JP7797732B2 - (Meth)acrylic resin, vehicle composition, slurry composition, and electronic component - Google Patents

Description

The present invention relates to a (meth)acrylic resin.

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 arranged to sandwich the laminate. The external electrodes are formed by applying a conductive paste for the external electrodes to the surface of the laminate and then sintering it.

In recent years, there has been a demand to lower the temperature of the degreasing process, which removes binder resin, in order to reduce the energy required for ceramic firing. In addition, there is a growing demand for lighter and more powerful ceramic parts, which has led to a demand for thinner ceramic green sheets and more multi-layered structures during the manufacturing process.

Patent Document 1 describes the use of acrylic resin, polyvinyl butyral resin, polyvinyl acetal resin, ethyl cellulose resin, etc. as binder resins for such ceramic molding, and in particular describes the use of polyvinyl butyral resin or polyvinyl acetal resin to make the sheet thinner.
Patent Document 2 describes a methacrylate copolymer obtained by copolymerizing isobutyl methacrylate, 2-ethylhexyl methacrylate, and a hydroxyl group-containing methacrylate in a predetermined ratio, and claims that the use of such a binder resin can provide good moldability and degreasing properties.

JP 2011-84433 A Japanese Patent Application Publication No. 10-167836

In order to thin ceramic green sheets, the binder resin must have sufficient strength, and increasing the strength generally requires increasing the molecular weight. However, if the molecular weight is increased, the viscosity of the slurry composition in which the inorganic particles and binder are dispersed becomes too high, reducing the dispersibility of the inorganic particles, resulting in the formation of foreign matter in the ceramic green sheet and reducing its strength. As described in Patent Document 1, while it is possible to thin the ceramic green sheet by using polyvinyl butyral resin, there is a problem in that the decomposition temperature is high and degreasing at low temperatures is not possible. Furthermore, as described in Patent Document 2, while methacrylic acid ester copolymers can be degreased at low temperatures, the resin itself is brittle and cannot be thinned. For this reason, there is a need for binder resins that can achieve both lower degreasing temperatures and thinning.

The present invention aims to provide a (meth)acrylic resin that can produce ceramic laminates that can be further thinned by achieving both excellent low-temperature decomposition properties of the slurry composition and high strength of the ceramic green sheet. It also aims to provide a vehicle composition, a slurry composition, and an electronic component that contain the (meth)acrylic resin.

The present disclosure (1) is a (meth)acrylic resin having a structural unit derived from a (meth)acrylic acid ester monomer, the (meth)acrylic acid ester monomer including a (meth)acrylic acid ester monomer A and a (meth)acrylic acid ester monomer B, wherein when the number of carbon atoms of an ester substituent of the (meth)acrylic acid ester monomer A is X, the number of carbon atoms of an ester substituent of the (meth)acrylic acid ester monomer B is 4X.
The present disclosure (2) is the (meth)acrylic resin of the present disclosure (1), in which the ratio of the content of the structural units derived from (meth)acrylic acid ester monomer B to the content of the structural units derived from (meth)acrylic acid ester monomer A (monomer B/monomer A) is 3 or more and 12 or less.
The present disclosure (3) is the (meth)acrylic resin of the present disclosure (1) or (2), in which the (meth)acrylic acid ester monomer is a methacrylic acid ester monomer.
The present disclosure (4) is a (meth)acrylic resin in any combination with any of the present disclosures (1) to (3), in which the Ti value of the resin solution dissolved in butyl acetate is 1.5 or more and 2.5 or less.
The present disclosure (5) is a (meth)acrylic resin in any combination with any of the present disclosures (1) to (4), wherein the (meth)acrylic acid ester monomer includes a (meth)acrylic acid ester monomer having a branched-chain ester substituent and a (meth)acrylic acid ester monomer having a linear-chain ester substituent, the ester substituents having the same number of carbon atoms.
The present disclosure (6) is a (meth)acrylic resin according to the present disclosure (5), in which the ratio of the content of structural units derived from (meth)acrylic ester monomers having branched-chain ester substituents to the content of structural units derived from (meth)acrylic ester monomers having straight-chain ester substituents, the ester substituents having the same number of carbon atoms, ((meth)acrylic ester monomers having branched-chain ester substituents/(meth)acrylic ester monomers having straight-chain ester substituents (the ester substituents have the same number of carbon atoms)) is 0.5 or more and 2.0 or less.
The present disclosure (7) is a vehicle composition containing the (meth)acrylic resin of any one of the present disclosures (1) to (6) and an organic solvent.
The present disclosure (8) is the vehicle composition of the present disclosure (7), further containing water, wherein the content of the water is 10 ppm by weight or more and 12,000 ppm by weight or less.
The present disclosure (9) is a slurry composition containing the vehicle composition of the present disclosure (7), inorganic particles, and a dispersant.
The present disclosure (10) is a slurry composition containing the vehicle composition of the present disclosure (8), inorganic particles, and a dispersant.
The present disclosure (11) is an electronic component formed using the slurry composition of the present disclosure (9).
The present disclosure (12) is an electronic component formed using the slurry composition of the present disclosure (10).
The present invention will be described in detail below.

The inventors have discovered that a slurry composition capable of exhibiting excellent low-temperature decomposition properties can be obtained by combining multiple (meth)acrylic acid ester monomers such that, when the number of carbon atoms in the ester substituent of (meth)acrylic acid ester monomer A is X, the number of carbon atoms in the ester substituent of (meth)acrylic acid ester monomer B is 4X. Furthermore, they have discovered that when such a (meth)acrylic resin is used as a binder for dispersing inorganic particles, a ceramic green sheet with high strength can be obtained, enabling even thinner sheets. They have also discovered that the use of such a (meth)acrylic resin enables the production of a ceramic laminate with excellent properties, leading to the completion of the present invention.

The (meth)acrylic resin has structural units derived from (meth)acrylic acid ester monomers. The (meth)acrylic acid ester monomers include a (meth)acrylic acid ester monomer A and a (meth)acrylic acid ester monomer B. When the number of carbon atoms in the ester substituent of the (meth)acrylic acid ester monomer A is X, the number of carbon atoms in the ester substituent of the (meth)acrylic acid ester monomer B is 4X.
By using a (meth)acrylic resin having the above-mentioned structure, six-membered ring carbon atoms are less likely to be formed during the decomposition process during sintering, which reduces residue during sintering and allows for excellent low-temperature decomposition properties. Furthermore, the portion of the (meth)acrylic resin derived from (meth)acrylic acid ester monomer A has a short molecular chain of the ester substituent, which exerts strong van der Waals forces, while the portion of the (meth)acrylic resin derived from (meth)acrylic acid ester monomer B has a long molecular chain of the ester substituent, which exerts weak van der Waals forces. The mixture of these two portions allows for the production of molded articles with excellent tensile properties.

The (meth)acrylic resin has structural units derived from the (meth)acrylic acid ester monomer.
Examples of the (meth)acrylic acid ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, and n-octyl (meth)acrylate. [0043] Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates having a linear alkyl group or a branched alkyl group, such as n-ethylhexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, isolauryl (meth)acrylate, n-tetradecyl (meth)acrylate, n-stearyl (meth)acrylate, and isostearyl (meth)acrylate.
Examples of the (meth)acrylic acid ester monomer include (meth)acrylates having a polyoxyalkylene structure, such as polytetramethylene glycol monomethacrylate, poly(ethylene glycol-polytetramethylene glycol) monomethacrylate, poly(propylene glycol-tetramethylene glycol) monomethacrylate, propylene glycol-polybutylene glycol monomethacrylate, methoxypolytetramethylene glycol monomethacrylate, methoxypoly(ethylene glycol-polytetramethylene glycol) monomethacrylate, methoxypoly(propylene glycol-tetramethylene glycol) monomethacrylate, and methoxypropylene glycol-polybutylene glycol monomethacrylate.
Furthermore, examples of the (meth)acrylic acid ester monomer include (meth)acrylates having a polar group, such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, (meth)acrylic acid, glycidyl (meth)acrylate, and glycerol mono(meth)acrylate.
Among these, the (meth)acrylic acid ester monomer is preferably an alkyl (meth)acrylate, and more preferably methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or n-lauryl (meth)acrylate.
Furthermore, the (meth)acrylic acid ester monomer is preferred because it can reduce residues during sintering and improve low-temperature decomposition properties.

The (meth)acrylic acid ester monomer is preferably a (meth)acrylic acid ester monomer having a linear ester substituent (hereinafter also referred to as a "linear monomer") or a (meth)acrylic acid ester monomer having a branched ester substituent (hereinafter also referred to as a "branched monomer"). From the viewpoint of improving the strength of the resulting ceramic green sheet, it is preferable to include a (meth)acrylic acid ester monomer having a linear ester substituent and a (meth)acrylic acid ester monomer having a branched ester substituent.

From the viewpoint of improving the strength of the resulting ceramic green sheet, the ratio of the content of structural units derived from (meth)acrylic acid ester monomers having branched-chain ester substituents to the content of structural units derived from (meth)acrylic acid ester monomers having straight-chain ester substituents in the (meth)acrylic resin (branched monomer/straight-chain monomer) is preferably 0.5 or more and 2.0 or less, more preferably 0.6 or more and more preferably 1.6 or less.

The ester substituent of the (meth)acrylic acid ester monomer preferably has 1 to 18 carbon atoms, more preferably 1 to 14 carbon atoms, and even more preferably 1 to 12 carbon atoms.

The (meth)acrylic acid ester monomer preferably includes a (meth)acrylic acid ester monomer having an ester substituent with 1 to 4 carbon atoms.
The (meth)acrylic acid ester monomer having an ester substituent having 1 to 4 carbon atoms is preferably methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, or isobutyl (meth)acrylate, and more preferably methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, or isobutyl methacrylate.
The (meth)acrylic acid ester monomer having an ester substituent with 1 to 4 carbon atoms is more preferably a (meth)acrylic acid ester monomer having an ester substituent with 1 to 3 carbon atoms, and even more preferably a (meth)acrylic acid ester monomer having an ester substituent with 1 to 2 carbon atoms.

The content of structural units derived from (meth)acrylic acid ester monomers in which the ester substituent has 1 to 4 carbon atoms in the (meth)acrylic resin is preferably 20% by weight or more, preferably 100% by weight or less, and more preferably 30% by weight or more.

Furthermore, as the (meth)acrylic acid ester monomer having an ester substituent with 1 to 4 carbon atoms, a (meth)acrylic acid ester monomer having a straight-chain ester substituent with 1 to 4 carbon atoms (hereinafter also referred to as a "C1-4 straight-chain monomer") and a (meth)acrylic acid ester monomer having a branched-chain ester substituent with 3 to 4 carbon atoms (hereinafter also referred to as a "C3-4 branched monomer") may be used in combination.
In the (meth)acrylic resin, the ratio of the content of structural units derived from (meth)acrylic acid ester monomers having a branched-chain ester substituent having 3 to 4 carbon atoms to the content of structural units derived from (meth)acrylic acid ester monomers having a linear ester substituent having 1 to 4 carbon atoms (C3-4 branched monomer/C1-4 linear monomer) is preferably 0 or more, and is preferably 12 or less, and more preferably 3 or less.

Furthermore, the content of structural units derived from (meth)acrylic acid ester monomers in which the ester substituent has 1 to 3 carbon atoms in the (meth)acrylic resin is preferably 0% by weight or more, more preferably 3% by weight or more, and even more preferably 5% by weight or more, and is preferably 70% by weight or less, and more preferably 50% by weight or less.
Furthermore, the content of structural units derived from (meth)acrylic acid ester monomers in which the ester substituent has 1 to 2 carbon atoms in the (meth)acrylic resin is preferably 0% by weight or more, more preferably 3% by weight or more, and even more preferably 5% by weight or more, and is preferably 70% by weight or less, and more preferably 50% by weight or less.

The (meth)acrylic acid ester monomer preferably includes a (meth)acrylic acid ester monomer having an ester substituent with 4 to 16 carbon atoms.
Examples of the (meth)acrylic acid ester monomer having an ester substituent having 4 to 16 carbon atoms include n-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, and isolauryl (meth)acrylate.
Of these, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and n-lauryl (meth)acrylate are preferred, and n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, and n-lauryl methacrylate are more preferred.
The (meth)acrylic acid ester monomer having an ester substituent with 4 to 16 carbon atoms is more preferably a (meth)acrylic acid ester monomer having an ester substituent with 4 to 12 carbon atoms, and even more preferably a (meth)acrylic acid ester monomer having an ester substituent with 4 to 8 carbon atoms.

The content of structural units derived from (meth)acrylic acid ester monomers in which the ester substituent has 4 to 16 carbon atoms in the (meth)acrylic resin is preferably 30% by weight or more, and preferably 100% by weight or less, more preferably 50% by weight or more, more preferably 97% by weight or less, and even more preferably 95% by weight or less.

Furthermore, as the (meth)acrylic acid ester monomer having an ester substituent with 4 to 16 carbon atoms, a (meth)acrylic acid ester monomer having a straight-chain ester substituent with 4 to 16 carbon atoms (hereinafter also referred to as a "C4-16 straight-chain monomer") and a (meth)acrylic acid ester monomer having a branched-chain ester substituent with 4 to 16 carbon atoms (hereinafter also referred to as a "C4-16 branched monomer") may be used in combination.
In the (meth)acrylic resin, the ratio of the content of structural units derived from (meth)acrylic acid ester monomers having a branched-chain ester substituent having 4 to 16 carbon atoms to the content of structural units derived from (meth)acrylic acid ester monomers having a linear ester substituent having 4 to 16 carbon atoms (C4-16 branched monomer/C4-16 linear monomer) is preferably 0 or more and 3.5 or less, more preferably 0.2 or more, and more preferably 2.5 or less.

Furthermore, the content of structural units derived from (meth)acrylic acid ester monomers in which the ester substituent has 4 to 12 carbon atoms in the (meth)acrylic resin is preferably 30% by weight or more and 100% by weight or less, more preferably 50% by weight or more, more preferably 97% by weight or less, and even more preferably 95% by weight or less.
Furthermore, the content of structural units derived from (meth)acrylic acid ester monomers in which the ester substituent has 4 to 8 carbon atoms in the (meth)acrylic resin is preferably 25% by weight or more, more preferably 95% by weight or less, and more preferably 50% by weight or more.

The (meth)acrylic acid ester monomer may contain a (meth)acrylic acid ester monomer in which the ester substituent has 17 or more carbon atoms, but preferably does not contain a (meth)acrylic acid ester monomer in which the ester substituent has 17 or more carbon atoms.
Furthermore, the (meth)acrylic acid ester monomer may contain a (meth)acrylic acid ester monomer in which the ester substituent has 13 or more carbon atoms, but more preferably does not contain a (meth)acrylic acid ester monomer in which the ester substituent has 13 or more carbon atoms.

The (meth)acrylic acid ester monomer is preferably an alkyl (meth)acrylate. The (meth)acrylic acid ester monomer may also contain a (meth)acrylic acid ester monomer other than an alkyl (meth)acrylate (hereinafter also referred to as "other monomer"), but it is more preferable that it does not contain any other monomers.

From the viewpoint of improving the strength of the resulting ceramic green sheet, it is preferable that the above-mentioned (meth)acrylic acid ester monomer contains a linear monomer and a branched monomer in which the number of carbon atoms in the ester substituents is the same.

From the viewpoint of improving the strength of the resulting ceramic green sheet, the ratio of the content of structural units derived from branched monomers to the content of structural units derived from linear monomers having the same number of carbon atoms in the ester substituents in the (meth)acrylic resin (branched monomer/linear monomer (having the same number of carbon atoms in the ester substituents)) is preferably 0.5 or more and 2.0 or less, more preferably 0.6 or more and more preferably 1.7 or less.

The (meth)acrylic acid ester monomer includes a (meth)acrylic acid ester monomer A (hereinafter also referred to as "monomer A") and a (meth)acrylic acid ester monomer B (hereinafter also referred to as "monomer B"). When the number of carbon atoms of the ester substituent possessed by the monomer A is X, the number of carbon atoms of the ester substituent possessed by the monomer B is 4X.
By adopting the above-mentioned constitution, it is possible to obtain a ceramic green sheet having excellent low-temperature decomposition property and high strength.

As the monomer A, a (meth)acrylic acid ester monomer having an ester substituent with 1 to 4 carbon atoms is preferred, a (meth)acrylic acid ester monomer having an ester substituent with 1 to 3 carbon atoms is more preferred, and a (meth)acrylic acid ester monomer having an ester substituent with 1 to 2 carbon atoms is even more preferred.
The monomer A may be a straight-chain monomer or a branched monomer, and is preferably a straight-chain monomer.

The content of the structural unit derived from the monomer A in the (meth)acrylic resin is preferably 2% by weight or more and 70% by weight or less, more preferably 3% by weight or more and 65% by weight or less.
In addition, when there are two or more types of (meth)acrylic acid ester monomers corresponding to the above-mentioned monomer A, the content of the structural units derived from the above-mentioned monomer A means the total amount of the (meth)acrylic acid ester monomers corresponding to the above-mentioned monomer A.

The above-mentioned monomer B may be a linear monomer, a branched monomer, or a monomer containing both a linear monomer and a branched monomer, as long as the number of carbon atoms in the ester substituent of the above-mentioned monomer A is X, and the number of carbon atoms in the ester substituent of the above-mentioned monomer B is 4X.

The content of the structural units derived from the monomer B in the (meth)acrylic resin is preferably 20% by weight or more and 85% by weight or less, more preferably 25% by weight or more and 80% by weight or less.
In addition, when there are two or more types of (meth)acrylic acid ester monomers corresponding to the above-mentioned monomer B, the content of the structural units derived from the above-mentioned monomer B means the total amount of the (meth)acrylic acid ester monomers corresponding to the above-mentioned monomer B.

When the monomer B contains a linear monomer and a branched monomer, the ratio of the content of structural units derived from branched monomers to the content of structural units derived from linear monomers in the structural units derived from the monomer B (branched monomer/linear monomer) is preferably 0.5 or more and 2.0 or less, more preferably 0.6 or more and more preferably 1.7 or less.

From the viewpoint of improving decomposition properties, the ratio of the content of the structural units derived from the monomer B to the content of the structural units derived from the monomer A in the (meth)acrylic resin (monomer B/monomer A) is preferably 3 or more and 12 or less, more preferably 4 or more and more preferably 7 or less.
In addition, when the number of carbon atoms X of the ester substituent in the above-mentioned Monomer A and Monomer B is two or more, the above-mentioned ratio (Monomer B/Monomer A) is calculated by summing up the product of the ratio (Monomer B/Monomer A) in the cases where X is the same and the total content of the cases where X is the same, and dividing this product by the sum of the total content of Monomer A and Monomer B for each case where X is the same.
For example, when the (meth)acrylic resin contains 5% by weight and 15% by weight of structural units derived from monomer A and monomer B where X is 1, respectively, and 10% by weight and 70% by weight of structural units derived from monomer A and monomer B where X is 2, respectively, the ratio (monomer B/monomer A) is (15/5×20+70/10×80)/(20+80)=6.2.

In the (meth)acrylic resin, the content of structural units derived from a (meth)acrylic acid ester monomer different from the structural units derived from monomer A and the structural units derived from monomer B may be 0% by weight, and is preferably 1% by weight or more, preferably 80% by weight or less, more preferably 5% by weight or more, and more preferably 70% by weight or less.

The content of the structural units derived from acrylic monomers in the (meth)acrylic resin is preferably 5% by weight or less, more preferably 1% by weight or less, since a smaller content has the advantage of improving low-temperature decomposition. The lower limit is not particularly limited, but is, for example, 0% by weight or more. The content of the structural units derived from acrylic monomers is preferably 0 to 5% by weight, more preferably 0 to 1% by weight, and even more preferably 0% by weight.
The acrylic monomer means acrylic acid and acrylic acid ester.

The weight-average molecular weight (Mw) of the (meth)acrylic resin is preferably 30,000 or more and 5,000,000 or less. When the weight-average molecular weight is 30,000 or more, the tensile performance of the resulting resin sheet is high. When the weight-average molecular weight is 5,000,000 or less, undissolved (meth)acrylic resin is less likely to be produced in the resulting resin sheet, resulting in high tensile performance. For this reason, by setting the weight-average molecular weight within the above range, the strength of the resulting ceramic green sheet can be further increased, allowing for the production of thinner green sheets.
The weight average molecular weight (Mw) is more preferably 200,000 or more, more preferably 4,500,000 or less, even more preferably 300,000 or more, still more preferably 4,000,000 or less, and particularly preferably 1,000,000 or more.

The ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the (meth)acrylic resin is at least 1 and preferably at most 5.0, more preferably at most 4.0, and even more preferably at most 3.5. Within this range, fine undissolved matter is less likely to be generated in the vehicle composition, the strength of the ceramic green sheet can be further increased, and the generation of voids in the ceramic laminate after firing can be prevented.
The weight average molecular weight (Mw) and the number average molecular weight (Mn) are average molecular weights calculated in terms of polystyrene, and can be obtained by GPC measurement using, for example, Column LF-804 (manufactured by Showa Denko K.K.).

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

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 content within the above range, the solubility of the (meth)acrylic resin can be further improved. Improved solubility increases productivity, and the reduction in undissolved resin improves tensile properties.
The lower limit is not particularly limited, and is, for example, 0%.
The CV value can be calculated from the average particle size and standard deviation of 100 particles observed using a scanning electron microscope. The CV value tends to be smaller when a persulfate such as ammonium persulfate or potassium persulfate is used.

The (meth)acrylic resin preferably has a Ti value of 1.5 or more and 2.5 or less in a resin solution obtained by dissolving the resin in butyl acetate. By setting the Ti value in this range, the dispersibility of the inorganic particles can be improved, and the strength of the ceramic green sheet can be increased.
The Ti value is more preferably 1.6 or more and more preferably 2.2 or less.
The Ti value can be determined by calculating the ratio (viscosity (2 rpm)/viscosity (20 rpm)) of the viscosity (2 rpm) measured at 25°C and 2 rpm using a BH type viscometer to the viscosity (20 rpm) measured at 25°C and 20 rpm.
As the resin solution, for example, a butyl acetate solution containing 15% by weight of (meth)acrylic resin can be used.
The Ti value can be set within a preferred range by adjusting the ratio of the content of the structural unit derived from the monomer A to the content of the structural unit derived from the monomer B.

The glass transition temperature (Tg) of the (meth)acrylic resin is preferably 30°C or higher and 85°C or lower, more preferably 32°C or higher and 80°C or lower, even more preferably 42°C or higher and 75°C or lower.
By setting the content within the above range, the amount of plasticizer added can be reduced, and low-temperature decomposition properties can be further improved.
The glass transition temperature (Tg) can be measured using, for example, a differential scanning calorimeter (DSC).

The (meth)acrylic resin preferably has a 90% decomposition temperature of 280°C or lower when heated from 30°C at a rate of 5°C/min, more preferably 270°C or lower, and even more preferably 260°C or lower. There is no particular lower limit, but it is 30°C or higher, and the lower the temperature, the better. The 90% decomposition temperature is preferably 30 to 280°C, more preferably 30 to 270°C, and even more preferably 30 to 260°C.

Examples of a method for producing the (meth)acrylic resin include a method in which an organic solvent or the like is added to a raw material monomer mixture containing a (meth)acrylic acid ester monomer or the like to prepare a monomer mixture, and a polymerization initiator and a chain transfer agent are further added to the obtained monomer mixture to copolymerize the raw material monomers.
The polymerization method is not particularly limited, and examples thereof include emulsion polymerization, suspension polymerization, bulk polymerization, interfacial polymerization, solution polymerization, etc. Among these, emulsion polymerization is preferred.

Examples of the organic solvent 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, and cresol. 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 alone or in combination of two or more.

Examples of the polymerization initiator include t-butyl peroxypivalate, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroxyperoxide, t-butyl hydroxyperoxide, cyclohexanone peroxide, and disuccinic acid peroxide. In addition, acid mixtures of imidazole-based azo compounds such as 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane]sulfatohydrate, and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]; 2,2'-azobis(2-methylpropionamidine)dihydrochloride; 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropane]; Examples of suitable peroxides include water-soluble azo compounds such as [2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamidine] tetrahydrate, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], and 4,4'-azobis-4-cyanovaleric acid; oxoacids such as potassium persulfate (potassium peroxodisulfate), ammonium persulfate (ammonium peroxodisulfate), and sodium persulfate (sodium peroxodisulfate); and peroxides such as hydrogen peroxide, peracetic acid, performic acid, and perpropionic acid.

The amount of the polymerization initiator added is preferably 0.03 parts by weight or more and 4.0 parts by weight or less, more preferably 0.05 parts by weight or more and more preferably 3.6 parts by weight or less, per 100 parts by weight of raw material monomer. The amount of the polymerization initiator added is preferably 0.03 to 4.0 parts by weight, more preferably 0.05 to 3.6 parts by weight, per 100 parts by weight of raw material monomer.

Examples of the chain transfer agent include 3-mercapto-1,2-propanediol, 3-mercapto-1-propanol, 3-mercapto-2-butanol, 8-mercapto-1-octanol, 2-mercaptobenzimidazole, mercaptosuccinic acid, and mercaptoacetic acid.

The amount of the chain transfer agent added is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, and preferably 10.0 parts by weight or less, more preferably 5.0 parts by weight or less, per 100 parts by weight of raw material monomer. The amount of the chain transfer agent added is preferably 0.01 to 10.0 parts by weight, more preferably 0.02 to 5.0 parts by weight, per 100 parts by weight of raw material monomer.

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

A vehicle composition can be prepared using the above (meth)acrylic resin and a solvent containing an organic solvent.
The present invention also provides a vehicle composition containing the above-mentioned (meth)acrylic resin and a solvent containing an organic solvent.

The content of the (meth)acrylic resin in the vehicle composition is preferably 5% by weight or more, more preferably 10% by weight or more, and is preferably 50% by weight or less, more preferably 40% by weight or less.

The vehicle composition contains a solvent including an organic solvent.
Examples of the organic solvent include alcohols such as aliphatic alcohols, glycols, terpene alcohols, and aromatic alcohols, aromatic hydrocarbons, esters, ketones, and N-methylpyrrolidone.
Examples of the 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, and neopentyl glycol.
Examples of the glycols 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 terpene alcohols include terpineol, dihydroterpineol, terpineol acetate, and dihydroterpineol acetate.
Examples of the aromatic alcohols include benzyl alcohol.
Examples of the aromatic hydrocarbons include toluene.
Examples of the 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 ketones include methyl isobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, and isophorone.
Of these, esters are preferred, with methyl acetate, ethyl acetate, butyl acetate, hexyl acetate and dodecyl acetate being more preferred, ethyl acetate, butyl acetate and hexyl acetate being even more preferred, and butyl acetate being even more preferred.

The content of the organic solvent in the vehicle composition is not particularly limited, but is preferably 50% by weight or more and 95% by weight or less, more preferably 55% by weight or more and 88.8% by weight or less.

In the vehicle composition, the solvent preferably further contains water.
The content of water in the vehicle composition is preferably 10 ppm by weight or more and 12,000 ppm by weight or less.
By including water in the above range, compatibility with the dispersant improves and low-temperature decomposition properties are further improved.
The content of water in the vehicle composition is more preferably 300 ppm by weight or more, more preferably 1000 ppm by weight or less, even more preferably 400 ppm by weight or more, and even more preferably 700 ppm by weight or less.

The content of the solvent in the vehicle composition is not particularly limited, but is preferably 50% by weight or more, and preferably 95% by weight or less, more preferably 60% by weight or more, and more preferably 90% by weight or less.

One example of a method for producing the vehicle composition is to add an organic solvent, water, etc. to the (meth)acrylic resin obtained by the above method and then stir and mix them.

A slurry composition can be prepared using the vehicle composition, inorganic particles, and dispersant.
A slurry composition containing the above vehicle composition, inorganic particles, and a dispersant also constitutes one aspect of the present invention.

The content of the (meth)acrylic resin in the slurry composition is preferably 3% by weight or more and 10% by weight or less, more preferably 5% by weight or more and 8% by weight or less.

The content of the organic solvent in the slurry composition is preferably 25% by weight or more and 70% by weight or less, more preferably 30% by weight or more and 60% by weight or less.

The water content in the above slurry composition is preferably 5 ppm by weight or more, preferably 15,000 ppm by weight or less, more preferably 10 ppm by weight or more, more preferably 12,000 ppm by weight or less, even more preferably 50 ppm by weight or more, even more preferably 10,000 ppm by weight or less, and even more preferably 7,500 ppm by weight or less.

The content of the solvent in the slurry composition is preferably 25% by weight or more, and preferably 70% by weight or less, more preferably 30% by weight or more, and more preferably 60% by weight or less.

The slurry composition contains inorganic particles.
The inorganic particles are not particularly limited, and examples thereof include glass powder, ceramic powder, phosphor particles, silicon oxide particles, metal particles, and the like.

The glass powder is not particularly limited, and examples thereof include glass powders such as bismuth oxide glass, silicate glass, lead glass, zinc glass, and boron glass, as well as glass powders of various silicon oxides such as CaO-Al ₂ O ₃ -SiO ₂ , MgO-Al ₂ O ₃ -SiO ₂ , and LiO ₂ -Al ₂ O ₃ -SiO ₂ .
Further, examples of the glass powder include a SnO-B ₂ O ₃ -P ₂ O ₅ -Al ₂ O ₃ mixture, a PbO-B ₂ O ₃ -SiO ₂ mixture, a BaO-ZnO-B ₂ O ₃ -SiO ₂ mixture, a ZnO-Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ mixture, a Bi ₂ O ₃ -B ₂ O ₃ -BaO-CuO mixture, a Bi ₂ O ₃ -ZnO-B ₂ O ₃ -Al ₂ O ₃ -SrO mixture, a ZnO-Bi ₂ O ₃ -B ₂ O ₃ mixture, a Bi ₂ O ₃ -SiO ₂ mixture, a P ₂ O ₅ -Na ₂ O-CaO-BaO-Al ₂ O ₃ -B ₂ O ₃ mixture, P ₂ O ₅ -SnO mixture, P ₂ O ₅ -SnO-B ₂ O ₃ mixture, P ₂ O ₅ -SnO-SiO ₂ mixture, CuO-P ₂ O ₅ -RO mixture, SiO ₂ -B ₂ O ₃ -ZnO-Na ₂ O-Li ₂ O-NaF-V ₂ O ₅ mixture, P ₂ O ₅ -ZnO-SnO-R ₂ O-RO mixture, B ₂ O ₃ -SiO ₂ -ZnO mixture, B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ -ZrO ₂ mixture, SiO ₂ -B ₂ O ₃ -ZnO-R ₂ O-RO mixture, SiO ₂ -B ₂ O ₃ Glass powders such as an -Al ₂ O ₃ -RO-R ₂ O mixture, an SrO-ZnO-P ₂ O ₅ mixture, an SrO-ZnO-P ₂ O ₅ mixture, or a BaO-ZnO-B ₂ O ₃ -SiO ₂ mixture can also be used, where R is an element selected from the group consisting of Zn, Ba, Ca, Mg, Sr, Sn, Ni, Fe, and Mn.
In particular, a glass powder of a PbO-B ₂ O ₃ -SiO ₂ mixture, or a lead-free glass powder such as a lead-free BaO-ZnO-B ₂ O ₃ -SiO ₂ mixture or a lead-free ZnO-Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ mixture is preferred.

The ceramic powder is not particularly limited, and examples thereof include 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, alumina nitride, silicon nitride, boron nitride, boron carbide, barium stannate, calcium stannate, magnesium silicate, mullite, steatite, cordierite, and forsterite.
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, etc. can also be used.
The phosphor particles are not particularly limited, and examples of the phosphor material include blue, red, and green phosphor materials _that are conventionally known as phosphor materials for displays. Examples of the blue phosphor material include _MgAl10O17 :Eu-based, _Y2SiO5 :Ce-based _{, CaWO4} :Pb-based, _BaMgAl14O23 :Eu-based, _BaMgAl16O27 :Eu- _based , _BaMg2Al14O23 :Eu- _based , _BaMg2Al14O27 :Eu-based, _{and ZnS} :(Ag,Cd _{) -based} materials. Examples of _red phosphor materials that can be _{used include Y2O3:Eu-based, Y2SiO5 : Eu - based} , _Y3Al5O12 :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. Examples of green phosphor materials that can be _{used include Zn2SiO4:Mn-based, BaAl12O19:Mn-based, SrAl13O19 : Mn - based , CaAl12O19} :Mn-based, _YBO3 :Tb-based, _BaMgAl14O23 :Mn-based, _LuBO3 :Tb-based, _GdBO3 :Tb _- based, _ScBO3 : _Tb - _based , _{and Sr6Si3O3Cl4} :Eu-based materials. Other examples that can be _{used include ZnO:Zn-based, ZnS:(Cu,Al)-based, ZnS:Ag-based, Y2O2S :} Eu-based, ZnS:Zn-based, (Y,Cd) _BO3 :Eu- _based , and _BaMgAl12O23 :Eu-based.

The metal particles are not particularly limited, and examples thereof include powders of iron, copper, nickel, palladium, platinum, gold, silver, aluminum, tungsten, and alloys thereof.
In addition, 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 particles may be used alone or in combination of two or more types.
The metal particles may be metal complexes, or may be various types of carbon black, carbon nanotubes, or the like.

The inorganic particles preferably contain lithium or titanium. Specific examples include low-melting point glass such as _{LiO2.Al2O3.SiO2 - based} inorganic glass, lithium sulfur-based glass such as _Li2S - _MxSy (M = B, Si, Ge, _P ), lithium cobalt composite oxide such as _LiCeO2 , lithium manganese composite oxide such as _{LiMnO4 ,} lithium nickel composite oxide, lithium vanadium composite oxide, lithium zirconium composite oxide, lithium hafnium composite _oxide , lithium _{silicophosphate} ( _{Li3.5Si0.5P0.5O4} ), lithium titanium phosphate ( _LiTi2 ( _PO4 ) _{3 )} , lithium titanate ( _Li4Ti5O12 ), Li4 _{/ 3Ti5 / 3O4} , _LiCoO2 , lithium germanium phosphate ( _LiGe2 ( _PO4 ) _{3 )} , _Li2 -SiS-based glass, Li ₄ GeS ₄ -Li ₃ PS ₄ -based glass, LiSiO ₃ , LiMn ₂ O ₄ , Li ₂ S-P ₂ S ₅ -based glass/ceramics, Li ₂ O-SiO ₂ , Li ₂ O-V ₂ O ₅ -SiO ₂ , LiS-SiS ₂ -Li ₄ SiO ₄ -based glass, ion-conductive oxides such as LiPON, lithium oxide compounds such as Li ₂ O-P ₂ O ₅ -B ₂ O ₃ and Li ₂ O-GeO ₂ Ba, Li _x Al _y Ti _z (PO ₄ ) ₃ -based glass, La _x Li _y TiO _z -based glass, Li _x Ge _y P _z O _4- based glass, Li ₇ La ₃ Zr ₂ O ₁₂ -based glass, Li _v Si _w P _x S _y Cl _z -based glass, lithium niobium oxides such as LiNbO ₃ , lithium alumina compounds such as Li-β-alumina, and lithium zinc oxides such as Li ₁₄ Zn(GeO ₄ ) ₄ .

The average particle size of the inorganic particles is preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more, more preferably 3 μm or less, even more preferably 0.1 μm or more, and even more preferably 1 μm or less. The average particle size of the inorganic particles is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and even more preferably 0.1 to 1 μm.
The average particle size can be determined, for example, by measuring the volume average particle size using a laser diffraction/scattering particle size distribution measuring device.

The content of the inorganic particles in the slurry composition is preferably 20% by weight or more and 90% by weight or less, which provides sufficient viscosity, excellent coating properties, and excellent dispersibility of the inorganic particles.
The content of the inorganic particles is more preferably 25% by weight or more, more preferably 70% by weight or less, even more preferably 30% by weight or more, even more preferably 60% by weight or less, even more preferably 40% by weight or more, and even more preferably 55% by weight or less.

The slurry composition contains a dispersant.
Suitable examples of the dispersant include fatty acids, aliphatic amines, alkanolamides, and phosphate esters. Silane coupling agents may also be added.
The fatty acid is not particularly limited, and examples thereof include saturated fatty acids such as behenic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, caprylic acid, coconut fatty acid, etc.; and unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, sorbic acid, beef tallow fatty acid, castor hydrogenated fatty acid, etc. Among these, lauric acid, stearic acid, oleic acid, etc. are preferred.
The aliphatic amine is not particularly limited, and examples thereof include laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, alkyl(coconut)amine, alkyl(hardened beef tallow)amine, alkyl(beef tallow)amine, and alkyl(soybean)amine.
The alkanolamide is not particularly limited, and examples thereof include coconut fatty acid diethanolamide, beef tallow fatty acid diethanolamide, lauric acid diethanolamide, and oleic acid diethanolamide.
The phosphate ester is not particularly limited, and examples thereof include polyoxyethylene alkyl ether phosphate ester and polyoxyethylene alkyl allyl ether phosphate ester.

The content of the dispersant in the slurry composition is preferably 0.1% by weight or more and 1.5% by weight or less, more preferably 0.15% by weight or more and 1.0% by weight or less.

The above-mentioned slurry composition may further contain additives such as a plasticizer and a surfactant.
Examples of the plasticizer include di(butoxyethyl adipate), dibutoxyethoxyethyl adipate, triethylene glycol dibutyl, triethylene glycol bis(2-ethylhexanoate), triethylene glycol dihexanoate, triethyl acetylcitrate, tributyl acetylcitrate, diethyl acetylcitrate, dibutyl acetylcitrate, dibutyl sebacate, triacetin, diethyl acetyloxymalonate, and diethyl ethoxymalonate.

The surfactant is not particularly limited, and examples thereof include cationic surfactants, anionic surfactants, and nonionic surfactants.
The nonionic surfactant is not particularly limited, but is preferably a nonionic surfactant with an HLB value of 10 or more and 20 or less. Here, the HLB value is used as an index representing the hydrophilicity and lipophilicity of a surfactant, and several calculation methods have been proposed. For example, for an ester-based surfactant, the HLB value is defined as 20 (1-S/A), where S is the saponification number and A is the acid value of the fatty acid constituting the surfactant. Specifically, nonionic surfactants having polyethylene oxide with alkylene ether added to the fatty chain are suitable, and specific examples of suitable surfactants include polyoxyethylene lauryl ether and polyoxyethylene cetyl ether. Although the nonionic surfactants have good thermal decomposition properties, adding a large amount of them may reduce the thermal decomposition properties of the inorganic particle dispersion slurry composition, so the preferred upper limit of their content is 5 wt %.

The viscosity of the slurry composition is not particularly limited, but the viscosity measured at 25°C using a Brookfield viscometer is preferably 200 mPa·s or more, more preferably 500 mPa·s or more, and is preferably 100,000 mPa·s or less, more preferably 50,000 mPa·s or less, and is preferably 200 to 100,000 mPa·s, more preferably 500 to 50,000 mPa·s.
By setting the content within the above range, it becomes possible for the obtained inorganic particle-dispersed sheet to maintain a predetermined shape after coating by a die coating printing method or the like. In addition, problems such as indelible die coating marks can be prevented, and excellent printability can be achieved.

The method for preparing the slurry composition is not particularly limited, and examples thereof include conventionally known stirring methods. Specific examples include a method in which the vehicle composition, inorganic particles, dispersant, and other components, such as additional solvents and plasticizers, which are added as needed, are stirred using a triple roll or the like. The order in which the components of the slurry composition are added can be determined as appropriate.

The above-mentioned slurry composition can be used to produce electronic components.
An electronic part made using the above slurry composition also constitutes one aspect of the present invention.
Examples of the electronic components include die attach paste (ACP), die attach film (ACF), via electrodes for TSV/TGV, touch panels, various circuits for RFID and sensor substrates, various die bonding agents, sealants for MEMS devices, and electrode materials for solar cells, multilayer ceramic capacitors, LTCC, silicon capacitors, all-solid-state batteries, etc. In addition to the electrode circuit applications, the material can also be used for antibacterial materials, electromagnetic wave shields, catalysts, fluorescent materials, etc.

For example, the slurry composition can be applied to a support film that has been subjected to a release treatment on one side, the organic solvent is dried, and the film is molded to produce an inorganic particle-dispersed molded product.
The shape of the inorganic particle dispersion molded product is not particularly limited, but may be, for example, a sheet.

Examples of methods for producing the inorganic particle dispersion molding include a method in which the slurry composition is applied to a support film using a coating method such as a roll coater, die coater, squeeze coater, or curtain coater to form a uniform coating film.

For example, when the inorganic particle dispersion molding is in the form of a sheet, the support film used in producing the inorganic particle dispersion molding is preferably a resin film that is heat-resistant, solvent-resistant, and flexible. The flexibility of the support film allows the inorganic particle dispersion slurry composition to be applied to the surface of the support film using a roll coater, blade coater, or the like, and the resulting inorganic particle dispersion sheet-forming film can be stored and supplied in a rolled state.

Examples of resins that can form the support film include polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, fluorine-containing resins such as polyfluoroethylene, nylon, cellulose, and the like.
The thickness of the support film is preferably, for example, 10 to 100 μm.
It is also preferable that the surface of the support film is subjected to a release treatment, which allows the support film to be easily peeled off in the transfer step.

The above slurry composition can be applied and dried to produce a molded product containing dispersed inorganic particles.
Furthermore, by using the above-mentioned slurry composition and inorganic particle dispersion molded product in a conductive paste for external electrodes, a multilayer ceramic capacitor, which is an electronic component, can be produced.

The method for producing the multilayer ceramic capacitor includes the steps of printing and drying a conductive paste on the inorganic particle dispersion molding to produce a dielectric sheet, and laminating the dielectric sheets.

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

The method for printing the conductive paste is not particularly limited, and examples include screen printing, die coating printing, offset printing, gravure printing, and inkjet printing.

In the manufacturing method for the multilayer ceramic capacitor, dielectric sheets printed with the conductive paste are stacked to produce a raw ceramic laminate, which is then fired in a reducing atmosphere at temperatures between 300 and 1500°C, resulting in a large number of component elements.

Next, a conductive paste for external electrodes containing the above-mentioned (meth)acrylic resin is applied to both end surfaces of each component element by dipping, and then dried at 100-200°C. After that, it is fired in a reducing atmosphere at 300-800°C to form external electrodes on both end surfaces of the component element.

Next, electrolytic plating is applied to the external electrodes, and a Cu film, a Ni film, and a Sn film are sequentially formed on the external electrodes, thereby obtaining a multilayer ceramic capacitor.

The present invention provides a (meth)acrylic resin that combines excellent low-temperature decomposition properties of a slurry composition with high strength of a ceramic green sheet, enabling the production of ceramic laminates that can be further thinned. It also provides a vehicle composition, a slurry composition, and an electronic component that contain the (meth)acrylic resin.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

(Examples 12 to 17, Reference Examples 1 to 11, 18 to 19, Comparative Examples 1 to 9)
(Preparation of (meth)acrylic resin particles)
A 2 L separable flask equipped with a stirrer, a condenser, a thermometer, a hot water bath, and a nitrogen gas inlet was prepared, and a total of 100 parts by weight of monomers was charged into the 2 L separable flask so as to obtain the composition shown in Table 1. Furthermore, 900 parts by weight of water was mixed to obtain a monomer mixture.
The following monomers were used:
MMA: methyl methacrylate (number of carbon atoms in ester substituent: 1)
EMA: ethyl methacrylate (number of carbon atoms in ester substituent: 2)
nPMA: n-propyl methacrylate (number of carbon atoms in the ester substituent: 3)
nBMA: n-butyl methacrylate (number of carbon atoms in the ester substituent: 4)
iBMA: isobutyl methacrylate (number of carbon atoms in ester substituent: 4)
OMA: n-octyl methacrylate (number of carbon atoms in the ester substituent: 8)
2EHMA: 2-ethylhexyl methacrylate (number of carbon atoms in the ester substituent: 8)
LMA: n-lauryl methacrylate (number of carbon atoms in ester substituent: 12)
MA: methyl acrylate (number of carbon atoms in ester substituent: 1)
BA: butyl acrylate (number of carbon atoms in ester substituent: 4)

The resulting monomer mixture was bubbled with nitrogen gas for 20 minutes to remove dissolved oxygen, and then the atmosphere in the separable flask was replaced with nitrogen gas, and the water bath was heated to 80° C. with stirring. Thereafter, a chain transfer agent and a polymerization initiator were added in the amounts shown in Table 1 to initiate polymerization.
After 7 hours from the start of polymerization, the polymerization was terminated by cooling to room temperature. The resulting resin solution was then dried in an oven at 100° C. to remove water, thereby obtaining (meth)acrylic resin particles.
The chain transfer agent and polymerization initiator used were as follows:
<Chain transfer agent>
CT-1: 3-mercapto-1,2-propanediol (polymerization initiator)
KPS: Potassium persulfate (Fujifilm Wako Pure Chemical Industries, Ltd.)

(Preparation of vehicle composition for dispersing inorganic particles)
To 10 parts by weight of the obtained (meth)acrylic resin particles, 90 parts by weight of a solvent having the composition shown in Table 2 was added, and the mixture was stirred until homogeneous, to obtain a vehicle composition for dispersing inorganic particles.

(Preparation of inorganic particle dispersion slurry composition)
To the obtained vehicle composition for dispersing inorganic particles, a solvent, a dispersant, and inorganic particles were added in the proportions shown in Table 2, and the mixture was kneaded with a high-speed stirrer to obtain an inorganic particle dispersion slurry composition.
The solvents used in the preparation of the vehicle composition for dispersing inorganic particles were used in the same proportions.
The dispersants and inorganic particles used were as follows:
<Dispersant>
Nopcosperse 092 (manufactured by Sanyo Chemical Industries, Ltd.)
<Inorganic particles>
Barium titanate (BT-02, manufactured by Sakai Chemical Industry Co., Ltd., average particle size 0.2 μm)

<Evaluation>
The (meth)acrylic resin particle and inorganic particle dispersion slurry compositions obtained in the Examples , Reference Examples , and Comparative Examples were evaluated as follows. The results are shown in Tables 1 and 3.

(1) Ti Value: 85 parts by weight of butyl acetate was added to 15 parts by weight of the obtained (meth)acrylic resin particles, and the mixture was heated to 80°C while stirring. The mixture was kept at 80°C for 12 hours with stirring, and then cooled to obtain a resin solution. The viscosity of the obtained resin solution was measured using a BH-type viscometer with a No. 5 rotor at 25°C and 2 rpm. The viscosity was also measured in the same manner at 25°C and 20 rpm, and the Ti value was calculated based on the following formula.
Ti value = viscosity (2 rpm) / viscosity (20 rpm)

(2) Average particle diameter D and CV value of particle diameter The obtained (meth)acrylic resin particles were observed using a scanning electron microscope (Regulus 8220 manufactured by Hitachi High-Technologies Corporation), and the particle diameters of 100 particles were measured. The CV value was calculated from the average particle diameter D [μm] and the standard deviation σ of the particle diameters using the following formula.
CV value of particle size [%] = σ/D × 100

(3) Weight average molecular weight (Mw)
The weight average molecular weight (Mw) of the obtained (meth)acrylic resin particles was measured in terms of polystyrene by gel permeation chromatography using an LF-804 (manufactured by SHOKO Corporation) as a column.

(4) Low temperature decomposition (TGDTA)
The obtained inorganic particle dispersion slurry composition was packed into a platinum pan of a TGDTA, and the temperature was raised from 30° C. at a rate of 5° C./min in a nitrogen atmosphere to evaporate the solvent and thermally decompose the resin and dispersant. Thereafter, the time (minutes) until 90% by weight degreasing was completed (the weight was 40.4% by weight) was measured.

(5) Sintering residue (TGDTA)
The obtained (meth)acrylic resin particles were packed into a platinum pan of a TGDTA, and the temperature was raised from 30°C to 350°C at a rate of 5°C/min in a nitrogen atmosphere, and maintained at that temperature for 2 hours to thermally decompose the (meth)acrylic resin particles. The ratio of the weight after measurement to the weight before measurement was measured as the sintering residue.

(6) Dispersibility (6-1) Filterability 2 ml of the obtained inorganic particle dispersion slurry composition was placed in a 2.5 ml syringe, and a syringe needle having an outer diameter of 0.81 mm, an inner diameter of 0.51 mm, and a length of 38 mm was attached to the tip of the syringe. A force of 5 kgf was applied, and the time until all of the slurry composition came out of the tip of the syringe needle was measured.
If the time it takes for the slurry composition to completely come out of the tip of the syringe needle is short, it can be said that the filterability is excellent, and when the filterability is excellent, it can be said that the effect of inhibiting aggregation of inorganic particles is high and the dispersibility is excellent.

(6-2) Surface Roughness Using a screen printer, a screen plate, and a printing glass substrate, an inorganic particle dispersion slurry composition was printed in an environment of a temperature of 23° C. and a humidity of 50%, and the solvent was dried in a fan oven for 30 minutes at 100° C. Using the obtained printed pattern, the surface roughness was measured at 10 points using a surface roughness meter (Surfcom, manufactured by Tokyo Seimitsu Co., Ltd.).
The following screen printing machine, screen plate, and printing glass substrate were used.
Screen printing machine (MT-320TV, manufactured by Microtec)
Screen plate (Tokyo Process Services, ST500, emulsion 2 μm, 2012 patterns, screen frame 320 mm × 320 mm)
Printed glass substrate (soda glass, 150 mm x 150 mm, thickness 1.5 mm)
A small surface roughness means that the dispersibility of inorganic particles is excellent.

(7) Particles: The resulting (meth)acrylic resin particles were diluted with a mixed solvent of ethanol and toluene (1:1 by weight) to a resin content of 2% by weight. The particle size distribution of the polyvinyl acetal resin in 10 mL of this solution was measured using a particle counter ("KL-11A," manufactured by Rion Co., Ltd.). The number of particles with diameters of 0.5 to 1.0 μm or greater per mL of solution was confirmed. Furthermore, for particles with diameters of 0.5 to 1.0 μm, the particle volume was calculated assuming a true sphere with a diameter of 0.75 μm. Based on the measurement results, the proportion of particles with diameters of 0.5 to 1.0 μm ( ^10-8 % by volume) was calculated. Fewer particles result in fewer voids in the ceramic laminate, which is considered superior.

(8) Tensile Test: The obtained (meth)acrylic resin particles were dissolved in butyl acetate to obtain a resin solution, which was applied to a release-treated PET film using an applicator and dried for 10 minutes in a 100°C air oven to prepare a resin sheet having a thickness of 20 μm. Using graph paper as a cover film, a strip-shaped test piece having a width of 1 cm was prepared with scissors.
The obtained test pieces were subjected to a tensile test under conditions of 23°C and 50RH using an Autograph AG-IS (manufactured by Shimadzu Corporation) with a chuck distance of 3 cm and a tensile speed of 10 mm/min, and the stress-strain characteristics (yield stress, elongation at break, and tensile performance (yield stress × elongation at break)) were confirmed.
If the strength of the resin sheet is high, it can be predicted that the strength of the resulting ceramic green sheet will also be high.

(9) Thinning test The obtained inorganic particle dispersion slurry composition was applied to a release-treated PET film using an applicator and dried for 10 minutes in a 100°C air oven to produce green sheets with dried thicknesses of 1.0 μm, 2.0 μm, 3.0 μm, 4.0 μm, 5.0 μm, 6.0 μm, 7.0 μm, 8.0 μm, 9.0 μm, and 10.0 μm. The green sheets were checked for tears when peeled from the PET film, and the one without tears and with the smallest thickness was regarded as the evaluation result.

The present invention provides a (meth)acrylic resin that can produce a ceramic laminate that can be further thinned by achieving both excellent low-temperature decomposition properties of a slurry composition and high strength of a ceramic green sheet, and also provides a vehicle composition, a slurry composition, and an electronic component that contain the (meth)acrylic resin.

Claims (11)

having a structural unit derived from a (meth)acrylic acid ester monomer,
The (meth)acrylic acid ester monomer includes a (meth)acrylic acid ester monomer A and a (meth)acrylic acid ester monomer B,
When the number of carbon atoms of the ester substituent possessed by the (meth)acrylic acid ester monomer A is X, the number of carbon atoms of the ester substituent possessed by the (meth)acrylic acid ester monomer B is 4X;
the number of carbon atoms X of the ester substituent of the (meth)acrylic acid ester monomer A is 1,
The (meth)acrylic acid ester monomer further includes 2-ethylhexyl (meth)acrylate,
a ratio of the content of the structural units derived from the (meth)acrylic acid ester monomer B to the content of the structural units derived from the (meth)acrylic acid ester monomer A (monomer B/monomer A) is 4 or more and 7 or less;
the content of the structural unit derived from the (meth)acrylic acid ester monomer A is 5% by weight or more,
A (meth)acrylic resin having a Ti value of 1.5 or more and 2.5 or less when dissolved in butyl acetate . The ( meth)acrylic resin according to claim 1, wherein the content of the structural unit derived from the (meth)acrylic acid ester monomer B is 20% by weight or more. The (meth)acrylic resin according to claim 1 or 2, wherein the (meth)acrylic acid ester monomer is a methacrylic acid ester monomer. The (meth)acrylic resin according to claim 1 or 2, wherein the (meth)acrylic acid ester monomers include a (meth)acrylic acid ester monomer having a branched-chain ester substituent and a (meth)acrylic acid ester monomer having a linear-chain ester substituent, the ester substituents having the same number of carbon atoms. 5. The (meth)acrylic resin according to claim 4, wherein the ratio of the content of structural units derived from (meth)acrylic ester monomers having branched-chain ester substituents to the content of structural units derived from (meth)acrylic ester monomers having straight-chain ester substituents, wherein the ester substituents have the same number of carbon atoms ((meth)acrylic ester monomers having branched-chain ester substituents/(meth)acrylic ester monomers having straight-chain ester substituents (the ester substituents have the same number of carbon atoms)) is 0.5 or more and 2.0 or less. A vehicle composition containing the (meth)acrylic resin according to claim 1 or 2 and an organic solvent. The vehicle composition according to claim 6 , further comprising water, the content of said water being 10 ppm by weight or more and 12,000 ppm by weight or less. A slurry composition comprising the vehicle composition according to claim 6 , inorganic particles, and a dispersant. A slurry composition comprising the vehicle composition according to claim 7 , inorganic particles, and a dispersant. An electronic part obtained by using the slurry composition according to claim 8 . An electronic part obtained by using the slurry composition according to claim 9 .