JP4706868B2 - Antistatic micro-contact printing plate - Google Patents

Description

  The present invention relates to a silicone rubber plate material for microcontact printing, and more specifically, a silicone rubber plate for microcontact printing, which is cured into a rubber shape and forms a fine pattern by transferring conductive ink, semiconductor ink or the like. The present invention relates to an antistatic microcontact printing plate having sufficient antistatic performance and excellent insulating properties.

  In the present invention, the plate material refers to a silicone rubber material in which a silicone rubber composition is flowed in an uncured state on a master on which a fine pattern is formed, cured, demolded, and the fine pattern is inverted. .

  Conventionally, silicone rubber has been widely used in various fields by taking advantage of its excellent heat resistance, cold resistance, electrical characteristics and the like. In particular, it has attracted attention as a plate material for microcontact printing because it has good fluidity and can be reversed with good dimensional reproducibility from a master having a fine pattern. In particular, in terms of dimensional reproducibility and workability, addition reaction curable liquid silicone rubber compositions have been frequently used.

  These silicone rubber compositions are generally supplied in the form of a composition containing an organopolysiloxane having a high degree of polymerization and a reinforcing resin. This composition is prepared by mixing a reinforcing resin and various dispersants with a raw material polymer using a mixing device such as a universal mixer or a kneader. Organopolysiloxane and reinforcing resin are electrically insulating materials, and the silicone rubber composition obtained by blending them and the cured silicone rubber are charged by contact with various substances, generating static electricity, Adsorbs dust in the air. In particular, a plate material for microcontact printing used for printing a fine pattern has problems such as very poor workability and foreign matter in the next shot, and a predetermined pattern cannot be transferred.

  Conventionally, antistatic rubbers are polyether-based as an antistatic agent (Patent Document 1: JP-T-2002-500237) or carbon black (Patent Document 2: JP-T-2002-507240, Patent Document 3: JP-A No. 2002-151405). 2002-327122). When a polyether type is used, there is a problem that the polyether is decomposed at a high temperature and a sufficient antistatic effect is not exhibited. Further, when carbon black is used, there is a problem that the fine pattern cannot be reversed because the carbon black particles are large.

Special Table 2002-500237 Special table 2002-507240 gazette JP 2002-327122 A

  An object of the present invention is to provide an antistatic microcontact printing plate material made of silicone rubber that maintains insulation and is excellent in antistatic properties.

  As a result of intensive studies to achieve the above object, the present inventor solved the above problems by adding a small amount of an ion conductive antistatic agent to an addition reaction curable silicone rubber composition and curing it. As a result, the present invention has been completed.

That is, the present invention provides excellent under Symbol antistatic performance antistatic microcontact printing stamp.
[1]. (A) a linear organopolysiloxane containing two or more aliphatic unsaturated monovalent hydrocarbon groups in one molecule;
(B) an organohydrogenpolysiloxane containing two or more silicon-bonded hydrogen atoms (SiH groups) in one molecule;
(C) addition reaction catalyst,
^{_{(D) R 1 3 SiO 1/2}} ( wherein, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group.) Siloxane units and formula represented: represented by SiO _4/2 Organopolysiloxane resin with a three-dimensional network structure containing siloxane units
(E) Ion conductive antistatic agent
An antistatic microcontact printing plate comprising a cured product of an addition reaction curable silicone rubber composition containing
[2]. (E) The plate material for antistatic microcontact printing according to [1], wherein the ion conductive antistatic agent is a lithium salt.
[3]. (E) is ion-conductive antistatic _{agent, LiBF 4, LiClO 4, LiPF} 6, LiAsF 6, LiSbF 6, LiSO 3 CF 3, LiN (SO 2 CF 3) 2, LiSO 3 C 4 F 9, LiC (SO _The plate material for antistatic microcontact printing according to [2], which is one or more selected from ₂ CF ₃ ) and LiB (C ₆ H ₅ ) ₄ .
[4]. The plate material for antistatic microcontact printing according to any one of [1] to [3], wherein the volume resistivity of the cured product is 1 GΩ · m or more.

  The cured product of the plate material for antistatic microcontact printing of the present invention maintains insulation and is excellent in antistatic properties.

The plate material for antistatic microcontact printing of the present invention comprises a cured product of an addition reaction curable silicone rubber composition containing an ion conductive antistatic agent. In this case, as the addition reaction curable silicone rubber composition, those containing the following components (A) to (E) are preferably used.
(A) an organopolysiloxane containing two or more aliphatic unsaturated monovalent hydrocarbon groups in one molecule;
(B) an organohydrogenpolysiloxane containing two or more silicon-bonded hydrogen atoms (SiH groups) in one molecule;
(C) addition reaction catalyst,
(D) a reinforcing resin;
(E) An ion conductive antistatic agent.

  The (A) organopolysiloxane used in the present invention is a component that serves as a base polymer of the plate material in the present invention. This component (A) has 2 or more, preferably 3 or more aliphatic unsaturated monovalent hydrocarbon groups bonded to a silicon atom, and can form a network structure by addition reaction. Anything may be used.

  Examples of the aliphatic unsaturated monovalent hydrocarbon group include alkenyl groups having 2 to 6 carbon atoms such as vinyl, allyl, propenyl, 1-butenyl, and 1-hexenyl. A vinyl group is most advantageous from the viewpoint that the fluidity of the composition and the heat resistance of the composition after curing are not impaired.

  As the other organic group bonded to the silicon atom of the component (A), an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms excluding an aliphatic unsaturated monovalent hydrocarbon group is preferable, and methyl, ethyl Alkyl groups such as propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl; aryl groups such as phenyl; aralkyl groups such as benzyl, 2-phenylethyl, 2-phenylpropyl; chloromethyl, chlorophenyl, 2-cyanoethyl, Examples thereof include substituted hydrocarbon groups such as halogen substitution such as 3,3,3-trifluoropropyl and cyano substitution. Of these, a methyl group is most preferred because it is easy to synthesize and has a good balance of properties such as mechanical strength and fluidity before curing.

  The aliphatic unsaturated monovalent hydrocarbon group may be present at either the end or in the middle of the molecular chain of the (A) organopolysiloxane, or may be present at both of them, but is excellent in the composition after curing. In order to provide mechanical properties, the component (A) is a linear diorganopolysiloxane whose main chain is composed of repeating diorganosiloxane units and whose both ends are blocked with triorganosiloxy groups. It is also preferred that aliphatic unsaturated monovalent hydrocarbon groups such as alkenyl groups are present at least at both ends thereof.

The siloxane skeleton may be linear, branched, or a three-dimensional network structure. In order to improve the mechanical properties of the cured composition and use it as a plate for microcontact printing, it is preferable to use a mixture of a linear diorganopolysiloxane and a branched organopolysiloxane. When used for casting of resins, especially transparent epoxy resins that require smoothness of the surface, the presence of branched organopolysiloxane increases the hardness of the silicone rubber mold due to its resination, It may cause a loss of sex. In the case of using the mixture as described above, in order to increase the mechanical strength and elastic modulus of the cured product, R ₃ SiO _1/2 unit and SiO ₂ unit and necessary in the organopolysiloxane of component (A) are necessary. R ₂ SiO _2/2 unit (wherein R represents the above-mentioned organic group and aliphatic unsaturated monovalent hydrocarbon group, and at least 2, preferably 3 or more in the molecule are aliphatic unsaturated monovalent) A branched and / or three-dimensional network organopolysiloxane composed of a hydrocarbon group) is blended in an amount of 2 to 40% by weight of the total component (A), and the remainder is composed of repeating R ₂ SiO _2/2 units in the main chain. A mixture of a linear diorganopolysiloxane having R ₃ SiO _1/2 units at the ends, in particular a linear diorganopolysiloxane having an aliphatic unsaturated monovalent hydrocarbon group at both ends of the molecular chain. It is preferable to use it.

  In order to clarify the distinction from the (D) component described later, when the (D) component contains an alkenyl group in the molecule, the (A) component is a linear diorganopolyester. Siloxane.

The degree of polymerization of the component (A) is such that the composition before curing has good fluidity and workability, and the composition after curing has an appropriate elasticity at 25 ° C. in viscosity measurement with an Ostwald viscometer. preferably it has a viscosity of 500~500,000mm ² / s, particularly preferably from 1,000~100,000mm ² / s.

  The (B) organohydrogenpolysiloxane used in the present invention is an aliphatic unsaturated monovalent compound in which the hydrosilyl group contained in the molecule (that is, a hydrogen atom bonded to a silicon atom represented by SiH) is contained in the component (A). By performing an addition reaction to a hydrocarbon group, it functions as a crosslinking agent for the component (A), and in order to reticulate the cured product, at least a hydrogen atom bonded to a silicon atom involved in the addition reaction is present. Two (usually 2 to 300), preferably 3 or more (for example, about 3 to 200).

  Examples of the organic group bonded to the silicon atom of the siloxane unit are the same as the organic group other than the aliphatic unsaturated monovalent hydrocarbon group in the component (A) described above, and among them, from the viewpoint of easy synthesis The methyl group is most preferred.

  The siloxane skeleton in the component (B) may be linear, branched, cyclic, or three-dimensional network. Moreover, although a mixture of these may be used, a linear thing is preferable.

The degree of polymerization of the component (B) (or the number of silicon atoms in one molecule) is not particularly limited, but organohydrogenpolysiloxanes in which two or more hydrogen atoms are bonded to the same silicon atom are difficult to synthesize. It is preferably composed of one or more siloxane units (for example, about 3 to 300 silicon atoms, preferably about 4 to 200 silicon atoms in one molecule), easy to handle, and heated during storage and curing reaction Since it does not volatilize, it is more preferable that the viscosity by an Ostwald viscometer at 25 ° C. is 15 to 200 mm ² / s.

  The blending amount of the component (B) is 0.5 to 5 hydrogen atoms bonded to silicon atoms in the component (B) with respect to one aliphatic unsaturated monovalent hydrocarbon group in the component (A). The amount is preferably 1 to 3. In such an amount that the abundance ratio of hydrogen atoms is less than 0.5, the curing is not completely completed, so that the mold obtained by curing the composition is sticky and has a fine pattern from the master. The mold releasability when molding a microcontact printing plate is reduced. On the other hand, if the abundance ratio is more than 5, foaming is likely to occur during curing, and it accumulates at the interface where the microcontact printing plate is molded from the master having a fine pattern, There is a possibility that the problem that the fine pattern cannot be reversed may occur.

  The (C) addition reaction catalyst used in the present invention is preferably a platinum compound. The platinum-based compound is a catalyst for promoting the addition reaction between the aliphatic unsaturated monovalent hydrocarbon group in the component (A) and the hydrosilyl group in the component (B). It is excellent in that the catalytic ability is good.

  Examples of platinum compounds include chloroplatinic acid, complexes obtained by reacting chloroplatinic acid and alcohol, platinum-olefin complexes, platinum-vinylsiloxane complexes, platinum-ketone complexes, platinum-aldehyde complexes, and the like.

  Among these, the reaction product of chloroplatinic acid and alcohol, a platinum-vinylsiloxane complex, and the like are preferable from the viewpoints of solubility in the component (A) and the component (B) and good catalytic activity.

  (C) The compounding quantity of a component is 1-100 ppm in conversion of the mass of a platinum atom with respect to (A) component, Preferably it is 2-50 ppm. If it is less than 1 ppm, the curing speed is slow and the curing is not completely completed. Therefore, the silicone rubber mold is sticky, and the mold release property of the silicone rubber mold from the original mold and the mold release from the silicone rubber mold are released. Sexuality decreases. If it exceeds 100 ppm, the curing rate becomes excessively fast, so the workability after blending each component is impaired, and it is also uneconomical.

The (D) reinforcing resin in the present invention imparts mechanical properties (strength) to the cured product of the composition, and has the formula: R ¹ ₃ SiO _1/2 (wherein R ¹ is independently non- A substituted or substituted monovalent hydrocarbon group) and a siloxane unit represented by the formula: SiO _4/2 and containing or not containing an alkenyl group, a three-dimensional network structure organopoly It is preferable to blend siloxane resin or the like.

In this case, the unsubstituted or substituted monovalent hydrocarbon group for R ¹ is the same as the aliphatic unsaturated monovalent hydrocarbon group and the organic group other than the aliphatic unsaturated hydrocarbon group in component (A). Is mentioned.

The ratio of R ¹ ₃ SiO _1/2 units to SiO ₂ units is such that the molar ratio of R ¹ ₃ SiO _1/2 / SiO ₂ is 0.3 to ₂ , particularly 0.7 to 1. It is preferable in terms of mechanical properties of the product.

In the reinforcing resin, R ¹ ₂ SiO units and R ¹ SiO _3/2 units (R ¹ is as described above) are optionally added in an amount of 0 to 10 mol%, particularly 0 to 5 mol. % May be included.

  The amount of component (D) is 5 to 100 parts by mass with respect to 100 parts by mass of component (A) because it gives good mechanical properties (strength) to the microcontact printing plate obtained by curing. 10 to 60 parts by mass is preferable.

  In the present invention, an ion conductive antistatic agent is blended as the component (E) into the addition reaction curable silicone rubber composition containing the components (A) to (D).

The (E) ionic conductive antistatic agent contained in the silicone rubber composition (antistatic microcontact printing plate material) of the present invention may be an ionic conductive material, not an electronic conductive material such as carbon black. Although not particularly limited, a lithium salt is preferable.
Specifically, LiBF ₄ , LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiSO ₃ CF ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiSO ₃ C ₄ F ₉ , LiC (SO ₂ CF ₃ ) ₃ , Examples include LiB (C ₆ H ₅ ) ₄ . These may be used alone or in combination of two or more.

  (E) The addition amount of an ion conductive antistatic agent is 0.0001-5 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.0005-3 mass parts, More preferably, it is 0.001-1. Part by mass, particularly preferably 0.001 to 0.5 part by mass. If the amount is less than 0.0001 parts by mass, the antistatic effect may be insufficient. If the amount is more than 5 parts by mass, the insulating properties may not be maintained, and the physical properties and heat resistance of the silicone rubber may be adversely affected.

  The addition reaction curable silicone rubber composition of the present invention can be blended with other components in addition to the above components (A) to (E) as long as the characteristics of the present invention are not impaired, depending on the purpose. That is, in order to improve the workability by extending the curing time at room temperature of the silicone rubber composition of the present invention, a curing delay such as acetylene compound, diallyl maleate, triallyl isocyanurate, nitrile compound or organic peroxide is used. An agent may be blended. Furthermore, you may mix | blend a mold release agent, a pigment, a plasticizer, a flame retardance imparting agent, a thixotropy imparting agent, an antibacterial agent, an antifungal agent, etc. as needed.

  The silicone rubber composition for obtaining the antistatic microcontact printing plate material of the present invention comprises components (A) to (E), and other components blended as necessary, with a planetary mixer and a Shinagawa mixer. It can be prepared by uniformly kneading by a mixing means such as a universal kneader or a kneader. Usually, the component group containing the component (B) and the component group containing the component (C) are separately prepared and stored, and both components can be mixed and used immediately before use. However, it is also possible to store all components in the same container in the presence of a retarder.

  The plate material for microcontact printing according to the present invention is the above-mentioned silicone rubber composition obtained by supplying the above-mentioned silicone rubber composition to a master on which a fine pattern is formed, curing it, removing the mold, and inverting and copying the fine pattern. In this case, the curing condition of the silicone rubber composition is not particularly limited, and is cured by heating at a low temperature of about room temperature (25 ° C.) to about 100 ° C. However, it is preferably cured at 120 to 200 ° C., particularly 150 to 180 ° C. for 0.5 to 2 hours, particularly about 1 to 2 hours.

  The volume resistivity of the cured product is preferably 1 GΩ · m or more, particularly 2 GΩ · m or more, and can have a sufficiently usable insulation level.

  In addition, the antistatic performance is a time in which the charged voltage is halved after 6 kV of static electricity is charged to the surface of the silicone rubber molding by corona discharge using a static one meter (manufactured by Sisid Electric Co., Ltd.). The (half-life) is preferably within 2 minutes, particularly preferably within 1 minute.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to a following example. In addition, in the following example, a part shows a mass part and a viscosity is a viscosity in 25 degreeC by an Ostwald viscometer. Me represents a methyl group and Vi represents a vinyl group.

The charge amount and the volume resistivity were measured by the following methods.
Using a static amount meter (Static Static Electric Co., Ltd.), the surface of the molded product was charged with 6 kV of static electricity by corona discharge, and then the time during which the charged voltage was halved was measured.
Volume resistivity measurement Measured based on JIS-K6249.

[Example 1]
100 parts of a linear dimethylpolysiloxane having a viscosity of 5,000 mm ² / s, having both ends blocked with dimethylvinylsiloxy groups, and the intermediate unit (that is, the repeating unit structure of the main chain) being a dimethylsiloxane unit, and a viscosity of 5 Vinyl group-containing methylpolysiloxane resin composed of Vi (Me) ₂ SiO _1/2 units and SiO _4/2 units at 1,000 mm ² / s (mol of Vi (Me) ₂ SiO _1/2 units relative to SiO _4/2 units) Ratio: 0.8) 40 parts are mixed in a planetary mixer for 1 hour at room temperature, and 20 parts by mass of LiN (SO ₂ CF ₃ ) ₂ is contained as an antistatic agent with respect to 100 parts of the composition. 0.05 parts of adipic acid ester was mixed to obtain a silicone compound (1).

[Preparation of curing agent]
100 parts of molecular chain both ends dimethylvinylsiloxy group-blocked dimethylpolysiloxane having a viscosity of 1,000 mm ² / s (vinyl group content = 0.2 mass%), (B) molecular chain both ends trimethylsiloxy having a viscosity of 30 mm ² / s 3 parts of blocked methyl hydrogen polysiloxane (SiH-bonded hydrogen atom content = 1.5 mass%), (C) a complex of chloroplatinic acid and vinylsiloxane is dispersed in a thermoplastic silicone resin having a softening point of 80 to 90 ° C. Then, 0.3 parts of the finely divided catalyst (in this composition, the amount of platinum metal in the catalyst is 5 ppm) was uniformly mixed to prepare the curing agent (1).
Silicone compound (1) and curing agent (1) were mixed at a mass ratio of 100: 10, a 2 mm thick sheet was prepared from this silicone rubber composition, and cured at 150 ° C. for 1 hour.
The amount of charge (half life) and volume resistivity of this silicone rubber were measured. The results are shown in Table 1.

[Example 2]
The charge amount (half life) and volume resistivity were measured in the same manner as in Example 1 except that the addition amount of the antistatic agent was 0.01 part. The results are shown in Table 1.

[Comparative Example 1]
The charge amount (half-life) and the volume resistivity value were measured in the same manner as in Example 1 except that no antistatic agent was added. The results are shown in Table 1.

[Comparative Example 2]
Instead of the antistatic agent, the charge amount (halved) was obtained in the same manner as in Example 1 except that a polyether-modified silicone oil (KF351F, manufactured by Shin-Etsu Chemical Co., Ltd.) having a viscosity at 25 ° C. of 75 mm ² / s was used. Period), the volume resistivity value was measured. The results are shown in Table 1.

  Adhesion of dust, dust, etc. to the microcontact printing plate is confirmed visually, and a L / S: 5 μm pattern is printed on a PET film using silver ink using this microcontact printing plate. The printability was observed with a microscope.

Claims (4)

(A) a linear organopolysiloxane containing two or more aliphatic unsaturated monovalent hydrocarbon groups in one molecule;
(B) an organohydrogenpolysiloxane containing two or more silicon-bonded hydrogen atoms (SiH groups) in one molecule;
(C) addition reaction catalyst,
^{_{(D) R 1 3 SiO 1/2}} ( wherein, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group.) Siloxane units and formula represented: represented by SiO _4/2 Organopolysiloxane resin with a three-dimensional network structure containing siloxane units
(E) An antistatic microcontact printing plate comprising a cured product of an addition reaction curable silicone rubber composition containing an ion conductive antistatic agent . (E) Ion conductive antistatic agent according to claim 1 Symbol placement antistatic microcontact printing stamp of a lithium salt. (E) is ion-conductive antistatic _{agent, LiBF 4, LiClO 4, LiPF} 6, LiAsF 6, LiSbF 6, LiSO 3 CF 3, LiN (SO 2 CF 3) 2, LiSO 3 C 4 F 9, LiC (SO ₂ CF ₃₎ and LiB (C ₆ H ₅₎ 1 kind or at two or more, characterized in claims 2 antistatic microcontact printing stamp according selected from _4. The plate material for antistatic microcontact printing according to any one of claims 1 to 3 , wherein the volume resistivity of the cured product is 1 GΩ · m or more.