Vehicle compositions, slurry compositions and electronic components

Abstract

The present invention provides a vehicle composition capable of producing a conductive paste with minimal viscosity changes due to temperature and low viscosity variation. It also provides a slurry composition containing the vehicle composition and an electronic component using the slurry composition. [Solution] 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.

Description

Technical Field

[0001] The present invention relates to vehicle compositions, slurry compositions, and electronic components.

Background Art

[0002] A multilayer ceramic capacitor is known to have a structure including a laminate in which a plurality of dielectric layers and internal electrodes are alternately laminated, and a pair of external electrodes provided so as to sandwich the laminate. The external electrodes are formed by applying an external electrode slurry composition onto the surface of the laminate and sintering it.

[0003] In recent years, with the miniaturization of multilayer ceramic capacitors, the miniaturization of inorganic particles used for external electrodes has also advanced. The miniaturized inorganic particles tend to aggregate in the slurry composition, and when aggregation occurs, voids tend to remain in the debinding process and the firing process, or the dispersibility of the inorganic particles decreases. As a result, when used in electronic components such as multilayer ceramic capacitors, it causes deterioration of the electrical characteristics of the product.

[0004] As the binder resin used for the external electrodes, for example, (meth)acrylic resins and ethyl cellulose are generally used. For example, Patent Document 1 describes a configuration using an organic vehicle in which alcohols such as terpineol and a (meth)acrylic resin as an organic binder are combined.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, efforts have been made to improve yield in order to increase the production efficiency of multilayer ceramic capacitors. Among the production processes, the process of applying external electrode paste to the chip is particularly prone to process defects, and in order to improve yield, it is necessary to keep the viscosity of the external electrode paste constant. However, in conventional configurations using organic vehicles, such as the configuration described in Patent Document 1, the viscosity changes significantly with temperature, and there is a problem that process defects are likely to occur due to viscosity variations caused by variations in ambient temperature. In addition, there are variations in the viscosity of the resulting paste itself, which can cause process defects. Therefore, there is a need for conductive pastes that exhibit minimal viscosity changes due to temperature and have low viscosity variability.

[0007] The present invention aims to provide a vehicle composition capable of producing a conductive paste with minimal viscosity change due to temperature and low viscosity variation. Furthermore, it aims to provide a slurry composition containing the vehicle composition, and an electronic component using the slurry composition. [Means for solving the problem]

[0008] Disclosure 1 is 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 a total of 90 to 99.99% by weight of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and a total of 0.01 to 10% by weight of borneol, isoborneol, bornyl acetate, and isobornyl acetate. Disclosure 3 is the vehicle composition of Disclosure 1, wherein the vehicle solvent contains a total of 96.5 to 99.9% by weight of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and a total of 0.1 to 3.5% by weight of borneol, isoborneol, bornyl acetate, and isobornyl acetate. Disclosure 4 is a vehicle composition of Disclosure 1, 2, or 3, wherein the (meth)acrylic resin contains 10 to 100% by weight of segments 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 made using the slurry composition of Disclosure 5. The present invention will be described in detail below.

[0009] The present inventors have discovered that by adopting a vehicle composition containing a binder resin and a vehicle solvent, and specifically including a (meth)acrylic resin or polyvinyl acetal resin, a particular organic solvent A, and a particular bornyl compound, it is possible to produce a conductive paste with minimal viscosity changes due to temperature and minimal viscosity variations, thus completing the present invention.

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

[0011] The above (meth)acrylic resin preferably has segments derived from a (meth)acrylic acid ester having a branched structure in the ester substituent. (Meth)acrylic resins, primarily composed of (meth)acrylic acid esters with branched ester substituents, have a lower decomposition termination temperature than (meth)acrylic resins, primarily composed of (meth)acrylic acid esters with linear ester substituents. While (meth)acrylic resins exhibit depolymerization reactions, decomposing into monomers in environments exceeding the ceiling temperature, (meth)acrylic acid esters with branched ester substituents are less likely to repolymerize, resulting in a lower decomposition termination temperature. For this reason, (meth)acrylic resins having the above structure exhibit excellent low-temperature decomposition properties.

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

[0013] Examples of alkyl (meth)acrylate esters having the branched alkyl group mentioned above include isopropyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isopentyl (meth)acrylate, isohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, and isodecyl (meth)acrylate. Among these, isopropyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isodecyl (meth)acrylate are preferred, isopropyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, 2-ethylhexyl methacrylate, and isodecyl methacrylate are more preferred, and isobutyl methacrylate and 2-ethylhexyl methacrylate are even more preferred.

[0014] Examples of polyalkylene glycols (meth)acrylates having the branched alkylene glycol units described above include those having propylene glycol units. Furthermore, polyalkylene glycols (meth)acrylates having the branched alkylene glycol units described above may also have alkoxy groups at their terminal ends. Examples of such alkoxy groups include methoxy groups, ethoxy groups, and butoxy groups. The polyalkylene glycol (meth)acrylate having alkylene glycol units having the branched structure described above preferably has 3 or more alkylene glycol units, more preferably 4 or more, preferably 10 or less, and more preferably 8 or less.

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

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

[0017] Furthermore, it is preferable that the (meth)acrylic resin 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 a segment derived from a (meth)acrylic acid ester having a branched structure in its ester substituent. Having the above configuration, a slurry composition with superior low-temperature decomposition properties can be obtained.

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

[0019] The content of segments derived from (meth)acrylic acid esters in the above-mentioned (meth)acrylic resin, in which the ester substituent has 1 to 4 carbon atoms, is preferably 60% by weight or more, more preferably 90% by weight or more, and preferably 100% by weight or less. Within the above range, a slurry composition with superior low-temperature decomposition properties can be obtained.

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

[0021] Examples of alkyl (meth)acrylate esters having the linear alkyl group mentioned above include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, and n-hexyl (meth)acrylate. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, and n-butyl (meth)acrylate are preferred, and methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate are more preferred. Furthermore, it is preferable that the above (meth)acrylic resin has segments derived from n-butyl methacrylate, as this allows for the formation of a slurry composition with superior low-temperature decomposition properties.

[0022] Examples of (meth)acrylate polyalkylene glycols having linear alkylene glycol units include those having ethylene glycol units and those having trimethylene glycol units. Furthermore, the (meth)acrylate polyalkylene glycol having linear alkylene glycol units may also have alkoxy groups at its termini. Examples of such alkoxy groups include methoxy groups, ethoxy groups, and butoxy groups. These alkoxy groups do not have a branched structure. Among these, (meth)acrylate polyalkylene glycol having ethylene glycol units is preferred, and methoxypolyethylene glycol (meth)acrylate is more preferred. The polyalkylene glycol (meth)acrylate having the linear alkylene glycol units described above preferably has 4 or more alkylene glycol units, more preferably 10 or more, preferably 23 or less, and more preferably 20 or less.

[0023] Examples of (meth)acrylic acid esters having a cyclic structure in the above-mentioned ester substituent 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, it is preferable to use a (meth)acrylic resin that contains a large amount of oxygen as a monomer, and (meth)acrylic acid polyalkylene glycol having linear polyalkylene glycol units has a high oxygen content and preferably has segments derived from such (meth)acrylic acid esters. The depolymerization reaction of (meth)acrylic resin is an endothermic reaction, and it is difficult to obtain the heat necessary for decomposition at low temperatures. By having segments derived from monomers that contain a large amount of oxygen, as described above, combustion decomposition using its own oxygen can occur even in a nitrogen atmosphere near the ceiling temperature of (meth)acrylic resin, thus improving its low-temperature decompositionability. The (meth)acrylate polyalkylene glycol having the linear alkylene glycol units described above preferably has an oxygen composition ratio of 30% by weight or more, and more preferably 35% by weight or more.

[0025] The content of segments in the above (meth)acrylic resin that are derived from a linear (meth)acrylic acid ester 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, 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 range as described above, handling characteristics such as printability will be improved. The above content can be measured, for example, by pyrolysis GC-MS.

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

[0027] The above (meth)acrylic resin may have segments derived from a (meth)acrylic acid ester having a glycidyl group, a carboxyl group, or a hydroxyl group. Examples of (meth)acrylic acid esters having the above-mentioned glycidyl group include glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl methacrylate. Examples of (meth)acrylic acid esters 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 segments derived from the (meth)acrylic acid ester having the glycidyl group, carboxyl group, or hydroxyl group in the above (meth)acrylic resin is preferably 1% by weight or more, more preferably 4% by weight or more, preferably 10% by weight or less, and more preferably 7% by weight or less. By setting the range as described above, the low-temperature decomposition properties can be further enhanced, and the toughness of the resulting inorganic particle dispersion sheet can be improved.

[0029] The weight-average molecular weight (Mw) of the above (meth)acrylic resin is preferably 20,000 or more, and preferably 4,000,000 or less. When the above Mw is 20,000 or more, the viscosity of the slurry composition does not become too low, and the dispersibility of inorganic particles can be improved. When the above Mw is 4 million or less, the coating strength can be increased, and the viscosity of the slurry composition becomes sufficiently high, improving storage stability and resulting in excellent printability. The above Mw is preferably 30,000 or more, more preferably 50,000 or more, preferably 3,500,000 or less, more preferably 3,000,000 or less, even more preferably 2,000,000 or less, and even more preferably 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 above (meth)acrylic resin is usually 1.0 or higher, preferably 1.5 or higher, more preferably 2.0 or higher, preferably 10.0 or lower, and even more preferably 8.0 or lower. By keeping the viscosity within the above range, a suitable amount of low-polymerization components are included, resulting in a viscosity within a desirable range for the slurry composition and increasing productivity. Note that the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are average molecular weights calculated on a polystyrene basis, and can be obtained by performing GPC measurements using, for example, column LF-804 (manufactured by Showa Denko Corporation).

[0031] The glass transition temperature (Tg) of the above (meth)acrylic resin is preferably 20°C or higher, more preferably 30°C or higher, even more preferably 40°C or higher, preferably 80°C or lower, more preferably 70°C or lower, even more preferably 60°C or lower, and even more preferably 50°C or lower. The glass transition temperature (Tg) can be measured, for example, using a differential scanning calorimeter (DSC).

[0032] The method for producing the above-mentioned (meth)acrylic resin is not particularly limited. For example, one method involves first preparing a monomer mixture by adding an organic solvent to a raw material monomer mixture containing a (meth)acrylic acid ester having a branched structure in the ester substituent, and then further producing a (meth)acrylic resin by adding a polymerization initiator to the obtained monomer mixture and polymerizing it. The polymerization method is not particularly limited and includes emulsion polymerization, suspension polymerization, bulk polymerization, interfacial polymerization, and solution polymerization. Among these, solution polymerization is preferred.

[0033] Examples of polymerization initiators include dilauryl peroxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, cyclohexanone peroxide, disuccinate peroxide, potassium persulfate, and ammonium persulfate. Examples of these commercially available products include Permenta H, Percmill P, Perocta H, Percmill H-80, Perloyle 355, Perbutyl H-69, Perhexa H, Perloyle SA, Perloyle 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 above polyvinyl acetal resin is preferably 1000 or higher, preferably 1500 or higher, preferably 4000 or lower, and more preferably 3000 or lower. The degree of polymerization of the polyvinyl acetal resin mentioned above 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 conforming to JIS K6726. Furthermore, if the polyvinyl acetal resin is a mixture of two or more types, the degree of polymerization can be determined by summing the products of the degree of polymerization of each polyvinyl acetal resin and their respective blending ratios.

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

[0036] The amount of hydroxyl groups in the polyvinyl acetal resin described above is preferably 16 mol% or more, more preferably 20 mol% or more, preferably 50 mol% or less, and more preferably 33 mol% or less. The amount of hydroxyl groups can be measured, for example, by NMR.

[0037] The amount of acetyl groups in the above polyvinyl acetal resin is preferably 0.1 mol% or more, preferably 20 mol% or less, more preferably 1 mol% or more, and more preferably 15 mol% or less. The amount of acetyl groups can be measured, for example, by NMR.

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

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

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

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

[0042] The above polyvinyl acetal resin preferably has α-olefin units in its main chain. Because the α-olefin mentioned above weakens the hydrogen bonding of the polyvinyl acetal resin, it is possible to improve the viscosity stability over time and enhance screen printability.

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

[0044] The α-olefin unit content of the above polyvinyl acetal resin is preferably 1 mol% or more, preferably 20 mol% or less, more preferably 5 mol% or more, and more preferably 15 mol% or less. By setting the range as described above, the solubility in organic solvents can be sufficiently increased.

[0045] The above-mentioned polyvinyl acetal resin may also have other ethylenically unsaturated monomer units. Examples of the above-mentioned other ethylenically unsaturated monomers include acrylic acid, methacrylic acid, fumaric anhydride, maleic anhydride, itaconic anhydride, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, trimethyl-(3-acrylamido-3-dimethylpropyl)-ammonium chloride, acrylamide-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 vinylsulfonate, and sodium allylsulfonate.

[0046] The above-mentioned polyvinyl acetal resin can be obtained, for example, by dissolving a polyvinyl alcohol resin in hot water, adding an aldehyde in the presence of an acid catalyst to obtain a predetermined amount of acetal groups, reacting the mixture, washing with water, neutralizing, and drying. The acid catalyst is not specifically defined, and both organic and inorganic acids can be used, but examples include acetic acid, p-toluenesulfonic 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 above polyvinyl alcohol resin is obtained by saponifying a polymer of vinyl ester. Examples of the vinyl esters mentioned above include vinyl formate, vinyl acetate, vinyl propionate, and vinyl pivalate, but vinyl acetate is preferred from an economic standpoint. Furthermore, it is preferable that the polyvinyl alcohol resin contains α-olefin in its main chain. The α-olefin weakens the hydrogen bonding of the polyvinyl acetal resin, thereby improving the viscosity stability over time and enhancing screen printability.

[0048] The aldehyde used in the above reaction is not particularly limited, but examples 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, and phenylpropionaldehyde. These aldehydes may be used alone or in combination of two or more, with acetaldehyde and / or butyraldehyde being preferred.

[0049] The above vehicle composition may contain other binder resins besides (meth)acrylic resin and polyvinyl acetal resin, but it is preferable that it does not contain other binder resins. Other binder resins include, for example, cellulose resins such as hydroxymethylcellulose, carboxymethylcellulose, and ethylcellulose, as well as polyester resins, epoxy resins, and polycarbonate resins.

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

[0051] The above vehicle composition contains a vehicle solvent. The above vehicle solvent contains organic solvent A and bornyl compound B. The above organic solvent A contains at least one selected from the group consisting of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate. Furthermore, the above-mentioned bornyl compound B contains at least one selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate. By using the above-mentioned binder resin and vehicle solvent in combination, it is possible to produce a conductive paste with minimal viscosity changes due to temperature and low viscosity variation.

[0052] The above organic solvent A only needs to contain at least one of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, and may also contain other organic solvents not listed above. Other organic solvents include terpene-based organic solvents other than those mentioned 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, hydrocarbon-based solvents, etc. Other terpene-based organic solvents include, for example, dihydroterpineol oxyethanol, terpinyl methyl ether, dihydroterpineol methyl ether, α-pinene, β-pinene, camphene, Δ-2-carene, Δ-3-carene, limonene, terpinene, and terpinolene. Note that these terpene-based organic solvents are different from the bornyl compound B described later. Examples of the above-mentioned aliphatic alcohol-based organic solvents include ethanol, isopropanol, and butanol. Examples of the above-mentioned aromatic hydrocarbon organic solvents include toluene and benzene. Examples of the above-mentioned acetate ester-based organic solvents include ethyl acetate, butyl acetate, and methyl acetate. Examples of the ketone-based organic solvents mentioned above include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the hydrocarbon solvents mentioned above include cyclohexane, hexane, and heptane.

[0053] The total content of terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate in the above 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, 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 made that produces a conductive paste with little viscosity change due to temperature and little viscosity variation.

[0054] The above-mentioned organic solvent A may contain other organic solvents besides terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate, but it is preferable that it does not contain any.

[0055] The above vehicle solvent contains bornyl compound B. The above-mentioned bornyl compound B contains at least one selected from the group consisting of borneol, isoborneol, bornyl acetate, and isobornyl acetate. The above-mentioned bornyl compound B may contain at least one of borneol, isoborneol, bornyl acetate, and isobornyl acetate, and may also contain other bornyl compounds, but it is preferable that it does not contain other bornyl compounds. The above-mentioned bornyl compound B preferably contains at least one of borneol and isoborneol. Other bornyl compounds include, for example, bornane and 2,3-bornanedione.

[0056] If the above vehicle solvent contains dihydroterpineol acetate, it is preferable to contain bornyl acetate or isobornyl acetate; if it contains dihydroterpineol, it is preferable to contain borneol or isoborneol; and if it contains terpineol, it is preferable to contain borneol or isoborneol. By doing so, a vehicle composition can be made that produces a conductive paste with little viscosity change due to temperature and little viscosity variation.

[0057] The total content of borneol, isoborneol, bornyl acetate, and isobornyl acetate in the above vehicle solvent is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, even more preferably 0.5% by weight or more, 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 made that produces a conductive paste with little viscosity change due to temperature and little viscosity variation.

[0058] The content of the vehicle solvent in the above vehicle composition is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, preferably 95% by weight or less, and more preferably 90% by weight or less, from the viewpoint of coating properties and dispersibility of inorganic particles.

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

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

[0061] The method for preparing the above vehicle composition is not particularly limited. For example, one method involves mixing a binder resin containing (meth)acrylic resin or polyvinyl acetal resin with an organic solvent A containing a predetermined component 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 above vehicle composition. The above vehicle composition and slurry composition containing inorganic particles are also part of the present invention.

[0063] The above slurry composition contains inorganic particles. The inorganic particles mentioned above are not particularly limited and include, for example, ceramic powder, glass powder, phosphor particles, silicon oxide, metal particles, etc.

[0064] The above ceramic powders are not particularly limited and include, for example, alumina, ferrite, zirconia, zircon, barium zirconate, calcium zirconate, titanium oxide, barium titanate, strontium titanate, calcium titanate, magnesium titanate, zinc titanate, lanthanum titanate, neodymium titanate, lead zirconate titanate, aluminum nitride, silicon nitride, boron nitride, boron carbide, barium stanate, calcium stanate, magnesium silicate, mullite, steatite, cordierite, forsterite, and the like. In addition, ITO, FTO, niobium oxide, vanadium oxide, tungsten oxide, lanthanum strontium manganite, lanthanum strontium cobalt ferrite, yttrium stabilized zirconia, gadolinium doped ceria, nickel oxide, lanthanum chromite, Sm2Fe 17 N3, Nd2Fe 14 B, MnAlC, L 10 FeNi, La 2 / 3-x Li 3x TiO3, La (1-x) / 3 Li x NbO3, LaGaO3, LaScO3, CaZrO3, (La 0.875 Sr 0.125 )MnO3, PbZrTiO3, SrBi2Ta2O9, BiFeO3, KNbO3, PbVO3, BiCo3, Bi(Zn 1 / 2 Ti 1 / 2 )3 etc. can also be used.

[0065] The above glass powder is not particularly limited, and examples include glass powders such as bismuth oxide glass, silicate glass, lead glass, zinc glass, boron glass, and glass powders of various silicon oxides such as CaO-Al2O3-SiO2 system, MgO-Al2O3-SiO2 system, LiO2-Al2O3-SiO2 system, etc. Furthermore, the above glass powders include: SnO-B2O3-P2O5-Al2O3 mixture, PbO-B2O3-SiO2 mixture, BaO-ZnO-B2O3-SiO2 mixture, ZnO-Bi2O3-B2O3-SiO2 mixture, Bi2O3-B2O3-BaO-CuO mixture, Bi2O3-ZnO-B2O3-Al2O3-SrO mixture, ZnO-Bi2O3-B2O3 mixture, Bi2O3-SiO2 mixture, P2O5-Na2O-CaO-BaO-Al2O3-B2O3 mixture, P2O5-SnO mixture, and P2O5-SnO-B2O3 mixture. Glass powders such as composites, P2O5-SnO-SiO2 mixtures, CuO-P2O5-RO mixtures, SiO2-B2O3-ZnO-Na2O-Li2O-NaF-V2O5 mixtures, P2O5-ZnO-SnO-R2O-RO mixtures, B2O3-SiO2-ZnO mixtures, B2O3-SiO2-Al2O3-ZrO2 mixtures, SiO2-B2O3-ZnO-R2O-RO mixtures, SiO2-B2O3-Al2O3-RO-R2O mixtures, SrO-ZnO-P2O5 mixtures, and BaO-ZnO-B2O3-SiO2 mixtures can also be used. Note that R is an element selected from the group consisting of Zn, Ba, Ca, Mg, Sr, Sn, Ni, Fe, and Mn. In particular, lead-free glass powders such as PbO-B2O3-SiO2 mixtures, BaO-ZnO-B2O3-SiO2 mixtures, or ZnO-Bi2O3-B2O3-SiO2 mixtures that do not contain lead are preferred.

[0066] The above-mentioned phosphor particles are not particularly limited, and for example, as phosphor materials, conventionally known phosphor materials for displays, such as blue phosphor materials, red phosphor materials, and green phosphor materials, can be used. As a blue phosphor material, for example, MgAl 10 O 17 :Eu series, Y2SiO5:Ce series, CaWO4:Pb series, BaMgAl 14 O 23 :Eu system, BaMgAl 16 O 27 :Eu-based, BaMg2Al 14 O 23 :Eu-based, BaMg2Al 14 O 27Eu-based and ZnS:(Ag,Cd)-based materials are used. Examples of red phosphors include Y2O3:Eu-based, Y2SiO5:Eu-based, and Y3Al5O 12 Eu-based, Zn3(PO4)2:Mn-based, YBO3:Eu-based, (Y,Gd)BO3:Eu-based, GdBO3:Eu-based, ScBO3:Eu-based, and LuBO3:Eu-based materials are used. As for green phosphor materials, for example, Zn2SiO4:Mn-based and BaAl 12 O 19 :Mn-based, SrAl 13 O 19 :Mn-based, CaAl 12 O 19 :Mn series, YBO3:Tb series, BaMgAl 14 O 23 :Mn-based, LuBO3:Tb-based, GdBO3:Tb-based, ScBO3:Tb-based, and Sr6Si3O3Cl4:Eu-based compounds are used. Others include ZnO:Zn-based, ZnS:(Cu,Al)-based, ZnS:Ag-based, Y2O2S:Eu-based, ZnS:Zn-based, (Y,Cd)BO3:Eu-based, and BaMgAl 12 O 23 EU-based products can also be used.

[0067] The above-mentioned metal particles are not particularly limited and include, for example, powders made of copper, nickel, palladium, platinum, gold, silver, aluminum, tungsten, or alloys thereof. Furthermore, metals such as copper and iron, which have good adsorption properties with carboxyl groups, amino groups, amide groups, etc., and are easily oxidized, can also be suitably used. These metal powders may be used individually or in combination of two or more types. In addition to metal complexes, various types of carbon black, carbon nanotubes, etc., may also be used.

[0068] Other inorganic particles include Li2S-M x S yLithium sulfur-based glasses such as (M=B, Si, Ge, P), lithium cobalt composite oxides such as LiCeO2, lithium manganese composite oxides such as LiMnO4, lithium nickel composite oxides, lithium vanadium composite oxides, lithium zirconium composite oxides, lithium hafnium composite oxides, lithium silicate (Li 3.5 Si 0.5 P 0.5 O4), lithium titanium phosphate (LiTi2(PO4)3), lithium titanate (Li4Ti5O 12 ), Li 4 / 3 Ti 5 / 3 O4, LiCoO2, lithium germanium phosphate (LiGe2(PO4)3), Li2-SiS glass, Li4GeS4-Li3PS4 glass, LiSiO3, LiMn2O4, Li2S-P2S5 glass / ceramics, Li2O-SiO2, Li2O-V2O5-SiO2, LiS-SiS2-Li4SiO4 glass, ion-conductive oxides such as LiPON, lithium oxide compounds such as Li2O-P2O5-B2O3 and Li2O-GeO2Ba, Li x Al y Ti z (PO4)3-type glass, La x Li y TiO z Glass system, Li x Ge y P z O4-based glass, Li7La3Zr2O 12 Glass system, Li v Si w P x S y Cl z Glass or similar materials can also be used.

[0069] The average particle size of the inorganic particles is preferably 0.01 μm or more, preferably 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 above average particle diameter can be determined, for example, by measuring the volume-average particle diameter using a laser diffraction / scattering particle size distribution analyzer.

[0070] The content of the inorganic particles in the slurry composition described above 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, 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 these ranges, the slurry composition can have sufficient viscosity and excellent coating properties, and the inorganic particles can have excellent dispersibility.

[0071] The above slurry composition preferably contains a dispersant. Suitable dispersants include, for example, fatty acids, aliphatic amines, alkanolamides, and phosphate esters. Silane coupling agents may also be included. The above fatty acids are not particularly limited and include saturated fatty acids such as behenic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, caprylic acid, and coconut fatty acid; and unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, sorbic acid, beef tallow fatty acid, and hydrogenated castor fatty acid. Among these, lauric acid, stearic acid, and oleic acid are preferred. The above-mentioned aliphatic amines are not particularly limited and include, for example, laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, alkyl(coconut)amine, alkyl(hydrogenated beef tallow)amine, alkyl(beef tallow)amine, alkyl(soybean)amine, etc. The above-mentioned alkanolamides are not particularly limited and include, for example, coconut fatty acid diethanolamide, beef tallow fatty acid diethanolamide, lauric acid diethanolamide, oleic acid diethanolamide, etc. The above-mentioned phosphate esters are not particularly limited, and examples include polyoxyethylene alkyl ether phosphate esters and polyoxyethylene alkyl allyl ether phosphate esters.

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

[0073] The above slurry composition may further contain additives such as plasticizers and surfactants. Examples of the plasticizers mentioned above include di(butoxyethyl) adipate, dibutoxyethoxyethyl adipate, triethylene glycol dibutyl, triethylene glycol bis(2-ethylhexanoate), triethylene glycol dihexanoate, triethyl acetyl citrate, tributyl acetyl citrate, diethyl acetyl citrate, dibutyl acetyl citrate, dibutyl acetyl citrate, tributyl sebacate, triacetin, diethyl acetyloxymalonate, and diethyl ethoxymalonate.

[0074] The above-mentioned surfactants are not particularly limited and include, for example, cationic surfactants, anionic surfactants, and nonionic surfactants. The above nonionic surfactant is not particularly limited, but it is preferable that it is a nonionic surfactant with an HLB value of 10 or more and 20 or less. Here, the HLB value is used as an indicator of the hydrophilicity and lipophilicity of a surfactant, and several calculation methods have been proposed. For example, for ester-based surfactants, the saponification value is S and the acid value of the fatty acid constituting the surfactant is A, and the HLB value is defined as 20 (1-S / A). Specifically, nonionic surfactants having polyethylene oxide obtained by adding alkylene ether to a fatty acid chain are preferred, and specifically, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, etc. are preferably used. Although the above nonionic surfactant has good thermal decomposition properties, adding a large amount may reduce the thermal decomposition properties of the slurry composition, so the preferred upper limit of the content is 5% by weight.

[0075] The method for preparing the above-mentioned slurry composition is not particularly limited, and conventionally known stirring methods can be used. Specifically, for example, a method of stirring the above-mentioned vehicle composition, the above-mentioned inorganic particles, the above-mentioned dispersant, and other components such as additional solvents and plasticizers added as needed, using a three-roll mixer or the like. The order in which the components of the slurry composition are added can be set as appropriate.

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

[0077] For example, an inorganic particle dispersion molded product can be manufactured by coating the slurry composition onto a support film that has been treated with a single-sided release agent, drying the organic solvent, and then molding the product. The shape of the above-mentioned inorganic particle dispersion molded product is not particularly limited, but it can be in the shape of a sheet, for example.

[0078] Examples of methods for producing the above-mentioned inorganic particle dispersion molded product include a method of uniformly forming a coating film on a support film using a coating method such as a roll coater, die coater, squeeze coater, or curtain coater with the slurry composition.

[0079] For example, if the inorganic particle dispersion molded product is in the form of a sheet, the support film used in manufacturing the inorganic particle dispersion molded product is preferably a resin film that is heat-resistant, solvent-resistant, and flexible. The flexibility of the support film allows the slurry composition to be applied to the surface of the support film using a roll coater, blade coater, etc., and the resulting inorganic particle dispersion sheet-forming film can be stored and supplied in a rolled state.

[0080] Examples of resins used to form the support film include polyethylene terephthalate resin, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyimide resin, polyvinyl alcohol resin, polyvinyl chloride resin, fluorine-containing resins such as polyfluoroethylene, nylon, and cellulose resin. The thickness of the above-mentioned support film is preferably, for example, 20 to 100 μm. Furthermore, it is preferable that the surface of the support film be treated with a release agent, which facilitates the peeling operation of the support film during the transfer process.

[0081] An inorganic particle dispersion molded product can be manufactured by coating and drying the above slurry composition. Furthermore, by using the above-mentioned slurry composition and inorganic particle dispersion molded product as a conductive paste for external electrodes, a multilayer ceramic capacitor, which is an electronic component, can be manufactured.

[0082] A method for manufacturing the above-mentioned multilayer ceramic capacitor includes the steps of printing a conductive paste onto the inorganic particle dispersion molded product, drying it to produce a dielectric sheet, and laminating the dielectric sheets.

[0083] The conductive paste described above contains conductive powder. The material of the conductive powder described above is not particularly limited as long as it is a conductive material, and examples include nickel, palladium, platinum, gold, silver, copper, molybdenum, tin, and alloys thereof. These conductive powders may be used individually or in combination of two or more types.

[0084] The method for printing the conductive paste described above is not particularly limited and includes, for example, screen printing, die-coating, offset printing, gravure printing, and inkjet printing.

[0085] In the above-described method for manufacturing multilayer ceramic capacitors, a raw ceramic laminate is produced by stacking dielectric sheets printed with the conductive paste, and then subjected to a firing process in a reducing atmosphere at 1000 to 1500°C, thereby obtaining a large number of component bases.

[0086] Next, a conductive paste for external electrodes containing the (meth)acrylic resin is applied to both end faces of each component body by immersion. Then, after drying at 100-200°C, it is fired at 450-800°C in a reducing atmosphere to form external electrodes on both ends of the component body.

[0087] Next, electroplating is applied to the external electrodes to sequentially form Cu, Ni, and Sn films on the external electrodes, thereby obtaining a multilayer ceramic capacitor. [Effects of the Invention]

[0088] According to the present invention, a vehicle composition can be provided that enables the production of a conductive paste with minimal viscosity change due to temperature and minimal viscosity variation. Furthermore, a slurry composition containing the vehicle composition and an electronic component using the slurry composition can be provided. [Modes for carrying out the invention]

[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 1-33, Comparative Examples 1-11) (Preparation of resin microparticles) Pure water was added to a stirring vessel in the amounts shown in Tables 1-3, and then monomers, chain transfer agents, and polymerization initiators were added as shown in Tables 1-3. The following monomers, chain transfer agents, and polymerization initiators were used. <Monomer> 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 movement agent> 8-Mercapto-1-Octanol: Manufactured by Sigma-Aldrich <Polymerization initiator> t-Butyl peroxypivalate: Manufactured by Kayaku Akzo, Kaya Ester P-70

[0091] Next, the mixture was mixed for 3 minutes at a rotation speed of 10,000 rpm using a comb-type high-speed rotary emulsifier. After that, it was transferred to a reaction vessel equipped with a stirrer and jacket, and nitrogen gas was supplied while stirring at 150 rpm to create a nitrogen atmosphere in which the monomer composition was prepared. Next, the temperature was raised to 70°C using a jacket to initiate aqueous suspension polymerization. Three hours after the start of polymerization, the temperature was raised to 80°C, and aqueous suspension polymerization was carried out for another hour to complete the polymerization and obtain a suspension containing resin fine particles.

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

[0093] (Preparation of vehicle composition) To 5.79 parts by weight of the obtained resin fine particles, 32.71 parts by weight of a vehicle solvent, which was a mixture of organic solvent A and bornyl compound B in the proportions shown in Tables 4 to 6, was added and mixed to prepare a vehicle composition. In Comparative Example 11, ethylcellulose resin (DOW Corporation, ETHOCEL STD-10, Mw 80,000, Mw / Mn 3.5) was used instead of resin microparticles.

[0094] (Preparation of slurry composition) To the obtained vehicle composition, 0.2 parts by weight of a dispersant (Sunopco, Nopco Spers 092), copper powder (Fujino Metal Co., Ltd., average particle size 1 μm), and glass frit (AGC, Inc., average particle size 0.8 μm) were added and mixed in the proportions shown in Tables 8 to 10 to prepare a slurry composition (conductive paste).

[0095] (Examples 34-41, Comparative Examples 12-14) (Synthesis Example 1) (Synthesis of polyvinyl acetal resin A) 230 g of polyvinyl alcohol resin with 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 stirred at 90°C for about 2 hours to dissolve. This solution was cooled to 40°C, and 80 g of hydrochloric acid with a concentration of 35 wt% and 165 g of n-butyraldehyde were added. The solution temperature was lowered to 15°C and maintained at this temperature to carry out the acetalization reaction, and the reaction product was precipitated. After that, the solution temperature was maintained at 50°C for 3 hours to complete the reaction, and 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-d6 (dimethyl sulfoxide), 13Measurements using 13C-NMR (nuclear magnetic resonance spectroscopy) revealed that the ethylene content was 6 mol%, the acetyl group content was 2 mol%, the acetal group content was 72 mol%, and the hydroxyl group content was 20 mol%.

[0096] (Synthesis Example 2) (Preparation of carboxylic acid-modified polyvinyl acetal resin B) Thirty parts by weight of a vinyl acetate copolymer obtained by copolymerizing 99.4 mol% vinyl acetate and 0.6 mol% itaconic acid by a conventional method in the presence of a radical polymerization initiator was dissolved in 60 parts by weight of methanol. Then, one part by weight of a 45% aqueous sodium hydroxide solution was added and the mixture was stirred for two hours. After neutralization with concentrated acetic acid, the precipitated product was washed with methanol to obtain carboxylic acid-modified polyvinyl alcohol resin B. According to measurements based on JIS K6726, the residual acetyl content was 1.8 mol%, and the average degree of polymerization was 500. Furthermore, the amount of carboxyl groups was measured by FT-IR and found to be 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 1000 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-butyraldehyde were added to the solution. The solution temperature was lowered to 10°C and maintained at this temperature to carry out the acetalization reaction. After the reaction was completed, 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%, acetacetal group content 23.3 mol%, butyral group content 53.4 mol%, carboxyl group content 1.0 mol%). Note that the amount of acetyl groups, hydroxyl groups, acetacetal groups, butyral groups, and carboxyl groups is 13 It was measured by 13C-NMR.

[0098] (Synthesis Example 3) (Preparation of carboxylic acid-modified polyvinyl acetal resin C) Thirty parts by weight of a vinyl acetate copolymer obtained by copolymerizing 99.4 mol% vinyl acetate and 0.6 mol% dimethyl itaconate by a conventional method in the presence of a radical polymerization initiator was dissolved in 60 parts by weight of methanol. Then, one part by weight of a 45% aqueous sodium hydroxide solution was added and the mixture was stirred for two hours. After neutralization with concentrated acetic acid, the precipitated product was washed with methanol to obtain carboxylic acid-modified polyvinyl alcohol resin C. According to measurements based on JIS K6726, the residual acetyl content was 1.4 mol%, and the average degree of polymerization was 500. Furthermore, FT-IR measurements showed that the amount of carboxyl groups was 1.0 mol%. Except for using 100 g of the above-mentioned carboxylic acid-modified polyvinyl alcohol resin (average degree of polymerization 500, carboxyl group content 1.0 mol%), a white powder of polyvinyl acetal resin (average degree of polymerization 500, acetyl group content 1.0 mol%, hydroxyl group content 20.1 mol%, acetacetal group content 20.2 mol%, butyral group content 57.3 mol%, carboxyl group content 1.0 mol%) was obtained in the same manner as in Synthesis Example 2. Note that the amounts of acetyl groups, hydroxyl groups, acetacetal groups, butyral groups, and carboxyl groups are as follows: 13 It was measured by 13C-NMR.

[0099] (Preparation of vehicle composition) A vehicle solvent was prepared by mixing organic solvent A and bornyl compound B to the binder resin and the formulation shown in Table 7, weighing the amounts to the formulation shown in Table 11, and mixing them using a high-speed stirring device to prepare the vehicle composition. In addition to the polyvinyl acetal resins obtained in Synthesis Examples 1-3, polyvinyl butyral resin (Seslec BM-S, Mw 100,000, manufactured by Sekisui Chemical Co., Ltd.) and ethyl cellulose resin (ETHOCEL STD-10, manufactured by DOW, 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) To the obtained vehicle composition, nickel particles and barium titanate were added as inorganic particles in the proportions shown in Table 11 and mixed. The mixture was then dispersed in a three-roll mill to obtain a slurry composition (conductive paste).

[0101] <Rating> The obtained vehicle composition and slurry composition were evaluated as follows. The results are shown in Tables 8-11.

[0102] (Temperature resistance) The vehicle compositions obtained in the examples and comparative examples were designated as measurement vehicle composition 1. Furthermore, 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 the measurement vehicle composition 2. 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 the measurement vehicle composition 2. Viscosity of measurement vehicle composition 1 at 25°C (μ AB 25 The viscosity was measured using a B-type viscometer. Similarly, the viscosity (μ) of the measurement vehicle composition 1 at 26°C is measured. AB 26 ), viscosity of the measurement vehicle composition 2 at 25°C (μ A 25 ), viscosity of the measurement vehicle composition 2 at 26°C (μ A 26 ) was measured. Based on the results obtained, the temperature resistance was evaluated using the following formula. Temperature resistance=(μ AB 25 -μ AB 26 ) / (μ A 25 -μ A 26 ) × 100 Furthermore, a smaller value indicates less viscosity change due to temperature rise, suggesting superior temperature resistance.

[0103] (Viscosity variation) Ten slurry compositions were prepared for each example and comparative example using the same method. For each sample, the viscosity at 25°C was measured using an E-type viscometer, and the standard deviation of the viscosity was evaluated as viscosity variability. A smaller standard deviation indicates less viscosity variation.

[0104] [Table 1]

[0105] [Table 2]

[0106] [Table 3]

[0107] [Table 4]

[0108] [Table 5]

[0109] [Table 6]

[0110] [Table 7]

[0111] [Table 8]

[0112] [Table 9]

[0113] [Table 10]

[0114] [Table 11] [Industrial applicability]

[0115] According to the present invention, a vehicle composition can be provided that enables the production of a conductive paste with minimal viscosity change due to temperature and minimal viscosity variation. Furthermore, a slurry composition containing the vehicle composition and an electronic component using the slurry composition can be provided.

Claims

1. It contains a binder resin and a vehicle solvent. The binder resin contains (meth)acrylic resin or polyvinyl acetal resin. The vehicle solvent contains organic solvent A and 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. The vehicle solvent contains terpineol, terpineol acetate, dihydroterpineol, and dihydroterpineol acetate in total at 90 to 99.99% by weight, and borneol, isoborneol, bornyl acetate, and isobornyl acetate in total at 0.01 to 10% by weight. The vehicle composition wherein the (meth)acrylic resin contains 10 to 100% by weight of segments derived from a (meth)acrylic acid ester having a branched structure in its ester substituent.

2. The vehicle composition according to claim 1, wherein the polyvinyl acetal resin is a carboxylic acid-modified polyvinyl acetal resin.

3. The vehicle composition according to claim 2, wherein the amount of carboxyl groups in the carboxylic acid-modified polyvinyl acetal resin is 1.5 mol% or less.

4. The vehicle composition according to claim 1 or 2, wherein the amount of acetal groups in the polyvinyl acetal resin is 60 mol% or more and 80 mol% or less.

5. The vehicle composition according to claim 1 or 2, wherein the amount of hydroxyl groups in the polyvinyl acetal resin is 16 mol% or more and 50 mol% or less.

6. The vehicle composition according to claim 1 or 2, wherein the amount of acetyl groups in the polyvinyl acetal resin is 0.1 mol% or more and 20 mol% or less.

7. The vehicle composition according to claim 1 or 2, wherein the polyvinyl acetal resin contains α-olefin units in its main chain.

8. The vehicle composition according to claim 7, wherein the content of α-olefin units in the polyvinyl acetal resin is 1 mol% or more and 20 mol% or less.

9. A slurry composition comprising the vehicle composition according to claim 1 or 2 and inorganic particles.

10. An electronic component comprising the slurry composition described in claim 9.

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