New Products
Sealant for clean rooms
Pure Sealant / Pure Sealant S-type
Pure Sealant cures at room temperature by reacting with moisture in the air to become an elastic sealing material with outstanding adhesiveness. It is particularly suited to clean rooms where a high degree of cleanliness is required, and for airtight sealing of semiconductor production equipment and clean room joints for which control of chemical contaminants is a must.
Features
- Excellent durability, heat resistance and weather resistance.
- Low-molecular-weight dimethyl siloxane is almost not evaporated.
- Outstanding adhesiveness.
- Easy-to-use one-component type. Simply squeeze from the cartridge to apply.
- Testing shows that the amount of organic compounds adsorbed to Si wafers is much lower than with common sealants. (Pure Sealant S-type)
- In wafer absorption tests, our Pure Sealant S-type performed far better than conventional sealants.
Applications
- Sealing interior trim joints and sealing around air filters, etc. in clean rooms used in the manufacturing and processing of semiconductors and other types of precision electronic materials.
Colors
- Pure Sealant: White, light gray, ivory, dark ivory, translucent
- Pure Sealant S-type: Light gray, ivory
General Properties
| Grade | Pure Sealant | Pure Sealant S-type | ||
|---|---|---|---|---|
Before |
Appearance |
Paste | Paste | |
Fluidity |
None | None | ||
Tack-free time |
3 | 3 | ||
After |
*1 |
Appearance |
Elastic | Elastic |
Density 23°C g/cm3 |
1.05 | 1.05 | ||
Hardness Durometer A |
44 | 37 | ||
Elongation at break % |
340 | 360 | ||
Tensile strength MPa |
2.70 | 2.60 | ||
*2 |
Modulus at 50% Elongation N/mm2 |
0.70 | 0.50 | |
Tensile stress at |
0.76 | 0.70 | ||
Elongation at maximum load % |
70 | 100 | ||
Cohesive failure % |
100 | 100 | ||
*3 |
Low-molecular-weight- |
60 | 40 | |
*4 |
Phosphorous element ppm |
1 › | 1 › | |
Boron element ppm |
1 › | 1 › | ||
Antimony element ppm |
1 › | 1 › | ||
(Not specified values)
*1: Sheet physical properties(measured according to JIS K 6249)
Curing conditions: 7 days at 23°C/50% RH
*2: H-type block physical properties(measured according to JIS A 5758)
Adherend: Float glass. Curing conditions: 14 days at 23°C/50% RH, then 14 days at 30°C
*3: Total content dimethyl cyclic siloxane from 3-compound to 20-compound (D3-D20)
Extraction performed on cured samples using acetone and measured by gas chromatography.
*4: Measured by the ICP-AES method.
Properties
Measurement results of low-molecular-weight siloxane by extraction
Sample preparation
- Using Pure Sealant, Pure Sealant S-type and one of our conventional products, we made 2 mm-thick uncured sheets and let them cure for 7 days at 23°C/50% RH.
Extraction and measurement methods
- Extraction was performed on the cured samples using a solvent (acetone) and the extracted liquid was measured by gas chromatography.
Measurement results
Extracted amount of low-molecular-weight siloxane
| Extracted dimethyl cyclic siloxane | Pure Sealant | Pure Sealant S-type | Our conventional product |
|---|---|---|---|
| D3 | 10 › | 10 › | 10 › |
| D4 | 10 › | 10 › | 10 › |
| D5 | 10 › | 10 › | 130 |
| D6 | 10 › | 10 › | 340 |
| D7 | 10 › | 10 › | 240 |
| D8 | 10 › | 10 › | 260 |
| D9 | 10 › | 10 › | 280 |
| D10 | 10 › | 10 › | 340 |
| ΣD3 - 10 | － | － | 1,590 |
| D11 | 10 › | 10 › | 400 |
| D12 | 10 › | 10 › | 460 |
| D13 | 10 › | 10 › | 670 |
| D14 | 10 › | 10 › | 870 |
| D15 | 10 › | 10 › | 1,020 |
| D16 | 10 › | 10 › | 1,170 |
| D17 | 20 | 10 | 1,190 |
| D18 | 20 | 10 | 1,220 |
| D19 | 10 | 10 | 1,260 |
| D20 | 10 | 10 | 1,630 |
| ΣD11 - 20 | 60 | 40 | 9,890 |
10 › : Detection limit
(not specified values) Gas chromatogram of extracted low-molecular-weight dimethyl siloxane
Four types of dimethyl cyclic siloxanes(D17 to D20) were
detected in low-molecular-weight siloxane extracted from the Pure Sealant
and Pure Sealant S-type samples. They were detected
in concentrations of 60 ppm and 40 ppm respectively. The extracted
amounts of all dimethyl cyclic siloxanes were found to be much lower
than with our conventional product.
Low-molecular-
weight siloxane Dn
Measurement results of low-molecular-weight siloxane in the vapor phase
Sample preparation
- Using Pure Sealant and one of our conventional products, we made 2 mm-thick uncured sheets and let them cure for 7 days at 23°C/50% RH.
Measurement method
- A 10-gram sample of cured material was placed in a 1-liter bottle with an airtight stopper and then left for 24 hours respectively at 25°C (77°F) and 80°C (176°F). Next, low-molecular-weight siloxane was adsorbed in an active carbon while in taking one liter of the vapor through its tube. The active carbon was extracted using carbon tetrachloride and the extract was measured using pyrolysis gas chromatography. (This measurement method also detects dimethyl liner siloxane.)
Measurement results
Evaporated amount of low-molecular-weight dimethyl siloxane (Units: µg/l)
| Vapor phase extraction conditions | Pure Sealant | Our conventional product |
|---|---|---|
| After hermetic sealing for 24 hrs at 25°C (77°F) |
1 › | 610 |
| After hermetic sealing for 24 hrs at 80°C (176°F) |
10 | 6,500 |
Pure Sealant exhibited a much lower amount of evaporated low-molecular-weight dimethyl siloxane compared with our conventional product. Consequently, it is assumed that the evaporated amount of low-molecular-weight dimethyl siloxane in the actual clean room vapor will be even lower.
Test of organic compound adsorption to Si wafer
(substrate surface adsorption-thermal desorption method: JACA, No.34)
Measurement method
- Uncured sheets of sealant (100 mm×100 mm×1 mm) were cured for 7 days at 23°C/50% RH. Polished wafer chips were placed with the sealant sample inside a glass desiccator (approx. 5 liter) such that the wafer did not touch the sealant. They were left in the desiccator for 24 hours. Next, the wafer chips were removed and heated in a purge-and-trap headspace sampler, and the desorbed gases were analyzed using GC-MS.
Measurement results
Total amount of adsorbed organic compounds by calculation (Corresponding value n-C16H34)
(Units: ng/cm2)
| Pure Sealant | Pure Sealant S-type |
Our conventional Sealant | Reduced LMW Sealant* | |
|---|---|---|---|---|
| Siloxane | 0.01 › | 0.01 › | 1.7 | 0.34 |
| Other than Siloxane | 1.40 | 0.04 | 1.8 | 1.39 |
| Total organic compounds | 1.40 | 0.04 | 3.5 | 1.73 |
* Competitor's product
(not specified values)