KR100343549B1 - A water-dispersive fluoro-polyurethane - Google Patents

Abstract

The present invention relates to a water dispersible fluorine-based polyurethane, and more particularly to a fluorine-based polyurethane prepared by copolymerizing a fluorine-based macromonomer, a diisocyanate and a hydrophilic diol, wherein the fluorine-based macromonomer is represented by the following formula (1) Is a polymerized monomer containing an unsaturated double bond with a hydrocarbon-based comonomer, which gives the polyurethane excellent surface properties such as water repellency, oil repellency, and antifouling properties. It relates to a polyurethane. Since the fluorine-based polyurethane of the present invention has excellent solubility or dispersibility in water, it can be usefully used as a coating agent in textiles, paper, construction industry, etc., and water can be solved by using organic solvents as a dispersion medium. .

_{XC n F 2n - (Y)} -OCOCR 1 = CH 2

In Formula 1, Y is-(CH) ₂ -,-(CH ₂ ) _m- , -CH ₂ CH (OH) (CH ₂ ) _m- , or -SO ₂ NR ₂ (CH ₂ ) _m- ; R ₁ is H or —CH ₃ ; R ₂ is a C ₁ to C ₄ alkyl group; X is H or a halogen atom; m is an integer from 2 to 6; n represents the integer of 3-21.

Description

Fluorinated water dispersible polyurethane {A water-dispersive fluoro-polyurethane}

The present invention relates to a fluorine-based water-dispersible polyurethane, and more particularly, to a fluorine-based polyurethane made of fluorine-based macromonomer, diisocyanate and hydrophilic diol, a monomer containing a perfluorinated alkyl group selected from monomers represented by the following formula (1) A fluorine-based macromonomer prepared from a comonomer having an unsaturated double bond with; Diisocyanate; In addition, the present invention relates to a fluorine-based polyurethane having excellent surface properties such as antifouling property, water repellency, oil repellency, and the like, by copolymerizing diol containing a hydrophilic group. In addition, the fluorine-based polyurethane of the present invention is excellent in solubility or dispersibility in water, and can be usefully used as a coating agent in textile, paper, construction industry, etc. As water is used as a dispersion medium, it is possible to solve the problem of environmental pollution by organic solvents. have.

Formula 1

_{XC n F 2n - (Y)} -OCOCR 1 = CH 2

In Formula 1, Y is-(CH) ₂ -,-(CH ₂ ) _m- , -CH ₂ CH (OH) (CH ₂ ) _m- , or -SO ₂ NR ₂ (CH ₂ ) _m- ; R ₁ is H or CH ₃ ; R ₂ is a C ₁ to C ₄ alkyl group; X is H or a halogen atom; m is an integer from 2 to 6; n represents the integer of 3-21.

Fluorinated copolymers prepared from conventional polymer polymerization methods such as radical, condensation or ion polymerization of monomers copolymerizable with monomers containing perfluoroalkyl groups have very low energy surface properties and are known to be very useful as various low energy surface modifiers. (FMC, 1981, CMC). The perfluoroalkyl group-containing fluorine-based copolymer is excellent in water repellency, oil repellency and fouling resistance and can be used as a coating agent for fibers, plastics, rubber, ceramics, metals, etc., but poor adhesion to the substrate.

The perfluoroalkyl group is chemically stable and water-repellent because it has a molecular structure in which thirteen carbons are twisted due to the steric hindrance of fluorine atoms attached to the carbon, and a structure in which carbon atoms are protected by fluorine atoms. It has excellent surface properties such as oil repellency, release property and surface mobility. However, the fluorine-based copolymer containing the perfluoroalkyl group is not soluable because of poor solubility derived from the chemical stability of the perfluoroalkyl group, and is not easily dissolved even in a fluorocarbon solvent (eg, CCl ₄ ). In addition, since the bond between carbon atoms is inflexible due to its molecular structure, when used as a surface modifier, it gives a very hard touch, and when used alone, it has a limitation in providing excellent surface properties and soft texture unique to fluorine compounds.

Thus, in order to solve the problems such as poor solubility and hard surface feel, a method of introducing a perfluoroalkyl group into a urethane structure exhibiting soft properties has been proposed. As a result, the surface can be smoother than the fluorine-based polymer alone and has excellent adhesion and abrasion resistance. Therefore, various industries such as artificial leather, textile processing, transparent waterproofing, gloss processing, electrodeposition paint for automobiles, adhesives and binder resins are modified. It can be applied in the field to impart water repellency, oil repellency, antifouling property and friction resistance.

On the other hand, the existing surface coating polyurethane is used in the form of dissolved or dispersed in volatile organic solvents, when used as a mechanical material or coating, the working environment is very poor, and the environmental pollution problem caused by the leakage of organic solvents is very serious Organic solvent recovery after use has a difficult problem. In particular, as environmental concerns have increased in recent years, polyurethanes using organic solvents have been regulated due to increased environmental regulations.They have gradually declined in the market and turned into water-soluble or water-dispersible emulsions that use water as a solvent. It is losing. As water-dispersible polyurethane does not use solvents or uses only a minimum amount of water and uses water as a dispersion medium, there is no danger of toxicity and fire, and there is little pollution of air and water. Therefore, research and development for commercialization of water-dispersible polyurethane is active. It's going on.

In order to improve the water solubility and dispersibility of the water-dispersible polyurethane, it contains a large amount of hydrophilic segments or hydrophilic groups in the molecule. The hydrophilic group used at this time increases the surface free energy of the urethane during coating. There was a disadvantage in reducing the surface properties of the formed polyurethane coating film.

Recently, studies on water-dispersible fluorine-based polyurethanes containing fluorine compounds described above have been actively conducted as new attempts to increase the surface properties of the hydrophilic-containing polyurethanes.

Specifically, a water-dispersible fluorine-based polyurethane using a tetrafluoroethylene oxide-based diol containing a fluorine group having a molecular weight of 2000 to 4000 represented by the following Chemical Formulas 2 to 4 as a monomer has been proposed [tetrafluoroethylene oxide, trade name Z-DOL, Ausimont SpA, EP 273,449 A1 (1987); 5333,159 A1 (1992); 689,908 A1; S. Yang et al., J. Macromol. Sci.-re and Appl., Chem., A30 (23), pp. 241 to 252 (1993).

_{^{HO-R 1 -CF 2 -O- (}} C 2 F 4 O) a - (CF 2 O) b -CF 2 -R 1 -OH

HO-R ¹ -CF ₂ -O- (C ₂ F ₄ O) _c- (CF ₂ O) _d- (C (CF ₃ ) FCF ₂ O) _e- (C (CF ₃ FO) _f -CF _2- R ¹ -OH

HO-R ¹ -CF ₂ -O- (C ₃ F ₆ O) _g -CF ₂ -R ¹ -OH

In Chemical Formulas 2 to 4, R ¹ is CH ₃ or CH ₂ CH ₃ .

When synthesizing a water-dispersed polyurethane using the tetrafluoroethylene tetrafluoride-based diol monomer of Formula 2 to 4 when used as a coating, there is a disadvantage that low energy surface properties are not sufficiently expressed.

Such poor surface characteristics can be explained in two ways. First, the surface properties of solids including polymers depend on the chemical composition of the outermost molecular layer. The fluorine-containing monomer tetrafluoride ethylene oxide contains a large amount of oxygen atoms, which are hydrophilic groups, and thus has no hydrophilic compounds. Compared to the case of using the low energy surface properties are lowered. In addition, surface free energy is increased by oxygen atoms in ethylene tetrafluoride in the outermost molecular layer, and the surface migration effect due to hydrophobic defect of fluorine-containing aggregates is poor, resulting in low energy surface characteristics. Degrades. The two causes are accompanied by a mutually rising or falling effect with each other, the minute hydrophobic difference of the aggregate in the polyurethane has a great effect on the performance of the final product fluorine-containing water-dispersible polyurethane.

The inventors of the present invention, in order to find the optimal conditions of low-energy surface properties and water dispersion stability using another series of fluorine-based monomers other than ethylene tetrafluoride series, studies on synthesis, water dispersibility, surface properties and surface modification effects It has been intensive for years. As a result, a fluorinated macromonomer capable of condensation polymerization was prepared using a comonomer having an unsaturated double bond with a monomer containing a perfluorinated alkyl group. The fluorine-based macromonomer has completed the present invention by producing a fluorine-based polyurethane stably dispersed in an aqueous solution by copolymerization with diisocyanate and hydrophilic diol. Since the fluorine-based polyurethane of the present invention has better water dispersibility than the conventional fluorine-based polyurethane and has excellent surface properties when forming a coating film, when used as a coating agent in textile, paper, construction industry, water repellency, oil repellency, fouling resistance, etc. It shows excellent functionality and can prevent contamination by organic solvents, which is industrially useful and is expected to create high added value.

Accordingly, an object of the present invention is to provide a fluorine-based polyurethane and a synthesis method which are excellent in low energy surface properties and capable of water dispersion.

The present invention is a fluorine-based polyurethane prepared by copolymerizing a fluorine-based macromonomer, diisocyanate and hydrophilic diol containing a perfluoroalkyl group,

As the fluorine-based macromonomer, water dispersibility prepared by condensation polymerization of a macromonomer capable of condensation polymerization and a hydrophilic monomer prepared using a comonomer having an unsaturated double bond with a monomer containing a perfluoroalkyl group represented by Formula 1 It is characterized by a fluorine-based polyurethane.

Formula 1

_{XC n F 2n - (Y)} -OCOCR 1 = CH 2

In Formula 1 above, Y is-(CH) ₂ -,-(CH ₂ ) _m- , -CH ₂ CH (OH) (CH ₂ ) _m- , or -SO ₂ NR ₂ (CH ₂ ) _m- ; R ₁ is H or —CH ₃ ; R ₂ is a C ₁ to C ₄ alkyl group; X is H or a halogen atom; m is an integer from 2 to 6; n represents the integer of 3-21.

Referring to the present invention in more detail as follows.

The fluorine-based polyurethane of the present invention is prepared by copolymerizing a specific fluorine-based macromonomer containing a diol group capable of intramolecular condensation reaction with a diisocyanate and a hydrophilic diol which are commonly used, and has a water dispersibility, low energy surface properties and adhesion to a substrate. Because of its excellent properties, it can be suitably used as a coating agent in textile, paper, and construction industries.

In the production of the fluorine-based polyurethane of the present invention, the fluorine-based macromonomer to be used as a characteristic uses a monomer containing a perfluorinated alkyl group represented by the formula (1) to give a low energy surface properties, and perfluorinated during condensation polymerization Comonomers having hydrocarbon-based unsaturated double bonds are polymerized to enhance solubility of alkyl macromonomers in other water-soluble monomers.

As the comonomer having an unsaturated double bond, a conventional one is used, and specifically, acrylic acid (AA), methacrylic acid (MAA), methyl acrylate (MA), methyl methacrylate (MMA), ethyl acrylate (EA) , Ethyl methacrylate (EMA), butyl acrylate (BA), butyl methacrylate (BMA), hexyl acrylate (HA), hexyl methacrylate (HMA), dodecyl acrylate (DA), dodecyl meta Acrylate (DMA), stearyl acrylate (SA), stearyl methacrylate (SMA), benzyl acrylate (BA), benzyl methacrylate (BMA), cyclohexyl acrylate (CHA), cyclohexyl methacrylate Acrylate (CHMA), acrylonitrile (AN), acrylamide (AAM), vinyl acetate (VA), styrene, N-methylol acrylamide (MAAM), N-methylol methacrylamide (MMAAM), N-methyl Ole acrylamide butyl ether (MAAMBE), N-butoxy methacrylamide (BAAM), N-butoxy methacrylamide ( BMAAM), 2-hydroxyacrylate (HEA), 2-hydroxymethacrylate (HEMA), 2-hydroxypropylacrylate (HPA) and 2-hydroxypropylmethacrylate (HPMA) alone or Two or more kinds can be used together.

A fluorine-based macromonomer prepared by polymerizing a monomer containing a perfluorinated alkyl group represented by Formula 1 and a comonomer having an unsaturated double bond has a number average molecular weight of 1,500 to 30,000 and more preferably 2,000 to 5,000 monomers. Hydroxyl groups are contained at both ends to allow condensation reaction with other monomers. In the fluorine-based macromonomer, a monomer containing a perfluorinated alkyl group represented by Formula 1 and a comonomer having an unsaturated double bond are present in a weight ratio of 95/5 to 5/95, wherein the perfluorinated alkyl group is contained in the fluorine-based macromonomer. When the content of the monomer is insufficient, the low energy surface properties are very poor, when the lack of the comonomer having an unsaturated double bond, there is a disadvantage that the condensation polymerization is not smoothly performed because the solubility of the other monomer is reduced during the condensation polymerization.

In addition, the fluorine-based macromonomer is synthesized using a diol-derived branching regulator for the purpose of introducing a diol group and molecular weight control, such a diol-derived branching regulator is preferably thioglycerol, 3-mulsotto-1,2-propanediol and the like. Can be used.

Subsequently, the prepared fluorine-based macromonomer is a comonomer to prepare a fluorine-based polyurethane by a conventional urethane condensation reaction with diisocyanate and hydrophilic diol. The fluorine-based polyurethane has excellent surface properties as the perfluorinated alkyl group is contained in the molecule, and may exhibit a smooth surface feel as the urethane group is contained.

Thus, the comonomer may be used a conventional one used in the production of polyurethane.

Specifically, the diisocyanate is hexamethylene diisocyanate (HMDI), toluene diisocyanate (TDI), diphenylmethyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), 2,2,4 (2,4,4) -Trimethyl hexamethylene diisocyanate (TMDI), p-phenylene diisocyanate (PPDI), 4,4'-dicyclohexylmethane diisocyanate (TODI), 3,3'-dimethyldiphenyl 4,4'-diisocyanate (TODI), dianisidine diisocyanate (DADI), m-xylene diisocyanate (XDI), tetramethylsilane diisocyanate (TMXDI), isophoric diisocyanate (IPDI), 1,5-naphthalene diisocyanate (NDI ), t-1,4-cyclohexyl diisocyanate (CHDI) can be used alone or in combination of two or more.

The hydrophilic diol may be used alone or in combination of two or more selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), polycaprolactonediol (PCLD) and polybutadienediol (PBDD). .

In order to enhance the water oxidation and solubilization of the synthesized urethane and to facilitate the parallel use with other compounds, a comonomer which is combined with an acid or a base to enhance water solubility and compatibility is used. As the carboxylic acid monomer, it is selected from dimethylol acetic acid (DMA), dimethyl propionic acid (DMPA), dimethylol butyric acid (DMBA) and 2,2-bishydroxymethyl propionic acid (HMPA), To prepare cationic polyurethanes, 3-dimethylamino-1,2-propanediol (DMAPD), methyldiethanolamine (MDA), dimethyldiethanolamine (DMEA), butyl diethanolamine (BDA) and methyldiiso It can be used alone or in combination of two or more selected from propanolamine (MDPA).

As described above, the water-dispersible fluorine-based polyurethane of the present invention is excellent in water repellency, oil repellency and fouling resistance by being used as a coating agent in textile, paper, construction industry due to low energy surface property, stable water dispersibility and high adhesion to the substrate. It shows functionality. In particular, the use of water as a dispersion medium improves the working environment and fundamentally prevents the problems of environmental pollution caused by organic solvents. Currently, the total amount of water-dispersible fluorinated polyurethane is dependent on imports, and the demand is continuously increasing. The outlook for high value-added industries is great.

Hereinafter, the present invention will be described in more detail with reference to the following Examples, but the present invention is not limited thereto.

Preparation Example Synthesis of Macromonomer

Next, a fluorine-based macromonomer was prepared by the radical polymerization method using the composition and content of Table 1. Perfluoroalkylethyl acrylate (C ₈ F ₁₇ C ₂ H ₄ OCOCH = CH ₂ ; hereinafter referred to as "FA") was used as a monomer containing a perfluoroalkyl group, and methyl methacrylate ( Hereinafter, "MMA") and 3-mercapto-1,2-propanediol (HSCH ₂ CH (OH) CH ₂ OH; hereafter referred to as "TG") were used as diol-derived branch regulators.

First, FA, MMA, TG, THF and AIBN were added to a 1000 ml three-necked glass reactor equipped with a stirrer and a thermometer, and then sealed and degassed using nitrogen or helium, which is an inert gas, for oxygen removal. Subsequently, the reactor was stirred for 10 minutes at room temperature for dissolution of the solute, and the reaction temperature was raised to 60 ° C. for 10 hours. The resulting fluorine-based macromonomer was precipitated using n-hexane, and then purified three times using THF and n-hexane to remove unreacted material, and then dried in a vacuum oven at room temperature to obtain a fluorine-based macromonomer.

The molecular weight and composition of the prepared fluorine-based macromonomer were measured by GPC and ¹ H-NMR. In order to investigate the surface characteristics, water and methylene iodide were used as contact liquids, and the contact angles were measured by the anchoring method, and the surface free energy was calculated by using the geometric mean equation. .

Example 1 Water Dispersible Fluorine-Based Polyurethane Prepared by Mac-1

The water-dispersible fluorine-based polyurethane was prepared using the fluorine-based macromonomer Mac-1 prepared in the above preparation, and the content thereof was changed as shown in Table 2 below.

First, Mac-1, 50 g of hexamethylene diisocyanate (HMDI), 94 g of polyethylene glycol 600 (PEG 600), 9 g of dimethylpropionic acid (DMPA), and 82.25 g of acetone were added to the same reactor as in Preparation Example, and then sealed. Purge with nitrogen and then dissolve while stirring. Subsequently, after raising the reaction temperature to 60 ° C., 0.06 g of dibutyl tin dilaurate (DBTDL), a reaction catalyst, was added and reacted for 9 hours, and then cooled to room temperature to prepare a fluorine-based polyurethane.

Immediately, the prepared fluorine-based polyurethane was dispersed in water to prepare a coating composition containing the fluorine-based polyurethane. First, 82.25 g of acetone was added to the fluorine-based polyurethane to reduce the viscosity, and then diluted. Then, a stirring speed was increased, and a mixture of 5.97 g of dimethylethanolamine (DMEA) and 82.25 g of distilled water was added thereto. Here, 435.37 g of distilled water was again added, and acetone, an organic solvent, was distilled off to prepare a coating composition stably dispersed in an aqueous solution.

Subsequently, the particle size distribution was measured using a Coulter particle size analyzer (Coulter Model N4SD) to measure the water-dispersible fluorine-based polyurethane properties prepared above, and after forming a film on the slide glass in the contact angle measurement method using a fixing coalescence method Surface free energy was calculated, and these results are shown in Table 2 below.

Example 2 Water Dispersible Fluorine-Based Polyurethane Prepared by Mac-2

Using Mac-2 prepared in the above Preparation Example, a fluorine-based polyurethane was synthesized in the same manner as in Example 1, and dispersed to prepare a coating composition. At this time, the properties of the prepared water-dispersible fluorine-based polyurethane are as shown in Table 3 below.

Example 3 Water Dispersible Fluorine-Based Polyurethane Made of Mac-3

Using Mac-3 prepared in the above Preparation Example, a fluorine-based polyurethane was synthesized in the same manner as in Example 1, and dispersed to prepare a coating composition. At this time, the properties of the prepared water-dispersible fluorine-based polyurethane are as shown in Table 4 below.

Comparative example

As a comparative example, Z-DOL 4000, a fluorine-based macromonomer containing a commercially available perfluorinated polyether, was used, and was carried out in the same manner as in Example 1. The prepared fluorine-based polyurethane had a relatively good water dispersion with a particle size of 370 nm, and the surface free energy of the formed film was measured to be 21 dyn / cm.

In the above results, the water-dispersible fluorine-based polyurethanes of Examples 1 to 3 had surface free energy of 15 to 20 dyn / cm, which showed superior surface characteristics and showed a stable dispersion state in aqueous solution. In addition, as the content of the fluorine-based macromonomer increases in the production of the fluorine-based polyurethane, the content of the perfluorinated alkyl group in the fluorine-based polyurethane molecule is increased to have a low surface free energy, thereby exhibiting excellent surface properties. However, when the content of the fluorine-based macromonomer is excessive, as the perfluorinated alkyl group is contained in excess, the particle size uniformity and the size of the water-dispersible fluorinated polyurethane have decreased due to the increase in hydrophobicity.

On the other hand, in the comparative example, the diol monomers of ethylene tetrafluoride-based series used in the production of fluorine-based macromonomers contained a large amount of hydrophilic groups in the molecule, thus showing high surface free energy.

As described above, according to the present invention, a fluorine-based polyurethane was prepared using a macromonomer containing a perfluorinated alkyl group, followed by water dispersion to prepare a coating composition. The water dispersible fluorine-based polyurethane exhibited very low energy properties with a surface free energy of 15 to 20 dyn / cm and formed stable water dispersion. As a result, the coating composition can be usefully used as a coating agent in textiles, paper, construction industry, etc. due to its excellent surface properties, it is possible to fundamentally eliminate the environmental pollution problems caused by organic solvents by not using an organic solvent as a dispersion medium. .

Currently, water-soluble polyurethanes depend on total imports and their usage is on a steady increase, so the water-dispersible polyurethanes prepared according to the present invention are expected to have very good profitability prospects.

Claims (5)

In the fluorine-based polyurethane prepared by copolymerizing a fluorine-based macromonomer, diisocyanate and hydrophilic diol containing a perfluoroalkyl group, The water-dispersible fluorine-based polyurethane, characterized in that the fluorine-based macromonomer is prepared using a comonomer having an unsaturated double bond with a monomer containing a perfluoroalkyl group represented by the following formula (1). Formula 1 _{XC n F 2n - (Y)} -OCOCR 1 = CH 2 In Formula 1, Y is-(CH) ₂ -,-(CH ₂ ) _m- , -CH ₂ CH (OH) (CH ₂ ) _m -or -SO ₂ NR ₂ (CH ₂ ) _m- ; R ₁ is H or —CH ₃ ; R ₂ is a C ₁ to C ₄ alkyl group; X is H or a halogen atom; m is an integer from 2 to 6; n represents the integer of 3-21. The method of claim 1, wherein the fluorine-based macromonomer is prepared by using a monomer containing a perfluorinated alkyl group represented by Formula 1 and a comonomer having an unsaturated double bond in a 95/5 to 5/95 weight ratio Water dispersible fluorine based polyurethane. The method of claim 1 or 2, wherein the comonomer having an unsaturated double bond is acrylic acid (AA), methacrylic acid (MAA), methyl acrylate (MA), methyl methacrylate (MMA), ethyl acrylate (EA ), Ethyl methacrylate (EMA), butyl acrylate (BA), butyl methacrylate (BMA), hexyl acrylate (HA), hexyl methacrylate (HMA), dodecyl acrylate (DA), dodecyl Methacrylate (DMA), stearyl acrylate (SA), stearyl methacrylate (SMA), benzyl acrylate (BA), benzyl methacrylate (BMA), cyclohexyl acrylate (CHA), cyclohexyl meta Acrylate (CHMA), acrylonitrile (AN), acrylamide (AAM), vinyl acetate (VA), styrene, N-methylol acrylamide (MAAM), N-methylol methacrylamide (MMAAM), N- Methylolacrylamide butyl ether (MAAMBE), N-butoxy methacrylamide (BAAM), N-butoxy methacrylamide (BMAAM), 2-hydrate Hydroxyacrylate (HEA), 2-hydroxy methacrylate (HEMA), 2-hydroxypropyl acrylate (HPA), 2-hydroxypropyl methacrylate (HPMA), characterized in that the one or more selected from Water dispersible fluorine based polyurethane. The method of claim 1, wherein the carboxylic acid monomers include dimethylol acetic acid (DMA), dimethyl propionic acid (DMPA), dimethylol butyric acid (DMBA) and 2,2-bishydroxymethylpropionic acid (HMPA). Fluorine-based water-soluble polyurethane synthesized by condensation polymerization of single or two or more selected from The method of claim 1, wherein 3-dimethylamino-1,2-propanediol (DMAPD), methyldiethanolamine (MDA), dimethylethanolamine (DMEA) butyl diethanol to prepare the cationic water-dispersible fluorine-based polyurethane A water-soluble fluorine-based polyurethane synthesized by condensation polymerization of one or two or more selected from amine (BDA) and methyldiisopropanolamine (MDPA) together.