Ceramic slurry composition and manufacturing method therefor

• US 6,790,907 B2
• Filed: 06/28/2001
• Issued: 09/14/2004
• Est. Priority Date: 06/29/2000
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Tanaka, Satoru, Takata, Masachika, Miyazaki, Makoto
• Primary Examiner(s): Yoon, Tae H.
• Application Number:
  US09/894,036
• Publication Number:
  US 20020019462A1
• Time in Patent Office: 1,174 Days
• Field of Search: 524/413, 524/401, 524/833
• US Class Current: 524/833
• CPC Class Codes: C04B 35/63424 Polyacrylates; Polymethacrylates

Abstract

A ceramic slurry composition is obtained by mixing a ceramic raw material powder, a water-soluble acrylic binder and water, wherein the water-soluble acrylic binder has a weight average molecular weight of from about 10,000 to 500,000, and has an inertial square radius of not more than about 100 nm in water. The ceramic slurry composition can have a low viscosity as well as good dispersion characteristics for the ceramic raw material powder, good flow characteristics and good form characteristics, and can provide ceramic green sheets having a high density and excellent drying characteristics, by decreasing the solution viscosity, without decreasing the molecular weight of the water-soluble acrylic binder containing a hydrophobic component.

Claims

1. A ceramic slurry composition comprising:

a ceramic raw material powder;

a water-soluble acrylic binder; and

an aqueous solvent,

wherein said water-soluble acrylic binder has a weight average molecular weight of from about 10,000 to 500,000, and has an inertial square radius of not more than about 100 nm in the aqueous solvent.

2. A ceramic slurry composition according to claim 1, wherein said water-soluble acrylic binder has a number of aggregated molecules denoted by X and a second virial coefficient denoted by Y in the range satisfying the following relationship:

3. The ceramic slurry composition according to claim 2, wherein said water-soluble acrylic binder is a copolymer containing from about 93 to 99% by weight of alkyl (meth)acrylate which does not dissolve in water as a homopolymer at ambient temperatures and under atmospheric pressure, and from about 1.0 to 7.0% by weight of a carboxyl group-containing unsaturated monomer.

4. The ceramic slurry composition according to claim 3, wherein the alkyl groups of said alkyl (meth)acrylate have from 1 to 8 carbon atoms.

5. The ceramic slurry composition according to claim 4, wherein said alkyl acrylate is at least one member selected from the group consisting of methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, cyclohexyl acrylate and 2-ethylhexyl acrylate.

6. The ceramic slurry composition according to claim 4, wherein said alkyl methacrylate is at least one selected from the group consisting of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate and 2-ethylhexyl methacrylate.

7. The ceramic slurry composition according to claim 3, wherein said carboxyl group-containing unsaturated monomer is an unsaturated carboxylic acid or partial ester thereof.

8. The ceramic slurry composition according to claim 7, wherein said carboxyl group-containing unsaturated monomer is (meth)acrylic acid or a half ester thereof.

9. The ceramic slurry composition according to claim 1, wherein said water-soluble acrylic binder is a neutralized salt.

10. The ceramic slurry composition according to claim 1, wherein said water-soluble acrylic binder is a copolymer containing from about 93 to 99% by weight of alkyl (meth)acrylate which does not dissolve in water as a homopolymer at ambient temperatures and under atmospheric pressure, and from about 1.0 to 7.0% by weight of a carboxyl group-containing unsaturated monomer.

11. The ceramic slurry composition according to claim 10, wherein the alkyl groups of said alkyl (meth)acrylate have from 1 to 8 carbon atoms.

12. The ceramic slurry composition according to claim 11, wherein said carboxyl group-containing unsaturated monomer is an unsaturated carboxylic acid or partial ester thereof.

13. The ceramic slurry composition according to claim 12, wherein said carboxyl group-containing unsaturated monomer is (meth)acrylic acid or a half ester thereof.

14. The ceramic slurry composition according to claim 10 in the form of a ceramic green sheet.

15. The ceramic slurry composition according to claim 4 in the form of a ceramic green sheet.

16. The ceramic slurry composition according to claim 3 in the form of a ceramic green sheet.

17. The ceramic slurry composition according to claim 2 in the form of a ceramic green sheet.

18. The ceramic slurry composition according to claim 1 in the form of a ceramic green sheet.