KR20050006825A - Water-based polyurethane resine containing a ring structure and method for preparing the same - Google Patents

Abstract

PURPOSE: Provided are an aqueous polyurethane resin having a cyclic structure which is excellent in water dispersion stability and smear fastness, has satisfactory flexibility resistance, mechanical strength and heat resistance and is free from residual solvent odor, and its preparation method. CONSTITUTION: The method comprises the steps of reacting a polyol and a single chain glycol having a carboxyl group with a diisocyanate to prepare a prepolymer; dissolving the prepolymer completely in an organic solvent; neutralizing it with an amine having an intramolecular cyclic structure to prepare a self-emulsifying prepolymer; adding water to the self-emulsifying prepolymer to emulsify it; extending chain with an amine having intramolecular at least two primary amine groups; and removing the organic solvent, wherein the contents of the single chain glycol, the diisocyanate and the amine having an intramolecular cyclic structure are 0.05-2.0 mol, 1.5-4.0 mol and 0.8-1.1 mol, respectively, to 1 mol of the polyol.

Description

Water-based polyurethane resine containing a ring structure and method for preparing the same}

The present invention relates to an aqueous polyurethane resin having a cyclic structure and a method for preparing the same, and more particularly, to use a short chain glycol having a carboxyl group in a molecule when preparing a prepolymer, and to neutralize the prepolymer with an amine having an intramolecular cyclic structure. By preparing a self-emulsifying prepolymer, the present invention relates to an aqueous polyurethane resin having excellent adhesion to mechanical materials, mechanical strength, heat resistance, and water dispersion stability, and having no odor such as amine.

Conventional adhesives contain a large amount of organic solvents, but in recent years, interest and development of water-based polyurethane resins are increasing due to social demands such as environmental protection, resource saving, and safety.

As a method of producing an aqueous polyurethane resin, a method of forcibly dispersing a hydrophobic polyurethane using a large amount of emulsifier and a method of introducing a hydrophilic group into a polyurethane skeleton to prepare a self-emulsifying resin and then dispersing it in water (US Patent 4,066,591, U.S. Patent 4,147,679, U.S. Patent 4,857,565, and U.S. Patent 5,552,496) and the method of using an emulsifier not only satisfies the physical properties of the resin itself but also may cause environmental pollution. The study of emulsion type water-based polyurethane is actively progressing.

Water-based polyurethane resin must have excellent physical properties such as adhesion to various adherends, water resistance of the resin itself, mechanical strength, heat resistance, flex resistance, and water dispersion stability, and have little or no residual solvent, resulting in no smell. Should not, yet a product that satisfies the above characteristics has not been developed yet.

Therefore, in the present invention, extensive research has been conducted to solve the above-mentioned problems. As a result, when preparing a prepolymer, short chain glycol having a carboxyl group in a molecule is used, and the prepolymer is neutralized with an amine having an intramolecular cyclic structure. Adhesion, water resistance, bending resistance, and water dispersion stability are excellent at the same time, and have a ring-shaped structure in the molecule, which is excellent in heat resistance and mechanical strength, and does not produce residual organic solvent or amine odor. The invention has been completed based on this.

Accordingly, an object of the present invention is an aqueous polyurethane having a cyclic structure that is excellent in adhesion, water resistance, flex resistance, water dispersion stability, and solvent resistance, as well as excellent in heat resistance and mechanical strength, and does not smell of residual organic solvent or amine. It is to provide a method for producing a resin.

Another object of the present invention is to provide an aqueous polyurethane resin having a cyclic structure produced by the above method.

The method for producing an aqueous polyurethane resin having a cyclic structure for achieving the object of the present invention, in the preparation of an aqueous polyurethane resin, to prepare a prepolymer by reacting a short chain glycol having a polyol and intramolecular carboxyl groups with diisocyanate, After completely dissolving the prepolymer with an organic solvent, it is neutralized with an amine having an intramolecular cyclic structure to prepare a self-emulsifying prepolymer. The water is emulsified by adding water to the self-emulsifying prepolymer, and an amine having at least two primary amine groups in the molecule. After performing the chain extension reaction, the step of removing the organic solvent in the reactant, wherein the content of the short chain glycol having a carboxyl group in the molecule with respect to 1 mol of the polyol is 0.05 to 2.0 mol, the content of the diisocyanate Is 1.5 to 4.0 mol, the intramolecular cyclic The amine having a structure consists of 0.8 to 1.1 moles.

An aqueous polyurethane resin having a cyclic structure for achieving another object of the present invention is produced by the above method.

Hereinafter, the present invention will be described in more detail.

As described above, the method for producing an aqueous polyurethane resin according to the present invention is a prepolymer having an isocyanate group at both ends of a molecule by reacting a polyol and short-chain glycol having an intramolecular carboxyl group with diisocyanate in the preparation of the aqueous polyurethane resin. Get

The polyol used in the present invention is a polyester-based polyol having at least two primary hydroxyl groups at both ends of the molecule, and has a number average molecular weight of 200 to 10,000, preferably 500 to 3,000.

The polyester-based polyol is obtained through the condensation reaction of dibasic acid and dihydric alcohol, and the dibasic acid may be used alone or in combination of two or more kinds from adipic acid, azelaic acid, and succinic acid, but adipic acid is used alone. It is desirable to. The dihydric alcohol is ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentylglycol, 2-methylpropanediol, 1,4-cyclohexanedimethanol, and bisphenol A It can be used alone or in combination of two or more, but it is preferable to use 1,4-butanediol and 1,6-hexanediol alone or mixed.

The short-chain glycol having a carboxyl group in the molecule used in the present invention uses 2,2-dimethylol propionic acid (DMPA), or 2,2-dimethylol butanoic acid (DMBA), preferably 2,2-dimethylol moiety. Carbonic acid (DMBA) is used. Its amount is used in the range of 0.05 to 2.0 moles per 1 mole of the polyol, if less than 0.05 moles of water dispersion stability is poor, if it exceeds 2.0 moles the viscosity of the water-dispersed resin is too high and water resistance is poor.

The diisocyanate used in the present invention can be used for both aliphatic, cycloaliphatic, and aromatic, but in order to satisfy various physical properties of flex resistance, yellowing resistance, and water dispersion stability, aliphatic and cycloaliphatic diisocyanates may be used alone or in combination of two or more. Use it. Examples thereof include isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (1,6-HDI), 4,4'-methylenebiscyclohexane diisocyanate (4-4'-H12MDI), 1,3 Xylene diisocyanate (1,3-XDI), and / or 1,3-tetramethylxylene diisocyanate (1,3-TMXDI).

The amount of diisocyanate used is in the range of 1.5 to 4.0 moles per 1 mole of polyol. When the amount of diisocyanate is less than 1.5 moles, the viscosity of the prepolymer is too high, making it difficult to disperse water, and the mechanical strength of the final resin is weak and exceeds 4.0 moles. The dispersion stability and the bending resistance of the final resin are lowered.

In the present invention, a self-emulsifying prepolymer is prepared by neutralizing the prepolymer with an amine having a cyclic structure in the molecule.

Amines having a cyclic structure in the molecule include 2-aminopyrimidine, 2-aminopyridine, 2-amino-4-hydroxy-6-methylpyrimidine, aminopyrazine, 2-amino-4,6-dimethoxypy Limidine, 2-amino-2-cyclohexen-1-one, 2-amino-2-thiazole, 2- (2-aminoethyl) pyridine, 6-methylisocytosine, 2-amino-4-pyridone, 6-phenylisocytosine, 6-methyl-2-amino-4-pyrimidine, 2-amino-4,6-dimethoxy-1,3,5-triazine, 2-amino-4-dimethoxyamino-6 -Methyl-1,3,5-thiazine, 2-amino-4,6-dimethyl-1,3,5-triazine, 2-amino-4-ethoxy-6-methyl-1,3,5- Triazine, 2-amino-4-ethyl-6-methoxy-1,3,5-triazine, 2-amino-4-methoxy-6-methyl-1,3,5-triazine and 2-amino Used alone or in combination of two or more from -4-methyl-6-phenyl-1,3,5-triazine, the amount of use is 0.8 to 1.1 moles per 1 mole of short-chain glycol (DMPA or DMBA) having a carboxyl group in the molecule. In the range of Use.

If the amount is less than 0.8 mol, water dispersion stability and water resistance is insufficient, and if the amount exceeds 1.1 mol, the appearance of the final aqueous polyurethane resin is poor.

The prepolymer thus prepared is completely dissolved in an organic solvent having a low boiling point in order to facilitate water dispersion.

The organic solvent used in the present invention may be used singly or in combination of two or more from acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, N, N-dimethylformamide, and N, N-dimethylacetamide. Preferably, acetone or methyl ethyl ketone is used. The amount of the organic solvent is preferably 60 to 250 parts by weight based on 100 parts by weight of the prepolymer. If the amount is less than 60 parts by weight, the viscosity of the prepolymer solution is too high, it is difficult to disperse the water, and if it exceeds 250 parts by weight, productivity and economy are not good.

Meanwhile, in the present invention, after completely dissolving the prepolymer in an organic solvent, a primary amine having an ethylene oxide and a propylene oxide repeating unit structure in the molecule may be further added. Primary amines having ethylene oxide and propylene oxide repeating unit structures in the molecule used in the present invention are those of Jeffamine XTJ-505, XTJ-506, XTJ-507, XTJ- of Huntsman Corporation, USA. 508, and XTJ-234 or the like are used alone or in combination of two or more thereof, and 1 mol or less is used per 1 mol of the polyol. If the amount of use exceeds 1 mol, there is a disadvantage in that the mechanical strength, heat resistance and water resistance of the final resin are poor.

According to the present invention, the self-emulsifying prepolymer is emulsified by adding water, performing a chain extension reaction with a chain extender, and finally removing the organic solvent under reduced pressure to obtain an aqueous polyurethane.

The chain extender is a polyamine compound containing at least two primary amine groups in the molecule, hydrazine, ethylene diamine, 1,3-propane diamine, 1,4-butane diamine, 1,5-pentane diamine, di One or more selected from ethylene triamine, triethylene tetraamine, diaminohexane, isophorone diamine, dicyclohexylmethylene diamine and 1,6-hexamethylene diamine may be used and mixed. The amount of the chain extender used is preferably 80 to 100% of the theoretical equivalent required to prepare the final polyurethane polymer.

Thus, the aqueous polyurethane resin prepared according to the present invention is excellent in moisture stability, water resistance, flex resistance, heat resistance and the like, in particular, does not smell of residual solvent.

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

Example 1

1 mol of polyester polyol having a molecular weight of 2000 prepared from 1500 g of 1,6-hexanediol and 1500 g of adipic acid, 0.5 mol of 2,2-dimethylolbutanoic acid, 1.5 mol of 1,6-hexamethylene diisocyanate, and isophorone After adding 1 mole of diisocyanate and reacting at 90 ° C. for 3 hours, neutralization was performed with 0.5 mole of 2-aminopyridine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule.

The prepared polyurethane prepolymer was cooled to 60 ° C., and then 2700 g of acetone was added to completely dissolve the prepolymer. 3700 g of water was added thereto, and 1 mole of 1,6-hexamethylene diamine was added dropwise thereto. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

Example 2

1 mol of polyester polyol having a molecular weight of 2000 prepared from 1200 g of 1,4-butanediol and 1500 g of adipic acid, 0.5 mol of 2,2-dimethylolbutanoic acid, 1.5 mol of 1,6-hexamethylene diisocyanate, and isophorone diisocyanate 1 mole was added and reacted at 90 ° C. for 3 hours, followed by neutralization with 0.5 mole of 2-aminopyridine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule.

The prepared polyurethane prepolymer was cooled to 60 ° C., and then 2700 g of acetone was added to completely dissolve the prepolymer. Then, 0.1 mol of Jeffamine XTJ507 was added together with 3700 g of water, and 1 mol of 1,6-hexamethylene diamine was added to water. Dissolve and add dropwise. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

Example 3

1 mol of polyester polyol prepared from 1200 g of 1,4-butanediol and 1500 g of adipic acid, 0.7 mol of 2,2-dimethylolbutanoic acid, 2.5 mol of 1,6-hexamethylene diisocyanate, and isophorone diisocyanate After adding 1.5 mol, the mixture was reacted at 90 DEG C for 3 hours, and neutralized with 0.7 mol of 2-aminopyridine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule.

The prepared polyurethane prepolymer was cooled to 60 ° C., 3200 g of acetone was added to completely dissolve the prepolymer, and then 4100 g of water was added thereto, and 1.3 mol of hexamethylene diamine was added dropwise thereto. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

Example 4

1 mol of polyester polyol prepared from 1200 g of 1,4-butanediol and 1500 g of adipic acid, 0.1 mol of 2,2-dimethylolbutanoic acid, 1.5 mol of 1,6-hexamethylene diisocyanate, and isophorone diisocyanate 1 mole was added and reacted at 90 ° C. for 3 hours, followed by neutralization with 0.1 mole of 2-aminopyridine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule. The prepared polyurethane prepolymer was cooled to 60 ° C., 1900 g of acetone was added to completely dissolve the prepolymer, and then 3300 g of water was added thereto, and 1.4 mole of 1,6-hexamethylene diamine was added dropwise thereto. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

Comparative Example 1

1 mol of polyester polyol prepared from 1200 g of 1,4-butanediol and 1500 g of adipic acid, 0.1 mol of 2,2-dimethylolbutanoic acid, 1.5 mol of 1,6-hexamethylene diisocyanate, and isophorone diisocyanate After 1 mole was added and reacted at 90 ° C. for 3 hours, neutralization was performed with 0.1 mole triethyl amine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule.

The prepared polyurethane prepolymer was cooled to 60 ° C., 1900 g of acetone was added to completely dissolve the prepolymer, and then 3300 g of water was added thereto, and 1.4 mol of hexamethylene diamine was added dropwise thereto. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

Comparative Example 2

1 mole of polyester polyol having a molecular weight of 2000 prepared from 1200 g of 1,4-butanediol and 1500 g of adipic acid, 3 moles of 2,2-dimethylolbutanoic acid, 3 moles of 1,6-hexamethylene diisocyanate, and isophorone diisocyanate After adding 2 mol and reacting at 90 DEG C for 3 hours, neutralization was performed with 3 mol of 2-aminopyridine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule.

The prepared polyurethane prepolymer was cooled to 60 ° C., 4200 g of acetone was added to completely dissolve the prepolymer, 5700 g of water was added thereto, and 2 moles of 1,6-hexamethylene diamine was added dropwise thereto. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

Comparative Example 3

1 mole of polyester polyol having a molecular weight of 2000 prepared from 1500 g of 1,6-hexanediol and 1500 g of adipic acid, 0.01 mol of 2,2-dimethylolbutanoic acid, 1.5 mol of 1,6-hexamethylene diisocyanate, and isophorone di After adding 1 mole of isocyanate and reacting at 90 ° C. for 3 hours, it is neutralized with 0.01 mole of 2-aminopyridine to prepare a polyurethane prepolymer having an isocyanate group at both ends of the molecule.

The prepared polyurethane prepolymer was cooled to 60 ° C., 2700 g of acetone was added to completely dissolve the prepolymer, and then 3700 g of water was added thereto, and 1.49 mol of 1,6-hexamethylene diamine was added dropwise thereto. This was stirred for 2 hours to proceed the chain extension reaction, and acetone in the solution was removed by distillation under reduced pressure to prepare an aqueous polyurethane resin.

The properties of the aqueous polyurethane resins prepared by the Examples and Comparative Examples above are summarized in Table 1 below.

* Water dispersion stability * Water resistance * Flexibility Mechanical strength Heat resistance Amine odor Example 1 Good Good Good Good Good Good Example 2 Good Good Good Good Good Good Example 3 Good Good Good Good Good Good Example 4 Good Good Good Good Good Good Comparative Example 1 Good Good Good Bad Bad Bad Comparative Example 2 Bad Bad Bad Good Bad Good Comparative Example 3 Bad - - - - -

* In case of Comparative Example 3, no dispersion.

1) Water dispersion stability: The presence or absence of the deposit at the time of manufacturing an aqueous polyurethane resin according to Examples 1-4 and Comparative Examples 1-3, when disperse | distributing or leaving the final aqueous polyurethane solution at room temperature for 1 week.

Good: No deposits generated, Poor: Deposits

2) Water resistance: The aqueous polyurethane solution prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was left at 50 ° C. for 3 days to prepare a film to compare the retention of tensile strength compared to that before leaving.

Good: [(Tension strength after standing) × 100 ÷ (Tension strength before standing)] is 80% or more

Poor: [(Tension strength after neglect) × 100 ÷ (Tension strength before neglect)] is less than 80%

3) Flex resistance: The aqueous polyurethane solution prepared in Examples 1-4 and Comparative Examples 1-3 was spray-coated and dried on the polyurethane foam for shoes, and then cracked on the surface during the flex resistance test using a Demattia Flexion Tester. Measure when this happens.

Good: 100,000 or more, Poor: less than 100,000

4) Mechanical strength: After the aqueous polyurethane film specimens prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were prepared, the tensile strength of the specimen was measured using a tensile strength tester.

Good: More than 300Kgf / ㎠, Bad: More than 300Kgf / ㎠

5) Heat resistance: After preparing the water-based polyurethane film specimens prepared according to Examples 1 to 4 and Comparative Examples 1 to 3, the specimens were placed in an oven at 70 ° C. for one week, and then the tensile strength tester was used to break the specimens. Compare the breaking strength of the entire specimen.

Good: [(Tension strength after standing) × 100 ÷ (Tension strength after standing)] is over 90%

Poor: [(tensile strength after neglect) × 100 ÷ (tensile strength before neglect)] is less than 90%

6) Amine odor: The presence of odors such as amines in the aqueous polyurethane urine solution prepared in Examples 1 to 4 and Comparative Examples 1 to 3 itself.

Good: No smell, Bad: Odor

As can be seen from Table 1, in the case of the aqueous pulley polyurethane resins synthesized according to Examples 1 to 4, water dispersion stability, water resistance, flex resistance, mechanical strength, heat resistance, odor, etc. are simultaneously good, but are synthesized in Comparative Examples 1-3. In the case of the resin of the water-based polyurethane, the water dispersion stability, water resistance, flex resistance, mechanical strength, heat resistance, and odor are not good at the same time.

As can be seen from the results of the above examples and comparative examples, the aqueous polyurethane resin prepared by the present invention not only has excellent water dispersion stability and water resistance, but also satisfies bending resistance, mechanical strength, and heat resistance at the same time. There is also an advantage that can be used as an adhesive for various adherends.

Claims (9)

In the manufacture of an aqueous polyurethane resin, A short chain glycol having a polyol and an intramolecular carboxyl group is reacted with a diisocyanate to prepare a prepolymer, the prepolymer is completely dissolved in an organic solvent, and then neutralized with an amine having an intramolecular cyclic structure to prepare a self-emulsifying prepolymer. Adding water to the self-emulsifying prepolymer to emulsify and performing a chain extension reaction with an amine having at least two primary amine groups in the molecule, followed by removing the organic solvent in the reactant, Here, the content of the short-chain glycol having a carboxyl group in the molecule with respect to 1 mol of the polyol is 0.05 to 2.0 mol, the content of the diisocyanate is 1.5 to 4.0 mol, the amine having the intramolecular cyclic structure is 0.8 to 1.1 mol. Method for producing an aqueous polyurethane resin, characterized in that. The method according to claim 1, wherein the polyol is a polyester polyol having at least two hydroxyl groups at the terminal of the molecule prepared by condensation of dibasic acid and dihydric alcohol, and has an average molecular weight of 200 to 10,000. The dibasic acid according to claim 2, wherein the dibasic acid is one or two or more mixtures selected from adipic acid, azelaic acid, and succinic acid, and the dihydric alcohol is ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentylglycol, 2-methylpropanediol, 1,4-cyclohexanedimethanol, and bisphenol A. 2. The method of claim 1, wherein the short-chain glycol having a carboxyl group in the molecule is 2,2-dimethylol propionic acid (DMPA) or 2,2-dimethylol butanoic acid (DMBA). The diisocyanate of claim 1, wherein the diisocyanate is isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (1,6-HDI), 4,4'-methylenebiscyclohexane diisocyanate (4,4 ' -H ₁₂ MDI), 1,3-xylene diisocyanate (1,3-XDI), and 1,3-tetramethylxylene diisocyanate (1,3-TMXDI) are used in combination with one or more Characterized in that. The method of claim 1, wherein the organic solvent is one or more mixtures of acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, N, N- dimethylformamide, and N, N- dimethylacetamide, The amount of use is 60 to 250 parts by weight based on 100 parts by weight of the prepolymer. The method of claim 1, wherein the amine having an intramolecular cyclic structure is 2-aminopyrimidine, 2-aminopyridine, 2-amino-4-hydroxy-6-methylpyrimidine, aminopyrazine, 2-amino-4, 6-dimethoxypyrimidine, 2-amino-2-cyclohexen-1-one, 2-amino-2-thiazole, 2- (2-aminoethyl) pyridine, 6-methylisocytosine, 2-amino- 4-pyridone, 6-phenylisocytosine, 6-methyl-2-amino-4-pyrimidine, 2-amino-4,6-dimethoxy-1,3,5-triazine, 2-amino-4- Dimethoxyamino-6-methyl-1,3,5-thiazine, 2-amino-4,6-dimethyl-1,3,5-triazine, 2-amino-4-ethoxy-6-methyl-1 , 3,5-triazine, 2-amino-4-ethyl-6-methoxy-1,3,5-triazine, 2-amino-4-methoxy-6-methyl-1,3,5-tri And at least one selected from the group consisting of azine and 2-amino-4-methyl-6-phenyl-1,3,5-triazine. The amine of claim 1 wherein the amine having at least two primary amine groups in the molecule is hydrazine, ethylene diamine, 1,3-propane diamine, 1,4-butane diamine, 1,5-pentane diamine, diethylene triamine, tri A mixture of one or two or more selected from ethylene tetraamine, diaminohexane, isophorone diamine, dicyclohexylmethylene diamine and 1,6-hexamethylene diamine. An aqueous polyurethane resin having a cyclic structure produced by the method of any one of claims 1 to 8.