Silicon oxide membrane

• US 20030165696A1
• Filed: 01/06/2003
• Published: 09/04/2003
• Est. Priority Date: 05/11/2001
• Status: Active Grant

• Current Assignee: TOYO Seikan Kaisha Limited
• Original Assignee: TOYO Seikan Kaisha Limited
• Inventors: Tanikawa, Miwako, Yamada, Koji, Inagaki, Hajime, Kobayashi, Akira, Ieki, Toshihide, Namiki, Tsunehisa, Kurashima, Hideo
• Granted Patent: US 6,818,310 B2
• Time in Patent Office: Days
• US Class Current: 428/446
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31667 Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product

Abstract

A silicon oxide film is formed on the surfaces of a plastic substrate and contains methyl groups and methylene groups in a portion near the interface to the plastic substrate. The silicon oxide film exhibits not only excellent adhesion to the plastic substrate, softness and flexibility but also exhibits excellent gas shut-off property (gas barrier property), makes it possible to achieve excellent gas-shutoff property with a smaller film thickness than that of the conventional films, and can be mass-produced favorably.

Claims

1. A silicon oxide film formed on the surfaces of a plastic substrate, wherein methyl groups and methylene groups are contained in the silicon oxide film in a portion near the interface to the plastic substrate.

2. A silicon oxide film according to claim 1, wherein an infrared absorption peak due to the methyl group and an infrared absorption peak due to the methylene group in a region of wave numbers of from 2800 to 3000 cm⁻

1, are contained in a first infrared absorption spectrum measured for a layer of said silicon oxide film of a portion near the interface to the plastic substrate.

3. A silicon oxide film according to claim 2, wherein an infrared absorption peak due to SiO in a region of wave numbers of from 1000 to 1300 cm⁻

1, is contained in said first infrared absorption spectrum.

4. A silicon oxide film according to claim 1, wherein said silicon oxide film has a two-layer structure comprising a first layer positioned on the side of the interface to the plastic substrate and a second layer on the first layer, and the methyl groups and methylene group are more distributed in the first layer than in the second layer.

5. A silicon oxide film according to claim 4, wherein an infrared absorption speak due to SiCH₃ at wave numbers of from 845 to 833 cm⁻

1, is not substantially contained in a second infrared absorption spectrum measured for the second layer.

6. A silicon oxide film according to claim 5, wherein an absorption peak in a region of wave numbers of from 1215 to 1250 cm⁻

1 is contained in said second infrared absorption spectrum.

7. A silicon oxide film according to claim 6, wherein in said second infrared absorption spectrum, the absorbency ratio defined by the following formula (1),

Ri=A₁/A₂×

100 

 

(1)

wherein A₁ is an area of an absorbency of wave numbers over a range of from 1215 to 1250 cm<sup>−

1</sup>, and

A₂ is an area of an absorbency of wave numbers over a range of from 985 to 1250 cm<sup>−

1</sup>,

is not smaller than 1%.

8. A silicon oxide film according to claim 5, wherein in said second infrared absorption spectrum, the infrared absorbency ratio (A) of SiOH/SiO is not larger than 0.25.

9. A silicon oxide film according to claim 5, wherein a silicon distribution coefficient represented by a ratio of the silicon content and the film thickness (silicon content/thickness) is not smaller than 0.3 g/cm³, and an oxygen permeation coefficient is not larger than 0.5×

10<sup>−

16</sup> cc·

cm/cm²/sec/cmHg (30°

C.).

10. A silicon oxide film according to claim 4, wherein a 10-point average surface roughness (Rz) is smaller than 25 nm and a center line average roughness (Ra) is smaller than 10 nm.

11. A silicon oxide film according to claim 1, wherein the thickness of the silicon oxide film is from 2 to 500 nm.

12. A silicon oxide film according to claim 1, wherein the silicon oxide film is formed by a plasma CVD method.

13. A gas shut-off plastic material having an inner layer and an outer layer of a thermoplastic resin, and an oxygen-absorbing layer between the inner layer and the outer layer, wherein a silicon oxide film of claim 1 is formed on the surface of the inner layer and/or on the surface of the outer layer.