JP7640345B2 - Laminate and manufacturing method thereof - Google Patents

Description

This disclosure relates to a laminate in which a coating layer is formed on the surface of a plastic material substrate, and a method for manufacturing the same.

Development is underway to replace window glass for vehicles such as automobiles, trains, and aircraft with plastic window materials (hereinafter referred to as resin glazing) in order to reduce weight and improve fuel efficiency and safety. A major challenge in changing from glass to plastic is to impart hardness, scratch resistance, and abrasion resistance similar to glass while maintaining high transparency. To address the above issue, a method of coating a hard film made of a silicone resin on a transparent and strong polycarbonate resin (PC) substrate has been widely used (see, for example, Patent Document 1 or Patent Document 2). In addition, a method has been proposed in which an acrylic resin primer is formed as an intermediate layer on a PC substrate, and a silica film layer is formed thereon by a plasma CVD method to produce a transparent, abrasion-resistant laminate (see, for example, Patent Document 3).

In addition, to apply low-cost film formation under atmospheric pressure to automobile glazing materials with large areas and three-dimensional shapes, a remote atmospheric pressure plasma method that allows a large distance from the plasma nozzle is generally required (see, for example, Patent Document 4 or Patent Document 5).

Japanese Patent Application Publication No. 1-306476 JP 2002-36870 A JP 2009-67049 A JP 2010-209281 A JP 2016-199797 A

However, as in Patent Document 1 or Patent Document 2, resin glazing with a hard silicone resin film does not have sufficient hardness and abrasion resistance for use as automotive resin glazing. In addition, long-term heat curing is required at a temperature that the plastic substrate can withstand, and there are major issues in terms of time and cost required for production. As in Patent Document 3, a laminated film in which a silica thin film is formed by a plasma CVD method via a primer does not have sufficient abrasion resistance and scratch resistance for use as automotive resin glazing. Furthermore, since reduced pressure is required, there is an issue that a large amount of equipment cost and film formation time are required. As in Patent Document 4 or Patent Document 5, the existing remote atmospheric pressure plasma method has not been able to obtain a material that satisfies the abrasion resistance and scratch resistance required for automotive glazing materials.

The present disclosure aims to provide a laminate that is excellent in transparency, hardness, and abrasion resistance, and to provide a method for producing the laminate, the production process of which does not require reduced pressure, can be produced in a short time, and is low cost.

The laminate according to the present invention is a laminate having a plastic substrate and a laminate film, the laminate film comprising a cured resin film and a silicon oxide-based film provided on the surface of the cured resin film, the silicon oxide-based film having a thickness of 0.05 to 1.00 μm, the cured resin film comprising inorganic crystal particles having an average particle size of 10 to 100 nm, the inorganic crystal particles being locally dispersed on the silicon oxide-based film side and also present at the interface between the cured resin film and the silicon oxide-based film, the inorganic crystal particles present at the interface being embedded in the silicon oxide-based film.

In the laminate according to the present invention, it is preferable that the cured resin film contains silicone oil. This makes it easier for inorganic crystal particles to be localized on the silicon oxide film side, and more particles are embedded in the silicon oxide film, which increases the adhesion between the cured resin film and the silicon oxide film. As a result, the hardness and abrasion resistance of the laminate film can be further increased.

In the laminate according to the present invention, the silicon oxide-based film is preferably a plasma vapor deposition film formed under normal pressure. By plasma vapor deposition under normal pressure, the cured resin film is etched, partially exposing inorganic crystal particles contained in the cured resin film, and more particles are embedded in the silicon oxide-based film, which further increases the adhesion between the cured resin film and the silicon oxide-based film. As a result, the hardness and abrasion resistance of the laminate film can be further increased.

In the laminate according to the present invention, it is preferable that the silicon oxide film contains oxygen atoms and silicon atoms, and further contains at least one of carbon atoms, hydrogen atoms, and nitrogen atoms. This can further improve adhesion with the cured resin film.

In the laminate according to the present invention, the resin of the cured resin film is preferably an acrylic resin. This can further increase transparency.

In the laminate of the present invention, the surface of the silicon oxide film includes a form in which the change in haze value before and after the test is 2.0% or less when a Taber abrasion test is performed according to JIS K 7204:1999 "Plastics - Abrasion test method using abrasive wheels" using a CS-10F wheel with a load of 500 g at 1,000 revolutions, and the pencil hardness is 6H or more in the pencil hardness test according to JIS K 5600-5-4:1999 "General test methods for paints - Part 5: Mechanical properties of coatings - Section 4: Scratch hardness (pencil method)".

The method for producing a laminate according to the present invention is a method for producing a laminate having a plastic substrate and a laminate film, the laminate film having a cured resin film and a silicon oxide-based film provided on the surface of the cured resin film, the method comprising the steps of: forming the cured resin film by applying a coating material for a cured resin film, the coating material containing inorganic crystal particles having an average particle size of 10 to 100 nm; and disposing a pair of electrodes arranged opposite to each other perpendicular to the surface of the cured resin film, applying a high-frequency voltage between the electrodes while supplying argon gas between the electrodes under an atmospheric pressure atmosphere to cause atmospheric pressure glow discharge to convert the argon gas into plasma, generating plasmatized argon gas, and then discharging the plasmatized argon gas from the electrodes. and a step of: disposing the plastic substrate having the cured resin film on its surface downstream of the direction of spraying of the argon gas; supplying a source gas consisting of an organosilicon compound for film formation and oxygen to an outer electrode region between the two electrodes and the cured resin film of the plastic substrate in a direction intersecting the flow of the plasmatized argon gas, thereby converting at least a portion of the source gas and oxygen into a plasmatized source gas and a plasmatized oxygen gas, which are then sprayed together with the plasmatized argon gas toward the surface of the cured resin film, thereby forming the silicon oxide-based film on the surface of the cured resin film, wherein the silicon oxide-based film has a thickness of 0.05 to 1.00 μm .

In the method for producing a laminate according to the present invention, the coating material for the cured resin film preferably contains silicone oil. This makes it easier for inorganic crystal particles to be localized on the silicon oxide film side, and more particles are embedded in the silicon oxide film, which improves the adhesion between the cured resin film and the silicon oxide film. As a result, the hardness and abrasion resistance of the laminate film can be further improved.

In the method for producing a laminate according to the present invention, it is preferable that the organosilicon compound is at least one selected from the group consisting of trimethylsilane, tetraethoxysilane, tetramethoxysilane, and hexamethyldisiloxane. This can further improve adhesion to the cured resin film.

The present disclosure provides a laminate that is excellent in transparency, hardness, and abrasion resistance, and a method for producing the laminate, which does not require reduced pressure, can be produced in a short time, and is low cost.

FIG. 2 is a schematic cross-sectional view showing an example of a laminate according to the present embodiment. 2 is a schematic diagram showing an example of an internal structure of a laminated film of the laminate shown in FIG. 1 . FIG. 1 is a schematic diagram illustrating an example of a film forming apparatus. 1 is a graph showing the results of Experimental Example 1. FIG. 1 is a schematic diagram of a surface of a substrate divided into areas in Experimental Example 2. 6 is a graph showing the element abundance ratios on each line shown in FIG. 5 by XPS measurement. 7 is a graph showing the abundance ratios of Si and O selected from the elements present in FIG. 6 . 13 is a graph showing the results of Experimental Example 3. 1 shows the results for Example 1 of Experimental Example 4, where (a) is an SEM image showing the surface state after the formation of a cured resin film and before the formation of a silicon oxide-based film, (b) is an SEM image showing the surface state after the formation of the silicon oxide-based film and before the abrasion test, and (c) is an SEM image showing the surface state after the formation of the silicon oxide-based film and after the abrasion test. 1 shows the results for Comparative Example 1 of Experimental Example 4, where (a) is an SEM image showing the surface state after the formation of a cured resin film and before the formation of a silicon oxide-based film, (b) is an SEM image showing the surface state after the formation of the silicon oxide-based film and before the abrasion test, and (c) is an SEM image showing the surface state after the formation of the silicon oxide-based film and after the abrasion test.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that the present invention is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings are considered to be identical to each other.

Figure 1 is a schematic cross-sectional view showing an example of a laminate according to this embodiment. Figure 2 is a schematic diagram showing an example of the internal structure of the laminate film of the laminate shown in Figure 1. As shown in Figure 1, the laminate 1 according to this embodiment is a laminate having a plastic substrate 10 and a laminate film 20. The laminate film 20 has a resin cured film 21 and a silicon oxide-based film 22 provided on the surface of the resin cured film 21. As shown in Figure 2, the resin cured film 21 has inorganic crystal particles 30 with an average particle size of 10 to 100 nm. The inorganic crystal particles 30 are locally dispersed on the silicon oxide-based film 22 side and are further present at the interface between the resin cured film 21 and the silicon oxide-based film 22. The inorganic crystal particles 30 (30A) present at the interface are embedded in the silicon oxide-based film 22.

The laminate 1 is a component that can be used as a substitute for window glass for vehicles such as automobiles, trains, and aircraft. More specifically, the laminate 1 is a resin glazing that can be used as a window material for vehicles and the like to replace glass, in which a coating layer that is excellent in transparency, high in hardness, and excellent in abrasion resistance and scratch resistance is laminated on the surface of a transparent plastic material.

Traditionally, polycarbonate (PC) substrates have been used as suitable resin glazing for automobiles. However, the abrasion resistance of the PC substrate was about 50% in the Taber abrasion test, which was more prone to fogging than glass, which had a haze change rate of 1%, making it unsuitable as a window material as is. When an acrylic resin was formed on the PC substrate by UV curing, the abrasion resistance was only 2.5-10% haze change rate, which was still insufficient for a window material. Even when a silicon oxide film was formed directly on the PC substrate by atmospheric pressure plasma CVD, the abrasion resistance was only about 2-10% haze change rate, which was still insufficient for a window material. This is thought to be mainly due to insufficient adhesion between the silicon oxide film and the PC substrate, and the fact that the silicon oxide film is thin, so that the load during the abrasion test is applied locally, causing deformation and shear stress. Therefore, in the laminate 1 according to this embodiment, it was discovered that by forming a laminate film 1 on a substrate, the laminate film 1 includes a cured resin film containing a main resin such as an ultraviolet-curable acrylic resin and inorganic crystal particles 30, and a silicon oxide film provided on the cured resin film, a laminate that fully satisfies the transparency, hardness, abrasion resistance, and scratch resistance can be obtained.

The plastic substrate 10 is preferably transparent, and is, for example, an acrylic resin such as polycarbonate or polymethyl methacrylate, or a polyester resin such as polyethylene terephthalate. Of these, the plastic substrate 10 is preferably a polycarbonate resin, which is suitable as an automobile glazing material.

The laminated film 20 preferably has a resin cured film 21 as an intermediate layer provided on the substrate, and a silicon oxide-based film 22 as an outermost layer provided on the surface of the resin cured film. The laminated film 20 may also have other layers in addition to the resin cured film 21 and the silicon oxide-based film 22, as long as the effects of the present invention are not impaired.

The resin cured film 21 serves to improve weather resistance and adhesion of the silicon oxide film 22. The main resin constituting the resin cured film 21 is, for example, an acrylic resin, an acrylic urethane resin, an acrylic silicone resin, or an organosiloxane resin. In the laminate 1 according to this embodiment, it is preferable that the main resin constituting the resin cured film 21 is an acrylic resin. This can further increase transparency.

The resin cured film 21 is preferably a photocured film containing a photocurable resin as the main resin. The photocurable resin is preferably an ultraviolet-curable acrylic resin.

In the laminate 1 according to this embodiment, the resin cured film 21 preferably contains silicone oil. The inorganic crystal particles 30 are more likely to be localized on the silicon oxide film 22 side, and more particles are embedded in the silicon oxide film 22, so that the adhesion between the resin cured film 21 and the silicon oxide film 22 is improved. As a result, the hardness and abrasion resistance of the laminate film 20 can be further improved. The silicone oil is, for example, unmodified silicone oil or modified silicone oil. Of these, polyether modified silicone is preferred.

The thickness of the resin cured film 21 is preferably 15 to 25 μm, and more preferably 18 to 23 μm. If the thickness of the resin cured film 21 is less than 15 μm, the weather resistance may be insufficient. If the thickness of the resin cured film 21 exceeds 25 μm, the adhesion between the resin cured film 21 and the plastic substrate, as well as the adhesion between the resin cured film 21 and the silicon oxide film 22, may decrease, causing peeling.

The inorganic crystal particles 30 are, for example, silicon oxide, aluminum oxide, or zirconium oxide. Of these, silicon oxide is more preferable. This can further increase adhesion with the silicon oxide-based film 22. In addition, transparency can be further increased.

The inorganic crystal particles 30 have an average particle size of 10 to 100 nm. If the inorganic crystal particles 30 have an average particle size of less than 10 nm, they may be prone to aggregation and may not be dispersed uniformly. If the inorganic crystal particles 30 have an average particle size of more than 100 nm, transparency may decrease. The inorganic crystal particles 30 have an average particle size of 20 to 80 nm, more preferably 30 to 70 μm.

The content of inorganic crystal particles 30 relative to the mass of the main resin constituting the resin cured film 21 is arbitrary, but is preferably 10 to 50 mass%. If the content of inorganic crystal particles 30 relative to the mass of the main resin constituting the resin cured film 21 is less than 10 mass%, the adhesion of the resin cured film 21 to the silicon oxide-based film 22 may be insufficient. Even if the content of inorganic crystal particles 30 relative to the mass of the main resin constituting the resin cured film 21 exceeds 50 mass%, the adhesion of the resin cured film 21 to the silicon oxide-based film 22 may be insufficient. Furthermore, the weather resistance of the laminated film 20 may be insufficient.

The silicon oxide film 22 has the role of imparting transparency and improving hardness. In the laminate 1 according to this embodiment, the silicon oxide film 22 is preferably a plasma vapor deposition film under normal pressure. The plasma vapor deposition film under normal pressure is, for example, a film formed by providing sufficient oxygen in a plasma CVD method under normal pressure to plasmatize an organic silicon compound. By plasma vapor deposition under normal pressure, the resin cured film 21 is etched, and the inorganic crystal particles 30 contained in the resin cured film 21 are partially exposed, and more particles are embedded in the oxygen silicon film 22, so that the adhesion between the resin cured film 21 and the silicon oxide film 22 is further improved. As a result, the hardness and abrasion resistance of the laminate film 20 can be further improved.

In the laminate 1 according to this embodiment, the silicon oxide film 22 contains oxygen atoms and silicon atoms, and preferably also contains at least one of carbon atoms, hydrogen atoms, and nitrogen atoms. This can further improve adhesion with the cured resin film 21.

In the laminate 1 according to this embodiment, the surface of the silicon oxide film 22 includes a form in which the change in haze value before and after the test is 2.0% or less when the Taber abrasion test is performed according to JIS K 7204:1999 "Plastics - Abrasion test method using abrasive wheels" using a CS-10F wheel with a load of 500 g and 1000 revolutions, and the pencil hardness is 6H or more in the pencil hardness test according to JIS K 5600-5-4:1999 "General test methods for paints - Part 5: Mechanical properties of coatings - Section 4: Scratch hardness (pencil method)".

The thickness of the silicon oxide film 22 is preferably 0.05 to 1 μm, more preferably 0.05 to 0.8 μm, and even more preferably 0.05 to 0.3 μm. If the thickness of the silicon oxide film 22 is less than 0.05 μm, the wear performance may be significantly reduced. If the thickness of the silicon oxide film 22 exceeds 1 μm, peeling may occur.

As shown in FIG. 2, the inorganic crystal particles 30 are locally dispersed on the silicon oxide film 22 side. In FIG. 2, the inorganic crystal particles 30 are shown with a circular cross-sectional shape, but in the present invention, the cross-sectional shape of the inorganic crystal particles 30 is not limited to this and may be an irregular shape. When the resin cured film 21 is divided into two in the thickness direction, with the substrate side being the lower layer 21a and the silicon oxide film 22 side being the upper layer 21b, it is preferable that the number of inorganic crystal particles 30 present in the upper layer 21b is greater than the number of inorganic crystal particles 30 present in the lower layer 21a. The fact that the inorganic crystal particles 30 are locally dispersed on the silicon oxide film 22 side may be predicted, for example, by observing the surface state of the resin cured film 21 at a magnification of 1,000 to 20,000 times using a scanning electron microscope (SEM) and observing a sea-island structure in which the inorganic crystal particles 30 form islands.

Furthermore, the inorganic crystal particles 30 are dispersed locally on the silicon oxide-based film 22 side, and are also present at the interface between the resin cured film 21 and the silicon oxide-based film 22, and the inorganic crystal particles 30 (30A) present at the interface are embedded in the silicon oxide-based film 22. The form in which the inorganic crystal particles 30 are present at the interface between the resin cured film 21 and the silicon oxide-based film 22 is preferably, for example, a form in which the inorganic crystal particles 30 are present across the resin cured film 21 and the silicon oxide-based film 22. It is preferable that the inorganic crystal particles 30 embedded in the silicon oxide-based film 22 are partly fixed to the silicon oxide-based film 22 and integrated therewith, and it is more preferable that a part is fixed to the resin cured film 21 and the remaining part is fixed to the silicon oxide-based film 22. The fact that the inorganic crystal particles 30 are embedded in the silicon oxide-based film 22 can be indirectly confirmed by, for example, abrading the surface of the laminated film 20 with an abrasion tester to peel off a part or the whole of the silicon oxide-based film 22, and observing the peeled off part of the silicon oxide-based film 22 with an SEM at a magnification of 1,000 to 20,000 times, finding that the sea-island structure of the inorganic crystal particles 30 is not observed. This is presumably because the inorganic crystal particles 30 are embedded in the silicon oxide-based film 22, and when the silicon oxide-based film 22 is peeled off, the inorganic crystal particles 30 are also peeled off together with the silicon oxide-based film 22.

Fig. 3 is a schematic diagram showing an example of a film forming apparatus. As shown in Fig. 3, the method for producing a laminate according to this embodiment is a method for producing a laminate having a plastic substrate 10 and a laminate film 20, the laminate film 20 having a resin cured film 21 and a silicon oxide-based film 22 provided on the surface of the resin cured film 21, and includes the following steps (1) and (2).
(1) A step of forming a cured resin film 21 by applying a coating material for a cured resin film, which contains inorganic crystal particles 30 (shown in FIG. 2) having an average particle size of 10 to 100 nm.
(2) A step of arranging a pair of electrodes 51 facing each other perpendicularly to the surface of the resin cured film 21, supplying argon gas 56 between both electrodes 51 under atmospheric pressure while applying a high-frequency voltage between the electrodes 51, thereby causing atmospheric pressure glow discharge to convert the argon gas 56 into plasma and generating plasmatized argon gas, disposing a plastic substrate 10 having the resin cured film 21 on its surface downstream of the direction in which the plasmatized argon gas is sprayed from both electrodes 51, and supplying a source gas made of an organosilicon compound for film formation and oxygen to an outer region between both electrodes 51 and the resin cured film 21 of the plastic substrate 10 in a direction intersecting the flow of the plasmatized argon gas, thereby converting at least a part of the source gas and oxygen into a plasmatized source gas and a plasmatized oxygen gas, which are then sprayed toward the surface of the resin cured film 21 together with the plasmatized argon gas, thereby forming a silicon oxide-based film 22 on the surface of the resin cured film 21.

In the process of forming the resin cured film 21, the resin cured film coating preferably contains at least a main resin and inorganic crystal particles 30 (shown in FIG. 2). When the resin cured film 21 is a photocured film, the resin cured film coating preferably contains an ultraviolet absorber in addition to the main resin and inorganic crystal particles 30 (shown in FIG. 3). The ultraviolet absorber is preferably an organic ultraviolet absorber such as a benzotriazole-based or triazine-based ultraviolet absorber. The resin cured film coating may further contain various auxiliary agents such as a light stabilizer.

In the method for manufacturing a laminate according to this embodiment, the coating material for the cured resin film preferably further contains silicone oil. This makes it easier for the inorganic crystal particles 30 (shown in FIG. 2) to be localized on the silicon oxide film 22 side, and more particles are embedded in the silicon oxide film 22, so that the adhesion between the cured resin film 21 and the silicon oxide film 22 is improved. As a result, the hardness and abrasion resistance of the laminate film 1 can be further improved.

The method for forming the resin cured film 21 is not particularly limited, and may be, for example, a method in which a coating material for an ultraviolet cured film is applied to the substrate 10 or a primer layer (not shown) provided on the substrate 10, dried, and cured by irradiating with active energy rays such as ultraviolet rays. The coating method is not particularly limited, and known methods such as a dip method, a flow coating method, a spray method, a bar coating method, a gravure coating method, a roll coating method, a blade coating method, an air knife coating method, a spin coating method, a slit coating method, and a microgravure coating method may be used.

In the process of forming the silicon oxide-based film 22, for example, a film forming apparatus 50 as shown in FIG. 3 can be used. The film forming apparatus 50 shown in FIG. 3 is a remote atmospheric pressure plasma apparatus. The film forming apparatus 50 includes a pair of electrodes 51 arranged opposite each other, an AC power source 52 that applies an AC voltage between the electrodes 51, an inert gas supply pipe 53 that supplies an inert gas 56, and a raw material gas supply pipe 54 that supplies a raw material gas for film formation.

The electrode 51 is, for example, a rectangular flat plate, and is made of a conductive material such as copper. The electrodes 51 are arranged parallel to each other at a predetermined distance, and are arranged perpendicular to the plastic substrate 10 having the resin cured film 21 on its surface, which is the object to be coated. The distance between the electrodes 51 is preferably 0.1 to 5.0 mm, and more preferably 0.3 to 2.0 mm. A dielectric 55 is arranged on the opposing surface of the electrode 51. The dielectric 55 is, for example, a plastic such as polytetrafluoroethylene, polyethylene terephthalate, or polyethylene, glass, or a metal oxide such as alumina.

The AC power supply 52 is a means for applying a high-frequency voltage, and is electrically connected to both electrodes 51. The AC power supply 52 is, for example, a high-voltage pulse power supply or an RF power supply. The high-frequency voltage is preferably 1 to 100 kV, and more preferably 10 to 15 kV. If the high-frequency voltage is less than 1 kV, the argon gas 56 may not be easily ionized. If the high-frequency voltage exceeds 100 kV, an arc discharge may occur. In addition, the frequency of the high-frequency voltage is preferably 1 kHz or higher. When a voltage is applied between both electrodes 51 by the AC power supply 52, the region between both electrodes 51 becomes a high-electric field plasma generation region 59.

The inert gas supply pipe 53 is arranged with its nozzle facing the plasma generation region 59. The inert gas is argon gas. In this embodiment, the argon gas may be mixed with other inert gases, such as helium gas, as long as this does not impair the effects of the present invention. An argon gas cylinder is connected to the base end of the inert gas supply pipe 53.

The raw material gas supply pipe 54 is provided downstream of both electrodes 51 in the direction of ejection of the argon gas 56, and upstream of the position where the film-forming body is placed in the direction of ejection of the argon gas 56. The raw material gas supply pipes 54 are disposed facing each other along the lower surfaces of both electrodes 51. The distance between the ejection ports of the pair of raw material gas supply pipes 54 is preferably 1 to 10 mm, and more preferably 2 to 5 mm. A raw material gas cylinder and an oxygen gas cylinder are connected to the base end of the raw material gas supply pipe 54. A raw material mixed gas 57, which is a mixture of the raw material gas and the oxygen gas, is supplied from the raw material gas supply pipe 54 to the outside-electrode region between both electrodes 51 and the resin cured film 21 of the plastic substrate 10 in a direction intersecting the flow of the plasmatized argon gas.

In the method for manufacturing a laminate according to this embodiment, the organosilicon compound is preferably at least one selected from trimethylsilane, tetraethoxysilane, tetramethoxysilane, and hexamethyldisiloxane. This can further improve adhesion to the cured resin film 21.

The object to be coated is a plastic substrate 10 with a resin cured film 21 on its surface, and is placed with the resin cured film 21 facing the electrode 51 in a region outside the plasma generation region 59 downstream of both electrodes 51 in the direction of argon gas 56 ejection. At this time, the distance between both electrodes 51 and the surface of the resin cured film 21 is preferably 1 to 100 mm, and more preferably 2 to 50 mm. If it is less than 1 mm, the coating range will be too narrow, and it may take a long time to form the coating. If it exceeds 100 mm, the coating range will be expanded, but the coating may become unstable.

The substrate is preferably placed on a conductor (not shown) made of a conductive material. The conductor is, for example, a conductive metal such as copper, silver, or aluminum, or carbon.

The film forming apparatus 50 may further include a heater 58 for heating the object to be formed. By heating the object to be formed with the heater 58, the film forming accuracy can be improved. The heating temperature by the heater 58 is preferably, for example, 40 to 300°C, and more preferably 50 to 250°C.

Next, we will explain the film formation method.

First, while applying a high-frequency voltage between the electrodes 51 by the AC power source 52, only argon gas 56 is supplied as an inert gas gas from the inert gas supply pipe 53 to the high electric field plasma generation region 59 under atmospheric pressure. This generates a glow discharge plasma, converts the argon gas 56 into plasma, and generates plasma-converted argon gas. At this time, the flow rate of the argon gas 56 is preferably 100 to 5000 mm/sec, more preferably 300 to 4000 mm/sec. If the flow rate of the argon gas 56 is less than 100 mm/sec, the supply pressure of the argon gas is small, so it is necessary to reduce the distance between the electrodes 51 and the film-forming body, and the film-forming range may be reduced. If the flow rate of the argon gas 56 exceeds 5000 mm/sec, the gas flow may be disturbed or abnormal discharge may occur. In this specification, "atmospheric pressure" means that the film is formed in an open atmospheric pressure environment, and the pressure is preferably 0.5 to 2 atm.

While supplying argon gas 56, a raw material mixed gas 57 of raw material gas and oxygen gas is supplied from the raw material gas supply nozzle 54. As a result, at least a part of the raw material gas and oxygen becomes plasma raw material gas and plasma oxygen gas. The ratio of the supply amount of raw material gas 55 to oxygen gas is preferably 1:200 to 1:3000, more preferably 1:400 to 1:1000, by volume. In addition, the total flow rate of raw material gas 55 and oxygen gas is preferably 50 to 2000 mm/sec, more preferably 150 to 1000 mm/sec. If the total flow rate of raw material gas 55 and oxygen gas is less than 50 mm/sec, film formation may not be performed due to a shortage of film raw material. If the total flow rate of raw material gas 55 and oxygen gas exceeds 2000 mm/sec, plasma formation may not be performed and film formation may not be performed.

The plasma source gas and the plasma oxygen gas flow further downstream under the flow pressure of the argon gas 56, and a silicon oxide film 22 is formed on the surface of the object to be coated (the surface of the resin cured film 21). When the object to be coated is large, the object to be coated is placed on a slidable mounting table, and the film is formed sequentially while sliding the mounting table as shown by the black bold arrow in Figure 3. At this time, the transport speed of the object to be coated is preferably 0.01 mm/sec or more, and more preferably 0.10 mm/sec or more. There is no particular limit to the upper limit of the transport speed of the object to be coated, but it is, for example, 5.00 mm/sec.

In the manufacturing method of the laminate according to the present embodiment, a resin cured film 21 is formed by adding inorganic crystal particles 30 such as silicon oxide crystal microparticles to a main resin such as an ultraviolet-curable acrylic resin, and then, in a remote plasma CVD method at atmospheric pressure, argon is used as an inert plasma gas, sufficient oxygen is provided to plasmatize the organic silicon compound, and a silicon oxide film is formed. The plasmatized argon gas has high kinetic energy and etches the cured product of the main resin. At this time, the surface of the resin cured film 21 is sputtered by the plasmatized argon, resulting in atomic level irregularities (phenomenon 1). Furthermore, the inorganic crystal particles 30 contained in the resin cured film 21 are partially exposed (phenomenon 2). At the same time as phenomena 1 and 2, a silicon oxide-based film 22 is formed. This process increases the adhesion area between the resin cured film and the silicon oxide film. Then, a laminated film structure in which inorganic crystal particles 30 with very high hardness are embedded in the formed silicon oxide-based film 22 was formed. As a result, the adhesion between the formed silicon oxide film 22 and the cured resin film 21 is greatly improved, and the embedded inorganic crystal particles 30, which have high hardness, serve to reduce wear of the silicon oxide film 22, making it possible to create a laminated structure that fully satisfies the transparency, hardness, wear resistance, and scratch resistance required for automobile glazing, for example, at extremely low cost.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1
A resin cured film 21 was formed by coating the surface of a polycarbonate substrate (length 100 mm, width 100 mm, thickness 3.5 mm, manufactured by Mitsubishi Chemical Corporation) with a resin cured film paint prepared by Daikyo Nishikawa Corporation, which was prepared by using an acrylic resin monomer as the acrylic resin raw material, an active energy ray polymerization initiator such as a UV absorber, a light stabilizer, and a UV polymerization initiator, and a surfactant, as auxiliary raw materials, and having silica particles (diameter approximately 50 μm) dispersed therein, and then drying at 100° C.

Next, using the film-forming apparatus 50 shown in FIG. 3, a silicon oxide film 22 was formed on the surface of the cured resin film 21 under the following conditions.
Electrode 51: Alumina flat plate (thickness 0.2 mm)
Distance between electrodes 51: 1.2 mm
High frequency voltage applied to electrode 51: frequency 30 kHz, voltage 11.5 kV
Inert gas 56: argon gas, flow rate: 500 mm/sec
Raw material mixed gas 57: trimethylsilane/oxygen gas: 0.5/250, total flow rate 250.5 mm/sec
Distance between the electrode 51 and the surface of the cured resin film 21: 9 mm
Conveying speed of the substrate 10: 0.1 mm/sec
Film formation atmosphere: open atmospheric pressure (101 kPa)
Heating by the heater 58 was not performed.

Example 2
A silicon oxide-based film was formed in the same manner as in Example 1, except that the type of inert gas was changed from argon gas alone to a mixed gas of argon gas and helium gas (argon gas/helium gas=2/1).

(Comparative Example 1)
A silicon oxide based film was formed in the same manner as in Example 1, except that the type of inert gas was changed from argon gas to helium gas.

(Experimental Example 1)
The laminates of the examples and comparative examples were evaluated for adhesion as follows. The adhesion was evaluated by measuring the critical peel load according to the scratch test method (JIS R3255:1997 "Test method for adhesion of thin films on glass substrates"), except that the substrate was changed to a laminate and the thin film was prepared by plasma CVD instead of vapor deposition. The critical peel load was shown as the adhesion. The results are shown in Table 1 and FIG. 4.

(Experimental Example 2)
In Example 1, film formation was performed without transporting the substrate, and the effect of surface modification by plasma argon gas was confirmed. The results are shown in Figures 5 to 7 and Table 2. Figure 5 is a schematic diagram of the surface of the substrate divided into areas in Experimental Example 2. In Figure 5, the dotted lines are area division lines, and have area division line numbers 1 to 11 in order from the left, such as 1, 2, ... 8, ... 11 shown below. Figure 6 is a graph showing the element abundance ratios by XPS measurement on each area division line shown in Figure 5. Figure 7 is a graph showing the abundance ratios of Si and O extracted from the existing elements shown in Figure 6.

As shown in Figures 5 to 7 and Table 2, in the area directly below the film formation device (area between lines 2 and 8), the total abundance ratio of Si (silicon) and O (oxygen) was 50 atomic % or more, and it was confirmed that a silicon oxide-based film had been formed. It is difficult to say that a silicon oxide-based film had been formed in areas other than the area between lines 2 and 8, suggesting that film formation occurs only directly below the film formation device. On the other hand, in the area between lines 2 and 8 directly below the film formation device, the abundance ratio of O was higher than in other areas, and it was confirmed that surface modification had been performed by plasmatized argon gas. In conclusion, it is believed that the area surface-modified by plasmatized argon gas and the area where a film is formed are the same area.

(Experimental Example 3)
An experiment was conducted to confirm that the inorganic crystal particles were dispersed locally on the silicon oxide film side as follows. The surface of the resin cured film was modified by applying plasma argon gas to the surface. The flow rates of the argon gas were 0 L/min, 1 L/min, 2 L/min, and 3 L/min. The results are shown in FIG. 8 and Table 3. FIG. 8 is a graph showing the results of Experimental Example 3. In FIG. 8 and Table 3, Si is derived from silicon oxide crystal fine particles or silicone oil, which are inorganic crystal particles in the resin cured film, and C is derived from acrylic resin, which is the main resin. As shown in FIG. 8 and Table 3, the sample with a flow rate of 1 L/min had a higher proportion of Si than the sample with a flow rate of 0 L/min. This is thought to be because impurities on the surface of the sample were removed by surface modification, and the surface of the sample was clearly displayed. In addition, the samples with flow rates of 2 L/min and 3 L/min had a lower proportion of Si and a higher proportion of C than the sample with a flow rate of 1 L/min. The reason for this is believed to be that the sputtering effect of the argon plasma gas was stronger than when the flow rate was 1 L/min, causing the sample to be dug up. These results suggest that Si is localized on the surface of the cured resin film on the silicon oxide film side.

(Experimental Example 4)
An experiment was carried out to confirm that inorganic crystal particles present at the interface between the cured resin film and the silicon oxide film are embedded in the silicon oxide film, as follows. Abrasion tests were carried out on the laminates of Example 1 and Comparative Example 1, and the surface conditions after the abrasion tests were observed by SEM at a magnification of 10,000 times. The abrasion tests were carried out in accordance with JIS K 7204:1999 "Plastics - Abrasion test method using abrasive wheels" using a Taber abrasion test with a load of 500 g and a CS-10F wheel at 1000 revolutions. The results are shown in Figs. 9 and 10. Fig. 9 shows the results for Example 1 of Experimental Example 4, where (a) is an SEM image showing the surface condition after the formation of the cured resin film and before the formation of the silicon oxide film, (b) is an SEM image showing the surface condition after the formation of the silicon oxide film and before the abrasion test, and (c) is an SEM image showing the surface condition after the formation of the silicon oxide film and after the abrasion test. 10 shows the results for Comparative Example 1 of Experimental Example 4, where (a) is an SEM image showing the surface state after the formation of the cured resin film and before the formation of the silicon oxide film, (b) is an SEM image showing the surface state after the formation of the silicon oxide film and before the abrasion test, and (c) is an SEM image showing the surface state after the formation of the silicon oxide film and after the abrasion test. The scale bars in the images are all 1 μm.

In the surface state after the formation of the resin cured film and before the formation of the silicon oxide-based film shown in Figures 9(a) and 10(a), a sea-island structure was confirmed, suggesting that the silicon oxide crystal fine particles were localized on the surface of the resin cured film. In the surface state after the abrasion test shown in Figures 9(c) and 10(c), the part surrounded by the solid line is the part where the silicon oxide-based film has peeled off, and the part surrounded by the dashed line is the part where the silicon oxide-based film remains. In the part where the silicon oxide-based film has peeled off surrounded by the solid line in Example 1 shown in Figure 9(c), the sea-island structure of silicon oxide crystal fine particles localized on the surface of the resin cured film seen before the silicon oxide-based film was formed was not observed. From this, it is considered that the silicon oxide crystal fine particles in the sample of Example 1 are peeled off together with the silicon oxide-based film, and it is suggested that the silicon oxide crystal fine particles (inorganic crystal particles) and the silicon oxide-based film are integrated, that is, the silicon oxide crystal fine particles (inorganic crystal particles) are embedded in the silicon oxide-based film. On the other hand, in the area of the silicon oxide film in Comparative Example 1 surrounded by the solid line in FIG. 10(c) where the silicon oxide film had peeled off, a sea-island structure of silicon oxide crystal fine particles localized on the surface of the resin cured film seen before the silicon oxide film was formed was observed. This suggests that in the sample of Comparative Example 1, only the silicon oxide film was peeled off, and the silicon oxide crystal fine particles (inorganic crystal particles) and the silicon oxide film were not integrated, that is, the silicon oxide crystal fine particles (inorganic crystal particles) were not embedded in the silicon oxide film. The reason why the silicon oxide crystal fine particles (inorganic crystal particles) were embedded in the silicon oxide film when the film was formed using plasma argon gas as in Example 1 is thought to be because argon has a larger atomic weight than helium, so the etching effect was greater and surface modification occurred.

Example 3
A cured resin film 21 was formed on the surface of a polycarbonate substrate in the same manner as in Example 1. Next, a silicon oxide film 22 was formed on the surface of the cured resin film 21 using a film forming apparatus 50 shown in Fig. 3 under the following conditions.
Electrode 51: Alumina flat plate (thickness 0.2 mm)
Distance between electrodes 51: 1.2 mm
High frequency voltage applied to electrode 51: frequency 30 kHz, voltage 11.5 kV
Inert gas 56: argon gas, flow rate: 250 mm/sec
Raw material mixed gas 57: trimethylsilane/oxygen gas: 0.25/313, total flow rate 313.25 mm/sec
Distance between the electrode 51 and the surface of the cured resin film 21: 9 mm
Conveying speed of the substrate 10: 0.1 mm/sec
Number of scans: 1 Film formation atmosphere: Open atmospheric pressure (101 kPa)
Heating by the heater 58 was not performed.

Example 4
A cured resin film 21 was formed on the surface of a polycarbonate substrate in the same manner as in Example 1. Next, a silicon oxide film 22 was formed on the surface of the cured resin film 21 using a film forming apparatus 50 shown in Fig. 3 under the following conditions.
Electrode 51: Alumina flat plate (thickness 0.2 mm)
Distance between electrodes 51: 1.2 mm
High frequency voltage applied to electrode 51: frequency 30 kHz, voltage 11.5 kV
Inert gas 56: argon gas, flow rate: 500 mm/sec
Raw material mixed gas 57: trimethylsilane/oxygen gas: 0.5/313, total flow rate 313.5 mm/sec
Distance between the electrode 51 and the surface of the cured resin film 21: 9 mm
Conveying speed of the substrate 10: 0.1 mm/sec
Number of scans: 2 times Film formation atmosphere: Atmospheric pressure open environment (101 kPa)
Heating by the heater 58 was not performed.

Example 5
A cured resin film 21 was formed on the surface of a polycarbonate substrate in the same manner as in Example 1. Next, a silicon oxide film 22 was formed on the surface of the cured resin film 21 using a film forming apparatus 50 shown in Fig. 3 under the following conditions.
Electrode 51: Alumina flat plate (thickness 0.2 mm)
Distance between electrodes 51: 1.2 mm
High frequency voltage applied to electrode 51: frequency 30 kHz, voltage 11.5 kV
Inert gas 56: argon gas, flow rate: 500 mm/sec
Raw material mixed gas 57: trimethylsilane/oxygen gas: 0.25/313, total flow rate 313.25 mm/sec
Distance between the electrode 51 and the surface of the cured resin film 21: 9 mm
Conveying speed of the substrate 10: 0.3 mm/sec
Number of scans: 3 times Film formation atmosphere: under atmospheric pressure (101 kPa)
Heating by the heater 58 was not performed.

(Experimental Example 5)
For the laminates of Examples 3 to 5, the change rate ΔH in haze value before and after the test was measured in a Taber abrasion test according to JIS K 7204:1999 "Plastics - Abrasion test method using abrasive wheels" at a load of 500 g and a CS-10F wheel at 1000 revolutions. The results are shown in Table 4.

In Table 4, the deposition time is calculated as deposition time 1 when the transport speed of the substrate 10 is 0.1 mm/sec and the number of scans is 1. The rate is the film thickness formed when plasma is irradiated to an arbitrary location for 1 second, and is calculated as (film thickness [nm] ÷ deposition time) ÷ (distance between electrodes [mm] ÷ transport speed [mm/sec]).

Reference Signs List 1 Laminate 10 Plastic substrate 20 Laminated film 21 Resin cured film 22 Silicon oxide film 30 Inorganic crystal particle 30A Inorganic crystal particle present at interface 51 Electrode 52 AC power source 53 Inert gas supply pipe 54 Raw material gas supply pipe 55 Dielectric 56 Argon gas (inert gas)
57 raw material mixed gas 58 heater 59 plasma generation region

Claims (9)

A laminate having a plastic substrate and a laminate film,
the laminated film has a cured resin film and a silicon oxide film provided on the surface of the cured resin film, the silicon oxide film having a thickness of 0.05 to 1.00 μm;
the cured resin film contains inorganic crystal particles having an average particle size of 10 to 100 nm, the inorganic crystal particles being locally dispersed on the silicon oxide-based film side and also present at the interface between the cured resin film and the silicon oxide-based film;
A laminate comprising inorganic crystal particles present at the interface, the inorganic crystal particles being embedded in the silicon oxide film. The laminate according to claim 1, characterized in that the resin cured film contains silicone oil. The laminate according to claim 1, characterized in that the silicon oxide film is a plasma vapor deposition film formed under normal pressure. The laminate according to any one of claims 1 to 3, characterized in that the silicon oxide film contains oxygen atoms and silicon atoms, and further contains at least one of carbon atoms, hydrogen atoms, and nitrogen atoms. The laminate according to any one of claims 1 to 4, characterized in that the resin of the cured resin film is an acrylic resin. The surface of the silicon oxide film is characterized in that the change in haze value before and after the test is 2.0% or less when the surface is subjected to a Taber abrasion test according to JIS K 7204:1999 "Plastics - Abrasion test method using abrasive wheels" with a load of 500 g and a CS-10F wheel at 1000 revolutions, and the pencil hardness is 6H or more in the pencil hardness test according to JIS K 5600-5-4:1999 "General test methods for paints - Part 5: Mechanical properties of coatings - Section 4: Scratch hardness (pencil method)". A method for producing a laminate having a plastic substrate and a laminate film, comprising the steps of:
the laminated film has a cured resin film and a silicon oxide film provided on a surface of the cured resin film,
A step of forming the cured resin film by applying a coating material for the cured resin film, the coating material containing inorganic crystal particles having an average particle size of 10 to 100 nm;
a step of disposing a pair of electrodes arranged opposite to each other perpendicular to a surface of the cured resin film, supplying argon gas between the electrodes in an atmospheric pressure atmosphere while applying a high frequency voltage between the electrodes, thereby generating plasmatized argon gas by atmospheric pressure glow discharge of the argon gas, disposing the plastic substrate having the cured resin film on its surface downstream from the electrodes in a direction in which the plasmatized argon gas is sprayed, and supplying a source gas made of an organosilicon compound for film formation and oxygen to an outer electrode region between the electrodes and the cured resin film of the plastic substrate in a direction intersecting the flow of the plasmatized argon gas, thereby converting at least a part of the source gas and oxygen into a plasmatized source gas and a plasmatized oxygen gas, which are then sprayed toward the surface of the cured resin film together with the plasmatized argon gas, thereby forming the silicon oxide based film on the surface of the cured resin film ,
The method for producing a laminate is characterized in that the silicon oxide film has a thickness of 0.05 to 1.00 μm . The method for manufacturing a laminate according to claim 7, characterized in that the coating material for the resin cured film contains silicone oil. The method for producing a laminate according to claim 7 or 8, characterized in that the organosilicon compound is at least one selected from the group consisting of trimethylsilane, tetraethoxysilane, tetramethoxysilane, and hexamethyldisiloxane.

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