JP3378133B2 - Ceramic molding binder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramics forming binder, and more particularly to an aqueous ceramic green sheet forming binder.

2. Description of the Related Art For forming a ceramic sheet, a binder such as polyvinyl butyral resin is dissolved in an organic solvent such as alcohol, ketone or trichlorethylene, and fine powder of ceramic raw material is mixed with the binder, and the slurry is mixed with a ball mill or the like. There is a method in which (slurry) is prepared, and after defoaming, it is applied to a film such as polyester to a certain thickness and dried by heating. Recently, it has been proposed to use water instead of the organic solvent due to ignition of vapors of the organic solvent, problems in the working environment due to the organic solvent, etc., and water-soluble polyvinyl alcohol, water-soluble acrylic acid ester, water-soluble polyurethane, etc. Binders and binders using an aqueous emulsion (JP-A-60-180955) have been developed. Further, Japanese Patent Publication No. Sho 49-16086 discloses a method in which a solvent such as trichloroethylene or acetone is applied to a ceramic green sheet and the binder is dissolved and laminated, which is obtained by using such an aqueous binder. Further, in the ceramic green sheet, since the aqueous binder does not dissolve in these organic solvents, it is difficult to manufacture a laminated body of the ceramic green sheets.
At this time, if the content of the hydrophobic monomer is increased in order to improve the stacking property, the binder does not dissolve in the alkaline water, which makes it difficult to reslurry the green sheet after processing. In addition, with the high integration of electronic substrates, ceramic green sheets that are thin but have sufficient strength are required, and the effect of residual carbon after degreasing of green sheets on the circuit becomes large. Degreasing properties have been demanded.

[0002]

DISCLOSURE OF THE INVENTION The present invention provides a ceramic binder for producing a ceramic green sheet having both excellent laminating property and solubility in alkaline water, and further excellent strength and degreasing property. With the goal.

The present invention provides a certain amount of methacrylic acid, a specific unsaturated monomer having a hydrophilic group other than methacrylic acid, a (meth) acrylic acid ester, and a (meth) acrylic having a polyoxyethylene structure. What was made based on the finding that the above problems can be solved by using a copolymer or a salt thereof obtained from a composition in which an acid ester monomer is combined and the amount of the methacrylic monomer is a certain amount or more. Is. That is, the present invention provides (A) methacrylic acid 0.5 to 4.4 wt% (B) unsaturated carboxylic acid hydroxyalkyl ester and / or unsaturated carboxylic acid other than methacrylic acid 5.0.
~ 20.0% by weight (C) Alkyl group having 1 to 8 carbon atoms (meth) acrylic acid alkyl ester 25.6 to 84.5% by weight (D) Monomer represented by the following general formula (1) 1.0
~ 5.0% by weight

[0003]

[Chemical 3]

(Wherein R ₁ is hydrogen or a methyl group, R ₂ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, and n is 2 or more), and the content of the methacrylic monomer is Emulsion polymerization of 80% by weight or more of monomer composition in water
Provided is a binder for molding a ceramics laminate, which comprises the copolymer obtained by the above or a salt thereof.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As a hydroxyalkyl ester of an unsaturated carboxylic acid of a monomer (B) constituting a monomer mixture which is a raw material of a binder composition of the present invention,
Esters of unsaturated carboxylic acids having 3 to 4 carbon atoms such as acrylic acid and methacrylic acid and hydroxyaliphatic alcohols having 2 to 4 carbon atoms can be mentioned. Of these, especially
An ester of methacrylic acid such as 2-hydroxyethyl methacrylate and a hydroxy alcohol having 2 to 4 carbon atoms is preferable. Further, examples of unsaturated carboxylic acids other than methacrylic acid include unsaturated carboxylic acids having 3 to 4 carbon atoms such as monocarboxylic acids such as acrylic acid and dicarboxylic acids such as maleic acid. Examples of the (meth) acrylic acid alkyl ester in which the alkyl group of the monomer (C) constituting the monomer mixture that is the raw material of the binder composition of the present invention has 1 to 8 carbon atoms include methyl (meth) acrylate, Examples thereof include ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Particularly, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and methacrylate 2 -Ethylhexyl, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate are preferred.

As the monomer (D) constituting the monomer mixture which is the raw material of the binder composition of the present invention, n in the formula (1) is preferably 2 to 40, more preferably 4
~ 25. Specifically, phenoxy polyethylene glycol (n = 2 or 6) mono (meth) acrylate, methoxy polyethylene glycol (n = 2 to 4, 9 or 2)
3) (Meth) acrylate and the like. Of these, methacrylic acid type is preferable. The ratio of each monomer component constituting the mixture of the monomers (A) to (D) is 0.5 in the total amount of methacrylic acid which is the monomer (A).
To 4.4% by weight (hereinafter abbreviated as%), preferably 2.0
˜4.4%, the monomer (B) is 5.0 to 2.0%, preferably 7.5 to 15%, and the monomer (D) is 10.0%.
˜50.0%, preferably 20-40%. Monomer (C) is 25.6 to 84.5%, preferably 40.6 to 71.5
%. When the amount of the monomer (A) is less than 0.5%, the solubility of the green sheet in alkaline water is poor, and when it exceeds 4.5%, the green sheet becomes too hard to be suitable for practical use. When the amount of the monomer (B) is less than 5.0%, the dispersibility of the ceramic powder is deteriorated and the viscosity of the ceramic slurry is increased to lower the workability, and when it exceeds 20%, the solvent solubility of the binder is decreased, The stackability of the green sheet deteriorates. When the amount of the monomer (C) is out of the range of 25.6% to 84.5%, a green sheet having good strength cannot be obtained. When the amount of the monomer (D) is less than 10%, the dispersibility of the ceramic powder is deteriorated, the ceramic slurry is thickened, and the formability is lowered. On the other hand, if it exceeds 50%, the solubility of the green sheet in a solvent is deteriorated, so that the stackability is deteriorated and the strength is decreased, which is not suitable for practical use. Monomers (A) to (D)
80% of the methacrylic monomer in the composition of
It is necessary to set the above, and if it is less than 80%, the thermal decomposability of the binder is insufficient and the degreasing property of the green sheet will not reach the level required for a laminated substrate. In addition, it is preferably 85% or more, and is preferably 85 to 100%.

In the present invention, only the above components (A) to (D) can be copolymerized, but other copolymerizable monomers can be added in addition to the above monomers.
Examples of the copolymerizable monomer include (meth) acrylic acid alkyl ester having an alkyl group having 9 or more carbon atoms, (meth) acrylic acid alkoxyalkyl ester, and the like. As such (meth) acrylic acid alkyl ester, lauryl acrylate and stearyl acrylate are preferable. Further, (meth) acrylic acid alkoxyalkyl ester can also be used, and as such, methoxyethyl methacrylate and methoxyethyl acrylate are preferable. In addition to the above, acrylonitrile, acrylamide, styrene, vinyl acetate, vinyl chloride, ethylene and the like can be copolymerized and used.
However, these must be blended so that the proportion of the methacrylic monomer in the monomer composition is 80% by weight or more, and usually 20% or less of the total amount, preferably 1%.
Used at a rate of ~ 5%.

The binder of the present invention is preferably prepared by polymerizing the above-mentioned monomer mixture, preferably by a method such as emulsion polymerization or phase inversion polymerization to obtain a product as an emulsion. The weight average molecular weight is preferably 10,000 to 2,000,000, and more preferably 30,000 to 1,500,000. These can be easily measured by gel permeation chromatography using a standard substance. The production of the binder of the present invention by emulsion polymerization can be easily performed by a usual method. As the emulsifier, those generally used such as anionic surfactants, nonionic surfactants, and polyvinyl alcohol can be used, but those represented by the following general formula (2) are particularly preferable. You may use these individually or in mixture of 2 or more types.

[Chemical 4]     R¹-X- (AO)_n-R²                (2) (In the formula, R¹Is a hydrogen atom, C₁~_{twenty four}The alkyl group of
Kenyl group, alkylphenyl group, or polystyrylphene
Nyl group, R²Is a hydrogen atom or -BNH_Four(B is an anion
A functional group), n is an integer of 5 or more,-(AO)_n-Is po
50% or more of reoxyethylene group or oxyethylene group
Poly (oxyethylene / oxypropylene) group
Or a poly (oxyethylene / oxybutylene) group
X is an oxygen atom, N [(AO)_n-R²] Or -C
Represents (O) -O-. However, R¹And R ²At the same time hydrogen
Never be a child. ]. Incidentally, as -B, -SO₃
And -COO are preferred.

Polymerization initiators used during polymerization include peroxide-based initiators such as peracetic acid, potassium persulfate and ammonium persulfate, and azo-based initiators such as 2,2'-azobispropaneamidine hydrochloride. Other resox type initiators can be mentioned. You may use these individually or in mixture of 2 or more types. Further, at the time of polymerization, it is preferable to add a chain transfer agent for controlling the molecular weight. As the chain transfer agent, a general-purpose one such as n-dodecyl mercaptan can be used. The obtained emulsion can be used as it is or as a binder composition by adding additives such as a plasticizer. Besides emulsion polymerization, it can be synthesized and used by phase inversion polymerization or solution polymerization using a non-aqueous solvent.

The copolymer thus obtained can be used after being further neutralized with ammonia, an organic amine or the like, and a slurry having good mixing stability can be obtained by the neutralization. Examples of usable organic amines include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, and N-.
Examples thereof include alkanolamines such as methylethanolamine and dimethylaminopropanol, alkylamines such as trimethylamine and triethylamine, and morpholine. The above-mentioned copolymer used as the binder of the present invention or the copolymer after neutralization has a glass transition temperature (T
g) is preferably in the range of -20 ° C to + 50 ° C. Binders having such a glass transition temperature are
This can be achieved by appropriately adjusting factors that affect Tg, such as the combination of monomers used in the polymerization reaction and the proportion of each monomer, or the desired Tg can be adjusted by using a plasticizer. The ceramic green sheet using the binder of the present invention can be manufactured as follows.

That is, first, the solid content in the binder composition is 0.3 to 25.0 parts by weight, preferably 1.0 to 100 parts by weight of the ceramic fine powder.
A binder is added so as to be 20.0 parts by weight, and if necessary, molding aids such as water, a plasticizer, a dispersant and an antifoaming agent are appropriately added. As fine ceramic powder, alumina, zirconia, magnesia, beryllia, titania, barium titanate, lead zirconate titanate, PLZT, P
Oxide-based or composite oxide-based ceramics fine powder of ZT, ferrite, manganese, silicon carbide, silicon nitride,
Non-oxide ceramic fine powder such as sialon may be used. Examples of the plasticizer include polyhydric alcohols such as polyethylene glycol and glycerin, and phthalic acid esters such as dibutyl phthalate. Examples of the dispersant include polyacrylic acid ammonium salt, acrylic acid-acrylic acid ester copolymer ammonium salt, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and the like. Then, the obtained mixed solution is sufficiently mixed with a ball mill or the like to form an aqueous slurry composition, which is uniformly applied onto a carry film such as polyester using a doctor blade or a reverse coater, and dried by heating. Manufactured. The ceramic green sheet laminate is manufactured by stacking sheets having an organic solvent applied on the surface, press-bonding the sheets, and further sintering and the like.

[0012]

According to the present invention, when a ceramic green sheet is molded, it functions as a water-based binder, and when a laminated body is manufactured after molding, it is dissolved in an organic solvent to enable the manufacture of a laminated body, and A binder for ceramics having excellent degreasing property is provided. The ceramic green sheet prepared by using this binder also has high alkaline water solubility. Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0013]

Example 1 A reactor equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen introducing tube was charged with ion-exchanged water (150.0 parts by weight), polyoxyethylene (16 mol) distyryl phenyl ether sulfate. 5.0 parts by weight of ammonium was charged and nitrogen gas was flowed to remove dissolved oxygen. The reactor was heated to 73 ° C., 4.0 parts by weight of methacrylic acid, 10 parts by weight of 2-hydroxyethyl methacrylate, 31.0 parts by weight of methyl methacrylate, 15.0 parts by weight of butyl methacrylate, methoxypolyethylene glycol. 5% of a mixed solution of 4.0 parts by weight of (# 400) methacrylate and 0.2 parts by weight of n-dodecyl mercaptan was added, and 0.25 parts by weight of azobiscyanovaleric acid was added to initiate polymerization. Keep the reactor at 73 ° C,
The remaining 95% of the above solution was added dropwise over 3 hours with stirring. After completion of the dropping, 0.05 part by weight of azobiscyanovaleric acid was added, and the reactor was kept at 80 ° C. and stirred for 1 hour to obtain a copolymer emulsion (binder A).

Example 2 Ammonia was added to the binder A obtained in Example 1 for neutralization, and ion-exchanged water was added to obtain an aqueous solution (binder B) having a polymer content of 30%. However, it was prepared using alcohol as a viscosity reducing agent. Example 3 Binders C to I were obtained in the same manner as in Example 2 except that the composition of the charged monomers was changed. Comparative Example 1 Binders J * to O * were obtained in the same manner as in Example 2 except that the composition of the charged monomers was changed. Binder A to O
The types and proportions of the monomers used for the preparation of are summarized in Table 1.

[0015]

[Table 1] Table-1 Methaku Monomer Monomer (C) Monomer (D) Phosphoric acid (B) No. (Parts by weight) (Parts by weight) (Parts by weight) (Parts by weight) A (4.0) HEMA (10.0) MMA (31.0) BMA (15.0) M90G (40.0) B (4.0) HEMA (10.0) MMA (31.0) BMA (15.0) M90G (40.0) C (4.4) AA (10.0) MMA (10.6) BMA (45.0) M90G (30.0) D (0.5) HEMA (10.0 ) MMA (10.6) BMA (45.0) M90G (30.0) E (4.0) HEMA (5.0) MMA (16.0) BMA (35.0) M90G (40.0) F (4.0) HEMA (15.0) MMA (21.0) BMA (30.0) M90G (30.0) G (4.0) HEMA (12.5) MMA (23.5) BMA (45.0) M90G (15.0) H (4.0) HEMA (10.0) MMA (11.0) BMA (45.0) M40G (30.0) I (4.0) HEMA (5.0 ) MMA (35.0) BMA (6.0) M90G (50.0) J * (5.5) AA (10.0) MMA (74.5) M90G (10.0) K * (0.3) HEMA (5.0) MMA (60.0) BMA (20.0) M90G (14.7) ) L * (0.5) HEMA (4.0) MMA (60.0) BMA (25.0) M90G (10.0) M * (4.0) AA (30.0) MMA (20.0) EMA (6.0) M90G (40.0) N * (0.5) HEMA (10.0) MMA (70.0) BMA (14.5) M90G (5.0) O * (4.0) AA (25.0) MMA (10.0) BMA (1.0) M90G (60.0) AA: acrylic acid, HEMA: 2-hydroxyethyl methacrylate, MMA: methacrylic acid Methyl, EMA: ethyl methacrylate, BMA: butyl methacrylate, M90G: methoxypolyethylene glycol (# 400) methacrylate, M40G: methoxypolyethylene glycol (# 180) methacrylate.

Example 4 Binder P was obtained in the same manner as in Example 2, except that polyoxyethylene (13 mol) nonylphenyl ether was used instead of polyoxyethylene (16 mol) distyryl phenyl ether sulfate ammonium. It was Example 5 Alumina (AL-manufactured by Showa Denko KK
45) 100 parts by weight, dispersant (A611 manufactured by Toagosei Co., Ltd.)
4) Mix 0.5 parts by weight and Binder A in a ball mill so that the solid content becomes 10 parts by weight, distill off water under reduced pressure to adjust the water content, and obtain a uniform aqueous slurry with a viscosity of 5000 cP. A composition (invention product 1) was obtained. This has a thickness of 0.7
After coating the polyester film with a doctor blade so that the thickness becomes mm, the temperature is 45 ° C for 1 hour, and then 80 ° C.
After drying for 1 hour, a ceramic green sheet having a thickness after drying of about 0.5 mm was obtained. Ceramic green sheets were obtained in the same manner except that the binder A was changed to B to I (invention products 2 to 9). About the obtained ceramic green sheet, moldability, organic solvent solubility, degreasing property,
The stackability and the disconnection of the wiring board were tested. The test methods and evaluation criteria are as follows.

The moldability: a ceramic green sheet form of a sheet when peeled from the polyester film to observe whether is good. A sheet without cracks was obtained ... Evaluation ○ Cracks were generated ... Evaluation × Alkaline water solubility : A small piece of ceramic green sheet was shaken in 1% ammonia water, and the solution was dissolved by dissolving the binder. It was observed whether it became cloudy. Turbidity ・ ・ ・ ・ Evaluation ○ No turbidity ・ ・ Evaluation × Organic solvent solubility : A small piece of the ceramic green sheet was shaken in toluene, and it was observed whether or not the liquid became turbid due to the dissolution of the binder. . Turbidity ・ ・ ・ ・ Evaluation ○ No turbidity ・ ・ Evaluation ×

Degreasing property : 5 ceramic green sheets
It was heated to 00 ° C. and it was observed whether or not it was completely decomposed. Completely decomposed with no residue .... Evaluation ○ Residue was found .... Evaluation x Lamination : 50 mm x 50 mm ceramic green sheet surface was coated with toluene, and another sheet was overlaid and pressure-bonded. It was fired and observed whether or not the two sheets were peeled off. It was integrated and was not peeled off ... Evaluation O peeled off ... Evaluation x Green sheet strength / elongation : The prepared green sheet was subjected to a tensile strength test (JIS K7113). Strength: ○: 20 kg / cm ² or more, △: 5 to 20 kg / cm ² , ×:
Elongation less than 5 kg / cm ² ◯: 30% or more, Δ: 10 to 30%, ×: 10%
Less than

Example 6 The ceramic fine powder was changed to lead zirconate titanate (HiZirco L manufactured by Hayashi Chemical Co., Ltd.), and the amount of the dispersant was changed to 1.0 part by weight.
Further, a ceramic green sheet was prepared (invention product 10) in the same manner as in Example 5 except that the binder A was added so that the solid content was 15 parts by weight, and the same experiment was conducted. Comparative Example 2 A ceramic green sheet was prepared in the same manner as in Example 5 except that the binder A was changed to J to O, and the same test was performed (Comparative products 11 * to 16 *). Comparative Example 3 A ceramic green sheet was prepared in the same manner as in Example 6 except that the binder A was changed to J (Comparative Product 17).
*), The same test was conducted. Examples 4 to 6 and Comparative Example 2
The compositions of the aqueous sludge compositions prepared in Examples 1 to 3 are summarized in Table 2, and the test results for each ceramic green sheet are summarized in Table 3.

[0020]

[Table 2] Table-2 ─────────────────────────────────── Binder used Fine ceramic powder Dispersant No. (Parts by weight of solid content) (Parts by weight) (Parts by weight) 1 A (10) Alumina (100) 0.5 2 B (10) Alumina (100) 0.5 3 C (10) Alumina (100) 0. 5 4 D (10) Alumina (100) 0.5 5 E (10) Alumina (100) 0.5 6 F (10) Alumina (100) 0.5 7 G (10) Alumina (100) 0.5 8 H (10) Alumina (100) 0.5 9 I (10) Alumina (100) 0.5 10 A (15) Lead zirconate titanate (100) 1.0 11 * J (10) Alumina (100) 0 .5 12 * K (10) Alumina (100) 0.5 13 * L (10) Alumina (100) 0.5 14 * M (10) Alumina (100) 0.5 15 * N (10) Alumina (100) 0.5 16 * O (10) Alumina (100) 0.5 17 * J (15) Lead zirconate titanate (100) 1.0

[0021]

[Table 3] Table-3 ─────────────────────────────────── Moldability Alkaline water Organic solvent Degreasing Stackability No. Solubility Solubility 1 ○ ○ ○ ○ ○ 2 ○ ○ ○ ○ ○ 3 ○ ○ ○ ○ ○ 4 ○ ○ ○ ○ ○ 5 ○ ○ ○ ○ ○ 6 ○ ○ ○ ○ ○ 7 ○ ○ ○ ○ ○ ○ 8 ○ ○ ○ ○ ○ 9 ○ ○ ○ ○ ○ 10 ○ ○ ○ ○ ○ 11 * ○ ○ ○ ○ ○ 12 * ○ ~ × × ○ ○ ○ 13 * × ○ ○ ○ 14 * ○ ○ × × × 15 * × ○ ~ × ○ ○ ○ 16 * ○ ○ × ○ × 17 * ○ ○ ○ ○ ○

[0022]

[Table 4] Table-3 (continued) ────────────────────────── Green Sheet Green Sheet No. Strength Elongation 1 ○ ○ 2 ○ ○ 3 ○ ○ 4 ○ ○ 5 ○ ○ 6 ○ ○ 7 ○ ○ 8 ○ ○ 9 ○ ○ 10 ○ ○ 11 * ○ × 12 * ○ ○ 13 * ○ △ 14 * ○ △ 15 * ○ △ 16 * ○ × 17 * ◯ × As shown in Tables 2 and 3 above, the binders (A to I) of the present invention have good moldability and are green sheets having physical properties suitable for a laminated substrate (invention products 1 to 10). ) Is obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C04B 35/622

Claims (2)

(57) [Claims] 1. (A) Methacrylic acid 0.5-4.4% by weight (B) Hydroxyalkyl ester of unsaturated carboxylic acid and / or unsaturated carboxylic acid other than methacrylic acid 5.0
~ 20.0% by weight (C) Alkyl group having 1 to 8 carbon atoms (meth) acrylic acid alkyl ester 25.6 to 84.5% by weight (D) Monomer represented by the following general formula (1) 1.0
~ 5.0% by weight [Chemical formula 1] (In the formula, R ₁ is hydrogen or a methyl group, and R ₂ has 1 to 4 carbon atoms.
Is an alkyl group or a phenyl group, and n is 2 or more. And a methacrylic monomer content of 80% by weight or more is emulsion polymerized in water.
A binder for molding a ceramics laminate, comprising the copolymer obtained by the above or a salt thereof. 2. The ceramic product according to claim 1, which is obtained by emulsion-polymerizing the monomer composition in an aqueous system containing a surfactant represented by the following general formula (2).
Binder for forming layered body . ## STR2 ## _{^{R 1 -X- (AO) n -R}} 2 (2) ( wherein, R ¹ represents a hydrogen atom, an alkyl group of C ₁ ~ _24, an alkenyl group, an alkylphenyl group, or polystyryl phenyl group, R ² represents a hydrogen atom or —BNH ₄ (B is an anionic group), n is an integer of 5 or more, and — (AO) _n — is a polyoxyethylene group or a poly (oxy) having an oxyethylene group of 50% or more. It represents ethylene / oxypropylene) group or poly (oxyethylene / oxybutylene) group, X is an oxygen atom, n [(AO) _n -R ^2] or -C
Represents (O) -O-. However, R ¹ and R ² are not hydrogen atoms at the same time. ]