EP1230986A1 - Procede d'application de revetement pulverulent a base de fluororesine thermodurcissable - Google Patents

Procede d'application de revetement pulverulent a base de fluororesine thermodurcissable Download PDF

Info

Publication number
EP1230986A1
EP1230986A1 EP99974085A EP99974085A EP1230986A1 EP 1230986 A1 EP1230986 A1 EP 1230986A1 EP 99974085 A EP99974085 A EP 99974085A EP 99974085 A EP99974085 A EP 99974085A EP 1230986 A1 EP1230986 A1 EP 1230986A1
Authority
EP
European Patent Office
Prior art keywords
coating
powder coating
temperature
coated
article
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99974085A
Other languages
German (de)
English (en)
Inventor
Ryoichi Yodogawa-seisakusho FUKAGAWA
Ryuji Yodogawa-seisakusho IWAKIRI
Keisuke Yodogawa-seisakusho TANO
Daisuke Yodogawa-seisakusho TANIZAWA
Nobuhiko Yodogawa-Seisakusho Tsuda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries Ltd filed Critical Daikin Industries Ltd
Publication of EP1230986A1 publication Critical patent/EP1230986A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00Processes for applying liquids or other fluent materials
    • B05D1/02Processes for applying liquids or other fluent materials performed by spraying
    • B05D1/04Processes for applying liquids or other fluent materials performed by spraying involving the use of an electrostatic field
    • B05D1/06Applying particulate materials
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/02Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
    • B05D3/0218Pretreatment, e.g. heating the substrate
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D5/00Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
    • B05D5/08Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain an anti-friction or anti-adhesive surface
    • B05D5/083Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain an anti-friction or anti-adhesive surface involving the use of fluoropolymers

Definitions

  • the present invention relates to a coating method characterized by pre-treatment of an article to be coated by electrostatic coating of a thermosetting fluorine-containing resin powder coating composition.
  • thermoplastic powder coating compositions prepared by using thermoplastic resins (JP-A-9-302306, etc.) and thermosetting powder coating compositions prepared by using thermosetting resins.
  • thermosetting powder coating compositions there are known those comprising a general-purpose resin such as polyester, acrylic resin or epoxy resin as a resin component and those comprising a thermosetting fluorine-containing resin as a resin component (JP-B-6-104792, etc.).
  • the fluidized bed coating method is a method of coating by dipping a heated substrate into a powder coating composition, and in many cases, is used for thick coating of thermoplastic powder coating compositions.
  • the electrostatic coating method is a method of spraying a statically charged powder coating composition onto a substrate and in many cases, is used for thermosetting powder coating compositions.
  • thermosetting fluorine-containing resin powder coating composition is easily subject to electric repellence between the particles of powder coating composition due to a high static charge inherent to the fluorine-containing resin to lower an adhesion efficiency of the coating composition, unlike general-purpose resin powder coating compositions.
  • problems of the thermosetting fluorine-containing resin powder coating composition means to-solve them are not known.
  • JP-B-6-104792 discloses an electrostatic coating method of a thermosetting fluorine-containing resin powder coating composition, but there is no suggestion as to improvements in an adhesion efficiency and a coating method.
  • An object of the present invention is to provide an electrostatic coating method for improving the both of an adhesion efficiency of a thermosetting fluorine-containing resin powder coating composition and an appearance of a coating film such as smoothness.
  • the present invention relates to the electrostatic coating method of a thermosetting fluorine-containing resin powder coating composition by previously heating an article to be coated to a temperature in a range higher than a glass transition temperature of the powder coating composition and up to a temperature higher than a curing starting temperature by 10°C.
  • a surface of the article to be coated is a surface of metal subjected to chemical conversion treatment or a surface of metal subjected to plastic coating or coating with a paint. It is particularly preferable that the surface is subjected to coating with an aqueous paint.
  • thermosetting fluorine-containing resin powder coating composition in the coating method of the present invention, known electrostatic coating equipment and electrostatic coating conditions can be employed except that the article to be coated is previously heated to a temperature in a range higher than a glass transition temperature of the thermosetting fluorine-containing resin powder coating composition and up to a temperature higher than a curing starting temperature by 10°C.
  • the glass transition temperature means a glass transition temperature of a thermosetting fluorine-containing resin to be used as a resin component of the powder coating composition and is an inherent physical property of the thermosetting fluorine-containing resin.
  • the glass transition temperature of the thermosetting fluorine-containing resin to be used for the thermosetting fluorine-containing resin powder coating composition is a temperature higher than room temperature, usually 30° to 70°C.
  • the curing starting temperature means a temperature where the curing reaction starts.
  • the curing starting temperature is a temperature which is determined by a combination of the thermosetting fluorine-containing resin and the curing agent and is higher than the glass transition temperature.
  • the curing starting temperature is usually from 120° to 150°C in case of the generally used thermosetting fluorine-containing resin powder coating compositions.
  • thermosetting fluorine-containing resin powder coating composition When a temperature of the article to be coated is not more than a glass transition temperature of thermosetting fluorine-containing resin powder coating composition at electrostatic coating, adhesion of the powder coating composition to the article to be coated is insufficient and an adhesion efficiency is not enhanced.
  • a lower limit of the heating temperature of the article to be coated is a temperature higher than the glass transition temperature preferably by 5°C, further preferably by 10°C.
  • An upper limit of the heating temperature of the article to be coated is a temperature higher than the curing starting temperature by 10°C. When higher than the upper limit temperature, the curing reaction advances quickly and the curing starts before the applied coating composition flows. Thus a surface of the obtained coating film does not become smooth.
  • the upper limit of the heating temperature is preferably a temperature higher than the curing starting temperature by 5°C, further preferably the curing starting temperature.
  • thermosetting fluorine-containing resin powder coating composition generally has a lower adhesive property to an article to be coated, particularly to a metallic substrate as compared with general-purpose resin powder coating compositions. Therefore in order to further enhance an effect of the present invention, it is preferable that a surface of the article to be coated is subjected to a specific treatment.
  • a surface of the substrate to be coated is subjected to chemical conversion treatment or subjected to plastic coating or coating with a paint. It is particularly preferable that the surface is subjected to coating with an aqueous paint from the viewpoint of enhancement of adhesion of the composition to the metallic substrate and excellent environmental protection.
  • Examples of the preferred chemical conversion treatment are dipping in zinc phosphate, iron phosphate, chromate, chromic acid and chromate phosphate and spraying thereof.
  • plastic coating treatment examples include coating with polyamide, polyolefin, polyester, polyvinyl chloride, polyvinylidene fluoride, and the like.
  • Examples of the coating with a paint are coating of an aqueous paint comprising a thermosetting acrylic resin, polyester resin, urethane resin, epoxy resin or the like in a coating thickness of 1 to 50 ⁇ m, and the like.
  • thermosetting fluorine-containing resin powder coating composition to be used in the present invention is a usual thermosetting fluorine-containing resin powder coating composition basically comprising a thermosetting fluorine-containing resin powder, a curing agent and as case demands, a pigment and various additives.
  • thermosetting fluorine-containing resin as a resin component is not limited particularly as far as the resin is a polymer having a fluorine-containing monomer unit and a crosslinkable reactive group as essential components.
  • fluorine-containing monomer examples include, for instance, one or two or more of tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, hexafluoropropylene, pentafluoropropylene, perfluoro(vinyl ether), monofluoroethylene, and the like.
  • the fluorine-containing monomer may be copolymerized with a non-fluorine-containing monomer, as case demands.
  • crosslinkable reactive group examples include hydroxyl group, carboxyl group, amino group, amido group, isocyanate group, halogen atoms such as bromine and iodine, and the like.
  • thermosetting fluorine-containing resin for example, an epoxy resin, acrylic resin, polyester resin, or the like may be blended as a powder resin component.
  • thermosetting powder coating compositions those which have been used for thermosetting powder coating compositions can be used.
  • examples thereof are, for instance, a blocked isocyanate compound, acid anhydride, polyamine compound, glycidyl compound, isocyanurate compound, polybasic acid, and the like.
  • the pigment examples include organic pigments such as condensed azo compound, isoindolenone, quinacridone, diketopyrrolopyrol, anthraquinone and dioxane; inorganic oxide pigments such as titanium oxide, iron oxide, carbon black, chromium oxide, lead chromate, white lead and molybdenum orange; metal powders such as aluminum powder and stainless steel powder; and the like.
  • organic pigments such as condensed azo compound, isoindolenone, quinacridone, diketopyrrolopyrol, anthraquinone and dioxane
  • inorganic oxide pigments such as titanium oxide, iron oxide, carbon black, chromium oxide, lead chromate, white lead and molybdenum orange
  • metal powders such as aluminum powder and stainless steel powder; and the like.
  • additives which are usually used for powder coating compositions may be optionally blended.
  • examples thereof are, for instance, a filler, ultraviolet ray absorber, leveling agent, flowability control agent, antioxidant, heat deterioration preventive agent, gloss control agent, electrostatic charge control agent, and the like.
  • thermosetting fluorine-containing resin powder coating composition which can be used suitably in the method of the present invention are, for instance, powder coating compositions prepared by using thermosetting fluorine-containing resins which are described in JP-B-6-104792, JP-A-5-331388, Japanese Patent No. 2782726, etc. and have a relatively low glass transition temperature.
  • a method and conditions for imparting an electrostatic charge to the powder coating composition may be those usually employed.
  • a frictional electrification method and corona electrical charging method are suitable for imparting an electrostatic charge at electrostatic powder coating. Since a fluorine-containing resin is easily charged with negative electricity, the corona electrical charging method is suitable.
  • a suitable applied voltage is from 20 to 80 kV, further 40 to 60 kV. When the voltage is too high, a surface of the coating film easily becomes rough, and when too low, an adhesion efficiency is lowered.
  • thermosetting fluorine-containing resin powder coating composition Preparation of thermosetting fluorine-containing resin powder coating composition
  • thermosetting fluorine-containing resin powder was prepared by pulverizing a chlorotrifluoroethylene/cyclohexyl vinyl ether/isobutyl vinyl ether/hydroxybutyl vinyl ether (weight ratio: about 50/16/9/25) copolymer (hydroxyl value: 120 mgKOH/g, glass transition temperature: 45°C, weight reduction by heating: 2 % by weight or less, intrinsic viscosity ( ⁇ ) measured in tetrahydrofuran at 30°C: 0.21) with an impact hammer mill.
  • thermosetting fluorine-containing resin powder coating composition to be used in Examples was prepared.
  • thermosetting fluorine-containing resin With respect to the glass transition temperature of the thermosetting fluorine-containing resin, a heat balance was measured by heating 10 mg of sample from -25°C to 200°C at a temperature increasing rate of 10°C/min by using Thermal Analysis System available from Perkin Elmer Co., Ltd. and a temperature at a center point between the two variable polar points was assumed to be a glass transition temperature.
  • a curing starting temperature of the obtained powder coating composition was measured with a pendulum viscometer (DDV-OPA) available from Orientec Corporation.
  • the curing starting temperature was 140°C.
  • a pre-heating temperature of an article to be coated is within a temperature range higher than 45°C and not more than 150°C.
  • a steel sheet subjected to zinc phosphate treatment in a thickness of 0.8 mm was coated with an aqueous polyurethane resin paint (VD100N available from Mitsui Toatsu Kagaku Kabushiki Kaisha) in a thickness of 10 ⁇ m to give an article to be coated.
  • the article to be coated was heated to 100°C and immediately mounted in a booth provided with a corona discharge gun (GX3300 available from Onoda Cement Kabushiki Kaisha), followed by electrostatic coating of the above-mentioned powder coating composition at an applied voltage of 60 kV.
  • an adhesion efficiency (%) (Total amount of adhered composition (g)/Effective amount of discharged composition (g)) ⁇ 100) was 75 %.
  • Electrostatic coating and baking were carried out in the same manner as in Example 1 except that the following articles to be coated were used and the articles were heated to a temperature shown in Table 1. An adhesion efficiency and characteristics of the coating film were evaluated. The results are shown in Table 1.
  • Example 2 The same steel sheet as in Example 1 which is subjected to chemical conversion treatment with phosphate but not subjected to coating with a urethane resin paint
  • Example 3 A steel sheet which is not subjected to any treatment
  • Comparative Examples 1 and 2 The same steel sheet as in Example 1 which is coated with a urethane resin paint
  • the coating method of the present invention since an adhesion efficiency per one coating is enhanced, the number of coats until a desired coating thickness is obtained can be decreased and productivity is enhanced. Also since a smoothness of a surface of coating film is excellent, a coated article having good appearance can be provided.

Landscapes

  • Application Of Or Painting With Fluid Materials (AREA)
  • Paints Or Removers (AREA)
EP99974085A 1999-10-04 1999-10-04 Procede d'application de revetement pulverulent a base de fluororesine thermodurcissable Withdrawn EP1230986A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1999/005461 WO2001024944A1 (fr) 1999-10-04 1999-10-04 Procede d'application de revetement pulverulent a base de fluororesine thermodurcissable

Publications (1)

Publication Number Publication Date
EP1230986A1 true EP1230986A1 (fr) 2002-08-14

Family

ID=14236902

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99974085A Withdrawn EP1230986A1 (fr) 1999-10-04 1999-10-04 Procede d'application de revetement pulverulent a base de fluororesine thermodurcissable

Country Status (3)

Country Link
EP (1) EP1230986A1 (fr)
AU (1) AU6002699A (fr)
WO (1) WO2001024944A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10139971A1 (de) * 2001-08-21 2003-03-27 Rodenstock Optik G Optische Linse oder Glas mit einer Kennzeichnung und/oder Markierung auf der Vorder- und/oder Rückfläche
KR102552900B1 (ko) 2015-12-24 2023-07-07 엘지전자 주식회사 이슬맺힘방지부재의 제조방법 및 이를 구비한 냉장고와 증발기

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61111335A (ja) * 1984-11-05 1986-05-29 Dainippon Toryo Co Ltd プラスチツク成形方法
IE67143B1 (en) * 1991-01-10 1996-03-06 Bhp Steel Jla Pty Ltd Method and apparatus for continuously coating a moving metal strip
JPH07148458A (ja) * 1993-09-17 1995-06-13 Nippon Paint Co Ltd 塗装方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0124944A1 *

Also Published As

Publication number Publication date
WO2001024944A1 (fr) 2001-04-12
AU6002699A (en) 2001-05-10

Similar Documents

Publication Publication Date Title
JP6447498B2 (ja) 粉体塗料、塗装物品およびそれらの製造方法
JP5010806B2 (ja) 粉体塗料組成物及びアルミホイールの塗装方法
US4220675A (en) Method of metallic finishing
JP6834490B2 (ja) 塗膜の補修方法及び塗装物品
JP6567783B1 (ja) 粉体塗料組成物及び塗膜形成方法
WO2016002725A1 (fr) Composition pour peinture en poudre, peinture en poudre et article peint
US10655022B2 (en) Powder coating material, method for producing powder coating material, and coated article
EP1219686B1 (fr) Composition de revetement pulverulent a resistance aux intemperies elevees
US11135615B2 (en) Process for producing coated article
WO2015159890A1 (fr) Peinture en poudre et article peint
JPH06104792B2 (ja) 熱硬化性粉体塗料組成物
JP2000017197A (ja) 熱硬化性粉体塗料組成物
JP2000026767A (ja) 熱硬化性粉体塗料組成物
EP1230986A1 (fr) Procede d'application de revetement pulverulent a base de fluororesine thermodurcissable
EP1219685B1 (fr) Composition de revetement a base de poudre de fluororesine, dotee d'un excellent pouvoir de protection de bases
JP2018002878A (ja) 塗料組成物、塗装物品、含フッ素重合体および化合物
JPH04277569A (ja) 弗素含有粉末被覆剤
JP3834845B2 (ja) 複層塗膜形成方法
JPWO2001024944A1 (ja) 熱硬化型フッ素樹脂粉体塗料の塗装方法
WO2001024943A1 (fr) Procede relatif a l'application d'un revetement a base de poudre de fluororesine thermodurcissable
JP2009119360A (ja) 塗装鋼板及び鋼板の塗装方法
JPWO2001024943A1 (ja) 熱硬化型フッ素樹脂粉体塗料の塗装方法
JP2003096378A (ja) フッ素樹脂粉体塗料組成物および塗装物品
JP2003003122A (ja) 熱硬化型粉体塗料及び熱硬化粉体塗膜形成方法
JPH04310272A (ja) 自動車の塗装方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20010823

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20040223

RBV Designated contracting states (corrected)

Designated state(s): DE FR GB IT