JPH01503391A - Printing improvements - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Printing improvements The present invention relates to printing, particularly screen printing (silk screen printing). (well known as ). Silk screen printing as well known The printing method is silk, polyester, nylon, wire mesh or other suitable mesh or Use porous materials. For convenience (and technical terminology historically used in this field) K) "Silk screen printing" is used here, but "silk screen printing" ”It is not limited only to materials.

Although silk screen printing is a very old technology, it has many problems and/or Therefore, there are limitations that arise. For example, the size of a poster to be pasted on a billboard. When silk-screening several large multicolored sheets, a large number of expensive special Requires special screen printing ink.

The printing ink required for screen printing is completely different from that used for other types of printing. do. Screen printing inks commonly used today are organic solvent-based and usually Contains ethyl or nitrocellulose resin. This ink releases organic solvents Dry in a heated air tunnel. Therefore, it is a potential poses a serious danger. Another advantage of organic solvent-based screen printing inks The problem is that solvent is lost from the ink on the printing screen, resulting in a decrease in the viscosity of the ink. increases, and after a certain time the ink no longer passes through the printing mesh properly. . This "drying in" causes the disappearance of the printed image, This is therefore an evaluation of screen stability. That is, the screen stability is small. The ink ``dries in'' rapidly.

A recent development in the past decade has been the introduction of UV-curable screen inks.

In this case, the ink does not increase in viscosity on the printing screen and is exposed to strong UV light. This method uses raw materials that are dried. This means that this type of ink is non-UV curable. Almost infinite stability compared to organic solvent-based screen printing inks means.

However, such UV-curable inks are expensive and especially for multicolored, even For example, when performing 4-color silk screen printing, it is necessary to print very thickly on the paper surface. Once the film is imaged, a special treatment is applied to effectively attach the poster to the billboard. Adhesives (other than cheap starch-based adhesives) will have to be used. similar Problems often occur with older types of organic solvent-based silk screen printing inks. arise. This adhesion problem occurs when sheets overlap, e.g. This often occurs when poster sheets overlap at their edges. . The back side of the upper sheet has sufficient adhesion to the printing ink surface on the lower sheet. Not yet. When the poster glue dries, the overlapping top sheets often It curls and separates from the sheet below. The paper is completely covered with several layers of ink. This problem is especially serious if you POS printed with offset litho ink tar has a tendency to curl when drying compared to those made with screen printing inks. few. The screen printing method achieves high quality by adhering ink to a higher degree. The problem of curl is a problem with screen printing inks because it is what gives the appearance of printed matter. It is remarkable that Therefore, the adhesive used in screen-printed posters is They need to have good adhesion to prevent curling when they rub together.

Applicants use one or more starch adhesives and one or more polyvinyl alcohol (PVA) As a result of research on mixtures with adhesives, this The mixture significantly improves the adhesion of the overlapping edges of overlapping sheets. I understand. However, starch and PVA adhesive mixtures are expensive and The improved adhesion makes it difficult to remove the poster from the billboard.

Therefore, flyers are not liked by people. i.e. people cleaning up posters on billboards It is not liked by people.

Therefore, the above and/or other deficiencies associated with traditional screen printing methods. Even if the points are not completely eliminated, some or all of them can be reduced. It is considered desirable that

According to the invention, the resin is at least partially curable upon irradiation and is dispersed in water. A silk screen mark characterized by being a water-based ink consisting of an emulsion of Printing ink is provided.

The term ``irradiation,'' used here alone with respect to curing, refers to wavelengths in the visible spectrum. also refers to the irradiation of electromagnetic radiation with short wavelengths; therefore, the term also includes UV (violet) radiation. external radiation) and electron beam irradiation.

Preferably, in the emulsion the resin is completely (or at least substantially) dispersed phase and completely (or at least substantially) insoluble in water (this water is form the continuous phase of the emulsion).

This resin constitutes 30%-60% (preferably 50%) of the emulsion. is advantageous.

The resin is preferably an unsaturated acrylate resin, such as a polyester acrylate resin. It is made of rate resin. Epoxy acrylate resin and/or urethane It is also conceivable to use acrylate resins additionally or alternatively.

Preferably, the aqueous screen printing ink has a composition comprising one or more photoinitiators. irradiation consisting of electromagnetic radiation in the ultraviolet wavelength band. It can also be partially cured.

Alternatively or additionally, this screen printing ink can be treated with an electron beam. It may also be at least partially curable by irradiation.

If this screen printing ink can be cured only by electron beam irradiation, Photoinitiators can be omitted from the printing ink composition.

Preferably, and in any case, the aqueous printing ink composition is coated before curing. Treated with heat or thermal radiation treatment, for example with electromagnetic radiation in the infrared wavelength band.

The manufacturing and dissemination of individual silk screen printed sheets according to embodiments of the present invention is described below. Shows the process for pasting on notice boards. Not only a single poster but also a large billboard. A combination of multiple posters to be printed (for example, 16 posters, 48 posters) ” or “96 posters”) are also shown. Screens used in these aspects Printing methods include not only continuous line and gradation color prints, but also four-color mesh prints. It can be used for any purpose.

The following aspects of the present invention relate to screen printing ink used for printing sheets. It is. The screen printing ink in each of these embodiments consists of a resin dispersed in water. It consists of an emulsion, i.e. it is water-miscible and resistant to exposure to ultraviolet radiation. It dries. In this emulsion, the resin is completely (or at least (also substantially) dispersed phase and completely (or at least substantially) insoluble in water. water is the continuous phase of this emulsion.

In other words, this screen printing ink contains water and can be diluted by a considerable amount of lost water. Wear. However, this water is used more as a carrier or diluent (ink viscosity should be thought of as something that reduces the amount of water to the point that it is dispersed in water).

The water-based screen ink preferably contains at least 40% water. be.

In a first aspect of the invention, the printing ink composition is an ultraviolet curable emulsified with water. It consists of a resin, eg water in equal parts, a photoinitiator and an aqueous pigment dispersion. This emal In the emulsion, water is the continuous phase and the resin (50% of the emulsion) is the dispersed phase. be. One specific composition is Example ID Darocur*1173(2) Photoinitiator 2. ．． 0Aquadisperse*Phtb41o Blue GB EP ( 3) 17 The composition shown in Example 1 was semi-calendered and the number of strokes was 165/c. It was printed through a screen made from polyester mesh. calendar - Place the finished side down on the base paper (i.e. M, G, (machine polished) poster) - paper]. The stencil is made directly with emulsion using a net positive. I made it from Print on S, P, S cylinder screen printing press Manufactured. 2 units 7 equipped with S, P, S, U, V, dry tjk machine (300 The ink was dried using '7)/A:/f>. The resulting dry print is It was an excellent halftone image with high clarity.

However, testing with this first composition showed poor screen stability. this The disadvantage is that in the second embodiment, n-vinylpyrrolidone (water-miscible This was improved by adding a sterile solvent). The formulation of this second aspect is similarly linked. Contains water as a continuous phase and resin (50% of the emulsion) as a dispersed phase However, this is shown in Example 2.

Darocur" 1173" ZO Aquadisperse*Phthalo Blue GB EP (3) 2 ．． 7n-vinylpyrrolidone (4) 10.0 Example of the composition formulated in Example 2 It was printed and dried in the same manner as in 1. The resulting dry prints have excellent clarity and It was a halftone image.

This water-miscible solvent compared to the other ingredients used in the above formulation, i.e. The final material cost was considered uneconomical as the tonne is relatively expensive. compensate for this shortcoming. Calcium carbonate extender may be added to this composition to increase the Obtained a third aspect of cost. Also, a mixture of photoinitiators was used instead of a single initiator. . The formulation of this third embodiment similarly uses water as the continuous phase and resin (emulsion). 50%) as a dispersed phase.

This is shown in Example 3.

Aquadisperse*Phthalo Blue GB EP (3) 1 7N-vinylpyrrolidone (4) 5. O QmyBlite 95T” Kistender (5) 20.0 Photoinitiator Irga cure*651 (6) 6.0 photoinitiator Quantacure*ITX (7) 3.0 The composition formulated in Example 3 was printed and dried in the same manner as in Example 1. profit The dried prints obtained were excellent halftone images with high definition.

Accommodates ink samples of four colors, i.e. primary colors yellow, magenta and cyan and black. It was prepared to examine storage stability. After 4 weeks storage, magenta ink and bra The quick ink gelled, but the yellow and cyan inks did not change. . Further treatments were carried out to improve storage stability. Screen stability and economy The fourth aspect was devised in order to keep raw material costs low. That is, n-vinylpyro of solvent, ethoxypropanol and photoinitiator instead of lydone and photoinitiator mixture. Single initiator compounds were used rather than mixtures. In this case calcium carbonate extract Dar was not used as it was not necessary to obtain acceptable raw material costs. thickener was added to keep the ink viscosity at a printable level. In this case too, the emulsion had water as a continuous phase and resin as a dispersed phase. The smell of this mode Add small amounts of humectant/surfactant compounds and silicone emulsion lubricants. A slight improvement in screen stability was obtained. Features of this fourth aspect A specific formulation is shown in Example 4.

Darocur” 1173 (2) 19 Ethoxypropanol (8) 9,7 Curlout Plus*(9) 5.8Alcoprint*PTFα’l o, 5Alcoprint*PHL0υ 1.0Alcoprint*PSJ O”) 1.9Aquadisperse*Phthalo Blue GB EP (3) 3.0 The composition formulated in Example 4 was printed and dried in the same manner as in Example 1. It was dry. The dried image obtained was an excellent halftone image with high definition.

Using this formulation, the three primary colors yellow, magenta, cyan and black printing inks can be produced. Retested storage stability.

The results were satisfactory.

The fifth embodiment avoids the use of flammable solvents and provides a completely aqueous composition. (i.e., ethoxyglobin is added to maintain proper dispersion of resin solids.) Water and acrylic monomer instead of alcohol [tripropylene glycol diacrylate] (T, P, G, D, A, )) was used. Implementing the particular formulation of this fifth aspect This is shown in Example 5.

Darocur*1173(2)3.17 Krylic monomer T, P, G, D, A, α3) 7.7 water 15.4 Curlout Plus*(9) 5.7Alcoprint*PTFα0) o, 5Alcoprint*PHL(lυ　1.0Alcoprint*PSJ Q”) ZOAquadisperse*Phthalo Blue GB EP (3) 3.0 The composition formulated in Example 5 was printed and dried in the same manner as in Example 1. It was dry. The resulting dry print was an excellent halftone image with high definition.

All the above tests were performed using a 60'X40' (1,5tnX1ff) mechanical polish. M, G, ) paper poster paper was used.

If there is a lot of ink adhering to the entire surface of the paper, a high degree of curl may occur at the edges of the paper. It was. This drawback (applicant's pending UK Patent Application Nos. 8,618,595 and 8) 619245)), the first color to be printed on the paper is set to minimize curl. For example, sheets of paper can be re-fed to a printing machine for printing with screen printing ink. ) and then each subsequent print with a water-based UV curable ink. By doing this, I was able to overcome it. Screen printing ink with minimal curl as a conventional non-aqueous UV curable ink, or a conventional solvent-based printing ink, or a water-based printing ink. A water-based ink with a small content (for example, 20% or less) can be used.

When the above water-based ink of Example 1-5 is cured only by U, V, irradiation, its moisture resistance It was found that the lubrication properties were not suitable for all purposes and caused uneven gloss levels. . An experiment was conducted in which infrared heating was performed immediately before UV curing.

Are the prints obtained by this method good moisture resistance? f4 friction and substantially uniform It had luster. This is because excess water was removed by infrared heating. It seems to be that. Use a jet air dryer to pass cold air over the print. It has also been found that more efficient water removal can be achieved by removing excess water. may additionally or alternatively be carried out by microwave drying or high frequency drying. It will be possible.

The test was conducted by gluing each sheet together to create a billboard poster. this In their tests, starch-based glues (Wilsons Adhesives and Morris Greenhaugh) was used. Using the ink of the above example The surface of the print made using the same method is printed using solvent-based inks commonly used today. The starch-based glue used by people to paste flyers makes it easier to print than prints. I found out that it accepts.

Prints made using the water-based inks of Examples 1-5 were dried by UV irradiation alone. When dried, it exhibited excellent adhesion with starch adhesives. These prints are infrared Adhesion was reduced when dried with both radiation and UV irradiation, but this still achieved in multicolor prints made using solvent-based screen printing inks. It was better than before. Nevertheless, this decrease in adhesion may cause the print to Prints with good gloss and wet abrasion resistance are overcome by electrodischarge treatment was gotten. In a preferred embodiment, the dried precipitate is dried by infrared and UV radiation. Sherman Treaters Corona Discharge It was processed using a machine at 73 dia/mm. These prints are fi Excellent adhesion similar to that obtained by drying with UV irradiation alone showed his sexuality.

remarks * means trademark.

1. Laromer” PE ssw is a polyester available from B, A, S, F. It is a 50% aqueous emulsion of steracrylate.

2-Darocur*1173 is a hydroxy- 2-methyl-1-propan-1-one.

3. Aquadisperse * Phthalo Blue GB EP is T Pigment Blue 15 aqueous dispersion available from ennant -, V, Ni, It is.

4, n-vinylpyrrolidone is B, A, S, F. UV-reactive solvents available from be.

5.0myalite*95'r can be obtained from Croxton' & Garry It is an extremely strong calcium carbonate compound.

6. Irgacure*651 is benzyl dimethyl available from Ciba Geigy. It is Ketar.

7. Quantacure*ITX is input from ward Blenkinsop. It is isopropylthioxanthone that can be prepared by hand.

B, B, P, Ethoxyglobylene glycol that can be made manually from Chemicals Ruether.

9. Curlout*Plus is American Carbonyl In Modified acrylic solution polymer available from C.

10. Alcoprint*PTF is available from Al11ed Co11oids. Acrylic copolymer in mineral oil thickener available at hand.

11. Alcoprint*PHL is input from Al11ed Co11oids. It is a mixture of hand moisturizer and surfactant.

12-Alcoprint*PSJ is obtained from A11ied Co11oids It is a silicone emulsion softener/lubricant.

13. T, P, G, D, A are triplets that can be manually done from Degu　s　s　a. Lopyleneglyfur diacrylate.

Correction officer's translation submission form (Article 184-8 of the Patent Law) January 30, 1989

Claims (13)

[Claims] 1. A resin emulsion dispersed in water that is at least partially curable by irradiation. A silk screen printing ink characterized by being a water-based ink consisting of: 2. In the emulsion, the resin is at least substantially contained as a dispersed phase, and Screen printing according to claim 1, which is insoluble in water, which is the continuous phase of the emulsion. Ink for 3. Claim 1 or 2, wherein the resin accounts for 30% to 60% of the emulsion. screen printing ink. 4. A screen according to any of the preceding claims, wherein the resin is 50% of the emulsion. printing ink. 5. A screen according to any of the preceding claims, wherein the resin is an unsaturated acrylate resin. Ink for printing. 6. Any of the above claims wherein the resin is made of polyester acrylate resin. Ink for clean printing. 7. Irradiation comprising one or more photoinitiators and consisting of electromagnetic radiation in the ultraviolet wavelength band A screen mark according to any preceding claim which is at least partially curable by Printing ink. 8. Claims curable at least partially by irradiation with an electron beam The screen printing ink according to any one of items 1 to 6. 9. A printing ink that is substantially the ink of Example 1. 10. A printing ink that is substantially the ink of Example 2. 11. A printing ink that is substantially the ink of Example 3. 12. A printing ink that is substantially the ink of Example 4. 13. A printing ink that is substantially the ink of Example 5.