Process for formation of coating film on plastic material and coated article

• US 20030194500A1
• Filed: 04/07/2003
• Published: 10/16/2003
• Est. Priority Date: 04/15/2002
• Status: Abandoned Application

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Nippon Bee Chemical Co. Ltd., Nippon Paint Company Limited (Rainbow Light Limited)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Nippon Bee Chemical Co. Ltd., Nippon Paint Company Limited (Rainbow Light Limited)
• Inventors: Takenaka, Hiroyuki, Masuda, Kazuaki, Nakaoka, Ryoichi, Kobayashi, Seiji, Ogawa, Takeshi, Mizuguchi, Katsumi
• Application Number:
  US10/408,411
• Publication Number:
  US 20030194500A1
• Time in Patent Office: Days
• US Class Current: 427/407.1
• CPC Class Codes: B05D 2201/02 Polymeric substrate
• CPC Class Codes: B05D 7/574 at least some layers being let to dry at least partially before applying the next layer B05D7/577 takes precedence
• CPC Class Codes: C08J 2423/12 Polypropene
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/056 Forming hydrophilic coatings

Abstract

The present invention provides: a process for formation of a coating film on a plastic material, which process enables formation of the coating film with good productivity wherein the coating film is excellent in the adhesion, the moisture-resisting adhesion, and the gasohol resistance, and has good appearance; and a coated article. The process for formation of a coating film on a plastic material is a process for formation of a coating film, which process comprises the steps of: coating the plastic material with a specific aqueous primer coating composition; and thereafter drying the resultant primer coating film in such a manner that its nonvolatile content will not be less than 70 weight %; and thereafter overcoating the primer coating film with a specific aqueous base paint composition; and thereafter drying the resultant base coating film in such a manner that its nonvolatile content will not be less than 60 weight %; and thereafter overcoating the base coating film with a two-component clear paint; and thereafter baking the resultant three-layered coating film onto the plastic material.

Claims

1. A process for formation of a coating film on a plastic material, which comprises the steps of:

coating the plastic material with an aqueous primer coating composition; and

thereafter drying the resultant primer coating film in such a manner that its nonvolatile content will not be less than 70 weight %; and

thereafter overcoating the primer coating film with an aqueous base paint composition; and

thereafter drying the resultant base coating film in such a manner that its nonvolatile content will not be less than 60 weight %; and

thereafter overcoating the base coating film with a two-component clear paint; and

thereafter baking the resultant three-layered coating film onto the plastic material;

with the process being characterized in that;

the aqueous base paint composition includes;

an emulsion resin (a) as obtained by carrying out emulsion polymerization of an α

,β

-ethylenically unsaturated monomer mixture having a nonvolatile acid value of 3 to 50 mgKOH/g;

a water-soluble (meth)acrylic resin (b) having a nonvolatile acid value of 110 to 200 mgKOH/g; and

a polyether-modified carbodiimide (c);

wherein the α

,β

-ethylenically unsaturated monomer mixture includes a (meth)acrylate ester in an amount of not smaller than 65 weight % wherein the (meth)acrylate ester has an ester portion containing 1 or 2 carbon atoms; and

wherein;

the nonvolatile content of the (a) is in the range of 55 to 75 weight %, that of the (b) is in the range of 0.5 to 15 weight %, and that of the (c) is in the range of 15 to 44.5 weight %, relative to the total nonvolatile content of the (a) to (c); and

the aqueous primer coating composition includes an acid-anhydride-modified chlorinated polyolefin emulsion resin (A), an aqueous urethane dispersion (B), an aqueous epoxy resin (C), and an organic strong base and/or its salt (D), wherein;

the nonvolatile content of the (A) is in the range of 20 to 60 weight %, that of the (B) is in the range of 10 to 40 weight %, that of the (C) is in the range of 20 to 60 weight %, and the (D) is in the range of 1 to 5 weight % relative to the total nonvolatile content of the (A), (B), and (C).

2. A process according to claim 1, wherein the organic strong base is at least one member selected from the group consisting of 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN).

3. A coated article, which is obtained by the process as recited in claim 1.