JP2022154632A - Ink composition for screen printing and method for producing printed matter - Google Patents

Abstract

To provide an ink composition for screen printing which has excellent printability and hardly causes surface roughness on a printed matter even when a thick printed matter is formed.SOLUTION: There is provided an ink composition for screen printing which comprises a rubber-forming component having polymer viscosity (0.1 rad/s) of 2000 to 50000 Pa s as a main component, wherein the viscosity (0.1/s) obtained by an E-type viscometer at a temperature of 25°C is 300 to 50000 Pa s and the viscosity (10/s) obtained by the E-type viscometer at a temperature of 25°C is 50 to 1500 Pa s.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to an ink composition for screen printing and a method for producing a printed matter.

In a fuel cell consisting of a multi-layered structure of cells, a rubber material or a synthetic resin having rubber-like elasticity is applied to the surface of a substrate such as a separator that constitutes a fuel cell in order to seal hydrogen gas, oxygen gas, etc. It is known to provide a flat-topped gasket made of material.

Although the above gasket can be manufactured by a press molding method, an injection molding method, or the like, a manufacturing method using screen printing has been proposed in consideration of the tact time (for example, Patent Document 1 (Patent Document 1). Japanese Patent Laid-Open No. 2008-34383)).

JP-A-2008-34383

When the gasket is formed by screen printing, the following procedures (1) to (3) are performed.
(1) As shown in the schematic cross-sectional view of FIG. 1, a screen having a mask M formed with a predetermined pattern of paste application openings O corresponding to the planar shape of the gasket is formed on the lower side of the screen S1 made of stainless steel mesh or the like. The plate S is placed, and the substrate B is brought into contact with the lower portion of the screen plate S for positioning.
(2) After the paste 1 made of an uncrosslinked rubber material for forming a gasket supplied to the upper part of the screen plate S is extruded into the paste application opening O of the mask M by running the squeegee R and adhered to the surface of the substrate B. 2, the substrate B is separated from the screen plate S, and a paste coating layer P is formed on the surface of the substrate B in a predetermined printing pattern, as shown in the schematic sectional view corresponding to FIG.
(3) A gasket (having a shape corresponding to the coating layer P) is integrally formed on the substrate 1 by curing the coating layer P by heat or the like.

By the way, as the above gasket, a relatively thick one having a thickness of about 90 μm to 100 μm or more is required.

However, as a result of investigations by the present inventors, when attempting to manufacture a thick gasket by screen printing using an ink composition (a paste made of an uncrosslinked rubber material) with a relatively low viscosity, the ink composition Due to the low viscosity, the shape of the printed material cannot be maintained after printing, making it difficult to perform suitable printing.

Therefore, as an ink composition for screen printing (a paste made of an uncrosslinked rubber material), it was considered to use an ink composition with high thixotropy or an ink composition with high viscosity. As a result of investigation, it was found that when an ink composition with high thixotropy or an ink composition with high viscosity is used, surface roughness such as mesh marks (screen marks) is likely to occur on the surface of the resulting gasket, resulting in poor appearance and poor appearance. It was found that performance defects tend to occur.

Under such circumstances, the present invention uses a screen printing ink composition which is excellent in printability even when a thick printed matter is formed and which is less likely to cause surface roughness on the printed matter, and the screen printing ink composition. It aims at providing the manufacturing method of printed matter.

In order to achieve the above object, as a result of extensive studies by the present inventors, the polymer viscosity (0.1 rad/s) is 2000 to 50000 Pa s as a main component, and The viscosity (0.1 / s) obtained with an E-type viscometer is 300 to 50000 Pa s, and the viscosity (10 / s) obtained by an E-type viscometer at a temperature of 25 ° C. is 50 to 1500 Pa s. We have found that the above technical problems can be solved by a certain screen printing ink composition, and have completed the present invention based on this finding.

That is, the present invention
(1) containing as a main component a rubber-forming component having a polymer viscosity (0.1 rad/s) of 2000 to 50000 Pa·s;
Viscosity (0.1 / s) obtained by an E-type viscometer at a temperature of 25 ° C. is 300 to 50000 Pa s,
A screen printing ink composition characterized by having a viscosity (10/s) of 50 to 1500 Pa s as measured by an E-type viscometer at a temperature of 25°C;
(2) A method for producing a printed matter, characterized by forming a printed matter by screen-printing the screen printing ink composition according to (1) above and then subjecting it to a curing treatment.
(3) The method for producing a printed matter according to (2) above, wherein the printed matter is a gasket;
It provides

According to the present invention, the rubber-forming component constituting the screen printing ink composition has a polymer viscosity (0.1 rad/s) of 2000 to 50000 Pa·s, thereby reducing the viscosity during drying. This facilitates smoothing of the surface, thereby easily improving the leveling property (surface smoothness).
Furthermore, according to the present invention, the viscosity (0.1 / s) of the screen printing ink composition obtained by an E-type viscometer at a temperature of 25 ° C. is 300 to 50000 Pa s, and at a temperature of 25 ° C. When the viscosity (10/s) of the screen printing ink composition obtained by an E-type viscometer is 50 to 1500 Pa·s, printability can be favorably ensured.
For this reason, according to the present invention, even when a thick printed matter is formed, the screen printing ink composition is excellent in printability and does not easily cause surface roughness on the printed matter, and the printed matter using the screen printing ink composition. can provide a manufacturing method of

It is a schematic sectional drawing for demonstrating the printing method by screen printing. It is a schematic sectional drawing for demonstrating the printed matter obtained by screen printing.

The screen printing ink composition according to the present invention is
containing as a main component a rubber-forming component having a polymer viscosity (0.1 rad/s) of 2000 to 50000 Pa s,
Viscosity (0.1 / s) obtained by an E-type viscometer at a temperature of 25 ° C. is 300 to 50000 Pa s,
It is characterized by having a viscosity (10/s) of 50 to 1500 Pa·s obtained by an E-type viscometer at a temperature of 25°C.

The screen printing ink composition according to the present invention contains, as a main component, a rubber-forming component having a polymer viscosity (0.1 rad/s) of 2000 to 50000 Pa s (hereinafter, the rubber-forming component is appropriately referred to as (a ) shall be referred to as rubber-forming components).
In the screen printing ink composition according to the present invention, (a) the rubber-forming component means one composed of (a-1) a rubber component alone or (a-2) a mixture of a rubber component and a plasticizer. .

In the screen-printing ink composition according to the present invention, the rubber component constituting (a) the rubber-forming component specifically includes silicone rubber, acrylic rubber, chloroprene rubber, polysulfide rubber, urethane rubber, butyl rubber, and natural rubber. , ethylene-propylene rubber, nitrile rubber, fluororubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, chlorosulfonated polyethylene rubber, polyisobutylene, modified silicone, etc. The above can be mentioned, and at least one selected from ethylene-propylene-diene rubber, fluororubber and acrylonitrile-butadiene rubber is preferable, and ethylene-propylene-diene rubber is more preferable.

In the screen printing ink composition according to the present invention, when (a) the rubber-forming component comprises (a-2) a mixture of a rubber component and a plasticizer, the plasticizer is used to adjust the polymer viscosity of the rubber-forming component to the desired range. It is not particularly limited as long as it can adjust to
Specific examples of plasticizers constituting rubber-forming components include, when the rubber component is ethylene-propylene-diene rubber (EPDM), ethylene-propylene rubber (EPM), fatty acid esters, phthalic acid esters, and aliphatic dibasic bases. One or more selected from acid esters, phosphate esters, trimetate esters, polyesters, linose esters, acetate esters, mineral oils and the like can be mentioned.

In the screen printing ink composition according to the present invention, the polymer viscosity (0.1 rad/s) of (a) the rubber-forming component is 2,000 to 50,000 Pa s, preferably 10,000 to 45,000 Pa s, and preferably 10,000 Pa s. More preferably, it is up to 40000 Pa·s.

In the screen printing ink composition according to the present invention, (a) the polymer viscosity (0.1 rad/s) of the rubber-forming component is within the above range, so that after the ink composition is extruded from the screen plate during screen printing, When the extrudate is dried or heat-cured with a cross-linking agent, the viscosity of the extrudate can be easily reduced to a desired range, and the leveling property (surface smoothness) of the extrudate can be easily improved.

In this application document, the polymer viscosity (0.1 rad/s) of the rubber-forming component is the state in which the solvent is completely removed by dissolving the polymer-forming component in the main solvent and then drying it with hot air at 60°C for 12 hours or more. with an E-type viscometer (Anton-paar Rheometer MCR301), using a parallel plate (PP12) with a diameter of 12 mm, 120 ° C., angular frequency 0.1 radian / sec, strain 0.1%
means the value obtained by measuring under the conditions of

The screen printing ink composition according to the present invention preferably contains 15.0 to 60.0% by mass, more preferably 20.0 to 50.0% by mass, of the rubber component, and 28.0% by mass. More preferably, it contains up to 40.0% by mass.

When the screen printing ink composition according to the present invention contains a plasticizer in the rubber-forming component, the screen printing ink composition according to the present invention contains 1.0 to 20.0% by mass of the plasticizer. It preferably contains 3.0 to 18.0% by mass, even more preferably 5.0 to 15.0% by mass.

The screen printing ink composition according to the present invention preferably contains (a) a rubber-forming component in an amount of 15.0 to 80.0% by mass, more preferably 30.0 to 80.0% by mass. More preferably, it contains 35.0 to 65.0% by mass, and even more preferably 40.0 to 60.0% by mass.

The screen printing ink composition according to the present invention preferably contains (a) a rubber-forming component and (b) a cross-linking agent.
In the screen printing ink composition according to the present invention, the cross-linking agent (b) is not particularly limited as long as it can cross-link the rubber component in the rubber-forming component (a). can be selected, preferably a thermal cross-linking agent.

In the screen printing ink composition according to the present invention, the (b) cross-linking agent is specifically one selected from sulfur, organic peroxides, quinoid compounds, phenol resins, amines, metal oxides, polyol compounds, and the like. The above can be mentioned.

The screen printing ink composition according to the present invention preferably contains 1.5 to 15.0% by mass, more preferably 2.0 to 10.0% by mass, of (b) a crosslinking agent, More preferably, it contains 3.0 to 8.0% by mass.

When the ink composition for screen printing according to the present invention contains (b) a crosslinking agent within the above range, the rubber component in (a) the rubber-forming component can be suitably crosslinked.

The screen printing ink composition according to the present invention preferably contains (a) a rubber-forming component and (c) a main solvent that dissolves the rubber-forming component (hereinafter referred to as The main solvent is referred to as "(c) main solvent").

In the screen printing ink composition according to the present invention, the main solvent for dissolving the (c) rubber-forming component is not particularly limited as long as it exhibits solubility in the (c) rubber-forming component. When the component is ethylene-propylene-diene rubber (EPDM), aromatic hydrocarbons such as toluene, benzene, mesitylene, and xylene, and aliphatic carbonization such as hexane, heptane, octane, nonane, decane, undecane, and dodecane One or more selected from hydrogen can be mentioned.

In the present application documents, "to dissolve the rubber-forming component" means that a sheet-shaped rubber-forming component having a thickness of 1 mm is cut into a square shape of 5 mm in length × 5 mm in width, and the obtained cut product and the main A solvent was added at a weight ratio of 1:9, stirred with a stirrer for 12 hours, and then allowed to stand still for 12 hours.

The screen printing ink composition according to the present invention may contain (a) a rubber-forming component and (d) a poor solvent that dissolves in the main solvent but does not dissolve in the rubber-forming component (hereinafter referred to as (d) A poor solvent that dissolves in the main solvent but does not dissolve in the rubber-forming component is referred to as "(d) poor solvent").
In the screen printing ink composition according to the present invention, the poor solvent (d) that is soluble in the main solvent but not in the rubber-forming component (a) can be appropriately selected according to the type of the rubber-forming component. For example, when the rubber component is ethylene-propylene-diene rubber (EPDM), one or more selected from diethylene glycol monoethyl ether acetate, ester solvents such as butyl lactate, ether solvents, and the like can be used.

In the present application documents, "dissolve in the main solvent" means that the main solvent and the poor solvent are mixed at a volume ratio of 1:1 in a glass container and allowed to stand for 12 hours. Observation means that no emulsification or separation occurred.

In addition, in the present application documents, "insoluble in rubber-forming components" means that a rubber-forming component containing 10 to 50% by mass of a colored filler such as carbon black and a poor solvent are added at a weight ratio of 1:9. It means that the rubber-forming component (colored by the filler) was not dispersed by visual observation when the mixture was stirred for 12 hours with a stirrer and allowed to stand still for 12 hours.

The ink composition for screen printing according to the present invention contains (c) the main solvent and (d) the poor solvent, thereby improving the cohesion of the rubber-forming component in the ink composition and applying the ink composition to the screen plate. It is possible to effectively suppress the occurrence of printing sagging by reducing the adhesion of the ink and improving the extrusion property of the ink.

When the screen printing ink composition according to the present invention contains (c) a main solvent that dissolves the rubber-forming component and (d) a poor solvent that dissolves in the main solvent but does not dissolve in the rubber-forming component, the content ratio is a mass ratio of (c) main solvent that dissolves the rubber-forming component to (d) poor solvent that dissolves in the main solvent but does not dissolve in the rubber-forming component, and is 80:20 to 97:3. preferably 80:20 to 96:4, even more preferably 85:15 to 95:5.

In the screen printing ink composition according to the present invention, the content ratio of (c) the main solvent that dissolves the rubber-forming component and (d) the poor solvent that dissolves in the main solvent but does not dissolve in the rubber-forming component is within the above range. This improves the cohesiveness of the rubber-forming component in the ink composition, reduces the adhesion of the ink composition to the screen plate, improves the extrudability, and effectively suppresses the occurrence of printing sagging. be able to.

The screen printing ink composition according to the present invention comprises (a) a rubber-forming component, (b) a cross-linking agent, (c) a main solvent for dissolving the rubber-forming component, and (d) a rubber-forming compound dissolved in the main solvent. In addition to the poor solvent which does not dissolve in the components, for example, one or more selected from fillers, plasticizers, dispersants, cross-linking aids, antifoaming agents, foaming agents and the like may be included.

The screen printing ink composition according to the present invention preferably contains (c) the main solvent and (d) the poor solvent in a total amount of 15.0 to 70.0% by mass. It preferably contains 0 to 70.0% by mass, more preferably 35.0 to 65.0% by mass, and even more preferably 40.0 to 60.0% by mass.

The screen printing ink composition according to the present invention has a viscosity (0.1/s) of 300 to 50,000 Pa·s and 300 to 10,000 Pa·s as measured by an E-type viscometer at a temperature of 25°C. , preferably 400 to 1000 Pa·s, more preferably 450 to 900 Pa·s.

When the viscosity (0.1/s) obtained by an E-type viscometer at a temperature of 25° C. in the ink composition for screen printing according to the present invention is within the above range, and a thick print is formed. Also, it is possible to suppress the occurrence of sagging after printing and easily maintain the shape of the printed matter.

In addition, in this application document, the viscosity (0.1 / s) obtained by an E-type viscometer at a temperature of 25 ° C. is measured at a temperature of 25 ° C. Lower means the viscosity measured under the condition of shear rate of 0.1/s.

The screen printing ink composition according to the present invention has a viscosity (10/s) of 50 to 1500 Pa s and 100 to 800 Pa s as measured by an E-type viscometer at a temperature of 25°C. It is preferably 100 to 500 Pa·s, more preferably.

In the screen printing ink composition according to the present invention, the viscosity (10 / s) obtained by an E-type viscometer at a temperature of 25 ° C. is within the above range, so that screen printing is performed while suitably ensuring printability. can do.

The screen printing ink composition according to the present invention preferably has a loss tangent (0.1 rad/s) of 10.0 to 20.0 as measured by an E-type viscometer at a temperature of 25°C. 0 to 17.0, more preferably 10.0 to 13.0.

In the screen printing ink composition according to the present invention, the loss tangent (0.1 rad/s) obtained with an E-type viscometer at a temperature of 25 ° C. is within the above range, so that the screen printing ink composition By reducing the adhesion to the ink and improving the extrudability, it is possible to effectively suppress the occurrence of printing sag.

In the screen printing ink composition according to the present invention, the loss tangent (0.1 rad/s) obtained by an E-type viscometer at a temperature of 25° C. is determined by, for example, (a) blending of constituent components such as rubber-forming components It can be easily controlled by adjusting the ratio.

In addition, in this application document, the loss tangent (0.1 rad/s) obtained by an E-type viscometer at a temperature of 25 ° C. is obtained by stirring the screen printing ink composition for 12 hours or more, and After visually confirming that there are no bubbles, vacuum degassing is performed to remove internal bubbles, and an E-type viscometer (Anton-paar Rheometer MCR301) is used with a parallel plate (PP25) with a diameter of 25 mm. , a sample thickness of 1 mm, 25° C., an angular frequency of 0.1 radian/second, and a strain of 0.1%.

The method for preparing the screen printing ink composition according to the present invention is not particularly limited.
The screen printing ink composition according to the present invention can be prepared, for example, by collecting desired amounts of (a) a rubber-forming component, (b) a cross-linking agent, and, if necessary, other components, and then intermixing and kneading. , a known kneading machine such as a Banbury mixer or a known kneading apparatus such as an open roll, and the resulting kneaded product is mixed with (c) a main solvent for dissolving the rubber-forming component, and (d) a main solvent can be prepared by further adding a poor solvent that dissolves in the rubber-forming component but does not dissolve in the above-mentioned rubber-forming component and stirring with a known stirrer.

The method of screen printing using the ink composition for screen printing according to the present invention is as detailed in the description of the method for producing a printed matter according to the present invention described below.

The screen printing ink composition according to the present invention can be suitably used when printing thick prints by screen printing.
The screen printing ink composition according to the present invention can be suitably used, for example, when forming a gasket by screen printing, and can be more suitably used when forming a fuel cell gasket by screen printing. .

According to the present invention, it is possible to provide a screen printing ink composition which is excellent in printability even when a thick printed matter is formed and which hardly causes surface roughness in the printed matter.

Next, a method for manufacturing printed matter according to the present invention will be described.
The method for producing a printed matter according to the present invention is characterized by forming a printed matter by performing a curing treatment after screen-printing the ink composition for screen printing according to the present invention.

The details of the screen printing ink composition according to the present invention, which is used in the method for producing a printed matter according to the present invention, are as described above.

The printed matter manufacturing method according to the present invention can be carried out, for example, by the following procedures (1) to (3).
(1) As shown in the schematic cross-sectional view of FIG. 1, a mask in which paste application openings O of a predetermined pattern corresponding to the planar shape of the printed matter to be obtained are formed on the lower surface of a screen S1 made of stainless steel mesh or the like. A screen plate S having M is placed, and the substrate B is brought into contact with the lower surface of the screen plate S for positioning.
(2) The paste 1 (screen printing ink composition according to the present invention) supplied to the upper portion of the screen plate S is extruded into the paste application openings O of the mask M by running the squeegee R, and adhered to the surface of the substrate B. After that, the substrate B is separated from the screen plate S, and a paste coating layer P is formed on the surface of the substrate B in a predetermined printing pattern as shown in the schematic sectional view corresponding to FIG.
(3) The desired printed material is formed on the substrate 1 by curing the coating layer P with heat or the like.

The thickness of the printed matter can be easily controlled by adjusting the thickness of the screen plate.
The thickness of the printed matter obtained by the manufacturing method according to the present invention is preferably 90 μm or more, more preferably 100 μm or more, still more preferably 100 to 150 μm, and even more preferably 100 to 120 μm. .

In addition, in this application document, the thickness of printed matter means the maximum value when the cross section of the printed matter is cut out and measured at eight points with a microscope.
In the method for producing a printed matter according to the present invention, since the ink composition for screen printing according to the present invention is used, even if the thickness of the obtained printed matter is 100 μm or more, the printability is excellent and the surface roughness is reduced. It is possible to easily form a printed matter while suppressing the occurrence.

In the printed matter manufacturing method according to the present invention, a gasket can be mentioned as the printed matter obtained, and a fuel cell gasket can be mentioned as the gasket.

When the printed matter obtained by the manufacturing method according to the present invention is a fuel cell gasket, examples of the substrate on which the printed matter is formed include separators constituting fuel cells.
When the substrate is a separator, an integrated product of the separator and the gasket can be easily formed.

According to the present invention, there is provided a method for producing a printed matter that can easily form a printed matter while suppressing the occurrence of surface roughness under excellent printability even if the thickness of the obtained printed matter is 100 μm or more. be able to.

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but these are examples and are not intended to limit the present invention.

(Example 1)
As shown in Table 1, (a) 28.5 parts by weight of ethylene propylene diene rubber 1 (EPDM1) and 9.1 parts by weight of a plasticizer as rubber-forming components, (b) 3.1 parts by weight of a cross-linking agent, 11.4 parts by weight of carbon black were kneaded in an open roll to prepare a kneaded product, and the resulting kneaded product was mixed with (c) 43.4 parts by weight of dodecane as a main solvent and (d) a poor solvent. A screen printing ink composition was prepared by further adding 4.8 parts by weight of certain diethylene glycol monoethyl ether acetate (EDGAC) and stirring with a stirrer.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 35300 Pa·s.
Further, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 16.5 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 541 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 328 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed under the following conditions, and a printed matter (gasket) could be obtained with excellent printability.
The number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Screen printing method)
The ink composition for screen printing is supplied onto a screen plate (165 mesh/inch), and after filling the openings of the screen plate with a scraper, the ink composition filled in the openings is transferred to the substrate with a squeegee. did. The transferred ink composition was dried in a hot air oven at 120° C. for 30 minutes and then heated at 200° C. for 30 minutes for cross-linking and curing to obtain a desired gasket with a thickness of 124 μm.

(number of rough surfaces)
Using a microscope, an arbitrary location on the surface of the gasket obtained by the above screen printing is observed at a magnification of 5 times, and (number of surface roughness such as screen marks/total observed area) x 100 at the observed location is the number of surface roughness. I asked as
Table 1 shows the results.

(Comparative example 1)
As shown in Table 1, (a) 31.3 parts by weight of ethylene propylene diene rubber 1 (EPDM1) as rubber-forming components, (b) 3.1 parts by weight of a cross-linking agent, and 12.5 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and 53.0 parts by weight of (c) dodecane, which is the main solvent, is further added to the obtained kneaded product and stirred with a stirrer to obtain a screen printing An ink composition was prepared.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 237000 Pa·s.
Further, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 22.0 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 596 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 375 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1 to obtain a gasket having a thickness of 106 μm. Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Example 2)
As shown in Table 1, (a) 28.5 parts by weight of ethylene propylene diene rubber 1 (EPDM1) and 9.1 parts by weight of a plasticizer as rubber-forming components, (b) 2.8 parts by weight of a cross-linking agent, 11.4 parts by weight of carbon black were kneaded with an open roll to prepare a kneaded product, and (c) 48.2 parts by weight of dodecane, which is the main solvent, was further added to the obtained kneaded product and mixed with a stirrer. A screen printing ink composition was prepared by stirring.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 35300 Pa·s.
In addition, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 23.8 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 535 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 340 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1. As a result, a gasket with a thickness of 113 μm was obtained with excellent printability.
Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Example 3)
As shown in Table 1, (a) 35.9 parts by weight of ethylene propylene diene rubber 2 (EPDM2) as rubber-forming components, (b) 3.6 parts by weight of a cross-linking agent, and 14.4 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and the resulting kneaded product is mixed with (c) 41.5 parts by weight of dodecane as a main solvent and (d) diethylene glycol monoethyl ether acetate (EDGAC) as a poor solvent. ) was further added and stirred with a stirrer to prepare an ink composition for screen printing.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 11900 Pa·s.
Further, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 19.0 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 804 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 532 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1. As a result, a gasket with a thickness of 117 μm was obtained with excellent printability.
Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Example 4)
As shown in Table 1, (a) 34.7 parts by weight of ethylene propylene diene rubber 2 (EPDM2) as rubber-forming components, (b) 3.5 parts by weight of a cross-linking agent, and 13.9 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and (c) 47.9 parts by weight of dodecane, which is the main solvent, is further added to the obtained kneaded product and stirred with a stirrer to obtain a screen printing An ink composition was prepared.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 11900 Pa·s.
Further, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 28.8 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 560 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 443 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1. As a result, a gasket having a thickness of 108 μm was obtained with excellent printability.
Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Comparative example 2)
As shown in Table 1, (a) 23.8 parts by weight of ethylene propylene diene rubber 3 (EPDM3) as rubber-forming components, (b) 2.4 parts by weight of a cross-linking agent, and 9.5 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and 64.3 parts by weight of (c) dodecane, which is the main solvent, is further added to the obtained kneaded product and stirred with a stirrer to obtain a screen printing An ink composition was prepared.
The polymer viscosity (0.1 rad/s) of the rubber forming component was 300000 Pa·s.
Further, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 25.0 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 572 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 349 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1 to obtain a gasket having a thickness of 65 μm. Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Comparative Example 3)
As shown in Table 1, (a) 28.0 parts by weight of ethylene propylene diene rubber 1 (EPDM1) as rubber-forming components, (b) 2.8 parts by weight of a cross-linking agent, and 11.2 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and (c) 58.0 parts by weight of dodecane, which is the main solvent, is further added to the obtained kneaded product and stirred with a stirrer to obtain a screen printing An ink composition was prepared.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 237000 Pa·s.
In addition, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 47.1 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 154 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 127 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1 to obtain a gasket having a thickness of 81 μm.
At this time, since the viscosity (0.1/s) of the ink composition obtained by an E-type viscometer at a temperature of 25° C. is outside the predetermined range, it is difficult to maintain the print thickness, and the resulting print is the target. It was not thick enough.
Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Comparative Example 4)
As shown in Table 1, (a) 31.4 parts by weight of ethylene propylene diene rubber 1 (EPDM1) as rubber-forming components, (b) 3.1 parts by weight of a cross-linking agent, and 12.5 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and (c) 53.0 parts by weight of decane, which is the main solvent, is further added to the obtained kneaded product and stirred with a stirrer to obtain a screen printing An ink composition was prepared.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 237000 Pa·s.
In addition, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 17.2 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 269 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 201 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1 to obtain a gasket having a thickness of 119 μm.
Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

(Example 5)
As shown in Table 1, (a) 28.5 parts by weight of ethylene propylene diene rubber 1 (EPDM1) as rubber-forming components, (b) 2.8 parts by weight of a cross-linking agent, and 11.4 parts by weight of carbon black. is kneaded with an open roll to prepare a kneaded product, and the resulting kneaded product is mixed with (c) 43.4 parts by weight of dodecane as a main solvent and (d) diethylene glycol monoethyl ether acetate (EDGAC) as a poor solvent. ) was further added and stirred with a stirrer to prepare an ink composition for screen printing.
The polymer viscosity (0.1 rad/s) of the rubber-forming component was 31,300 Pa·s.
In addition, the resulting screen printing ink composition has a loss tangent (0.1 rad/s) of 19.9 obtained by an E-type viscometer at a temperature of 25 ° C., and an E-type viscometer at a temperature of 25 ° C. The viscosity (0.1/s) obtained by the method was 439 Pa·s, and the viscosity (10/s) obtained by an E-type viscometer at a temperature of 25°C was 287 Pa·s.

Using the obtained ink composition for screen printing, screen printing was performed in the same manner as in Example 1 to obtain a gasket having a thickness of 91 μm. Then, in the same manner as in Example 1, the number of surface roughenings in the printed matter obtained was measured. Table 1 shows the results.

The screen printing ink compositions obtained in Examples 1 to 5 have a viscosity (0.1/s) of 300 to 300, which is obtained by an E-type viscometer at a temperature of 25°C. It is 50000 Pa s, and the viscosity (10 / s) of the screen printing ink composition obtained by an E-type viscometer at a temperature of 25 ° C. is 50 to 1500 Pa s, so that the printability is suitably secured. It was possible.
Further, as shown in Table 1, in the screen printing ink compositions obtained in Examples 1 to 5, the polymer viscosity (0.1 rad/s) of the rubber forming component was 2000 to 50000 Pa s. It can be seen that the viscosity at the time of drying is reduced, smoothing is promoted, the leveling property is easily improved, and the number of rough surfaces can be suppressed.

On the other hand, as shown in Table 1, in the comparative screen printing ink compositions obtained in Comparative Examples 1 to 4, the polymer viscosity (0.1 rad/s) of the rubber-forming component was outside the predetermined range. Therefore, it can be seen that the leveling property (surface smoothness) of the extrudate after extrusion by the screen plate cannot be improved, and the number of surface roughening numbers is high.
In addition, the comparative screen printing ink composition obtained in Comparative Example 3 has a viscosity (0.1/s) of the ink composition obtained by an E-type viscometer at a temperature of 25°C outside the predetermined range. Therefore, it was difficult to maintain the printing thickness, and the obtained printed matter could not achieve the target thickness.

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a screen printing ink composition which is excellent in printability even when a thick printed matter is formed and which is less likely to cause surface roughness on the printed matter, and a method for producing a printed matter using the screen printing ink composition. can be provided.

1 paste M mask S screen plate S1 screen O opening B substrate R squeegee P paste coating layer

Claims (3)

containing as a main component a rubber-forming component having a polymer viscosity (0.1 rad/s) of 2000 to 50000 Pa s,
Viscosity (0.1 / s) obtained by an E-type viscometer at a temperature of 25 ° C. is 300 to 50000 Pa s,
A screen printing ink composition having a viscosity (10/s) of 50 to 1500 Pa·s as measured by an E-type viscometer at a temperature of 25°C. A method for producing a printed matter, comprising screen-printing the ink composition for screen printing according to claim 1, followed by curing to form a printed matter. 3. The method of manufacturing a printed matter according to claim 2, wherein the printed matter is a gasket.

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