JPH04328136A - Method for manufacturing chemisorption membrane - Google Patents

Abstract

PURPOSE:To obtain a film with high durability containing fluoroalkyl groups via siloxane links onto the surface of a base material without impairing the surface characteristics, by bringing a specific mixed solution into contact with the base material surface. CONSTITUTION:The surface of a base material 1 such as of plastic, metal or ceramic (pref. made of a polymer) is, pref., in advance, treated with dichlorosilane, trichlorosilane or tetrachlorosilane. The resulting surface is then brought into contact with a mixed solution predominant in (A) a chlorosilane-based surfactant (pref. having fluoroalkyl group, e.g. heptadecafluorodecyl trichlorosilane) and (B) an active H-free fluorine-contg. non-aqueous solvent reactive with the component A (pref. fluoroalkyl group- contg. tertiary amine or cyclic ether) to effect washing away the unreacted component A with the component B followed by washing with pure water, thus providing the surface of the base material 1 with the objective fluoroalkyl group-contg. chemical adsorption film 3 via siloxane links 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method for forming a chemically adsorbed film on the surface of a substrate through siloxane bonds.

0002

BACKGROUND OF THE INVENTION There is a need in various fields to modify the surface of base materials such as plastics, metals, ceramics, fibers, wood, concrete, painted surfaces, etc. according to purposes. Taking polymers as an example, methods for modifying the surface of polymers include, for example, coating them with a fluorine-containing silane coupling agent to impart water and oil repellency, and coating them with a fluorine-containing silane coupling agent to impart lubricity. Coating methods such as coating with wax, coating with polyvinyl alcohol to impart hydrophilic properties, and coating with a suspension of fluorocarbon polymer to impart antifouling properties are generally well known. It is being

0003

[Problems to be Solved by the Invention] However, the coating film obtained by the conventional method has a weak bonding force with the substrate containing polymers, and when the surface is repeatedly wiped with a cloth or washed with water, the coating film can become attached to the substrate. There was a problem that the surface treatment effect would be lost due to peeling off from the surface. In addition, because the molecules of conventional coating films are oriented in random directions, there are many pinholes in the coating film, resulting in insufficient properties. Furthermore, for example, there is a problem in that fluorocarbon polymer coating films cannot be used in transparent plastic optical materials that strongly require transparency because of their lack of transparency.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art described above, it is an object of the present invention to provide a method for producing a highly functional chemisorption membrane with excellent durability.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the method for producing a chemically adsorbed film of the present invention includes a method for producing a chemically adsorbed film on the surface of a base material. A mixed solution containing at least a fluorine-containing non-aqueous solution having no reactive active hydrogen and a surfactant is brought into contact with the surface of the substrate to form a chemisorption film having a siloxane bond on the surface of the substrate. Features.

[0006] In the above configuration, it is preferable that the fluorine-containing nonaqueous solution contains at least one of a tertiary amine or a cyclic ether. Further, in the above configuration,
It is preferable to treat the surface of the base material in advance with dichlorosilane, trichlorosilane, or tetrachlorosilane before the reaction step of forming the chemically adsorbed film.

Furthermore, in the above structure, it is preferable that the surface of the base material is made of a polymer compound.

[0008]

[Operation] According to the structure of the method of the present invention, a chemically adsorbed film is provided on the surface of the base material through siloxane bonds, so a highly functional chemically adsorbed film with superior durability compared to conventional ones can be manufactured. be able to. Furthermore, since a fluorine-containing nonaqueous solution that does not have active hydrogen that reacts with the chlorosilane surfactant is used as a solvent, a high-density monomolecular film without pinholes can be produced.

Furthermore, according to the preferred configuration of the method of the present invention in which the fluorine-containing non-aqueous solution contains at least one of a tertiary amine or a cyclic ether, even if the base material is a polymer, resin, coating film, etc. The above-mentioned highly functional chemisorption membrane can be produced without dissolving the base material. In addition, according to a preferred configuration of the method of the present invention, in which the surface of the base material is treated in advance with dichlorosilane, trichlorosilane, or tetrachlorosilane before the reaction step for forming the chemisorption film, silanol bonds are formed on the surface of the base material at a high density. can be granted.

Furthermore, according to the preferred configuration of the method of the present invention in which the surface of the substrate is made of a polymer compound, the high functionality of the method of the present invention can be applied to the surface of a polymer compound, which has been relatively difficult to achieve with conventional methods. It has become possible to form chemisorption films.

[0011]

[Examples] The method of the present invention will be explained in more detail below with reference to Examples. The method of the present invention can be applied to many base materials such as plastics, metals, ceramics, fibers, wood, concrete, painted surfaces, etc., but in the following, polymer materials will be used as an example of the base material. explain. As shown in FIG. 1, one embodiment of the polymer composition is one in which a chemisorption film 3 is formed on the surface of a substrate 1 containing a polymer through siloxane bonds 2.

[0012] Examples of the polymeric material of the substrate that can be used in the present invention include polycarbonate resin, acrylic resin, vinyl chloride resin, polystyrene resin, polyethylene resin,
Thermoplastic resins such as polypropylene resins, polyamide resins, acrylic butadiene styrene copolymer (ABS) resins, acetal resins, methylpentene resins, such as epoxy resins, urea resins, melamine resins, phenolic resins, alkyd resins, urethane resins, unsaturated resins Examples include thermosetting resins such as polyester curing resins and ebonite, and rubbers such as butadiene-styrene rubber, butyl rubber, nitrile rubber, chloroprene rubber, urethane rubber, and silicone rubber, and any general-purpose plastic material may be used. In addition, the above-mentioned polymeric materials may be mixed with so-called fillers such as silicon dioxide, calcium carbonate, and titanium oxide, and may also be mixed with so-called plasticizers such as dibutyl phthalate. Alternatively, it may be dyed with a pigment and is applied to a substrate containing a polymeric material.

[0013] When imparting water repellency, oil repellency, stain resistance or slipperiness to the polymer composition by the method of the present invention, the material constituting the chemical adsorption film is a chlorosilane interface having a fluorinated alkyl group. An activator is used. In addition, when imparting superhydrophilicity to the polymer composition of the present invention, a chlorosilane surfactant having an alkyl group with a terminal vinyl group is used to form a chemically adsorbed film, and then, for example, an electron beam is applied to the polymer composition in an oxygen atmosphere. The terminals are changed into hydroxyl groups by irradiation with radiation such as X-rays, γ-rays, and ultraviolet rays, or after a chemically adsorbed film is formed using tetrachlorosilane, the chlorosilyl bonds are changed into silanol bonds by reacting with water.

Examples of the chlorosilane surfactant having a fluorinated alkyl group include CF3 (CF2)7
(CH2)2SiCl3,CF3CH2O(
CH2)15SiCl3,CF3(CH2)2
Si(CH3)2(CH2)15SiCl3
,F(CF2)4(CH2)2Si(CH3
)2 (CH2)9 SiCl3,F(CF2)
8 (CH2)2 Si(CH3)2 (CH2
)9 SiCl3, CF3 COO(CH2)15
SiCl3, CF3 (CF2)5 (CH2)
2 SiCl3, etc., as well as trichlorosilane surfactants such as CF3 (CF2)7 (C
H2)2SiCln(CH3)3-n,CF
3 (CF2)7 (CH2)2 SiCln (
C2 H5 )3-n , CF3 CH2O(CH2
)15SiCln (CH3)3-n, CF3C
H2O(CH2)15SiCln(C2H5)
3-n, CF3(CH2)2Si(CH3)
2 (CH2)15SiCln (CH3)3-n
,F(CF2)4(CH2)2Si(CH3
)2 (CH2 )9 SiCln (C2 H5
)3-n,F(CF2)8(CH2)2Si
(CH3 )2 (CH2 )9 SiCln (CH
3)3-n,CF3COO(CH2)15Si
Cln (CH3)3-n, CF3 (CF2)
5 (CH2)2 SiCln (CH3)3-n
Examples include lower alkyl group-substituted monochlorosilane or dichlorosilane surfactants such as (where n in the formula is either 1 or 2). Among these, chlorosilyl bonds other than the chlorosilyl bond bonded to the hydrophilic group of the trichlorosilane surfactant form intermolecular bonds with adjacent chlorosilane groups and siloxane bonds, resulting in a stronger chemisorption film, which is preferable. Also, CF3
(CF2)n CH2 CH2 SiCl3 (However, n in the formula is an integer, and 3 to 25 is easiest to handle) is a balance between solvent solubility, chemical adsorption, and functionality such as water repellency and stain resistance. This is preferable because the ratio is well matched. Furthermore,
If an ethylene group or an acetylene group is incorporated into the fluorinated alkyl chain portion, it is possible to further improve the hardness of the chemisorption film itself since it can be crosslinked by electron beam irradiation of about 5 megarads after formation of the chemisorption film.

As the chlorosilane surfactant having an alkyl group, for example, CH3 (CH2)18Si
Cl3,CH3(CH2)15SiCl3,C
H3 (CH2 )10SiCl3 ,CH3 (CH
2) Including trichlorosilane surfactants such as 25SiCl3, for example, CH3 (CH2)1
8SiCln (CH3)3-n, CH3 (CH
2) 18SiCln (C2H5)3-n,C
H3 (CH2)15SiCln (CH3)3-
n, CH3 (CH2)10SiCln (CH3
)3-n, CH3 (CH2)25SiCln
Examples include lower alkyl group-substituted monochlorosilane or dichlorosilane surfactants such as (C2H5)3-n. Among these, CH3 (CH2)
n SiCl3 (however, n in the formula is an integer, 3 to 2
5 is the easiest to handle) is preferable from the viewpoint of solvent solubility. Also, for example, CH2=CH(CH2)nSiC
The alkyl group of the chlorosilane surfactant may have a vinyl group at the end, as in 13 (where n in the formula is an integer and is most easily handled from about 3 to 25). As mentioned above, such a chlorosilane surfactant containing a hydrocarbon group can be treated with, for example, an electron beam or an electron beam in an oxygen atmosphere.
By irradiating with radiation such as X-rays, γ-rays, and ultraviolet rays, the terminals can be changed into hydroxyl groups, thereby making the polymer composition hydrophilic. The chlorosilane surfactant used in the present invention is not only linear as exemplified above, but also has a branched form with a fluorinated alkyl group or a hydrocarbon group, or a fluorinated alkyl group or a hydrocarbon group on the terminal silicon. A form in which a hydrocarbon group is substituted (i.e., a form with the general formula R2 SiC where R, R1, R2, and R3 are fluorinated alkyl groups or hydrocarbon groups)
12 , R3 SiCl, R1 R2 SiCl2 or R1 R2 R3 SiCl, etc.), but in order to increase the adsorption density, a linear shape is generally preferred. Furthermore, for example, SiCl4, SiHCl3,
SiH2Cl2, Cl-(SiCl2O)n-S
iCl3 (where n is a natural number in the formula), SiClm (C
H3)4-m, SiClm(C2H5)4-m
(However, in the formula, m is an integer of 1 to 3), HSiCll (C
H3)3-l, HSiCll (C2H5)3
-l (where l is 1 or 2 in the formula), etc., when a substance containing multiple chlorosilyl bonds is chemically adsorbed and then reacted with water, the chlorosilyl bonds on the surface change to hydrophilic silanol bonds, and the polymer composition Things become hydrophilic. Among these substances containing a plurality of chlorosilyl groups, tetrachlorosilane (SiCl4) is preferable because it has high reactivity and a small molecular weight, so that silanol bonds can be provided at a higher density. By making the substrate hydrophilic in this way, the hydrophilicity can be made higher than by oxidation treatment of a substrate containing a polymer. Although the polymer composition made superhydrophilic in this way can be used as it is, for example, a chlorosilane surfactant containing a fluorinated alkyl group can be chemically adsorbed onto it, and the chemically adsorbed film obtained in this way can be Since the density is higher, functions such as water repellency, oil repellency, and stain resistance are further enhanced.

The method for producing a polymer composition of the present invention includes the steps of oxidizing the surface of a substrate containing a polymer to make it hydrophilic;
The method includes a step of immersing the oxidized surface in a fluorine-containing non-aqueous solution to chemically adsorb a chlorosilane surfactant onto the surface to form a chemically adsorbed film having siloxane bonds. As a method for oxidizing a substrate containing a polymer, conventional methods such as oxygen plasma treatment, corona treatment, or immersion in a mixed solution of concentrated sulfuric acid and potassium dichromate (chromium mixed acid solution treatment) are applied. .

The fluorine-containing nonaqueous solution used in the method for producing the polymer composition of the present invention does not dissolve the polymer contained in the substrate forming the chemisorption film, and contains active hydrogen that reacts with the chlorosilane surfactant. Any solution that does not have . For example, a tertiary amine having a fluoroalkyl group or a cyclic ether having a fluoroalkyl group is preferable. Examples of tertiary amines include N(Cn F2n+1)3
(n = 2 to 10, even if the fluoroalkyl group is linear,
Examples of cyclic ethers include those having the structure shown below (chemical formula 1).

[0018]

[Chemical formula 1]

Further, the chemically adsorbed film formed on the surface of the polymer composition of the present invention can sufficiently exhibit its function even with only one layer of monomolecular chemically adsorbed film. To form only one layer of monomolecular chemisorption film, all that is required is to chemically adsorb a chlorosilane surfactant or a substance containing multiple chlorosilyl groups and then wash it with a non-aqueous solvent without contacting it with water. No process required. Furthermore, it goes without saying that the chemically adsorbed film may be an accumulation of monomolecular films. In this way, when the chemisorption film forms a cumulative film, the groups exhibiting the imparted functionality are oriented and the density is also improved, so that higher functionality can be exhibited.

Next, the present invention will be explained using specific examples. Example 1 A substrate containing a polymer, 5 cm in length and width and 0.3 cm in thickness.
Using a polycarbonate substrate of Heptadecafluorodecyltrichlorosilane was used as the chlorosilane surfactant, and the concentration was 10-2 mol.
/l of tri(n-nonafluorobutyl)amine solution for 60 minutes at room temperature under a nitrogen atmosphere.
-nonafluorobutyl) amine solution and then with pure water to form a chemically adsorbed monomolecular film via siloxane bonds containing fluorinated alkyl groups on the surface of the polycarbonate substrate.

Example 2 An experiment was conducted in the same manner as in Example 1, except that the polycarbonate substrate in Example 1 was replaced with an acrylic resin substrate. Example 3 An experiment similar to Example 1 was conducted except that the polycarbonate substrate in Example 1 was replaced with a polypropylene substrate.

Example 4 The same experiment as in Example 1 was conducted except that the polycarbonate substrate in Example 1 was replaced with an ABS resin substrate. Example 5 The same experiment as in Example 1 was conducted except that the polycarbonate substrate in Example 1 was replaced with a PET substrate.

Example 6 The same experiment as in Example 1 was conducted except that tri(n-nonafluorobutyl)amine in Example 1 was replaced with tri(nonafluoroisobutyl)amine. Example 7 An experiment similar to Example 1 was conducted except that tri(n-nonafluorobutyl)amine in Example 2 was replaced with tri(nonafluoroisobutyl)amine.

Example 8 An experiment similar to Example 1 was conducted except that tri(n-nonafluorobutyl)amine in Example 3 was replaced with tri(nonafluoroisobutyl)amine. Example 9 An experiment similar to Example 1 was conducted except that tri(n-nonafluorobutyl)amine in Example 4 was replaced with tri(nonafluoroisobutyl)amine.

Example 10 An experiment similar to Example 1 was conducted except that tri(n-nonafluorobutyl)amine in Example 5 was replaced with tri(nonafluoroisobutyl)amine. Example 11 Tri(n-nonafluorobutyl)amine of Example 1 was converted into 2
An experiment similar to Example 1 was conducted except that -(n-nonafluorobutyl)perfluorofuran was used.

Example 12 The tri(n-nonafluorobutyl)amine of Example 2 was
An experiment similar to Example 1 was conducted except that -(n-nonafluorobutyl)perfluorofuran was used. Example 13 The tri(n-nonafluorobutyl)amine of Example 3 was
An experiment similar to Example 1 was conducted except that -(n-nonafluorobutyl)perfluorofuran was used.

Example 14 The tri(n-nonafluorobutyl)amine of Example 4 was
An experiment similar to Example 1 was conducted except that -(n-nonafluorobutyl)perfluorofuran was used. Example 15 The tri(n-nonafluorobutyl)amine of Example 5 was
An experiment similar to Example 1 was conducted except that -(n-nonafluorobutyl)perfluorofuran was used.

Example 16 An experiment was conducted in the same manner as in Example 1, except that the polycarbonate substrate in Example 1 was replaced with a butadiene-styrene rubber substrate. Example 17 An experiment was conducted in the same manner as in Example 1 except that the polycarbonate substrate in Example 1 was replaced with a butyl rubber substrate.

Example 18 An experiment was conducted in the same manner as in Example 1 except that the polycarbonate substrate in Example 1 was replaced with a nitrile rubber substrate. Example 19 An experiment was carried out in the same manner as in Example 1, except that the oxidation treatment method was changed to a method of immersion in concentrated sulfuric acid containing 10 wt % potassium dichromate for 5 minutes.

Comparative Example 1 A silane coupling agent (
2w of heptadecafluorodecyltrimethoxysilane)
After spin-coating a t% methanol solution, it was dried at 120° C. for 1 hour. Comparative Example 2 A chemically adsorbed monomolecular film of heptadecafluorodecyltrichlorosilane was formed on the polycarbonate substrate of Example 1 without oxidation treatment.

Comparative Example 3 A suspension of polytetrafluoroethylene was spray-coated on the surface of the polycarbonate substrate of Example 1, and then heated at 120°C.
It was heated and dried for 1 hour. Examples 1 to 19 and Comparative Example 1
The contact angles of samples ~2 to ultrapure water and oil (Nissin Salad Oil) were investigated. Contact angle measurements were made both immediately after forming the chemisorbed film or coating and after rubbing the surface 10,000 times with a cloth moistened with water. The results are shown in Table 1.

[0032]

[Table 1]

[0033] As is clear from Table 1, the polymer composition obtained by the method of the present invention retains water- and oil-repellency or hydrophilicity even after washing the surface by repeatedly rubbing it with a water-soaked cloth. However, in Comparative Example 1, water and oil repellency were lost. Furthermore, in the sample of Comparative Example 2 in which the surface of the polymer composition was not subjected to oxidation treatment, a chemisorption film having siloxane bonds could not be formed.

[0034] In the polymer composition obtained by the method of the present invention,
The material on which a chemically adsorbed monomolecular film containing fluorinated alkyl groups was formed had excellent antifouling properties. After the friction test, when the sample of Example 1 was immersed in salad oil and wiped with tissue paper, the oil was completely wiped off, but the sample of Comparative Example 1
The sample remained sticky with an oil film on the surface even after wiping it several times with tissue paper.

The polymer composition obtained by the method of the present invention can also be used as an optical material. The visible light transmittance of the polycarbonate substrate of Example 1 was 92%, which was unchanged from before forming the chemically adsorbed monomolecular film, but in the sample coated with polytetrafluoroethylene of Comparative Example 3, the transmittance was 50%. % or less, and the transparency had deteriorated like that of frosted glass.

Note that the chemically adsorbed films described in the above examples are cases where only a single layer of monomolecular film is used, but even if the polymer composition has an accumulation of chemically adsorbed monomolecular films, unreacted chlorosilane surfactant Even when the chemically adsorbed film was formed without washing, there was no change in its functionality. Furthermore, in each of the above examples, an example was shown in which a single polymer substrate was used as a substrate containing a polymer, but even if the polymer contains a filler, a plasticizer, a coloring agent, etc., the polymer composition There was no change in the function given to the object.

As explained above, according to the embodiment of the present invention, after the surface of a substrate containing a polymer is oxidized to form a hydrophilic group such as a hydroxyl group, a chlorosilane surfactant is applied to the surface of the substrate. Since the polymer is chemically adsorbed to form a chemically adsorbed film having siloxane bonds, a chemically adsorbed film can be easily formed even if the polymer does not have a hydrophilic active hydrogen such as a hydroxyl group as a repeating unit. Moreover, a chemisorption film with close packing can be formed simply by immersing a substrate containing a polymer in a fluorine-containing non-aqueous solution containing a chlorosilane surfactant. As a result, the formed chemisorption film exhibits functions such as high water repellency, oil repellency, antifouling properties, or superhydrophilicity depending on the function of the chlorosilane surfactant.

As described above, the polymer composition obtained by the method of the present invention has a chemically adsorbed film having siloxane bonds on the surface, so it has excellent durability against repeated washing compared to conventional compositions. When the chemisorption film contains a fluorinated alkyl group, it exhibits high water repellency, oil repellency, and stain resistance. In addition, in the method for producing a polymer composition of the present invention, by oxidizing the surface of the polymer composition in advance,
A chlorosilane surfactant can be easily chemically adsorbed onto the surface of the polymer composition to form a chemically adsorbed film having siloxane bonds. As described above, the present invention has great industrial value.

[0039]

[Effects of the Invention] As described above, according to the method of the present invention, a chemically adsorbed film is provided on the surface of a base material through siloxane bonds, so a highly functional chemically adsorbed film with superior durability compared to conventional methods can be obtained. can be manufactured. Furthermore, since a fluorine-containing nonaqueous solution that does not have active hydrogen that reacts with the chlorosilane surfactant is used as a solvent, a high-density, highly oriented monomolecular film without pinholes can be produced.

[Brief explanation of drawings]

FIG. 1: Cross-sectional view of an example of a polymer composition obtained by the method of the present invention

[Explanation of symbols]

1 Substrate containing polymer 2 Siloxane bond 3. Chemical adsorption membrane

Claims (4)

[Claims] 1. A method for producing a chemically adsorbed film on the surface of a substrate, comprising: a mixture comprising at least a chlorosilane surfactant and a fluorine-containing nonaqueous solution that does not have active hydrogen that reacts with the chlorosilane surfactant; A method for producing a chemically adsorbed film, comprising bringing a solution into contact with the surface of the base material to form a chemically adsorbed film having siloxane bonds on the surface of the base material. 2. The method for producing a chemisorption membrane according to claim 1, wherein the fluorine-containing nonaqueous solution contains at least one of a tertiary amine and a cyclic ether. [Claim 3] Before the reaction step of forming the chemisorption film,
2. The method for producing a chemisorption film according to claim 1, wherein the surface of the substrate is treated with dichlorosilane, trichlorosilane, or tetrachlorosilane in advance. 4. The method for producing a chemisorption film according to claim 1, wherein the surface of the base material is made of a polymer compound.