Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
137 words
A biaxially oriented polyester film formed from an aromatic polyester composition containing: (A) 100 parts by weight of an aromatic polyester, and (B) 0.005 to 5 parts by weight of calcium carbonate particles defined by: (a) a length/width ratio (2a/2b) in the range of from 1.25 to 3, (b) an average particle diameter ( D ¯ ), as a diameter of a circle converted from an area, in the range of from 0.05 to 5 µm, and (c) an ellipse coefficient, represented by the following equation (1), in the range of from 0.7 to 1.2, R = S₁ S₂ wherein R is an ellipse coefficient, S₁ is an observed area of a projected plane of a particle, and S₂ is an elliptical area determined on the basis of observed values of the length (2a) and width (2b).
Claim 2
Dependent Claim
21 words
The biaxially oriented polyester film of Claim 1 wherein the length/width ratio is in the range of from 1.3 to 2.5.
Claim 3
Dependent Claim
33 words
The biaxially oriented polyester film of Claim 1, wherein the average article diameter as a diameter of a circle converted from an area is in the range of from 0.1 to 2 µm.
Claim 4
Dependent Claim
25 words
The biaxially oriented polyester film of Claim 1, wherein the calcium carbonate particles have an ellipse coefficient in the range of from 0.75 to 1.05
Claim 5
Dependent Claim
74 words
The biaxially oriented polyester film of Claim 1, wherein the calcium carbonate particles has a relative standard deviation, represented by the following equation, of not more than 0.5, in which D i is a particle diameter, a diameter of a circle converted from an area, of each particle, D ¯ is an average particle diameter as a diameter of a circle converted from an area, and n is a number (100 pieces) of particles.
Claim 6
Dependent Claim
23 words
The biaxially oriented polyester film of Claim 5, which contains calcium carbonate particles having a relative standard deviation of not more than 0.3.
Claim 7
Dependent Claim
40 words
The biaxially oriented polyester film of Claim 1, wherein the aromatic polyester is formed from an aromatic dicarboxylic acid as a main carboxylic acid component and an aliphatic diol having 2 to 10 carbon atoms as a main glycol component.
Claim 8
Dependent Claim
34 words
The biaxially oriented polyester film of Claim 1, wherein the aromatic polyester has, as a main recurring unit, a unit selected from the group consisting of ethylene terephthalate and butylene-2,6-naphthalate, butylene terephthalate and butylene-2,6-naphthalate.
Claim 9
Dependent Claim
30 words
The biaxially oriented polyester film of Claim 1, which contains 0.01 to 3 parts by weight of the calcium carbonate particles per 100 parts by weight of the aromatic polyester.
Claim 10
Dependent Claim
21 words
A magnetic recording medium formed of the biaxially oriented polyester film recited in Claim 1 and a magnetic layer formed thereon.