JP5084182B2 - Coated plastic products and coatings - Google Patents

Description

  The present invention relates to a coated plastic product obtained by coating a plastic product with a coating mainly composed of carbon and hydrogen and having a structure different from that of DLC (diamond-like carbon), and has a gas barrier property (a property of low oxygen permeability) and impact resistance. It improves basic properties such as heat resistance, abrasion resistance, scratch resistance, affinity, heat resistance, and environmental properties. Thereby, a covering plastic product exhibits the outstanding performance in uses, such as a packaging container, a sliding member, a recording medium, a fiber, or a card | curd. The present invention also relates to the coating film formed on the surface of a substrate of metal, ceramics or glass as well as plastic.

  Plastics are widely used in a very wide range of industries, for example, in applications such as packaging materials, containers, and parts. In particular, plastic containers are one of the mainstream beverage containers because they are widely adopted as alternative materials for glass and aluminum. However, there are applications for which it has been pointed out that basic properties such as gas barrier properties, abrasion resistance, impact resistance or scratch resistance are insufficient. Therefore, in recent years, further improvement of these basic characteristics has been demanded. Accordingly, an invention has been disclosed in which an inorganic substance or glass is coated on the surface of a molded body made of polyethylene terephthalate (PET) resin, and gas barrier properties, wear resistance, impact resistance, scratch resistance, and the like have been improved. For example, a technique in which a polyethylene terephthalate bottle is coated with a carbon film or an inorganic thin film is disclosed (for example, see Patent Documents 1, 2, or 3).

JP-A-8-53116 JP 2002-68308 A JP 2001-158415 A

  However, since the coating is a brittle material, when the resin that is the base material of the coating is greatly deformed, the coating may not follow the deformation and may be broken or peeled off. Alternatively, due to the difference in coefficient of thermal expansion between the coating and the resin, the coating may not follow the dimensional change of the resin that is the base material at the time of temperature rise, which may cause destruction or peeling.

  In recent years, since plastic products have been used in a wider range of fields, it is desirable to have excellent deformation resistance while having excellent gas barrier properties, wear resistance, impact resistance, and scratch resistance.

  Further, not only plastic products but also products made of metals, ceramics, or glass materials are required to improve basic characteristics such as impact resistance, wear resistance, scratch resistance, and affinity.

  Therefore, the present invention aims to impart excellent deformation resistance in addition to excellent gas barrier properties, wear resistance, impact resistance and scratch resistance by coating the surface of a plastic product with a coating. To do.

  In addition to plastic products, products made of metals, ceramics, or glass materials are also used to improve basic characteristics such as impact resistance, wear resistance, scratch resistance, and affinity. An object of the present invention is to provide a coating for coating the surface of a product.

As a result of intensive research and development to solve the above-mentioned problems, the inventors of the present invention have the same constituent elements as DLC (diamond-like carbon), but coat the surface of a plastic product with a coating having a different atomic bonding structure. As a result, the inventors have found that the above object can be achieved, and completed the present invention. That is, the coated plastic product according to the present invention is a coated plastic product in which a coating containing carbon atoms and hydrogen atoms as main constituent atoms is formed on the surface of a plastic molded body by an atmospheric pressure low temperature plasma CVD method. Covers the electrode surface of at least one of the high-frequency application electrode and the ground electrode facing each other with a gap therebetween with a dielectric having a relative dielectric constant of 3 to 100, and the high-frequency application electrode and the ground electrode Alternatively, a plastic molded body is disposed on either of the dielectrics so as to face the gap, and in the gap, a source gas and an inert gas serving as a carbon atom source and a hydrogen atom source (source gas volume% / A supply gas containing an inert gas volume%) of 50/50 to 100/0 is flowed at a flow rate of 2.5 to 50 m / min. And supplying high-frequency power electrode area per 0.02~0.2W / mm ^2, the result of the feed gas is formed by plasma at atmospheric pressure, and time-of-flight secondary ion mass spectrometry (TOF -SIMS) In the anion analysis of the method, (1) the intensity ratio of the peak of triatomic carbon to the peak of monoatomic carbon (C3 / C1) in the measurement after cleaning the surface with pure water using the primary ion source Au 0.02 or more, and (2) the ratio of the intensity of the peak of 4-atomic carbon to the peak of monoatomic carbon (C4 / C1) in the measurement after cleaning the surface with pure water using the primary ion source Au is 0.05 As described above, (3) the intensity ratio (C5 / C1) of the pentaatomic carbon peak to the monoatomic carbon peak in the measurement after cleaning the surface with pure water using the primary ion source Au is 0.02 or more ( Less of 1) to (3) In the analysis of the differential scanning calorimetry (DSC) method, the peak of the exothermic peak appears at 140 ° C to 150 ° C under the measurement conditions of a heating rate of 10 ° C / min and nitrogen atmosphere. The end point of the endothermic peak appears between 70 and 80 ° C. Note that the ratio of (source gas volume% / inert gas volume%) to 50/50 to 100/0 is (source gas volume% / inert gas volume%) = 50/50 (source gas volume%). / Inert gas volume%) = 100/0 is included (hereinafter the same in the same notation).

  Here, in the coated plastic product according to the present invention, the raw material gas is preferably acetylene. High carbon / hydrogen atom ratio and high deposition efficiency.

Alternatively, the coated plastic product according to the present invention is a coated plastic product in which a coating containing carbon atoms and hydrogen atoms as main constituent atoms is formed on the surface of a plastic molding, wherein the coating is a time-of-flight secondary ion In the anion analysis of the mass spectrometry (TOF-SIMS) method, it is preferable to satisfy all of the above (1), (2), and (3).

  Here, in the coated plastic product according to the present invention, the coating includes any one of a single layer having the same composition, a plurality of layers having different compositions, or a gradient composition layer having a continuously gradient composition. It is.

  In the coated plastic product according to the present invention, the plastic molded body is preferably made of a polyethylene terephthalate resin. It is optimal when the oxygen permeability is low and the plastic product is a beverage container.

  The coated plastic product according to the present invention includes a packaging container, a sliding part, a recording medium, a sheet, a fiber, or a card.

The film according to the present invention is a film containing carbon atoms and hydrogen atoms formed as main constituent atoms on the surface of a substrate by atmospheric pressure low temperature plasma CVD, wherein the films are opposed to each other with a gap therebetween. The electrode surface on the opposite side of at least one of the application electrode and the ground electrode is covered with a dielectric having a relative dielectric constant of 3 or more and 100 or less, and is placed on any of the high-frequency application electrode, the ground electrode, or the dielectric. A substrate is arranged facing the gap, and a raw material gas and an inert gas (raw material gas volume% / inert gas volume%) of 50/50 to 100 are provided in the gap as a carbon atom source and a hydrogen atom source. The supply gas respectively contained at a rate of 0/0 is flowed at a flow rate of 2.5 to 50 m / min, and high frequency power of 0.02 to 0.2 W / mm ² per unit electrode area is supplied to the high frequency application electrode. The supply gas In the negative ion analysis of the time-of-flight secondary ion mass spectrometry (TOF-SIMS) method, (1) the surface is purified using the primary ion source Au. After the water cleaning, the intensity ratio (C3 / C1) of the triatomic carbon peak to the monoatomic carbon peak is 0.07 or more, and (2) the surface is cleaned with pure water using the primary ion source Au. The intensity ratio (C4 / C1) of the peak of the 4-atomic carbon to the peak of the monoatomic carbon in the measurement of 0.05 is 0.05 or more, and (3) the measurement after the surface is cleaned with pure water using the primary ion source Au. The intensity ratio (C5 / C1) of the peak of 5 atomic carbons to the peak of monoatomic carbons satisfies at least one of (1) to (3) of 0.02 or more, and differential scanning calorimetry (DSC ) In the analysis of the method, Raising rate 10 ° C. / min, the apex of the exothermic peak between 140 to 150 ° C. under measurement conditions of a nitrogen atmosphere appeared, characterized in that the apex of the endothermic peak appearing between 70 to 80 ° C..

  The present invention can impart excellent deformation resistance in addition to excellent gas barrier properties, wear resistance, impact resistance, and scratch resistance by covering the surface of a plastic product with a coating. Further, the substrate that is the film formation body may be not only a plastic product but also a product made of each material of metal, ceramics, or glass, and depending on the coating, impact resistance, wear resistance, scratch resistance, or affinity It is possible to improve basic characteristics such as property. Further, since this film has little residual stress, for example, even if the film thickness is 10 μm or 10 μm or more, cracks are hardly generated and it has deformation resistance, so that deformation or thermal expansion of the substrate is possible. High compliance with expansion and contraction due to.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions.

(Function)
For example, Patent Document 3 discloses a coated plastic product in which a coating containing carbon atoms and hydrogen atoms as main constituent atoms is formed on the surface of a plastic molded body by atmospheric pressure low temperature plasma CVD. In the technique disclosed in Patent Document 3, the supply gas to be converted into plasma uses an inert gas such as helium gas as the main gas (see, for example, claim 6 or 7 of Patent Document 3). This is because in the atmospheric pressure low temperature plasma CVD method, it is difficult to convert the supply gas into plasma unless the inert gas is used as the main gas. However, if the inert gas is used as the main gas, (1) the gas barrier property is reduced with the same film thickness, and (2) the content of the source gas is small, so that the film formation rate is low (for example, the embodiment of Patent Document 3). , The film formation time is as long as 1 minute).

  On the other hand, in the coated plastic product according to the present embodiment, the coating covering the surface uses atmospheric pressure low temperature plasma CVD using a supply gas containing a source gas as a carbon atom source and a hydrogen atom source as a main gas. The film is formed by the method. That is, the supply gas having the source gas as the main gas, which has been difficult in the past, is turned into plasma. Therefore, although it is speculated, the coating film is composed of carbon and hydrogen as main components, a mixed composition of a three-dimensional structure of a carbon skeleton and a linear structure of hydrocarbon, and unavoidable impurities. In other words, the coating has a three-dimensional structure of a carbon skeleton, so that it exhibits excellent performance in wear resistance, impact resistance and scratch resistance, and the structure is retained by a flexible hydrocarbon linear structure. Therefore, it has a property with excellent deformation resistance. Thereby, internal stress hardly remains in the coating, and the maximum thickness at which cracks do not occur can be increased (for example, the maximum thickness is 100 μm). The plastic product coated with this film has gas barrier properties, abrasion resistance, impact resistance, and scratch resistance, and also has excellent deformation resistance. In addition, since the supply gas containing the source gas as the main gas is used, the film forming rate is very high and the maximum 3 μm / second is possible, resulting in a coated plastic product with excellent productivity.

(Coated plastic product according to this embodiment)
Specifically, the coated plastic product according to the present embodiment is a coated plastic product in which a coating containing carbon atoms and hydrogen atoms as main constituent atoms is formed on the surface of a plastic molded body by an atmospheric pressure low temperature plasma CVD method. And the coating film contains a source gas and an inert gas which are a carbon atom source and a hydrogen atom source in a ratio of 50/50 to 100/0 (source gas volume% / inert gas volume%). It is formed by converting the supplied gas into plasma under normal pressure.

  In the coated plastic product according to the present embodiment, the film can be formed by various film forming methods such as a well-known plasma CVD method, sputtering method, vacuum deposition method, etc., but the film forming efficiency, the smoothness of the film, and the film body The plasma CVD method is preferable because of its high degree of freedom in shape selection. In particular, the normal pressure low temperature plasma CVD method performed at normal pressure is more preferable from the viewpoints of film formation speed and ease of control of the film structure, and simplification and space saving associated with the need for a vacuum apparatus. In the normal-pressure low-temperature plasma CVD method, the normal pressure refers to an atmospheric pressure or a sub-atmospheric pressure of 0.1 atm (10000 Pa) or more in the present embodiment. In addition, since the low temperature plasma CVD method is used, the film formation target is not heated, or the plastic substrate is not damaged even if heated. For example, when the substrate is made of PET, the substrate temperature is set to 80 ° C. or lower.

  The plastic molded body to be the film-forming body is not particularly limited because it has a form corresponding to the application. For example, it is a bottle shape for a packaging container, a shaft part for a sliding part, and a disk for a recording medium. If it is a shape or a card, it is a thin plate shape, if it is a sheet, it is a fabric shape, if it is a fiber, it is a thread or hollow fiber. The packaging container is used as a one-way or returnable and usable beverage container or food container filled with, for example, a carbonated beverage or a sparkling beverage. By forming a film on the surface of the plastic molded body, the coated plastic product according to the present embodiment is obtained.

  Examples of plastic molding materials include polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin (PP), cycloolefin copolymer resin (COC, cyclic olefin copolymer), and ionomer. Resin, poly-4-methylpentene-1 resin, polymethyl methacrylate resin, polystyrene resin, ethylene-vinyl alcohol copolymer resin, acrylonitrile resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyamide resin, polyamideimide resin, polyacetal Exemplifying resin, polycarbonate resin, polysulfone resin, or tetrafluoroethylene resin, acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin It can be. Among these, PET is particularly preferable. It is optimal when the oxygen permeability is low and the plastic product is a beverage container.

  In the present embodiment, the case where the film formation target is a plastic molded body has been described. However, for example, a film may be coated on the surface of a base made of metal, ceramics, or glass. Similarly, basic characteristics such as impact resistance, wear resistance, scratch resistance, or affinity can be improved.

  Examples of the source gas used as the carbon atom source and the hydrogen atom source include alkane gases such as methane, ethane, propane, butane, pentane, and hexane, alkene gases such as ethylene, propylene, and butyne, butadiene, pentadiene, and the like. Alkadiene gases, alkyne gases such as acetylene and methylacetylene, aromatic hydrocarbon gases such as benzene, toluene, xylene, indene, naphthalene and phenanthrene, cycloalkane gases such as cyclopropane and cyclohexane, cyclohexane There are cycloalkene gases such as bentene and cyclohexene, alcohol gases such as methanol and ethanol, ketone gases such as acetone and methyl ethyl ketone, and aldehyde gases such as formaldehyde and acetaldehyde.Of these, acetylene is preferred. High carbon / hydrogen atom ratio and high deposition efficiency.

  The inert gas is, for example, a rare gas such as helium or argon or a nitrogen gas.

  The supply gas preferably contains 70 to 100% by volume of the source gas, 0 to 30% by volume of the inert gas, and 85 to 100% by volume of the source gas. More preferably, the inert gas is contained in an amount of 0% by volume to 15% by volume. If the coating gas is formed by converting the supply gas containing less than 50% by volume of the source gas and more than 50% by volume of the inert gas into plasma, as described above, (1) the gas barrier property is low with the same film thickness. (2) Since the content of the source gas is small, there is a problem that the film forming speed is low. The supply gas may contain other additive gases such as oxygen gas and water vapor as long as the effects of the present invention are not affected. Moreover, it is good also as inert gas by mixing rare gas and nitrogen gas.

  The coating includes carbon atoms and hydrogen atoms as main constituent atoms. As described above, the coating consists of a mixed composition of a three-dimensional structure of a carbon skeleton and a straight chain structure of hydrocarbons, and unavoidable impurities. . In other words, the coating has a three-dimensional structure of a carbon skeleton, so that it exhibits excellent performance in wear resistance, impact resistance and scratch resistance, and the structure is retained by a flexible hydrocarbon linear structure. Therefore, it has a property with excellent deformation resistance. The coating may contain at least one of oxygen and nitrogen as long as the atomic ratio is 15% or less. Beyond that, the desired film properties are reduced.

  The coating of the coated plastic product has a peak of monoatomic carbon in the measurement after cleaning the surface with pure water using the primary ion source Au in the anion analysis of time-of-flight secondary ion mass spectrometry (TOF-SIMS) method. In the analysis of the differential scanning calorimetry (DSC) method, the intensity ratio (C3 / C1) of the peak of the triatomic carbon with respect to is 0.07 or more, and the temperature rise rate is 10 ° C./min under the measurement conditions of the nitrogen atmosphere. It includes a film in which the peak of the exothermic peak appears between 140 and 150 ° C and the peak of the endothermic peak appears between 70 and 80 ° C.

  Further, the coating of the coated plastic product has four atoms relative to the peak of the monoatomic carbon in the measurement after the surface is cleaned with pure water using the primary ion source Au in the anion analysis of the time-of-flight secondary ion mass spectrometry. The carbon peak intensity ratio (C4 / C1) is 0.05 or more, and in the analysis of the differential scanning calorimetry method, the temperature rise rate is 10 ° C./min, and the measurement condition in the nitrogen atmosphere is 140 to 150 ° C. The film includes a film in which the peak of the exothermic peak appears and the peak of the endothermic peak appears between 70 to 80 ° C.

  Moreover, the coating of the coated plastic product is 5 atoms relative to the peak of the monoatomic carbon in the measurement after the surface is cleaned with pure water using the primary ion source Au in the anion analysis of the time-of-flight secondary ion mass spectrometry. The intensity ratio of carbon peak (C5 / C1) is 0.02 or more, and in the analysis of the differential scanning calorimetry method, the heating rate is 10 ° C./min, and the measurement condition in the nitrogen atmosphere is 140 to 150 ° C. The film includes a film in which the peak of the exothermic peak appears and the peak of the endothermic peak appears between 70 to 80 ° C.

  Alternatively, the coating of the coated plastic product is a coated plastic product in which a coating containing carbon atoms and hydrogen atoms as main constituent atoms is formed on the surface of a plastic molded body, and the coating is a time-of-flight secondary ion mass spectrometry In the anion analysis of the method, the intensity ratio (C3 / C1) of the peak of triatomic carbon to the peak of monoatomic carbon in the measurement after cleaning the surface with pure ion source Au is 0.07 or more. Yes, the intensity ratio (C4 / C1) of the peak of the 4-atomic carbon to the peak of the monoatomic carbon is 0.05 or more, and the intensity ratio (C5 / C1) of the peak of the 5-atomic carbon to the peak of the monoatomic carbon is 0. 0.02 or more, and in the differential scanning calorimetry analysis, the peak of the exothermic peak was observed at 140 ° C. to 150 ° C. under the measurement conditions of a heating rate of 10 ° C./min and a nitrogen atmosphere. There appeared, including coatings top of an endothermic peak appearing between 70 to 80 ° C..

  In time-of-flight secondary ion mass spectrometry using Au ions, fragments of the coating consisting only of carbon atoms are detected in anion analysis. In this analysis, the more the carbon skeleton having a three-dimensional structure is rich in the film, the more the fragments having a large number of carbon atoms among the fragments composed of only carbon atoms. In the case of a straight-chain carbon skeleton, only atoms of foreign elements such as hydrogen bonded to each other are removed in the sputtering process, and a fragment in which only straight-chain carbon is connected is generated. This is because it is less probable than the fragmentation in a straight chain state in which atoms such as carbon are removed or in a three-dimensional skeleton state. Therefore, DLC (diamond-like carbon), which is a typical hydrocarbon compound having a three-dimensional structure carbon skeleton, has a larger number of carbon atoms than fragments of general linear hydrocarbon compounds. There are relatively many fragments. Specifically, the relative amount becomes clear by observing the peak height, which is the ratio between the detected amount of single carbon atoms and the detected amount of multiple carbon atoms. However, in the accuracy of general analysis, peaks derived from single carbon atoms and two carbon atoms are not significantly different between DLC and general linear hydrocarbon compounds, and as the number of carbons increases, Specifically, from the region where the number of carbon atoms exceeds 5, the analysis background is relatively high with respect to the fragment generation probability, and the reliability with respect to the peak height is poor. As a result, for the carbon numbers 3, 4 and 5 which are regions between these carbon numbers, the relative amount of the three-dimensional carbon skeleton constituting the coating can be read with high reliability.

The analysis conditions for anion analysis of time-of-flight secondary ion mass spectrometry are as follows.
Analyzer: TOF-SIMS300 (manufactured by ION-TOF)
Primary ion source: Au
Measured over a 200 μm square area after cleaning with the outermost ultrapure water.

  The film of plastic products having properties with excellent deformation resistance is the peak of the exothermic peak between 140 ° C and 150 ° C under a measurement condition in a nitrogen atmosphere in the analysis by differential scanning calorimetry. And the end of the endothermic peak appears between 70 and 80 ° C. This is presumed to be because the structure of the coating contains a linear structure. In the DLC film, neither an endothermic peak nor an exothermic peak is detected. In terms of deformation resistance, the coating preferably has a softer structure than the DLC film, and such a flexible structure forms a mixed composition of a three-dimensional structure of a carbon skeleton and a linear structure of a hydrocarbon. It is presumed that it was obtained. Among these, the deformation resistance is considered to be derived from a linear structure, but with such a structure, when the film is subjected to differential scanning calorimetry, distinct endothermic peaks and exothermic peaks are detected, unlike the DLC film.

  The composition of the coating is uniform in the thickness direction, but a structure in which two or more kinds of compositions are laminated by a method such as changing the raw material gas content in the supply gas during film formation may be employed. Residual stress is moderated as appropriate. Alternatively, the composition may be continuously inclined from the interface between the plastic molded body and the coating toward the surface of the coating, and the coating may be a gradient composition layer.

  When the film thickness is 0.01 to 100 μm, excellent deformation resistance is obtained while gas barrier properties, abrasion resistance, impact resistance and scratch resistance are obtained. It is preferable to set it as 0.01-10 micrometers, and it is more preferable to set it as 0.05-5 micrometers. In addition, since this film is a mixed composition of a three-dimensional structure of a carbon skeleton and a linear structure of a hydrocarbon, cracks are hardly generated even when the thickness is 10 μm or more.

In the coated plastic product according to the present embodiment, one form of the film forming method is as follows. FIG. 1 is a schematic diagram showing an embodiment of a film forming apparatus for a coated plastic product. Here, FIG. 1 shows a case where the plastic molded body is a PET sheet 5. As shown in FIG. 1, in the present embodiment, the coating film has a relative dielectric constant of 3 or more on electrode surfaces 2 a and 3 a on both sides of the high-frequency applying electrode 2 and the ground electrode 3 facing each other with a gap 1 therebetween. Covered with the following dielectrics 4a and 4b, a PET sheet 5 which is a plastic molded body is disposed on the dielectric 4b so as to face the gap 1, and in the gap 1, a source gas serving as a carbon atom source and a hydrogen atom source Supply gas 12 containing inert gas at a ratio of 50/50 to 100/0 (raw gas volume% / inert gas volume%) is flowed at a flow rate of 2.5 to 50 m / min for high frequency application. It is formed by supplying 0.02 to 0.2 W / mm ² of high frequency power per unit electrode area to the electrode 2 and converting the supply gas 12 into plasma under normal pressure. The electrode area of the high-frequency application electrode 2 is the area of the end face facing the gap 1 side.

In the film forming apparatus 100 of FIG. 1, the output of the high frequency power source 6 is connected to the high frequency application electrode 2. The high-frequency power source 6 is a type that outputs high-frequency power of 1 kHz to 1 MHz, and a type that outputs high-frequency power of 9 kHz to 40 kHz is more preferable. If the frequency is less than 1 kHz, the coating of carbon in the three-dimensional network becomes insufficient and the film formation time becomes long. On the other hand, when the frequency exceeds 1 MHz, arc discharge is likely to occur. The voltage of the high frequency power is appropriately changed depending on the apparatus because the discharge start voltage of the raw material gas varies depending on the discharge area and dielectric constant, but is 0.02 to 0.2 W / mm ² per unit electrode area, preferably It is set to 0.04 to 0.1 W / mm ² .

  The high-frequency applying electrode 2 and the ground electrode 3 may be formed of any material as long as they are conductors, and are, for example, copper, aluminum, and stainless steel. The inter-electrode distance between the high-frequency applying electrode 2 and the ground electrode 3, that is, the distance of the gap 1 is appropriately changed depending on the thickness of the dielectric 4, but is preferably about 0.1 to 15 mm, for example. Of the gap 1, the distance of the spatial gap 1 a serving as a flow path for the supply gas is preferably about 0.1 to 3 mm. If the distance between the spatial gaps 1a is too small, sparking or arc discharge is likely to occur. On the other hand, if the distance is too wide, high frequency power is required. The high-frequency applying electrode 2 is embedded in an insulator 11, and a supply gas flow path 7 and an exhaust flow path 9 are formed in the insulator 11. Examples of the material of the insulator 11 include resins such as tetrafluoroethylene resin.

  The relative dielectric constants of the dielectrics 4a and 4b are 3 or more and 100 or less, and preferably 7 or more and 40 or less. The dielectrics 4a and 4b are glass, such as soda glass and lead glass, and alumina, for example. When the relative dielectric constant is less than 3, it becomes difficult to discharge. On the other hand, when the relative dielectric constant exceeds 100, arc discharge is likely to occur and heat is easily generated.

  Although the discharge is maintained by increasing the supply concentration of an inert gas such as helium gas as in the technique of Patent Document 3, in this embodiment, the discharge is accelerated by sandwiching the dielectrics 4a and 4b. The use of an inert gas can be eliminated. For this reason, the supply gas 12 which contains the source gas and inert gas which become a carbon atom source and a hydrogen atom source in the ratio (source gas volume% / inert gas volume%) will be 50 / 50-100 / 0, respectively. Can be turned into plasma. By reducing the inert gas, the film formation rate is improved, and a film composed of a mixed composition of a three-dimensional structure of a carbon skeleton and a linear structure of a hydrocarbon is obtained.

  The supply gas 12 is supplied from the supply gas generation means 8 and flows into the spatial gap 1 a through the supply gas flow path 7. Next, after flowing almost in parallel with the surface of the PET sheet 5, it is exhausted out of the system by the exhaust blower 10 through the exhaust passage 9. The flow rate when the supply gas 12 flows parallel to the surface of the PET sheet 5 is preferably 2.5 to 50 m / min. When the flow rate is less than 2.5 m / min, plasma is hardly generated and the film formation rate is reduced. On the other hand, if the flow rate exceeds 50 m / min, the adhesion efficiency decreases.

  In the film forming apparatus 100 shown in FIG. 1, the dielectrics 4 a and 4 b are arranged on the electrode surfaces on the opposite sides of both the high-frequency applying electrode 2 and the ground electrode 3. Only one of them may be arranged. However, if a dielectric is not disposed, arc discharge is likely to occur, and an inert gas for promoting discharge is required. A PET sheet 5 that is a plastic molded body is disposed on one of the high-frequency applying electrode 2, the ground electrode 3, and the dielectrics 4 a and 4 b so as to face the gap 1. FIG. 2 shows an arrangement pattern of the high-frequency applying electrode 2, the ground electrode 3, the dielectric, and the plastic molded body, (a) is an enlarged view of A in FIG. 1, and (b) to (f) are (a). It is another example of an aspect. In FIG. 2, (b) shows an arrangement example in which the supply gas 12 is caused to flow between the PET sheet 5 and the dielectric 4b, and (c) shows that the dielectric 4a is arranged only on the electrode surface of the high-frequency applying electrode 2. In the arrangement example in which the supply gas 12 is allowed to flow between the dielectric 4 a and the PET sheet 5, (d) shows that the dielectric 4 b is arranged only on the electrode surface of the ground electrode 3, and between the dielectric 4 b and the PET sheet 5. (E) is an arrangement example in which the dielectric 4b is arranged only on the electrode surface of the ground electrode 3, and the supply gas 12 is caused to flow between the PET sheet 5 and the high-frequency applying electrode 2. f) shows an arrangement example in which the dielectric 4a is disposed only on the electrode surface of the high-frequency applying electrode 2, and the supply gas 12 is allowed to flow between the PET sheet 5 and the ground electrode 3. As shown in FIG. 2, the supply gas 12 flows in the gap between the plastic molded body and the dielectric 4 a or 4 b, the gap between the PET sheet 5 and the high frequency application electrode 2, or the gap between the PET sheet 5 and the ground electrode 3. .

Example 1
A film was formed on the surface of the PET sheet using the film forming apparatus shown in FIG. The PET sheet has a size of 40 mm × 40 mm and a thickness of 0.3 mm. The plasma discharge conditions were a frequency of 9 kHz, a voltage of 20 kV, an acetylene gas flow rate of 1.0 liter / min as the supply gas, a gap distance of 1.0 mm between the PET sheet and the electrode, a film formation time of 5 seconds, a discharge area of 40 cm ² , and a substrate temperature. The temperature was 50 ° C. In this case, the applied power density was 0.05 W / mm ² .

(Example 2)
The conditions of plasma discharge were the same as in Example 1 except that the frequency was 35 kHz, the voltage was 24 kV, the supply gas was an acetylene gas flow rate of 1.0 liter / minute, and the nitrogen gas flow rate was 1.0 liter / minute. In this case, the applied power density was 0.08 W / mm ² .

(Comparative Example 1)
A high-density polyethylene sheet having a thickness of 0.3 mm was prepared.

(Comparative Example 2)
A polystyrene sheet having a thickness of 0.3 mm was prepared.

(Comparative Example 3)
The same PET sheet (non-film-formed) as in Example 1 was prepared.

(Comparative Example 4)
The conditions of plasma discharge were the same as in Example 1 except that the frequency was 3 kHz, the voltage was 15 kV, the flow rate of acetylene gas as the supply gas was 3.0 liters / minute, and the film formation time was 10 seconds. In this case, the applied power density was 0.01 W / mm ² .

(Comparative Example 5)
The conditions of plasma discharge were the same as in Comparative Example 1 except that the frequency was 9 kHz, the voltage was 20 kV, the acetylene gas flow rate was 0.75 liter / min as the supply gas, and the nitrogen gas flow rate was 2.25 liter / min. In this case, the applied power density was 0.05 W / mm ² .

(Comparative Example 6)
Using the apparatus of Patent Document 1, a DLC film is formed on the inner surface of a PET bottle having a thickness of 0.3 mm at a frequency of 13.56 MHz of a high frequency power source, its output is 1200 W, a source gas is acetylene, and a film formation time is 2 seconds. A DLC film having a thickness of 30 nm was formed.

(Comparative Example 7)
In Comparative Example 6, a silicon oxide film was formed in the same manner except that the source gas was changed from acetylene to hexamethyldisiloxane (HMDSO) and oxygen. For Comparative Example 7, the surface friction coefficient was measured in the same manner.

  The film thickness of the coating was measured using Veeco DEKTAK3.

  For Examples 1-2 and Comparative Examples 1-6, by anion analysis of TOF-SIMS ((TOF-SIMS300 (manufactured by ION-TOF), measured after pure water cleaning using primary ion source Au)) The peak intensities of the single carbon atom peak (atomic weight 12.00) and the 3-5 carbon atom peak (atomic weights 36.00, 48.00, 60.00 respectively) were determined, and the intensity ratio was calculated.

  About Examples 1-2 and Comparative Examples 1-6, 40-300 degreeC endothermic of the film piece by DSC analysis (Differential scanning calorimeter DSC-60 Shimadzu Corporation make, temperature increase rate 10 degrees / min, nitrogen atmosphere) The profile was measured, and the positions of the endothermic peak and the exothermic peak were measured. For the plastic sheet pieces of Comparative Examples 1 to 3, the endothermic profile was similarly measured, and the positions of the endothermic peak and the exothermic peak were measured.

  About Examples 1-2 and Comparative Examples 4-7, oxygen permeability was measured with an oxygen permeability measuring device (Oxtran 2/20 (manufactured by Modern Control, 23 ° C., RH 90%)).

  About Examples 1-2 and Comparative Examples 4-7, a rotating disk type friction meter (FPR-2000, manufactured by Reska, SUS304 3/16 inch sphere use, load 100 g, interval 0.1 second, radius 5 mm, rotation speed 100 r The coefficient of friction of the surface was measured using a linear velocity of 5.2 cm / second, 23 ° C., 20 minutes).

  About Examples 1-2 and Comparative Examples 4-7, the sample which adjusted only film-forming time and made all the films into a film thickness of 50 nm was prepared, it was immersed in 85 degreeC hot water, and it was left until it cooled to room temperature. Then, the adhesion of the coating after PET thermal deformation was visually observed.

Tables 1 and 2 show the analysis results.

  When the elemental composition of Example 1 was analyzed by the HFS (Hydrogen Scattering Analysis) / RBS (Rutherford Backscattering Spectrometry) method, the elemental ratio of carbon: hydrogen: oxygen: nitrogen was 41: 48: 11: 0.

About Example 1, when the composition profile in the film thickness direction was measured by SIMS (secondary ion mass spectrometry) analysis (Physical Electronic 6650, primary ion species: Cs ⁺ , primary acceleration voltage 5 kv), carbon in the thickness direction: The composition of hydrogen: oxygen: nitrogen is almost constant, and the concentrations of hydrogen, oxygen, and nitrogen are about 3 × 10 ²¹ atoms / cm ³ , 9 × 10 ²⁰ atoms / cm ³ , and 2 × 10 ²⁰ atoms / cm ³ , respectively. there were.

About Example 1, solid state 13C-NMR analysis (CMX300 7.5 mm probe (manufactured by Chemicals)), CPMAS method (90 ° pulse 4.5 μsec, bandwidth: 30 kHz, repetition time: 5 sec, integration number: 3000, rotation speed: From the 13 C-NMR spectrum obtained in 9 kHz)), the peak intensity ratio of sp ² : sp ³ : —CO: —COO separated for the bonding state with respect to the carbon atom is 32.5: 57.8: 4. .6: 5.1.

It is the schematic which shows one form of the film-forming apparatus of the film of a covering plastic product. The mode of the arrangement pattern of the high frequency applying electrode 2, the ground electrode 3, the dielectric and the plastic molded body is shown, (a) is an enlarged view of A in FIG. 1, and (b) to (f) are other modes of (a). It is an example.

Explanation of symbols

1, gap 1a between electrodes, spatial gap 2, electrode 2a for high frequency application, electrode surface 3 on the opposite side of the electrode for high frequency application 3, ground electrode 3a, electrode surfaces 4, 4a, 4b on the opposite side of the ground electrode, dielectric Body 5, PET sheet 6, high frequency power source 7, supply gas flow path 8, supply gas generating means 9, exhaust flow path 10, exhaust blower 11, insulator 12, supply gas 100, film forming apparatus

Claims (7)

In a coated plastic product in which a coating containing carbon atoms and hydrogen atoms as main constituent atoms is formed on the surface of a plastic molded body by a normal pressure low temperature plasma CVD method,
The coating is
The electrode surface of at least one of the high-frequency applying electrode and the ground electrode facing each other with a gap is covered with a dielectric having a relative dielectric constant of 3 to 100, and the high-frequency applying electrode, the ground electrode, or the ground electrode A plastic molded body is disposed on one of the dielectrics so as to face the gap, and a raw material gas and an inert gas serving as a carbon atom source and a hydrogen atom source (raw material gas volume% / inert gas) are placed in the gap. Gas supplied in a ratio of 50/50 to 100/0 at a flow rate of 2.5 to 50 m / min, and 0.02 to 0.2 W per unit electrode area through the high-frequency application electrode. / Mm ² of high frequency power is supplied, and the supply gas is formed into plasma under normal pressure , and
In anion analysis of time-of-flight secondary ion mass spectrometry (TOF-SIMS) method,
(1) The intensity ratio (C3 / C1) of the peak of triatomic carbon to the peak of monoatomic carbon in the measurement after cleaning the surface with pure water using the primary ion source Au is 0.07 or more,
(2) The intensity ratio (C4 / C1) of the peak of the 4-atomic carbon to the peak of the monoatomic carbon in the measurement after cleaning the surface with pure water using the primary ion source Au is 0.05 or more,
(3) (1) The intensity ratio (C5 / C1) of the peak of the five atomic carbon to the peak of the monoatomic carbon in the measurement after the surface is cleaned with pure water using the primary ion source Au is 0.02 or more. Satisfy at least one of (3), and
In the differential scanning calorimetry (DSC) method, the peak of the exothermic peak appears between 140 and 150 ° C. under the measurement conditions of a temperature rising rate of 10 ° C./min and nitrogen atmosphere, and the endothermic peak between 70 and 80 ° C. Coated plastic products characterized by the appearance of The coated plastic product according to claim 1 , wherein the source gas is acetylene. The said film satisfy | fills all said (1) (2) (3) in the anion analysis of a time-of-flight type secondary ion mass spectrometry (TOF-SIMS) method, The said 1 or 2 is characterized by the above-mentioned. coated plastic products. Said coating is a single layer composed of the same composition, according to claim 1, 2 or 3 more layers or continuously composition a heterogeneous composition is characterized in that either a graded composition layer which is inclined Coated plastic products. The coated plastic product according to claim 1, 2, 3, or 4 , wherein the plastic molded body is made of polyethylene terephthalate resin. The coated plastic product according to claim 1, 2, 3, 4, or 5 , wherein the coated plastic product is a packaging container, a sliding part, a recording medium, a sheet, a fiber, or a card. In a film containing carbon atoms and hydrogen atoms as main constituent atoms formed on the surface of the substrate by atmospheric pressure low temperature plasma CVD method,
The coating covers the electrode surface on at least one of the high-frequency applying electrode and the ground electrode facing each other with a gap therebetween with a dielectric having a relative dielectric constant of 3 to 100, and the high-frequency applying electrode, A substrate is disposed on either the ground electrode or the dielectric so as to face the gap, and a raw material gas and an inert gas serving as a carbon atom source and a hydrogen atom source are contained in the gap (raw material gas volume% / The inert gas volume%) is supplied at a flow rate of 2.5 to 50 m / min, respectively, at a rate of 50/50 to 100/0, and 0.02 to 0 per unit electrode area is supplied to the high-frequency application electrode. Formed by supplying high frequency power of ² W / mm ^{2 and} converting the supply gas into plasma under normal pressure, and
In anion analysis of time-of-flight secondary ion mass spectrometry (TOF-SIMS) method,
(1) The intensity ratio (C3 / C1) of the peak of triatomic carbon to the peak of monoatomic carbon in the measurement after cleaning the surface with pure water using the primary ion source Au is 0.07 or more,
(2) The intensity ratio (C4 / C1) of the peak of the 4-atomic carbon to the peak of the monoatomic carbon in the measurement after cleaning the surface with pure water using the primary ion source Au is 0.05 or more,
(3) (1) The intensity ratio (C5 / C1) of the peak of the five atomic carbon to the peak of the monoatomic carbon in the measurement after the surface is cleaned with pure water using the primary ion source Au is 0.02 or more. Satisfy at least one of (3), and
In the differential scanning calorimetry (DSC) method, the peak of the exothermic peak appears between 140 and 150 ° C. under the measurement conditions of a temperature rising rate of 10 ° C./min and nitrogen atmosphere, and the endothermic peak between 70 and 80 ° C. A film characterized by the appearance of vertices .

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