Resin composition for ceramic green sheet, and laminated ceramic capacitor
阅读说明：本技术 陶瓷生片用树脂组合物、陶瓷生片及层叠陶瓷电容器 (Resin composition for ceramic green sheet, and laminated ceramic capacitor ) 是由 前田贵之 于 2020-03-27 设计创作，主要内容包括：本发明提供陶瓷生片用树脂组合物以及使用了该陶瓷生片用树脂组合物的陶瓷生片及层叠陶瓷电容器,所述陶瓷生片用树脂组合物能够制作即使在制成薄层的情况下也具有高机械强度、不易产生切断后的外观不良、干燥后的尺寸变化的陶瓷生片。本发明为一种陶瓷生片用树脂组合物,其含有聚乙烯醇缩醛树脂,tanδ的峰顶为1.25以上,并且损耗模量E”为2.30×10～(8)Pa以上。(The invention provides a resin composition for a ceramic green sheet, which has high mechanical strength even when formed into a thin layer, is less likely to cause appearance defects after cutting, and has a dimension after dryingA modified ceramic green sheet. The present invention is a resin composition for a ceramic green sheet, which contains a polyvinyl acetal resin, has a tan delta peak of 1.25 or more, and has a loss modulus E' of 2.30X 10 8 Pa or above.)
1. A resin composition for ceramic green sheets, which comprises a polyvinyl acetal resin,
tan delta has a peak top of 1.25 or more and a loss modulus E' of 2.30X 108Pa or above.
2. The resin composition for ceramic green sheet according to claim 1, wherein the hydroxyl group of the polyvinyl acetal resin is determined by NMR measurement and IR measurementThe half-value width of the peak was 0.01 mol%/cm in terms of mol%-10.15 mol%/cm-1。
3. The resin composition for a ceramic green sheet according to claim 1 or 2, wherein the content of the plasticizer is 25 parts by weight or less based on 100 parts by weight of the polyvinyl acetal resin.
4. The resin composition for a ceramic green sheet according to claim 1, 2 or 3, wherein the polyvinyl acetal resin is an acetal group amount of a polyvinyl alcohol resin having a saponification degree of 75 mol% or more.
5. The resin composition for a ceramic green sheet according to claim 1, 2, 3 or 4, wherein an acetal group amount of the polyvinyl acetal resin is 45 mol% to 83 mol%.
6. The resin composition for a ceramic green sheet according to claim 1, 2, 3, 4 or 5, wherein the polyvinyl acetal resin has an average polymerization degree of 1000 to 10000.
7. A ceramic green sheet comprising the resin composition for ceramic green sheets according to claim 1, 2, 3, 4, 5 or 6.
8. A laminated ceramic capacitor having the ceramic green sheet according to claim 7.
Technical Field
The present invention relates to a resin composition for ceramic green sheets capable of producing ceramic green sheets having high mechanical strength even when formed into a thin layer, and being less likely to cause appearance defects after cutting and dimensional changes after drying, and a ceramic green sheet and a laminated ceramic capacitor using the resin composition for ceramic green sheets.
Background
In recent years, electronic components mounted on various electronic devices have been reduced in size and laminated, and multilayer electronic components such as multilayer circuit boards, multilayer coils, and multilayer ceramic capacitors have been widely used.
Among these, the laminated ceramic capacitor is generally manufactured through the following steps.
First, a plasticizer, a dispersant, and the like are added to a solution obtained by dissolving a binder resin such as a polyvinyl butyral resin and a poly (meth) acrylate resin in an organic solvent, and then ceramic raw material powder is added, and is mixed more uniformly by a mixing device such as a bead mill or a ball mill, and a ceramic slurry composition having a certain viscosity is obtained after defoaming. The slurry composition is cast onto a support surface of a polyethylene terephthalate film or SUS plate subjected to a mold release treatment using a doctor blade, a reverse roll coater, or the like, and volatile components such as a solvent are distilled off by heating or the like, and then the slurry is peeled from the support to obtain a ceramic green sheet.
Next, a plurality of materials coated with a conductive paste to be internal electrodes by screen printing were alternately stacked on the obtained ceramic green sheet, and subjected to thermocompression bonding to prepare a laminate. Then, a treatment of thermally decomposing and removing the binder resin component and the like contained in the laminate, so-called degreasing treatment, is performed, and an external electrode is sintered on the end face of the ceramic sintered body obtained by firing, thereby obtaining a laminated ceramic capacitor.
In addition, along with the multifunction and miniaturization of electronic devices, a multilayer ceramic capacitor is required to have a large capacity and a small size. In response to this, attempts have been made to coat a ceramic green sheet with a peelable support in a thinner film form (e.g., 5 μm or less) using a ceramic powder having a finer particle size (e.g., 0.5 μm or less).
However, in each step of producing the ceramic green sheet, a stress such as a tensile stress or a bending stress is applied to the thin film-like ceramic green sheet. Therefore, a ceramic green sheet having strength capable of withstanding these stresses is required.
On the other hand, patent documents 1 and 2 describe that by setting the polymerization degree, acetyl group amount, and acetal group amount to predetermined ranges, a slurry composition having excellent coatability can be obtained without adding an excessive amount of an organic solvent.
Documents of the prior art
Patent document
Patent document 1: japanese patent No. 5462700
Patent document 2: japanese patent No. 5702311
Disclosure of Invention
Problems to be solved by the invention
However, even the slurry compositions described in patent documents 1 and 2 have a problem that the strength of the obtained ceramic green sheet is insufficient and the ceramic green sheet is broken when peeled off from the support.
In addition, in the cutting step in the production of the ceramic green sheet, there is a problem that the cut surface is not uniform and appearance defects occur.
Further, in the drying step, there is a problem that dimensional defects after cutting occur due to dimensional changes.
In view of the above-described situation, an object of the present invention is to provide: a resin composition for ceramic green sheets, which can produce ceramic green sheets having high mechanical strength even when formed into thin layers, and being less likely to cause appearance defects after cutting and dimensional changes after drying, and a ceramic green sheet and a laminated ceramic capacitor using the same.
Means for solving the problems
The present invention is a resin composition for ceramic green sheets, which contains a polyvinyl acetal resin, has a tan delta peak of 1.25 or more, and a loss modulus E' of 2.30X 108Pa or above.
The present invention is described in detail below.
As a result of intensive studies, the present inventors have found that a resin composition for a ceramic green sheet having a peak top of tan δ and a loss modulus E ″ within predetermined ranges has high mechanical strength even when formed into a thin layer, and can produce a ceramic green sheet in which appearance defects after cutting and dimensional changes after drying are unlikely to occur, thereby completing the present invention.
The resin composition for a ceramic green sheet of the present invention has a peak top of tan δ of 1.25 or more. This can impart appropriate flexibility. The peak top of tan δ has a preferred lower limit of 1.55 and a preferred upper limit of 3.00.
The peak top of tan δ is, for example: the measured value of tan. delta. at the peak temperature was measured using DMA (manufactured by IT measurement Co., Ltd.) under conditions of a temperature range of 30 ℃ to 150 ℃, a temperature rise rate of 6 ℃/min and a frequency of 1 Hz. The DMA measurement is preferably performed after the resin composition for a ceramic green sheet is formed into a sheet.
The loss modulus E' of the resin composition for ceramic green sheet of the present invention is 2.30X 108Pa or above. By setting the range above, appropriate flexibility can be provided. The lower limit of the loss modulus E' is preferably 2.30X 108Pa, preferably upper limit of 2.80X 108Pa。
The loss modulus is, for example: the measured value of the loss modulus at the peak temperature was measured using DMA (manufactured by IT measurement Co., Ltd.) under the conditions of a temperature range of 30 ℃ to 150 ℃, a temperature rise rate of 6 ℃/min and a frequency of 1 Hz. The DMA measurement is preferably performed after the resin composition for a ceramic green sheet is formed into a sheet.
The difference between the peak top temperature of tan delta and the peak top temperature of loss modulus E "(peak top temperature difference: [ peak top temperature of tan delta ] - [ peak top temperature of loss modulus E") (preferably, 8.0 to 15.0 ℃ C.) in the resin composition for ceramic green sheets of the present invention. By setting the range, a strong film strength can be obtained. A more preferable lower limit of the peak top temperature difference is 9.0 ℃ and a more preferable upper limit is 14.0 ℃.
The resin composition for a ceramic green sheet of the present invention contains a polyvinyl acetal resin.
The polyvinyl acetal resin has a structural unit having an acetal group represented by the following general formula (1), a structural unit having a hydroxyl group represented by the following general formula (2), and a structural unit having an acetyl group represented by the following general formula (3).
[ chemical formula 1]
In the above formula (1), R1Represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
In the above formula (1), in R1When the alkyl group has 1 to 20 carbon atoms, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Further, there may be mentioned pentyl, hexyl, heptyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, octadecyl and the like. Among them, methyl and n-propyl are preferable.
In the polyvinyl acetal resin, the content of the structural unit having an acetal group represented by the general formula (1) (hereinafter, also referred to as "acetal group amount") preferably has a lower limit of 45 mol% and an upper limit of 83 mol%.
When the amount of the acetal group is 45 mol% or more, the solubility in an organic solvent can be improved. When the amount of the acetal group is 83 mol% or less, a polyvinyl acetal resin having excellent toughness can be obtained.
The amount of the acetal group is more preferably 60 mol% at the lower limit, still more preferably 62 mol% at the lower limit, particularly preferably 65 mol% at the lower limit, still more preferably 80 mol% at the upper limit, and still more preferably 78 mol% at the upper limit.
In the present specification, as a method for calculating the amount of acetal groups, since acetal groups of a polyvinyl acetal resin are obtained by acetalizing 2 hydroxyl-containing structural units of a polyvinyl alcohol resin, the amount of acetal groups is calculated by counting the acetalized 2 hydroxyl-containing structural units.
In the polyvinyl acetal resin, the content of the structural unit having a hydroxyl group represented by the general formula (2) (hereinafter, also referred to as "hydroxyl group amount") has a preferable lower limit of 18 mol% and a preferable upper limit of 45 mol%.
When the amount of the hydroxyl group is 18 mol% or more, a polyvinyl acetal resin having excellent toughness can be obtained. When the amount of the hydroxyl group is 45 mol% or less, the solubility in an organic solvent can be sufficiently improved.
A more preferable lower limit of the amount of the hydroxyl group is 20 mol%, a further more preferable lower limit is 22 mol%, a further more preferable upper limit is 40 mol%, and a further more preferable upper limit is 37 mol%.
In the polyvinyl acetal resin, the content of the structural unit having an acetyl group represented by the general formula (3) (hereinafter, also referred to as "acetyl amount") has a preferable lower limit of 0.5 mol% and a preferable upper limit of 20 mol%.
When the acetyl group content is 0.5 mol% or more, the polyvinyl acetal resin can be inhibited from becoming highly viscous due to intramolecular and intermolecular hydrogen bonds of hydroxyl groups. When the acetyl group content is 20 mol% or less, the flexibility of the polyvinyl acetal resin is not excessively improved, and the handleability can be improved.
The lower limit of the amount of the acetyl group is more preferably 1.0 mol%, and the upper limit is more preferably 18 mol%.
The polyvinyl acetal resin preferably has an average polymerization degree of 1000 to 10000.
By setting the average polymerization degree to 1000 or more, sufficient mechanical strength can be provided even when a thin-film resin sheet having a thickness of 20 μm or less is produced. When the average polymerization degree is 10000 or less, the solubility in an organic solvent can be sufficiently improved, and the coating property and the dispersibility can be excellent. By setting the content within the above range, a ceramic green sheet having high mechanical strength, less prone to appearance defects after cutting, and dimensional changes after drying can be obtained.
A more preferable lower limit of the average polymerization degree is 1050, a further preferable lower limit is 1100, a further preferable upper limit is 5000, a further preferable upper limit is 4900, and a most preferable upper limit is 4800.
The polyvinyl acetal resin preferably has a half-value width in terms of mol% of hydroxyl groups determined by NMR measurement and IR measurement of 0.01 to 0.15 mol%/cm-1. By setting the content within the above range, a ceramic green sheet having high mechanical strength, less prone to appearance defects after cutting, and dimensional changes after drying can be obtained. Further, the half-value width in terms of mol% of hydroxyl groups is more preferably 0.01 to 0.145 mol%/cm-1。
The IR measurement is a measurement of an absorption spectrum by an infrared absorption spectroscopy, and can be performed by an IR meter, for example.
The half width in terms of mol% of the hydroxyl group can be calculated as follows: measured by IR and measured at 3500cm-1The peak width at 1/2 of the peak height appearing in the vicinity was measured for the half-peak width of the hydroxyl group, and then the amount of the hydroxyl group was measured by NMR measurement, and the hydroxyl group amount was divided by the half-peak width of the hydroxyl group, thereby calculating the hydroxyl group content.
The polyvinyl acetal resin can be usually produced by acetalizing a polyvinyl alcohol resin.
The acetalization method is not particularly limited, and conventionally known methods can be used, and examples thereof include: and a method of adding various aldehydes to an aqueous solution, an alcohol solution, a water/alcohol mixed solution, or a Dimethylsulfoxide (DMSO) solution of a polyvinyl alcohol resin in the presence of an acid catalyst.
Examples of the aldehyde include linear, branched, cyclic saturated, cyclic unsaturated or aromatic aldehydes having 1 to 19 carbon atoms. Specific examples thereof include formaldehyde, acetaldehyde, propionaldehyde (Japanese: プロピオニルアルデヒド), n-butyraldehyde, isobutyraldehyde, tert-butyraldehyde, benzaldehyde, and cyclohexanal. The above aldehydes may be used alone, or 2 or more kinds may be used in combination. The aldehyde compound may be a compound in which 1 or more hydrogen atoms other than formaldehyde are substituted with halogen or the like.
As the polyvinyl alcohol resin, for example: a conventionally known polyvinyl alcohol resin such as a resin produced by saponifying polyvinyl acetate with an alkali, an acid, ammonia water, or the like.
The polyvinyl alcohol resin may be completely saponified, but may be a partially saponified polyvinyl alcohol-based resin without being completely saponified, as long as a unit having 2-unit group hydroxyl groups (i.e., 2 linked acidic groups) with respect to the meso-position and the racemic position, of which at least 1 unit is present at least at 1 position of the main chain. As the polyvinyl alcohol resin, a copolymer of a monomer copolymerizable with vinyl alcohol, such as an ethylene-vinyl alcohol copolymer resin or a partially saponified ethylene-vinyl alcohol copolymer resin, and vinyl alcohol may be used.
Examples of the polyvinyl acetate resin include an ethylene-vinyl acetate copolymer.
The polyvinyl acetal resin constituting the resin composition for a ceramic green sheet of the present invention is preferably an acetal compound of a polyvinyl alcohol resin having a saponification degree of 75 mol% or more. In particular, the polyvinyl acetal resin constituting the resin composition for a ceramic green sheet of the present invention preferably has a half-value width of hydroxyl group determined by IR measurement of 300 to 400cm-1An acetal compound of the polyvinyl alcohol resin of (1). Particularly preferably, the half-value width of hydroxyl group determined by IR measurement is 340-400 cm-1An acetal compound of the polyvinyl alcohol resin of (1). Thus, the peak top of tan δ and the loss modulus E ″ of the resin composition for a ceramic green sheet of the present invention can be set within predetermined ranges.
The polyvinyl alcohol resin usually contains a carboxylic acid salt which is an alkali component generated during saponification, and therefore, it is preferably used after being washed away or neutralized. By washing away or neutralizing the carboxylic acid salt, the condensation reaction of the aldehyde catalyzed under alkaline conditions can be effectively suppressed, and thus the coloration of the resin can be further suppressed.
Examples of the cleaning method in the cleaning step include: a method of extracting an alkaline component with a solvent; a method in which a resin is dissolved in a good solvent, and then a poor solvent is added to reprecipitate only the resin; a method of adding an adsorbent to a solution containing a polyvinyl alcohol resin to adsorb and remove an alkaline component; and the like.
Examples of the neutralizing agent used in the neutralizing step include: mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, inorganic acids such as carbonic acid, carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, and caproic acid, aliphatic sulfonic acids such as methanesulfonic acid and ethanesulfonic acid, aromatic sulfonic acids such as benzenesulfonic acid, and phenols such as phenol.
The resin composition for a ceramic green sheet of the present invention may contain a plasticizer. By adding the plasticizer, the mechanical strength and flexibility of the obtained ceramic green sheet can be greatly improved.
Examples of the plasticizer include: phthalic acid diesters such as dioctyl phthalate (DOP) and dibutyl phthalate (DBP), adipic acid diesters such as dioctyl adipate, and alkylene glycol diesters such as triethylene glycol-di-2-ethylhexanoate and tetraethylene glycol-di-2-ethylhexanoate. Further, alkylene glycol diesters such as triethylene glycol-di-2-ethylbutyrate, tetraethylene glycol-di-heptanoate, and triethylene glycol-di-heptanoate may be mentioned.
In the resin composition for a ceramic green sheet of the present invention, the content of the plasticizer is preferably 7 parts by weight at the lower limit, more preferably 8.5 parts by weight at the upper limit, more preferably 25 parts by weight at the upper limit, more preferably 15 parts by weight at the upper limit, and still more preferably 11.5 parts by weight at the upper limit, based on 100 parts by weight of the polyvinyl acetal resin.
The resin composition for a ceramic green sheet of the present invention may contain an organic solvent.
The organic solvent is not particularly limited as long as it can dissolve the polyvinyl acetal resin, and examples thereof include ketones such as acetone, methyl ethyl ketone, dipropyl ketone, and diisobutyl ketone. Examples thereof include alcohols such as methanol, ethanol, isopropanol and butanol, and aromatic hydrocarbons such as toluene and xylene. Further, esters such as methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, methyl valerate, ethyl valerate, butyl valerate, methyl hexanoate, ethyl hexanoate, butyl hexanoate, 2-ethylhexyl acetate, and 2-ethylhexyl butyrate may be mentioned. Examples thereof include methyl cellosolve, ethyl cellosolve, butyl cellosolve, terpineol, dihydroterpineol, butyl cellosolve acetate, butyl carbitol acetate, terpineol acetate, and dihydroterpineol acetate. Alcohols, ketones, aromatic hydrocarbons, and mixed solvents thereof are particularly preferable from the viewpoint of coating properties and drying properties. Among them, a mixed solvent of ethanol and toluene and a mixed solvent of methyl ethyl ketone and toluene are preferable.
The resin composition for a ceramic green sheet of the present invention may contain, within a range not impairing the effects of the present invention: other resins than the above polyvinyl acetal resin, such as polyvinyl acetal resin, acrylic resin, and ethyl cellulose. In this case, the content of the polyvinyl acetal resin is preferably 50% by weight or more with respect to the entire binder resin.
In the resin composition for a ceramic green sheet of the present invention, if necessary, inorganic powder, a dispersant, an antioxidant, an ultraviolet absorber, a surfactant, a filler, and the like may be added as appropriate, and if necessary, other resins such as an acrylic resin and a urethane resin may be added in a small amount.
Examples of the inorganic powder include metal or nonmetal oxide or non-oxide powder, and ceramic powder. The composition of these powders may be a single composition powder or a compound powder, and these powders may be used alone or in combination. In addition, the metal oxide or non-oxide constituent elements, cations or anions may be composed of one element, may be composed of a plurality of elements, and may contain additives added to improve the characteristics of the oxide or non-oxide. Specifically, there may be mentioned: oxides, carbides, nitrides, borides, sulfides, and the like of Li, K, Mg, B, Al, Si, Cu, Ca, Sr, Ba, Zn, Cd, Ga, In, Y, lanthanides, actinides, Ti, Zr, Hf, Bi, V, Nb, Ta, W, Mn, Fe, Co, Ni, and the like.
In addition, if oxide powders containing a plurality of metal elements, which are generally called composite oxides, are subjected to crystallizationWhen specific substances are classified, examples of the substance having a perovskite structure include NaNbO3、SrZrO3、PbZrO3、SrTiO3、BaZrO3、PbTiO3、BaTiO3And the like. Examples of the material having a spinel structure include MgAl2O4、ZnAl2O4、CoAl2O4、NiAl2O4、MgFe2O4And the like. Examples of the substance having an ilmenite type structure include MgTiO3、MnTiO3、FeTiO3And the like. Examples of the substance having a garnet structure include GdGa5O12、Y6Fe5O12And the like. Among them, the modified polyvinyl acetal resin of the present application is suitable for use with BaTiO3The ceramic green sheet obtained by mixing the powders of (4) shows high characteristics.
The average particle size of the inorganic powder is not particularly limited, and is preferably 0.05 to 0.5 μm or less for the production of a thin ceramic green sheet (having a thickness of 5 μm or less), for example.
When the resin composition for a ceramic green sheet of the present invention contains an inorganic powder, the lower limit of the content of the polyvinyl acetal resin is preferably 0.1 part by weight and the upper limit is preferably 20 parts by weight with respect to 100 parts by weight of the inorganic powder. When the content of the polyvinyl acetal resin is 0.1 parts by weight or more, the dispersibility of the inorganic powder becomes sufficient, and when the content is 20 parts by weight or less, the viscosity can be in an appropriate range, and the handling property can be improved. The lower limit of the content is more preferably 0.6 parts by weight, and the upper limit is more preferably 15 parts by weight. In particular, by setting the content to 0.6 parts by weight or more, the polyvinyl acetal resin can be sufficiently adsorbed on the surface of the inorganic powder, and thus the inorganic powder can be more finely dispersed.
When the resin composition for a ceramic green sheet of the present invention contains an inorganic powder, the lower limit of the content of the organic solvent is preferably 20 parts by weight and the upper limit is preferably 60 parts by weight with respect to 100 parts by weight of the inorganic powder. By setting the content of the organic solvent to 20 parts by weight or more, the viscosity can be set in an appropriate range, and sufficient dispersibility can be obtained without restricting the movement of the inorganic powder, and by setting the content to 60 parts by weight or less, the inorganic powder concentration is not excessively lowered, and the number of times of collision between the inorganic powders can be reduced, and sufficient dispersibility can be obtained.
The method for producing the resin composition for ceramic green sheets of the present invention is not particularly limited, and examples thereof include: and a method of mixing the polyvinyl acetal resin, the organic solvent, and, if necessary, various additive inorganic powders with the use of various mixers such as a ball mill, a mixing mill, and a three-roll mill. The inorganic powder may be added separately after the preparation of the inorganic dispersion.
After coating the resin composition for a ceramic green sheet of the present invention, it is dried by heating to obtain a resin sheet.
The method for coating the resin composition for a ceramic green sheet of the present invention is not particularly limited, and examples thereof include roll coater, die coater, curtain coater, and the like. As for other specific methods, conventionally known methods can be used.
A resin sheet containing ceramic powder may be used as the ceramic green sheet. Such a ceramic green sheet is also one of the present invention.
Ceramic electronic components can be manufactured by using the ceramic green sheet. For example, a ceramic electronic component can be manufactured by performing a step of applying an electrode layer paste on the surface of a ceramic green sheet, a step of stacking the ceramic green sheets on which the electrode layers are formed, heating and pressing the stacked bodies to obtain a stacked body, and a step of degreasing and firing the stacked body obtained.
The ceramic electronic component is not particularly limited, and examples thereof include a multilayer ceramic capacitor, a multilayer ceramic inductor, a capacitor, a piezoelectric actuator, a multilayer varistor, a multilayer thermistor, an EMI filter, an aluminum nitride multilayer substrate, and an aluminum oxide multilayer substrate. Such a ceramic electronic component is also one of the present invention.
In the method for manufacturing a ceramic electronic component, a step of applying an electrode layer paste to the surface of the ceramic green sheet is performed.
The electrode layer paste can be obtained by dissolving a polyvinyl acetal resin, ethyl cellulose, an acrylic resin, or the like as a binder resin in an organic solvent, and dispersing conductive powder or the like. These resins may be used alone or in combination of 2 or more. A paste for an electrode layer containing a polyvinyl acetal resin is preferable because it exhibits excellent adhesion to a ceramic green sheet in the heat-pressure bonding step.
In the above-described method for manufacturing a ceramic electronic component, after the above-described ceramic green sheets having the electrode layers formed thereon are produced, the ceramic green sheets having the electrode layers formed thereon produced in the same manner are stacked and subjected to heat pressure bonding to obtain a laminate, and the obtained laminate is degreased and fired, whereby a laminated ceramic electronic component in which problems such as sheet corrosion (japanese patent application No. シートアタック) and cracks are solved is obtained.
The heating and pressure bonding step and the step of degreasing and firing the laminate are not particularly limited, and conventionally known methods can be used.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, it is possible to provide a resin composition for a ceramic green sheet which has high mechanical strength even when formed into a thin layer, is less likely to cause appearance defects after cutting, and dimensional changes after drying, and a ceramic green sheet and a laminated ceramic capacitor using the resin composition for a ceramic green sheet.
Detailed Description
The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
(example 1)
(preparation of polyvinyl Acetal resin)
The average degree of polymerization was 1000, the degree of saponification was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-12700g of pure water was added to 250g of the polyvinyl alcohol resin (2), and the mixture was stirred at 90 ℃ for about 2 hours to dissolve the polyvinyl alcohol resin (250). The solution was cooled to 40 ℃ and 100g of hydrochloric acid having a concentration of 35% by weight and n-butanol were added thereto115g of aldehyde was subjected to acetalization reaction to precipitate a reaction product. Then, acetalization reaction was completed at 40 ℃, and neutralization, washing with water and drying were carried out by a conventional method to obtain a white powder of a polyvinyl acetal resin.
The obtained polyvinyl acetal resin was dissolved in DMSO-d at a concentration of 10% by weight6In, use13The amount of acetal groups, the amount of hydroxyl groups, and the amount of acetyl groups were measured by C-NMR. The half-peak width of the hydroxyl group of the polyvinyl alcohol resin was measured using HORIBA FT-720 (HORIBA ltd.).
(preparation of resin composition for ceramic Green sheet)
10.0 parts by weight of the obtained polyvinyl acetal resin and 1.0 part by weight of DOP as a plasticizer were added, and 45.0 parts by weight of an ethanol/toluene mixed solvent (weight ratio 1: 1) was added and dissolved by stirring to obtain a resin composition for a ceramic green sheet.
(preparation of resin sheet)
The obtained resin composition for a ceramic green sheet was applied to a PET film subjected to mold release treatment so that the thickness after drying became 15 μm using a coater, and then heated and dried at 70 ℃ for 120 minutes to prepare a resin sheet.
(example 2)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 1700, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 3)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 3300, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 4)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 4900, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 5)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 1700, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 6)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 1700, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 7)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 1700, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 8)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 5000, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 9)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 9200, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 10)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 8000, the saponification degree was 98.5 mol%, and the half-peak width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(example 11)
(preparation of polyvinyl Acetal resin)
The polymerization degree was 1700, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 350cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
Comparative example 1
The polymerization degree was 600, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 335cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
Comparative example 2
The polymerization degree was 4900, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 335cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
Comparative example 3
The polymerization degree was 1700, the saponification degree was 98.5 mol%, and the half-peak width of hydroxyl group was 335cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
Comparative example 4
The polymerization degree was 3300, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 335cm-1Polyethylene ofA polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except that 250g of an alcoholic resin was used.
Comparative example 5
The polymerization degree was 4900, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 335cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
Comparative example 6
The polymerization degree was 9000, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 335cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
Comparative example 7
The polymerization degree was 9000, the saponification degree was 98.5 mol%, and the half-value width of hydroxyl group was 335cm-1A polyvinyl acetal resin, a resin composition for a ceramic green sheet, and a resin sheet were prepared in the same manner as in example 1, except for 250g of the polyvinyl alcohol resin.
(evaluation)
The following evaluations were made with respect to the polyvinyl acetal resins, the resin compositions for ceramic green sheets, and the resin sheets obtained in examples and comparative examples. The results are shown in Table 1.
(1) Confirmation of half-value Width converted from mol%
The polyvinyl acetal resins obtained in examples and comparative examples were measured for the half-peak width of the hydroxyl group by IR measurement using HORIBA FT-720 (HORIBA, Ltd.). half-Width and passing of hydroxyl groups according to IR measurement13The half-width of the hydroxyl group in terms of mol% was determined for the polyvinyl acetal resin based on the amount of hydroxyl groups measured by C-NMR.
(2) tan delta and loss modulus E "
The obtained resin sheet was cut into 0.5cm × 2.0cm to prepare a test piece, and then the dynamic viscoelasticity was measured under the following conditions using DMA (manufactured by IT measurement company).
The tan δ (loss tangent) is a value at the peak top temperature. The storage modulus E' and the loss modulus E ″ were also measured in the same manner at the peak top temperature. In addition, the difference between the peak top temperature of tan δ and the peak top temperature of loss modulus E "(peak top temperature difference: [ peak top temperature of tan δ ] - [ peak top temperature of loss modulus E ]) was calculated.
(measurement conditions)
Measurement mode: stretching mode
Forced vibration frequency: 1Hz
Temperature range: 30-150 DEG C
Temperature rise rate: 6 ℃/min
(3) Tensile modulus of elasticity, elongation at break and stress at break
(preparation of ceramic Green sheet)
1 part by weight of a polyvinyl acetal resin (BL-1, manufactured by Water chemical industries, Ltd.) was added to a mixed solvent of 20 parts by weight of toluene and 20 parts by weight of ethanol, and the mixture was stirred and dissolved. Next, 100 parts by weight of a powder of barium titanate (made by sakai chemical industry corporation, BT01, average particle size 0.1 μm) was added to the obtained solution, and stirred for 180 minutes by a bead mill (ready mill made by AIMEX corporation), thereby preparing an inorganic dispersion.
The resin composition for a ceramic green sheet was added to the obtained inorganic dispersion, stirred for 90 minutes by a bead mill, and then applied to a PET film subjected to mold release treatment using a coater so that the thickness after drying became 20 μm. Then, the ceramic green sheet was heated and dried at 40 ℃ for 30 minutes, and the PET film was peeled off to produce a ceramic green sheet.
The obtained ceramic green sheet was measured for tensile elastic modulus (MPa), elongation at break (%) and stress at break (MPa) at a tensile rate of 20 mm/min using a tensile tester (AUTOGRAPH AGS-J, manufactured by shimadzu corporation) in accordance with JIS K7113.
(4) State of cut cross section
The fracture surface after the "(3) tensile modulus of elasticity, elongation at break and stress at break" measurement was observed by SEM and evaluated according to the following evaluation criteria.
Very good: no gap, crack or scar on the fracture surface
O: the fracture surface has no gap or crack but has flaw
And (delta): the fracture surface being unnotched but having cracks
X: with a gap in the fracture surface
(5) Rate of change of dimension
The ceramic green sheet was produced by the same method as "(3) tensile modulus of elasticity, elongation at break and stress at break". The obtained ceramic green sheet was dried at 70 ℃ for 3 hours, and the dimensional change rate before and after drying at 70 ℃ was calculated and evaluated according to the following criteria.
Very good: 2% or less
O: more than 2% and not more than 3%
And (delta): more than 3% and not more than 4%
X: more than 4 percent
[ Table 1]
Industrial applicability
According to the present invention, it is possible to provide a resin composition for a ceramic green sheet which has high mechanical strength even when formed into a thin layer, is less likely to cause appearance defects after cutting, and dimensional changes after drying, and a ceramic green sheet and a laminated ceramic capacitor using the resin composition for a ceramic green sheet.
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