PL189669B1 - Flexible self-extinguishing polyurethane foam and method of obtaining same - Google Patents

Abstract

1. A method for producing a flexible, self-extinguishing polyurethane foam, characterized in that 1-5 parts by weight of a surfactant, 50-100 parts by weight of a polyol, 2-60 parts by weight of tri(di-Sanolaminomethyl)melamine mono- or diphosphate and optionally up to 40 parts by weight of aliphatic bromine derivatives and 0.1-7 parts by weight of a catalyst are mixed, after mixing 70-130 parts by weight of monomeric diphenylmethane 4,4'-diisocyanate are added to the reaction product, the mixture is mixed until a creamy consistency is obtained and then the product is poured into a mold.

Description

The subject of the invention is a method of producing a flexible, self-extinguishing polyurethane foam intended for the furniture and automotive industries.

The main problem of modern polymer materials is their flammability - it gives tangible losses to the national economy, and also poses a direct threat to the lives of their producers and users, so it concerns the broad masses of society.

Polyurethanes (PUR) are flammable materials, especially PUR foams, with a large polymer-gas phase interface. During burning, they release large amounts of toxic substances, including hydrogen cyanide and carbon monoxide.

On January 1, 1997, in accordance with the decisions of the Montreal conference, CCI3F freon was withdrawn from use worldwide, which was so far the best blowing agent for the production of polyurethane foams (PTPUR). Research by scientists has shown that it contributes significantly to the destruction of the ozone layer. Withdrawal of this compound resulted in the need to search for new, ecological technologies for obtaining polyurethane foams with the use of ecological blowing agents. Currently, attempts are being made to use low-boiling hydrocarbons such as pentane or isopentane as blowing agents. Although they do not affect the destruction of the ozone layer, they are flammable and pose a high risk of fire in places where polyurethane foams are produced.

For many years to reduce the flammability of various materials, including polymers, compounds containing elements such as chlorine, bromine, nitrogen, phosphorus, antimony and others have been used for many years. The combinations of phosphorus with nitrogen and phosphorus with bromine are particularly effective. When using such compounds, there is a synergistic effect, i.e. enhancing the material extinction process.

One of the best flame retardants for polymers are ammonium phosphate, brominated phosphoric esters, brominated glycols and other substances such as melamine. Powdered melamine has been used for many years as a flame retardant for polyurethane foams. Melamine containing 67% nitrogen, used in the amount of 25-50% in relation to the polymer, ensured the production of polyurethane foams with reduced flammability. Unfortunately, the addition of a powdered substance constituting a separate phase in the polymer significantly deteriorated the strength properties of the material. Therefore, research was started on the introduction of melamine into the polymer chain, which would not deteriorate the strength properties of the material, and at the same time would provide reduced flammability of polyurethane foams.

In order to introduce melamine into the polymer chain, it was necessary to obtain such liquid derivatives which would contain reactive hydroxyl groups capable of reacting with isocyanates to form urethane polymers.

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The works disclosed in publications (Lubczak J, Chmiel E .: Polimery 1990, 35, 194-199, and Lubczak J .: Polimery 1995, 40, 509-516) consist in obtaining hydroxymethyl derivatives of melamine and then reacting them with oxiranes (mainly ethylene and propylene oxide). Then, liquid polyetherols are formed, from which self-extinguishing polyurethane foams with increased heat resistance are obtained.

The works presented in the publication (Z. Wirpsza:, XII Conference - Modification of Polymers, Kudowa Zdrój, September 1995, RP-13 materials, pp. 38-42) consist in obtaining the so-called reactive solvents, i.e. the reaction products of formaldehyde with ketones, in which the melamine is then dissolved to obtain liquid products that can react with isocyanates to give urethane polymers. In this way, flame retardant polyurethane foams were obtained.

There are also many publications on the preparation of flame retardant polyurethane foams with the use of bromine compounds.

The existing solutions aimed at obtaining self-extinguishing polyurethane foams based on liquid melamine derivatives (flame retardants), both at home and abroad, have many disadvantages, and the best confirmation of them is the fact that nowhere in the world are polyurethane foams with the use of this type of flame retardant produced in larger scale.

In the works disclosed in publications (Lubczak J, Chmiel E .: Polimery 1990, 35, 194-199, and Lubczak J .: Polimery 1995, 40, 509-516), the reaction of obtaining flame retardants-polyetherols containing a melamine ring (very rich in nitrogen) takes place from several dozen to several hundred hours (at 40-60 ° C) in the presence of toxic solvents such as DMSO or DMF, which are difficult to separate from the main product. During such a long reaction time, condensation of -CH2OH groups takes place, leading to gelation of the product.

Attempts to replace the solvents that are toxic and very inconvenient for the industry (DMSO and DMF), for example with water, were unsuccessful, because in this case pyrene-polyetherols containing 20-85% of by-products, mainly low molecular weight glycols, were obtained. Due to the above-mentioned disadvantages, it was not possible to obtain flame retardants-melamine polyetherols on a larger scale, and therefore, self-extinguishing polyurethane foams based on these intermediates.

In the works presented in the publication (Z. Wirpsza:, XII Conference - Polymer Modification, Kudowa Zdrój, September 1995, RP-13 materials, pp. 38-42) the so-called reactive solvents (RR), i.e. formaldehyde reaction products with ketones. In these products, after partial removal of water, melamine is dissolved hot to a content of several to several% (at a temperature of 130-150 ° C) to obtain a concentrated solution of melamine resin (approx. 80-90%) that can be used as a reactive flame retardant containing large amounts of flame-retardant element - nitrogen. However, the durability of the thus obtained melamine derivative at room temperature is up to 24 hours, and it is a solid product at room temperature. By slightly modifying the preparation procedure, it is possible to obtain this type of liquid flame retardant, but its durability is very limited (up to 48 hours).

By using RR, liquid melamine flame retardants are obtained, which contain a very high content of free formaldehyde. Due to the short durability of these compounds and the very high content of free formaldehyde in them, polyurethane foams based on them emit large amounts of free formaldehyde and cannot be used in closed spaces.

It turned out that the above-mentioned disadvantages can be avoided and a new type of flexible, self-extinguishing polyurethane foams containing in their composition the s-triazine melamine ring can be obtained, meeting the requirements for this type of product.

The process according to the invention consists in obtaining, in the first step, tri (diethanolaminomethyl) melamine mono- or diphosphate as new, liquid, reactive nitrogen-phosphorus flame retardants, and then using them to obtain self-extinguishing polyurethane foams.

According to the invention, 1-5 parts by weight of surfactant, 50-100 parts by weight of polyol, 2-60 parts by weight of tri (diethanolaminomethyl) melamine mono- or diphosphate and optionally up to 40 parts by weight of aliphatic polyol are mixed.

After mixing, 70-130 parts by weight of monomeric diphenylmethane 4,4'-diisocyanate are added to the reaction product, mixed until a creamy consistency, and the product is poured into a mold after 1869,669 bromine derivatives and 0.1-7 parts by weight of the catalyst. The catalyst is preferably dibutyltin dilaurate. Preferred aliphatic bromo derivatives are dibromobutendiol or dibromoneopentyl glycol.

Thanks to the use of tri (diethanolaminomethyl) melamine mono and diphosphates as reactive, liquid flame retardants, it was possible to obtain PUR foams without the use of amine catalysts harmful to health, which is very important and promising from an ecological point of view.

It was found that the use of the above flame retardants greatly increases the oxygen index of the polyurethane polymer to a value exceeding 25%, without the use of other bromine flame retardants. In addition, polyurethane foams containing new phosphorus-nitrogen antipyrins in their composition have 2-4 times greater hardness than the foams obtained without them.

Due to the fact that cheap and domestically produced raw materials are used for the production of the above phosphorus-nitrogen flame retardants, the polyurethane foams obtained on their basis also have lower costs than the foams obtained on the basis of more expensive foreign flame retardants with a similar nature of action.

The subject of the invention is illustrated on the examples of its implementation.

Example I

In a plastic container with a capacity of 500 ml, 160 g of polyoxyalkylene triol (Rokopol M 111), 40 g of tri (diethanolaminomethyl) melamine monophosphate, 2 g of sodium lauryl sulfate surfactant and 3.0 g of dibutyl tin dilaurate as catalyst were weighed. The mixture was mixed with a high-speed laboratory stirrer for 3 minutes, and then 240 g of the liquid monomeric diphenylmethane 4,4'-diisocyanate (MDI named Suprasec X2412) was added. The reaction mixture was stirred until cremated and poured quickly into a 20 x 20 x 20 cm wooden mold lined with polyethylene foil. After several minutes, a flexible, self-extinguishing polyurethane foam was obtained.

Example II

In a plastic container with a capacity of 500 ml, 170 g of polyoxyalkylene triol (Rokopol M 12), 30 g of tri (diethanolaminomethyl) melamine monophosphate, 20 g of tribromoneopentyl alcohol, 2 g of sodium lauryl sulfate surfactant and 3.0 g of dibutyl tin dilaurate as catalyst were weighed. The whole was mixed with a high-speed laboratory mixer for 3 minutes, and then 220 g of liquid, monomeric MDI called Suprasec X2412 was added. The reaction mixture was stirred until cremated and poured quickly into a 20 x 20 x 20 cm wooden mold lined with polyethylene foil. After several minutes, a flexible, self-extinguishing polyurethane foam was obtained.

Example DI

In a plastic container with a capacity of 500 ml were weighed 160 g Rokopol M 111, 40 g of non-amine tri (diethanolaminomethyl) diphosphate, 2 g of sodium lauryl sulfate as a surfactant and 6.0 g of dibutyl tin dilaurate as a catalyst. The whole was mixed with a high-speed laboratory stirrer for 3 minutes, and then 240 g of liquid, monomeric MDI called Suprasec Χ2412 was added. The reaction mixture was stirred until cremated and poured quickly into a 20 x 20 x 20 cm wooden mold lined with polyethylene foil. After several minutes, a flexible, self-extinguishing polyurethane foam was obtained.

Example IV

In a plastic container with a capacity of 500 ml were weighed 160 g Rokopol M 111, 40 g tri (diethanolaminomethyl) melamine, 30 g dibromobutendiol, 2 g sodium lauryl sulfate as a surfactant and 2.0 g dibutyl tin dilaurate as a catalyst. The whole was mixed with a high-speed laboratory mixer for 3 minutes, and then 220 g of liquid, monomeric MDI called Suprasec Χ2412 was added. The reaction mixture was stirred until cremated and poured quickly into a 20 x 20 x 20 cm wooden mold lined with polyethylene foil. After several minutes, a flexible, self-extinguishing polyurethane foam was obtained.

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Example V

In a plastic container with a capacity of 500 ml were weighed 180 g Rokopol M 12, 20 g of tri (diethanolaminomethyl) melamine monophosphate, 2 g of sodium lauryl sulfate as a surfactant and 4.0 g of dibutyl tin dilaurate as a catalyst. The whole was mixed with a high-speed laboratory mixer for 3 minutes, and then 230 g of liquid, monomeric MDI called Suprasec X2412 was added. The reaction mixture was stirred until cremated and poured quickly into a 20 x 20 x 20 cm wooden mold lined with polyethylene foil. After several minutes, a flexible, self-extinguishing polyurethane foam was obtained.

Example Vi

In a plastic container with a capacity of 500 ml were weighed 120 g Rokopol M 111, 80 g of tri (diethanolaminomethyl) melamine monophosphate, 20 g of tribromoneopentyl alcohol, 2 g of sodium lauryl sulfate as a surfactant and 3.0 g of dibutyl tin dilaurate as a catalyst. The whole was mixed with a high-speed laboratory mixer for 3 minutes, and then 240 g of liquid, monomeric MDI called Suprasec X2412 was added. The reaction mixture was stirred until cremated and poured quickly into a 20 x 20 x 20 cm wooden mold lined with polyethylene foil. After several minutes, a flexible, self-extinguishing polyurethane foam was obtained.

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Publishing Department of the UP RP. Circulation of 50 copies

Price PLN 2.00.

Claims (3)

Patent claims A method for producing a flexible self-extinguishing polyurethane foam, characterized by mixing 1-5 parts by weight of a surfactant, 50-100 parts by weight of polyol, 2-60 parts by weight of tri (diethanolaminomethyl) melamine mono- or diphosphate, and optionally to 40 parts by weight of aliphatic bromine derivatives and 0.1-7 parts by weight of catalyst, after mixing, 70-130 parts by weight of monomeric 4'-diphenylmethane diisocyanate are added to the reaction product, mixed until a creamy consistency, and then poured the product into a mold. 2. The method according to p. The process of claim 1, wherein the catalyst is dibutyltin dilaurate. 3. The method according to p. A process as claimed in claim 1, characterized in that dibromobutendiol or dibromoneopentyl glycol is used as the aliphatic bromine derivatives.