JPH06100815A - Water-base printing ink binder - Google Patents

Abstract

PURPOSE:To provide the subject binder which gives a printed matter satisfactory in gloss and dryability. CONSTITUTION:This binder for water-base printing ink contains a water-base emulsion which is obtd. by polymerizing a vinyl monomer in emulsion in the presence of an alkylene oxide adduct of rosin represented by the formula: X-[(Y- O)n-H]m [wherein X is a rosin residue; Y indicates the same or different groups each represented by CH2CH2 or CH2CH(CH3); (n) is 5-100; and (m) is 1-4].

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to binders for aqueous printing inks. More specifically, it relates to a binder for an aqueous printing ink containing an aqueous emulsion obtained by emulsion-polymerizing a vinyl monomer in the presence of an alkylene oxide-added rosin derivative.

[0002]

2. Description of the Related Art Organic solvents have been the mainstream of binders used in printing inks. For example, magazines,
In oil-based printing inks (for gravure and flexographic printing) applied to weekly magazines and other materials, rosin-based compounds and metal compounds are used as the binder in consideration of performances such as dryness after printing and gloss of printed materials. The reaction product with (metal salt of resin acid) has been widely used.

However, in recent years, there has been a strong demand for water-based printing inks from the viewpoints of preventing air pollution, regulations under the Fire Service Law, occupational safety and health, etc. Therefore, water-based binders having performance comparable to the organic solvent-based binders have been demanded. The demand for development is increasing. Already, acrylic resins and styrene-acrylic resins have been mainly proposed as water-based binders for such applications, and various attempts have been made to make them water-soluble or water-dispersed, but these have not necessarily led to the expression of satisfactory properties. The current situation is not.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances regarding binders for printing inks, and is a water-based printing ink having gloss and drying properties comparable to those of conventional solvent-based inks using resin acid metal salts. The purpose is to obtain an excellent aqueous binder suitable for providing

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor uses a specific aqueous emulsion obtained by emulsion-polymerizing a vinyl monomer in the presence of a specific rosin derivative. Thus, it was found that an aqueous printing ink excellent in any of pigment dispersibility, gloss, and dryness can be obtained. The present invention has been completed based on such findings.

[0006] The present invention has the following general formula (1): X - [( Y-O) n -H] m (1) ( wherein, X is a rosin material residue, Y is -CH ₂ CH ₂
- or -CH ₂ CH (CH ₃₎ - the same or different groups represented, n represents the number of up to 5 to 100, m is a number from 1 to 4, respectively. The present invention relates to a binder for an aqueous printing ink, which comprises an aqueous emulsion obtained by emulsion-polymerizing a vinyl monomer in the presence of an alkylene oxide-added rosin derivative represented by

Examples of the rosin substance which is a raw material of the alkylene oxide-added rosin derivative of the present invention include natural rosins such as gum rosin, tall oil rosin and wood rosin and purified products thereof; disproportionation, hydrogenation, dehydration and dimerization of the rosin. , Various modified rosins obtained by sulfonation; acid addition rosins obtained by addition reaction of maleic acid, maleic anhydride, fumaric acid, acrylic acid, etc. with the rosins; partial ester or partial amidation products of such acid addition rosins Can be exemplified. Each of these rosin substances is used alone or 2
A combination of two or more species can be used.

As the alkylene oxide which is another raw material of the alkylene oxide-added rosin derivative of the present invention, ethylene oxide and propylene oxide are applicable, and these can be used alone or in combination.

The number of moles of the alkylene oxide added is carefully determined in consideration of the stability during emulsion polymerization and the performance of the binder or ink obtained, and is usually in the range of 5 to 100 moles, but preferably. Is 10 to 40 mol, more preferably 10 to 25 mol. If the number of added moles is less than 5 moles, there are disadvantages such that the water solubility is lowered, aggregates are generated during emulsion polymerization, and the gloss of the obtained ink is inferior. On the other hand, when the amount is 100 mol or more, the stability during emulsion polymerization is good, but there are disadvantages such that the water resistance of the obtained ink is poor and that it penetrates into paper.

The method for producing the above alkylene oxide-added rosin derivative is not particularly limited, and various conventionally known methods can be employed as they are. For example, (1) while heating and melting the rosin substance, ethylene oxide and / or propylene oxide is injected under pressure in the atmosphere of an inert gas such as nitrogen in the presence of an acidic or basic catalyst to 150 to 150 to
A method of performing addition polymerization at 200 ° C. under conditions of about 1 to 5 hours, (2) the rosin derivative and at least one of polyethylene glycol, polypropylene glycol, poly (ethylene-propylene) glycol and the like in the absence of a catalyst or Lewis acid Under known catalyst such as 200-300 ℃
The method of esterification under conditions of about 10 to 20 hours.

In the present invention, as described above, by passing through the step of emulsion-polymerizing a vinyl monomer in the presence of the alkylene oxide-added rosin derivative obtained above,
It is intended to obtain an intended aqueous emulsion for an aqueous printing ink. The emulsion polymerization step will be specifically described below.

After dissolving the alkylene oxide-added rosin derivative alone, or a very small amount of a surfactant if necessary, in the water, the temperature in the reaction system is usually raised to 65 to 95 ° C. Then, under stirring, a radical polymerization initiator, a vinyl monomer, and a chain transfer agent, etc., separately, respectively,
Alternatively, the mixture thereof may be dividedly or continuously added dropwise to obtain 1
The reaction is carried out for about 10 hours to complete the emulsion polymerization.

The amount of the alkylene oxide-added rosin derivative used is appropriately determined in consideration of the emulsion polymerization stability, the water resistance of the resulting emulsion, the luster, the drying property, etc., but usually 5 to 200 parts by weight of the vinyl monomer used. %, Preferably 50 to 150% by weight. If the amount of the alkylene oxide-added rosin derivative used is less than 5% by weight, the emulsion polymerization stability tends to decrease,
When it exceeds 0% by weight, the drying property of the obtained emulsion tends to decrease. In addition, since the alkylene oxide-added rosin derivative itself has appropriate hydrophilicity,
A stable polymer emulsion can be provided, but when the amount of the addition rosin derivative used is relatively small, the emulsion polymerization stability can be complemented by using a very small amount of a surfactant together. The surfactant is not particularly limited, and a known anionic or nonionic surfactant can be appropriately selected.

As the radical initiator, various known radical initiators such as organic peroxides, persulfates and water-soluble azo compounds can be used.

The type of the above vinyl monomer is not particularly limited as long as the desired performance can be exhibited, and various known vinyl monomers capable of radical polymerization can be appropriately selected and used. Specific examples thereof include acrylic acid esters, methacrylic acid esters, styrenes, acrylamide, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, etc. These may be used alone or in combination of two or more. it can. Among them, acrylic acid-based, methacrylic acid-based, and styrene-based monomers are preferable from the viewpoint of water resistance and dryness of the emulsion.

The nonvolatile content and viscosity of the above aqueous emulsion are not particularly limited, but in consideration of workability at the time of making into an ink, the nonvolatile content is usually about 30 to 70% by weight and the viscosity is about 5 to 6000 cP. Is preferred.

The aqueous printing ink binder of the present invention containing the thus obtained aqueous emulsion as an active ingredient is used in combination with various conventionally known pigments, if necessary, a hydrophilic solvent such as alcohol or glycol ether, and other additives,
The desired water-based printing ink can be easily prepared by kneading by a known method. The content of the binder solid content in the ink composition is not particularly limited, but it is usually appropriately determined in consideration of various properties and viscosity of the obtained ink, and the content in the ink composition is 10 to 10.
It is about 60% by weight, preferably 25 to 50% by weight. The alkylene oxide-added rosin derivative and other water-soluble polymers such as polyvinyl alcohol, water-soluble cellulose, and acrylic are added to the binder for the aqueous printing ink of the present invention within a range not departing from the objects and effects of the present invention. A system resin, styrene / maleic anhydride resin, α-olefin / maleic anhydride resin or the like may be appropriately added.

[0018]

By using the binder for water-based printing inks of the present invention, it is possible to provide a binder for water-based printing inks which is satisfactory in terms of glossiness and dryness of printed matter.

[0019]

EXAMPLES The present invention will be described in detail below with reference to production examples, examples and comparative examples, but the present invention is not limited to these examples. In addition, "part" and "%" below
All are by weight unless otherwise specified.

Production Example 1 300 parts of hydrogenated rosin and 2.0 parts of anhydrous potassium carbonate were charged into an autoclave, heated and melted while substituting with nitrogen, and then 880 parts of ethylene oxide was injected under pressure with nitrogen.
After completion of the press-fitting, the reaction was performed at 100 to 200 ° C. for 2 hours with stirring to obtain a hydrogenated rosin / ethylene oxide adduct (ethylene oxide addition mole number: 20 mol). Table 1 shows the acid value, hydroxyl value and color tone (Gardner) of the product.

Production Examples 2 to 4 Various rosin / ethylene oxide adducts were produced in the same manner as in Production Example 1, except that at least one of the type of rosin used and the amount of ethylene oxide used was changed as shown in Table 1. Got

[0022]

[Table 1] In the table, EO represents ethylene oxide.

Example 1 The hydrogenated rosin / ethylene oxide adduct 13 obtained in Production Example 1 was placed in a reactor equipped with a thermometer, a stirrer, and a nitrogen inlet tube.
0 part and 170 parts of water were charged and the temperature in the reaction system was raised to about 70 ° C. while stirring and dissolving under a nitrogen stream.
Next, 100 parts of styrene and an aqueous catalyst solution (2.0 parts of ammonium persulfate, 2.0 parts of sodium hydrogen carbonate) were added to the reaction system.
Parts and 70 parts of water) were separately added dropwise over a period of about time, and emulsion polymerization was performed for about 2 hours while maintaining the temperature at 70 to 80 ° C. After cooling, the contents were filtered to give an aqueous emulsion. The properties of the emulsion are shown in Table 3.

Examples 2 to 9 The same reaction as in Example 1 was carried out except that at least one of the rosin / ethylene oxide adduct type, the monomer type, and the amount used was changed as shown in Table 2. , Various aqueous emulsions were obtained. The properties of the emulsion are shown in Table 3.

[0025]

[Table 2] In the table, St: styrene, 2EHA: 2-ethylhexyl acrylate, 2HPMA: 2-hydroxypropyl methacrylate, BA: n-butyl methacrylate are shown.

[0026]

[Table 3]

(Evaluation of Ink Performance) 60.6 parts of the aqueous emulsion obtained in Example 1 was mixed with 1 part of an indigo pigment (manufactured by Toyo Ink Mfg. Co., Ltd., trade name "Rionol Blue KLH").
0.0 g and 29.4 parts of water were added. Kneading was performed using a sand mill to obtain indigo ink (binder solid content in ink: 30.0%). Each of the obtained indigo inks was spread on a coated paper using a bar coater # 10, and the gloss was visually evaluated according to the following criteria. The dryness was evaluated according to the following criteria by touching with fingers. The results are shown in Table 4. ◎: Very good ■: Good △: Inferior
×: Very poor

Regarding the aqueous emulsions obtained in Examples 2 to 9, as shown in Table 4, the type of the aqueous emulsion and its amount, if necessary, the amount of water used, and the post-addition of rosin / ethylene oxide adduct and its amount used. Indigo inks were prepared in the same manner except that at least one of the above items was changed, and these were evaluated in the same manner. The results are shown in Table 4.

Comparative Example 1 71.0 parts of acrylic emulsion (manufactured by Johnson Co.,
"Joncryl 775" (solid content: 45.5%) was added with 10.0 parts of lionol blue KLH and 18.9 parts of water, and kneaded with a sand mill for evaluation. The results are shown in Table 4.

Comparative Example 2 Toluene varnish of resin acid metal salt (trade name "Lime Resin No. 12" manufactured by Arakawa Chemical Industry Co., Ltd.) (nonvolatile content 5)
5.0% by weight) 68.2 parts of Lionol Blue KLH1
0.0 part and 21.8 parts of toluene were added, and the mixture was kneaded in a sand mill and evaluated. The results are shown in Table 4.

Comparative Example 3 70.0 parts of a varnish for neutralizing aqueous maleic rosin with ammonia (nonvolatile content: 50% by weight) was added to Lionol Blue KLH1.
0.0 parts and 20.0 parts of water were added, and the mixture was kneaded with a sand mill and evaluated. The results are shown in Table 4.

[0032]

[Table 4] In the case of prepared ink Nos. 2, 4, 5, 7, 8 and 9, 4.2 parts, 5.0 parts, 4.2 parts and 9. parts of the hydrogenated rosin / ethylene oxide adduct of Production Example 1 were sequentially formed into ink. 2 copies,
4.2 parts and 4.2 parts were used together.

Claims (2)

[Claims] 1. A following general formula (1): X - [( Y-O) n -H] m (1) ( wherein, X is a rosin material residue, Y is -CH ₂ CH ₂
- or -CH ₂ CH (CH ₃₎ - the same or different groups represented, n represents the number of up to 5 to 100, m is a number from 1 to 4, respectively. ) A binder for an aqueous printing ink, comprising an aqueous emulsion obtained by emulsion-polymerizing a vinyl monomer in the presence of an alkylene oxide-added rosin derivative. 2. The amount of the alkylene oxide-added rosin derivative used is 5 to 2 with respect to the total weight of vinyl monomers.
The binder for water-based printing ink according to claim 1, which is 00% by weight.