JPS60152520A - Manufacture of oxazolidine group-containing paint binders - 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 provides coating binders, particularly cathodically deposited coatings (C
The present invention relates to a method for producing oxazolidine group-containing cationic epoxy resins suitable for use as paint binders for formulation of ED paints.

European Patent (EP) No. B1-0028401, No. B1-
No. 0028402, No. A2-96768 and Austrian Patent (AT-PSS) No. 375952, No. 37
'4816, No. 375946 and No. 376231
For the preparation of compounds containing oxazolidine groups and their hydroxyl groups with epoxy resins as half-esters or monourethanes formed through reaction with dicarboxylic anhydrides or with diisocyanates. Various methods are known for reactions via ring functional groups.

The introduction of these basic groups makes it possible to substantially improve the solubility at relatively low degrees of neutralization. Also,
The wide variety of possible substituents provides many possibilities without affecting the properties of the paints and coatings.

However, to date, the direct addition of such hydroxy- or ring-functional oxazolidine compounds to epoxy resins has not made it possible to obtain binders that can be diluted with water after neutralization. This is because these compounds immediately cause crosslinking of the epoxy resin, causing the batch to gel.

The term "hexacyclic functional oxazolidine compounds" in this application contains a structure of -N-CH(R)-0- (R represents an H1 alkyl group or an aryl group), but contains an alcoholic hydroxyl function. It is understood that it is a five-membered ring system that does not have The production of compounds of this type is covered by Austrian Patent No. 3759 (ATTPS).
It is stated in No. 46.

This reaction partner
Direct binding of is still desirable for water-dilutable binders. This is because, on the one hand, the number of ester bonds which are susceptible to saponification is reduced and, on the other hand, interaction with incyanates and the production of intermediates can be avoided.

Surprisingly, it has been discovered that direct attachment of hydroxy- or ring-functional oxazolidine compounds is possible if this reaction is carried out in the presence of monocarboxylic compounds. If desired, the reaction with additional amine compounds can be carried out simultaneously, which further simplifies the process.

That is, the present invention provides a method for producing oxazolidine group-containing cationic epoxy resins suitable as paint binders, particularly paint binders for the formulation of cathodically depositable paints, in which an epoxy resin is converted into a monocarboxylic acid at 65-90°C. In the presence of a compound and preferably an additional amine compound, a hydroxy-functional oxazolidine compound or one 1'J-CH(R)-O- (R is a H1 alkyl or aryl group) structure containing in the ring but alcoholic reacting with an oxazolidine compound having no hydroxyl groups, the weight ratio of oxazolidine compound to monocarboxy compound being between 1:5 and 2:1;
The total number of moles of groups reacting with epoxy corresponds to the total number of moles of epoxy groups in the epoxy resin, and at least 30% of this basic component is at least 35 ■KOH/2, preferably from 40 to 120 ■KOH/7. The present invention relates to a method for producing oxazolidine group-containing cationic epoxy resins, which are characterized by having an oxazolidine structure having an amine value.

Groups that react with epoxy in this application are understood to include carboxyl groups, secondary and primary amino groups, and oxazolidine groups of the monocarboxy compounds used.

In order to achieve good dilutability in water after partial neutralization, this weight ratio should be within the following range, calculated on the basis of 1 epoxy equivalent (or 1 mole of epoxy group per syn).

Oxazolidine compound 0.1-0.8 mol, preferably 0.2-0.5 mol Monocarboxy compound 0.2-0.8 mol, preferably 0.3. -0.6 7 additional amines 0-0.8 mol preferably 0.2-0.5 mol In each case the final product is such that at least 30 mol of the basic component has an oxazolidine structure. At least 351nt Koa
, 'y, preferably 40 to 120 KOH/9 (
(as the sum of all components containing basic groups).

The products produced according to the invention surprisingly exhibit a substantially improved solubility in dredging art binders, which means that they have good water resistance, requiring only small amounts of neutralizing agents. It means achieving dilution.

Hydroxy or functional compounds used in accordance with the present invention and methods for their preparation are disclosed in various patents and patent applications.

Table 4 shows the structural formulas and references of such various compounds. Six-membered ring compounds are also included.

According to common nomenclature, these compounds are called perhydro-
1,3-oxazines.

Suitable monocarboxy compounds are straight-chain or branched monocarboxylic acids, especially those having 5 or more carbon atoms in the main chain. These acids, in addition to their function in process technology, contribute to the improvement of many of the coating and coating properties of the binders of the present invention.

The monocarboxy compounds can be monocarboxylic acids of the type synthetic or natural fatty acids. These include the corresponding alkane carboxylic acids such as n-hexane carboxylic acid, isooctanoic acid or isononanoic acid, oil fatty acids such as linseed oil, soybean oil, coco oil fatty acids, tall oil fatty acids, dehydrated castor oil fatty acids. There are other representative groups known to those skilled in the art. If desired, aromatic monocarboxylic acids such as benzoic acid or methacrylic acid can be used in part.

Other suitable monocarboxy compounds are half-esters of dicarboxylic acids, which are easily obtained by reaction of dicarboxylic anhydrides with monoalcohols. Examples of such starting materials are half esters of maleic acid, phthalic acids, succinic acid and their homologs with butanol, their isomers and higher homologs. Furthermore, suitable monocarboxy compounds are half esters of hydroxyoxazolidines (European Patent No. B1-0028402) or ring-functional oxazolidines and dicarboxylic anhydrides, as described in the above-cited literature. (Austrian Patent No. 375,946).

Preferred epoxy resins are the known di- or poly-epoxy compounds obtained by reaction of phenols or phenolic novolacs with shrimp chlorohydrin. Epoxy resins based on aliphatic alcohols or copolymers containing glycidyl groups are also suitable as starting materials in the process of the invention. Large numbers of such compounds are known to those skilled in the art from the literature.

The present binders are produced by a bonding reaction between epoxy resins, oxazolidine compounds, monocarboxy compounds and amines at 65 to 90°C.

The weight ratios between the components are such that the total number of moles of epoxy groups corresponds to the total number of moles of all groups (as defined above in 1) that react with the epoxy, and the ratio of oxazolidine compounds to monocarboxy compounds is It is chosen to be between 1:5 and 2=1. If this weight ratio is chosen correctly, no formation of quaternary ammonium ions will occur.

In a particular embodiment, the process is carried out in such a way that the oxazolidine compound and the dicarboxylic anhydride (in significant molar excess) are reacted with the epoxy resin. In addition to the amount of oxazolidine compound expected to react with the epoxy resin, monocarboxy compounds containing oxazolidine groups are formed in situ.

Conveniently, the products obtained are hydrolyzed at 50-80°C in the presence of catalytic amounts of formic acid or acetic acid.

The binders can be fractured by methods known for pigments and, after neutralization with inorganic or organic acids to a pn value between 4 and 7, are preferably reduced to 5% and 20% with deionized water for electrodeposition. diluted to a solids content between The binders produced according to the invention have excellent dilutability in water even at low degrees of neutralization.

The conditions for the use of additives and their deposition on a substrate connected as a cathode are known to those skilled in the art and will not be described further. The products of the invention are particularly suitable for powder base resins for pigments and extenders.
) is particularly suitable as These methods of manufacture are known to those skilled in the art.

The following implementation illustrates the invention without limiting its scope. Unless otherwise specified, parts or percentages are by weight. All quantities in the table are also by weight.

The following abbreviations were used in the examples.

MOLA Monoethanolamine MPA Monopropanolamine MIPA Monoisopropanolamine AEPD 2-
Amino-2-ethyl-propanediol-1,3 ETOLA Ethylethanolamine BA n-Butylamine DEAPA Diethylaminopropylamine DMAPA
Dimethylaminopropylamine DOLA Jetanolamine DIPA Diisopropanolamine DEA Diethylamine CE C9-C,□Glycidyl ester of monocarboxylic acids STO Styrene oxide AGE Allyl glycidyl ether HEA Hydrogyethyl acrylate BUAC Butyl acrylate EHAC 2-Ethylhexyl acrylate MIBK Methyl isobutyl ketone FA Paraformaldehyde, 91% BZA Benzaldehyde ANA Anisaldehyde (4-methoxybenzaldehyde) EPHI Epoxy resin based on bisphenol A Epoxy equivalent weight approx. 200 EPHII Epoxy resin based on bisphenol A
, epoxy resin approx. 500 EPHIII Epoxy resin based on phenol novolak Epoxy equivalent weight approx. 190 MCV 1 Half ester of phthalic anhydride and n-butanol MCV 2 Half ester of maleic anhydride and 2-ethylhexanol MCV 3 Half ester of tetrahydrophthalic anhydride and Half-ester MCV with hydroxyoxazolidine A1 4 Half-ester MCV with maleic anhydride and inbutanol 5 Oxazolidine compound of phthalic anhydride A5
+) modified carboxylic acid MCV 6 isononanoic acid MCv7 tall oil fatty acid MCV 8 oxazolidine compound of tetrahydrophthalic anhydride A9 Preparation of the oxazolidine compounds used The compounds are prepared from the reaction components shown in Table 1 under the conditions listed therein. The last column contains references for this group of compounds. Its general formula corresponds to each formula in Table 4.

Example 1-13 The binders at the weight ratios shown in Table 2 were used in an appropriate reaction vessel at 70 to 80°C, optionally in the presence of an inert solvent, to achieve an acid value of 3■KOH/7 or less. Manufacture by reacting until This batch is further reacted under the conditions listed in Table 2 to ensure reaction of all free epoxy groups. The specifications of the products obtained according to Examples 1-13 are shown in Table 3.

Comparative Example According to the composition of Example 7, 500 parts of EPH■ and 342 parts of EPHIII were mixed with MC at 75 to 80°C.
V3 149 copies, MCV 7112 copies, DEA 22 copies,
39 parts DEAPA and 250 parts secondary amine (MI
3 m'i KOH/f in 65% solution in ethylene glycol monoethyl ether. React until the acid value of .

The resin solution thus obtained has a 10% aqueous OpH value of 5.2, requiring 35 mmol of acetic acid per 1002 resin solids to exhibit good dilution in water. In comparison, the corresponding product prepared according to the invention has a resin solids content of 1002 at a pH value of 7.6.
only 15 mmol of acetic acid are required for the reaction (see Table 3).

0 o O Mi Sen Senmi - Country Country〆N /+ 〉 Wrinkle 11 = H or a straight or branched chain alkyl group having 1 to 4 carbon atoms, and optionally OH- or alkyl- an aryl group substituted with 0-, or an alkylene group connected to two R's to form a ring optionally substituted with an alkyl, aryl or alkoxy group R2 = having 2 to 12 carbon atoms straight-chain or branched-chain or cyclic alkylene group R3 = H or CH3- R4 = saturated or unsaturated aliphatic, cycloaliphatic or aromatic hydrocarbon group optionally containing an ether or ester group R5 = R3 or an alkyl group having one or more carbon atoms or a phenyl group R6=H4 or a straight chain or branched chain or cyclic alkyl group having 2 to 12 carbon atoms optionally containing a hydroxyl group R7 - remaining groups R8 of the acrylic or methacrylic monomer which are monofunctional with respect to the double bond and which are linked to the nitrogen after reaction with the active H atom = linear or branched alkylene or polyalkylene ether group; R0=H or alkyl group or phenyl group RIo=
Alkyl group R, having 1 to 4 carbon atoms, = straight-chain or branched alkyl group having 2 to 18 carbon atoms, aralkyl group or tertiary amine group containing said groups

Claims (1)

[Claims] 1. A method for producing oxazolidine group-containing cationic epoxy resins suitable as paint binders, especially paint binders for preparing cathodically deposited paints, in which an epoxy resin is mixed with a monocarboxy compound and a monocarboxy compound at 65-90°C. A hydroxy-functional oxazolidine compound or one can-CH(R)-', preferably in the presence of an additional amine compound.
0- (R is H, an alkyl group or an aryl group) structure in the ring but does not contain an alcoholic hydroxyl group, and the weight ratio of the oxazolidine compound and the monocarboxy compound is 1. :5 and 2:1, the total number of moles of groups reacting with the epoxy resin corresponds to the total number of moles of epoxy groups in this epoxy resin, and at least 30% of this basic component is at least 35 ■KOH/7, preferably 40 to 1
A method for producing oxazolidine group-containing cationic epoxy resins, characterized in that the resin has an oxazolidine structure having an amine value of 20■KOH/9. 01 to 0.8 calculated based on 2.1 epoxy equivalent,
Preferably 0.2 to 0.5 mol of oxazolidine compound, 0.2 to 0.8 mol, preferably 0.3 to 0.6 mol of monocarboxy compound and O to 0.8 mol of additional amine compound. A method according to claim 1, characterized in that the method uses: 3. Straight chain or branched monocarboxylic acids and/or dicarboxylic acids containing 5 or more carbon atoms in their main chain as monocarboxy compounds and monoalcohols and/or hydroxyoxazolidine having 3 or more carbon atoms. Claims 1 or 2, characterized in that half-esters with oxazolidines and/or reaction products of monkey-functional oxazolidines with dicarboxylic anhydride and/or methacrylic acid are used. The method described in section. 4. The oxazolidine group-containing monocarboxy compound is
4. The method according to claim 1, wherein the method is produced by reacting a corresponding molar amount of an oxazolidine compound with a dicarboxylic anhydride in the presence of an epoxy resin.