JPS5850270B2 - Suiseihifufusseibutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous coating composition that is cured and dried by irradiation or heating.

In recent years, gravure printing has made remarkable progress not only in the publishing industry, but also in the fields of packaging, building materials, and other industrial applications.

This is because gravure printing not only has excellent suitability for high-speed printing and excellent gradation reproducibility, but also can be widely applied to a variety of printing materials, which is an extremely large advantage not found in other printing methods. It is thought that the demand will further increase in the future.

Most of the current gravure inks are solvent-based inks in which a natural or synthetic resin is made into a solution using an organic solvent.

Therefore, during ink production and handling, there is a risk of toxicity from organic solvents, ignition, explosion, etc., so there has recently been a demand for the development of non-toxic and safe water-based inks, especially for disaster prevention.

The water-based inks that have been developed up to now use a maleic acid resin, shellac, or a copolymer resin mainly composed of acrylic acid or maleic acid as a vehicle.

One of the common drawbacks of water-soluble inks such as those mentioned above is that the water resistance of the printed surface is poor.

As a result of intensive research aimed at improving the above-mentioned drawbacks of water-based inks, the present inventors have discovered that the water resistance of water-based inks can be improved by using a new water-soluble resin as a vehicle that is cross-linked and cured by ultraviolet irradiation or heat. They discovered this and completed the present invention.

According to the present invention, a copolymer resin of dicyclopentadiene and maleic anhydride is reacted with at least one of the compounds represented by the following general formula 1. A coating composition is provided which is dissolved in a solvent and is curable by radiation or heating.

The present invention will be explained in more detail below.

The copolymer resins used as starting materials in the present invention include cyclopentadiene, dicyclopentadiene, tricyclopentadiene, tetracyclopentadiene, and their lower alkyl substituted products having 1 to 3 carbon atoms (for example, methyldicyclopentadiene). Although it is a resin obtained by a copolymerization reaction of one or more selected from the group consisting of (such as pentadiene) and maleic anhydride, in this specification, in order to avoid the complexity of the description, The other component to be reacted with one component, maleic anhydride, in the above copolymerization reaction will be represented by dicyclopentadiene, and will be simply abbreviated as dicyclopentadiene.

The copolymer resin of dicyclopentadiene and maleic anhydride used in the present invention can be obtained by reacting dicyclopentadiene and maleic anhydride at 150°C to 350°C without a catalyst, in the presence of a solvent if desired. It will be done.

Although the molar ratio of dicyclopentadiene/maleic anhydride in the above reaction can be set to any desired ratio, it is particularly preferable that the molar ratio is between 40/60 and 70/30.

The above copolymer resin is a solid resin at room temperature, but the softening point of the resin can be adjusted as appropriate by selecting reaction conditions, such as reaction time or reaction temperature, depending on the purpose of use. It is adjusted in the range of 50-250°C.

Furthermore, in producing the above resin, it is not necessarily necessary that dicyclopentadiene be of high purity.

For example, by thermally dimerizing cyclopentadiene and methylcyclopentadiene contained in the C5 fraction of high-temperature pyrolysis byproduct oil such as naphtha, most of the C6 fraction such as C5 olefins and C5 paraffins is removed by distillation. Dicyclopentadiene purity fraction of about 85 can be used.

In the present invention, the copolymer resin obtained as described above is then subjected to a conventional esterification reaction with one or more compounds represented by the above formula (1) or formula (2). The acid anhydride groups of the copolymer resin are esterified by the reaction in the presence or absence of a catalyst under conditions to produce an esterified modified resin.

In carrying out this esterification reaction, 0.5 to (.5 moles of the compound represented by formula (1) or formula (2) above is reacted with 1 mole of acid anhydride group in the copolymer resin. It is possible to achieve the intended purpose.

If the amount of the compound represented by formula (1) or formula (2) is too small, the water resistance of the coating will be insufficient when heating or irradiating the esterified resin as an aqueous coating composition, which is preferable. If the amount is too much, the solubility of the esterified resin in the aqueous solvent containing ammonia or amine will be insufficient, which is not preferable.

The aqueous coating composition of the present invention can be obtained by dissolving the esterified modified resin obtained as described above in water containing ammonia or amine.

Examples of amine compounds added to the solvent water include methylamine, ethylamine, ethylmethylamine, diethylamine, triethylamine, tert-butylamine,
Primary, secondary, and tertiary organic amine compounds such as monoethanolamine, jetanolamine, and triethanolamine are suitable.

The amount of these ammonia or amine compounds added is suitably 0.01 to 3 times, more preferably 0.4 to 1.2 times by mole, relative to the acid groups of the reactive resin used.

If desired, a small amount of an organic solvent such as a lower alcohol such as isopropanol may be added to the aqueous solvent containing ammonia or amine.

The quantitative ratio of the esterified modified resin and the above aqueous solvent is
It can be varied over a wide range depending on various factors, and is appropriately selected depending on the purpose of use.

When the aqueous coating composition of the present invention obtained as described above is used as a vehicle for paints or printing inks, it is possible to obtain coatings with very good water resistance. The water-based ink produced by blending the above compounds has the advantage that the water resistance of the printed surface is significantly better than that of conventional water-based inks.

Another feature of the aqueous coating composition of the present invention is that upon heating or irradiation with radiation such as ultraviolet rays or electron beams, polymerization occurs and the drying rate is significantly increased.

Although the composition of the present invention dries even if it is left as it is after being applied, in order to shorten the drying time, it is preferable to dry it by heating or irradiating with radiation immediately after application, and in this case, it is better to leave it as it is. A double advantage is obtained that the water resistance of the resulting coating is much better than if it were dried.

When the coating composition of the invention is used as a vehicle for a paint or printing ink, a curing accelerator may be included in order to further accelerate curing, and in many cases this is preferred.

As such a curing accelerator, when the composition of the present invention is cured by heating, an organic peroxide can be used alone or in combination with a decomposition accelerator.

Furthermore, when the composition of the present invention is cured by ultraviolet irradiation, sensitizers such as various benzoin ethers, benzophenones, Michler's ketones, etc. can be used as curing accelerators.

The present invention will be explained below using actual cases.

Example 1 420 g of dicyclopentadiene 980.9° maleic anhydride with a purity of 97% and commercially available mixed xylene 600, @ were charged into a 31 capacity autoclave equipped with a stirrer and reacted at a temperature of 250° C. for 2 hours.

After the reaction was completed, the autoclave was cooled, and the contents were distilled to remove unreacted monomers, low polymers, and xylene, yielding 1120 g of resin 'tD.

[I] had a softening point of 110°C and an acid value of 214.

Next, CI) so, y, 2-hydroxyethyl acrylate 21 and 0.1 g of phenothiazine were placed in a three-necked flask and reacted at 100°C for 9 hours to form resin CI-E).
I got it.

(I-E150.!7 was dissolved in 59 g of aqueous ammonia according to Section 3.6 to obtain a varnish [I-E-Vl.

CI-E-V: ] (7) Viscosity is 57 centipoise (25
°C) and the pH was 7.5.

Two types of inks, Ink A and Ink B, were prepared using (I-E-v) according to the following formulations.

Ink A (ultraviolet curing type) Varnish (I-E-Vl 81 parts carbon black 12 parts navy blue
Blue 2 parts Benzoin methyl ether 5 parts pH 7.5, viscosity Serfkup Arashi 4 (25°C) 12"2 Ink B (thermosetting type) Varnish C1-E-V 186 parts Carbon black 12 parts Navy blue
Blue 2 parts dicumyl peroxide 0.1 part pH 7.5, viscosity Serf Cup A4 (25°C) 12"0 Print on art paper using a gravure proofing machine using the above ink A, and apply a high-pressure ultraviolet lamp (A2000L) ) lower 10C
Drying was carried out at a speed of 10 m/min at a distance of IrL.

When we conducted a water resistance test on the printed matter in a wet state using a Sutherland Love Tester, we found that the printed surface was not attacked and remained almost in its original state when dried by ultraviolet irradiation, whereas ink A When dried without irradiation, the printed surface was significantly damaged in the above water resistance test.

This result shows that the water resistance was significantly improved by ultraviolet irradiation.

Ink B was similarly printed on art paper using a gravure proofing machine, and dried by placing it in an electric oven at 230°C.

A water resistance test of the printed matter revealed that the heat-dried printed matter had extremely good water resistance.

Example 2 Resin Q synthesized in Example 1] 20 g of N-methylolacrylamide and 0.0 g of hydroquinone.
1 g of the resin (n-
I got El.

Then CU -E ] 1100g 33.6% ammonia water 91 and isopropyl alcohol 20! ! A varnish (II-E-Vl) was obtained by dissolving it in a mixed solvent of

(The viscosity of n-E-v, t is 40 centimeters, and the pH is 8.
．． It was 0.

Using this, an ink was prepared with the following formulation.

Ink blend varnish (l-e-vl 83 parts carbon black 10 parts navy blue
Blue 2 parts Ink blend 5 parts Benzophenone The above ink was printed on art paper using a gravure proofing machine and irradiated with a high pressure ultraviolet lamp for 2 seconds at a distance of 10 cfrL.

A water resistance test using a wet Sutherland rub tester similar to that used in Practical Example 1 revealed that the printed matter had extremely good water resistance.

Example 3 70 g of the tree JIKI) synthesized in Example 1, 50 g of glycidyl methacrylate, 0.1 g of benzoquinone and triethylamine i were mixed and reacted at 110°C for 8 hours to obtain resin [:IE].

Next, (m-E) 50g was added to 50g of 3.0 ammonia water.
A varnish (1-EV) was obtained by dissolving it in the following.

(I-E-■) has a viscosity of 45 centimeters and a pH of 7.
It was 5.

Using this, an ink was prepared with the following formulation. Ink-containing varnish (l[-E-V) 80 parts carbon black 13 parts navy blue
Blue 2 parts Benzoin methyl ether 5 parts The above ink was printed on art paper using a gravure proofing machine and irradiated for 3 seconds with a high pressure ultraviolet lamp at a distance of l0CII'L.

In a water resistance test using the same wet Sutherland rub tester as in Example 1, it was found that the printed matter had extremely good water resistance.

Claims (1)

[Scope of Claims] 1. A resin obtained by reacting dicyclopentadiene and maleic anhydride resin with at least one of the compounds represented by the following general formula, and dissolving it in an aqueous solvent containing ammonia or amine. , a coating composition that can be cured by radiation or heating.