—Test Evaluation Method—

(Hardness)

The hardness of the seal material produced was measured as an instantaneous value by means of a type A durometer in accordance with HS K6253-3.

(Tensile Strength, Elongation, 100% Modulus)

The tensile strength, elongation, and 100% modulus of the seal material produced were measured using a No. 3 dumbbell-shaped test piece having a thickness of 2 mm based on HS K6252.

(Compression Set)

The compression set of the seal material produced was measured based on JIS K6262, using a test piece obtained by cutting an AS-214 O-ring in half.

(Plasma Resistance)

The plasma resistance of the seal material produced was measured by exposing an AS-214 O-ring to plasma by means of a small plasma etching device (manufactured by Shinko Seiki Co., Ltd.) and obtaining a weight reduction rate. In this measurement, the following conditions were set: a high-frequency power source was 1500 W; gas was O₂+CF₄(50:1); a pressure was 100 Pa; and a time was 30 minutes.

Further, the appearance of the exposed O-ring was visually observed to confirm the presence or absence of dust.

(Vulcanization Rate)

As a vulcanization rate at the time of producing the seal material, t90 was obtained using a device in conformity with HS K6300-2.

—Test Evaluation Results—

TABLE 1

Example
Comparative Example

1
2
3
4
5
1
2

Base Rubber
FKM
Tecnoflon P959
100
100
100
100
100
100
100

Crosslinking
Organic
PERHEXA 25B
1.5
1.5
1.5
1.5
1.5
1.5
1.5

Agent
Peroxide

Crosslinking
Polyfunctional
TAIC
2
2
2
2
2
2
2

Aid
Compound

Filler
Phenol Resin
BellPearl R100
1
10
25
50
—
—
—

BellPearl R200
—
—
—
—
10
—
—

BellPearl R800
—
—
—
—
—
—
—

Carbon Black
Thermax N990
—
—
—
—
—
—
10

DIABLACK H
—
—
—
—
—
—
—

Silica
AEROSIL R972
—
—
—
—
—
—
—

Silica-
OPTOBEADS
—
—
—
—
—
—
—

Melamine
2000M

Complex

PVDF
KYNAR MG15
—
—
—
—
—
—
—

PTFE
Fluon L173JE
—
—
—
—
—
—
—

Normal
Hardness (Type-A)
51
58
69
85
58
51
55

Physical
Tensile Strength (Mpa)
12
15
20
21
12
8.9
15

Properties
Elongation (%)
270
210
190
120
230
290
210

100% Modulus (Mpa)
1.4
2.8
7.5
17
2.2
1.3
2.8

Thermal
Compression Set (%)
20
13
17
24
13
27
25

Resistance

Plasma
Weight Reduction Rate (%)
2
2.1
2.3
2.6
2.2
2
3.1

Resistance
Dust Generation
A
A
A
A
A
A
B

Comparative Example

3
4
5
6
7
8
9
13

Base Rubber
FKM
Tecnoflon P959
100
100
100
100
100
100
100
100

Crosslinking
Organic
PERHEXA 25B
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5

Agent
Peroxide

Crosslinking
Polyfunctional
TAIC
2
2
2
2
2
2
2
2

Aid
Compound

Filler
Phenol Resin
BellPearl R100
—
—
—
—
—
—
—
—

BellPearl R200
—
—
—
—
—
—
—
—

BellPearl R800
—
—
—
—
—
—
—
10

Carbon Black
Thermax N990
25
—
—
—
—
—
—
—

DIABLACK H
—
10
—
—
—
—
—
—

Silica
AEROSIL R972
—
—
10
—
—
—
—
—

Silica-
OPTOBEADS
—
—
—
10
—
—
—
—

Melamine
2000M

Complex

PVDF
KYNAR MG15
—
—
—
—
10
25
—
—

PTFE
Fluon L173JE
—
—
—
—
—
—
10
—

Normal
Hardness (Type-A)
68
63
65
59
55
68
55
58

Physical
Tensile Strength (Mpa)
24
23
20
18
13
17
16
9.5

Properties
Elongation (%)
260
220
270
210
280
270
350
240

100% Modulus (Mpa)
5.6
3.7
3.7
2.5
2.3
5.4
1.4
2.4

Thermal
Compression Set (%)
25
24
36
30
26
30
28
Crushed

Resistance

Plasma
Weight Reduction Rate (%)
4.3
3.2
2.4
2.2
2.1
2.3
3
2.2

Resistance
Dust Generation
B
B
A
A
A
A
B
A

Table 1 shows the formulation of the rubber composition and test evaluation results for the seal materials of Examples 1 to 5 and Comparative Examples 1 to 9 and 13.

Examples 1 to 5, where the phenol resin powder is added, each show the improved (reduced) compression set and the improved hardness and modulus as compared to Comparative Example 1, where the phenol resin powder is not added.

Moreover, Examples 1 to 5 are superior in the compression set to Comparative Examples 2 to 4 where carbon black is added. Further, Comparative Examples 2 to 4 show dust generation after plasma irradiation, but Examples 1 to 5 show no dust generation after plasma irradiation. The weight reduction rates of Examples 1 to 5 are lower than the weight reduction rates of Comparative Examples 2 to 4. Thus, Examples 1 to 5 are superior in the plasma resistance to Comparative Examples 2 to 4.

Moreover, Examples 1 to 5 are superior in the compression set to Comparative Examples 5 to 8 where silica, the silica-melamine complex, or PVDF are added.

Moreover, Examples 1 to 5 are superior in the compression set to Comparative Example 9 where PTFE is added. Further. Comparative Example 9 shows dust generation after plasma irradiation, but Examples 1 to 5 show no dust generation after plasma irradiation.

As described above. Examples 1 to 5, where fluororubber is used as the rubber component and the phenol resin powder is added, achieve the improved compression set and the improved plasma resistance (reduced generation of dust due to plasma irradiation).

Comparative Example 13 is similar to Examples 1 to 5 in that the phenol resin powder is added. However, the average particle size of the phenol resin powder of Examples 1 to 4 is 1.5 μm and the average particle size of the phenol resin powder of Example 5 is 5.8 μm, whereas the average particle size of phenol of Comparative Example 13 is 22 μm. Comparative Example 13 did not show improved compression set, and was crushed under the measurement conditions similar to those of Examples 1 to 5, This means that there is a preferred range for the particle size of the phenol resin powder. For example, the range is preferably 20 μm or less, more preferably 10 μm or less, and much more preferably 6 μm or less.

Among Examples 1 to 4 different from each other only in the content of the phenol resin powder, Example 2 is the best in terms of the compression set. The content of the phenol resin powder with respect to 100 parts by mass of the rubber component is preferably 1 part by mass or more. The content is preferably 50 parts by mass or less, more preferably 25 parts by mass or less, and much more preferably 15 parts by mass or less.

TABLE 2

Example
Comparative Example

6
7
3
10
14
15
16

Base Rubber
FKM
Tecnoflon P959
100
—
100
—
—
—
—

Viton E60C
—
100
—
100
—
—
—

VMQ
KE-871C-U
—
—
—
—
100
100
—

EPDM
EP51
—
—
—
—
—
—
100

Crosslinking
Organic Peroxide
PERHEXA 25B
1.5
—
1.5
—
—
—
1.5

Agent

C-8
—
—
—
—
1
1
—

Crosslinking
Polyfunctional
TAIC
2
—
—
—
—
—
2

Aid
Compound

Acid Acceptor
Magnesium Oxide
Kyowamag 150
—
3
—
3
—
—
—

Calcium Hydroxide
CALVIT
—
6
—
6
—
—
—

Filler
Phenol Resin
BellPearl R100
10
10
—
—
—
10
10

Carbon Black
Thermax N990
10
25
10
25
—
—
—

Normal Physical
Hardness (Type-A)
64
71
55
68
70
72
Unmeasurable

Properties
Tensile Strength (Mpa)
21.5
18.9
14.5
16.6
7.4
7.3
due to

Elongation (%)
200
180
210
190
180
160
surface layer

100% Modulus (Mpa)
5.1
8.9
2.8
7
5.3
6
cracking

Thermal
Compression Set (%)
13
9
25
18
10
18

Resistance

Table 2 shows the formulation of the rubber composition and test evaluation results for the seal materials of Examples 6 and 7 and Comparative Examples 3, 10, and 14 to 17.

Example 6 and Comparative Example 3 are examples where carbon black is added. Example 6 is different from Comparative Example 3 in that the phenol resin powder is further added. Preferably, the seal material for the semiconductor manufacturing device does not contain carbon black in order to avoid dust generation. However, it is conceivable that carbon black is added due to, e.g., requirement associated with other properties.