JPH0236292A - Friction material - Google Patents

Abstract

PURPOSE:To obtain a friction material, containing a fiber substrate containing glass fibers, filler, resin or rubber binder, capable of improving rotation burst strength and useful in automotive dry or wet clutch facings, brake pads, etc. CONSTITUTION:The objective friction material, containing (A) a fiber substrate consisting essentially of a glass fiber woven fabric consisting of glass fibers with <=20mum diameter and having 1-3mm texture spacing, (B) a filler consisting of calcium carbonate, diatomaceous earth, graphite, etc., and (C) a resin binder consisting of preferably unmodified phenolic resin, or rubber binder consisting of a synthetic rubber, such as SBR or EPDM, natural rubber or a crosslinked substance thereof. The glass fiber woven fabric is arranged in parallel with the friction surface. Furthermore, inorganic short fibers, such as glass, ceramic or silica fibers, or organic short fibers, such as aromatic polyamide, phenolic or carbon fibers, can be used as the component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a friction material that can be used for dry clutch facings, wet clutch facings, brake pads, etc. of automobiles.

[Prior art 1] Conventional friction materials used for automobile clutch facings include resin mold types and rubber mold types, which are based on long glass fibers and use resin or rubber as fillers and binders. ing.

There are various proposals for improving the fiber base material in order to improve its friction performance. In particular, rubber mold type tires are said to have low rotational burst strength. For this reason, for example, bulk-processed glass fiber may be used as a fiber base material, or chopped strands of long glass fibers or milled fibers of a specific length may be used as a V&fiber base material.
Although there is a disclosure of a fiber H base material made of a mixture of aromatic polyamide fiber and glass fiber, a fully satisfactory material has not yet been obtained (Japanese Patent Application Laid-open No. 167934/1983,
JP-A-51-87549, JP-A-59-4538
Publication No. 3).

[Problems to be Solved by the Invention] In the above-mentioned friction material, the length of the long fibers of the fiber N base material may be broken or shortened during mixing or molding processing, and may not be uniformly dispersed. It often does not function well as a base material. Furthermore, when used as a long m-width tm miscellaneous base material, the 4M miscellaneous coating is not sufficiently performed during molding, and the fibers are exposed during use, reducing the performance of the friction material. For this reason, the rotational burst strength tends to decrease in the clutch facings obtained using f rods, especially short fibers as the fiber base material.

Therefore, in view of the various points mentioned above, the present invention further improves the rotational burst strength of the friction material by specifying the structure of the fiber base material, and balances the three elements of the clutch facing: not decreasing, not slipping, and not breaking. The technical challenge is to create a friction material that holds well.

[Means for Solving the yI Problem] The friction material of the present invention is a friction material composed of a fiber base material and a filler, a resin, or a rubber binder, and includes at least a portion of the fiber T4M material. , diameter is 20μ
The present invention is characterized in that a glass fiber fabric made of glass fibers having a diameter of 1 to 3 mm and having a weave gap of 1 to 3 mm is used and arranged parallel to the S vibration section.

The fiber base material of the present invention has a woven structure such as a plain weave, a twill weave, and a satin weave, in which at least a portion thereof is made of glass fiber fabric, and the gaps between the weaves are 1 to 31.

As a result, due to the affinity between the II fiber base material and the binder and the reinforcing effect due to their entanglement, the binder sufficiently penetrates into the gaps between the textures of the fiber base material and the fiber base material and the binder become integrated. , the rotational bust strength of the friction material can be improved.

This glass fiber H fabric has a diameter of 20 μm or less.
It is made of A fiber, woven so that the gaps between the weaves are 1 to 3 mm, and fixed with resin or the like so that the gaps between the 11 stitches do not move. This glass fiber fabric is woven by a conventional method, and the glass fibers used may be in the form of roving, twisting, or other processed materials.

If the gap between the weave of the glass fiber fabric is less than 1 m+, adhesion and penetration with the binder and entanglement will be insufficient, and sufficient physical properties as a friction material cannot be imparted. On the other hand, if the gap between the weaves exceeds 3 mm, the binder will penetrate too much and the shape of the weave of the uA fiber base material will be deformed, causing variations in the gap, reducing its performance as a friction material and reducing its rotational burst strength. Therefore, it is not desirable. Also, this glass! ! If the diameter of the strip exceeds 20 μm, it becomes difficult to process it into a fabric, which is not preferable.

This glass fiber M fabric can be used as a single piece, but
In particular, in the case of a rubber mold type, it is preferable to use this glass fiber fabric as a core material and cover both sides with a rubber mold material, or to use a plurality of sheets of this glass fiber fabric in a stacked manner in order to increase the rotational burst strength. It is preferable that this glass fiber fabric is impregnated with a processing resin in advance to fix the gaps between the weaves. Furthermore, the glass fiber fabric coated with this rubber molding material has meshes arranged parallel to the FJ rubbing surface to form a friction material. In order to increase the burst strength, it is preferable to form the clutch facing by forming this fabric into a disk shape.

In addition to the glass fiber H fabric, this fiber M base material also includes short fibers such as short glass fibers, inorganic fibers such as ceramic fibers, silica fibers, and alumina fibers, and organic fibers such as aromatic polyamide fibers and polyamide-imide fibers. Short fibers such as fibers, phenol resin type fibers, and carbon fibers can be added.

The rubber used as a binder is SBR.

Synthetic rubber such as NBR, EPDMlNRX rR, f fR, etc. or natural rubber can be used. Further, a crosslinked rubber can be obtained by adding a crosslinking agent to the above rubber.

As the crosslinking agent, sulfur, zinc oxide, etc. can be used.

In addition, as the resin binder, a phenol resin type, a melamine resin type, etc. are used, and a phenol resin type is usually used. Further, as the resin binder, a modified phenol resin modified with cashew nut oil, polyvinyl butyral, vegetable oil, melamine, an epoxy compound, etc. may be used. In addition, unmodified phenolic resin is preferable in that it is less prone to fading.

As the filler, calcium carbonate, barium sulfate, diatomaceous earth, molybdenum disulfide, graphite, carbon black, etc. can be used.

In the present invention, a crosslinking aid and an organic filler may be included in addition to the above. As this crosslinking aid, active zinc white or cashew-modified resin can be used. As a crosslinking accelerator, thiuram-based TMTM, TMT
D, sulfenamide-based cz, oz, etc. can be used.

[Action and effect of invention! $! ] The friction material of the present invention is made of glass fibers having a diameter of 20 μm or less as at least a part of the fiber base material, and has a weave gap of 1.
~3 mm III glass fiber fabric is used.

In order to sufficiently impregnate the binder into the weaves of this glass fiber fabric, it is necessary that the gaps between the weaves be 1 to 3 ml. Since the binder and the glass fiber fabric intertwine and reinforce each other through the gaps between the weaves, the rotational burst strength is significantly improved compared to the conventional structure in which short fibers are dispersed. The binder in this case is I
In the case of jA fat, the rotational burst strength is similarly increased.

[Example] The present invention will be explained below with reference to Examples.

(Example 1) The friction material of this example was glass JMI! It was formed by laminating a plurality of fabrics with rubber attached to them, and was formed using the ingredients shown in Table 1 and their blends υj. First, a fiber base material mainly made of glass fiber fabric was impregnated with a binder consisting of a filler and rubber, and then molded to form a clutch facing of a friction material using a conventional manufacturing method such as heat treatment.

Binder Rubber A (SBR1 crosslinking agent (sulfur), crosslinking aids (D, Z) containing glass fiber with a fiber length of 30 man) or Rubber B (SBR, crosslinking agent (sulfur) containing glass fiber with a fiber length of 5 mm) The filler barium sulfate and graphite were used in combination. The fiber base material has a diameter of 6 μm.
A glass fiber chop having a diameter of 6 μm and a glass fiber fabric having a weave gap of 100 m were used. The fiber base material of this glass fiber fabric was used by stacking a plurality of sheets as shown in Table 1.

Therefore, first, the binder and filler excluding the glass fiber were weighed and blended in the amounts shown in Table 1, and then
Rubber kneading was carried out using a roller, and then the crosslinking agent and glass [t] were mixed and kneaded using a nipple roll. Next, the filler and binder were dissolved and dispersed using toluene as a solvent.

The glass fiber fabric has a predetermined disc shape (outer diameter 2QQmlllΦ
, an inner diameter of 150 mmΦ). (Glass fiber fabric 8
0 parts by weight is impregnated with 20 parts by weight of a melamine-modified phenol resin, which is a thermosetting resin to improve compatibility with rubber, and after drying, it is formed by punching into predetermined dimensions). Rubber was attached to the disk-shaped glass fiber fabric by a roll coating method using a rubber component dissolved and dispersed in the above-mentioned solvent, toluene. The rubber adhesion It can be adjusted by adjusting the rubber concentration in the solvent or by adjusting the roll interval during roll squeezing. The glass fiber fabric to which the rubber was attached was precured under conditions of 60 to 90°C, and at the same time, the solvent was removed. Next, several sheets of glass fiber tissue to which this rubber had been adhered and precured were laminated (with the dimensions shown in Table 1) at a temperature of 165°C and a pressure of 90°C.
Pressure molded at kg/cII12. Then this is 23
Clutch facings Nos. 1 to 5 having the same shape were produced by heat treatment under conditions of 0° C. x 5 hours for 43 hours, and further surface polishing and antirust treatment.

As comparative examples, comparative examples Nos. 1 and 2 of rubber-molded clutch facings were created using glass fiber H fabric.

(Example 2) This polish! The material is glass fiber! It is formed by using a woven fabric as the core material and pressing conventional rubber mold type friction materials on both sides.

A rubber mold type friction material ( Nos. 7 to 12) were formed.

The glass fiber fabrics had fiber diameters and weave gaps shown in Table 2, and were formed into a predetermined disc shape.

In addition, this glass fiber fabric contains 20% of phenolic resin.
It is impregnated with insect suspension.

Next, this glass fiber fabric was sandwiched between the rubber molded friction materials described above as a core material, and subjected to pressure heat treatment in the same manner as in Example 1 to obtain a clutch facing. In this case, only one core material is used, but a plurality of core materials may be used if necessary.

As a comparative example, Comparative Example No. 1 is a rubber molded friction material using the above-mentioned Rubber A and Rubber B without using glass fiber fabric.
I created 3-4.

(Example 3) Instead of the rubber in Example 1, resin component A (phenolic resin resident Jurez TR-311) or resin component [3 (phenolic resin resident Jurez TR8645) was used as a binder, and barium ll1lI acid was used as an inorganic filler. A resin-molded [γ vibration material] was prepared in the same manner as in Example 2 by using a glass fiber chop as a base material. The friction material of the resin mold in this example is made of glass fiber fabric as the core material, and both sides of it are made of resin mold type I! i! If
It is covered with f material. The compositions are listed in Nos. 013 to 15 in Table 3.

Comparative example No. 1 of a resin-molded clutch facing that does not use glass fiber fabric as a core material.
5 and 6 were produced.

(Evaluation results) Using a full-size dynamo tester, the above Examples Nos. 1 to 1
Performance evaluation was performed on the clutch facings of No. 5 and Comparative Examples Nos. 1 to 6. The dimensions of the clutch facing are Φ200X 140×3.5111m1 Inertia 0.2kg-m-5ec2 Revolutions''!800r'p
The test was carried out under the conditions of 2000 joints at 300°C. And friction coefficient, wear rate (X10-4mI13
/kg-m), and the rotational burst strength (rpm) was measured. The results are shown in Tables 1-3. Note that the rotational burst strength was 200°C.

The friction coefficient and wear rate of Examples Nos. 1 to 5 and Comparative Examples 1 to 2 are almost the same, but the rotational burst strength is
There are more than 14,000 O1-5, but Comparative Example No.1 is i
1500, and No. 2 was only 8200L, indicating that this example was significantly improved (Table 1).

Even when glass fiber fabric was used as the core material in Example 2, Examples Nos. 6 to 12 and Comparative Example N.

Compared to 3-4, there are 14,000 examples,
In the comparative example, it was 115° at the most, indicating that the rotational burst strength of the friction material of the present invention is excellent (Table 2).

, Also regarding the resin mold system, Example Nos. 13 to 1
5 and Comparative Examples Nos. 5 to 6, the example is 120.
00 to 11500, whereas in the comparative example it was 600.
0 to 6500, indicating a significant improvement (Table 3).

In addition, since the resin mold system has one laminated glass 814H material, the absolute value of the rotational burst strength is lower than that of the rubber mold system. It is estimated that the rotational burst strength becomes approximately constant when the number of 81-layer glass fiber N fabrics is around six.

Claims (1)

[Claims] (1) A friction material composed of a fiber base material and a filler, resin, or rubber binder, wherein at least a portion of the fiber base material has a diameter of 20 μm.
A friction material characterized in that a glass fiber fabric made of the following glass fibers and having a weave gap of 1 to 3 mm is used and arranged parallel to a friction surface.