阅读说明：本技术 陶瓷生片层叠助剂及陶瓷生片组合物 (Ceramic green sheet laminating aid and ceramic green sheet composition ) 是由 吉川文隆 松崎健太 砂田和辉 于 2020-03-05 设计创作，主要内容包括：本发明的技术问题在于不使片材强度下降,且抑制陶瓷生片间的剥离与层叠错位。作为解决手段,本发明提供一种陶瓷生片层叠助剂,其特征在于,其由式(1)所表示的化合物构成,Z-[O-(AO)n-H]x···(1)Z表示从碳原子数为1～22且具有1～6个羟基的化合物中去除了全部羟基的残基,x表示1～6的数,AO表示碳原子数为2～4的氧化烯基,n表示5～500的数,ⅹ×n为5～500的范围,碳原子数为2～4的所述氧化烯基AO中所包含的碳原子数为2的氧化乙烯基EO的重量比例为0～80重量％。(The invention aims to prevent the peeling and the stacking dislocation between ceramic green sheets without reducing the strength of a sheet. The invention provides a ceramic green sheet laminating auxiliary agent, which is characterized in that the laminating auxiliary agent is composed of a compound represented by a formula (1), Z- [ O- (AO) n-H ] x · (1) Z represents a residue obtained by removing all hydroxyl groups from a compound having 1-6 hydroxyl groups and 1-22 carbon atoms, x represents a number of 1-6, AO represents an oxyalkylene group having 2-4 carbon atoms, n represents a number of 5-500, x n is in a range of 5-500, and the weight proportion of an oxyethylene group EO having 2 carbon atoms contained in the oxyalkylene group having 2-4 carbon atoms is 0-80 wt%.)

1. A ceramic green sheet stacking aid characterized by being composed of a compound represented by the formula (1),

Z-[O-(AO)n-H]x···(1)

in the formula (1), Z represents a residue obtained by removing all hydroxyl groups from a compound having 1-22 carbon atoms and 1-6 hydroxyl groups, x represents a number of 1-6, AO represents an oxyalkylene group having 2-4 carbon atoms, n represents a number of 5-500, x n is in the range of 5-500, and the weight proportion of oxyethylene EO contained in the oxyalkylene group AO having 2-4 carbon atoms is 0-80 wt%.

2. A ceramic green sheet composition comprising 0.01 to 5 mass% of the following component (A), 1 to 25 mass% of the following component (B) and 70 to 98 mass% of the following component (C),

component (A): the ceramic green sheet stacking aid according to claim 1,

component (B): the polyvinyl butyral resin is polymerized by using a polyvinyl butyral resin,

component (C): a ceramic powder.

Technical Field

The present invention relates to a lamination aid used in a step of laminating a ceramic green sheet, and a ceramic green sheet composition containing the lamination aid. More specifically, the present invention relates to a lamination aid capable of suppressing peeling and stacking misalignment between ceramic green sheets with a small amount of addition, and suppressing a decrease in sheet strength and an increase in residue during firing, and a ceramic green sheet composition containing the lamination aid.

Background

Electronic components such as a multilayer ceramic capacitor (MLCC) and a multilayer chip inductor are manufactured mainly by a method of laminating green sheets made of ceramics such as barium titanate and ferrite and a binder resin.

In recent years, with the miniaturization and high performance of electronic devices, the miniaturization and high capacity of MLCCs have been demanded. Miniaturization and increase in capacity can be achieved by making the ceramic green sheet and the conductive layer, which are constituent members thereof, thinner and simultaneously multi-layered.

If the strength of the green sheet is reduced by thinning, defects such as cracking of the green sheet may occur during lamination. Therefore, a high-strength binder is often selected, and for example, polyvinyl butyral is widely used. However, the high-strength adhesive has higher hardness than conventional adhesives, and the adhesiveness between sheets tends to be lower than that of conventional adhesives. When the adhesiveness is lowered, interlayer peeling may occur in the lamination step of green sheets or the hot pressing step, and defects may occur.

When the adhesiveness of the green sheet is lowered, the resin can be softened by adding a large amount of a plasticizer, thereby obtaining the adhesiveness. However, if the strength of the resin is reduced by softening the resin, deformation occurs during hot pressing, and dimensional accuracy is deteriorated, so that it is necessary to achieve both adhesion and strength of the resin. In order to solve such a problem, patent document 1 discloses a method of combining polyvinyl butyral with a specific plasticizer to suppress interlayer peeling without lowering the strength of the resin.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2001 and 106580

Disclosure of Invention

Technical problem to be solved by the invention

However, with the recent progress of thinning and multilayering of green sheets, troubles between green sheets are more likely to occur. Particularly, when a load is applied in the laminating step or the hot pressing step, the green sheets slip with each other, resulting in lamination misalignment, which causes unstable product quality. In view of such a problem, it is not sufficient to prevent only conventional interlayer peeling, and a method for suppressing lamination misalignment in a lamination step or a hot press step is desired.

As described above, the present invention has an object to suppress peeling and stacking misalignment between ceramic green sheets without lowering sheet strength.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above-mentioned technical problems, and as a result, have found that a polyether compound having a specific structure can solve the above-mentioned technical problems.

Namely, the present invention is [1] to [2] below.

[1] A ceramic green sheet stacking aid characterized by being composed of a compound represented by the formula (1),

Z-[O-(AO)n-H]x ···(1)

in the formula (1), Z represents a residue obtained by removing all hydroxyl groups from a compound having 1-22 carbon atoms and 1-6 hydroxyl groups, x represents a number of 1-6, AO represents an oxyalkylene group having 2-4 carbon atoms, n represents a number of 5-500, x n is in the range of 5-500, and the weight proportion of oxyethylene EO contained in the oxyalkylene group AO having 2-4 carbon atoms is 0-80 wt%.

[2] A ceramic green sheet composition comprising 0.01 to 5 mass% of the following component (A), 1 to 25 mass% of the following component (B) and 70 to 98 mass% of the following component (C),

component (A): the ceramic green sheet stacking aid according to claim 1,

component (B): the polyvinyl butyral resin is polymerized by using a polyvinyl butyral resin,

component (C): a ceramic powder.

Effects of the invention

According to the present invention, peeling and stacking displacement between ceramic green sheets can be suppressed without causing a decrease in sheet strength and an increase in residue during firing.

Detailed Description

The laminating assistant of the present invention and a ceramic green sheet composition containing the same will be described below.

(laminating auxiliary)

The laminating assistant of the present invention is a polyether compound represented by the following formula (1).

Z-[O-(AO)n-H]x ···(1)

Z in the formula (1) is a residue obtained by removing all hydroxyl groups from an alcohol compound having 1-22 carbon atoms and 1-6 hydroxyl groups. That is, the alcohol compound is represented by (Z (OH) x), and a residue obtained by removing all (OH) from the alcohol compound is Z. Examples of the alcohol compound include methanol, ethanol, n-butanol, n-octanol, 2-ethylhexanol, 3,5, 5-trimethylhexanol, dodecanol, octadecanol, behenyl alcohol, ethylene glycol, propylene glycol, butylene glycol, pentanediol, hexanediol, octanediol, glycerol, 1,2, 3-butanetriol, 1,2, 4-butanetriol, 1,2, 5-pentanetriol, 1,2, 3-cyclohexanetriol, 1,3, 5-cyclohexanetriol, 1,2, 6-cyclohexanetriol, 3-methylpentane-1, 3, 5-triol, diglycerol, 1,2,3, 4-butanetetraol, erythritol, pentaerythritol, sorbitan, triglycerin, glucose, ribitol, xylitol, mannose, sorbitol, and mannitol.

The number of carbon atoms of z is more preferably 2 or more, and still more preferably 10 or less, and particularly preferably 5 or less.

The x in the formula (1) is the number of AO chains bonded to Z, corresponding to the number of hydroxyl groups possessed by the above alcohol (Z (OH) x). X is 1 to 6, preferably 1 to 5, more preferably 1 to 4, and most preferably 1 to 3. When x is more than 6, the lamination assistant has high viscosity, and the handling property may be deteriorated. From such a viewpoint, methanol, ethanol, butanol, 2-ethylhexanol, 3,5, 5-trimethylhexanol, ethylene glycol, propylene glycol, and glycerin are preferably used as the alcohol, and methanol, butanol, ethylene glycol, and glycerin are more preferably used.

AO in the formula (1) is an oxyalkylene group having 2 to 4 carbon atoms, and specifically is obtained by addition polymerization of ethylene oxide, propylene oxide, or butylene oxide. Among these alkylene oxides, ethylene oxide and propylene oxide are preferably used from the viewpoint of suppressing stacking faults, and propylene oxide is most preferably used. Further, one or two or more of the above alkylene oxides may be combined. When two or more kinds of alkylene oxides are added, the order is not particularly limited, and the alkylene oxides may be in a block form or a random form, and the random form is preferable because the strength of the ceramic green sheet is not easily lowered.

n represents an average addition mole number of AO, and when two or more types of AO are used, n represents a total average addition mole number of AO and represents a number of 5 to 500.

The average molar number [ xx n ] of addition of all AO's in the formula (1) is 5 to 500. The xx n is preferably 25 to 500, more preferably 10 to 450, further preferably 25 to 450, particularly preferably 30 to 450, particularly preferably 50 to 400, and most preferably 50 to 200. When xx is less than 5, peeling and stacking deviation between the ceramic green sheets may not be sufficiently suppressed, or the sheet strength may be lowered. When [ xx n ] is more than 500, the viscosity of the lamination assistant is high and the workability becomes poor.

From the viewpoint of improving the solubility with the resin, the lamination assistant of the present invention may contain an oxyethylene group (EO), and the upper limit of the weight ratio of EO contained in AO [ EO weight/AO weight × 100] is 80% by weight. The weight ratio of EO contained in AO is preferably 0 to 60% by weight, and more preferably 0 to 50% by weight. When the weight ratio of EO contained in AO is more than 80% by weight, solubility in the resin becomes high, but strength may be lowered.

The molecular weight of the lamination aid of the present invention can be measured by gel permeation chromatography, and is preferably 500 to 35,000, more preferably 2,000 to 35,000, further preferably 2,500 to 30,000, further preferably 3,000 to 25,000, and most preferably 3,000 to 10,000. When the molecular weight is more than 35,000, the polyether compound represented by the formula (1) has high viscosity, and therefore, the workability tends to be poor or the solvent solubility tends to be low. On the other hand, when the molecular weight is 500 or less, peeling between ceramic green sheets and stacking misalignment may not be sufficiently suppressed, or sheet strength may be reduced.

(ceramic Green sheet composition)

The ceramic green sheet composition of the present invention contains 0.01 to 5 mass% of a lamination auxiliary (component (A)), 1 to 25 mass% of polyvinyl butyral (component (B)), and 70 to 98 mass% of ceramic powder (component (C)).

Wherein the total amount of the component (A), the component (B) and the component (C) is set to 100% by weight.

The content of the lamination aid of the present invention is 0.01 to 5% by mass, preferably 0.05 to 3% by mass, and more preferably 0.1 to 2% by mass. When the content of the lamination aid is less than 0.01% by mass, peeling or sliding of the green sheet cannot be sufficiently suppressed. On the other hand, when the content of the lamination aid is more than 5% by mass, the green sheet may have insufficient strength.

The polyvinyl butyral (component (B)) in the ceramic green sheet composition is not particularly limited as long as it is a polyvinyl butyral that is generally used for green sheets, but polyvinyl butyral having a large molecular weight tends to be insufficient in adhesiveness. The weight average molecular weight of the polyvinyl butyral is preferably 500,000 or less, more preferably 300,000 or less, and particularly preferably 200,000 or less. Further, since the green sheet can be made thin to achieve strength, the weight average molecular weight of the polyvinyl butyral is preferably 50,000 or more, more preferably 100,000 or more.

The content of the polyvinyl butyral is 1 to 25% by mass, preferably 1 to 15% by mass, and particularly preferably 3 to 10% by mass.

The ceramic powder (component (C)) in the ceramic green sheet composition is not limited as long as it is a ceramic powder generally used for green sheets, and examples thereof include various powders such as silicate minerals, other silicic acid compounds, carbonic acid compounds, sulfuric acid compounds, hydroxides, oxides, nitrides, carbides, and titanic acid compounds. Examples of the powder include kaolin, clay, talc, mica, bentonite, dolomite, calcium silicate, aluminum silicate, magnesium silicate, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, aluminum hydroxide, iron hydroxide, zirconium oxide, magnesium oxide, aluminum oxide, titanium oxide, iron oxide, zinc oxide, antimony trioxide, indium oxide, indium tin oxide, silicon carbide, tungsten carbide, aluminum nitride, silicon nitride, boron nitride, barium titanate, calcium titanate, strontium titanate, carbon black, glass fiber, carbon nanofiber, and carbon nanotube (single-walled nanotube, double-walled nanotube, multi-walled nanotube).

The ceramic powder is preferably a powder of an oxide such as zirconium oxide, magnesium oxide, aluminum oxide, iron oxide, zinc oxide, or indium tin oxide, or a powder of a titanic acid compound such as barium titanate, calcium titanate, or strontium titanate, more preferably a powder of a titanic acid compound, and particularly preferably barium titanate.

The average particle size of the ceramic powder is not particularly limited, but ceramic powder having a smaller average particle size tends to be used as the green sheet becomes thinner. From this viewpoint, it is preferable to combine the ceramic powder with an average particle size of 300nm or less, and more preferably to combine the ceramic powder with an average particle size of 50 to 200nm or less. In addition, the average particle diameter of the dispersion can be measured by an electron microscopy method using SEM (scanning electron microscope) or TEM (transmission electron microscope) or a Micro-track method (laser diffraction/scattering method).

The content of the ceramic powder is 70 to 98 mass%, preferably 80 to 95 mass%, and more preferably 85 to 95 mass%.

In addition to the above blends, the ceramic green sheet composition may contain other ceramic additives, plasticizers, dispersants, antistatic agents, etc. as common components. In particular, by combining a plasticizer with the lamination assistant of the present invention, interlayer peeling and lamination dislocation can be effectively suppressed. In this case, the amount of the plasticizer is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the total amount of the components (a), (B), and (C).

Further, as the dispersant, a polymer having a polar group such as a hydroxyl group, a carboxyl group, a polyether group, or an amino group in a side chain is usually used, and a polymer having both a polyether group and a carboxyl group is preferable. Examples of the polymer of a vinyl ether having a polyoxyalkylene group and maleic anhydride are given. When the dispersant is added, the amount of the dispersant is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the total amount of the components (a), (B) and (C).

A solvent may be added to the composition. Examples of such solvents include ketones such as acetone and methyl ethyl ketone; alcohols such as ethanol and isopropanol; aromatic solvents such as toluene and xylene. These solvents may be used alone or in combination of two or more, and preferably, alcohols and aromatics are used simultaneously. When the solvent is added, the amount of the solvent is preferably 20 to 500 parts by mass, more preferably 50 to 300 parts by mass, based on 100 parts by mass of the total amount of the components (a), (B) and (C).

Examples

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

(laminating auxiliary)

As the lamination aids, the lamination aids 1 to 7 and comparative products 1 and 2 having the compositions shown in Table 1 were used. In table 1, the addition system of EO and PO of the lamination aids 3 and 4 is random, and the addition system of EO and PO of the lamination aids 6 and 7 is block, and the order thereof is EO-PO.

(Molding of ceramic Green sheet 1)

A 0.5 liter plastic pot was filled with a medium having a YTZ particle size of 2mm to 50% of the pot volume, and each material was added to the pot in each composition shown in table 2, table 3, and table 4. After stirring for 5 hours at 60rpm using MASUDA UNIVERSAL BALL MILL MODEL UBM-2, the medium was filtered to obtain a ceramic composition slurry.

The resulting slurry was coated on a PET film using a knife coater at a molding speed of 1.5 m/min. In this step, the groove of the blade was set to 140 μm, and a PET film having a thickness of 32 μm was used. Further, the applied slurry was dried at 40 ℃, 60 ℃, 75 ℃, 85 ℃ and 85 ℃ for 10 minutes, respectively, to obtain the target ceramic green sheet.

(evaluation of sheet Properties and adhesiveness)

The sheet strength, adhesive strength and static friction coefficient were evaluated by the following methods. The results are shown in tables 2, 3 and 4.

(method of measuring sheet Strength)

Using the green sheets shown in the tables, test pieces each having a width of 3 cm. times.10 cm were prepared. Tensile strength [ N/mm ] was measured for each test piece using MODEL9502B manufactured by Aikoh Engineering Co., Ltd²]. The results were evaluated on the basis of the following.

◎：16.0[N/mm²]The above

○：15.0～16.0[N/mm²]

X: less than 15.0[ N/mm ]²]

(method of measuring adhesive Strength between sheets)

Each green sheet described in the table was stacked at a rate of 500kg/cm²And 60 ℃ for 1 minute. The green sheet thus pressed was cut into a width of 2.5cm by a length of 25cm to prepare a test piece. One surface of each test piece was fixed to a table with JIS K-6854-1 (peel adhesion strength test method) as a reference, and the other surface was stretched at 500 mm/min using MODEL9502B manufactured by Aikoh Engineering co., ltd., to peel the adhesive surface. With the force [ N ] required at that time ]The adhesive strength (N/m) was calculated by dividing by the width of the test piece. The results were evaluated on the basis of the following criteria.

Very good: 15.0[ N/m ] or more

○：10.0～15.0[N/m]

X: less than 10.0[ N/m ]

(method of measuring coefficient of friction between sheets)

The sheets were measured for static friction coefficient and dynamic friction coefficient using the green sheets shown in the table. In the measurement of the friction coefficient, a friction tester (model: TL201Tt, manufactured by Trinity-Lab.inc.) was used to attach the green sheet to a portion (square 1 cm. times.1 cm) where the contact was in contact with the sample, and the friction coefficient between the sheets was measured. The measurement conditions were set at a temperature of 25 ℃, a moving speed of the friction member of 5 mm/sec and a load of 25g/cm². The results were evaluated on the basis of the following criteria.

Very good: 10.0 or more

○：5.0～10.0

X: less than 5.0

(Molding of ceramic Green sheet 2)

Evaluation of sheet properties and adhesiveness was performed in the same manner as in molding 1 of the ceramic green sheet except that the barium titanate powder used in molding 1 of the ceramic green sheet was changed to the alumina powder. The results are shown in Table 5.

[ Table 5]

As is clear from the results shown in tables 2, 3, 4 and 5, examples 1 to 13 exhibited good results in terms of sheet strength, adhesive strength and coefficient of static friction.

On the other hand, since the weight ratio of EO contained in AO of comparative examples 1 and 5 is out of the range of the present invention, a sufficient static friction coefficient is not obtained, and the sheet strength is also lowered.

Since the weight ratio of EO contained in AO of comparative example 2 is out of the range of the present invention, sufficient adhesive strength and static friction coefficient are not obtained.

Since comparative examples 3 and 4 do not contain a lamination aid, the adhesive strength and the static friction coefficient are insufficient.