JP2018104581A - Resin composition, cured product, conductive film, conductive pattern, and clothes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition that can form electric and/or electronic circuit wiring with a low possibility of breaking, on the surface of an extendable and/or bendable base material.SOLUTION: A resin composition contains (A) conductive particles, (B) a thermoplastic polyurethane resin with a 100% modulus of 7 MPa or more, and (C) a solvent. Relative to the total of (A) conductive particles and (B) thermoplastic polyurethane resin, the ratio of (A) conductive particles is 90 wt.% or more and less than 100 wt.%.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition that can be used to form an electrode on a base material that can be stretched and / or bent. The present invention also relates to a conductive paste containing the resin composition and a cured product of the conductive paste. Moreover, this invention relates to the electroconductive film or electroconductive pattern containing the resin composition. Furthermore, this invention relates to the garment containing the hardened | cured material, an electroconductive film, or an electroconductive pattern.

  In recent years, conductive pastes have been developed for forming electrodes on substrates that can be stretched and bent.

  For example, Patent Document 1 discloses a polymer containing an organic medium in which (a) a functional component and (b) 5 to 50% by weight (percentage by weight relative to the total weight of the organic medium) of a thermoplastic polyurethane resin are dissolved in an organic solvent. A thick film composition is described. In Patent Document 1, the elongation rate of the thermoplastic polyurethane resin is 200% or more, and the tensile stress when the thermoplastic polyurethane resin reaches 100% elongation is 1000 psi or less (about 6.895 MPa or less). It is described.

  Patent Document 2 describes a conductive paste in which a conductive filler (B) is uniformly dispersed in a resin (A). In Patent Document 2, the resin (A) is an aqueous dispersion (A1) of a conjugated double bond polymer containing a polyanion based on a sulfonated or sulfated rubber as a dopant, and a conductive filler (B). Is a metal powder (B1) having an average particle size of 0.5 to 10 μm, and the blending amounts of the resin (A) and the conductive filler (B) in the solid content of the conductive paste are 50 to 80 volumes, respectively. % And 20 to 50% by volume.

  Patent Document 3 discloses a stretchable wiring board comprising a stretchable base material made of a first elastomer and a stretchable wiring containing a conductive filler and a second elastomer, wherein the stretchable base material and the stretchable wiring are There is described a stretchable wiring board in which a stretchable adhesion layer is formed only between the stretchable wires and below the stretchable wiring.

International Publication No. 2016/073465 Japanese Patent Laying-Open No. 2015-65139 JP, 2014-151617, A

  In recent years, attempts have been made to form electric circuit and / or electronic circuit wiring on the surface of a base material that can be expanded and contracted and / or bent. In the case of the wiring formed on such a base material, the wiring may be disconnected due to expansion and contraction and / or bending of the base material.

  Accordingly, the present invention provides a resin composition and a cured product thereof capable of forming an electric circuit and / or electronic circuit wiring with a low possibility of disconnection on the surface of a base material that can be expanded and contracted and / or bent. The purpose is to do. Further, the present invention provides a conductive film or a conductive pattern for wiring an electric circuit and / or an electronic circuit with a low possibility of disconnection on the surface of a base material that can be expanded and contracted and / or bent. Objective. Another object of the present invention is to provide a garment including a conductive film or a conductive pattern.

  In order to solve the above problems, the present invention has the following configuration.

(Configuration 1)
Configuration 1 of the present invention includes (A) conductive particles, (B) a thermoplastic polyurethane resin having a 100% modulus of 7 MPa or more, and (C) a solvent, and includes (A) conductive particles and (B) thermoplastic polyurethane. It is a resin composition in which the ratio of (A) conductive particles is 90% by weight or more and less than 100% by weight with respect to the total resin.

  According to Configuration 1 of the present invention, there is provided a resin composition capable of forming an electric circuit and / or an electronic circuit wiring having a low possibility of disconnection on the surface of a base material capable of expansion and contraction and / or bending. be able to.

(Configuration 2)
Configuration 2 of the present invention is a resin according to Configuration 1, wherein the ratio of (A) conductive particles to the total of (A) conductive particles and (B) thermoplastic polyurethane resin is 90% by weight or more and 95% by weight or less. It is a composition.

  When the wiring formed using the resin composition having the constitution 2 of the present invention is elongated, an increase in the electrical resistance of the wiring due to the elongation can be reduced.

(Configuration 3)
Configuration 3 of the present invention is the resin composition according to Configuration 1 or 2, wherein (A) the conductive particles include at least one selected from Ag, Au, Cu, Ni, and Ti.

  According to the configuration 3 of the present invention, the metal coating layer contains a predetermined metal, whereby an electric circuit and / or electronic circuit wiring having a low electric resistance can be formed.

(Configuration 4)
Configuration 4 of the present invention is the resin composition according to any one of Configurations 1 to 3, wherein (B) the thermoplastic polyurethane resin is at least one selected from caprolactone, ester, ether, and carbonate. .

  According to Configuration 4 of the present invention, by using a resin composition using a predetermined type of polyurethane as the thermoplastic polyurethane resin (B), the surface of the base material that can be expanded and contracted and / or bent can be disconnected. Therefore, it is possible to reliably form the wiring of the electric circuit and / or the electronic circuit with low performance.

(Configuration 5)
Configuration 5 of the present invention is the resin composition according to any one of Configurations 1 to 4, wherein (C) the solvent is at least one selected from cyclohexanone, dimethylformamide, dimethylacetamide, and benzyl alcohol.

  According to Configuration 5 of the present invention, a predetermined thermoplastic polyurethane resin can be reliably dissolved by using a predetermined solvent. As a result, screen printing or the like of the resin composition for wiring formation can be facilitated.

(Configuration 6)
Configuration 6 of the present invention is a conductive paste containing the resin composition of any of Configurations 1 to 5.

  By using the conductive paste of the constitution 6 of the present invention, wiring of an electric circuit and / or an electronic circuit having a low possibility of disconnection on the surface of a base material that can be stretched and / or bent by means of screen printing or the like. Can be formed.

(Configuration 7)
Configuration 7 of the present invention is a cured product of the conductive paste of Configuration 6. The conductive paste of the present invention is formed into a wiring shape of an electric circuit and / or electronic circuit by means of screen printing or the like, and cured to form a wire on the surface of the base material that can be expanded and contracted and / or bent. It is possible to form wiring of an electric circuit and / or an electronic circuit with a low possibility.

(Configuration 8)
Configuration 8 of the present invention is a conductive film or a conductive pattern including the resin composition according to any one of Configurations 1 to 5.

  If the conductive film or conductive pattern of Configuration 8 of the present invention is formed on the surface of a base material that can be expanded and / or bent to form wiring of an electric circuit and / or an electronic circuit, the possibility of disconnection A low wiring can be obtained.

(Configuration 9)
Configuration 9 of the present invention is a garment including the cured conductive paste of Configuration 7, or the conductive film or conductive pattern of Configuration 8.

  If the conductive paste which is the resin composition of the present invention is used, a wiring can be formed as a cured conductive paste, a conductive film or a conductive pattern on a garment capable of stretching and / or bending.

  According to the present invention, there are provided a resin composition and a cured product thereof capable of forming an electric circuit and / or an electronic circuit wiring having a low possibility of disconnection on the surface of a base material capable of expansion and contraction and / or bending. Can do. Further, according to the present invention, it is possible to provide a conductive film or a conductive pattern for wiring an electric circuit and / or an electronic circuit with a low possibility of disconnection on the surface of a base material that can be expanded and contracted and / or bent. it can. In addition, according to the present invention, a garment including a conductive film or a conductive pattern can be provided.

  The present invention is a resin composition comprising (A) conductive particles, (B) a thermoplastic polyurethane resin having a 100% modulus of 7 MPa or more, and (C) a solvent. In the resin composition of the present invention, the ratio of (A) conductive particles is 90% by weight or more and less than 100% by weight with respect to the total of (A) conductive particles and (B) thermoplastic polyurethane resin.

  When a wiring for an electric circuit and / or an electronic circuit (also simply referred to as “wiring”) is formed using the conductive paste containing the resin composition of the present invention, there is a possibility of disconnection having excellent stretchability and flexibility. Low wiring can be formed. Therefore, the resin composition of the present invention can be suitably used to form wiring on the surface of a base material that can be expanded and contracted and / or bent.

  In this specification, “a base material that can be expanded and contracted and / or bent” refers to a material that can be bent and / or expanded and contracted, such as a cloth for forming clothes, a resin flat plate, and paper. be able to. However, the base material on which the wiring can be formed using the resin composition of the present invention is not limited to these, and may be a base material containing a material that can be stretched and / or bent. it can. In addition, wiring can also be formed in the base material which cannot be expanded-contracted and / or bent using the resin composition of this invention.

  The resin composition of the present invention has a ratio of (A) conductive particles to the total of (A) conductive particles and (B) thermoplastic polyurethane resin (sometimes simply referred to as “the ratio of conductive particles”). However, it is 90 weight% or more and less than 100 weight%. In order to reduce the increase in electrical resistance of the wiring due to the elongation of the wiring formed using the resin composition of the present invention, the ratio of the conductive particles is preferably 90% by weight or more and 99% by weight or less, preferably 90% by weight. % To 98% by weight, more preferably 90% to 95% by weight.

  The resin composition of the present invention contains conductive particles as the component (A).

  The conductive particles contained in the resin composition of the present invention preferably contain at least one selected from Ag, Au, Cu, Ni and Ti. When the conductive particles contain a predetermined metal, a wiring with low electrical resistance can be formed. More preferably, the conductive particles contained in the resin composition of the present invention comprise at least one selected from Ag, Au, Cu, Ni and Ti. In particular, silver (Ag) has high electrical conductivity. Therefore, it is preferable to use Ag particles (that is, metal particles made of Ag) as the conductive particles. In the present specification, the term “metal particles made of metal A” does not mean to exclude impurities inevitably contained. The same applies to components other than metal particles.

  The particle shape and particle size (also referred to as particle size or particle size) of the conductive particles are not particularly limited. As the particle shape, for example, a spherical shape or a flake shape can be used. The particle size of the conductive particles can be defined by a particle size (D50) of an integrated value of 50% of all particles. In the present specification, D50 is also referred to as an average particle size. In addition, an average particle diameter (D50) can be calculated | required from the result of a particle size distribution measurement by measuring a particle size distribution by the microtrack method (laser diffraction scattering method).

  The average particle diameter (D50) of the conductive particles is preferably 0.5 to 30 μm, more preferably 1 to 20 μm, from the viewpoints of resistance to expansion and contraction and / or bending and workability. More preferably, it is 15 micrometers, and it is especially preferable that it is 5-10 micrometers. When the average particle diameter (D50) is larger than the above range, problems such as clogging occur during screen printing. When the average particle size is smaller than the above range, the particles are excessively sintered during firing, and it is impossible to sufficiently form a wiring having resistance to expansion and contraction and / or bending.

Moreover, the magnitude | size of electroconductive particle can be represented as a BET value (BET specific surface area). The BET value of the conductive particles is preferably 0.1 to ⁵ m ² / g, more preferably 0.2 to ² m ² / g, and still more preferably 0.5 to 1.5 m ² / g.

  The resin composition of the present invention contains a thermoplastic polyurethane resin having a 100% modulus of 7 MPa or more as the component (B).

  In this specification, “100% modulus” means that when a pattern having a predetermined shape is formed using a resin composition, the pattern elongation is 100% (that is, the pattern length is doubled). Means the tensile stress of the wiring. Therefore, "100% modulus" is synonymous with the tensile stress when reaching 100% elongation described in Patent Document 1 (International Publication No. 2016/073465).

  The present inventors use a thermoplastic polyurethane resin having a 100% modulus of 7 MPa or more, and a group capable of stretching and / or bending by setting the ratio of the thermoplastic polyurethane resin and the conductive particles within a predetermined range. The present inventors have found that a resin composition capable of forming wiring on the surface of a material can be obtained, and have reached the present invention.

  In the resin composition of the present invention, it is preferable that the thermoplastic polyurethane resin (B) is at least one selected from caprolactone, ester, ether and carbonate. By using a resin composition using a predetermined type of polyurethane as the thermoplastic polyurethane resin, a wiring having a low possibility of disconnection can be formed on the surface of a base material that can be expanded and contracted and / or bent.

  The resin composition of the present invention can contain other resins such as a thermoplastic resin, a thermosetting resin, and / or a photocurable resin, as long as the effects of the present invention are not hindered. However, in order to obtain a suitable wiring, the resin contained in the resin composition is preferably a resin made of the above-described thermoplastic polyurethane resin.

  The resin composition of the present invention contains a solvent as the component (C).

  The solvent contained in the resin composition of the present invention is not particularly limited as long as it is a solvent capable of dissolving a predetermined thermoplastic polyurethane resin. In the resin composition of the present invention, the solvent is preferably at least one selected from cyclohexanone, dimethylformamide, dimethylacetamide, and benzyl alcohol, and more preferably dimethylacetamide. By using the predetermined solvent, the predetermined thermoplastic polyurethane resin can be surely dissolved. As a result, screen printing or the like of the resin composition for wiring formation can be facilitated.

  The addition amount of the solvent is 100 to 1000 parts by weight, preferably 200 to 600 parts by weight with respect to 100 parts by weight of the thermoplastic polyurethane resin. Usually, the thermoplastic polyurethane resin can be appropriately dissolved by using a solvent having a weight about 4 times the weight of the thermoplastic polyurethane resin.

  In addition, a solvent can be suitably added and added with respect to a resin composition for adjustment of the viscosity of a resin composition.

  The present invention is a conductive paste containing the above resin composition.

  The electrically conductive paste of this invention can be an electrically conductive paste which consists only of the above-mentioned resin composition. However, the conductive paste of the present invention can contain components other than the above-described resin composition so long as the effects of the present invention are not hindered or to improve the effects of the present invention. For example, the conductive paste of the present invention can further contain at least one selected from the group consisting of inorganic pigments, organic pigments, silane coupling agents, leveling agents, thixotropic agents, and antifoaming agents.

  The conductive paste of the present invention comprises a component contained in the above resin composition, and optionally other components, a meteor stirrer, a dissolver, a bead mill, a laika machine, a three-roll mill, a rotary mixer, or It can be manufactured by mixing in a mixer such as a twin screw mixer. Thus, it can prepare in the conductive paste suitable for screen printing, immersion, other desired coating films, or wiring formation methods.

  The viscosity of the conductive paste of the present invention can be adjusted to a viscosity that can be appropriately used for a predetermined coating film or wiring forming method such as screen printing. The adjustment of the viscosity can be performed by appropriately controlling the amount of the solvent.

  The viscosity of the conductive paste of the present invention is preferably 100 to 250 Pa · sec (measured at 1 rpm), 25 to 60 Pa · sec (measured at 10 rpm), and / or 5 to 40 Pa · sec (measured at 100 rpm). 120-200 Pa · sec (measured at 1 rpm), 30-50 Pa · sec (measured at 10 rpm), and / or 7-30 Pa · sec (measured at 100 rpm). The viscosity “(measured at 1 rpm)” indicates that the measurement was performed at a rotational speed of 1 rpm.

  The thixotropy index of the conductive paste of the present invention is preferably 1 to 25 (1 rpm / 100 rpm), and more preferably 2 to 23 (1 rpm / 100 rpm). The thixotropy index “(1 rpm / 100 rpm)” is a value obtained by dividing a measured value of viscosity measured at 1 rpm by a measured value of viscosity measured at 100 rpm (ratio of viscosity at 1 rpm to viscosity at 100 rpm). It shows that. In this specification, a viscosity is shown by the value measured at 25 degreeC using the Brookfield viscometer: B type (made by Brookfield).

  By using the conductive paste of the present invention, an electric circuit and / or electronic circuit wiring having a low possibility of disconnection is formed on the surface of the base material that can be stretched and / or bent by means of screen printing or the like. be able to.

  The present invention is a cured product of the above-described conductive paste.

  The conductive paste of the present invention is formed into a wiring shape of an electric circuit and / or electronic circuit by means of screen printing or the like, and cured to form a wire on the surface of the base material that can be expanded and contracted and / or bent. It is possible to form wiring of an electric circuit and / or an electronic circuit with a low possibility. The temperature and time for curing the conductive paste can be appropriately selected depending on the type of thermoplastic polyurethane resin contained in the resin composition. The temperature and time for curing the conductive paste can be determined by appropriately adjusting in consideration of the heat resistance of the substrate. For example, the temperature and time for curing the conductive paste can be 60 to 180 ° C. for 5 to 60 minutes, preferably 80 to 140 ° C. for 5 to 60 minutes, more preferably 110 to 130 ° C. 20 to 40 minutes.

  The present invention is a conductive film or a conductive pattern containing the resin composition described above.

  By printing the conductive paste containing the above-mentioned resin composition on the surface of a predetermined base material by a method such as screen printing so as to be a predetermined conductive film or conductive pattern, and curing as described above A conductive film or a conductive pattern can be formed.

  When the conductive film or conductive pattern of the present invention is formed on the surface of a base material that can be stretched and / or bent and used as a wiring of an electric circuit and / or an electronic circuit, a wiring with a low possibility of disconnection is used. Can be obtained.

  The present invention is a garment including the above-described cured conductive paste of the present invention, or the above-described conductive film or conductive pattern of the present invention.

  If the conductive paste which is the resin composition of the present invention is used, a wiring can be formed as a cured conductive paste, a conductive film or a conductive pattern on a garment capable of stretching and / or bending.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.

<Material and preparation ratio of conductive paste>
Tables 1 and 2 show the compositions of the conductive pastes of Examples and Comparative Examples. In addition, the electrically conductive paste of an Example and a comparative example is a resin composition which consists of silver particle (electroconductive particle), a thermoplastic polyurethane resin, and a solvent.

Table 3 shows the specific surface area, tap (TAP) density, and average particle diameter (D50) of the silver particles used in Examples and Comparative Examples. The tap density is a bulk density obtained after mechanically tapping a container containing a powder sample. Silver particles used in Examples and Comparative Examples are as follows.
Silver particles A: AA-40719 (manufactured by Metallow). The particle shape is scaly.
Silver particle B: SF135 (manufactured by Technique). The particle shape is scaly.

Table 4 shows the 100% modulus of the thermoplastic polyurethane resin used in Examples and Comparative Examples. The thermoplastic polyurethane resins used in Examples and Comparative Examples are as follows.
Polyurethane resin A: Thermoplastic urethane elastomer, P-4090 (manufactured by Dainichi Seika Kogyo Co., Ltd., caprolactone-based urethane resin)
Polyurethane resin B: Thermoplastic urethane elastomer, P-2294 (Daiichi Seika Kogyo Co., Ltd., ether urethane resin)
Polyurethane resin C: DESMOCOLL 406 (Covestro, ester urethane resin)

  The polyurethane resin used in Examples and Comparative Examples was used as a polyurethane resin solution dissolved in a solvent 4 times the weight of the polyurethane resin. Therefore, for example, in the case of Example 1, a polyurethane resin solution in which 5 parts by weight of polyurethane resin A was dissolved in 20 parts by weight of solvent (N, N-dimethylacetamide) was used. In Example 1, when the polyurethane resin solution was mixed with the silver particles, an additional 6.5 parts by weight of a solvent was added to adjust the viscosity. Therefore, the weight ratio of the solvent contained in the conductive paste (resin composition) of Example 1 was 26.5 parts by weight.

  The solvent used in Examples and Comparative Examples is N, N-dimethylacetamide (manufactured by Wako Pure Chemical Industries, Ltd.).

  Next, the conductive paste was prepared by mixing the materials of the above-mentioned predetermined preparation ratio with a planetary mixer, further dispersing with a three-roll mill, and forming a paste.

<Measurement method of viscosity>
The viscosity of the conductive pastes of Examples and Comparative Examples was measured at a temperature of 25 ° C. using a Brookfield viscometer (B type). The measurement of the viscosity was performed at the rotational speeds of 1 rpm, 10 rpm, and 100 rpm for the resin compositions of the examples and comparative examples. The thixotropy index was a value obtained by dividing the measured value of viscosity at 1 rpm by the measured value of viscosity at 100 rpm.

<Measurement method of electrical resistance value and specific resistance>
On the alumina substrate, the conductive pastes (resin compositions) of Examples and Comparative Examples were printed on a wiring pattern having a width of 1 mm and a length of 71 mm with a screen printer, and 30 at 120 ° C. with a constant temperature dryer. Heat cured for minutes. The film thickness of the obtained cured wiring pattern (simply referred to as “wiring pattern”) was measured using a surface roughness profile measuring machine (model number: Surfcom 1500SD-2) manufactured by Tokyo Seimitsu Co., Ltd. The electrical resistance value in a state where the wiring pattern was not elongated was defined as “initial resistance value”. The electrical resistance value of the wiring pattern was measured using a digital multimeter (model number: 2001) manufactured by TFF Keithley Instruments. The specific resistance was calculated from the electrical resistance value and the size of the wiring pattern. Tables 1 and 2 show initial resistance values and specific resistances of Examples and Comparative Examples.

  Next, the electrical resistance value after extending the wiring pattern by 30% in the longitudinal direction was measured, and the difference in electrical resistance value (ΔΩ) was calculated by subtracting the initial resistance value from the expanded electrical resistance value. Tables 1 and 2 show the difference in electrical resistance (ΔΩ) between the examples and the comparative examples. In order to extend the wiring pattern, the wiring pattern was printed on the surface of the urethane sheet. By extending the urethane sheet, the wiring pattern was extended to a predetermined length, and the electrical resistance value after the extension was measured.

<Measurement results of Examples and Comparative Examples>
In the conductive pastes of Comparative Examples 1 and 2, the ratio of the conductive particles to the total of the conductive particles and the thermoplastic polyurethane resin was 90% by weight or less. The difference (ΔΩ) in electrical resistance value between Comparative Examples 1 and 2 was 296Ω and 445Ω, respectively, and the electrical resistance value increased greatly with the extension of the pattern. Moreover, the conductive paste of Comparative Example 2 had a high specific resistance of 41 μΩ · cm.

  In the conductive pastes of Comparative Examples 3 and 4, the 100% modulus of the thermoplastic polyurethane resin was less than 7 MPa (3 MPa). The specific resistances of Comparative Examples 3 and 4 were as high as 63 μΩ · cm and 40 μΩ · cm, respectively. Further, the difference in electrical resistance value (ΔΩ) was 128Ω and 144Ω, respectively, and the electrical resistance value increased relatively greatly with the expansion of the wiring pattern.

  In contrast, the specific resistances of Examples 1 to 5 of the present invention were as low as 31 μΩ · cm or less, and were lower than the specific resistances of Comparative Examples 2 to 4. Moreover, the difference ((DELTA) (omega | ohm)) of the electrical resistance value of Examples 1-5 of this invention is 120 (ohm) or less, and the raise of the electrical resistance value was small compared with Comparative Examples 1-4.

  From the above, when the conductive paste of Examples 1 to 5 of the present invention is used, a wiring pattern with a low specific resistance can be obtained, and even when the wiring pattern is elongated, the electrical resistance value is increased. It has become clear that can be kept low. Therefore, if the resin composition of the present invention is used, an electric circuit and / or electronic circuit wiring having a low electrical resistance and a low possibility of disconnection is formed on the surface of the base material that can be stretched and / or bent. It can be said that it is possible.

Claims (9)

(A) conductive particles,
(B) a thermoplastic polyurethane resin having a 100% modulus of 7 MPa or more, and (C) a solvent,
(A) The resin composition whose ratio of (A) electroconductive particle is 90 to less than 100 weight% with respect to the sum total of (A) electroconductive particle and (B) thermoplastic polyurethane resin.   The resin composition according to claim 1, wherein the ratio of (A) conductive particles to the total of (A) conductive particles and (B) thermoplastic polyurethane resin is 90% by weight or more and 95% by weight or less.   (A) The resin composition according to claim 1 or 2, wherein the conductive particles include at least one selected from Ag, Au, Cu, Ni, and Ti.   The resin composition according to any one of claims 1 to 3, wherein the (B) thermoplastic polyurethane resin is at least one selected from caprolactone, ester, ether, and carbonate.   (C) The resin composition according to any one of claims 1 to 4, wherein the solvent is at least one selected from cyclohexanone, dimethylformamide, dimethylacetamide, and benzyl alcohol.   The electrically conductive paste containing the resin composition of any one of Claim 1 to 5.   A cured product of the conductive paste according to claim 6.   The electroconductive film or electroconductive pattern containing the resin composition of any one of Claim 1 to 5.   A garment comprising the cured conductive paste according to claim 7 or the conductive film or conductive pattern according to claim 8.