JPS5952676B2 - New printing ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel printing ink, and more particularly:
This invention relates to a novel printing ink that has excellent adhesion and printability to films, sheets, or synthetic paper made of synthetic resin.

Conventionally, polyamide resins have been mainly used as vehicle components of printing inks used for films, sheets, synthetic papers, etc. made of synthetic resins such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, and polyester.

Polyamide resin generally has excellent flexibility and gloss, but
It has the drawbacks of poor adhesion to synthetic resins and high price. Therefore, various attempts have been made to overcome these drawbacks. For example, nitrocellulose, maleic acid resin,
A method of simultaneously blending ketone resin, rosin, etc. is known. However, the reality is that even with these methods, the problem of insufficient adhesiveness with synthetic resins has not been solved. An object of the present invention is to provide a novel printing ink that has excellent adhesion and printability to the printing surface of a film, sheet, or synthetic paper made of synthetic resin. These objects of the present invention are based on polyamide resin 30-9
5% by weight and (B) cyclopentadiene monomer 50-9
0% by weight and 50-10% by weight of vinyl monomers containing monoolefinic unsaturated alcohols or ester bonds
This is achieved by using as a component of the ink vehicle a mixture with 70 to 5% by weight of a cyclopentadiene resin obtained by thermal copolymerization of a monomer mixture of

The cyclopentadiene resin used in the present invention is composed of 50 to 90% by weight, preferably 60 to 85% by weight of a cyclopentadiene monomer and a monoolefinic unsaturated alcohol or a vinyl monomer containing an ester bond (hereinafter referred to as (sometimes abbreviated as ester-containing monomer) 50~
A known method of thermally polymerizing a 10% by weight, preferably 40 to 15% by weight mixture at 250 to 300°C for 0.5 to 20 hours in the presence or absence of an inert solvent such as benzene, toluene, or xylene (e.g. U.S. Patent No. 268923
No. 2) with a softening point of 70 to 200°C, preferably 80 to 160°C, and a cardner chromaticity of 8 or less.

It is possible to adjust the molecular weight and softening point of the resulting resin by appropriately selecting polymerization conditions such as reaction temperature, reaction time, and monomer concentration, but if the amount of cyclopentadiene monomer is too large. If the amount is too low, the compatibility with the polyamide resin will deteriorate, and if the amount is too low, the softening point will decrease, resulting in a decrease in drying properties, gloss, and other ink suitability when made into an ink, so it is outside the scope of the present invention. Excluded. The cyclopentadiene monomers used in the polymerization include cyclopentadiene, lower alkyl-substituted cyclopentadiene such as methyl-substituted and ethyl-substituted cyclopentadiene, and lower Diels-Alda monomers such as dimers, trimers, and codimers thereof. These include adducts and mixtures thereof, and the higher the purity, the better.

On the other hand, the comonomer copolymerizable with the cyclopentadiene monomer used in the present invention is an ester-containing monomer or a monoolefinic unsaturated alcohol.

The ester-containing monomer is a compound represented by the general formula (in the formula, X, Y and Z represent hydrogen or a methyl group, and R represents an alkyl group having 1 to 8 carbon atoms), and its specific Examples include fatty acid esters of unsaturated alcohols such as vinyl acetate, vinyl propionate, and methyl acrylate, methyl methacrylate, methyl crotonate, ethyl acrylate, butyl acrylate, 2-acrylate, etc.
α such as ethylhexyl. Mention may be made of alkyl esters of β-monounsaturated fatty acids, among which vinyl acetate, ethyl acrylate and methyl methacrylate are preferred. Further, unsaturated alcohols are mono- and polyvalent monoolefinic unsaturated alcohols having 3 to 6 carbon atoms, and specific examples thereof include allyl alcohol, crotyl alcohol, 1,
Examples include 4-butenediol, 1,2-butenediol, 3-hexene-2,5-diol, and allyl alcohol is also used.

Other monomers that can be copolymerized with cyclopentadiene monomers include 1,3-butadiene, styrene, isoprene, acrolein, and furfural, but among these monomers, When using a resin obtained by copolymerizing a non-polar monomer with polyamide resin, it has poor compatibility with polyamide resin, making it impossible to obtain a practical ink; When acrolein and furfural are copolymerized, the hue of the resin is extremely poor, making it unsuitable for use in ink.

Further, in the present invention, instead of the cyclopentadiene resin, a derivative obtained by modifying the resin according to a known method can also be used.

Specific examples include acid-modified resins obtained by adding maleic anhydride or fumaric acid, phenol-modified resins obtained by adding a phenol-formaldehyde condensate, and hydrogen obtained by hydrogenation. Examples include additive resins, and these derivatives exhibit effects equivalent to those of unmodified cyclopentadiene resins. On the other hand, the polyamide resin used in the present invention can be prepared by adding alkylene polyamines or polyalkylene polyamines such as ethylene diamine, diethylene triamine, triethylene tetramine, etc. and fatty acids such as soybean oil fatty acids, tung oil fatty acids, tall oil fatty acids, etc. according to a conventional method. It is a thermoplastic resin obtained by reacting with dimers, trimers, etc., and has a softening point of 60 to 200°C, preferably 80 to 160°C.
℃ is prized.

The blending ratio of polyamide resin and citalopentadiene resin is 30 to 95% by weight, preferably 40 to 90% by weight of the former.
The latter is 70 to 5% by weight, preferably 60% by weight.
If the amount of polyamide resin is too large, the adhesion of the printing ink to the substrate will be poor, and if it is too small, the flexibility and gloss of the ink film will be poor, which is not preferable.

In the present invention, a printing ink is produced according to a conventional method except that a mixture of a polyamide resin and a citalope, ntadiene resin is used as an essential component of the bihital. That is, a solvent is usually added so that the solid content concentration of the resin mixture is 15 to 60% by weight, and when the resin content and the solvent are compatible, carbon bratulita, titanium white, carmine 6B, phthalocyanine, and benzicine yellow are added. Add pigments such as
Printing ink is prepared by kneading for about 10 hours in a ball mill, roll mill, or the like. At this time, the solvents used mainly include alcohols such as metall, ethanol, propanol, butanol, bentanol, and cyclohexanol, esters such as formic acid, acetic acid, propionic acid, butyric acid, and various distillates from naphtha, etc. Examples include aliphatic solvents, hydrocarbon solvents such as aromatic solvents, and water, which may be mixed and used as appropriate. Of course, in addition to the above components, other compounding agents commonly used in the field of printing inks such as resin components such as nitrocellulose, maleic acid resin, and rosin, wax, and plasticizers can also be blended. The printing ink of the present invention obtained in this way can be used for special gravure substrates made of synthetic resins such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, and polyester, aluminum foil, cardboard, etc. It is particularly suitable for ink and flexo ink, but is also useful as ink for gravure, offset, etc.

The present invention will be explained in more detail with reference to Examples below.

Note that all parts and percentages in Examples and Reference Examples are based on weight. Reference Example 1 480 parts of a monomer mixture having the composition shown in Table 1 was thermally polymerized in an autoclave in the presence of 120 parts of xylene at 250 to 270°C under a nitrogen atmosphere for 4 hours, and then
The unreacted monomers and xylene are recovered by distillation at ℃, and the cyclopentadiene hydrocarbon resin (
A) was obtained.

Example 1 Polyamide resin (softening point approximately 130°C, Versamide 725
manufactured by Daiichi General) and cyclopentadiene resin (A
-5) Add a 1:1:2 mixed solution of isopropanol, ethyl acetate, and toluene to a solid concentration of 30%, add phthalocyanine blue corresponding to 5% of the total, and mill in a ball mill for 10 minutes. After kneading for a period of time, the viscosity at 25°C was measured using an EH type viscometer.

The obtained ink was subjected to corona discharge treatment using a 25μ applicator and spread on a polypropylene film, which was used as a test object. After thoroughly drying the test object, the adhesion of the ink film was evaluated using a cellophane tape test, and the color spreading property was evaluated by observing the gloss of the color spreading surface. Furthermore, flexibility was evaluated by rubbing the developed film by hand and measuring the number of times the film was rubbed until the ink film peeled off. The results are shown in Table 2. This result shows that the adhesion of the ink is significantly improved by blending the cyclopentadiene resin.

However, if the amount is too large, the gloss and flexibility will be impaired, which is undesirable.
Example 2 An ink was prepared in the same manner as in Example 1 using a mixture of 70% polyamide and 30% of the various cyclopentadiene resins obtained in Reference Example 1, and its performance was evaluated.

The results are shown in Table 3. These results show that when a homopolymer of cyclopentadiene is blended (experiment number 9), the gloss and flexibility are poor, and when a resin copolymerized with a large amount of vinyl acetate is used (experiment number 14), the gloss is poor. Furthermore, when using resins copolymerized with styrene or isoprene (Experiment Nos. 18 and 19), it was found that the adhesiveness, gloss, and flexibility were inferior.

Example 3 50% polyamide resin, nitrocellulose (SS?IP
An ink was prepared in the same manner as in Example 1 using a mixture of 25% A (co-dipping) and 25% cyclopentadiene resin, and its performance was evaluated.

The results are shown in Table 4. This result shows that even when nitrocellulose is used in combination, the effects of the present invention can be achieved.

Claims (1)

[Scope of Claims] 1 (A) 30 to 95% by weight of polyamide resin, (B) 50 to 90% by weight of cyclopentadiene monomer, and 50% of vinyl monomer containing monoolefinic unsaturated alcohol or ester bond. Cyclopentadiene resin 70-5 obtained by thermal copolymerization of a monomer mixture with ~10% by weight
% by weight as a component of the vehicle. 2. The printing ink according to claim 1, wherein the polyamide resin has a softening point of 60 to 200°C. 3 The softening point of cyclopentadiene resin is 70-200
The printing ink according to claim 1, wherein the temperature is .degree. 4. The printing ink according to claim 3, wherein the cyclopentadiene monomer is cyclopentadiene, methylcyclopentadiene, or a dimer, trimer, or codimer thereof. 5 Monoolefinic unsaturated alcohol has 3 to 6 carbon atoms
The printing ink according to claim 1, which has the following. 6. The printing ink according to claim 5, wherein the monoolefinically unsaturated alcohol is allyl alcohol. 7. The printing ink according to claim 1, wherein the vinyl monomer containing an ester bond is a fatty acid ester of a monoolefinic unsaturated alcohol. 8. The printing ink according to claim 1, wherein the vinyl monomer containing an ester bond is an alkyl ester of an α,β-unsaturated fatty acid. 9. The printing ink according to claim 1, wherein the vinyl monomer containing an ester bond is vinyl acetate, methyl methacrylate or ethyl acrylate. 10. The printing ink according to claim 1, wherein the printing ink is for special gravure or flexography.