JP3121059B2 - Synthetic resin molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin molded product, and more particularly to a synthetic resin molded product having a hydrophilic surface.

[0002]

2. Description of the Related Art Conventionally, various synthetic resin molded products having a hydrophilic surface have been proposed. For example, those in which an anion, a cation, a nonionic surfactant and the like are added to a synthetic resin, and those in which an antistatic agent, a dropping agent and the like are added.

[0003] However, since these surfactants, antistatic agents and dropping agents are organic compounds having relatively low thermal decomposition temperatures, they are used as in fluorine-containing resins, polycarbonate resins and diallyl phthalate resins. The use of synthetic resins whose molding temperature is high is limited.

As a countermeasure against this, there has been proposed to apply the organic compound to the surface of a synthetic resin molded product, but it has not always been satisfactory in the effect of hydrophilization and its durability.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to newly propose a synthetic resin molded product which was hitherto unknown at all. Is what you do.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and mainly comprises an organosilica sol having a pH of 5 or less using an organic solvent as a dispersion medium and a surfactant having a fluoroalkyl group. An inorganic particle layer (A) obtained by applying an inorganic particle dispersion comprising
Layer) is provided.

Thus, according to the present invention, not only the synthetic resin whose molding temperature is high, but also the surface of a molded article made of any other synthetic resin is effectively made hydrophilic, and furthermore its durability is improved. Excellent inorganic particle layer (hereinafter referred to as "layer A")
That. ) Can be obtained. Hereinafter, the components of the present invention will be described in more detail.

The "synthetic resin" used in the present invention is not particularly limited, and any thermoplastic synthetic resin or thermosetting synthetic resin may be used.

As the thermoplastic synthetic resin, for example, fluorine-containing resin (PF), acrylic resin (PA), polyamide resin (NY), vinyl chloride resin (PVC), polycarbonate resin (PC), olefin resin (PO), epoxy resin (EO), polyacetal resin (PAC), polyester resin (PET), polyetherimide resin (P
EI), polyether sulfone resin (PES), polyetheretherketone resin (PEEK), polyphenylene sulfide resin (PPS), polysulfone resin (P
S), polyarylate resin (PAR), polyethylene naphthalate resin (PEN), polymethylpentene resin (PMP), ABS resin, vinyl acetate resin and polystyrene resin, among which PF, PA, NY, PV
C, PC, PO and PET are preferred, especially PF, P
A, PC and PET are preferred.

Here, the PF is not particularly limited as long as it is a thermoplastic resin containing fluorine in the molecular structural formula of the resin. Specifically, for example, four PFs are contained in the resin structure. It is a tetrafluoroethylene-based resin having atoms, furthermore, an ethylene trifluoride-based resin, an ethylene difluoride-based resin, a monofluoroethylene-based resin and a composite of these resins,
Among them, an ethylene tetrafluoride-based resin and an ethylene difluoride-based resin are preferable, and an ethylene tetrafluoride-based resin is more preferable.

Here, the ethylene tetrafluoride-based resin is specifically, for example, an ethylene tetrafluoride-based resin (PTF
E), ethylene tetrafluoride / perfluoroalkoxyethylene copolymer (PFA), ethylene tetrafluoride / propylene hexafluoride / perfluoroalkoxyethylene copolymer (E
PE) tetrafluoroethylene / hexafluoropropylene copolymer (FEP) and tetrafluoroethylene / ethylene copolymer (ETFE), among which PFA, ETFE, FE
P and EPE are preferred, and ETFE is particularly preferred.

To explain ETFE in detail, ethylene and ethylene tetrafluoride are mainly used (the molar ratio of ethylene / ethylene tetrafluoride is generally in the range of 40/60 to 60/40) . Small amount (usually 10 mol%
The following comonomer components are copolymerized, and in the present invention, particularly , the content molar ratio of ethylene / ethylene tetrafluoride is 40/60 to 60/40, preferably 45/55 to 55/55. 45
In the range of, and (where, n is an integer of 2 to 10.) Formula _{CH 2 = CH-C n F} 2n + 1 indicated by (Pafuru
Oroalkyl) ethylene unit (for example, CH ₂ CHCH —C ₄ F ₉
Alternatively, ETFE having a content of (CH ₂ = CH—C ₆ F ₁₃ ) in the range of 0.3 to 10 mol%, preferably 0.3 to 5 mol% is suitably used.

[0013] This ETFE is known per se, and can be produced, for example, by the method described in Japanese Patent Publication No. 59-50163. As a commercial product, a trade name of "Aflon COP" is available from Asahi Glass Co., Ltd. Can be used.

The above-mentioned ethylene trifluoride resin is
Specifically, for example, ethylene trifluoride chloride resin (CTF
E) and trifluoroethylene / ethylene copolymer (ECTFE). Specific examples of the ethylene difluoride-based and monofluoroethylene-based resins include, for example, vinylidene fluoride resin (PVDF) and vinyl fluoride resin (PVF). Further, in the present invention, a mixture with another thermoplastic resin mainly containing the above-mentioned fluororesin may be used.

Further, examples of the thermosetting resin include melamine resin, phenol resin, urea resin, furan resin, alkyd resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, silicon resin, polyurethane resin, and polyimide. Resin, polyparabanic acid resin, etc., among which epoxy resin, diallyl phthalate resin,
Polyimide resins are preferred.

The term "molded article" is not particularly limited, and may be any processed molded article. Among them, films, sheets and plate-like articles, heat exchangers, solar heat collectors, blow molded articles, etc. Products, vacuum molded products, compression molded products, cast molded products, etc., among which films, sheets and plate-like products are preferred.

The film, sheet and plate-like material according to the present invention can be used, for example, for windows used for shops, instruments, vehicles, general households and buildings, as well as packaging materials,
It is effectively used for applications such as goggles, spectacle lenses, mirrors, car mirrors, parabolic antennas, and covering materials for agricultural horticultural houses.

The term "hydrophilization" as used in the present invention means that the surface of the above-mentioned molded article has an A layer so that the surface of the synthetic resin which was originally hydrophobic is modified to be hydrophilic. As a result, the flowability, driplessness, anti-fogging property, anti-fog property, antistatic property and wettability of the synthetic resin molded article are improved.

The synthetic resin molded product thus obtained can be used, for example, when PF is used for windows and sun rooms.
Since dew condensation in the morning and evening can be completely prevented, sunlight can be directly incident and the appearance can be seen clearly.

Further, when PA is used in a frozen case, the interior of the case can always be seen clearly without freezing of dew, in combination with the good low-temperature characteristics of PA. PC
The PA and PA were prepared respectively, and the conditions in the morning and evening were examined. Surprisingly, the treated samples showed almost no "cloudiness" even in the morning and evening dew condensation conditions.

Further, as a result of performing the above processing on the parabolic antenna, the television was able to be watched on a clean screen with very little attenuation of the satellite broadcasting radio wave, which always occurred immediately after rainfall, as compared with before the processing.

In order to obtain the layer A on the surface of the synthetic resin molded product of the present invention, a dispersion is prepared by uniformly dispersing the above-mentioned inorganic particles and a surfactant in a dispersion medium, and this is prepared by adding the dispersion to the surface of the molded product. It is achieved by coating on top and drying.

The dispersion medium used here is not particularly limited, and is appropriately selected in consideration of the inorganic particles and the surfactant to be used. In general, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol , N-propyl alcohol, n-butyl alcohol,
Ethyl cellosolve, ethylene glycol, acetone, glycerin, amyl alcohol acetate, monoethyl ether, n-methylpyrrolidone, methyl ethyl ketone, dimethylformamide, triethanolamine, etc., among which methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl Alcohol, acetone, ethylene glycol and the like are preferably used.

From the viewpoint of coating properties, it is desirable that the amount of water contained in the organic solvent is small, and the water in the dispersion is H ₂ O / SiO ₂
A weight ratio of up to 4, preferably up to 1, is acceptable. If the amount of water in the dispersion is more than 4 in terms of the weight ratio of H ₂ O / SiO ₂ , it is not preferable because a uniform coating film cannot be formed when coating to form a coating film.

Further the "colloidal silica" in this invention is primarily directed to a colloidal particle by SiO _2, the components are not SiO ₂ is 100 wt% only, generally 50 wt%
The content is preferably at least 70 wt%, more preferably at least 80 wt%. The inorganic substance other than SiO ₂ is not particularly limited and may be any inorganic substance, for example, Al ₂ O ₃ , TiO _2
2 , MgCO ₃ and CaCO ₃ , among which Al ₂ O ₃ is preferably used.

Although the shape of the colloidal silica is not particularly limited, it is preferably spherical, and the colloidal silica within the range of ordinary colloidal particles can be used, but the transparency of the obtained coating film is high. From the viewpoint of the average particle size is
1 to 100 mμ, preferably 3 to 50 mμ, more preferably 5 to
30 mμ.

It is important that the layer A composed of the above-mentioned colloidal silica contains a surfactant having a fluoroalkyl group in addition to the above-mentioned colloidal silica.

Here, as the surfactant having a fluoroalkyl group, any of nonionic, anionic, cationic and amphoteric surfactants having a fluoroalkyl group can be used. , Perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyltrimethylammonium salt, perfluoroalkylpetaine, perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, etc. be able to. In particular, a surfactant of a perfluoroalkyl phosphate and a perfluoroalkyl petaine is preferable since the obtained hydrophilicity-imparting effect is stable for a long period of time.

In the inorganic particle dispersion of the present invention, the total amount of colloidal silica (as SiO ₂ ) using an organic solvent as a dispersion medium as a component and a surfactant having a fluoroalkyl group as a component (as a solid content) is used. On the other hand, the amount of the surfactant (as solid content) is 0.1 to 40% by weight, preferably 0.2 to 10% by weight.
It is desirably in the range of wt%. When the amount of the surfactant of the component is more than 40 wt%, the heat resistance of the obtained coating film,
The weather resistance and durability are poor, and the persistence of the hydrophilic effect tends to be short. On the other hand, if the amount of the surfactant is less than 0.1 wt%, the ability of the resulting coating film to decrease the hydrophilicity is reduced. Is not preferred.

The inorganic particle dispersion of the present invention may contain, as a diluent, an organic solvent which is the same as or different from the organic solvent which is a dispersion medium of the colloidal silica as a component. The amount of the diluent is not particularly limited,
The solid content concentration of the total amount of silica and surfactant in the dispersion is adjusted to 40 wt% or less, preferably in the range of 5 to 20 wt%. The dispersion may be further diluted to an appropriate concentration when used.

When an acidic organosilica sol having a pH of 5 or less in the dispersion is mixed with a surfactant, it is preferable because it is stable over a long period of time. Such an organosilica sol is produced, for example, from a silica sol using water as a dispersion medium by the method described in Japanese Patent Publication No. 2-1087 filed earlier.

As described above, as a method of applying the prepared dispersion to the surface of the fluororesin film, a conventionally used method can be used, for example, a gravure roll method, a roller touch method, a bar coater. Coating can be performed by a normal coating method such as a spraying method, a spraying method, a dipping method, and a brush coating method. Among them, the gravure roll method and the spray method are preferred. The amount of the inorganic particles applied on the surface of the fluorine-containing resin film is not particularly limited, but is generally 0.1 to 1.3 g / m ² , preferably 0.1 to 1.0.
g / m ^2, more preferably from 0.1 to 0.5 g / m ^2.

The surface of the synthetic resin article on which the layer A is to be set is subjected to a surface treatment in advance so that
The layer is bonded more firmly, and as a result, the hydrophilicity and its durability are improved.

The surface treatment methods usable here include:
For example, corona discharge treatment, metal deposition, vacuum discharge treatment, heterogeneous nucleation, crystallization, sputter etching, graft polymerization,
There are a plasma treatment, an alkali metal solution method, an alkali metal amalgam method and an electrolytic method, among which corona discharge treatment and plasma treatment are preferable.

The synthetic resin molded product thus obtained has a surface that is effectively hydrophilic and has excellent durability, and is extremely useful and contributes to the industry. It is enormous. Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention should not be limited to Examples.

Example A (Preparation of Inorganic Particle Dispersion) (1) Silica sol using water as a dispersion medium (SiO ₂ concentration 20 wt%,
After well mixing 1000 ml of an average particle diameter of 11 nm, Al ₂ O ₃ / SiO ₂ = 0.002 molar ratio) and 1000 ml of isopropyl alcohol (purity of 99% or more), the mixture was filtered through an ultrafiltration membrane, and the filtrate was 1000 ml.
When reached, another 1000 ml of isopropyl alcohol was added to the mother liquor. Thereafter, filtration is performed in the same manner, and the amount of
00 ml was collected. Repeat this operation a total of 6 times,
Colloidal silica using isopropyl alcohol having a silica concentration of 30% by weight as a dispersion medium was obtained (hereinafter referred to as "IPA dispersion"). The water concentration in this sol was 2.7 wt%, the pH of the sol was 2.1 and the viscosity was 5.6 cp.

32 g of colloidal silica using isopropyl alcohol as a dispersion medium and a perfluoroalkyl phosphate ester surfactant (manufactured by Asahi Glass Co., Ltd .; Surflon S-11)
2. 1 g of solid content 15%) 150 g of isopropyl alcohol
And a solution diluted with the above was mixed to prepare an inorganic particle dispersion. (Hereinafter, this is referred to as “dispersion A” and will be described in Examples).

(2) In the dispersion A, the obtained
IPA dispersion 66.7g and sorbitan monopalmitate 0.5g
Was diluted with 33.2 g of isopropyl alcohol to obtain a dispersion of inorganic particles (hereinafter referred to as "dispersion B" and used in Comparative Examples).

Examples 1 to 4 A colorless and transparent synthetic resin plate having a thickness of 3 mm shown in Table 1 was molded.
Then, the dispersion A was applied by spraying so that the coating amount after drying was 0.3 g / m ^2, and dried at 60 ° C. for 5 minutes to obtain a synthetic resin plate having an inorganic particle layer (A layer). This was attached to the transparent door of a frozen case for ice cream so that the coated surface was on the inside, and the anti-dew condensation property over time was investigated.

Good anti-condensation properties were maintained for a long time regardless of the type of the synthetic resin. The evaluation method is as follows. ◎: Dew condensation is hardly observed △: Slight dew condensation is observed ×: Dew condensation occurs on the entire surface

Comparative Examples 1 and 2 A synthetic resin molded plate was obtained in the same manner as in Example 1 except that Dispersion B was used instead of Dispersion A, and the anti-dew property over time was investigated. The results are shown in Table 1. Initially, it exhibited good dew condensation prevention properties, but the prevention ability gradually worsened over time.

[0042]

[Table 1]

[0043]

According to the present invention, the surface of a molded article made of not only a synthetic resin having a high molding temperature but also any other synthetic resin can be effectively made hydrophilic, and furthermore, its durability is excellent. Thus, a synthetic resin molded product having an inorganic particle layer can be obtained.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiro Komatsu 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Inside the Wakamatsu Plant, Co., Ltd. 13-2 Examiner at Wakamatsu Plant of Catalyst Chemicals Co., Ltd. Eiichi Yoshi ▼ (56) References JP-A-55-56177 (JP, A) JP-A-58-29832 (JP, A) 1-320161 (JP, A) JP-A-57-98578 (JP, A) JP-A-60-69181 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 7/04 -7/06 B32B 27/00-27/42

Claims (4)

(57) [Claims] Claims: 1. Mainly a pH of 5 or less using an organic solvent as a dispersion medium.
An inorganic particle dispersion composed of a lower organosilica sol and a surfactant having a fluoroalkyl group is applied to the surface,
A synthetic resin molded article having an inorganic particle layer (A layer) obtained by drying. 2. The synthetic resin molded product according to claim 1, wherein the synthetic resin is at least one of a fluorine-containing resin, an acrylic resin, a polyamide resin, a vinyl chloride resin, and a polycarbonate resin. 3. The synthetic resin molded product according to claim 1, wherein the surfactant is a carboxylate or phosphate ester salt. 4. The synthetic resin molded product according to claim 1, wherein said molded product is a film, a sheet or a plate.