Vehicle composition, slurry composition, and electronic component

Abstract

The present invention provides a vehicle composition that exhibits little change in viscosity due to temperature, and that makes it possible to produce a conductive paste in which there is little variation in viscosity. The present invention also provides a slurry composition that comprises said vehicle composition and an electronic component that is obtained using said slurry composition. The present invention is a vehicle composition comprising a binder resin and a vehicle solvent, wherein: the binder resin contains a (meth)acrylic resin or a polyvinyl acetal resin; the vehicle solvent contains an organic solvent A and a bornyl-based compound B; the organic solvent A contains at least one substance selected from the group consisting of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate; and the bornyl-based compound B contains at least one substance selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate.

Description

Vehicle composition, slurry composition and electronic component

[0001] The present invention relates to a vehicle composition, a slurry composition, and an electronic component.

[0002] A multilayer ceramic capacitor is known to have a structure comprising a laminate in which dielectric layers and internal electrodes are alternately stacked, and a pair of external electrodes sandwiching the laminate. The external electrodes are formed by applying a slurry composition for external electrodes to the surface of the laminate and sintering the composition.

[0003] In recent years, along with the miniaturization of multilayer ceramic capacitors, inorganic particles used in external electrodes have also become finer. Fine inorganic particles tend to aggregate in a slurry composition, and this aggregation can lead to voids remaining during the degreasing and firing processes, or to a decrease in the dispersibility of the inorganic particles. As a result, when these particles are used in electronic components such as multilayer ceramic capacitors, the electrical characteristics of the product can be degraded.

[0004] The binder resin used in the external electrodes is generally, for example, a (meth)acrylic resin or ethyl cellulose. For example, Patent Document 1 describes a configuration using an organic vehicle that combines an alcohol such as terpineol with a (meth)acrylic resin as an organic binder.

[0005] Patent No. 6950833

[0006] In recent years, efforts have been made to improve yields in order to increase the production efficiency of multilayer ceramic capacitors. Among the production processes, the step of applying external electrode paste to chips is particularly prone to process defects, and to improve yields, it is necessary to maintain a constant viscosity of the external electrode paste. However, with conventional configurations using organic vehicles, such as those described in Patent Document 1, viscosity changes significantly with temperature, which can lead to process defects due to viscosity variations caused by variations in environmental temperature. Furthermore, the viscosity of the resulting paste itself varies, which can lead to process defects. Therefore, there is a demand for a conductive paste with minimal temperature-dependent viscosity variation and viscosity variations.

[0007] The present invention aims to provide a vehicle composition that can be used to prepare a conductive paste with little change in viscosity due to temperature and little variation in viscosity, as well as a slurry composition containing the vehicle composition and an electronic component made using the slurry composition.

[0008] Disclosure 1 provides a vehicle composition comprising a binder resin and a vehicle solvent, wherein the binder resin comprises a (meth)acrylic resin or a polyvinyl acetal resin, the vehicle solvent comprises an organic solvent A and a bornyl compound B, the organic solvent A comprises at least one selected from the group consisting of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and the bornyl compound B comprises at least one selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate. Disclosure 2 is the vehicle composition of Disclosure 1, wherein the vehicle solvent contains 90 to 99.99% by weight in total of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and 0.01 to 10% by weight in total of borneol, isoborneol, bornyl acetate, and isobornyl acetate. Disclosure 3 is the vehicle composition of Disclosure 1, wherein the vehicle solvent contains 96.5 to 99.9% by weight in total of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and 0.1 to 3.5% by weight in total of borneol, isoborneol, bornyl acetate, and isobornyl acetate. Disclosure 4 is the vehicle composition of Disclosure 1, 2, or 3, wherein the (meth)acrylic resin contains 10 to 100% by weight of a segment derived from a (meth)acrylic acid ester having a branched structure in the ester substituent. Disclosure 5 is a slurry composition containing the vehicle composition of Disclosure 1, 2, 3, or 4 and inorganic particles. Disclosure 6 is an electronic component obtained using the slurry composition of Disclosure 5. The present invention is described in detail below.

[0009] The present inventors have discovered that a conductive paste with little change in viscosity with temperature and little variation in viscosity can be produced by employing a vehicle composition containing a binder resin and a vehicle solvent, which contains a (meth)acrylic resin or a polyvinyl acetal resin, a specific organic solvent A, and a specific bornyl-based compound, and have completed the present invention.

[0010] The vehicle composition contains a binder resin. The binder resin contains a (meth)acrylic resin or a polyvinyl acetal resin. The binder resin is preferably a (meth)acrylic resin or a polyvinyl acetal resin.

[0011] The (meth)acrylic resin preferably has a segment derived from a (meth)acrylic acid ester having a branched structure in the ester substituent. A (meth)acrylic resin mainly composed of a (meth)acrylic acid ester having a branched structure in the ester substituent has a lower decomposition end temperature than a (meth)acrylic resin mainly composed of a (meth)acrylic acid ester having a linear ester substituent. While a (meth)acrylic resin undergoes a depolymerization reaction in which it is decomposed into monomers in an environment exceeding the ceiling temperature, a (meth)acrylic acid ester having a branched structure in the ester substituent is difficult to repolymerize, and therefore has a low decomposition end temperature. Therefore, a (meth)acrylic resin having the above structure has excellent low-temperature decomposition properties.

[0012] Examples of the (meth)acrylic acid ester having a branched structure in the ester substituent include a (meth)acrylic acid alkyl ester having a branched alkyl group, a (meth)acrylic acid polyalkylene glycol having an alkylene glycol unit having a branched structure, etc. The number of carbon atoms in the ester substituent is preferably 3 or more, more preferably 4 or more, and is preferably 20 or less, more preferably 15 or less, and even more preferably 12 or less, for example, 10 or less.

[0013] Examples of the (meth)acrylic acid alkyl ester having a branched alkyl group 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, isodecyl (meth)acrylate, etc. 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.

[0014] The (meth)acrylate polyalkylene glycol having alkylene glycol units with a branched structure may include those having propylene glycol units. In addition, the (meth)acrylate polyalkylene glycol having alkylene glycol units with a branched structure may have an alkoxy group at the end. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group. The (meth)acrylate polyalkylene glycol having alkylene glycol units with a branched structure preferably has 3 or more alkylene glycol units, more preferably 4 or more, and preferably 10 or less, and more preferably 8 or less.

[0015] The content of the segment derived from the (meth)acrylic acid ester having a branched structure in the ester substituent in the (meth)acrylic resin is preferably 10% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, and is preferably 100% by weight or less, more preferably 90% by weight or less. Within this range, a slurry composition with excellent low-temperature decomposition properties can be obtained. The content can be measured, for example, by pyrolysis GC-MS.

[0016] The (meth)acrylic resin preferably has an ester substituent having 4 or more carbon atoms, and the ester substituent has a segment derived from a (meth)acrylic acid ester having a branched structure. By having the above-mentioned configuration, a slurry composition having excellent low-temperature decomposition properties can be obtained.

[0017] Furthermore, the (meth)acrylic resin preferably has at least one segment selected from the group consisting of a segment derived from isobutyl methacrylate, a segment derived from 2-ethylhexyl methacrylate, a segment derived from isodecyl methacrylate, and a segment derived from isononyl methacrylate, as the segment derived from a (meth)acrylic acid ester having a branched structure in the ester substituent. By having the above-mentioned configuration, a slurry composition having excellent low-temperature decomposability can be obtained.

[0018] The (meth)acrylic resin preferably contains 10% by weight or more of segments derived from a (meth)acrylic acid ester having 4 or more carbon atoms in the ester substituent and a branched structure in the ester substituent, more preferably 60% by weight or more, and even more preferably 70% by weight or more, and preferably 100% by weight or less, and more preferably 90% by weight or less. Within this range, a slurry composition having excellent low-temperature decomposition properties can be obtained.

[0019] The content of the segment derived from the (meth)acrylic acid ester in which the carbon number of the ester substituent is 1 to 4 in the (meth)acrylic resin is preferably 60% by weight or more, more preferably 90% by weight or more, and preferably 100% by weight or less. Within this range, a slurry composition with excellent low-temperature decomposability can be obtained.

[0020] The (meth)acrylic resin may further contain other segments, such as a segment derived from a (meth)acrylic acid ester having a linear ester substituent, or a segment derived from a (meth)acrylic acid ester having a cyclic ester substituent. The above-described structure can enhance coating film strength. Examples of the (meth)acrylic acid ester having a linear ester substituent include a (meth)acrylic acid alkyl ester having a linear alkyl group and a (meth)acrylic acid polyalkylene glycol having a linear alkylene glycol unit. The number of carbon atoms in the ester substituent is preferably 1 or more, more preferably 2 or more, and is preferably 10 or less, more preferably 6 or less.

[0021] Examples of the (meth)acrylic acid alkyl ester having a linear alkyl group 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, with methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate being more preferred. Furthermore, since a slurry composition with excellent low-temperature decomposition properties can be obtained, it is preferable that the (meth)acrylic resin further has a segment derived from n-butyl methacrylate.

[0022] Examples of the (meth)acrylate polyalkylene glycol having a linear alkylene glycol unit include those having an ethylene glycol unit and those having a trimethylene glycol unit. The (meth)acrylate polyalkylene glycol having a linear alkylene glycol unit may also have an alkoxy group at its terminal. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group. The alkoxy group does not have a branched structure. Among these, a (meth)acrylate polyalkylene glycol having an ethylene glycol unit is preferred, and a (meth)acrylate methoxypolyethylene glycol is more preferred. The polyalkylene glycol (meth)acrylate having a linear alkylene glycol unit preferably has 4 or more alkylene glycol units, more preferably 10 or more, and more preferably 23 or less, and more preferably 20 or less.

[0023] Examples of the (meth)acrylic acid ester in which the ester substituent has a cyclic structure include (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.

[0024] In particular, the (meth)acrylic resin preferably uses a monomer containing a large amount of oxygen, and polyalkylene glycol (meth)acrylates having linear polyalkylene glycol units have a high oxygen content, and it is preferable to have a segment derived from such a (meth)acrylic acid ester. The depolymerization reaction of (meth)acrylic resins is an endothermic reaction, and it is difficult to obtain the heat required for decomposition at low temperatures. By having a segment derived from such a monomer containing a large amount of oxygen, the (meth)acrylic resin can be decomposed by combustion using its own oxygen near the ceiling temperature of the resin even in a nitrogen atmosphere, thereby further improving low-temperature decomposition. The polyalkylene glycol (meth)acrylates having linear alkylene glycol units preferably have an oxygen composition ratio of 30% by weight or more, more preferably 35% by weight or more.

[0025] The content of segments derived from a (meth)acrylic acid ester in which the ester substituent in the (meth)acrylic resin is linear is, for example, 0% by weight or more, preferably 1% by weight or more, more preferably 5% by weight or more, even more preferably 10% by weight or more, and preferably 90% by weight or less, more preferably 80% by weight or less, even more preferably 40% by weight or less, and even more preferably 30% by weight or less. By setting the content within the above range, handleability such as printability is improved. The content can be measured, for example, by pyrolysis GC-MS.

[0026] The total content of the segments derived from isobutyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate in the (meth)acrylic resin is preferably 10% by weight or more. By satisfying the above-mentioned configuration, a slurry composition with excellent low-temperature decomposition properties can be obtained. The total content is more preferably 50% by weight or more, and even more preferably 80% by weight or more. There is no particular upper limit, and it is, for example, 100% by weight or less, and more preferably 90% by weight or less. The content can be measured, for example, by pyrolysis GC-MS.

[0027] The (meth)acrylic resin may have a segment derived from a (meth)acrylic acid ester having a glycidyl group, a carboxyl group, or a hydroxyl group. Examples of the (meth)acrylic acid ester having a glycidyl group include glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl methacrylate. Examples of the (meth)acrylic acid ester having a hydroxyl group or a carboxyl group include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and (meth)acrylic acid.

[0028] The content of the segment derived from the (meth)acrylic acid ester having a glycidyl group, a carboxyl group, or a hydroxyl group in the (meth)acrylic resin is preferably 1% by weight or more, more preferably 4% by weight or more, and is preferably 10% by weight or less, more preferably 7% by weight or less. By setting the content within this range, low-temperature decomposition property can be further improved, and the toughness of the obtained inorganic particle-dispersed sheet can be improved.

[0029] The weight average molecular weight (Mw) of the (meth)acrylic resin is preferably 20,000 or more and preferably 4,000,000 or less. When the Mw is 20,000 or more, the viscosity of the slurry composition does not become too low, and the dispersibility of the inorganic particles can be improved. When the Mw is 4,000,000 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 Mw is preferably 30,000 or more, more preferably 50,000 or more, and is 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 500,000 or less.

[0030] The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the (meth)acrylic resin is usually 1.0 or more, preferably 1.5 or more, more preferably 2.0 or more, and preferably 10.0 or less, more preferably 8.0 or less. By setting the ratio within the above range, a moderate amount of components with a low degree of polymerization is contained, so that the viscosity of the slurry composition falls within a suitable range, thereby improving productivity. The weight average molecular weight (Mw) and number average molecular weight (Mn) are average molecular weights calculated in terms of polystyrene, and can be obtained by GPC measurement using, for example, a column LF-804 (manufactured by Showa Denko KK).

[0031] The glass transition temperature (Tg) of the (meth)acrylic resin is preferably 20° C. or higher, more preferably 30° C. or higher, and even more preferably 40° C. or higher, and is 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 using, for example, a differential scanning calorimeter (DSC) or the like.

[0032] The method for producing the (meth)acrylic resin is not particularly limited. For example, an organic solvent or the like is added to a raw material monomer mixture containing a (meth)acrylic acid ester having a branched structure in the ester substituent to prepare a monomer mixture, and a polymerization initiator is added to the resulting monomer mixture to polymerize the monomer mixture to produce the (meth)acrylic resin. The polymerization method is not particularly limited, and examples thereof include emulsion polymerization, suspension polymerization, bulk polymerization, interfacial polymerization, and solution polymerization. Among these, solution polymerization is preferred.

[0033] Examples of the polymerization initiator include dilauryl peroxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroxyperoxide, t-butyl hydroxyperoxide, cyclohexanone peroxide, disuccinic acid peroxide, potassium persulfate, ammonium persulfate, etc. Commercially available products of these initiators include Permenta H, Percumyl P, Perocta H, Percumyl H-80, Perloyl 355, Perbutyl H-69, Perhexa H, Perloyl SA, and Perloyl L (all manufactured by NOF Corporation), Trigonox 27, and Trigonox 421 (all manufactured by Nouryon).

[0034] From the viewpoint of sinterability, the degree of polymerization of the polyvinyl acetal resin is preferably 1,000 or more, preferably 1,500 or more, and preferably 4,000 or less, more preferably 3,000 or less. The degree of polymerization of the polyvinyl acetal resin refers to the degree of polymerization of the raw material polyvinyl alcohol resin. The degree of polymerization of the raw material polyvinyl alcohol resin can be measured by a method in accordance with JIS K6726. When the polyvinyl acetal resin is a mixture of two or more types, the degree of polymerization can be determined by multiplying the degree of polymerization of each polyvinyl acetal resin by its blending ratio and adding up the results.

[0035] From the viewpoint of sinterability, the amount of acetal groups in the polyvinyl acetal resin is preferably 60 mol % or more, more preferably 65 mol % or more, and is preferably 80 mol % or less, more preferably 75 mol % or less. The amount of acetal groups can be measured, for example, by NMR.

[0036] The polyvinyl acetal resin preferably has a hydroxyl group content of 16 mol % or more, more preferably 20 mol % or more, and preferably has a hydroxyl group content of 50 mol % or less, more preferably 33 mol % or less. The hydroxyl group content can be measured, for example, by NMR.

[0037] The polyvinyl acetal resin preferably has an acetyl group content of 0.1 mol % or more and 20 mol % or less, more preferably 1 mol % or more and 15 mol % or less. The acetyl group content can be measured, for example, by NMR.

[0038] The ethylene content of the polyvinyl acetal resin is preferably 4 mol % or more and 8 mol % or less. The ethylene content can be measured, for example, by NMR.

[0039] The amount of carboxyl groups in the polyvinyl acetal resin is preferably 0.5 mol % or more and 1.5 mol % or less. The amount of carboxyl groups can be measured, for example, by NMR.

[0040] The amount of acetoacetal groups in the polyvinyl acetal resin is preferably 20.2 mol % or more and 23.3 mol % or less. The amount of acetoacetal groups can be measured, for example, by NMR.

[0041] The butyral group content of the polyvinyl acetal resin is preferably 50 mol % or more and 60 mol % or less. The butyral group content can be measured, for example, by NMR.

[0042] The polyvinyl acetal resin preferably has an α-olefin unit in the main chain, which weakens the hydrogen bonding strength of the polyvinyl acetal resin, thereby improving the stability of viscosity over time and improving screen printability.

[0043] Examples of the α-olefin include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, pentylene, hexylene, cyclohexylene, cyclohexylethylene, and cyclohexylpropylene, with ethylene being particularly preferred. The content of the α-olefin is desirably 1 to 20 mol %.

[0044] The content of α-olefin units in the polyvinyl acetal resin is preferably 1 mol % or more and 20 mol % or less, more preferably 5 mol % or more and 15 mol % or less, in order to sufficiently increase the solubility in organic solvents.

[0045] The polyvinyl acetal resin may contain other ethylenically unsaturated monomer units. Examples of the other ethylenically unsaturated monomers include acrylic acid, methacrylic acid, fumaric acid (anhydride), maleic acid (anhydride), itaconic acid (anhydride), acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, trimethyl-(3-acrylamido-3-dimethylpropyl)-ammonium chloride, acrylamido-2-methylpropanesulfonic acid and its sodium salt, ethyl vinyl ether, butyl vinyl ether, N-vinylpyrrolidone, vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, sodium vinyl sulfonate, and sodium allyl sulfonate.

[0046] The polyvinyl acetal resin can be obtained, for example, by dissolving a polyvinyl alcohol resin in warm water, adding an aldehyde in the presence of an acid catalyst so that a predetermined amount of acetal groups is obtained, reacting the mixture, washing with water, neutralizing, and drying. The acid catalyst is not particularly limited, and either an organic acid or an inorganic acid can be used, but examples thereof include acetic acid, paratoluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid. Examples of alkalis used for neutralization include sodium hydroxide, potassium hydroxide, ammonia, sodium acetate, sodium carbonate, sodium bicarbonate, and potassium carbonate.

[0047] The polyvinyl alcohol resin is obtained by saponifying a vinyl ester polymer. Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, and vinyl pivalate, with vinyl acetate being economically preferable. The polyvinyl alcohol resin preferably contains an α-olefin in its main chain. The α-olefin weakens the hydrogen bonding strength of the polyvinyl acetal resin, thereby improving the viscosity stability over time and improving screen printability.

[0048] The aldehyde used in the above reaction is not particularly limited, and examples thereof include formaldehyde (including paraformaldehyde), acetaldehyde (including paraacetaldehyde), propionaldehyde, butyraldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, glyoxal, glutaraldehyde, benzaldehyde, 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxyaldehyde, m-hydroxyaldehyde, phenylacetaldehyde, phenylpropionaldehyde, etc. These aldehydes may be used alone or in combination of two or more, with acetaldehyde and / or butyraldehyde being preferred.

[0049] The vehicle composition may contain a binder resin other than the (meth)acrylic resin and the polyvinyl acetal resin, but preferably does not contain any other binder resin, such as cellulose resins such as hydroxymethyl cellulose, carboxymethyl cellulose, and ethyl cellulose, polyester resins, epoxy resins, and polycarbonate resins.

[0050] The content of the binder resin in the vehicle composition is preferably 2% by weight or more, more preferably 10% by weight or more, and is preferably 20% by weight or less, more preferably 15% by weight or less.

[0051] The vehicle composition contains a vehicle solvent. The vehicle solvent contains an organic solvent A and a bornyl compound B. The organic solvent A contains at least one selected from the group consisting of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate. The bornyl compound B contains at least one selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate. By using the binder resin and the vehicle solvent in combination, a conductive paste can be produced that has little viscosity change due to temperature and little viscosity variation.

[0052] The organic solvent A may contain at least one of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and may also contain other organic solvents. Examples of other organic solvents include terpene-based organic solvents other than those listed above, alcohol-based organic solvents such as aliphatic alcohol-based organic solvents, aromatic hydrocarbon-based organic solvents, ester-based organic solvents such as acetate ester-based organic solvents, ketone-based organic solvents, and hydrocarbon-based solvents. Examples of other terpene-based organic solvents include dihydroterpineol oxyethanol, terpinyl methyl ether, dihydroterpineol methyl ether, α-pinene, β-pinene, camphene, Δ-2-carene, Δ-3-carene, limonene, terpinene, and terpinolene. The terpene-based organic solvent is different from the bornyl compound B described below. Examples of the aliphatic alcohol-based organic solvent include ethanol, isopropanol, and butanol. Examples of the aromatic hydrocarbon-based organic solvent include toluene and benzene. Examples of the acetate-based organic solvent include ethyl acetate, butyl acetate, and methyl acetate. Examples of the ketone-based organic solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the hydrocarbon-based solvent include cyclohexane, hexane, and heptane.

[0053] The total content of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate in the vehicle solvent is preferably 85% by weight or more, more preferably 90% by weight or more, even more preferably 96.5% by weight or more, even more preferably 98% by weight or more, and is preferably 99.99% 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 obtained that can produce a conductive paste with little viscosity change due to temperature and little viscosity variation.

[0054] The organic solvent A may contain, but preferably does not contain, any organic solvent other than terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate.

[0055] The vehicle solvent contains a bornyl compound B. The bornyl compound B contains at least one selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate. The bornyl compound B needs to contain at least one of borneol, isoborneol, bornyl acetate, and isobornyl acetate, and may contain other bornyl compounds other than those listed above, but preferably does not contain other bornyl compounds. The bornyl compound B preferably contains at least one of borneol and isoborneol. Examples of other bornyl compounds include bornane and 2,3-bornanedione.

[0056] When the vehicle solvent contains dihydroterpineol acetate, it preferably contains bornyl acetate or isobornyl acetate, when the vehicle solvent contains dihydroterpineol, it preferably contains borneol or isoborneol, and when the vehicle solvent contains terpineol, it preferably contains borneol or isoborneol. By doing so, it is possible to obtain a vehicle composition that can produce a conductive paste with little change in viscosity with temperature and little variation in viscosity.

[0057] The total content of borneol, isoborneol, bornyl acetate, and isobornyl acetate in the vehicle solvent is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and even more preferably 0.5% by weight or more, and is preferably 15% by weight or less, more preferably 10% by weight or less, even more preferably 3.5% by weight or less, and even more preferably 2% by weight or less. By setting the content within the above range, a vehicle composition can be obtained that can produce a conductive paste with little change in viscosity with temperature and little variation in viscosity.

[0058] From the viewpoints of coatability and dispersibility of inorganic particles, the content of the vehicle solvent in the vehicle composition is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight or more, and is preferably 95% by weight or less, and more preferably 90% by weight or less.

[0059] In addition, in the vehicle composition, the content of the vehicle solvent relative to 100 parts by weight of the binder resin is preferably 150 parts by weight or more, more preferably 230 parts by weight or more, and is preferably 1900 parts by weight or less, more preferably 900 parts by weight or less.

[0060] The vehicle composition may contain a dispersant, a thixotropic agent, etc. in addition to the (meth)acrylic resin and the vehicle solvent.

[0061] The method for preparing the vehicle composition is not particularly limited, and examples thereof include a method of mixing a binder resin containing a (meth)acrylic resin or a polyvinyl acetal resin, an organic solvent A containing predetermined components, and a bornyl compound B.

[0062] A slurry composition can be prepared by adding inorganic particles, a dispersant, and other components as needed to the vehicle composition. The vehicle composition and the slurry composition containing the inorganic particles also constitute one aspect of the present invention.

[0063] The slurry composition contains inorganic particles, and the inorganic particles are not particularly limited, and examples thereof include ceramic powder, glass powder, phosphor particles, silicon oxide particles, metal particles, and the like.

[0064] 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, aluminum nitride, silicon nitride, boron nitride, boron carbide, barium stannate, calcium stannate, magnesium silicate, mullite, steatite, cordierite, forsterite, etc. 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, Sm ２ Fe １７ N ３ , Nd ２ Fe １４ B, MnAlC, L １０ FeNi, La ２／３－ｘ Li ３ｘ TiO ３ , La （１－ｘ）／３ Li ｘ NbO ３ , LaGaO ３ , LaScO ３ , CaZrO ３ , (La ０．８７５ Sr ０．１２５ ) MnO ３ , PbZrTiO ３ , SrBi ２ Ta ２ O ９ , BiFeO ３ , KNbO ３ , PbVO ３ , BiCo ３ , Bi(Zn １／２ Ti １／２ ) ３ etc. can also be used.

[0065] 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, and CaO—Al ２ O ３ -SiO ２system, MgO-Al ２ O ３ -SiO ２ system, LiO ２ -Al ２ O ３ -SiO ２ Examples of the glass powder include glass powders of various silicon oxides such as SnO—B ２ O ３ -P ２ O ５ -Al ２ O ３ mixture, PbO-B ２ O ３ -SiO ２ Mixture, BaO-ZnO-B ２ O ３ -SiO ２ Mixture, ZnO-Bi ２ O ３ -B ２ O ３ -SiO ２ mixture, Bi ２ O ３ -B ２ O ３ -BaO-CuO mixture, Bi ２ O ３ -ZnO-B ２ O ３ -Al ２ O ３ -SrO mixture, ZnO-Bi ２ O ３ -B ２ O ３ mixture, Bi ２ O ３ -SiO ２ mixture, 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 ２mixture, 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 -Al ２ O ３ -RO-R ２ O mixture, SrO-ZnO-P ２ O ５ Mixture, BaO-ZnO-B ２ O ３ -SiO ２ Glass powders such as mixtures can also be used. R is an element selected from the group consisting of Zn, Ba, Ca, Mg, Sr, Sn, Ni, Fe, and Mn. In particular, PbO—B ２ O ３ -SiO ２ Mixture glass powder and lead-free BaO-ZnO-B ２ O ３ -SiO ２ Mixture or ZnO-Bi ２ O ３ -B ２ O ３ -SiO ２ Lead-free glass powders such as mixtures are preferred.

[0066] The phosphor particles are not particularly limited, and for example, a blue phosphor material, a red phosphor material, a green phosphor material, etc., which are conventionally known as phosphor materials for displays, can be used as the phosphor material. １０ O １７ : Eu-based, Y ２ SiO ５ : Ce-based, CaWO ４ : Pb-based, BaMgAl １４ O ２３ :Eu-based, BaMgAl １６ O ２７ : Eu-based, BaMg ２ Al １４ O ２３ : Eu-based, BaMg ２ Al １４ O ２７ :Eu-based and ZnS:(Ag,Cd)-based materials are used. ２ O ３ : Eu-based, Y ２ SiO ５ : Eu-based, Y ３ Al ５ O １２ : Eu-based, Zn ３ (P.O. ４ ) ２ : Mn-based, YBO ３ :Eu-based, (Y,Gd)BO ３ : Eu-based, GdBO ３ : Eu-based, ScBO ３ : Eu-based, LuBO ３ : Eu-based materials are used. As the green phosphor material, for example, Zn ２ SiO ４ : Mn-based, BaAl １２ O １９ :Mn-based, SrAl １３ O １９ : Mn-based, CaAl １２ O １９ : Mn-based, YBO ３ :Tb series, BaMgAl １４ O ２３ : Mn-based, LuBO ３ :Tb series, GdBO ３ :Tb series, ScBO ３ : Tb-based, Sr ６Si ３ O ３ Cl ４ Other examples include ZnO:Zn, ZnS:(Cu,Al), ZnS:Ag, Y ２ O ２ S: Eu-based, ZnS: Zn-based, (Y, Cd)BO ３ :Eu-based, BaMgAl １２ O ２３ : Eu-based materials can also be used.

[0067] The metal particles are not particularly limited, and examples thereof include powders of copper, nickel, palladium, platinum, gold, silver, aluminum, tungsten, and alloys thereof. Metals such as copper and iron, which have good adsorption properties with carboxyl groups, amino groups, amide groups, and the like and are easily oxidized, can also be suitably used. These metal powders may be used alone or in combination of two or more. In addition to metal complexes, various carbon blacks, carbon nanotubes, and the like may also be used.

[0068] Other inorganic particles include Li ２ S-M ｘ S ｙ Lithium sulfur-based glass such as (M=B, Si, Ge, P), LiCeO ２ Lithium cobalt composite oxides such as LiMnO ４ Lithium manganese composite oxide, lithium nickel composite oxide, lithium vanadium composite oxide, lithium zirconium composite oxide, lithium hafnium composite oxide, lithium silicophosphate (Li ３．５ Si ０．５ P ０．５ O ４ ), lithium titanium phosphate (LiTi ２ (P.O. ４ ) ３ ), lithium titanate (Li ４ Ti ５ O １２ ), Li ４／３ Ti ５／３ O ４ , LiCoO ２ , lithium germanium phosphate (LiGe ２ (P.O. ４ ) ３ ), Li２ -SiS-based glass, Li ４ GeS ４ -Li ３ P.S. ４ LiSiO based glass ３ , LiMn ２ O ４ , Li ２ S-P ２ S ５ 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, Li ２ O-P ２ O ５ -B ２ O ３ , Li ２ O-GeO ２ Lithium oxide compounds such as Ba, Li ｘ Al ｙ Ti ｚ (P.O. ４ ) ３ Glasses containing La ｘ Li ｙ TiO ｚ Li-based glass ｘ Ge ｙ P ｚ O ４ Li-based glass ７ La ３ Zr ２ O １２ Li-based glass ｖ Si ｗ P ｘ S ｙ Cl ｚ Glass containing fluorine may also be used.

[0069] The inorganic particles have an average particle size of preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more and 3 μm or less, still more preferably 0.1 μm or more and still more preferably 1 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 analyzer.

[0070] The content of the inorganic particles in the slurry composition is not particularly limited, but 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, and is 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 ranges, the slurry composition can have sufficient viscosity and excellent coatability, and can also have excellent dispersibility of the inorganic particles.

[0071] The slurry composition preferably contains a dispersant. Suitable examples of the dispersant include fatty acids, aliphatic amines, alkanolamides, and phosphate esters. A silane coupling agent or the like may also be added. The fatty acids are 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, and coconut fatty acid; and unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, sorbic acid, tallow fatty acid, and hardened castor fatty acid. Among these, lauric acid, stearic acid, and oleic acid are preferred. The aliphatic amines are not particularly limited, and examples thereof include laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, alkyl (coconut) amines, alkyl (hardened tallow) amines, alkyl (beef tallow) amines, and alkyl (soybean) amines. The alkanolamide is not particularly limited, and examples thereof include coconut fatty acid diethanolamide, beef tallow fatty acid diethanolamide, lauric acid diethanolamide, oleic acid diethanolamide, etc. The phosphate ester is not particularly limited, and examples thereof include polyoxyethylene alkyl ether phosphate ester, polyoxyethylene alkyl allyl ether phosphate ester.

[0072] The content of the dispersant in the slurry composition is 0% by weight or more, preferably 0.1% by weight or more, more preferably 0.15% by weight or more, and is preferably 1% by weight or less, more preferably 0.5% by weight or less.

[0073] The slurry composition may further contain additives such as a plasticizer, a surfactant, etc. 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.

[0074] 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 to 20. 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 saponification value is S, 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 with an alkylene ether attached to the fatty chain are suitable, and specific examples include polyoxyethylene lauryl ether and polyoxyethylene cetyl ether. Although the nonionic surfactant has good thermal decomposition properties, adding a large amount may reduce the thermal decomposition properties of the slurry composition. Therefore, the preferred upper limit of the content is 5 wt%.

[0075] The method for preparing the slurry composition is not particularly limited, and examples thereof include conventionally known stirring methods, specifically, for example, a method in which the vehicle composition, the inorganic particles, the dispersant, and other components added as needed, such as an additional solvent and a plasticizer, are stirred using a triple roll, etc. The order of addition of the components of the slurry composition can be appropriately determined.

[0076] Electronic components can be produced using the above-mentioned slurry composition. Electronic components produced using the above-mentioned slurry composition also constitute one aspect of the present invention. Examples of the electronic components include die attach paste (ACP), die attach film (ACF), TSV, TGV via electrodes, touch panels, various circuits for RFID and sensor substrates, various die bonding agents, sealants for MEMS devices, solar cells, laminated ceramic capacitors, LTCC, silicon capacitors, and electrode materials for all-solid-state batteries. In addition to the above-mentioned electrode circuit applications, the composition can also be used for antibacterial materials, electromagnetic wave shielding, catalysts, fluorescent materials, and the like.

[0077] For example, the slurry composition may be applied to a support film having one side subjected to a release treatment, the organic solvent may be dried, and the resulting product may be molded to produce an inorganic particle-dispersed molded product. The shape of the inorganic particle-dispersed molded product is not particularly limited, and may be, for example, a sheet.

[0078] Examples of methods for producing the inorganic particle-dispersed molded product include a method in which the slurry composition is applied to a support film by a coating method such as a roll coater, die coater, squeeze coater, or curtain coater to form a uniform coating film.

[0079] For example, when the inorganic particle-dispersed molded product is in the form of a sheet, the support film used in producing the inorganic particle-dispersed 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, or the like, and the resulting inorganic particle-dispersed sheet-forming film can be stored and supplied in a rolled state.

[0080] Examples of resins that 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 support film is preferably, for example, 20 to 100 μm. The surface of the support film is preferably subjected to a release treatment, which allows the support film to be easily peeled off in the transfer step.

[0081] The slurry composition can be applied and dried to produce an inorganic particle dispersion molded product. Furthermore, the slurry composition and the inorganic particle dispersion molded product can be used in a conductive paste for external electrodes to produce a multilayer ceramic capacitor, which is an electronic component.

[0082] A method for producing the multilayer ceramic capacitor includes a step of printing a conductive paste on the inorganic particle dispersion molding and drying it to produce a dielectric sheet, and a step of laminating the dielectric sheets.

[0083] The conductive paste contains a conductive powder. The material of the conductive powder is not particularly limited as long as it is a conductive material, 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.

[0084] The method for printing the conductive paste is not particularly limited, and examples thereof include screen printing, die coating printing, offset printing, gravure printing, and inkjet printing.

[0085] In the method for manufacturing the laminated ceramic capacitor, dielectric sheets on which the conductive paste is printed are stacked to produce a green ceramic laminate, which is then fired in a reducing atmosphere at 1000 to 1500°C, thereby obtaining a large number of component elements.

[0086] Next, a conductive paste for external electrodes containing the above-mentioned (meth)acrylic resin is applied to both end surfaces of each of these component elements by a dipping method, and then the applied paste is dried at 100 to 200°C and then fired at 450 to 800°C in a reducing atmosphere to form external electrodes on both end surfaces of the component elements.

[0087] Next, the external electrodes are electrolytically plated to form a Cu film, a Ni film, and a Sn film in this order on the external electrodes, thereby obtaining a laminated ceramic capacitor.

[0088] According to the present invention, there is provided a vehicle composition that can be used to prepare a conductive paste with little change in viscosity due to temperature and little variation in viscosity, as well as a slurry composition containing the vehicle composition and an electronic component made using the slurry composition.

[0089] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0090] (Examples 1 to 33, Comparative Examples 1 to 11) (Preparation of Resin Microparticles) Pure water was added to a stirring vessel in the amounts shown in Tables 1 to 3, and then monomers, chain transfer agents, and polymerization initiators were added as shown in Tables 1 to 3. The following monomers, chain transfer agents, and polymerization initiators were used. <Monomers> Methyl methacrylate (MMA): manufactured by Tokyo Chemical Industry Co., Ltd. Ethyl methacrylate (EMA): 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. 2-Ethylhexyl methacrylate (2EHMA): manufactured by Tokyo Chemical Industry Co., Ltd. <Chain transfer agent> 8-Mercapto-1-octanol: manufactured by Sigma-Aldrich <Polymerization initiator> t-Butyl peroxypivalate: manufactured by Kayaku Akzo Co., Ltd., Kayaester P-70

[0091] Next, using a comb-tooth high-speed rotary emulsifier, the mixture was mixed at a rotation speed of 10,000 rpm for 3 minutes, and then transferred to a reaction vessel equipped with a stirrer and a jacket. Nitrogen gas was supplied to create a nitrogen atmosphere while stirring at 150 rpm to prepare a monomer composition. The temperature was then raised to 70°C using the 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 continued for another hour, completing the aqueous suspension polymerization and obtaining a suspension containing resin microparticles.

[0092] (Washing and Drying of Resin Microparticles) Next, the obtained suspension containing the resin microparticles was filtered through a Nutsche filter, washed with 1000 parts by weight of ion-exchanged water per 100 parts by weight of the resin microparticles, and dried to obtain resin microparticles. The weight average molecular weight (Mw) and number average molecular weight (Mn) of the obtained (meth)acrylic resin microparticles, calculated in terms of polystyrene, were measured by gel permeation chromatography using an LF-804 (manufactured by SHOKO Corporation) column, and the molecular weight distribution (Mw / Mn) was determined.

[0093] (Preparation of Vehicle Composition) A vehicle composition was prepared by adding 32.71 parts by weight of a vehicle solvent prepared by mixing organic solvent A and bornyl compound B to 5.79 parts by weight of the obtained resin microparticles so as to obtain the formulations shown in Tables 4 to 6. In Comparative Example 11, an ethyl cellulose resin (manufactured by DOW, ETHOCEL STD-10, Mw 80,000, Mw / Mn 3.5) was used instead of the resin microparticles.

[0094] (Preparation of Slurry Compositions) To the obtained vehicle composition, 0.2 parts by weight of a dispersant (manufactured by San Nopco Ltd., Nopcosperse 092), copper powder (manufactured by Fujino Metals Co., Ltd., average particle size 1 μm), and glass frit (manufactured by AGC Corporation, average particle size 0.8 μm) were added and mixed to obtain the formulations shown in Tables 8 to 10, thereby preparing slurry compositions (conductive pastes).

[0095] (Examples 34-41, Comparative Examples 12-14) (Synthesis Example 1) (Synthesis of Polyvinyl Acetal Resin A) 230 g of polyvinyl alcohol resin having a degree of polymerization of 1000, a degree of saponification of 98 mol%, and an ethylene content of 6 mol% was added to 2900 g of pure water and dissolved by stirring at a temperature of 90°C for about 2 hours. This solution was cooled to 40°C, and 80 g of hydrochloric acid with a concentration of 35 wt% and 165 g of n-butyl aldehyde were added thereto. The liquid temperature was lowered to 15°C and maintained at this temperature to carry out an acetalization reaction, and the reaction product was precipitated. Thereafter, the liquid temperature was maintained at 50°C for 3 hours to complete the reaction. After neutralization, washing with water, and drying by conventional methods, a white powder of polyvinyl acetal resin was obtained. The obtained polyvinyl acetal resin was dissolved in DMSO-d ６ (dimethyl sulfoxide), １３ Measurement by C-NMR (nuclear magnetic resonance spectroscopy) revealed that the ethylene content was 6 mol %, the amount of acetyl groups was 2 mol %, the amount of acetal groups was 72 mol %, and the amount of hydroxyl groups was 20 mol %.

[0096] Synthesis Example 2 (Preparation of Carboxylic Acid-Modified Polyvinyl Acetal Resin B) 30 parts by weight of a vinyl acetate copolymer obtained by copolymerizing 99.4 mol % of vinyl acetate and 0.6 mol % of itaconic acid in the presence of a radical polymerization initiator using a conventional method was dissolved in 60 parts by weight of methanol. Next, 1 part by weight of a 45% aqueous sodium hydroxide solution was added and stirred for 2 hours. The solution was then neutralized with concentrated acetic acid, and the precipitated product was washed with methanol to obtain a carboxylic acid-modified polyvinyl alcohol resin B. Measurements based on JIS K6726 revealed that the residual acetyl content was 1.8 mol % and the average degree of polymerization was 500. Furthermore, measurements using FT-IR revealed that the amount of carboxyl groups was 1.0 mol %.

[0097] 100 g of carboxylic acid-modified polyvinyl alcohol resin B (average degree of polymerization: 500, carboxyl group content: 1.0 mol%) was added to 1,000 g of pure water and stirred at 90°C for approximately 2 hours to dissolve. This solution was cooled to 40°C, and 90 g of hydrochloric acid (concentration: 35 wt%), 20 g of acetaldehyde, and 55 g of n-butylaldehyde were added to the solution. The liquid temperature was lowered to 10°C, and the acetalization reaction was carried out while maintaining this temperature. After completion of the reaction, the solution was neutralized, washed with water, and dried to obtain carboxylic acid-modified polyvinyl acetal resin B (average degree of polymerization: 500, acetyl group content: 1.8 mol%, hydroxyl group content: 20.5 mol%, acetoacetal group content: 23.3 mol%, butyral group content: 53.4 mol%, carboxyl group content: 1.0 mol%). The amount of acetyl groups, hydroxyl groups, acetoacetal groups, butyral groups, and carboxyl groups is １３ Measurement was performed by C-NMR.

[0098] Synthesis Example 3 (Preparation of Carboxylic Acid-Modified Polyvinyl Acetal Resin C) 30 parts by weight of a vinyl acetate copolymer obtained by copolymerizing 99.4 mol% of vinyl acetate and 0.6 mol% of dimethyl itaconate in the presence of a radical polymerization initiator using a conventional method was dissolved in 60 parts by weight of methanol. Next, 1 part by weight of a 45% aqueous sodium hydroxide solution was added and the mixture was stirred for 2 hours. The mixture was then neutralized with concentrated acetic acid, and the precipitated product was washed with methanol to obtain a carboxylic acid-modified polyvinyl alcohol resin C. Measurements based on JIS K6726 revealed that the residual acetyl content was 1.4 mol% and the average degree of polymerization was 500. Furthermore, measurements using FT-IR revealed that the amount of carboxyl groups was 1.0 mol%. A white powder of polyvinyl acetal resin (average polymerization degree 500, acetyl group amount 1.0 mol%, hydroxyl group amount 20.1 mol%, acetoacetal group amount 20.2 mol%, butyral group amount 57.3 mol%, carboxyl group amount 1.0 mol%) was obtained in the same manner as in Synthesis Example 2, except that 100 g of the carboxylic acid-modified polyvinyl alcohol resin (average polymerization degree 500, carboxyl group amount 1.0 mol%) was used. The amounts of acetyl groups, hydroxyl groups, acetoacetal groups, butyral groups, and carboxyl groups were １３ Measurement was performed by C-NMR.

[0099] (Preparation of Vehicle Composition) A vehicle solvent prepared by mixing a binder resin, an organic solvent A, and a bornyl compound B in the formulation shown in Table 7 was weighed out to the formulation shown in Table 11, and mixed using a high-speed stirrer to prepare a vehicle composition. In addition to the polyvinyl acetal resins obtained in Synthesis Examples 1 to 3, polyvinyl butyral resin (S-LEC BM-S, manufactured by Sekisui Chemical Co., Ltd., Mw 100,000) and ethyl cellulose resin (ETHOCEL STD-10, manufactured by DOW Corporation, Mw 80,000, Mw / Mn 3.5) were used as binder resins. The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) were measured in the same manner as for the (meth)acrylic resin fine particles described above.

[0100] (Preparation of Slurry Composition) Nickel particles as inorganic particles and barium titanate were added to the obtained vehicle composition to obtain the formulation shown in Table 11, and mixed, and then dispersed using a three-roll mill to obtain a slurry composition (conductive paste).

[0101] <Evaluation> The vehicle compositions and slurry compositions obtained were evaluated as follows, and the results are shown in Tables 8 to 11.

[0102] (Temperature Resistance) The vehicle compositions obtained in the Examples and Comparative Examples were designated as Vehicle Composition 1 for Measurement. For Examples 1 to 33 and Comparative Examples 1 to 11, 15 parts by weight of the binder resin used in each Example and Comparative Example was mixed with 85 parts by weight of organic solvent A to prepare Vehicle Composition 2 for Measurement. For Examples 34 to 41 and Comparative Examples 12 to 14, 11 parts by weight of the binder resin used in each Example and Comparative Example was mixed with 89 parts by weight of organic solvent A to prepare Vehicle Composition 2 for Measurement. The viscosity (μ) of Vehicle Composition 1 for Measurement at 25°C was ＡＢ ２５ ) was measured using a Brookfield viscometer. Similarly, the viscosity (μ ＡＢ ２６ ), the viscosity of the measurement vehicle composition 2 at 25°C (μ Ａ ２５ ), viscosity of measurement vehicle composition 2 at 26°C (μ Ａ ２６) was measured. Based on the obtained results, the temperature resistance was evaluated by the following formula: Temperature resistance = (μ ＡＢ ２５ -μ ＡＢ ２６ ) / (μ Ａ ２５ -μ Ａ ２６ )×100 The smaller the value, the smaller the change in viscosity due to temperature rise, and the better the temperature resistance.

[0103] (Viscosity Variation) Ten samples of slurry compositions were prepared in the same manner as in each Example and Comparative Example. The viscosity of each sample at 25°C was measured using an E-type viscometer, and the standard deviation of the viscosity was evaluated as the viscosity variation. The smaller the standard deviation, the smaller the viscosity variation.

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] According to the present invention, there is provided a vehicle composition that can be used to prepare a conductive paste with little change in viscosity due to temperature and little variation in viscosity, as well as a slurry composition containing the vehicle composition and an electronic component made using the slurry composition.

Claims

Contains a binder resin and a vehicle solvent, the binder resin contains a (meth)acrylic resin or a polyvinyl acetal resin, the vehicle solvent contains an organic solvent A and a bornyl compound B, the organic solvent A contains at least one selected from the group consisting of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, The vehicle composition, wherein the bornyl compound B contains at least one selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate.

2. The vehicle composition according to claim 1, wherein the vehicle solvent contains 90 to 99.99% by weight in total of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and 0.01 to 10% by weight in total of borneol, isoborneol, bornyl acetate, and isobornyl acetate.

2. The vehicle composition according to claim 1, wherein the vehicle solvent contains 96.5 to 99.9% by weight in total of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and 0.1 to 3.5% by weight in total of borneol, isoborneol, bornyl acetate, and isobornyl acetate.

4. The vehicle composition according to claim 1, wherein the (meth)acrylic resin contains 10 to 100% by weight of a segment derived from a (meth)acrylic acid ester having a branched structure in an ester substituent. A slurry composition comprising the vehicle composition according to claim 1, 2, 3 or 4 and inorganic particles. An electronic part obtained by using the slurry composition according to claim 5.

Images