Polyvinyl acetal resin

Patent metadata

Field	Value
Publication number	US-12486347-B2
Application number	US-202017762849-A
Country	US
Kind code	B2
Filing date	Sep 25, 2020
Priority date	Sep 27, 2019
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

The present invention provides a polyvinyl acetal resin which leaves less fine undissolved matter when dissolved in an organic solvent and thus can improve productivity particularly when used as a binder for a ceramic green sheet, and which can also provide a ceramic green sheet having excellent toughness and enables production of a highly reliable multilayer ceramic capacitor. Provided is a polyvinyl acetal resin having: a wavenumber A (cm −1 ) of a peak within a range of 3,100 to 3,700 cm −1 in an IR absorption spectrum measured using an infrared spectrophotometer; and a hydroxy group content (mol %), the wavenumber A of the peak and the hydroxy group content satisfying relations of the following formulas (1) and (2):

[(3,470− A )/Hydroxy group content]≤5.5  (1)

(3,470− A )≤185  (2)

wherein A is a wavenumber which is lower than 3,470 cm −1 and at which a transmittance a (%) satisfying [100−(100−X)/2] is exhibited, where X (%) is a minimum transmittance of the peak within the wavenumber range of 3,100 to 3,700 cm −1 .

First claim

The invention claimed is:

1 . A polyvinyl acetal resin having:
a wavenumber A in cm −1 of a peak within a range of 3,100 to 3,700 cm −1 in an IR absorption spectrum measured using an infrared spectrophotometer; and a hydroxy group content in mol %, wherein the wavenumber A of the peak and the hydroxy group content satisfy relations of the following formulas (1) and (2):
[(3,470 −A )/Hydroxy group content]≤5.5  (1)

(3,470− A )≤185  (2)

wherein A is a wavenumber which is lower than 3,470 cm −1 and at which a transmittance a in % satisfies [100−(100−X)/2],
wherein X in % is a minimum transmittance of the peak within the wavenumber range of 3,100 to 3,700 cm −1 , and
wherein a solution of the polyvinyl acetal resin at a concentration of 0.2% by weight in a 1:1 weight ratio mixture solution of ethanol and toluene has a percentage of particles having a diameter of 0.5 to 1.0 μm of 4.42×10 −8 % by volume or lower relative to 100% by volume of the resin solution when a particle size distribution of the resin solution is determined using a particle counter.

2 . The polyvinyl acetal resin according to claim 1 ,
wherein the hydroxy group content is 18 to 40 mol %.

3 . The polyvinyl acetal resin according to claim 1 ,
wherein the polyvinyl acetal resin has a wavenumber B in cm −1 of the peak within the wavenumber range of 3,100 to 3,700 cm −1 in the IR absorption spectrum measured using the infrared spectrophotometer, and wherein the wavenumber A of the peak and the wavenumber B of the peak satisfy a relation of the following formula (3):
(3,470− A )/( B− 3,470)≤3.0  (3)

wherein B is a wavenumber which is higher than 3,470 cm −1 and at which the transmittance a in % satisfies [100−(100−X)/2],
wherein X in % is the minimum transmittance of the peak within the wavenumber range of 3,100 to 3,700 cm −1 .

4 . The polyvinyl acetal resin according to claim 1 ,
wherein the polyvinyl acetal resin is for a ceramic green sheet.

5 . The polyvinyl acetal resin according to claim 2 ,
wherein the polyvinyl acetal resin has a wavenumber B in cm −1 of the peak within the wavenumber range of 3,100 to 3,700 cm −1 in the IR absorption spectrum measured using the infrared spectrophotometer, and wherein the wavenumber A of the peak and the wavenumber B of the peak satisfy a relation of the following formula (3):
(3,470− A )/( B− 3,470)≤3.0  (3)

wherein B is a wavenumber which is higher than 3,470 cm −1 and at which the transmittance a in % satisfies [100−(100−X)/2],
wherein X in % is the minimum transmittance of the peak within the wavenumber range of 3,100 to 3,700 cm −1 .

6 . The polyvinyl acetal resin according to claim 2 ,
wherein the polyvinyl acetal resin is for a ceramic green sheet.

7 . The polyvinyl acetal resin according to claim 3 ,
wherein the polyvinyl acetal resin is for a ceramic green sheet.

8 . The polyvinyl acetal resin according to claim 5 ,
wherein the polyvinyl acetal resin is for a ceramic green sheet.

Assignees

• Sekisui Chemical Co Ltd

Inventors

• Nakamura Kazuto
• Arai Yoshito
• Higuchi Isao

Classifications

• C08F16/38 Primary

  by an acetal or ketal radical · CPC title

• H01G4/12

  Ceramic dielectrics {(H01G4/085 takes precedence)} · CPC title

• C08F116/38

  by a acetal or ketal radical · CPC title

• C04B2235/3236

  Alkaline earth titanates · CPC title

• C04B35/6342 Primary

  Polyvinylacetals, e.g. polyvinylbutyral [PVB] · CPC title