DE1720418C3

DE1720418C3 - Process for curing epoxy resins

Info

Publication number: DE1720418C3
Application number: DE19671720418
Authority: DE
Inventors: Arnold Dipl.-Chem. Dr. 6204 Wehen; Jacobi Paul 6202 Wiesbaden-Biebrich Giller
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1967-11-16
Filing date: 1967-11-16
Publication date: 1976-12-23

Description

example 1

2283 g eines 98,5%igen in Toluol gelösten Epoxydharzes aus 4,4'-Dioxy-diphenyl-2,2-propan und Epichlorhydrin mit einem Epoxydsauerstoffgehalt von 3,5 g/100 S Harz, werden mit 960 g des Methylesters einer isomerisierten Fettsäure mit 60 bis 70% konjugierten Dienen und 300 g Ligroin erhitzt und vollständig entwässert. Dabei wird das gebildete Wasser durch eine längere Abdestillation entfermt und das Schleppmittel nach Abtrennung des Wassers wieder in das Reaktionsgemisch zurückgeführt (im folgenden kurz mit »im Umlauf« bezeichnet).2283 g of a 98.5% strength epoxy resin, dissolved in toluene, from 4,4'-dioxydiphenyl-2,2-propane and epichlorohydrin with an epoxy oxygen content of 3.5 g / 100% resin, 960 g of the methyl ester are added an isomerized fatty acid with 60 to 70% conjugated dienes and 300 g ligroin heated and completely drains. The water formed is removed by a longer distillation and that Entrainer returned to the reaction mixture after the water has been separated off (hereinafter briefly referred to as "in circulation").

Danach wird eine frisch hergestellte Lösung von 2 g Natrium in 50 ml absolutem Methanol allmählich zugetropft und weiter im Umlauf destilliert. Die Umesterung ist mit Methanolabspaltung verbunden. Ihr Fortgang kann durch Kpntrolle der abdestillierten MethanoJmenge verfolgt werden. Wenn kein Methanol mehr übergeht, wird mit 6 g Eisessig, gelöst in 50 g Toluol, neutralisiert und auf einen Festharzgehalt von etwa 70% eingestellt.After that, a freshly prepared solution of 2 g of sodium in 50 ml of absolute methanol is gradually added added dropwise and further distilled in circulation. The transesterification is associated with elimination of methanol. Their progress can be followed by checking the amount of methanol distilled off. If no methanol more passes over, is neutralized with 6 g of glacial acetic acid dissolved in 50 g of toluene and adjusted to a solid resin content of about 70% adjusted.

143 g dieses Harzes werden mit 90 g Tiitandioxyd, 64 g Quarzmehl, 18 g Talkum, 23 g Diatomeenerde, 10 g Al-Ca-Silikat, 25 g Toluol und 7,5 g 2,4,6-Tris-(dimethylaminomethyl)-phenol gemischt. Die erhaltene Farbe hat im DIN-Becher 4 mm eine Auslaufviskosität von 80 bis 90 see. Die Topfzeit der Farbe beträgt 2V₄ h. Es wird ein 600 μ dicker Film auf Glas aufgezogen und daran die Härtung beurteilt. Nach 75 min ist der Film bereits so fest, daß ein Abdruck143 g of this resin are mixed with 90 g of titanium dioxide, 64 g of quartz flour, 18 g of talc, 23 g of diatomaceous earth, 10 g of Al-Ca silicate, 25 g of toluene and 7.5 g of 2,4,6-tris (dimethylaminomethyl) - phenol mixed. The color obtained has an outlet viscosity of 80 to 90 seconds in the 4 mm DIN cup. The pot life of the paint is 2V ₄ hours. A 600 μ thick film is drawn onto glass and the hardening is assessed on it. After 75 minutes the film is so firm that an impression can be made

mit dem Daumen nicht mehr möglich ist. Nach 24 h läßt sich der Farbaufstrich nicht mehr ritzen, ist sehr zäh, fest und haftet ausgezeichnet auf der Unterlage. Die angesetzte pigmentierte Masse härtet beim Stehen innerhalb von 24 h zu einem zähen, harten Block aus, der mechanisch bearbeitet werden kann.is no longer possible with the thumb. After 24 hours the paint coat can no longer be scratched, it is very tough, strong and has excellent adhesion to the surface. The applied pigmented mass hardens when standing within 24 hours into a tough, hard block that can be machined.

Example 2

1350 g Epoxydharz mit 3,5% Epoxydsauerstoff werden zusammen mit 660 g Sojaölfettsäuremethyl-1350 g of epoxy resin with 3.5% epoxy oxygen are added together with 660 g of soybean oil fatty acid methyl

*5 ester in Gegenwart von 200 g Ligroin durch Destillation wie nach Beispie! 1 entwässert. Dann läßt man eine Lösung von 0,95 g Na-metall in 50 ml wasserfreiem Methanol eintropfen und verfolgt während der Umesterung die abgespaltene Methanol-Menge. Man* 5 esters in the presence of 200 g of ligroin by distillation as in the example! 1 drains. A solution of 0.95 g of sodium metal in 50 ml of anhydrous is then left Drop in methanol and monitor the amount of methanol split off during the transesterification. Man

"o neutralisiert mit 3,0 g Eisessig, gelöst in 50 g Toluol, und stellt auf einen Festgehalt von 60% ein. 167 g d'eses Harzes werden wie im Beispiel 1 pigmentiert und mit 7,5 g 2,4,6-Tris-(dimethylaminomethyl)-phenol gemischt. Die erhaltene Farbe hat im DIN-Becher"o neutralized with 3.0 g of glacial acetic acid, dissolved in 50 g of toluene, and adjusts to a fixed salary of 60%. 167 g of this resin are pigmented as in Example 1 and with 7.5 g of 2,4,6-tris (dimethylaminomethyl) phenol mixed. The color obtained is in the DIN cup

«5 4 mm eine Auslaufviskosität von 80 bis 90 sec. Die Topfreit beträgt 2¹I₂ h. Der Aufstrich verhält sich praktisch ebenso wie der im Beispiel 1 beschriebene.«5 4 mm an outlet viscosity of 80 to 90 seconds. The pot free is 2 ¹ I ₂ h. The spread behaves practically the same as that described in Example 1.

Claims

it was therefore desirable to further improve the curing conditions of the patent claims esterified epoxy resins.

There has now been a method for curing epoxy

1 Process for curing epoxy resins, resins which have been produced by reacting 4,4-pioxydiphenyl which have been produced by reacting 4,4-dioxydiphenyl-5 alkanes and epichlorohydrin and alkanes and epichlorohydrin have their secondary OK groups wholly or partially and their secondary OH groups have been wholly or partially esterified, but the way that epoxy resins can be hardened into perfect products is found to have been esterified based on epoxy resin, of "0.5 to 15, preferably 4 to 10 Ge Dimethylaminomethylphenolen is used as the hardener UNJ d! 2 weight percent, based on epoxy resin, transit of di-cure at a temperature up to 12O ⁰ C and used methylammomethylphenolen the Härführt [;. ~ R.- processing carried out at a temperature up to 120 C Man.

2. The method according to claim 1, characterized thus used according to the invention instead of previously for indicates that the tertiary amines in a proportion »5 primary or secondary used for this purpose from 4 to 10 percent by weight, based on the amine, now special tertiary amines. Epoxy resin. The inventive method is the

3. The method according to claim 1 or 2, characterized in that the partially esterified epoxy characterized in that the curing is carried out ^{surprisingly temperature below 60 0 C in a thermal resin with terminal epoxy groups.} ^a ° to cure catalytically quickly and without difficulty. The pot life can be 2 to 3 hours. In addition, the inventively manufactured

turn products into paints that are very

adhere well to their base. It is also possible to produce masses »5 which are very hard when hardened

It is known to use epoxy resins, e.g. B. such on the will and not jump.

• Based on 4,4-dioxydiphenyl-2,2-propane and epichloro as dioxdiphenylalkanes for the production of the epoxy

hydrin, with tertiary amines, the at least 2 ter resins are dioxydiphenylpropane and dioxydiphenyltaires Containing amino groups, harden. Methane is also particularly suitable.

known that such amines undergo rapid cold curing 3 <> The epoxy resin esters can be preferred with esters. With tertiary amines, epoxy-like methyl esters of various saturated or However, resins only give poorly adhering, already unsaturated, z. B. those with conjugated or after a short time splintering spreads, the only slightly isolated double bonds, such as linseed oil, cotton value to have. In addition, such reaction oils have either vegetable or soybean fatty acids or aromatic acids mix only a short pot life of generally 35 acids, such as benzoic acid or toluic acid less than Va h. The tertiary amines mentioned may have been. Preferably one will be for being invented therefore, such epoxy resin esters are generally only used as accelerators Set hardening of epoxy resins with acid anhydrides that do not yellow, e.g. B. Esters of ricin fat or polysulfides are used. acid. These substances also form after curing

On the other hand, it is known to convert epoxy resins into light-resistant compounds.

esters, in that the OH groups in the condensates are used as dimethylaminomethylphenols, preferably

with unsaturated acids, e.g. B. fatty acids or their way 2,4,6-tris- (dimethylaminomethyl) -phenol, 2,4-esters, implemented. Here are both the bis (dimethylaminomethyl) phenol and the o-disecondary OH groups as well as the epoxy groups methylaminomethyl-phenol are used. Are suitable esterified. 45 also o, p-bis (dimethylaminomethyl) phenols with a

It is now possible while maintaining certain ner -CH ₂ OH groups in the o-position. These -CH ₂ OH reaction conditions, e.g. B. by transesterification with group can also be etherified by a monohydric alcohol fatty acid methyl esters in the presence of very small men or by reaction with the -CH ₂ OH group of a gene alkali metal alcoholate only the secondary OH second molecule. Esterify groups. As it turned out at 5 ° own sub Curing is preferably investigations at temperatures let the thus formed up to 5O ⁰ C. However, it is also possible to use partially esterified resins having terminal epoxy higher temperatures up to 12O ⁰ C. In ranging from middle to films strength process, they, however, implementation of the so-called cold curing can be difficult with amines or within 1 to 3 hours already sufficient Festig-amidoamines as generally comparable for cold curing achieve ^5S ness. Further hardening is essentially applied hardening. completed after about 24 hours. The special advantage

This may be because the partially obtained the curing systems of the present process esterified epoxy resins always still residual amounts is that cures itself already contained in Tejnpe-fatty acid methyl ester, the amines by temperatures of 0 to 1O ⁰ C with practically interesting amide formation make ineffective or at least ^allow at least 60 curing times to be carried out, inhibit. The products made according to the invention are

It is also known that the OH groups of epoxy can be used in many ways, namely except for paint resins by reaction with ß-ketonic acids, a medium, coatings and linings and also chlorinated fatty acid or with acrylonitrile in counter- as casting and / or molding compounds. In particular, let wait of tert. To decrease amines. The implementation ⁶ S they can be processed into cold-curable mixtures. B. also with, for example, as coatings for building material or tert. Amines are hot cured. But these are road marking paints are used Kings-Temoeraturen of at least 14O ⁰ C required. NEN.