KR100842411B1 - Composition of Water-soluble Polyurethane/Epoxy Hybrid and Method of Producing the Same - Google Patents

Abstract

The present invention relates to a water-soluble polyurethane compound and a method for producing the same.

The present invention provides a stable water dispersion system by mixing a polyurethane prepolymer containing an ionic group with a modified compound obtained by reacting the terminal of an epoxy resin with a silane compound and dispersing it in water. The present invention relates to a method for preparing a powder that can be re-emulsified by dehydration and drying by salting them, and a composition for preparing a re-emulsified polyurethane / epoxy hybrid powder.

 The present invention is to produce a water-dispersed polyurethane / epoxy hybrid by powdering through dehydration and drying by salting and re-emulsification in water to simplify the transport and storage compared to conventional water-dispersed polyurethane There is. In addition, when the powder is re-emulsified in water and used to increase the solid content, it is possible to shorten the drying time.

  Reemulsifying Powder Resin, Water Dispersed Polyurethane, Epoxy Resin, Hybrid, Silane

Description

Composition for preparing water-dispersible polyurethane / epoxy hybrid resin powder and preparation method thereof {Composition of Water-soluble Polyurethane / Epoxy Hybrid and Method of Producing the Same}

1 is a reaction schematic of a prepolymer for preparing a water-dispersed polyurethane prepared by the reaction of an isocyanate with a glycol having a carboxylic acid group and a polyol,

2 is a schematic diagram illustrating the production of a silane modified product for producing a silane-modified epoxy resin using an aminosilane compound and an epoxy resin,

3 is a representative chemical formula of the water-dispersed polyurethane / epoxy hybrid according to the present invention.

The present invention relates to a water-dispersed polyurethane compound and a method for manufacturing the same, and more particularly, to a novel water-dispersed polyurethane / epoxy hybrid having a larger particle size and better water dispersibility than a conventional water-dispersed polyurethane prepolymer. Novel water-dispersed polyurethane powders obtained by further flocculating and drying the water-dispersible polyurethane / epoxy hybrids and a process for producing them.

In general, polyurethane is widely used in foams, fibers, elastomers, paints, adhesives and the like. In particular, polyurethane has good adhesion, chemical resistance, and mechanical properties, and is widely used for the production of paints and adhesives.

Polyurethanes, which are used as paints and adhesives today, are mainly used as solvents dissolved in organic solvents. However, as the severity of environmental problems caused by volatile organic solvents has recently emerged, the necessity of developing water-dispersed polyurethanes has been raised to solve them. Accordingly, water-dispersed polyurethanes have been developed and demand is increasing, but performances such as water resistance and mechanical strength are inferior to those of organic solvents.

Looking at the production method of the water-dispersed polyurethane that is developed today and the product obtained by the production method, it is progressed by the method shown in FIG. Looking at this in more detail, polyol and diisocyanate are reacted with each other using lower glycols such as dimethylol propionic acid (DMPA) or dimethylol butanoic acid (DMBA) as reactants. Resulting polyurethane prepolymers. Thereafter, by introducing ionic groups into the main chain of the polyurethane prepolymer, water solubility is imparted, thereby allowing self emulsification without adding a surfactant separately.

However, the water-dispersed polyurethane prepolymer prepared in this way tends to cause precipitation when stored for a long time, and has a poor storage stability. Also, since it is less emulsified in water, it is expensive to transport to other regions. There is a disadvantage to bear. In addition, the conventional water-dispersed polyurethane prepolymer has a disadvantage in that the water resistance and mechanical properties of the coating film is weak when used as a raw material of the paint after drying.

On the other hand, with respect to the manufacturing method of the water-dispersed polyurethane can be exemplified the powdering technology of the synthetic resin copolymer as a similar technical field. For example, in order to simplify the storage, transportation and use of polymer latex for paints and adhesives obtained through emulsion polymerization, a technique for powdering them has been developed and used for cement mixing. Powdered resins used for this purpose are acrylic copolymers, ethylene-vinylacetate copolymers, styrene-butadiene copolymers, and the like, which have a thermal property in which a coating film can be formed at room temperature. Such a synthetic resin copolymer may be used as an adhesive resin after being manufactured by a method of powdering moisture through spray drying at a high temperature so that a coating film is not formed in a drying process. However, such a synthetic resin copolymer has a disadvantage in that, when used as a paint after re-emulsification, its dry coating film exhibits poor water resistance.

On the other hand, the polyurethane elastomer has a low glass transition temperature of the main chain segment of the polyol which imparts flexibility, so that spray drying at a high temperature is impossible, and thus spray drying at a high temperature cannot be performed. Therefore, no technique for powdering a polyurethane resin has been reported to date.

As such, in recent years, polyurethane-based paints and adhesives using organic solvents have been replaced by water-dispersed polyurethanes due to environmental problems. However, water resistance, mechanical properties, and storage stability are limited. There is a need to develop a new raw material that can solve the stability problem of the bed and complement the water resistance and mechanical properties.

Accordingly, an object of the present invention is to provide a water-dispersible polyurethane / epoxy resin composition that can replace a solvent-type polyurethane, can be re-emulsified, and has improved storage stability, water resistance after drying, and mechanical properties.

Another object of the present invention is to provide a method for producing a water-dispersible polyurethane / epoxy resin composition which can replace a solvent-based polyurethane, can be re-emulsified, and improves storage stability, water resistance after drying, and mechanical properties. There is.

The water-dispersible polyurethane / epoxy resin composition according to the present invention can be re-emulsified, and can be usefully used in the same manner as water-dispersed polyurethane paints and adhesives by dispersing it in an appropriate concentration in water, and when re-emulsifying in water Increasing the solid content has the advantage of showing a faster drying properties and excellent water resistance compared to the water-dispersed polyurethane.

The present invention relates to a water-dispersed polyurethane compound and a method for producing the same.

The present invention is to prepare a polyurethane prepolymer having an ionic group in the main chain, to prepare a prepolymer in which an epoxy group of an epoxy resin is reacted with a silane compound, and then to prepare a water-dispersed polyurethane / epoxy resin hybrid by dispersing them in water. And drying them to prepare powders capable of re-emulsification.

It is preferred that the water-dispersed polyurethane compound according to the invention is made of a polyurethane / epoxy hybrid.

단, 상기의 화학식(III)에 있어서, n은 1 이상의 정수를 나타낸다. In the present invention, the polyurethane / epoxy hybrid is more preferably a compound represented by the formula (III).

However, in said General formula (III), n represents the integer of 1 or more.

The manufacturing method of the water-dispersed polyurethane / epoxy hybrid according to the present invention,

a) A water-soluble polyurethane prepolymer is reacted with an aliphatic or aromatic or cycloaliphatic diisocyanate by reacting an ether or ester polyol having a weight average molecular weight of 500 to 6000 with a glycol comprising an ionizable carboxylic acid. Preparing and neutralizing with a neutralizing agent;

b) reacting an epoxy group of the epoxy resin with a silane compound to prepare an epoxy resin modified body in which the terminal of the epoxy is replaced with a silane group;

c) mixing the water-dispersed polyurethane prepolymer and the above-mentioned epoxy resin modified body to disperse and stir in water, and then adding a chain extender to prepare a chain-dispersed polyurethane compound by chain extension; It includes.

In the present invention, it is preferable to further include the step of preparing the water-dispersed polyurethane compound, d) adding dilute hydrochloric acid to the obtained solution, salting it, dehydrating it, and then drying to powder it.

Hereinafter, the present invention will be described in detail.

1. Preparation of Water Dispersible Polyurethane Prepolymer (I)

The present invention includes preparing a water-dispersed polyurethane prepolymer. This step can be carried out in a conventional manner. 1 shows schematically this step.

The present invention prepares a water-dispersed polyurethane prepolymer by reacting an aliphatic or aromatic or cycloaliphatic diisocyanate with an ether or ester polyol having a weight average molecular weight of 500 to 6000 with glycol.

In the present invention, representative examples of the aromatic diisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-toluene diisocyanate (2, 4-or 2,6-toluene diisocyanate (TDI), polymeric MDI.

In the present invention, as the alicyclic diisocyanate, 4,4-dicyclohexylmethane diisocyanate (H12MDI), isophorone diisocyanate (IPDI) 1,4-cyclohexane Diisocyanate (1,4-cyclohexylmethane diisocyanate (CHDI)).

In the present invention, the aliphatic or aromatic or cycloaliphatic diisocyanate may be used in the form of a single compound or a mixture, respectively. In addition, the said diisocyanate is not limited to the kind mentioned above as long as the objective of this invention can be achieved.

In the present invention, the polyol is preferably an ether polyol or an ester polyol having a weight average molecular weight of 500 to 6000.

In the present invention, it is preferable that the glycol contains a carboxylic acid which can be ionized. More preferably, the glycol may include one containing carboxylic acid such as dimethyrolpropionic acid.

In addition, in the present invention, the amount of the reactant used is in the equivalence ratio of the polyol: the diisocyanate = 1: 1.0 to 1: 2.5, more preferably 1: 2.

이때, 상기 화학식(I)에 있어서, 사각형() 기호는 이 기술분야에서 통상적으로 사용되어지는 우레탄 세그먼트를 나타낸다. In the present invention, when the polyol: the diisocyanate is reacted in an equivalent ratio in the range of 1: 1.0 to 1: 2.5, a conventional water-dispersed polyurethane prepolymer is obtained. This reaction can be carried out in a conventional manner, which is well illustrated in FIG. At this time, as the water-dispersed polyurethane prepolymer obtained in a conventional manner, a representative example thereof is represented by the formula (I).

At this time, in the formula (I), Symbol represents a urethane segment commonly used in the art.

In the present invention, when the above water-dispersed polyurethane prepolymer (I) is produced, a neutralizing agent is added thereto and then neutralized. It is preferable to use triethylamine as said neutralizing agent.

2. Preparation of Silane Epoxy Modifier (II)

The present invention includes preparing a silane epoxy modified body. 2 shows schematically this step.

The present invention reacts a silane compound with an epoxy resin to produce a silane epoxy modified body (II).

In the present invention, the silane compound is preferably a silane compound having a reactor capable of reacting with an epoxy group of an epoxy resin, such as amino silane, carboxyl silane, hydroxyl silane, or the like, and the silane group is alkoxy silane, acetoxy silane, or the like. Preference is given to using those which can be hydrolyzed in water and converted into silanol groups.

In the present invention, the epoxy resin is a bisphenol A type epoxy resin (bis-phenol A based epoxy resin), novolak based epoxy resin (Novolak based epoxy resin), polypropylene glycol based epoxy resin (polypropylene glycol based epoxy resin) Etc. can be used, and these are used individually or in mixture.

In the present invention, the reaction between the epoxy resin and the silane compound is in the range of 1: 0.2 to 1: 1.5 in an equivalent ratio, and more preferably in the range of 1: 0.7 to 1: 1. If the ratio is exceeded, it becomes difficult to disperse the epoxy resin reactant in water in a stable form together with the polyurethane prepolymer.

In the present invention, when the epoxy resin: the silane compound is reacted in an equivalent ratio in the range of 1: 0.2 to 1: 1.5, a silane epoxy modified body is obtained. A case where amino silane was selected as the silane compound and reacted was shown in FIG. 2, and the aminosilane-modified epoxy obtained in that case was represented by the formula (II).

3. Preparation of Polyurethane / Epoxy Resin Hybrid (III)

단, 상기의 화학식(III)에 있어서, 사각형(

) 기호는 우레탄 세그먼트를 나타내고, n은 1 이상의 정수를 나타낸다. The present invention includes the step of preparing a water-dispersible polyurethane compound by reacting the polyurethane prepolymer with the silane epoxy modified material and a mixture thereof. It is preferable that the water-dispersed polyurethane compound is a polyurethane / epoxy resin hybrid represented by the general formula (III).

However, in the formula (III), the square (

) Represents a urethane segment, and n represents an integer of 1 or more.

In the present invention, the reactant of the polyurethane prepolymer and the epoxy resin reacted with the silane compound are mixed at a weight ratio of 1: 0.1-1: 0.7, more preferably 1: 0.2-1: 0.3 It is mixed at the ratio of. This mixture is dispersed in water and stirred at high speed. Then, the chain extender is added to proceed with the reaction. As said chain extender, an amine compound is preferable, More preferably, diethylene triamine, ethylene diamine, or triethylene tetraamine can be illustrated.

In the present invention, the polyurethane prepolymer is preferably a compound represented by the above formula (I), and it is preferable to use an ionic group containing about 2 to 6% by weight. In the present invention, the silane epoxy modified compound is preferably a compound represented by the formula (II).

When the reaction by the chain extender is finished, a polyurethane compound is produced. In the present invention, the above polyurethane compound can be obtained by embodying as a polyurethane / epoxy resin hybrid.

In the present invention, when the polyurethane compound is neutralized with a neutralizing agent by a base, a water-dispersed polyurethane compound is obtained. As a neutralizing agent, a normal base product can be used. FIG. 3 shows the form of the polyurethane / epoxy resin hybrid as the representative example of the water-dispersible polyurethane compound, represented by Formula (III).

4. Preparation of Powdered Products

The present invention preferably further comprises the step of converting the water-dispersible polyurethane compound into a powder product. This is because storage and storage properties can be improved as a final product, and the scope of application to other uses can be further diversified.

In the present invention, in order to powder the water-dispersed polyurethane compound, a salting agent is administered to undergo a salting process. Under the present circumstances, a salt additive may use a normal additive and dilute hydrochloric acid may be used. In the case of using the dilute hydrochloric acid, since it is easily volatilized in a later drying process, there is no residual component at all, thereby further improving the purity of the final product, it can be used as the most preferred salting agent.

In the present invention, after the salting out process, dehydration is performed using a filtration device. Dehydrated powders still contain large amounts of moisture and therefore require further drying for powdering. In this case, when heated with hot air to dry, a film is formed in a drying process, and then dispersed in water, the dispersibility is weakened. Therefore, in the drying process, it is more preferable to vacuum dry at room temperature than hot air drying.

<< Production Example 1 >>

As the ether polyol, polytetramethylene ether glycol having a molecular weight of 1000 and dimethylol butanoic acid (DMBA) and isophorone diisocyanate (IPDI, Aldrich Chemical), which is an alicyclic isocyanate, have an equivalent ratio of hydroxyl and isocyanate groups. The mixture was adjusted to 2, and reacted at 60 ° C. for 3 hours to prepare a polyurethane prepolymer. The content of DMBA here is 6% by weight in the prepolymer. The isocyanate terminated prepolymer was kept below 60 ° C. and triethylamine was added to neutralize the carboxylic acid group of DMBA.

Bisphenol A type epoxy resin was added to an epoxy resin having an epoxy equivalent value of 187 (Kukdo Chemical YD-128) by adding A link 15 of GE specialty chemical, an amino methoxysilane compound, in a ratio of 1: 1 in an equivalent ratio of 1: 1 for 6 hours at 120 ° C. Reaction was carried out to prepare a silane-modified epoxy resin.

The polyurethane prepolymer and the silane-modified epoxy were mixed at a weight ratio of 1: 0.2, and then added to deionized water so that the solid content was 40% by weight when dispersed, and stirred for 30 minutes to obtain a stable colloid. Subsequently, the isocyanate groups of the polyurethane prepolymer were added with diethylene amine, which is necessary to prepare a high molecular weight polyureaurethane by chain extension, and then reacted at 60 ° C. for 2 hours to obtain a water-dispersed polyurethane / epoxy hybrid.

In order to confirm the water-dispersed polyurethane / epoxy hybrid obtained in Production Example 1, its particles were measured. The particle size was measured using UPtra 150, a light scatterometer from Microtrac. The volume average particle diameter of the water-dispersed polyurethane / epoxy hybrid was 0.07 micron as measured by the light scattering method. It was confirmed that the storage stability was excellent as a good colloid.

<< production example 2 >>

In order to dry the water-dispersed polyurethane / epoxy hybrid obtained in Preparation Example 1 above to obtain a powdered product, the subsequent steps were continued.

To the water-dispersed polyurethane / epoxy hybrid, dilute hydrochloric acid, which may be volatilized upon drying, was added to form a salt, and then the aggregated resins were filtered and then dried in vacuo at room temperature.

The dried powder was added again to water in which triethyl amine was added to deionized water and stirred for 30 minutes. As a result, the polyurethane / epoxy hybrid powder was reemulsified. The volume average particle diameter after re-emulsification of the powdered water-dispersed polyurethane / epoxy hybrid was 0.6 micron as determined by light scattering, and still showed stable colloidal properties. The light scattering method was used in the same manner as the measuring instrument used in Preparation Example 1 above.

《Physical Properties Test 1 ~ 4》

Performed by the method of Preparation Example 1 and Preparation Example 2, except that only the ratio of the epoxy (YD-128): silane compound (A link 15) to each other to prepare a water-dispersed polyurethane / epoxy hybrid. In order to confirm the physical properties of the obtained water-dispersed polyurethane / epoxy hybrid, it was prepared as a specimen, and then subjected to a tensile test.

Tensile test method was followed the method of ASTM D 638, LLoyd's universal testing machine AMETEK was used, the pulling rate of the specimen was set to 500mm / min.

As a result, it was confirmed that the water-dispersed polyurethane / epoxy hybrid according to the present invention had the properties shown in Table 1 below according to the ratio of the epoxy (YD-128): silane compound (A link 15).

YD-128: A link 15 (equivalent ratio) 100% Tensile Modulus (MPa) Tensile Strength (MPa) Elongation at Break (%) 1: 1 22 24 110 1: 0.9 20 20 130 1: 0.8 19 17 150 1: 0.7 20 26 230

As such, the water-dispersed polyurethane compound according to the present invention has good dispersibility in water, and thus has an advantage that it can be used as a substitute for a conventional solvent-type polyurethane.

In addition, the water-dispersed polyurethane compound according to the present invention may be prepared as a water-dispersed polyurethane / epoxy hybrid obtained by dispersing in water, which has the advantage that it can be salted and powdered through dehydration and drying.

In addition, since the water-dispersed polyurethane compound according to the present invention can be re-emulsified by powdering and re-dispersing it in water, there is also an advantage that can be applied to various products without causing problems of environmental pollution.

In addition, since the water-soluble polyurethane compound according to the present invention has good water solubility and re-emulsification property, there is also an effect that the transportation and storage can be simplified as compared with the conventional water-dispersed polyurethane.

In addition, the water-dispersed polyurethane compound according to the present invention can shorten the drying time of the final product by using a high solid content when the dry powder is re-emulsified in water.

Although the water-dispersed polyurethane compound and its preparation method according to the present invention have been described in detail above, this is only for describing the most preferred embodiment of the present invention, and the present invention is not limited thereto, and the appended claims The range is determined and defined by.

In addition, anyone of ordinary skill in the art will be able to make various modifications and imitations by the description of the specification of the present invention, but it will be apparent that this is also outside the scope of the present invention.

Claims (9)

a) an ether- or ester-based polyol having a weight average molecular weight of 500-6000 is reacted with a diisocyanate together with a glycol containing an ionizable carboxylic acid to prepare a water-dispersed polyurethane prepolymer, followed by neutralizing Neutralizing; b) reacting an epoxy group of the epoxy resin with a silane compound to prepare an epoxy resin modified body in which the terminal of the epoxy is replaced with a silane group; c) mixing the neutralized water-dispersed polyurethane prepolymer and the epoxy resin modified body with each other, dispersing and stirring in water, and then adding a chain extender to prepare a water-dispersed polyurethane compound through chain extension. step; Method for producing a water-dispersed polyurethane compound, comprising a. The method of claim 1, After the step of preparing the water-dispersed polyurethane compound, the addition of dilute hydrochloric acid salted, dehydrated and then powdered through room temperature vacuum drying; further comprising, Manufacturing method. The method of claim 1, The silane compound may be a silane compound having a reactor capable of reacting with an epoxy group of an epoxy resin, and the silane group may be hydrolyzed in water to use a silane group which may be converted into a silanol group. One method of producing a water-dispersed polyurethane compound. The method of claim 1, The epoxy resin is any one selected from bisphenol A type epoxy resin, novolak based epoxy resin, and polypropylene glycol based epoxy resin. Or a mixture of two or more thereof, wherein the water-dispersed polyurethane compound is produced. The method of claim 1, The reaction of the epoxy resin and the silane compound is carried out in the range of 1: 0.2 to 1: 1.5 in equivalent ratio, the method of producing a water-dispersed polyurethane compound. The method of claim 1, The method of producing a water-dispersed polyurethane compound, characterized in that the reactant of the polyurethane prepolymer and the epoxy resin reacted with the silane compound are mixed in a weight ratio of 1: 0.1 to 1: 0.7. The method of claim 6, The reactant of the polyurethane prepolymer and the epoxy resin reacted with the silane compound are mixed in a weight ratio of 1: 0.1 to 1: 0.7 to obtain a mixture, the mixture is dispersed in water, stirred at high speed, and then A process for producing a water-dispersed polyurethane compound, characterized in that the reaction proceeds by adding an amine compound as a chain extender. The method of claim 1, The above polyurethane prepolymer uses a compound represented by the formula (I);

[At this time, in the formula (I), the square (

Symbol represents a urethane segment commonly used in the art.] The above silane epoxy modified body uses a compound represented by the formula (II);

A method for producing a water-dispersed polyurethane compound, characterized in that they are mixed with each other, dispersed in water and stirred, and then chain extended by adding a chain extender. A water-dispersed polyurethane compound represented by formula (III), characterized in that it is prepared according to any one of claims 1 to 8.

However, in the formula (III), the square (

) Represents a urethane segment, and n represents an integer of 1 or more.

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