KR100284387B1 - Manufacturing method of polycarbonate transparent plate with improved abrasion resistance and scratch resistance using plasma assisted chemical vapor deposition - Google Patents

Abstract

The present invention relates to a method for producing a polycarbonate transparent plate with improved wear resistance and scratch resistance.

According to the present invention, a polycarbonate transparent plate is placed on an electrode in a vacuum apparatus and vacuumed, argon gas is introduced to generate an argon plasma to remove impurities on the polycarbonate transparent plate, and a monomer and a reaction gas are mixed to form an electrode. Through the step of feeding through and supplying a current through a radio frequency current generator to the electrode having a gas inlet electrode and the polycarbonate transparent plate to form a plasma on both electrodes to form a wear-resistant layer on the polycarbonate transparent plate It is a method for producing a polycarbonate transparent plate with improved scratchability.

As described above, the present invention can improve abrasion resistance and scratch resistance in which a wear resistant layer is uniformly generated on the polycarbonate transparent plate by generating plasma at both sides.

Description

Manufacturing method of polycarbonate transparent plate with improved abrasion resistance and scratch resistance using plasma assisted chemical vapor deposition

The present invention relates to a method for producing a polycarbonate transparent plate. More specifically, the present invention relates to a method of manufacturing a polycarbonate transparent plate having improved wear resistance and scratch resistance using plasma enhanced chemical vapor deposition (PECVD).

Polycarbonate resins have excellent mechanical and chemical properties and are widely used in various fields. In particular, this resin has a low weight, high transparency, and strong impact strength compared to glass, so it is widely used in automobile headlights and transparent soundproof walls, replacing glass materials. However, the application of resins is limited due to the relatively low wear and scratch resistance compared to glass. Various methods have been used to overcome this disadvantage, and techniques for increasing wear resistance by coating organic or inorganic materials on polycarbonate resins have been actively studied.

Coating with organic materials improves the wear resistance of polycarbonate resins, but it is difficult to obtain high wear resistance such as glass because the material to be coated is organic. Therefore, in applications where high wear resistance is required, the glass replacement wear resistant polycarbonate product is preferably produced by an inorganic coating method.

As a form of inorganic coating, a method of improving the wear resistance by depositing a glass thin film on a plastic resin has been studied. Examples of this are French Patent No. 1,520,125 and British Patent No. 1,144,099, which report that the scratch and abrasion resistance of polycarbonate plates is improved when the glass (SiO ₂ ) is deposited on the polycarbonate resin at a thickness of 1 μm. Doing. The deposition of glass was made using oxygen gas and electron beam under high vacuum, and the plastic resin was designed to move constantly in glass vapor during processing. However, the wear-resistant polycarbonate resin produced by this technique has the disadvantage of being easily cracked or peeling off of the glass film and the resin due to a strong impact or a large temperature change due to the large thermal expansion coefficient difference between the resin and the glass.

Many methods have been proposed to solve the cracking or peeling phenomenon of the glass film. U.S. Patent No. 3,645,779 introduced a method of producing a plastic transparent plate having no cracking and high scratch resistance by depositing B ₂ O ₃ -SiO ₂ glass containing 5 wt% or less of Na ₂ O on a polycarbonate resin.

U. S. Patent No. 3,713, 869 describes a technique for forming an interlayer between two layers to improve the adhesion between plastic and glass plates. In the glow discharge state, the vapor of the low molecular weight organic material is polymerized to form an intermediate layer on the surface of the polymer resin. The vapor of organic material was made of organic material containing acetylene, xylene and silicon (Si).

U.S. Patent No. 4,200,681 relates to a technique for producing glass-coated polycarbonate consisting of an intermediate layer prepared by photopolymerizing a polycarbonate resin, a glass film and an acrylic monomer by ultraviolet light.

The polycarbonate resin prepared by such a technique has improved cracking and glass peeling problems as compared to the polycarbonate prepared by the conventional technique, but has a problem of weak adhesive strength and cracking resistance.

U.S. Patent No. 4,762,730 relates to a technique for producing a transparent protective film by alternating plasma on a transparent plastic. The siloxane and silazane are used as monomers to react with oxygen to prepare a SiO ₂ wear-resistant layer on a plastic transparent plate.

The method of manufacturing a wear resistant layer using a conventional plasma proceeds in the following order.

1) Fix the polycarbonate transparent plate on the electrode connected to the radio frequency (hereinafter referred to as RF) current generator.

2) After removing the air from the reactor, monomer is injected into other electrode or gas inlet.

3) Plasma is generated to generate a wear resistant layer on the surface of the polycarbonate by chemical vapor deposition.

Wear resistant layers made in a conventional manner are difficult to deposit uniformly over the polycarbonate surface. In order for the wear resistant layer to be made by plasma chemical vapor deposition, the monomers supplied must be decomposed by the plasma and the decomposition products must be recombined again on the polycarbonate surface. In the conventional plasma method, the plasma is generated only on the surface of the polycarbonate, which adversely affects the uniformity of the wear-resistant thin film due to the heterogeneous decomposition reaction of the monomers.

Accordingly, the present inventors generate a plasma at both the electrode inlet electrode of the monomer and the reaction gas and the electrode having the polycarbonate transparent plate so that the decomposition reaction of the monomer occurs from the monomer inlet, so that the uniformity of the wear resistant layer generated on the polycarbonate transparent plate can be obtained. I found it could be improved.

Accordingly, an object of the present invention is to uniformly produce one or more wear resistant layers on a polycarbonate surface by generating plasma on both sides to solve the above problems and to improve wear resistance and scratch resistance of the polycarbonate plate.

1 is a manufacturing apparatus for producing a wear-resistant polycarbonate transparent plate according to the present invention.

2 is an apparatus for producing a wear-resistant polycarbonate transparent plate using a conventional plasma assisted chemical vapor deposition method.

The present invention comprises the steps of putting a polycarbonate transparent plate on the electrode in the vacuum apparatus 1 to make a vacuum, by introducing an argon gas to generate an argon plasma to remove impurities on the polycarbonate transparent plate, mixing the monomer and the reaction gas Injecting through the electrode, by supplying a current through the radio frequency current generator (5, 6) to the electrode 3 and the gas inlet electrode with a polycarbonate transparent plate to form a plasma on both electrodes polycarbonate It is a method of manufacturing a polycarbonate transparent plate with improved wear resistance and scratch resistance consisting of forming a wear resistant layer on the transparent plate.

Hereinafter, the present invention will be described in more detail.

The present invention is to uniformly prepare one or more wear-resistant layers by generating a plasma to the two electrodes for fixing the gas inlet of the monomer and the reaction gas and the polycarbonate transparent plate in order to improve the wear resistance and scratch resistance of the polycarbonate transparent plate It features.

A method of manufacturing a polycarbonate transparent plate having improved wear resistance and scratch resistance according to the present invention will be described in detail with reference to the accompanying drawings.

First, the surface of the polycarbonate transparent plate is removed using a chemical solvent such as ethanol or isopropyl alcohol, and then dried well using nitrogen gas.

The polycarbonate transparent plate is placed on the electrode 3 in the vacuum apparatus 1 of FIG. 2 used in the present invention, and the air in the apparatus is discharged using the vacuum pump 2. When a certain degree of vacuum is obtained, argon gas is introduced and an RF current generator 5 connected to the electrode 3 on which the polycarbonate transparent plate is placed is operated to generate an argon plasma on the surface of the polycarbonate transparent plate. Argon plasma is operated for a certain time (a few minutes) to remove contaminants present on the surface of the polycarbonate transparent plate.

In addition, the RF current generator 6 connected to the gas inlet and the RF current generator 5 connected to the electrode 3 having a polycarbonate transparent plate while supplying a mixture of the monomer and the reaction gas necessary for the wear-resistant layer to the gas inlet 4 Works. At this time, the argon gas is slowly replaced with the reaction gas to produce a wear resistant layer having a desired thickness on the polycarbonate transparent plate for a given time.

The monomer used for the wear resistant layer may be selected from one of the following siloxane compounds. Representative siloxane compounds include tetramethylcyclosiloxane, hexamethyldissiloxane, hexamethyldisilazne, tetraethoxylsilane, octamethylcyclotetrasiloxane (Octamethyl cyclo tetrasiloxane). Etc.

As the reaction gas, oxygen, nitrous acid (NO ₂ , NO) gas, argon, helium, hydrogen, carbon dioxide, nitrogen gas, or a mixed gas thereof is used.

The mixing ratio of the monomer and the reaction gas is not particularly limited, but is preferably used in the range of 1:10 to 1: 0.1.

The applied RF power uses a frequency between 50 kHz and 60 MHz, preferably 13.56 MHz.

After the wear resistant layer of the desired thickness is obtained, the two plasma generators are turned off and the supply of the monomer gas and the reactant gas is stopped. Air is added to maintain the vacuum degree of the reactor at atmospheric pressure to obtain a polycarbonate transparent plate having a wear resistant layer.

The characteristics generated by the present invention have been described through comparative examples and examples. Samples used in the experiment and pretreatment of the samples are as follows.

Put 10cm × 10cm polycarbonate resin in isopropyl alcohol and wash it for 1 hour with an ultrasonic cleaner and dry well using nitrogen gas. Experiments were performed under various conditions using each polycarbonate transparent plate.

Example 1

After washing, put well-dried polycarbonate resin into a vacuum device and remove air in the device with a vacuum degree of about 10 ^-4 Torr. Argon gas is supplied through the gas inlet to maintain the vacuum of the device at 100 mtorr, and then 100W RF power is supplied to the electrode on which the polycarbonate resin is placed to generate an argon plasma. The generated argon plasma removes impurities on the resin surface (plasma etching).

A mixed gas having a mixing ratio of tetraethoxysilane and oxygen gas of 1: 5 is introduced through an electrode provided with a gas inlet, and the vacuum of the device is maintained at 120 mtorr. 50W of power is supplied to the gas inlet electrode and 100W of RF current is supplied to the electrode on which the polycarbonate resin is placed, thereby simultaneously forming a plasma at both the gas inlet and the polycarbonate resin. Wear resistant layers were prepared on polycarbonate, maintaining the same conditions for 40 minutes. In order to confirm the uniformity of the wear resistant layer, silicon wafers were placed on a polycarbonate at regular intervals to measure the thickness of the wear resistant layer produced according to the position.

Example 2

The same process as in Example 1 was conducted except that a mixed gas having a mixing ratio of tetraethoxysilane and nitrite gas was 1: 5.

Example 3

The same procedure as in Example 1 was conducted except that a mixed gas having a mixing ratio of hexamethyldisilazane and oxygen gas was 1: 3.

Example 4

The same process as in Example 1 was conducted except that a mixed gas having a mixing ratio of hexamethyldisilazane and argon gas was 1: 2.

Example 5

In the same manner as in Example 1 except that a mixed gas having a mixing ratio of tetraethoxysilane and oxygen gas was added 1: 4 to form a plasma, and the same condition was maintained for 120 minutes to prepare a wear resistant layer on the polycarbonate. Was carried out.

Comparative Example 1

After washing, put well-dried polycarbonate resin into a vacuum device and remove the air in the device to a degree of vacuum of about 10 ^-4 Torr with a vacuum pump. Argon plasma is generated by the RF current generator of the electrode where the polycarbonate resin is placed to remove impurities on the surface of the resin by plasma etching.

A mixed gas having a mixing ratio of tetraethoxysilane and oxygen gas of 1: 5 is placed in a plasma apparatus, and an RF current having a power of 100 W is supplied to the electrode on which the polycarbonate resin is placed to form a plasma. Under the same conditions for 40 minutes, an antiwear layer was prepared on the polycarbonate resin. In order to confirm the uniformity of the wear resistant layer, the silicon wafers were placed on the polycarbonate resin at regular intervals, and the thickness of the wear resistant layer produced according to the position was measured.

Comparative Example 2

After washing, put well-dried polycarbonate resin into a vacuum device and remove air in the device with a vacuum degree of about 10 ^-4 Torr. Argon plasma is generated by the RF current generator of the electrode where the polycarbonate is placed to remove impurities on the resin surface by plasma etching.

A mixed gas having a mixing ratio of tetraethoxysilane and nitrite gas of 1: 5 is placed in a plasma apparatus, and an RF current having a power of 100 W is supplied to an electrode on which a polycarbonate sample is placed to form a plasma. Under the same conditions for 40 minutes, a wear resistant layer was prepared on the polycarbonate resin. In order to confirm the uniformity of the wear resistant layer, the silicon wafers were placed on the polycarbonate resin at regular intervals, and the thickness of the wear resistant layer produced according to the position was measured.

Comparative Example 3

A 10 cm × 10 cm window glass sample is placed in isopropyl alcohol, washed for 1 hour with an ultrasonic cleaner, and dried well using nitrogen gas.

The samples obtained in the above-mentioned experiments were measured for the wear resistance of the samples according to the ASTM 1044, ASTM 1003 test method to obtain the results shown in Table 1. In addition, scratch resistance was measured by a pencil hardness tester according to the ASTM D3363-92a test method.

The abrasion resistance test was performed using a taper abrasion resistance measuring instrument. The conditions used were wear lubrication CS-10F, wear cycle 100 cycles, and load 500g. Abrasion resistance was quantified by △% Haze value, and △% Haze value was the value of the average of the preselected four-part Haze value using Gardner hazemeter before and after the abrasion test. Means.

Table 1

Scratch resistance Abrasion Resistance (△% Haze) Wear Resistant Layer Thickness Uniformity (µm) I'm after Left Ooh center Standard Deviation Comparative Example 1 4H 4.0 0.9 0.7 1.1 0.6 1.2 0.25 Comparative Example 2 4H 4.1 0.8 0.6 1.0 0.7 1.1 0.21 Comparative Example 3 9H 1.2 Example 1 7H 2.4 2.2 2.2 1.9 2.0 2.1 0.13 Example 2 7H 2.7 2.1 2.0 1.9 2.0 2.0 0.07 Example 3 6H 2.9 1.9 2.0. 2.1 2.1 1.9 0.1 Example 4 5H 3.1 3.7 3.4 3.6 3.8 3.5 0.15 Example 5 9H 1.2 6.5 6.4 6.4 6.7 6.5 0.12

Note) The uniformity of the wear-resistant layer thickness was tested by attaching five silicon wafers on the polycarbonate, and the thickness of the wear-resistant layer on the silicon was confirmed, and the silicon was attached to the polycarbonate before, after, left, right and center. It means one location.

Comparative Examples 1 and 2 are experimental examples of producing a wear-resistant layer by a method used for conventional plasma assisted chemical vapor deposition, and Examples 1 to 5 were experimental examples when plasma was generated at two places on a gas inlet and a polycarbonate surface. to be. In Comparative Examples 1 and 2 and Examples 1 and 2, all experimental conditions were the same except for the presence / absence of plasma generation at the gas inlet. It can be seen that the wear resistance of the examples under the same experimental conditions is superior to that of the comparative example. The wear resistance is improved because the monomer decomposition in the plasma region of the gas inlet is promoted to increase the thickness of the wear resistant layer deposited at the same time. In addition, it can be seen that the decomposition of the monomer proceeds in the gas inlet plasma region and the thickness variation of the wear resistant layer deposited on the polycarbonate is very small.

Comparative Example 3 was selected to compare the wear resistance of the general window glass with the wear resistance of the polycarbonate of the present invention. As can be seen in Example 5, when the thickness of the wear resistant layer was 6 μm or more, the wear resistance similar to glass (Δ% haze value) was exhibited.

Examples 3 and 4 were experimented by changing the monomer, the type of reaction gas and the mixing ratio of the two components. As the total amount of the monomer increases, the thickness of the wear-resistant thin film increases, but wear resistance and scratch resistance tend to decrease.

Such a method according to the present invention can obtain a polycarbonate transparent plate with a uniform wear resistance layer and improved wear resistance and scratch resistance, thereby widening the use of the polycarbonate transparent plate .

Claims (3)

Putting a polycarbonate transparent plate on the electrode (3) in the vacuum apparatus 1 to make a vacuum, adding an argon gas to generate an argon plasma to remove impurities on the surface of the polycarbonate transparent plate, mixed monomer and reaction gas And a plasma is formed on the two electrodes by supplying a current through the radio frequency current generators 5 and 6 to the electrode 3 and the gas inlet electrode 4 having the polycarbonate transparent plate. Method for producing a polycarbonate transparent plate with improved wear resistance and scratch resistance consisting of forming a wear resistant layer thereon. The polycarbonate transparent according to claim 1, wherein the monomer is tetramethylcyclosiloxane, hexamethyldisiloxane, hexamethyldisilase, tetraethoxysilane, or octamethylcyclotetrasiloxane. Method of manufacturing plate. The method of claim 1, wherein the reaction gas is at least one selected from oxygen, nitrous acid gas, argon, helium, hydrogen, carbon dioxide, nitrogen gas, and a mixed gas thereof.