JPH02251590A - Surface modifying material - Google Patents

Abstract

PURPOSE:To obtain the subject material, improved in properties such as resistance to weather, damage, anti-fogging properties, etc., and useful for molded plastic products, etc., by impregnating a substrate with a fluororesin dispersion containing an ultraviolet ray absorber and anti-fogging agent and drying the impregnated substrate. CONSTITUTION:The objective material obtained by impregnating a substrate consisting of a molded plastic product such as polyolefinic resin, polyamide-based resin or PS-based resin, glass, etc., with a fluororesin dispersion containing an ultraviolet ray absorber such as benzophenone-based, benzotriazole-based or salicylic acid ester-based absorber, and/or anti-fogging agent such as sorbitan ester of a fatty acid, fatty acid monoglyceride or polyether-modified silicone oil, and then drying the impregnated substrate. Furthermore, homopolymer or a copolymer of tetrafluoroethylene is especially useful as the fluororesin.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to materials such as plastic moldings that have improved properties such as weather resistance, anti-fogging properties, and damage resistance.

Technology at the end of the article Plastic molded products are used for a variety of purposes, but with the exception of a limited number of resins, they often lack weather resistance (including #light resistance, hereinafter the same).

In addition, in addition to weather resistance, anti-fog (condensation (including preventive properties, hereinafter the same) and damage resistance are also often required.

As a method for obtaining a weather-resistant plastic molded article, a method is generally adopted in which a UV absorber is internally added to a resin raw material and then subjected to molding.

When anti-fogging properties are required, hydrophilic plastics are generally used as the material, but since anti-fogging properties are insufficient just by selecting the material, anti-fogging agents such as surfactants are added internally. Molding is done.

Problems to be Solved by the Invention However, the method of improving weather resistance and anti-fog properties by internally adding ultraviolet absorbers and anti-fog agents is difficult to apply unless the product is mass-produced; In addition to the fact that the long-lasting effects on the properties are not necessarily sufficient, - once these effects have diminished, it is no longer possible to recover them, - damage resistance cannot be imparted, - it cannot be applied to anything other than plastic molded products, etc. There are limits.

Regarding the improvement of anti-fogging properties, it is known to apply an anti-fogging agent to the molded product, but the effect in this case is only temporary, and even at -300 degrees, water may come into contact with it or wash it. As a result, the antifogging effect is significantly reduced or lost.

If we could provide properties such as excellent weather resistance, anti-fogging properties, and damage resistance by post-processing base materials such as plastic molded products, and if we could maintain these effects for a long time, The advantages will be immeasurable.

One of the applicants has proposed that by providing a permeable layer of an aqueous fluororesin dispersion on a plastic molded product, it will improve dimensional stability against changes in temperature and humidity, prevent abrasion and deformation during use under load, Although a technology has been proposed to impart properties such as heat resistance (see JP-A-59-199241), the improvement effect is not sufficient in terms of weather resistance, and no consideration has been given to anti-fogging properties. There wasn't.

Against this background, the present invention provides a technology that permanently imparts properties such as weather resistance, anti-fogging properties, and damage resistance to base materials such as plastic molded products by post-processing them. The purpose is to

Means for Solving the Problems The modified material of the present invention is obtained by impregnating a base material with a fluororesin dispersion containing an ultraviolet absorber and/or an antifogging agent, and drying the impregnated material.

The present invention will be explained in detail below.

As the base material, a plastic molded product is used, and glass and other materials can also be used.

Here, the plastic molded products include polyolefin resin, polyamide resin, polystyrene resin, AB
S resin, polyvinyl chloride resin, polyvinylidene chloride resin, acrylic resin, polycarbonate resin, polyacetal resin.

Polyester resin, polysulfone resin, polyphenylene oxide resin, vinyl alcohol resin, cellulose polymer, polyurethane resin, polyimide resin, epoxy resin, phenol resin, urea resin, guanamine resin, melamine resin, unsaturated polyester resin Examples include molded products of arbitrary shapes molded from various resins including sia rifthalate resin, synthetic rubber, and natural rubber.

The surface of the base material, especially the plastic molded product, may be activated in advance. Examples of activation treatment means include plasma treatment, ultraviolet treatment, electron beam treatment, radiation treatment, ion beam treatment, corona discharge treatment, chemical treatment, solvent treatment, steam treatment, mechanical roughening treatment, and the like.

The fluororesin in the fluororesin dispersion includes tetrafluoroethylene homopolymer or copolymer, vinylidene fluoride homopolymer or copolymer,
Examples include homopolymers or copolymers of glocotrifluoroethylene. In particular, homopolymers or copolymers of tetrafluoroethylene are useful, and in the case of copolymers, comonomers other than tetrafluoroethylene include olefins, fluorine-containing olefins, perfluoroolefins, fluoroalkyl vinyl ethers, and the like.

These fluororesins are used as a dispersion, especially an aqueous dispersion.

In the present invention, the dispersion contains either or both of an ultraviolet absorber and an antifogging agent depending on the use.

As the ultraviolet absorber, 2,4-dihydroxybenzophenone, 2-hydroxy-4-7cetoxyethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2°-dihydroxy-4-methoxybenzophenone, 2,2''-dihydroxy-4,4'-methoxybenzophenone, 2-hydroxy-4-〇-octoxybenzophenone, 2-hydroxy-4-f-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2 -Hydroxy-4-octadecyloxybenzophene, 2,2'-dihydroxy-4
, 4'-dimethoxy-5,5'-disulfobenzophenone-disodium, 2-hydroxy-4-(2-hydroxy-3-methacryloxy)flopoxybenzophenone, etc.: 2-(2'-hyVroxy) 59-
methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5''-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-
Butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy -3',5'-di-monoamylphenyl)-5-benzotriazole, 2(2'-
Benzotriazole series such as hydroxy-5'-t-butylphenyl)penztriazole, 2-(2'-hydroxy-'5'-t-octylphenyl)benzotriazole: phenyl salicylate, p-t-butylphenyl salicylate, p - Salicylic acid esters such as octylphenyl salicylate; Benzoates such as 2°,4'-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate;2-ethoxy-2"
-Oxalic acid anilide series such as ethyl oxalic acid bisanilide, 2-nithoxy-5-t-butyl-2'ethyl oxalic acid bisanilide:
Cyanoacrylates such as ethyl-2-cyano-3,5-diphenylacrylate; bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,
2,2,6,6-bentamethyl-4-piperidyl) sebacate, dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylbiveridine polycondensate Examples include hindered amine systems such as;

Various antifogging agents have been used or proposed, such as sorbitan fatty acid esters (sorbitan monolaurate, sorbitan monopalmitate, sorbitan monolaurate, sorbitan monopalmitate,
sorbitan monostearate, etc.), sorbitan fatty acid alkylene oxide adducts (polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monooleate, etc.), fatty acid monoglycerides (stearic acid monoglyceride, oleic acid monoglyceride) etc),
Polyether-modified silicone oil and the like can be used.

The concentration of fluororesin in the fluororesin dispersion is 0.
．． The concentration of the ultraviolet absorber or antifogging agent is often set to be about 0.01 to 10% by weight, but it is not necessarily limited to this range.

The fluororesin dispersion liquid contains, in addition to the above-mentioned window absorber or antifogging agent, a fluorine surfactant, silicone oil, other surfactants, wax, pH adjuster, polyhydric alcohol, softener, and viscosity adjuster. Even in the case of an aqueous dispersion, if an appropriate solvent is used in an appropriate amount, a dispersion close to an emulsion can be obtained.

Impregnation of a base material such as a plastic molded article with a fluororesin dispersion is usually carried out by immersing the base material in the fluororesin dispersion. Immersion is not only possible under normal pressure.
It can also be carried out under reduced pressure or increased pressure, which is advantageous in terms of the amount of impregnation and the rate of impregnation.

The impregnated layer can be formed not only by the dipping method described above but also by a coating method or a spraying method.

After the impregnation treatment, the dispersion liquid adhering to the surface of the base material is removed by washing or wiping as required, and then the base material is dried by air drying or heat drying. As a result, the desired surface-modified material can be obtained.

Action and Effect of the Invention When the fluororesin dispersion containing the ultraviolet absorber and/or antifogging agent comes into contact with the substrate, the fluororesin dispersion attracts the ultraviolet absorber and/or antifogging agent onto the surface of the substrate. It quickly penetrates into the interior, and after drying, it contains UV absorbers and plasters along with fluorine resin! ! (It firmly settles there and does not fall off easily.

Therefore, the surface-modified material of the present invention can withstand weathering even under harsh environments, including applications that are used outdoors, applications that are exposed to light, and applications that come into contact with liquids such as water and oil. It has excellent properties such as hardness, antifogging properties, and damage resistance, and its modification effect is also long lasting. Note that excellent antifogging properties also mean excellent antistatic properties.

Method of the present invention (method of impregnating a plastic molded product, etc. with a fluororesin dispersion containing an ultraviolet absorber and an antifogging agent)
The internal addition method (a method in which a UV absorber or antifog agent is blended with the raw resin and used for molding) or the coating impregnation method (a method in which a UV absorber or an antifog agent is simply applied or impregnated onto a plastic molded product) Compared to the method of the present invention, the initial weather resistance and antifogging properties are in the order of the method of the present invention>internal addition method and the impregnation method, but if water comes into contact with the method or washing is performed even at -degrees, the method of the present invention>internal addition method 〉〉It is an impregnation method, and after a certain period of time, the significant difference between them becomes more noticeable. This is considered to be because in the method of the present invention, a layer impregnated with a high-temperature ultraviolet absorber or an antifogging agent is present on the surface of the molded product, and this layer does not easily peel off due to the presence of the fluororesin.

Since the present invention treats base materials such as plastic molded products after the fact, it can be applied to any number of base materials, and even if the effectiveness decreases due to long-term use, the UV absorber can be reused. The original effect can be restored by treatment with a fluororesin dispersion containing an antifogging agent, and properties such as weather resistance and antifogging properties, as well as damage resistance, abrasion resistance, heat resistance, and dimensional stability. It also has the advantage of being able to improve

Example Next, the present invention will be further explained with reference to Examples.

<Example 1> A fluororesin aqueous dispersion having the following composition was prepared.
%" means % by weight) per Ren film, 20% by weather meter.
00 hour and 3000 hour exposure tests were conducted to measure the tensile strength. The results were as follows.

Example 1 4300psi 4100psi 4
000psi Comparative Example 1 4300psi 3700
psi 2800psi A high-density polyethylene film as a test piece was added to this dispersion at a temperature of 50°C for 5 hours.
After being immersed for several minutes under normal pressure conditions, it was taken out, then water was sprayed to remove the dispersion liquid adhering to the surface, and finally it was dried at 40 to 50°C in a hot air dryer.

<Comparative Example 1> A high-density polyethylene film formed by internally adding 1.0% of pt-butylphenyl salicylate as an ultraviolet absorber was prepared.

<Test method and results> High-density polyethylene 2 to 32 of Example 1 and Comparative example 1 (Example 2) A fluororesin aqueous dispersion having the following composition was prepared. (1
%" means % by weight) A polypropylene plate as a test piece was immersed in this dispersion at a temperature of 40°C for 5 minutes and a pressure of 300 to 400 Torr, taken out, and then sprayed with water to coat the surface. The adhering dispersion liquid was removed, and finally it was dried at 50 to 60°C in a hot air dryer.

(Example 3) A fluororesin aqueous dispersion having the following composition was prepared.
%" means % by weight) A polypropylene plate as a test piece was immersed in this dispersion at a temperature of 40°C for 1 hour and 3 minutes and a pressure of 4 to 5 atm, taken out, and then sprayed with water to coat the surface. Remove the adhering dispersion liquid and finally dry it in a hot air dryer for 50~
It was dried at 60°C.

<Comparative Example 2) 1% by weight of sorbitan monolaurate and 1% by weight of stearic acid monoglyceride as an antifogging agent, and 1% by weight of 2-(2'-hydroxy-5'-1-butylphenyl)benzotriazole as an ultraviolet absorber. A polypropylene plate prepared by blending and molding was prepared.

<Test Method and Results> The polypropylene plates of Examples 2 to 3 and Comparative Example 2 were examined for antifogging properties and abrasion fastness.

The anti-fog properties were tested by steam spraying on the original product and the product left outdoors for one month, and the anti-fog properties were ranked in order of 0.0. Evaluation was made on a four-level scale of Δ and ×.

The rubbing fastness is the same as the scratches on the surface that occur when the original test pieces of Comparative Example 2 are rubbed against the original product and the product left outdoors for one month, and the original test pieces of Comparative Example 2 are rubbed together 50 times. The evaluation was based on the number of reciprocations that caused the degree of damage.

The results were as follows.

Claims (1)

[Scope of Claims] 1. A surface-modified material obtained by impregnating a base material with a fluororesin dispersion containing an ultraviolet absorber and/or an antifogging agent and drying the impregnated material. 2. The modified material according to claim 1, wherein the base material is a plastic molded product.