CN101687220B

CN101687220B - Multilayer coating film-forming method

Info

Publication number: CN101687220B
Application number: CN200880021056.8A
Authority: CN
Inventors: 汤川嘉之
Original assignee: Kansai Paint Co Ltd
Current assignee: Kansai Paint Co Ltd
Priority date: 2007-06-20
Filing date: 2008-06-12
Publication date: 2013-05-29
Anticipated expiration: 2028-06-12
Also published as: JP4991883B2; WO2008156125A3; MY149319A; JP2010530291A; WO2008156125A8; WO2008156125A2; CN101687220A

Abstract

This invention provides a multilayer coating film-forming method comprising applying base coating paint (A) onto a coating object, successively applying onto the so formed uncured coated surface water-based coloring paint (B) and clear paint (C), and then heating to simultaneously cure the three-layered coating film composed of the paints (A), (B) and (C), in which the base coating paint (A) contains carboxyl group- and hydroxyl group-containing resin; tertiary amino group -containing resin which is obtained by copolymerizing tertiary amino group -containing unsaturated monomer, polyoxyalkylene group -containing nonionic unsaturated monomer and other unsaturated monomer (b-3); and crosslinking agent reactable with hydroxyl group.

Description

Form the method for multilayer film

Technical field

The present invention relates to a kind of method that forms multilayer film, it can reduce the consumption of solvent and shorten procedure of processing, and still has excellent coating processability and final outward appearance.

Background technology

These years, environmental problem has caused widely in the world to be paid close attention to, and equally in auto industry, must advance the such effort of environment that improves in the manufacturing step.The generation of for example global warming of such problem, industrial waste and the discharging of volatile organic solvent (VOC) have appearred in automobile manufacturing process.Particularly speak of VOC, its overwhelming majority produces in coating step, and the effective countermeasures of exigence.

Equally from increasing productivity and reducing the viewpoint of energy consumption, need and proposed a kind of painting method for this reason, it has saved the heat cure in the coating step.

The outer panels of car body part is coated with multilayer film usually, its comprise the cationic electrodeposition lacquer bottom coating, in film and face is filmed, be used for giving corrosion resistance and welcome outward appearance.

In order to reduce VOC, the employing water-based paints has also been proposed as floating coat and finishing coat.Yet, because the primary solvent composition of water-based paints is water, and compare with organic solvent based lacquer, this solvent more is difficult to evaporation from film, therefore they have such shortcoming as under the temperature and humidity impact that applies environment, the easier tendency that causes coating flowing hanging and final cosmetic damage.

As the such method of forming layered coating film of thermal cure step that can reduce VOC and allow cancellation to film, for example, JP Sho 61 (1986)-141969A disclose a kind of metal-modified method, it comprises, and (it comprises the neutralized reaction product of polyvalent carboxylic acid's resin and amino resins with organic solvent based or non-aqueous dispersions type thermosetting varnish, but containing metal pigment pigment not) paint applies on the object, the viscosity of coated lacquer is adjusted at least 10 pools (20 ℃), apply a kind of thermosetting water-base metal lacquer thereon, further apply a kind of transparent thermosetting varnish thereon, and come curing simultaneously therefore formed three-layer coated by heating.But, even the viscosity of or non-aqueous dispersions type thermosetting varnish organic solvent based when this be adjusted to above the scope of method defined when above, after application of heat solidity water-base metal lacquer, the deteriorated of such defective such as FINAL APPEARANCE or the crack of filming still can occur, for example, such defective occurs under high humidity, and therein viscosity control becomes and is not enough to disturb the even orientation of the metallic pigments in the thermosetting water-base metal lacquer of paint on it.

As a kind of metal-modified method that prevents such defective, for example, JP Hei11 (1999)-197592A has proposed a kind of method of forming layered coating film, is characterised in that the thin polymer beads that has comprised special gel without the organic solvent based of metallic pigments or non-aqueous dispersions type thermosetting varnish.This method prevents that the effect of aforementioned disadvantages from remaining not enough, and concrete, and the problem that can occur the crack under high humidity still exists.

Summary of the invention

Target of the present invention provides a kind of method, and it has been realized the reduction solvent load and has shortened procedure of processing, and it can form such multilayer film, coating processability and FINAL APPEARANCE that this is filmed even still have excellence under high humidity.

By concentrating the accumulation of research, we have been found that now top target can realize by a kind of method of forming layered coating film, and finished thus the present invention, the method comprises and applies primary coat lacquer (base coating paint), continuous water base colored paint and the colored varnish of applying on this uncured coating surface, then heat by this primary coat lacquer, water base colored paint and the colored varnish formed three-layer coated, solidify simultaneously them, wherein a kind of lacquer that contains the resin that specifically contains uncle's amino group and specific crosslinking agent is used as described primary coat lacquer.

Therefore the invention provides a kind of method of forming layered coating film, it comprises on primary coat lacquer (A) paint coating object, continuous water base colored paint (B) and the colored varnish (C) of applying on the uncured coating surface that forms like this, then heating comes curing simultaneously this comprises lacquer (A), (B) and (C) three-layer coated, the method is characterized in that primary coat coats with lacquer (A) and comprise:

(a) contain the resin of carboxylic group and oh group,

(b) contain the resin of uncle's amino group, this resin contains by copolymerization that the unsaturated monomer (b-1) of uncle's amino group, the nonionic unsaturated monomer (b-2) that contains the polyoxyalkylene group and other unsaturated monomers (b-3) obtain, and

(c) can with the crosslinking agent of oh group reaction.

In method of forming layered coating film of the present invention, primary coat lacquer (A) is comprising the resin (a) that contains carboxylic group and oh group and the resin (b) that contains uncle's amino group.Therefore, apply in rear formed the filming at primary coat lacquer (A), form a kind of structure and shown viscosity rising effect, this structure can be considered to owing to the Acid-Base between uncle's amino group of the carboxylic group of resin (a) and resin (b) interact and to cause false crosslinked, this viscosity rising effect has produced favourable viscous effect in two coating films that form by applying subsequently water base colored paint (B).Because this effect, therefore even under the condition (for example in high humidity) that the layer that tends to cause in two coating films mixes, layer mixes also can be suppressed, and show very excellent coating processability.Because in resin (b), steric effect derived from the polyoxyalkylene group pendant moiety of monomer (b-2) has suppressed the too much false crosslinked formation between resin (a) and resin (b), in addition, realized a kind of like this effect, namely, primary coat lacquer (A) does not have owing to the destruction of assembling the smoothness that causes, and therefore can form a kind of multilayer film with splendid FINAL APPEARANCE.

Hereinafter method of forming layered coating film of the present invention is carried out further detailed explanation.

The specific embodiment

Primary coat lacquer (A):

According to this method of the present invention, at first to apply the primary coat lacquer (A) on the object be a kind of like this lacquer to paint, the crosslinking agent (c) that it is comprising the resin (a) that contains carboxylic group and oh group, the resin (b) that contains uncle's amino group and can react with oh group.

The resin (a) that contains carboxylic group and oh group:

Any resin that comprises carboxylic group and oh group in its molecule can be used as resin (a), and without any concrete restriction.As the resin of concrete kind, can should be mentioned that for example acrylic resin, mylar, polyether resin, polycarbonate resin, polyurethane resin etc.

Carboxylic group in the resin (a) is in the filming of primary coat lacquer (A), and interacting by the Acid-Base with uncle's amino group of resin (b) forms false cross-linked structure, thereby has produced the viscosity development effect.Equally, the oh group in the resin (a) is filmed by solidifying this with the reaction of crosslinking agent (c).

From so that contain the viewpoint that the resin (a) of carboxylic group and oh group shows viscosity development effect (this effect is produce by interacting with the resin that contains uncle's amino group (b)), resin (a) can have the acid number scope of 2-100mgKOH/g usually, preferred 5-80mgKOH/g, especially 5-65mgKOH/g.Consider equally the curing performance of filming or the resistance to water that obtain, this resin (a) that contains carboxylic group and oh group can have the hydroxyl value scope of 20-200mgKOH/g usually, preferred 35-180mgKOH/g, especially 50-150mgKOH/g.

As this preferred example of resin (a) that contains carboxylic group and oh group, can should be mentioned that the acrylic resin that contains carboxylic group and oh group, contain the mylar of carboxylic group and oh group and contain carboxylic group and the polyurethane resin of oh group.

The acrylic resin that contains carboxylic group and oh group:

Contain the acrylic resin of carboxylic group and oh group can be for example according to the practice of generally acknowledging, by copolymerization contain carboxylic group unsaturated monomer (M-1), contain oh group unsaturated monomer (M-2) but and other copolymerization unsaturated monomers (M-3) synthesize.

The unsaturated monomer (M-1) that contains carboxylic group is included in these compounds that have at least one carboxylic group and an insatiable hunger chemical bond in each molecule, and its example comprises acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride.These compounds can use separately or two or more are used in combination.

The unsaturated monomer (M-2) that contains oh group is included in these compounds that have at least one oh group and an insatiable hunger chemical bond in each molecule, this oh group has mainly served as the functional group in the functionalization of the acrylic resin that contains carboxylic group and oh group and crosslinking agent (c), and crosslinking agent (c) can react with oh group.As the unsaturated monomer that contains oh group (M-2), particularly preferably be (methyl) acrylic acid and C _2-10The mono-esterification product of dihydroxylic alcohols, concrete example comprise for example (methyl) HEA of (methyl) acrylic acid hydroxy alkyl ester, (methyl) acrylic acid 2-hydroxypropyl ester, (methyl) acrylic acid 4-hydroxyl butyl ester etc.

In this manual, " (methyl) acrylate " expression acrylate or methacrylate.

Same unsaturated monomer (M-2) as containing oh group, what can be convenient to use is for example by (methyl) acrylic acid hydroxy alkyl ester further compound of obtaining of ring-opening polymerisation of (methyl) HEA and 6-caprolactone etc. for example, PLACCEL FA-1 for example, PLACCEL FA-2, PLACCEL FA-3, PLACCEL FA-4, PLACCEL FA-5, PLACCEL FM-1, PLACCELFM-2, PLACCEL FM-3, PLACCEL FM-4, PLACCEL FM-5 (trade (brand) name, DaicelChemical Industries, Ltd.) etc.In addition, contain the unsaturated monomer (M-2) of oh group as this, can also use polyethyleneglycol (methyl) acrylate, polypropylene glycol list (methyl) acrylate, (methyl) acrylic acid 2-hydroxyl-3-phenoxy propyl ester, (methyl) acrylic acid 2-hydroxyl-3-butoxy propyl diester, monohydroxy ethyl (methyl) acrylate phthalic acid ester etc.

But other copolymerization unsaturated monomers (M-3) comprise these compounds that have a unsatisfied chemical bond in each molecule, it is different from the unsaturated monomer (M-2) that contains the unsaturated monomer (M-1) of carboxylic group and contain oh group above-mentioned, and as they concrete examples, can should be mentioned that listed these in following (1)-(6):

(1) (methyl) acrylic acid and C _1-20The mono-esterification product of monohydric alcohol: for example, (methyl) methyl acrylate, (methyl) ethyl acrylate, (methyl) propyl acrylate, (methyl) n-butyl acrylate, (methyl) isobutyl acrylate, (methyl) tert-butyl acrylate, (methyl) 2-EHA, (methyl) cyclohexyl acrylate, (methyl) acrylic acid Lauryl Ester, (methyl) isobornyl acrylate, (methyl) tridecyl acrylate, (methyl) stearyl acrylate acyl ester and (methyl) butoxyethyl acrylate;

(2) aromatics unsaturated monomer: for example, styrene, AMS and vinyltoluene;

(3) contain the unsaturated monomer of glycidyl group: contain at least one the compound in each of glycidyl group and unsatisfied chemical bond in each molecule, for example, acrylic acid glycidyl esters and methyl propenoic acid glycidyl base ester;

(4) contain the amide compound of unsatisfied chemical bond: acrylamide for example, Methacrylamide, DMAA, N, N-dimethyl propyl acrylamide, N-butoxymethyl acrylamide, N hydroxymethyl acrylamide, N-methylol methacrylamide and DAAM;

(5) other unsaturated compounds: vinyl acetate for example, propionate, vinyl chloride, and special capric acid (versatic acid) vinyl esters for example Veo Va9 and Veo Va10 (trade (brand) name, JapanEpoxy Resin Co.);

(6) contain the nitrile compound of unsatisfied chemical bond: for example acrylonitrile and methacrylonitrile.

These other unsaturated monomers (M-3) can use separately or two or more are used in combination.

The acrylic resin that contains carboxylic group and oh group can have the acid number scope of 5-100mgKOH/g usually, preferred 20-80mgKOH/g, especially 35-65mgKOH/g.In the acid number of this resin occasion less than 5mgKOH/g, exist such situation here, therein owing to this resin and the viscosity development effect that the interaction that contains the resin (b) of uncle's amino group produces are reduced.Yet when it surpassed 100mgKOH/g, the resistance to water of filming can variation.The hydroxyl value of common scope: 20-150mgKOH/g below this acrylic resin that contains carboxylic group and oh group also can have, preferred 35-120mgKOH/g, especially 50-100mgKOH/g.When the hydroxyl value of this resin during less than 20mgKOH/g, it is not enough that curing property can become, and when it surpassed 150mgKOH/g, the resistance to water that this is filmed was understood variation.

This number-average molecular weight scope that contains the acrylic resin of carboxylic group and oh group can be 2000-100000 usually, preferred 3000-50000, especially 4000-20000.When the number-average molecular weight of this resin less than 2000 the time, the weatherability that this is filmed can be not enough, and when its molecular weight above 100000 the time, can cause the deteriorated of coating surface smoothness.

In this manual, the number-average molecular weight of resin is based on the number-average molecular weight of polystyrene standard, with the conversion value of the measured number-average molecular weight of gel permeation chromatography HLC8120GPC (trade (brand) name, Tosoh Corporation).

The mylar that contains carboxylic group and oh group:

The mylar that contains carboxylic group and oh group can prepare by known reaction itself, and for example the esterification by polyacid and polyalcohol prepares.

Polyacid is the compound that has at least two carboxylic groups in a kind of each molecule, and its example comprises phthalic acid, M-phthalic acid, terephthalic acid (TPA), butanedioic acid, adipic acid, azelaic acid, decanedioic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, fumaric acid, itaconic acid, trimellitic acid, benzenetetracarboxylic acid and acid anhydrides thereof.Polyalcohol is the compound that has at least two oh groups in a kind of each molecule, and its example comprises for example ethylene glycol of dihydroxylic alcohols, propane diols, 1,3-PD, BDO, 1,5-PD, 1, the 6-hexylene glycol, 2,2-diethyl-1,3-PD, neopentyl glycol, 1,9-nonanediol, Isosorbide-5-Nitrae-cyclohexanediol, the hydroxy new pentane acid DOPCP, 2-butyl-2-ethyl-1,3-PD, 3-methyl isophthalic acid, the 5-pentanediol, the bisphenol-A of 2,2,4-TMPD and hydrogenation; At least trivalent polyalcohol trimethylolpropane for example, trimethylolethane, glycerine and pentaerythrite; With multi-hydroxy carboxy acid for example 2, the 2-dihydromethyl propionic acid, 2,2-dimethylolpropionic acid, 2,2-dihydroxymethyl valeric acid, 2,2-dihydroxymethyl caproic acid and 2,2-dihydroxymethyl are sad.These compounds also can form ether with lower alcohol.

Also allow mono-epoxy compounds alpha-olefin epoxides for example, expoxy propane for example, epoxy butane etc., CARDURA E10 (trade (brand) name, Japan Epoxy Resin Co., the ethylene oxidic ester of the saturated fatty acid of synthetic high branching) etc. react with acid, and such compound is incorporated in the mylar.

Carboxylic group can be incorporated into by such method in the mylar, for example uses excessive polyacid to carry out above-mentioned esterification; Perhaps after the esterification of polyacid and polyalcohol, further for example trimellitic acid or its acid anhydrides react with product and polyacid.

This mylar that contains carboxylic group and oh group can be fatty acid modified mylar, it is that use-case comes modification such as following (partly) drying oil fatty acid: linseed oil fatty acid, coco-nut oil fatty acid, safflower oil aliphatic acid, soya fatty acid, the acid of sesame oil fat, perilla herb oil fat acid, hemp-seed oil aliphatic acid, ready denier oil acid, dehydrated castor oil fatty acid etc.Aspect oil content, the modification amount that is not more than 30 quality % of these aliphatic acid is normally enough.This mylar that contains carboxylic group and oh group also can be a kind of like this resin, its part with monoacid for example benzoic acid react.

This mylar that contains carboxylic group and oh group can have the acid number scope of 5-70mgKOH/g usually, preferred 15-55mgKOH/g, especially 25-45mgKOH/g.In the acid number of this resin occasion less than 5mgKOH/g, exist such situation here, therein owing to this resin and the viscosity development effect that the interaction that contains the resin (b) of uncle's amino group produces are reduced.Yet when it surpassed 70mgKOH/g, the resistance to water of filming can variation.The hydroxyl value of common scope: 30-200mgKOH/g below this mylar that contains carboxylic group and oh group can have, preferred 50-180mgKOH/g, especially 70-150mgKOH/g.When the hydroxyl value of this resin during less than 30mgKOH/g, it is not enough that curing property can become, and when it surpassed 200mgKOH/g, the resistance to water that this is filmed was understood variation.

This number-average molecular weight scope that contains the mylar of carboxylic group and oh group can be 300-50000, particularly 500-20000, especially 1000-10000 usually.When the number-average molecular weight of this resin here less than 300 the time, the weatherability that this is filmed can be not enough, and when its molecular weight above 50000 the time, can cause the deteriorated of coating surface smoothness.

The polyurethane resin that contains carboxylic group and oh group:

The polyurethane resin that contains carboxylic group and oh group can for example by the generally acknowledged practice, react polyalcohol (it is comprising the polyalcohol that contains carboxylic group) and polyisocyanates to obtain.

As the polyalcohol that contains carboxylic group, for example can mention 2, the 2-dihydromethyl propionic acid, 2,2-dimethylolpropionic acids etc. particularly preferably are 2, the 2-dihydromethyl propionic acid.When using these polyalcohols, can with the solvent of small amount for example 1-METHYLPYRROLIDONE accelerate this reaction.

Same feasible is the not polyalcohol of carboxyl group of use simultaneously.The example of the low molecular weight polyols of carboxyl group does not comprise for example ethylene glycol of dihydroxylic alcohols, diethylene glycol (DEG), propane diols, butanediol, hexylene glycol etc.; With trihydroxylic alcohol trimethylolpropane for example, glycerine, pentaerythrite etc.These polyalcohols as HMW can should be mentioned that for example PPG, PEPA, acryloyl group polyalcohol, epoxy polyol etc.As PPG, can should be mentioned that for example polyethylene glycol, polypropylene glycol, polytetramethylene glycol etc.As PEPA, for example can should be mentioned that for example aforesaid dihydroxylic alcohols of alcohols, DPG, BDO, 1,6-hexylene glycol, neopentyl glycol etc. and binary acid be adipic acid for example, azelaic acid, the polycondensation product of decanedioic acid etc.; The ring-opening polymerization polymer polyalcohol that lactone is derived is polycaprolactone for example, PCDL etc.

As the polyisocyanates that is used for top polyol reaction, below for example can should be mentioned that these: aliphatic polyisocyante is hexamethylene diisocyanate for example, trimethyl hexamethylene diisocyanate, dimer acid diisocyanate, the addition product of the biuret type of LDI etc. and these polyisocyanates or isocyanurate ring addition product; Alicyclic diisocyanate is IPDI for example, and 4,4 '-di-2-ethylhexylphosphine oxide (cyclohexyl isocyanate), hexahydrotoluene-2,4-or 2,6-vulcabond, 1,3-or Isosorbide-5-Nitrae-two (isocyanato-methyl) cyclohexane, 1, the 4-cyclohexane diisocyanate, 1,3-pentamethylene vulcabond, the biuret type addition product of 1,2-cyclohexane diisocyanate etc. and these polyisocyanates or isocyanurate ring addition product; The aromatic diisocyanates compound is eylylene diisocyanate for example, between eylylene diisocyanate, the tetramethyl eylylene diisocyanate, the toluylene group diisocyanate, 4,4 '-methyl diphenylene diisocyanate, 1, the 5-naphthalene diisocyanate, Isosorbide-5-Nitrae-naphthalene diisocyanate, 4,4-toluidines vulcabond, 4,4 '-diphenyl ether vulcabond, meta-or p-phenylene vulcabond, 4,4 '-diphenylene vulcabond, 3,3 '-dimethyl-4,4 '-diphenylene vulcabond, two (4-isocyanato-phenyl) sulfone, isopropylidene is two-biuret type addition product or the isocyanurate ring addition product of (4-phenyl isocyanate) etc. and these polyisocyanates; The polyisocyanates that has at least three isocyanate groups in each molecule is triphenyl methane-4 for example, and 4 '-4 "-triisocyanate, 1; 3; 5-three isocyanato-benzene, 2,4; 6-three isocyanato-toluene; 4,4 '-dimethyl diphenylmethane-2,2 '; 5, the biuret type addition product of 5 '-tetraisocyanate etc. and these polyisocyanates or isocyanurate ring addition product.

The polyurethane resin that contains carboxylic group and oh group can have the acid number scope of 2-50mgKOH/g usually, preferred 5-40mgKOH/g, especially 5-20mgKOH/g.In the acid number of this resin occasion less than 2mgKOH/g, exist such situation here, therein owing to this resin and the viscosity development effect that the interaction that contains the resin (b) of uncle's amino group produces are reduced.Yet when it surpassed 50mgKOH/g, the resistance to water of filming can variation.

The number-average molecular weight scope that contains the polyurethane resin of carboxylic group and oh group can be 1000-3000000, particularly 10000-2000000, especially 20000-1000000 usually.When the number-average molecular weight of this resin here less than 1000 the time, the weatherability that this is filmed can be not enough, and when its molecular weight above 3000000 the time, can cause the deteriorated of coating surface smoothness.

This contains carboxylic group in the resin (a) of carboxylic group and oh group the neutralization of making us expecting.Be desirable in addition at the resin that will contain carboxylic group and oh group (a) and the resin (b) that contains uncle's amino group, carry out this neutralization before crosslinking agent (c) etc. mixes.The example that is used for the alkaline matter of this neutralization comprises ammonia; Uncle's monoamine is ethylamine for example, propyl group amine, butylamine, benzyl amine, MEA, neopentyl alcohol amine, 2-aminopropanol, 3-aminopropanol etc.; Secondary monoamine is diethylamide for example, diethanol amine, two-just-or diisopropanolamine (DIPA), N-methylethanolamine, N-ehtylethanolamine etc.; Uncle's monoamine is N for example, N-dimethyl-monoethanolamine, Trimethylamine, triethylamine, triisopropylamine, methyl diethanolamine etc.; With polyamine diethylenetriamine for example, hydroxyethylamino ethylamine, ethylamino ethylamine, methylamino propyl group amine etc.These materials can use separately or two or more are used in combination.

The suitable usage ratio of alkaline matter that is used for neutralization is the 0.1-1.0 equivalent with respect to the carboxylic group of resin (a) normally, particularly the 0.2-0.8 equivalent.

The resin (b) that contains uncle's amino group:

The resin (b) that contains uncle's amino group comprises particularly such acrylic resin that contains uncle's amino group, and it is to contain the unsaturated monomer (b-1) of uncle's amino group, the nonionic unsaturated monomer (b-2) that contains the polyoxyalkylene group and other unsaturated monomers (b-3) by copolymerization to obtain.

The unsaturated monomer (b-1) that contains uncle's amino group:

The polymerizable unsaturated monomer (b-1) that contains uncle's amino group is a kind of for uncle's amino group being incorporated into resin (b) monomer component that contains uncle's amino group, and has uncle's amino group and unsaturated group in its each molecule.

As concrete example is N, N-dialkyl aminoalkyl (methyl) acrylate is N for example, N-dimethyl aminoethyl (methyl) acrylate, N, N-diethylamino ethyl (methyl) acrylate, N, N-dimethylaminopropyl (methyl) acrylate, N, N-two-tert-butyl group amino-ethyl (methyl) acrylate, N, N-dimethylamino butyl (methyl) acrylate etc.; And N, N-dialkyl aminoalkyl (methyl) acrylamide is N for example, N-dimethyl aminoethyl (methyl) acrylamide, N, N-diethylamino ethyl (methyl) acrylamide, N, N-dimethylaminopropyl (methyl) acrylamide etc.These monomers can use separately or two or more are used in combination.

In these monomers, N, N-dialkyl aminoalkyl (methyl) acrylate, particularly N, N-dimethyl aminoethyl (methyl) acrylate is preferably used as the polymerisable unsaturated monomer that contains uncle's amino group.

Be incorporated into the viscosity that uncle's amino group in the resin (b) that contains uncle's amino group is used for the lacquer that performance applies by so polymerisable unsaturated monomer (b-1) that contains uncle's amino group, this is cross-linked to form effect owing to the vacation that produces that interacts by the Acid-Base with the carboxylic group of resin (a).

Contain polyoxyalkylene group nonionic unsaturated monomer (b-2):

Containing polyoxyalkylene group nonionic unsaturated monomer (b-2) is such monomer component, its be used for the polyoxyalkylene group be incorporated into the resin (b) that contains uncle's amino group give this resin that contains uncle's amino group (b) hydrophily and suppress resin (a) and (b) between excessive interaction, it has polyoxyalkylene group and unsaturated group in each molecule.

As the polyoxyalkylene group, can should be mentioned that the poly suboxygen ethyl group, the poly suboxygen propyl group has group of poly suboxygen ethyl group-poly suboxygen propyl group block structure etc.The preferred molecular weight ranges of polyoxyalkylene group is 200-3000, particularly 300-2500 normally.

As the typical example of monomer (b-2), what can mention for example is the compound of following formula (1) representative:

CH ₂＝C(R ¹)COO(C _nH _2nO) _m-R ² (1)

R wherein ¹Represent hydrogen or methyl, R ²Represent hydrogen or C _1-4Alkyl, m are 4-60, and the preferably integer of 6-50, and n is 2 or 3, preferred 2 integer, wherein m oxyalkylene unit (C _nH _2nO) can be identical or different.

The object lesson of such monomer (b-2) comprises (methyl) acrylic acid TEG ester, (methyl) acrylic acid methoxyl group TEG ester, (methyl) acrylic acid ethyoxyl TEG ester, (methyl) acrylic acid n-butoxy TEG ester, (methyl) acrylic acid four propylene glycol esters, (methyl) acrylic acid methoxyl group four propylene glycol esters, (methyl) acrylic acid ethyoxyl four propylene glycol esters, (methyl) acrylic acid n-butoxy four propylene glycol esters, polyethylene glycol (methyl) acrylate, polypropylene glycol (methyl) acrylate, methoxy poly (ethylene glycol) (methyl) acrylate, ethyoxyl polyethylene glycol (methyl) acrylate etc.In these, particularly preferably be polyethylene glycol (methyl) acrylate and polypropylene glycol (methyl) acrylate.These monomers can be separately with or two or more make up to use.

Because the steric hindrance of poly suboxygen ethyl group pendant moiety (it induces one to contain in the resin (b) of uncle's amino group by monomer (b-2)), therefore suppressed resin (a) and (b) between the excessive formation of false cross-linked structure, can obtain the FINAL APPEARANCE of the excellence of multilayer film thus, and not have because the variation of the smoothness that the gathering of primary coat lacquer (A) causes.

Other unsaturated monomers (b-3):

Still other unsaturated monomers (b-3) comprise and are different from above-mentioned monomer (b-1) and unsaturated monomer (b-2), its with these monomers (b-1) but and (b-2) copolymerization, and carry out suitable selection according to the performance of the desired resin that contains uncle's amino group (b).

The concrete example of such monomer (b-3) comprises C _1-24Alkyl straight chain or Cheng Huan (methyl) acrylate monomer is (methyl) methyl acrylate for example, (methyl) ethyl acrylate, (methyl) acrylic acid n-propyl, (methyl) isopropyl acrylate, (methyl) n-butyl acrylate, (methyl) isobutyl acrylate, (methyl) tert-butyl acrylate, (methyl) 2-EHA, (methyl) acrylic acid n-octyl, (methyl) lauryl acrylate, (methyl) stearyl acrylate acyl ester, (methyl) cyclohexyl acrylate, (methyl) isobornyl acrylate, (methyl) tridecyl acrylate etc.; The unsaturated monomer (typical (methyl) acrylic acid hydroxy alkyl ester monomer) that contains oh group is (methyl) HEA for example, (methyl) acrylic acid 2-hydroxypropyl ester, (methyl) acrylic acid 4-hydroxyl butyl ester etc.; Acrylamide, Methacrylamide; (methyl) acrylate that contains the oxetanes ring is 3-ethyl-3-(methyl) acryloyl-oxy ylmethyl oxetanes for example, 3-methyl-3-(methyl)-acryloyl-oxy ylmethyl oxetanes, 3-butyl-3-(methyl) acryloyl-oxy ylmethyl oxetanes etc.; Aromatic vinyl compound is styrene for example, AMS, vinyltoluene etc.; (methyl) acrylonitrile, vinyl acetate, etc.These unsaturated monomers can use separately or two or more are used in combination.

From the viewpoint of coat film performance, the resin (b) that contains uncle's amino group preferably comprises the functional group that can react with crosslinking agent (c).As the functional group that can react with crosslinking agent (c), preferably oh group.In this case, as its at least a composition, monomer (b-3) preferably comprises the unsaturated monomer that contains oh group.

The object lesson that contains the unsaturated monomer of oh group comprises polyalcohol and (methyl) acrylic acid mono-esterification product, (methyl) HEA for example, (methyl) acrylic acid hydroxypropyl ester, (methyl) acrylic acid 2,3-dihydroxy butyl ester, (methyl) acrylic acid 4-hydroxyl butyl ester, polyethyleneglycol (methyl) acrylate etc.; And by the ring-opening polymerisation formed compound of polyalcohol with (methyl) acrylic acid these mono-esterification products and 6-caprolactone.In these, aspect reactive, (methyl) acrylic acid 4-hydroxyl butyl ester preferably, polyethyleneglycol (methyl) acrylate, and the formed compound of ring-opening polymerisation by polyalcohol and (methyl) acrylic acid mono-esterification product and 6-caprolactone.These compounds can use separately or two or more are used in combination.

This resin (b) that contains uncle's amino group can contain by copolymerization the unsaturated monomer (b-1) of uncle's amino group, contain the nonionic unsaturated monomer (b-2) of poly suboxygen ethyl group and still other unsaturated monomers (b-3) obtain.

Such monomer (b-1), (b-2) and usage ratio (b-3) do not have strict restriction, but it is according to the physical property of the desired resin that contains uncle's amino group but transformable.Yet, based on monomer (b-1), total amount (b-2) and (b-3), the scope of monomer (b-1) can be 1-25 quality % usually, preferred 3-20 quality %, especially 5-15 quality %; The scope of monomer (b-2) is 5-40 quality % normally, preferred 7-35 quality %, especially 10-30 quality %; The scope of monomer (b-3) is 35-94 quality % normally, preferred 45-90 quality %, especially 55-85 quality %.

Equally, the preferred amount ranges of unsaturated monomer that contains oh group is 3-30 quality %, particularly 5-25 quality % normally, based on monomer (b-1), (b-2) and total amount (b-3).

These monomers (b-1) (b-2) can be undertaken by known method itself with copolymerization (b-3), for example, are undertaken by the polymerisation in solution in organic solvent.Concrete, copolymerization by solution polymerization process can for example as get off to carry out: with monomer (b-1), (b-2) and mixture (b-3) dissolve with radical polymerization initiator or be dispersed in the organic solvent, and this solution or dispersion were under agitation heated about 1-10 hour at about 80 ℃-about 200 ℃ usually, finish polymerization.As the organic solvent that is used for such polymerisation in solution, preferably use the hydrophilic organic solvent of propane diols type for example or DPG type.

For favourable viscosity expression effect, this preferred amine value scope of resin (b) that contains uncle's amino group is 3-100mgKOH/g, particularly 10-80mgKOH/g, especially 15-60mgKOH/g normally.Aspect water-resistance property of coating and curing property, the resin (b) that contains uncle's amino group is preferred hydroxyl value scope 10-130mgKOH/g normally also, 20-100mgKOH/g particularly, especially 30-70mgKOH/g, and consider coating surface smoothness and the weatherability of filming that forms, its preferred number-average molecular weight scope is 500-20000, particularly 1000-10000, especially 3000-7000 normally.

The viscosity that monomer (b-1) composition that consists of the resin (b) that contains uncle's amino group helps to apply lacquer is expressed, this is cross-linked to form effect owing to itself and the vacation that contains the resin (a) of carboxylic group and oh group, monomer (b-2) composition that consists of the resin (b) contain uncle's amino group helps to form and has filming of excellent FINAL APPEARANCE, and this has suppressed the excessive formation of false cross-linked structure owing to it.

Can with the crosslinking agent (c) of oh group reaction:

There is not concrete restriction for the used crosslinking agent of the present invention (c), as long as it be a kind of can with the compound of oh group reaction, for example can be convenient to use following melamine resin, the polyisocyanate compound of end-blocking, polyisocyanate compound of water-dispersible end-blocking etc.

Melamine resin:

The concrete example of melamine resin comprises two-, three-, four-, five-and alkyl etherification product (example of alkyl comprises methyl, ethyl, propyl group, isopropyl, butyl, isobutyl group, 2-ethylhexyl etc.) and their condensation products of six-methylol melamine and they and alcohol.

The concrete example of melamine resin also comprises for example Nihon Cytec Industries, Inc. Cymel 303, Cymel 323, and Cymel 325, Cymel 327, Cymel 350, and Cymel 370, and Cymel 380, Cymel 385, Cymel 212, and Cymel 251, Cymel 254 and Mycoat 776 (all being trade (brand) name); The Regimin 735 of Monsanto Chemical Co, Regimin 740, and Regimin 741, and Regimin 745, Regimin 746 and Regimin 747 (all being trade (brand) name); The Sumimal M55 of Sumitomo Chemicals Co., Sumimal M30W and SumimalM50W (all being trade (brand) name); With Mitsui Chemicals, the U-VAN series of Inc. is U-VAN20SB (trade (brand) name) for example.

As melamine resin, preferably have at least 30 quality %, particularly at least 40 quality %, especially these resins of the monocaryon content of at least 45 quality %.Consider equally FINAL APPEARANCE and storage stability, melamine resin as the alkyl etherificate, the melamine resin methoxyl group etherificate or that methoxyl group-butoxy is complex etherified preferably, wherein methoxy group is a high proportion of, so that the molar ratio range of methoxy group and butoxy radicals (methoxy group/butoxy radicals) normally 100/0-60/40, particularly 100/0-70/30.The concrete example of such melamine resin comprises Cymel 325, and Cymel 327, and Cymel 350, and Cymel 212, and Cymel 251, Mycoat 212 and Mycoat 776 (all be trade (brand) name, by Nihon Cytec Industries, Inc. makes).

When melamine resin was used as crosslinking agent, sulfonic acid is p-methyl benzenesulfonic acid for example equally, DBSA, and dinonylnaphthalene sulfonic acid etc., perhaps these acid can be used as catalyst with salt of amine.

These melamine resins can use separately or two or more are used in combination.

The polyisocyanate compound of end-blocking:

The polyisocyanate compound of end-blocking is the polyisocyanate compound that has at least two free isocyanate group groups in each molecule, and its isocyanate groups carries out end-blocking with end-capping reagent.

The example of polyisocyanate compound that forms the polyisocyanate compound of such end-blocking comprises for example hexamethylene diisocyanate of aliphatic polyisocyante, trimethyl hexamethylene diisocyanate, dimer acid diisocyanate, LDI etc., and the biuret type addition product of these polyisocyanates and isocyanuric acid ester addition product; Alicyclic diisocyanate is IPDI for example, and 4,4 '-di-2-ethylhexylphosphine oxide (cyclohexyl isocyanate), hexahydrotoluene-2,4-or 2,6-vulcabond, 1,3-or Isosorbide-5-Nitrae-two (isocyanato-methyl) cyclohexane, Isosorbide-5-Nitrae-cyclohexane diisocyanate, 1,3-pentamethylene vulcabond, 1,2-cyclohexane diisocyanate etc., and the biuret type addition product of these polyisocyanates and isocyanurate ring addition product; The aromatic diisocyanates compound is eylylene diisocyanate for example, between eylylene diisocyanate, the tetramethyl eylylene diisocyanate, toluylene group diisocyanate, 4,4 '-methyl diphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1, the 4-naphthalene diisocyanate, 4,4 '-toluidines vulcabond, 4,4 '-diphenyl ether vulcabond, meta-or p-phenylene vulcabond, 4,4 '-diphenylene vulcabond, 3,3 '-dimethyl-4,4 '-diphenylene vulcabond, two (4-isocyanato-phenyl)-sulfones, isopropylidene two (4-phenyl isocyanate) etc., and the biuret type addition product of these polyisocyanates and isocyanurate ring addition product; The polyisocyanates that has at least three isocyanate groups in each molecule is triphenyl methane-4 for example, and 4 ', 4 "-triisocyanate; 1,3,5-, three isocyanato-benzene; 2,4,6-, three isocyanato-toluene; 4; 4 '-dimethyl diphenylmethane-2,2 ', 5; 5 '-tetraisocyanate etc., and the biuret type addition product of these polyisocyanates and isocyanurate ring addition product; As the carbamate addition product that gets off and form: with polyalcohol (ethylene glycol for example, propane diols, 1, the 4-butanediol, dihydromethyl propionic acid, PAG, trimethylolpropane, hexanetriol etc.) with polyisocyanate compound so that the ratio excessive with respect to the former oh group of the isocyanate groups among the latter reacted the biuret type addition product of these polyisocyanates and isocyanurate ring addition product.These polyisocyanate compounds can use separately or two or more are used in combination.

End-capping reagent is a kind of compound, its by with polyisocyanate compound in isocyanate groups react freely isocyanate groups of end-blocking.Usually such blocked polyisocyanates compound be when being heated to for example at least 100 ℃, preferably at least 130 ℃ the time, discharges end-capping reagent, regenerate freely, can with the isocyanate groups of oh group reaction.The reaction of end-capping reagent and polyisocyanate compound can be undertaken by known method itself.

The example of such end-capping reagent comprises for example phenol of phenolic compound, cresols, xylenols, nitrophenols, ethyl phenol, hydroxy diphenyl, butylphenol, isopropyl-phenol, nonyl phenol, octyl phenol, benzoic acid methyl hydroxy ester etc.; Lactams is epsilon-caprolactams for example, δ-valerolactam, butyrolactam, azetidinone etc.; Aliphatic alcohol is methyl alcohol for example, ethanol, propyl alcohol, butanols, amylalcohol, laruyl alcohol etc.; Ethers is the glycol monomethyl methyl ether for example, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diglycol monotertiary methyl ether, carbiphene, propylene glycol monomethyl ether, methoxyl group methyl alcohol etc.; Benzylalcohol; Glycolic; Ethyl glycolate is methyl glycollate for example, ethyl glycolate, butyl glycolate etc.; Lactic acid; Lactate is methyl lactate for example, ethyl lactate, butyl lactate etc.; Alcohols is methylolurea for example, methylol melamine, diacetone alcohol, HEA, HEMA etc.; Oximes is formamidoxime for example, acetylamino oxime, acetyl oxime, methyl ethyl ketoxime, diacetyl monoxime, benzene first oxime, hexamethylene oxime etc.; Active methylene group is dimethyl malenate for example, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, acetylacetone,2,4-pentanedione etc.; Mercaptan is butanethiol for example, tert-butyl mercaptan, hexyl mercaptans, uncle's lauryl mercaptan, 2-mercaptobenzothiazole, thiophenol, methyl thiophenol, ethyl thiophenol etc.; The acid amide-type is antifebrin for example, p-methoxyacetanilide, acetyl toluidine, acrylamide, Methacrylamide, acetamide, stearmide, benzamide etc.; Acid imide is succinimide for example, phthalimide, maleimide etc.; Amine is diphenylamines for example, phenyl naphthyl amines, xylidine, N-phenyl xylidine, carbazole, aniline, naphthylamine, butylamine dibutylamine, butyl phenyl amine etc.; Imidazolium compounds is imidazoles for example, 2-ethyl imidazol(e) etc.; Pyrazoles for example 3, the 5-dimethyl pyrazole; Carbamide compound is urea for example, thiocarbamide, ethylene urea, ethylene thiourea, diphenyl urea etc.; Carbamate is phenyl N-carbanilate for example; The imines class is aziridine for example, propyleneimine etc.; With sulphite sodium hydrogensulfite for example, potassium bisulfite etc.These end-capping reagents can use separately or two or more are used in combination.

The polyisocyanate compound of water-dispersible end-blocking:

Polyisocyanate compound as end-blocking, also can use these polyisocyanate compounds above-mentioned, their isocyanate groups is with the end-capping reagent end-blocking that contains the hydroxyl monocarboxylic acid, and they have been endowed water-dispersible by the carboxylic group in the polyisocyanate compound that is incorporated into this end-blocking, and this carboxyl is introduced by described hydroxyl monocarboxylic acid.

As end-capping reagent, can use to be similar to above-mentioned these.The example of hydroxyl monocarboxylic acid comprises the 2-glycolic acid, 3-hydracrylic acid, 12-hydroxyl-9-octadecanoid acid (castor oil acid), 3-hydroxyl-PA (hydroxy new pentane acid), dihydromethyl propionic acid (DMPA) etc.In these, 3-hydroxyl-PA (hydroxy new pentane acid) is preferred.The solvent that is used for end capping reaction is preferably with the isocyanate groups reaction, and therefore preferably for example ketone such as acetone, MEK etc.; The ester class is ethyl acetate for example; And 1-METHYLPYRROLIDONE (NMP).

When the polyisocyanate compound that uses end-blocking during as crosslinking agent, can use for the catalyst that accelerates urethane reaction organo-tin compound for example.

In primary coat lacquer (A), resin (a), the preferred content ratio of resin (b) and crosslinking agent (c) is: based on the total solids content of these three kinds of compositions, the scope of resin (a) is 20-80 quality % normally, particularly 30-70 quality %, especially 40-60 quality %; The scope of resin (b) is 5-35 quality %, particularly 10-30 quality % normally, especially 15-25 quality %; And the scope of crosslinking agent (c) normally 15-45 quality %, particularly 20-40 quality %, especially 25-35 quality %.

Thin polymer beads (d):

Primary coat lacquer (A) can further comprise thin polymer beads (d) and improve thickening effect and anti-rear viscosity.As thin polymer beads (d), it for example is such polymer beads, it is to comprise in the presence of the reactive emulsifier of allyl group, emulsion polymerisation by monomer (d-1) and other unsaturated monomers (d-2) obtains, and comprises at least two unsaturated groups in each molecule of this monomer (d-1).Thin polymer beads so for example is disclosed among JP Hei 3 (1991)-66770A.

As the monomer (d-1) that comprises at least two unsaturated groups in each molecule, what can mention is the unsaturated monocarboxylic ester of for example polyalcohol, the unsaturated alcohol ester of polyacid, and the aromatic compounds that replaces with at least two unsaturated groups.Concrete example comprises ethylene glycol diacrylate, GDMA, dimethacrylate triethyleneglycol ester, dimethacrylate tetraethylene glycol ester, dimethacrylate 1,3-BDO ester, trimethylolpropane triacrylate, trimethylol-propane trimethacrylate, diacrylate 1, the 4-butanediol ester, diacrylic acid pentyl diol ester, diacrylate 1,6-hexylene glycol ester, the diacrylate pentaerythritol ester, pentaerythritol triacrylate, pentaerythritol tetracrylate, the dimethacrylate pentaerythritol ester, trimethyl acrylic acid pentaerythritol ester, pentaerythritol tetramethacrylate, dimethyl allene acid glyceride, glycerol diacrylate, glycerine allyloxy dimethylacrylate, 1,1,1-trihydroxy-methyl ethane diacrylate, 1,1,1-trihydroxy methyl ethane triacrylate, 1,1,1-trihydroxy methyl ethane dimethylacrylate, 1,1,1-trihydroxy-methyl ethane trimethyl acrylic ester, 1,1,1-trihydroxy methyl propane diacrylate, 1,1,1-trihydroxy methyl propane triacrylate, 1,1,1-trihydroxy methyl propane dimethylacrylate, 1,1,1-trihydroxy methyl propane trimethyl acrylic ester, cyanuric acid alkatriene propyl diester, isocyanuric acid triallyl ester, the trimellitic acid triallyl ester, diallyl terephthalate, diallyl phthalate, divinylbenzene etc.These monomers can use separately or two or more common uses.

As other unsaturated monomers (d-2), can similarly use these unsaturated monomers that contains carboxylic group (M-1), contain the unsaturated monomer (M-2) of oh group and such as the resin (a) that contains carboxylic group and oh group but as shown in other copolymerization unsaturated monomers (M-3) of example.Equally, also can use for example (methyl) acrylic acid dimethyl aminoethyl ester of nitrogenous alkyl (methyl) acrylate; Diolefin compound is butadiene for example, isoprene etc.; With the monomer that contains alkoxysilane groups vinyltrimethoxy silane for example, VTES, vinyl three (2-methoxy ethoxy) silane, γ-methacryloxypropyl-trimethoxy silane, vinyltriacetoxy silane etc.These monomers can use separately or two or more are used in combination.

Top monomer (d-1) and usage ratio (d-2) do not have strict restriction, but be variable according to the desired physical property of this thin polymer beads, it can be such scope based on monomer (d-1) and total amount (d-2), namely, the scope of monomer (d-1) is 1-60 quality % normally, preferred 1-50 quality %, especially 1-40 quality %, the scope of monomer (d-2) is 40-99 quality % normally, preferred 50-99 quality %, especially 60-99 quality %.

Monomer (d-1) and copolymerization (d-2) can be undertaken by emulsion polymerisation, and the instrument (means) that its use itself is known in the presence of the reactive emulsifier that comprises allyl group, carries out with polymerization initiator.Comprise the reactive emulsifier of allyl group as this, can use any anion, cation or non-ionic reaction emulsifying agent, as long as they are the reactive emulsifiers that comprise allyl group, particularly preferably be the reactive emulsifier that comprises the anion allyl group.The object lesson that comprises the reactive emulsifier of anion allyl group comprises the ammonium salt of the sulfoacid compound that contains allyl group, concrete, it for example is anion emulsifier, its basic structure is the polyoxyethylene alkyl ether sulfate, and the part of the polymerisable allyl group of free radical as its hydrophobic grouping is incorporated into wherein.As so commercially available emulsifying agent, what can mention for example is Aqualon KH-10 (trade (brand) name, Daiichi Kogyo Seiyaku Co., Ltd.), Latemul S-180A (trade (brand) name, Kao Corporation), SR-1025 (trade (brand) name, AsahiDenka Co., Ltd.) etc.

With respect to monomer (d-1) and total amount (d-2), the enough usage ratio of reactive emulsifier is 0.1-10 quality % normally, preferred 1-5 quality %.

In required part, can will be different from the anion surfactant of top reactive emulsifier, non-ionic surface active agent, zwitterionic surfactant etc. simultaneously as emulsifying agent.Concrete example comprises: as anion surfactant be aliphatic acid, alkyl sulfate, alkylbenzenesulfonate, alkylphosphonic etc.; As non-ionic surface active agent be poly suboxygen ethyl alkyl ether, poly suboxygen ethyl alkyl allyl ether, poly suboxygen ethyl derivative, sorbitan fatty acid esters, poly suboxygen ethyl sorbitan fatty acid esters, poly suboxygen ethyl alkylamine, alkyl alkanolamine etc.; Be alkyl betaine etc. as zwitterionic surfactant.Based on monomer (d-1) and total amount (d-2), the common scope of enough amounts of these optional emulsifying agents that add is 0.1-10 quality %, preferred 1-5 quality %.

As polymerization initiator, can should be mentioned that such as the peroxide by representatives such as ammonium persulfate, potassium peroxydisulfate, ammonium peroxide; " redox " initator, these peroxide are combined with for example sodium hydrogensulfite of reducing agent therein, sodium thiosulfate, rongalite (Rongalit), ascorbic acid etc.; With azo-compound for example 4,4 '-azo two (4-cyano butyric acid) etc.In these, the use that azo-compound, particularly water dissolvable azo amide compound can suit.The water-soluble azo amide compound itself is known (for example referring to JP Sho 61 (1986)-218618A, JPSho 61 (1986)-63643A), and the object lesson of commercially available prod comprises VA Series (trade (brand) name, Wako Pure Chemical Industries, Ltd.).

Based on monomer (d-1) and total amount (d-2), the common scope of the usage ratio of this polymerization initiator is 0.01-10 quality %, preferred 0.1-5 quality %.

In this emulsion polymerization process, the suitable concn scope of total unsaturated monomer is 0.1-50 quality % normally, preferred 0.5-30 quality %.

The reaction temperature of this emulsion polymerisation changes according to for example kind of used polymerization initiator, but it can be 60-90 ℃ usually, and normally 5-10 hour reaction time.

From the viewpoint of formed resistance to water of filming, the hydroxyl value scope of thin polymer beads (d) can be 0-70mgKOH/g usually, preferred 0-60mgKOH/g, especially 0-50mgKOH/g.Equally, consider water dispersible, this thin polymer beads (d) can have the acid number scope of 0-90mgKOH/g usually, preferred 0-70mgKOH/g, especially 0-50mgKOH/g.This thin polymer beads (d) can have following particle size range in addition: 10-500nm normally, preferred 20-250nm, especially 30-150nm.

In this manual, grain diameter measurement is to carry out with COULTER N4 type submicron particles analyzer (Nikkaki Bios Co., Ltd.).

In the needs part, thin polymer beads (d) can neutralize with alkali compounds.As the nertralizer that is used for this thin polymer beads (d), can similarly use these neutralizations to contain the alkaline matter shown in the resin (a) of carboxylic group and oh group.

The preferred amount ranges of thin polymer beads (d) is 0-40 quality %, particularly 0-30 quality %, especially 0-20 quality % normally, based on resin (a), and the total solids content of resin (b) and crosslinking agent (c).

Primary coat lacquer (A) can pass through above-mentioned resin (a), resin (b), and crosslinking agent (c) and optional thin polymer beads (d) mix to prepare with solvent.

Primary coat lacquer (A) can be water base or the hydrophilic organic solvent base, but common preferably hydrophilic organic solvent base.

In this manual, hydrophilic organic solvent represents such organic solvent, and it can dissolve 20g at least in the water of 100g.

As this hydrophilic organic solvent, for example can use the ester class, ethers, alcohols, amide-type and the ketones solvent that satisfy above-mentioned condition.These hydrophilic organic solvents can use separately or two or more are used in combination.Concrete, such hydrophilic organic solvent is the ethylene glycol monomethyl ether acetate for example, the diethylene glycol (DEG) monomethyl ether acetate, diethylene glycol monoethyl ether acetate ， diox, the glycol monomethyl methyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diglycol monotertiary methyl ether, carbiphene, diethylene glycol diethyl ether, diglycol monotertiary butyl ether, propane diols list ethylether, DPGME, methyl alcohol, ethanol, allyl alcohol, normal propyl alcohol, isopropyl alcohol, the tert-butyl alcohol, ethylene glycol, 1,2-PD, 1, the 3-butanediol, 2,3-butanediol, hexylene glycol (hexyleneglycol), hexylene glycol (hexanediol), DPG, the use that acetone, diacetone alcohol etc. can be suitable.

Hydrophilic organic solvent also comprises hydrophilic organic solvent-water mixed system, and it is by forming with the above-mentioned hydrophilic organic solvent of the replacement of the parts such as deionized water.In such hydrophilic organic solvent-water mixed system, based on the total solvent that exists in the primary coat lacquer (A), this hydrophilic organic solvent usually enough proportions is 50-100 quality %; Water is 0-50 quality %.

Comprise in the situation of thin polymer beads (d) at primary coat lacquer (A), this thin polymer beads (d) can add when it is in the aqueous dispersion form, perhaps when this primary coat lacquer (A) is the hydrophilic organic solvent base, they can at first change into the form that is dispersed in the hydrophilic organic solvent, then add.The dispersion that the aqueous dispersion of thin polymer beads (d) changes in hydrophilic organic solvent can for example realize by following method, the method comprises solvent dimethylbenzene for example, butanols, butyl acetate, MEK, toluene etc. join in the aqueous dispersion of thin polymer beads (d), and the azeotropic by water and solvent dewaters, and should be dispersed in the hydrophilic organic solvent by thin polymer beads (d); Or such method, it comprises the water in the aqueous dispersion of thin polymer beads (d) is evaporated by spray drying system or simple drying, subsequently this particle is dispersed in the hydrophilic organic solvent again.

Pigment also can be blended in the primary coat lacquer (A).Here do not have concrete restriction for pigment, and the pigment below for example can being convenient to use: inorganic and organic coloring pigment is titanium dioxide for example, the flowers of zinc (zinc flower), carbon black, iron oxide red, phthalocyanine blue, Prussian blue, cobalt blue, AZOpigments, phthalocyanine color, quinoline Azone pigment, isoindoline pigment, vat pigment is with perylene dye; Filler is talcum for example, clay, and kaolin, heavy soil, barium sulfate, brium carbonate, calcium carbonate, silica and aluminium are white; With effect pigment aluminium powder for example, mica powder, the mica powder of coated by titanium dioxide, micaceous iron-ore, silver-plated glass flake, the graphite that titanium coats, metal titanium sheet, phthalocyanine thin slice etc.These pigment can use separately or two or more are used in combination.

Based on resin (a), the total solids content of resin (b) and crosslinking agent (c), the enough common scopes of mixed proportion of pigment are 0-250 quality %, particularly 0.1-150 quality %.

In required part, primary coat lacquer (A) is can be further suitable is mixed with for example curing catalysts of different oil paint additives, dispersant, sagging inhibitor, defoamer, thickener, UV absorbent, light stabilizer, surface conditioner, antioxidant etc.

Concentration common scope when it applies of the involatile constituent in the primary coat lacquer (A) can be 20-65 quality %, preferably take the high solids content type, organic solvent content is lowered therein, and the concentration of involatile constituent is adjusted in the following scope: 30-60 quality % normally, 40-60 quality % particularly comes air conservation and economizes on resources.

Primary coat lacquer (A) single film normally painted and opaque or painted and transparent solid tone or metal tone.Here opaque filming represents a kind of filming, and its transmittance percentage is less than 5%, and it is to measure at the thick cured coating film of 20 μ m of being made separately by this primary coat lacquer; And transparent filming to be a kind of transmittance percentage be 5% or higher filming, it is to measure at the thick cured coating film of 20 μ m of being made separately by this primary coat lacquer.

Apply object

The coating object that method of the present invention is applied thereon does not have concrete restriction, and for example can use for example cold-rolled steel sheet of steel plate, galvanized steel plain sheet, galvanized alloy steel plate, corrosion resistant plate and tin plate; Metallic substrates is aluminium sheet and aluminium alloy plate for example; With different plastic materials.They also can be the car bodies of different vehicle, automobile for example, sulky vehicle and by its container car that forms.

This coating object also can be the metal surface of metallic substrates or car body, and it has carried out for example phosphate treated of surface treatment, and chromate is processed or complex oxide is processed.

In addition, apply object and can be endowed in advance priming coat (for example cationic electrodeposition coating), and according to occasion, can need part to apply for example floating coat of other coating.

The method according to this invention at first applies primary coat lacquer (A) paint on the object.Applying usually of (A) of primary coat lacquer can be finished by following step: use such as retarder thinner etc. the coating viscosity of primary coat lacquer (A) to be adjusted to be generally 13-60s, preferred 15-40s, this viscosity uses No. 4 Ford cups to measure at 20 ℃, and rely on such means such as aerial spraying, airless spraying, rotary-atomizing coating etc. to apply this primary coat lacquer, optional uses electrostatic coating in required part, reach following curing thickness: normally about about 25 μ m of 5-, particularly about about 20 μ m of 10-.Therefore formed bottom coating (A) is not cured by heating, and optional it is being placed the about 1-20 of environment temperature minute or further after surperficial about 3-10 minute in about about 80 ℃ of preheating this coating of 60-, in required part, on the surface with this uncured coating of water base colored paint (B) paint.

Water base colored paint (B)

Water base colored paint (B) is a kind of water fluid lacquer, it will be coated with on the surface of uncured primary coat lacquer (A) by paint, this colored paint can pass through binder resin (B-1) usually, crosslinking agent (B-2) and coloring pigment (B-3) are sneaked into, and are dispersed in water to prepare.

As binder resin (B-1), for example can should be mentioned that the acrylic resin that contains carboxylic group and oh group, contain mylar of carboxylic group and oh group etc.

From the viewpoint of water dispersible, the preferred acid number scope of binder resin (B-1) is 10-150mgKOH/g, particularly 30-100mgKOH/g normally.Consider curing, the preferred hydroxyl value scope of this binder resin (B-1) is 10-150mgKOH/g, particularly 30-100mgKOH/g normally.Further contemplate weatherability, as the preferred number-average molecular weight scope of the acrylic resin of binder resin (B-1) normally 3000-100000, particularly 5000-50000; And mylar is 500-50000 normally, particularly 3000-30000.

As binder resin (B-1), can similarly use these resins described in the resin that contains carboxylic group and oh group (a) used in the primary coat lacquer (A).As acrylic resin, also can use in the presence of the aqueous solution of dispersion stabilizer equally these that produce by emulsion polymerisation.The preferred number-average molecular weight of such acrylic resin of producing by emulsion polymerisation is 100000 usually at least, particularly the scope of 200000-2000000.

As dispersion stabilizer useful in this emulsion polymerisation, except non-ionic surface active agent or anion surfactant, can be convenient to use water-base resin for example acid number be that 10-150mgKOH/g and number-average molecular weight are the acrylic resins of 5000-30000.

This emulsion polymerisation can be undertaken by these known means own.Concrete, preferably by the multistage polymerization method, with the acrylic emulsion that uses the unsaturated monomer that contains carboxylic group to produce, this is can give the coating processability of water base colored paint excellence because of them.Namely, as the acrylic emulsion that gets off and obtain: polymeric monomer intermixture at first, this mixture does not comprise or comprises the unsaturated monomer that contains carboxylic group (usually being not more than 3 quality % of total monomer) seldom, then continue this polymerisation with a kind of monomer mixture, this monomer mixture is comprising the unsaturated monomer (the normally 5-30 quality % of total monomer) that contains carboxylic group, by with in the alkaline matter and show the viscosity development effect, provide to have for example water base colored paint of sag resistance of excellent coating processability, and therefore this colored paint is preferred.As the used alkaline matter of neutralization, can similarly use relevant described these alkaline matters of resin (a) with primary coat lacquer (A).Its common scope of enough consumptions is the 0.1-1.5 equivalent, and 0.3-1.2 equivalent particularly is with respect to the carboxylic group of the acrylic emulsion of producing by top multistage polymerization method.

As crosslinking agent (B-2), can use be selected from described in the crosslinking agent (c) of primary coat lacquer (A) these can with the crosslinking agent of oh group reaction at least a.

Binder resin (B-1) and the suitable usage ratio of crosslinking agent (B-2) are: based on the total amount of two kinds of compositions, the scope of binder resin (B-1) is 50-90 quality %, particularly 60-85 quality % normally, especially 65-80 quality %; Crosslinking agent (B-2) is 10-50 quality %, particularly 15-40 quality % normally, especially 20-35 quality %.

Coloring pigment (B-3) is used to filming of photo tint primary colours lacquer (B), and this film can be painted with transparent, or painted with opaque.As such coloring pigment (B-3), can similarly use at described in the primary coat lacquer (A) these.Coloring pigment can use separately or two or more are used in combination.

Water base colored paint (B) can for example pass through binder resin (B-1), and crosslinking agent (B-2) and coloring pigment (B-3) are sneaked in the water and disperseed them to prepare.

Be similar to the situation of primary coat lacquer (A), as required, this water base colored paint can be further mixes with filler etc.In required part, use oil paint additive that can be suitable is curing catalysts for example equally, dispersant, sagging inhibitor, defoamer, thickener, UV absorbent, light stabilizer, surface conditioner, antioxidant etc.

Content common scope when it applies of preferred involatile constituent can be 15-65 quality % in the water base colored paint (B), and lacquer (B) single filming can be opaque or transparent solid tone or metal tone.Here the opaque expression of filming is a kind of by filming that this water base colored paint is made separately, its transmissivity % when its cured thickness is 20 μ m less than 5%, and transparent filming is a kind of film, and transmissivity % thereon is that 20 μ m are 5% at least at its cured thickness.

This water base colored paint (B) is applied to primary coat and coats with lacquer on the uncured coating surface of (A), in required part, primary coat lacquer (A) placed environment temperature 1-20 minute, and equally in required part, its further in about 60 ℃ of one about 80 ℃ of preheating about 3-10 minute.

Applying of water base colored paint (B) can be generally 15-60s adjusting to 20 ℃ of coating viscosity with it with No. 4 Ford cups for example, after the preferred 20-50s, rely on such means such as aerial spraying, airless spraying, rotary-atomizing coating etc. to carry out, carry out under electrostatic interaction in required part, reach following curing thickness: about about 40 μ m of 5-, particularly about about 35 μ m of 10-.

The method according to this invention on the uncured coating surface of water base colored paint (B) paint with primary coat lacquer (A), then applies the colored varnish (C).But, in required part, applying the colored varnish (C) before, can carry out drying in about about 100 ℃ temperature of 50-in advance by primary coat lacquer (A) and formed two coating films of water base colored paint (B).By this predrying, evaporated in this two coating film for example organic solvent of most volatile ingredient, water etc.

Because this is filmed dry by the volatilization of the volatile ingredient under predrying and solidifies, therefore on the surface that the colored varnish (C) paint should be applied, and be included in become the to grade infiltration and when being diffused in described two coating films of solvent in this transparent coating, low-molecular-weight resin, can suppress the reduction of this two coating films viscosity.As a result, when using metallic pigments, can suppress flowing again of metallic pigments, prevent the appearance that metal is inhomogeneous.

The colored varnish (C)

As the colored varnish (C), can use to be generally used in the car paint these, for example, contain the organic solvent based or water based transparent lacquer of compositions of thermosetting resin.The such compositions of thermosetting resin that is used for this colored varnish comprises for example such composition, it comprises having for example binder resin acrylic resin for example of hydroxyl of crosslinkable functionality, mylar, carbamate resins etc., with crosslinking agent melamine resin for example, (end-blocking) polyisocyanate compound etc.; And acid-epoxy cross-linking resin combination, it is comprising the resin that contains acid groups and is containing the resin of epoxide group as constituent.As the colored varnish, from reducing the viewpoint of solvent, the water base type of use that can be favourable.

In addition, in the colored varnish (C), coloring pigment, filler pigment etc. can use with the degree that does not weaken the transparency.As such coloring pigment and filler pigment, for example can use at described in the primary coat lacquer (A) these.This coloring pigment and filler pigment can each use separately or two or more are used in combination.

In required part, the colored varnish (C) is can be further suitable comprises such oil paint additive, curing catalysts for example, defoamer, thickener, UV absorbent, light stabilizer, antioxidant, surface conditioner, dispersant, sagging inhibitor etc.

The concentration of the preferred involatile constituent of the colored varnish (C) when it applies usually in the scope of 30-70 quality %.

The colored varnish (C) is coated to by on primary coat lacquer (A) and formed two coating films of water base colored paint (B).

The colored varnish (C) is after adjusting to it enough coating viscosity with solvent and/or water, and these known methods of dependence itself apply, such as airless spraying, aerial spraying, rotary-atomizing coating etc.Its coating can be carried out under electrostatic interaction.Suitable coating thickness is based on the normally about about 50 μ m of 25-of cured coating film, and in is special, approximately the scope of the about 45 μ m of 30-.

After the coating of the colored varnish (C), will be coated with lacquer by primary coat (A), water base colored paint (B) and the colored varnish (C) are formed three-layer coated by heating curing simultaneously, form multilayer film.

After the colored varnish (C) applies and before carrying out heat cure, in required part, this three-layer coated can be in advance at about the about 100 ℃ of about 1-10 of drying of 50-minutes, accelerate the volatilization of volatile ingredient main in the filming of the colored varnish (C).This predrying vapored away this three-layer coated in existing most of volatile ingredient organic solvent for example, water etc.

Three-layer coated heat cure can be by being typically about about 180 ℃ of 100-, and preferably approximately the about 170 ℃ temperature of 120-heated usually approximately 5-60 minute, realized in preferably approximately 10-40 minute.

In the method for the invention, heating and optional predrying can being undertaken by known heater itself.Concrete, they can be with drying box air oven for example, electric dry oven, and infrared induction heated oven etc. carries out.

Above-mentioned method of forming layered coating film can reduce solvent load and shorten procedure of processing, and provides even also show excellent coating processability and the multilayer film of FINAL APPEARANCE in super-humid conditions.What therefore the method can be favourable is applied in the middle japanning and finish paint coating step of automobile coating as method of forming layered coating film.

Explain more specifically the present invention below with reference to work embodiment and Comparative Examples, be to be understood that to the invention is not restricted to this." part " hereinafter and " % " are always take quality as unit, and the thickness of filming is always based on filming of solidifying.

Embodiment

Contain the manufacturing of the acrylic resin (a) of carboxylic group and oh group

Routine 1-4 is executed in manufacturing

Pack in the four neck flasks that are equipped with agitator, thermometer, cooling tube and nitrogen inlet 37.5 parts isopropyl alcohol, then at nitrogen by lower, its temperature is elevated to 85 ℃.Reach after 85 ℃ at it, stop nitrogen gas supply, and dropwise added each monomer mixture in this flask in 3 hours, this mixture has the blending constituent of the monomer shown in the following table 1 and polymerization initiator.(this system has adopted weak counterflow condition in the starting stage that dropwise adds, but along with the continuation that dropwise adds, has stopped this counterflow condition.) with this reaction system when nitrogen passes through, 85 ℃ aging other 2 hours, and be cooled to 60 ℃.Dilute this product with 29 parts methoxypropanol, having obtained solid content is the solution of the acrylic resin that contains respectively carboxylic group and oh group (a-1)-(a-4) of 60 quality %.The solid masses concentration (%) of formed resin (a-1)-(a-4) solution and resin Parametric Representation are in following table 1.

In table 1, PLACCEL FM-3 is a kind of trade (brand) name (Daicel Chemical Industries Ltd.) of methacrylic acid hydroxyethyl ester (the modification ratio is the 6-caprolactone that every mole of methacrylic acid hydroxyethyl ester uses 3mol) of 6-caprolactone modification.

Table 1

(annotating 1) polymerization initiator

Contain the manufacturing of the resin (b) of uncle's amino group

Make embodiment 5-7

Pack in the four neck flasks that are equipped with agitator, thermometer, cooling tube and nitrogen inlet 20 parts ethylene glycol monobutyl ether by lower, is elevated to 95 ℃ with its temperature at nitrogen.Reach after 95 ℃ at it, stop nitrogen gas supply, and dropwise added each monomer mixture in this flask in 3 hours, this mixture has the blending constituent of the monomer shown in the following table 2 and polymerization initiator.Then under nitrogen passes through, each product was worn out 2 hours at 95 ℃, be cooled to 60 ℃, with 15 parts ethylene glycol monobutyl ether dilution, it is the solution of the resin that contains respectively uncle's amino group (b-1)-(b-3) of 50 quality % that solid content is provided.The solid masses concentration (%) of formed resin (b-1)-(b-3) solution and resin Parametric Representation are in following table 2.

At table 2, MPEG2000MA (trade (brand) name) is a kind of methoxy poly (ethylene glycol) 2000 methacrylates, (trade (brand) name) is a kind of methoxy poly (ethylene glycol) 1000 methacrylates with MPEG 1000MA, and the two all is Degussa Japan Co., the monomer that Ltd. produces.The active component of MPEG2000MA is 50%.

Table 2

(annotating 2) polymerization initiator

The manufacturing of thin polymer beads (d)

Pack in the four neck flasks that are equipped with agitator, thermometer, cooling tube and mantle heater 355 parts of deionized waters and 4 parts of LATEMUL S-120A (trade (brand) name, the anionic reactive emulsifying agent that contains allyl group that a kind of sulfosuccinate is derived, KAO Corporation, solid content 50%), under agitation its temperature is elevated to 90 ℃.Then be added in 1.25 parts VA-086 (trade (brand) name in 50 parts the deionized water, a kind of water-soluble azo acid amides polymerization initiator, 2,2 '-azo two [2-methyl-N-(2-ethoxy)-propionamide], Wako Pure Chemical Industries, Ltd.) 20% the aqueous solution.After ten five (15) minutes, add 5% monomer mixture (48 parts styrene, 22 parts methyl methacrylate, the diacrylate 1 of 22 parts n-butyl acrylate and 8 parts, the mixture of 6-hexylene glycol ester), stirred subsequently 30 minutes.Then begin dropwise to add remaining monomer mixture and the remaining polymerization initiator aqueous solution.Divide other, dripping this monomer mixture needs 3 hours, and dripping the polymerization initiator aqueous solution needs 3.5 hours, and polymerization temperature is remained on 90 ℃ during this period.After the polymerization initiator aqueous solution is added dropwise to complete, this reactant mixture was worn out 30 minutes at 90 ℃.With this mixture cool to room temperature, and filter by 200 order nylon cloths, obtained a kind of thin polymer beads aqueous dispersion, it has 20% solid content.

Formed thin polymer beads aqueous dispersion is carried out drying at 60 ℃ in the stainless steel cask of electrothermal air drier dewater.Therefore the solid that obtains is dispersed in again solid content is provided in 60 ℃ of glycol monomethyl methyl ethers is the dispersion (d-1) of 20% thin polymer beads.

Be used for the manufacturing of aqueous dispersion of the acrylic resin (i) of water base colored paint (B)

Make embodiment 9

As get off to make the aqueous dispersion of acrylic resin (i), it is used for water base colored paint (B) as resin dispersion.

Pack in the reactor that is equipped with thermometer, self-operated thermostatic controller, agitator, reflux condenser and Dropping feeder 145 parts deionized water and 1.2 parts Newcol 562SF (annotating 3), in nitrogen stream with its Agitation and mixing.Be warmed up to 80 ℃, 3% ammonium persulfate aqueous solution of the monomer emulsions of the following total amount with 5% (1) and 5.2 parts joins in this reactor, and keeps 20 minutes at 80 ℃.

Then remaining monomer emulsions (1) was dropwise joined in this reactor aging 30 minutes subsequently in 3 hours.Then the monomer emulsions (2) below in 1.5 hours, dropwise adding.With aging 2 hours of this reactant mixture, and at 1.5% the N that adds gradually 89 parts, N-dimethyl ethanol amine aqueous solution was cooled to 30 ℃ in the process of this reactor.This reactant mixture is discharged by 100 purpose nylon cloths, obtain a kind of solid content and be the aqueous dispersion of 25% acrylic resin (i).The hydroxyl value of this acrylic resin (i) is 22mgKOH/g, and acid number is 30mgKOH/g, and particle mean size is 100nm.

(annotating 3) Newcol 562SF: trade (brand) name, Nippon Nyukazai Co., Ltd., poly suboxygen ethyl alkyl benzene sulphonate ammonium, active component, 60%.

Monomer emulsions (1): by under agitation with 94.3 parts of deionized waters, 17 parts methyl methacrylate, 80 parts n-butyl acrylate, the Newcol 562SF of 3 parts ALMA and 1.2 parts mixes to obtain monomer emulsions (1).

Monomer emulsions (2): by under agitation with 37.3 parts of deionized waters, 15.4 the methyl methacrylate of part, 2.9 the n-butyl acrylate of part, 5.9 the hydroxyethyl acrylate of part, 5.1 the methacrylic acid of part, 0.5 part Newcol 562SF and 1.7 parts 3% ammonium persulfate aqueous solution obtain monomer emulsions (2).

The manufacturing of primary coat lacquer (A)

Make embodiment 10

Pigment dispersion paste 1 is the acrylic resin (a-1) that obtains among 33.3 parts the manufacturing embodiment 1 by mixing, 1 part CARBON MA-100 (trade (brand) name, carbon black, Mitsubishi ChemicalCo.), 40 parts JR-806 (trade (brand) name, titanium white, Tayca Corporation), 25 parts BARIACEB-32 (trade (brand) name, barium sulfate, Sakai Chemical Industry Co., Ltd.), 1.6 the N of part, the ethylene glycol monobutyl ether of N-dimethylethanolamine and 24.1 parts obtains, and this mixture was disperseed in paint mixer 30 minutes.

Make embodiment 11

Repeat to make embodiment 10, provide pigment dispersion paste 2 except replacing with acrylic resin (a-2) solution acrylic resin (a-1) solution.

Make embodiment 12

Repeat to make embodiment 10, provide pigment dispersion paste 3 except replacing with acrylic resin (a-3) solution acrylic resin (a-1) solution.

Make embodiment 13

Repeat to make embodiment 10, provide pigment dispersion paste 4 except replacing with acrylic resin (a-4) solution acrylic resin (a-1) solution.

Make embodiment 14-20

The solution of the acrylic resin (a-1)-(a-4) that will in making embodiment 1-4, obtain, these that obtain in making embodiment 5-7 contain the resin (b-1)-(b-3) of uncle's amino group, the pigment dispersion paste 1-4 that in making embodiment 10-13, obtains, Cymel 325 (trade (brand) names, Mitsui Cytec Co., methylated melamine resin, solid content 80%), thin polymer beads (d-1) dispersion of making embodiment 8 and obtaining, and N, mixed proportion shown in the N-dimethylethanolamine following table 3 is mixed by stirring, and adds in addition the glycol monomethyl methyl ether and the viscosity of each mixture is adjusted at 20 ℃ is measured as 30s with No. 4 Ford cups.Therefore obtain primary coat lacquer (A-1)-(A-7).In each primary coat lacquer, use N, in the N-dimethylethanolamine and the neutralization equivalent of the carboxylic group in the acrylic resin (a) always 0.5.

Table 3

The manufacturing of water base colored paint (B)

Make embodiment 21

SETAL 6306 (the trade (brand) names that under agitation add 50 parts in 37.5 parts the Cymel 325 according to described order, Akzo Co., water-soluble polyester resin, solid content 60%) and make the aqueous dispersion of 160 parts the acrylic resin (i) that embodiment 9 obtains.Then under agitation adding aluminium pigment is the Alumipaste GX 180A (trade (brand) name, Asahi ChemicalIndustry Co., Ltd., flake aluminum paste) of 20 deals, and mixes and dispersion.Add other N, N-dimethylethanolamine and deionized water are adjusted into 8.0 with pH, and viscosity is adjusted at 20 ℃ and is measured as 30s with the No.4 Ford cup, and water base colored paint (B-1) is provided.

The formation of multilayer film (preparation of test sample plate)

Embodiment 1-6 and Comparative Examples 1

As get off to prepare test sample plate, each primary coat lacquer (A-1)-(A-7) that use obtains in making embodiment 14-20 is used as primary coat lacquer (A), and the water base colored paint (B-1) that obtains in making embodiment 21 is as water base colored paint (B).

In PALBOND#3020 (trade (brand) name, Nippon Parkerizing Co., a kind of zinc phosphate treatment agent) electroplates ELECRON GT-10 (trade (brand) name on the cold-rolled steel sheet that applies, Kansai PaintCo., a kind of cationic electrodeposition lacquer), and by being cured in 30 minutes 170 ℃ of heating, form thick the filming of 20 μ m.

Then with each primary coat lacquer (A-1) to (A-7) Minibell G (trade (brand) name, JapanRansburg Co., a kind of rotary atomizing electrostatic coating machine) under the condition of 25 ℃ of temperature and humidity 80%, applies to provide thick the filming of 20 μ m, the surface of this coating was placed 7 minutes, use REA (trade (brand) name thereon, Japan Ransburg Co., a kind of static air spraying coating machine) applying water base colored paint (B-1) provides thick the filming of 25 μ m, the surface of this coating was placed 3 minutes, and with them 70 ℃ of preheatings 5 minutes.This model was placed 6 minutes in addition, apply the colored varnish (C) (KINO#1200TW with Minibell G, trade (brand) name, Kansai Paint Co., the colored varnish in acid/curable epoxide type acrylic resin source, and its viscosity adjusted at 20 ℃ be measured as 25s with the No.4 Ford cup) the thick film of 35 μ m is provided.This sample was placed other 10 minutes, by they were solidified this in 30 minutes by primary coat lacquer (A) 140 ℃ of heating in the electrothermal air drying oven, the trilamellar membrane that water base colored paint (B-1) and the colored varnish (C) form provides test sample plate (multilayer film).

The performance test results

Therefore the test sample plate that obtains is carried out performance test.The result of this performance test is illustrated in the table 4 shown in the back.

Crack in the water-based coloring coating:

Be according to following standard in the crack of this middle appearance of filming afterwards applying water base filming (B), estimate by visualization:

Zero: the crack do not occur in this water-based coloring coating (metal deposit), it is good;

*: the crack occurred in this water-based coloring coating (metal deposit), it is poor;

Final outward appearance:

Wave Scan (trade (brand) name) with BYK Gardner measures, and it measures long wave value (LW) and shortwave value (SW).The long wave value is that a kind of wave-length coverage is the amplitude indication of the surface roughness of about 1.2-12mm, and can estimate the situation of the medium wave tissue on coat film surface.The shortwave value is that a kind of wave-length coverage is the amplitude indication of the surface roughness of about 0.3-1.2mm, and can estimate the situation of the microstructure on coat film surface.For these two kinds of Wave Scan values, lower measured value represents the smoothness that film coated surface is higher.As a kind of standard, the favourable coating surface smoothness of the SW value representation less than 15 of usually measuring with Wave Scan.

The IV value:

The IV value is to measure with laser metal effect measurement device (ALCOPE LMR-200, trade (brand) name, KansaiPaint Co.).IV is a kind of whiteness indication of metal deposit.The even degree of orientation of the metallic pigments parallel with coating surface is higher, and whiteness is higher, and metallic effect is better.The higher higher whiteness of IV value representation.

The metal inhomogeneities:

The degree that the metal inhomogeneities occurs in the test sample plate is estimated by visualization:

Zero: the metal inhomogeneities does not almost have;

△: few metal inhomogeneities is arranged;

*: many metal inhomogeneities are arranged.

Crush resistance:

Each test sample plate is installed on the test pieces, this test pieces is bearing in Suga TestInstruments Co., Ltd. slungshot tester JA-400Model (trade (brand) name, a kind of fragment testing arrangement) on, and the compressed air 0.392MPa (4kgf/cm that the granite of the crushing of the No.7 granularity of 50g is used ²,-20 ℃) blow on this coating surface.The damaged condition of filming that visualization causes thus, and estimate:

Zero: it is little to damage size, and plate surface or base steel sheet are not exposed;

△: it is little to damage size, but plate surface or base steel sheet are exposed;

*: it is quite large to damage size, and the base steel sheet large tracts of land is exposed.

Table 4

Claims

1. method that forms multilayer film, it comprises and the A paint is coated with lacquer in primary coat applies on the object, on the uncured coating surface that forms like this, apply in succession water base colored paint B and colored varnish C, then heating is solidified simultaneously this and is comprised the three-layer coated of primary coat lacquer A, colored paint B and colored varnish C, the method is characterized in that primary coat lacquer A comprises:

The resin a that contains carboxylic group and oh group;

The resin b that contains uncle's amino group, this resin contain by copolymerization that the unsaturated monomer b-1 of uncle's amino group, the nonionic unsaturated monomer b-2 that contains the polyoxyalkylene group and other unsaturated monomers b-3 obtain; With

Can with the crosslinking agent c of oh group reaction,

Wherein, monomer b-2 is the compound of following formula (1) representative:

CH ₂＝C(R ¹)COO(C _nH _2nO) _m-R ² (1)

R wherein ¹Represent hydrogen or methyl, R ²Represent hydrogen or C _1-4Alkyl, m are the integers of 4-60, and n is 2 or 3 integer, and wherein m oxygen alkylidene unit is C _nH _2nO can be identical or different.

2. according to claim 1 method, wherein resin a has the acid number scope of 2-100mgKOH/g and the hydroxyl value scope of 20-200mgKOH/g.

3. according to claim 1 method, wherein resin a is selected from the acrylic resin that contains carboxylic group and oh group, contains the mylar of carboxylic group and oh group and contain carboxylic group and the polyurethane resin of oh group.

4. according to claim 1 method, wherein monomer b-1 comprises N, and N-dialkyl group Diaminoalkyl (methyl) acrylate is as constituent.

5. according to claim 1 method, wherein resin b has the amine value scope of 3-100mgKOH/g and the hydroxyl value scope of 10-130mgKOH/g.

6. according to claim 1 method, wherein crosslinking agent c is selected from the polyisocyanate compound of melamine resin and end-blocking.

7. according to claim 1 method, wherein primary coat lacquer A comprises the resin b of resin a, 5-35 quality % of 20-80 quality % and the crosslinking agent c of 15-45 quality %, based on the total solids content of resin a, resin b and crosslinking agent c.

8. according to claim 1 method, wherein primary coat lacquer A further comprises the thin polymer beads of d, this thin polymer beads is in the presence of the reactive emulsifier that contains allyl group, emulsion polymerisation by monomer d-1 and other unsaturated monomers d-2 obtains, and comprises at least two unsaturated groups in wherein said each molecule of monomer d-1.

9. according to claim 8 method, wherein primary coat lacquer A comprises the thin polymer beads d that is no more than 40 quality %, based on the total solids content of resin a, resin b and crosslinking agent c.

10. according to claim 1 method, wherein primary coat lacquer A is the primary coat lacquer of hydrophilic organic solvent base.

11. the goods by any one described method coating among the claim 1-10.