JP2889115B2 - Radiation-curable aqueous resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-curable aqueous resin composition which is polymerized by irradiation with various radiations.

[0002]

BACKGROUND OF THE INVENTION Polyurethane resins are useful materials conventionally used in paints and a wide variety of other applications, and are usually used as compositions. Conventionally, a composition using a solvent has been frequently used as such a composition, but it has been pointed out that such a solvent-based composition is harmful to the human body due to environmental pollution due to scattering of the used solvent into the air. . Recently, without such problems,
Water-soluble or aqueous emulsion-based synthetic resins have become particularly beneficial, and their use is expanding in the future.

A water-soluble or water-based emulsion resin used in the composition includes a polyurethane resin, and one of them is a heat-reactive polyurethane emulsion having a blocked isocyanate group and having a relatively low molecular weight to a medium molecular weight. . Another example is a polyurethane emulsion having a relatively high molecular weight region mainly composed of a linear structure having no reactive group.

[0004] These emulsions impart self-emulsifying dispersibility by introducing an anionic, cationic or nonionic hydrophilic group into the urethane skeleton of the contained polyurethane, and disperse them in water. Or a mixture obtained by adding an emulsifier to a hydrophobic urethane resin and forcibly dispersing it in water.

On the other hand, in recent years, the demand for radiation curable resins, which have the advantages of energy saving, low temperature, and short processing time, has been rapidly increasing. Non-aqueous radiation-curable resins dominate the conventional radiation-curable resins, and as described above, 100% of the constituent components are composed of resin components in order to achieve energy saving, low temperature, and short-time processing. As its main constituents, it contains a radiation curable resin in a medium molecular weight region and a large amount of a monomer for improving coating suitability, that is, a diluent monomer.

[0006]

However, the above-mentioned conventional water-soluble or aqueous polyurethane emulsion has the following problems. That is, in the case of a heat-reactive polyurethane emulsion having a blocked isocyanate group and having a relatively low molecular weight to a medium molecular weight, it is necessary to treat at a temperature higher than the temperature at which the blocking agent dissociates. Is a problem, and the applicable temperature range is limited.

Further, in the case of a polyurethane emulsion having a relatively high molecular weight region mainly composed of a linear structure having no reactive group, for example, it is inferior in performance such as heat resistance, solvent resistance, chemical resistance and the like. It is the present situation that is desired. In order to improve the various drawbacks of these conventional polyurethane emulsions, blending of various crosslinking agents such as melamine, such as trimethylolmelamine, epoxy, and blocked isocyanate has been attempted. As a result, although some performance improvements have been observed, most are still inadequate in performance. In addition, when these crosslinking agents are added for crosslinking, a film can be formed at a temperature necessary for drying, for example, because a processing temperature higher than the reaction temperature of the reactive group of the crosslinking agent is required, and good physical properties can be exhibited. The advantage of the conventional polyurethane emulsion is impaired. Considering the heat resistance of the adherend material, the processing conditions are restricted and the applicable temperature range is limited. Therefore, in fact, further improvement of the above performance is desired.

This lack of performance is mainly attributable to the fact that the polyurethane according to the prior art does not have a crosslinkable functional group. That is, it is considered that the modification with the crosslinking agent in the related art is at the level of the improvement of the physical properties due to entanglement of molecules such as an interpenetrating network (IPN) between the polyurethane resin and a self-polymer of the crosslinking agent.

Therefore, in order to improve the polyurethane composition in the prior art, a polyurethane emulsion composition incorporating a function capable of forming a network structure is urgently required.

Further, the radiation-curable resin in the prior art is composed of a polyurethane and a monomer having a low molecular weight to a medium molecular weight, so that the cured resin is inferior in flexibility and has a brittle coating layer. In addition, there is a disadvantage that adhesion shrinkage to an adherend material is liable to occur due to remarkable curing shrinkage.

The present invention solves such a conventional problem, and an object of the present invention is to provide a film having a function of forming a network structure and having excellent flexibility. An object of the present invention is to provide a radiation-curable aqueous composition having excellent physical properties such as adhesion, heat resistance, and water resistance.

[0012]

The radiation-curable aqueous resin composition of the present invention is obtained by adding a polymerizable unsaturated group-containing isocyanate compound to an active amino group-containing polyurethane emulsion in the presence of water to cause a reaction. It is characterized by containing a radiation-curable polyurethane aqueous dispersion, a double bond-containing monomer and / or oligomer, and a photosensitizer.

The above-mentioned active amino group-containing polyurethane emulsion is obtained by emulsifying and dispersing a urethane prepolymer having an isocyanate group at a molecular end obtained by reacting a compound containing two or more active hydrogens with an organic polyisocyanate in water. A polyamine having at least two primary amino groups and at least one secondary amino group in the same molecule in the presence of water and reacting.

Further, the addition of the polyamine to the urethane prepolymer may be performed by adjusting the molar ratio of (terminal NCO group of the urethane prepolymer) / (primary amino group of the polyamine) to 1/1 to 1 / 0.7. It is preferable to perform the process so as to fall within the range described above.

Further, the polymerizable unsaturated group-containing isocyanate compound has a (meth) acryloyl group,
It can be a compound containing at least one group selected from the group consisting of an allyl group and a styrene group and at least one isocyanate group.

Furthermore, the solid content of the radiation-curable polyurethane aqueous dispersion and the double bond-containing monomer and / or oligomer is 10/90 to 97 / weight ratio.
It is preferable to set the range to 3.

The radiation-curable polyurethane aqueous dispersion used in the present invention can be obtained by adding a polymerizable unsaturated group-containing isocyanate to an active amino group-containing polyurethane emulsion and reacting the same, as described above. Preparation of a group-containing polyurethane emulsion facilitates the introduction of polymerizable unsaturated groups into the urethane skeleton. The active amino group-containing polyurethane emulsion is obtained by reacting a urethane prepolymer having an isocyanate at a molecular terminal with a polyamine having at least two primary amino groups and at least one secondary amino group in the same molecule. Can be Production of a urethane prepolymer having an isocyanate group at a molecular terminal is carried out in a system in which a compound containing two or more active hydrogens and an organic polyisocyanate are in excess.

The above-mentioned compounds containing two or more active hydrogens include those containing two or more hydroxyl groups at the terminal or in the molecule, and include generally known polyethers, polyesters, polycarbonates, polyetheresters, polythioethers, and the like. Examples thereof include polyol compounds such as polyacetal, polybutadiene, and polysiloxane. The compound containing two or more active hydrogens has a molecular weight of 3
Those having a range of 00 to 5,000 are used. In addition, for adjustment of physical properties, adjustment of urethane concentration, etc., if necessary,
Low molecular weight glycols such as 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, ethylene glycol, butanediol, neopentyl glycol, diethylene glycol, trimethylolpropane, and cyclohexanedimethanol , Triol and the like may be used.

As the organic polyisocyanate compound, an aromatic, aliphatic or alicyclic organic polyisocyanate conventionally used is used. For example, organic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexyl methane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, tetramethyl xylylene diisocyanate, and mixtures thereof. Is raised.

The reaction between a compound containing two or more active hydrogens and an excess amount of an organic polyisocyanate is carried out at 50 to 120 ° C. by a conventionally known one-stage or multi-stage isocyanate polyaddition reaction method. Will be

In this reaction, if necessary, a reaction controlling agent such as phosphoric acid, adipic acid, benzoyl chloride, a reaction catalyst such as dibutyltin dilaurate, stannasoctoate, triethylamine, and an organic solvent which does not react with isocyanate groups May be added during or after the reaction. These organic solvents include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, ethyl acetate, toluene, xylene and the like.

It is possible not to use an organic solvent at all, but if a solvent is used for dilution due to the high viscosity of the urethane prepolymer, it may be used after the preparation of the active amino group-containing polyurethane emulsion described later or After the reaction between the amino group-containing polyurethane emulsion and the polymerizable unsaturated bond-containing isocyanate compound is completed,
It can be collected under reduced pressure.

If there is a concern that polymerization of a polymerizable unsaturated group due to recovery under reduced pressure may occur, the solvent may be recovered after preparing the active amino group-containing polyurethane emulsion, that is, when the polymerizable unsaturated group is introduced into the polyurethane skeleton. It is more preferable to carry out in the step before performing.

If necessary, a stabilizer such as an antioxidant may be added during or after the reaction. Further, the isocyanate group content at the terminal of the urethane polymer is preferably 3.0 to 0.3% by weight, and 2.0 to 0.3% by weight.
More preferably, it is 1.0%. If the terminal isocyanate group content is more than 3.0% by weight, emulsification is destroyed during the reaction with a polyamine described below to cause gelation, or the product stability and temporal stability are poor, and the terminal isocyanate group content is 0%. When the amount is less than 0.3% by weight, the amount of active amino groups introduced by the reaction with a polyamine described below decreases, and as a result, the amount of polymerizable unsaturated group-containing isocyanate introduced in the subsequent reaction decreases, and the urethane skeleton is reduced. And the amount of polymerizable unsaturated groups introduced into the polymer is reduced. Therefore, it is impossible to expect improvement in physical properties of the coating film after the coating film is formed using the radiation-curable aqueous resin composition of the present invention and cured by radiation.

The urethane prepolymer having an isocyanate group at the molecular terminal is emulsified and dispersed in water. The following methods are available. That is,. In the urethane prepolymer preparation step described above, a carboxyl group is introduced in advance by reacting a carboxyl group-containing polyol component in the molecule, for example, dimethylol propionic acid or the like with an organic polyisocyanate, and converting the carboxyl group into triethylamine, trimethylamine, A method of neutralizing with a basic compound such as diethanol monomethylamine, diethylethanolamine, caustic soda, caustic potassium, etc., and converting to a salt of a carboxyl group.

[0026] In the urethane prepolymer preparation step described above, a nonionic surfactant having an oxyethylene chain content of 5 to 20% by weight in the molecule in advance and an HLB value of 6 to 18 is added at 50 ° C. or less after the urethane prepolymer preparation. How to mix. However, the use amount of this activator is emulsifying dispersibility,
In consideration of the water resistance and the like of the product film, the content is preferably 2 to 15% by weight based on the urethane prepolymer.

[0027] After preparing the urethane prepolymer,
50 to 5% of the terminal isocyanate group, more preferably 3%
An aqueous solution of sodium salt or potassium salt such as aminoethanesulfonic acid or aminoacetic acid equivalent to 0 to 5% was prepared at 5 to 50 ° C.
A method in which the reaction is preferably performed at 20 to 40 ° C for 60 minutes.
And the like.

The urethane prepolymer having self-water dispersibility does not require the above-mentioned hydrophilization.

After performing any of the above operations,
Water is added, and emulsification and dispersion are performed using an emulsification and dispersion device such as a homomixer and a homogenizer. In the case of performing emulsification and dispersion, the emulsification and dispersion temperature is preferably low in the sense of suppressing the reaction between the terminal isocyanate group of the urethane prepolymer and water, and is preferably 5 to 40 ° C, more preferably 5 to 30 ° C. It is preferably carried out in the range of 5 to 20 ° C.

Next, the polyamine compound used in the present invention has at least two primary amino groups in the same molecule.
And a compound having at least one secondary amino group, for example, diethylenetriamine, triethylenetetramine, dipropylenetriamine and the like.
These polyamine compounds are used in such amounts that the ratio of (the number of moles of terminal isocyanate groups of the urethane prepolymer) / (the number of moles of primary amino groups of the polyamine) is 1/1/1 / 0.7. I can decide. When this ratio is smaller than 1/1 (molar ratio of primary amino groups is large), effective increase in molecular weight tends to be inhibited, and when the ratio is larger than 1 / 0.7 (molar ratio of primary amino groups is small). The amount of active amino groups introduced is reduced, the amount of polymerizable unsaturated groups introduced in the next step is necessarily reduced, and the effect of exhibiting physical properties as the emulsion composition of the present invention is reduced, and the It is not preferable because the composition thickens and gels.

After the above-mentioned urethane prepolymer is emulsified and dispersed in water, the above-mentioned polyamine compound is added, and the terminal isocyanate group of the urethane prepolymer is reacted with the polyamine in the emulsified and dispersed system. In performing this reaction, an emulsifying and dispersing device such as a homomixer and a homogenizer is used in order to perform a uniform reaction. Further, in consideration of gelation caused by abrupt reaction, emulsification destruction due to local reaction, and the like, stability of the product afterwards, and stability over time, 5 to 40 ° C, preferably 5 to 30 ° C, more preferably 5 to 30 ° C. The reaction is carried out in a temperature range of ２０20 ° C., and the polyamine chain extension reaction is usually carried out over 10 to 120 minutes.

According to this method, the primary amino group in the polyamine compound molecule having a higher reaction rate with respect to the isocyanate group selectively participates in the chain extension reaction. As a result, the site of the secondary amino group in the polyamine compound molecule is introduced into the polyurethane skeleton structure. Thus, the active amino group-containing polyurethane emulsion used in the present invention is produced. When an organic solvent is contained during the emulsification and dispersion, if necessary, 30-70 under reduced pressure.
The active amino group-containing polyurethane emulsion used in the present invention is obtained by distilling off the organic solvent at ℃.

At this time, phosphoric acid, hydrochloric acid, benzoyl chloride or the like can be added in order to suppress a side reaction between water and an isocyanate group and promote a reaction between the isocyanate group and the polyamine compound.

Next, examples of the polymerizable unsaturated isocyanate used for preparing the radiation-curable polyurethane aqueous dispersion of the present invention include hexamethylene diisocyanate, xylylene diisocyanate, cyclohexylmethane diisocyanate, isophorone diisocyanate, and tolylene diisocyanate. General organic polyisocyanates such as isocyanate and diphenylmethane diisocyanate, or dimers or trimers thereof, and acryloyl group-containing hydroxyl group compounds such as hydroxyl methacrylate and hydroxyl acrylate and / or alkylene oxide adducts thereof, or allyl An addition reaction product of an alcohol and / or allyl alcohol with an alkylene oxide adduct is exemplified. Other examples include 2-methacryloyloxyethyl isocyanate represented by the chemical formula 1 and m-
Isopropenyl-α, α-dimethylbenzyl isocyanate; and methacryloyl isocyanate represented by the structural formula.

[0035]

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[0036]

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[0037]

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These polymerizable unsaturated group-containing isocyanate compounds are added to the active amino group-containing polyurethane emulsion obtained in the above step, more preferably, added dropwise and mixed to carry out the reaction.

The addition reaction of the polymerizable unsaturated group-containing isocyanate compound to the active amino group-containing polyurethane emulsion is carried out at a temperature of 5 to 40 ° C., more preferably 5 to 30 ° C., for 15 minutes to 120 minutes. Implemented. If the reaction temperature is lower than 5 ° C., the reaction between the active amino group and the polymerizable unsaturated group-containing isocyanate compound is delayed, and a side reaction between the polymerizable unsaturated group-containing isocyanate compound and water occurs. On the other hand, when the reaction temperature is higher than 40 ° C., since a side reaction between the polymerizable unsaturated group-containing isocyanate compound and water is induced, the reaction rate between the active amino group and the polymerizable unsaturated group-containing isocyanate compound decreases. . Therefore, the amount of polymerizable unsaturated groups introduced into the urethane skeleton is inevitably reduced.

The amount of the polymerizable unsaturated group-containing isocyanate compound to be added is (molar number of active amino groups of the active amino group-containing polyurethane emulsion) / (molar number of isocyanate groups of the polymerizable unsaturated group-containing isocyanate compound). Is set and added so that the ratio of 1 / 1.05 to 1 / 0.8 is added. If this ratio is less than 1 / 1.05 (the molar ratio of isocyanate groups is large), the urea body containing a polymerizable unsaturated group containing a polymerizable unsaturated group due to the reaction between the polymerizable unsaturated group-containing isocyanate compound and water may be used. It is not preferable because the amount of the amine compound containing a saturated group increases. Also,
If this ratio is greater than 1 / 0.8 (the molar ratio of isocyanate groups is small), the amount of polymerizable unsaturated groups introduced will necessarily decrease, and the effect of expressing the physical properties of the emulsion composition of the present invention will decrease. It is not preferable. Furthermore, if a large amount of active amino groups remain, burning and yellowing of the film after curing are undesirably increased.

By the above reaction, a radiation-curable polyurethane aqueous dispersion used in the radiation-curable aqueous resin composition of the present invention is obtained.

Next, the monomer having a double bond and the oligomer having a double bond used in the present invention will be described below.
These include monofunctional, bifunctional, and polyfunctional (meth) acryloyl group-containing compounds. For example,
Hydroxyethyl acrylate, hydroxypropyl acrylate, ethylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, methyl acrylamide, polyethylene glycol mono (meth) acrylate, mono (meth) acrylate of polyethylene oxide adduct of alcohol and phenol, etc. A monofunctional (meth) acryloyl group-containing compound of
Bifunctional (such as trimethylolpropane di (meth) acrylate, pentaerythritol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and di (meth) acrylate of polyethylene oxide adduct of bisphenol A) Examples of the compound include a (meth) acryloyl group-containing compound, and a polyfunctional (meth) acryloyl group-containing compound such as trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate.

The compounding method for mixing these double bond-containing monomers and / or double bond-containing oligomers is a method of adding the above-mentioned radiation-curable polyurethane aqueous dispersion used in the present invention directly after addition, or A method can be adopted in which these double bond-containing monomers and / or double bond-containing oligomers are dissolved and dispersed in water in advance, and then added to the radiation-curable polyurethane aqueous dispersion. Further, an emulsifier can be used if necessary.

The radiation-curable polyurethane aqueous dispersion and the double bond-containing monomer and / or oligomer are mixed in a solid content ratio of 10/90 to 97/3, preferably 20/80 to 95 /. 5, more preferably 30/7
0 to 95/5.

If the proportion of the radiation-curable polyurethane aqueous dispersion is less than 10% in terms of solid content, the cured film obtained by using the radiation-curable aqueous resin composition of the present invention has low flexibility and is brittle. It is not preferable because it shows physical properties. On the other hand, if the mixing ratio of the double bond-containing monomer and / or oligomer is less than 3% in terms of the solid content ratio, it is not preferable because the physical properties are not substantially improved by copolymerization of the two.

Next, the photosensitizer which is one of the components of the radiation-curable aqueous resin composition of the present invention will be described. Examples of the photosensitizer include acetophenone-based, benzoin ether-based, ketal-based, benzophenone-based, and anthraquinone-based derivatives. For example, 2-hydroxy-2
Alkyl benzoin ethers such as -methyl-1-phenylpropan-1-one and isopropenyl benzoin ether; methyl orthobenzoyl benzoate; benzyl methyl ketal; and ethyl anthraquinone. These may be used alone or in combination of two or more.

In order to achieve photocrosslinking, the amount of addition is 0.3 to 10 with respect to the total resin solid content contained in the radiation-curable polyurethane aqueous dispersion and the double bond-containing monomer and / or oligomer. %, More preferably 0.3 to 5%
It is. These may be added as they are or after emulsification in water using an emulsifier, and then added to a liquid mixture of the radiation-curable polyurethane aqueous dispersion and a double bond-containing monomer and / or oligomer.

As described above, the radiation-curable aqueous resin composition of the present invention containing the radiation-curable polyurethane aqueous dispersion, the double bond-containing monomer and / or oligomer, and the photosensitizer as essential components is obtained. .

[0049]

The radiation-curable water resin composition of the present invention contains a radiation-curable polyurethane aqueous dispersion, a double bond-containing monomer and / or oligomer, and a photosensitizer.
The radiation-curable polyurethane co-crosslinks the radiation-curable polyurethane with the double bond-containing monomer and / or oligomer to form a dense network structure.

As a result, energy-saving and short-time UV light curing become possible, and the problem of the heat resistance of the adherend material due to the high-temperature treatment, which has not been solved by the conventional heat-reactive emulsion having a blocked isocyanate group. The point is resolved, and application to a wide range of fields is possible.

Further, since the radiation-curable polyurethane aqueous dispersion, which is one of the constituents, has a high molecular weight, the cured film has high flexibility, does not become brittle, and has good adhesion to the adherend material. Is good.

Further, by changing the crosslinking density of the cured film by changing the amount of the double bond-containing monomer and / or oligomer, it is possible to appropriately change the physical properties of the formed film. Therefore, it is possible to solve the shortcomings of the conventional polyurethane emulsion having no reactive group, such as the lack of performance such as heat resistance, solvent resistance and chemical resistance of the film. Therefore, it is possible to respond to the demand for physical properties that differ for each application field, and it is possible to respond to a wide range of demand.

In addition, the radiation-curable aqueous resin composition of the present invention contains a high-molecular weight radiation-curable polyurethane aqueous dispersion and a double bond-containing monomer and / or oligomer. It is possible to solve problems such as insufficient adhesion to an adherend due to resin curing shrinkage observed in resin. In addition, since the diluent monomer in the conventional radiation-curable resin functions as a diluent for adjusting the viscosity separately from the physical properties, it has to be used excessively at the expense of the physical properties of the obtained film. Was. On the other hand, since the composition of the present invention can be diluted with water, the compounding amount of the double bond monomer and / or oligomer can be set so as to conform to the target physical properties, so that the physical properties of the film are sacrificed. Never.

[0054]

The radiation-curable aqueous resin composition according to the present invention has the following specific effects. That is, (1) The radiation-curable aqueous resin composition of the present invention contains a polyurethane aqueous dispersion having a polymerizable unsaturated group in a polyurethane skeleton, a double bond-containing monomer and / or oligomer, and a photosensitizer. Therefore, co-crosslinking can be performed by UV irradiation.

Therefore, energy saving and processing in a short time, which cannot be obtained by the conventional polyurethane emulsion, can be performed, and workability and film properties can be improved.

(2) Since one of the constituent components is a high molecular weight radiation-curable polyurethane aqueous dispersion, the cured film is rich in flexibility and does not become brittle.

(3) Further, since it can be diluted with water, the double bond-containing monomer and / or oligomer does not need to fulfill the function as a diluent as in the prior art, and the compounding amount suitable for the target physical properties is not required. Can be used. Therefore,
Physical properties are not sacrificed by excessively using the double bond-containing monomer and / or oligomer. Therefore,
Problems such as a decrease in adhesiveness to the adherend material can be solved.

[0058]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. still,
“Parts” and “%” in Examples, Synthesis Examples, Comparative Examples, Comparative Synthesis Examples, and the like described below indicate parts by weight and% by weight, respectively, unless otherwise specified.

<Synthesis Example 1> 350 parts of polyester polyol (butylene adipate, molecular weight: 2,000), 10.1 parts of trimethylolpropane, 35 parts of polyethylene glycol (molecular weight: 600), and a random copolymer of PO (propylene oxide) / EO (ethylene oxide) 35 parts of polymerized polyether polyol, (PO / EO = 30/7)
0, molecular weight 3400), and 1,4-butanediol 7
After 8.3 parts were added to and dissolved in 400 parts of methyl ethyl ketone, 310 parts of isophorone diisocyanate was added at a system temperature of 50 ° C. Thereafter, 0.05 parts of dibutyltin dilaurate was added, and the temperature was gradually increased to 75 ° C. in the system. At the stage where the reaction was carried out at 75 ° C. for 60 minutes, 0.05 part of dibutyltin dilaurate was further added. Thereafter, the reaction was continued and cooled at the time when 75 ° C./200 minutes had elapsed, and the temperature in the system was set to 50 ° C. The free isocyanate group of the urethane prepolymer after cooling to 50 ° C. was 2.0% (based on solid content).

Next, at a system temperature of 45 ° C., 80 parts of a polyoxyethylene arylphenol ether type nonionic surfactant (HLB = 15), which is an ethylene oxide adduct of distyrenated phenol, was added and mixed for 10 minutes. . Then, the contents in the system were removed using a homomixer for 300 minutes.
The mixture was stirred at 0 rpm at a high speed, and 1300 parts of distilled water was gradually added thereto, and then emulsification was performed at a system temperature of 30 ° C. for 20 minutes.

After the temperature in the system was further cooled to 20 ° C., an aqueous solution of diethylenetriamine in which 18 parts of diethylenetriamine was dissolved in 130 parts of distilled water (molar ratio of urethane prepolymer terminal NCO group / primary amino group in diethylenetriamine = 1/0. 9) was added. Keep the temperature in the system between 20 and 2
The stirring was continued at 3000 rpm for 60 minutes using a homomixer while controlling the temperature at 5 ° C. Next, methyl ethyl ketone used as a solvent was recovered under reduced pressure (water bath 40 ° C.) using an evaporator. As described above, the active amino group-containing polyurethane emulsion used in the present invention could be prepared.

The obtained active amino group-containing polyurethane emulsion was analyzed. Table 1 shows the results. Amount of active amino groups contained (amine value, hereinafter referred to as "Am V")
Was determined by dissolving 10 parts of the emulsion in 300 parts of N-methyl-2-pyrrosodone with stirring and titrating with hydrochloric acid using bromophenol blue as an indicator.

[0063]

[Table 1]

Next, 1000 parts of the active amino group-containing polyurethane emulsion obtained above is kept at a system temperature of 25 ° C., and stirred with a homomixer at 1000 rpm. Into which hydroquinone monomethyl ether 0.2
Was added to a solution prepared by dissolving 2 parts of isopropyl alcohol in 2 parts of isopropyl alcohol, and then 2-methacryloyloxyethyl isocyanate 1
0.2 parts was gradually added dropwise over 10 minutes. afterwards,
Stirring was continued at 25 ° C. until the measured value of Am · V became constant.

As a result, stirring was required for 60 minutes, and Am · V
The value was 0.25 (based on the whole system), which clearly indicates that the active amino group in the active amino group-containing polyurethane emulsion was reacted with the isocyanate group of 2-methacryloyloxyethyl isocyanate. As a result, a white liquid emulsion having a solid content of 40.2% was obtained.

<Synthesis Example 2> Polyether polyol 35
0 parts (PO / EO copolymer, PO / EO = 90/10, molecular weight 2000), 15 parts of trimethylolpropane, 30 parts of polyethylene glycol, 40 parts of PO / EO random copolymerized polyether polyol (PO / EO = 30 / 7
0, molecular weight 3600) and 150 parts of cyclohexanedimethanol were dissolved in 400 parts of methyl ethyl ketone.

Next, isophorone diisocyanate 360
Was added, and 0.1 part of dibutyltin dilaurate was added at a system temperature of 50 ° C.
And The reaction was further continued at 75 ° C., and after reacting for 300 minutes, the temperature in the system was cooled to 50 ° C. After cooling to 50 ° C., the free isocyanate groups of the urethane prepolymer were 1.80% (based on solid type).

Next, at a system temperature of 40 ° C., 90 parts of the same polyoxyethylene arylphenol ether type nonionic surfactant (HLB = 15) as in Synthesis Example 1 was added, and
Mix for minutes. Next, the contents in the system were stirred at a high speed of 3000 rpm using a homomixer, and distilled water 169 was introduced into the system.
0 parts were gradually added, and then the system was heated at 25 ° C for 20 minutes.
The emulsification was carried out for a minute.

Next, an aqueous solution of diethylenetriamine in which 18.7 parts of diethylenetriamine was dissolved in 100 parts of distilled water was added at a system temperature of 25 ° C. Temperature 20-25 in the system
℃ and 3000 with a homomixer
Stirring was continued at rpm for 60 minutes.

Next, methyl ethyl ketone used as a solvent was recovered under reduced pressure (water bath 40 ° C.) by an evaporator.
did. Thus, an active amino group-containing polyurethane emulsion used in the present invention was obtained. The obtained active amino group-containing polyurethane emulsion was analyzed.
Table 2 shows the results. The amount of amino group contained was measured in the same manner as in Synthesis Example 1.

[0071]

[Table 2]

Next, 1000 parts of the active amino group-containing polyurethane emulsion obtained above was maintained at a system temperature of 25 ° C., and stirred at 1000 rpm with a homomixer.
A solution in which 0.2 part of hydroquinone monomethyl ether is dissolved in 2 parts of isopropyl alcohol is added thereto. Next, 9.0 parts of 2-methacryloyloxyethyl isocyanate was gradually added dropwise over 10 minutes.

Thereafter, the stirring was continued at 25 ° C.
The mixture was stirred until the measured value of V became constant. As a result, 70
After stirring for minutes, the Am.V value became 0.10 (based on the total system), and the active amino groups in the polyurethane emulsion containing active amino groups clearly reacted with the isocyanate groups of 2-methacryloyloxyethyl isocyanate. You can see that it is. From the above, the solid content was 38.4%,
A radiation-curable aqueous polyurethane dispersion used in the present invention in which a polymerizable unsaturated group was introduced into a white liquid polyurethane skeleton was obtained.

<Synthesis Example 3> 1000 parts of the active amino group-containing polyurethane emulsion prepared in Synthesis Example 2 was added at 25 ° C.
And keep it at 1000 rpm with a homomixer.
Then, a solution prepared by dissolving 0.2 part of hydroquinone monomethyl ether in 2 parts of isopropyl alcohol was added thereto, and 11.7 parts of m-isopropenyl-α, α-dimethylbenzyl isocyanate was added dropwise over 10 minutes. .

Thereafter, the stirring was continued at 25 ° C.
The mixture was stirred until the measured value of V became constant. As a result, 12
After stirring for 0 minutes, the Am · V value was 0.15 (based on the whole system), and apparently the amino group in the active amino group-containing polyurethane emulsion and the isocyanate group of the polymerizable unsaturated group-containing isocyanate were It turns out that is reacting.

As described above, a radiation-curable polyurethane aqueous dispersion used in the present invention having a solid content of 38.0% and a polymerizable unsaturated group introduced into a white liquid polyurethane skeleton was obtained.

<Comparative Synthesis Example> A urethane prepolymer having 2.0% free isocyanate groups was prepared in the same manner as in Synthesis Example 1. Thereafter, emulsification was carried out in the same manner as in Synthesis Example 1, and the same molar amount of ethylenediamine was added instead of diethylenetriamine, followed by stirring. Next, methyl ethyl ketone used as a solvent was recovered by an evaporator. Thus, a polyurethane emulsion according to the prior art was obtained. Table 3 shows the analysis results of the polyurethane emulsion.
Shown in As can be seen from the amino group content in Table 3, this polyurethane emulsion has almost no active amino groups.

[0078]

[Table 3]

<Examples 1 to 4> The radiation-curable polyurethane aqueous dispersion used in the present invention obtained in Synthesis Example 1 was added to the double bond-containing monomers (A) to (C) shown in Table 4 or The oligomer was added and blended, and the photosensitizer shown in Chemical formula 4 was further blended to prepare a film.

[0080]

[Table 4]

[0081]

Embedded image

The coating film of each example was applied on a Teflon plate, dried at room temperature overnight, and dried at 60 ° C. for 2 hours. Then, using a high-pressure mercury lamp (irradiation intensity: 80 W / cm ² , irradiation distance: 8 cm), Ultraviolet irradiation was performed at a speed of 5 m / mim to carry out photocopolymerization. The thickness of each coating was 100 microns.

The photosensitizer was formulated as a photosensitizer / polyoxyethylene arylphenol ether type nonionic activator (HLB = 15) / water = 10/8/82 as shown in Chemical formula 4. .

For the coating film after curing, the strength, elongation, 10
Each physical property of 0% modulus (100% Mo), 200% modulus (200% Mo), solvent resistance and warm water resistance was measured. Table 5 shows the results. In addition, the measuring method of each physical property is mentioned later.

[0085]

[Table 5]

<Examples 5 to 6> The radiation-curable polyurethane aqueous dispersion used in the present invention obtained in Synthesis Example 2 was mixed with the double bond-containing oligomers (A) and (D) shown in Table 4 respectively. The photosensitizer shown in Chemical formula 4 was further blended in the same manner as in Examples 1 to 4. Thereafter, photocopolymerization was performed in the same manner as in Examples 1 to 4.

For the cured coating film, the strength, elongation,
Each physical property of 0% modulus (100% Mo), 200% modulus (200% Mo), solvent resistance and warm water resistance was measured. Table 6 shows the results. In addition, the measuring method of each physical property is mentioned later.

[0088]

[Table 6]

<Examples 7 to 10> The radiation-curable polyurethane aqueous dispersion used in the present invention obtained in Synthesis Example 3 was
The double bond-containing monomers or oligomers (A) and (E) shown in Table 4 were added, and a photosensitizer shown in Chemical Formula 4 was further blended in the same manner as in Examples 1 to 4. Thereafter, photocopolymerization was performed in the same manner as in Examples 1 to 4.

The trimethacrylate of trimethylolpropane used as the double bond-containing monomer (E) was compounded after emulsification with a polyoxyethylene arylphenol ether type nonionic activator (HLB = 13) in advance. . At that time, the ratio of the emulsion was trimethacrylate of trimethylolpropane / nonionic surfactant /
Water = 40/4/56.

The cured coating film was measured for solvent resistance and hot water resistance. Table 7 shows the results. In addition, the measuring method of each physical property is mentioned later.

[0092]

[Table 7]

<Comparative Examples 1 to 3> The radiation-curable polyurethane aqueous dispersions obtained in Synthesis Examples 1 to 3 were used alone, and a photosensitizer represented by Chemical Formula 4 was prepared in the same manner as in Examples 1 to 4. It was blended and similarly photopolymerized to form a film. The physical properties of these films were also measured, and the results were shown in Tables 5 to 7.
Are also shown.

<Comparative Example 4> The double bond-containing oligomer (A) shown in Table 4 was blended with the aqueous polyurethane dispersion having no reactive group according to the prior art obtained in the Comparative Synthesis Example, and the process was further carried out. The photosensitizer shown in Chemical formula 4 was blended in the same manner as in Examples 1 to 4, and irradiation with ultraviolet light was performed in the same manner to form a film. The physical properties of this film were also measured, and the results are shown in Table 5.

<Measurement Methods for Various Physical Properties>
The strength, elongation, 100% modulus (100% Mo) and 200% modulus (200% Mo) were measured according to JIS-K-
According to 6301, a tensile tester (Autograph manufactured by Shimadzu Corporation) was used to measure at a tensile speed of 100 mm / min.

The solvent resistance was as follows: ethyl acetate / toluene = 1 /
A 2 × 4 cm piece of the coating was immersed in 1
It was measured by the swelling ratio (%) of the film area after immersion for a time.
The swelling ratio was determined by the following equation.

[0097]

(Equation 1)

The warm water resistance was determined by immersing a 2 × 4 cm piece of the coating in 70 ° C. hot water and measuring the swelling ratio of the coating area after immersion at 70 ° C. for 24 hours. The swelling ratio was determined by the above equation.

As a result, the coating film prepared by using the radiation-curable aqueous resin composition in each of the above Examples was clearly obtained by using the composition of the prior art in any of the Examples. Compared with the thus-obtained coating film, improvements in strength, elongation, modulus, solvent resistance, hot water resistance and the like are observed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) C08F 290/00-290/06 C08F 299/06 C08G 18 / 64,18 / 81 C09D 175/16

Claims (3)

(57) [Claims] 1. A compound containing two or more active hydrogens.
Molecular powder obtained by reaction with organic polyisocyanate
Urethane prepolymer having isocyanate group at the end
Emulsified and dispersed in water, then in the same molecule in the presence of water
At least two primary amino groups and at least one secondary amino group
By adding and reacting a polyamine having an amino group.
A radiation-curable polyurethane aqueous dispersion obtained by adding and reacting a polymerizable unsaturated group-containing isocyanate compound to an active amino group-containing polyurethane emulsion in the presence of water, and a double bond-containing monomer and / or oligomer; A radiation-curable aqueous resin composition comprising a photosensitizer. 2. The method according to claim 2, wherein the addition of the polyamine to the urethane prepolymer is carried out by the method of (Terminal N of the urethane prepolymer).
The radiation-curable aqueous resin composition according to claim 1 , wherein the molar ratio of (CO group) / (primary amino group of the polyamine) is in the range of 1/1 to 1 / 0.7. Stuff. 3. The solid content of the radiation-curable polyurethane aqueous dispersion and the double bond-containing monomer and / or oligomer is in the range of 10/90 to 97/3 by weight. The radiation-curable aqueous resin composition according to the above.