JP6696493B2 - Insulating paste - Google Patents

Description

  The present invention relates to an insulating paste.

  In recent years, various developments have been made on materials used for a substrate that constitutes a stretchable wiring substrate. As this type of technology, for example, the technology described in Patent Document 1 is known. According to the document, as a method for producing the elastomer substrate 11, a kneaded material obtained by kneading a silicone rubber polymer, a processing aid, and a cross-linking agent is heated at 150 ° C. for 5 minutes by far-infrared radiation to obtain a silicone rubber. Is described (paragraph 0037 of Patent Document 1).

JP, 2005-55615, A

However, the present inventors have studied in the kneaded product for use in the silicone rubber described in the above literature, the mechanical strength and durability, in terms of coating property, to have a room for improvement has been found.

  The present inventor has further studied and found that by adding silica particles to an insulating paste containing an elastomer composition and a solvent, an insulating resin film such as a substrate using such an insulating paste has a mechanical property. It was found that the mechanical strength and durability can be improved, and the present invention has been completed.

According to the invention,
A substrate forming a stretchable wiring board, an interlayer insulating layer provided between stretchable wirings, and an insulating paste used for forming at least one of cover materials for covering the stretchable wiring,
An elastomer composition containing silica particles (C),
Including a solvent,
The solvent contains any one of tetradecane, decane, toluene, mesitylene, dipropylene glycol dimethyl ether, and diethyl carbonate,
The viscosity of the insulating paste at room temperature of 25 ° C. is 1 Pa · s or more and 100 Pa · s or less,
An insulating paste is provided.

According to the present invention, an insulating paste having excellent mechanical strength, durability , and coatability can be provided.

It is sectional drawing which shows the outline of the electronic device in this embodiment. FIG. 6 is a cross-sectional view schematically showing a manufacturing process of the electronic device according to the present embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, the same constituents will be given the same reference numeral, and the description thereof will not be repeated. Moreover, in this specification, "-" represents the following from the above unless there is particular notice.

The outline of the insulating paste of this embodiment will be described.
The insulating paste of the present embodiment can include an elastomer composition containing silica particles (C) and a solvent.

  Since the insulating paste of the present embodiment is composed of a paste-like insulating resin composition containing a solvent, it has excellent coating properties and film forming properties on a supporting substrate. Since this insulating paste contains silica particles (C), the mechanical strength and durability of the elastomer composed of a cured product of the insulating paste can be increased. By applying the elastomer made of the insulating paste to the insulating resin film forming the stretchable wiring board, the mechanical strength and durability of the insulating resin film can be improved. Accordingly, the insulating paste of the present embodiment can be suitable for use in forming a substrate that constitutes a stretchable wiring board, for example.

  Hereinafter, each component of the insulating paste of this embodiment will be described.

  The insulating paste of this embodiment may include an elastomer composition. Thereby, when an elastomer made of an insulating paste is used for a stretchable substrate or the like, it is possible to exhibit appropriate stretchability for the elastomer. Further, the insulating paste of the present embodiment can contain silica particles (C). Thereby, the mechanical strength of the elastomer made of the insulating paste can be improved.

  The elastomer composition is used to form an elastomer, for example, a thermosetting elastomer used to form one or more thermosetting elastomers selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. A composition may be included, and preferably a silicone rubber-based curable composition may be included.

As the elastomer, silicone rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, ethylene propylene rubber or the like can be used. Among these, the elastomer can include one or more thermosetting elastomers selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. The elastomer can contain silicone rubber from the viewpoint of being chemically stable and also excellent in mechanical strength.
The thermosetting elastomer can be composed of a cured product of a thermosetting elastomer composition. For example, the silicone rubber can be composed of a cured product of a silicone rubber-based curable composition. The thermoplastic elastomer may be composed of a dried thermoplastic elastomer. In the present specification, the elastomer of the insulating paste means an elastomer formed by drying or curing the insulating paste.

  Hereinafter, the case where a silicone rubber-based curable composition is used as the silicone rubber which is an example of the elastomer of the present embodiment will be described.

  The silicone rubber-based curable composition of the present embodiment can include a vinyl group-containing organopolysiloxane (A). The vinyl group-containing organopolysiloxane (A) is a polymer that is the main component of the silicone rubber-based curable composition of this embodiment.

  The vinyl group-containing organopolysiloxane (A) may include a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

  The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains a vinyl group, and the vinyl group serves as a crosslinking point during curing.

  The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but for example, it is preferable that the vinyl group-containing linear organopolysiloxane (A1) has two or more vinyl groups in the molecule and is 15 mol% or less. , 0.01 to 12 mol% is more preferable. As a result, the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1) is optimized, and it is possible to reliably form a network with each component described below. In this embodiment, “to” means to include the numerical values at both ends thereof.

  In the present specification, the vinyl group content is the mol% of the vinyl group-containing siloxane unit when all the units constituting the vinyl group-containing linear organopolysiloxane (A1) are 100 mol%. .. However, it is considered that there is one vinyl group for one vinyl group-containing siloxane unit.

  The degree of polymerization of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is, for example, preferably about 1000 to 10000, more preferably about 2000 to 5000. The degree of polymerization can be determined, for example, as a polystyrene-equivalent number average degree of polymerization (or number average molecular weight) in GPC (gel permeation chromatography) using chloroform as a developing solvent.

  Further, the specific gravity of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably in the range of about 0.9 to 1.1.

  By using the vinyl group-containing linear organopolysiloxane (A1) having a polymerization degree and a specific gravity within the above ranges, the resulting silicone rubber has heat resistance, flame retardancy, chemical stability, etc. Can be improved.

  The vinyl group-containing linear organopolysiloxane (A1) is particularly preferably one having a structure represented by the following formula (1).

In the formula (1), R ¹ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group in which these are combined. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include a vinyl group, an allyl group and a butenyl group, and among them, a vinyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group and the like.

R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group obtained by combining these. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include a vinyl group, an allyl group and a butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ³ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group.

Furthermore, examples of the substituent of R ¹ and R ^{2 in} the formula (1) include a methyl group and a vinyl group, and examples of the substituent of R ³ include a methyl group and the like.

In the formula (1), the plurality of R ^1's are independent of each other and may be different from each other or the same. Furthermore, the same applies to R ² and R ³ .

  Further, m and n are the numbers of repeating units constituting the vinyl group-containing linear organopolysiloxane (A1) represented by the formula (1), m is an integer of 0 to 2000, and n is 1000 to 10000. Is an integer. m is preferably 0 to 1000 and n is preferably 2000 to 5000.

  Further, as a specific structure of the vinyl group-containing linear organopolysiloxane (A1) represented by the formula (1), for example, a structure represented by the following formula (1-1) can be mentioned.

In formula (1-1), R ¹ and R ² are each independently a methyl group or a vinyl group, and at least one is a vinyl group.

  Furthermore, as the vinyl group-containing linear organopolysiloxane (A1), the first vinyl group-containing vinyl group containing two or more vinyl groups in the molecule and 0.4 mol% or less A linear organopolysiloxane (A1-1) and a second vinyl group-containing linear organopolysiloxane (A1-2) having a vinyl group content of 0.5 to 15 mol%. Preferably. As raw rubber which is a raw material of silicone rubber, a first vinyl group-containing linear organopolysiloxane (A1-1) having a general vinyl group content and a second vinyl group-containing straight chain having a high vinyl group content By combining with the chain organopolysiloxane (A1-2), vinyl groups can be unevenly distributed, and the cross-linking density of the silicone rubber can be more effectively formed. As a result, the tear strength of the silicone rubber can be increased more effectively.

Specifically, as the vinyl group-containing linear organopolysiloxane (A1), for example, in the above formula (1-1), a unit in which R ¹ is a vinyl group and / or a unit in which R ² is a vinyl group are represented. A first vinyl group-containing linear organopolysiloxane (A1-1) having two or more molecules in the molecule and 0.4 mol% or less, and a unit in which R ¹ is a vinyl group and / or R ^It is preferable to use a second vinyl group-containing linear organopolysiloxane (A1-2) containing 0.5 to 15 mol% of a unit in which ² is a vinyl group.

  Further, the first vinyl group-containing linear organopolysiloxane (A1-1) preferably has a vinyl group content of 0.01 to 0.2 mol%. The second vinyl group-containing linear organopolysiloxane (A1-2) preferably has a vinyl group content of 0.8 to 12 mol%.

  Furthermore, when the first vinyl group-containing linear organopolysiloxane (A1-1) and the second vinyl group-containing linear organopolysiloxane (A1-2) are combined and blended, (A1-1) The ratio of (A1-2) to (A1-2) is not particularly limited, but for example, (A1-1) :( A1-2) is preferably 50:50 to 95: 5 by weight, and 80:20 to 90 :. More preferably, it is 10.

  Each of the first and second vinyl group-containing linear organopolysiloxanes (A1-1) and (A1-2) may be used alone or in combination of two or more. Good.

  Further, the vinyl group-containing organopolysiloxane (A) may include a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

<< Organohydrogenpolysiloxane (B) >>
The silicone rubber-based curable composition of the present embodiment can include an organohydrogenpolysiloxane (B).
The organohydrogenpolysiloxane (B) is classified into a linear organohydrogenpolysiloxane having a linear structure (B1) and a branched organohydrogenpolysiloxane having a branched structure (B2). Either or both may be included.

  The straight-chain organohydrogenpolysiloxane (B1) has a straight-chain structure and a structure in which hydrogen is directly bonded to Si (≡Si—H), and has a vinyl group-containing organopolysiloxane (A). In addition to vinyl groups, it is a polymer that crosslinks these components by hydrosilylation reaction with vinyl groups contained in the components blended in the silicone rubber-based curable composition.

  The molecular weight of the linear organohydrogenpolysiloxane (B1) is not particularly limited, but for example, the weight average molecular weight is preferably 20,000 or less, more preferably 1,000 or more and 10,000 or less.

  The weight average molecular weight of the linear organohydrogenpolysiloxane (B1) can be measured, for example, by polystyrene conversion in GPC (gel permeation chromatography) using chloroform as a developing solvent.

  In addition, the linear organohydrogenpolysiloxane (B1) usually preferably has no vinyl group. This makes it possible to properly prevent the crosslinking reaction from proceeding in the molecule of the linear organohydrogenpolysiloxane (B1).

  As the above linear organohydrogenpolysiloxane (B1), for example, one having a structure represented by the following formula (2) is preferably used.

In the formula (2), R ⁴ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

In the formula (2), a plurality of R ^4's are independent of each other and may be different from each other or the same. The same applies to R ⁵ . However, at least two or more of the plurality of R ⁴ and R ⁵ are hydrido groups.

R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. A plurality of R ^6's are independent of each other and may be different from each other or the same.

In addition, as a substituent of R ⁴ , R ⁵ and R ^{6 in} the formula (2), for example, a methyl group, a vinyl group and the like can be mentioned, and a methyl group is preferable from the viewpoint of preventing intramolecular crosslinking reaction.

  Further, m and n are the number of repeating units constituting the linear organohydrogenpolysiloxane (B1) represented by the formula (2), m is an integer of 2 to 150, and n is an integer of 2 to 150. Is. Preferably, m is an integer of 2-100 and n is an integer of 2-100.

  The linear organohydrogenpolysiloxane (B1) may be used alone or in combination of two or more.

  Since the branched organohydrogenpolysiloxane (B2) has a branched structure, it forms a region having a high crosslink density, and is a component that greatly contributes to the formation of a sparse crosslink density structure in the silicone rubber system. Further, like the above-mentioned linear organohydrogenpolysiloxane (B1), it has a structure in which hydrogen is directly bonded to Si (≡Si—H), and in addition to the vinyl group of the vinyl group-containing organopolysiloxane (A), silicone It is a polymer that crosslinks these components by hydrosilylation reaction with the vinyl groups of the components blended in the rubber-based curable composition.

  The specific gravity of the branched organohydrogenpolysiloxane (B2) is in the range of 0.9 to 0.95.

  Furthermore, it is preferable that the branched organohydrogenpolysiloxane (B2) usually has no vinyl group. This makes it possible to properly prevent the crosslinking reaction from proceeding in the molecule of the branched organohydrogenpolysiloxane (B2).

  As the branched organohydrogenpolysiloxane (B2), those represented by the following average composition formula (c) are preferable.

Average composition formula (c)
^{_{(H a (R 7) 3}} -a SiO 1/2) m (SiO 4/2) n
(In Formula (c), R ⁷ is a monovalent organic group, a is an integer in the range of 1 to 3, m is the number of H _a (R ⁷ ) _3-a SiO _1/2 units, and n is SiO _{4 /} It is a number of ₂ units)

In the formula (c), R ⁷ is a monovalent organic group, preferably a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

  In the formula (c), a is the number of hydride groups (hydrogen atoms directly bonded to Si), and is an integer in the range of 1 to 3, preferably 1.

Further, in the equation (c), m is ^{_{H a (R 7) 3-}} a number of _{SiO 1/2} units, n is the number of _{SiO 4/2} units.

  The branched organohydrogenpolysiloxane (B2) has a branched structure. The linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) are different in that their structures are linear or branched, and when the number of Si is 1, The number (R / Si) of alkyl groups R to be bonded is 1.8 to 2.1 for the straight chain organohydrogenpolysiloxane (B1) and 0.8 to 1 for the branched organohydrogenpolysiloxane (B2). It will be in the range of 0.7.

  Since the branched organohydrogenpolysiloxane (B2) has a branched structure, for example, the residue amount when heated to 1000 ° C. at a heating rate of 10 ° C./min in a nitrogen atmosphere has a residue amount of 5% or more. Becomes On the other hand, since the linear organohydrogenpolysiloxane (B1) is linear, the amount of residue after heating under the above conditions becomes almost zero.

  Further, specific examples of the branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3).

In the formula (3), R ⁷ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, a hydrocarbon group obtained by combining these, or a hydrogen atom. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group and a propyl group, and among them, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. Examples of the substituent of R ⁷ include a methyl group and the like.

In the formula (3), a plurality of R ^7's are independent of each other and may be different from each other or the same.

  Further, in the formula (3), “—O—Si≡” represents that Si has a branched structure that spreads three-dimensionally.

  The branched organohydrogenpolysiloxane (B2) may be used alone or in combination of two or more.

  Further, in the straight-chain organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2), the amount of hydrogen atoms (hydrido groups) directly bonded to Si is not particularly limited. However, in the silicone rubber-based curable composition, the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane are added to 1 mol of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1). The total amount of hydride groups of the siloxane (B2) is preferably 0.5 to 5 mol, more preferably 1 to 3.5 mol. As a result, a crosslinked network is reliably formed between the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) and the vinyl group-containing linear organopolysiloxane (A1). Can be made

In the present embodiment, the content of the elastomer composition in the insulating paste is preferably 5% by mass or more, more preferably 8% by mass or more, and more preferably 10% by mass with respect to the entire insulating paste. It is more preferable that the above is satisfied. Further, the content of the elastomer composition in the insulating paste is preferably 50% by mass or less, more preferably 45% by mass or less, and 40% by mass or less with respect to the entire insulating paste. Is more preferable.
When the content of the elastomer composition is not less than the above lower limit, the elastomer made of the insulating paste can have appropriate flexibility. Further, by setting the content of the elastomer composition to be equal to or less than the above upper limit value, the mechanical strength of the elastomer can be improved.

<< silica particles (C) >>
The insulating paste of the present embodiment can contain silica particles (C), if necessary. Thereby, the hardness and mechanical strength of the elastomer formed from the insulating paste can be improved. In addition, the insulating property of the elastomer of the insulating paste can be improved.

  The silica particles (C) are not particularly limited, but for example, fumed silica, calcined silica, precipitated silica and the like are used. These may be used alone or in combination of two or more.

The silica particles (C) preferably have a specific surface area by BET method of, for example, 50 to 400 m ² / g, and more preferably 100 to 400 m ² / g. The average primary particle diameter of the silica particles (C) is preferably 1 to 100 nm, more preferably about 5 to 20 nm.

  By using the silica particles (C) having such a specific surface area and an average particle diameter within the above ranges, it is possible to improve the hardness and mechanical strength of the silicone rubber to be formed, especially the tensile strength.

In the present embodiment, the content of silica particles (C) in the insulating paste is preferably 1% by mass or more, more preferably 3% by mass or more, based on the entire insulating paste. More preferably, it is at least mass%. Further, the content of the silica particles (C) in the insulating paste is preferably 50% by mass or less, more preferably 45% by mass or less, and 40% by mass or less with respect to the entire insulating paste. Is more preferable.
By setting the content of the silica particles (C) to the above lower limit value or more, the elastomer of the insulating paste can have appropriate mechanical strength. On the other hand, when the content of the silica particles (C) is not more than the above upper limit value, the elastomer can have appropriate stretching properties. As a result, durability can be enhanced during repeated use.

<< silane coupling agent (D) >>
The silicone rubber-based curable composition of this embodiment may include a silane coupling agent (D).
The silane coupling agent (D) can have a hydrolyzable group. The hydrolyzable group is hydrolyzed by water to form a hydroxyl group, and this hydroxyl group undergoes a dehydration condensation reaction with the hydroxyl group on the surface of the silica particle (C), whereby the surface of the silica particle (C) can be modified.

  Further, the silane coupling agent (D) can contain a silane coupling agent having a hydrophobic group. As a result, this hydrophobic group is imparted to the surface of the silica particles (C), so that the cohesive force of the silica particles (C) decreases in the silicone rubber-based curable composition and further in the silicone rubber (hydrogen due to silanol groups). It is presumed that the dispersibility of silica particles in the silicone rubber-based curable composition is improved as a result of the reduction in aggregation due to bonding. Thereby, the interface between the silica particles and the rubber matrix increases, and the reinforcing effect of the silica particles increases. Furthermore, it is presumed that the slipperiness of the silica particles within the matrix is improved when the rubber is deformed into the matrix. Then, the mechanical strength (for example, tensile strength and tear strength) of the silicone rubber by the silica particles (C) is improved by the improvement of the dispersibility and the slipperiness of the silica particles (C).

  Furthermore, the silane coupling agent (D) can include a silane coupling agent having a vinyl group. As a result, a vinyl group is introduced on the surface of the silica particles (C). Therefore, when the silicone rubber-based curable composition is cured, that is, the vinyl group contained in the vinyl group-containing organopolysiloxane (A) and the hydride group contained in the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction. In forming the network (crosslinked structure) by these, the vinyl group contained in the silica particles (C) also participates in the hydrosilylation reaction with the hydrido group contained in the organohydrogenpolysiloxane (B), and therefore, in the network. The silica particles (C) will also be taken into. As a result, it is possible to reduce the hardness and the modulus of the formed silicone rubber.

  As the silane coupling agent (D), a silane coupling agent having a hydrophobic group and a silane coupling agent having a vinyl group can be used in combination.

  Examples of the silane coupling agent (D) include those represented by the following formula (4).

_{Y n -Si- (X) 4-} n ··· (4)
In the above formula (4), n represents an integer of 1 to 3. Y represents a functional group selected from those having a hydrophobic group, a hydrophilic group or a vinyl group. When n is 1, it is a hydrophobic group, and when n is 2 or 3, at least one of them is It is a hydrophobic group. X represents a hydrolyzable group.

  The hydrophobic group is an alkyl group having 1 to 6 carbon atoms, an aryl group, or a hydrocarbon group in which these are combined, and examples thereof include a methyl group, an ethyl group, a propyl group, and a phenyl group. A methyl group is preferred.

  Further, examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, a carbonyl group and the like, and among them, a hydroxyl group is particularly preferable. The hydrophilic group may be contained as a functional group, but is preferably not contained from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

Furthermore, examples of the hydrolyzable group include an alkoxy group such as a methoxy group and an ethoxy group, a chloro group, or a silazane group. Among them, the silazane group is preferable because it has high reactivity with the silica particles (C). Incidentally, those having a silazane group as hydrolyzable groups, the characteristics of its structure the formula (4) in the structure of (Y _n -Si-) comes to have two.

  Specific examples of the silane coupling agent (D) represented by the above formula (4) include, for example, those having a hydrophobic group as a functional group, such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, and methyltri. Alkoxysilanes such as ethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane; methyltrichlorosilane. Chlorosilanes such as dimethyldichlorosilane, trimethylchlorosilane, and phenyltrichlorosilane; hexamethyldisilazane, and those having a vinyl group as a functional group include methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, and methacryloxy. Alkoxysilanes such as propylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane and vinylmethyldimethoxysilane; chlorosilanes such as vinyltrichlorosilane and vinylmethyldichlorosilane; divinyltetramethyldi Among them, silazane can be mentioned, but in view of the above description, hexamethyldisilazane having a hydrophobic group and divinyltetramethyldisilazane having a vinyl group are particularly preferable.

In the present embodiment, the lower limit of the content of the silane coupling agent (D) is preferably 1% by mass or more based on 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). It is more preferably at least mass% and even more preferably at least 5 mass%. Further, the upper limit of the content of the silane coupling agent (D) is preferably 100% by mass or less, and 80% by mass or less with respect to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). Is more preferable and 40% by mass or less is further preferable.
By setting the content of the silane coupling agent (D) to be the above lower limit or more, the elastomer of the insulating paste has appropriate adhesion to the substrate, and when the silica particles (C) are used, the elastomer is It can contribute to the improvement of the mechanical strength as a whole. Further, by setting the content of the silane coupling agent (D) to be the above upper limit value or less, the elastomer can have appropriate mechanical properties.

<< platinum or platinum compound (E) >>
The silicone rubber-based curable composition of this embodiment may contain platinum or a platinum compound (E).
Platinum or a platinum compound (E) is a catalyst component that acts as a catalyst during curing. The amount of platinum or platinum compound (E) added is a catalytic amount.

  As platinum or a platinum compound (E), known ones can be used, and examples thereof include platinum black, platinum supported on silica or carbon black, chloroplatinic acid or an alcohol solution of chloroplatinic acid, or chloroplatinic acid. Examples thereof include a complex salt of platinic acid and olefin, a complex salt of chloroplatinic acid and vinylsiloxane, and the like.

  In addition, platinum or a platinum compound (E) may be used individually by 1 type, and may be used in combination of 2 or more type.

In the present embodiment, the content of platinum or platinum compound (E) in the insulating paste is preferably 0.0001% by mass or more, and 0.0002% by mass or more, based on the entire insulating paste. It is more preferable that the content is 0.0003% by mass or more. The content of platinum or platinum compound (E) in the insulating paste is preferably 1% by mass or less, more preferably 0.5% by mass or less, based on the entire insulating paste. It is more preferably 0.1% by mass or less.
By setting the content of platinum or the platinum compound (E) to the above lower limit value or more, the insulating paste can be cured at an appropriate rate. Further, by setting the content of platinum or the platinum compound (E) to the above upper limit value or less, it is possible to contribute to the reduction of the cost when producing the insulating paste.

<< water (F) >>
Further, the silicone rubber-based curable composition of the present embodiment may contain water (F) in addition to the components (A) to (E).

  Water (F) is a component that functions as a dispersion medium for dispersing each component contained in the silicone rubber-based curable composition and contributes to the reaction between the silica particles (C) and the silane coupling agent (D). .. Therefore, the silica particles (C) and the silane coupling agent (D) can be more reliably connected to each other in the silicone rubber, and uniform properties can be exhibited as a whole.

  Furthermore, when water (F) is contained, its content can be appropriately set. Specifically, for example, 10 to 100 parts by weight relative to 100 parts by weight of the silane coupling agent (D). The range is preferably, and more preferably 30 to 70 parts by weight. This allows the reaction between the silane coupling agent (D) and the silica particles (C) to proceed more reliably.

(Other ingredients)
Furthermore, the silicone rubber-based curable composition of the present embodiment may further contain other components in addition to the components (A) to (F). As other components, for example, other than silica particles (C) such as diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, mica, etc. Examples of such additives include inorganic fillers, reaction inhibitors, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, and thermal conductivity improvers.

(solvent)
The insulating paste of this embodiment contains a solvent. As this solvent, various known solvents can be used, and for example, a high boiling point solvent can be included. These may be used alone or in combination of two or more.

  The lower limit of the boiling point of the high-boiling solvent is, for example, 100 ° C. or higher, preferably 130 ° C. or higher, and more preferably 150 ° C. or higher. Accordingly, when the insulating paste is applied on the supporting substrate, it is possible to improve the film forming property of the obtained coating film and suppress the variation in the film thickness of the coating film. On the other hand, the upper limit of the boiling point of the high boiling point solvent is not particularly limited, but may be, for example, 300 ° C. or lower, 290 ° C. or lower, or 280 ° C. or lower. As a result, excessive heat history during wiring formation can be suppressed, and damage to electronic components and wiring can be suppressed. Further, since the solvent in the elastomer of the insulating paste in which the solvent is sufficiently volatilized can be used as the substrate, the shape of the wiring formed by printing using the conductive paste on the surface of the substrate can be favorably maintained. ..

  Further, the solvent of the present embodiment can be appropriately selected from the viewpoint of solubility and boiling point of the elastomer, but for example, an aliphatic hydrocarbon having 5 to 20 carbon atoms, preferably an aliphatic hydrocarbon having 8 to 18 carbon atoms Hydrocarbons, more preferably aliphatic hydrocarbons having 10 to 15 carbon atoms can be included.

Further, as an example of the solvent of the present embodiment, for example, pentane, hexane, cyclohexane, heptane, methylcyclohexane, ethylcyclohexane, octane, decane, dodecane, tetradecane and other aliphatic hydrocarbons; benzene, toluene, ethylbenzene, xylene , Aromatic hydrocarbons such as mesitylene, trifluoromethylbenzene and benzotrifluoride; diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, cyclopentyl ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol mono ether Ethers such as butyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl-n-propyl ether, 1,4-dioxane, 1,3-dioxane, tetrahydrofuran; dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane. Haloalkanes such as 1,1,1-trichloroethane and 1,1,2-trichloroethane; Carboxamides such as N, N-dimethylformamide and N, N-dimethylacetamide; Sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide Examples thereof include esters such as diethyl carbonate and the like. These may be used alone or in combination of two or more.
The solvent used here may be appropriately selected from the solvents capable of uniformly dissolving or dispersing the composition components in the insulating paste.

In the above solvent, the upper limit of the polar term (δ _p ) of the Hansen solubility parameter is, for example, 10 MPa ^1/2 or less, preferably 7 MPa ^1/2 or less, and more preferably 5.5 MPa ^1/2 or less. A first solvent may be included. This makes it possible to improve the dispersibility and solubility of the elastomer composition such as the silicone rubber-based curable resin composition in the insulating paste. The lower limit of the polar term (δ _p ) of the first solvent is not particularly limited, but may be 0 Pa ^1/2 or more, for example.

The upper limit of the hydrogen bond term (δ _h ) of the Hansen solubility parameter in the first solvent is, for example, 20 MPa ^1/2 or less, preferably 10 MPa ^1/2 or less, and more preferably 7 MPa ^1/2 or less. is there. This makes it possible to improve the dispersibility and solubility of the elastomer composition such as the silicone rubber-based curable resin composition in the insulating paste. The lower limit of the hydrogen bond term (δ _h ) of the first solvent is not particularly limited, but may be 0 Pa ^1/2 or more, for example.

The Hansen solubility parameter (HSP) is a measure of the solubility of a substance in another substance. HSP represents solubility as a three-dimensional vector. This three-dimensional vector can be typically represented by a dispersion term (δ _d ), a polar term (δ _p ), and a hydrogen bond term (δ _h ). And it can be judged that those having similar vectors have high solubility. It is possible to determine the degree of vector similarity by the distance (HSP distance) of the Hansen solubility parameter.

The Hansen solubility parameter (HSP value) used in the present specification can be calculated by using software called HSPiP (Hansen Solution Parameters in Practice). Here, the computer software HSPiP developed by Hansen and Abbott includes a function for calculating the HSP distance and a database describing Hansen parameters of various resins and solvents or non-solvents.
The solubility of each resin in a pure solvent and a mixed solvent of a good solvent and a poor solvent was investigated, and the results were input to HSPiP software, and D: dispersion term, P: polar term, H: hydrogen bond term, R0: radius of dissolved sphere. To calculate.

  As the solvent of the present embodiment, for example, one having a small difference between the HSP distance, the polar term and the hydrogen bond term between the elastomer or the constituent units constituting the elastomer and the solvent can be selected.

  The lower limit value of the viscosity of the insulating paste when measured at a shear rate of 20 [1 / s] at room temperature of 25 ° C. is, for example, 1 Pa · s or more, preferably 5 Pa · s or more, and more preferably 10 Pa · s. s or more. Thereby, the film forming property can be improved. Further, it is possible to suppress variation in film thickness even when forming a thick film. On the other hand, the upper limit of the viscosity of the insulating paste at room temperature of 25 ° C. is, for example, 100 Pa · s or less, preferably 90 Pa · s or less, and more preferably 80 Pa · s or less. Thereby, the ease of applying the insulating paste can be improved.

  In the insulating paste according to the present embodiment, at room temperature of 25 ° C., the viscosity when measured at a shear rate of 1 [1 / s] is η1, and the viscosity when measured at a shear rate of 5 [1 / s] is η5, The thixo index is the viscosity ratio (η1 / η5). At this time, the lower limit value of this thixo index is, for example, 1.0 or more, preferably 1.1 or more, and more preferably 1.2 or more. This facilitates the application operation of the insulating paste with a squeegee or the like. On the other hand, the upper limit value of the thixo index is, for example, 3.0 or less, preferably 2.5 or less, and more preferably 2.0 or less. Thereby, the leveling property of the insulating paste can be improved.

  The upper limit of the durometer hardness A of the elastomer of the insulating paste of the present embodiment (for example, a cured product of the insulating paste) defined in accordance with JIS K6253 (1997) may be 70 or less, It may be preferably 68 or less, more preferably 65 or less. As a result, the elastomer of the insulating paste can have improved flexibility and can be easily deformed such as bent or stretched. The lower limit value of the durometer hardness A of the elastomer of the insulating paste is, for example, 10 or more, preferably 20 or more, and more preferably 30 or more. By using such an elastomer as the base substrate, the wiring formability on the surface of the base substrate can be improved. For example, it is possible to suppress variations in the shape and height of the wiring formed by printing such as screen printing.

  The lower limit of the tensile strength of the elastomer of the insulating paste of the present embodiment (for example, a cured product of the insulating paste) measured according to JIS K6251 (2004) is, for example, 5.0 MPa or more, The pressure is preferably 6.0 MPa or more, more preferably 7.0 MPa or more. Thereby, the mechanical strength of the elastomer of the insulating paste can be improved. Also, the breaking energy can be increased. Therefore, it is possible to realize an elastomer having excellent durability that can withstand repeated deformation. On the other hand, the upper limit of the tensile strength of the elastomer of the insulating paste is not particularly limited, but may be, for example, 15 MPa or less, or 13 MPa or less. This makes it possible to balance the elasticity and mechanical strength of the elastomer of the insulating paste.

  The lower limit of the tear strength of the elastomer of the insulating paste of the present embodiment (for example, a cured product of the insulating paste) measured according to JIS K6252 (2001) is, for example, 25 N / mm or more, It is preferably 30 N / mm or more, more preferably 33 N / mm or more, and further preferably 35 N / mm or more. As a result, durability and mechanical strength of the insulating paste elastomer during repeated use can be improved. On the other hand, the upper limit of the tear strength of the elastomer of the insulating paste is not particularly limited, but may be, for example, 70 N / mm or less, or 60 N / mm or less. This makes it possible to balance the various properties of the elastomer of the insulating paste of the present embodiment.

  In the present embodiment, for example, the viscosity, thixo index, hardness, tensile strength and tear strength can be determined by appropriately selecting the type and amount of each component contained in the insulating paste, the method for preparing the insulating paste, and the like. It is possible to control. Among these, for example, a solvent such as a hydrophobic solvent, a hydrocarbon solvent, a high-boiling point solvent suitable for printing, or a solvent having a small polar term or hydrogen bond term is appropriately selected, silica particles (C ) Is used to control the cross-linking density and uneven distribution of the cross-linking structure of the resin by using a vinyl group-containing organopolysiloxane (A) having a vinyl group at the end, and a silane cup of silica particles (C). The above-mentioned viscosity and thixo index can be obtained by more surely promoting the reaction between the silane coupling agent (D) and the silica particles (C) such as surface modification with the ring agent (D) and addition of water. , Hardness, tensile strength, and tear strength are included as factors for achieving desired numerical ranges.

(Method of manufacturing insulating paste)
Hereinafter, a method for manufacturing the insulating paste according to this embodiment will be described.

  The insulating paste of the present embodiment can be manufactured, for example, by undergoing the following steps.

  First, each component of the silicone rubber-based curable composition is uniformly mixed by an arbitrary kneading device to prepare a silicone rubber-based curable composition.

[1] For example, a vinyl group-containing organopolysiloxane (A), silica particles (C), and a silane coupling agent (D) are weighed in predetermined amounts, and then kneaded by an arbitrary kneading device, A kneaded product containing each of these components (A), (C), and (D) is obtained.

  The kneaded product is preferably obtained by previously kneading the vinyl group-containing organopolysiloxane (A) and the silane coupling agent (D), and then kneading (mixing) the silica particles (C). This further improves the dispersibility of the silica particles (C) in the vinyl group-containing organopolysiloxane (A).

  When obtaining this kneaded product, water (F) may be added to the kneaded product of each of the components (A), (C), and (D), if necessary. This allows the reaction between the silane coupling agent (D) and the silica particles (C) to proceed more reliably.

  Further, it is preferable that the kneading of the respective components (A), (C), and (D) is performed through a first step of heating at a first temperature and a second step of heating at a second temperature. Thereby, the surface of the silica particles (C) can be surface-treated with the coupling agent (D) in the first step, and the silica particles (C) and the coupling agent (D) can be treated in the second step. By-products generated in the reaction can be reliably removed from the kneaded product. Then, if necessary, the component (A) may be added to the obtained kneaded product and further kneaded. Thereby, the familiarity of the components of the kneaded product can be improved.

  The first temperature is preferably about 40 to 120 ° C, more preferably about 60 to 90 ° C, for example. The second temperature is preferably about 130 to 210 ° C, more preferably about 160 to 180 ° C, for example.

  The atmosphere in the first step is preferably an inert atmosphere such as a nitrogen atmosphere, and the atmosphere in the second step is preferably a reduced pressure atmosphere.

  Furthermore, the time of the first step is, for example, preferably about 0.3 to 1.5 hours, more preferably about 0.5 to 1.2 hours. The time of the second step is preferably, for example, about 0.7 to 3.0 hours, more preferably about 1.0 to 2.0 hours.

  By setting the first step and the second step under the conditions as described above, the effect can be more remarkably obtained.

[2] Next, the organohydrogenpolysiloxane (B) and a predetermined amount of platinum or a platinum compound (E) are weighed, and then the kneaded material prepared in the above step [1] using an arbitrary kneading device. The respective components (B) and (E) are kneaded with, to obtain a silicone rubber-based curable composition (elastomer composition).

  When kneading the respective components (B) and (E), the kneaded product previously prepared in the above step [1] and the organohydrogenpolysiloxane (B) were prepared in the above step [1]. It is preferable to knead the kneaded product and platinum or the platinum compound (E), and then knead the respective kneaded products. As a result, the components (A) to (E) can be reliably incorporated into the silicone rubber-based curable composition without causing the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) to proceed. Can be dispersed in

  The temperature at which the components (B) and (E) are kneaded is, for example, about 10 to 70 ° C., and more preferably about 25 to 30 ° C., as a roll set temperature.

  Further, the time for kneading is, for example, preferably about 5 minutes to 1 hour, and more preferably about 10 to 40 minutes.

  In the above-mentioned step [1] and the above-mentioned step [2], by setting the temperature within the above range, the progress of the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) is more accurately performed. It can be prevented or suppressed. Further, in the step [1] and the step [2], by setting the kneading time within the above range, each of the components (A) to (E) can be more surely dispersed in the silicone rubber-based curable composition. You can

  The kneading device used in each of the steps [1] and [2] is not particularly limited, but for example, a kneader, two rolls, a Banbury mixer (continuous kneader), a pressure kneader, or the like can be used.

  In addition, in this step [2], a reaction inhibitor such as 1-ethynylcyclohexanol may be added to the kneaded product. Thereby, even if the temperature of the kneaded product is set to a relatively high temperature, the progress of the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) can be prevented or suppressed more accurately. be able to.

  [3] Next, the elastomer composition (of the silicone rubber-based curable composition) obtained in the step [2] is dissolved in a solvent to obtain the insulating paste of the present embodiment.

[Use]
Hereinafter, an example of application of the insulating paste of the present embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of an electronic device 100 including wiring.

  As shown in FIG. 1, the electronic device 100 may include a wiring board 50 and an electronic component 60. The wiring board 50 is configured by providing the wiring 10 on the board 20. As the substrate 20, an insulating substrate having elasticity can be used. The substrate 20 can be composed of a cured product obtained by curing the insulating paste of this embodiment. The electronic component 60 may be configured to be electrically connected to the wiring 10 that constitutes such a stretchable wiring board (wiring board 50).

Since the insulating paste of the present embodiment can maintain mechanical strength and durability when repeatedly expanded and contracted with respect to the obtained cured product, it is possible to realize a structure of the electronic device 100 having excellent connection reliability. You can
The electronic device 100 of the present embodiment is used as, for example, a wearable device, and can be suitably used for a device that is repeatedly expanded and contracted in each direction.

The wiring 10 that constitutes the electronic device 100 of the present embodiment is usually made of a conductive material having flexibility. The conductive material can include, for example, an elastomeric composition and a conductive filler.
As this elastomer composition, the same elastomer composition as the material of the above-mentioned insulating paste can be adopted. Specifically, an elastomer composition used for forming silicone rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, ethylene propylene rubber, etc. can be used, and depending on the application etc. The material can be selected appropriately.

  The wiring 10 may be composed of a cured product of a conductive paste containing the silicone rubber-based curable composition and a conductive filler.

As the conductive filler in the conductive paste, for example, a known conductive material may be used, but the following metal powder (G) may be included.
The metal constituting the metal powder (G) is not particularly limited, but for example, at least one of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, or a metal powder obtained by alloying them. Alternatively, two or more of these may be included.
Among these, it is preferable that the metal powder (G) contains silver or copper, that is, contains silver powder or copper powder because of its high conductivity and high availability. It should be noted that these metal powders (G) may be coated with other metal.

  In the present embodiment, the shape of the metal powder (G) is not limited, but a conventionally used one such as a dendritic shape, a spherical shape, and a flaky shape can be used.

Further, the particle size of the metal powder (G) is not limited, but for example, the average particle size D ₅₀ is preferably 0.001 μm or more, more preferably 0.01 μm or more, and further preferably 0.1 μm or more. is there. The particle diameter of the metal powder (G) is, for example, preferably 1,000 μm or less in terms of average particle diameter D ₅₀ , more preferably 100 μm or less, and further preferably 20 μm or less.
By setting the average particle diameter D ₅₀ in such a range, it is possible to exhibit appropriate conductivity as a cured product of the conductive paste. The particle size of the metal powder (G) is defined as an average value of 200 arbitrarily selected metal powders by observing the conductive paste or the cured product with a transmission electron microscope or the like and performing image analysis. can do.

The content of the conductive filler in the conductive paste is preferably 30% by mass or more, more preferably 40% by mass or more, and 50% by mass or more with respect to the entire conductive paste. Is more preferable. Further, the content of the conductive filler in the conductive paste is preferably 85% by mass or less, more preferably 75% by mass or less, and 65% by mass or less with respect to the entire conductive pace. Is more preferable.
By setting the content of the metal powder (G) to be equal to or more than the above lower limit, the cured product of the insulating paste can have appropriate conductivity characteristics. Further, by setting the content of the metal powder (G) to be the above upper limit value or less, the cured product can have appropriate flexibility.

  The lower limit of the content of the silica particles (C) in the conductive paste is, for example, 1% by mass or more based on 100% by mass of the total amount of the silica particles (C) and the conductive filler, and is preferable. Is 3% by mass or more, and more preferably 5% by mass or more. Thereby, the mechanical strength of the cured product of the conductive paste can be improved. On the other hand, the upper limit of the content of the silica particles (C) in the conductive paste is, for example, 20 mass% or less with respect to 100 mass% of the total amount of the silica particles (C) and the conductive filler. , Preferably 15% by mass or less, more preferably 10% by mass or less. This makes it possible to achieve a balance between the stretchable electric characteristics and the mechanical strength of the cured product of the conductive paste.

In the present embodiment, as the solvent of the conductive paste, it is possible to use the above-mentioned solvent species, but among them, a solvent exhibiting solubility in the insulating sheet which is a cured product of the insulating paste or the insulating paste. Can be used. As a specific solvent for the conductive paste, for example, a high boiling point solvent or a solvent having a HSP polar term (δ _p ) or hydrogen bond term (δ _h ) not more than the above upper limit value can be used.

  The insulating paste of the present embodiment can be used for a substrate that constitutes a stretchable substrate including stretchable wiring formed of a cured product of the above-described conductive paste, and an interlayer insulating layer between these wirings.

  Further, the electronic component 60 may be appropriately selected from known components according to the application. Specifically, a semiconductor element and resistors and capacitors other than the semiconductor element can be mentioned. Examples of semiconductor elements include transistors, diodes, LEDs, capacitors, and the like. In the electronic device 100 of this embodiment, the electronic component 60 is electrically connected by the wiring 10.

Further, the electronic device 100 of the present embodiment may be provided with the cover material 30 as necessary. By providing the cover member 30, it is possible to prevent the wiring 10 and the electronic component 60 from being damaged. The cover material 30 may be configured to cover the electronic component 60 and the wiring 10 on the substrate 20.
The cover material 30 can be made of the same material as the substrate 20. Since the cover material 30 follows the expansion and contraction of the substrate 20 and the wiring 10, the electronic device 100 as a whole can be expanded and contracted without unevenness, and the life of the electronic device 100 can be extended.

Next, an example of a manufacturing process of the electronic device 100 of this embodiment will be described with reference to FIG.
FIG. 2 is a cross-sectional view showing the outline of the manufacturing process of the electronic device 100 according to the present embodiment.

  First, as shown in FIG. 2A, the support 120 is placed on the workbench 110, and the insulating paste 130 is applied onto the support 120. Although various methods can be used as the coating method, for example, a printing method such as a squeegee method using the squeegee 140 can be used. Subsequently, the coated insulating paste 130 can be dried to form the insulating layer 132 (dried insulating sheet) on the support 120. The drying conditions can be appropriately set according to the type and amount of the solvent in the insulating paste 130, but for example, the drying temperature is 150 ° C. to 180 ° C. and the drying time is 1 minute to 30 minutes. it can.

  Subsequently, as shown in FIG. 2B, a mask 160 having a predetermined opening pattern shape is arranged on the insulating layer 132. Then, as shown in FIGS. 2B and 2C, the conductive paste 150 is applied onto the insulating layer 132 through the mask 160. As the coating method, the same method as the coating method of the insulating paste 130 can be used, and for example, squeegee printing with the squeegee 140 may be used. Here, when the insulating paste 130 and the conductive paste 150 each include a thermosetting elastomer composition, after a conductive coating film (conductive layer 152) having a predetermined pattern shape is laminated on the dried insulating layer 132. Alternatively, these may be collectively cured. The curing treatment can be appropriately set depending on the thermosetting elastomer composition, but for example, the curing temperature can be 160 ° C. to 220 ° C. and the curing time can be 1 hour to 3 hours. After the curing process or before the curing process, the mask 160 can be removed as shown in FIG. Thus, a wiring which is a cured product of the conductive layer 152 and has a predetermined pattern shape can be formed over the substrate formed of the cured product of the insulating layer 132.

Subsequently, as shown in FIG. 2E, an insulating paste 170 is further applied onto the insulating layer 132 and the patterned conductive layer 152, and an insulating layer 172 is formed as shown in FIG. Can be formed. You may repeat these processes suitably. Further, the support 120 can be separated from the insulating layer 132.
As described above, the electronic device 100 shown in FIG. 2F can be obtained.

  When an insulating sheet is used instead of the insulating paste, the process shown in FIG. 2B may be started. That is, the insulating sheet may be placed on the support 120, and after predetermined drying, the conductive paste 150 may be applied to the insulating sheet via the mask 160. Subsequent steps can be performed according to the above steps. This makes it possible to obtain the electronic device 100 shown in FIG.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope of achieving the object of the present invention are included in the present invention.
Hereinafter, an example of the reference mode will be additionally described.
1. An elastomer composition containing silica particles (C),
An insulating paste containing a solvent.
2. 1. An insulating paste as described in,
An insulating paste, wherein the elastomer composition contains a thermosetting elastomer composition for forming one or more elastomers selected from the group consisting of silicone rubber, urethane rubber, and fluororubber.
3. 1. Or 2. An insulating paste as described in,
An insulating paste used to form a substrate that constitutes a stretchable wiring board.
4. 1. To 3. The insulating paste according to any one of
An insulating paste in which the solvent contains a high boiling point solvent having a boiling point of 100 ° C. or higher and 300 ° C. or lower.
5. 1. To 4. The insulating paste according to any one of
An insulating paste in which the solvent contains an aliphatic hydrocarbon having 5 to 20 carbon atoms.
6. 1. To 5. The insulating paste according to any one of
An insulating paste, wherein the solvent includes a first solvent having a Hansen solubility parameter polar term (δ _p ) of 10 MPa ^1/2 or less.
7. 1. To 6. The insulating paste according to any one of
An insulating paste in which the viscosity of the insulating paste at room temperature of 25 ° C. is 1 Pa · s or more and 100 Pa · s or less.
8. 1. To 7. The insulating paste according to any one of
Regarding the insulating paste at room temperature of 25 ° C., the viscosity ratio when the viscosity when measured at a shear rate of 1 [1 / s] is η1 and the viscosity when measured at a shear rate of 5 [1 / s] is η5, the viscosity ratio An insulating paste having a thixo index of (η1 / η5) of 1.0 or more and 3.0 or less.
9. 1. To 8. The insulating paste according to any one of
Insulating paste whose content of the said silica particle (C) is 1 mass% or more and 50 mass% or less with respect to the said insulating paste whole.
10. 1. To 9. The insulating paste according to any one of
An insulating paste in which the elastomer composition contains a silicone rubber-based curable composition.
11. 10. An insulating paste as described in,
An insulating paste in which the silicone rubber-based curable composition contains a vinyl group-containing organopolysiloxane (A).
12. 10. Or 11. An insulating paste as described in,
An insulating paste in which the silicone rubber-based curable composition further contains an organohydrogenpolysiloxane (B).
13. 10. To 12. The insulating paste according to any one of
An insulating paste in which the silicone rubber-based curable composition further contains platinum or a platinum compound (E).
14. 1. To 13. The insulating paste according to any one of
Insulating paste whose content of the said elastomer composition is 5 mass% or more and 50 mass% or less with respect to the said insulating paste whole.
15. 1. To 14. The insulating paste according to any one of
An insulating paste in which an elastomer made of the insulating paste has a durometer hardness A of 10 or more and 70 or less defined according to JIS K6253 (1997).
16. 1. To 15. The insulating paste according to any one of
An insulating paste in which the elastomer made of the insulating paste has a tensile strength of 5.0 MPa or more and 15 MPa or less measured according to JIS K6251 (2004).
17. 1. To 16. The insulating paste according to any one of
An insulating paste in which an elastomer composed of the insulating paste has a tear strength of 25 N / mm or more measured according to JIS K6252 (2001).

  Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The materials used in Examples and Comparative Examples are as follows.
(Vinyl group-containing organopolysiloxane (A))
(A1-1): First linear vinyl group-containing organopolysiloxane: vinyl group content 0.13 mol%, Mn = 227,734, Mw = 573,903, IV value (dl / g) = 0.89), vinyl group-containing dimethylpolysiloxane synthesized by the following synthesis scheme 1 (structure represented by the above formula (1-1))
(A1-2): Second linear vinyl group-containing organopolysiloxane: vinyl group content is 0.92 mol%, vinyl group-containing dimethylpolysiloxane synthesized by the following synthesis scheme 2 (the above formula (1- (Structure represented by 1), wherein R ¹ and R ² are vinyl groups)

(Organohydrogenpolysiloxane (B))
(B1): Organohydrogenpolysiloxane: "88466" manufactured by Momentive Co.

(Silica particles (C))
(C1): Silica fine particles (particle size 7 nm, specific surface area 300 m ² / g), "AEROSIL300" manufactured by Nippon Aerosil Co., Ltd.

(Silane coupling agent (D))
(D1): Hexamethyldisilazane (HMDZ), manufactured by Gelest, "HEXAMETHYLDISILAZANE (SIH6110.1)"

(Platinum or platinum compound (E))
(E1): Platinum compound, PLATINUM DIVINYLTETRAMETHYLDISILOXANE COMPLEX (in xylene) (manufactured by Gelest, trade name "SIP6831.2")

(Water (F))
(F1): Pure water

(Additive)
(Reaction inhibitor 1): 1-ethynyl-1-cyclohexanol (manufactured by Tokyo Kasei)

(Synthesis of vinyl group-containing organopolysiloxane (A))
[Synthesis Scheme 1: Synthesis of First Vinyl Group-Containing Linear Organopolysiloxane (A1-1)]
According to the following formula (7), the first vinyl group-containing linear organopolysiloxane (A1-1) was synthesized.
That is, 74.7 g (252 mmol) of octamethylcyclotetrasiloxane and 0.1 g of potassium siliconate were placed in a 300 mL separable flask having a cooling tube and a stirring blade, which was replaced with Ar gas, and the temperature was raised and the temperature was increased to 120 ° C. for 30 minutes. It was stirred. At this time, an increase in viscosity could be confirmed.
Then, the temperature was raised to 155 ° C. and stirring was continued for 3 hours. Then, after 3 hours, 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was added, and the mixture was further stirred at 155 ° C. for 4 hours.
Furthermore, after 4 hours, it was diluted with 250 mL of toluene, and then washed with water three times. The washed organic layer was washed several times with 1.5 L of methanol for reprecipitation purification, and the oligomer and the polymer were separated. The obtained polymer was dried under reduced pressure at 60 ° C. overnight to obtain a first vinyl group-containing linear organopolysiloxane (A1-1) (Mw = 573,903, Mn = 227,734). The vinyl group content calculated by H-NMR spectrum measurement was 0.13 mol%.

[Synthesis Scheme 2: Synthesis of Second Vinyl Group-Containing Linear Organopolysiloxane (A1-2)]
In the synthesis step (A1-1), octamethylcyclotetrasiloxane (74.7 g, 252 mmol) was added, and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (0.1%) was added. By the same procedure as in the synthesis step of (A1-1) except that 86 g (2.5 mmol) was used, the second vinyl group-containing linear organopolysiloxane (A1-2) represented by the following formula: ) Was synthesized. The vinyl group content calculated by H-NMR spectrum measurement was 0.92 mol%.

[Preparation of insulating paste]
(Preparation of silicone rubber-based curable compositions 1 to 3)
Silicone rubber-based curable compositions 1 to 3 were prepared as follows. First, 90% of a mixture of vinyl group-containing organopolysiloxane (A), silane coupling agent (D) and water (F) was kneaded in advance at a ratio shown in Table 1 below, and then the silica particles ( C) was added and further kneaded to obtain a kneaded product (silicone rubber compound).
Here, the kneading after the addition of the silica particles (C) includes the first step of kneading for 1 hour under a nitrogen atmosphere at 60 to 90 ° C. for the coupling reaction and the removal of the by-product (ammonia). For this purpose, the second step of kneading for 2 hours under the condition of 160 to 180 ° C. under a reduced pressure atmosphere is performed, and then the mixture is cooled and the remaining 10% of vinyl group-containing organopolysiloxane (A) is added twice. Added separately and kneaded for 20 minutes.
Subsequently, 100 parts by weight of the obtained kneaded product (silicone rubber compound) was added with organohydrogenpolysiloxane (B), platinum or a platinum compound (E) and a reaction inhibitor at a ratio shown in Table 1 below. Then, the mixture was kneaded with a roll to obtain silicone rubber-based curable compositions 1 to 3 (elastomer compositions 1 to 3).

(Elastomer composition 4)
As the elastomer composition 4, "C6-135 ELASTOMER (including silica particles)" manufactured by Toray Dow Corning Co., Ltd. was used.

(Elastomer composition 5)
Silica particles surface-treated with 9.2 g of urethane diacrylate (manufactured by Toagosei Co., Ltd., trade name “Aronix M-1200”) and 0.9 g of a silane coupling agent (hexamethyldisilazane (manufactured by Gelest)). Elastomer composition 5 was obtained by mixing 3.5 g (Nippon Aerosil Co., Ltd., trade name “AEROSIL300”) and 0.1 g of an organic peroxide initiator (Nippon Yushi Co., Ltd. trade name, “Perhexa 3M”). ..

<Example 1: Insulating paste 1>
The obtained 32 parts by weight of the silicone rubber-based curable composition 1 (elastomer composition 1) was immersed in 68 parts by weight of tetradecane, and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 1. It was

<Example 2: Insulating paste 2>
The obtained 32 parts by weight of the silicone rubber-based curable composition 2 (elastomer composition 2) was immersed in 68 parts by weight of decane and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 2. It was

<Example 3: Insulating paste 3>
The obtained 32 parts by weight of the silicone rubber-based curable composition 1 (elastomer composition 1) was immersed in 68 parts by weight of toluene, and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 3. It was

<Example 4: Insulating paste 4>
The obtained 32 parts by weight of the elastomer composition 4 (containing 7.0 parts by weight of silica particles) was immersed in 68 parts by weight of decane, and subsequently stirred by a rotation / revolution mixer to prepare a liquid insulating paste 4 Got

<Example 5: Insulating paste 5>
The obtained 32 parts by weight of the elastomer composition 5 was immersed in 68 parts by weight of toluene, and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 5.

<Example 6: Insulating paste 6>
The obtained 32 parts by weight of the elastomer composition 1 was dipped in 68 parts by weight of mesitylene and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 6.

<Example 7: Insulating paste 7>
The obtained 32 parts by weight of the elastomer composition 2 was immersed in 68 parts by weight of dipropylene glycol dimethyl ether, and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 7.

<Example 8: Insulating paste 8>
The obtained 32 parts by weight of the elastomer composition 1 was dipped in 68 parts by weight of diethyl carbonate and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 8.

<Example 9: Insulating paste 9>
The obtained 20 parts by weight of the elastomer composition 1 was dipped in 80 parts by weight of tetradecane and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 9.

<Example 10: Insulating paste 10>
The obtained 40 parts by weight of the elastomer composition 2 was immersed in 60 parts by weight of decane and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 10.

<Comparative Example 1: Elastomer composition>
The obtained 100 parts by weight of the elastomer composition 1 (containing 25.6 parts by weight of the silica particles (C)) was used as it was as a sample of Comparative Example 1 without being immersed in a solvent.

<Comparative Example 2: Insulating paste 11>
The obtained 32 parts by weight of the elastomer composition 3 (excluding silica particles (C)) was immersed in 68 parts by weight of tetradecane, and subsequently stirred by a rotation / revolution mixer to obtain a liquid insulating paste 11. It was

In the solubility parameter (HSP) of Hansen of the solvent in Table 2, tetradecane dispersion term (δ _d ): 15.8 MPa ^1/2 , polar term (δ _p ): 0 MPa ^1/2 , hydrogen bond term (δ _h ). : 0 MPa ^1/2 , decane dispersion term (δ _d ): 15.7 MPa ^1/2 , polar term (δ _p ): 0 MPa ^1/2 , hydrogen bond term (δ _h ): 0 MPa ^1/2 , dispersion term of toluene (δ _d): 17.8MPa ^1/2, polarity term (δ _p): 3.0MPa ^1/2, hydrogen bond (δ _h): ^{0MPa 1/2,} dispersion term of mesitylene (Δ _d ): 18.0 MPa ^1/2 , polar term (δ _p ): 0.6 MPa ^1/2 , hydrogen bond term (δ _h ): 0.6 MPa ^1/2 , and dispersion term of dipropylene glycol dimethyl ether. (Δ _d ): 15.1 MPa ^1/2 , polar term (δ _p ): 6.3 MPa ^1/2 , hydrogen bond term (δ _h ): 4.9 MPa ^1/2 , and the dispersion term of diethyl carbonate (δ _d): 15.7 MPa ^1/2, polarity term (δ _p): 5.1MPa ^1/2, hydrogen bond (δ _h): 3.5MPa was ^1/2. Further, the boiling point of tetradecane is 253 ° C., the boiling point of decane is 174 ° C., the boiling point of toluene is 111 ° C., the boiling point of mesitylene is 165 ° C., the boiling point of dipropylene glycol dimethyl ether is 175 ° C., The boiling point of diethyl carbonate was 126 ° C.
Further, "-" in Comparative Example 1 in Table 2 indicates that each evaluation item could not be measured because the coating operation could not be performed on the sample of Comparative Example 1. Therefore, the sample of Comparative Example 1 could not be used as a paste, and it was judged that the coating property (film forming property) was poor.

[Evaluation of insulating paste]
The obtained insulating pastes 1 to 11 and the sample of Comparative Example 1 were evaluated according to the following items.
Regarding the tensile strength, three samples were used, and three average values were used as measured values. Moreover, about tear strength, it carried out by 5 samples and made 5 average values the measured value. Further, regarding hardness, two samples were used, each sample was measured at n = 5, and an average value of 10 measurements was taken as a measured value. The average value for each is shown in Table 2.

<Production of sheet elastomer>
With respect to the obtained insulating pastes 1 to 11 and the sample of Comparative Example 1, a bar coater was used to apply a 100 × 100 mm size on a release-treated aluminum foil, and after curing at 170 ° C. for 120 minutes, Then, it was peeled from the aluminum foil to prepare a sheet-like elastomer to be used in each evaluation.

<Viscosity>
The viscosity of the obtained insulating paste at a shear rate of 20 [1 / s] at room temperature of 25 ° C. was measured immediately after the production of the insulating paste by using TPE-100H manufactured by Toki Sangyo Co., Ltd. The unit of viscosity is Pa · s.
<Thixo index>
About the obtained insulating paste, the viscosity when measured at a shear rate of 1 [1 / s] at room temperature of 25 ° C. using TPE-100H manufactured by Toki Sangyo Co., Ltd. is η1, and a shear rate of 5 [1 / s]. ] The viscosity when measured in [] was set to η5, and each viscosity was measured immediately after the insulating paste was prepared. The unit of viscosity is Pa · s. The thixo index was determined as the viscosity ratio (η1 / η5).

<Tensile strength>
Using the obtained sheet-shaped elastomers of Examples and Comparative Examples with a thickness of 1 mm, dumbbell-shaped No. 3 test pieces were prepared according to JIS K6251 (2004), and the obtained dumbbell-shaped No. 3 specimens were prepared. The tensile strength of the shaped test piece at room temperature of 25 ° C. was measured. The unit is MPa.

<Tear strength>
Using the obtained sheet-shaped elastomers of Examples and Comparative Examples with a thickness of 1 mm, a crescent-type test piece was prepared in accordance with JIS K6252 (2001), and the obtained crescent-type test piece had a room temperature of 25. The tear strength at ° C was measured. The unit is N / mm.

<Hardness: Durometer hardness A>
Six sheets of the obtained sheet-like elastomers of Examples and Comparative Examples having a thickness of 1 mm were laminated to prepare a 6-mm test piece. The type A durometer hardness at room temperature of 25 ° C. was measured on the obtained test piece according to JIS K6253 (1997).

<Film forming property evaluation>
Each of the insulating pastes of Examples and Comparative Examples was applied on a glass substrate in a size of 100 × 100 mm using a bar coater so that the thickness after curing at 170 ° C. for 120 minutes was within a range of about 100 μm. A film was formed. Thickness is measured at the center and four corners of the obtained coating film, and the variation (maximum value of film thickness-minimum value of film thickness) is evaluated. It was set to x. The results are shown in Table 2.

<Extension durability>
Using the obtained 1 mm sheet-shaped elastomer, a dumbbell-shaped No. 3 type test piece was produced in accordance with JIS K6251 (2004).
Next, the following tensile repetition test was performed. The results are shown in Table 2.
When the stretching operation for stretching the obtained dumbbell-shaped No. 3 type test specimen to 500% was carried out, ◎ means that the elongation is 500%, ○ means that the elongation is 200%, and × means that the elongation is 200% or less. did.
Testing machine: Autograph AG5kNX (Shimadzu Corporation, "Model number AG-5kNX")
・ Initial value: 60 mm (distance between chucks), 0% extension rate ・ When extended: 360 mm (distance between chucks), 500% extension rate ・ Extension speed: Maximum speed of 1,000 mm / min

  The insulating pastes obtained in Examples 1 to 10 are superior in coating property (film forming property) as compared with Comparative Example 1, and are superior in extension durability as compared with Comparative Example 2. Furthermore, it has been found that an insulating resin film having excellent mechanical strength such as tensile strength and tear strength can be obtained. It was found that the insulating pastes of Examples 1 to 10 are suitable for forming the stretchable substrate.

10 wiring 20 substrate 30 cover material 50 wiring board 60 electronic component 100 electronic device 110 workbench 120 support 130 insulating paste 132 insulating layer 140 squeegee 150 conductive paste 152 conductive layer 160 mask 170 insulating paste 172 insulating layer

Claims (12)

A substrate forming a stretchable wiring board, an interlayer insulating layer provided between stretchable wirings, and an insulating paste used for forming at least one of cover materials for covering the stretchable wiring,
An elastomer composition containing silica particles (C),
Including a solvent,
The solvent contains any one of tetradecane, decane, toluene, mesitylene, dipropylene glycol dimethyl ether, and diethyl carbonate,
The viscosity of the insulating paste at room temperature of 25 ° C. is 1 Pa · s or more and 100 Pa · s or less,
Insulating paste. The insulating paste according to claim 1,
An insulating paste, wherein the elastomer composition contains a thermosetting elastomer composition for forming one or more elastomers selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. The insulating paste according to claim 1 or 2 , wherein:
Regarding the insulating paste at room temperature of 25 ° C., the viscosity ratio when the viscosity when measured at a shear rate of 1 [1 / s] is η1 and the viscosity when measured at a shear rate of 5 [1 / s] is η5, the viscosity ratio An insulating paste having a thixo index of (η1 / η5) of 1.0 or more and 3.0 or less. The insulating paste according to any one of claims 1 to 3 ,
Insulating paste whose content of the said silica particle (C) is 1 mass% or more and 50 mass% or less with respect to the said insulating paste whole. The insulating paste according to any one of claims 1 to 4 ,
An insulating paste in which the elastomer composition contains a silicone rubber-based curable composition. The insulating paste according to claim 5 ,
An insulating paste in which the silicone rubber-based curable composition contains a vinyl group-containing organopolysiloxane (A). The insulating paste according to claim 5 or 6 , wherein:
An insulating paste in which the silicone rubber-based curable composition further contains an organohydrogenpolysiloxane (B). The insulating paste according to any one of claims 5 to 7 ,
An insulating paste in which the silicone rubber-based curable composition further contains platinum or a platinum compound (E). The insulating paste according to any one of claims 1 to 8 , wherein:
Insulating paste whose content of the said elastomer composition is 5 mass% or more and 50 mass% or less with respect to the said insulating paste whole. The insulating paste according to any one of claims 1 to 9 ,
An insulating paste in which an elastomer made of the insulating paste has a durometer hardness A of 10 or more and 70 or less defined according to JIS K6253 (1997). The insulating paste according to any one of claims 1 to 10 , wherein:
An insulating paste in which an elastomer made of the insulating paste has a tensile strength measured according to JIS K6251 (2004) of 5.0 MPa or more and 15 MPa or less. The insulating paste according to any one of claims 1 to 11 ,
An insulating paste in which an elastomer made of the insulating paste has a tear strength of 25 N / mm or more measured according to JIS K6252 (2001).

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