JP2006210202A - Manufacturing method of plastic sheet with circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of plastic sheet with a circuit in which it is not destroyed even if the circuit is formed on the plastic sheet by utilizing a conductive paste and the seat is bent. <P>SOLUTION: After a circuit pattern is formed on a temporary supporting substrate by using a sintering conductive paste in which the binder resin component is heat decomposed at a temperature under a sintering temperature of a conductive powder, and the conductive paste is sintered on a temporary supporting substrate by heating the conductive powder at a temperature at least not less than the sintering temperature of the conductive powder, the sintering conductive pattern is transcribed from the temporary supporting substrate to the plastic sheet of which the heat resistant temperature is lower than the sintering temperature of the conductive powder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a plastic sheet on which a circuit comprising a sintered conductive pattern is formed, and a circuit comprising a sintered conductive pattern is obtained by thermally decomposing a binder resin component during firing of the sintered conductive paste. The present invention relates to a method for producing a plastic sheet to be formed.

  Conductive paste is widely used for forming fine wiring. The conductive paste is a paste-like material in which a minute conductive powder is contained in a binder resin, and is used for pattern formation on a circuit board by screen printing or ink jet printing.

  The fine wiring using the conductive paste can form a wiring having a thickness of 100 μm or less and a width of 100 μm or less, for example. Here, the binder resin serves to connect the conductive powder and maintain the wiring shape.

  As an example of use of such a conductive paste, for example, a plastic sheet is disclosed in which a conductive paste is used for antenna wiring of a non-contact IC card (Patent Documents 1 and 2). Here, after the conductive paste is printed on the surface of the inlet sheet, the inlet sheet is heated to cure the thermosetting binder resin component in the conductive paste, thereby forming the antenna wiring.

  Thus, the conductive paste is in the form of a paste at the time of printing, but it is necessary to cure the conductive paste in order to form a conductive wiring. Therefore, the binder resin component usually has a thermosetting property or a photocuring property. Or a solvent was added and solidified by heating. Therefore, the fine wiring obtained has a structure in which conductive fine powders are in contact with each other, but a resin is interposed between the conductive fine powders.

JP 2003-242472 A JP 2003-223626 A

  However, conductive wiring containing a resin component is fragile, and when conductive wiring is formed on a flexible substrate formed of a plastic sheet using a conductive paste, the conductive wiring is easily destroyed when the substrate is bent. The point turned out.

  Therefore, in view of the state of the prior art described above, an object of the present invention is a plastic with a circuit that does not break a circuit even if the sheet is bent even when a circuit is formed on a plastic sheet using a conductive paste. To provide a sheet.

The method for producing a plastic sheet with a circuit according to the present invention comprises forming a circuit pattern on a temporary support substrate using a sinterable conductive paste in which a binder resin component is thermally decomposed at a temperature equal to or lower than a sintering temperature of the conductive powder, After heating the conductive powder above the sintering temperature of the conductive powder to sinter the conductive paste on the temporary support substrate, the sintered metal pattern is transferred from the temporary support substrate to a plastic whose heat resistance temperature is lower than the sintering temperature of the conductive powder. This is a method of manufacturing a plastic sheet with a circuit to be transferred to a sheet.
The plastic sheet with a circuit of the present invention is a plastic sheet with a circuit in which a sintered conductive pattern is formed on the plastic sheet by the method of claim 1.
The non-contact information card of the present invention is a non-contact information card in which another plastic sheet is bonded to the antenna forming surface of a plastic sheet on which an antenna made of a sintered conductive pattern is formed.

Details of the present invention will be described below.
The conductive paste used in the present invention is a sinterable conductive paste containing a binder resin component and a conductive powder, and the binder resin component is thermally decomposed at a temperature equal to or lower than the sintering temperature of the conductive powder.

The conductive powder is not particularly limited as long as it is a conductive powder having sinterability used for a normal conductive paste. For example, nickel, copper, aluminum, silver, gold, platinum, palladium, solder , Tin oxide, antimony-doped tin oxide (ATO), indium oxide, tin-doped indium oxide (ITO), and the like.
The minimum with a preferable average particle diameter of the said electroconductive powder is 0.01 micrometer, and a preferable upper limit is 10 micrometers. When the particle diameter is less than 0.01 μm, it may be difficult to uniformly disperse in the binder resin, and when it exceeds 10 μm, the accuracy of the pattern to be formed may be lowered.

  The amount of the conductive powder is appropriately selected depending on the type of the binder resin and the conductive powder to be used, but is preferably 50 to 1000 parts by volume, more preferably 100 parts by volume with respect to 100 parts by volume of the binder resin component. ~ 900 parts by volume. When the amount of the conductive powder is less than 50 parts by volume, volume shrinkage is increased during sintering after pyrolysis of the binder resin component, and the conductive pattern is easily cracked, making it difficult to obtain stable conduction. On the other hand, when it exceeds 1000 parts by volume, the determination of the conductive powder due to the binder resin component is remarkably lowered, and pattern formation becomes difficult.

As the binder resin component, a binder resin generally used for a conductive paste may be used, and it is appropriately selected according to the sintering temperature of the conductive powder. For example, when copper or aluminum is used as the conductive powder, since the sintering temperature is as high as 400 ° C. or higher, commonly used binder resins such as epoxy resins, acrylic resins, polyurethane resins, polyester resins, and phenol resins are used. May be used. Of these binder resins, thermoplastic resin binders are preferable from the viewpoint of thermal decomposability and the like, and acrylic resins are more preferable.
In addition, when silver, gold, platinum, palladium, or the like is used as the conductive powder, the sintering temperature is relatively low. Therefore, an acrylic resin that can be decomposed at a lower temperature is preferably used as the binder resin. .
By heating the acrylic resin to a temperature of 150 to 350 ° C., the resin component can be easily and completely eliminated by leaving the conductive powder by baking at a relatively low temperature for a short time. As a result, when the conductive powder is sintered, there is no residual organic component, and the conductive powder can be sintered neatly. In this case, it is more preferable that the acrylic resin contains a polyoxyalkylene chain, and since the acrylic resin contains a polyalkylene chain, 95% or more of the weight disappears within 10 minutes. The resin component can be easily extinguished at a low temperature.

  When the conductive powder is baked in a process described later, the binder resin component is lost and becomes a sintered metal.

The acrylic resin as a binder resin imparts excellent binding properties to the conductive powder, and imparts properties that make it easy to suppress the adhesion of dust by making the coating surface tack-free.
Although it does not specifically limit as said acrylic resin, For example, it is preferable that it is a methacrylic acid alkylester type polymer.

Although it does not specifically limit as said alkyl methacrylate, It is preferable that the glass transition temperature of a homopolymer is 30 degreeC or more, More preferably, it is 40 degreeC or more. If the glass transition temperature is less than 30 ° C., tackiness is likely to occur on the coating surface, and dust adhesion and blocking are likely to occur.
Such methacrylic acid alkyl ester is not particularly limited, and examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, n-stearyl acrylate, and benzyl methacrylate. Etc.

In addition to the methacrylic acid alkyl ester whose homopolymer has a glass transition temperature of 30 ° C. or higher, the acrylic resin contains a (meth) acrylic acid alkyl ester monomer whose homopolymer has a glass transition temperature of 0 ° C. or lower. It is preferable to contain as a copolymerization component. In such a copolymer, the viscosity of the binder resin can be easily adjusted by adjusting the content of the segment derived from the above (meth) acrylic acid alkyl ester monomer.
The (meth) acrylic acid alkyl ester monomer having a glass transition temperature of 0 ° C. or lower is not particularly limited, and examples thereof include ethyl acrylate, n-butyl acrylate, tert-butyl acrylate, isoamyl acrylate, 2- Examples include ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, isononyl acrylate, isomyristyl acrylate, lauryl methacrylate, isodecyl methacrylate, tridecyl methacrylate, and 2-ethylhexyl methacrylate. Of these, lauryl methacrylate and 2-ethylhexyl methacrylate are preferred because of their excellent decomposability.

In the acrylic polymer, a segment derived from a methacrylic acid alkyl ester monomer having a glass transition temperature of 30 ° C. or higher in the acrylic polymer, and a glass transition temperature of the homopolymer being 0 ° C. or lower (meth) The ratio with the segment derived from the alkyl acrylate monomer is not particularly limited, and may be appropriately selected as necessary, but is preferably 100: 0 to 50:50 by weight, more Preferably it is 100: 0 to 70:30.
If the ratio of the segment derived from the methacrylic acid alkyl ester monomer having a glass transition temperature of 30 ° C. or higher of the homopolymer is less than this, tackiness is likely to occur on the coating surface, and dust adhesion and blocking are prevented. May be easier to wake up.

The polyoxyalkylene chain plays a role of increasing the content of the oxygen component in the binder resin component and preventing the binder resin component from remaining as a carbonized residue during thermal decomposition of the binder resin component. .
In the binder resin component, the acrylic resin and the polyoxyalkylene chain may exist in a mixture state or in a combined state, but the conductive paste has a uniform dispersibility and dispersion stability. It is preferable to exist in a bonded state because it is easy to adjust the viscosity of the binder resin component.

  In the acrylic resin to which the polyoxyalkylene chain is bonded, the bonding position of the polyoxyalkylene chain may be any of the seed chain, the side chain, and the terminal of the acrylic resin. The polymer chain and the polyoxyalkylene chain may form an alternating block copolymer.

  The polyoxyalkylene chain is not particularly limited, and examples thereof include polyoxyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, polyethylethylene glycol, polybenzylethylene glycol, and copolymer pairs thereof. . The method for introducing these polyoxyalkylene chains into the acrylic resin is not particularly limited. For example, a compound having a copolymerizable functional group copolymerizable with the above-mentioned alkyl methacrylate and a polyoxyalkylene structure is copolymerized. The method of doing is mentioned. Examples of the compound having a copolymerizable functional group and a polyoxyalkylene structure include compounds represented by the following [Compound 1] to [Compound 18].

[Compound 1]
_{CH 2 = CH-C (O} ) O- (CH 2 CH 2 O) n -H
(N = 1-12)
[Compound 2]
_{CH 2 = C (CH 3)} -C (O) O- (CH 2 CH 2 O) n -H
(N = 1-12)
[Compound 3]
_{CH 2 = CH-C (O} ) O- [CH 2 CH (CH 3) O] n -H
(N = 1-12)
[Compound 4]
_{CH 2 = C (CH 3)} -C (O) O- [CH 2 CH (CH 3) O] n -H
(N = 1-12)
[Compound 5]
_{CH 2 = C (CH 3)} -C (O) O- (CH 2 CH 2 O) n - [CH 2 CH (CH 3) O] m -H
(M, n = 1-12)
[Compound 6]
_{CH 2 = CH-C (O} ) O- (CH 2 CH 2 O) n - [CH 2 CH (CH 3) O] m -H
(M, n = 1-12)
[Compound 7]
_{CH 2 = C (CH 3)} -C (O) O- (CH 2 CH 2 O) n - (CH 2 CH 2 CH 2 CH 2 O) m H
(M, n = 1-12)
[Compound 8]
_{CH 2 = CH-C (O} ) O- (CH 2 CH 2 O) n - (CH 2 CH 2 CH 2 CH 2 O) m H
(M, n = 1-12)
[Compound 9]
_{CH 2 = CH-C (O} ) O- (CH 2 CH 2 O) n -CH 3
(N = 1-10)
[Compound 10]
_{CH 2 = C (CH 3)} -C (O) O- (CH 2 CH 2 O) n -CH 3
(N = 1-30)
[Compound 11]
_{CH 2 = CH-C (O} ) O- [CH 2 CH (CH 3) O] n -CH 3
(N = 1-10)
[Compound 12]
_{CH 2 = C (CH 3)} -C (O) O- [CH 2 CH (CH 3) O] n -CH 3
(N = 1-10)
[Compound 13]
_{CH 2 = C (CH 3)} -C (O) O- (CH 2 CH 2 O) n - [CH 2 CH (CH 3) O] m -H
(M, n = 1-10)
[Compound 14]
_{CH 2 = CH-C (O} ) O- (CH 2 CH 2 O) n - [CH 2 CH (CH 3) O] m -H
(M, n = 1-10)
[Compound 15]
_{CH 2 = CH-C (O} ) O- [CH 2 CH (CH 3) O] n -C (O) -CH = CH 2
(N = 1-20)
[Compound 16]
_{CH 2 = C (CH 3)} -C (O) O- [CH 2 CH (CH 3) O] n -C (O) -C (CH 3) = CH 2
(N = 1-20)
[Compound 17]
_{CH 2 = CH-C (O} ) O- (CH 2 CH 2 O) n -C (O) -CH = CH 2
(N = 1-20)
[Compound 18]
_{CH 2 = C (CH 3)} -C (O) O- (CH 2 CH 2 O) n -C (O) -C (CH 3) = CH 2
(N = 1-20)

  The content of the polyoxyalkylene chain in the acrylic resin is not particularly limited, but a preferred lower limit is 1% by weight, a preferred upper limit is 50% by weight, a more preferred lower limit is 3% by weight, and a more preferred upper limit is 30%. % By weight. If it is less than 1% by weight, residual carbonization residue may not be suppressed, and if it exceeds 50% by weight, in the case of a polyoxyalkylene chain having a relatively weak cohesion, for example, a polypropylene oxide segment, the resin is not sticky. It may develop and become susceptible to blocking, making handling difficult.

  The acrylic resin may further contain a hydroxyl group-containing methacrylic acid ester monomer as a copolymer component in order to improve thread breakage when the conductive paste is formed. Examples of hydroxyl group-containing methacrylic acid ester monomers include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, cyclohexanedimethanol monomethacrylate, neopentyl glycol monomethacrylate, glycerol mono Examples include methacrylate, trimethylolpropane monomethacrylate, and pentaerythritol monomethacrylate. The preferred content of the methacrylic acid ester monomer having an ester functional group containing a hydroxyl group in the acrylic polymer is preferably 30 parts by weight or less in 100 parts by weight of the acrylic polymer, and more preferably 1-15. Parts by weight. If the amount exceeds 30 parts by weight, water absorption is likely to occur, and when a conductive powder is dispersed into a paste, it may be difficult to obtain a composition having a stable viscosity over a long period of time.

  In the acrylic resin, a copolymerizable monomer other than the (meth) acrylic acid alkyl ester may be copolymerized within a range not inhibiting the thermal decomposability of the acrylic resin.

  The number average molecular weight of the acrylic resin is preferably 5,000 to 5,000,000, more preferably 1,000 to 500,000, still more preferably 5,000 to 100,000, and still more preferably 5,000 to 50,000. If the number average molecular weight is less than 500, the viscosity may be too low to make it difficult to handle the binder resin stably. If the number average molecular weight exceeds 5 million, stringing is likely to occur during printing, or even when heated May not disappear.

  The polymerization method for producing the acrylic resin is not particularly limited. For example, a conventionally known method such as a free radical polymerization method, a living radical polymerization method, an iniferter polymerization method, an anion polymerization method, or a living anion polymerization method is used. be able to.

The binder resin component preferably further contains a polyalkylene oxide for the purpose of lowering the firing temperature.
The polyalkylene oxide is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, poly (ethyl) ethylene glycol, poly (benzyl) ethylene glycol, and copolymers thereof. Can be mentioned.
The molecular weight of the polyalkylene oxide is not particularly limited, and may be appropriately selected according to the viscosity of the binder resin.

  The blending amount of the polyalkylene oxide is not particularly limited, but is preferably 100 parts by weight or less, more preferably 50 parts by weight or less with respect to 100 parts by weight of the acrylic resin. When the amount of the polyalkylene resin exceeds 100 parts by weight, the low temperature baking property by the polyalkylene oxide is improved, but depending on the combination of the binder resin and the polyalkylene oxide, the phase separation is easy, and a paste having a stable viscosity can be obtained. May be difficult.

  Furthermore, the resin binder component may contain a liquid resin. By containing the liquid resin, the disappearance start temperature of the low-temperature baking type binder resin composition of the present invention can be lowered, and can be rapidly extinguished even at a temperature of about 150 ° C. The liquid resin is not particularly limited. For example, polyethylene glycol oligomer, polypropylene oligomer, polytetramethylene glycol oligomer, polyester polyol oligomer, butyl acrylate oligomer, 2-ethylhexyl oligomer, polyisoprene oligomer, polybutadiene oligomer, polyisobutylene oligomer, etc. Oligomers, dioctyl phthalate, dibutyl phthalate, glycerin monooleate and the like.

  The sinterable conductive paste of the present invention preferably contains a decomposition accelerator. By containing a decomposition accelerator, the binder resin component can be quickly decomposed during the thermal decomposition. The decomposition accelerator is not particularly limited. For example, azo compounds; heavy metal compounds such as iron sulfate, sodium nitrate, cobalt naphthenate; carboxylic acids such as oxalic acid, linolenic acid, ascorbic acid; hydroquinone, peroxide, oxidation Tin etc. are mentioned. Especially, the said peroxide is suitable from the ability to suppress also the decomposition residue resulting from a decomposition accelerator low. The azo compound is preferable because it can promote the volatilization of the decomposition product by the nitrogen gas generated by the decomposition of the azo compound as well as the decomposition promoting effect by the decomposition accelerator.

The peroxide is not particularly limited, and may be an inorganic peroxide or an organic peroxide. Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, ammonium persulfate, potassium perchlorate, sodium perchlorate, ammonium perchlorate, and potassium periodate.
As the organic peroxide, those having a 10-hour half-life temperature of 100 ° C. or more are preferable from the viewpoint of storage property. Examples of the organic peroxide having a 10-hour half-life temperature of 100 ° C. or higher include P-menthane hydroxy peroxide, diisopropylbenzene hydroxy peroxide, 1,1,3,3-tetramethylbutyl hydroxy peroxide, cumene hydroxyperoxide. Hydroxide peroxides such as oxide, t-hexylhydroxyperoxide, t-butylhydroxyperoxide; dicumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropylbenzene), 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne- Dialkyl peroxides such as 3 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy)- 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) Peroxyketals such as butane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane; t-hexylperoxy Isopropyl monocarbonate, t-butyl peroxymaleic acid, t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl pero Xylaurate, 2,5-dimethyl-2,5-bis (m-toluylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis ( m-benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxybenzoate, bis-t-butylperoxyisophthalate, and peroxyesters such as t-butylperoxyallyl monocarbonate.

  The azo compound is not particularly limited. For example, azodicarbonamide, azobisisobutyronitrile (AIBN), 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2- Azobis (2-cyclopropylpropionitrile), 2,2-azobis (2-methylbutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile) and the like can be mentioned.

The sinterable conductive paste may contain a decomposition retarder for the purpose of improving the handleability. The decomposition retardant is not particularly limited, and examples thereof include mercapto compounds, amine compounds, organic tin compounds, and organic boron compounds.
The mercapto compound is not particularly limited, and examples thereof include propanethiol, butanethiol, pentanethiol, 1-octanethiol, dodecanethiol, cyclopentanethiol, cyclohexanethiol, 1,3-propanediol, and the like.
The amine compound is not particularly limited, and examples thereof include propylamine, butylamine, hexylamine, dodecylamine, isopropylamine, hexamethylenediamine, cyclohexylamine, benzylamine, aniline, and methylaniline.
The organic tin compound is not particularly limited, and examples thereof include dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, dibutyltin bis (2,4-pentanedione), and dilauryltin dilaurate.
The organoboron compound is not particularly limited, and examples thereof include trimethyl borate, tripropyl borate, tributyl borate, trimethoxyboroxine, and trimethylene borate.

  Although it does not specifically limit as content of the said decomposition accelerator or a decomposition retarder, Preferably, it is 1-10 weight part with respect to 100 weight part of binder resins.

  The sinterable conductive paste may contain an organic solvent in order to prepare a viscosity suitable for the pattern formation method. The organic solvent is not particularly limited. For example, ester solvents such as methyl acetate, ethyl acetate, propyl acetate, and isobutyl acetate, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, and cyclohexanone, methanol, Alcohol solvents such as ethanol, propanol, hexanol, cyclohexyl alcohol, aliphatic solvents such as hexane, pentane, heptane, cyclohexane, aromatic solvents such as benzene, toluene, xylene, mesitylene, etc. It is appropriately selected and used depending on the method of using the conductive conductive paste.

  Further, a solvent having a boiling point of 150 ° C. or higher is preferable in order to provide the solid content stability of the sinterable conductive paste and the viscosity stability during printing. Such an organic solvent is not particularly limited, and examples thereof include terpineol, ethylene glycol ethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, butyl carbitol, butyl carbitol acetate, isophorone, butyl lactate, dioctyl phthalate. , Dioctyl adipate, benzyl alcohol, phenylpropylene glycol, cresol and the like.

  The sinterable conductive paste may contain a silane coupling agent. Examples of the silane coupling agent include vinyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, and 3-aminopropyl. Trimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyl Triethoxysilane, N, N′-bis- [3- (trimethoxysilyl) propyl] ethylenediamine, N, N′-bis- [3- (triethoxysilyl) propyl] ethylenediamine, N, N′-bis- [ 3- (Torime Kishishiriru) propyl] hexaethylenediamine, N, N'-bis - [3- (triethoxysilyl) propyl] hexaethylenediamine the like.

  The sinterable conductive paste may contain a titanium coupling agent. Examples of the titanium coupling agent include isopropyl triisostearoyl titanate, isopropyl-n-dodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphite) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraisopropyl bis (ditri). Decyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridodecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl And tri (N-aminoethyl-aminoethyl) titanate.

  The sinterable conductive paste may contain a tackifier for the purpose of increasing the tackiness. Examples of the tackifier include rosin, rosin ester, disproportionated rosin ester, hydrogenated rosin ester, polymerized rosin ester, terpene resin, terpene phenol resin, aromatic modified terpene resin, Examples thereof include C5 / C9 petroleum resin, hydrogenated petroleum resin, phenol resin, coumarone-indene resin, ketone resin, and xylene resin.

  The method for producing the sinterable conductive paste is not particularly limited, and examples thereof include a method of adding conductive powder, an organic solvent, etc. to a binder resin, uniformly mixing with a three roll or bead mill, and defoaming. It is done.

  In the method for producing a plastic sheet with circuit of the present invention, a circuit pattern is formed on a temporary support substrate using the above-mentioned sinterable conductive paste, and then heated at least to a sintering temperature of the conductive powder. After the conductive paste is sintered on the temporary support substrate, a circuit pattern made of a sintered conductor is transferred from the temporary support substrate to the plastic sheet to produce a plastic sheet with a circuit.

  The temporary support substrate is not particularly limited as long as it is a material that can be applied with a sinterable conductive paste in a circuit pattern and can withstand the firing temperature. As a temporary support base material, a polyimide resin, glass, ceramics etc. are mention | raise | lifted, for example. Further, the temporary support substrate is not limited to a hard plate, and may be a flexible sheet or film.

  The method of forming the circuit pattern made of the conductive paste is not particularly limited, and examples thereof include a method of applying the conductive paste to the temporary support base material in the shape of the wiring pattern using a screen printing apparatus, an inkjet apparatus, or the like. It is done. At this time, the film thickness of the coating film made of the conductive paste is not particularly limited. However, if it is too thin, there is a possibility that even a sintered conductive wiring may be destroyed during transfer. If it is too thick, the necessity of using the conductive paste is lost. Therefore, the film thickness is preferably 0.1 μm to 100 μm.

  In addition, a photoconductive resin-containing conductive paste is applied on a temporary support substrate to give a photosensitivity, and the thin film is solidified into a wiring pattern shape by photolithography to obtain an uncured conductive paste. May be removed to form a circuit pattern.

  When the circuit pattern made of the conductive paste formed on the temporary substrate is heated to 250 ° C. or higher in an electric furnace and fired, the binder resin component is thermally decomposed and disappears, and the conductive powder is sintered. Thus, a sintered conductive pattern is formed on the temporary substrate.

The sintered conductive pattern on the temporary support substrate is transferred to a plastic sheet having higher adhesion than the temporary support substrate.
Examples of the plastic sheet include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester resin such as polyethylene naphthe tray and (PEN), polyamide resin such as nylon 6 and nylon 66, polyethylene (PE), polypropylene (PP), Examples include polyolefin resins such as polymethylpentene, polyvinyl chloride resins, acrylic resins, polyimide resins, polysulfone resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, and PET resins are preferably used.
Here, in order to facilitate the transfer from the temporary support substrate onto the plastic sheet, a pressure sensitive adhesive or a hot melt pressure sensitive adhesive may be applied to the surface of the plastic sheet to positively give the pressure sensitive adhesive or adhesiveness. On the contrary, silicone may be applied to the temporary support base material to give release properties. Further, the plastic sheet may be heated during transfer in order to enhance the adhesion of the plastic sheet.

The plastic sheet to which the sintered conductive pattern is transferred becomes a plastic sheet on which a circuit is formed.
A plastic sheet on which such a sintered conductive pattern is formed is suitable for a fine wiring pattern that requires toughness such as an antenna used in a non-contact information card. Therefore, it is particularly suitable for a non-contact information card using a plastic sheet on which an antenna circuit is formed by a sintered conductive pattern.

The method for producing a plastic sheet with a circuit according to the present invention is as described above. Since the obtained plastic sheet with a circuit is formed with a circuit made of a sintered conductive pattern on the plastic sheet, the conductive wiring is strong. Even if the sheet is bent, the circuit is not destroyed.
Moreover, since the antenna which consists of a sintered conductive pattern is formed, the non-contact information card | curd of this invention can give the antenna the toughness required for the card | curd in the environment bent repeatedly.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited only to these examples.
[Example 1]
(Synthesis of binder resin)
In a 0.5 L separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen gas inlet, 95 g of methyl methacrylate, 5 g of polypropylene glycol monomethacrylate (Nippon Yushi Co., Ltd., Bremer PP-1000), 1 g of lauryl mercaptan and ethyl acetate 100 g was added and mixed to obtain a monomer mixed solution. The obtained monomer mixed solution was bubbled with nitrogen gas for 20 minutes to remove dissolved oxygen, and then the inside of the separable flask system was replaced with nitrogen gas, and the temperature was raised until it reached reflux while stirring. After refluxing, a solution obtained by diluting 0.024 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane as a polymerization initiator with 1 g of ethyl acetate was added to the polymerization system. After 1 hour, a solution prepared by diluting 0.036 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate was added. Further, 2 hours after the start of polymerization, a solution obtained by diluting 0.08 g of di (3,5,5-trimethylhexanoyl) peroxide with 1 g of ethyl acetate was added. Five hours after the first introduction of the polymerization initiator, after cooling to room temperature to complete the polymerization, 100 g of terpineol was added, and vinyl acetate was removed by a rotary evaporator to obtain a terpineol solution of acrylic resin.
When the obtained acrylic resin was analyzed by gel permeation chromatography, the number average molecular weight in terms of polystyrene was about 30,000.

(Preparation of conductive paste)
200 parts by weight of the terpineol solution of acrylic resin obtained and 3000 parts by weight of silver powder (S-133, particle size: 1.1 μm, manufactured by Daiken Kogyo Co., Ltd.) are mixed with three rolls to prepare a sinterable conductive paste. did.

(Manufacture of plastic sheets with circuits)
Using the conductive paste, 10 stripe electrode patterns having a thickness of 20 μm, a width of 100 μm and a length of 50 mm were printed on a polyimide film at intervals of 2 mm using a screen printing apparatus. Then, after drying the solvent at 100 ° C. for 20 minutes, the binder resin was degreased and the silver was sintered by heating at 220 ° C. for 30 minutes and further at 260 ° C. for 10 minutes. The surface of the obtained sintered conductive pattern surface is bonded to a polyester film having a length of 8 cm, a width of 5 cm, and a film thickness of 75 μm in which an acrylic adhesive layer having a thickness of 75 μm is laminated, and the polyimide film and the polyester film are pressure-bonded. Then, the polyimide film was gently peeled off, and the sintered conductive pattern was transferred to the polyester film to produce a plastic sheet with a circuit. Next, a test piece having a non-contact information card was prepared by laminating a 150 μm thick polyester film using a two-pack type epoxy adhesive except for both ends of the sintered conductive pattern of the plastic sheet with circuit. .

(Measurement of resistance value)
Both ends in the longitudinal direction of the test piece obtained above were fixed, and a 1000 times repeated deformation test was performed at a bending displacement of 20 mm at the center and a repetition rate of 30 times / minute. The resistance value before and after the repeated deformation test was measured according to the measurement method of JIS K 6911. The results are shown in Table 1.

[Example 2]
The synthesis of the binder resin of Example 1 was performed in the same manner as in Example except that methyl methacrylate was changed to isobutyl methacrylate. The results are shown in Table 1.

[Comparative Example 1]
Using the conductive paste prepared in Example 1, 10 stripe electrode patterns having a thickness of 20 μm, a width of 100 μm, and a length of 50 mm were printed on a polyester film using a screen printing apparatus at intervals of 2 mm, and then at 100 ° C. The solvent was dried for 20 minutes to obtain a plastic sheet with a circuit.
It carried out similarly to Example 1 using the obtained plastic sheet with a circuit. The results are shown in Table 1.

[Comparative Example 2]
Using silver paste (DW-250H-5, manufactured by Toyobo Co., Ltd.), using a screen printer, print 10 stripe electrode patterns with a thickness of 20 μm, a width of 100 μm, and a length of 50 mm on a polyester film at intervals of 2 mm. Then, it was cured at 130 ° C. for 30 minutes to obtain a plastic sheet with a circuit.
It carried out similarly to Example 1 using the obtained plastic sheet with a circuit. The results are shown in Table 1.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the plastic sheet which forms the circuit which consists of a sintered conductive pattern can be provided.

Claims (3)

  A circuit pattern is formed on the temporary support substrate using a sinterable conductive paste in which the binder resin component is thermally decomposed below the sintering temperature of the conductive powder, and heated at least above the sintering temperature of the conductive powder. After sintering the sinterable conductive paste on the temporary support base material, the sintered conductive pattern is transferred from the temporary support base material to a plastic sheet whose heat resistance temperature is lower than the sintering temperature of the conductive powder. To manufacture plastic sheet with circuit.   A plastic sheet with a circuit, wherein the sintered conductive pattern is formed on the plastic sheet by the method according to claim 1.   A non-contact information card, wherein another plastic sheet is bonded to an antenna forming surface of a plastic sheet on which an antenna made of a sintered conductive pattern is formed.