Polymer film, and phase difference film, polarizing plate and liquid crystal display device using the same

Patent metadata

Field	Value
Publication number	US-9512295-B2
Application number	US-34268608-A
Country	US
Kind code	B2
Filing date	Dec 23, 2008
Priority date	Dec 26, 2007
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

There is provided a polymer film including a polymer; and a high molecular weight plasticizer that has a number average molecular weight of 700 to 10,000 and has a repeating unit derived from a dicarboxylic acid and a diol, wherein the dicarboxylic acid for forming the high molecular weight plasticizer includes at least one aliphatic dicarboxylic acid having 2 to 20 carbon atoms and at least one aromatic dicarboxylic acid having 8 to 20 carbon atoms, and the diol includes at least one diol selected from the group consisting of an aliphatic diol having 2 to 12 carbon atoms, an alkyl ether diol having 4 to 20 carbon atoms and an aromatic ring-containing diol having 6 to 20 carbon atoms.

First claim

What is claimed is:

1. A polymer film comprising:
a cellulose acylate,
wherein
a degree of substitution of acetyl groups substituted at the hydroxyl groups of the cellulose of the cellulose acylate is taken as SA, and a degree of substitution of acyl groups with 3 or more carbon atoms substituted at the hydroxyl groups of the cellulose of the cellulose acylate is taken as SB,
wherein
2.40≦ SA+SB≦ 3.00; and

a high molecular weight plasticizer that has a number average molecular weight of 700 to 10,000 and has a repeating unit derived from a dicarboxylic acid and a diol,
wherein
the dicarboxylic acid for forming the high molecular weight plasticizer comprises at least one aliphatic dicarboxylic acid having 2 to 20 carbon atoms and at least one aromatic dicarboxylic acid having 8 to 20 carbon atoms, and
the diol comprises at least one diol selected from the group consisting of an aliphatic diol having 2 to 12 carbon atoms, an alkyl ether diol having 4 to 20 carbon atoms and an aromatic ring-containing diol having 6 to 20 carbon atoms,
wherein
both ends of the high molecular weight plasticizer are at least one selected from the group consisting of an aliphatic group having 1 to 22 carbon atoms, an aromatic ring-containing group having 6 to 20 carbon atoms, an aliphatic carbonyl group having 1 to 22 carbon atoms, and an aromatic carbonyl group having 6 to 20 carbon atoms,
wherein
the high molecular weight plasticizer is contained in an amount of 2 to 30% by mass based on an amount of the polymer, and
wherein
the retardation values meet the following relational expressions:
| Re (10%)− Re (85%)|<8 and

| Rth (10%)− Rth (85%)|<35,

wherein
the retardation values Re (H %) in the in-plane direction and Rth (H %) in the thickness direction at the time when the relative humidity is H (unit: %) are obtained by conditioning the film at 25° C. and a humidity of H % for 24 hours, and then measuring and calculating the retardation values at the time when the wavelength at a relative humidity of H % and 25° C., is 590 nm.

2. The polymer film according to claim 1 , wherein
the aliphatic dicarboxylic acid is a malonic acid, a succinic acid, a glutaric acid, an adipic acid, a sebacic acid, an azelaic acid, a cyclohexanedicarboxylic acid, a maleic acid or a fumaric acid, and
the aromatic dicarboxylic acid is a phthalic acid, an isophthalic acid, a terephthalic acid, a 1,5-naphthalenedicarboxylic acid, a 1,4-naphthalenedicarboxylic acid, a 1,8-naphthalene-dicarboxylic acid, a 2,8-naphthalenedicarboxylic acid or a 2,6-naphthalenedicarboxylic acid.

3. The polymer film according to claim 1 , wherein
the aliphatic diol is an ethanediol, a 1,2-propanediol, a 1,3-propanediol, a 1,2-butanediol, a 1,3-butanediol, a 2-methyl-1,3-propanediol, a 1,4-butanediol, a 1,5-pentanediol, a 2,2-dimethyl-1,3-propanediol (neopentyl glycol), a 1,4-hexanediol, a 1,4-cyclohexanediol or a 1,4-cyclohexanedimethanol, and
the aromatic ring-containing diol is a bisphenol A, a 1,4-dihydroxyphenol or a benzene-1,4-dimethanol.

4. The polymer film according to claim 1 , wherein
the high molecular weight plasticizer contains a component having a number average molecular weigh of 500 or less in an amount of 10% by mass or less.

5. The polymer film according to claim 1 , wherein
the high molecular weight plasticizer has a rate of mass decrease of at least either 5% or less when the high molecular weight plasticizer is heated at 200° C. for 10 minutes or 1% or less when the high molecular weight plasticizer is heated at 140° C. for 60 minutes.

6. The polymer film according to claim 1 , wherein
the polymer film is a cellulose acylate film prepared by a solution film forming method or a melt film forming method, and having a film thickness of from 20 to 200 gm.

7. The polymer film according to claim 1 , wherein
the polymer film is stretched 60 to 400% during or after film formation.

8. The polymer film according to claim 1 , wherein
the polymer film has an in-plane retardation (Re) of 0 to 300 nm, and a retardation in a thickness direction (Rth) of −200 to +300 nm.

9. A polarizing plate comprising:
at least one polymer film according to claim 1 .

10. A liquid crystal display device comprising:
at least one polymer film according to claim 1 .

11. The polymer film according to claim 1 , wherein the both ends of the high molecular weight plasticizer are an aliphatic group having 1 to 22 carbon atoms or an aromatic ring-containing group having 6 to 20 carbon atoms, and
the aliphatic group and the aromatic ring-containing group of the both ends are blocked via an ester bond.

Assignees

• Mukunoki Yasuo
• Sakurazawa Mamoru
• Fujifilm Corp

Inventors

• Mukunoki Yasuo
• Sakurazawa Mamoru

Classifications

• C08K5/11 Primary

  of acyclic polycarboxylic acids · CPC title

• G02B27/0006

  with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation (G02B1/18 takes precedence; cleaning in general B08B) · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08K5/12

  of cyclic polycarboxylic acids · CPC title

• G02B5/3033

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title