Summary of the invention
The objective of the invention is to, a kind of cathode electrophoresis dope resin emulsion of low-temperature curing is provided,, can solidify and to give paint film ornamental at 120~140 ℃ with the paint film of the cathode electrophoresis dope of this resin emulsion preparation.
The technical scheme that realizes the object of the invention is: a kind of cathode electrophoresis dope resin emulsion of low-temperature curing, it is by modified epoxy 20~70%, polyamine 5~50% and can be at the blocked polyisocyanate 10~30% of 120~140 ℃ of complete deblockings, through chemical reaction and mixing, use again in the organic acid and after, dispersion is made in water, above percentage number average is with solid weight meter, wherein modified epoxy is epoxy compounds and polyol, under catalyst action, make with the Resins, epoxy synthetic method, molecular weight is 300~3000, its epoxy compounds is 5~8/2~5 with the pure solid weight ratio of polyol, described epoxy compounds is bisphenol A diglycidyl ether and glycidyl ether or the glycidyl ester that contains flexible chain, and described polyol is dihydroxyphenyl propane and the polyol that contains flexible chain.
Above-mentioned resin emulsion, as the glycidyl ether that contains flexible chain or the glycidyl ester of epoxy compounds, its weight is 5~50% of bisphenol A diglycidyl ether weight; As the polyol that contains flexible chain of polyol, its weight is 0~35% of dihydroxyphenyl propane weight.
Above-mentioned resin emulsion, the described glycidyl ether that contains flexible chain is neopentylglycol diglycidyl ether, butanediol diglycidyl ether, propylene glycol diglycidylether or ethylene glycol diglycidylether; The described glycidyl ester that contains flexible chain is tertiary carbonic acid glycidyl ester or Succinic Acid 2-glycidyl ester.
Above-mentioned resin emulsion, the described polyol that contains flexible chain are one or more in butyleneglycol, propylene glycol, hexylene glycol, a shrink ethylene glycol, butyl glycol ether, polypropylene glycol, polyoxyethylene glycol, polycaprolactone trivalent alcohol, the polycaprolactone dibasic alcohol.
Above-mentioned resin emulsion, described polyamine is the aliphatics amine, or the polycaprolactam polyamine class of modification, or both mixtures such as hexanediamine, diethylenetriamine, butanediamine, ketoimine, amino-polyether, polyamide resin, if select the modified polyamide resin, then the amine value is 50~500, is preferably 80~450.
Above-mentioned resin emulsion, described can be at the blocked polyisocyanate of 120~140 ℃ of complete deblockings, the encapsulant that is adopted is methyl ethyl ketoxime, methyl amylketone oxime, phenol, dimethyl pyrazole, diethyl pyrazoles, 1,2,4-triazole, diethyl malonate, acid amides alcohol, or their mixture.
Above-mentioned resin emulsion, described can be to adopt the Totally-enclosed-type of traditional method preparation or type semienclosed at the blocked polyisocyanate of 120~140 ℃ of complete deblockings, or both mixtures.Wherein used polyisocyanates can be an aliphatic polyisocyante, as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI); Can be alicyclic polyisocyanates, as 1,3-pentamethylene vulcabond, 1,4-cyclohexyl diisocyanate, isophorone diisocyanate; Can be aromatic polyisocyanate, as tolylene diisocyanate (TDI), PPDI, to the phenylmethane vulcabond; Also can be the polymkeric substance of polyisocyanates, as the tripolymer of tolylene diisocyanate, the tripolymer of hexamethylene diisocyanate; Can also be polyisocyanate prepolymers, as the toluene diisocyanate prepolymer of TriMethylolPropane(TMP), the PPDI of polyoxyethylene glycol.
When the preparation modified epoxy, catalyst system therefor is benzyldimethylamine, 2-ethyl-4-methylimidazole or phosphines.Its consumption is 0.03~1% of a reactant gross weight, and temperature of reaction is 130~180 ℃, and the reaction times is 1~3 hour.
When preparation resin emulsion of the present invention, neutralization is lactic acid or acetic acid with organic acid.
Resin emulsion of the present invention has following characteristic index:
(1) solid content: 32~40%;
(2) tank liquor temperature: 25~35 ℃;
(3) construction voltage: 50~400V;
(4) film curing temperature: 120~140 ℃/30min of workpiece temperature.
Technique effect of the present invention: after adopting technical scheme of the present invention, since resin emulsion be adopt 120~140 ℃ fully the blocked polyisocyanate made of the encapsulant of deblocking make solidifying agent, and traditional pure ethers encapsulant such as ethylene glycol ethyl ether, butyl glycol ether etc., its complete deblocking temperature is at 170~180 ℃, though the complete deblocking temperature of hexanolactam is low slightly, but still need 160 ℃.Encapsulant of the present invention is getting final product complete deblocking below 140 ℃.Therefore, but with the formed paint film of cathode electrophoresis dope of such resin emulsion preparation 120~140 ℃ of completely solidified.In addition, for guaranteeing to have good levelling property at 120~140 ℃ of solidified paint films, determined modified epoxy in the technical solution of the present invention, by selected epoxy compounds and polyol and ratio thereof, control the molecular weight of modified epoxy, wherein in epoxy compounds and polyol, contain an amount of composition that contains flexible chain, make after the resin emulsion film forming, at the dry film that 120~140 ℃ of curing obtain, still have good ornamental.
Embodiment
Below in conjunction with embodiment the present invention is further described in detail, but is not limited to this.
Embodiment 1
One, preparation modified epoxy A
1, prescription sees Table 1
Table 1
Component | Raw material | Consumption (g) |
Title | Specification |
Epoxy compounds | GY 2600 (bisphenol A diglycidyl ether) | Epoxy equivalent (weight) 187, Ciba company produces | 140 |
Cardura E-10 (tertiary carbonic acid glycidyl ester is as the glycidyl ester that contains flexible chain) | Epoxy equivalent (weight) 250, Shell company produces | 13.4 |
Polyol | Dihydroxyphenyl propane | Commercially available, industrial goods | 51 |
Polyethers 204 (polypropylene glycol is as the polyol that contains flexible chain) | Hydroxyl equivalent 200, the DOW chemistry produces | 15 |
Wherein: epoxy compounds/polyol weight ratio equals 6.97/3; The weight that contains the glycidyl ester of flexible chain is 9.5% of bisphenol A diglycidyl ether; The weight that contains the polyol of flexible chain is 29% of dihydroxyphenyl propane. |
2, technological operation
In a four-hole boiling flask that is equipped with agitator, prolong, logical nitrogen pipe, thermometer, add 15g polyethers 204,140gGY2600 and 13.4gCardura E-10, also logical nitrogen in the presence of 0.2g benzyl dimethyl amine catalyst and 15g xylene solvent, be heated to 150 ℃, be incubated 2 hours, and then adding dihydroxyphenyl propane 51g, continuation was 150 ℃ of reactions 4 hours, cooling at last, add solvent ethylene glycol dibutyl ether 45g, propylene glycol phenylate 10g makes solid and is divided into 80% modified epoxy A, epoxy equivalent (weight) was 784 (not containing solvent), and is standby.
Two, preparation blocked polyisocyanate A-I
1, prescription sees Table 2
Table 2
Component | Raw material | Consumption (g) |
Title | Specification |
Polyisocyanates | HDT-90 (hexamethylene diisocyanate trimer) | Rhodia produces (NCO content 19.8%) | 100 |
Encapsulant | Methyl ethyl ketoxime | Commercially available, industrial goods | 54 |
Catalyzer | Dibutyl tin laurate | Commercially available, industrial goods | 0.2 |
Solvent | Hexone | Commercially available, industrial goods | 10 |
Propylene glycol monomethyl ether | Commercially available, industrial goods | 16 |
2, operating procedure
In a there-necked flask that is equipped with agitator, prolong, thermometer, add HDT-90 100g, hexone 10g, dibutyl tin laurate 0.2g, under 50 ℃, drip methyl ethyl ketoxime 54g then, dropwised in 2~3 hours, be warming up to 90 ℃ of insulations 2 hours with dropping funnel, cooling at last, add propylene glycol monomethyl ether 16g, make Totally-enclosed-type polyisocyanates A-I, discharging, standby, its solid is divided into 80%, and isocyanurate equivalent is 382.
Three, preparation resin emulsion A
1, prescription sees Table 3
Table 3
Component | Raw material | Consumption |
Title | Specification | Weight (g) | With the shared per-cent of solid weight meter (%) |
Modified epoxy (A) | The present embodiment self-control | Solids constituent 80% epoxy equivalent (weight) is 784 | 200 | 68.6 |
Polyamine | Diethanolamine | Commercially available, industrial goods | 12 | 5.1 |
Hexanediamine | Amine equivalent 58 is commercially available, industrial goods | 5.2 | 2.3 |
Blocked polyisocyanate (A-I) | The present embodiment self-control | Solids constituent 80% isocyanurate equivalent 382 | 70 | 24.0 |
2, operating procedure
Modified epoxy (A) 200g is joined 1000ml be equipped with in the there-necked flask of agitator, prolong, thermometer, be heated to 100 ℃, add diethanolamine 12g, 110 ℃ were reacted 2 hours, were cooled to 80 ℃ then, added hexanediamine 5.2g, 110 ℃ of reactions were cooled to 80 ℃ after 2 hours.Add blocked polyisocyanate (A-I) 70g, fully mixed 2 hours, add organic acid lactic acid 15g neutralization then at 80 ℃, continue to stir after 30 minutes, after adding deionized water 429g dispersion, form the cathode electrophoresis dope resin emulsion A of low-temperature curing, its solid is divided into 34.4%.
Four, resin emulsion A service check
Resin emulsion A mixed being made into varnish with deionized water by 4: 5 (weight ratio),,, under the construction voltage 200V, model is carried out electrophoretic painting 25 ℃ of tank liquor temperatures as the ability cathode electrophoresis tank liquor.The gained model was 120~140 ℃ of bakings 30 minutes after the application.Detecting model thickness by national standard method is 20~28 μ m; The visual inspection paint film, the outward appearance light is fine and smooth smooth, not xanthochromia; Film curing is (the two-way wiping of acetone is not seen loss of gloss 50 times) fully.
Embodiment 2
One, preparation modified epoxy B
1, prescription sees Table 4
Table 4
Component | Raw material | Consumption (g) |
Title | Specification |
Epoxy compounds | GY2600 (bisphenol A diglycidyl ether) | Epoxy equivalent (weight) 187 Ciba companies produce | 150 |
Neopentylglycol diglycidyl ether (glycidyl ether that contains flexible chain) | Epoxy equivalent (weight) 142 is commercially available, industrial goods | 10 |
Polyol | Dihydroxyphenyl propane | Commercially available, industrial goods | 50 |
Wherein: epoxy compounds/polyol weight ratio equals 6.40/2; The weight that contains the glycidyl ether of flexible chain is 6.67% of bisphenol A diglycidyl ether; Do not add the polyol that contains flexible chain in the polyol; |
2, operating procedure
In a four-hole boiling flask that is equipped with agitator, prolong, logical nitrogen pipe, thermometer, add 10g neopentylglycol diglycidyl ether, 50g dihydroxyphenyl propane, 0.1g catalyzer benzyl dimethyl amine and 15g solvent xylene, under the situation of logical nitrogen, be heated to 150 ℃, be incubated 2 hours, be cooled to 100 ℃ then, add 150gGY2600, reacted 4 hours down at 150 ℃, cooling adds solvent propylene glycol monomethyl ether 37.5g, make the modified epoxy B of solids constituent 80%, epoxy equivalent (weight) was 484 (not containing solvent), and is standby.
Two, preparation blocked polyisocyanate B-I
1, prescription sees Table 5
Table 5
Component | Raw material | Consumption (g) |
Title | Specification |
Polyisocyanates | TDI (tolylene diisocyanate) | Commercially available, industrial goods | 174 |
Encapsulant | Methyl ethyl ketoxime | Commercially available, industrial goods | 87 |
Catalyzer | Dibutyl tin laurate | Commercially available, industrial goods | 0.5 |
Solvent | Hexone | Commercially available, industrial goods | 29 |
2, operating procedure
In flask, add TDI 174g, hexone 29g, dibutyl tin laurate 0.5g drips methyl ethyl ketoxime 87g with dropping funnel under 30~40 ℃, dropwised in 3 hours, makes type semienclosed polyisocyanates B-I, and sealing is stored, and is standby.Solid is divided into 90%, and isocyanurate equivalent is 145.
Three, preparation blocked polyisocyanate B-II
1, prescription sees Table 6
Table 6
Component | Raw material | Consumption (g) |
Title | Specification |
Polyisocyanates | TDI (tolylene diisocyanate) | Commercially available, industrial goods | 174.0 |
Encapsulant | Methyl ethyl ketoxime | Commercially available, industrial goods | 87.0 |
Glycol ether | Commercially available, industrial goods | 42.4 |
PLACCEL-205 (poly-own interior pure dibasic alcohol) | Japan Daicel company produces hydroxyl equivalent 265 | 53.0 |
Catalyzer | Dibutyl tin laurate | Commercially available, industrial goods | 0.3 |
Solvent | Hexone | Commercially available, industrial goods | 20.0 |
Propylene glycol monomethyl ether | Commercially available, industrial goods | 69.0 |
2, operating procedure
In flask, add TDI 174g, hexone 20g, dibutyl tin laurate 0.3g drips methyl ethyl ketoxime 87g down at 36~40 ℃, be warming up to 80 ℃ of insulations 1 hour then, add glycol ether 42.4g then, react after 1 hour, add poly-own interior pure dibasic alcohol 53g again, continue reaction 2 hours, cooling adds propylene glycol monomethyl ether 69.0g, makes Totally-enclosed-type polyisocyanates B-II discharging, standby.Solid is divided into 80%, and isocyanurate equivalent is 445.
Four, preparation resin emulsion B
1, prescription sees Table 7
Table 7
Component | Raw material | Consumption |
Title | Specification | Weight (g) | With the shared per-cent of solid weight meter (%) |
Modified epoxy (B) | The present embodiment self-control | Solids constituent 80% epoxy equivalent (weight) 484 | 200 | 50.5 |
Polyamine | Diethanolamine | Commercially available, industrial goods | 23.9 | 7.5 |
Polyetheramine JeffamineD-2000 | HUNTSMAN company produces, amine equivalent 1000 | 76.1 | 24.0 |
Blocked polyisocyanate | Present embodiment self-control B-I | Solids constituent 90% (isocyanurate equivalent 145) | 10.0 | 2.8 |
Present embodiment self-control B-II | Solids constituent 80% (isocyanurate equivalent 445) | 60.0 | 15.2 |
2, operating procedure
With above-mentioned modified epoxy (B) 200g, join 1000ml and be equipped with agitator, prolong, in the there-necked flask of thermometer, be heated to 100 ℃, add diethanolamine 23.9g, 110 ℃ were reacted 2 hours, be cooled to 90 ℃ and add polyetheramine JeffamineD-2000 76.1g, 80~90 ℃ of insulation reaction 3 hours add type semienclosed polyisocyanates B-I 10g, 75~80 ℃ of reactions 1 hour, add Totally-enclosed-type polyisocyanates B-II 60g again, thorough mixing adds lactic acid 20g neutralization after 1 hour, add deionized water 542g after 15 minutes, disperse the back to form the cathode electrophoresis dope resin emulsion B of low-temperature curing, its solid is divided into 34.8%.
Five, resin emulsion B service check
Press same procedure check among the embodiment 1, the gained result is with identical with resin emulsion A.
Resin emulsion of the present invention cooperates also with the pigment slurry that suits can make colored paint.The condition application of adopting the cathode electro-coating method to press embodiment 1, the gained paint film toasted 30 minutes down at 120~140 ℃, and paint film fully solidifies (the two-way wiping of acetone is not seen loss of gloss 50 times), and the outward appearance light is fine and smooth, not xanthochromia.