JP2923187B2 - Radiation-curable aqueous printing ink 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 printing ink composition which is polymerized by irradiation with UV light.

[0002]

2. Description of the Related Art Resin binders such as polyurethane, polyamide, nitrocellulose and polyester are used as printing inks for various plastic films and metal foils. These resins are used alone or in combination and dissolved in an organic solvent. In this organic solvent type ink, the binder itself has water resistance, and by obtaining a crosslinked ink film using an isocyanate compound or an epoxy compound, excellent physical properties such as solvent resistance and chemical resistance are obtained. Has been expressed.

On the other hand, in recent years, radiation curable resins that are polymerized by various radiations, for example, ultraviolet rays, electron beams, etc., have the advantages of energy saving, low temperature, and short processing time. I have. Among the radiation curable printing ink compositions according to the prior art, non-aqueous type ink compositions have become mainstream. As described above, these radiation-curable resins are directed to energy saving, low temperature, and short-time processing. Therefore, 100% of the constituent components are composed of resin components, and the mainstream is radiation-curable resin in a medium molecular weight region. It contains a large amount of low molecular components of a monomer for adjusting viscosity to improve coating suitability, that is, a so-called reactive diluent monomer. Examples of the reactive diluent monomer include vinyl acetate, vinyl pyrrolidone, and alkyl acrylate.

[0004]

However, these printing inks have a risk of fire due to an organic solvent.
It has the problem of polluting the atmosphere. It is not preferable from the viewpoint of resource saving. Therefore, development of water-based printing inks having excellent physical properties such as solvent resistance, chemical resistance, and water resistance in place of these organic solvent-based inks has been actively conducted.

[0005] In aqueous printing inks, styrene-maleic acid copolymer resin, styrene-acrylic copolymer resin, acrylic resin and the like are generally used as a binder. However, when printing is performed using an aqueous ink using a binder composed of these resins, it has been pointed out that physical properties such as water resistance, solvent resistance, and chemical resistance of the printed matter are extremely low in practical use. ing.

[0006] In order to obtain sufficient physical properties such as solvent resistance, chemical resistance and water resistance, an epoxy compound,
It is known that a certain degree of physical properties can be obtained by adding a crosslinking agent such as a carbodiimide compound and drying and then crosslinking the ink film. However, because the crosslinking between the functional groups of these aqueous binders and these crosslinking agents is weak,
At present, sufficient solvent resistance, chemical resistance, and water resistance are not obtained.

Further, aqueous urethane binders have been proposed because of their excellent flexibility and adhesiveness to various materials. However, since the conventional aqueous urethane binder is basically an aqueous dispersion of thermoplastic urethane, it is insufficient in solvent resistance, chemical resistance, water resistance, etc. as described above, and further performance At present, improvement is desired.

Further, in a printing ink composition of the prior art using a radiation-curable resin, a low-molecular-weight reactive diluent monomer for adjusting viscosity and adjusting film thickness is used in a proportion of 20 to 70 parts by weight. Since it is necessary to add to the molecular weight resin component,
The addition of the reactive diluent monomer causes a problem in safety management, and is also harmful to the human body and a problem of odor pollution.

In order to reduce or completely eliminate the above disadvantages, it is important to take chemical and industrial measures. A simple method to solve this problem is to reduce the amount of reactive diluent monomer used by adding water. However, since the radiation-curable resin in the prior art is insoluble in water, a small amount of water is used. Although it can be used and blended, it cannot be blended in a large amount and cannot be drastically solved. At present, as a chemical method for solving this point, the use of a water-based radiation-curable ink composition in water is highly desired.

On the other hand, Japanese Patent Application Laid-Open No. Sho 62-22816 discloses an ionomer urethane acrylate and a method for producing the same in view of these problems. JP-A-3-166216 similarly discloses an ionomer urethane acrylate and a method for producing the same.

In the former, first, hydroxyacrylate and organic diisocyanate are reacted in the first step, and then the remaining isocyanate groups are reacted with the polyol compound. Thereafter, a production method has been proposed in which an aminocarboxylic acid is reacted in water to convert the aminocarboxylic acid into a salt thereof, and the remaining isocyanate group is subjected to a chain extension reaction with water or a diamine.

In the latter, first, a polyol compound is reacted with a carboxyl group-containing diol and an organic diisocyanate, and then a hydroxy acrylate is reacted.
Further, a production method has been proposed in which a carboxyl group is converted into a salt and the remaining isocyanate group is subjected to a chain extension reaction with water or a diamine.

In each of the production methods disclosed in these publications, the hydroxy acrylate used has only one hydroxyl group, and therefore has the following problems. In the former, a monohydroxy acrylate and an organic diisocyanate are first reacted to synthesize a partial acrylate of isocyanate, and then reacted with a polyol,
We are synthesizing urethane acrylate containing isocyanate. For this reason, all the ends of the urethane acrylate containing isocyanate are not converted into isocyanate groups, and a state in which the terminal is partially a double bond group occurs, and a case where the number of isocyanate groups becomes 2 or less occurs. .

For this reason, in the chain extension reaction between the isocyanate group and water or diamine which is carried out in the final stage, an ideal high molecular weight reaction may not be realized. Further, even when an ideal high molecular weight reaction can be realized, there is a problem that the range of the urethane structure is considerably limited.

Similarly, since the latter uses monohydroxy acrylate, all the ends of urethane acrylate are not converted into isocyanate groups, and a partial double bond occurs, which causes the same problem as the former. Have.

The present invention has been made to solve such problems of the prior art.
An object of the present invention is to provide an aqueous printing ink composition which has excellent physical properties such as solvent resistance, chemical resistance, and water resistance and can be cured by radiation.

[0017]

The radiation-curable aqueous printing ink composition of the present invention is selected from the group consisting of (A) a compound containing two or more active hydrogens and (B) an acryloyl group and a methacryloyl group. A double bond-containing polyol compound containing at least one group and a plurality of hydroxy groups, and (C) a urethane prepolymer having an isocyanate group at a terminal obtained by a reaction with an organic polyisocyanate are dispersed in water. A group consisting of a polyamine compound containing a primary amino group and / or a secondary amino group, a diamine and / or a triamine ketimine compound, and water. Radiation-curable aqueous polyurethane water obtained by a reaction to increase the molecular weight using a compound selected from Characterized in that it contains a Chikarada and a photosensitizer.

The aqueous radiation-curable polyurethane dispersion used in the present invention can be produced by the following method.

Examples of the compound containing two or more active hydrogens used in the preparation of the urethane prepolymer used herein include those having a plurality of hydroxyl groups at terminals and / or side chains. For example, polyether polyols obtained by single or copolyaddition of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, polyether polyols in which the alkylene oxides are polyadded to low molecular weight glycols, triols, etc., polyester polyols, polycarbonates Polyols, caprolactone polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, silicone polyols and the like can be mentioned.
Incidentally, the molecular weight of the compound containing two or more active hydrogens is preferably in the range of 500 to 5,000.

If necessary, low molecular weight 1,4-butanediol, 1,6-hexanediol, 3-methyl-
A glycol such as 1,5-pentanediol, ethylene glycol, neopentyl glycol, diethylene glycol, trimethylolpropane, or cyclohexanedimethanol, or a triol may be used in combination.

The double bond-containing polyol compound used for preparing the urethane prepolymer includes an acryloyl group and an acryloyl group.
It contains at least one group selected from the group consisting of methacryloyl groups and a plurality of hydroxy groups. Specific examples include triol monoacrylates and monomethacrylates such as glycerol and trimethylolpropane. Further, a mono- or diacrylate, mono- or dimethacrylate of tetraol such as pentaerythritol may be used. Further, mono- or di-acrylates or methacrylates of alkylene oxide adducts such as the above-mentioned triols and tetraols may be mentioned. As described above, acrylate and methacrylate derivatives containing at least two hydroxyl groups are included as one group.

Next, specific examples include monohydroxyalkyl acrylates such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate, methacrylates, hexamethylene diisocyanate, xylylene diisocyanate, and cyclohexyl methane diisocyanate. Diisocyanates such as, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, tetramethyl xylylene diisocyanate, and triols such as trimethylolpropane, glycerol, caprolactone triol, diethanolamine, triethanolamine, etc.
Addition reaction products with amino alcohols are included.

In this case, it is preferable that the respective molar ratios of the above-mentioned monohydroxyalkyl acrylate, methacrylates: the above-mentioned diisocyanates: the above-mentioned triols, amino alcohols = 1: 1: 1 to 1.2.

In addition, the above monohydroxyalkyl acrylates and methacrylates, the triisocyanates which are the trimer of the diisocyanates such as buret and isocyanurate , and ethylene glycol,
1,4-butanediol, 1,6-hexanediol,
Addition products with 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, cyclohexane dimethanol, glycols such as monoethanolamine, and amino alcohols. In this case, the molar ratios of the respective monohydroxyacrylates, methacrylates : the triisocyanates: the glycols, and the aminoacoles are 1: 1: 2 to 2.2.
It is preferred that

In these addition reactions, after reacting the monohydroxyacrylates with the isocyanates,
The addition reaction of the above triol and amino alcohol is carried out.

The reaction is preferably carried out at a temperature in the range of 20 ° C. to 80 ° C. In order to prevent polymerization of double bonds, benzoquinone, hydroquinone, hydroquinone monomethyl ether, phenothiazine, 2,6
Addition of a polymerization inhibitor such as -di-tert-butyl-4-methylphenol to promote the reaction between a hydroxyl group and an isocyanate group, if necessary, such as dibutyltin dilaurate, stannas octoate, triethylamine, etc. A reaction catalyst, or an organic solvent that does not react with the isocyanate group, may be added during the reaction or after completion of the reaction.

These organic solvents include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, ethyl acetate and the like.

As described above, an acryloyl group or methacryloyl group-containing polyol compound which is a urethane compound of acrylate or methacrylate having at least two hydroxyl groups is obtained.

Other examples of the double bond-containing polyol compound include an addition reaction product of methacryloyl isocyanate represented by the structural formula 2 and an amino alcohol such as the above triols, diethanolamine and triethanolamine. Can be In this case, the respective molar ratios are as follows: the isocyanates of the formulas 1 to 2: the triols and the amino alcohols are in the range of 1: 1 to 1.2. Will be implemented.

[0030]

[0031]

Embedded image

Next, as the organic polyisocyanate compound used in the present invention, conventionally used aromatic, aliphatic or alicyclic organic polyisocyanates are used. For example, organic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexyl methane diisocyanate, isophorone diisocyanate, water-added xylylene diisocyanate, tetramethyl xylylene diisocyanate, and mixtures thereof. .

The reaction between the compound containing two or more active hydrogens, the double bond-containing polyol compound and the organic polyisocyanate is carried out using an excess amount of the organic polyisocyanate. In this case, the reaction is carried out at 50 to 120 in consideration of prevention of polymerization of a double bond of an acryloyl group or a methacryloyl group.
It is performed in a temperature range of ° C. At this time, in order to prevent polymerization of an acryloyl group or a methacryloyl group, benzoquinone, hydroquinone, hydroquinone monomethyl ether, phenothiazine, 2,6-di-tert-butyl-
A polymerization inhibitor such as 4-methylphenol may be used, or dry air may be introduced. Further, if necessary, a generally used reaction catalyst such as dibutyltin dilaurate, stannas octoate, triethylamine or the like for promoting the reaction between the hydroxyl group and the isocyanate group may be used.

Further, depending on the viscosity of the reaction system, organic solvents which do not react with isocyanate groups may be added so that the reaction system can be smoothly stirred. Examples of these organic solvents include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane and the like. , Ethyl acetate and toluene. It is possible to use an organic solvent, but if a solvent is used as described above, it is recovered under reduced pressure in the final stage.

If necessary, a stabilizer such as an antioxidant can be added during or after the reaction.

As described above, a urethane prepolymer having an isocyanate group at the molecular terminal and containing at least one group selected from the group consisting of an acryloyl group and a methacryloyl group in the main chain and / or side chain in the molecule ( Hereinafter, referred to as “urethane prepolymer”).

Next, the urethane prepolymer is emulsified and dispersed in water. In this dispersion, when the urethane prepolymer itself has dispersibility, it is directly added to water. When the urethane prepolymer does not have self-dispersibility, the following method can be employed as a treatment method performed before dispersing in water. In the urethane prepolymer preparation step, a carboxyl group-containing polyol component in the molecule is previously introduced, for example, a carboxyl group is introduced by a reaction between dimethylolpropionic acid or the like and an organic polyisocyanate, and the carboxyl group is converted into triethylamine, trimethylamine, Diethanol monomethylamine, diethylethanolamine,
A method of neutralizing with a basic compound such as caustic soda, potassium hydroxide or the like to convert into a salt of a carboxyl group.

In the above urethane prepolymer preparation step, a tertiary amino group is introduced in advance by reacting a tertiary amino group-containing polyol component, for example, triethanolamine, N-methyldiethanolamine or the like, with an organic polyisocyanate in the molecule. And reacting the tertiary amino group with an organic acid such as formic acid or acetic acid, an inorganic acid such as phosphoric acid, hydrochloric acid or sulfuric acid, a quaternizing agent such as diethyl sulfate or an alkyl halide, or the like. A method of converting to a quaternary amine salt form.

In the urethane prepolymer preparation step, the oxyethylene chain is previously contained in the molecule in an amount of 5 to 20% by weight, and a nonionic activator having an HLB value of 6 to 18 is added to the urethane prepolymer. The method of adding and mixing below. However, the use amount of this activator is emulsifying dispersibility,
In consideration of the water resistance and the like of the obtained film, the content is preferably 2 to 15% by weight based on the urethane prepolymer.

After the above-mentioned urethane prepolymer preparation, 50 to 5% of the terminal isocyanate groups are more preferable,
A method of reacting an aqueous solution of a sodium salt or a potassium salt such as aminoethanesulfonic acid or aminoacetic acid equivalent to ５5% at 5 to 50 ° C., preferably 20 to 40 ° C., for 60 minutes, etc. These treatments are unnecessary when the urethane prepolymer itself has dispersibility as described above.

After performing any of the above operations, water is added, or in the case of a urethane prepolymer having self-dispersibility, water is added without performing these treatments, and emulsified dispersion using a homomixer, homogenizer, or the like is performed. Perform emulsification and dispersion using an apparatus. When emulsifying and dispersing, the emulsifying and dispersing temperature is preferably low in order to suppress the reaction between the terminal isocyanate group of the urethane prepolymer and water.
It is carried out in the range of -40C, preferably 5-30C, more preferably 5-20C.

Next, the urethane prepolymer having an isocyanate group at the molecular end is subjected to a high molecular weight reaction in an emulsion. The following method can be adopted as the method. A method for carrying out a high molecular weight reaction while generating a urea bond by a reaction between a terminal isocyanate group and water. A method in which a urea bond is formed by a reaction between a terminal isocyanate group and a polyamine such as diamine or triamine to carry out a high molecular weight reaction. A method in which a reaction between a terminal isocyanate group and a ketimine compound is carried out to increase the molecular weight while generating a urea bond.

In the above case, after the above-mentioned emulsifying operation is performed, a urea bond is formed by a reaction between the terminal isocyanate group and water contained in the polymer emulsion composition. This reaction is carried out at an emulsification system temperature of 5 to 40 ° C, preferably 1 to 40 ° C.
The reaction is usually performed at 5 to 30 ° C. for 30 to 120 minutes.

Examples of the polyamines used above include diamines and triamines. Specific examples of the polyamine having two primary amino groups and / or secondary amino groups per minute include ethylenediamine, piperazine, N −
Examples thereof include aminoethylpiperazine, isophoronediamine, dicyclohexyldiamine, hexamethylenediamine, and other hydrazines. Examples of the compound having three primary amino groups and / or secondary amino groups include, for example, a low-molecular triamine composed of diethylenetriamine and dipropylenetriamine. Is raised.

These diamine and triamine compounds are
(Molar number of terminal isocyanate groups of the urethane prepolymer) / (molar number of primary and / or secondary amino groups of the polyamine compound) used in a ratio of 1/1 to 1 / 0.7. It is preferred to determine the amount. This ratio is
In particular, when it is smaller than 1/1 (the molar ratio of amino groups is large), it is not preferable because effective high molecular weight tends to be inhibited or the emulsified system tends to be broken.

In this reaction, an emulsifying and dispersing apparatus such as a homomixer and a homogenizer is used to perform a uniform reaction. Further, in consideration of rapid reaction, gelation caused by emulsification destruction due to local reaction, etc., and later product stability, stability with time, 5 to 40 ° C, preferably 5 to 30 ° C,
More preferably, the reaction is carried out in a temperature range of 5 to 20 ° C,
The reaction for increasing the molecular weight of diamine and triamine is usually performed over 10 to 60 minutes.

Examples of the ketimine compound used above include a ketimine compound dehydrated between a primary amino group of a diamine or a triamine and isobutyl ketone described above.

The amount of the ketimine compound used is set so that the number of moles of the primary amino group formed by hydrolysis and the number of the secondary amino group contained therein and the number of moles of the terminal isocyanate group are the same as described above. You. The reaction temperature, time and operating method are also carried out as described above.

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

Next, the photosensitizer used in the present invention will be described. Photosensitizers include acetophenone, benzoin ether, ketal, benzophenone,
Derivatives such as anthraquinone type are exemplified. For example, 2
-Hydroxy-2-methyl-1-phenylpropane-1
And alkylbenzoin ethers such as -one and isopropylbenzoin ether, methyl orthobenzoyl benzoate, benzyl methyl ketal, and ethyl anthraquinone. These may be used alone or in combination of two or more.

The amount of addition is from 0.3 to 10%, preferably from 0.3 to 5%, based on the solid content of the radiation-curable polyurethane aqueous dispersion in order to achieve photocrosslinking. In addition, these additives are added as they are, or after emulsification in water using an emulsifier, and then added to the radiation-curable polyurethane aqueous dispersion.

As described above, the radiation-curable aqueous printing ink composition of the present invention containing the radiation-curable polyurethane aqueous dispersion and a photosensitizer as essential components is obtained.

[0053]

The radiation-curable aqueous printing ink composition of the present invention contains a radiation-curable polyurethane aqueous dispersion containing a UV-curable double bond in the polyurethane skeleton and a photosensitizer. Therefore, photocrosslinking is caused by UV light irradiation, and a structure having a high crosslinking density is formed. Therefore, performances such as water resistance, solvent resistance, and chemical resistance, which were disadvantages of the conventional polyurethane emulsion having no reactive group, can be improved.

Since the radiation-curable aqueous printing ink composition of the present invention is aqueous, water can be used as a diluting medium. Therefore, viscosity control and film thickness adjustment can be easily performed. In other words, the radiation curable resin of the prior art has problems such as residual monomer odor after curing caused by the reactive diluent monomer used in combination and insufficient adhesion to the adherend due to resin curing shrinkage. Solvable.

A feature of the radiation-curable aqueous printing ink composition of the present invention is that a double bond-containing polyol containing an acryloyl group or a methacryloyl group for introducing a polymerizable double bond into the aqueous polyurethane dispersion used. The use of compounds. A compound containing two or more active hydrogens, a polymerizable double bond-containing polyol,
Due to the reaction with an excess amount of the organic polyisocyanate, the polymerizable double bond is introduced into the main chain and / or side chain in the molecule of the polyurethane skeleton, so that all molecular terminals become isocyanate groups. Therefore, there is no problem that a molecular terminal is partially converted into a double bond component and not entirely converted into an isocyanate group, which is a problem of the prior art using a monohydroxyalkyl acrylate or the like. Therefore, the final reaction, ie, the high molecular weight by the isocyanate group and the amine is sufficiently performed, and the polyurethane skeleton is sufficiently formed.

Since the radiation-curable aqueous printing ink composition of the present invention is an aqueous emulsion, water can be used as a diluting medium. Therefore, viscosity management and film thickness adjustment can be easily performed. That is, the radiation curable resin of the prior art has a problem, the problem of residual odor inherent in the monomer after curing caused by the reactive diluent monomer used for viscosity control and film thickness adjustment, resin curing shrinkage It is possible to solve the problem of insufficient adhesiveness to the adhered material and the like.

When it is necessary to increase the hardness of the cured film, a water-soluble reactive diluent monomer can be used in combination with the radiation-curable aqueous printing ink composition of the present invention. As water-soluble reactive diluent monomers, for example, dimethylacrylamide, vinylpyrrolidone, ethylene glycol, diacrylate of diethylene glycol,
Examples include diacrylate of low molecular weight polyethylene glycol.

[0058]

The radiation-curable aqueous printing ink composition according to the present invention has the following specific effects.

The radiation-curable aqueous printing ink composition of the present invention comprises, as essential components, a radiation-curable polyurethane aqueous dispersion having a polymerizable unsaturated group in the polyurethane skeleton and a photosensitizer. Therefore, photocrosslinking is caused by irradiation with UV light, and a structure having high energy saving and high crosslink density is formed. Accordingly, the disadvantages of the conventional polyurethane emulsion having no reactive group, such as water resistance, solvent resistance, and chemical resistance, are improved.

Since this is an aqueous emulsion, the viscosity can be adjusted by adding water to adjust the ink film thickness and the like. Therefore, problems such as residual monomer odor after curing caused by the monomer used as a reactive diluent used for dilution with conventional radiation-curable resins, and insufficient adhesion to the adherend due to resin curing shrinkage, etc. Is resolved.

From the viewpoint of physical properties, since the polyurethane skeleton is sufficiently formed and the high molecular weight is achieved, the adhesion and chemical resistance of the ink film are equivalent to those of a polyurethane emulsion generally obtained only by drying. And further excellent physical properties can be achieved by radiation polymerization.

Since the aqueous printing ink composition of the present invention uses a double bond-containing polyol, the degree of freedom in designing a polyurethane structure is increased, and therefore, it is possible to meet performance requirements in various applications.

[0063]

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 Synthesis Examples, Comparative Synthesis Examples, Examples, Comparative Examples, Experimental Examples, Comparative Experimental Examples, and the like described below indicate parts by weight and% by weight, respectively, unless otherwise specified.

<Synthesis Example 1> Bifunctional polyether polyol (PO / EO = 90 /
10, molecular weight 2,000) 300 parts, 12.9 parts of trimethylolpropane, 1,4-cyclohexanedimethanol 92.0 parts of glycerol monomethacrylate 36.
0 parts, and hydroquinone monomethyl ether 0.38
Parts were dissolved in 300 parts of ethyl acetate. System temperature 50 ℃
333 parts of isophorone diisocyanate and 0.04 parts of dibutyltin dilaurate were added under the conditions of
The reaction was carried out for 60 minutes under the conditions described above to obtain a urethane prepolymer having 3.8% of terminal isocyanate groups (based on solid content).

333 parts of isophorone diisocyanate and 0.04 parts of dibutyltin dilaurate were added at a temperature of 50 ° C. in the system, and the reaction was carried out at 75 ° C. for 60 minutes to obtain 3.8% of terminal isocyanate groups ( (Solid portion)
Was obtained.

Next, dimethylolpropionic acid (26 parts) and dibutyltin laurate (0.04 part) were added at a system temperature of 50 ° C., and the reaction was carried out at 75 ° C. for 300 minutes to give a terminal isocyanate. A urethane prepolymer having 1.60% of groups (based on solids) was obtained.

Next, 19.6 parts of triethylamine was added, and the mixture was mixed at a temperature of 50 ° C. for 15 minutes to carry out a neutralization reaction.

Next, 1,100 parts of ion-exchanged water was added, and emulsification was carried out with a homomixer under stirring at a rotation speed of 4,000 rpm.

Next, 96.0 parts of an ethylenediamine aqueous solution (10% concentration aqueous solution) was added to 5
Over a period of 40 minutes, and then use a homomixer for 40 minutes.
Polymerization and dispersion operations were performed at 00 rpm for 60 minutes.

Next, the mixture was heated using an evaporator.
Ethyl acetate solvent used was 90
It was collected under reduced pressure over minutes. Thus, a white liquid polyurethane polymer emulsion having a solid content of 40% was obtained.

<Synthesis Example 2> 300 parts of polyester polyol (butylene adipate, molecular weight: 2,000), trimethylolpropane
9 parts, polyethylene glycol (molecular weight 600) 35
Parts, polyether polyol (PO / EO = 30/7)
0, a random copolymer, the molecular weight 3,400) 35 parts of glycerol monomethacrylate (hydroxyl value (OH · V) =
678, molecular weight 165.4), and 80 parts of hydroquinone monomethyl ether were dissolved in 300 parts of ethyl acetate. Next, 164 parts of hexanemethylene diisocyanate and 0.01 part of dibutyltin dilaurate were added at 50 ° C.

The reaction was carried out at a temperature of 75 ° C. for 180 minutes, and 1.80% of terminal isocyanate groups (based on solid content)
Was obtained.

Next, 50 parts of a nonionic surfactant (ethylene oxide polyadduct of distyrenated phenol, HLB = 15) was added in the system at 50 ° C. and mixed for 15 minutes.

Next, 4,000 r using a homomixer
Under stirring at pm, 1,000 parts of ion-exchanged water was added little by little, and emulsification was carried out at 30 ° C.

Next, an aqueous solution prepared by mixing 7.5 parts of hydrazine hydrate and 63 parts of ion-exchanged water was added, and polymerization and dispersion were performed at 25 ° C. for 90 minutes.

Next, the mixture was heated using an evaporator.
Ethyl acetate solvent used was 90
The solution was collected under reduced pressure over a period of minutes.

Thus, a composition comprising a white liquid polyurethane polymer emulsion having a solid content of 40% was obtained.

<Comparative Synthesis Example> Bifunctional polyether polyol (PO / EO = 90/10, molecular weight 2,000)
300 parts, 12.9 parts of trimethylolpropane, 1,4
123 parts of cyclohexanedimethanol was dissolved in 300 parts of methyl ethyl ketone. At a temperature of 50 ° C., 333 parts of isophorone diisocyanate and 0.04 part of dibutylssuslaurate are added, and the mixture is added at 75 ° C.
The reaction was carried out for 0 minutes, and 3.60%
A urethane prepolymer having (solid content) was obtained.

Next, 26 parts of dimethylolpropionic acid and 0.04 part of dibutylsdilaurate were added at a temperature of 50 ° C. in the system, and the mixture was reacted at 75 ° C. for 300 minutes to obtain 1.50% of terminal isocyanate (to solid type). Min) was obtained.

Next, 19.6 parts of triethylamine was added and mixed at 50 ° C. for 5 minutes to carry out a neutralization reaction.

Next, 1,100 parts of ion-exchanged water was added, and emulsification was carried out with a homomixer under stirring at a rotation speed of 4,000 rpm.

Next, 94.0 parts (% concentration) of an aqueous solution of ethylenediamine was added dropwise over 5 minutes at a temperature of 20 ° C. in the system, and then 4,000 rpm using a homomixer.
And the operation of polymerizing and dispersing was carried out for 60 minutes.

Next, the mixture was heated by an evaporator, and the methyl ethyl ketone solvent used at 60 ° C. in hot water was recovered under reduced pressure over 90 minutes.

As described above, a polyurethane emulsion composition of a comparative example according to the prior art, which was a semi-transparent liquid, having a solid content of 40% was obtained.

<Examples 1 and 2, Reference Examples 1 and 2> To the polyurethane emulsion obtained in the synthesis example, phthalocyanine blue TGR-1 (manufactured by Dainippon Ink and Chemicals, Inc.) as a pigment was added to a resin solid content / pigment. = 3/1 and kneaded to obtain an aqueous printing ink. This aqueous printing ink was used as the aqueous printing ink of Reference Examples 1 and 2.

In the aqueous printing inks of Reference Examples 1 and 2, the photosensitizer represented by Chemical Formula 3 was added in an amount of 3% by weight based on the solid content of the resin.
Those added were used as the radiation-curable aqueous printing inks of Examples 1 and 2, respectively. The photosensitizer is added as an aqueous solution, and the composition of the aqueous solution contains a photosensitizer, a polyoxyethylene allylphenol ether type nonionic surfactant (HLB = 15) and water, and the ratio is 10 parts. / 8 parts / 82 parts.

[0087]

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Comparative Example The same amount of phthalocyanine blue TGR-1 (manufactured by Dainippon Ink and Chemicals, Inc.) in the same manner as in Examples 1 and 2 was mixed with the conventional polyurethane emulsion obtained in the Comparative Synthesis Example, and kneaded. did. The obtained product was used as a water-based printing ink of Comparative Example.

<< Evaluation of Physical Properties of Ink Film >> Examples 1 and 2,
The physical properties of the ink films obtained using the aqueous printing inks of Reference Examples and Comparative Examples were evaluated.

A corona-discharge-treated surface of a stretched polypropylene film having a thickness of 20 μm was treated with a film having a thickness of 5 μm.
m, the aqueous printing inks of Examples 1 and 2, Reference Example, and Comparative Example were applied and left in a dryer at 40 ° C. for 24 hours, and then a high-pressure mercury lamp (irradiation intensity: 80 W / cm ² ,
A test piece was prepared by performing photopolymerization by ultraviolet irradiation at a speed of 5 m / min using an irradiation point distance of 8 cm). The adhesion, solvent resistance, and water resistance of the printed surface of each test piece were evaluated, and the results are shown in Table 1. The test method and evaluation criteria are as follows.

[0091]

[Table 1]

<Adhesiveness> A peel test of a test piece was performed using Nichiban cellotape. The evaluation criteria are as follows.

し な い Does not peel even if it is suddenly separated. △ Adhesive strength intermediate between △ and △. す る Peels off when it is suddenly separated, but does not peel off when it is gradually released. <Solvent resistance> Apply ethanol to the printed surface of the test piece,
After 30 minutes, the surface condition was determined by rubbing with absorbent cotton (using a Gakushin type fastness tester). The evaluation criteria are as follows.

○ The ink film is retained even 30 times. △ The ink film disappears after 10 to 30 times. × The ink film disappears after 10 times or less. <Water resistance> The test piece is immersed in warm water of 60 ° C. for 30 minutes. After that, the surface condition of the ink film was determined. The evaluation criteria are as follows.

○ Transparent and clear print color △ Partially whitened and partially unclear print color × White and unclear print color From Table 1, the radiation-curable polyurethane aqueous dispersions of Examples 1 and 2 were prepared. The ink film obtained by using the aqueous printing ink containing the photosensitizer has improved adhesiveness, warm water resistance and solvent resistance by ultraviolet irradiation, as is apparent from comparison with the inks of Reference Examples 1 and 2. You can see that it is doing. this is,
It is considered that the polymerizable unsaturated group of the aqueous dispersion of the radiation-curable active polyurethane undergoes a crosslinking reaction by light irradiation.

On the other hand, the ink film obtained using the polyurethane emulsion of the comparative example according to the prior art has an adhesive property,
It is inferior to Examples 1 and 2 in both hot water resistance and solvent resistance.

Continuation of the front page (56) References JP-A-3-17113 (JP, A) JP-A-4-91162 (JP, A) JP-A-56-38316 (JP, A) JP-A-2-294320 (JP, A) JP-A-62-22816 (JP, A) JP-A-5-155975 (JP, A) JP-A-2-245015 (JP, A) JP-A-61-97318 (JP, A) (58) Surveyed field (Int.Cl. ⁶ , DB name) C09D 11/00-11/20 C09D 175/00-175/16 C08G 18/00-18/87

Claims (1)

(57) [Claims] 1. A double compound containing (A) a compound containing two or more active hydrogens and (B) at least one group selected from the group consisting of an acryloyl group and a methacryloyl group and a plurality of hydroxy groups. An urethane prepolymer having an isocyanate group at a terminal obtained by the reaction of a bond-containing polyol compound and (C) an organic polyisocyanate is dispersed in water with respect to an emulsified dispersion in which the urethane prepolymer in the emulsified dispersion is used. to terminal isocyanate polymer, a primary amino group and / or a polyamine compound containing a secondary amino group and is selected from the group consisting of ketimine compound of diamine and / or triamine compound, (the number of moles of the terminal isocyanate groups) /
(Hydrolysis of the polyamine or the ketimine compound
Moles of primary and / or secondary amino groups generated by the solution
Radiation, characterized by containing a radiation-curable aqueous polyurethane aqueous dispersion obtained by carrying out a high-molecular-weight reaction using ( number) = 1/1 to 1 / 0.7, and a photosensitizer. A curable aqueous printing ink composition.