JPS61176621A - Production of rosin-based water-soluble resin - Google Patents

Abstract

PURPOSE:To produce the titled resin giving an ink having excellent pigment dispersibility and gloss, and useful as a binder for water-soluble ink, by carrying out the graft-copolymerization of a vinyl monomer to a rosin ester in the presence of a polymerization initiator. CONSTITUTION:The objective resin can be produced by the graft- copolymerization of (A) a rosin ester with (B) a vinyl monomer at a weight ratio (A:B) of preferably (15-75):(85-25) in the presence of a polymerization initiator (e.g. azobisisobutyronitrile). The component B is preferably a mixture of a carboxyl-free monomer (e.g. styrene) and a carboxyl-containing monomer (e.g. acrylic acid) at a molar ratio of preferably 1:0.2-5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a rosin ester-based water-soluble resin, in particular, which can be used as a binder for water-soluble ink. The present invention relates to a method for producing a water-soluble resin.

Conventional technology Conventionally, shellac, rosin-maleic acid resin, styrene-maleic acid resin, styrene-acrylic resin, etc. have been made into aqueous solutions using ammonia, organic amines, etc., and used as binders for water-soluble inks. .

Problems that the invention aims to solve However, shellac is a natural resin that is completely dependent on imports in Japan, and its quality varies depending on the place of production and the time of collection, making it extremely inconvenient for industrial use. It is well known that this is the case. In addition, rosin-maleic acid resin, styrene-maleic acid resin, styrene-acrylic resin, etc. have resins that are not flexible (and have problems with gloss and pigment dispersibility, such as acrylic and rosin emulsions). Blending has been attempted to compensate for these drawbacks, but it has not been sufficiently effective.

On the other hand, rosin esters are used in combination with other resins in the field of oil-soluble inks and have excellent properties as modifiers, but rosin esters themselves have strong lipophilic properties. Therefore, it could not be used in the field of water-soluble inks.

The present invention has been made in view of the above circumstances, and has been developed by imparting water solubility to rosin ester, which has conventionally had excellent performance as a modifier in the field of oil-soluble inks, and which can be used as a binder for water-soluble inks. Its purpose is to enable the use of

As a means to solve the problem, the present invention is characterized in that a vinyl monomer is graft copolymerized with a rosin ester using a polymerization initiator.

The rosin ester used in the present invention is obtained by esterifying a known rosin, such as gum rosin, tall oil rosin, wood rosin, a modified product thereof, or a mixture thereof, with a known polyhydric alcohol. Examples of the modified rosin include hydrogenated rosin, polymerized rosin,
Examples include asymmetric rosin and aldehyde-modified rosin. In addition, polyhydric alcohols include ethylene glycol,
Examples include glycerin, pentaerythritol, trimethylolpropane and the like.

Vinyl monomers used in the present invention include styrene, methylstyrene, vinyltoluene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, acrylonitrile, vinyl acetate, 2-hydroxyethyl methacrylate, dimethyl methacrylate. Examples include aminoethyl, dimethylaminoethyl methacrylate methyl chloride salts, and these may be used alone or in combination.

Furthermore, as polymerization initiators for graft copolymerizing these vinyl monomers to rosin ester, azobisisobutyl nitrile, methyl emerketone peroxide, methyl isobutyl ketone peroxide, benzoyl peroxide, tert-butyl peroxyiso Butyrate, di-tert-butyl peroxide, etc. are used.

The ratio of the rosin ester to the vinyl monomer is not particularly limited, but the weight ratio of the two is 15 to 75 for the rosin ester and 85 to 85 for the vinyl monomer.
It is preferable to set it to 25.

When the weight ratio of rosin eltel is lower than 15% by weight,
Ink gloss and pigment dispersibility decrease. Moreover, if it exceeds 75%, radicals will undergo chain transfer to the rosin ester during the reaction, resulting in hindering copolymerization of the vinyl monomer, resulting in poor storage stability of the aqueous solution.

As the vinyl monomer, various monomers as mentioned above can be used, but monomers that do not contain a carboxyl group such as styrene, methyl acrylate, and methyl methacrylate, and monomers that do not contain a carboxyl group such as acrylic acid and methacrylic acid are used. It is preferable to use them in combination with a monomer containing a carboxyl group. In this case, it is desirable to use a mixture of 0.2 to 5 moles of a monomer containing a carboxyl group to 1 mole of a monomer that does not contain a carboxyl group. If the ratio of the monomer containing a carboxyl group is less than 0.2 mol, it will be difficult to make it water-solubilized after neutralization with an alkali, and if it is larger than 5 mol,
Storage stability decreases when solubilized.

In the graft copolymerization reaction between rosin ester and vinyl monomer, radicals generated from the polymerization initiator are captured by the double bonds on the rosin or on the unsaturated acid to which the rosin and polyhydric alcohol are bonded. It is believed that when the radical is captured, it becomes an active site for graft copolymerization, and when the vinyl monomer approaches it, it reacts and initiates chain polymerization.

Effects of the Invention According to the present invention, since the obtained resin is water-soluble, it can be used as a binder for water-soluble ink, and since the resin is rosin ester-based, it can be used as a binder for ink. As a result, the ink has excellent gloss and pigment dispersibility.

Furthermore, the resin obtained according to the present invention is not limited to use as a binder for water-soluble printing inks, but can also be used as a binder for paints or legal applications, a raw material resin for surface sizing agents for paper manufacturing, a resin for toners, etc. can also be used.

In the present invention, instead of the rosin ester, it is also possible to graft copolymerize rosin or a modified rosin with a vinyl monomer (Japanese Unexamined Patent Publication No. 78987/1987). However, in this case, there are disadvantages in the storage stability of the varnish when it is made water-solubilized after neutralization with an alkali, and in the gloss and pigment dispersibility when it is made into an ink.

Actual example Specific examples of the present invention will be described below.

Example 1 Hallnister MS was placed in a 1e volume four-loaf flask equipped with a stirrer, a cooling condenser, a nitrogen inlet tube, and a hygrometer.
R-4 (rosin ester manufactured by Harima Kasei Kogyo Co., Ltd., acid value 130, softening point 130°C) was charged at 63°C, and 210g of isopropyl alcohol was charged, and then heated in a nitrogen atmosphere to dissolve the rosin ester at 80°C. Next, at the same temperature, a mixture of styrene 195 (1), 160 g of methacrylic acid, and 5 (l) of Verbutyl IB (reported by NOF Corporation, decomposition temperature 77°C) as a polymerization initiator was added dropwise over 2 hours. After the completion of the dropping and aging at 85°C for 6 hours, 28% ammonia water 1229 and water 8
8o was added to obtain 840 g of about 50% aqueous solution.

The viscosity of this aqueous solution is 16,000 cp at 25°C, and p
H (at a solid content concentration of 10%; the same applies hereinafter in this specification) was 8.9.

Example 2 Two Hallnister MSR-4 were added to the same device as in Example 1.
00g and 200g of isopropyl alcohol to dissolve the rosin ester, then styrene 110!
A mixture of 90 g of methacrylic acid and barbutyl IB5Q was added thereto and reacted in the same manner as in Example 1, and 92 g of 28% ammonia water and 108 g of water were added to obtain about 50% aqueous solution 8009.

The viscosity of this aqueous solution is 2000 cp at 25°C, and the pH
was 8.9.

Example 3 Three Hallnister MSR-4 were added to the same apparatus as in Example 1.
00g and 200a of isopropyl alcohol to dissolve the rosin ester, then 55g of styrene,
A mixture of 45 g of methacrylic acid and barbutyl IB4Q was added and reacted in the same manner as in Example 1, and 74 Q of 28% aqueous ammonia and 1260 g of water were added to obtain 800 g of an approximately 50% aqueous solution.

The viscosity of this aqueous solution was 700 cp at 25°C, and the pH was 8.8.

Example 4 Two Hallnister MSR-4 were added to the same apparatus as in Example 1.
Prepare 00g and heat to melt at 200℃. Styrene 119, methacrylic acid 90
A mixture of g and Verbutyl H (manufactured by NOF Corporation, decomposition temperature 172° C.) as a polymerization initiator was added dropwise over 2 hours. After completion of dropping, after aging at 200℃ for 6 hours, the acid value was 1.
8o1 amber resin 4009'4i with a softening point of 130℃
-I got it.

Dissolve 40 (l) of this resin in 200a of isopropyl alcohol at 80°C, add 80g of 28% aqueous ammonia and 12g of water.
0g was added to obtain 800g of approximately 50% aqueous solution.

The viscosity of this aqueous solution was 20,000p at 25°C, and the pH was 8.9.

Example 5 Two Hallnister MSR=4 were added to the same device as in Example 1.
000 and 200g of isopropyl alcohol to dissolve the rosin ester, then 172g of styrene.
A mixture of 28 g of methacrylic acid and 4 g of barbutyl IB was added and reacted in the same manner as in Example 1, and 929 g of 28% aqueous ammonia and 1089 g of water were added to obtain 800 g of an approximately 50% aqueous solution.

The viscosity of this aqueous solution is 2000 cp at 25°C, and 1)
H was 8.9.

Example 6 Two Hallnister MSR-4 were added to the same apparatus as in Example 1.
009 and 200g of isopropyl alcohol to dissolve the rosin ester, then 39g of styrene,
A mixture of 161 g of methacrylic acid and barbutyl IBIJ was added and reacted in the same manner as in Example 1, and 142 g of 28% aqueous ammonia and 58 o of water were added to obtain about 50% aqueous solution 800 a.

The viscosity of this aqueous solution is 1,000,001) at 25°C,
I)H was 8.9.

Comparative Example 1 Four Hallinister MSR-4 were added to the same device as in Example 1.
00g and 200g of isopropyl alcohol to dissolve the rosin ester, then add 579g of 28% ammonia water and 143g of water to make an approximately 50% aqueous solution of 80g.
Obtained 0g.

The viscosity of this aqueous solution is 1000 cp at 25°C, and DH
was 8.8.

Comparative Example 2 In the same apparatus as in Example 1, 20% of isopropyl alcohol was added.
0! ;1 and heat the liquid temperature to 80°C.

Next, a mixed solution of 220 g of styrene, 180 g of methacrylic acid, and barbutyl IBII was added dropwise from the dropping funnel over 2 hours. After the completion of the dropwise addition and aging at 85°C for 6 hours,
Add 8% ammonia water 1279 and water 73a, about 5
800 g of 0% aqueous solution was obtained.

The viscosity of this aqueous solution is 3000 cp at 25°C, and the pH
was 8.9.

Comparative Example 3 40 (l) of each of the aqueous solutions obtained from Comparative Example 1 and Comparative Example 2 were mixed to obtain 800 g of a 50% aqueous solution.

The viscosity of this aqueous solution is 2000 cp at 25°C, and the EI
H was 8.9.

Comparative Example 4 Into the same apparatus as in Example 1, 400 g of commercially available styrene-maleic acid resin (11 value: 190, softening point: 135°C) was charged, and 200 g of isopropyl alcohol was added thereto and dissolved at 80°C. Then 28% ammonia water 83o and water 11o
7 g was added to obtain 800 g of approximately 50% aqueous solution.

The viscosity of this aqueous solution is 15,000 El at 25°C, and D
H was 8.9.

Comparative Example 5 Into the same apparatus as in Example 1, 180 g of gum rosin (acid value 165) and 209 g of maleic anhydride were charged.
React for 2 hours at a temperature of .degree. Thereafter, the mixture is cooled, and 200 g of isopropyl alcohol is added and dissolved at 80°C.

Next, at the same temperature, a mixture of 110 g of styrene, 90 g of methacrylic acid, and 4 g of Barbutyl IB was added dropwise from the
After two drops were added over time, the mixture was aged at 85° C. for 6 hours, and 120 g of 28% ammonia water and 809 g of water were added to obtain 800 g of an approximately 50% aqueous solution.

The viscosity of this aqueous solution is 10,000 cp at 25°C, and p
H was 8.8.

Ink suitability test The aqueous solutions 1209 of each example and comparative example were diluted with 30 g of isopropyl alcohol and water to set the viscosity of Zahnkapp N014 to 8 seconds. 120 g of the diluted solution was mixed with 15 g of pigment (common pigment used for water-soluble printing inks) in a sand mill for 7 hours.
000rl)1. It was kneaded with Thereafter, Zahnkup N004 was further diluted with water to a viscosity of 8 seconds to obtain a water-soluble printing ink.

Printing: The color was spread on gravure paper using Bar Coater N013, and the gloss and drying properties of the color spread surface were observed.

Gloss: Using a 60-60 degree specular reflection gloss needle, the color development surface was measured at several locations, and the average value was determined.

Drying property: The ink on the color spread surface was dry to the touch.

Pigment dispersibility: 5 g of the obtained ink was diluted with 459 g of water,
The determination was made based on the sedimentation rate of the pigment in a test tube with a diameter of 3011 mm.

Varnish storage stability: Changes in viscosity and appearance during storage at 50°C were observed.

Test results The results of the test were as shown in the table.

The surface pigment dispersibility was determined by using Comparative Example 4 as a standard, and looking at the slow settling speed of the pigment.

As shown in the table, the resin obtained by the present invention as a binder is superior in all performances compared to the comparative example, and the resin obtained by the present invention is excellent as a binder for water-soluble ink. I can understand that there are.

Claims (1)

[Claims] 1. A method for producing a water-soluble rosin resin, which comprises graft copolymerizing a vinyl monomer to a rosin ester using a polymerization initiator. 2. Weight of the rosin ester and the vinyl monomer. Method 3 for producing a rosin-based water-soluble resin according to claim 1, characterized in that the ratio of the rosin ester is 15-75 and the vinyl monomer is 85-25. The rosin according to claim 1, characterized in that the monomer containing a carboxyl group is combined at a ratio of 0.2 to 5 moles per 1 mole of the monomer not containing a carboxyl group. Method for producing water-soluble resin