KR102567588B1 - Polymers, paste compositions containing the polymers, binder resins for conductive pastes, conductive paste compositions, binder resins for ceramics and ceramic compositions - Google Patents

Abstract

(R¹ 은 수소 원자 또는 메틸기를 나타내고, R² 는 수소 원자, 메틸기 또는 에틸기를 나타내고, R³ 은 탄소수 1 ∼ 18 의 알킬기를 나타내고, X 및 Y 는, 각각 독립적으로, NH 또는 O 를 나타낸다)The molar ratio of the monomer (A) represented by the general formula (1) is 10 mol% to 100 mol%, the molar ratio of the other monomers (B) copolymerizable with the monomer (A) is 0 to 90 mol%, and the weight average molecular weight is A binder resin comprising a polymer of 10,000 to 1,000,000 phosphorus.

(R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom, a methyl group or an ethyl group, R ³ represents an alkyl group having 1 to 18 carbon atoms, and X and Y each independently represent NH or O)

Description

Polymers, paste compositions containing polymers, binder resins for conductive pastes, conductive paste compositions, binder resins for ceramics, and ceramics compositions AND CERAMIC COMPOSITIONS}

The present invention relates to a polymer particularly suitable as a binder resin having excellent thixotropic properties and thermal decomposition properties, and a paste composition containing the polymer.

Further, the present invention relates to a polymer particularly suitable as a binder resin for ceramics, which is excellent in molded article strength and thermal decomposability.

A metal paste used for forming internal electrode layers of multilayer electronic components such as multilayer ceramic capacitors or conductive layers of solar cells is mainly composed of metal particles such as nickel or copper, a solvent, and a binder resin, and is used for screen printing and the like. By the method, it is printed on a sheet. As shown in Patent Literature 1, ethyl cellulose resin suitable for printing was used as the binder resin, which has high thixotropy and does not cause threading or bleeding during printing. However, since ethyl cellulose has low thermal decomposition and remains during firing, there is a problem that a large amount of heating residue leads to defects in the electrode. On the other hand, acrylic resins have excellent performance in thermal decomposition, but have low thixotropic properties, and when the viscosity is increased, thread drag becomes stronger, and when the viscosity is lowered to reduce thread drag, blurring occurs during printing. There was an assignment.

Here, the thixotropic property of the metal paste means a property in which the apparent viscosity decreases when the shear rate is high, and the apparent viscosity increases when the shear rate is slow and not sheared.

In recent years, multilayer devices such as multilayer ceramic capacitors are being made thinner or multilayered for the purpose of miniaturization. However, as thinning progresses, the problem that the influence of defects caused by the residual carbon content in the electrode layer increases during firing becomes present. For this reason, there has been a demand for a binder resin having excellent thixotropic properties, no thread dragging or blurring during printing, properties suitable for printing, and more excellent thermal decomposability and a small residual carbon content.

In addition, ethyl cellulose has a problem of low thermal decomposition and a large amount of heating residue during firing, leading to electrode defects. In addition, the conductive paste using ethyl cellulose has low adhesiveness to the sheet, and there is also a problem that a problem occurs during lamination due to peeling of the electrode.

Therefore, as shown in Patent Literature 2, improvement in sheet adhesion has been studied by adding polyvinyl butyral to ethyl cellulose, but there have been problems in that thermal decomposability is reduced and sufficient adhesiveness is not obtained.

In addition, the ceramic slurry used for sheet formation, such as the formation of the dielectric layer of multilayer electronic components such as multilayer ceramic capacitors, is mainly composed of ceramic particles such as metal oxides such as barium titanate and alumina, nitrides such as silicon nitride, solvents, and binder resins. and formed into a sheet by a doctor blade method or the like. The sheet-formed green sheet is required to have strength so that there is no dimensional change or breakage during handling of the sheet.

Therefore, as shown in Patent Document 3, a polyvinyl butyral resin having excellent strength has been used as the binder resin. However, since polyvinyl butyral resin has low thermal decomposability and remains during firing, there is a problem that a large amount of heating residue leads to defects in the sheet. On the other hand, although acrylic resins have excellent performance in thermal decomposition, they have low sheet strength, and in particular, when thinning, the low sheet strength becomes apparent, and there is a problem that they are not suitable as binder resins.

Japanese Laid-Open Patent Publication 2012-181988 Japanese Laid-open Patent Publication 2016-033998 Japanese Laid-Open Patent Publication 2006-089354

In order to solve such a problem, a binder resin having excellent thixotropic properties, excellent thermal decomposition properties, and a small amount of heating residue has been required. In addition to these, a binder resin and conductive paste composition having high printability without thread drag or blurring during printing are required.

In recent years, multilayer ceramic capacitors have become smaller and larger in size, and multilayering and thinning are progressing. However, as thinning progresses, problems such as the problem that defects caused by slight heating residues cause a decrease in insulation properties, and problems such as lamination misalignment and peeling between layers due to low adhesiveness due to multilayering become present, resulting in more thermal decomposition and A binder resin having excellent adhesive properties has been required.

In order to solve such a problem, a binder resin excellent in thixotropy and thermal decomposability, with a small heating residue, and also excellent in adhesiveness has been required.

In recent years, thinning and multilayering of ceramic green sheets are progressing for the purpose of miniaturizing multilayer devices such as multilayer ceramic capacitors. However, when thinning progresses, the influence of defects caused by the residual carbon content in the dielectric layer during firing increases, causing problems such as occurrence of dielectric breakdown.

In order to solve such a problem, a binder resin for ceramics capable of increasing the strength of a ceramic molded body and having excellent thermal decomposition properties is required.

An object of the first invention is to provide a binder resin excellent in thixotropy and thermal decomposition.

Another object of the present invention is to further provide a binder resin that does not cause threading or bleeding during printing and a conductive paste composition having high printability using the binder resin.

An object of the second invention is to provide a binder resin for electrically conductive pastes having excellent thixotropic properties, thermal decomposition properties and adhesive properties.

An object of the third invention is to provide a binder resin for ceramics capable of increasing the strength of a ceramic molded body and having excellent thermal decomposition properties.

As a result of studies to solve the above problems, the present inventors have found that a binder resin composed of a polymer having a specific structure having a urea structure or a urethane structure can solve the above problems.

That is, 1st invention is the following.

[1] The molar ratio of the monomer (A) represented by the following general formula (1) is 10 mol% to 100 mol%, and the molar ratio of the other monomers (B) copolymerizable with the monomer (A) is 0 to 90 mol%, A binder resin comprising a polymer having a weight average molecular weight of 10,000 to 1,000,000.

(In formula (1),

R ¹ represents a hydrogen atom or a methyl group;

R ² represents a hydrogen atom, a methyl group or an ethyl group;

R ³ represents an alkyl group having 1 to 18 carbon atoms;

X and Y each independently represent NH or O)

[2] A conductive paste composition characterized by containing the binder resin, an organic solvent, and metal particles.

[3] The above conductive paste composition characterized by containing 0.5 to 30 parts by weight of binder resin and 10 to 200 parts by weight of organic solvent with respect to 100 parts by weight of metal particles.

The polymer of the first invention has excellent thixotropic properties and excellent thermal decomposition properties, and when used for printing applications, there is no threading or bleeding during printing. As a result, a paste using the polymer of the present invention as a binder resin, particularly a metal paste, has a small residual carbon content during firing, and has high printability when used for printing applications.

In addition, as a result of studies to solve the above problems, the present inventors have found that a binder resin composed of a polymer having a specific structure having a urea structure or a urethane structure can solve the above problems.

That is, the second invention is as follows.

[4] The molar ratio of the monomer (A) represented by the following general formula (1) is 10 mol% to 90 mol%, and the molar ratio of the (meth)acrylic acid alkyl ester (D) represented by the following general formula (2) is 10 to 90 mol%, the molar ratio of the monomer (A) and the other monomer copolymerizable with the (meth)acrylic acid alkylester (D) is 0 to 30 mol%, and the weight average molecular weight is 10,000 to 1,000,000. , Binder resin for conductive paste.

(In formula (1),

R ¹ represents a hydrogen atom or a methyl group;

R ² represents a hydrogen atom, a methyl group or an ethyl group;

R ³ represents an alkyl group having 1 to 18 carbon atoms;

X and Y each independently represent NH or O)

(In formula (2),

R ⁴ represents a hydrogen atom or a methyl group;

R ⁵ represents an alkyl group having 1 to 18 carbon atoms)

[5] The binder resin for conductive paste according to [4], wherein the other monomer is acrylonitrile or alkylacrylamide.

[6] A conductive paste composition characterized by containing the binder resin of [4] or [5], an organic solvent, and metal particles.

[7] The conductive paste composition according to [6], wherein a mass ratio of the binder resin is 0.5 to 30 parts by mass and a mass ratio of the organic solvent is 10 to 200 parts by mass with respect to 100 parts by mass of the metal particles.

The polymer of the second invention has excellent thixotropic properties, thermal decomposability and adhesiveness. As a result, the conductive paste using the polymer of the present invention as a binder resin has high printability and adhesiveness, and a small amount of residual carbon during firing.

As a result of studies to solve the above problems, the present inventors have found that a binder resin composed of a polymer having a specific structure having a urea structure or a urethane structure can solve the above problems.

That is, 3rd invention is the following.

[8] The molar ratio of the monomer (A) represented by the following general formula (1) is 10 mol% to 100 mol%, and the molar ratio of the monomer (A) and the other monomer (E) copolymerizable is 0 to 90 mol%, A binder resin for ceramics characterized by being composed of a polymer having a weight average molecular weight of 10,000 to 1,000,000.

(In formula (1),

R ¹ represents a hydrogen atom or a methyl group;

R ² represents a hydrogen atom, a methyl group or an ethyl group;

R ³ represents an alkyl group having 1 to 18 carbon atoms;

X and Y each independently represent NH or O)

[9] A ceramic composition characterized by containing the binder resin according to [8], an organic solvent, and ceramic particles.

[10] The ceramic composition according to [9], characterized by containing 0.5 to 30 parts by mass of the binder resin and 10 to 200 parts by mass of the organic solvent with respect to 100 parts by mass of the ceramic particles.

[11] A ceramic molded body characterized by comprising the ceramic composition of [9] or [10].

The ceramic composition using the binder resin for ceramics according to the third aspect of the invention has excellent strength and excellent thermal decomposition properties. As a result, the ceramic molded body using the binder resin composition for ceramics of the present invention has excellent strength (particularly sheet strength) and has a small residual carbon content during firing.

[Monomer (A)]

The monomer (A) used in the present invention is represented by the following general formula (1).

In Formula (1), R ¹ is a hydrogen atom or a methyl group, and a methyl group is particularly preferable from the viewpoint of the ease of polymerization.

Although R ² represents a hydrogen atom, a methyl group or an ethyl group, a hydrogen atom is particularly preferred from the viewpoint of reactivity with amines or alcohols.

R ³ is an alkyl group having 1 to 18 carbon atoms. Examples of the C1-C18 alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-hexyl, n-octyl, 2 -An ethylhexyl group, a decyl group, a dodecyl group, a stearyl group, etc. are mentioned, From a viewpoint of synthetic|combination easiness and thixotropic property, as for carbon number of R ^<3> , 2-12 are preferable, and 3-6 are more preferable.

X and Y are oxygen atoms (-O-) or NH groups, and from the viewpoint of thixotropic properties, it is preferable that at least one of X and Y is an NH group, and it is more preferable that both X and Y are NH groups.

A monomer (A) may be used individually by 1 type, and may use two or more types together.

In the 1st invention and the 2nd invention, when the whole monomer which comprises a polymer is 100 mol%, the mole ratio of a monomer (A) is 10 mol% or more. If the molar ratio of the monomer (A) is too low, the thixotropy may deteriorate, so it is set to 10 mol% or more, preferably 15 mol% or more, and more preferably 20 mol% or more.

In the first invention, the molar ratio of the monomer (A) among the monomers constituting the polymer is 100 mol% or less. When the mole ratio of the monomer (A) is 100 mol%, the polymer of the present invention is a homopolymer, and when the mole ratio of the monomer (A) is less than 100 mol%, the polymer of the present invention is a copolymer. When the molar ratio of the monomer (A) is 50 mol% or less, the thermal decomposability of the polymer is further improved, but from this point of view, it is more preferably 40 mol% or less.

In the second invention, the molar ratio of the monomer (A) is 90 mol% or less when the total amount of the monomers constituting the polymer is 100 mol%. When the molar ratio of the monomer (A) is 50 mol% or less, the thermal decomposability of the polymer is further improved, but from this point of view, it is more preferably 40 mol% or less.

In the third invention, the molar ratio of the monomer (A) is 100 mol% or less when the total amount of the monomers constituting the polymer is 100 mol%. When the mole ratio of the monomer (A) is 100 mol%, the polymer of the present invention is a homopolymer, and when the mole ratio of the monomer (A) is less than 100 mol%, the polymer of the present invention is a copolymer. When the molar ratio of the monomer (A) is 50 mol% or less, the thermal decomposability of the polymer is further improved, but from this point of view, it is more preferably 40 mol% or less.

[First Invention: Monomer (B)]

The monomer (B) in the first invention is a vinyl monomer copolymerizable with the monomer (A), and examples thereof include (meth)acrylic acid ester compounds, aromatic alkenyl compounds, vinyl cyanide compounds, and acrylamide compounds. can

As a (meth)acrylic acid ester compound, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth) ) Acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl ( Meth) acrylate etc. are mentioned.

As an aromatic alkenyl compound, styrene, (alpha)-methylstyrene, p-methylstyrene, p-methoxy styrene etc. are mentioned, for example.

As a vinyl cyanide compound, acrylonitrile, methacrylonitrile, etc. are mentioned, for example.

As an acrylamide compound, acrylamide, methacrylamide, etc. are mentioned, for example.

A monomer (B) may be used individually by 1 type, and may use two or more types together. Among them, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and iso-butyl (meth)acrylate are particularly preferred from the viewpoints of solvent solubility and thermal decomposition.

In the monomer mixture, the total amount of the monomer (A) and the monomer (B) is 100 mol%. Therefore, the molar ratio of the monomer (B) is 0 to 90 mol%.

[Second invention: (meth)acrylic acid alkyl ester (D)]

The (meth)acrylic acid alkyl ester (D) used in the second invention is represented by the following general formula (2).

In Formula (2), R ⁴ is a hydrogen atom or a methyl group.

R ⁵ is an alkyl group having 1 to 18 carbon atoms. Examples of the C1-C18 alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-hexyl, n-octyl, 2 -An ethylhexyl group, a decyl group, a dodecyl group, a stearyl group, etc. are mentioned, From a viewpoint of polymerizability and glass transition point of a polymer, as for carbon number of ^R5 , 1-12 are preferable, and 1-8 are more preferable. .

(meth)acrylic-acid alkylester (D) may be used individually by 1 type, and may use two or more types together. From the viewpoint of strength and adhesiveness, it is preferable to use together a monomer (b1) in which R ⁴ is a hydrogen atom and a monomer (b2) in which R ⁴ is a methyl group. The ratio of (b1) to the total amount of (b1) and (b2) [(b1)/{(b1) + (b2)}] is preferably 1 to 50 mol%, and more preferably 5 to 30 mol% desirable.

The molar ratio of the (meth)acrylic acid alkyl ester (D) is 10 mol% or more when the total monomers constituting the polymer are 100 mol%. If the molar ratio of the alkyl (meth)acrylate ester (D) is too low, the strength as a binder resin and thermal decomposability may decrease. Therefore, it is set to 10 mol% or more, preferably 30 mol% or more, and 50 mol% or more. particularly preferred.

Moreover, when the whole monomer which comprises a polymer is 100 mol%, the molar ratio of (meth)acrylic-acid alkylester (D) shall be 90 mol% or less. If the molar ratio of (meth)acrylic acid alkylester (D) is too high, the thixotropic property may deteriorate, so it is 90 mol% or less, preferably 85 mol%, particularly preferably 80 mol% or less.

Examples of the (meth)acrylic acid ester compound (D) include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, and tert-butyl. (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, ester Aryl (meth)acrylate etc. are mentioned.

The polymer of the second invention may consist of the monomer (A) and the (meth)acrylic acid alkyl ester (D), or may further contain 30 mol% or less of another monomer copolymerizable with these. The ratio of the other monomers is 30 mol% or less, more preferably 15 mol% or less, and may be 0 mol%.

Examples of such other monomers include acrylamide, alkyl acrylamides such as dimethyl acrylamide and diethyl acrylamide, and acrylonitrile.

[Third Invention: Monomer (E)]

The monomer (E) in the third invention is a vinyl monomer copolymerizable with the monomer (A), and examples thereof include (meth)acrylic acid ester compounds, aromatic alkenyl compounds, vinyl cyanide compounds, and acrylamide compounds. can

As a (meth)acrylic acid ester compound, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth) ) Acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl ( Meth) acrylate etc. are mentioned.

As an aromatic alkenyl compound, styrene, (alpha)-methylstyrene, p-methylstyrene, p-methoxy styrene etc. are mentioned, for example.

As a vinyl cyanide compound, acrylonitrile, methacrylonitrile, etc. are mentioned, for example.

As an acrylamide compound, acrylamide, dimethylacrylamide, methacrylamide etc. are mentioned, for example.

Among them, from the viewpoint of resin strength and thermal decomposability, (meth)acrylic acid ester compounds are preferred, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and iso-butyl methacrylate are more preferred, and methyl Methacrylate and iso-butyl methacrylate are more preferred.

A monomer (E) may be used individually by 1 type, or may use 2 or more types together, but it is preferable to use 2 or more types together. In that case, when the total amount of the monomer (A) and the monomer (E) is 100 mol%, it is particularly preferable to use 5 to 25 mol% of methyl methacrylate.

In addition, since the total amount of the monomer (A) and the monomer (E) is 100 mol%, the molar ratio of the monomer (E) is the remainder of the monomer (A), that is, 0 to 90 mol%.

[First invention and second invention: polymer]

The weight average molecular weight of the polymers of the first invention and the second invention can be obtained in terms of polystyrene using gel permeation chromatography (GPC), and is 10,000 to 1,000,000, preferably 10,000 to 800,000, more preferably 30,000 ~ 300,000. If the weight average molecular weight of the polymer is too low, the strength or viscosity of the polymer is insufficient, and if the weight average molecular weight is too high, solvent solubility or printability may deteriorate.

[Third Invention: Polymer]

The weight average molecular weight of the polymer of the third invention can be obtained in terms of polystyrene using gel permeation chromatography (GPC), and is 10,000 to 1,000,000, preferably 30,000 to 800,000, more preferably 50,000 to 500,000. If the weight average molecular weight of the polymer is too low, the sheet strength is insufficient, and if the weight average molecular weight is too high, the slurry may thicken and adversely affect the coating properties.

[Method for producing monomer (A)]

The monomer (A) of the present invention is a monomer having a urea bond or a urethane bond.

The monomer (A) can be obtained by, for example, reaction between an isocyanate group-containing monomer and an amine compound or an alcohol compound or a reaction between a hydroxyl group-containing monomer and an alkyl isocyanate.

As said isocyanate group containing monomer, 2-(meth)acryloyloxyethyl isocyanate is preferable, and 2-methacryloyloxyethyl isocyanate is more preferable from a viewpoint of polymerization stability.

It is preferable that it is a primary amine compound or a secondary amine compound, and, as for the said amine compound, it is more preferable that it is a primary amine compound.

Examples of the primary amine compound include ethylamine, n-propylamine, isopropylamine, n-butylamine, sec-butylamine, tert-butylamine, n-pentylamine, n-hexylamine, and n-butylamine. -octylamine, 2-ethylhexylamine, decylamine, dodecylamine, stearylamine, cyclohexylamine, benzylamine, aniline and the like, and these may be used alone or in combination of two or more. Among them, from the viewpoint of thixotropic properties of the binder resin composition, n-butylamine, n-pentylamine, n-hexylamine, n-octylamine, 2-ethylhexylamine, decylamine, and dodecylamine are preferable, and n -Butylamine is more preferred.

In addition, examples of the secondary amine compound include diethylamine, dipropylamine, dibutylamine, diisopropylamine, dioctylamine, di-n-octylamine, di-2-ethylhexylamine, Piperidine, morpholine, etc. are mentioned, These can be used individually or in combination of 2 or more types.

In addition, examples of the alcohol compound include methanol, ethanol, propanol, butanol, pentanol, hexanol, cyclohexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, and tridecane. ol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol and the like, and these may be used alone or in combination of two or more types. Especially, it is preferable that the said alcohol compound is C2-C8 alcohol from a viewpoint of stability at the time of reaction. Examples of the alkanol having 2 to 8 carbon atoms include ethanol, propanol, butanol, pentanol, hexanol, cyclohexanol, heptanol, n-octanol, 2-ethyl-1-hexanol, etc. Among these, ethanol, propanol, and butanol are preferable.

As the hydroxyl group-containing monomer, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxy and monoesters of (meth)acrylic acids such as butyl (meth)acrylate and dihydric alcohols having 2 to 8 carbon atoms. Especially, 2-hydroxyethyl methacrylate is preferable from a reactive viewpoint with an isocyanate group.

Examples of the alkyl isocyanate include ethyl isocyanate, n-butyl isocyanate, iso-butyl isocyanate, tert-butyl isocyanate, hexyl isocyanate, n-octyl isocyanate, 2-ethylhexyl isocyanate, cyclohexyl isocyanate, etc. , From the viewpoint of the thixotropic property of the copolymer, n-butyl isocyanate is preferred.

The reaction between the isocyanate group-containing monomer and the amine compound or alcohol compound and the reaction between the hydroxyl group-containing monomer and alkyl isocyanate can be carried out by a known method by mixing the two and raising the temperature as desired. Moreover, a catalyst may be added as needed, and known catalysts, such as tin catalysts, such as stannous octoate and dibutyl tin dilauryate, and amine catalysts, such as triethylenediamine, can be used. This reaction is preferably carried out at a temperature of 5 to 100°C, preferably 20 to 80°C. In addition, the reaction may be carried out using a solvent, for example, in the presence of acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene, xylene, tetrahydrofuran or the like.

[1st, 2nd and 3rd Invention: Polymer Manufacturing Method]

Next, methods for producing the polymers of the first, second and third inventions will be described.

The polymer in 1st invention can be obtained by radically polymerizing the monomer mixture containing at least a monomer (A). Polymerization can be carried out by a known method. Although solution polymerization, suspension polymerization, emulsion polymerization, etc. are mentioned, for example, solution polymerization and suspension polymerization are preferable from the viewpoint of being easy to adjust the weight average molecular weight of a copolymer within the said range.

The polymer in the second invention can be obtained by radical polymerization of a monomer mixture containing at least the monomer (A) and the (meth)acrylic acid alkyl ester (D). Polymerization can be carried out by a known method. Although solution polymerization, suspension polymerization, emulsion polymerization, etc. are mentioned, for example, solution polymerization and suspension polymerization are preferable from the viewpoint of being easy to adjust the weight average molecular weight of a copolymer within the said range.

The polymer in 3rd invention can be obtained by radically polymerizing the monomer mixture containing at least a monomer (A). Polymerization can be carried out by a known method. Although solution polymerization, suspension polymerization, emulsion polymerization, etc. are mentioned, for example, solution polymerization and suspension polymerization are preferable from the viewpoint of being easy to adjust the weight average molecular weight of a copolymer within the said range.

In each invention, a known polymerization initiator can be used. For example, organic peroxides such as di-(4-t-butylcyclohexyl)peroxydicarbonate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,2'-azo Azo type polymerization initiators, such as bisisobutyronitrile, etc. are mentioned. These polymerization initiators may use only 1 type, and may use 2 or more types together.

The usage amount of the polymerization initiator can be appropriately set depending on the combination of monomers used, reaction conditions, and the like.

In addition, when introducing a polymerization initiator, for example, the whole amount may be injected at once, a part may be injected at once and the rest may be added dropwise, or the entire amount may be added dropwise. Moreover, it is preferable to add a polymerization initiator dropwise together with the monomers because the control of the reaction becomes easy, and adding a polymerization initiator even after dropping the monomers is preferable because the remaining monomers can be reduced.

As the polymerization solvent used in solution polymerization, those in which the monomer and the polymerization initiator are dissolved can be used, and specific examples include methanol, ethanol, 1-propanol, acetone, methyl ethyl ketone, propylene glycol monomethyl ether, and the like. there is.

The concentration of the monomers (total amount) relative to the polymerization solvent is preferably 10 to 60% by mass, particularly preferably 20 to 50% by mass. If the concentration of the monomer mixture is too low, the monomers tend to remain and the molecular weight of the obtained copolymer may decrease. If the concentration of the monomer is too high, it may be difficult to control heat generation.

When the monomer is injected, for example, the entire amount may be injected at once, a part may be injected at once and the remainder may be added dropwise, or the entire amount may be added dropwise. From the viewpoint of easy control of heat generation, it is preferable to inject a part at once and drop the rest, or to drop the entire amount.

The polymerization temperature depends on the type of polymerization solvent and the like, and is, for example, 50°C to 110°C. The polymerization time depends on the type of polymerization initiator and the polymerization temperature. For example, when di(4-t-butylcyclohexyl)peroxydicarbonate is used as the polymerization initiator and polymerization is performed at a polymerization temperature of 70°C, As for polymerization time, about 6 hours is suitable.

By carrying out the above polymerization reaction, the copolymer related to the resin composition of the 1st, 2nd, and 3rd invention is obtained. The obtained copolymer may be used as it is, or may be isolated by filtering or purifying the reaction liquid after the polymerization reaction.

[First and Second Invention: Conductive Paste]

The binder resin is a metal particle made of nickel, palladium, platinum, gold, silver, copper or an alloy thereof, an organic solvent such as terpineol or butyl cellosolve, and, if necessary, other substances such as a surfactant or antioxidant. The components can be blended and a conductive paste containing metal particles (hereinafter also referred to as a metal paste) can be obtained using a kneading device such as a mixer or a three-roll mill. Since the binder resin of the present invention has excellent thixotropic properties and thermal decomposition properties, the metal paste is printed in a sheet form by screen printing or the like and then fired to form an internal electrode layer of a multilayer electronic component or a conductive layer of a solar cell. can form

[First Invention: Metal Paste]

The polymer of 1st invention is especially preferable as a binder resin of a metal paste. The metal paste contains, in addition to the polymer of the present invention, metal particles and a solvent.

Examples of such metal particles include platinum, gold, silver, copper, nickel, tin, palladium, aluminum, and alloys of these metals. The central particle diameter (D50) of the metal particles, that is, the volume cumulative particle diameter D50 measured by a laser diffraction scattering particle size distribution analyzer is preferably 0.05 μm to 50.0 μm.

Examples of the organic solvent include hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 1-butanol, and diacetone alcohol. solvents, glycol ether solvents such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, etc. of glycol ether acetate-based solvents, terpineol-based solvents such as terpineol, dihydroterpineol, and dihydroterpineol acetate, ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; , These may be used alone or in combination of two or more.

The content of the binder resin in the metal paste is preferably from 0.1 to 50 parts by weight, more preferably from 0.5 to 30 parts by weight, based on the weight of the metal particles being 100 parts by weight. Further, the content of the solvent in the metal paste is preferably from 10 to 200 parts by weight, more preferably from 30 to 150 parts by weight, based on the weight of the metal particles being 100 parts by weight. In addition, other components such as surfactants and antioxidants may be incorporated as needed.

These mixtures are stirred and dispersed to obtain a metal paste. For stirring, a known means can be used without particular limitation, preferably, for example, a PD mixer or a planetary kneader can be used, and a planetary kneader is particularly preferably used. For dispersion, known means can be used without particular limitation, preferably, for example, a kneader, bead mill, or three rolls can be used, and three rolls are particularly preferably used.

The metal paste is printed on the sheet by a method such as screen printing.

[Second Invention: Conductive Paste Composition]

The conductive paste composition of the second invention contains metal particles and an organic solvent in addition to the polymer of the invention.

Examples of such metal particles include platinum, gold, silver, copper, nickel, tin, palladium, aluminum, and alloys of these metals. The central particle diameter (D50) of the metal particles, that is, the volume cumulative particle diameter D50 measured by a laser diffraction scattering particle size distribution analyzer is preferably 0.05 μm to 50.0 μm.

Examples of the organic solvent include hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 1-butanol, and diacetone alcohol. solvents, glycol ether solvents such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, etc. of glycol ether acetate-based solvents, terpineol-based solvents such as terpineol, dihydroterpineol, and dihydroterpineol acetate, ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; , These may be used alone or in combination of two or more.

The content of the binder resin in the conductive paste composition is preferably 0.5 to 30 parts by mass, more preferably 1 to 15 parts by mass, based on the mass of the metal particles being 100 parts by mass. The content of the solvent in the conductive paste is preferably 10 to 200 parts by mass, more preferably 50 to 150 parts by mass, based on the mass of the metal particles being 100 parts by mass. In addition, other components such as surfactants and antioxidants may be incorporated as needed.

These mixtures are stirred and dispersed to obtain an electrically conductive paste. For stirring, a known means can be used without particular limitation, preferably, for example, a PD mixer or a planetary kneader can be used, and a planetary kneader is particularly preferably used. For dispersion, known means can be used without particular limitation, preferably, for example, a kneader, bead mill, or three rolls can be used, and three rolls are particularly preferably used.

The conductive paste can be printed on the sheet by a method such as screen printing.

[Third Invention: Ceramic Composition]

The polymer of 3rd invention is especially preferable as a binder resin for ceramic compositions. The ceramic composition contains ceramic particles and an organic solvent in addition to the polymer of the present invention.

Examples of such ceramic particles include metal oxides such as alumina and barium titanate, and nitrides such as silicon nitride and aluminum nitride.

The central particle diameter (D50) of the ceramic particles, that is, the volume cumulative particle diameter D50 measured by a laser diffraction scattering particle size distribution analyzer is preferably 0.05 µm to 50.0 µm.

Examples of the organic solvent include hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 1-butanol, and diacetone alcohol. solvents, glycol ether solvents such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, etc. , glycol ether acetate solvents, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and the like, and these may be used alone or in combination of two or more.

The content of the binder resin of the present invention in the ceramic composition is preferably 0.5 to 30 parts by mass based on 100 parts by mass of the ceramic particles. Further, the content of the solvent in the ceramic composition is preferably 10 to 200 parts by mass based on the weight of the ceramic particles being 100 parts by mass. In addition, other components such as surfactants and antioxidants may be incorporated as needed.

These mixtures are stirred and dispersed to obtain a ceramic composition. For stirring, any known means can be used without particular limitation, preferably, for example, a ball mill, a bead mill, or a planetary kneader can be used, and a ball mill is particularly preferably used.

The ceramic composition is preferably in the form of a slurry, and a ceramics green sheet is obtained by molding the slurry onto a carrier film by a method such as a doctor blade method. However, a molded body can also be obtained by molding the ceramic composition into a sheet shape or the like by cast molding, press molding or the like.

Embodiment of the first invention

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples.

In Table 1 below, the structure and symbol of the monomer (A) are shown.

(Synthesis Example 1: Monomer A1)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 51.2 g of 2-methacryloyloxyethyl isocyanate (“Karenz MOI” manufactured by Showa Electric Co., Ltd.), 40 g of tetrahydrofuran, 0.012 g of methoquinone was injected. Air was introduced into the flask, and 24.1 g of n-butylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A1 (yield: 92%).

(Synthesis Example 2: Monomer A2)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 51.2 g of 2-methacryloyloxyethyl isocyanate ("Karenz MOI" manufactured by Showa Denko Co., Ltd.), 0.012 g of methoquinone, 0.034 g of butyltindilaurate was injected. Air was introduced into the flask, and n-butanol was added dropwise over 1 hour while maintaining the internal temperature at 60°C. Then, after raising the temperature to 80°C and aging for 6 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A2 (yield: 95%).

(Synthesis Example 3: Monomer A3)

Into a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet pipe, 2-hydroxyethyl methacrylate (Nichiyu Co., Ltd. "Bremmer E") and 0.012 g of methoquinone were charged. Air was introduced into the flask, and n-butyl isocyanate was added dropwise over 1 hour while maintaining the internal temperature at 60°C. Then, after raising the temperature to 80°C and aging for 6 hours, after cooling to 40°C, 100 ml of ion-exchanged water was added, stirred, and left still. The monomer A3 layer of the lower layer was removed, the pressure was reduced at 80°C, and the mixture was dehydrated to obtain monomer A3 (yield: 70%).

(Synthesis Example 4: Monomer A4)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 46.6 g of 2-acryloyloxyethyl isocyanate (“Karenz AOI” manufactured by Showa Denko Co., Ltd.), 40 g of tetrahydrofuran, and methotrexate 0.012 g of quinone was injected. Air was introduced into the flask, and 24.1 g of n-butylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A4 (yield: 90%).

(Synthesis Example 5: Monomer A5)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 46.6 g of 2-acryloyloxyethyl isocyanate (“Karenz AOI” manufactured by Showa Denko Co., Ltd.), 40 g of tetrahydrofuran, and methotrexate 0.012 g of quinone was injected. Air was introduced into the flask and 61.1 g of n-dodecylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A5 (yield: 90%).

(Polymerization Example 1: Copolymer A)

250 g of isopropanol was charged into a 1 L separable flask equipped with a stirrer, thermometer, condenser, dropping funnel and nitrogen inlet tube, and the inside of the flask was purged with nitrogen to create a nitrogen atmosphere. A monomer solution obtained by mixing 66.2 g of isobutyl methacrylate (product name: acrylic ester IB (manufactured by Mitsubishi Rayon Co., Ltd.) and 233.8 g of monomer A1, and 50 g of isopropanol and 2,2'-azobis (2,4 -Dimethylvaleronitrile) (product name: V-65 (Wako Pure Chemical Industries, Ltd. product)) 0.6g was mixed, and the polymerization initiator solution was prepared, respectively.

The inside of the reaction vessel was heated up to 75°C, and the monomer solution and the polymerization initiator solution were simultaneously added dropwise over 3 hours, respectively. Then, it was made to react at 75 degreeC for 3 hours, and the isopropanol solution of the copolymer A was obtained. Subsequently, the solvent was removed under reduced pressure at 60°C for 180 minutes to obtain copolymer A.

(Polymerization Example 2: Copolymer B)

Copolymer B was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 177.7 g and the amount of monomer A1 was changed to 122.3 g.

(Polymerization Example 3: Copolymer C)

Copolymer C was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 115.1 g and the amount of monomer A1 was changed to 184.9 g.

(Polymerization Example 4: Copolymer D)

Copolymer D was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 177.4 g and monomer A1 to monomer A2, and 122.6 g was used.

(Polymerization Example 5: Copolymer E)

Copolymer E was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 177.4 g and monomer A1 was changed to monomer A3, and 122.6 g was used.

(Polymerization Example 6: Copolymer F)

Copolymer F was obtained by the same method as in Polymerization Example 1, except that 182.3 g of isobutyl methacrylate and monomer A1 were replaced with monomer A4, and 117.7 g of isobutyl methacrylate was used.

(Polymerization Example 7: Copolymer G)

Copolymer G was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 151.2 g and monomer A1 was changed to monomer A5, and 148.8 g was used.

(Polymerization Example 8: Copolymer H)

Copolymer H was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 133.6 g and the amount of monomer A1 was changed to 128.7 g and 37.7 g of methyl methacrylate was used.

(Polymerization Example 9: Copolymer I)

Copolymer I was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 133.0 g and the amount of monomer A1 was changed to 128.1 g and 38.9 g of styrene was used.

(Polymerization Example 10: Copolymer J)

Copolymer J was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 160.9 g and the amount of monomer A1 was changed to 129.1 g, and 10.0 g of acrylonitrile was used.

(Polymerization Example 11: Copolymer K)

Copolymer K was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 159.1 g and the amount of monomer A1 was changed to 127.7 g, and 13.2 g of acrylamide was used.

(Polymerization Example 12: Copolymer L)

Copolymer L was obtained by the same method as in Polymerization Example 1, except that the amount of isobutyl methacrylate was changed to 276.6 g and the amount of monomer A1 was changed to 23.4 g.

(Polymerization Example 13: Copolymer M)

Copolymer M was obtained in the same manner as in Polymerization Example 1 except that 84.5 g of 2-hydroxyethyl methacrylate was used instead of 215.5 g of isobutyl methacrylate and monomer A1.

[Measurement of Weight Average Molecular Weight]

The weight average molecular weight of the copolymers A to M was determined by gel permeation chromatography (GPC) under the following conditions.

Device: Tosoh Co., Ltd., HLC-8220

Column: LF-804, manufactured by Shodex

Standard material: polystyrene

Eluent: THF (tetrahydrofuran)

Flow rate: 1.0 ml/min

Column temperature: 40 ℃

Detector: RI (Differential Refractive Index Detector)

[Evaluation of thixotropic properties]

20 parts by weight of the copolymer and 80 parts by weight of dihydroterpineol were mixed, and the solution was stirred for 2 hours while heating at 60 ° C. to complete the solution. Shear rate dependence of viscosity in the range of 1 s ^-1 to 1,000 s ^-1 was measured. The ratio of viscosities at 1 s ^-1 and 1,000 s ^-1 was calculated as a TI value.

[Evaluation of thermal decomposition]

5 mg of the copolymer was placed in an aluminum pan, heated up to 500°C by TG/DTA at an air atmosphere at a heating rate of 10°C/min, and the remaining amount of the sample was measured.

[Evaluation of printability]

Based on 100 parts by weight of Ni powder (manufactured by JFE Mineral: NFP201S), 1 part by weight of oleoylsarcosine (manufactured by Nichiyu: Esrim 221P), 3 parts by weight of each binder resin, and 90 parts by weight of dihydroterpineol add part After stirring these mixtures using a planetary kneader, they were kneaded with three rolls to obtain Ni paste.

The obtained Ni paste was screen-printed, and the obtained printed body was checked with an optical microscope, and it was visually confirmed that there were no traces of bleeding or thread drag. If no bleeding or threading was observed, it was rated as ○ (good), and if bleeding or threading was observed, it was rated as × (poor).

In Examples 1 to 11, the thixotropy value was high, the heating residue was small, and the printability was high.

In Comparative Example 1, although the ratio of monomer 1 was less than 10 mol%, the heating residue was small, but the thixotropy value was low and the printability was also low.

In Comparative Example 2, the monomer-free copolymer of the present invention was used, but the heating residue was reduced, but the thixotropy value was low and the printability was also low.

In Comparative Example 3, ethyl cellulose was used, but the thixotropy value was large and the printability was high, but the heating residue was increased.

Embodiment of the second invention

Table 5 below shows the structure and symbol of the monomer (A).

(Synthesis Example 1: Monomer A1)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 46.6 g of 2-acryloyloxyethyl isocyanate (“Karenz AOI” manufactured by Showa Denko Co., Ltd.), 40 g of tetrahydrofuran, and methotrexate 0.012 g of quinone was injected. Air was introduced into the flask, and 24.1 g of n-butylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A1 (yield: 90%).

(Synthesis Example 2: Monomer A2)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 51.2 g of 2-methacryloyloxyethyl isocyanate (“Karenz MOI” manufactured by Showa Electric Co., Ltd.), 40 g of tetrahydrofuran, 0.012 g of methoquinone was injected. Air was introduced into the flask, and 24.1 g of n-butylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A2 (yield: 92%).

(Synthesis Example 3: Monomer A3)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 51.2 g of 2-methacryloyloxyethyl isocyanate ("Karenz MOI" manufactured by Showa Denko Co., Ltd.), 0.012 g of methoquinone, 0.034 g of butyltindilaurate was injected. Air was introduced into the flask, and n-butanol was added dropwise over 1 hour while maintaining the internal temperature at 60°C. Then, after raising the temperature to 80°C and aging for 6 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A3 (yield: 95%).

(Synthesis Example 4: Monomer A4)

Into a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet pipe, 2-hydroxyethyl methacrylate (Nichiyu Co., Ltd. "Bremmer E") and 0.012 g of methoquinone were charged. Air was introduced into the flask, and n-butyl isocyanate was added dropwise over 1 hour while maintaining the internal temperature at 60°C. Then, after raising the temperature to 80°C and aging for 6 hours, after cooling to 40°C, 100 ml of ion-exchanged water was added, stirred, and left still. The monomer A3 layer of the lower layer was removed, the pressure was reduced at 80°C, and the mixture was dehydrated to obtain monomer A4 (yield: 70%).

(Polymerization Example 1: Copolymer A)

In a 500 ml separable flask equipped with a stirrer, thermometer, condenser and nitrogen inlet tube, 210 g of isopropanol, 47.3 g of isobutyl methacrylate (product name: acrylic ester IB (manufactured by Mitsubishi Rayon Co., Ltd.)) and butyl acrylate (Product name: butyl acrylate (manufactured by Nippon Catalyst Co., Ltd.)) 7.1 g of monomer A1 and 35.6 g of monomer solution mixed with 2,2'-azobis (2,4-dimethylvaleronitrile) (product name: V-65 (manufactured by Wako Junyaku Kogyo Co., Ltd.) After injecting 0.2 g and purging the inside of the flask with nitrogen, the inside of the reaction container was heated up to 75°C, and it was made to react for 6 hours to obtain an isopropanol solution of the copolymer A. Subsequently, the solvent was removed under reduced pressure at 60°C for 180 minutes to obtain copolymer A.

(Polymerization Example 2: Copolymer B)

Copolymer B was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 69.2 g, the amount of butyl acrylate was changed to 7.8 g, and the amount of monomer A1 was changed to 13.0 g.

(Polymerization Example 3: Copolymer C)

Copolymer C was obtained in the same manner as in Polymerization Example 1 except that 37.0 g of monomer A2 was used instead of 6.9 g and monomer A1 for the amount of isobutyl methacrylate used at 46.1 g and the amount used for butyl acrylate.

(Polymerization Example 4: Copolymer D)

Copolymer D was obtained by the same method as in Polymerization Example 1 except that 37.1 g of monomer A3 was used instead of 6.9 g and monomer A1 for the amount of isobutyl methacrylate used at 46.0 g and the amount used for butyl acrylate.

(Polymerization Example 5: Copolymer E)

Copolymer E was obtained in the same manner as in Polymerization Example 1 except that 37.0 g of monomer A4 was used instead of 6.9 g and monomer A1 for the amount of isobutyl methacrylate used at 46.0 g and the amount of butyl acrylate used.

(Polymerization Example 6: Copolymer F)

11.7 g of methyl methacrylate (product name: Acrylic Ester M (manufactured by Mitsubishi Rayon Co., Ltd.)) was used, the amount of isobutyl methacrylate was 33.2 g, the amount of butyl acrylate was 7.5 g, and the amount of monomer A1 was used. Copolymer F was obtained in the same manner as in Polymerization Example 1 except that the amount of was changed to 37.0 g.

(Polymerization Example 7: Copolymer G)

20.6 g of 2-ethylhexyl methacrylate (product name: acrylic ester EH (manufactured by Mitsubishi Rayon Co., Ltd.)) was used, the amount of isobutyl methacrylate was 29.5 g, the amount of butyl acrylate was 6.6 g, monomer Copolymer G was obtained in the same manner as in Polymerization Example 1 except that the amount of A1 was changed to 33.3 g.

(Polymerization Example 8: Copolymer H)

11.6 g of ethyl acrylate (product name: ethyl acrylate (manufactured by Nippon Catalyst Co., Ltd.)) was used, and the amount of isobutyl methacrylate was changed to 41.2 g and the amount of monomer A1 was changed to 37.2 g. Copolymer H was obtained by the same method.

(Polymerization Example 9: Copolymer I)

5.6 g of dimethylacrylamide (product name: DMAA (manufactured by KJ Chemical Co., Ltd.)) was used, the amount of isobutyl methacrylate was 40.5 g, the amount of butyl acrylate was 7.3 g, and the amount of monomer A1 was 36.6 g. Copolymer I was obtained in the same manner as in Polymerization Example 1 except for changing.

(Polymerization Example 10: Copolymer J)

3.1 g of acrylonitrile (product name: acrylonitrile (manufactured by Tokyo Chemical Industry Co., Ltd.)) was used, the amount of isobutyl methacrylate was 41.7 g, the amount of butyl acrylate was 7.5 g, and the amount of monomer A1 was Copolymer J was obtained in the same manner as in Polymerization Example 1 except for changing to 37.7 g.

(Polymerization Example 11: Copolymer K)

Copolymer K was obtained in the same manner as in Polymerization Example 1, except that the amount of isobutyl methacrylate was changed to 29.0 g, the amount of butyl acrylate was changed to 6.5 g, and the amount of monomer A1 was changed to 54.5 g.

(Polymerization Example 12: Copolymer L)

Copolymer L was obtained by the same method as in Polymerization Example 1, except that the amount of isobutyl methacrylate was changed to 83.4 g and the amount of monomer A1 was changed to 6.6 g.

(Polymerization Example 13: Copolymer M)

In the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was changed to 64.7 g and 25.3 g of 2-hydroxyethyl methacrylate (product name: Bremmer E (manufactured by Nichiyu Co., Ltd.)) was used. Copolymer M was obtained.

[Measurement of Weight Average Molecular Weight]

The weight average molecular weight of the copolymers A to M was determined by gel permeation chromatography (GPC) under the following conditions.

Device: Tosoh Co., Ltd., HLC-8220

Column: LF-804, manufactured by Shodex

Standard material: polystyrene

Eluent: THF (tetrahydrofuran)

Flow rate: 1.0 ml/min

Column temperature: 40 ℃

Detector: RI (Differential Refractive Index Detector)

[Evaluation of thixotropic properties]

20 parts by mass of the copolymer and 80 parts by mass of dihydroterpineol were mixed, and the solution was stirred for 2 hours while heating at 60°C and completely dissolved. The shear rate of the viscosity in the range of 1 s ^-1 to 1,000 s ^-1 with a rheometer Dependence was measured. The ratio of the viscosity at 1 s ^-1 and 1,000 s ^-1 was calculated as a TI value.

[Evaluation of thermal decomposition]

5 mg of the copolymer was placed in an aluminum pan, heated up to 500°C by TG/DTA in an air atmosphere at a heating rate of 10°C/minute, and the remaining amount of the sample was measured.

[Evaluation of adhesion]

Based on 100 parts by mass of barium titanate powder (Sakai Chemicals: BT-03), 0.8 parts by mass of a high-molecular polycarboxylic acid-based dispersing agent (Mariarim AKM-0531 by Nichiyu), 18 parts by mass toluene, 18 parts by mass ethanol, 100 parts by mass of zirconia balls having a particle size of 1 mm were put in a ball mill, and after mixing for 8 hours, 8 parts by mass of polyvinyl butyral (Sekisui Chemical Co., Ltd.: BM-2), 10 parts by mass of toluene, and 10 parts by mass of ethanol were added. After further mixing for 12 hours, the zirconia balls were separated by filtration to prepare a ceramic slurry. Then, the ceramic slurry was applied in a sheet form having a thickness of 5 μm on a PET film serving as a carrier sheet by a doctor blade method, and then dried at 90° C. for 10 minutes to prepare a green sheet.

To 100 parts by mass of Ni powder (manufactured by JFE Mineral: NFP201S), 1 part by mass of oleoylsarcosine (manufactured by Nichiyu: Esrim 221P), 3 parts by mass of a binder resin, and 90 parts by mass of dihydroterpineol were added. do. After stirring these mixtures with a planetary kneader, they were kneaded with three rolls to obtain a Ni paste. The obtained Ni paste was printed on a green sheet prepared by screen printing, dried at 90°C for 10 minutes, and then a green sheet was additionally overlaid thereon and pressed under conditions of 50°C, 100 kg/cm2, and 5 seconds. The compressed sheet was peeled with a tensile tester, and the force required for peeling was measured.

In Examples 1 to 11, the thixotropy value was high, the heating residue was small, and the adhesiveness to the sheet was high.

In Comparative Example 1, the proportion of the monomer (A) was less than 10 mol% and the heating residue was reduced, but the thixotropy value was low.

In Comparative Example 2, the monomer-free copolymer of the present invention was used, and although the heating residue was reduced, the thixotropy value was lowered.

In Comparative Example 3, ethyl cellulose was used, and although the thixotropy value was large, there were many heating residues and the adhesiveness was low.

Embodiment of the third invention

Table 9 below shows the structure and symbol of the monomer (A).

(Synthesis Example 1: Monomer A1)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 51.2 g of 2-methacryloyloxyethyl isocyanate (“Karenz MOI” manufactured by Showa Electric Co., Ltd.), 40 g of tetrahydrofuran, 0.012 g of methoquinone was injected. Air was introduced into the flask, and 24.1 g of n-butylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging|ripening at 40 degreeC for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60 degreeC, and monomer A1 was obtained (yield 92%).

(Synthesis Example 2: Monomer A2)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 51.2 g of 2-methacryloyloxyethyl isocyanate ("Karenz MOI" manufactured by Showa Denko Co., Ltd.), 0.012 g of methoquinone, 0.034 g of butyltindilaurate was injected. Air was introduced into the flask, and n-butanol was added dropwise over 1 hour while maintaining the internal temperature at 60°C. Then, after raising the temperature to 80°C and aging for 6 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A2 (yield: 95%).

(Synthesis Example 3: Monomer A3)

Into a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet pipe, 2-hydroxyethyl methacrylate (“Bremmer E” manufactured by Nichiyu Co., Ltd.) and 0.012 g of methoquinone were charged. Air was introduced into the flask, and n-butyl isocyanate was added dropwise over 1 hour while maintaining the internal temperature at 60°C. Then, after raising the temperature to 80°C and aging for 6 hours, after cooling to 40°C, 100 ml of ion-exchanged water was added, stirred, and left still. The monomer A3 layer of the lower layer was removed, the pressure was reduced at 80°C, and the mixture was dehydrated to obtain monomer A3 (yield: 70%).

(Synthesis Example 4: Monomer A4)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 46.6 g of 2-acryloyloxyethyl isocyanate (“Karenz AOI” manufactured by Showa Denko Co., Ltd.), 40 g of tetrahydrofuran, and methotrexate 0.012 g of quinone was injected. Air was introduced into the flask, and 24.1 g of n-butylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A4 (yield: 90%).

(Synthesis Example 5: Monomer A5)

To a 300 ml flask equipped with a stirrer, thermometer, condenser, dropping funnel and air inlet tube, 46.6 g of 2-acryloyloxyethyl isocyanate (“Karenz AOI” manufactured by Showa Denko Co., Ltd.), 40 g of tetrahydrofuran, and methotrexate 0.012 g of quinone was injected. Air was introduced into the flask and 61.1 g of n-dodecylamine was added dropwise over 1 hour while maintaining the internal temperature at 40°C. Then, after aging at 40°C for 2 hours, tetrahydrofuran was distilled off under reduced pressure at 60°C to obtain monomer A5 (yield: 90%).

(Polymerization Example 1: Copolymer A)

250 g of isopropanol was charged into a 1 L separable flask equipped with a stirrer, thermometer, condenser, dropping funnel and nitrogen inlet tube, and the inside of the flask was purged with nitrogen to create a nitrogen atmosphere. 212.1 g of isobutyl methacrylate (iBMA: product name: acrylic ester IB (manufactured by Mitsubishi Rayon Co., Ltd.)), 19.9 g of methyl methacrylate (MMA: product name: acrylic ester M (manufactured by Mitsubishi Rayon Co., Ltd.)) A monomer solution obtained by mixing 68.0 g of monomer A1, and 50 g of isopropanol and 2,2'-azobis(2,4-dimethylvaleronitrile) (product name: V-65 (manufactured by Wako Junyaku Kogyo Co., Ltd.)) 0.3 g Polymerization initiator solutions mixed with each were prepared.

The inside of the reaction vessel was heated up to 75°C, and the monomer solution and the polymerization initiator solution were simultaneously added dropwise over 3 hours, respectively. Then, it was made to react at 75 degreeC for 3 hours, and the isopropanol solution of the copolymer A was obtained. Subsequently, the solvent was removed under reduced pressure at 60°C for 180 minutes to obtain copolymer A.

(Polymerization Example 2: Copolymer B)

Copolymer B was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 156.3 g, the amount of methyl methacrylate was changed to 18.3 g, and the amount of monomer A1 was changed to 125.3 g.

(Polymerization Example 3: Copolymer C)

Copolymer C was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 94.3 g, the amount of methyl methacrylate was changed to 16.6 g, and the amount of monomer A1 was changed to 189.1 g.

(Polymerization Example 4: Copolymer D)

Copolymer D was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 155.8 g and the amount of methyl methacrylate was changed from 18.3 g and monomer A1 to monomer A2, and 126.0 g was used.

(Polymerization Example 5: Copolymer E)

Copolymer E was obtained in the same manner as in Polymerization Example 4 except that the monomer A2 was replaced with the monomer A3.

(Polymerization Example 6: Copolymer F)

Copolymer F was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 160.4 g and the amount of methyl methacrylate was changed to 18.8 g and monomer A1 was changed to monomer A4, and 120.8 g was used.

(Polymerization Example 7: Copolymer G)

Copolymer G was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 132.4 g and the amount of methyl methacrylate was changed from 15.5 g and monomer A1 to monomer A5, and 152.0 g was used.

(Polymerization Example 8: Copolymer H)

Copolymer H was obtained by the same method as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 133.7 g, the amount of methyl methacrylate was changed to 37.7 g, and the amount of monomer A1 was changed to 128.6 g.

(Polymerization Example 9: Copolymer I)

Copolymer I was prepared in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 109.3 g, the amount of methyl methacrylate was changed to 19.2 g, and the amount of monomer A1 was changed to 131.4 g, and 40.0 g of styrene was used. Got it.

(Polymerization Example 10: Copolymer J)

Copolymer in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 137.8 g, the amount of methyl methacrylate was changed to 19.4 g, and the amount of monomer A1 was changed to 132.5 g, and 10.3 g of acrylonitrile was used. got J.

(Polymerization Example 11: Copolymer K)

Copolymer K was prepared in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate was changed to 136.2 g, the amount of methyl methacrylate was changed to 19.2 g, and the amount of monomer A1 was changed to 131.0 g, and 13.6 g of acrylamide was used. got

(Polymerization Example 12: Copolymer L)

Copolymer L was obtained by the same method as in Polymerization Example 1, except that the amount of isobutyl methacrylate was changed to 276.6 g and the amount of monomer A1 was changed to 23.4 g.

(Polymerization Example 13: Copolymer M)

Copolymer M was obtained in the same manner as in Polymerization Example 1 except that 84.5 g of 2-hydroxyethyl methacrylate (HEMA) was used instead of 215.5 g of isobutyl methacrylate and monomer A1.

[Measurement of Weight Average Molecular Weight]

The weight average molecular weight of the copolymers A to M was determined by gel permeation chromatography (GPC) under the following conditions.

Device: Tosoh Co., Ltd., HLC-8220

Column: LF-804, manufactured by Shodex

Standard material: polystyrene

Eluent: THF (tetrahydrofuran)

Flow rate: 1.0 ml/min

Column temperature: 40 ℃

Detector: RI (Differential Refractive Index Detector)

[Evaluation of Resin Strength]

A solution obtained by dissolving 30 parts by mass of the binder resin in a mixed solvent of 35 parts by mass of toluene and 35 parts by mass of ethanol was applied onto a PET film with bar coater No. 32, dried at 100 ° C. for 1 hour, and then peeled off, A resin sheet with a thickness of 30 µm was obtained. The obtained resin sheet was cut out to a size of 1 cm x 5 cm, and the resin strength was measured with a tensile tester at a tensile speed of 10 mm/min, and the average value measured 5 times was used.

[Evaluation of sheet strength]

Based on 100 parts by mass of barium titanate particles (Sakai Chemical Co., Ltd.: BT-03), 0.8 parts by mass of a high-molecular polycarboxylic acid-based dispersant (Mariarim AKM-0531 manufactured by Nichiyu), 18 parts by mass toluene, 18 parts by mass ethanol, 100 parts by mass of zirconia balls having a particle size of 1 mm were put into a ball mill, and after mixing for 8 hours, 8 parts by mass of binder resin, 10 parts by mass of toluene, and 10 parts by mass of ethanol were added, and after mixing for further 12 hours, the zirconia balls were separated by filtration Thus, a ceramic slurry was prepared. Then, the ceramic slurry was applied in a sheet form having a thickness of 20 μm on a PET film serving as a carrier sheet by a doctor blade method, and then dried at 90° C. for 10 minutes to prepare a green sheet. The strength of the prepared green sheet was measured with a tensile tester at a tensile speed of 10 mm/min, and an average value obtained by measuring 5 times was used.

[Evaluation of thermal decomposability]

5 mg of the copolymer was placed in an aluminum pan, heated up to 500°C by TG/DTA at an air atmosphere at a heating rate of 10°C/min, and the remaining amount of the sample was measured.

In Examples 1 to 11, the sheet strength of the ceramics green sheet was increased, and the heating residue was reduced.

In Comparative Example 1, although the ratio of monomer A1 was less than 10 mol%, the heating residue was reduced, but the sheet strength was lowered.

In Comparative Example 2, a copolymer not containing the monomer (A) of the present invention was used, but the heating residue was reduced, but the sheet strength was lowered.

In Comparative Example 3, polyvinyl butyral resin was used, and the sheet strength was high, but the heating residue was large.

Claims (11)

delete A conductive paste composition characterized by containing a binder resin, an organic solvent and metal particles,
In the binder resin, the molar ratio of the monomer (A) represented by the following general formula (1) is 10 mol% to 100 mol%, and the molar ratio of the monomer (A) and other monomers (B) copolymerizable with the monomer (A) is 0 to 90 mol%. , A conductive paste composition comprising a polymer having a weight average molecular weight of 10,000 to 1,000,000.

(In formula (1),
R ¹ represents a hydrogen atom or a methyl group;
R ² represents a hydrogen atom, a methyl group or an ethyl group;
R ³ represents an alkyl group having 1 to 18 carbon atoms;
X and Y each represent NH) According to claim 2,
A conductive paste composition comprising 0.5 to 30 parts by weight of the binder resin and 10 to 200 parts by weight of the organic solvent based on 100 parts by weight of the metal particles. As a binder resin for conductive paste made of a binder resin,
In the binder resin, the molar ratio of the monomer (A) represented by the following general formula (1) is 10 mol% to 90 mol%, and the molar ratio of the (meth)acrylic acid alkyl ester (D) represented by the following general formula (2) is 10 to 90 mol%. 90 mol%, the molar ratio of the monomer (A) and the other monomer copolymerizable with the (meth)acrylic acid alkylester (D) is 0 to 30 mol%, and the weight average molecular weight is 10,000 to 1,000,000. Binder resin for conductive paste.

(In formula (1),
R ¹ represents a hydrogen atom or a methyl group;
R ² represents a hydrogen atom, a methyl group or an ethyl group;
R ³ represents an alkyl group having 1 to 18 carbon atoms;
X and Y each represent NH)

(In formula (2),
R ⁴ represents a hydrogen atom or a methyl group;
R ⁵ represents an alkyl group having 1 to 18 carbon atoms) According to claim 4,
A binder resin for conductive paste, characterized in that the other monomer copolymerizable with the monomer (A) and the (meth)acrylic acid alkyl ester (D) is acrylonitrile or alkyl acrylamide. A conductive paste composition characterized by containing the binder resin according to claim 4 or 5, an organic solvent and metal particles. According to claim 6,
The conductive paste composition, characterized in that the mass ratio of the binder resin is 0.5 to 30 parts by mass and the mass ratio of the organic solvent is 10 to 200 parts by mass with respect to 100 parts by mass of the metal particles. As a binder resin for ceramics made of a binder resin,
The binder resin has a molar ratio of a monomer (A) represented by the following general formula (1) of 10 mol% to 100 mol%, and a molar ratio of another monomer (E) copolymerizable with the monomer (A) of 0 to 90 mol%. , A binder resin for ceramics characterized by comprising a polymer having a weight average molecular weight of 10,000 to 1,000,000.

(In formula (1),
R ¹ represents a hydrogen atom or a methyl group;
R ² represents a hydrogen atom, a methyl group or an ethyl group;
R ³ represents an alkyl group having 1 to 18 carbon atoms;
X and Y each represent NH) A ceramic composition characterized by containing the binder resin according to claim 8, an organic solvent and ceramic particles. According to claim 9,
A ceramic composition characterized by containing 0.5 to 30 parts by mass of the binder resin and 10 to 200 parts by mass of the organic solvent with respect to 100 parts by mass of the ceramic particles. A ceramic molded body characterized by comprising the ceramic composition according to claim 9 or 10.