reactive monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers and unsaturated monomers, reactive silanes, epoxy-based reactive compounds, An acrylic polyol resin composition comprising a high boiling point plasticizer and a solvent is provided.

The present invention provides a water-dispersible acrylic polyol resin composition comprising an acrylic polyol resin, an amine compound, and water, which is a polymer of the acrylic polyol resin composition.

Moreover, this invention provides the urethane coating composition containing the main part containing the water-dispersible acrylic polyol resin mentioned above, and the hardening | curing agent part containing an isocyanate.

The aqueous acrylic polyol resin composition according to the present invention has a higher molecular weight of the resin, a smaller amount of volatile solvent, and excellent storage stability without sedimentation even after long-term storage, compared to conventional acrylic polyol resin dispersions. Coating film properties such as gloss, appearance, water resistance, solvent resistance, weather resistance, adhesion, corrosion resistance, and strength can be imparted.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail. However, the present invention is not limited only to the following contents, and each component may be variously modified or optionally mixed as necessary. Therefore, it is to be understood that all changes, equivalents, and substitutes included in the spirit and scope of the present invention are included.

In this specification, "(meth) acrylate" shows an acrylate and methacrylate, and "(meth) acryl" shows an acryl and methacryl. In the present specification, "monomer" and "monomer" have the same meaning. The monomer in the present invention is distinguished from an oligomer and a polymer, and refers to a compound having a weight average molecular weight of 1,000 or less. In the present specification, "unsaturated group" refers to an ethylenically unsaturated group. And, "polyol" or modification thereof broadly refers to a material having an average value of at least two hydroxyl groups per molecule.

<Acryl polyol resin composition>

The acrylic polyol resin composition according to the present invention is a mixed monomer containing three or more of a non-functional (meth) acrylate monomer, a nonionic hydrophilic reactive monomer, a carboxyl group-containing monomer, a hydroxyl group-containing monomer and an unsaturated monomer, and a reactive silane. , An epoxy-based reactive compound, a high boiling point plasticizer and a solvent.

Hereinafter, the composition of the acrylic polyol resin composition will be described in detail.

Monomer mixture

The acrylic polyol resin composition of this invention mixes at least 3 types or more of the conventional monomers in the art which can form an acrylic polyol resin. Examples of the monomer that can be used include nonfunctional (meth) acrylate monomers, nonionic hydrophilic reactive monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers, unsaturated monomers, and the like.

As an example, a monomer mixture containing a nonionic hydrophilic reactive monomer, a carboxyl group-containing monomer and a hydroxyl group-containing monomer can be used. As another example, a monomer mixture including all of a nonfunctional (meth) acrylate monomer, a nonionic hydrophilic reactive monomer, a carboxyl group-containing monomer, a hydroxyl group-containing monomer and an unsaturated monomer can be used. The monomers can be used in combination in specific component ratios.

Non-functionality  ( Meta ) Acrylate  Monomer

Non-functional (meth) acrylate monomers serve to improve the weatherability and adhesion of the acrylic polyol resin. As the nonfunctional (meth) acrylate monomer, a (meth) acrylate monomer known in the art, that is, an acrylate monomer that does not contain a functional group may be used without limitation. For example, a nonfunctional alicyclic (meth) acrylate monomer, a nonfunctional aliphatic (meth) acrylate monomer, or both can be used.

Non-functional alicyclic (meth) acrylate monomers are monomers in the form of cycloaliphatic esters of acrylic acid and methacrylic acid. Non-limiting examples of non-functional alicyclic (meth) acrylate monomers that can be used include cyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate with alkyl groups, 4-tert-butylcyclohexyl (meth) Acrylate, norbornyl (meth) acrylate, isobonyl (meth) acrylate and the like. The above-mentioned components can be used individually or in combination of 2 or more types.

The nonfunctional aliphatic (meth) acrylate monomer may be an alkyl (meth) acrylate monomer having 1 to 18 carbon atoms. Non-limiting examples of non-functional aliphatic (meth) acrylate monomers that can be used include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. The above-mentioned components may be used alone or in combination of two or more thereof.

The content of the nonfunctional (meth) acrylate monomer is not particularly limited, and may be, for example, 10 to 50 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the non-functional (meth) acrylate monomer exceeds 50 parts by weight, the content (OHV, mgKOH / g) of the hydroxyl group-containing monomer reacting with the curing agent is relatively low, thereby deteriorating the physical properties of the coating film. On the other hand, when the content of the non-functional (meth) acrylate monomer is less than 10 parts by weight, the hardness, weather resistance, and adhesion of the coating film become insufficient.

Nonionic  Hydrophilic Reactive Monomer

The nonionic hydrophilic reactive monomer serves to further improve water dispersibility by forming a hydrophilic protective colloid on the outer surface of the acrylic polyol resin. As the nonionic hydrophilic reactive monomer, conventional monomers in the art including a nonionic hydrophilic group may be used without limitation.

The nonionic hydrophilic reactive monomer may be an etherified unsaturated monomer including a polyalkylene oxide group having a molecular weight of 200 to 3,000 g / mol, for example, 350 to 1,000 g / mol. Ethylene oxide, propylene oxide or a mixed form thereof may be used as the alkylene oxide group.

The nonionic hydrophilic reactive monomer may be represented by the following Chemical Formula 1.

Where

X is hydrogen or an alkyl group having 1 to 6 carbon atoms,

R is an alkyl group having 1 to 18 carbon atoms,

n is an integer of 5-25.

The content of the nonionic hydrophilic reactive monomer is not particularly limited and may be, for example, 1 to 20 parts by weight, for example, 1 to 10 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the nonionic hydrophilic reactive monomer exceeds 20 parts by weight, the viscosity of the resin is excessively increased, and the water resistance of the coating film is reduced due to the introduction of excessive hydrophilic groups. On the other hand, when the content of the nonionic hydrophilic reactive monomer is less than 1 part by weight, the effect of water dispersion improvement due to introduction of hydrophilic groups may not be sufficiently expressed.

Carboxyl group-containing monomer

The carboxyl group-containing monomer imparts hydrophilicity to the acrylic polyol resin and serves to impart water dispersion stability by forming an anionic group upon neutralization by the amine compound described below. As the carboxyl group-containing monomer, unsaturated monomers containing carboxyl groups or carboxylic anhydride groups known in the art may be used without limitation. For example, it may be an olefinically unsaturated monomer containing a carboxyl group and / or a carboxylic anhydride group.

Non-limiting examples of carboxyl group-containing monomers that can be used include acrylic acid, methacrylic acid, β-carboxyethyl acrylate, crotonic acid, fumaric acid, maleic hydride, itaconic acid, maleic acid monoalkyl esters, and the like. Monoalkyl esters of dibasic acids or unhydrides. The monomers mentioned above may be used alone or in combination of two or more thereof. In one example, acrylic acid and / or methacrylic acid may be used.

The content of the carboxyl group-containing monomer is not particularly limited, and may be, for example, 5 to 30 parts by weight, for example, 5 to 20 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the carboxyl group-containing monomer exceeds 30 parts by weight, the viscosity is high due to excessive hydrophilic groups, water resistance is lowered and the pot life is shortened. On the other hand, if less than 5 parts by weight of water dispersion is not made properly, storage stability after dispersion is poor.

Hydroxyl group-containing monomer

The hydroxyl group-containing monomer plays a role of reacting with polyisocyanate which is a curing agent of the urethane coating composition described below to crosslink. As the hydroxyl group-containing monomer, unsaturated monomers containing hydroxyl groups known in the art may be used without limitation. For example, it may be an unsaturated monomer such as hydroxyalkyl ester of unsaturated acrylic acid, for example, hydroxylalkyl (meth) acrylate having 2 to 12 carbon atoms.

Non-limiting examples of the carboxyl group-containing monomers that can be used include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, caprolactone modified heights. Roxy (meth) acrylate, etc. are mentioned. The above-mentioned components can be used individually or in combination of 2 or more types. For example, 2-hydroxyethyl (meth) acrylate can be used.

The content of the hydroxyl group-containing monomer is not particularly limited, and may be, for example, 10 to 50 parts by weight, for example, 10 to 30 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the hydroxyl group-containing monomer is less than 10 parts by weight, the coating film formation due to the crosslinking reaction is insufficient, the coating film properties are poor, when the content of more than 50 parts by weight it is difficult to fully express the effects of the present invention.

Unsaturated monomer

The unsaturated monomer serves to improve the gloss and appearance of the coating film formed by the crosslinking reaction between the acrylic polyol resin and the polyisocyanate curing agent described below. As the unsaturated monomer, a monomer having an ethylenically unsaturated group known in the art may be used without limitation.

The unsaturated monomer may be an aromatic styrene monomer having a refractive index of 1.5 to 1.7. When the unsaturated monomer having such a high refractive index is used, the gloss, water resistance, saline resistance, impact resistance, and adhesion of the coating film can be excellently expressed.

The content of the unsaturated monomer is not particularly limited, and may be, for example, 15 to 30 parts by weight, for example, 20 to 25 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the unsaturated monomer is less than 15 parts by weight, the relatively expensive acrylate monomer may be used in excess of necessary or gloss may be partially reduced. On the other hand, when used in excess of 30 parts by weight it is difficult to fully express the expected effect of the present invention.

In addition to the monomers described above, the acrylic polyol resin composition of the present invention may further include various types of monomers known in the art.

Responsive Silane

Reactive silane is introduced to improve the weatherability and adhesion of the acrylic polyol resin and to increase the crosslinking density, and can express solvent resistance, high weather resistance and scratch resistance. As the reactive silane, a conventional silane compound known in the art can be used without limitation, and examples thereof include epoxy silane, vinyl silane, acrylic silane, amino silane and the like.

Examples of the epoxysilanes include glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, epoxycyclohexylethyltrisilane, and the like. Examples of the vinyl silanes include vinyltrimethoxy silane, vinyltriethoxy silane, vinyltrimethoxyethoxy silane, vinylmethyldimethyl silane, and the like. Examples of the acrylic silanes include methacryloxypropyltrimethoxy silane and the like. Examples of aminosilanes include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, aminonehexyltrimethoxysilane, aminonehexylmethyldimethoxysilane, ethylaminopropylmethyldimethoxy Silanes and the like. The above-mentioned components can be used individually or in combination of 2 or more types. For example, methacryloxypropyl trimethoxysilane can be used.

The content of the reactive silane is not particularly limited, and may be included in an amount of 0.1 to 5 parts by weight, for example, 1 to 5 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the reactive silane is less than 0.1 parts by weight, improvement in physical properties such as weather resistance and adhesion through the reactive silane is insufficient, and when it exceeds 5 parts by weight, stability is poor such as forming a gel during synthesis due to excessive crosslinking reaction. Lose.

Epoxy Reactive Compound

In order for a coating film to show the outstanding water resistance, impact resistance, high hardness, etc., the high molecular weight of resin used is calculated | required. However, increasing the molecular weight of the acrylic polyol resin within a limited amount of solvent causes the viscosity to rise so that the water dispersion process becomes impossible or the desired water dispersion cannot be obtained. On the other hand, when additional solvent is added to lower the viscosity, there is a problem in that the dispersion stability is poor.

In the present invention, an epoxy reactive compound is used together with a solvent to prepare a high molecular weight acrylic polyol resin and at the same time adjust the viscosity. The epoxy reactive compound serves as a viscosity modifier, and in particular, it is possible to polymerize by reacting with a carboxyl group-containing monomer and to lower the viscosity when the molecular weight is increased.

As the epoxy reactive compound, those known in the art may be used without limitation, and for example, glycidyl ester compounds of α-branched monocarboxylic acids may be used.

The content of the epoxy reactive compound is not particularly limited, and may be, for example, 5 to 30 parts by weight, for example, 5 to 20 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the epoxy reactive compound is less than 5 parts by weight, it is difficult to form a low viscosity resin, and when it exceeds 30 parts by weight, the hardness of the coating film may be lowered.

High boiling point  Plasticizer

In the present invention, it is possible to increase the molecular weight of the resin to a certain level by using the above-described epoxy-based reactive compound, etc., if you want to further increase the molecular weight it is difficult to prevent the phenomenon of viscosity increase without increasing the solvent. On the other hand, when the amount of the solvent used is increased, storage stability such as sedimentation during storage for a long time after dispersion is poor.

Thus, in the present invention, in order to greatly improve the storage stability after water dispersion and to increase the molecular weight of the resin, a high boiling point plasticizer is mixed with the solvent.

The high boiling point plasticizer can be used without limitation as long as the plasticizer has a boiling point of 160 ° C. or higher. The high boiling point plasticizer may be an environmentally friendly high boiling point plasticizer while minimizing the glass transition temperature (Tg) of the coating film.

 As the high boiling point plasticizer, aromatic ester plasticizer, fatty acid plasticizer, trimellitate plasticizer, phosphate plasticizer, glycol plasticizer, and the like can be used. For example, an aromatic ester plasticizer can be used.

Examples of aromatic ester plasticizers include benzoate esters, dioctyl terephthalate (DOTP), diisodecyl phthalate (DIDP), or mixtures thereof. The aromatic ester plasticizer may be, for example, a benzoate ester plasticizer having a boiling point of 160 ° C. or higher, such as dipropylene glycol benzoate (benzoflex 9-88).

Since the aromatic ester plasticizer is a liquid, it can be used as a solvent of the acrylic polyol resin to further increase the molecular weight of the resin without adding a solvent. In addition, since the aromatic ester plasticizer is a hydrophobic plasticizer, by imparting hydrophobicity to the inner core of the resin particles to maximize the structural stability of the resin particles can be significantly improved storage stability during water dispersion.

The content of the high boiling point plasticizer is not particularly limited, and may be, for example, 1 to 15 parts by weight, for example, 1 to 10 parts by weight based on 100 parts by weight of the total acrylic polyol resin composition. When the content of the high boiling point plasticizer is less than 1 part by weight, the effect is insignificant, and when the content of the high boiling point plasticizer exceeds 15 parts by weight, the glass transition temperature of the acrylic polyol resin may be lowered, resulting in poor coating properties.

solvent

The acrylic polyol resin composition of this invention contains the conventional solvent known in the art.

The solvent may be one or more organic solvents selected from the group consisting of alcohol solvents, ethylene glycol solvents, ether acetate solvents, ester solvents, aromatic hydrocarbon solvents, ketone solvents, and mixed solvents thereof. Non-limiting examples of solvents that can be used include methanol, ethanol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, methyl carbitol, ethyl Alcohols such as carbitol; Ethylene glycols such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether; Ether acetates such as methyl cellosolve acetate, ethyl cellosolve acetate, and propylene glycol monomethyl ether acetate; Aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane and n-heptane; It can be used individually or in combination among ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and diisobutyl ketone. For example, propylene glycol monobutyl ether can be used.

The content of the solvent is not particularly limited, and may be, for example, 30 parts by weight or less, for example, 20 parts by weight or less based on 100 parts by weight of the total acrylic polyol resin composition. If the content of the solvent exceeds 30 parts by weight, the water dispersion stability of the acrylic polyol resin is poor, there is a risk of environmental damage due to the use of excess organic solvent.

<Water Dispersion Acrylic Polyol Resin Composition>

The water-dispersible acrylic polyol resin composition according to the present invention comprises an acrylic polyol resin, a neutralizer and water. If necessary, it may further include conventional polymerization initiators and at least one additive in the art.

The acrylic polyol resin of the present invention can be prepared by conventional methods known in the art, using the acrylic polyol resin composition described above. For example, an acrylic polyol resin polymer may be prepared through solution polymerization (radical polymerization) after adding a monomer mixture, a reactive silane and an initiator mixture to an organic solvent including an epoxy-based reactive compound and a high boiling point plasticizer.

In the polymerization step, as the initiator, conventional polymerization initiators known in the art may be used without limitation. For example, an azo compound, a peroxide, or these can be mixed. Non-limiting examples of initiators that can be used include 2,2'-azobisisobutyronitrile, 2,2'-azobis- (2-methylbutyronitrile), benzoyl peroxide, auroyl peroxide, gumenhydro Peroxide, t-butylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, and the like. The above-mentioned components can be used individually or in combination of 2 or more types. For example, t-amylperoxy-2-ethylhexanoate can be used.

In the present invention, in order to control the viscosity during the polymerization process, a conventional chain transfer agent known in the art may be selectively used. Non-limiting examples of the chain transfer agent that can be used include thiol chain transfer agents such as octanethiol, decanthiol, dodecanethiol, hexadecanethiol, and octadecanethiol; unsaturated hydrocarbon compounds such as α-methylstyrene dimer, α-terpinene, γ-terpinene, dipentene, and tapinolene. The aforementioned components may be used alone or in combination thereof.

The polymerization temperature can be appropriately adjusted depending on the type of the initiator and the solvent used, and is not particularly limited. For example, the polymerization temperature may be 0 to 200 ° C, and in another example, 120 to 180 ° C.

After neutralizing the acrylic polyol resin polymerized as described above with a neutralizing agent, a water-dispersible acrylic polyol resin composition may be obtained through a conventional dispersion process in the art. For example, after neutralizing at least a portion of the carboxylic acid groups contained in the acrylic polyol resin using a neutralizing agent, water (eg, ion-exchanged water) may be added dropwise while stirring the neutralized material to disperse the water. The dropping method and dropping temperature of water can be appropriately adjusted within the range known in the art, and are not particularly limited. For stable phase separation, a method of slowly introducing ion-exchanged water at a temperature of 100 ° C. or lower may be used. The amount of water to be added is not particularly limited and may be appropriately adjusted within the content range known in the art.

The neutralizing agent is not particularly limited as long as it is a component capable of neutralizing a carboxylic acid group, and conventional amine compounds in the art may be used. As an example, a secondary or tertiary amine compound can be used, for example, dimethylethanolamine, N-methyl diethanolamine, diethanolamine, triethanolamine and the like. The above-mentioned components can be used individually or in combination of 2 or more types. For example, a mixture of dimethylethanolamine and triethanolamine can be used.

The amount of the neutralizing agent is not particularly limited and may be, for example, 30 to 150 mol%, for example, 50 to 100 mol%, based on the total number of 100 mol of the carboxylic acid groups included in the acrylic polyol resin.

The acrylic polyol resin obtained by the above-described process may have a specific acid value by using a carboxyl group-containing monomer, and may have a specific hydroxyl group by using a hydroxyl group-containing monomer. In addition, by applying a high boiling point plasticizer having a hydrophobicity to a certain content, while ensuring a high molecular weight of the resin, while minimizing the content of the solvent can exhibit excellent storage stability after water dispersion without an increase in viscosity.

The acrylic polyol resin may have an acid value of 5 to 50 mgKOH / g, for example, 5 to 40 mgKOH / g, and another example of 10 to 40 mgKOH / g. When the acid value of the acrylic polyol resin is more than 50 mgKOH / g because the hydrophilicity of the obtained resin is excessively high, the water resistance is weak, and the viscosity of the resin is increased while being solubilized rather than water dispersion, the solid content may be lowered. On the other hand, if the acid value is less than 5 mgKOH / g, the water dispersion of the resin is not made properly, the water dispersion stability is also lowered, it may be impossible to manufacture the water-dispersible acrylic polyol resin composition itself.

The acrylic polyol resin may have a solid value hydroxyl value (OHV, OH group content) of 50 to 250 mgKOH / g, for example, 70 to 200 mgKOH / g, and other examples of 100 to 200 mgKOH / g. When hydroxyl value (OHV) is less than 50 mgKOH / g, coating film formation is inadequate by crosslinking reaction with the hardening | curing agent mentioned later, and physical property falls. On the other hand, when the hydroxyl value exceeds 250 mg KOH / g, it is difficult to fully express the effect.

The acrylic polyol resin may have a weight average molecular weight (Mw) of 1,000 to 50,000 g / mol, for example 2,000 to 30,000 g / mol. If the weight average molecular weight (Mw) is less than 1,000 g / mol, it is difficult to secure the water resistance and water dispersion stability of the coating film, when it exceeds 50,000 g / mol it is difficult to secure the excellent appearance because of poor workability and poor leveling. In addition, the glass transition temperature (Tg) of the acrylic polyol resin may be 0 to 65 ℃.

The water dispersion acrylic polyol resin composition has a solid content of 0 to 60 parts by weight, a viscosity of 1,000 to 30,000 cps, and may have a storage stability of 30 days or more at room temperature.

<Urethane coating composition>

The urethane coating composition of this invention contains the main part containing the water-dispersible acrylic polyol resin mentioned above, and the hardening | curing agent part containing an isocyanate.

Isocyanate included in the curing agent portion serves to form a urethane resin by the isocyanate group (-NCO) contained in the molecule reacts with the hydroxyl group (-OH) contained in the above-mentioned acrylic polyol resin.

As isocyanate, any conventional isocyanate compound used for polyurethane synthesis in the art can be used without limitation. For example, methylene diphenyl diisocyanate (MDI), toluene diisocyante (TDI), hexamethylene diisocyanate (Hexa Methylene Di-isocyanate (HMDI), isophorone di-isocyanate, IPDI), metaxylene diisocyanate (MXDI), tetramethylxylene diisocyanate (TMXDI), alicyclic diisocyanate (H12 MDI) made by adding hydrogen to the benzene ring of the MDI, xylene diisocyanate (XDI) Diisocyanate (hydrogenated XDI), polyisocyanate, etc. made by adding hydrogen to the benzene ring of the alicyclic ring. The above-mentioned components may be used alone or in combination of two or more thereof. For example, polyisocinates containing hydrophilic groups can be used. The curing agent may include silanes containing a functional group as necessary. Moreover, it can use, after diluting the said hardening | curing agent with the organic solvent.

The acrylic polyol resin of this invention forms a urethane coating film through a crosslinking reaction with the polyisocyanate compound which is a hardening | curing agent. The amount of the curing agent used may be appropriately adjusted according to the use. In one example, the equivalent of the isocyanate in the curing agent portion relative to 1 equivalent of the hydroxyl group in the acrylic polyol resin of the main portion may be 0.5 to 3.0, for example 0.8 to 2.0, other examples 1.0 to 2.0. If the hydroxy group remains outside the equivalent range, the hardness and strength of the coating film may be reduced, or the isocyanate group may remain and bond with moisture to cause foaming or cracking of the coating film.

The water-soluble two-component urethane coating composition of the present invention may optionally further include at least one additive conventionally used in the field of coating, within the range that does not impair the inherent properties of the composition.

Non-limiting examples of the additives that can be used include antioxidants, ultraviolet absorbers, ultraviolet stabilizers, flow regulators, polymerization inhibitors, leveling agents, wetting agents, antibacterial agents, coupling agents, surfactants, pigments, dispersants, lubricants, flame retardants, defoamers, Colorants, curing accelerators, diluents, chain extenders, adhesion improvers, curing retardants, surface conditioners, softeners, thickeners, defoamers, weathering additives, desiccants, appearance modifiers, coupling agents, water absorbing agents, coupling agents, colorants or these two Mixtures of species or more. The content of the additive may be appropriately added within the content range known in the art, for example, may be 0.1 to 10 parts by weight based on the total weight of the coating composition.

The urethane coating composition of the present invention may be prepared according to a conventional method known in the art, for example, the main portion containing the above-described water-dispersible acrylic polyol resin, the hardener portion containing the isocyanate, and the aforementioned 1 as necessary. It can be prepared by mixing more than one additive in a specific ratio.

By coating the above-mentioned urethane coating composition on a substrate and curing, a cured coating film suitable for various applications can be formed.

As the substrate, any conventional substrate in the art to which a paint is applicable may be applied without limitation. Non-limiting examples of substrates include glass, aluminum, iron, zinc and other metal substrates, polyethylene, polyvinyl chloride, ABS, fiber reinforced plastics, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polystyrene, polypropylene And plastic substrates such as polyester, polyolefin, acrylic resin, epoxy resin and nylon resin, synthetic leather, wood, fiber, paper and the like.

The coating method and the hardening method of a coating film at the time of forming a coating film using the said urethane coating composition are not restrict | limited, According to a use, it can adjust suitably. Examples of the coating method include dip coating, brush coating, roll brush coating, spray coat, roll coat, dip coat, bar coat, flow coat and the like. As a hardening method, there exist normal temperature hardening, heat hardening, etc., and hardening conditions etc. can be set suitably according to a use.

Since the urethane coating composition of the present invention is water-soluble, it is not only environmentally friendly, but also has a beautiful appearance after coating, and has excellent coating strength such as water resistance and hardness. Therefore, the urethane coating composition of the present invention is not only applicable to various applications to which a conventional urethane coating is applied, such as industrial coating, but also to various other process steps and uses.

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.

Example 1-3

Example 1

As shown in Table 1, 19 parts by weight of propylene glycol n-butyl ether (PnB) in a four-necked flask, 20 parts by weight of glycidyl ester of α-branched monocarboxylic acid (Cardura E10P, Hexion), high boiling point After adding 7.5 parts by weight of a plasticizer (aromatic ester plasticizer, Benzoflex 9-88) and raising the temperature to 160 ° C, 25 parts by weight of styrene (SM), 20 parts by weight of isobornyl methacrylate (IBOMA), and n-butyl acrylate ( n-BA) 1.5 parts by weight, 21 parts by weight of 2-hydroxyethyl methacrylate (2-HEMA), 3 parts by weight of hydrophilic reactive monomer (ADEKA ER10), 10 parts by weight of acrylic acid (AA), reactive silane (3- The mixed liquid which mixed 2 weight part of methylacryloxy propyl methyl diethoxysilane, KBM-503) and 0.9 weight part of initiators (Di-tert-amyl peroxide, DTAP) was dripped over 3 hours. After completion of the dropping, the mixture was kept at 160 ° C for 1 hour, and then 0.25 part by weight of an initiator was added thereto, held for 1 hour, and cooled. After cooling, 1.5 parts by weight of dimethylethanolamine (DMEA) and 3.3 parts by weight of triethanolamine (TEOA) were added to neutralize for 30 minutes, and then 130 parts by weight of ion-exchanged water (DIW) was added thereto over 30 minutes while stirring to obtain a hydroxyl value of 160 mgKOH. / g, an acid value of 28 mgKOH / g, a water dispersion two-component acrylic polyol resin composition A having a glass transition temperature (Tg) of 33 ℃ was prepared.

Example  2

As shown in Table 1, the hydroxyl value is 160 mgKOH / g, the acid value is 28 mgKOH / g, glass transition temperature (Tg) 33 in the same manner as in Example 1, except that 5.0 parts by weight of a high boiling point plasticizer was used. An aqueous dispersion two-component acrylic polyol resin composition B was prepared.

Example  3

As shown in Table 1, the hydroxyl value is 160 mgKOH / g, the acid value is 28 mgKOH / g, glass transition temperature (Tg) 33 in the same manner as in Example 1, except that 2.5 parts by weight of a high boiling point plasticizer was used. An aqueous dispersion two-component acrylic polyol resin composition C was prepared.

Comparative Example 1-3

Comparative Example 1

As shown in Table 1, except that the high boiling point plasticizer is not added, the hydroxyl value is 160 mgKOH / g, the acid value is 28 mgKOH / g, glass transition temperature (Tg) 35 ℃ in the same manner as in Example 1 Phosphorous water dispersion two-component acrylic polyol resin composition D was prepared.

Comparative example  2

As shown in Table 1, the hydroxyl value is 160 mgKOH / g in the same manner as in Example 1, except that 25 parts by weight of a propylene glycol n- butyl ether (PnB) solvent was used without adding a high boiling point plasticizer Was 28 mgKOH / g, and a water dispersion two-component acrylic polyol resin composition E having a glass transition temperature (Tg) of 35 ° C was prepared.

Comparative example  3

As shown in Table 1, except that 30 parts by weight of a propylene glycol n-butyl ether (PnB) solvent was used without adding a high boiling point plasticizer, the hydroxyl value was 160 mgKOH / g in the same manner as in Example 1, and the acid value Was 28 mgKOH / g, and a water dispersion two-component acrylic polyol resin composition F having a glass transition temperature (Tg) of 35 ° C was prepared.

[ Experimental Example  One. Water dispersion 2-part  Evaluation of Physical Properties of Acrylic Polyol Resin]

Physical properties of the aqueous dispersion two-component acrylic polyol resins A to F prepared in Examples 1-3 and Comparative Examples 1-3 were evaluated as follows, and the results are shown in Table 1 above.

(1) Measurement of nonvolatile content (NV%)

Each resin composition was taken on a flat plate having a diameter of 80 cm, evenly dried, and then dried in an oven (150 ° C.) for 15 minutes, and the remaining solid content was measured.

(2) molecular weight measurement

Measured using GPC (Gel Permeation Chromatography, Waters Alliance E2695 / 2414D), Shodex KF805, 804, 802.5 was used as a column, THF was used as a solvent.

(3) viscosity measurement

Brookfield viscometer LVF was used based on the test method of rotational viscometer of non-Newtonian material of ASTM 2196, measured at spindle No. 3, 30 rpm, and the unit is cps (mPa.s).

(4) Storage stability after water dispersion

The aqueous dispersion two-component acrylic polyol resin was stored in a transparent container for 30 days, and then the state of the resin composition was visually observed. The delamination phenomenon and the degree of viscosity change were evaluated according to the following criteria.

No layer separation and no viscosity change: 5 (good)

-Layer separation is not obvious but changes in viscosity: 3 (weak temperature)

-Sediment formation: 1 (bad)

As shown in Table 1, the water-dispersible acrylic polyol resin composition of Example 1-3 containing a high boiling point plasticizer has a low viscosity compared to the water-dispersible acrylic polyol resin composition of Comparative Examples 1-3 containing no plasticizer. In addition, it was found that the dispersion stability of water dispersion was improved. In particular, in the case of Comparative Example 1 using less solvent for the high molecular weight of the resin, the viscosity was excessively increased during the synthesis of the resin, and in Comparative Example 2-3 in which the amount of the solvent was increased, the workability and storage stability were inferior. Could.

[ Experimental Example  2. Evaluation of Physical Properties of Urethane Resin Composition]

After diluting the aqueous dispersion two-component acrylic polyol resins A to F prepared in Examples 1-3 and Comparative Examples 1-3 with ion-exchanged water, a polyisocyanate curing agent (XP2655, Bayer) was added with stirring to disperse the aqueous dispersion. The urethane resin composition was prepared. The equivalent of isocyanate in the added polyisocyanate curing agent was 1.44 relative to the hydroxyl group equivalent in the acrylic polyol resin.

After applying the prepared water-dispersible urethane resin composition on the substrate, it was dried for 30 minutes and then dried in an oven (80 ℃) for 30 minutes to evaluate the physical properties of the resin coating as follows, the results are shown in Table 1 Indicated.

(1) coating film appearance

Evaluation criteria of the appearance were good: 5, normal (there was some defects): 3, bad: 1.

(2) water resistance

The coating film test piece was immersed in warm water at room temperature for 480 hours, and then the change of appearance was visually observed. Evaluation criteria are as follows.

-No change: 5, some blisters occur: 3, many blisters occur: 1

As shown in Table 1, when the urethane resin composition of Example 1-3 containing a high boiling point plasticizer was used, it was confirmed that the appearance characteristics and water resistance of the coating film is excellent. On the other hand, when the urethane resin composition of Comparative Example 1-3 which does not contain a high boiling point plasticizer was used, serious physical property decline was exhibited in the external appearance and water resistance of a coating film.

As described above, when using the acrylic polyol resin composition according to the present invention, it is possible to produce a high molecular weight acrylic polyol resin having a good viscosity and water dispersion storage stability while minimizing the amount of solvent. It was confirmed that the coating film formed using such a high molecular weight acrylic polyol resin is excellent in appearance characteristics and water resistance.

Claims (10)

Monomer mixtures containing three or more of non-functional (meth) acrylate monomers, nonionic hydrophilic reactive monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers and unsaturated monomers,
Reactive silane,
Epoxy-based reactive compounds,
High boiling point plasticizers and
solvent
Acrylic polyol resin composition comprising a. The acrylic polyol resin composition of claim 1, wherein the nonionic hydrophilic reactive monomer is represented by the following Chemical Formula 1:
[Formula 1]

Where
X is hydrogen or an alkyl group having 1 to 6 carbon atoms,
R is an alkyl group having 1 to 18 carbon atoms,
n is an integer from 5 to 25. The acrylic polyol resin composition of claim 1, wherein the unsaturated monomer is an aromatic styrene monomer having a refractive index of 1.5 to 1.7. The method of claim 1, wherein the high boiling point plasticizer has an boiling point of more than 160 ℃ aromatic esters (aromatic esters) plasticizers, fatty acid (Aliphates) plasticizers, trimellitates (Primellitates) plasticizers, phosphate plasticizers (Phosphates) plasticizers and 1 or more acrylic polyol resin composition selected from the group consisting of Glycol plasticizer. The acrylic polyol resin composition according to claim 4, wherein the aromatic ester plasticizer is at least one selected from the group consisting of benzoate ester, dioctyl terephthalate and diisodecyl phthalate. According to claim 1, 10 to 50 parts by weight of the non-functional (meth) acrylate monomer, 1 to 20 parts by weight of the nonionic hydrophilic reactive monomer, 5 to 5 carboxyl group-containing monomers, based on 100 parts by weight of the total acrylic polyol resin composition 30 parts by weight, 10 to 50 parts by weight of hydroxyl group-containing monomer, 15 to 30 parts by weight of unsaturated monomer, 0.1 to 5 parts by weight of reactive silane, 5 to 30 parts by weight of epoxy-based reactive compound, 1 to 15 parts by weight of high boiling point plasticizer Part and 30 parts by weight or less of an acrylic polyol resin composition. A water-dispersible acrylic polyol resin composition comprising an acrylic polyol resin, a neutralizing agent and water polymerized from the acrylic polyol resin composition of any one of claims 1 to 6. According to claim 7, wherein the acrylic polyol resin has a hydroxyl value of 50 to 250 mgKOH / g based on solids, an acid value of 5 to 50 mgKOH / g, a weight average molecular weight of 1,000 to 50,000 g / mol, the glass transition temperature ( A water-dispersible acrylic polyol resin composition having a Tg) of 0 to 65 ° C. 8. The water-dispersible acrylic polyol resin composition according to claim 7, wherein the solid content is 0 to 60 parts by weight, the viscosity is 1,000 to 30,000 cps, and has a storage stability of 30 days or more at room temperature. The urethane coating composition containing the main part containing the water-dispersible acrylic polyol resin of Claim 7, and the hardening | curing agent part containing an isocyanate.