DE2246697A1 - POLYURETHANE FOAMS AND METHOD FOR THEIR PRODUCTION - Google Patents

Description

DR. MÜLLER-BORE DIPL.-PHYS. DR. MANiTZ OIPL.-CHEM. DR. DEUFEL DIPL.-ING. FINSTERWALD DIPL.-ING. GRÄMKOW

PATENT LAWYERS

2 Sep. 1972

D / Lo / Sh - D 1367

DUMLOP LIMIiEED

Dunlop House, Byder Street, St. James's London S V 1 / EHGLAHD

Polyurethane foams and processes for their Manufacturing

Priority: Great Britain v. 22nd September 1971 44-n 4-3 / 71

The invention relates to polyurethane foams and, in particular, to non-flammable polyurethane foams and to a method for their manufacture »

It has been found that, according to the invention, polyurethane foams with good resistance to burning, i.e. Non-flammability, can be obtained by a process in which a polymeric polyol with an organic polyisocyanate is reacted in a foam-forming reaction mixture, which is characterized in that a mixture

BATH ORIGINAL 309816/1035

is applied, which (a) as a foam modifier substance normally effective as a catalyst for the polymerization of tolylene diisocyanate, (b) an acid generator Substance to substantially eliminate any deleterious effect of the foam modifier on the aging of the Polyurethane foam, and (c) a surfactant that contains an ester of a carboxylic acid 10 to 20 carbon atoms and an aliphatic polyhydroxy compound is, contains.

In particular, the term "polymerization of tolylene diisocyanate" means the polymerization of three molecules Tolylene diisocyanate, hereinafter abbreviated to TDI, for To understand preparation of a cyclic trimer of usually isocyanurate or perhydrotriazine structure. It is not known for sure if the foam modifier in the present invention actually results in the polymerization of TDI in the reaction mixture, es, cLrd but assumed that polymerization occurs, at least when pure TDI is initially present «

A particular advantage of the foams according to the invention is that they emit much less smoke than conventional, non-flammable, large amount of halogen compounds or Foams containing similar flame retardants when exposed to a flame, this is a special one valuable, practical advantage, since the release of harmful breaths or harmful vapors when exposed to Flaming is one of the main disadvantages of such conventional, non-flammable foams.

Substances that catalyze the polymerization of TDI include the following substances:

BATH ORIGINAL 309816 / 103S

Alkali and alkaline earth of organic and weak inorganic acids, for _o example, salts of carboxylic acids such as sodium and potassium, other metal salts of carboxylic acids, eg. B _{0 lead} heptane carboxylate (lead octoate) and calcium naphthenate, alkoxides or phenoxides of alkali. Or alkaline earth metals, z. B. sodium methoxide and sodium phenate, quaternary ammonium bases, ζ »B. tetramethyl and tetraethylammonium hydroxide, and certain tertiary amines, e.g. tetramethylgusLnidine.

Substances of particular interest are alkaline substances, e.g. B. alkali metal hydroxides and alkali metal salts or derivatives of weak organic or inorganic acids. Examples of such acids are monocarboxylic acids such as acetic acid and aliphatic ^ carboxylic acids with 10 to 20 carbon atoms, ζ «. B. Lauric, oleic, myristic and palmitic acids, and hydroxyaromatic Compounds such as / phenols, e.g. phenol itself (CgHj-OH), and boric acid. Suitable modifiers are z. B. sodium phenate, sodium acetate, potassium acetate, 'sodium tetraborate (Borax), sodium sesquicarbonate, sodium carbonate, sodium oleate and potassium oleate. Of course that should special substance or the special substances which are used as foam modifiers in the process according to the invention are used, are selected in such a way that there is no undesirable effect on the scliaum formation reaction ' is.

Particularly important foam modifiers for the inventive .Processes are basic substances, which are preferably are easily soluble in water. The following description relates in particular to such foam modifications ikationsiaittel.

The amount of foam modifier added depends _; .ι »- of the particular modifier used and the

3 0 9 8 16/1 03 5 BAD ORIGINAL

Type of ingredients in the foam-forming reaction mixture away. Obxirohl can be used in larger quantities, it is in generally not required, larger quantities alö ■■ *>. Weight-96 of the polyol component, and the preferred amount is 0.05 to 2% by weight, particularly preferably 0.2 to 0.5 Wt%. However, if the foam modifier is a tertiary When is amine, the preferred amount is slightly higher, and amounts up to 5% by weight or even more may be required get good results. Likewise, larger quantities can be used than 5% by volume may be required when using the foam modifier is a salt of a long chain fatty acid. The foam modifier can be incorporated in a variety of ways as appropriate.

The polyhydroxy compound from which the surfactant Substance derived in the form of an ester can be, for example, one or more of the following compounds:

a) polyhydric alcohols with 2, 3 »4- or more hydroxyl groups, z. B. glycol, glycerin, pentaerythritol and trimethylolpropanj

b) sugars and their derivatives, e.g. B, sorbitol and mannitol;

c) Adducts of the abovementioned compounds (a) or (b) with Ethylene oxide, e.g. B. Adducts with up to 20 moles of ethylene oxide per hydroxyl group.

The acid component of the ester can be saturated or unsaturated Be fatty acids, e.g. lauric oil, stearic, myristic, Ricinoleic or palmitic acid. Acids with 16 to 18 carbon atoms are particularly beneficial.

One or more of the hydroxyl groups of the polyhydroxy compound can be esterified, e.g. B, the praying person can be a mono- or di-teter be of glycerin. In general, it is preferred that

309816 / 103S

Ester has one or more non-esterified hydroxyl groups. Very suitable surfactants are those which are effective as emulsifying agents for water-in-oil emulsions and those used in the food sector as an air entrainment additive are useful, e.g. B »glycerol monostearate,

The amount of the surfactant introduced into the foam-forming reaction mixture depends on the particular surfactant used and the nature of the other components in the foam-forming reaction mixture. Suitable amounts of the surfactant are up to 15% by weight, e.g. B ₀ ρ to 12% by weight, of the polyol component. The surfactant can be incorporated in a number of ways which are most appropriate. The surfactants used in the process of the present invention have been found to be effective to permit the use of polyols which are normally considered to be relatively slow reacting For example, the polyol can be a poly (oxypropylene) polyol which, if at all, has only a few terminal, primary hydroxyl groups.Suitable polyols of this type are, for example, poly (oxypropylene) poly (oxyethylene) triols, e.g. B. those with a molecular weight of 3,000 to 6,000 in which virtually all of the terminal hydroxyl groups are secondary hydroxyl groups. Polyols of greater activity can optionally be used, e.g. B. Polyols which have a substantial proportion of terminal, primary hydroxyl groups, which are commonly referred to as "ethylene oxide terminated polyols". Suitable polyols terminated with ethylene oxide are those in which the primary hydroxyl groups are 20 to 70 fo, e.g. B. 50 to 60% or 60 to 70%, the total number of hydroxyl groups in this polyol make up

309816/10 35

Plurality of active hydrogen atoms having "jftit an alkylene _ζ β B. Eropylenoxid or a mixture of Eropylenoxid and ethylene oxide, and subsequent! Attaching has been obtained in the thus obtained product with Athylenöxid with introduction of terminal primary hydroxyl groups · examples of polyether polyols of this type are Fölyäthertrlole with very high activity, which have an average molecular weight of 4500 to 5100 and a hydroxy number of 33 to 37.

The non-flammable foams according to the invention can, for example Foams with a density up to 64 kg / ur and in particular Foams with densities in the range of 16 to 40 kg / m »

The anti-aging agents used in the method according to the invention are generally acid-generating substances which under the conditions in the foam-forming reaction mixture can release a strong enough acid to effectively remove any excess or undesirable to neutralize basic foam modifier Heat and / or water are produced

It is particularly advantageous if the anti-aging agent is influenced by the exothermic foaming reaction generated heat is decomposed to form an acid, and if any residue not so decomposed is stable. The anti-aging agent should be selected so that neither it nor any residue left after the acid is released interferes with the foaming reaction interferes with or has a detrimental effect on the resulting foam product owns

309816/1035

2246637

The aging foam agent can, for example, be a substance which contains labile halogen. Suitable anti-aging agents are halogenated, aliphatic ^ phosphate esters such as chlorine and bromine derivatives of trialkyl orthophosphates, e.g. B. Compounds of the formula KJPO, in which JB is a halogenated and preferably polyhalogenated alkyl radical having 2, 3 or 4 carbon atoms. Examples of suitable anti-aging agents are tri-betachloräthylphosphat, trisdichloropropyl phosphate and tris-dibromopropyl ((DBPP) xielches is particularly liirksam ₀ Although einige''dieser compounds are flame retardants themselves, and although they contribute to the Mchtentflammbarkeit the foams is their effect in the Direction is only secondary, and the non-flammability of the foams is mainly due to the use of the particular foam modifier according to the invention. The amount of anti-aging agent to be used depends of course on the particular additive used and also on the type of foam for which it is to be used. It has been found, however, that generally an amount of 0.4 to 5 parts, and more particularly 1.5 ^> ± 3 parts per 100 ropes of the polyol component is effective. It should be noted that such amounts are much less than the amounts in which, for example, TBPP is usually referred to as flam Inhibiting additive is used, which is usually about 15 to 20 parts per 100 parts of polyol. It has been found that when an organic bromine compound is used as an additive, particularly effective amounts correspond to an amount up to 0.25% by weight, for example 0.05 to 0.1% by weight, of bromine per 100 parts of the polyol component . When the additive is a chlorine compound, particularly effective amounts correspond to a ^ close up to 0.5 wt .-%, for example 0.1 to 0.2 wt _{e o} -%, of chlorine per 100 parts of the polyol component *

The anti-aging agents are generally covalent, organic

309816/1035

niche compounds containing a labile halogen atom or labile Contain halogen atoms. Such compounds can have their labile halogen, for example, as a result of the interaction between lose the halogen and alkali metal ions. The additives should be selected so that neither they nor any after the loss of the labile halogen residual substance remaining exert an undesirable influence on the reactions in the foaming reaction mixture. It is believed, that the preferred additives described above are unlikely to lose their halogen until the first stages the foaming reaction is complete, but it then releases its halogen, perhaps as a result of the exothermic Reaction generated heat, lose, which then combines with alkali metal ions in the reaction mixture. being their interaction with the reaction mechanism or a harmful influence on the foam product is excluded.

Many of the foam modifiers described above are also catalysts for polyurethane foam-forming reactions. However, if the foam modifier is not such a catalyst to a sufficient extent, it should a catalyst for the foaming reactions can be used up. "

Suitable catalysts are amine catalysts, e.g. B. dimethylethanolamine, IT-methyl- and N-ethylmorpholine, triethylamine and Triethylenediamine (also known as 1,4-diazobicyclo-2,2,2-octane known) and other tertiary amines.

In certain circumstances, for example when harder foams are desired, crosslinking agents can be used.

Examples of such suitable crosslinking agents are hydroxyamines /

309816/1035

Triethanolamine and tetrakis-N-betahydroxypropylethylenediamine, Low molecular weight polyols such as tetrols, hydroxy ethers, z. B. Tris-hydroxypropylglycerin, and qrtho-dichloromethylene-bis-aniline.

In general, the polyisocyanate and polyol components are used in such amounts that the isocyanate index has a normal value, e.g. B. is in the range of 100 Ms. If necessary, however, values of the isocyanate index can also be used outside of this range, however, it has been found that exceeding a value of 150 is not required.

The polyisocyanate can be, for example, tolylene diisocyanate (TDI). When referring to TDI in the description can contain one or more isomers thereof. For example, it can be tolylene-2,6-diisocyanate or a mixture this "compound with other isomers of tolylene diisocyanate, e.g. a mixture of the 2,4- and 2,6-isomers in the weight ratios of 80/20 (80:20 TDI) or 65/36 (65:35 TDI).

The TDI can, for example, be pure TDI, raw TDI or TDI be in polymeric form or a mixture thereof. Crude TDI can be obtained by reacting the corresponding diaminotoluene with Phosgene can be obtained without any substantial purification. It is assumed that there are substances with polyurea and polybiuret structure. If a mixture of 2,4- and 2,6-diaminotoluene is used contains the crude TDI the corresponding 2,4- and 2,6-diisocyanates.

Polymeric TDIII usually has a uretdione or isocyanurate structure. It can be prepared from pure TDI in a separate pre-reaction using polymerisation procedures known per se can be obtained.

309816/1035

224669?

- ίο -

It has been found advantageous to include small amounts of polydimethylsiloxane in the approach to modify the Enter pore structure. A typical content is, for example, in the range from 0.05 to 0.1% by weight of a variety with a viscosity of 5 centistokes, based on the weight of the polyol ο Alternatively or in addition, small Amounts of a polysiloxane-oxyalkylene block polymer used »If such block copolymers are used, They should preferably be in a 0.2 wt, - $ », in particular 0.05 to 0.1% by weight, based on the weight of the polyol, Do not use excessive amounts · The use of larger amounts of polysiloxane-pxyalkylene block copolymers should be avoided as they have the non-detentiflamnability properties of the polyurethane foams obtained could.

In addition to the usual foam sheets (block moldings and the Moldings vulcanized in the strand can be the Polyurethane foams by an ifpr method with cold vulcanization be shaped, d. H. according to a procedure in which the sphaumpildende reaction mixture without application formed by heat and left to vulcanize wi: pd.

In addition, the β2? Ϊ́ίηα.μη535 ^ 8ίββη foams are used in the process of coating φβχΐί ^ ΐβη and other substrates suitable.

Although the invention is not intended to be limited by reference to any particular theory, it is believed that the catalyst has the effect of producing a polyurethane foam having a special structure so that the foam, when exposed to a flame, melts inclines and thereby withdraws from the flame. These

OHIQ) NAL INSPECTED 309816/1035

View is supported by the observation that the area of the foam which is exposed to the heat of the flame, if an inflamed match is placed on a block of foam of the invention, withdraws from the flame without any substantial burning ₀

The invention is illustrated below with reference to examples in which flexible polyurethane foams according to the one-step method can be obtained.

In the examples, polyol A is a poly (oxypropylene) -poly (oxyethylene) -triol with the following properties:

Molecular weight = about 5000

Hydroxyl number 35 to 37

Polyoxyethylene) content about 12 to 13% by weight

The proportion of primary hydroxyl groups in the polyol is in the range of 60 to 70 ° / ° eggs total number of hydroxyl groups.

The polyol B is a poly (oxypropylene) -poly (oxyethylene) triol having the following properties:

Molecular weight = about 3500

Hydroxyl number about 48

Virtually all of the hydroxyl groups in this polyol are secondary Hydroxyl groups.

The silicone is a commercially available silicone oil with a viscosity of 5 Oentistoke.s, namely a dimethylsiloxane homopolymer. .

TBPP is iEris-dibromopropyl phosphate and is used as an anti-aging agent applied·

. . ORIGlNAL BATHROOM

3098i6 / i03S

Unless otherwise stated, TDI is eia 80 (20 Example 1

Using the following approach, a polyurethane foam was made obtain:

Polyol A. 100 TDI 54.4 Glycerol monoricinoleate 5.0 Sodium, anhydrous 0.2 Amine catalyst 0.14 TBPP 2.0 Silicone 0.05 water 4.55

In this example and in the other examples, the Quantities of the components given in parts by weight

The procedure used to produce the foam was as follows:

First of all, the amine catalyst, TBPP, was added to the polyol. the glyceryl monoricinoleate and a solution of sodium carbonate in water and the mixture was stirred TDI added while stirring continued. As soon as the foam-forming reaction mixture obtained becomes creamy it was immediately poured into an open mold.

The subsequent rise of the foam was within Completed 50 seconds, once the foam was no longer tacky, it was removed from the mold. The one obtained in this way Polyurethane foam had a fine, regular structure,

BATH ORIGINAL 309816/1035

and although it had a substantial closed cell content, it easily "passed into an open cell foam." Carrying out transferred between rollers "

Example 2

Using the following approach, a polyurethane foam was made obtain:

Polyol B 100 Sorbitan monooleate 10 EDI 54.4 Sodium, anhydrous 0.2 Amine catalyst or 0.14 TBPP 2.0 Silicone 0.05 water 4.55

The foam rising was completed in 60 seconds, and the foam product obtained had open pores of medium-sized Size*

Example 5

Example 2 was repeated using G-lycerol monolaurate in place of the sorbitan monooleate of this example _β

The foam rising was completed in 60 seconds, and the resulting polyurethane foam had medium open pores Size.

Example 4

Example 2 was repeated, but with glyceryl dioleate instead of sorbitan monooleate was used.

BATH ORIGINAL 309816/1035

224669?

The foam rising was completed in 60 seconds, and the polyurethane foam obtained had a finely textured, open-pored structure.

Comparative experiments to repeat Example 2 without any Esters were completely unsuccessful as the foam produced collapsed and no "usable product was obtained ·

On the other hand, it can be seen from Examples 2 to 4 that by using the esters, a polyurethane foam is obtained which is completely comparable to that ia / fc that is mentioned under Use of the more expensive and highly reactive polyol A. is obtained

The foam products of Examples 1-4 were all self-extinguishing, if Ede according to the British Standard 4735 * 1971 were investigated, with the mean exhaustion being the dismantling (MEB) of each product had the following values:

Example no.MEB (mm)

1 37.5

2 20

3 17.5

4 115

Patent claims:

BATH ORIGINAL 309816/10 35

Claims (10)

Claims A process for the production of non-flammable polyurethane foam, in which a polymeric polyol is reacted with an organic polyisocyanate in a foam-forming reaction mixture, characterized in that a mixture is used which (a) as a foam modifier is normally effective as a catalyst for the polymerization of tolylene diisocyanate Substance, (b) an acid generating substance as an anti-aging agent, and (c) a surfactant which is an ester of a carboxylic acid having 10 to 20 carbon atoms and an aliphatic polyhydroxy compound. 2. The method according to claim 1, characterized in that that an ester is used in which the acid has 16 to 18 carbon atoms. 3. The method according to claim 1 or 2, characterized in that an ester is used in which the aliphatic ^ polyhydroxy compound is a polyhydric alcohol with 2, -3 or more hydroxyl groups. 4. The method according to claim 1, 2 or 3, characterized in that an ester is used which has one or more non-esterified hydroxyl groups. 5. The method according to any one of the preceding claims, characterized in that an acid generating Substance is used which contains labile halogen " 6. The method according to claim 5? characterized , that the acid-generating substance is a halogenated, aliphatic BATH 309816 / 10.35 shear phosphate esters, especially a chlorine or bromine derivative a trialkyl phosphate is used. 7. The method according to claim 6, characterized in that that the acid generating substance Iris-2, J-dibromopropyl orthophosphate is used. 8. The method according to any one of the preceding claims, characterized in that as a foam modifier an alkali metal hydroxide, an alkali metal salt of a weak inorganic acid or an alkali metal salt weak organic acid is used. 9. The method according to any one of the preceding claims, characterized in that · a polyol is used
whose hydroxyl groups are practically all secondary hydroxyl groups. 10. Non-flammable polyurethane foam manufactured according to Method according to one of Claims 1 to 9 309816/1035