DE1520741C3 - METHOD OF MANUFACTURING EPOXY POLY ADDUCTS - Google Patents

Description

Epoxy polyadducts are well known products. They are generally caused by the action of Epichlorohydrin made on a phenol that contains at least two hydroxyl groups. These polyadducts can with acids or anhydrides, such as maleic anhydride or amines, such as triethanolamine, can be converted into thermosetting products as hardeners. All of these adducts burn on the Air, and its field of application is severely limited by its flammability.

Attempts have been made to overcome this disadvantage by adding mineral fillers, such as Talc or kaolin, to fix. The decrease in flammability was only slight and was mostly achieved at the expense of physical and mechanical properties.

It has long been known that by introducing chlorine into a molecule the product obtained Incombustibility is conferred, which is the more pronounced the higher the chlorine content. It was therefore logical to try to introduce chlorine in various forms into the epoxy polyadducts. to Various methods have already been described for this purpose.

British patent 741 870 describes polyepoxides of chlorinated polyethers. which only contain aliphatic chlorine in their molecule, which makes the polyadduct unstable when exposed to heat. Further, in the end product does not exceed the chlorine content of 10 to ll ° / _0th This is not enough to ensure satisfactory incombustibility.

According to French patent specification 1154 500, the polyadduct is modified by adding pentachlorophenol or its glycidyl ether. This is how chlorine is introduced into the product. But the amount of the addition does not exceed 65% without the risk of exudation. Incidentally, the maximum chlorine content of the resin itself is then no higher than 43.5 ° / _0; in addition, a substantial part of the pentachlorophenol is not chemically bound. In order to obtain a product in which the pentachlorophenol is chemically bonded, fused to bisphenol A and epichlorohydrin with enough pentachlorophenol, but under these conditions, a chlorine content of 15 is / ₀ ° virtually not exceeded. In one example, a chlorine content of 30% is mentioned, but such a content corresponds to a monofunctional compound that is not polymerizable.

British patent specification 744 388 teaches the introduction of chlorine with the aid of the hardening agent that in the form of certain chlorinated di-acids, especially as anhydride of hexachlorendomethylenetetrahydrophthalic acid or HET acid. However, the dissolution of this hardener is slow, and to achieve a homogeneous mixture, it is necessary to work at a relatively high temperature will. In this case, the hardening also takes place during

ίο the dissolution very quickly, which eliminates the use of the product and its technical development is impaired.

According to British Patent 773,655, this difficulty is avoided by adding the hardener is introduced in solution into the pentachlorodiphenyl, but the resulting polyadducts are only in curable by heat, and it takes a long time to cure. They only contain 30% chlorine, which is also used for Part is not bound to the molecule.

In French patent specification 1 180 194 it is proposed to use the chlorinated derivatives of bisphenol A, ie the derivatives of bis (hydroxyphenyl) propane chlorinated on the core, as the starting material. These products are obtained by direct chlorination of bisphenol A, but the yields are moderate, namely 40 to 45% for the derivative with 4 chlorine atoms per molecule. Although higher chlorine contents are mentioned in the patent, in practice it is hardly possible to achieve more than 4 chlorine atoms without great difficulties in cleaning. The epoxy resins corresponding to tetrachlorobisphenol contain 27 to 30 ⁰ I ₀ chlorine.

The invention relates to a process for the production of cured epoxy polyadducts known reaction of epoxy compounds with polybasic or polybasic carboxylic acids ■ amines cold or in the heat, which is characterized is that such chlorine-containing compounds are used as epoxy compounds that by reacting epichlorohydrin or glycerol dichlorohydrin with octachlorodihydroxydiphenyl in Presence of alkaline agents.

The inventive method makes it possible to produce epoxy polyadducts from chlorine-rich and to obtain economically and technically easily accessible chlorodiphenols, resulting in products which are characterized by the following properties:

Their very high content of chlorine, which is chemically bound to the molecule,
their ability to self-extinguish as measured by ASTM method D 757-49,
their high Rockwell hardness and

their high Vi cat softening point, without the usual properties of these resins being impaired.

In the recovery of the reaction products, sodium hydroxide is generally used as the alkaline agent used, especially in the form of an aqueous solution, but the other alkali bases work just as well. The chlorohydrin component of these reaction products is epichlorohydrin or glycerol dichlorohydrin used.

The octochlorodihydroxydiphenyl used can be produced via the deca-

chlorodiphenyl, its phenolization with sodium hydroxide to octachlorodihydroxydiphenyl leads. This product can be used alone or in admixture with other compounds compatible with it and can react with a chlorohydrin to form an epoxy polyadduct, for example the diphenols or in particular with bisphenol A are reacted.

By changing the proportion and concentration of the alkaline agent and the nature and excess of the chlorohydrin one obtains a whole Range of polyadducts from solid products to those with a honey consistency, depending on the grade of the epoxy equivalent.

These reaction products are then cold or in the heat in the presence of classic hardeners, such as polyacids and polyamines, hardened. After curing, the ability of the epoxy polyadducts to extinguish by itself, completely. They easily meet the conditions of the A.S.T.M.test D 757-49. If they are flamed with a soldering torch, they will char, but go out immediately, when the flame is removed.

- Example 1

5 parts of an epoxy compound, which consisting of 231 parts of Octachlordihydroxydiphenyl, 321 parts of 10 ° / ₀ sodium of sodium hydroxide and 57.8 parts of epichlorohydrin was recovered at 100 ⁰ C, a softening point of 150-165 ° C and an epoxy equivalent of 1040 had, and its chlorine content 53.5% are dissolved in 8 parts of methyl ethyl ketone. 2 parts of maleic anhydride are added to the solution. A glass plate is coated with this solution, which is allowed to air dry for 1 hour and tempered at 150 ° C. for 16 hours. In this way a transparent, colorless varnish is obtained which is difficult to scratch and exhibits very good adhesive strength.

Example 2

4.9 parts of maleic anhydride are dissolved hot in 22 parts of a compound consisting of 462 parts of biphenol, 925 parts of epichlorohydrin and 164 parts of an aqueous 48.9 ° / _o sodium hydroxide solution at 108 ⁰ C and subsequent azeotropic distillation was obtained, an epoxy equivalent of 428 and had a chlorine content of 51.5 ⁰ I ₀ . After adding 0.5 part of tri-n-butylamine, the homogeneous mixture is poured into a mold lined with polyvinyl alcohol. The mixture is ^{kept at 130 °} C. for 14 hours (the mixture was gelled in 20 minutes). In this way, a light yellow, transparent, very hard polyadduct is obtained which has a Rockwell hardness of 111.3 and a softening point according to Vi cat 140.5 ⁰ C.

Example 3

The procedure is as in Example 2, but with the difference that 25 parts of there in maleic anhydride dissolved compound can now be dissolved in 25 parts of pentachlorodiphenyl. To the received 2.5 parts of diethylaminopropylamine are added to the solution. After 4 hours at room temperature the mixture is gelled. It is completely hardened after 16 hours. To improve the For dimensional stability in the heat, hardening can be supplemented by heating at 80 ° C for 4 hours.

The Rockwell hardness of the cured resin is 101.3, its Vi cat softening point 127 ° C.

The resins cured according to these examples

char during the test according to the A.S.T. M.-Method D 757-49 in the flame of a burner, however, they do not continue to burn when the flame is stopped .. They go out by themselves.

Similar results are obtained if reaction products of epichlorohydrin and octochlorodihydroxydiphenyl are used hardens, during the manufacture of which the ratio of the two components varies was, for example, a reaction product of 1 part epichlorohydrin and 2 parts octochlorodihydroxydiphenyl with an epoxy equivalent of 1670, a reaction product of 1 part epichlorohydrin and 2 parts of octachlorodihydroxydiphenyl with an epoxy equivalent of 900 or a reaction product of 8 parts of epichlorohydrin and 2 parts of octachlorodihydroxydiphenyl and 1 part bisphenol A with an epoxy equivalent of 331.

Claims (1)

Claim: Process for the production of cured epoxy polyadducts by reaction known per se of epoxy compounds with polybasic carboxylic acids or polyvalent amines cold or in the warm, characterized that such chlorine-containing compounds are used as epoxy compounds, by reacting epichlorohydrin or glycerol dichlorohydrin with octachlorodihydroxydiphenyl have been prepared in the presence of alkaline agents.