(Meth)acrylic resin, vehicle composition, slurry composition and electronic components

Abstract

The present invention provides a (meth)acrylic resin capable of producing conductive pastes with minimal viscosity variation. The present invention also provides a vehicle composition containing the (meth)acrylic resin, a slurry composition containing the vehicle composition, and an electronic component using the slurry composition. The present invention relates to a (meth)acrylic resin having at least one constituent unit from monomer A, which is a methacrylic acid ester monomer having repeating units of propylene oxide, a weight-average molecular weight (Mw) of 600 to 900 on a polystyrene basis, and a molecular weight dispersion of 1.03 to 1.09, and monomer B, which is a methacrylic acid ester monomer having repeating units of ethylene oxide, a weight-average molecular weight (Mw) of 1400 to 2100 on a polystyrene basis, and a molecular weight dispersion of 1.02 to 1.07, wherein when the content of constituent units derived from all monomer components is 100% by weight, the total content of constituent units derived from monomer A and constituent units derived from monomer B is 1 to 30% by weight.

Description

[Technical Field]

[0001] The present invention relates to (meth)acrylic resin, vehicle composition, slurry composition, and electronic components. [Background technology]

[0002] Multilayer ceramic capacitors are known to have a structure comprising a laminate in which multiple dielectric layers and internal electrodes are alternately stacked, and a pair of external electrodes provided to sandwich the laminate. The external electrodes are formed by applying an external electrode slurry composition to the surface of the laminate and sintering it.

[0003] In recent years, with the miniaturization of conductive metal particles, the miniaturization of inorganic particles used in external electrodes has also progressed. Miniaturized inorganic particles tend to aggregate in slurry compositions, and when aggregation occurs, voids tend to remain in the degreasing and firing processes, and the dispersibility of the inorganic particles decreases. As a result, when used in electronic components such as multilayer ceramic capacitors, this can cause a decrease in the electrical characteristics of the product.

[0004] Common binder resins used for external electrodes include, for example, (meth)acrylic resins and ethyl cellulose. For instance, Patent Document 1 describes a configuration using an organic vehicle that combines alcohols such as terpineol with a (meth)acrylic resin as an organic binder. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6950833 [Overview of the project] [Problems that the invention aims to solve]

[0006] In recent years, yield improvement has been progressing to improve the production efficiency of multilayer ceramic capacitors. Among the production processes, the process of applying a paste for external electrodes to the chips is particularly prone to process defects, and in order to improve the yield, it is necessary to keep the viscosity of the paste for external electrodes constant. However, in a configuration using a conventional organic vehicle such as the configuration described in Patent Document 1, there is a problem that process defects are likely to occur due to variations in the viscosity of the resulting paste. Therefore, there is a demand for a conductive paste with little variation in viscosity.

[0007] An object of the present invention is to provide a (meth)acrylic resin capable of producing a conductive paste with little variation in viscosity. Another object is to provide a vehicle composition containing the (meth)acrylic resin, a slurry composition containing the vehicle composition, and an electronic component using the slurry composition.

Means for Solving the Problems

[0008] The present disclosure 1 is a methacrylic acid ester monomer having a repeating unit of propylene oxide, a weight average molecular weight (Mw) in terms of polystyrene of 600 to 900, and a molecular weight dispersity of 1.03 to 1.09, and a methacrylic acid ester monomer having a repeating unit of ethylene oxide, a weight average molecular weight (Mw) in terms of polystyrene of 1400 to 2100, and a molecular weight dispersity of 1.02 to 1.07. It has at least one structural unit selected from the structural units derived from monomer B, and when the content of the structural units derived from all monomer components is 100% by weight, the total content of the structural units derived from monomer A and the structural units derived from monomer B is 1 to 30% by weight. It is a (meth)acrylic resin. The present disclosure 2 is the (meth)acrylic resin of the present disclosure 1 in which the weighted average molecular weight of the monomer component is 135 or more and 530 or less. The present disclosure 3 is the (meth)acrylic resin of the present disclosure 1 in which the weighted average molecular weight of the monomer component is 160 or more and 485 or less. Disclosure 4 is a vehicle composition comprising the (meth)acrylic resin of Disclosure 1, 2, or 3 and a vehicle solvent. Disclosure 5 is a slurry composition containing the vehicle composition of Disclosure 4, inorganic particles, and a dispersant. Disclosure 6 is an electronic component made using the slurry composition of Disclosure 5. The present invention will be described in detail below.

[0009] The inventors of the present invention have discovered that a conductive paste with less viscosity variation can be produced by using a (meth)acrylic resin containing a predetermined amount of constituent units derived from a specific long-chain methacrylic monomer component as a binder resin, and have completed the present invention.

[0010] The (meth)acrylic resin of the present invention has at least one constituent unit from monomer A, which is a methacrylic acid ester monomer having repeating units of propylene oxide, a weight-average molecular weight (Mw) on a polystyrene basis of 600 to 900, and a molecular weight dispersion of 1.03 to 1.09, and monomer B, which is a methacrylic acid ester monomer having repeating units of ethylene oxide, a weight-average molecular weight (Mw) on a polystyrene basis of 1400 to 2100, and a molecular weight dispersion of 1.02 to 1.07. The (meth)acrylic resin of the present invention may have at least one of the constituent units derived from monomer A and the constituent units derived from monomer B, or it may have only the constituent units derived from monomer A, or only the constituent units derived from monomer B. It may also have both the constituent units derived from monomer A and the constituent units derived from monomer B.

[0011] The above monomer A is a methacrylic acid ester monomer having repeating units of propylene oxide, and specifically, polypropylene glycol methacrylate is an example. Furthermore, the above monomer A may have an alkoxy group at its terminus. Examples of such alkoxy groups include a methoxy group, an ethoxy group, and a butoxy group.

[0012] The weight-average molecular weight (Mw) of monomer A, calculated on a polystyrene basis, is 600 to 900. The Mw is preferably 700 or higher, and preferably 800 or lower. Furthermore, the dispersion (Mw / Mn) of monomer A is 1.03 to 1.09. The dispersion is preferably 1.04 or higher, and preferably 1.07 or lower. Having a constituent unit with the above-described structure makes it possible to suppress variations in the viscosity of the resulting conductive paste. Furthermore, when multiple monomers with different compositions are used as methacrylate ester monomers having repeating propylene oxide units for monomer A, Mw and dispersion can be measured by GPC or the like. Specifically, when multiple monomers with different compositions are used, a mixture can be prepared by mixing the monomers in the ratios used, and Mw and dispersion can be measured by GPC measurement using this mixture.

[0013] The monomer B mentioned above is a methacrylic acid ester monomer having repeating units of ethylene oxide, and specifically, polyethylene glycol methacrylate is an example. Furthermore, the monomer B may have an alkoxy group at its terminus. Examples of such alkoxy groups include a methoxy group, an ethoxy group, and a butoxy group.

[0014] The weight-average molecular weight (Mw) of monomer B, calculated on a polystyrene basis, is 1400 to 2100. The Mw is preferably 1600 or higher, and preferably 1900 or lower. Furthermore, the dispersion degree of monomer B is 1.02 to 1.07. The dispersion degree is preferably 1.04 or higher, and preferably 1.06 or lower. Having a constituent unit with the above-described structure makes it possible to suppress variations in the viscosity of the resulting conductive paste. Furthermore, when multiple monomers with different compositions are used as methacrylic acid ester monomers having repeating ethylene oxide units for monomer B, Mw and dispersion can be measured by GPC or the like. Specifically, when multiple monomers with different compositions are used, a mixture can be prepared by mixing the monomers in the ratios used, and Mw and dispersion can be measured by GPC measurement using this mixture. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) are average molecular weights calculated on a polystyrene basis using THF as the mobile phase. These can be obtained by performing GPC measurements using, for example, one ACQUITY APC XT 125 column linked with two ACQUITY APC XT 45 columns (ACQUITY APC XT125-XT45-XT45, manufactured by Waters).

[0015] The Mw and dispersion of monomer A can be controlled, for example, by adjusting the blending ratio of multiple polypropylene glycols with different number-average molecular weights (Mn) for the polypropylene glycol used as a raw material for the methacrylic acid ester monomer. Furthermore, the Mw and dispersion of monomer B can be controlled, for example, by adjusting the blending ratio of multiple polyethylene glycols with different number-average molecular weights (Mn) for polyethylene glycol, which is used as a raw material for methacrylic acid ester monomers.

[0016] In the (meth)acrylic resin of the present invention, when the content of constituent units derived from all monomer components is set to 100% by weight, the total content of constituent units derived from monomer A and constituent units derived from monomer B is 1 to 30% by weight. By using a (meth)acrylic resin containing a predetermined amount of constituent units derived from the above-mentioned specific long-chain methacrylic monomer component as a binder resin, variations in the viscosity of the resulting conductive paste can be suppressed. The above content is preferably 5% by weight or more, more preferably 8% by weight or more, preferably 25% by weight or less, and more preferably 20% by weight or less. The above content can be measured, for example, by pyrolysis GC-MS.

[0017] When the (meth)acrylic resin of the present invention has both constituent units derived from monomer A and constituent units derived from monomer B, the content ratio (weight ratio) of constituent units derived from monomer A to constituent units derived from monomer B is preferably 1.0 / 2.0 or more, and preferably 2.0 / 1.0 or less.

[0018] The (meth)acrylic resin of the present invention may have constituent units derived from other (meth)acrylic acid polyalkylene glycols other than the constituent units derived from monomer A and the constituent units derived from monomer B. Other polyalkylene glycols (meth)acrylates mentioned above include polyethylene glycol acrylate, polypropylene glycol acrylate, polytetramethylene glycol (meth)acrylate, and polyethylene glycol methacrylate and polypropylene glycol methacrylate, whose Mw and dispersion are outside the above ranges.

[0019] The (meth)acrylic resin of the present invention preferably has structural units derived from alkyl (meth)acrylate in addition to structural units derived from monomer A and structural units derived from monomer B. The above (meth)acrylate alkyl ester may have a linear alkyl group or a branched alkyl group.

[0020] The (meth)acrylic resin of the present invention preferably has constituent units derived from an alkyl (meth)acrylate ester having a branched alkyl group. (Meth)acrylic resins containing alkyl (meth)acrylate esters having branched alkyl groups exhibit excellent decomposition properties under an inert gas atmosphere.

[0021] As the alkyl (meth)acrylate ester having the branched alkyl group described above, it is preferable that the branched alkyl group has 3 or more carbon atoms, more preferably 4 or more, preferably 20 or fewer, more preferably 15 or fewer, even more preferably 12 or fewer, and even more preferably 10 or fewer.

[0022] Examples of alkyl (meth)acrylate esters having the branched alkyl group mentioned above include isopropyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isopentyl (meth)acrylate, isohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, and isodecyl (meth)acrylate. Among these, isopropyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isodecyl (meth)acrylate are preferred, isopropyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, 2-ethylhexyl methacrylate, and isodecyl methacrylate are more preferred, and isobutyl methacrylate and 2-ethylhexyl methacrylate are even more preferred. The above-mentioned (meth)acrylic resin preferably has at least one constituent unit selected from the group consisting of constituent units derived from isobutyl methacrylate and constituent units derived from 2-ethylhexyl methacrylate, as a constituent unit derived from the above-mentioned alkyl (meth)acrylate having a branched alkyl group. Having such a configuration can increase the decomposition rate of the (meth)acrylic resin.

[0023] In the (meth)acrylic resin of the present invention, when the content of constituent units derived from all monomer components is 100% by weight, the content of constituent units derived from the branched alkyl group-containing alkyl (meth)acrylate is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 70% by weight or less, and more preferably 60% by weight or less. Within the above range, a conductive paste composition with excellent low-temperature decomposition properties can be obtained. The above content can be measured, for example, by pyrolysis GC-MS.

[0024] The (meth)acrylic resin of the present invention preferably has constituent units derived from an alkyl (meth)acrylate ester having a linear alkyl group. The number of carbon atoms in the linear alkyl group described above is preferably 1 or more, more preferably 2 or more, preferably 10 or less, and more preferably 6 or less.

[0025] Examples of alkyl (meth)acrylate esters having the linear alkyl group mentioned above include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, and n-hexyl (meth)acrylate. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, and n-butyl (meth)acrylate are preferred, and ethyl methacrylate and n-butyl methacrylate are more preferred.

[0026] In the (meth)acrylic resin of the present invention, when the content of constituent units derived from all monomer components is set to 100% by weight, the content of constituent units derived from the alkyl (meth)acrylate ester having the linear alkyl group is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 80% by weight or less, and more preferably 70% by weight or less. By setting the range as described above, handling characteristics such as printability will be improved. The above content can be measured, for example, by pyrolysis GC-MS.

[0027] The (meth)acrylic resin of the present invention may further have constituent units derived from (meth)acrylic acid esters in which the ester substituent has a cyclic structure. Examples of (meth)acrylic acid esters having a cyclic structure in the above-mentioned ester substituent include alkyl (meth)acrylic acid esters having a cyclic alkyl group such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate, and (meth)acrylic acid esters having a glycidyl group such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate.

[0028] In the (meth)acrylic resin of the present invention, when the content of constituent units derived from all monomer components is taken as 100% by weight, the content of constituent units derived from the alkyl (meth)acrylate is preferably 70% by weight or more, more preferably 75% by weight or more, preferably 99% by weight or less, and more preferably 92% by weight or less.

[0029] In the (meth)acrylic resin of the present invention, from the viewpoint of further suppressing viscosity variations, the weighted average molecular weight of the monomer component is preferably 135 or more, more preferably 160 or more, preferably 530 or less, and more preferably 485 or less. The above weighted average molecular weight can be calculated by multiplying the molecular weight of each monomer component by the proportion of each monomer component in the total monomer components (weight % / 100) and summing these results.

[0030] The weight-average molecular weight (Mw) of the (meth)acrylic resin of the present invention is preferably 20,000 or more, and preferably 4,000,000 or less. When the above Mw is 20,000 or more, the viscosity of the slurry composition does not become too low, and the dispersibility of inorganic particles can be improved. When the above Mw is 4 million or less, the coating strength can be increased, and the viscosity of the slurry composition becomes sufficiently high, improving storage stability and resulting in excellent printability. The above Mw is preferably 30,000 or more, more preferably 50,000 or more, preferably 3,500,000 or less, more preferably 3,000,000 or less, even more preferably 2,000,000 or less, and even more preferably 1,000,000 or less.

[0031] The ratio (Mw / Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the (meth)acrylic resin of the present invention is usually 1.0 or higher, preferably 1.5 or higher, more preferably 2.0 or higher, preferably 10.0 or lower, more preferably 8.0 or lower, and even more preferably 6.0 or lower. By keeping the viscosity within the above range, a suitable amount of low-polymerization components are included, resulting in a viscosity within a desirable range for the slurry composition and increasing productivity. Note that the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are average molecular weights calculated on a polystyrene basis, and can be obtained by performing GPC measurements using, for example, column LF-804 (manufactured by Showa Denko Corporation).

[0032] The glass transition temperature (Tg) of the (meth)acrylic resin of the present invention is preferably 20°C or higher, more preferably 30°C or higher, even more preferably 40°C or higher, preferably 80°C or lower, more preferably 70°C or lower, even more preferably 60°C or lower, and even more preferably 50°C or lower. The glass transition temperature (Tg) can be measured, for example, using a differential scanning calorimeter (DSC).

[0033] When the (meth)acrylic resin of the present invention is in the form of particles, the average particle size of the resin particles is preferably 0.1 μm or more, more preferably 0.2 μm or more, even more preferably 0.3 μm or more, preferably 1.0 μm or less, more preferably 0.9 μm or less, and even more preferably 0.8 μm or less, from the viewpoint of solubility. The above average particle diameter can be determined, for example, by measuring the volume-average particle diameter using a laser diffraction / scattering particle size distribution analyzer.

[0034] The CV value of the particle size of the (meth)acrylic resin particles is preferably 15% or less, more preferably 12% or less, even more preferably 10% or less, and even more preferably 8% or less. By setting the range as described above, the solubility of (meth)acrylic resin can be further improved. Improved solubility increases productivity, and the reduction in undissolved resin improves tensile performance. The lower limit is not particularly limited; for example, it could be 0%. The above CV value can be calculated by observing (meth)acrylic resin particles using a scanning electron microscope and taking the average and standard deviation of the particle diameters of 100 particles. The above CV value tends to decrease when persulfates such as ammonium persulfate or potassium persulfate are used.

[0035] The method for producing the (meth)acrylic resin of the present invention is not particularly limited. For example, multiple polyethylene glycols or polypropylene glycols with different number-average molecular weights (Mn) may be mixed with methacrylic anhydride or the like to produce monomers A and B having a weight-average molecular weight (Mw) and dispersion within a predetermined range. Then, a dispersion medium such as water is added to the raw material monomer mixture containing the obtained monomers A and B, and other alkyl (meth)acrylate esters, etc., to prepare a monomer mixture. Furthermore, a polymerization initiator is added to the obtained monomer mixture to polymerize and produce a (meth)acrylic resin. Alternatively, a chain transfer agent may be added to the monomer mixture. The polymerization method is not particularly limited and includes emulsion polymerization, suspension polymerization, bulk polymerization, interfacial polymerization, and solution polymerization. Among these, solution polymerization is preferred.

[0036] In addition to water, organic solvents can also be used as the dispersion medium. Examples of the above-mentioned organic solvents include toluene, ethyl acetate, butyl acetate, pentyl acetate, hexyl acetate, ethyl butyrate, butyl butyrate, pentyl butyrate, hexyl butyrate, isopropanol, methyl isobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol ethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisobutyl ether, trimethylpentanediol monoisobutyrate, butyl carbitol, butyl carbitol acetate, terpineol, terpineol acetate, dihydroterpineol, dihydroterpineol acetate, texanol, isophorone, butyl lactate, dioctyl phthalate, dioctyl adipate, benzyl alcohol, phenylpropylene glycol, cresol, and the like. Among these, butyl acetate, terpineol, terpineol acetate, dihydroterpineol, dihydroterpineol acetate, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisobutyl ether, butyl carbitol, butyl carbitol acetate, and texanol are preferred. Furthermore, butyl acetate, terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate are more preferred. These organic solvents may be used individually or in combination of two or more.

[0037] Examples of polymerization initiators include lauroyl peroxide, dilauryl peroxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, cyclohexanone peroxide, disuccinate peroxide, potassium persulfate, and ammonium persulfate. Examples of these commercially available products include Permenta H, Permil P, Perocta H, Permil H-80, Perloyle 355, Perbutyl H-69, Perhexa H, Perloyle SA, Perloyle L (all manufactured by NOF Corporation), Trigonox 27, Trigonox 421 (all manufactured by Nouryon).

[0038] Examples of the above-mentioned chain transfer agents include 1-decanethiol, butanethiol, octanthiol, dodecanethiol, hexadecanethiol, octadecanethiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, octyl 2-mercaptopropionate, octyl 3-mercaptopropionate, 2-ethylhexyl mercaptopropionate, 2-ethylhexyl thioglycolate, butyl-3-mercaptopropionate, methyl-3-mercaptopropionate, 2,2-(ethylenedioxy)diethanethiol, ethanethiol, and 4-methylbenzene. Examples of thiols include thiols, 2-mercaptoethyl octanoate, 1,8-dimercapto-3,6-dioxaoctane, decantrithiol, dodecyl mercaptan, diphenyl sulfoxide, dibenzyl sulfide, 2,3-dimethylcapto-1-propanol, mercaptoethanol, thiosalicylic acid, thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, mercaptoacetic acid, mercaptosuccinic acid, 2-mercaptoethanesulfonic acid, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and other thiol compounds.

[0039] The polymerization temperature is preferably 50°C or higher, more preferably 60°C or higher, preferably 90°C or lower, and more preferably 80°C or lower.

[0040] A vehicle composition can be prepared using the (meth)acrylic resin and vehicle solvent of the present invention. A vehicle composition containing the (meth)acrylic resin and vehicle solvent of the present invention is also one of the present inventions.

[0041] The above vehicle composition contains a vehicle solvent. Organic solvents can be used as the vehicle solvent mentioned above. Examples of the above-mentioned organic solvents include aliphatic alcohols, glycols, terpene-based organic solvents, aromatic alcohols and other alcohols, aromatic hydrocarbons, esters, ketones, and N-methylpyrrolidone. Examples of the above-mentioned aliphatic alcohols include ethanol, propanol, isopropanol, heptanol, octanol, decanol, tridecanol, lauryl alcohol, tetradecyl alcohol, cetyl alcohol, 2-ethyl-1-hexanol, octadecyl alcohol, hexadecenol, oleyl alcohol, texanol, 2-butyl-2-ethyl-1,3-propanediol, neopentyl glycol, and the like. Examples of the glycols mentioned above include ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisobutyl ether, butyl carbitol, ethylene glycol monoethyl ether acetate, trimethylpentanediol monoisobutyrate, butyl carbitol acetate, Texanol, ethylene glycol monophenyl ether, propylene glycol monophenyl ether, and ethylene glycol ethyl ether. Examples of the above-mentioned terpene-based organic solvents include terpineol, dihydroterpineol, terpineol acetate, dihydroterpineol acetate, dihydroterpineol oxyethanol, terpinyl methyl ether, dihydroterpineol methyl ether, α-pinene, β-pinene, camphene, Δ-2-carene, Δ-3-carene, limonene, terpinene, and terpinolene. Examples of the above-mentioned aromatic alcohols include benzyl alcohol. Examples of the above-mentioned aromatic hydrocarbons include toluene. Examples of the above-mentioned esters include methyl acetate, ethyl acetate, butyl acetate, hexyl acetate, dodecyl acetate, isoamyl acetate, butyl butyrate, butyl lactate, dioctyl phthalate, and dioctyl adipate. Examples of the above-mentioned ketones include methyl isobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, and isophorone. The above organic solvent preferably contains at least one selected from the group consisting of terpineol, terpineol acetate, dihydroterpineol and dihydroterpineol acetate, butyl carbitol, and butyl carbitol acetate.

[0042] The total content of terpineol, terpineol acetate, dihydroterpineol, dihydroterpineol acetate, butyl carbitol, and butyl carbitol acetate in the above vehicle solvent is preferably 90% by weight or more, more preferably 93% by weight or more, even more preferably 96.5% by weight or more, even more preferably 98% by weight or more, preferably 100% by weight or less, more preferably 99.9% by weight or less, and even more preferably 99.5% by weight or less. By setting the content within the above range, a vehicle composition can be made that produces a conductive paste with little viscosity change due to temperature and little viscosity variation.

[0043] The content of the vehicle solvent in the above vehicle composition is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, preferably 95% by weight or less, and more preferably 90% by weight or less, from the viewpoint of coating properties and dispersibility of inorganic particles.

[0044] Furthermore, in the above vehicle composition, the content of the vehicle solvent per 100 parts by weight of the (meth)acrylic resin is preferably 150 parts by weight or more, more preferably 230 parts by weight or more, preferably 1900 parts by weight or less, and more preferably 900 parts by weight or less.

[0045] The above vehicle composition may contain, in addition to the (meth)acrylic resin and the above vehicle solvent, a dispersant, a thixotropic agent, etc.

[0046] The method for preparing the above vehicle composition is not particularly limited. For example, one method is to mix the (meth)acrylic resin of the present invention with the above vehicle solvent.

[0047] A slurry composition can be prepared by adding inorganic particles, a dispersant, and other components as needed to the above vehicle composition. A slurry composition containing the above vehicle composition, inorganic particles, and a dispersant is also one of the present inventions.

[0048] The content of the (meth)acrylic resin of the present invention in the above slurry composition is preferably 3% by weight or more, more preferably 4% by weight or more, preferably 10% by weight or less, and more preferably 8% by weight or less.

[0049] The content of the vehicle solvent in the slurry composition is preferably 20% by weight or more, more preferably 24% by weight or more, preferably 50% by weight or less, and more preferably 40% by weight or less.

[0050] The above slurry composition contains inorganic particles. The inorganic particles mentioned above are not particularly limited and include, for example, ceramic powder, glass powder, phosphor particles, silicon oxide, metal particles, etc.

[0051] The above ceramic powders are not particularly limited and include, for example, alumina, ferrite, zirconia, zircon, barium zirconate, calcium zirconate, titanium oxide, barium titanate, strontium titanate, calcium titanate, magnesium titanate, zinc titanate, lanthanum titanate, neodymium titanate, lead zirconate titanate, aluminum nitride, silicon nitride, boron nitride, boron carbide, barium stanate, calcium stanate, magnesium silicate, mullite, steatite, cordierite, forsterite, and the like. In addition, ITO, FTO, niobium oxide, vanadium oxide, tungsten oxide, lanthanum strontium manganite, lanthanum strontium cobalt ferrite, yttrium stabilized zirconia, gadolinium-doped ceria, nickel oxide, lanthanum chromite, Sm2Fe 17 N3, Nd2Fe 14 B, MnAlC, L 10 FeNi, La 2 / 3-x Li 3x TiO3, La (1-x) / 3 Li x NbO3, LaGaO3, LaScO3, CaZrO3, (La 0.875 Sr 0.125 )MnO3, PbZrTiO3, SrBi2Ta2O9, BiFeO3, KNbO3, PbVO3, BiCo3, Bi(Zn 1 / 2 Ti 1 / 2 )3 etc. can also be used.

[0052] The glass powder is not particularly limited, and examples thereof include glass powders such as bismuth oxide glass, silicate glass, lead glass, zinc glass, boron glass, and glass powders of various silicon oxides such as CaO-Al2O3-SiO2-based, MgO-Al2O3-SiO2-based, LiO2-Al2O3-SiO2-based, etc. Furthermore, the above glass powders include: SnO-B2O3-P2O5-Al2O3 mixture, PbO-B2O3-SiO2 mixture, BaO-ZnO-B2O3-SiO2 mixture, ZnO-Bi2O3-B2O3-SiO2 mixture, Bi2O3-B2O3-BaO-CuO mixture, Bi2O3-ZnO-B2O3-Al2O3-SrO mixture, ZnO-Bi2O3-B2O3 mixture, Bi2O3-SiO2 mixture, P2O5-Na2O-CaO-BaO-Al2O3-B2O3 mixture, P2O5-SnO mixture, and P2O5-SnO-B2O3 mixture. Glass powders such as composites, P2O5-SnO-SiO2 mixtures, CuO-P2O5-RO mixtures, SiO2-B2O3-ZnO-Na2O-Li2O-NaF-V2O5 mixtures, P2O5-ZnO-SnO-R2O-RO mixtures, B2O3-SiO2-ZnO mixtures, B2O3-SiO2-Al2O3-ZrO2 mixtures, SiO2-B2O3-ZnO-R2O-RO mixtures, SiO2-B2O3-Al2O3-RO-R2O mixtures, SrO-ZnO-P2O5 mixtures, and BaO-ZnO-B2O3-SiO2 mixtures can also be used. Note that R is an element selected from the group consisting of Zn, Ba, Ca, Mg, Sr, Sn, Ni, Fe, and Mn. In particular, lead-free glass powders such as PbO-B2O3-SiO2 mixtures, BaO-ZnO-B2O3-SiO2 mixtures, or ZnO-Bi2O3-B2O3-SiO2 mixtures that do not contain lead are preferred.

[0053] The above-mentioned phosphor particles are not particularly limited, and for example, as phosphor materials, conventionally known phosphor materials for displays, such as blue phosphor materials, red phosphor materials, and green phosphor materials, can be used. As a blue phosphor material, for example, MgAl 10 O 17 :Eu series, Y2SiO5:Ce series, CaWO4:Pb series, BaMgAl 14 O 23 :Eu system, BaMgAl 16 O 27 :Eu-based, BaMg2Al 14 O 23 :Eu-based, BaMg2Al 14 O 27Eu-based and ZnS:(Ag,Cd)-based materials are used. Examples of red phosphors include Y2O3:Eu-based, Y2SiO5:Eu-based, and Y3Al5O 12 Eu-based, Zn3(PO4)2:Mn-based, YBO3:Eu-based, (Y,Gd)BO3:Eu-based, GdBO3:Eu-based, ScBO3:Eu-based, and LuBO3:Eu-based materials are used. As for green phosphor materials, for example, Zn2SiO4:Mn-based and BaAl 12 O 19 :Mn-based, SrAl 13 O 19 :Mn-based, CaAl 12 O 19 :Mn series, YBO3:Tb series, BaMgAl 14 O 23 :Mn-based, LuBO3:Tb-based, GdBO3:Tb-based, ScBO3:Tb-based, and Sr6Si3O3Cl4:Eu-based compounds are used. Others include ZnO:Zn-based, ZnS:(Cu,Al)-based, ZnS:Ag-based, Y2O2S:Eu-based, ZnS:Zn-based, (Y,Cd)BO3:Eu-based, and BaMgAl 12 O 23 EU-based ones can also be used.

[0054] The above-mentioned metal particles are not particularly limited and include, for example, powders made of copper, nickel, palladium, platinum, gold, silver, aluminum, tungsten, or alloys thereof. Furthermore, metals such as copper and iron, which have good adsorption properties with carboxyl groups, amino groups, amide groups, etc., and are easily oxidized, can also be suitably used. These metal powders may be used individually or in combination of two or more types. In addition to metal complexes, various types of carbon black, carbon nanotubes, etc., may also be used.

[0055] Other inorganic particles include Li2S-M x S yLithium sulfur-based glasses such as (M=B, Si, Ge, P), lithium cobalt composite oxides such as LiCeO2, lithium manganese composite oxides such as LiMnO4, lithium nickel composite oxides, lithium vanadium composite oxides, lithium zirconium composite oxides, lithium hafnium composite oxides, lithium silicate (Li 3.5 Si 0.5 P 0.5 O4), lithium titanium phosphate (LiTi2(PO4)3), lithium titanate (Li4Ti5O 12 ), Li 4 / 3 Ti 5 / 3 O4, LiCoO2, lithium germanium phosphate (LiGe2(PO4)3), Li2-SiS glass, Li4GeS4-Li3PS4 glass, LiSiO3, LiMn2O4, Li2S-P2S5 glass / ceramics, Li2O-SiO2, Li2O-V2O5-SiO2, LiS-SiS2-Li4SiO4 glass, ion-conductive oxides such as LiPON, lithium oxide compounds such as Li2O-P2O5-B2O3 and Li2O-GeO2Ba, Li x Al y Ti z (PO4)3-type glass, La x Li y TiO z Glass system, Li x Ge y P z O4-based glass, Li7La3Zr2O 12 Glass system, Li v Si w P x S y Cl z Glass or similar materials can also be used.

[0056] The average particle diameter of the inorganic particles is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, preferably 50 μm or less, more preferably 30 μm or less, even more preferably 10 μm or less, even more preferably 5 μm or less, particularly preferably 3 μm or less, and most preferably 1 μm or less. The above average particle diameter can be determined, for example, by measuring the volume-average particle diameter using a laser diffraction / scattering particle size distribution analyzer.

[0057] The content of the inorganic particles in the slurry composition is preferably 10% by weight or more, more preferably 20% by weight or more, even more preferably 30% by weight or more, even more preferably 40% by weight or more, preferably 90% by weight or less, more preferably 80% by weight or less, even more preferably 70% by weight or less, and even more preferably 65% ​​by weight or less. Within the above range, it is possible to obtain a material that has sufficient viscosity, excellent coating properties, and excellent dispersibility of inorganic particles.

[0058] The above slurry composition contains a dispersant. Suitable dispersants include, for example, fatty acids, aliphatic amines, alkanolamides, and phosphate esters. Silane coupling agents may also be included. The above fatty acids are not particularly limited and include saturated fatty acids such as behenic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, caprylic acid, and coconut fatty acid; and unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, sorbic acid, beef tallow fatty acid, and hydrogenated castor fatty acid. Among these, lauric acid, stearic acid, and oleic acid are preferred. The above-mentioned aliphatic amines are not particularly limited and include, for example, laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, alkyl(coconut)amine, alkyl(hydrogenated beef tallow)amine, alkyl(beef tallow)amine, alkyl(soybean)amine, etc. The above-mentioned alkanolamides are not particularly limited and include, for example, coconut fatty acid diethanolamide, beef tallow fatty acid diethanolamide, lauric acid diethanolamide, oleic acid diethanolamide, etc. The above-mentioned phosphate esters are not particularly limited, and examples include polyoxyethylene alkyl ether phosphate esters and polyoxyethylene alkyl allyl ether phosphate esters.

[0059] The content of the dispersant in the slurry composition described above is preferably 0.1% by weight or more, more preferably 0.15% by weight or more, preferably 1% by weight or less, and preferably 0.5% by weight or less.

[0060] The above slurry composition may further contain additives such as plasticizers and surfactants. Examples of the plasticizers mentioned above include di(butoxyethyl) adipate, dibutoxyethoxyethyl adipate, triethylene glycol dibutyl, triethylene glycol bis(2-ethylhexanoate), triethylene glycol dihexanoate, triethyl acetyl citrate, tributyl acetyl citrate, diethyl acetyl citrate, dibutyl acetyl citrate, dibutyl acetyl citrate, tributyl sebacate, triacetin, diethyl acetyloxymalonate, and diethyl ethoxymalonate.

[0061] The above-mentioned surfactants are not particularly limited and include, for example, cationic surfactants, anionic surfactants, and nonionic surfactants. The above nonionic surfactant is not particularly limited, but it is preferable that it is a nonionic surfactant with an HLB value of 10 or more and 20 or less. Here, the HLB value is used as an indicator of the hydrophilicity and lipophilicity of a surfactant, and several calculation methods have been proposed. For example, for ester-based surfactants, the saponification value is S and the acid value of the fatty acid constituting the surfactant is A, and the HLB value is defined as 20 (1-S / A). Specifically, nonionic surfactants having polyethylene oxide obtained by adding alkylene ether to a fatty acid chain are preferred, and specifically, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, etc. are preferably used. Although the above nonionic surfactant has good thermal decomposition properties, adding a large amount may reduce the thermal decomposition properties of the slurry composition, so the preferred upper limit of the content is 5% by weight.

[0062] The method for preparing the above-mentioned slurry composition is not particularly limited, and conventionally known stirring methods can be used. Specifically, for example, a method of stirring the above-mentioned vehicle composition, the above-mentioned inorganic particles, the above-mentioned dispersant, and other components such as additional solvents and plasticizers added as needed, using a three-roll mixer or the like. The order in which the components of the slurry composition are added can be set as appropriate.

[0063] Electronic components can be manufactured using the above-mentioned slurry composition. An electronic component using the above-mentioned slurry composition is also one of the present inventions. Examples of the above-mentioned electronic components include die attach paste (ACP), die attach film (ACF), via electrodes for TSV and TGV, touch panels, various circuits for RFID and sensor substrates, various die bonding agents, encapsulants for MEMS devices, electrode materials for solar cells, multilayer ceramic capacitors, LTCC, silicon capacitors, and all-solid-state batteries. In addition to the above-mentioned electrode circuit applications, they can also be used as antibacterial components, electromagnetic shielding, catalysts, and fluorescent materials.

[0064] For example, an inorganic particle dispersion molded product can be manufactured by coating the slurry composition onto a support film that has been treated with a single-sided release agent, drying the organic solvent, and then molding the product. The shape of the above-mentioned inorganic particle dispersion molded product is not particularly limited, but it can be in the shape of a sheet, for example.

[0065] Examples of methods for producing the above-mentioned inorganic particle dispersion molded product include a method of uniformly forming a coating film on a support film using a coating method such as a roll coater, die coater, squeeze coater, or curtain coater with the slurry composition.

[0066] For example, if the inorganic particle dispersion molded product is in the form of a sheet, the support film used in manufacturing the inorganic particle dispersion molded product is preferably a resin film that is heat-resistant, solvent-resistant, and flexible. The flexibility of the support film allows the slurry composition to be applied to the surface of the support film using a roll coater, blade coater, etc., and the resulting inorganic particle dispersion sheet-forming film can be stored and supplied in a rolled state.

[0067] Examples of resins used to form the support film include polyethylene terephthalate resin, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyimide resin, polyvinyl alcohol resin, polyvinyl chloride resin, fluorine-containing resins such as polyfluoroethylene, nylon, and cellulose resin. The thickness of the above-mentioned support film is preferably, for example, 20 to 100 μm. Furthermore, it is preferable that the surface of the support film be treated with a release agent, which facilitates the peeling operation of the support film during the transfer process.

[0068] An inorganic particle dispersion molded product can be manufactured by coating and drying the above slurry composition. Furthermore, by using the above-mentioned slurry composition and inorganic particle dispersion molded product as a conductive paste for external electrodes, a multilayer ceramic capacitor, which is an electronic component, can be manufactured.

[0069] A method for manufacturing the above-mentioned multilayer ceramic capacitor includes the steps of printing a conductive paste onto the inorganic particle dispersion molded product, drying it to produce a dielectric sheet, and laminating the dielectric sheets.

[0070] The conductive paste described above contains conductive powder. The material of the conductive powder described above is not particularly limited as long as it is a conductive material, and examples include nickel, palladium, platinum, gold, silver, copper, molybdenum, tin, and alloys thereof. These conductive powders may be used individually or in combination of two or more types.

[0071] The method for printing the conductive paste described above is not particularly limited and includes, for example, screen printing, die-coating, offset printing, gravure printing, and inkjet printing.

[0072] In the above-described method for manufacturing multilayer ceramic capacitors, a raw ceramic laminate is produced by stacking dielectric sheets printed with the conductive paste, and then subjected to a firing process in a reducing atmosphere at a temperature of 1000 to 1500°C, thereby obtaining a large number of component bases.

[0073] Next, a conductive paste for external electrodes containing the (meth)acrylic resin is applied to both end faces of each component body by immersion. Then, after drying at 100-200°C, it is fired at 450-800°C in a reducing atmosphere to form external electrodes on both ends of the component body.

[0074] Next, electroplating is applied to the external electrodes to sequentially form Cu, Ni, and Sn films on the external electrodes, thereby obtaining a multilayer ceramic capacitor. [Effects of the Invention]

[0075] According to the present invention, a (meth)acrylic resin capable of producing a conductive paste with minimal viscosity variation can be provided. Furthermore, a vehicle composition containing the (meth)acrylic resin, a slurry composition containing the vehicle composition, and an electronic component using the slurry composition can be provided. [Modes for carrying out the invention]

[0076] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0077] (Synthesis Examples 1-10) (Preparation of polyethylene glycol methacrylate) A 2 L separable flask equipped with a stirrer, Liebig condenser, vacuum recovery device, thermometer, oil bath, and nitrogen gas inlet was prepared. In the 2 L separable flask, 154 parts by weight of methacrylic anhydride and 700 parts by weight of polyethylene glycol in the proportions shown in Table 1 were mixed to prepare a mixture. The mixture was heated to 90°C under reduced pressure of -0.6 MPa while stirring for 3 hours. After 3 hours, the mixture temperature was raised to 120°C to remove unreacted methacrylic anhydride and water, thereby obtaining polyethylene glycol monomer (polyethylene glycol methacrylate). The obtained monomer was prepared as a 2000 ppm THF solution, and the weight-average molecular weight (Mw) and dispersion (Mw / Mn) in polystyrene equivalent were determined by gel permeation chromatography under the following conditions. Equipment: ACQUITY APC Columns: ACQIUTY APC XT125-XT45-XT45 4.6mm x 150mm x 3 Flow rate: 0.3mL / min Column temperature: 40℃ Injection volume: 10μL Detector: RI Mobile phase: THF Standard sample: Polystyrene standard The results are shown in Table 1. The following polyethylene glycol was used. Polyethylene glycol 400: Number average molecular weight (Mn) 400, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Polyethylene glycol 600: Number average molecular weight (Mn) 600, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Polyethylene glycol 1000: Number average molecular weight (Mn) 1000, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Polyethylene glycol 1540: Number average molecular weight (Mn) 1540, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Polyethylene glycol 2000: Number average molecular weight (Mn) 2000, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0078] [Table 1]

[0079] (Synthesis Examples 11-20) Polypropylene glycol monomer (polypropylene glycol methacrylate) was obtained in the same manner as in Synthesis Example 1, except that polypropylene glycol was used in the proportions shown in Table 2 instead of polyethylene glycol. Mw and dispersion were determined in the same manner as in Synthesis Example 1. The results are shown in Table 2. The following polypropylene glycol was used. Sannix PP-200: Number average molecular weight (Mn) 200, manufactured by Sanyo Chemical Industries, Ltd. Poly(propylene glycol) average Mn ~425: Number average molecular weight (Mn) 425, manufactured by Sigma-Aldrich. Poly(propylene glycol) average Mn ~725: Number average molecular weight (Mn) 725, manufactured by Sigma-Aldrich. Poly(propylene glycol) average Mn ~1000: Number average molecular weight (Mn) 1000, manufactured by Sigma-Aldrich.

[0080] [Table 2]

[0081] (Examples 1-27, Comparative Examples 1-12) (Preparation of resin particles) Pure water was added to a stirring vessel in the amounts shown in Tables 3 and 4 as a dispersion medium, and then monomers, chain transfer agents, and polymerization initiators were added as shown in Tables 3 and 4. In addition to the monomers obtained in Synthesis Examples 1-20, the following were used as monomers, chain transfer agents, and polymerization initiators. <Monomer> Methyl methacrylate (MMA): Manufactured by Tokyo Chemical Industry Co., Ltd. n-butyl methacrylate (BMA): Manufactured by Tokyo Chemical Industry Co., Ltd. Isobutyl methacrylate (iBMA): Manufactured by Tokyo Chemical Industry Co., Ltd. Methyl acrylate (MA): Manufactured by Tokyo Chemical Industry Co., Ltd. Tetracosyl methacrylate (TCMA): Manufactured by Angene International Limited. <Chain movement agent> 1-Decanthiol: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. <Polymerization initiator> Lauroyl peroxide: Manufactured by Thermo Scientific.

[0082] Next, the mixture was mixed for 3 minutes at a rotation speed of 10,000 rpm using a comb-type high-speed rotary emulsifier. After that, it was transferred to a reaction vessel equipped with a stirrer and jacket, and nitrogen gas was supplied while stirring at 150 rpm to create a nitrogen atmosphere in which the monomer composition was prepared. Next, the temperature was raised to 70°C using a jacket to initiate aqueous suspension polymerization. Three hours after the start of polymerization, the temperature was raised to 80°C, and aqueous suspension polymerization was carried out for another hour to complete the polymerization and obtain a suspension containing resin particles.

[0083] (Washing and drying of resin particles) Next, the suspension containing the obtained resin particles was filtered through a Nutsche filter, washed with 1000 parts by weight of deionized water per 100 parts by weight of the resin particles, and dried to obtain resin particles. The obtained (meth)acrylic resin particles were measured by gel permeation chromatography using an LF-804 column (manufactured by SHOKO Corporation) to determine the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in polystyrene equivalents, and the molecular weight distribution (Mw / Mn) was determined. Furthermore, the obtained (meth)acrylic resin was measured by pyrolysis GC-MS using a JEOL JMS-Q1500GC instrument, and it was confirmed that the component content was equivalent to the monomer ratio.

[0084] [Table 3]

[0085] [Table 4]

[0086] (Preparation of vehicle composition) A vehicle composition was prepared by adding 23.8 parts by weight of butyl carbitol (diethylene glycol monobutyl ether, manufactured by Tokyo Chemical Industry Co., Ltd.) as a vehicle solvent to 4.6 parts by weight of the obtained resin particles and mixing.

[0087] (Preparation of slurry composition) To 28.4 parts by weight of the obtained vehicle composition, 0.2 parts by weight of a dispersant (Sunopco, Nopco Sperse 092), 70.2 parts by weight of silver powder (Fujifilm Wako Pure Chemical Industries, average particle size 45 μm), and 1.2 parts by weight of glass frit (AGC, average particle size 0.8 μm) were added and mixed to prepare a slurry composition (conductive paste).

[0088] <Rating> The obtained slurry compositions were evaluated as follows. The results are shown in Tables 5 and 6.

[0089] (Viscosity variation) Ten slurry compositions were prepared for each example and comparative example using the same method. For each sample, the viscosity at 25°C was measured using an E-type viscometer, and the coefficient of variation of viscosity (CV value %), i.e., viscosity standard deviation ÷ mean viscosity × 100, was evaluated as viscosity variability. A smaller coefficient of variation indicates less viscosity variation.

[0090] [Table 5]

[0091] [Table 6] [Industrial applicability]

[0092] According to the present invention, a (meth)acrylic resin capable of producing a conductive paste with minimal viscosity variation can be provided. Furthermore, a vehicle composition containing the (meth)acrylic resin, a slurry composition containing the vehicle composition, and an electronic component using the slurry composition can be provided.

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