CN113336540B

CN113336540B - Ceramic green sheet and coated sheet

Info

Publication number: CN113336540B
Application number: CN202110585931.2A
Authority: CN
Inventors: 岛住夕阳
Original assignee: Kuraray Europe GmbH
Current assignee: Kuraray Europe GmbH
Priority date: 2016-07-28
Filing date: 2017-07-26
Publication date: 2022-11-08
Anticipated expiration: 2037-07-26
Also published as: WO2018021439A1; CN113336540A; CN109563001A; TW201819340A; JPWO2018021439A1; KR20190038864A

Abstract

Provided are a ceramic green sheet and a coating sheet which have excellent adhesion during pressure bonding and are less likely to cause delamination. Provided is a ceramic green sheet which has excellent adhesiveness when a coated sheet obtained by applying an arbitrary conductive paste to a ceramic green sheet is pressure-bonded, and which is less likely to cause delamination. A ceramic slurry comprising at least a binder resin (A) having a hydroxyl group in the molecule and an organic compound (B) represented by the chemical formula (1), and further comprising an organic solvent (C) and an inorganic compound (D), wherein R1 and R4 each independently represents an organic group having at least one ether bond, R2 represents an optionally branched alkylene group having 1 to 20 carbon atoms, R3 represents an optionally branched alkylene group having 1 to 4 carbon atoms, and m represents an integer of 0 to 5.

Description

Ceramic green sheet and coated sheet

The present application is a divisional application of an application having an application date of 2017, 26.7.63, an application number of 201780046608X, and an invention name of "ceramic green sheet and coating sheet".

Technical Field

The present invention relates to a ceramic green sheet having excellent adhesiveness during pressure bonding and little dimensional change during pressure bonding. The present invention also relates to a coated sheet having excellent adhesiveness when pressure-bonded.

Background

Polyvinyl acetal has been proposed as a polymer having a unique structure in which a tough film can be obtained and which has both a hydrophilic hydroxyl group and a hydrophobic acetal group.

Among them, polyvinyl butyral is widely used as a binder for ceramic molding, various binders, films, and the like.

The binder for ceramic molding is used as a suitable molding binder in the process of manufacturing a circuit board of a laminated ceramic capacitor or an IC chip, for example. Among them, the binder is widely used as a binder used for producing ceramic green sheets.

Polyvinyl acetal is also used as a binder for a conductive paste used for producing a multilayer ceramic capacitor or the like. The forming step of the electrode layer includes: a method of directly forming the electrode layer by printing on the ceramic green sheet; and a method of forming an electrode layer on the carrier film by printing or the like, and then transferring the electrode layer from the carrier film to a ceramic green sheet by hot pressing.

Here, the multilayer ceramic capacitor is a chip-type ceramic capacitor obtained by laminating a plurality of layers of a dielectric such as titanium oxide or barium titanate and an internal electrode. In such a laminated ceramic capacitor, for example, a conductive paste to be an internal electrode is applied to the surface of a ceramic green sheet by screen printing or the like, a plurality of the obtained materials are laminated and thermally pressed to obtain a laminate, and then the laminate is heated to decompose and remove (degrease) a binder and fired to produce a laminated ceramic capacitor. There are also cases where ceramic green sheets, in which a circuit is not formed by a conductive paste, are partially stacked. Among them, barium titanate is widely used in laminated ceramic capacitors because it is a high dielectric substance.

In recent years, along with the multifunctionality and miniaturization of electronic devices, there is a demand for a multilayer ceramic capacitor having a large capacity and a small size. Attempts have been made to meet these requirements by thinning ceramic green sheets and further increasing the number of layers of laminated ceramic capacitors. For example, as a method for making a thin film, a method of coating a releasable support in a thin film of 5 μm or less on a ceramic green sheet using a ceramic powder having a fine particle size of 0.5 μm or less as a ceramic green sheet has been attempted.

On the other hand, in the process of temporarily crimping the ceramic green sheets in the production of a laminated ceramic capacitor, if the crimping is enhanced, the ceramic green sheets and the conductor layers are deformed, and it is difficult to achieve the high precision required for the laminated ceramic component. On the other hand, if the pressure bonding is weakened, in the conventional manufacturing method, the adhesive strength between the ceramic green sheets is weak or the adhesive strength between the ceramic green sheet and the conductor layer is weak, and the upper and lower ceramic green sheets may not adhere to each other or the ceramic green sheet and the electrode layer may not adhere to each other. When such adhesion failure occurs, there is a problem that cutting failure due to displacement of the bonding surface, delamination after firing of the ceramic laminate, and the like occur, and reliability of the component is lowered. Further, when an excessive amount of plasticizer is added to improve adhesiveness, there is a problem that deformation occurs during pressure bonding, and it is difficult to obtain a desired laminate sheet.

As an attempt to solve the above problem, for example, patent document 1 describes using a ceramic slurry containing a phthalic acid plasticizer and a diol plasticizer and/or an alcohol plasticizer. Patent document 2 describes a ceramic paste having a high plasticizing effect and containing appropriate volatility. Patent document 3 describes a production method for improving adhesiveness by performing surface treatment on a thin film using an atmospheric pressure plasma apparatus.

Documents of the prior art

Patent literature

Patent document 1: japanese patent laid-open No. 2001-106580

Patent document 2: japanese patent laid-open publication No. 2006-027990

Patent document 3: international publication No. 2011/046143

Disclosure of Invention

Problems to be solved by the invention

However, as described above, the particle size of barium titanate is minimized for the purpose of making a thin film. If a ceramic powder having a fine particle size is used, the packing density and the surface area increase, and therefore the surface of the barium titanate cannot be sufficiently covered, the barium titanate itself exists on the surface of the ceramic green sheet, and the thin films of the ceramic green sheet are laminated in a plurality of layers in accordance with poor adhesion between the sheets and further multilayering of the laminated ceramic capacitor.

The present invention has been made to solve the above problems, and a main object thereof is to provide: a ceramic green sheet and a coating sheet having excellent interlayer adhesiveness.

Another object of the present invention is to provide: the ceramic green sheet of the present invention is coated with an arbitrary conductive paste to obtain a coating sheet having excellent adhesiveness in pressure bonding.

A complementary object of the present invention is to provide a ceramic green sheet and a coating sheet which are less likely to cause delamination when a fired body is produced by stacking the ceramic green sheet and/or the coating sheet of the present invention.

Means for solving the problems

According to the present invention, the above object is achieved by providing:

[1] a ceramic green sheet, wherein, when a secondary ion analysis is performed on at least one side of the ceramic green sheet by a time-of-flight secondary ion mass spectrometer, the ratio of the intensity of detected Ba + ions to the intensity of detected Ti + ions, i.e., (the intensity of Ba + ions)/(the intensity of Ti + ions) satisfies 20< (the intensity of Ba + ions)/(the intensity of Ti + ions) <1000;

[2] the ceramic green sheet according to [1], which comprises at least: a binder resin (A) having a hydroxyl group in the molecule and an organic compound (B) represented by the chemical formula (1):

(wherein R1 and R4 each independently represents an organic group having at least one ether bond, R2 represents an optionally branched alkylene group having 1 to 20 carbon atoms, R3 represents an optionally branched alkylene group having 1 to 4 carbon atoms, and m represents an integer of 0 to 5.);

[3] the ceramic green sheet according to [2], wherein the acid value of the organic compound (B) is 5mgKOH/g or less;

[4] the ceramic green sheet according to [2] or [3], wherein R1 and/or R4 are each independently an organic group having at least one ether bond represented by the chemical formula (2):

(wherein R5 represents an optionally branched alkyl group having 1 to 10 carbon atoms; R6 represents an optionally branched alkylene group having 1 to 10 carbon atoms; R7 represents an alkylene group having 1 to 4 carbon atoms; and n represents an integer of 0 to 2);

[5] the ceramic green sheet according to any one of [2] to [4], wherein the organic compound (B) is contained in an amount of 1 to 60 parts by mass per 100 parts by mass of the binder resin (A);

[6] the ceramic green sheet according to any one of [2] to [5], wherein the binder resin (A) contains at least 1 selected from the group consisting of polyvinyl acetal and a (meth) acrylic resin;

[7] the ceramic green sheet according to [6], wherein the binder resin (A) comprises a polyvinyl acetal having an acetalization degree of 50 to 85 mol%, a content of a vinyl ester monomer unit of 0.1 to 20 mol%, and a viscosity average polymerization degree of 200 to 5000;

[8] the ceramic green sheet according to any one of [2] to [7], which comprises barium titanate, and contains 3 to 20 parts by mass of a binder resin (A) per 100 parts by mass of barium titanate;

[9] a coated sheet having a layer obtained by drying a conductive paste disposed on at least one surface of a ceramic green sheet according to any one of [1] to [8 ];

[10] the coated sheet according to [9], wherein at least a part of the ceramic green sheet is subjected to plasma treatment;

[11] the coated sheet according to [9] or [10], wherein at least a part of a surface of the coated sheet is subjected to plasma treatment.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a ceramic green sheet having excellent adhesiveness when pressure bonded can be provided.

In addition, when the ceramic green sheet and/or the coating sheet of the present invention are laminated to produce a fired body, a ceramic green sheet and a coating sheet in which delamination is less likely to occur can be provided.

Detailed Description

The ceramic green sheet of the present invention relates to a ceramic green sheet in which, when secondary ion analysis is performed on an adhesive surface of the ceramic green sheet by a time-of-flight secondary ion mass spectrometer, a ratio of an intensity of detected Ba + ions to an intensity of Ti + ions as cations satisfies 20< (intensity of Ba + ions)/(intensity of Ti + ions) <1000.

[ Binder resin (A) having hydroxyl groups in the molecule ]

Examples of the binder resin (a) having a hydroxyl group in the molecule (hereinafter, may be simply referred to as "binder resin (a)") include polyvinyl acetal, polyvinyl alcohol, a (meth) acrylic resin having a hydroxyl group, polyacrylic acid, and polyalkylene oxide. Among them, polyvinyl acetal or a (meth) acrylic resin having a hydroxyl group is preferable, and polyvinyl acetal is more preferable, from the viewpoints of dispersibility of an inorganic compound, and flexibility and adhesiveness of the ceramic green sheet and the coated sheet.

(polyvinyl Acetal)

When the binder resin (a) contains polyvinyl acetal, the content of polyvinyl acetal in the binder resin (a) is preferably 5% by mass or more, more preferably 30% by mass or more, further preferably 50% by mass or more, particularly preferably 70% by mass or more, and most preferably 100% by mass.

The acetalization degree of the polyvinyl acetal is preferably 50 mol% or more, more preferably 55 mol% or more, further preferably 60 mol% or more, and particularly preferably 65 mol% or more. The acetalization degree of the polyvinyl acetal is preferably 85 mol% or less, more preferably 82 mol% or less, still more preferably 78 mol% or less, and particularly preferably 75 mol% or less. The acetalization degree represents a ratio of acetalized vinyl alcohol monomer units to all monomer units constituting the polyvinyl acetal. When the acetalization degree exceeds 85 mol%, the efficiency of the acetalization reaction tends to be low.

The vinyl acetal has a vinyl ester monomer unit content of preferably 0.1 mol% or more, more preferably 0.3 mol% or more, still more preferably 0.5 mol% or more, and particularly preferably 0.7 mol% or more. The content of the vinyl ester monomer unit of the polyvinyl acetal is preferably 20 mol% or less, more preferably 18 mol% or less, further preferably 15 mol% or less, and particularly preferably 13 mol% or less. When the content of the vinyl ester monomer unit is less than 0.1 mol%, when polyvinyl alcohol is dissolved in a solvent for acetalization, undissolved polyvinyl alcohol may be formed, and the quality of the obtained polyvinyl acetal tends to be lowered.

The content of the vinyl alcohol monomer unit of the polyvinyl acetal is preferably 15 mol% or more, and more preferably 25 mol% or more. The content of the vinyl alcohol monomer unit of the polyvinyl acetal is preferably 50 mol% or less, more preferably 40 mol% or less, and still more preferably 35 mol% or less.

The content of other monomer units (monomer units other than the acetalized monomer unit, vinyl ester monomer unit, and vinyl alcohol monomer unit) in the polyvinyl acetal is preferably 20 mol% or less, and more preferably 10 mol% or less.

The viscosity average degree of polymerization of the polyvinyl acetal is preferably 200 or more and 5000 or less. More preferable ranges are as described below. The viscosity average degree of polymerization of the polyvinyl acetal contained in the binder resin (a) is determined in accordance with JIS K6726: 1994, the viscosity average degree of polymerization of polyvinyl alcohol (hereinafter, abbreviated as "PVA" in some cases) as a starting material. That is, PVA is saponified again to a degree of saponification of 99.5 mol% or more, purified, and then the intrinsic viscosity [ η ] (l/g) is measured in water at 30 ℃ and can be obtained from the intrinsic viscosity [ η ] (l/g) obtained by the measurement by the following formula (I):

P＝([η]×10000/8.29) ^(1/0.62) (I)

the viscosity average degree of polymerization of PVA is substantially the same as that of polyvinyl acetal obtained by acetalization thereof.

(method for producing polyvinyl Acetal)

The polyvinyl acetal is usually produced by acetalizing PVA.

The saponification degree of the PVA as a raw material is preferably 80 mol% or more, more preferably 82 mol% or more, further preferably 85 mol% or more, and most preferably 87 mol% or more. The saponification degree of the PVA as a raw material is preferably 99.9 mol% or less, more preferably 99.7 mol% or less, still more preferably 99.5 mol% or less, and most preferably 99.3 mol% or less.

When the saponification degree of the raw material PVA exceeds 99.9 mol%, the PVA may not be stably produced. Note that the saponification degree of PVA is in accordance with JIS K6726: 1994.

The PVA material can be obtained by a conventionally known method of polymerizing a vinyl ester monomer and saponifying the obtained polymer. As the method for polymerizing the vinyl ester monomer, conventionally known methods such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization and the like can be used. The polymerization initiator may be appropriately selected from azo initiators, peroxide initiators, redox initiators, and the like, depending on the polymerization method. The saponification reaction may be carried out by conventionally known alcoholysis or hydrolysis using an alkali catalyst or an acid catalyst, and among them, the saponification reaction using methanol as a solvent and caustic soda (NaOH) as a catalyst is simple and most preferable.

Examples of the vinyl ester monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and vinyl benzoate, and vinyl acetate is particularly preferable.

In addition, when the vinyl ester monomer is polymerized, it may be copolymerized with another monomer within a range not to impair the gist of the present invention. Therefore, the polyvinyl alcohol in the present invention is a concept that also includes a polymer composed of a vinyl alcohol unit and other monomer units. Examples of the other monomer include α -olefins such as ethylene, propylene, n-butene, and isobutylene; acrylic acid and salts thereof; acrylic esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate; methacrylic acid and salts thereof; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate and octadecyl methacrylate; acrylamide derivatives such as acrylamide, N-methylacrylamide, N-ethylacrylamide, N-dimethylacrylamide, diacetoneacrylamide, acrylamidopropanesulfonic acid and salts thereof, acrylamidopropyldimethylamine and acid salts or quaternary salts thereof, and N-methylolacrylamide and derivatives thereof; methacrylamide derivatives such as methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, methacrylamidopropanesulfonic acid and salts thereof, methacrylamidopropyldimethylamine and acid salts or quaternary salts thereof, N-methylolmethacrylamide and derivatives thereof; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, dodecyl vinyl ether and stearyl vinyl ether; nitriles such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride and vinyl fluoride; vinylidene halides such as vinylidene chloride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid and its salts, esters or anhydrides; vinyl silyl compounds such as vinyltrimethoxysilane; isopropenyl acetate, and the like. These monomers are usually used in a ratio of less than 10 mol% relative to the vinyl ester monomers.

When the other monomer unit is an α -olefin unit, the lower limit of the content is preferably 1 mol% and the upper limit is preferably 20 mol%. If the content of the α -olefin unit is less than 1 mol%, the effect of containing the α -olefin is insufficient, and if it exceeds 20 mol%, the hydrophobicity of the obtained polyvinyl acetal becomes too strong, and the dispersibility of the ceramic powder is lowered, or the solubility of the polyvinyl alcohol resin as a raw material is lowered, so that it is difficult to perform acetalization and counter-strain.

In the present invention, the acid catalyst used in the acetalization reaction is not particularly limited, and any of organic acids and inorganic acids may be used. Examples thereof include acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid. Among them, hydrochloric acid, sulfuric acid, and nitric acid are preferably used. In addition, in general, when nitric acid is used, the reaction rate of the acetalization reaction becomes high, and productivity is expected to be improved, but on the other hand, particles of the obtained polyvinyl acetal tend to be easily coarsened and the fluctuation among batches becomes large, and therefore hydrochloric acid is particularly preferable as an acid catalyst used in the acetalization reaction.

The aldehyde used in the acetalization reaction is not particularly limited, and known aldehydes having a hydrocarbon group may be used. Among the aldehydes having a hydrocarbon group, examples of the aliphatic aldehyde include formaldehyde (including paraformaldehyde), acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, caproaldehyde, 2-ethylbutyraldehyde, pivalinaldehyde, caprylic aldehyde, 2-ethylcaproaldehyde, nonanal, decanal, dodecanal, and the like, examples of the alicyclic aldehyde include cyclopentylaldehyde, methylcyclovaleraldehyde, dimethylcyclopentylaldehyde, cyclohexanal, methylcyclohexylaldehyde, dimethylcyclohexanal, cyclohexaneacetaldehyde, and the like, examples of the cyclic unsaturated aldehyde include cyclopentenal, cyclohexenal, and the like, examples of the aromatic aldehyde or the aldehyde having an unsaturated bond include benzaldehyde, methylbenzaldehyde, dimethylbenzaldehyde, methoxybenzaldehyde, phenylacetaldehyde, phenylpropionaldehyde, cuminaldehyde (cuminaldehyde), naphthaldehyde, anthracenal, cinnamaldehyde, crotonaldehyde, acrolein, 7-octene-1-aldehyde, and the like, and examples of the heterocyclic aldehyde, methylfurfural, and the like. Among these aldehydes, aldehydes having 1 to 8 carbon atoms are preferable, aldehydes having 4 to 6 carbon atoms are more preferable, and n-butyraldehyde is particularly preferably used. In the present invention, polyvinyl acetals obtained by using 2 or more kinds of aldehydes in combination can also be used.

The aldehyde used in the acetalization reaction may be any aldehyde other than hydrocarbon-based ones. For example, aldehydes having functional groups selected from amino groups, ester groups, carbonyl groups, and vinyl groups may also be used.

Examples of the aldehyde having an amino group as a functional group include aminoacetaldehyde, dimethylaminoacetaldehyde, diethylaminoacetaldehyde, aminopropionaldehyde, dimethylaminopropionaldehyde, aminobutyraldehyde, aminopentanal, aminobenzaldehyde, dimethylaminobenzaldehyde, ethylmethylaminobenzaldehyde, diethylaminobenzaldehyde, pyrrolylacetaldehyde, piperidinylacetaldehyde, pyridylacetaldehyde and the like, and aminobutyraldehyde is preferable from the viewpoint of productivity.

Examples of the aldehyde having an ester group as a functional group include methyl glyoxylate, ethyl glyoxylate, methyl formylacetate, ethyl formylacetate, methyl 3-formylpropionate, ethyl 3-formylpropionate, methyl 5-formylvalerate, ethyl 5-formylvalerate and the like.

As the aldehyde having a carbonyl group as a functional group, glyoxylic acid and a metal salt or ammonium salt thereof, 2-formylacetic acid and a metal salt or ammonium salt thereof, 3-formylpropionic acid and a metal salt or ammonium salt thereof, 5-formylvaleric acid and a metal salt or ammonium salt thereof, 4-formylphenoxyacetic acid and a metal salt or ammonium salt thereof, 2-carboxybenzaldehyde and a metal salt or ammonium salt thereof, 4-carboxybenzaldehyde and a metal salt or ammonium salt thereof, 2,4-dicarboxybenzaldehyde and a metal salt or ammonium salt thereof, and the like can be mentioned.

As the aldehyde having a vinyl group as a functional group, acrolein and the like can be mentioned.

In addition, a heterocyclic aldehyde, an aldehyde having an amide group, an aldehyde having a hydroxyl group, an aldehyde having a sulfonic acid group, an aldehyde having a phosphoric acid group, an aldehyde having a cyano group, a nitro group, a quaternary ammonium salt or the like, an aldehyde having a halogen atom or the like may be used as long as the characteristics of the present invention are not impaired.

(meth) acrylic resin having hydroxyl group)

When a (meth) acrylic resin having a hydroxyl group is used as the binder resin (a), for example, the following resins can be used: a copolymer of a (meth) acrylic monomer having a hydroxyl group and a (meth) acrylic monomer having no hydroxyl group is used as the (meth) acrylic resin having a hydroxyl group. Examples of the (meth) acrylic monomer having a hydroxyl group include acrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2,3-dihydroxypropyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene glycol-polytetramethylene glycol monoacrylate, and polypropylene glycol-polytetramethylene glycol monoacrylate; methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 2,3-dihydroxypropyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polyethylene glycol-polytetramethylene glycol monomethacrylate, and polypropylene glycol-polytetramethylene glycol monomethacrylate. Among them, methacrylates having a hydroxyl group are preferable in view of sinterability, and specifically, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, polyethylene glycol monomethacrylate, and polypropylene glycol monomethacrylate are preferable.

Examples of the (meth) acrylic monomer having no hydroxyl group include acrylic esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, isodecyl acrylate, isobornyl acrylate, and tetrahydrofurfuryl acrylate; methacrylic acid esters such as ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, isodecyl methacrylate, isobornyl methacrylate, and tetrahydrofuryl methacrylate. Among them, methacrylic acid esters are preferable from the viewpoint of sinterability, and specifically, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl methacrylate are preferable.

The content of the segment derived from a (meth) acrylic monomer having a hydroxyl group in the (meth) acrylic resin is preferably 30% by mass or less, and more preferably 20% by mass or less. If the content of the segment derived from the (meth) acrylic monomer having a hydroxyl group exceeds 30 mass%, residual carbon after firing may increase. The content of the segment derived from the (meth) acrylic monomer having a hydroxyl group is preferably 1% by mass or more. If the content of the segment derived from the (meth) acrylic monomer having a hydroxyl group is less than 1% by mass, when the segment is used as the binder resin (a) together with a polyvinyl acetal resin, the compatibility with the polyvinyl acetal resin may be deteriorated.

(other Binder resin (A))

The binder resin (a) may be used alone in 1 kind, or may be used in combination of 2 or more kinds. When 2 or more species are used in combination, a mixture of polyvinyl acetal and another binder resin (a) or the like can be used. When the polyvinyl acetal is mixed with the other binder resin (a), for example, the mass ratio of the polyvinyl acetal to the other binder resin (a) is preferably 5/95 or more, more preferably 10/90 or more. The mass ratio of the polyvinyl acetal to the other binder resin (a) is preferably 95/5 or less, and more preferably 90/10 or less. As the other binder resin (a), a (meth) acrylic resin having a hydroxyl group is preferable.

The ceramic green sheet of the present invention may contain a binder resin having no hydroxyl group in the molecule in addition to the binder resin (a) within a range not to impair the effects of the present invention. When a binder resin having no hydroxyl group in the molecule is used, the ratio thereof is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, per 100 parts by mass of the binder resin (a). The ratio of the binder resin having no hydroxyl group in the molecule is preferably 80 parts by mass or less, and more preferably 50 parts by mass or less, per 100 parts by mass of the binder resin (a).

[ organic Compound (B) ]

The ceramic green sheet of the present invention contains an organic compound (B) represented by chemical formula (1):

r2 in the chemical formula (1) represents an optionally branched alkylene group having 1 to 20 carbon atoms. The number of carbon atoms of R2 is preferably 15 or less, more preferably 10 or less, and further preferably 8 or less. The number of carbon atoms in R2 is preferably 2 or more, more preferably 3 or more, and further preferably 4 or more. If the number of carbon atoms of R2 is outside the above range, the compatibility between the organic compound (B) and the binder resin (a) is deteriorated, and the storage stability of the ceramic slurry and the adhesiveness of the ceramic green sheet tend to be lowered. R3 represents an optionally branched alkylene group having 1 to 4 carbon atoms. The number of carbon atoms in R3 is preferably 3 or less, more preferably 2 or less. R2 and R3 may have a linear structure or may have a branched structure, and R2 and R3 are preferably each independently a linear structure.

m is an integer of 0 to 5. m is preferably 2 or less, more preferably 1 or less, and still more preferably 0. When m is larger than the above range, the boiling point of the organic compound (B) becomes high, which may cause delamination at the time of firing.

R1 and R4 are each independently an organic group having at least one ether linkage. R1 and R4 may each independently have a plurality of ether bonds. R1 and R4 are preferably each independently a hydrocarbon group having at least one ether bond. R1 and R4 may be different or the same. R1 and R4 are respectively chemical formula (2):

the organic group having at least one ether bond is preferable from the viewpoint of compatibility with the binder resin (a).

R5 represents an optionally branched alkyl group having 1 to 10 carbon atoms. The number of carbon atoms in R5 is preferably 8 or less, more preferably 6 or less, and still more preferably 4 or less. If the number of carbon atoms of R5 exceeds the above range, the compatibility between the organic compound (B) and the binder resin (a) is deteriorated, and the adhesiveness tends to be lowered. R6 represents an optionally branched alkylene group having 1 to 10 carbon atoms. The number of carbon atoms of R6 is preferably 8 or less, more preferably 6 or less, and further preferably 4 or less. If the number of carbon atoms of R6 exceeds the above range, the compatibility between the organic compound (B) and the binder resin (a) is deteriorated, and the adhesiveness of the ceramic green sheet tends to be lowered. R7 represents an optionally branched alkylene group having 1 to 4 carbon atoms. The number of carbon atoms of R7 is preferably 3 or less, more preferably 2 or less. R6 and R7 may each independently have a straight chain structure or may have a branched chain structure. R6 and R7 are preferably linear structures. The plural R7 s may be the same or different.

n is an integer of 0 to 2. n is preferably 0 or 1, more preferably 0. If n exceeds the above range, the boiling point of the organic compound (B) becomes high, which may cause delamination during firing.

The acid value of the organic compound (B) is preferably 5mgKOH/g or less, more preferably 3mgKOH/g or less, still more preferably 1mgKOH/g or less, and particularly preferably 0.5mgKOH/g or less. As described above, when the above range is satisfied, the composition is suitable from the viewpoint of reducing delamination due to rapid decomposition during degreasing and from the viewpoint of reducing corrosivity in the step. The acid value of the organic compound (B) increases due to the production of carboxylic acid by deesterification during storage, or the remaining unreacted carboxylic acid during production of the organic compound (B).

The molecular weight of the organic compound (B) is preferably 200 or more, more preferably 250 or more. If the molecular weight is less than the above range, the volatility is high, and the sheet volatilizes during drying, and sufficient adhesiveness may not be exhibited. The molecular weight of the organic compound (B) used in the present invention is preferably 500 or less, and more preferably 400 or less. When the molecular weight is larger than the above range, the viscosity of the organic compound (B) becomes high or the organic compound (B) is solidified, and the compatibility with the resin tends to be lowered.

The structure of the organic compound (B) is preferably one containing no hydroxyl group in the molecule. When the organic compound (B) contains a hydroxyl group, the function at the interface tends to be reduced during pressure bonding, and sufficient adhesiveness may not be obtained.

Examples of the organic compound (B) include bis (2-butoxyethyl) adipate, bis (2-methoxyethyl) adipate, bis (2-ethoxyethyl) adipate, bis [2- (2-butoxyethoxy) ethyl ] adipate, bis (3-methoxy-3-methylbutyl) adipate, bis (2-methoxyethyl) sebacate, bis (2-methoxyethyl) diglycolate, and the like. Among them, bis (2-butoxyethyl) adipate and bis (2-methoxyethyl) adipate are preferable from the viewpoint of excellent storage stability of the ceramic slurry, excellent adhesiveness of the ceramic green sheet, and maintenance of appropriate strength.

[ organic solvent (C) ]

The ceramic green sheet of the present invention can be obtained by, for example, drying a ceramic slurry containing a binder resin (a), an organic compound (B), an organic solvent (C), and an inorganic compound (D) and forming the dried ceramic slurry into a sheet shape. As the organic solvent (C), solvents suitable for the purpose and use thereof can be suitably used, and examples thereof include: alcohols such as methanol, ethanol, isopropanol, n-propanol, and butanol; cellosolves such as methyl cellosolve, butyl cellosolve, and the like; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as toluene and xylene; halogen hydrocarbons such as dichloromethane and chloroform, esters such as ethyl acetate and methyl acetate, menthene, menthane, menthone, myrcene, alpha-pinene, alpha-terpinene, gamma-terpinene, limonene, perillyl acetate, menthyl acetate, carvacrol acetate, dihydrocarvacrol acetate, perillyl alcohol, terpineol diacetate, terpineol acetate, dihydroterpineol, terpinoxyethanol, dihydroterpinoxyethanol, terpinomethyl ether, dihydroterpinomethyl ether, dihydroterpinoyl propionate, isobornyl acetate, isobornyl propionate, isobornyl butyrate, isobornyl isobutyrate, acetate (noble acetate) of dendrobium nobile, octyl acetate, dimethyloctyl acetate, butyl carbitol acetate, acetoxy-methoxyethoxy-cyclohexanol acetate, dihydrocarvacrol, 2-ethylhexanediol, benzyl glycol, phenylpropanediol, methyl decalin, pentylbenzene, isopropylbenzene, cymene, 8978-diisopropylhexane, and citronellol. Among them, alcohols such as methanol, ethanol, isopropanol, n-propanol, and butanol; cellosolves such as methyl cellosolve, butyl cellosolve, and the like; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as toluene and xylene; halogen-based hydrocarbons such as methylene chloride and chloroform, and esters such as ethyl acetate and methyl acetate. These may be used alone or in combination of 2 or more. Further, butanol, ethanol, toluene, ethyl acetate, or a mixed solvent thereof is more preferable from the viewpoint of volatility and solubility.

The content of the organic solvent (C) in the ceramic slurry is not particularly limited, and is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more, based on 100 parts by mass of the ceramic powder described later. If the content of the organic solvent (C) is less than the above range, the viscosity of the ceramic slurry tends to be too high, and the kneadability tends to be lowered. The content of the organic solvent (C) is more preferably 200 parts by mass or less, and still more preferably 150 parts by mass or less, per 100 parts by mass of the ceramic powder. If the content of the organic solvent (C) exceeds the above range, the viscosity of the ceramic slurry becomes too low, and the workability in forming the ceramic green sheet tends to be deteriorated.

[ inorganic Compound (D) ]

The ceramic green sheet of the present invention contains at least barium titanate as the inorganic compound (D), and other inorganic compounds (D) may be used. Examples of the other inorganic compound (D) include glass powder, ceramic powder, phosphor fine particles, silicon oxide, and the like, depending on the purpose and use thereof. These inorganic compounds (D) can be used in combination of 2 or more and suitable.

Examples of the glass powder include glass powders of bismuth oxide glass, silicate glass, lead glass, zinc glass, boron glass, etc., and CaO-Al ₂ O ₃ -SiO ₂ System, mgO-Al ₂ O ₃ -SiO ₂ Series, liO ₂ -Al ₂ O ₃ -SiO ₂ And various silicon oxides, and the like.

The ceramic powder may be powder of an oxide, carbide, nitride, boride, sulfide or the like of a metal or nonmetal used for producing ceramics, in addition to barium titanate. Specific examples thereof include oxides, carbides, nitrides, borides, and sulfides of Li, K, mg, B, al, si, cu, ca, sr, ba, zn, cd, ga, in, Y, lanthanides, actinides, ti, zr, hf, bi, V, nb, ta, W, mn, fe, co, and Ni.

[ ceramic Green sheet ]

The content of the binder resin (a) in the ceramic green sheet varies depending on the purpose of use of the ceramic green sheet, and is usually preferably 3 parts by mass or more, more preferably 5 parts by mass or more, based on 100 parts by mass of barium titanate. The content of the binder resin (a) is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less, based on 100 parts by mass of barium titanate. When the content of the binder resin (a) is less than 3 parts by mass with respect to 100 parts by mass of barium titanate, the obtained ceramic green sheet may have poor adhesion and insufficient strength. If the amount of the binder resin (a) used exceeds 20 parts by mass, the density of barium titanate in the ceramic green sheet decreases, which may cause a reduction in the quality of a laminated ceramic capacitor as a final product, and may cause delamination due to an increase in volatile components during firing and shrinkage of a fired body.

When polyvinyl acetal is contained as the binder resin (a) contained in the ceramic green sheet, if the vinyl alcohol monomer unit of polyvinyl acetal is less than 50 mol%, the ceramic green sheet absorbs a large amount of moisture during storage, and thus may cause delamination. On the other hand, if the acetalization degree of polyvinyl acetal exceeds 85 mol%, the content of hydroxyl groups (vinyl alcohol monomer units) in the polyvinyl acetal decreases, and the adhesiveness of the ceramic green sheet and the dimensional stability at the time of pressure bonding tend to decrease. When the acetalization degree of the polyvinyl acetal is within the above-described suitable range, the adhesiveness of the obtained ceramic green sheet at the time of pressure bonding tends to be further excellent.

When polyvinyl acetal is contained as the binder resin (a) contained in the ceramic green sheet, the content of the vinyl ester monomer unit of polyvinyl acetal is preferably in the range described above, and if the content of the vinyl ester monomer unit exceeds 20 mol%, the amount of carbon residue in the obtained ceramic molded article tends to increase. Further, the flexibility of the obtained ceramic green sheet is increased, and the strength of the ceramic green sheet tends to be lowered.

When polyvinyl acetal is contained as the binder resin (a) contained in the ceramic green sheet, the appropriate range of the viscosity average degree of polymerization of polyvinyl acetal is as described above, and if the viscosity average degree of polymerization does not satisfy 200, the strength of the resulting ceramic green sheet may be reduced. The degree of viscosity average polymerization of the polyvinyl acetal is preferably 300 or more, more preferably 500 or more, and further preferably 800 or more. On the other hand, if the degree of viscosity-average polymerization of polyvinyl acetal exceeds 5000, the viscosity of the ceramic slurry prepared in the production of the ceramic green sheet becomes too high, and the productivity may be lowered. The viscosity average polymerization degree of the polyvinyl acetal is preferably 4500 or less, more preferably 4000 or less, and further preferably 3500 or less. In addition, the degree of viscosity average polymerization of polyvinyl acetal is preferably 1400 or more, and more preferably 1500 or more, from the viewpoint of making the dimensional stability of the ceramic green sheet excellent when it is further pressure-bonded.

When polyvinyl acetal is contained as the binder resin (a) contained in the ceramic green sheet, an appropriate range of the degree of saponification of the raw material PVA is as described above, and if the degree of saponification of the raw material PVA is less than 80 mol%, the strength of the ceramic green sheet containing polyvinyl acetal may decrease.

Suitable conditions for the organic compound (B) contained in the ceramic green sheet are as described above.

The content of the organic compound (B) in the ceramic green sheet is not particularly limited, and is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more, based on 100 parts by mass of the binder resin (a). If the content of the organic compound (B) is less than the above range, the resulting ceramic green sheet may have poor adhesion. The content of the organic compound (B) is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and further preferably 40 parts by mass or less. If the content of the organic compound (B) exceeds the above range with respect to 100 parts by mass of the binder resin (a), the strength of the ceramic green sheet tends to be reduced, and the dimensional stability at the time of pressure bonding tends to be reduced.

The ceramic green sheet may further contain an organic compound other than the organic compound (B) as a plasticizer. Such a plasticizer is not particularly limited as long as it does not impair the effects of the present invention and has no problem in compatibility with the binder resin (a). As plasticizers, it is possible to use: monoesters or diesters of oligoalkylene glycols having hydroxyl groups at both ends with carboxylic acids, diesters of dicarboxylic acids with alcohols, and the like. These can be used alone or in combination of 2 or more. Specifically, there may be mentioned: monoesters or diesters of a carboxylic acid with an oligoalkylene glycol having hydroxyl groups at both terminals, such as triethylene glycol or tetraethylene glycol, such as triethylene glycol di-2-ethylhexanoate, tetraethylene glycol di-2-ethylhexanoate, triethylene glycol di-n-heptanoate, and tetraethylene glycol di-n-heptanoate; diesters of dicarboxylic acids and alcohols such as dioctyl phthalate, dibutyl phthalate, dioctyl adipate and dibutyl adipate.

When the plasticizer is added, the mass ratio of the total of the plasticizer and the organic compound (B) to the binder resin (a) (total of the mass of the plasticizer and the organic compound (B)/the mass of the binder resin (a)) in the ceramic green sheet is preferably 0.01 or more, more preferably 0.05 or more. The mass ratio is preferably 2 or less, more preferably 1.5 or less.

As the ceramic powder other than barium titanate contained in the ceramic green sheet, the ceramic powder described above is preferably used.

Suitable methods for molding the ceramic green sheet include: a so-called sheet molding method in which a ceramic green sheet is obtained by coating a ceramic slurry on a carrier film using a blade coater or the like, drying the ceramic slurry, and then releasing the ceramic slurry from the carrier film.

The ceramic green sheet may contain, in addition to the binder resin (a), the organic compound (B) and the ceramic powder, as necessary, unless departing from the gist of the present invention: deflocculating agent, adhesion promoter, dispersant, thickener, storage stabilizer, defoaming agent, thermal decomposition promoter, antioxidant, surfactant, lubricant, adhesiveness improver, and other conventionally known additives. In addition, a resin other than the binder resin (a) may be contained as long as the effect of the present invention is not inhibited.

A suitable embodiment of the present invention is a ceramic green sheet, wherein, when secondary ion analysis is performed on at least one surface of the ceramic green sheet by a time-of-flight secondary ion mass spectrometer, a ratio of an intensity of detected Ba + ions to an intensity of detected Ti + ions, that is, (intensity of Ba + ions)/(intensity of Ti + ions), satisfies 20< (intensity of Ba + ions)/(intensity of Ti + ions) <1000. By using the ceramic green sheet of the present invention, a ceramic green sheet having excellent adhesiveness at the time of pressure bonding and little dimensional change at the time of pressure bonding can be obtained. When the ratio (the strength of Ba + ions)/(the strength of Ti + ions) is in the above range, rapid burning-out of the binder component from the laminate can be suppressed when the ceramic green sheet is fired, and delamination in the production of a laminated ceramic capacitor can be suppressed.

The (strength of Ba + ion)/(strength of Ti + ion) is preferably more than 100, more preferably more than 150. In addition, the (strength of Ba + ion)/(strength of Ti + ion) is preferably less than 700, more preferably less than 500.

The ceramic green sheet was subjected to TOF-SIMS analysis so that Ba + ions and Ti + ions measured as secondary ions were Ba atoms and Ti atoms derived from barium titanate used as a ceramic powder. In the case of performing TOF-SIMS analysis, the method for obtaining a ceramic green sheet in which (the strength of Ba + ions)/(the strength of Ti + ions) falls within the above range is not particularly limited, and examples thereof include the following methods: a ceramic green sheet was produced from a ceramic slurry containing an organic compound (B) represented by chemical formula (1) and using barium titanate as a ceramic powder, and subjected to plasma treatment.

However, if the contents of the organic compound (B) and an organic compound (plasticizer) other than the organic compound (B) in the ceramic green sheet are reduced, the ceramic green sheet becomes hard, and dimensional stability at the time of pressure bonding is improved, while adhesiveness at the time of pressure bonding tends to be lowered. Therefore, it is generally difficult to achieve both dimensional stability and adhesiveness. In the present invention, by setting the ratio of (Ba + ion strength)/(Ti + ion strength) to the above range, it is possible to obtain a ceramic green sheet which is excellent not only in dimensional stability at the time of pressure bonding but also in adhesiveness at the time of pressure bonding even when the contents of the organic compound (B) and an organic compound (plasticizer) other than the organic compound (B) are reduced.

The ceramic green sheet of the present invention is suitably used as a material for various electronic components. Particularly, it is suitably used as a material for a chip-type multilayer capacitor, a circuit board of an IC chip, or the like. These are produced by forming electrodes on ceramic green sheets, stacking the ceramic green sheets, pressing the stacked ceramic green sheets, and then firing the pressed ceramic green sheets.

As a method for producing the ceramic green sheet, for example, a method of applying a ceramic slurry to a supporting film subjected to a single-side release treatment, drying the organic solvent (C), and molding the dried organic solvent into a sheet can be cited. The ceramic slurry may be applied using a roll coater, a knife coater, a die coater, an extrusion coater, a curtain coater, or the like.

As the support film used in the production of the ceramic green sheet, a film made of a flexible resin having heat resistance and solvent resistance is preferable. The support film is made of a flexible resin, and the ceramic slurry is applied to the support film, and the film on which the obtained ceramic green sheet is formed is stored in a rolled state and can be supplied as needed.

The resin constituting the support film is not particularly limited, and examples thereof include fluorine-containing resins such as polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, polyvinyl fluoride, nylon, cellulose, and the like. The thickness of the support film is not particularly limited, but is preferably 20 μm or more, and preferably 100 μm or less. Further, the surface of the support film is preferably subjected to a mold release treatment. By performing the release treatment on the surface of the support film, the peeling operation of the support film can be easily performed in the transfer step. A preferable specific example of the support film is a silicone-coated PET film.

The thickness of the ceramic green sheet varies depending on the purpose of use, and therefore, is not limited to a specific one, but is preferably 0.1 μm or more, and preferably 300 μm or less. The drying temperature at the time of drying the coating film formed on the carrier film differs depending on the thickness of the ceramic green sheet, and the like, and therefore, it is not limited thereto, and is preferably 25 ℃ or higher, and preferably 200 ℃ or lower.

[ coated sheet ]

A preferred embodiment of the present invention is a coated sheet obtained by coating the surface of the ceramic green sheet of the present invention with a conductive paste. When used in combination with the ceramic green sheet of the present invention, the conductive paste may be a commonly used conductive paste.

The method of applying the conductive paste is not particularly limited, and examples thereof include screen printing, die printing, offset printing, gravure printing, and inkjet printing. By applying the conductive paste to the surface of the ceramic green sheet, a coated sheet having a conductive paste coating film on at least a part of the surface of the ceramic green sheet can be obtained.

[ TOF-SIMS analysis ]

TOF-SIMS analysis is a measurement method in which the surface of an object to be measured is scanned, and the distribution state of a component contained in the object to be measured can be observed. For example, the identification of the species of the component and the intensity of the secondary ion in each minute region can be measured by dividing a 50 to 500 μm square region on the surface of the object to be measured into 0.1 to 3 μm square minute regions, irradiating the minute regions with primary ions, and observing the secondary ions that fly out of the minute regions. This minute region is referred to as a primary ion irradiation spot. This minute region is referred to as a primary ion irradiation spot. The ratio of the intensity of Ba + ions to the intensity of Ti + ions, i.e., (the intensity of Ba + ions)/(the intensity of Ti + ions), is a value obtained by dividing the intensity of Ba + ions by the intensity of Ti + secondary ions.

In the case where the surface of the ceramic green sheet is subjected to plasma treatment, the surface state of the ceramic green sheet may change depending on the storage state after plasma irradiation, and therefore, it is preferable to perform surface measurement by TOF-SIMS analysis quickly after plasma irradiation. The time from the plasma irradiation to the surface measurement by TOF-SIMS analysis is preferably within 12 hours, more preferably within 3 hours, still more preferably within 1 hour, and most preferably the surface measurement is performed immediately after the plasma irradiation. When the sheet after the conductive paste coating was analyzed, a surface analysis was performed on a portion of the ceramic green sheet not coated with the conductive paste among the surfaces coated with the conductive paste.

In the measurement by TOF-SIMS analysis, in order to suppress volatilization of components on the surface of the ceramic green sheet, it is preferable to cool the ceramic green sheet to, for example, -100 ℃ to-200 ℃ and perform TOF-SIMS analysis under vacuum.

[ plasma treatment ]

The ceramic green sheet of the present invention is preferably in a state in which at least a part of at least one surface of the ceramic green sheet is subjected to plasma treatment. That is, the production thereof preferably includes the steps of: plasma treatment is performed on at least one of the front surface and the back surface of the ceramic green sheet. The ceramic green sheet thus obtained is also a suitable embodiment of the present invention. At least one of the front surface and the back surface of the ceramic green sheet is subjected to plasma treatment, and the plasma-treated surface is laminated so as to be in contact with the surface of another ceramic green sheet. The laminate thus obtained had better adhesiveness than the laminate produced using a ceramic green sheet whose surface was not subjected to plasma treatment.

The coating sheet of the present invention is preferably a coating sheet in which at least a part of at least one surface of the coating sheet is subjected to plasma treatment. That is, the production thereof preferably includes the steps of: plasma treatment is performed on at least one surface of the coated sheet. The coating sheet may be obtained by subjecting at least a part of at least one surface of the coating sheet to plasma treatment, and may be obtained by: a method of performing plasma treatment on the ceramic green sheet before the conductive paste is applied; the method of applying the plasma treatment to the coated sheet after the conductive paste is coated on the ceramic green sheet may be any method.

The surface coated with the conductive paste is subjected to plasma treatment on the coated sheet, and the plasma-treated surface is laminated so as to be in contact with one surface of another coated sheet. The laminate thus obtained exhibits good adhesion as compared with the case of producing a laminate using a coated sheet whose surface is not subjected to plasma treatment.

The surface to be subjected to the plasma treatment may be a surface coated with a conductive paste (conductive paste surface), a back surface of a coated sheet (ceramic green sheet surface), or a front and back surface of the coated sheet. When a multilayer ceramic capacitor is manufactured by laminating a plurality of coated sheets, the surface of the conductive paste may be subjected to plasma treatment and laminated so that the surface comes into contact with the surface of a ceramic green sheet of another coated sheet. The laminate thus obtained exhibits good adhesion.

Further, the ceramic green sheet surface may be subjected to plasma treatment and laminated so that the surface is in surface contact with the conductive paste in another coated sheet. The laminate thus obtained also exhibited good adhesion. As the coating sheet in this case, a coating sheet in which a generally used conductive paste is coated on the surface of the ceramic green sheet of the present invention is suitably used. Further, the surface or the back surface of the coated sheet is subjected to plasma treatment, and the plasma-treated surface is laminated so as to be in surface contact with the ceramic green sheet surface or the conductive paste surface in another coated sheet. The laminate thus obtained also exhibited good adhesion.

Further, the ceramic green sheet may be subjected to plasma treatment, and the plasma-treated surface may be coated with a conductive paste. The surface coated with the conductive paste is laminated so as to be in contact with one surface of another coated sheet after the plasma treatment. The laminate thus obtained exhibits good adhesion as compared with the case of producing a laminate using a coated sheet whose surface is not subjected to plasma treatment. As the coating sheet in this case, a coating sheet in which a generally used conductive paste is coated on the surface of the ceramic green sheet of the present invention is suitably used.

When the adhesiveness of a laminate obtained by laminating a ceramic green sheet with a plasma-treated surface coated with a conductive paste so that the surface of the ceramic green sheet is in contact with one surface of a ceramic green sheet which is not subjected to the plasma treatment and a laminate obtained by laminating a ceramic green sheet with a surface coated with a conductive paste so that the surface of the ceramic green sheet which is not subjected to the plasma treatment is in contact with a plasma-treated surface of a ceramic green sheet, the adhesiveness of the laminate is higher than that of the laminate. Similarly, when the adhesiveness of a laminate obtained by laminating a ceramic green sheet with a coating surface when a conductive paste is applied to one surface of the ceramic green sheet and then a plasma-treated surface with a surface not subjected to plasma treatment in contact with one surface of the ceramic green sheet not subjected to plasma treatment and a laminate obtained by laminating a ceramic green sheet with a surface not subjected to plasma treatment and coated with a conductive paste in contact with a plasma-treated surface of the ceramic green sheet, the adhesiveness of the ceramic green sheet with a large surface area is compared with that of the laminate.

The method of plasma treatment used in the present invention is not particularly limited, and examples thereof include low-pressure plasma, high-pressure plasma, corona discharge treatment, atmospheric pressure plasma, and the like. The treatment method may be appropriately performed as long as the properties of the present invention are not impaired, and the low-pressure plasma must be performed in a vacuum state, which makes it difficult to perform on-line production. Since the corona treatment is high energy, the surface shape may be changed and the treated surface may be unexpectedly uniform. On the other hand, the atmospheric pressure plasma treatment does not need to be performed in a vacuum state, and the energy can be selected. From the viewpoint of productivity and performance, atmospheric pressure plasma is particularly preferable as the treatment method.

Various atmospheric pressure plasma apparatuses can be used for the atmospheric pressure plasma treatment. As the atmospheric pressure plasma device, any device may be used, and various modifications may be selected depending on the purpose of use and the like. For example, a device or the like capable of generating low-temperature plasma by applying an inert gas at a pressure near atmospheric pressure between electrodes covered with a dielectric and performing intermittent discharge is preferable. The "pressure in the vicinity of atmospheric pressure" in the "atmospheric pressure plasma" in the present invention means a range of 70kPa to 130kPa inclusive, preferably 90kPa to 110kPa inclusive. The temperature and humidity at the time of performing the atmospheric pressure plasma treatment are not particularly limited and may be appropriately changed, and the atmospheric pressure plasma treatment is preferably performed at normal temperature and normal humidity.

As the discharge gas used for the atmospheric pressure plasma generation, any of nitrogen, oxygen, hydrogen, carbon dioxide, helium, and argon, or a mixed gas of 2 or more kinds thereof can be used. As the inert gas, a rare gas such as He or Ar or nitrogen is preferably used, and particularly a rare gas such as Ar or He is preferably used. For example, when a mixed gas of nitrogen and air is used, nitrogen is preferably supplied at a flow rate of 10L/min to 500L/min. Further, it is preferable to supply dry air at a flow rate of 0.1L/min to 3L/min.

In order to generate plasma using an atmospheric pressure plasma device, the voltage applied between the electrodes is preferably 5kv or more and preferably 15kv or less. The distance between the electrodes is preferably 1mm or more, more preferably 2mm or more. The distance between the electrodes is preferably 10mm or less, more preferably 5mm or less.

For example, the surface of the ceramic green sheet to be subjected to plasma processing is kept in a state perpendicular to the plasma irradiation direction, and the ceramic green sheet is moved in a direction perpendicular to the plasma irradiation direction, whereby the ceramic green sheet can be subjected to plasma processing. The time immediately below the irradiation port for which the ceramic green sheet passes is preferably 0.1 second or more, and more preferably 0.5 second or more. Further, it is preferably 40 seconds or less, and more preferably 20 seconds or less. The periphery immediately below the irradiation port may be a plasma atmosphere.

If the voltage applied between the electrodes, the distance between the electrodes, or the moving speed of the ceramic green sheet is out of the above range, the value of (the strength of Ba + ions)/(the strength of Ti + ions) tends to be lower than 20 or higher than 1000.

Examples

The present invention will be described in further detail below with reference to examples and comparative examples. In the following examples and comparative examples, "degree of polymerization" means "viscosity-average degree of polymerization". In the following examples and comparative examples, the term "ceramic green sheet" means a portion not including a polyester film as a support film.

[ evaluation method ]

(1. Measurement of polyvinyl Acetal)

The content (mol%) of vinyl acetate monomer units, the acetalization degree (mol%) and the content (mol%) of vinyl alcohol monomer units of polyvinyl acetals used in examples and comparative examples were adjusted in accordance with JIS K6728: 1977. The viscosity-average degree of polymerization of polyvinyl acetal was determined in accordance with JIS K6726: 1994, the viscosity-average degree of polymerization of PVA as a starting material.

(2. Measurement of acid value of organic Compound)

Acid values of the organic compounds used in examples and comparative examples were determined in accordance with JIS K6728: 1977. More specifically, about 1g of each organic compound was put into a Erlenmeyer flask with a stopper, and 30ml of ethanol was added and dissolved. The resulting solution was titrated with N/50 potassium hydroxide using phenolphthalein as an indicator, and the titration amount up to the point of maintaining reddish color for 30 seconds or more was defined as a (mL). Separately, the same titration was performed with respect to 30mL of ethanol, and the amount of the titration to the point of maintaining reddish color was taken as b (mL), and the acid value was calculated from the following formula (II).

Acid value =1.122 × (a-b) × F (factor for N/5O potassium hydroxide)/s (II)

F: factor of N/50 potassium hydroxide

s: mass (g) of each organic compound

(3. TOF-SIMS analysis of surface of ceramic Green sheet)

In the measurement, cooling measurement was performed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) in order to suppress volatilization of components on the surface of the ceramic green sheet. The surface of the ceramic green sheet obtained in the production example was subjected to atmospheric pressure plasma treatment, and then the ceramic green sheet was cooled to-150 ℃. Time-of-flight secondary ION mass spectrometry (TOF-SIMS) TOF-SIMS5 manufactured by ION-TOF was used. The primary ion source used was a bismuth cluster ion source (Bi 3+ +), with a current value of 0.2 pa and an acceleration voltage of 25 kv, and the measurement mode was a high-mass-resolution normal mode (bunching mode). An arbitrary 500 × 500 μm of the plane of the ceramic green sheet (an arbitrary one of the surfaces having the widest area of the ceramic green sheet) was set as a measurement region, the measurement region was divided into 128 × 128 pixels, the irradiation mode of the ion beam was set to a random raster mode, the measurement region was scanned, and the number of scans was set to 64 scans. The intensity of Ti + ions and the intensity of Ba + ions were calculated from the mass spectra obtained by the measurement, and the ratio of the intensity of Ba + ions to the intensity of Ti + ions was calculated. The results are shown in Table 2-1, table 2-2 and Table 3. Since the surface state of the sheet after plasma irradiation may change depending on the storage state, the measurement of the surface analysis after plasma irradiation is performed quickly after plasma irradiation.

(4-1. Evaluation of adhesiveness of ceramic Green sheet)

The ceramic green sheets used in examples and comparative examples, which were subjected to atmospheric plasma treatment under the following conditions, and the ceramic green sheets used in examples and comparative examples, which were not subjected to atmospheric plasma treatment, were stacked, and a thermocompression bonding test was performed under the following conditions by using a thermocompressor. At this time, the surface subjected to the atmospheric pressure plasma treatment was laminated so as to be in contact with the surface of the other ceramic green sheet which was not subjected to the atmospheric pressure plasma treatment, to obtain a laminate.

< plasma irradiation >

The ceramic green sheets (on the polyester film) used in examples and comparative examples were cut into a size of 10cm × 10cm together with the polyester film. After the ceramic green sheet was peeled off from the polyester film, an atmospheric pressure plasma treatment was performed on the surface of the ceramic green sheet under conditions that the voltage between electrodes was 11kV, the distance between electrodes was 2mm, the moving speed of the sample (ceramic green sheet) was 10 mm/sec, and the time right under the passage of the ceramic green sheet through an irradiation port having a width of 2cm was 2 seconds (10 seconds with respect to the entire ceramic green sheet having a width of 10cm × 10 cm) using a mixed gas of nitrogen gas having a flow rate of 150L/min and dry clean air having a flow rate of 0.5L/min at normal temperature and normal humidity by using an atmospheric pressure plasma apparatus.

< Hot pressing Condition >

The pressurizing temperature is 45 DEG C

Pressure 1MPa

Time 5 seconds

The obtained laminate was cut into pieces of 5mm × 5mm, and 100 pieces were arbitrarily extracted. The adhesion surface of the arbitrarily extracted laminate was visually observed, and the adhesion between the ceramic green sheets was evaluated in the following 5 stages.

A: no interlayer peeling was observed at all, and firm adhesion was achieved.

(number of laminates to be delaminated/optional laminate = 0/100)

B: delamination was slightly observed, but firm adhesion was observed.

(number of laminates to be delaminated/optional laminate =1 to 10/100)

C: some delamination was observed, but adhesion was observed.

(number of laminates to be delaminated/optional laminate =11 to 30/100)

D: it was found that interlayer peeling was considerable and adhesiveness was hardly exhibited.

(number of laminates to be delaminated/optional laminate =31 to 99/100)

E: adhesion is not exhibited.

(number of laminates to be delaminated/optional laminate = 100/100)

(4-2. Evaluation of adhesion of coating sheet)

The adhesiveness was evaluated by the method described in "4-1. Evaluation of adhesiveness of ceramic Green sheet" except that the coating sheets used in examples and comparative examples were used instead of the ceramic Green sheets. At this time, the atmospheric plasma treatment was performed on the surface coated with the conductive paste, and the surface treated with the atmospheric plasma was laminated so as to be in contact with the surface (surface not coated with the conductive paste) of the other coated sheet which was not subjected to the atmospheric plasma treatment.

(5-1. Evaluation of dimensional stability of ceramic Green sheet)

The ceramic green sheets used in examples and comparative examples, which were dried (after air-drying at room temperature for 1 hour, drying at 80 ℃ for 2 hours using a hot air dryer, and then drying at 120 ℃ for 2 hours) and had a film thickness of 2 μm, were subjected to plasma treatment in the same manner as described above. The sheet was cut into 5cm square pieces, and 2 pieces were stacked, followed by pressing at 45 ℃ (pressing pressure: 3 MPa) to determine the deformation ratio (area after pressing/area before pressing × 100). At this time, the surface subjected to the atmospheric pressure plasma treatment was laminated so as to be in contact with the surface of the other ceramic green sheet which was not subjected to the atmospheric pressure plasma treatment.

A: the sheet deformation rate is less than 2%

B: the sheet deformation rate is more than 2 percent and less than 4 percent

C: the sheet deformation rate is more than 4%

These 3 stages were evaluated.

(5-2. Evaluation of dimensional stability of coated sheet)

Dimensional stability evaluation was performed in the same manner as in "evaluation of dimensional stability of ceramic green sheet" 5-1, except that the coating sheets used in examples and comparative examples were used instead of the ceramic green sheets. At this time, the atmospheric plasma treatment was performed on the surface coated with the conductive paste, and the surface treated with the atmospheric plasma was laminated so as to be in contact with the surface (surface not coated with the conductive paste) of the other coated sheet which was not subjected to the atmospheric plasma treatment.

(6-1. Evaluation of delamination of fired body in ceramic Green sheet laminate)

100 sheets of the materials obtained by cutting the ceramic green sheets (on the polyester film) used in examples and comparative examples into 10cm square were prepared. After the cut ceramic green sheets were peeled from the polyester film, each surface was subjected to atmospheric plasma treatment in the same manner as in "4-1. Evaluation of adhesiveness of ceramic green sheets", and 100 sheets were stacked so that the surface subjected to atmospheric plasma treatment was overlapped with the surface not subjected to atmospheric plasma treatment, to obtain a stacked body of ceramic green sheets. Then, the mixture was heated at a temperature of 70 ℃ under a pressure of 150kg/cm ² Then, the laminate was heated and pressure-bonded for 10 minutes to obtain a laminate. The obtained laminate was cut into 5mm × 5mm, 100 pieces were arbitrarily drawn out from the cut laminate, and the temperature was raised to 400 ℃ at a temperature raising rate of 15 ℃/min under a nitrogen atmosphere for 5 hours, and then further raised to 1350 ℃ at a temperature raising rate of 5 ℃/min for 10 hours, thereby obtaining a ceramic fired body.

After the obtained fired body was cooled to normal temperature, the cross section of the fired body was observed with an electron microscope, and the presence or absence of delamination between ceramic layers was evaluated in the following 4 stages.

A: no delamination.

(number of layered baked bodies/optional baked body =0 to 2/100)

B: delamination was slightly visible.

(number of layered baked bodies/optional baked body =3 to 7/100)

C: there is a portion of the layering.

(number of layered baked bodies/optional baked body =8 to 20/100)

D: there is a large number of layers.

(number of layered baked bodies/arbitrary baked body =21 to 100/100)

(6-2. Evaluation of delamination of fired body in coating sheet laminate)

100 pieces of the material used in examples and comparative examples, which was 10cm square and was cut into 10cm square pieces, were prepared. The surface coated with the conductive paste was subjected to atmospheric plasma treatment in the same manner as in "4-2. Evaluation of adhesion of coated sheet", and 100 sheets of the surface subjected to atmospheric plasma treatment were stacked so as to overlap the surface not subjected to atmospheric plasma treatment, to obtain a laminated body of coated sheets. Then, the mixture was heated at a temperature of 70 ℃ under a pressure of 150kg/cm ² Then, the laminate was heated and pressure-bonded for 10 minutes to obtain a laminate. The obtained laminate was cut into 5mm × 5mm, 100 pieces of the laminate were arbitrarily pulled out from the cut laminate, and the temperature was raised to 400 ℃ at a temperature raising rate of 15 ℃/min under a nitrogen atmosphere and held for 5 hours, and then further raised to 1350 ℃ at a temperature raising rate of 5 ℃/min and held for 10 hours, thereby obtaining a ceramic fired body.

After the obtained fired body was cooled to room temperature, the cross section of the fired body was observed with an electron microscope, and the presence or absence of delamination between ceramic layers and between the ceramic layers and the electrode layers was evaluated in the following 4 stages.

A: no delamination.

(number of layered baked bodies/optional baked body =0 to 2/100)

B: delamination was slightly visible.

(number of layered baked bodies/optional baked body =3 to 7/100)

C: there is a portion of the layering.

(number of layered baked bodies/optional baked body =8 to 20/100)

D: there is a large number of layers.

(number of layered baked bodies/optional baked body =21 to 100/100)

[ Binder resin (A) ]

(Synthesis example 1)

In a 10-liter glass vessel equipped with a reflux condenser, a thermometer and an anchor stirring blade, 7280g of ion-exchanged water and 720g (PVA concentration: 9.0 mass%) of polyvinyl alcohol (hereinafter referred to as PVA-1) having a polymerization degree of 1700 and a saponification degree of 98.4 mol% were charged, and the contents were heated to 95 ℃ to completely dissolve the PVA. Subsequently, while the contents were stirred at 120rpm, the mixture was gradually cooled to 10 ℃ over about 30 minutes, and then 400g of n-butyraldehyde and 830mL of 20 mass% hydrochloric acid were added to the vessel to conduct butyraldehyde condensation reaction for 150 minutes. Then, the temperature was raised to 70 ℃ over 90 minutes, and the mixture was held at 70 ℃ for 120 minutes, and then cooled to room temperature. The precipitated resin was washed with ion-exchanged water, and then neutralized by adding an excessive amount of an aqueous sodium hydroxide solution. Subsequently, the resin was washed with ion-exchanged water again, and then dried to obtain polyvinyl butyral (PVB-1).

(Synthesis example 2)

Polyvinyl butyral (PVB-2) was obtained in the same manner as in Synthesis example 1, except that 336g of n-butyraldehyde was used in place of PVA-1, instead of PVA-1, PVA having the degree of polymerization and the degree of saponification shown in Table 1.

(Synthesis example 3)

Polyvinyl butyral (PVB-3) was obtained in the same manner as in Synthesis example 1, except that 388g of n-butyraldehyde was used in place of PVA-1, instead of PVA-1, the PVA having the degree of polymerization and the degree of saponification shown in Table 1.

(Synthesis example 4)

Polyvinyl butyral (PVB-4) was obtained in the same manner as in Synthesis example 1, except that instead of PVA-1, PVA having the polymerization degree and saponification degree shown in Table 1 was used and 453g of n-butyraldehyde was used.

(Synthesis example 5)

Polyvinyl butyral (PVB-5) was obtained in the same manner as in Synthesis example 1, except that PVA having the polymerization degree and the saponification degree shown in Table 1 was used in place of PVA-1 and that 511g of n-butyraldehyde was used.

(Synthesis example 6)

Polyvinyl butyral (PVB-6) was obtained in the same manner as in Synthesis example 1, except that 398g of n-butyraldehyde was used in place of PVA-1, instead of PVA-1, the PVA having the polymerization degree and the saponification degree shown in Table 1.

(Synthesis example 7)

Polyvinyl butyral (PVB-7) was obtained in the same manner as in Synthesis example 1, except that PVA having the polymerization degree and the saponification degree shown in Table 1 was used in place of PVA-1 and 405g of n-butyraldehyde was used.

(Synthesis example 8)

Polyvinyl butyral (PVB-8) was obtained in the same manner as in Synthesis example 1, except that PVA having the polymerization degree and the saponification degree shown in Table 1 was used in place of PVA-1 and 399g of n-butyraldehyde was used.

(Synthesis example 9)

Polyvinyl butyral (PVB-9) was obtained in the same manner as in Synthesis example 1, except that, in place of PVA-1, 399g of n-butyraldehyde was used in a mass ratio of 70/30, which was PVA having a polymerization degree of 2400 and a saponification degree of 98.8 mol%, and PVA having a polymerization degree of 500 and a saponification degree of 98.8 mol%, as shown in Table 1.

(Synthesis example 10)

Polyvinyl butyral (PVB-10) was obtained in the same manner as in synthesis example 1, except that in synthesis example 1, acetalization was performed using isobutyraldehyde instead of butyralization using n-butyraldehyde.

(Synthesis example 11)

Polyvinyl butyral (PVB-11) was obtained in the same manner as in synthesis example 1, except that in synthesis example 1, acetalization was performed using acetaldehyde and n-butyraldehyde in a weight ratio of 100/64 instead of butyralization using n-butyraldehyde.

The degree of polymerization, the content of vinyl acetate monomer units, the degree of acetalization, and the content of vinyl alcohol monomer units were measured for PVB-1 to PVB-11 by the methods described in the above evaluation method "1. Measurement of polyvinyl acetal". The measurement results are shown in table 1.

[ Table 1]

[ production of ceramic Green sheet ]

Production example 1

< preparation of inorganic Compound Dispersion solvent >

After 10 parts by mass of PVB-1 was added to a mixed solvent of 30 parts by mass of toluene and 30 parts by mass of ethanol, the solution was stirred to dissolve PVB-1, and bis (2-butoxyethyl) adipate was added to the solution so as to be 38 parts by mass with respect to 100 parts by mass of PVB-1, and the solution was stirred to prepare an inorganic compound-dispersing solvent.

< production of ceramic slurry >

To 100 parts by mass of barium titanate ("BT-02", made by sakai chemical industry corporation, having an average particle diameter of 0.2 μm), 15 parts by mass of toluene and 15 parts by mass of ethanol were added, and the mixture was mixed in a ball mill for 15 hours to obtain a ceramic dispersion. Next, the inorganic compound dispersion solvent was added to the ceramic dispersion liquid so that 7.5 parts by mass of PVB-1 was present with respect to 100 parts by mass of ceramic, and the mixture was mixed in a ball mill for 24 hours to obtain ceramic slurry.

< production of ceramic Green sheet >

The ceramic slurry thus obtained was applied to a polyester film subjected to mold release treatment by a bar coater so that the thickness of the dried film became 2 to 3 μm, and after drying the film for 1 hour at normal temperature, the film was dried for 2 hours at 80 ℃ in a hot air dryer, and then dried for 2 hours at 120 ℃ to obtain a ceramic green sheet GS-1 on the polyester film.

Production examples 2 to 8

Ceramic green sheets GS-2 to GS-8 were produced in the same manner as in production example 1, except that PVB-2 to PVB-8 were used instead of PVB-1.

Production examples 9 to 14

Ceramic green sheets GS-9 to GS-14 were produced in the same manner as in production example 1, except that the organic compounds shown in Table 2-1 were used in place of bis (2-butoxyethyl) adipate.

Production examples 15 to 18

Ceramic green sheets GS-15 to GS-18 were produced in the same manner as in production example 1, except that bis (2-butoxyethyl) adipate was added to the binder resin (a) at the ratio shown in table 2-2.

Production examples 19 to 21

Ceramic green sheets GS-19 to GS-21 were produced in the same manner as in production example 1, except that PVB-9 to PVB-11 were used instead of PVB-1 and that the organic compounds shown in Table 2-2 were used.

Production example 22

As shown in Table 2-2, a ceramic green sheet GS-22 was produced in the same manner as in production example 1, except that 19 parts by mass of bis (2-butoxyethyl) adipate and 19 parts by mass of triethylene glycol di-2-ethylhexanoate were added to 100 parts by mass of PVB-1.

Production examples 23 to 25

As shown in Table 2-2, ceramic green sheets GS-23 to GS-25 were produced in the same manner as in production example 1 except that bis (2-butoxyethyl) adipate having different acid values was used. The reason why the acid values of bis (2-butoxyethyl) adipate used in production examples 23 to 25 were different from each other was that the acid component derived from adipic acid was contained in different amounts.

Production examples A to H

Ceramic green sheets GS-A to GS-H were produced in the same manner as in production example 1, except that the organic compounds shown in Table 3 were used instead of bis (2-butoxyethyl) adipate.

Production example I

As shown in Table 3, a ceramic green sheet GS-I was produced in the same manner as in production example 1, except that bis (2-butoxyethyl) adipate was not used.

The acid values of the organic compounds used for producing the respective ceramic green sheets were measured with respect to the obtained ceramic green sheets GS-A to GS-I according to the method described in the above evaluation method "2 measurement of acid values of organic compounds". The measurement results are shown in table 3.

The acid values of the organic compounds used for producing the respective ceramic green sheets were measured with respect to the obtained ceramic green sheets GS-1 to GS-25 and GS-A to GS-I according to the method described in the above evaluation method "2 measurement of acid value of organic compound". The measurement results are shown in Table 2-1, table 2-2 and Table 3.

[ Table 2-1]

[ tables 2-2]

[ Table 3]

[ production of conductive paste, coating sheet, and laminate ]

Production example 1

< preparation of conductive paste >

Ethyl cellulose (STD-45, manufactured by Dow Chemical Company) and dihydroterpinyl acetate were charged into a 2L separable flask equipped with a stirrer, a cooler, a thermometer, a hot water bath, and a nitrogen inlet.

Next, the mixture was mixed with nickel powder ("NFP 201", JFE Mineral co., ltd.) as a conductive powder, and further 20 parts by mass of barium titanate powder having an average particle size of 0.1 μm, which is commercially available, was added to the nickel powder, and the mixture was passed through a three-roll mill a plurality of times to obtain a conductive paste. The composition ratio in the conductive paste was prepared so that the binder resin (a) was 3 mass%, the nickel powder was 50 mass%, the barium titanate was 10 mass%, and the binder resin was an organic solvent, to obtain a conductive paste.

< preparation of coated sheet >

The ceramic green sheet GS-1 obtained in production example 1 was cut into a size of 10cm × 10cm, and subjected to atmospheric pressure plasma treatment according to the method described in the above evaluation method "4-1. Evaluation of adhesiveness of ceramic green sheet". The conductive paste was screen-printed on the surface subjected to atmospheric plasma treatment by a screen printer (DP-320, manufactured by Newlong precision industries, ltd.), and the resultant was dried at 120 ℃ for 1 hour to form a conductive paste coating film having a thickness of 2 μm and a square width of 10mm, a paste-to-paste distance (margin) of 2.5mm, and a coating sheet TS-1 was obtained.

(preparation example 2)

The ceramic green sheet GS-1 obtained in production example 1 was cut into a size of 10cm × 10cm, and the conductive paste was screen-printed by a screen printer (DP-320, manufactured by Newling Seiki Kogyo Co., ltd.), and dried at 120 ℃ for 1 hour to form a conductive paste film having a thickness of 2 μm and a square dimension of 10mm, a distance (margin) between pastes of 2.5 mm. The surface on which the conductive paste film was formed was subjected to atmospheric pressure plasma treatment in accordance with the method described in the aforementioned evaluation method "4-1. Evaluation of adhesiveness of ceramic green sheet", thereby obtaining a coated sheet TS-2.

(preparation example 3)

A coated sheet TS-3 was obtained in the same manner as in preparation example 2, except that GS-C was used instead of the ceramic green sheet GS-1.

TS-1 to TS-3 are shown in Table 4.

[ Table 4]

[ examples ]

Examples 1 to 25

The dimensional stability of the ceramic green sheets at the time of pressure bonding, the adhesiveness of the ceramic green sheets, and the delamination of the fired body obtained using the ceramic green sheets were evaluated for each of the ceramic green sheets GS-1 to GS-25 according to the methods described in the above evaluation methods. The evaluation results are shown in table 5.

(example 26)

The dimensional stability at the time of compression bonding of TS-1, the adhesiveness of TS-1, and the delamination of the fired body obtained by using TS-1 were evaluated according to the methods described in the above evaluation methods. The evaluation results are shown in table 5.

(example 27)

The coating sheet TS-2 was evaluated for dimensional stability at the time of pressure bonding of TS-2 and adhesiveness of TS-2 according to the methods described in the evaluation methods. The evaluation results are shown in table 7.

[ comparative example ]

Comparative examples 1 to 9

The dimensional stability of the ceramic green sheets at the time of pressure bonding, the adhesiveness of the ceramic green sheets, and the delamination of the fired body obtained using the ceramic green sheets were evaluated for each of the ceramic green sheets GS-se:Sup>A to GS-I according to the methods described in the above evaluation methods. The evaluation results are shown in table 6.

Comparative example 10

Evaluation was performed in the same manner as in example 1, except that the sample moving speed during plasma irradiation was set to 0.1 mm/sec. The ratio of the intensity of Ba + ions to the intensity of Ti + ions on the surface of the ceramic green sheet at this time was 1064. The evaluation results are shown in table 6.

Comparative example 11

The coating sheet TS-3 was evaluated for dimensional stability at the time of pressure bonding of TS-3 and adhesiveness of TS-3 according to the methods described in the evaluation methods. The evaluation results are shown in table 7.

[ Table 5]

[ Table 6]

[ Table 7]

Claims

1. A ceramic slurry comprising at least a binder resin (A) having a hydroxyl group in the molecule and an organic compound (B) represented by the chemical formula (1), and comprising an organic solvent (C) and an inorganic compound (D),

wherein R1 and R4 are each independently an organic group having at least one ether bond represented by the formula (2):

wherein R5 represents an optionally branched alkyl group having 1 to 10 carbon atoms, R6 represents an optionally branched alkylene group having 1 to 10 carbon atoms, R7 represents an alkylene group having 1 to 4 carbon atoms, n represents an integer of 0 to 2,

r2 represents an optionally branched alkylene group having 1 to 20 carbon atoms, R3 represents an optionally branched alkylene group having 3238 carbon atoms zxft 3238, and m represents an integer of 0~5.

2. The ceramic slurry according to claim 1, wherein the organic compound (B) has an acid value of 5mgKOH/g or less.

3. The ceramic slurry according to claim 1~2, wherein the organic compound (B) is contained in an amount of 1 to 60 parts by mass based on 100 parts by mass of the binder resin (A).

4. The ceramic slurry of any one of claims 1~2, wherein binder resin (A) comprises at least 1 selected from the group consisting of polyvinyl acetal and (meth) acrylic resin.

5. The ceramic slurry according to claim 4, wherein the binder resin (A) comprises a polyvinyl acetal having an acetalization degree of 50 to 85 mol%, a content of a vinyl ester monomer unit of 0.1 to 20 mol%, and a viscosity average polymerization degree of 200 to 5000.

6. The ceramic slurry according to claim 1~2, comprising barium titanate, wherein the binder resin (A) is contained in an amount of 3 to 20 parts by mass based on 100 parts by mass of barium titanate.

7. A ceramic green sheet obtained by drying and forming the ceramic slurry of any one of claims 1~6 into a sheet shape.

8. The ceramic green sheet according to claim 7, wherein a ratio of an intensity of detected Ba + ions to an intensity of detected Ti + ions, that is, (intensity of Ba + ions)/(intensity of Ti + ions) satisfies 20< (intensity of Ba + ions)/(intensity of Ti + ions) <1000 when secondary ion analysis is performed with a time-of-flight secondary ion mass spectrometer with respect to at least one surface of the ceramic green sheet.

9. A coated sheet comprising a layer obtained by drying a conductive paste, which is disposed on at least one surface of the ceramic green sheet according to claim 7 or 8.

10. The coated sheet according to claim 9, wherein at least a part of the ceramic green sheet is subjected to plasma treatment.

11. The coated sheet according to claim 9 or 10, wherein at least a part of the surface of the coated sheet is subjected to plasma treatment.

12. An inorganic compound dispersion solvent for use in the ceramic slurry of any one of claims 1~6 comprising a resin composition comprising a binder resin (A) having a hydroxyl group in a molecule, an organic compound (B) represented by the following chemical formula (1) and an organic solvent (C),