JPH02202563A - Ultraviolet curing type printing ink composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, consisting of an oligomer consisting of a urethane-based resin, monomer consisting of an acrylic acid ester, etc., and polymerization initiator in a specific proportion, excellent in curability, adhesion, flexibility and elongation characteristics and capable of increasing film thickness according to reprinting. CONSTITUTION:The objective composition consisting essentially of (A) 20-70wt.% oligomer consisting of a urethane-based resin (preferably 30-40wt.% white or black color, 40-50wt.% colored and matte clear composition and 50-60wt.% for transparent composition) and (B) 5-50wt.% monomer consisting an acrylic acid ester and vinylic resin (preferably a mixed composition of 20-30wt.% acrylic acid ester and 5-8wt.% vinylic resin) and (C) 2-10wt.%, preferably 3-5wt.% polymerization initiator (e.g. benzyl ketal or thioxanthone-based initiator).

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to an ultraviolet curable printing ink composition.

[Prior Art] In recent years, the development of ultraviolet curable screen printing inks has been rapidly progressing as screen printing inks, which are inexpensive printing methods. Compared to conventional solvent-based inks, this ultraviolet-curable screen printing ink generates radicals and causes polymerization by irradiation with electromagnetic waves, so it reacts very quickly and can increase work efficiency. Because it does not use drying, it causes less air pollution, saves resources, and is more energy efficient than heat drying.
It has many advantages, such as being able to print on printing substrates that are sensitive to heat. As these ultraviolet curable screen printing inks, for example, - Funatsuri JP Publication No. 53-37902;
Special Publication No. 54-15691, Special Publication No. 54-1547
Epoxy acrylate disclosed in Publication No. 3 etc.
Those using resins such as urethane-modified acrylate and oligoester acrylate are known.

[Problems to be Solved by the Invention] However, many of these UV-curable screen printing inks are effective in terms of curing speed;
Because the cured paint film is too hard, there are problems in terms of adhesion, flexibility, and processability, and there is a problem in which the adhesion of the ink film is particularly poor when multiple printing is performed by increasing the number of printings. .

Therefore, an object of the present invention is to provide an ultraviolet curable printing ink composition that has excellent adhesiveness, flexibility, and workability.

[Means for Solving the Problems] The present invention provides oligomers 20 to 70 made of urethane resin.
This is an ultraviolet curable printing ink composition containing as essential components 5 to 50 weight % of a monomer consisting of an acrylic ester and a vinyl resin, and 2 to 10 weight % of a polymerization initiator.

[Example] The blending ratio of the oligomer used in the present invention is 20 to 70% by weight of the urethane resin, and depending on the type or presence of the ink pigment, preferably 30 to 40% by weight for white and black, colored and matte clear. For transparent, 40 to 50% ffi is suitable, and for transparent 50 to 60% by weight.The blending ratio of zero-order mono and mer is 5 to 50% by weight, preferably 20 to 30% by weight of acrylic ester. and vinyl resin 5
A mixed composition of ~8% by weight is preferable. In addition, the polymerization initiator contains at least one of pendylgetal, thioxanthone, and acetophenone derivatives in an amount of 2 to 10% by weight, preferably 3% by weight.
~5 weight percent is used. The auxiliary agents include a silicone resin as an antifoaming agent, silicon oxide as a matting agent, and a leveling filler or filler as an auxiliary agent. Various pigments are used and added as appropriate.

Next, examples of formulation and characteristic tests of the ultraviolet curable printing ink composition of the present invention will be shown in Examples.

Example 1 30 to 40% by weight of urethane resin as oligomer, 20 to 30% by weight of acrylic acid ester and 5 to 8% by weight of vinyl resin as monomer, 3 to 5% by weight of pendyl ketal as polymerization initiator, antifoaming agent 1-2% by weight of silicone antifoaming agent, 3-5% by weight of silicon oxide as a matting agent, and 10-15% by weight of a leveling filler as an auxiliary agent.
A white ink composition for ultraviolet curable screen printing was obtained using titanium oxide as a pigment in a blending ratio of 20 to 30% by weight.

Example 2 30 to 40% by weight of urethane resin as oligomer, 20 to 30% by weight of acrylic acid ester and 5 to 8% by weight of vinyl resin as monomer, 3 to 5% by weight of thioxanthone as polymerization initiator, antifoaming agent A blending ratio of 1 to 2% by weight of silicone antifoaming agent, 3 to 5% by weight of silicon oxide as a matting agent, 10 to 15% by weight of filler as an auxiliary agent, and 10 to 15% by weight of carbon iron oxide as face f1. A UV-curable black ink composition for screen printing was obtained.

Example 3 40-50% by weight of urethane resin as oligomer, 20-30% by weight of acrylic acid ester and 5-8% by weight of vinyl resin as monomer, 3-5% by weight of benzyl ketal as polymerization initiator, defoaming A blending ratio of 1 to 2% by weight of a silicone antifoaming agent as an agent, 3 to 5% by weight of silicon oxide as a matting agent, 10 to 15% by weight of a filler as an auxiliary agent, and 5 to 10% by weight of an organic pigment as a pigment. Obtain an ultraviolet curable colored ink composition for screen printing.

Example 4 50-60% by weight of urethane resin as oligomer, 20-30% by weight of acrylic acid ester and 5-8% by weight of vinyl resin as monomer, 3-5% by weight of acetophenone derivative as polymerization initiator, and 3-5% by weight of antifoaming agent. A transparent ink composition for ultraviolet curable screen printing was obtained with a blending ratio of 1 to 2% by weight of a silicone antifoaming agent.

Example 5 40 to 50 il of urethane resin as oligomer! amount%
, 20-30% by weight of acrylic ester as monomer
and 5 to 8% by weight of vinyl resin, 3 to 5% by weight of aceI to phenone derivatives as a polymerization initiator, 1 to 2% by weight of silicone antifoaming agent, and 10 to 12% by weight of silicon oxide as a matting agent.
A matte clear ink composition for ultraviolet curable screen printing was obtained at a blending ratio of %.

Comparative Example 1 Table 1 shows the results of an adhesion test using the ultraviolet curable black ink composition for screen printing obtained in Example 2.

The test conducted was a method of peeling cellophane tape, and the conveyor speed was 31/nin and 6n+/1.
It shows the relationship between the number of overprints and adhesiveness for four types: lin, 7i/nin, and 111/nin.

At any conveyor speed, good adhesion was obtained between 1 and 5 overprints, and it was possible to increase the film thickness by multiple overprints. Here, the conditions for printing and curing when conducting the adhesion test are as shown below.

Plate used: Tetron mesh 355T yellow emulsion film thickness
6 μm Irradiation conditions Rung output indication voltage lamp height peak intensity 180 W/■ 020 V 110 interval 1, 63 W/cd Comparative example 2 Next, ultraviolet curing black ink for screen printing was printed and cured under the same conditions as in the above example. Pencil hardness test and bending resistance test on the composition.

The results of the surface impact resistance test are shown in Table 2.1 The coating film of the present invention has a hardness of F according to the pencil mark I test specified in J I 5K5400, and the coating film formed into a thick film by screen printing has a hardness of F. However, it can be seen that it is sufficiently hardened. Further, in a 90° bending test conducted to confirm bending resistance, no abnormality was observed in the coating film, and since it has excellent elongation properties, it is possible to perform press punching after printing. The impact resistance test was carried out using a DuPont Street 1A tester at 500"
The weight was dropped from a height of 50 degrees, and no cracks or cracks were observed.

Comparative Example 3 The adhesion of the white, black, red, and green UV-curable screen printing ink compositions obtained in Examples 1 to 3 to the substrate sheet is shown in Table 3. This is a sellotape peel test, and the substrate sheet was made by Yodai Co., Ltd.
Panlite P, C sheets and Mitsubishi Gas Chemical Co., Ltd. Kneepilon P, C sheets were used.

At a curing furnace conveyor speed of 3 to 1011/n+in, both the curability and the adhesion to the substrate sheet were excellent, and similarly good results were obtained in overprinting.

The printing and curing conditions under which the adhesion test was conducted are shown below.

Printing plate used Tetron mesh emulsion film thickness Irradiation conditions Lamp output instruction voltage Lamp height Peak intensity Lamp integrated light amount #380 6 μm 20 W/cm Q60V 10 mm 1.47 W/cd O, 49 J /cffl Comparative example 4 Next, Examples 1- Multicolor overprinting using the ultraviolet curable screen printing ink compositions of white, black, red, green, and orange obtained in step 3 was performed by changing the irradiation conditions of the curing furnace to confirm curing and adhesion. Table 4-(A>

Table 1l-(B) and Table 4-(C), and the irradiation conditions for each are shown in Table 5. Table 4-(A) is for the case where the cumulative light amount of the irradiation lamp is 1.41 J/d, and all In this process, excellent adhesion and curing properties were obtained. Next, increase the lamp output to 100W.
/■ Table 4-(B) shows the test results when the integrated light intensity was changed to 1.35 J/cd. Among the ultraviolet curable screen printing inks, colored orange, red, and green colors were slightly sticky. There was no problem when forming the next coating layer, and there was no stickiness in the final step of overcoat coating, and the adhesion was good in all steps. Furthermore, the test results when the rung integrated light amount was lowered to 1.02 J/cd are shown in Table 4-(C), and the stickiness was almost the same as that of Cloth 1-(B), and the adhesion was good. Ta.

As mentioned above, the adhesion between the substrate and coating film, which has been a practical problem with conventional UV-curable screen printing inks, can be improved by using 20 to 70% by weight of oligomers made of urethane resin, acrylic ester, and vinyl resin. monomer 5
It can be improved by using an ultraviolet curable ink with a blending ratio of ~50% by weight and a polymerization initiator of 2 to 10% by weight.
It is possible to thicken the coating film by overprinting. Furthermore, by using vinyl resin as the monomer, excellent flexibility and elongation properties were obtained, resulting in good workability without the risk of cracking during processing such as press punching after printing. .

In addition, by blending different polymerization initiators for each color of ink pigment, even if pigments with different ultraviolet absorption ratios are used, the ultraviolet irradiation time can be controlled by controlling the polymerization initiation time of the resin. In other words, in the past, the absorption rate of ultraviolet rays differed depending on the ink pigment used or the presence or absence of pigment, so the irradiation time had to be changed depending on the color and type of pigment, or the presence or absence of pigment.
By blending polymerization initiators according to each color, the time from the start of irradiation to the start of polymerization can be controlled, and the irradiation time can be standardized for all colors, making process management easier. can.

[Effect of the invention] The present invention provides oligomers 20 to 70 made of urethane resin.
Weight % and acrylic ester and vinyl 151
A mixed composition containing 5 to 50% by weight of a monomer consisting of M and 2 to 10% by weight of a polymerization initiator as essential components,
It has excellent curability and adhesion, and the coating film is overprinted in multiple layers.
g, J'J can be made thicker, further improving visibility and
Due to its excellent elongation properties, we have developed an ultraviolet curable printing ink composition with improved workability such as press punching.
can.

Claims (1)

[Claims] (1) Ultraviolet curing type whose essential components are 20 to 70% by weight of an oligomer made of urethane resin, 5 to 50% by weight of monomer made of acrylic acid ester and vinyl resin, and 2 to 10% by weight of a polymerization initiator. Printing ink composition.