JPH07310177A - Material for vapor deposition - Google Patents

Abstract

PURPOSE:To prevent the warpage or crack of a fired body and to improve vapor deposition rate and film charactristic by controlling the ratio of thermal expansion coefficient of silicon to that of silicon dioxide within a fixed range, at the time of forming the fired body of a mixture of silicon with silicon dioxide, where the mixture is a material for vapor deposition used for forming a transparent barrier film from silicon oxide. CONSTITUTION:This material for vapor deposition is obtained by firing the mixture of silicon with silicon dioxide, where the ratio of their thermal expansion coefficients is regulated to 0.6<=betaSi/betaSiO2<=10. Though the mixing method of silicon with silicon dioxide is not particularly restricted, from the view point of the transparency of the vapor deposition film, the ratio of silicon to silicon dioxide in the mixture is controlled to 1:1.2 to 1:1.7 and their particle diameters are restricted to <=10mum, preferably <=3mum to improve the vapor deposition sperated and to prevent the generation of splash phenomenon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for vapor deposition, particularly a material for vapor deposition made of SiO _x material for forming a transparent barrier film by vacuum vapor deposition, which is capable of preventing warpage and cracks in the vapor deposition film produced from this. It is about.

[0002]

2. Description of the Related Art Plastic films used for packaging materials such as foods and pharmaceuticals use a small substance for permeating gases such as water vapor and oxygen in order to prevent alteration of the contents of the package. Therefore, there is a packaging material using an aluminum foil having a gas barrier property, a metal vapor deposition film, or the like, but these have the disadvantage that the contents cannot be seen from the outside.

To solve this problem, a plastic film having silicon monoxide vapor-deposited thereon has been developed (see Japanese Patent Laid-Open No. 3-197665), which has a high gas barrier property but is transparent. Has the disadvantage that it is inadequate, and it has also been proposed to deposit a mixture of silicon and silicon dioxide on a plastic film (see Japanese Patent Laid-Open No. 1-253434), which has a high gas barrier. Although it has transparency, silicon and silicon dioxide are melted in this, and since this silicon compound is deposited, the deposition rate becomes slower than when using silicon monoxide as the deposition material, and it is easy to handle. Also has a problem.

[0004]

Regarding this packaging material having an excellent gas barrier property, there is also known a method of firing a mixture of silicon and silicon dioxide and using this as a material for vapor deposition (special feature). However, depending on the type of raw material powder used, warping or cracking may occur in the fired product made from this, which is disadvantageous in terms of handling and significantly reduces productivity. There is a problem.

[0005]

The present invention relates to a material for vapor deposition which solves the disadvantages, drawbacks and problems in the conventional method, and it is a transparent material provided with a thin film of silicon oxide by vacuum vapor deposition. A vapor deposition material used in the production of barrier films with a coefficient of thermal expansion of 0.6 ≦ βsi / βsio ₂ ≦
It is characterized by being formed by firing silicon and silicon dioxide within the range of 10.

The present inventors have conducted various studies to develop a vapor deposition material capable of efficiently producing a packaging film having high gas barrier properties and transparency, and the coefficient of thermal expansion largely depends on the crystal structure of physical properties. However, it was found that the crystal structure of silicon dioxide powder differs depending on the manufacturing method, and therefore the coefficient of thermal expansion also differs. That is, as the silicon dioxide powder, there are a crushed quartz powder and a vitrified powder obtained by heat treatment, which have different crystal structures and thermal expansion coefficients. Then, a sintered product of a mixture of various silicon dioxide powders and silicon powders having different thermal expansion coefficients was produced, and the characteristics were examined. As a result, it was found that the ratio of the thermal expansion coefficients was 0.6 ≦ βsi / βsi.
It was found that a molded body free from warpage and cracking can be obtained when o ₂ ≤10, and this product also has excellent handling properties.Since this firing melts silicon and silicon dioxide, the deposition rate is As soon as it was confirmed that the characteristics of the obtained film were superior to those obtained by using silicon monoxide as a material, the present invention was completed. This will be described in more detail below.

[0007]

The present invention relates to a vapor deposition material for vapor depositing a transparent silicon oxide film having a gas barrier property on a packaging material, which has a coefficient of thermal expansion of 0.6≤βsi / βsio ₂ ≤
A silicon and silicon dioxide is 10 is made by firing but, SiO _x such as a plastic film using the same
The vapor deposition of the system film has an advantage that a packaging material having high gas barrier property and transparency can be obtained easily and with high productivity.

Silicon and silicon dioxide used to obtain the vapor deposition material of the present invention have a coefficient of thermal expansion of 0.6 ≦ β.
It is required to be a mixture of si / βsio ₂ ≦ 10. This is because if the ratio of these coefficients of thermal expansion is outside this range, it will not be possible to perform uniform firing, so warpage or cracks will occur in the fired product that will be produced from this, but the ratio of these coefficients of thermal expansion will fall within this range. Then, this firing is performed uniformly,
No warpage or cracks occur in the fired body made from this, which makes it easy to handle, and since this firing melts silicon and silicon dioxide, the deposition rate is silicon monoxide. It has the advantage of being faster than the above-mentioned ones and having excellent gas barrier properties and transparency.

The method of mixing silicon and silicon dioxide to obtain this vapor deposition material is not particularly limited, and may be carried out by a conventional method. In this mixing, the silicon atoms in this mixture are mixed. If the ratio of oxygen atom to oxygen atom is less than 1: 1.2, the vapor deposition film made from this fired product becomes pale yellow and its transparency deteriorates. If this ratio exceeds 1: 1.7, the vapor deposition film obtained is Since the gas barrier property is remarkably lowered, the ratio of silicon atoms to oxygen atoms is 1: 1.2 to 1: 1.7.
It is necessary to mix them in such a proportion that the range becomes. Therefore, when blending this silicon and silicon dioxide, it is advisable to mix them in the range of 1.5 to 5.7 mol of silicon dioxide to 1 mol of silicon.

The silicon and silicon dioxide used here are both powders, but if the particle size is 10 μm or more, the evaporation rate slows down and the productivity decreases, or the splash. As it causes the phenomenon, the particle size
The particle size is preferably 10 μm or less, and preferably, the particle size is 3 μm or less.

In addition, the molding of silicon and silicon dioxide,
The firing method is not particularly limited, and may be performed by a conventionally known method, for example, this mixture may be press-molded using a uniaxial molding machine, and the firing may be performed at 1,830 ° C. in an argon gas atmosphere. It suffices to sinter for 30 minutes, and it is possible to obtain a high-quality molded product without warping or cracking.

[0012]

EXAMPLES Next, examples and comparative examples of the present invention will be described. Examples 1 to 3 and Comparative Examples 1 to 2 Silicon powders having a thermal expansion coefficient of 7.63 × 10 ⁻⁶ cm / cm · ° C. and a particle size of 2 μm, and the thermal expansion coefficients shown in Table 1 1-3
μm and silicon dioxide were mixed at a ratio of 3 mol of silicon dioxide to 1 mol of silicon, and the mixture was mixed in methanol for 8 hours and dried to prepare a mixed powder, and then the mixed powder. 40mm × 45mm × 15 using a uniaxial press
Press-molded to a size of mm and baked at 1,380 ° C for 30 minutes in an argon gas atmosphere. A material for use was obtained.

However, for comparison, this silicon dioxide has a coefficient of thermal expansion of 13.8 × 10 ⁻⁶ cm / cm · ° C. or 0.6 × 10 ⁻⁶ cm / cm · ° C. as shown in Table 1, and When a material having a coefficient of thermal expansion βsi / βsio ₂ of 0.55 or 12.67 was treated in the same manner as in the example to produce a vapor deposition material,
As shown in Table 1, the vapor-deposited film produced from this had warpage and cracks.

[0014]

[Table 1]

[0015]

The present invention relates to a material for vapor deposition, which has a coefficient of thermal expansion of 0.6 ≦ βsi /
A vapor deposition material for producing a transparent barrier film of a silicon compound by vacuum vapor deposition obtained by firing a mixture of silicon and silicon dioxide in the range of β sio ₂ ≦ 10. However, this fired product prevents warpage and cracks from being generated, and also has good handleability,
Since the vapor deposition rate is also high, the advantage of high productivity is given.

Claims (3)

[Claims] 1. A vapor deposition material used in the production of a transparent barrier film provided with a thin film of silicon oxide by vacuum vapor deposition, the silicon having a coefficient of thermal expansion within the range of 0.6 ≦ βsi / βsio ₂ ≦ 10. A material for vapor deposition, which is obtained by firing a mixture of: and silicon dioxide. 2. The vapor deposition material according to claim 1, wherein silicon and silicon dioxide are mixed so that the ratio of silicon atoms to oxygen atoms is 1: 1.2 to 1: 1.7. 3. The vapor deposition material according to claim 1, wherein the particle size of silicon and silicon dioxide is 10 μm or less.