JP3099899B2 - Molded article having fluorine-containing surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to surface modification of polymers. More specifically, on the surface of a hydrocarbon polymer molded product,
By directly reacting hexafluoroacetone,
The surface is fluorinated. According to this method, since --CF ₃ can be imparted to the surface, it is possible to obtain a molded article having excellent water and oil repellency, lubricity, antistatic properties and weather resistance.

[0002]

_2. Description of the Related Art Conventionally, a method of forming a fluorine-containing film on the surface of a polymer compound is roughly classified into direct fluorination using F ₂ gas (J. Appl. Polym. Sci.,
19 , 1439 (1975). Plasma polymerization method by glow discharge (Japanese Unexamined Patent Publication (Kokai) Nos. 55-99932 and 61-1332)
39 etc.). Langmuir-Blodgett method (Japanese Unexamined Patent Publication No. Sho 62)
-572), a number of methods such as a surface graft reaction method, a vacuum evaporation method, a sputtering method, and a coating method using a fluorine-containing silane coupling agent or a fluorine-containing resin are known.

[0003] Particularly, the conditions for producing a durable thin film require a chemical reaction between the film molecules and the base material.
Direct fluorination with _two gases, surface gravitational reaction, and plasma polymerization have been attracting attention.

[0004] In any of these methods, fluorine is introduced into the surface of a substrate to provide water and oil repellency, weather resistance, low refractive index,
It is intended to improve low friction and chemical resistance. However, in the direct fluorination with F ₂ gas in addition to F ₂ gas itself is dangerous and may not be suitable in practical use, such as the substrate molecule is become brittle disadvantage is disconnected.

Further, the surface graft reaction has a disadvantage that it is difficult to provide a reactive site on the surface, and radiation or plasma is required in modifying a substrate having no reactive site. In the case of plasma polymerization, there are many advantages and many studies have been conducted. However, there is a problem of coloring such as yellowing of the film, and it is not particularly suitable for a transparent material.

Further, according to these methods, there is a disadvantage that the adhesion and printability of the base material are remarkably reduced with an increase in the fluorine concentration on the surface, and are not suitable for processing after the treatment.

[0007]

Means for Solving the Problems An object of the present invention is to form a fluorine-containing surface having a chemical bond on the surface of a hydrocarbon polymer molded article without impairing the transparency of the substrate. As a result of intensive studies, the present invention has been completed.

That is, the present invention uses hexafluoroacetone (CF ₃ ) ₂ C ＝ O as a reactant,
And it is possible to efficiently impart -CF ₃ on the surface, the nature of the substrate for a thin film of molecular order can be formed uniform and strong fluorine-containing surface while maintaining.

According to the present invention, an appropriate amount of -OH
Therefore, it is a suitable treatment method such that the substrate after treatment also has adhesiveness and printability. Hereinafter, the present invention will be described in detail.

[0010] The hydrocarbon polymer molded article usable in the present invention has a reaction temperature of hexafluoroacetone (70 ° C or higher).
Any general-purpose material such as polyethylene, polypropylene, polystyrene, acrylic resin, polyester, polycarbonate, polyimide, and vulcanized rubber can be used. The shape of the molded article is not particularly limited, and can correspond to a sheet or a fiber to a complicated shape.

The reaction agent of the present invention is hexafluoroacetone and a peroxide capable of abstracting hydrogen from the reaction catalyst. Examples of the peroxide include di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl −
2,5-di (t-butylperoxy) hexane or 2,5
Diallyl peroxides such as -dimethyl-2,5-di (t-butylperoxy) hexyl-3, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1- Bis (t-butylperoxy)
Peroxy such as cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valerate and 2,2-bis (t-butylperoxy) butane Those which generate t-butoxy radicals represented by ketals are preferred.

The reaction temperature depends on the half-life of the peroxide used,
The reaction rate can be arbitrarily selected in the range of 70 ° C. to 180 ° C. in consideration of the reaction rate. However, it is necessary to consider the deformation of the substrate, and the temperature is preferably 70 ° C. to 150 ° C.

The reaction time is determined as appropriate depending on the half-life of the peroxide used and the reaction temperature.
2 hours to 2 hours at half-life to 10 hours half-life
Four hours are employed.

The reaction is carried out in a container capable of sealing hexafluoroacetone at the above-mentioned reaction temperature and reaction time, and it is desirable to carry out the reaction in an appropriate organic solvent in order to progress the reaction mildly. Such an organic solvent is appropriately selected and determined depending on the solvent resistance of the substrate.

[0015] That is, Freon as the organic solvent usable in the present invention, straight-chain hydrocarbon, ketone, and an ester-based, such as many types available, organic solvent having a like -OH or -NH ₂ is hexafluoro Cannot be used because it reacts directly with acetone. Specific examples include 1,1,2-trichloro-1,2,2-trifluoroethane, hexane, heptane, octane, acetone, methyl isobutyl ketone, ethyl acetate, propyl acetate, and butyl acetate.

When an organic solvent cannot be used due to the nature of the base material, the reaction catalyst may be attached to the surface of the base material and subjected to the reaction, and the reaction catalyst at this time may be diluted and applied. It can be attached to the substrate surface by spraying, dipping, or the like.

As described above, the fluorine content on the substrate surface can be controlled by adjusting various conditions such as the concentration of hexafluoroacetone, the amount of the reaction catalyst, and the reaction time. Further, the fluorination concentration can be measured by an F / C elemental analysis value calculated by an X-ray photoelectron spectrum (ESCA spectrum) analysis. The fluorination depth was less than the surface FT-IR measurement range, and was found to be a very shallow region.

[0018]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 In a 100 cc stainless steel pressure vessel, 40 cc of 1,1,2-trichloro-1,2,2-trifluoroethane,
0.2 g of t-butyl peroxide, heated press film of high-density polyethylene as a substrate (100 μm) 2c
The m square was charged and sealed, followed by degassing. Then, 10 g of hexafluoroacetone was charged in a gaseous state, and the whole container was heated at 100 ° C.
And reacted for 24 hours. After the reaction, the polyethylene film was washed with 1,1,2-trichloro-1,2,2-trifluoroethane and vacuum dried at 40 ° C. for 2 hours. The polyethylene film thus obtained was used as a sample A
And Samples B and C were obtained in the same manner by changing the charged amount of di-t-butyl peroxide and the reaction time in the same manner.

Table 1 shows the reaction conditions and the surface energy (critical surface tension: γ _c ) of the samples A, B and C, and the fluorine content on the surface (F / C calculated from the ESCA spectrum).

[0021]

[Table 1]

From Table 1, it can be seen that there is almost no difference in the critical surface tension as compared with commercially available PTFE. Example 2 A film surface treatment reaction of polyvinylidene fluoride, polycarbonate (bisphenol A type) and polyethylene terephthalate was carried out in the same manner as in Example 1.

As a reaction catalyst, t-butylcumyl peroxide was used. The treated film (Sample D ~
As the physical properties of I), the critical surface tension (γ _c ) and the fluorine content (F / C) were measured in the same manner as in Example 1, and the results are shown in Table 2.

Reference Examples The samples obtained in Examples 1 and 2 were reactions on the extreme surfaces, and qualitative analysis of surface modification by infrared absorption spectrum was impossible. Therefore, a fluorination reaction was performed in a fine powder state using a polycarbonate having a high reaction rate as a sample.

The reaction conditions were t-
Butyl cumyl peroxide 0.1 g, reaction temperature 130
The reaction time at 5 ° C. was 5 hours, and the amount of the polycarbonate subjected to the reaction was 1.0 g. After the reaction, the same treatment as in Example 1 was performed, and the infrared absorption spectrum was measured by a transmission method. According to this, -OH and -CF ₃ were 3416 cm ^-1 and 13 respectively.
It was found around 00 cm ^-1 .

[0026]

[Table 2]

[0027]

According to the present invention, it is possible to obtain a molded article having a uniform and strong fluorine-containing surface having a chemical bond with the substrate surface regardless of the type and shape of the substrate. Can be. Further, since the surface fluorine component is composed of --CF ₃ , the surface free energy can be reduced with a small amount, so that the surface has water and oil repellency, weather resistance, low refractive index resistance, and water resistance while maintaining the properties of the molded article. Chemical properties and the like are achieved.

Further, since the surface can contain an appropriate amount of --OH, it has adhesiveness to other molded articles and printability.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-99244 (JP, A) JP-A-1-268728 (JP, A) JP-A-3-237402 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08J ^7/ 00-7/18

Claims (2)

(57) [Claims] 1. A hexafluoroacetone (CF ₃₎ on the surface of the hydrocarbon-based polymer molded article by reacting ₂ C = O reforming by
A method of producing a molded article having a fluorine-containing surface, wherein the reaction is performed using a peroxide . 2. A file obtained by the method according to claim 1.
A molded article having a nitrogen-containing surface.