Molded article coated with silicon oxide vapor deposition film and method for producing same

Abstract

The purpose of the present invention is to provide: a molded article coated with a silicon oxide vapor deposition film; and a method for producing the same. Specifically, the present invention provides a method for producing a molded article coated with a silicon oxide vapor deposition film, the method comprising: (i) a step for disposing a molded article before being coated with the silicon oxide vapor deposition film inside a plasma processing chamber that is provided with at least one gas feed port, electrodes that are connected to a high-frequency power supply device, and an exhaust port that is connected to an exhaust device; (ii) a step for introducing an organosilicon compound from the gas feed port into the plasma processing chamber at a flow rate that satisfies a desired condition, and maintaining a specific pressure while discharging exhaust from the exhaust port; and (iii) a step for generating a glow discharge by applying a voltage between the electrodes at the output of a desired condition by means of the high-frequency power supply device, and plasma processing the molded article so as to prepare a molded article coated with a silicon oxide vapor deposition film.

Description

Molded product coated with silicon oxide vapor deposition film and its manufacturing method

[0001] The present invention relates to a method for producing a molded article coated with a silicon oxide vapor-deposited film. The present invention particularly relates to a method for producing a molded article coated with a silicon oxide vapor-deposited film having high oil-slip properties and / or oil-repellent function.

[0002] Conventionally, films have been formed on the surfaces of various substrates to improve their properties. For example, in the case of packaging materials, vapor-deposited films are formed on the surfaces of plastic molded products by plasma CVD to improve their gas barrier properties.

[0003] For example, a method for manufacturing a plastic container is known in which the concentration of the organosilicon compound changes when a barrier layer (vapor-deposited film) containing silicon oxide and at least one compound consisting of at least one or more elements selected from carbon, hydrogen, silicon, and oxygen is formed on at least one side of the plastic container by plasma CVD using at least an organosilicon compound and oxygen or a gas having oxidizing power. The gas flow ratios of the organosilicon compound (hexamethyldisiloxane) and oxygen were 1:2, 1:20, and 1:100 (see Patent Document 1).

[0004] It has also been shown that a silicon oxide film produced at a flow rate ratio of an organosilicon compound gas to a gas containing oxygen atoms in the range of 1:3 to 50, and having a component ratio of 100 Si atoms to 170 to 200 O atoms and 30 or less C atoms, has gas barrier properties (see Patent Document 2).

[0005] On the other hand, for containers, cooking utensils, etc., if the ease of cleaning and discharging of contents after use is good, workability will improve and the burden on the environment will be reduced. Therefore, water and oil repellency are also required as characteristics of the substrate of containers, cooking utensils, etc. For water repellency, for example, a bottle with good drainage properties has been proposed in which an organic silicon compound film containing nitrogen, silicon, carbon, and hydrogen is formed, and then a silicon oxide compound film containing a silicon oxide compound as the main component is formed on the surface by a CVD method (a flow rate ratio of hexamethyldisiloxane to oxygen gas of 1:4) (see Patent Document 3). However, sufficient research has not been conducted on silicon oxide compound films with good oil repellency.

[0006] JP 2000-255579 A JP 2003-53873 A JP 2009-46162 A

[0007] One object of the present invention is to provide a method for producing a molded article coated with a silicon oxide vapor-deposited film, and in particular, to provide a method for producing a molded article coated with a silicon oxide vapor-deposited film that has excellent oil-slip properties and / or oil-repellent properties.

[0008] As a result of extensive research, the present inventors discovered that by adjusting the conditions of the plasma CVD method used to form a silicon oxide vapor deposition film on the surface of a molded article, it is possible to obtain a molded article coated with the desired silicon oxide vapor deposition film, and thus completed the present invention.

[0009] That is, aspects of the present invention may relate to the following: Still other aspects of the present invention may be as follows. [1] A method for producing a molded article coated with a silicon oxide vapor deposition film, comprising coating a molded article with a silicon oxide vapor deposition film by a plasma CVD method, wherein the plasma treatment in the plasma CVD method comprises the following steps: (i) placing a molded article before being coated with the silicon oxide vapor deposition film inside a plasma treatment chamber equipped with at least one gas inlet, a first electrode and a second electrode connected to a high-frequency power supply, and an exhaust port connected to an exhaust device; (ii) introducing an organosilicon compound from the gas inlet into the plasma treatment chamber at a flow rate that satisfies either (a) or (b) below: (a) when the output of the high-frequency power supply is 10 to 900 W, the flow rate of the organosilicon compound is 1 to 100 sccm; (b) when the output of the high-frequency power supply is more than 900 W but not more than 2000 W, the flow rate of the organosilicon compound is 15 to 100 sccm; and maintaining a pressure of 1 to 100 Pa while exhausting from the exhaust port; (iii) applying a voltage between the first electrode and the second electrode using the high-frequency power supply device at a frequency of 5 to 20 MHz and at the output of (a) or (b) to generate a glow discharge, and plasma-treating the molded article for 1 to 300 seconds to prepare a molded article coated with a silicon oxide vapor-deposited film. [2] The method for producing a molded article according to [1] above, wherein the organosilicon compound is hexamethyldisiloxane, tetraethoxysilane, tetramethoxysilane, or hexamethyldisilazane, and the pressure P (Pa) in the plasma treatment chamber, the flow rate F (sccm) of the organosilicon compound, and the output A (W) of a high-frequency power supply device during the plasma treatment satisfy the following formula (I): (Pressure P × Flow Rate F) / Output A ≧ X (I), where X is 0.07 when the organosilicon compound is hexamethyldisiloxane, 0.20 when the organosilicon compound is tetraethoxysilane, 0.30 when the organosilicon compound is tetramethoxysilane, or 0.07 when the organosilicon compound is hexamethyldisiloxane, 0.20 when the organosilicon compound is tetraethoxysilane, 0.30 when the organosilicon compound is hexamethyldisilaz ...[4] The method for producing a molded article according to any one of [1] to [3] above, wherein step (ii) is carried out without introducing an oxidizing gas, and step (iii) is carried out in the absence of an oxidizing gas. [5] The method for producing a molded article according to [4] above, wherein step (ii) is a step of introducing the organosilicon compound into the plasma treatment chamber at a flow rate of 10 to 60 sccm while maintaining a pressure of 3 to 50 Pa, regardless of the conditions of (a) or (b). [6] The method for producing a molded article according to [4] or [5] above, wherein step (iii) is a step of applying a voltage between the first electrode and the second electrode with the high-frequency power supply device at a frequency of 13±2 MHz and an output of 150±100 W to generate a glow discharge, and plasma-treating the molded article for 1 to 200 seconds, thereby preparing a molded article coated with a silicon oxide vapor-deposited film, regardless of the conditions of (a) or (b). [7] A molded article having a substrate and a silicon oxide vapor-deposited film coating the surface of the substrate, produced by the method of any one of [1] to [6]. [8] The molded article of [7], wherein the substrate is molded from a material selected from resin, glass, paper, china clay, and metal. [9] The molded article of [7] or [8], wherein the silicon oxide vapor-deposited film is a film formed by vapor-depositing tetraethoxysilane or hexamethyldisiloxane.

[10] The molded article of any one of [7] to [9], wherein the substrate surface coated with the silicon oxide vapor-deposited film is the inner surface of the molded article.

[11] The molded article of any one of [7] to

[10] , wherein the contact angle of refined rapeseed oil at 20°C on the surface of the molded article covered with the silicon oxide vapor-deposited film is 25° or more.

[0010] According to the present invention, it is possible to provide a molded article coated with a silicon oxide vapor-deposited film that has excellent oil-slide properties and / or oil-repellent properties. More specifically, the present invention makes it possible to deposit a silicon oxide vapor-deposited film that has excellent oil-slide properties and / or oil-repellent properties, preferably under low-oxygen conditions or by using low-power plasma. Furthermore, molded articles whose surfaces are coated with the silicon oxide vapor-deposited film according to the present invention are expected to have excellent oil-repellent properties and / or oil-repellent properties, to be easily stained with oil, and to have good cleanability against oil stains. Furthermore, when the molded article is a container, piping, or the like, it is expected that oil will drain easily and will not easily leave oil residue.

[0011] 1 is a schematic diagram of a plasma CVD apparatus according to the present invention.

[0012] The present invention will be described in detail below by way of example. In the embodiments of the present invention, A (numerical value) to B (numerical value) means A or more and B or less. The preferred and more preferred embodiments exemplified below can be used in appropriate combinations with each other, regardless of expressions such as "preferable" or "more preferred." Furthermore, the descriptions of numerical ranges are merely examples, and ranges obtained by appropriately combining the upper and lower limits of each range and the numerical values ​​of the examples can also be preferably used, regardless of expressions such as "preferable" or "more preferred." Furthermore, terms such as "contain" or "comprise" may be interpreted as "essentially consisting of" or "consisting only of," as appropriate.

[0013] [Method for producing a molded article coated with a silicon oxide vapor-deposited film] One aspect of the present invention relates to a method for producing a molded article coated with a silicon oxide vapor-deposited film, which includes coating a molded article with a silicon oxide vapor-deposited film by a plasma CVD method. Specifically, the plasma treatment in the plasma CVD method comprises the following steps: (i) placing a molded product before being coated with the silicon oxide vapor deposition film inside a plasma treatment chamber equipped with at least one gas inlet, a first electrode and a second electrode connected to a high-frequency power supply, and an exhaust port connected to an exhaust device; (ii) introducing an organosilicon compound from the gas inlet into the plasma treatment chamber at a flow rate that satisfies either (a) or (b) below: (a) when the output of the high-frequency power supply is 10 to 900 W, the flow rate of the organosilicon compound is 1 to 100 sccm; (b) when the output of the high-frequency power supply is more than 900 W but not more than 2000 W, the flow rate of the organosilicon compound is 15 to 100 sccm; and maintaining a pressure of 1 to 100 Pa while exhausting from the exhaust port; (iii) applying a voltage between the first electrode and the second electrode at a frequency of 5 to 20 MHz and at the output of (a) or (b) by the high-frequency power supply device to generate a glow discharge, and subjecting the molded article to plasma treatment for 1 to 300 seconds to prepare a molded article coated with a silicon oxide vapor-deposited film. Each step will be described in detail below.

[0014] (i) A step (i) of placing a molded article before being coated with the silicon oxide vapor deposition film inside a plasma treatment chamber equipped with at least one gas inlet, first and second electrodes connected to a high-frequency power supply, and an exhaust port connected to an exhaust device. The method for producing a molded article of the present invention is carried out by placing the molded article inside a plasma treatment chamber and subjecting the molded article to plasma treatment. The plasma treatment chamber is equipped with at least one gas inlet, first and second electrodes connected to a high-frequency power supply, and an exhaust port connected to an exhaust device. The first electrode may also serve as the plasma treatment chamber. The at least one gas inlet is provided in the plasma treatment chamber for introducing an organosilicon compound (gaseous), as well as an oxidizing gas, a carrier gas, etc., as needed, and mixtures thereof. Multiple gas inlets may be provided depending on the number of gases to be introduced. Alternatively, if multiple gases are mixed before being introduced into the plasma treatment chamber, a single gas inlet may be provided for introducing the mixed gas. The gas introduced into the plasma treatment chamber in this manner is exhausted through an exhaust port provided in the plasma treatment chamber. The exhaust port is further connected to an exhaust device, and gas discharged from the plasma processing chamber through the exhaust port is exhausted by the exhaust device. The pressure inside the plasma processing chamber can be maintained at a desired pressure by adjusting the flow rate of gas introduced through the gas inlet and the flow rate of gas exhausted through the exhaust port. A commonly available vacuum pump can be used as the exhaust device. Preferred exhaust devices include, for example, a mechanical booster pump, a rotary pump, a dry pump, a turbomolecular pump, and an oil diffusion pump, which can be used alone or in combination. The plasma processing chamber may be formed from a material such as glass, aluminum, an aluminum alloy, stainless steel, or steel, but must be capable of maintaining a vacuum. The capacity of the plasma processing chamber is, for example, 0.1 to 10 liters, preferably 0.3 to 2 liters, and more preferably 0.5 to 1.6 liters or 0.5 to 1 liter.

[0015] The plasma treatment chamber is provided with a first electrode and a second electrode. These electrodes are further connected to a high-frequency power supply, and a high-frequency voltage is applied between the first and second electrodes by the power supply. Alternatively, multiple electrodes, such as a third electrode and a fourth electrode, may be provided in the plasma treatment chamber and connected to the high-frequency power supply. Alternatively, an electrode such as the first electrode may also serve as the plasma treatment chamber. Each electrode may be a single piece or divided into two or more pieces. For example, by using an electrode of a similar shape that is slightly larger than the molded product that can be divided into two pieces, the electrode can be positioned to enclose the molded product. When the molded product to be plasma treated has a planar shape, the molded product can be appropriately plasma-treated by placing the molded product between the first and second electrodes. When the molded product is bottle-shaped, the molded product can be appropriately plasma-treated by placing electrodes inside and outside the bottle, for example, by inserting a rod-shaped electrode inside the bottle and placing electrodes around the sides and bottom of the bottle. The rod-shaped electrode may be hollow and may also serve as an inlet for discharging a gas such as an organosilicon compound from the electrode end. The inlet at the electrode end may be a single inlet at the end, or multiple inlets may be provided at a width of approximately 0 to 500 mm from the end, allowing for shower-like gas discharge. Examples of materials that can be used for the electrode include aluminum, stainless steel, copper, iron, gold, and alloys thereof. Commercially available high-frequency power supplies generally suitable for plasma processing can be used, but preferably, a high-frequency power supply with a frequency of 5 to 20 MHz and a maximum output of approximately 2,000 to 3,000 W is used.

[0016] The molded article before being coated with the silicon oxide vapor-deposited film is also called a substrate, and is preferably molded from a material selected from resin, glass, paper, china clay, and metal. By having a silicon oxide vapor-deposited film on the surface of the molded article, it is possible to obtain a molded article that is prevented from being stained with oil and has improved oil removability. Suitable resins include thermoplastic resins known per se, such as low-density polyethylene, high-density polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, polyolefins (e.g., polyolefins such as random or block copolymers of α-olefins such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene), ethylene-vinyl compound copolymers (e.g., ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl chloride copolymer), styrene-based resins (e.g., polystyrene, acrylonitrile-styrene copolymer, A copolymer), and the like. Examples of suitable resins include biodegradable resins such as polyethylene terephthalate, polybutylene terephthalate, and polylactic acid, as well as mixtures thereof. Resins such as polyethylene and polyethylene terephthalate are more preferred. Furthermore, preferred metals include one or more metals selected from iron, nickel, copper, zinc, lead, aluminum, chromium, titanium, and the like, or alloys containing at least one of these metals as a main component, with stainless steel being more preferred.

[0017] These molded articles may be films, sheets, piping, containers, etc., or cooking utensils. Examples of piping include pipes, valves, nozzles, etc. Examples of containers include bottles, bags, tanks, cups, plates, etc., as well as caps and nozzles that constitute containers. Examples of cooking utensils include colanders, strainers, stoves, microwave ovens, etc., as well as kitchen extractor fans and countertops. Molded articles such as bottles, tanks, valves, and nozzles for oils and fats are particularly preferred. The oils and fats are preferably edible. The silicon oxide vapor-deposited film may cover all or part of the molded article, and may particularly cover only the surface portion that comes into contact with oil. When the molded article is a container, its usable volume (filled mass of the contents) is, for example, 80 to 1500 g, preferably 400 to 900 g, and more preferably 500 to 800 g.

[0018] (ii) A step (ii) of introducing an organosilicon compound into the plasma treatment chamber through the gas inlet at a flow rate that satisfies either (a) or (b) below: (a) when the output of the high-frequency power supply device is 10 W to 900 W, the flow rate of the organosilicon compound is 1 to 100 sccm, or (b) when the output of the high-frequency power supply device is greater than 900 W but less than 2000 W, the flow rate of the organosilicon compound is 15 to 100 sccm, and maintaining a pressure of 1 to 100 Pa while exhausting through the exhaust port. Any organosilicon compound can be used as the "organosilicon compound" as long as it can form a silicon oxide vapor-deposited film on the surface of a molded article by the method of the present invention. The organosilicon compound can be liquid or gaseous at room temperature (20°C ± 5°C). If the organosilicon compound is liquid at room temperature, it may be transported using a carrier gas such as helium gas, vaporized, and used in gaseous form. Examples of the organosilicon compound include organosilane compounds (e.g., hexamethyldisilane, vinyltrimethylsilane, methylsilane, dimethylsilane, tetramethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane), and organosiloxane compounds (e.g., octamethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane, and hexamethyldisiloxane), diethoxydimethylsilane, and dimethyldimethoxysilane. In addition to these materials, silazanes such as hexamethyldisilazane and aminosilanes can also be used. These organosilicon compounds can be used alone or in combination of two or more. Furthermore, silane (SiH4) or silicon tetrachloride can be used in combination with the above-mentioned organosilicon compounds. As the organosilicon compound, an organosilicon compound having, as a carbon-containing organic functional group, a functional group selected from a methyl group, a methoxy group, an ethyl group, and an ethoxy group is preferred, an organosilicon compound having an ethoxy group and / or a methoxy group is more preferred, and an organosilicon compound having only an ethoxy group is even more preferred.Organosilicon compounds having only methyl groups are also preferred. Hexamethyldisiloxane (HMDSO), tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), and hexamethyldisilazane (HMDSN) are preferred, with tetraethoxysilane (TEOS) and hexamethyldisiloxane (HMDSO) being more preferred. It is preferred that the organosilicon compound does not contain fluorine.

[0019] When an organosilicon compound that is liquid at room temperature is mixed with a carrier gas such as helium gas to produce a gaseous organosilicon compound, the organosilicon compound (liquid) may be introduced into a carrier gas such as helium gas beforehand and vaporized. Vaporization methods include, for example, heating to about 50 to 120°C, applying a low pressure of 1000 Pa or less, and bubbling with a carrier gas. When a liquid organosilicon compound is mixed with a carrier gas to produce a gaseous organosilicon compound, it is preferable to add, for example, 0.01 to 10 g, preferably 0.05 to 1 g, of the liquid organosilicon compound to 100 ml of carrier gas.

[0020] The flow rate of the organosilicon compound satisfies either (a) or (b) below: (a) when the output of the high-frequency power supply device is 10 W to 900 W, the flow rate of the organosilicon compound is 1 to 100 sccm, (b) when the output of the high-frequency power supply device is more than 900 W but not more than 2000 W, the flow rate of the organosilicon compound is 15 to 100 sccm. Regarding the above condition (a), when the output of the high-frequency power supply device is 10 W to 900 W, the flow rate of the organosilicon compound is preferably 5 to 80 sccm, more preferably 10 to 70 sccm, and even more preferably 15 to 60 sccm. Regarding the above condition (b), when the output of the high-frequency power supply device is more than 900 W but not more than 2000 W, the flow rate of the organosilicon compound is preferably 20 to 80 sccm, more preferably 25 to 70 sccm, and even more preferably 30 to 60 sccm. In this specification, "sccm" refers to the amount (cc or ml) of gas flowing per minute at 0° C. and 1 atmosphere.

[0021] By introducing various gases such as the organosilicon compound into the plasma processing chamber through the gas inlet and exhausting the gas through the exhaust port, the pressure inside the plasma processing chamber is maintained at 1 to 100 Pa. The pressure inside the plasma processing chamber is preferably maintained at 3 to 80 Pa, more preferably 5 to 70 Pa, and even more preferably 10 to 50 Pa.

[0022] When the organosilicon compound is hexamethyldisiloxane (HMDSO), tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), or hexamethyldisilazane (HMDSN), it is preferable that the pressure P (Pa) in the plasma processing chamber, the flow rate F (sccm) of the organosilicon compound, and the output A (W) of the high-frequency power supply device during plasma processing satisfy the following formula (I): (pressure P × flow rate F) / output A≧X (I). In formula (I), X is 0.07, preferably 0.1 or 0.2, and more preferably 0.25 when the organosilicon compound is hexamethyldisiloxane; 0.20, preferably 0.40, and more preferably 0.50 when the organosilicon compound is tetraethoxysilane; 0.30, preferably 0.40, and more preferably 0.9 or more when the organosilicon compound is tetramethoxysilane; and 0.07, preferably 0.8, and more preferably 1 when the organosilicon compound is hexamethyldisilazane.

[0023] The upper limit of (pressure P×flow rate F) / output A is not particularly limited, but is preferably 200 or less or 100 or less, more preferably 50 or less, and even more preferably 20 or less.

[0024] In the present invention, a silicon oxide vapor deposition film is formed from an organosilicon compound by plasma CVD, but it is preferable to treat the film so that organic substituents remain. Since organic substituents remain in the film if the reaction is insufficient during plasma CVD, the lower the output of the high-frequency power supply is, the better. Also, the greater the amount of gas in the film-forming chamber, which is related to the gas flow rate and pressure, the better. Furthermore, the higher the proportion of organic substituents in the silicon oxide compound, the better, and the lower the amount of oxygen is.

[0025] In a more preferred embodiment, regardless of the conditions (a) or (b) above, step (ii) may be carried out by introducing the organosilicon compound into the plasma processing chamber at a flow rate of 10 to 60 sccm while maintaining a pressure of 3 to 50 Pa. More preferably, regardless of the conditions (a) or (b) above, step (ii) may be carried out by maintaining a pressure of 30 to 50 Pa while introducing the organosilicon compound into the plasma processing chamber at a flow rate of 20 to 50 sccm.

[0026] The carrier gas may be a rare gas such as argon or helium, or nitrogen gas. The rare gas may be introduced into the plasma processing chamber as a discharge stabilizing gas. The flow rate of the carrier gas is preferably, for example, 20 to 200 sccm, more preferably 25 to 120 sccm, and even more preferably 40 to 110 sccm. The discharge stabilizing gas is used to stabilize the glow discharge in the plasma CVD method. The type of discharge stabilizing gas may be the same as or different from the carrier gas. The flow rate of the discharge stabilizing gas is preferably, for example, 1 to 200 sccm, more preferably 10 to 120 sccm, and even more preferably 30 to 100 sccm. The total flow rate of the carrier gas and discharge stabilizing gas introduced into the plasma processing chamber is, for example, 1 to 400 sccm, preferably 1 to 200 sccm, and even more preferably 30 to 120 sccm. Furthermore, the ratio of the total flow rate (volume) of the carrier gas and discharge stabilization gas to the total flow rate (volume) of gases introduced into the plasma treatment chamber is, for example, 0 to 95% by volume, preferably 1 to 80% by volume or 0 to 70% by volume, and even more preferably 2 to 50% by volume or 5 to 40% by volume. By maintaining these conditions, a coating with excellent oil-repellent properties and / or oil-repellent properties can be formed on the surface of the molded product. To simplify the process and the equipment, it is preferable not to introduce the carrier gas and discharge stabilization gas.

[0027] Furthermore, an oxidizing gas may or may not be introduced into the plasma processing chamber, with a small amount being preferable. Examples of oxidizing gases include oxygen and NOx, with oxygen being preferred. The upper limit of the flow rate of the oxidizing gas introduced into the plasma processing chamber is, for example, 800 sccm, preferably 500 sccm, more preferably 250 sccm, and even more preferably 200 sccm. The lower limit of the flow rate of the oxidizing gas introduced into the plasma processing chamber is suitably 0 sccm, but when an oxidizing gas is present, it is, for example, 5 sccm, preferably 10 sccm. Furthermore, the ratio of the flow rate (volume) of the oxidizing gas to the total flow rate (volume) of gases introduced into the plasma processing chamber is, for example, 0 to 99% by volume, preferably 0 to 98% by volume or 1 to 96% by volume, and even more preferably 2 to 91% by volume or 2 to 90% by volume. By maintaining these conditions, a silicon oxide vapor deposition film with particularly excellent oil sliding properties and / or oil repellency can be obtained. Furthermore, before introducing various gases such as the organosilicon compound, oxidizing gas, and carrier gas into the plasma processing chamber, the inside of the plasma processing chamber may be depressurized to 100 Pa or less using the exhaust device. By depressurizing in this manner, air and impurities can be removed from the plasma processing chamber, enabling stable and reliable glow discharge and plasma processing. The depressurization may be, for example, 80 Pa or less, preferably 50 Pa or less, more preferably 30 Pa or less, and even more preferably 10 Pa or less, and may be 0.01 Pa or more, or 0.1 Pa or more. When step (ii) is performed without depressurizing, the inside of the plasma processing chamber may be purged with the organosilicon compound, carrier gas, discharge stabilization gas, and the like.

[0028] (iii) a step (iii) of applying a voltage between the first electrode and the second electrode using the high-frequency power supply device at a frequency of 5 to 20 MHz and at the output of (a) or (b) to generate a glow discharge, and plasma-treating the molded article for 1 to 300 seconds to prepare a molded article coated with a silicon oxide vapor-deposited film. Through this step (iii), the molded article is plasma-treated, and a molded article coated with a silicon oxide vapor-deposited film can be prepared. First, the plasma treatment of the molded article surface is carried out by performing a glow discharge in an atmosphere of an organosilicon compound, thereby vapor-depositing a silicon oxide film on the surface of the molded article. Glow discharge is generated, for example, by applying a voltage between the first electrode and the second electrode using the high-frequency power supply device at a frequency of 5 to 20 MHz and at the output of (a) or (b). During discharge, the organosilicon compound of step (ii) is introduced into the plasma treatment chamber at a predetermined flow rate, thereby maintaining the plasma treatment chamber at the predetermined pressure (e.g., 1 to 100 Pa) described in step (ii). A high-frequency voltage is applied between the electrodes to form a glow discharge, and the resulting plasma generates active species such as Si and O from the organosilicon compound, thereby forming a silicon oxide vapor deposition film on the surface of the molded article. The frequency of the applied voltage is preferably 10 to 18 MHz, more preferably 13±2 MHz. The output of the applied voltage is as described in (a) or (b) above, and is preferably 10 to 2000 W or 10 to 1000 W, more preferably 50 to 800 W, even more preferably 70 to 600 W, and particularly preferably 150±100 W. The plasma treatment time (i.e., the time during which voltage is applied by the high-frequency power supply) is, for example, preferably 1 to 300 seconds, more preferably 2 to 200 seconds, and even more preferably 3 to 150 seconds. The upper limit of the plasma treatment time may be about 100 seconds, 50 seconds, 30 seconds, 20 seconds, or 15 seconds. The plasma treatment may be performed all at once, but it is preferable to perform the plasma treatment in multiple periods to prevent the temperature in the plasma treatment chamber from rising excessively. For example, the plasma treatment may be performed in two or three periods, each of which lasts 2 to 5 seconds.

[0029] In a more preferred embodiment, regardless of the conditions of (a) or (b), the step (iii) may be carried out by applying a voltage between the first electrode and the second electrode by the high-frequency power supply device at a frequency of 13±2 MHz and an output of 150±100 W or 100±20 W to generate a glow discharge, and plasma-treating the molded article for 1 to 20 seconds, 3 to 15 seconds, 1 to 200 seconds, or 3 to 150 seconds to prepare a molded article coated with a silicon oxide vapor-deposited film.

[0030] [Silicon oxide vapor deposition film] The silicon oxide vapor deposition film obtained by the method for producing a molded article coated with the silicon oxide vapor deposition film is mainly composed of silicon oxide (SiO2), but it is believed that a certain proportion of hydroxyl groups and alkoxy groups and / or alkyl groups remain in the silicon oxide vapor deposition film by the method of the present invention, and it is assumed that these residues or remaining organic substances provide the surface of the molded article with oil repellency and good oil sliding properties. Without being bound by theory, to form such a special silicon oxide vapor deposition film, plasma treatment is usually performed in a high-power and / or high-concentration oxidizing gas atmosphere. In the present invention, however, plasma treatment is performed at a relatively low power and / or a specific flow rate (concentration) of a specific organosilicon compound, preferably under low-oxygen conditions, so that a large number of active species incompletely converted from the organosilicon compound into plasma are present, and these are vapor-deposited on the surface of the molded article to form a vapor deposition film, which is thought to result in the formation of a special molded article surface with excellent oil sliding properties and oil repellency.

[0031] The silicon oxide vapor deposition film produced by the method of the present invention can achieve excellent oil sliding properties and / or oil repellency by covering the surface of a molded article, so the thickness of the film is not considered to have any particular effect. Therefore, the film thickness is not particularly limited, but is preferably 1 to 800 nm, more preferably 5 to 500 nm, even more preferably 8 to 400 nm, even more preferably 10 to 300 nm, and most preferably 10 to 150 nm. The thickness of the silicon oxide vapor deposition film can be measured, for example, using a microscopic automatic film thickness measurement system (model number: F54 XY 200UV) manufactured by Filmetrics Inc., a stylus film thickness meter "DEKTAK" manufactured by Bruker, or a cross-section of the film and a field emission scanning electron microscope "JSM-7800F Prime" manufactured by JEOL Ltd. (magnification: 30,000x, accelerating voltage: 2 kV, working distance: 10.3 mm).

[0032] [Molded Articles Coated with Silicon Oxide Vapor Deposition Films] Molded articles coated with a silicon oxide vapor deposition film by the method of the present invention are molded articles in which the surface of a molded article (substrate) is coated with a silicon oxide vapor deposition film formed by the method of the present invention. The surface coating may be the entire inner or outer surface of the molded article, or a portion thereof, but from the perspective of content dischargeability, it is preferable to refer to the coating of the inner surface of the molded article. Note that the aforementioned surface refers to the outermost layer of the molded article. Furthermore, the silicon oxide vapor deposition film of the present invention may have another coating between the substrate of the molded article being coated and the coating layer of the present invention.

[0033] The contact angle of refined rapeseed oil at 20°C on the surface of the molded article covered with the silicon oxide vapor-deposited film is preferably 25° or more, more preferably 30 to 70°, even more preferably 35 to 60°, and most preferably 33 to 55°.

[0034] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following, "%" refers to % by mass unless otherwise specified.

[0035] [Analysis Method] (Oil Sliding Property) The oil storage containers (samples) of the Examples and Comparative Examples were placed horizontally, and a drop (approximately 24.36 mg) of refined rapeseed oil ("Nissin Canola Oil" manufactured by Nisshin Oillio Group Co., Ltd., 99.9%) colored with carotene ("β-Carotene 30% FS" manufactured by DMS, 0.1%) was dropped onto the flat surface of the container from the opening of the container using a dropper. The sample was immediately placed on a stage ("Stage (Angle Inclination)" manufactured by AS ONE Corporation) set at an inclination of 70° relative to the vertical direction, and the time it took for the rear end of the oil droplet (the uppermost contact point between the sample surface and the oil droplet on the inclined sample surface) to move 6 mm across the sample surface was measured. The temperature during measurement was room temperature (23 ° C). Evaluation was performed based on the following criteria A to E according to the moving time, and if it was A to C, it was determined that there was an excellent oil sliding property. The shorter the travel time, the better the oil slides off, and the better the oil drains from the container. A rating: 10 seconds or less B rating: 10 to 20 seconds C rating: 20 to 60 seconds D rating: 60 to 300 seconds E rating: over 300 seconds

[0036] [Manufacturing method 1 for molded products coated with silicon oxide vapor deposition film] (Plasma CVD apparatus 1) The settings for the plasma CVD apparatus used in each of Examples No. 1 to 191 are as follows. A schematic diagram of the apparatus is shown in Figure 1. Name: Plasma CVD apparatus Film formation method: PECVD (Plasma Enhanced Chemical Vapor Deposition) Plasma source: CCP (Capacitively Coupled Plasma) First electrode: Made of aluminum alloy, the first electrode is a similar shape to the molded product (object to be plasma treated) but slightly larger, placed to cover the outside of the molded product except for the upper end, can be separated into two pieces, upper and lower, so that the molded product can be removed, no cooling mechanism, also serves as a plasma treatment chamber Second electrode: Made of stainless steel SUS304, the second electrode is placed inside the container that is the molded product, the end of the second electrode is an internal gas inlet electrode with a gas inlet port (inner dimension: φ6.35 mm), no heating mechanism

[0037] Plasma treatment chamber: Molded product shape, material is aluminum alloy High frequency power supply: Noda RF Technology Co., Ltd., product number NR2N-08Y, maximum output 2000W RF switch for high frequency power supply: For 2ch High frequency power supply matching method: Automatic impedance matching Exhaust system: Mechanical booster pump (main pull, plasma treatment chamber side, Edwards Corporation, product number EH250 Fomblin specification), rotary pump (auxiliary, connected in series to the mechanical booster pump, atmospheric pressure side, Edwards Corporation, product number E2M80 Fomblin specification)

[0038] (Production 1 of Molded Articles Coated with a Silicon Oxide Vapor Deposition Film) The first electrode, which also served as the plasma treatment chamber, contained the oxidizing gas inlet, the carrier gas inlet, and a hollow second electrode / gas inlet for the organosilicon compound. An exhaust port connected to the exhaust system was also provided. A commercially available polyethylene terephthalate (PET) container for edible oils and fats (used capacity 600 g; inner diameter of the top opening 27.6 mm, height 218.7 mm) was placed in the plasma treatment chamber (first electrode), and the uncoated container was used as the molded article before being coated with the silicon oxide vapor deposition film. A second electrode was inserted through the top opening of the container, and these electrodes were connected to the high-frequency power supply. The first electrode consisted of two pieces, upper and lower, and was capable of housing the container. In the plasma CVD apparatus 1 ( FIG. 1 , details described above) containing the PET container, the pressure in the plasma treatment chamber (first electrode) was reduced to 1 Pa using the exhaust system. Subsequently, an organosilicon compound gas, a carrier gas, and an oxidizing gas were introduced under the conditions (gas flow rates) shown in Table 1. After confirming that the pressure inside the plasma treatment chamber was maintained at the pressure shown in Table 1, a voltage was applied using the high-frequency power supply at the output and time shown in Table 1, glow discharge was performed, and the surface of the PET container was plasma-treated to coat the PET container with a silicon oxide vapor-deposited film. After glow discharge, the introduction of all gases was stopped, the pressure inside the plasma treatment chamber was reduced to 1 Pa again, the plasma treatment chamber was opened to the atmosphere, and the PET container was removed from the plasma treatment chamber. A 2 cm square PET plate was cut from the flat central portion of the PET container coated with a silicon oxide vapor-deposited film as described above, and its oil slide-off properties were analyzed and evaluated as described above. The results of the analysis and evaluation are shown in Tables 1-1 to 11. Furthermore, the pressure × flow rate / output was calculated from the pressure inside the plasma treatment chamber (Pa), the flow rate (sccm) of the organosilicon compound (sccm), and the output (W) of the high-frequency power supply, and the results are shown in Tables 1-1 to 11.

[0039]

[0040] In plasma treatments at a pressure of 1 to 100 Pa for 1 to 30 seconds, (a) the output of the high-frequency power supply was 10 to 900 W and the flow rate of the organosilicon compound was 1 to 100 sccm, or (b) the output of the high-frequency power supply was greater than 900 W but not greater than 2000 W and the flow rate of the organosilicon compound was 15 to 100 sccm, and the oil slideability was good, ranging from A to C. Furthermore, in the case of hexamethyldisiloxane (HMDSO), the slideability was E when the (pressure x flow rate) / output ratio was 0.05, but was good, ranging from A to C, when the ratio was 0.1 or greater. Furthermore, in the case of tetraethoxysilane (TEOS), the slideability was E when the (pressure x flow rate) / output ratio was 0.11, but was good, ranging from A to C, when the ratio was 0.2 or greater. Furthermore, in the case of tetramethoxysilane (TMOS), when the (pressure x flow rate) / output ratio was 0.2 or less, the sliding performance was rated D or E, but when it was 0.30 or more, the sliding performance was A to C, which was good. In the case of hexamethyldisilazane (HMDSN), when the (pressure x flow rate) / output ratio was 0.05 or less, the sliding performance was D, but when it was 0.1 or more, the sliding performance was A to C, which was good.

[0041] [Method 2 for Manufacturing Molded Articles Coated with Silicon Oxide Vapor Deposition Films] (Plasma CVD Apparatus 2) The plasma CVD apparatus used was the same as the plasma CVD apparatus 1 described above, except that the electrode portion was replaced with parallel flat electrodes (electrode distance 50 mm). The first electrode did not double as a plasma treatment chamber; instead, the parallel flat first and second electrodes were installed within the plasma treatment chamber. (Manufacturing Molded Articles Coated with Silicon Oxide Vapor Deposition Films 2) Uncoated, commercially available polyethylene caps (PE caps) were coated with a silicon oxide vapor deposition film using the plasma CVD apparatus described above under the conditions listed in Table 2, similar to [Method 1 for Manufacturing Molded Articles Coated with Silicon Oxide Vapor Deposition Films]. The flat surface of the resulting silicon oxide vapor deposition film-coated PE cap was analyzed and evaluated for oil slideability. The results of the analysis and evaluation are shown in Table 2. The pressure × flow rate / output ratio was calculated from the pressure (Pa) in the plasma treatment chamber, the flow rate (sccm) of the organosilicon compound, and the output (W) of the high-frequency power supply, and is shown in Table 2.

[0042] Table 2

[0043] Compared to No. 192, No. 193 had better oil sliding properties.

[0044] [Method 3 for producing molded articles coated with silicon oxide vapor deposition films] (Plasma CVD apparatus 3) A plasma CVD apparatus (model number: PD-220NL, manufactured by Samco Inc.) was used. (Production 3 of molded articles coated with silicon oxide vapor deposition films) A commercially available uncoated polyethylene film (PE film: 100 μm thick, manufactured by Toshin Scientific Industry Co., Ltd.) used for pillow containers was cut into 2 cm square pieces, and a silicon oxide vapor deposition film was coated using the aforementioned plasma CVD apparatus 3 under the conditions shown in Table 3, similar to [Method 1 for producing molded articles coated with silicon oxide vapor deposition films]. The 2 cm square PE film coated with the silicon oxide vapor deposition film as described above and a 2 cm square PE film not coated with the silicon oxide vapor deposition film were analyzed and evaluated for oil slide-off properties as described above. The analysis and evaluation results are shown in Table 3. Furthermore, the pressure (Pa) in the plasma processing chamber, the flow rate (sccm) of the organosilicon compound, and the output (W) of the high frequency power supply device were used to calculate the following formula: Pressure×Flow Rate / Output.

[0045] Table 3

[0046] Compared to No. 194, No. 195 had better oil sliding properties.

[0047] (Production 4 of Molded Articles Coated with Silicon Oxide Vapor Deposition Film) A number of commercially available, uncoated polyethylene terephthalate (PET) containers for edible oils and fats with different capacities were used as molded articles before being coated with a silicon oxide vapor deposition film. These containers were coated with a silicon oxide vapor deposition film under the conditions shown in Table 4, similar to [Production Method 1 of Molded Articles Coated with a Silicon Oxide Vapor Deposition Film]. A 2 cm square PET plate was cut from the flat central portion of the PET container coated with a silicon oxide vapor deposition film as described above, and the oil slide-off properties were analyzed and evaluated as described above. The results of the analysis and evaluation are shown in Table 4. Furthermore, the pressure × flow rate / output was calculated from the pressure (Pa) in the plasma treatment chamber, the flow rate (sccm) of the organosilicon compound, and the output (W) of the high-frequency power supply, and the result is shown in Table 4.

[0048] Table 4

[0049] In all of the containers No. 196 to 200, the oil was easily removed.

[0050] (Production 5 of a molded article coated with a silicon oxide vapor deposition film) The pressure inside the plasma treatment chamber (inside the first electrode) was reduced to 115 Pa using an exhaust device, and then various gases were introduced under the conditions (gas flow rates) shown in Table 5. Once the pressure inside the plasma treatment chamber reached the pressure shown in Table 5, a voltage was immediately applied using the high-frequency power supply. A 2 cm square PET plate was cut from the flat central portion of the PET container coated with the silicon oxide vapor deposition film described above, and its oil slide-off properties were analyzed and evaluated as described above. The results of the analysis and evaluation are shown in Table 5. Furthermore, the pressure × flow rate / output was calculated from the pressure inside the plasma treatment chamber (Pa), the flow rate (sccm) of the organosilicon compound, and the output (W) of the high-frequency power supply, and the result is shown in Table 5.

[0051] Table 5

[0052] Even under the film-forming conditions of No. 201, where the ultimate vacuum level was low, the oil slide-off was good.

[0053] (Production 6 of Molded Article Coated with Silicon Oxide Vapor Deposition Film) An uncoated PET plate (a 2 cm square PET plate cut from the flat central portion of a commercially available uncoated polyethylene terephthalate (PET) container for edible oils and fats (usage capacity 600 g: inner diameter of upper opening 27.6 mm, height 218.7 mm)) was coated with a silicon oxide vapor deposition film using the above-mentioned plasma CVD apparatus 2 under the conditions shown in Table 6, as in [Production Method 1 of Molded Article Coated with Silicon Oxide Vapor Deposition Film]. The oil slide-off properties of the resulting silicon oxide vapor deposition film-coated PET plate were analyzed and evaluated. The results of the analysis and evaluation are shown in Table 6. Furthermore, the pressure × flow rate / output was calculated from the pressure (Pa) in the plasma treatment chamber, the flow rate (sccm) of the organosilicon compound, and the output (W) of the high-frequency power supply device, and the result is shown in Table 6.

[0054] Table 6

[0055] The oil also had good sliding properties when the film was formed on the PET plates Nos. 202 to 204.

[0056] 1: Plasma treatment chamber 2: High frequency power supply 3: First electrode 4: Second electrode and gas inlet 5: Gas inlet 6: Molded product 7: Exhaust port 8: Exhaust device 9: Organosilicon compound (gas) 10: Oxidizing gas 11: Carrier gas

Claims

1. A method for producing a molded article coated with a silicon oxide vapor deposition film, comprising coating a molded article with a silicon oxide vapor deposition film by a plasma CVD method, wherein the plasma treatment in the plasma CVD method comprises the following steps: (i) placing a molded article before being coated with the silicon oxide vapor deposition film inside a plasma treatment chamber equipped with at least one gas inlet, a first electrode and a second electrode connected to a high-frequency power supply device, and an exhaust port connected to an exhaust device; (ii) introducing an organosilicon compound from the gas inlet into the plasma treatment chamber at a flow rate that satisfies the following (a) or (b): (a) when the output of the high-frequency power supply device is 10 to 900 W, the flow rate of the organosilicon compound is 1 to 100 sccm; or (b) when the output of the high-frequency power supply device is more than 900 W but not more than 2000 W, the flow rate of the organosilicon compound is 15 to 100 sccm; and maintaining a pressure of 1 to 100 Pa while exhausting from the exhaust port; (iii) applying a voltage having a frequency of 5 to 20 MHz and an output of (a) or (b) between the first electrode and the second electrode by the high-frequency power supply device to generate a glow discharge, and plasma-treating the molded article for 1 to 300 seconds to prepare a molded article coated with a silicon oxide vapor-deposited film.

2. A method for producing a molded product according to claim 1, wherein the organosilicon compound is hexamethyldisiloxane, tetraethoxysilane, tetramethoxysilane, or hexamethyldisilazane, and the pressure P (Pa) in the plasma processing chamber during the plasma processing, the flow rate F (sccm) of the organosilicon compound, and the output A (W) of a high-frequency power supply device satisfy the following formula (I): (pressure P x ​​flow rate F) / output A ≧ X (I), where X is 0.07 when the organosilicon compound is hexamethyldisiloxane, 0.20 when the organosilicon compound is tetraethoxysilane, 0.30 when the organosilicon compound is tetramethoxysilane, and 0.07 when the organosilicon compound is hexamethyldisiloxane.

3. The method for producing a molded article according to claim 1 or 2, wherein the step (ii) further comprises introducing an oxidizing gas into the plasma treatment chamber at a flow rate of 10 to 800 sccm.

4. The method for producing a molded article according to any one of claims 1 to 3, wherein step (ii) is carried out without introducing an oxidizing gas, and step (iii) is carried out in the absence of an oxidizing gas.

5. The method for producing a molded product according to claim 4, wherein step (ii) is a step of introducing the organosilicon compound into the plasma treatment chamber at a flow rate of 10 to 60 sccm while maintaining a pressure of 3 to 50 Pa, regardless of the conditions of (a) or (b).

6. The method for producing a molded article according to claim 4 or 5, wherein the step (iii) is a step of generating a glow discharge by applying a voltage at a frequency of 13±2 MHz and an output of 150±100 W between the first electrode and the second electrode by the high-frequency power supply device, regardless of the conditions of (a) or (b), and plasma-treating the molded article for 1 to 200 seconds to prepare a molded article coated with a silicon oxide vapor-deposited film.

7. A molded article having a substrate and a silicon oxide vapor-deposited film covering the substrate surface, produced by the method according to any one of claims 1 to 6.

8. The molded product according to claim 7, wherein the substrate is molded from a material selected from the group consisting of resin, glass, paper, china clay, and metal.

9. The molded product according to claim 7 or 8, wherein the silicon oxide vapor-deposited film is a film formed by vapor-depositing tetraethoxysilane or hexamethyldisiloxane.

10. The molded article according to any one of claims 7 to 9, wherein the substrate surface covered with the silicon oxide vapor-deposited film is the inner surface of the molded article.

11. The molded article according to any one of claims 7 to 10, wherein the contact angle of refined rapeseed oil at 20°C on the surface of the molded article covered with the silicon oxide vapor-deposited film is 25° or more.

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