JPS58113264A - Aqueous coating composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aqueous coating compositions containing sequestered isocyanate crosslinkers. More particularly, the present invention relates to aqueous coating compositions suitable for application to substrates by cathodic electrodeposition.

Blocked incyanates have hitherto been used very widely as crosslinking agents in aqueous coating compositions, especially in cationic electrodeposition systems. Representative examples of the numerous patents teaching this type of blocked isocyanate crosslinking agents include U.S. Pat. No. 3,799,854;
No. 087, No. 4,031,050, No. 4,036,7
No. 95 and No. 4. ．． 13 There is No. L865. According to the prior art, generally di- or trifunctional blocked incyanates or incyanate prepolymers are mixed with hydroxyl- or amine-functional polymers and then codispersed in water/acid solutions. However, the lack of ionizable groups in these blocked isocyanate or incyanate prepolymers imposes certain constraints on the formulation of coating baths. Specifically, there are constraints on the amount of crosslinking agent that can actually be co-dispersed in the composition and the type of capping agent that can be utilized to cap free inocyanate groups in preparing capped isocyanates. Both of these factors are related to the properties of the composition.

Depending on the type of resin synthesized and used as the primary film former of the composition (resin formed as a solution, emulsion or dispersion), the amount of ionizable groups present in the total mixture, including the crosslinking agent, will vary. Since the fluctuation of the hydrophilicity of the resin, which can be determined by a number, becomes larger or smaller,
The amount of crosslinking agent that can be introduced into systems of said type is limited.

Therefore, mixtures containing large amounts of crosslinking agents that do not contain ionizable groups result in systems that are substantially less stable. The type of sequestrant also affects the stability of the overall system. For example, crosslinking agents obtained using cyclic compounds such as lactams and triazoles commonly used as capping agents have bulky and rigid structures that are difficult to co-disperse with other components of the composition.

As a result of the above, in formulating stable solutions or baths in accordance with the teachings of these prior art, it is often necessary to use an amount of sequestered incyanate crosslinker that is less than the amount desired to bring the overall system into optimum condition. It is necessary to reduce the amount of silica and/or to limit the type of sequestering agent used. fact,
U.S. Patent Nos. 3,799,854 and 4,031,0
Some systems, such as those typified by No. 50, are unstable using the recommended levels of incyanate crosslinker when formulated into a water-in-oil dispersion, which is the most economical form for shipping. . Therefore, in order to stabilize the system, it is necessary to invert such a dispersion to an oil-in-water type by adding a significant amount of water to the system. Adding such additional water for stabilization purposes to convert the system to a relatively low solids content results in the shipping of large quantities of water, which is clearly not economically desirable.

Another method of using blocked isocyanates in electrodeposition systems is described in U.S. Pat. Nos. 4,190,564 and 4,197.2.
It is taught in numerous US patent specifications, including No. 24. According to these patents, semi-blocked isocyanates are reacted with a functional framework compound to obtain a self-crosslinking system. However, a major drawback of this type of system is that subsequent reactions such as chain extension or introduction of ionizable groups are limited by the risk of deblocking of the isocyanate groups at the temperatures at which these reactions are carried out. There are drawbacks.

Because of the use of specific capped isocyanate crosslinkers containing ionizable groups, the compositions of the present invention do not suffer from the limitations described above. By using a blocked isocyanate crosslinker containing such ionizable groups,
To produce aqueous coating compositions, especially cationic electrodeposited resin systems, which contain high solids content in the form of non-inverting dispersions due to the fact that they remain stable even when the system contains large amounts of crosslinking agent. is possible. By preparing compositions incorporating such blocked incyanate crosslinkers containing ionizable groups, it is possible to obtain cathodically deposited systems with increased crosslinking efficiency and thus curing at low temperatures. becomes.

The compositions of the present invention combine with a film-forming resin having a reactive functional group that is stable in the presence of the reactive functional group at room temperature and reactive toward the reactive functional group at elevated temperatures. and a sequestered isocyanate crosslinking agent. Particularly preferred compositions of this type according to the invention are aqueous coating compositions suitable for application to the cathode of a substrate by electrodeposition, the ionization resulting from protonation of the amine nitrogen with an organic acid. The composition is at least partially solubilized. Generally, such compositions include a hydroxyl-functionalized epoxy/amine-attached film-forming resin;
and a blocked isocyanate crosslinker that is stable in the presence of the hydroxyl functionality at room temperature and reactive towards the hydroxyl functionality at elevated temperatures. In particular, compositions of this type can be used in the form of aqueous bath compositions suitable for electrodepositing corrosion-resistant curable coatings onto cathode substrates.

Such baths generally include water, an organic acid having a dissociation constant of at least 10-5, an amine-functional film-forming resin that is at least partially solubilized by protonation with the organic acid, and a capped polyester resin. Consists of isocyanate crosslinking agent.

In all of the foregoing coating compositions or baths, the present invention features: (A) a terminal amine formed by reacting an excess of an organic diisocyanate with a dihydroxy-functional amine containing at least one tertiary nitrogen; inocyanate groups, forming an intermediate containing a tertiary amine, and Φ) sufficient to react with intermediate (A) substantially all of the terminal isocyanate groups of said intermediate The method consists of using an acid-solubilized blocked polyisocyanate-based crosslinking agent as a crosslinking agent in the system or composition, which is a compound prepared by reacting a compound with an active hydrogen-containing blocking agent.

By introducing an organic acid into the aqueous composition, at least a portion of the tertiary nitrogen of the crosslinker is zolotonized, ionizing the crosslinker molecule, so that the sequestered incyanate crosslinker formed as described above is At least partially solubilized or dispersed in the aqueous coating composition.

A detailed description of methods for making the blocked isocyanate-based crosslinking agents useful in the compositions of the present invention and other components in compositions employing this improved crosslinking agent is provided below. It will become clear from.

As described above, the first step in producing the capped inocyanate crosslinkers useful in the compositions of the present invention involves reacting an excess of an organic diisocyanate with a dihydroxy-functional amine containing at least one tertiary nitrogen. By letting
It is a reaction that forms an intermediate product that has a terminal incyanate group and contains a tertiary amine. The diincyanate is used in excess to ensure that the intermediate product is end-capped with isocyanate groups. Therefore, an organic diisocyanate,
The dihydroxy-functional amine containing at least one tertiary nitrogen is preferably reacted in a molar ratio of 1 to 2=1.

There are two preferred types of organic diisocyanates used to make this intermediate product. First, the organic diisocyanate can be selected from the group consisting of aliphatic, cyclofatty acid and aromatic diisocyanates, as well as mixtures thereof. Second, the organic diisocyanate is an incyanate-terminated polyurethane prepolymer prepared by reacting an excess of aliphatic, cycloaliphatic, or aromatic diisocyanate with a diol having a number average molecular weight (Mn) of up to about 500. It's good.

It will be apparent to those skilled in the art that there are numerous aliphatic, cycloaliphatic or aromatic diincyanates and hybrids thereof. Among the many useful diinsyanates of this food type are m- or 0-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2°6-dolylene diisocyanate, m
- or p-xylene diisocyanate, hexamethylene diisocyanate and inphorone diisocyanate. Since the production of the intermediate product by the above reaction mechanism does not depend on the relative reactivity between the two inocyanate groups contained in the diisocyanate, the related patent application specifications of the diisocyanate can be prepared without regard to the reactivity of each isocyanate group. This contrasts with the method for selecting diisocyanates for crosslinking agent production described in the book. Therefore, although it is unnecessary to use compositions in which one isocyanate group of the diisocyanate is more reactive than the other, it is always acceptable to use such materials. That is, it is also possible to produce the intermediate product using the diisocyanate described in the related patent application, in which one isocyanate group is more reactive than the other inocyanate group. Representative examples of these diisocyanates include 1-isocyana)-1-(p-phenylisocyanato)methane, 1
-isocyanato-2-(p-phenylisocyanato)ethane, 4,4'-diisocyanato-2-nitrobi (wherein R is methyl, ethyl, t-butyl, chloro, bromomethyl, ethoxy, isobutoxy, isozologyl, (selected from the group consisting of trichloromethyl and methoxy).

Production of an intermediate product for producing the crosslinking agent of the present invention using any of the representative aliphatic, cycloaliphatic, or aromatic diisocyanates, or mixtures thereof. A second type of organic diisocyanate can be prepared for use in organic diisocyanates. As noted above, this second type of organic diisocyanate is produced by reacting excess diisocyanate with a diol having a number average molecular weight up to 500 to form a polyurethane prepolymer terminated with isocyanate groups. It was obtained by doing. The diol used in the preparation of the incyanate-terminated polyurethane prepolymer can be selected from a wide variety of diols with which those skilled in the art are familiar.

Representative examples of preferred diols useful in making incyanate-terminated polyurethane prepolymers include formula H
Aliphatic diols with O(OH,)n-OH (n = 2-8), cycloaliphatic diols, polyester diols of the polycasilolactone type and formula H[00)1. O
H2), -OH (n=2-8). Particularly preferred diols for preparing the prepolymer are 1,4-il''tanediol, 1,6-hexanediol, neopentyl glycol% 1,5-bentanediol and 1,4-cyclohexanediol.

The diisocyanates and diols used in the production of incyanate-terminated polyurethane prepolymers are
It is most desirable to react at a molar ratio of ~2.0:1.

Another reactant used in the preparation of intermediate FA) is a dihydroxy-functional amine containing at least one tertiary nitrogen. It is generally stated that the dihydroxy functional amine may be selected from a variety of aliphatic, cycloaliphatic and aromatic amines. Preferred t-amine functional diols have the formula [wherein R1 and R2 are +0Ha) HOH (n =
1-5), JCH20H, 0) nOH, OH, -OH
(n = 1-12), day + 0H20H, cl (2cH2CH20-0) nl, 0
H3-0I ((n=1-12), OH.

1 or +(1!H,0H2-0)n-OH2cH2-OH
(n = 1 to 12), and R3 is a c0 to c4 alkyl group, preferably a methyl group. Preferred compounds included within this class of materials are particularly tertiary amine-functional diols such as methylgetanolamine, butylgetanolamine, methylgetanolamine, butyldizolopanolamine and Jetanolamine. It will be apparent to those skilled in the art that there are still many diols containing tertiary amine nitrogens.

As already mentioned, after producing the intermediate product (Al,
The intermediate product is reacted with an active hydrogen-containing capping agent in an amount sufficient to react with substantially all of the terminal isocyanate groups contained in the intermediate product. The active hydrogen-containing capping agent with which such intermediate is reacted can be selected from a large number of capping agents well known to those skilled in the art. Representative of preferred sequestrants are selected from the group consisting of (1+ aliphatic, cycloaliphatic and aromatic alkyl monoalcohols, (11) oximes, (11D lactams and qψ triazoles). Any suitable fat cycloaliphatic or aromatic alkyl monoalcohols can be used as blocking agents according to the invention, in particular aliphatic 7/
l/:l-ru, e.g. evamethyl, ethyl, chloroethyl, propyl, ethyl, amyl, hexyl, heptyl, odoryl, nonyl, 3,3.5-t++ methylhexanol, nacyl and lauryl alcohols, etc. may be used. Can be done. Suitable cycloaliphatic alcohols include, for example, cyclopentanol, cyclohexanol, and the like, and aromatic alkyl alcohols include phenylcarbinol, methylphenylcarbinol, and the like. Suitable oxime-based sequestering agents include, for example, methyl ethyl ketone oxime, acetone oxime, and cyclohexane oxime. Examples of vine lactams used as sequestering agents are:
-canololactam, α-butyrolactam and pyrrolidone, and suitable triazoles include 1.2.4-
Triazole, 1.2.3-benzotriazole, 1.
2.3-Tolyltriazole and 4,5-diphenyl-
1,2,3-) Compounds such as IJ azoles are included.

More specifically, the method of making a blocked incyanate crosslinker of the present invention involves first reacting a diisocyanate or isocyanate end-stopped prepolymer with a diol containing a tertiary amine group to form an ionizable crosslinker. Manufacture.

For example, from about 70 to about 2 in the presence of a non-reactive solvent.
At a temperature of 00'Ii', 1 equivalent of diol is gradually added to 2000 m of diisocyanate. Neo-
The isocyanate to hydroxyl equivalent ratio may be lower than 2 but must be higher than 1 to obtain a terminally terminated adduct. At least 30' above the deblocking temperature of the capping agent
One quantity of capping agent may be added to the adduct while keeping F at a low temperature. The termination of the first step of this reaction can be confirmed by measuring the free inocyanate groups by titration, while the termination of the second step can be confirmed by the same method or by the absence of isocyanate groups in the infrared spectrum. Can be confirmed by existence.

Representative of the many aqueous coating compositions to which the improved capped incyanate crosslinkers of the present invention can be applied are those based on epoxy/amine adducts and epoxy ester/amine adducts, as well as acrylic polymers. This is a cationic electrodeposition composition. Non-electrodepositable aqueous compositions in which the blocked isocyanate crosslinker can be used are waterborne coating compositions, including top coats and spray base coats.

As specific examples, some preferred electrodeposition compositions are described in detail below.

As already mentioned, one of the electrodeposition compositions to which the capped isocyanate crosslinker according to the invention can be applied is an epoxy/amine adduct. The epoxy materials used in this adduct formation are heptameric or polymeric compounds or mixtures thereof having an average of one or more epoxy groups per umbrella molecule. Although monoepoxides can also be used, it is preferred that the epoxy compound is resinous and contains two or more epoxy groups as the polyepoxide.

Preferred polyepoxides are of relatively high molecular weight, with a molecular weight of at least 650, preferably in the range of 350 to 2,000. The polyepoxide can be essentially any of the well-known types, e.g.
The polyglycidyl ether may be a polyglycidyl ether. these are,
It can be produced by etherifying a polyphenol with a halohydrin in the presence of an alkali. Examples of phenolic compounds include bis(4-hydroxyphenyl)-2,2-propane, 4,4'-dihydroxybenzophenone, bis(4-hydroxyphenyl)-1
, 1-ethane, bis(4-hydroxyphenyl)-1,
Examples include 1-isobutane, bis(4-hydroxy-t-butylphenyl)-2,2-propane, bis(hydroxynaphthyl)methane, and 1,5-dihydroxynaphthalene. In many cases, it is desirable to use polyepoxy P that has a high molecular weight and contains aromatic groups.

This is obtained by reacting the diglycidyl ether described above with a polyphenol such as bisphenol A and then further reacting this product with engineered chlorohydrin to form the polyglycidyl ether. It is desirable that the polyglycidyl ether of the polyphenol contains free hydroxyl groups in addition to epoxide groups.

Polyglycidyl ether of polyphenol may be used as it is, but in this type of composition,
It is often desired to change the coating properties of the resin by reacting some of the reactive sites (hydroxyl or in some cases epoxy) with a modifier material. Esterification of epoxy resins with carboxylic acids, especially fatty acids, is well known in the art and does not require detailed explanation. Particularly preferred is a saturated fatty acid, pelargonic acid. Similarly, epoxy resins can be modified with organic substances containing incyanate groups or other reactive organic substances.

Another highly useful class of polyepoxides are the polyglycidyl ethers of phenolic novolac resins.

Also suitable are similar polyglycidyl ethers of polyhydric alcohols. They are ethylene glycol, diethylene glycol, triethylene glycol, 1.2
--7''' Rangelicol, 1,4-zolo-rangelicol, 1,5-bentanediol, 1,2,6-hexanediol, glycerol, bis(4-hydroxycyclohexyl)-2,2-propane It can be derived from polyhydric alcohols such as.

Polyglycidyl ethers of polyphenols are preferred polyepoxides. Preferred polyglycidyl ethers of polyphenols have a polyglycidyl ether of at least 350, preferably 35
Molecular weight within the range of 0 to 2,000, and 180 to 1,0
It has an epoxy equivalent weight within the range of 0.00.

As previously mentioned, the epoxy-containing material and the amine are reacted to form an adduct. The amine used as a raw material may be any primary or secondary amine, but secondary amines are preferred. Preferably, the amine is a water-soluble amino compound. Examples of amines of this type include mono- and dialkylamines.

For example, methylamine, ethylamine, propylamine,
Butylamine, dimethylamine, diethylamine, dibutylamine, dibutylamine, methylbutylamine,
Includes methylethanolamine, jetanolamine, dibrobanolamine, etc.

In most cases fairly low molecular weight amines are used, but higher molecular weight monoamines may be used especially in cases where it is desired to soften or further modify the molecule through amine-induced structural changes. I can do it. Similarly, mixtures of low and high molecular weight amines can also be used to modify the performance of the resin.

Furthermore, as long as it does not interfere with the reaction between the amine and the epoxide and does not cause dellation of the reaction mixture, or is used under conditions that do not cause such dellation, Other components may be included in the amine.

The reaction between the amine and the epoxy group-containing substance occurs when they are mixed. In reality this reaction is exothermic. If desired, the reaction mixture can be heated to a moderate temperature of 50 DEG -150 DEG C., or higher or lower temperatures may be used depending on the desired reaction. In any case, it is often desirable to ensure complete reaction by at least slightly increasing the temperature at the end of the reaction for a suitable period of time.

The amount of amine reacted with the epoxy group-containing material is such that the resin becomes cationic when solubilized with acid, i.e.
There should be at least enough amount to make it mobile towards the cathode. In some cases, substantially all of the epoxy groups in the resin react with the amine.

However, an excess of epoxy groups may remain, which groups contact water to form hydroxyl groups.

The capped incyanate crosslinking agents of this invention are preferably mixed with the amine epoxy adduct in a ratio of about 0.5 to about 2.0 urethane groups per hydroxyl group.

In order to cause the two components to react quickly and completely,
It is usually necessary to include a urethane-forming catalyst in the coating mixture. However, if the curing temperature after deposition is high enough, no catalyst is necessary. Also, no catalyst is required if a suitable capping agent is used for the incyanate. Examples of externally added catalysts are tin compounds such as dibutyltin dilaurate and tin acetate, although other urethane-forming catalysts known in the art may also be used. The catalyst is present in an amount effective to promote the reaction within the deposited film, e.g.
from about 0.5 to about 4.0% for the amine/epoxy adduct.
It is used in amounts within the range of 4 weight ratios. Typically about 2 hours is preferred.

electrodepositing a mixture of the cached incyanate/amine epoxy adduct and catalyst onto a suitable substrate;
Elevated temperature, such as about 250° to about 600'F
harden with The coating is at least partially cured via urethane crosslinking. Depending on its boiling point, the liberated alcohol may be volatilized or may remain in the mixture as a plasticizer.

By reacting the polymeric polyepoxide with a dimer acid, the molecular weight of the polymeric polyepoxide can be increased by chain extension. A reaction occurs between the carboxylic acid group and the epoxide group, forming an ester bond and a secondary hydroxyl group. These epoxy ester resins have a ratio of about 0.1 to 1 epoxy group.
It is prepared by reacting from about 0 to about 0,000 g equivalents of dimer acid. Although products that are essentially linear polymers are preferred, branched polymers may also be utilized, and dimer acids containing up to 60 weight units of trimer may also be utilized. After mixing the dimer acid and polyepoxide, optionally in the presence of an inert solvent, from about 140° to
Chain extension is achieved by reacting in the presence of a catalyst, such as a tertiary amine catalyst, at 170° C. humidity. Chain extenders are organic dimer and trimer acids as known in the art. Relatively high molecular weight dimer and trimer acids are polymerization products of 04-C48 fatty acids.

Although several mixtures of dibasic, tribasic and -basic acids are commercially available, the acids most useful in this type of composition are mostly dibasic acids, tribasic and -basic acids. -Product with low content of basic acids. Low molecular weight tribasic and tribasic acids such as adipic acid and azelaic acid are also useful.

The introduction of ionizable groups into these chain-extended epoxy resins is carried out in the same manner as in the case of the non-chain-extended resins described above. The remaining components of the composition, such as the capped cross-linking agent, catalyst, etc., are also the same as for compositions containing non-chain-extended epoxy resins, with ionizable groups and sufficient hydroxyl functionality. Acrylic polymers containing can be synthesized in two ways. In the first method, amine-functional monoethylenically unsaturated monomers are copolymerized with hydroxy monomers and various other non-functional acrylic and -dyl monomers. Monoethylenically unsaturated monomers are well known and commercially available. Compounds useful in these compositions are dimethylaminozorobyl methacrylate, dimethylaminoethyl methacrylate, monomethylaminoethyl methacrylate, aminoethyl methacrylate and their corresponding acrylates. Aminoethyl methacrylate and t-butylaminoethyl methacrylate can also be used. Also useful in these types of compositions are monoethylenically unsaturated tertiary aminoamides. Amine-functional unsaturated monomers are combined with hydroxy-functional monomers
For example, hydroxyprogyl acrylate, hydroxyethyl methacrylate, hydroxyprogyl methacrylate, and other non-functional monoethylenically unsaturated monomers,
For example, it is copolymerized with styrene, vinyl, A/ene, methyl methacrylate, ethyl acrylate, acrylonitrile, etc.

A second method of making this type of acrylic polymer uses a monoethylenically unsaturated epoxy-functional superterminal and copolymerizes it with a hydroxy-functional superterminal and various non-functional superterminals. It consists of causing The copolymers include up to 30 epoxy-functional copolymers, such as glycidyl methacrylate, and up to 30 hydroxy-functional copolymers, such as hydroxyacrylate, hydroxyzolozal methacrylate, and the like. The epoxy groups of the acrylic resin are then reacted with a secondary amine of spinning type, and the system is combined with a sufficient amount of ionizable crosslinker and co-dispersed in a water/acid solution. The use of these resins in the electrodeposition composition and the properties of the composition are not described here in detail (although they will be clear to those skilled in the art from the description of the compositions already given).

Aqueous compositions containing the above components are extremely useful as coating compositions and are suitable for electrocoating, although they can also be applied by conventional coating methods. K to obtain a suitable aqueous composition
It is generally necessary to add a neutralizing acid to the composition. p) It is desirable to electrodeposit these coatings from a solution of 13 to about 9.

Neutralization of these products is achieved by reacting all or part of the amino groups with a water-soluble acid such as formic acid, acetic acid or phosphoric acid. The degree of neutralization will vary depending on the particular resin; the only requirement is that sufficient acid be added to solubilize or disperse the resin. In the composition of the present invention, the addition of this acid serves to solubilize or disperse the blocked isocyanate crosslinking agent of the present invention.

Electrodepositable compositions, both referred to as "solubilized" or "dispersed" in practice, may be complex aqueous solutions, dispersions or suspensions in water, or one of these classes or It is thought that there is a combination of more than this, which acts as an electrolyte under the influence of electric current. Although it is clear that the resin may be in solution,
It is clear that in most cases the resin is in the form of a dispersion, called a molecular dispersion, with a molecular size intermediate between that of a colloidal suspension and a true solution.

In most cases, the pigment composition and, if desired, various additives known in the electrodeposition art, such as antioxidants, surfactants, coupling agents, etc., can be included. As already mentioned, if a blocked incyanate crosslinker of the invention containing an ionizable tertiary amino group is used,
Compositions with higher concentrations of resin than those of conventional techniques can be obtained. Again, as previously mentioned, the compositions according to the invention can exist as non-inverted dispersions, thus avoiding the need to ship large quantities of water, and providing sufficient cross-linking to fully cure the compositions at low temperatures. It is also possible to include agents.

In a cathodic electrodeposition process using an aqueous coating composition of the type described above and a sequestered incyanate crosslinker of the present invention, the aqueous composition is contacted with an electrically conductive anode and an electrically conductive cathode;
The surface to be coated becomes the cathode. Passing an electric current between the anode and the cathode in contact with a bath containing the coating composition deposits an adherent film of the coating composition on the cathode. This is in contrast to methods that utilize polycarboxylic acid resins that are deposited on the anode.

The conditions under which electrodeposition is carried out are generally the same as those used for electrodeposition of other types of coatings. The applied voltage can vary over a wide range, ranging from as low as 1 volt to as high as several thousand volts, but is typically between 50 and 500 volts. Current density is typically about 1.0-1.5 amps/square foot and tends to decrease during the electrodeposition process.

After the deposition process 9, the coating is cured at elevated temperatures, for example by baking in an infrared heating lamp. Preferably, the curing temperature is from about 350° to about 425°F, but optionally from about 2500 to about 500"Pi', and sometimes 60"
Curing temperatures such as 0.01 may also be employed.

The present invention will be explained in more detail with reference to the following examples.

It should be understood that specific examples are provided for illustrative purposes and the invention is not limited thereto. Unless otherwise specified, all "parts" mentioned in the examples mean parts by weight.

Example 1 840 parts of hexamethylene diisocyanate were charged to a suitable reactor under a nitrogen atmosphere.

297.5 parts of N-methyljetanolamine were added over 6 hours. The reaction temperature at the end of the addition was 60°C, at which point 500 parts of acetone were added. The -Neo conversion factor was measured 30 minutes later and was 50.

Next, 565 parts of ε-caglolactam was added to one reactor mixture over 30 minutes while maintaining the temperature at 70°C. The reaction mixture was maintained at this temperature for an additional hour, at which point an infrared spectrum showed that all the isocyanate groups had reacted. This batch was then diluted with 635 parts of ethyl cellosolve.

Example ■ 348 parts of 2,4-) IJ under nitrogen atmosphere
The diisocyanate was charged to a suitable reactor.

178.5 parts of N while keeping the temperature below 50°C.
- Methyljetanolamine was added over 2 hours.

At this point 46.5 parts of methyl ethyl ketoxime was added. Infrared spectroscopy after 30 minutes confirmed that all incyanate groups had reacted, and the batch was diluted with 250 parts of ethyl cellosolve.

Example 1 1392 parts of 2.4-1 lylene diisocyanate were charged to a supplementary reactor under a nitrogen atmosphere. 1785 parts of N-methyljetanolamine was added over 2 hours while maintaining the reaction temperature below 50°C. At this point 2
2.5 parts of 1,4-butanediol were added and the mixture was kept at 50°C for 60 minutes. At this point 46.5 parts of methyl ethyl ketoxime was added. Infrared spectroscopy after 30 minutes confirmed that all isocyanate groups had reacted and the batch was diluted with 250 m of ethyl cellosolve.

Example ■ 1052 parts of engineering & n (upon) 829 and 606
of bisphenol A was charged to a suitable reactor.

When the mixture was heated to 300°F, an exothermic reaction occurred at a point where the temperature rose to 3501 degrees. The reaction mixture was kept at this temperature for 60 minutes before being cooled to 270ff.

352 parts of pc:p-0200 and 4 parts of dimethylbenzylamine were added. Reduce batch humidity to 270”I
It was held at 'i' for 1.5 hours and then cooled to 200'F'.

Add 100 parts of methylethanolamine and reduce the mixture to 25 parts.
It was kept at 0'P for 1 hour. At this point 800 parts of the ionizable crosslinking agent of Example I and 175 parts of hexyl cellosolve were added and after 10 minutes of mixing, the batch was mixed with 1000 parts of water, 50 parts of acetic acid, 8 urfynol 104 12 parts and Geigy, amine (()eigy Am1ne) C2
) to form an oil-in-water dispersion.

Next, when forming an electrodeposition bath, 1200 parts of water was added to perform phase inversion of this dispersion.

1) SulfiTool 104 was manufactured by Air Products and Chemicals Co., Allentown, Pennsylvania.
ir Products a'na Chemical
Acetylenic surfactants, specifically 2,4,7,9-tetramethyl-5-
Decyne-4,7-diol.

2) Geigy Amine C is manufactured by Chipa Gayer (C1b
a substituted imidacilline derivative sold by Geigy).

Example V 634 parts of Epon 1001 (75% non-volatile content in xylene) and 160 parts of PC! ? -02001) was charged into a suitable reactor. The mixture was heated to 350"F' and 140 parts of xylene was distilled off under reduced pressure.

The temperature of the batch was lowered to 260°C and 1.1 parts of dimethylbenzylamine was added. The batch was held at 260"F for 6 hours to achieve chain extension, then cooled to 200"Ei',
At that point 60 parts of N-methylethanolamine and 3
6.7 parts (70% solution in methyl isobutyl ketone) of diethylenetriamine methyl isobutyl diketoimine was added. Hold the batch at 250″F’ for 1 hour, and
3 parts hexyl cellomelf. 8.3 parts of diptyltin dilaurate and 410 parts of the ionizable crosslinker of Example 2 were added. Next, 1000 parts of water, 22 parts of acetic acid, 1 part of sulfitoul
The batch was dispersed in a solution containing 0.46 parts of Geigy amine and 0.6 parts of Geigy amine. An electrodeposition bath was prepared by diluting 250 parts of this active resin with 960 parts of water. Coated on phosphatized steel panels at 225 volts for 2 minutes.

After curing at 180℃ for 20 minutes, the thickness was about 0.5~0.
．． A smooth and hard effective coating of 6 mil was obtained - 1)F
oP-0200 is made of Union Carbide.
C! It is a polycaterolactone diol sold by arbidθ).

780 parts of the resin of Example n, 400 parts of butyl cellosolve, 1100 parts of aluminum silicate, and 250 parts of lead silicate.

It was mixed with 200 parts of carbon black. The resulting slurry was then placed in a suitable pulverizer using Heggman R-DiN01.
It was crushed to a size of 7. To produce an electrodeposition bath, 100 parts of this millbase was mixed with 110 parts of butyl cellulose and 2 parts of acetic acid.
Part 1 was mixed with 1000 parts of the resin of Example 2 and 1000 parts of water. After painting on phosphoricated parts at 180 volts for 2 minutes.

Cured at 660°F for 2 hours. A8TM D-
Salt water spraying was carried out at 1001 according to 117-73.

After 15 days there was only 4 inches of creep from the scribe marks.

Example 1 696 parts of 2,4-tolylene diisocyanate were charged to a suitable reactor. 357 parts of N-methyljetanolamine were added dropwise. After 30 minutes the temperature was 50°C and 100 parts of acetone were added. At this point, 52 parts of neopentyl glycol was added and the reactor was heated to 50°C for 60 minutes.
After keeping for a minute.

87 parts of methyl ethyl ketoxime were added dropwise over a period of 20 minutes. After the addition is complete, heat the mixture to 45 °C for 30
It was held for a minute, then cooled to room temperature. 200 parts of this resin and 4
00 parts of butyl cellosolve.

200 parts aluminum silicate, 36 parts lead silicate.

60 parts of carbon black were mixed. The resulting slurry was then milled in a suitable pulverizer using a Heggmann r-
It was ground to size No. 7.

To prepare an electrodeposition bath, 200 parts of the pigmented dispersion described above were mixed with 800 parts of the resin from Example 1, 800 parts of water and 5 parts of acetic acid. Painting on phosphoric acid treated panels was applied at 225 volts for 2 minutes and cured at 300''F' for 20 minutes.A.
Salt spray test conducted at 100"F' according to 8TM D-177-73.

Creep from the scribe mark after 15 days was only 4 inches.

Agent Asamura Hao 4 other people

Claims (1)

[Scope of Claims] 111 A film-forming resin having a reactive functional group, which is stable at room temperature in the presence of the reactive functional group, and is reactive toward the reactive functional group at elevated temperatures. In an aqueous coating composition comprising a capped polyisocyanate crosslinker of forming a tertiary amine-containing intermediate, and (B) containing sufficient active hydrogen to react with intermediate (A) and substantially all of the terminal isocyanate groups of cough intermediate (A). a capped polyisocyanate crosslinking agent which has been solubilized with an acid, and which is made of a compound prepared by reacting a capping agent containing a capped polyisocyanate crosslinking agent containing characterized in that the sequestered polyisocyanate crosslinker is at least partially solubilized or dispersed such that at least a portion of the tertiary nitrogen of the agent is protonated to ionize the crosslinker molecules. (2) a film-forming resin comprising an epoxy/amine adduct having hydroxyl functional groups, which is stable in the presence of the hydroxyl functional groups at room temperature, and which is stable in the presence of the hydroxyl functional groups at elevated temperatures; a blocked polyisocyanate crosslinking agent which is reactive towards groups, suitable for application to a cathode as a substrate by an electrodeposition method,
and in an aqueous coating composition that is at least partially solubilized by ionization as a result of protonation of the amine nitrogen by an organic acid, comprising: (A) an excess of organic diisocyanate and a dihydroxy functionality comprising at least one tertiary nitrogen; (B) forming an isocyanate-terminated tertiary amine-containing intermediate by reacting with an amine; comprises a capped polyisocyanate crosslinker that has been solubilized with an acid, and is made by reacting a capping agent containing sufficient active hydrogen to react with the organic acid. Upon introduction into an aqueous composition, the sequestered polyisocyanate crosslinker is at least partially solubilized such that at least a portion of the tertiary nitrogen of the crosslinker is zolotonized to ionize cough crosslinker molecules. 49. The composition is characterized by being dispersed or dispersed.