JPS60243177A - Composition for printing ink - Google Patents

Abstract

PURPOSE:The titled composition that contains, as a vehicle, a specific modified resin which is obtained by grafting an unsaturated acid ester onto a cyclopentadiene resin, thus showing stability in gloss, set and on the printer rollers. CONSTITUTION:The objective composition contains a modified resin which is obtained by grafting (A) an unsaturated acid ester such as methyl acrylate onto (B) a cyclopentadiene resin, having an acid value of 2-25 and a softening point of 100 deg.C as a vehicle. USE:It is suitable for use as offset printing ink.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel composition for printing ink, and more particularly, it relates to a novel composition for printing ink, and more specifically, it contains a graft polymer obtained by graft polymerizing an unsaturated acid ester to a cyclopentadiene resin as a vehicle component. This invention relates to a printing ink composition that has excellent stability on the roll of a printing press.

As vehicles for printing inks, resin/-modified fetol resins and alkyd resins have conventionally been generally used, but recently, technology that uses cyclopentadiene resins has been developed; for example, Graft-polymerized unsaturated polycardic acid and copolymerizable unsaturated monomer to pentanoene resin to form a modified dicyclopentadiene resin (Japanese Patent Publication No. 12232/1983), ■ Cyclointadiene resin and conjugated double bond. A modified resin obtained by adding an unsaturated monocardic acid ester to a reaction product of a higher fatty acid ester having
-95962) etc. have been developed. However, since the method (2) is mainly intended for gravure inks, the acid value of the resin is high. Therefore, when applied to offset printing inks, the ink varnish tends to thicken and glue, and the pigment wettability deteriorates. This results in deterioration and plate staining due to dampening water, making it difficult to put it to practical use. Also■
In this method, due to the presence of highly reactive tung oil, the molecular weight increases, resulting in poor solubility in ink solvents and drying oils, and when made into ink, the fluidity of the ink is also insufficient. When such a varnish is blended with a rosin-modified phenolic resin, the result is an ink with low fluidity, resulting in poor gloss and an insufficient balance between gloss and setting properties, which are important for ink physical properties.

Therefore, the present inventors conducted intensive studies to improve these drawbacks of the conventional technology, and as a result, discovered that it is effective to use a specific cyclopentadiene-based modified resin, and completed the present invention. .

Thus, according to the present invention, there is provided a graft polymer in which an unsaturated acid ester is graft-polymerized to a cyclopentadiene resin, which has an unsaturated acid unit in the molecule, an acid value of 2 to 25, and a softening point of 1'00°C or higher. Provided is a printing ink composition containing a modified resin as a vehicle component.

The modified resin used in the present invention is a graft polymer obtained by graft polymerizing an unsaturated acid ester to a cyclopentadiene resin, and has an acid value of 2 to 25, preferably 5 to 20, and a softening point of 100°C or higher, preferably It has a temperature of 110 to 170°C. Such modified resin usually has a molecular weight of 5.0.
00 to 25,000, preferably 7.000 to 2
It is 0,000.

The cyclointadiene resin used as a raw material is a polymer obtained by total thermal polymerization of a monomer mixture of a cyclopentadiene monoinhibitor (i! Tahako) 1 and a copolymerizable monomer. The polymer usually has a softening point of 70 to 170°C, preferably 80 to 150°C.
Known methods include thermally polymerizing monomers at 200 to 300°C in the presence or absence of an inert solvent such as benzene, toluene, xylene, etc.
No. 3)' can be obtained. The molecular weight and softening point of the resulting resin can be adjusted by appropriately selecting the reaction temperature, reaction time, and monomer concentration.

The cyclopentadiene monomers used in the polymerization include cyclopentadiene, lower alkyl-substituted cyclopentadiene such as methyl-substituted cyclopentadiene, ethyl fl [and dimers, dimers, and co-dimers thereof]. Diels Alder
Adducts and mixtures thereof are preferred, and the higher the purity, the better.

The comonomer used together with the cyclopentadiene monomer can be selected according to a conventional method, and specific examples thereof include 1,3-butadiene, 1,3-pentadiene, isoprene, 1,3-hexadiene, etc. Conjugated diolefins; monoolefins such as ethylene, propylene, butene, potassium, octene, styrene, α-methylstyrene, vinyltoluene, impropenyltoluene, p-tert-butylstyrene; vinyl acetate, vinyl propionate, acrylic acid Examples include unsaturated esters such as methyl, butyl acrylate, hexyl acrylate, methyl methacrylate, and butyl methacrylate, among which conjugated diolefins and monoolefins are preferred in terms of reactivity and economy.

The proportion of comonomers to be used can be selected as appropriate, but is usually 50% by weight or less, preferably 10 to 40% by weight. The polymer may also contain unsaturated acid units, and specific examples of such superficially unsaturated acids include maleic anhydride, itaconic anhydride, citraconic anhydride, acrylic acid, methacrylic acid, and croton. Examples include acids, among which maleic anhydride, acrylic acid, and methacrylic acid are preferred. Such a polymer can be synthesized by an appropriate method such as copolymerizing an unsaturated acid during the production of a cyclopentadiene resin or post-adding an unsaturated acid to a cyclointadiene resin.

On the other hand, the unsaturated acid Nisdel used may be any monomer having radical polymerization activity, and specific examples include methyl acrylate, methyl methacrylate,
Examples of unsaturated monocarboxylic acid esters include methyl crotonate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and butyl methacrylate. Even if styrenes are used in place of unsaturated acid esters, the effect of improving gloss is inferior and is not preferred.

The ratio of the cyclopentadiene polymer to the unsaturated acid ester can be selected as appropriate depending on the performance of the desired grafted product, but usually the cyclopentadiene polymer is
of<10 to 60 parts by weight of the cine saturated acid ester, preferably 15 to 50 parts by weight.

If the amount of unsaturated acid ester used is small, the effect of the present invention will be small; on the other hand, if the amount of unsaturated acid ester used is too large, the molecular weight will increase, resulting in a decrease in solubility in ink solvents and pigment wettability.

Grafting of the unsaturated acid ester onto the cyclopentadiene resin is carried out using a radical initiator according to a conventional method.

The radical initiator is not particularly limited as long as it is commonly used, and specific examples include diacyl peroxide such as benzoyl peroxide; cumene hydroperoxide, t-butyl hydroperoxide. Hydronos such as -oxide;
Examples include dialkyl and monooxides such as butyl peroxide and tsucumyl peroxide; and azo compounds such as azobisisobutyronitrile.

These radical initiators are appropriately selected and used depending on polymerization conditions such as polymerization temperature and polymerization time.

The amount of the radical initiator used is appropriately selected depending on the performance of the desired polymer, but it is usually in the range of 0.01 to 10% by weight based on the total polymerizable components, especially 0.
．． A graft polymer having excellent performance can be efficiently obtained in the range of 0.05 to 5% by weight.

Polymerization reactions using radical initiators include toluene, xylene,
It is carried out at 60-260° C. for 0.5-20 hours in the presence or absence of a known inert solvent such as mineral sugerite. Polymerization using a radical initiator may be carried out either batchwise or continuously.

Further, during the reaction, unsaturated acid units as described above can be present in order to introduce unsaturated acid units into the polymer. The amount of such unsaturated acid used is such that the acid value in the polymer is 2 to 2.
25, preferably in the range of 5 to 15; if the acid value is too high, the emulsifying property with dampening water becomes too large, and on the other hand, if it becomes too small, the wettability with the pigment decreases. .

In the present invention, the modified resin thus obtained can be used alone as a vehicle component, or, if desired, can be used as a modifier for rosin-modified phenolic resin. The rosin-modified phenolic resin in this case may be any resin that is commonly used in the field of printing inks, and its properties include, for example, a softening point of 110 to 1.
90°C, preferably 130-180°C, acid value 5-50,
Preferably it is in the range of 8-30.

Rosin-modified phenolic resin is generally obtained by reacting a rosin component with a phenol resin or its raw material components, and then reacting with a polyhydric alcohol. Specific examples thereof include Tamanol < 34 manufactured by Arayo Kagaku Kogyo Co., Ltd.
0,352,353,354°360.361,362
, 363), KG (801,805°807.809,
815, 81.6, 817, 818, 820), Perakasite (1126) manufactured by Nippon Reichhold, No Rifuenol (p-110゜P-1) manufactured by Harima Kakai Kogyo Co., Ltd.
20,, P-130, P-140, PN-717゜29
5), Hytanol (260, manufactured by Hitachi Chemical Co., Ltd.).

261.270.40G, 50G, 40P, 50F), etc.

These rosin-modified phenolic resins include those that are easily soluble in petroleum solvents and those that are poorly soluble1, depending on the type of raw materials and the proportions used. In this case, the compatibility with petroleum solvents can be improved by cooking with a drying oil such as linseed oil at high temperatures.

When used in combination with rosin-modified phenolic resin, can the proportion of modified resin used be appropriately selected depending on the purpose of use?
It is usually 5% by weight or more, preferably 10 to 70% by weight.

The ink composition of the present invention is produced according to a conventional method except that the modified resin as described above is used as the binder component of the vehicle. For example, a printing ink can be obtained by dissolving a modified resin in a petroleum solvent or drying oil, and then mixing the mixture with a pigment, a gelling agent, an ink dryer, etc.

The printing ink composition of the present invention thus obtained has excellent gloss of printed matter and setting properties after printing, which were conventionally said to be contradictory properties, as well as excellent ink misting during printing and wettability with pigments. It has good properties and is particularly suitable as an ink for offset printing.

The present invention will be explained in more detail below with reference to Examples. In addition, parts and parts in Examples and Reference Examples are based on weight unless otherwise specified.

Reference example 1 70 parts of cyclopentadiene! = 100 parts of cyclopentadiene resin (1) with a softening point of 125°C obtained by thermally polymerizing 30 parts of 3-pentadiene at 260°C for 4 hours in the presence of ticilene and heated to 160°C with 25 parts of xylene. Thereafter, it was added dropwise over 60 minutes to a heated solution consisting of 28 parts of butyl acrylate, 2.5 parts of maleic anhydride, and 3 parts of tert-butyl hydroperoxide, and after polymerization for an additional 60 minutes, the solvent was distilled off. , molecular weight 15,0
A modified resin (1) having a softening point of 151° C. and an acid value of 9.5 was obtained.

Reference Example 2 70 parts of cyclopentadiene, 15 parts of 1,3-pentadiene, and 15 parts of C7 fraction were mixed in the presence of xylene at 260°C for 4 hours.
100 parts of a cyclopentadiene resin [:II] having a softening point of 125°C obtained by time-thermal polymerization was heated to 160°C with 25 parts of xylene. Later, 35 parts of ethyl acrylate,
4 parts of methacrylic acid and tertiary glutyl hydro i4
- Add dropwise over 60 minutes to a heated solution consisting of 3 parts of oxide, and then proceed in the same manner as in Reference Example 1 to obtain a molecular weight of 12,000.
A modified resin [...] having a softening point of 140°C and an acid value of 16 was obtained.

Reference Example 3 100 parts of the cyclopentadiene resin (1) of Reference Example 1 After adding 25 parts of xylene and heating to 160°C, 28 parts of styrene, 2.5 parts of maleic anhydride and tertiary
The modified resin (III) having a molecular weight of 20,000, a softening point of 155° C., and an acid value of 10.0 was obtained by adding dropwise to a heated solution consisting of 3 parts of butyl hydroperoxide over 60 minutes and following the same procedure as in Reference Example 1. Ta.

Reference Example 4 A reaction was carried out in exactly the same manner as in Reference Example 1 except that maleic anhydride was not used to obtain a modified resin (IV)'e.

The softening point was 140°C and the acid value was 1 or less.

Reference Example 5 Other than using 158 parts of maleic anhydride Reference Example 1
The reaction was carried out in exactly the same manner as above to obtain a modified resin [V].

The softening point was 170°C and the acid value was 60.

Example 1 Modified resin (1) obtained in Reference Example 1, rosin modified phenolic resin (trade name Beccasai) 1126, softening point 160°C,
Acid value 17, manufactured by Nippon Reichhold Co., Ltd.) and linseed oil were heat-treated at 240°C for 2 hours according to the recipe shown in Table 1, and then a predetermined amount of petroleum solvent (manufactured by Nippon Oil Co., Ltd., No. 5 Solvent) was added. After heating and stirring for 20 minutes to form a varnish with a similar viscosity, the pigment content was 20 minutes.
An ink was prepared by adding Carmine 6B to the mixture and kneading it with a triple roll. The amount of petroleum solvent was adjusted appropriately so that the tack of the ink would be t-10±05 during ink formation.

Next, the obtained ink was spread on art paper using an R1 tester using a 172-segment roll under the conditions of 0.15-2.
After standing for a period of time, the gloss was measured at 60 degrees - 60 degrees. The results are shown in Table 1.

Table 1 *1 If there is a difference of 2 daints in gloss value, it can be clearly determined with the naked eye O *2 Ink 0.21R1'iR Etester Place the color on a two-part roll and spread it on coated paper, then stack high-quality paper and press. Using a roller, observe how the ink adheres to the coated paper.
Measure the time until ink stops sticking.

*3 When the incometer is 120 Or, p, m, check the state of mist scattering on the white paper placed under the roll, and indicate ○ if there is no scattering, △ if it is slightly observed, and × if it is completely observed. .

Example 2 30 parts of modified resin obtained in Reference Examples 2 to 5, rosin modified phenolic resin (trade name Tamanol 354, softening point 170°C,
An ink was prepared according to Example 1, except for using 70 parts of acid value 19.0 (manufactured by Aurayo Kagaku Co., Ltd.) and 50 parts of linseed oil, and its performance was evaluated, and the results shown in Table 2 were obtained. Ta.

22 Omote Town The results are the same as in other experimental examples except that 100 parts of rosin-modified phenolic resin is used. From this result, the ink composition of the present invention has antinomic properties compared to ink using rosin-modified phenolic resin. It can be seen that the relationship between gloss and cent (improving gloss but detracting from setting properties) has been greatly improved, and misting has also been reduced. On the other hand, when a modified resin made by graft polymerizing styrene was used, no improvement in gloss was observed (
Experiment No. 2-3), and when a modified resin with no acid value or a modified resin with a high acid value is used, the effects of the present invention cannot be achieved (Experiment No. 2-4, 2-5).

Nippon Zeon Co., Ltd.

Claims (1)

[Claims] 1. A graft polymer obtained by graft polymerizing an unsaturated acid ester to a cyclopentadiene resin, and contains a modified resin having an unsaturated acid unit in the molecule with an acid value of 2 to 25 and a softening point of 100°C or higher as a vehicle component. A printing ink composition characterized by: