CZ190499A3 - Protective substances against fire for polyurethanes, process for preparing polyurethane plastic materials protected against flame and their use when building railway vehicles - Google Patents

Abstract

Flame retardants for polyurethanes consist K of amine amine red phosphorus and / or melamine derivatives in weight ratio 1: 7.5 to 1: 100. In the production process flame-retardant polyurethane plastics the organic polyisocyanal reacts with at least the compounds two hydrogen isocyanate-reactive hydrogen atoms o molecular weights of 250 to 12,500, optionally crosslinking with at least two hydrogen atoms reactive with isocyanates having a molecular weight of 32 to 249, optionally fillers, blowing agents, stabilizers, activators and / or others known excipients and additives in the presence of a mixture red phosphorus amelamine and / or melamine derivative the weight ratio of red phosphorus of the amine and / or melamine derivative 1: 7.5 to 1: 100. These polyurethane plastics are used in the construction of rolling stock.

Description

Flame retardants for polyurethanes, method of production of flame-protected polyurethane plastics and their use in the construction of rail vehicles

Technical field

FIELD OF THE INVENTION The present invention relates to flame retardants for improving the burning behavior of polyurethane plastics, polyurethane plastics and their use in the construction of rail vehicles.

BACKGROUND OF THE INVENTION

Hard integral polyurethane foams have not yet been used in the construction of rail vehicles because they do not meet the requirements of DIN 5510.

DIN 5510 is a regulation that extensively controls preventive (passive) fire protection for rail vehicles. For this purpose, vehicles are classified in fire protection levels 1 to 4 according to their degree of danger. The classification is primarily based on the possibility of passengers escaping in the event of a fire. Accordingly, for example, vehicles which operate predominantly on underground routes (tunnel traffic, metro) with limited escape between stops are classified to a higher degree of fire protection than vehicles in surface traffic.

Furthermore, the fire behavior of materials and finished parts for the construction of rail vehicles or their resistance to fire is assessed. The fire resistance requirements are governed by

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(i) degree of fire protection;

(Iii) functions and positions of installation of the component in the vehicle.

The use of rigid polyurethane integral foams in rail operation would be a technological and economic advantage if they meet the requirements of DIN 5510 (see below). However, this cannot be achieved with known halogen-free flame retardants (for example, ammonium polyphosphate, and so on).

The use of melamine as a flame retardant is known, for example, from EP-A-0 422 797, EP-A-0 428 258, EP-A-347 J 497, EP-A-0 450 403, EP-A-0 JP-A-7 292 055

L? US-A-36 81 273, US-A-38 97 372. However, as research has shown, the requirements of DIN 5510 cannot be met by using only melamine.

The use of red phosphorus as a flame retardant is also known, for example, from Brandverhalten von Kunststoffen, Dr. Troizsch, Carl-Hanser-Verlag Munchen 1981, page 64, Kunststoffe 79th 1989/11, Carl-Hanser-Verlag Munchen, Halogenfreier Flammschutz mit Phosphorverbindungen, H.Staeneke, Hurth and D.J.Scharf, Coventry / USA.

However, as it has been found, the use of red phosphorus alone cannot meet the requirements of DIN 5510.

But even with the separate use of other flame retardants such as those described in the Kunststoffe Brandprüfungen Flammschutzmittel Umweltfragen, Bestandsaufnahrne und Perspektiven, Dr. Troizsch, page 21, Kunststoffe 79th 1989/11, Carl-Hanser-Verlag Munich, Halogenfreier

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Flammschutz mit Phosphorverbindungen, H.Staendeke, Hurth and D.J.Scharf, Coventry / USA, cannot meet the requirements of DIN 5510.

Even the known combinations of melamine with phosphoric acid derivatives as described in EP-A-0 377 891 do not lead to success.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide flame retardants for polyurethanes and flame retardant polyurethane plastics which are suitable for the construction of rail vehicles in terms of flame behavior.

As has surprisingly been discovered, flame-protected polyurethane plastics can be obtained by adding a flame inhibitor consisting of a mixture of red phosphorus and melamine and / or melamine derivatives in a weight ratio of 1: 7.5 to 1: 100, which are based on their behavior towards flame retardants. flame suitable for use in the construction of rail vehicles. The flame-protected polyurethane plastics according to the invention comply with the requirements of DIN 5510. It is surprising that this can be achieved precisely by this weight ratio of red phosphorus to melamine, while other quantity ratios have proved to be unusable.

The present invention therefore provides a flame retardant suitable for polyurethane plastics consisting of red phosphorus and melamine and / or a melamine derivative in a weight ratio of 1: 7.5 to 1: 100 based on red phosphorus.

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Preferably, the weight ratio is 1:10 to 1:40.

Melamine or melamine derivatives such as melamine cyanurate, melamine phosphate, melamine borate, melamine oxalate, melamine formate, melamine pyrophosphate, dimelamine phosphate and so on can be used.

A further object of the invention is a process for the production of a flame-protected polyurethane plastic in which it reacts

A) an organic polyisocyanate with

(B) compounds with at least two hydrogen atoms reacting with isocyanates of molecular weights of 250 to 12 500 B1), optionally crosslinking agents with at least two hydrogen atoms reacting with isocyanates of molecular weights of 32 to 249,

B2) optionally fillers, blowing agents, stabilizers, activators and / or other known excipients and additives in the presence of

C) a mixture of red phosphorus and melamine and / or melamine derivative in a weight ratio of red phosphorus to melamine and / or melamine derivative of 1: 7.5 to 1: 100.

Preferably mixture C) is used in a weight ratio

10:90 to 50:50, preferably 15:85 to 30:70, relative to the other components A) and Β), optionally A) and B1) and / or B2).

The following may be used as organic polyisocyanates a): polyisocyanates as described, for example, by V. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75-136, for example by the formulas:

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Q (NCO) _n ' ⁴ wherein n represents 2 to 4, preferably 2 to 3 a

Q an aliphatic hydrocarbon radical having 2 to 18, preferably up to 10 carbon atoms, a cycloaliphatic hydrocarbon radical having 4 to 15, preferably 5 to 10 carbon atoms, an aromatic hydrocarbon radical having 6 to 15, preferably 6 to 13 carbon atoms or an araliphatic hydrocarbon radical having 8 to 15, preferably 8 to 13, carbon atoms, for example those polyisocyanates described in DE-OS 28 32 253, pages to 11.

Generally, technically accessible polyA * isocyanates are used, for example 2,4- and 2,6-toluylenediisocyanates, as well as any mixtures of these isomers (TDI), polyphenyl polymethylene polyisocyanates, which are produced by aniline-formaldehyde condensation and subsequent phosgenation (crude MDI) And polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, as well as urea groups or biuret groups (modified | polyisocyanates), for example modified polyisocyanates, derived from 2,4- and 2,6- toluylene diisocyanate, optionally 4,4- and / or 2,4-diphenylmethane diisocyanate. Preferably, diisocyanate-diphenylmethane (MDI) is used as pure MDI monomer or as a MDI polymer in admixture with its multi-core hostologists.

Compounds having at least two isocyanate-reactive hydrogen atoms and having a molecular weight of generally 250 to 12,500 g / mol are used as the starting component B). These include; »9 9 9»

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in addition to compounds containing amino, thiol or carboxyl groups, hydroxyl-containing compounds, preferably polyethers, polyesters, polycarbonates, polylactones and polyamides, in particular compounds containing 2 to 8 hydroxyl groups, in particular compounds having a molecular weight of 250 to 10,000, for example compounds containing at least 2, as a rule 2 to 8, preferably 2 to 4 hydroxyl groups, which are known for the production of homogeneous and cellular polyurethanes and are described, for example, in DE-OS 28 32 253, pages 11 to 18. Mixtures according to the invention are also possible various compounds of this kind.

The crosslinkers used, if any, are also compounds having at least two hydrogen atoms reacting with isocyanates and having a molecular weight of 32 to 249. Also in this case are meant compounds containing hydroxyl groups and / or amino groups and / or thiol groups and / or carboxyl groups, preferably compounds containing hydroxyl groups and / or amino groups which serve as crosslinking agents. These compounds generally have 2 to 8, preferably 2 to 4, hydrogen atoms reacting with isocyanates. Examples of such compounds are described in DE-OS 28 32 253, pages 19 to 20.

Optionally, fillers, blowing agents, stabilizers, activators and other known excipients and additives such as emulsifiers, reaction inhibitors, structural regulators, plasticizers, colorants and fungistatically and bacteriostatically active substances can also be used as component B2). Details of the use and effect of these additives are described in Kunstoff-Handbuch, Volume VII, issued by Vieweg and Hötchtlen, Carl-Hansen Verlag, Munchen 1966, for example on pages 103 to 113.

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The blowing agents which may be used at the same time are the blowing agents which are commonly used for foaming polyurethane foams.

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Examples of such blowing agents are alkanes such as n-pentane, iso-pentane, mixtures of iso- and n-pentanes, cyclopentane, cyclohexane, mixtures of butane isomers and said alkanes, partially halogenated fluorochlorohydrocarbons such as 1,1,1-dichlorofluoroethane (R 141b), partially fluorinated hydrocarbons such as 1,1,1,3,3,3-hexafluorobutane (R 356) or 1,1,1,3,3-pentafluoropropane (R 245 fa).

The flame-protected polyurethane plastics according to the invention can be produced as elastomers by casting, as hard or soft foams by a continuous or discontinuous manufacturing process or as foamed or solid molded parts.

In the case where structural moldings are to be produced, foaming is usually carried out in a closed mold. The reaction mixture is then introduced into the mold. Possible mold materials are metals, for example aluminum, or plastics, for example epoxy resins. A foaming capable reaction mixture foams in a mold and forms a shaped body. The foaming in the mold can be conducted in such a way that the shaped part has a cellular structure on its upper side. However, it can also be realized that the molded part has a compact surface and a structured core. In this connection, it is possible to introduce so much reaction mixture capable of foaming into the mold that the foam formed just fills the mold. However, it can also be done by introducing more foamable reaction mixture into the mold than is necessary to fill the interior of the mold with foam.

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99 behind the stiffness. In the latter case, the overcharging conditions are applied; a method of this kind is well known from US-PS 3,178,490 and 3,182,104.

Of course, the foams of the invention can also be produced by block foaming or a double conveyor belt in a known manner.

Advantageously, the foams of the invention are produced as integral foams by the Reaction-Injection Molding (RIM) method.

The polyurethane plastics according to the invention show surprisingly good burning behavior and are therefore suitable for use in the construction of rail vehicles. In terms of their fire behavior, they comply with the requirements of DIN 5510.

It is therefore a further object of the invention to use the above-described polyurethane plastics in the construction of rail vehicles.

The following examples are intended to illustrate the invention without limiting it.

DETAILED DESCRIPTION OF THE INVENTION

Examples 1 to 3

Ingredients :

Baydur 6110

Phosphorus red / melamine Desmodur 44 V 10

100 parts by weight 60 to 80 parts by weight

135 parts by weight hmotnostních t t t t t 4 4 4 4 4 4 hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních hmotnostních 4 4 4 4 4 4 4 4 4 4 4 4 4 4 '3

The test plates are manufactured with a production density of 700 kg / m and a thickness of 10 mra. This is done on a Rimdomaten electronically controlled high pressure piston metering device. The production is carried out on the RIMDOMATEN plant of Hennecke (Germany,

St.Augustin).

Examples 4 to 6

Ingredients :

Baydur VP PU 1598 Phosphorus red / melamine Desmodur 44 V 10

100 parts by weight 60 to 80 parts by weight

113 parts by weight / For examples 4 to 6, the test plates are produced with a production density of 1200 kg / m @ 2 and a thickness of 4 mm. Production is also carried out on the RIMDOMATEN.

For the experiments of Examples 1 to 6, red phosphorus was used as a 50% paste (carrier: castor oil, Hostaflam AP 750, manufactured by Hoechst) and melamine as a powder with a grain size d of 99 175-200 μπι (manufactured by DSM).

Fire behavior tests

The fire behavior tests of materials and finished parts are carried out in accordance with DIN 54 837. The flame test measures the flammability class (S), the smoke evolution class (SR) and the dropping class (ST). For classification into flammability classes, both the volume of destruction during the flame effect and the post-flame burn-out time shall be taken into account.

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Table 1, (Classification criteria for flammability classes (S) according to DIN 5510

-Flammability class Destroyed length Burning time S2 not reached > 30 cm any S2 <30 cm any S3 25 cm s 100 s S4 with 20 cm 10 p S5 0 cm 0 sec

To determine the smoke evolution class, the integral light loss is measured throughout the experiment.

Table 2

Criteria for classification into smoke evolution classes (SR) according to DIN 5510

Smoke evolution class Integral loss of light SR 1 100% * min SR 2 <50% * min

The assessment of the dropping class is carried out according to the non-dripping, dripping or dripping burning criteria. Polyurethane dripping is less affected by flame retardants, but rather is a material property that is due to the chemical structure. The Baydur types tested here are so heavily crosslinked that they usually withstand the drop test.

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Table 3

Criteria for classification to dropping (ST) classes according to DIN 5510

Dropping class Observation ST 1 non-dripping ST 2 drips or drips non-flaming *

* maximum afterburning time 20 s

S4, SR2, JST2 are required to allow a wide range of PUR integral rigid foam applications.

Brief description of the procedure according to DIN 54837

In a flame box or a correspondingly changed flame shaft, a perpendicularly positioned test body is exposed to the flame of a gas burner with a wide flame adapter. The length of the test specimen destroyed by fire, smoke formation and drop behavior are determined.

Five specimens of 500 mm x 190 mm x d are used.

Overview of Examples 1 to 6

Experiment no. 1 2 3 4 5 6 Preservative means 1 mela- min worm. phosphorus worm. phosphorus mela- min worm. phosphorus worm. phosphorus Concentration% wt. 20 May 25 2 20 May 2 8 Preservative 2 - - mela- min mela- min mela- min Concentration% wt. - - 20 May - 20 May 20 May Flammability class S2 S2 S4 S3 S4 S3 Destroyed length cm 22.6 26.4 15.8 19.4 14.2 19.6 Burning time cm > 120 28.4 1.6 46 4.6 50 Development class of smoke products SR SRI SRI does not no SR2 SRI SR2 SRI Integral smoke density% x min 66.8 198 30 61 40 79 Dropping ST ST2 ST2 ST2 STÍ ST2 ST2

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Claims (10)

PATENTOVÉ Claims 1. Flame retardants for polyurethane plastics,. characterized in that they consist of red phosphorus and melamine and / or melamine derivatives in a weight ratio of 1: 7.5 to 1: 100. Fire-retardants according to claim 1, characterized in that the weight ratio of red phosphorus to melamine and / or melamine derivative is from 1:10 to 1:40. Flame retardants according to one of the preceding claims, characterized in that melamine derivatives used are melamine borate, melamine oxalate, melamine formate, melamine pyrophosphate and / or dimelamine phosphate. Fire protection agents according to one of the preceding claims, characterized in that red phosphorus is used in the form of a paste or powder and melamine is used as a powder with a grain size in the range of 150 to 350 μπι. 5. A method for producing flame-protected polyurethane plastics, characterized in that it is allowed to react A) an organic polyisocyanate with B) compounds having at least two hydrogen atoms reacting with isocyanates of molecular weight of 250 to 12, and having molecular weights of 250 to 12; '· · ··' · 9 · · · « - · ί · · <<....... i · f l · · 500, (B) optionally crosslinking agents with at least two hydrogen atoms reacting with isocyanates having a molecular weight of 32 to 249; B2) optionally fillers, blowing agents, stabilizers, activators and / or other known excipients and additives in the presence of C) a mixture of red phosphorus and melamine and / or melamine derivative in a weight ratio of red phosphorus to melamine and / or melamine derivative of 1: 7.5 to 1: 100. Method according to claim 5, characterized in that mixture C) is used in a weight ratio of 10:90 to 50:50, based on the sum of the other components. Process according to one of Claims 5 to 6, characterized in that the polyisocyanate used is a polymer-MDI diisocyanate. Method according to one of Claims 5 to 7, characterized in that a polyurethane integral foam is produced. Polyurethane foam produced according to any one of claims 5 to 8, characterized in that the polyurethane foam complies with the fire protection requirements of DIN 5510. Use of a polyurethane foam produced according to claims 5 to 8 in the construction of rail vehicles.