DE1298714B - Method of making a rigid, cellular polyurethane - Google Patents

Description

War of a propellant can be traced back to at least one organic, or it must be uneconomical Reacts polyisocyanate. Such conversions borrowed small foam bodies to be produced, are generally in the presence of a catalyzer. Recently, it has been proposed to make flame-retardant rigid

Sators, for example a tertiary amine or cellular polyurethanes to produce that one an organotin compound, carried out to- a soluble organic antimonate (III), namely Satisfying reaction rates for ethylene glycol antimonate (III) or 1,2-propylene glycol. col-antimonate (III). But it has

Such cellular polyurethanes are generally shown to destroy soluble organic antimony (III) flame retardant, d. That is, they ignite when a binding activators and / or Flame strikes them, and burn after de- catalysts for the implementation of active water ignition continue until they are practically completely chemical-containing compounds and organic are on fire. While it is already known, inorganic isocyanates are. That is, when mixing the and organic agents with hydrogen-containing compound to be active in these polyurethanes bring to make them more flame retardant, the organic isocyanate in the presence of an organ obtained Degree of flame resistance of the amount of the niche antimonate (III) the implementation of the added takes place Means is roughly proportional. By 25 art quickly, d. that is, the "Krem time", "Rise time" and the addition of these agents is unavoidable but the "tack-free time" of the reaction mixture is so short that also the mechanical and / or chemical that the mixture, especially when working in Properties of the mixture or of the technical scale from it, not in the desired holding cellular polyurethane modified. Way can be shaped. When rigid cellular

The modern technical processes for the production of polyurethane foams in the form of panels require rigid cellular polyurethanes to be provided, the mixture solidifies so quickly, precise monitoring. In general, the different components with the exception of the iso are not evenly filled in the cavities of the mold and the foam body obtained is premixed with cyanate, and immediately before the injection has a non-uniform cell structure. Therefore, bringing the mixture into the desired form 35 is the use of such soluble organic, this mixture is mechanically mixed with the isocyanate antimony (III) compounds, although they are the manufacture. These operations are carried out continuously
or at least semi-continuously. There are those
"Krem time," that is, the time it takes until

the reaction of polyol and isocyanate begins, 40 rigid cellular polyurethanes containing soluble antinach the reactants are mixed together (III) soluble antimonate (III) controlled len the form with one to produce the desired
Foam sufficient amount of foamable
Mass is required, the "rise time", the time required for a polyfunctional, active hydrogen to contain most of the foaming, ie 90% or more of the compound with an organic polyisocyanate, before the cellular in the presence of a thickening agent that does not solidify water, and the "tack-free time", that is to say, and an organic antimonate compound, the time required for the cellular mass to be soluble in the reaction mixture is, has solidified to such an extent that its surface is no longer characterized by the fact that the reaction is sticky in the presence, essential properties which must be controlled precisely from 0.25 to 1.25 percent by weight of water. For example, the polyfunctional, active hydrogen-containing one requires a short "Krem time" of, for example, 3 until compound is carried out. According to the invention 10 seconds a correspondingly short "pouring time", premixes of the polyfunctional, otherwise the mass in the compound containing hydrogen to fill the mold, the organic devices used to foam and these niche antimonates 11) compound and a small possibly blocked and also the amount of water formed, which is then used in the above-described foam, an inhomogeneous and irregular Zeil method, would be produced, would have structure. When the "rise time" and the The water dissolved in the premix that is used for

"Tack-free time" are relatively short, for example 60 attenuation of the implementation is used in If 10 to 30 seconds are wise, quantities of foams are used which are not sufficient for the with a non-uniform surface cell structure and the desired amount of propellant. That dark spots (signs of "shear") received, propellant consists mainly of one which adhere poorly to the mold surface. Such short, low-boiling organic liquid, like both "Rise" and "tack-free" times are also bad with a fluorocarbon, for example. Preferably ter fluidity of the mass connected so that the will the water in an amount of not more than Corners and the parts of the shape of more complicated 1.25 and preferably 1.0 and at least about Shape cannot be filled out completely. In the 0.25 percent by weight of the polyol to be converted

development of flame-retardant foams is not an ideal solution to the problem.
The aim of the invention is a method of manufacture

will. The method of the invention for making a rigid cellular polyurethane by reacting

depends largely on the soluble organic antimonate (III) compound and water used to a lesser extent on the reactivity of the polyol and isocyanate used.

Organic antimonate (III) compounds are known and can be easily prepared by heating antimony trioxide or antimony trichloride can be prepared with an alcohol, especially an alkanol.

Antimonic acid and can be represented by the following formula:

(RO) ₃ _, Sb -y. _v

where y is chlorine and λ; is an integer from 0 to 2, and where RO is the remainder of an alcohol, the substituents such as halogen, hydroxyl and ether oxygen

used. With this small modifying amount of up to ten hydroxyl groups that react with isocyanate groups on water, it becomes possible to control the "Krem time" and, and have hydroxyl numbers from 200 to other phases of the reaction of the reaction mixture 750, preferably 370 to 620. Such polyethers can be controlled It is known that mixing and pouring out the masses of polyols can be done by reacting one under controlled conditions. The 5 alkylene oxide, such as ethylenoxide, propylene oxide, epiimodifying amount to be used in individual cases, chlorohydrin, styrene oxide or mixtures thereof either alone or in a mixture with polyhydric alcohols and / or polyhydric phenols in the presence of suitable catalysts, such as triioalkylamines, for example trimethylamine, or inorganic bases , for example potassium hydroxide, or a halide such as boron trifluoride can be obtained. The polyols suitable for the production of these polyfunctional polyethers, ie more is also known, antimonates by heating i ₅ hydric alcohols or phenols, include glycerol, of antimony trichloride with an oxirane compound trimethylolpropane, hexanetriol, fructose, hexitol. To produce. The products obtained are esters of bit, maltose, cane sugar, triphenyloläthaii. Tetra -

phenylolethane, triphenylolpropane, resorcinol, pyrogallol, bisphenol A, chlorinated diphenol and mixtures thereof. Such polyethers are found, inter alia, in USA patents 2 902 478 and 2 ¹ K ¹ '' ¹ MK and in Belgian patent 584 7Iy.

Such polyethers are preferably used, atoms, may contain, represents. Examples of anti-25 the flame resistance of the Polyureili.wischäuine iuonate (III), which improve in the process of the invention, ie those which can be used in a large proportion, are tri- (2-chloroethyl) halogen and or or phosphorus and b / w. or antimonate (III) and tris- (l, 3-dichloro-2-propyl) antimony included in the molecule. Examples month (III). for such polyethers are the reaction products

As the active hydrogen-containing component 30 of an epihalohydrin and a polyol such as Ghk can are used: cerin or sorbitol, which in the presence of a catalyst

(a) polyfunctional polyesters, such as the reaction sators, for example fluoroboric acid or a metal product of adipic acid, phthalic anhydride and halide or boron trifluoride. Poly-trimethylolpropane, with a low acid number (among ethers of this type are in the USA. patents 10) and a high hydroxyl number (over 400), which describes 35 2 260 753 or 2 327 053 and 2 500 449, are practically anhydrous. Also comparable poly- The reaction product of such a polyether with ester with terminal hydroxyl groups, such as the alkali and then with antimony trichloride those who by known methods from more- particularly preferred.

basic acids, such as sebacic, glutaric, phthalic, many can be used to produce the polyurethanes

halogenated phthalic, hydrogenated phthalic, succinic, 40 different organic polyisocyanates or Ge-fumaric and maleic acid as well as mixtures thereof, mixtures thereof can be used. The liquid polyols with polyols such as ethylene glycol, propylene glycol, isocyanates and, in particular, liquid diisocyanates glycerol, sorbitol and polypropylene glycol and also ge are preferred. As examples of suitable isocyanates mixtures thereof that have been obtained, can be mentioned: can be used. Halogen is particularly suitable, 45 _n ,, ...

holding polyesters such as those that differ from the rn-phenylene-d..socyanate

2,4-toluene dnsocyanate,
2,6-toluylene diisocyanate,
Naphthalene-1,5-diisocyanate,
4,4'-methylene bis (phenyl isocyanate),
4,4'-methylene-bis (cyclohexyl isocyanate),
1,6-hexamethylene diisocyanate,
4,4 ', 4 "-triphenylmethane triisocyanate,
1,3,5-benzene triisocyanate.

Mixtures of these and equivalent compounds can also be used.

In addition , prepolymers and, in particular, liquid prepolymers based on polyisocyanates or mixtures thereof can be used. It is advantageous to use prepolymers which contain an excess of isocyanate groups, such as, for example, the reaction product of 10 parts by weight of hexanetriol with 100 parts of a mixture of 80 parts of 2,4- and 20 parts of 2,6-toluene-

derive carboxylic acid;

(b) polyfunctional polyester amides, in which part of the polyol portion or the entire polyol portion the polyester described above by an amine derivative is replaced, such as diethylenetriamine or ethanolamine;

(c) polyfunctional polyethers containing several hydroxyl groups and presumably the general one formula

(OH) ₂

O - f CH ₂ - CH - O] - H R ¹

where R is the remainder of a polyol according to the examples given below, R 'is hydrogen,

Methyl, halomethylene or phenyl, χ a 65 diisocyanate is used. Also quasi-prepolymers,

is integer from 1 to 5, y is an integer of 1 as the reaction products of polyesters, beispiels-

to 10 and ζ is an integer from 0 to 9. wise adipic acid trimethylolpropane polyesters, with

These polyether polyols preferably contain three toluene diisocyanates which can be used.

Preferably, aromatic polyisocyanates are made from volatile in the process of the invention Phosgenation products of aryl polyamines, the volatile aromatic polyisocyanates and so-called Contain »co-produced, synergistic flame retardants«. Such phosgenation products of aryl polyamines contain about 40 to 90 weight percent volatile aromatic Polyisocyanate that is produced in a molecular distillation device at pressures of about 1 mm Hg or by means of a gas chromatograph can be separated from the mass. They are particularly preferred aromatic polyisocyanates, the toluene diisocyanate and flame retardant synergists that were also created and have been obtained by phosgenating toluenediamines.

For the sake of simplicity, these preferred aromatic polyisocyanates are hereinafter referred to as phosgenation products of the particular aryl polyamine from which they are obtained. For example is a »toluylenediamine phosgenation product« an aromatic polyisocyanate containing 40 to 90 percent by weight of volatile toluene diisocyanates and flame retardant synergists produced at the same time.

Suitable blowing agents are in addition to the small amount of carbon dioxide that is produced by the reaction Water with polyisocyanate is formed, low-boiling, normally gaseous substances that are among the Polymerization conditions do not react. Examples of such agents are methylene chloride, Chloroform, isopropyl chloride, propyl chloride and preferably fluorinated aliphatic saturated hydrocarbons. These substances are poor solvents for the organic polymer and have Boiling points below the temperatures generated by polyurethane formation. They are preferably in The organic polyisocyanate is considerably soluble and in the gaseous state have such a solubility Molecular size that they can not easily at normal temperature through the spaces between the Diffuse polyurethane molecules through. Examples of the preferred propellants are: monofluorotrichloromethane, Dichlorodifluoromethane, monochlorotrifluoromethane, trichlorotrifluorethane, difluorotetrachlorethane, 1,1-difluoroethane and 1,1,1-dichlorofluoroethane. Mixtures of these and similar agents can also be used.

Dispersants and emulsifiers commonly used in polyurethane-forming mixtures are Polyethylene phenol ether, mixtures of polyalcohol-carboxylic acid esters, oil-soluble sulfonates and siloxaneoxyalkylene block copolymers. The preferred auxiliaries of this group in the process of the invention are the siloxane-oxyalkylene block copolymers the general formula

^ O - (R ^ SiO) ₁ , - (C _n H _2n O) ₁ R "

R - Si ^ - O - (R ₂ -SiO) ₄ - (C _n H _2n O) ₁ R "

^ O - (R ₂ SiO), - (C _n H _{2 n} O) ₌ R "

wherein R ₁ R 'and R "are alkyl radicals with 1 to 18 carbon atoms, p, q and r are integers from 2 to 15 and (C ₁₁ H _2n O) - a polyoxyalkylene block, preferably a polyoxyethylene polyoxypropylene block with 10 to 50 on each oxyalkylene unit Products of this type are described in US Pat. No. 2,834,748 and their use can be found in Belgian Patents 582 362-3. Such products are commercially available. One such product is "Silicone L-520", where in the above formula R = CH ₃ , R '= C ₂ H ₅ , R "= C ₄ H ₉ , ρ = q = r = 7 and the block - (C _n H _2n O) _{2 is} a polyoxyethylene polyoxypropylene block 50 is oxyalkylene units.

In addition to the usual auxiliaries mentioned above, the rigid cellular polyurethanes can also be used, for example Crosslinking agents, pigments, fillers, densifiers and additional flame retardants contain.

The invention is illustrated by the following examples. Parts and percentages relate focus on the weight.

example 1

A mixture of 405 parts of sorbitol and 2595 parts of epichlorohydrin is reacted at 10O ⁰ C in the presence of 4 parts of boron trifluoride etherate as catalyst in a known manner. The polyether formed has a hydroxyl number of 250 and contains 33.3% chlorine.

3000 parts of the polyether are ^{heated to 40 °} C. and diluted with about 1300 parts of methylene chloride. The mixture is cooled to 15 ° C and 858 parts of 50% aqueous sodium hydroxide are added at below 20 ° C. The mixture is stirred for 30 minutes. The mass is allowed to separate into two layers and the aqueous layer is discarded. The organic layer is washed with water and a sufficient amount of acetic acid to neutralize the residual base and then washed two more times with water, and the washed solution is dried over anhydrous magnesium sulfate. The solution is filtered and the solvent is removed by distillation. 2161 parts of solvent-free residue with an oxirane oxygen content of 4.7% are obtained, which corresponds to an equivalent weight of 340 per oxirane oxygen and an equivalent weight of 500 per remaining hydroxyl groups.

A mixture of 438 parts of the epoxy polyether polyol prepared as described above and 581 parts of a polyoxypropylene polyol based on cane sugar-glycerol with a hydroxyl number of 460 is heated to 40.degree. After addition of 70 parts of antimony trichloride, the mixture warmed spontaneously to 70 ⁰ C, and the now antimonate (III) groups containing mixture is allowed to cool to about 25 ° C.
A premix is prepared from 110 parts of the antimony (III) ester polyol prepared as described above, 0.4 part of water, 1 part of siloxaneoxyalkylene block copolymer (silicone oil) and 30.4 parts of trichloromonofluoromethane. 91.3 parts of a polyalkylene polyaryl polyisocyanate obtained from 4,4'-methylenedianiline, described in US Pat. No. 2,683,730 ("PAPI"), are added to this premix, and the mixture is stirred for 20 seconds ("Krem time") and poured into a suitable mold. The mixture rises for 70 seconds ("rise time") and is tack-free after 110 seconds. The cellular mass is aged for 24 hours at normal temperature. When tested in accordance with ASTM P-1692, the foam proves to be non-flammable.

Examples 2 to

Table I.

Rigid cellular polyurethanes are prepared essentially according to the process described in Example 1 , but using the following components:

Table I.

Premix

Polyol ¹ ), parts

Tris (2-chloroethyl) -

antimonate (III), parts ...

Silicone oil, parts

Trichloromonofluoromethane,

Parts

Water, parts

Polyisocyanates, parts

"Mixing time", seconds ...

Examples

2 3

Premix 2 Examples
3 4th "Krem time," seconds
"Climb time," seconds
"Tack-free time," seconds 3
5
5 12th
27
27 30th
63
63

100

15th

28

93

100

15 2

27 0.5 99 12

100

15th

26 1

105 30

') Polyoxypropylene polyol based on cane sugar-glycerine,

Hydroxyl number = 469.
² ) Toluylenediamine phosgenation product.

As can be seen from Table I, the composition of Example 2, which contains no water, reacts very quickly and is therefore extremely difficult and in automatic mixing and dispersing machines practically impossible to process at all.

The compositions of Examples 3 and 4 react more slowly and can therefore be used well in automatic systems are processed. All of these foams are non-flammable according to ASTM D-1692.

Examples 5 to 9

In an analogous manner, rigid cellular polyurethanes are made using those given in Table II Components manufactured:

Table II

Premix

Examples Polyol ¹ ), parts Tris (1,3-dichloro-2-propyl) -

antiraonat (Vi), parts

Silicone oil, parts

Water, parts

Trichloromonofluoromethane, parts

Polyisocyanate, parts

"Krem time," seconds

100

20th

0.5 30

107 ² ) 12 100

20th

0.75
30th

107 ² )
19th

100

20th

1.0
30th

107 ² )
25th

100

0.5 30

140 ³ ) 18

100

20th

1.0 30

140 ³ ) 35

') Polyether polyol, hydroxyl number 540.

² ) Toluylenediamine phosgenation product, amine equivalent 107.9.

³ ) Crude 4,4'-methylene-bis (phenyl isocyanate), amine equivalent 141.3.

These examples illustrate the influence of the rate of reaction on the rate of reaction of the polyol-isocyanate mixture with increasing amounts of water. This means,

Examples 10-14

These examples illustrate modifying the polymerization is carried out as in the effect of water on the Reaktionsgeschwindig- ⁵ ° preceding examples, but using speed of polyurethane reaction mixtures in which the following materials: the polyol also antimonate (III) groups.

Table III

Premix

10 11

Examples
12th

14th

Polyol ¹ ), parts

Silicone oil, parts

Trichloromonofluoromethane, parts Water, parts Polyisocyanate ² ), parts

"Krem time," seconds

100

2 28.5

0 94.5

100

2
25th

0.25
97.6
11

100
2

21.5
0.5
100.7
17th

100
2. 18th
0.75 103.8 19

100

2 20

1.0 96 28

') A product with a hydroxyl number of 478 obtained by transesterifying a polyether polyol with a hydroxyl number of 530 with tris-

(1,3-dichloro-2-propyI) -antimonate (IH) is obtained. ² l of toluene-diamine-phosgenation product, amine equivalent 108.

909527/475

Examples 15-17

Rigid cellular polyurethanes are made from the materials listed in Table IV in the example 1 produced:

Table IV

Premix

Polyol ¹ ), parts

Tris (2-chloroethyl) -

antimonate (III), parts ..

Silicone oil, parts

Water, parts

Trichloromonofluoromethane,

Parts

Polyisocyanates, parts ....
"Krem time", seconds ..

Examples 15th 16 100 100 3 " 3 2.2 2.2 0 0.5 27.1 27.1 92.3 98.3 12th 15th

IO

17th

100

2.2

1.0

27.1 104.3 30

') Hydroxyl number 427, about 38% chlorine content, viscosity at 25 ⁰ C = 9300OcP, water 0.2%, hydroxyl 126.3 (74 to 1.8 of Diamond Alkali Corp.).

² ) Toluylenediamine phosgenation product, amine equivalent 108.

Tabel Premix iV 15th Examples
16 17th "Climb time," seconds 35
30th 65
48 110
100 "Tack-free time", seconds ..

20 rigid cellular polyurethanes, the organic antimonates (III), may be less modifying amounts are prepared in water in the presence, while the same compounds in the absence of water to react so rapidly that its processing is difficult or practically impossible so in a practical and efficient manner .

Claims (1)

Claim: Process for making a rigid cellular polyurethane by reacting a polyfunctional, active hydrogen-containing compound with an organic polyisocyanate in the presence of a blowing agent other than water and an organic antimonate (III) compound which is soluble in the reaction mixture, characterized in that the reaction in the presence of 0.25 to 1.25 percent by weight Water, based on the polyfunctional, active hydrogen-containing compound carried out will.