JP5298426B2 - Printing ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing ink having excellent suitability for continuous printability in offset printing and hardly causing a piling phenomenon. <P>SOLUTION: An improvement in the printing ink used for an offset printing method comprises filling a printing plate having recessed patterns with an ink containing at least a powder component composed of inorganic powder or organic powder, a resin component, a solvent component and a dispersant, transferring the filled ink to a blanket for printing having a silicone rubber sheet on the surface and then transferring the ink from the blanket for printing to the material to be transferred. The characteristic constitution thereof satisfies a tack value after 1 min from the start of measurement within the range of 8-30 when the ink is measured under conditions of 400 rpm number of revolutions with an inkometer according to JIS K 5701. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a printing ink suitable for continuous printing by offset printing for forming a fine and highly accurate electrode pattern on a semiconductor device.

  Conventionally, photolithography has been used to form electrodes and the like in semiconductor devices such as electronic circuit boards and display devices. However, this photolithography method has a complicated manufacturing process and has a large material loss. There is a problem that the manufacturing cost becomes extremely high because a huge amount of cost is required for manufacturing equipment such as an exposure apparatus. Furthermore, the cost of processing the waste liquid generated in the development process at the time of pattern formation is high, and the waste liquid has a problem from the viewpoint of environmental protection.

  Thus, various researches have been conducted on pattern formation methods that are low in cost and do not generate harmful waste liquids. In particular, the intaglio offset printing method is attracting attention as an alternative to the photolithography method because it can form a fine pattern with high accuracy. The intaglio offset printing method uses a silicone rubber sheet for the printing blanket surface to transfer 100% of the printing ink from the printing blanket to a transfer medium such as a glass substrate, and the printing blanket surface for the printing ink. Easily soluble in silicone rubber, for example, adding a solvent, dissolving this solvent in silicone rubber, and reducing the interfacial tension between the printing ink and the silicone rubber interface makes it easier to peel the printing ink from the silicone rubber for printing The printing ink is transferred from the printing blanket onto the transfer medium.

As an optimal printing method using the intaglio offset printing method, a printing method is disclosed in which printing is performed so as to satisfy a specific viscosity range within a predetermined transition speed range (for example, Patent Document 1). reference.). By printing within a range that satisfies this Patent Document 1, it is possible to select a high transition speed with high printing accuracy.
JP 2005-63843 A ([0018])

  However, as printing is continuously performed in conventional intaglio offset printing, when printing ink is applied from a printing blanket to a transfer medium such as a glass substrate, the printing ink gradually remains on the printing blanket. There is a problem that a phenomenon called so-called piling occurs. Even if printing using the printing method disclosed in Patent Document 1 described above, the occurrence of the pyring phenomenon has not been sufficiently suppressed. One of the causes of the pyring phenomenon is that when the printing blanket is rotated to transfer the printing ink from the silicone rubber sheet on the surface of the printing blanket to the glass substrate, the printing ink is internally divided and used for printing. It is considered that a part of the ink remains on the silicone rubber sheet. Due to this pyring phenomenon, there is a problem that the obtained coating film causes a decrease or variation in film thickness and variation in line width.

  An object of the present invention is to provide a printing ink which is excellent in suitability for continuous printability in offset printing and hardly causes a piling phenomenon.

The invention according to claim 1, powder component, a resin component, a solvent component and a dispersing agent to fill the ink having containing a printing plate having a concave pattern, the printing blanket having a silicone rubber sheet to the filled ink surface This is an improvement of the printing ink used in the offset printing method in which the ink is transferred from the printing blanket to the transfer medium after the transfer. The characteristic configuration is a printing ink for forming an electrode pattern in a semiconductor device, and the powder component is an inorganic powder composed of metal powder, metal oxide, metal nitride, or mixed powder obtained by mixing these. Powder, or organic pigment, inorganic pigment, glitter pigment, organic dye, the organic powder is azo, polyazo, anthraquinone, quinacridone, isoindoline, isoindolinone, phthalocyanine, perylene, DPP type, fluorescent pigments, the above inorganic pigments are carbon powders such as acetyl carbon, carbon nanotubes, fullerene, graphite, synthetic silica, chromium oxide, iron oxide, titanium oxide, titanium black, calcined pigment, zinc sulfide, ruthenium oxide , Cobalt oxide, manganese oxide, copper oxide, and the glitter pigment is pearl The organic dye is an alcohol-soluble dye, an oil-soluble dye, a fluorescent dye, and a light-collecting dye, and the resin component is an acrylic-styrene copolymer, acrylic-urethane. Copolymer, acrylic-epoxy copolymer, urethane acrylate or epoxy acrylate, and the above solvent components are diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, γ-butyl lactone, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether And one or more selected from the group consisting of ethylene glycol monophenyl ether, and the proportion of the dispersant is 3 to 10% by weight when the ink is 100% by weight When the ink was measured under the condition of a rotational speed of 400 rpm with an incometer based on JIS K 5701, the tack value 1 minute after the start of the measurement is in the range of 10.4 to 12.5.
In the invention according to claim 1, printing ink that has a tack value 1 minute after the start of measurement when measured with the above-mentioned predetermined condition by an incometer according to JIS K 5701 is offset printing. It is excellent in the suitability for continuous printability, and it is difficult for a piling phenomenon to occur even if continuous printing is performed.

Moreover , if the component of printing ink is the said kind, it is especially suitable for the continuous printability in offset printing.

  The printing ink of the present invention is an offset printing in which the tack value 1 minute after the start of measurement satisfies the above range when measured under the above-mentioned predetermined conditions with an incometer according to JIS K 5701. It is excellent in the suitability for continuous printability, and it is difficult for a piling phenomenon to occur even if continuous printing is performed.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
As a result of intensive studies in order to solve the above-described problems with respect to continuous printability in offset printing, the present inventor has a correlation between the continuous printability in offset printing and the tack value obtained when measured under specific conditions. Found to have a relationship.
The present invention is a printing ink used in an offset printing method. The printing ink is a printing ink for forming the electrode pattern in a semiconductor device, comprising containing the powder component consists of an inorganic powder or organic powder, a resin component, a solvent component and a dispersing agent. In the offset printing method, as shown in FIG. 1, the printing ink 11 is filled into a printing plate 10 having a concave pattern 10a, and the filled ink is transferred to a printing blanket 13 having a silicone rubber sheet 13a on the surface. Thereafter, the ink 11 is transferred from the printing blanket 13 to the transfer medium 14. The characteristic configuration is that when the above printing ink is measured with an incometer conforming to JIS K 5701 at a rotation speed of 400 rpm, the tack value 1 minute after the start of measurement satisfies the range of 10.4 to 12.5. By the way.

  Ink for printing in which the tack value 1 minute after the start of measurement satisfies the above range when measured under the above-mentioned conditions with an incometer conforming to JIS K 5701 is the continuous printability and tack value in offset printing. Therefore, it is excellent in suitability for continuous printability in offset printing. Even if continuous printing is performed by offset printing using such a printing ink, an effect that a piling phenomenon hardly occurs can be obtained.

  Next, a method for measuring the tack value using an incommeter conforming to JIS K 5701 will be described. The incometer, which is also called a rotary tack meter, is composed of at least three rollers. Here, an incometer composed of three rollers will be described. The first roller is a driving roller that is driven by a motor, and is made of a metal roll. The size is exemplified by diameter: 76.2 mm × width: 155.4 mm. The second roller is in contact with the driving roller, and is disposed immediately above the driving roller. A sensor is connected to the roller, and the stress when the driving roller is driven to change the position of the equilibrium state. Is a measuring roller that measures the thickness of the NBR rubber roll having a hardness of 80 °. The size is exemplified by diameter: 79.3 mm × width: 150.4 mm. The third roller is a dispersing roller for dispersing the measurement sample, and is composed of an NBR rubber roll having a hardness of 30 ° to 50 °. The size is exemplified by diameter: 50.8 mm × width: 184.1 mm. In this evaluation method, the tack value is measured by a so-called open-type incometer in which each roller is not sealed.

  In this evaluation method, an incometer configured as described above is used. As shown in FIG. 2 (a), the driving roller 21 and the measuring roller 22 constituting the incometer are maintained in an equilibrium state even when the roller is rotated in a state where the printing ink is not applied. ing. First, each of the three rollers is maintained at a temperature of 30 ° C. About 1.31 cc of printing ink is applied as a measurement sample on three rollers maintained at this temperature. As shown in FIG. 2B, a coating film of the printing ink 23 is formed on the surface layer of the applied driving roller 21 and the surface layer of the measuring roller 22. Although not shown, an ink coating film is also formed on the surface layer of the dispersing roller.

  Next, each roller having the ink coating film 23 formed on the surface layer is rotated at a rotational speed of 400 rpm. As shown in FIG. 2B, by rotating the driving roller 21, the ink 23 applied to the roll passes through the gap between the driving roller 21 and the measuring roller 22 in the state of a coating film. In the coating film of the ink 23 that has passed through the gap between the driving roller 21 and the measuring roller 22, a force (torque F) required for the ink peeling occurs at the exit of the roll. As shown in FIG. 2C, the restoring force (paste cohesive force F) for returning the torque F to the equilibrium position is measured as a tack value by a sensor connected to the measuring roller 22. Such an incometer measures tack values at regular intervals from the start of measurement.

In the printing ink of the present invention, a value one minute after the start of the measurement of the tack value thus measured is used as a representative value. If the tack value 1 minute after the start of measurement is in the range of 10.4 to 12.5 , the correlation between the continuous printability in offset printing and the tack value is excellent in the suitability for continuous printability in offset printing, Pile phenomenon is unlikely to occur even with continuous printing.

The tack value 1 minute after the start of measurement is set within the range of 10.4 to 12.5. If the tack value is less than 10.4 , it is not possible to print the necessary number of times without piling in continuous printing. When the tack value exceeds 12.5 , the viscosity of the paste is too high, so that there is a problem that the paste cannot be embedded (doctoring) in a concave printing plate such as a gravure plate. There is .

  The powder component contained in the printing ink of the present invention is an inorganic powder or an organic powder. Specific examples include organic pigments, inorganic pigments, glitter pigments, and organic dyes. Among these, inorganic powders such as metal powders, metal oxides, metal nitrides, or mixed powders thereof are suitable because they can be used for printing conductive patterns and are particularly suitable for continuous printability in offset printing. Examples of organic pigments include azo, polyazo, anthraquinone, quinacridone, isoindoline, isoindolinone, phthalocyanine, perylene, DPP, and fluorescent pigments. Examples of inorganic pigments include carbon powders such as acetyl carbon, carbon nanotubes, fullerene, graphite, synthetic silica, chromium oxide, iron oxide, titanium oxide, titanium black, calcined pigment, zinc sulfide, ruthenium oxide, cobalt oxide, manganese oxide, Examples thereof include copper oxide. Examples of glitter pigments include pearl pigments, flake pigments, aluminum pigments and bronze pigments. Examples of organic dyes include alcohol-soluble dyes, oil-soluble dyes, fluorescent dyes, and light-collecting dyes.

  Among the resin components contained in the printing ink of the present invention, suitable components for continuous printability include polyacrylic acid esters such as polymethyl acrylate, polymethacrylic acid esters such as polymethyl methacrylate, polystyrene, polyurethane, and epoxy. A part of acrylic-styrene copolymer, acrylic-urethane copolymer, acrylic-epoxy copolymer, polyacrylic acid ester and polymethacrylic acid ester copolymerized with resin was substituted with urethane and epoxy. Examples thereof include urethane acrylate and epoxy acrylate. Moreover, the molecular weight of these resin components is suitably used in the range of hundreds to millions of oligomers to polymers. The low molecular weight resin component is effective for suppressing drying of the ink, and the high molecular weight resin component can suppress cohesive failure inside the ink. That is, it is effective for improving transferability. Therefore, by containing a resin having a low molecular weight to a high molecular weight and a wide molecular weight in the ink, it is possible to satisfy the ink drying suppression and the transferability improvement at the same time. Acrylic-styrene copolymer, acrylic-urethane copolymer, acrylic-epoxy copolymer, urethane acrylate or epoxy acrylate has a high cohesive force, and is used in the ink at the time of transfer to the transfer target. Cohesive failure can be suppressed. You may use the said acrylic styrene-type copolymer etc. individually or in mixture of 2 or more types.

  Among the solvent components contained in the printing ink of the present invention, components suitable for continuous printability include diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, γ-butyl lactone, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, And ethylene glycol monophenyl ether. A solvent component is comprised so that 1 type, or 2 or more types selected from the said group may be included.

Among the dispersants contained in the printing ink of the present invention, suitable dispersants for continuous printability include carboxylic acids, polycarboxylic acid type polymer anions, allyl ether copolymers, polyamine-fatty acid condensates, polymer interfaces. Activators, polymeric fatty acids, phosphate esters, fatty acid ester condensates, and the like. By including the dispersant, an effect of smoothing the coated layer surface can be obtained. The dispersing agent when 100 wt% ink you in a proportion of 3 to 10 wt%. In addition, the sharpness at the edge portion of the line to be formed is increased.

FIG. 3 shows three types of printing inks having different components and compositions, and these printing inks were measured as samples A to C, and measured with a rotational speed of 400 rpm using an incometer based on JIS K 5701. It is a result. Of these, meet tack value of the measurement sample A is 12.5, the tack value of the measurement sample B is 10.4, in the present invention, the scope tack value of 10.4 to 12.5 at the measurement starting 1 minute after It was. In FIG. 3, the tack value tends to increase as the measurement time progresses. However, since the tack value was measured with an open incometer, the solvent in the printing ink volatilized, This is because the cohesive force changes. After this measurement, when continuous printing was actually performed using these printing inks by the intaglio offset printing method, in the printing ink used for the measurement sample C, a piling phenomenon occurred on the blanket about 200 times from the start of printing. On the other hand, the printing ink used for the measurement samples A and B did not cause a pyring phenomenon even after exceeding 500 times. From such results, printing inks that have a tack value of 1 minute after the start of measurement when measured with the above-mentioned conditions using an incometer in conformity with JIS K 5701 are continuous in offset printing. It was confirmed that the printability was excellent and that the pyring phenomenon hardly occurred even when continuous printing was performed.

Schematic of the offset printing method. The figure which shows the measurement principle of the tack value by an incometer. The figure which shows the relationship between the measurement time and tack value in measurement sample AC using the printing ink from which a component and a composition differ.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Printing plate 10a Concave pattern 11 Printing ink 12 Squeegee 13 Printing blanket 13a Silicone rubber sheet 14 Transfer object 21 Driving roller 22 Measuring roller 23 Applied printing ink

Claims (1)

Powder component, a resin component, a solvent component and a dispersing agent to fill the ink having containing a printing plate having a concave pattern, after transfer to the printing blanket having a silicone rubber sheet to the filled ink surface, the printing In printing ink used for offset printing method to transfer ink from blanket to transfer object,
The ink is a printing ink for forming an electrode pattern in a semiconductor device,
The powder component is an inorganic powder composed of a metal powder, a metal oxide, a metal nitride or a mixed powder obtained by mixing these, or an organic pigment, an inorganic pigment, a bright pigment or an organic dye,
The organic pigment is an azo, polyazo, anthraquinone, quinacridone, isoindoline, isoindolinone, phthalocyanine, perylene, DPP or fluorescent pigment, and the inorganic pigment is acetyl carbon, carbon nanotube, Carbon powder such as fullerene, graphite, synthetic silica, chromium oxide, iron oxide, titanium oxide, titanium black, calcined pigment, zinc sulfide, ruthenium oxide, cobalt oxide, manganese oxide or copper oxide, and the glitter pigment is pearl Pigment, flake pigment, aluminum pigment or bronze pigment, the organic dye is an alcohol-soluble dye, oil-soluble dye, fluorescent dye or light-collecting dye,
The resin component includes an acrylic-styrene copolymer, an acrylic-urethane copolymer, an acrylic-epoxy copolymer, a urethane acrylate or an epoxy acrylate,
The solvent component includes one or more selected from the group consisting of diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, γ-butyl lactone, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and ethylene glycol monophenyl ether. ,
The ratio of the dispersant when the ink is 100% by weight is 3 to 10% by weight,
A printing ink characterized by having a tack value in the range of 10.4 to 12.5 after 1 minute from the start of measurement when the ink is measured under the condition of a rotational speed of 400 rpm with an incometer conforming to JIS K 5701 .

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