Friction Material
A friction material includes a binder, a reinforcement fiber, and a friction modifier which in turn includes flat layered titanate particles and baryte particles, wherein the baryte particles constitute less than 25% by volume of the friction material. The flat layered titanate particle may include alkali metal titanate particles, and more specifically potassium lithium titanate particles. Other flat layered titanates, including alkali metal alkaline earth metal titanates may also be used. The titanate particles may be used in an amount of 3-25% by volume of the friction material, and more specifically 5-15% by volume thereof. They may also have particle sizes ranging from 0.1-500 μm, and more specifically 1-30 μm, and even more specifically 15-30 μm. The friction material may include a binder or binders in an amount of about 8-31% by volume of the friction material. The friction material may also include reinforcement fibers in an amount of about 2-13% by volume of the friction material. These friction material may be used for any friction component including use in industrial machinery and vehicles, but are particularly useful as friction materials for use in various brake and clutch components.
1 . A friction material comprising:
a binder;
a reinforcement fiber; and
a friction modifier comprising flat layered titanate particles and baryte particles, wherein said baryte particles comprise less than about 25% by volume of the friction material.
2 . The friction material of claim 1 wherein said flat layered titanate particles comprise alkali metal titanate particles.
3 . The friction material of claim 2 wherein said alkali metal titanate particles comprise lithium potassium titanate particles.
4 . The friction material of claim 1 wherein said flat layered titanate has the general formula:
A x M y Ti 2-y O 4
wherein A represents an alkaline metal other than lithium; M represents one or more elements selected from the group consisting of lithium, magnesium, zinc, nickel, copper, iron, aluminum, gallium and manganese; x is a number from 0.5-1.0; and y is a number from 0.25-1.0, and flat layered titanic acids represented by general formula (2) as follows:
H x (M′ y ) z Ti 2-y O 4 .H 2 O
wherein M′ represents one or more elements selected from the group consisting of lithium, magnesium, zinc, nickel, copper, iron, aluminum, gallium and manganese; x is a number from 0.5-1.0; y is a number from 0.25-1.0; z is 0 or 1; and n is a number of 0≦n≦2.
5 . The friction material as recited in claim 4 , wherein A is potassium and M is zinc or magnesium.
6 . The friction material as recited in claim 4 , wherein M′ is zinc or magnesium.
7 . The friction material of claim 1 wherein said flat layered titanate is about 3-25% by volume of the friction material.
8 . The friction material of claim 7 wherein said flat layered titanate is about 5-15% by volume of the friction material.
9 . The friction material of claim 1 wherein said flat layered titanate has an average particle diameter of approximately 0.1-500 μm.
10 . The friction material of claim 9 wherein said flat layered titanate has an average particle diameter of approximately 15-30 μm.
11 . The friction material of claim 1 wherein said binder comprises about 8-31% by volume of the friction material.
12 . The friction material of claim 1 wherein said reinforcement fibers comprise about 2-13% by volume of the friction material.
13 . The friction material of claim 1 wherein said baryte particles comprise less than about 17% by volume of the friction material.
14 . A friction material comprising:
a binder;
a reinforcement fiber; and
a friction modifier comprising lithium potassium titanate particles and baryte particles, wherein said baryte particles comprise less than about 25% by volume of the friction material.
15 . The friction material of claim 14 wherein said lithium potassium titanate particles comprise about 3-25% by volume of the friction material.
16 . The friction material of claim 15 wherein said lithium potassium titanate particles comprise about 5-15% by volume of the friction material.
17 . The friction material of claim 14 wherein said lithium potassium titanate particles have an average particle diameter of approximately 0.1-500 μm.
18 . The friction material of claim 15 wherein said lithium potassium titanate particles have an average particle diameter of approximately 15-30 μm.
19 . The friction material of claim 14 wherein said baryte particles comprise less than about 17% by volume of the friction material.
20 . The friction material of claim 14 wherein said friction material comprises a formed friction control member which is attached to a backing member.
21 . The friction material of claim 20 , wherein said backing member is selected from a group consisting of a disc brake component, a drum brake component and a clutch component.