JPS6136863B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a synthetic resin molded product whose surface has been modified by forming an ultra-thin film made of a surface modifier such as an antistatic agent, an antifogging agent, and an antifungal agent.
The purpose of this is to ensure that the surface appearance of the synthetic resin molded product remains the same as before the modification, and that the modification effect is excellent, maintains its effect for a long period of time, and provides wear resistance and repeated pressure peeling of the pressure-sensitive protective film. The object of the present invention is to provide a surface-modified synthetic resin molded product that has excellent peeling resistance due to the above-mentioned methods, etc., and has no selectivity in the synthetic resin material to be treated, and can be molded at low cost. Conventionally, these surface modifiers have been applied to synthetic resin molded products using various methods, but as shown in Figure 1,
Even if the surface of a synthetic resin molded product has a mirror finish, it is extremely uneven, and the treatment film made of the surface modifier does not cover the uneven shape evenly and aggregates in many places. . This is because the treated film is thick and the surface tension of the treated film is greater than the surface tension of the synthetic resin. On the other hand, the critical surface tension of synthetic resins is, for example, vinyl chloride resin 39 dyne/cm, polyethylene 31 dyne/cm
cm, polystyrene 33 dyne/cm, polymethyl methacrylate resin 39 dyne/cm, etc. This invention focuses on these points, and uses an appropriate method to reduce the surface tension of a dilute aqueous solution or aqueous dispersion containing a surface modifier to 30 dyne/cm25°C or less using a fluorine-containing surfactant. By making the aerosol into a smoke form and adsorbing this aerosol with a particle size of 5μ or less on the surface of a synthetic resin molded product,
The particles spread over the surface of the synthetic resin molded product without agglomerating,
Coupled with the fineness of the particles, moisture evaporates rapidly, and an ultra-thin film made of a surface modifier with a film thickness of less than 400 mμ, that is, less than the wavelength of visible light, uniformly and evenly covers the surface of the synthetic resin molded product. It is.
Therefore, as shown in FIG. 2, even the details of the irregularities 3 of about 1 μm or less on the surface 2 of the synthetic resin molded product 1 are coated with an ultra-thin film 4.
is formed evenly along the shape of the unevenness 3. Here, the surface modifier includes appropriate agents such as antistatic agents, antifogging agents, and fungicides. Examples of fluorosurfactants include fluoroalkyl carboxylates (alkali metal salts, alkaline earth metal salts, amine salts), perfluoroalkyl carboxylates, fluoroalkyl phosphate ester salts, perfluoroalkyl phosphate ester salts, Polyoxyethylene・
Perfluoroalkyl phosphate salts, perfluoroalkyl sulfate salts, polyoxyethylene perfluoroalkyl sulfate salts, perfluoroalkyl sulfonamide derivatives, perfluoroalkylamine salts, perfluoroalkyl quaternary ammonium salts, perfluoroalkyl imidazolines derivatives, perfluoroalkylbedaine, polyoxyethylene perfluoroalkyl ether, polyoxyethylene perfluoroalkylphenol, polyoxyethylene perfluoroalkylamine, perfluoroalkylcarboxylic acid sorbitan ester, etc., among which fluorinated The number of carbon atoms in the alkyl group is not particularly limited, but in particular 6-22
It is preferred to use a range of . Specific examples include 16-fluorohexadecylcarboxylic acid, perfluorooctylcarboxylic acid N,N-diethanolamine, perfluorooctyl sodium phosphate, perfluorodecyl sodium phosphate, polyoxyethylene perfluorooctyl sodium phosphate, N -Polyoxyethylene-
N-ethyl perfluorooctyl sulfonamide,
N,N-di(polyoxyethylene) perfluorooctyl sulfonamide, N-polyoxyethylene-N-butyl perfluorodecylphonamide, N-
Polyoxyethylene-N-ethyl perfluorooctadecyl sulfonamide, perfluorododecyl trimethylammonium salt, perfluorooctadecyl-N-ethyldimethylammonium salt, perfluorooctadecyl betaine, polyoxyethylene perfluorooctyl ether, polyoxyethylene perfluoroocta Decenyl ether, polyoxyethylene perfluorohexylamine, perfluorododecylcarboxylic acid sorbitan ester, etc., and these may be used alone or in combination. As a result, since the ultra-thin film 4 made of the surface modifier has a wavelength below the visible light wavelength, the surface appearance of the synthetic resin molded product 1 remains the same as before modification, and therefore, the surface appearance of the synthetic resin molded product 1 remains the same as before modification. In this case, even if the surface is modified, the transparency will not change and the desired property effect will not be impaired, and as mentioned above, the ultra-thin film can be applied to the details of the minute irregularities 3 of about 1μ or less on the surface 2 of the synthetic resin molded product 1. Since 4 is covered, synthetic resin molded product 1
Even if the surface 2 is rubbed, the extremely thin film 4 at the tip of the convex portion 3a of the unevenness 3 is only locally scraped, but the extremely thin film 4 inside the concave portion 3b is not scraped. Therefore, these extremely thin films 4 are connected in a plane and do not affect the surface modification effect. Further, depending on the surface modifier of the ultra-thin film 4, the peripheral edge of the ultra-thin film 4 extends to cover the tip of the convex portion 3a again. Therefore, the antistatic surface modification effect does not decrease due to friction, and the wear resistance is extremely high, such as being able to withstand long-term friction. In addition, in this invention, as described above, since the ultra-thin film 4 is formed along the fine irregularities 3 on the surface 2 of the synthetic resin molded product 1, the ultra-thin film 4 can withstand repeated pressure-peeling operations of the pressure-sensitive protective film. Extremely strong peeling resistance.
Furthermore, since the ultra-thin film 4 of the present invention is formed differently from films treated by conventional resin kneading methods or coating methods, there is no bleed or stickiness due to the thickness of the coating film. Furthermore, since the ultra-thin film made of this surface modifier has exactly the same characteristics as any synthetic resin material, there is no selectivity of the synthetic resin molded product to be treated. Furthermore, with this invention, the amount of surface modifier per unit area of the synthetic resin molded product is extremely small, and surface treatment can be easily carried out using a dry process, making it possible to perform a low-cost in-line process for industrial mass production. can be applied. This invention will be described in detail with reference to examples below.
This invention is not limited to the following examples unless it exceeds the gist thereof. Example 1 (a) Lauryl diethanolamine as an antistatic agent

[Formula] is 2%, (b) a nonionic surfactant as a fluorine-based surfactant (e.g., Surflon manufactured by Asahi Glass Co., Ltd. (trade name) S-
An aqueous dispersion containing 0.1% of (c ) Polyethylene film, which is the object to be treated, was exposed. The surface tension of the fine particles adsorbed on the surface of the polyethylene film is 17 dyne/cm, which is much smaller than the surface tension of the polyethylene film, which is 31 dyne/cm.Therefore, the fine particles spread in a thin film shape on the surface of the polyethylene film, and the wavelength of visible light is uniform. The following ultrathin films were formed. Example 2 Lauryltrimethylammonium chloride as (a)

[Formula] is 2%, (b) is a nonionic surfactant (Surflon
An aqueous solution containing 0.1% of ((trade name))S-141) was prepared, and an extremely thin film was formed on the surface of an acrylic resin plate under the same conditions as in the above example. In this case, the surface tension of the aqueous solution was 16 dyne/cm. Example 3 Lauryl diethanolamide as (a)

[Formula] is 2%, (b) is an amphoteric surfactant (surflon ((trade name)) S-
An aqueous solution containing 0.1% of 131) was prepared, and the above Example 1
An ultrathin film was formed on the surface of a polystyrene sheet under the same conditions as above. The surface tension of the aqueous solution in this case is
It is 17dyne/cm. Example 4 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of an ABS resin plate under the same conditions as in Example 1 above. Example 5 An aqueous dispersion of Example 1 was prepared, and the aqueous dispersion of Example 1 was prepared.
An ultrathin film was formed on the surface of a foamed polystyrene sheet under the same conditions as above. Example 6 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of a polycarbonate resin sheet under the same conditions as in Example 1 above. Example 7 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of a polyethylene terephthalate resin molded product (bottle) under the same conditions as in Example 1 above. Example 8 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of the same hard vinyl chloride sheet as in Example 1 above. Example 9 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of a polypropylene film under the same conditions as in Example 1 above. Example 10 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of a record under the same conditions as in Example 1 above. Example 11 The aqueous dispersion of Example 1 was prepared, and an extremely thin film was formed on the surface of a fluororesin sheet under the same conditions as in Example 1 above. Regarding Examples 1 to 11 above, each ultrathin film had a thickness less than the wavelength of visible light, at a temperature of 25°C and a relative humidity of 45°C.
% measurement conditions, as shown in the table below, the electrical surface resistivity of these surface-modified molded products was approximately on the order of 10 ¹⁰ Ω, and the charge half-life time was 1.2 to 7.2 seconds. It was extremely short.

[Table] Regarding Example 2, the antistatic performance was not impaired at all in 10 repeated pressure-bonding and peeling tests of the pressure-sensitive protective film on the acrylic resin plate. Further, in the case of the record of Example 10, the grooves were subjected to friction by the record stylus, and with the conventional antistatic film, it was quickly scraped off and the antistatic effect was lost, but the treatment of the present invention The film is adsorbed to the fine surface of the grooves on the record, so it does not peel off due to the record stylus.
The antistatic effect was maintained even after multiple uses. The above examples are cases in which an antistatic agent is used, but the same effects as in the case where an antifogging agent is used were obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a synthetic resin molded product to which a conventional treatment film has been applied, and FIG. 2 is a cross-sectional view of a synthetic resin molded product to which the surface modification of the present invention has been applied. In the figure, 1 is a synthetic resin molded product, 2 is a surface, and 3 is a synthetic resin molded product.
4 is an uneven film, and 4 is an extremely thin film.

Claims (1)

[Claims] 1. The surface tension of a dilute aqueous solution or aqueous dispersion containing a surface modifier and a fluorine-based surfactant.
30dyne/Cm below 25°C is turned into atomized by an appropriate method, and this aerosol selected to have a particle size of below 5μ is adsorbed onto the surface of a synthetic resin molded product to form an ultra-thin film made of a surface modifier. Synthetic resin molded product with surface modification characterized by 2. The surface-modified synthetic resin molded product according to claim 1, wherein the surface modifier is at least one of an antistatic agent, an antifogging agent, and a fungicide.