JP2005272771A - Polyether sulfone emulsion and water-based coating composition using the same - Google Patents

Abstract

【Task】
In addition to transparency, polyethersulfone emulsion with excellent physical properties such as toughness, heat resistance and chemical resistance, natural environment, easy handling and excellent workability, and water-based paint using this A composition is provided.
[Solution]
A polyethersulfone emulsion is obtained by emulsifying and dispersing a polyethersulfone solution in water by adding a surfactant or a pigment as necessary. Moreover, it is a water-based coating composition containing a polyether sulfone emulsion and a fluororesin.
[Selection figure] None

Description

  The present invention relates to an easy-to-handle water-based coating composition capable of forming a coating film excellent in transparency and various physical properties, and a polyether sulfone emulsion used therein.

Conventionally, acrylic-based, urethane-based, acrylic-urethane-based, polyester-based, silicone-based, silicone-polyester-based, polyethersulfone-based, and the like are known as materials for forming a coating film having excellent colorless transparency.
However, among these, when applied to PCM (Precoat Metal), from the point of workability (press resistance), soft acrylic, urethane, acrylic urethane, polyester, silicone polyester with a low silicone ratio However, these materials are limited to polyether sulfone-based materials, and among these, since the heat resistance of those other than polyether sulfone is poor, their use is limited. However, only polyether sulfone-based paints are produced, which is problematic from the viewpoint of the natural environment and work environment. Therefore, it has been desired to develop water-based materials and water-based paints using polyethersulfone having excellent transparency, chemical resistance, heat resistance, and toughness as a binder.
On the other hand, in the conventional paint technology, a polyamide-imide resin, a polyimide resin, or the like is mainly used as an aqueous binder resin material that has heat resistance and requires mechanical strength and chemical resistance. However, polyamide-imide resins and polyimide resins have a dark brown dark color, and there is no known binder resin for water-based paints that is bright and colorless and transparent, and has excellent toughness, chemical resistance, and heat resistance.
Polyethersulfone is used as a molding material for copiers, printers and other office equipment parts, medical equipment parts, automotive electronic parts, etc. that require chemical resistance and high-temperature heat resistance. Although it is widely used, its application in the paint field is limited to a water-based composite material with polyamideimide, polyimide, or the like, or alone to a solvent system.

  In addition to transparency, the present invention is excellent in various properties such as toughness, heat resistance, chemical resistance, etc., is friendly to the natural environment, is easy to handle and has excellent workability, and a polyether sulfone emulsion. An object is to provide a water-based coating composition used.

  In order to achieve the above object, the present invention provides a polyethersulfone emulsion characterized in that a polyethersulfone solution is emulsified and dispersed in water.

  The present invention also provides a water-based coating composition comprising the polyether sulfone emulsion and a fluororesin.

  Since the polyether sulfone emulsion of the present invention is water-based, it is gentle to the natural environment, easy to handle and excellent in workability, physical properties such as mechanical strength and dimensional stability, heat resistance, chemical resistance, transparency, etc. In addition to being able to form an excellent coating film, it is possible to form a highly glossy and colorful coating film by dispersing various pigments. Depending on the purpose of use, it is possible to produce a glossiness according to the application by adding a matting agent. Furthermore, it became possible to provide a water-based coating composition by blending a fluororesin with a polyethersulfone emulsion.

The present invention will be described in detail below.
The polyethersulfone solution in the present invention is obtained by dissolving polyethersulfone in an organic solvent.

Examples of polyether sulfone include powdery resins supplied by Sumitomo Chemical Co., Ltd. under trade names such as Sumika Excel 4100P and 5003P, but other grades can of course be applied. What is necessary is just to select the material suitable for the purpose according to the use purpose or use conditions of the paint.
These can be used alone or in admixture of two or more.

Examples of the organic solvent include mesitylene, butylbenzene, P-cymene, pentylbenzene, dimethyl phthalate, diethyl phthalate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, benzyl acetate, isopentyl propionate, and isobutyric acid. Isobutyl, toluene, xylene, stearic acid ester, benzoic acid ester, ethyl cinnamate, abietic acid ester, bis (2-ethylhexyl) adipate, diethyl aronate, tributyl citrate, sebacic acid ester, diethyl carbonate, dimethyl sulfoxide, etc. Suitable solvents are those that do not dissolve in water.
These can be used alone or in admixture of two or more.

  Polyethersulfone is preferably used by dissolving in an organic solvent in the range of 10 to 40% by mass. Polyether sulfone can be dissolved preferably by heating to 50 to 80 ° C., for example.

  The polyether sulfone emulsion in the present invention is obtained by mechanically emulsifying and dispersing the polyether sulfone solution in water, or by adding a surfactant to the polyether sulfone solution and stirring in water. It can be emulsified and dispersed.

Examples of the surfactant include polyoxyethylene alkyl ether, polyoxyethylene 2-ethylhexyl ether, polyoxyethylene oleyl ether, polyoxyethylene dodecyl ether, polyoxyethylene castor oil ether, polyoxyethylene cetyl ether, polyoxyethylene Stearyl ether, polyoxyethylene alkyl ether, polyoxyethylene polycyclic phenyl ether, polyoxyethylene allyl ether, polyoxyethylene cumylphenyl ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene oleate, polyoxyethylene alkyl Amine, polyoxyethylene nonylphenyl ether sulfate, polyoxyethylene hydrogenated castor oil, polyoxyethylene Octylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene myristyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene Sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan oleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan laurate, poly Oxysorbitan fatty acid ester, polyethylene glycol monolaurate, Triethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monooleate, non-ionic surfactants such as polyoxyethylene sorbit tetraoleate and the like preferably.
These can be used alone or in admixture of two or more.
It is preferable that the compounding quantity of surfactant is 1-30 mass% in a polyether sulfone emulsion or a water-system coating composition.

  For example, the surfactant is added to a stirring vessel capable of maintaining a polyether sulfone solution at an arbitrary temperature of 0 to 100 ° C., the surfactant is added while stirring, and purified water is added while stirring. In addition, a polyethersulfone emulsion can be obtained. This is done by first putting purified water in a stirring vessel capable of maintaining an arbitrary temperature of 0 to 100 ° C., adding a surfactant while stirring, and further adding a polyethersulfone solution while continuing stirring. The method is also possible.

The water-based coating composition of the present invention contains a polyether sulfone emulsion and a fluororesin, and can be used for one-coat or multi-coat. When used for multi-coat, it is particularly suitable to use as a primer.
Examples of the fluororesin include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and ethylene-tetrafluoroethylene copolymer. A polymer (ETFE), a powder or dispersion of ethylene-chlorotrifluoroethylene copolymer (ECTFE) is preferably exemplified.
These can be used alone or in admixture of two or more.
It is preferable that the compounding quantity of a fluororesin (resin solid content) is 5-50 mass% in polyether sulfone (resin solid content) or the mixture (resin solid content) of polyether sulfone and a fluororesin.

The polyether sulfone emulsion or water-based coating composition of the present invention can be used by further blending a pigment. Specifically, by dispersing the pigment in the polyethersulfone emulsion or water-based paint composition, or by predispersing the pigment in the polyethersulfone solution, emulsifying and dispersing in water, and further blending a fluororesin, Various high-gloss water-based color paints can be manufactured.
Examples of the pigment include inorganic pigments such as titanium oxide and iron oxide, organic pigments such as copper phthalocyanine, and carbon black.
It is preferable that the compounding quantity of a pigment is 0-30 mass% with respect to the mixture (resin solid content) of polyether sulfone (resin solid content) or polyether sulfone and a fluororesin.
The glossiness can be adjusted by adding a matting agent according to the purpose of use.

Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “%” means “% by mass”.
Example 1
390 g of dimethyl phthalate, 293 g of toluene and 293 g of xylene were added to a reflux vessel and a jacketed stirring vessel. Hot water vapor or hot water was allowed to flow through the jacket to maintain the temperature of the contents at 50-80 ° C. While stirring this, 325 g of polyethersulfone powder (Sumika Excel 4100P) was added, and stirring was completed for 30 to 60 minutes to complete the dissolution. Steam or warm water was extracted and 5 to 10 ° C. cooling water was allowed to flow. When the temperature of the polyethersulfone solution was stabilized at 5 to 10 ° C., 20 g of a surfactant San Nopco SN-20T and 20 g of a nonionic surfactant (Newcol manufactured by Nippon Emulsifier Co., Ltd.) were added while stirring was continued. After stirring at 2000 rpm for 5 minutes, 660 g of purified water was added, the stirring speed was increased to 4000 rpm, and stirring was performed for 15 minutes. Next, the contents were taken out after leaving the cooling water to flow for a while.
The polyether sulfone emulsion thus obtained had an average particle size of 2 to 7 μm and a solid content concentration of 18%.
An untreated aluminum test piece was coated and baked at 400 ° C. for 10 minutes, and the glossiness was 110 at 60 ° reflection, the pencil hardness was 2H, and the cross-cut adhesion test was 100/100.

Example 2
A coating composition was prepared by dispersing 1.5% of Shepherd Brown # 153 in the polyethersulfone emulsion obtained in Example 1. As for the performance of the obtained coating composition, there was no difference in glossiness, pencil hardness and cross-cut adhesion strength before pigment dispersion, and a good brown colored coating film was obtained.

Example 3
70 g of the polyethersulfone emulsion obtained in Example 1 was blended with 20 g of a fluororesin dispersion (Dyneon TF5035, PTFE, solid content 58%) and 10 g of a fluororesin dispersion (Dyneon VP6900, PFA, solid content 50%). Thus, a coating composition was prepared.
This coating composition was sprayed on an untreated aluminum plate, dried at 120 ° C. for 3 minutes, and then fired at 400 ° C. for 10 minutes.
The obtained coating film had a thickness of 20 μm and a cross-cut adhesion strength of 100/100. The soy sauce / sugar / egg 1/1/1 mixed solution was dropped onto the coating surface and dried in an oven at 260 ° C. for 15 minutes, and then the operation of wiping off the dropped product was repeated 10 times. There was almost no residue on the surface of the coating film after repeating the test 10 times, and the releasability was good. Moreover, the friction coefficient of this coating film was 0.2.

Example 4
25.4 g of tetrafluoroethylene-hexafluoropropylene copolymer (DuPont FEP120) to 1000 g of the polyethersulfone emulsion obtained in Example 1, fluororesin dispersion (Dinion TF5035, PTFE, solid content 58%)
A coating composition (primer) was prepared by blending 137.5 g.
This coating composition (primer) was sprayed on an untreated aluminum plate and dried at 120 ° C. for 3 minutes, and then sprayed with Grebron 2483 topcoat. The film thickness of the coating film dried at 120 ° C. for 3 minutes and then baked at 430 ° C. was 10 μm for the primer and 15 μm for the top coat.
The obtained coating film had a cross-cut adhesion strength of 100/100 and a pencil hardness of 3H. Even after a 10-cycle corrosion resistance test with a 10% saline solution and a 2% oden solution, no blistering occurred and the cross-cut adhesion strength was 100/100. In addition, 1 cycle in this test means to stand for 16 hours after boiling for 8 hours.

The polyether sulfone emulsion and aqueous composition of the present invention are used not only for interiors of various kitchen appliances such as pans and pans, but also for exterior and handle designs, office machines, medical devices, home appliances, automobile parts, etc. It can be applied to the sliding member. Moreover, it can also be applied to a container other than the above that requires releasability and non-adhesiveness.

Claims (12)

  A polyethersulfone emulsion characterized in that a polyethersulfone solution is emulsified and dispersed in water.   A polyether sulfone emulsion, wherein a surfactant is added to a polyether sulfone solution and emulsified and dispersed in water.   The polyethersulfone emulsion according to claim 1 or 2, wherein the polyethersulfone solution is a polyethersulfone solution obtained by dissolving polyethersulfone in an organic solvent.   The organic solvent is mesitylene, butylbenzene, P-cymene, pentylbenzene, dimethyl phthalate, diethyl phthalate, 2-ethylhexyl acetate, cyclohexyl acetate, benzyl acetate, isopentyl propionate, isobutyl isobutyrate, toluene, xylene, stearic acid 1 type selected from the group consisting of ester, benzoic acid ester, ethyl cinnamate, abietic acid ester, bis (2-ethylhexyl) adipate, diethyl alloate, tributyl citrate, sebacic acid ester, diethyl carbonate and dimethyl sulfoxide The polyethersulfone emulsion according to claim 3, wherein there are two or more kinds.   The polyethersulfone emulsion according to claim 2, wherein the surfactant is a nonionic surfactant.   The nonionic surfactant is polyoxyethylene alkyl ether, polyoxyethylene 2-ethylhexyl ether, polyoxyethylene oleyl ether, polyoxyethylene dodecyl ether, polyoxyethylene castor oil ether, polyoxyethylene cetyl ether, polyoxyethylene Stearyl ether, polyoxyethylene alkyl ether, polyoxyethylene polycyclic phenyl ether, polyoxyethylene allyl ether, polyoxyethylene cumylphenyl ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene oleate, polyoxyethylene alkyl Amine, polyoxyethylene nonylphenyl ether sulfate, polyoxyethylene hydrogenated castor oil, polyoxyethylene Cutyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene myristyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene Sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan oleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan laurate, poly Oxysorbitan fatty acid ester, polyethylene glycol monolaurate, poly The polyether sulfone according to claim 5, which is one or more selected from the group consisting of ethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monooleate, and polyoxyethylene sorbitol tetraoleate. Emulsion.   The polyether sulfone emulsion of Claim 2 whose compounding quantity of the said surfactant is 1-30 mass%.   Furthermore, the polyether sulfone emulsion as described in any one of Claims 1-7 formed by mix | blending a pigment.   The polyethersulfone emulsion of Claim 8 whose compounding quantity of the said pigment is 0-30 mass%.   A water-based coating composition comprising the polyether sulfone emulsion according to any one of claims 1 to 9 and a fluororesin.   The fluororesin is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, and ethylene-chlorotrifluoroethylene copolymer. The water-based coating composition according to claim 10, which is a powder or dispersion of one or more fluororesins selected from the group consisting of coalesces.   The water-based coating composition of Claim 10 or 11 whose compounding quantity of the said fluororesin is 5-50 mass%.