JPH04266938A - Part for vehicle - Google Patents

Abstract

PURPOSE:To obtain a part for vehicle having excellent stain-proofing property from an inexpensive plastic molded article while utilizing the characteristic features of a plastic material such as mechanical strength by forming a chemically adsorbed film containing fluoroalkyl group on the surface of a plastic molded article through siloxane bond. CONSTITUTION:A plastic molded article is immersed in e.g. a cyclohexane solution of heptadecafluorodecyl trichlorosilane in nitrogen atmosphere at room temperature, the unreacted heptadecafluorodecyl trichlorosilane is washed off with cyclohexane and the article is washed with pure water to form a chemically adsorbed monomolecular film on the surface of the plastic molded article through siloxane bond containing fluoroalkyl group. When the plastics has few active groups on the surface such as an ABS resin, the article is subjected to an oxygen plasma treatment in a UV dry stripper to oxidize the surface.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to surface modification of plastic molded articles used for vehicle parts. In particular, it relates to plastic vehicle parts with excellent stain resistance.

0002

[Prior Art] Conventionally, vehicle parts have been manufactured using ABS resins, vinyl chloride resins, melamine resins, styrene resins, acrylic resins, AS resins, nylon (polyamide) resins, saturated polyester resins, and non-plastic resins that have excellent moldability and mechanical properties. Plastic molded products such as saturated polyester resin, polyacetal resin, polycarbonate resin, and polyarylate resin are used. For example, among plastic molded products, ABS resin is used in lamp covers for vehicle parts,
For instrument panels and motorcycle protectors, cellulose plastic for car marks and handles, FRP (fiber reinforced resin) for outer bumpers and engine covers, phenolic resin for brakes, and polyacetal for wiper gears, gas valves, and carburetor parts. ,
Polyamide is used in radiator fans, polyarylate is used in directional lenses, instrument panel lenses, and relay housings, polybutylene terephthalate is used in rear ends and front fenders, polyamino bismaleimide is used in engine parts, gearboxes, wheels, and suspension drive systems, and methacrylic resin is used in radiator fans. is used for lamp cover lenses, instrument panels and covers, and center markings; polypropylene is used for bumpers; polyphenylene oxide is used for radiator grilles and hubcaps; polyurethane is used for bumpers, fenders, instrument panels, and fans; unsaturated polyester resin is used for bodies, and fuel. Used for tanks, heater housings, instrument panels, etc.

0003

[Problems to be Solved by the Invention] However, the above-mentioned plastic molded products have a problem in that they have inferior stain resistance compared to, for example, fluororesins such as polytetrafluoroethylene. In addition, although fluororesin has excellent stain resistance,
There are problems in that the mechanical properties are not very high and it is expensive.

The present invention was developed in view of the conventional drawbacks, and it is possible to use inexpensive plastic molded products that have excellent antifouling properties and can take advantage of the mechanical strength and other properties of plastic base materials. The purpose of the company is to provide vehicle parts that are of high quality.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the vehicle part of the present invention is a plastic vehicle part in which a fluorinated alkyl group is added to the surface of a base material of a plastic molded product through a siloxane bond. It is characterized by using a plastic molded article provided with a chemically adsorbed film containing the same.

[0006] In the above structure, it is preferable that the chemisorption film is a monomolecular film.

[0007]

[Function] According to the structure of the present invention, since the chemically adsorbed film containing fluorinated alkyl groups is provided on the surface of the plastic molded product base material through siloxane bonds, it has excellent stain resistance and the plastic base material It is possible to take advantage of the mechanical strength and other properties of the material, and it is also possible to make vehicle parts using inexpensive plastic molded products. That is, since the fluorinated alkyl group is present in the surface layer of the chemisorption membrane, it has excellent antifouling properties. In addition, since the base of the chemisorption film is formed by chemical bonding through siloxane bonds, the film can be made with excellent durability, and even if the surface is repeatedly washed, the chemisorption film will remain plastic. Does not peel off easily from the surface. Furthermore, since the chemisorption film of the present invention is an extremely thin film on the order of nanometers or angstroms, it does not impair properties such as mechanical strength of the plastic substrate.

[0008] Furthermore, according to the preferred configuration of the present invention in which the chemisorption film is a monomolecular film, it is possible to form a thin film with a uniform thickness, which has excellent transparency and does not impair the aesthetic appearance of the base material. There is no.

[0009]

[Example] The vehicle parts of the present invention are as shown in FIG.
A plastic molded article is used in which a monomolecular film 3 containing a fluorinated alkyl group is formed on the surface of a plastic 1 via siloxane bonds 2.

[0010] The chemical adsorption film provided on the surface of the plastic molded product used in the automobile parts of the present invention is preferably formed using a chlorosilane surfactant having a fluorinated alkyl group.

Examples of the chlorosilane surfactant having a fluorinated alkyl group include CF3 (CF2)7
(CF2)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)15S
iCl3, CF3 (CF2)5 (CH2)2
Including trichlorosilane surfactants such as SiCl3, for example, CF3 (CF2)7 (CH
2)2SiCln(CH3)3-n,CF3
(CF2)7 (CH2)2 SiCln (C
2H5)3-n, CF3CH2O(CH2)
15SiCln (CH3)3-n, CF3CH
2O(CH2)15SiCln(C2H5)3
-n, CF3 (CH2)2 Si(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 (CH3
)3-n,CF3COO(CH2)15SiC
ln (CH3)3-n, CF3 (CF2)5
(CH2)2SiCln (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, in particular, 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.
This is preferable because it results in a stronger chemisorption film. Also,
CF3 (CF2)n CH2 CH2 SiCl3
(However, n in the formula is an integer, and 3 to 25 is easiest to handle) is preferable because it has a good balance between solvent solubility, chemical adsorption, and functionality such as water repellency and stain resistance. . Furthermore, if an ethylene group or acetylene group is incorporated into the fluorinated alkyl chain portion, the hardness of the chemisorption film itself can be further improved since it can be crosslinked by electron beam irradiation of about 5 megarads after formation of the chemisorption film. be.

The chlorosilane surfactant that can be 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 has a fluorinated alkyl group on the terminal silicon. or a hydrocarbon group (i.e., R, R1, R2, R3 are fluorinated alkyl groups or hydrocarbon groups, and the general formula R2 SiC
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-
SiCl3 (where n is a natural number in the formula), SiClm (
CH3)4-m, SiClm(C2H5)4
-m (where m is an integer from 1 to 3), HSiCll
(CH3)3-l, HSiCl(C2H5
)3-l (where l in the formula is 1 or 2) 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, forming a plastic. The surface of the molded product becomes 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 manner, the hydrophilicity can be made higher than when the substrate containing a polymer is oxidized. For example, a chlorosilane surfactant containing a fluorinated alkyl group can be chemically adsorbed onto this, and the chemically adsorbed film obtained in this way has a higher density, so it has higher functions such as water repellency and stain resistance. It will be done.

The method for forming a chemically adsorbed film containing a fluorinated alkyl group via siloxane bonds on the surface of a plastic molded product used in vehicle parts of the present invention involves oxidizing the surface of the plastic molded product to make it hydrophilic. The process of
The oxidized surface is brought into contact with a non-aqueous organic solvent by immersion, etc., and the chlorosilane surfactant is chemically adsorbed onto the surface of the base material, forming a chemically adsorbed film containing fluorinated alkyl groups via siloxane bonds. It is preferable to include a step of.

[0014] As a method for oxidizing the surface of a plastic molded product, ordinary 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) can be applied. be done.

[0015] The non-aqueous solvent used to form a chemically adsorbed film on the surface of a plastic molded product used in the vehicle parts of the present invention does not dissolve the plastic molded product forming the chemically adsorbed film and is compatible with the chlorosilane surfactant. Any organic solvent may be used as long as it does not have active hydrogen to react with. Examples include 1,1-dichloro,1-fluoroethane, 1,1-
dichloro, 2,2,2-trifluoroethane, 1,1-
Fluorine solvents such as dichloro, 2,2,3,3,3-pentafluoropropane, 1,3-dichloro, 1,1,2,2,3-heptafluoropropane, such as hexane, octane, hexadecane, cyclohexane, etc. Hydrocarbon solvents such as ether solvents such as dibutyl ether and dibenzyl ether, and ester solvents such as methyl acetate, ethyl acetate, isopropyl acetate and amyl acetate are preferred.

Further, the chemically adsorbed film formed on the surface of the plastic molded product used in the automobile parts of the present invention can sufficiently function with just 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. It can be easily performed without requiring any steps. Furthermore, it goes without saying that the chemically adsorbed film may be an accumulation of monomolecular films. In this way, when the chemically adsorbed film forms a monomolecular 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 An ABS resin molded product for a motorcycle protector was treated with UV light.
After oxidizing the surface by oxygen plasma treatment for 10 minutes in a dry stripper (oxygen flow rate: 1 l/min), the 10-
It was immersed in a 2 mol/l cyclohexane solution at room temperature under a nitrogen atmosphere for 60 minutes, and then unreacted heptadecafluorodecyltrichlorosilane was washed with cyclohexane, and then washed with pure water to remove the siloxane containing a fluorinated alkyl group. A chemically adsorbed monomolecular film was formed on the surface of an ABS resin molded product through bonding.

Example 2 The ABS resin molded product for a motorcycle protector in Example 1 was replaced with a methacrylic resin molded product for a lamp cover lens, and cyclohexane was replaced with 1,1-dichloro,1-fluoroethane. I did a similar experiment.

Example 3 The ABS resin molded product for a motorcycle protector in Example 1 was replaced with a urethane molded product for a bumper, and after oxygen plasma treatment, a 1 wt % tetrachlorosilane solution (solvent: 1,1-dichloro , 1-fluoroethane) for 60 minutes at room temperature under a nitrogen atmosphere, and subsequently unreacted tetrachlorosilane was washed with 1,1-dichloro,1-fluoroethane, then with pure water, and dried. An experiment similar to Example 1 was conducted using a sample and replacing cyclohexane with 1,1-dichloro,1-fluoroethane.

The molded products of Examples 1 to 3 were assembled into actual vehicles and left outdoors for one month. As a comparative example, a molded product on which no chemically adsorbed film was formed was used. One month later,
I compared the dirtiness of the two.

[0022] In the comparative example, dirt was stuck to the surface of the molded product, and the dirt could not be removed just by sprinkling water on it. On the other hand, in the example, there was almost no dirt. Also, just by sprinkling some water on the slightly dirty areas, they regained their original shine.

As is clear from the above results, in the vehicle parts of the comparative example, the water repellency and
The vehicle parts of the present invention were hardly stained due to poor stain resistance.

The present invention can be used, by way of example, in the following vehicle parts. (1) ABS resin: lamp covers, instrument panels, interior parts, motorcycle protectors (2)
Cellulose plastic: Car marks, handles (3) FRP (fiber reinforced resin): Exterior bumpers, engine covers (4) Phenolic resin: Brakes (5) Polyacetal: Wiper gears, gas valves,
Carburetor parts (6) Polyamide: Radiator fan (7) Polyarylate: Direction indicator lens, instrument panel lens, relay housing (8) Polybutylene terephthalate: Rear end, front fender (9) Polyamino bismaleimide: Engine parts, gear box, wheels , suspension drive system (10) Methacrylic resin for lamp cover lenses, instrument panels and covers, center mark (11) Polypropylene for bumpers (12) Polyphenylene oxide: radiator grille, wheel caps (13) Polyurethane: bumpers, fenders, instrument panels , fan (14) Unsaturated polyester resin: Can be applied to bodies, fuel tanks, heater housings, instrument panels, and various other parts other than those listed above.

As described above, the plastic molded product for vehicles of the present invention has a chemically adsorbed film containing a fluorinated alkyl group via a siloxane bond on the surface of the plastic molded product. , has excellent stain resistance.

Furthermore, since the vehicle parts of the present invention use a general-purpose resin, they can be made cheaper than using a fluororesin. Furthermore, since it is possible to coat a single layer of molecules, it can also be used where transparency is required. As described above, the present invention has great industrial value.

[0027]

[Effects of the Invention] As explained above, according to the present invention, a chemically adsorbed film containing a fluorinated alkyl group is provided on the surface of a base material of a plastic molded product through a siloxane bond, so that it has excellent antifouling properties. In addition, the characteristics such as mechanical strength of the plastic base material can be utilized as they are, and moreover, it is possible to make a vehicle part using an inexpensive plastic molded product.

[0028] Furthermore, according to the preferred configuration of the present invention in which the chemisorption film is a monomolecular film, it is possible to form a thin film with a uniform thickness, which has excellent transparency and does not impair the aesthetic appearance of the base material. There is no.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a plastic molded product used in a vehicle component of the present invention.

[Explanation of symbols]

1...Plastic molded product 2...Siloxane bond 3...Chemisorption film

Claims (2)

[Claims] [Claim 1] A plastic vehicle part, characterized in that a plastic molded article is provided with a chemisorption film containing a fluorinated alkyl group on the surface of a base material of the plastic molded article via a siloxane bond. vehicle parts. [Claim 2]Claim 1, wherein the chemisorption film is a monomolecular film.
Vehicle parts listed in .