DE1569571A1 - Process for making flexible cellular polyurethanes - Google Patents

Description

Allied Chemical Corporation * Mew York. H.Y .. USA

Process jsut manufacturing flexible larar polyurethanes

The invention relates to a method for production flexible cellular polyurethanes of very low density

Flexible cellular polyurethanes, especially those that using polyalkylene ether polyols jnoh des sos "one-a-hot" procedure, i.e. according to an initial procedure are manufactured * are often used as upholstery material, for furniture and many other purposes. The relatively high rusts of the Urethaopolyaerieat · but have up to now the use of these cellular polyurethanes as packaging «- and XsoliexMateriallen * tc. beochrokt.

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Such cellular polyurethanes are usually made load? a polyalkylene ether polyol and a polyisocyanate in Presence of a propellant, if desired together with Catalysts »surface-active agents and fillers.

flat these known methods are flexible cellular polyurethanes having densities down to 8 kg / he, usually aboratory in the range of about 2 hours to 160 lcg / ir been prepared or above. Attempts to make foams with very low densities or even stable foams by increasing the amount of blowing agent have not been successful. If water is used, which not only provides carbon dioxide as a blowing agent in flexible polyurethanes, but also forms urea groups through which the strength of the cellular mass is increased through the formation of crosslinking points, if it is used in excess, hard foams are formed obtained, which in some cases have undesirable shrinkage. If too large amounts of water are used, the polymer may also be destroyed ("burned out") as a result of the release of large amounts of heat. When using very good knowledge of low-boiling organic liquids, softer soles are obtained, but the tensile and tear strength of the product can be reduced at the same time

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will. In extreme cases, the foams can, according to the rapid distribution of the heat generated by the polymerization according to the evaporation of the organic liquid, the one Termination of the polymerization results in «coincide.

According to the known methods it is not suitable, the very wanted cellular polyurethanes of very low density " i.e. a density below 8 kg / s.

The invention relates to a method of production of a flexible cellular polyurethane with a density below 16 kg / he. The method is characterized in that one Polyalkylene ether polyol with a polylaooyanate in the presence a TretismitöelSj that of water and a halogenated «! Hydrocarbon with a boiling point not exceeding 4 ^ C » in an "oil-proof" form of halogenated hydrocarbons Water between O, 5ii and 2.2ti consists, converts, with the water an amount of at least 6 parts per 100 parts by weight of the FcyaL is selectable.

According to this process, foams with densities between 5 and 8 kg / nr.

The flexible cellular low density polyurethanes obtained by the process of the invention are made from the

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polyalkylene ether polyols known in the field of polyurethanes, for example diols or triplets or oetnisohen thereof, manufactured. These active hydrogen containing components presumably have the following general formula:

where R is the radical of a polyol, for which examples are given below, 1st, R _{1 is} hydrogen or methyl, A is hydrogen, -CH ₂ CH ₂ OH or -CH ₂ CH ₂ CHgOH, χ is an integer from 5 to ß $ .y is an integer of 2 or 3 1st and ζ is an integer of 0 or 1. Solo polyXtherpolyols can be prepared in a known manner by condensing alkylene oxide, for example ethylene oxide, 1,2-propylene oxide, 1,3-propylene oxide or ethylene sols thereof, with polyhydric alcohols, such as ethylene glycol, propylene glycol, dipropylene glycol, tetramethylene glycol or mixtures thereof, trimethylene glycol, olefin propane in the presence of a catalyst or initiator, such as a triacylamine, for example trioiethylamine, or an inorganic base, for example potassium hydroxide, or a metal halide, for example boron trifluoride.

Polyether polyols made with mixtures of 1,2-propylene oxide and

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Ethylene oxide are obtained, contain mainly secondary Hydroxyl groups and only a minor amount of the more reactive primary hydroxyl groups. the The reactivity of such polyols can be increased, by combining these polyols with ethylene oxide or 1,5-propylene oxide converts, with a polyether palyol with an increased Proportion of primary hydroxyl groups is obtained. Such Polyols are called "tipped" © represent "capped" polyether polyols designated.

A general description of? ®lyäthexpoXy © l®n., Their Production and use for di © Production f! © 2s! Bl <gr Polyurethane is described in Saunders et al «Polyurethanea'a Chemistry and Technology, Part I, Chemistry, High Polymers, Volume XVI, Interscience Publishers, I962, Since « contain.

In the process of the invention, all kinds of polyisocyanates, preferably diisocyanates or thereof, can be used. Examples of such® Polyiss © e | ^F atiat ©

Toluenediieooyanate,

1,8-diisooyanate » ¹ J, ^

4,4 * -Hethylene-bis (oyelohexyl-isocyanate), i, 6 *> H diisooyanat and nlobt-deatllXlevte

such as those described in French patent 1,375,975. A general description of isocyanates and their production is in Sauna · »et al, loc. Pages 17 * ·? 2 included.

The polyisooyanate is generally used in sufficient quantities, around with the hydroxyl groups of the polyol and alt de «in de« Reactively used water is used. Preferably, such an amount of polyisocyanate is used that the ratio of NCO groups to active water octoffate-cene of the polyol is in the range from 0.9 to 1.5-1. Particularly preferably an NCO: H ratio is in the range from 1.0 to 1.2: 1.

The flexible cellular polyurethanes of low density are produced according to the present invention, inea a blowing agent consisting of water and an inert organic liquid, the halogenated hydrocarbon, the boiling point of which is not above 3 ° C. The water reacts in the reaction mixture with the isocyanate with the formation of carbon dioxide, which supports the build-up and the formation of a cellular body. In this reaction, and urea linkages are formed which met Ve tongue -Make result and therefore dl · strength and other valuable property - ^ / improve ^ s Ur # thanpolymeriBats.

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The halogenated hydrocarbon is expediently methylene chloride or a fluorocarbon f., The b @ i nosraialea temperatures and pressures is liquid or gaseous and tea! under the temperatures, which at the
are, ie boiling at or below about 45 ⁴ C-. The last® property is in so far as it prevents a 'iSuoasEisasisslung in the polymerizing mass © υ & ύ thus elxi © local disintegration & mg of the polymer chains. libeispiel®,; these are fluorocarbons;

ι, Moiiofluortrichloxfsethan, n, l-chlorine-ifij
i _a 1-Chlorine-II
and I ₉ SB

Also Ge-siliSQhQ this and Squivalentor Flu @ s $ c @ foieEä © fc® ££ € M © thylenchlorid and or «

Msage to water

g - hydrocarbon and water is less for iäie Bs8rstellu & g% ü® cellular polyurethanes of the invention Biohte SSRiSQ Weser Aich and must be carefully within.

specified limits are kept. At least that's how it is 6 parts by weight of mass per 100 parts by weight of polyether polyol required to have a satisfactory flexible cellular

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To produce polyurethane with a density below 16 kg / nr, and preferably more than 10 and even up to about 20 parts by weight of water per 100 parts by weight of polyether polyol are used. Second, this amount of water must be used in conjunction with a sufficient amount of a halogenated hydrocarbon so that the molar ratio of halogenated hydrocarbon to water is at least 0.5-1. A molar ratio of halogenated hydrocarbon 2SU water of at least 1: 1 and in particular between 1.25: 1 and 1.75 μl is preferably used. That is to say, if the amount of halogenated hydrocarbon is increased, the amount of water used must also be increased so that a foam of sufficient stability is obtained and so that the desired strength of the product is achieved. Deviations from these ranges cause the formation of a weak gel during the polymerization with a loss of blowing agent, the formation of a high proportion of closed cells with a loss of flexibility or a collapse of the foam with complete destruction of the cell structure.

lter influence of these factors in the production more flexible

Cellular low density polyurethanes are made by a number of otherwise similarly manufactured cellular polyurethanes Polyurethanes in which only the amounts and molar ratios of the blowing agents, namely water and monofluorobromochloro

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taethan, were varied. For the production of the first of these foams, 6 parts (0.53 mol) of water per JJ) O, parts of polyol and 50 parts (0.363 Hol) of monofluorofluorofluorine chloride were used (molar ratio 1.1: 1). A flexible polyurethane with a density of 10 kg / nr was obtained. In a second approach, the amount of fluorocarbon was reduced to 25 Teil® (0.18 Hol, Kol ratio 0.55s1). The foam obtained had a high proportion of closed cells. When the amount of fluorocarbon was increased to 150 parts (1.09 mole, x 5 mole ratio, .ZT: 1) , the foaming box collapsed. When the amount of water was decreased to 4 parts, a foam containing numerous large cells, indicating a loss of propellant which was unsatisfactory, was obtained.

As is usual with the production of polyurethanes, this can Mixture of polyisocyanate and polyol In the presence of various Auxiliaries, such as activators and / or catalysts, Dispersants or emulsifiers, pigments, fillers, Color stabilizers * antioxidants; Flan delay agents and the like., implemented.

Catalysts and / or Aktivafcoren, which are necessary for the production of the flexible low density polyurethanes that can be used according to the invention are:

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-ΙΟΙ. Tertiary amines such as triethylamine, N-methylnorpholine, Triethylenediamine, Ν, Ν, ΙΓ, H * -Tetraaiethyl-1 ^ -butandl — In and soy lecithin.

2. Organotin compounds of the following general po reels:

wherein CHgX is a hydrocarbon of alkane radical with 1-18 carbon atoms, R ₁ , JR ₂ and R ,, which can be the same or different, hydrocarbons of felcan radical β with 1-18 carbon atoms, hydrogen, halogen or hydrocarbon aoyloxy radicals, or two of the radicals R-, R ₂ and R-. can be replaced by an oxygen or sulfur atom. Examples of compounds of this class are tetraethyltin, tetra-n-butyltin, tetra-n-octyltin, dimethyldiootyltin, di-n-butylsinn-diohloride, dilaurylsinn-difluoride, 2-ethylhexylsinn-triiodide, di-n-isobutyl-tin-oxy-tin - (monobutyl maleate), di-n-butyltin diaoetate, di-2-ethylhexyltin bis- (2-ethylhexanoate), tri-n-butylzlmv-acetonate and dibutyltin distearate.

J>. Organic tin salts, such as stannous octoate and stannooleate.

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- Ii -

These catalysts, or accelerators or activators can alone or in a Qessiseh niit one or more of the different »types of the substances listed above are used will.

Commonly used in this field dispersants issiü Bsulgatoren include PolyäthylenphenoXäther, mixtures of polyol / Carbonsäuraestern, oil-soluble sulfonates, Silusa & / ox? Alkylenblook copolymers, etc.. The in the Yerfa & ran there? Invention preferred auxiliaries of this group are the siloxane / oxyalkylene block Miechpolyfnerisate the following general Wotmelt

where R ₃ I ¹ u & ä H "Alkyiresfee mife t-IB SSe &

"- ^ f Pj, q mm. τ integers from 2-15» ind and.:> r- »2? © 3 ^ allc ^ lenblock, preferably a polyoxyethylene / polyox7p-ras ^ leiä» loek with 10-50 an Products of this type are described in Belgian patents 58c 362 and 582 363. Such siloxane / oxyalkylene block mixture polymers are commercially available

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of the above general formula is R-CBL, R'-poqsxWf and the block, - ( ^c X.0) "is a polyoxyethylene / polyoxypropylene block containing about 50 units on each polyoxyalkylene moiety.

The curing and use of the according to the invention The flexible cellular polyurethanes obtained are carried out in a known manner.

The invention is illustrated by the following examples. Parts and percentages are based on weight .

example 1

A mixture of 100 parts propylene glycol initiated Polyoxypropylene diol with a hydroxyl number of 56, 100 parts of a glycerol-initiated polyoxypropylene triol a hydroxyl number of 56, 10 parts of a siloxane / oxyalkyleneblook copolymer, 30 parts Stannous oil, 30 parts of water and 400 parts of Konofluortrichloraiethan (Fluorocarbon: water molar ratio 1.74: 1) was stirred vigorously while 308 parts of a mixture eus 8o # 2,4- and 20 # 2,6-toluylene diisocyanate added became. The resulting mass was stirred vigorously for about 15-20 seconds and then gasified into a mold. The foaming mass was allowed to rise and then about

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Left to stand for 16 hours at room temperature. The flexible cellular polyurethane that was formed had a fine 2-strand X ¹ UlCtUr and a density of 5 »! kg / ir

Example 2

The procedure of Example 1 was repeated with the difference that the amount of stannous octoate was reduced from 30 parts to 10 parts and the amount of Konofluortrlohloiwethan from 400 parts to 300 parts. The flexible cellular polyurethane formed had a fine scale structure and had a Qins density of 5Λ kg / nr.

Example 3 An Oemlsch of 200 parts of the poly used in Example 1

oxypropylene glycol, 200 parts of that used in Example 1 Polyoxypropylenetriols, 8 parts of SiloxiB / CgcyalScyieablook "Misehpctyaerieat, 24 parts of water" 12 parts of stinnooctoate and too parts of monofluorotriohlomethane (MolverhKltnie PluorkohlenBtofftW & seer - S, S, 2il) was strong, while gsrtif of a mixture of 80 - 264 - 4 - 2il, 209 parts - 264 - and 2il) 2j, 6-toluylene diisooyanate were added. The mass formed was stirred for a further 15 to 30 seconds and then poured into a mold in which the polymerizing mixture was allowed to rise without restriction. The cellular 'mass was about

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Left to stand at ambient temperature for 24 hours. The cellular polyurethane formed had few closed cells near the top layer and a weight of 7.9 kg / in ⁵ .

Example 4

The procedure of Example 3 was repeated with the difference that 32 parts instead of 2.4 parts of water were used and the amount of diisocyanate increased to J44 parts became. (Fluorocarbon: water molar ratio - 1.63: 1).

The flexible cellular polyurethane formed had a weight of 6.9 kg / kr. The foam contained a trace of closed cells that were easily broken when the foam was pounded became.

Example ft

A mixture of 200 parts of a propylene glycol initiated PolyoxypropylenediolB old with a hydroxyl number of 113, 6 parts Slloxan / Oxyalkgrlenblook- ^ isohpolynerisat, 0.4 parts Dimethyl / ethanolamine, 0.4 parts of sfcannooctoate, 12 parts Water and 100 parts of honofluorotrichloromethane (molar ratio Fluorocarbon: water «1.1: 1) was stirred rapidly, while 161 parts of a mixture of 80 pounds, 2.4- and 20 pounds 2,6-tolylene diisocyanate were added. The crowd became

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Stirred for about 15 seconds and then poured into a mold. The cellular product formed was allowed to stand at the ambient temperature for about 2k hours. This cellular polyurethane had a density of 10 kg / mm and a fine cell structure.

The procedure of Example 5 was repeated with the difference that k parts instead of 6 parts of siloxane-oxyalkylene-Miechpoljnerisat, Ι, Ό part instead of 0.4 part of whore thylethanolainin and 50 parts instead of 100 parts of monofluorotrichloromethane {molar ratio of fluorocarbon: water ° 0 , 55: 1) were used.

The cellular polyurethane formed had a density of 11.8 kg / nr.

Example 7 (comparative example)

ΈίΜ SsEiscli -ΨΟΪ & 50 parts of the folyoxyropylenediol used in Example 1 and 50 parts of the polyoxytropylenetriol used in Boispiol 1 , 2 parts of siloxane / oxyalkyleneblook polymerizate, 1.0 part of i-jtaiinooQtoat, 4 parts of Waferrietria and 100 parts of Konofluorkhohl molybdenum : Water ~ 3.27: 1)

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was stirred vigorously while 49.8 parts of a mixture of 80 £ 2,4- and 20% 2,6-tolylene diisocyanate were added. The mass was stirred for about 15-30 seconds and then poured into a mold.

The mixture rose for about 10 minutes but did not gel in 15 seconds. The ground collapsed, indicating that the propellant were not retained in the crowd. By the time the mass reached its maximum height, its density was about 22 kg / m * ".

Example 8

A mixture of 100 parts of a glycerine-initiated polyoxyethylene triol with a hydroxyl number of 46.1, 8 parts of water, 5 parts of silicone as a surface-active agent, 7.5 parts of stannous octoate and 50 parts of methylene chloride (molar ratio CH ₂ Cl ₂ IH ₂ O - l, 32il) was stirred vigorously while 84.5 parts of a mixture of 80 $ 2,4- and 20 $ 2,6-toluylene diisoeyanate was added. The foaming mass was poured into a mold and allowed to rise indefinitely. After standing for about 10 hours at the ambient temperature, the foam was stable, consisted essentially of open cells and had a density of 7.9 kg / m 2.

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Claims (1)

Pat ant to β ρ r ü ο nt 1. A process for the production of a flexible cellular polyurethane with a density below 16 kg / nr, characterized in that a polyalkylene rigid polyol with a polyisooyanate in the presence of a propellant is made up of water and a halogenated hydrocarbon whose boiling point does not exceed tyC Molar ratio of halogenated hydrocarbon to water between 0.5: 1 and 2.2: 1 », the water in an amount of at least 6 parts per 100 parts by weight of the polyol are present is being implemented 2. The method according to claim 1, characterized in that daS as halogenated hydrocarbon, a fluorinated hydrocarbon with a boiling point of not more than 43 ° C or several such fluorinated hydrocarbons, MetbjLenohlorid or an Oemisoh of Methylenohlorid with one or more such fluorinated hydrocarbons is used. 5. The method according to claim 1 or 2, characterized daduroh, that the ratio of halogenated hydrocarbon to 909840/1664 BATH ORIGINAL ■ - 18 - Water in the propellant in the range from 1.5: 1 to 1 * 75 * 1 is kept and dai water in an amount between IO and 15 parts per 100 parts by weight of polyol is used. 4. The method according to claim 1, 2 or 3, characterized «that the polyisocyanate is used in such an amount that the ratio of isocyanate groups to active hydrogen atoms in the polyol is between 0.9 * 1 1.5 χ ! 909840/1664