DD262030A1 - PROCESS FOR PREPARING EPOXY NETWORK POLYMERS WITH IMPROVED FLAME INEVENABILITY - Google Patents

Abstract

The invention relates to a process for the preparation of epoxy network polymers with improved flame retardancy, which are characterized by an unusually high phosphorus content and an associated unusually high oxygen index. These polymers are useful in the production of coatings, coatings, composites having reduced flammability.

Description

2. The method according to claim 1, characterized in that the curing reaction takes place in the temperature range between 20 to 220 ° C and optionally a catalyst or accelerator is added.

3. The method according to claim 1 and 2, characterized in that the curing reaction takes place with the addition of an organic or inorganic filler or in a laminating fabric.

4. The method according to claim 1 to 3, characterized in that reactive epoxide and / or aminic diluents are added to the curing mixture.

5. The method according to claim 1 to 4, characterized in that as polyfunctional epoxy compounds preferably N ^ N '^' - tetraglycidyl ^ ^ '- diaminodiphenylmethane, novolac epoxy resins, tetrakis [(2,3-epoxypropoxy) -p-phenyl] ethane and the like be used.

Field of application of the invention

The invention relates to a process for the preparation of epoxy network polymers having improved flame retardancy, which contain a flame-retardant phosphine oxide component in the polymer network and have an unusually high phosphorus content and an oxygen index which is unusually high for epoxy polymers.

Such reduced flame retardant network polymers are useful in the production of coatings, layers, composites, laminates, adhesives, passivation materials for electrical engineering / microelectronics and as construction materials.

Characterization of the known technical solutions

Epoxide-amine network polymers have favorable properties for producing low-tension, well-adhering coatings, laminates, composites, adhesives, etc. However, they are flammable materials that continue to burn even after the fire source has been removed. Under exclusion of air, they are subject to degradation above approx. 360 ° C. They are absolutely resistant to acid or basic hydrolysis.

An improvement in the flame retardancy of these materials is achieved by additional process steps and thus more expensive halogenation of the epoxide components (eg., Tetrabrom-bisphenol A diglycidyl ether) can be achieved.

Polyphosphonates and polyphosphoramides from diepoxide compounds have also been described in the past (US Pat. Nos. 17,232,367, 2,826,592, 2,856,369) and addition polymers of diepoxides and phosphoramideamines of piperazine (US Pat. No. 4,072,633).

However, such polyphosphonates or poly (phosphoramides) are sensitive to hydrolysis, especially under acidic conditions (total degradation in 0.1 N acids), and their thermal stability is often low (see U.S. Patent No. 4,077,633).

Recently, the improvement in flame retardancy of linear phosphine-containing epoxy-amine addition polymers has been reported. The investigations revealed that this addition polymer produced from dimethyl (aminomethyl) phosphine oxide (DMAPO) and bisphenol A diglycidyl ether (DGEBA) an oxygen index Ol = 29.5 at about 6% phosphorus content of the polymer and a glass transition temperature Tg = 82 ° C.

For certain technical applications, a further increase of oxygen index and glass transition temperature is necessary.

However, this task can not be solved by the use of linear DGEBA / DMAPO polymers.

Object of the invention

The object of the invention is to produce epoxy network polymers with improved flame retardancy. The oxygen index should be increased to Ol> 30. At the same time an increase in the glass transition temperature and a further improvement of the mechanical properties is desired.

Explanation of the essence of the invention

It has been found that dimethyl (aminomethyl) phosphine oxide

O (CH ₃ ) ₂

by reaction with polyfunctional glycidyl compounds (number of epoxide groups> 2), preferably by reaction with polyfunctional glycidyl ethers, glycidyl ethers and glycidylamines, polymerize to network polymers having an oxygen index Ol> 30 and a glass transition temperature Tg> 90 ° C and compared to previous epoxide amine Polymers characterized by a further improvement in mechanical properties.

These network polymers are insoluble and infusible, hydrolysis resistant and flame retardant novel epoxy network polymers.

Preferably, the following are used as polyfunctional glycidyl compounds:

- N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane

- Phenol novolak epoxy resin

- cresol novolak epoxy resin

- Tetrakis [(2,3-epoxypropoxy) -p-phenyl] ethane

- Glycidyl ether of glycerol

- Ν, Ν, Ο-triglycidyl-p-aminophenol

- Glycidyl compounds of 1,2,4-Triazolidindonderivaten

To obtain an oxygen index Ol> 30, it is necessary to increase the P content of the polymers to more than 6% phosphorus.

This value can only be achieved in conjunction with the lower epoxide equivalents of polyfunctional glycidyl compounds. The P content is given below for some network polymers:

Glycerol glycidyl ether (epoxide equivalent: 154) / DMAPO 7.5%

NXN''-tetraglycidyl W / t-diaminodiphenylmethane / DMAPO 9.7%

Ν, Ν, Ο-triglycidyl-p-aminophenol / DMAPO 10.6%

The addition polymerization of DMAPO with polyfunctional glycidyl compounds is carried out in bulk at 20 ⁰ C to 220 ⁰ C, preferably at 80 ° C to 150 ° C, optionally in the presence of an accelerator or catalyst.

DMAPO / epoxy compounds are suitable for the production of coatings, films, coatings or laminates. For this purpose, either the monomer mixture in substance or solutions of these compounds in organic solvents or the corresponding anreagierten, still soluble compounds with a low degree of conversion used for further processing.

The introduction of Füll.stoffmaterialien in the corresponding monomer mixtures allows the production of composite materials with increased oxygen index and improved mechanical properties.

embodiments Example 1 .

3.70 g (8.76 mmol) N, NSN'-tetraglycidyl - ^ ^ '- diaminodiphenylmethane and 1.88 g (17.51 mmol) of dimethyl (aminomethyl) phosphine oxide are homogeneously mixed with gentle heating and 6 hours at 20 ⁰ C and then reacted at 120 ⁰ C for 24 hours. The result is a very strong network polymer, which has an increased oxygen index Ol> 30.

Example 2

3.00 g of EPON 812 (epoxide equivalent 154) and 1.04 g of dimethyl (aminomethyl) phosphine oxide are mixed homogeneously and polymerized at 120 ° C. for 24 hours. The epoxide network polymer thus obtained is characterized by an increased oxygen index Ol> 30.

Example 3

6.20 g of phenol Novolakepoxidharz (epoxide equivalent 180) and 1.84 g of dimethyl (aminomethyl) phosphine oxide are mixed homogeneously with heating and then polymerized at 120 ⁰ C for 24 h.

An extremely impact-resistant, glassy amorphous polymer is obtained which is insoluble in organic solvents and has an oxygen index of> Ol> 30.

Claims (1)

1. A process for the preparation of Epoxidnetzwerkpolymeren with improved flame retardancy, characterized in that for curing epoxy compounds having more than two epoxide groups per molecule, preferably for curing of corresponding polyfunctional glycidylamines, glycidyl ethers or glycidyl esters, dimethyl (aminomethyl) phosphine oxide (I) is used. <J