DE1299425B - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

C08g

GERMAN

PATENT OFFICE German class:

39 b5, 22/44 39 b5,41 / 00 39 b5, 53/14

Interpretation document 1299425

File number: P 12 99 425.1-44 (A 43916) Filing date: August 28, 1963

Opened on: July 17, 1969

Exhibition priority: -

Union priority Date: Country: Case number:

November 1, 1962
V. St. v. America
234860

Name: Process for the production of rigid polyurethane foams

Addition to: Removed from: Applicant: Allied Chemical Corp., New York, N.Y. (V. St. A.)

Representative: Ruch, Dipl.-Chem. Dr. rer. nat. Ilse, patent attorney, 8000 Munich

Named inventors: Dickert, Eugene Arthur, Cheektowaga; Hallinan, Margaret R.,

Buffalo; N. Y. (V. St. A.)

Publications considered for the assessment of patentability:

7. 69 909 529 Γ

term dissolved polyisocyanates of higher molecular weight and higher functionality than the volatile aromatic diisocyanates. The non-volatile content of this dissolved fraction acts as a flame retardant and as a chain extender or crosslinker and gives the foams desirable properties, e.g. B. Rigidity. These components make the aromatic polyisocyanates also superior to distilled aromatic diisocyanates in the production of foams, First, because their higher viscosity allows for the mixing of the reactants and the retention of the Propellant during foam formation facilitates, secondly, the smaller amount of heat released during foam formation, the generation of larger amounts Enables foam masses and improves the properties of the foam, and thirdly, the lower one Vapor pressure counteracts the toxicity of the diisocyanate vapors.

The co-generated and not dissolved in the phosgenation products of the aromatic amines Volatile substances can thermally form aromatic diisocyanate vapors and tarry or solid residues decompose. In addition

30% toluene diisocyanate free when in a molecular distillation at 1 mm Hg to 225 ° C

The invention relates to a method of manufacture rigid, flame-retardant polyurethane foams.

Polyurethane foams are made from a polyfunctional, active hydrogen-containing polyester, polyether or polyester amide in the presence a common blowing agent and an organic polyisocyanate. Such polyurethane foams are not flame-retardant and continue to burn after ignition until the material is completely consumed is. It is known that polyurethane foams can be made flame-resistant by using halogen or phosphorus Brings containing agents. These either do not react with the polyisocyanate, like chlorinated ones Hydrocarbons, tri- (chloroethyl) phosphate and tri- (2,3-dibromopropyl) phosphate, or take them part of the reaction, such as halogen or phosphorus or containing both halogen and phosphorus Polyester and polyether. The flame resistance achieved is the amount of halogen and / or present Phosphorus directly proportional. However, the mechanical properties of the foam (Dimensional stability, tensile strength, shock resistance) deteriorated, especially when used non-reactive flame retardant.

The claimed process for the preparation 25 game set the dissolved solids obtained by extracting the rigid toluene polyurethane foams by reacting a diisocyanate with η-hexane from the phosgenation polyol with an organic polyisocyanate in the presence of a propellant and a flame retardant is characterized in that the Polyol
be heated in a known manner with the phosgenation 30. The aromatic diisoproduct of an aromatic diamine reacted cyanate used consists of both volatile aroma, this product being 40 to 90% by weight of diisocyanate of pyrolytic origin as a percentage of volatile aromatic diisocyanate as well as volatile aromatic diisocyanate which contains and at least one equivalent of isocyanate Polyisocyanates is included. The amine phosgenation products dissolved in the groups per equivalent of active hydrogen are not used. The flame retardant contains halogen-term polyisocyanates do not correspond to those for be or phosphorus or both. The polyol is a polyfunctional active hydrogen containing substance, e.g. B. a polyester, polyester amide or polyether with terminal hydroxyl groups. Such 4 ° in the preparation of the phosgenation polyols, halogen and / or phosphorus entaromatic amines can be kept too narrow, so that the polyol also acts as a flame retardant
can work.

Under "volatile aromatic diisocyanate"
one understands a phosgenation product of an aromatic product present flame retardant can be removed by matic diamine, which can be separated by molecular distillation changing the following variables with the phos at about 1 mm Hg or in a gas generation: ratio amine to chromatograph. Called solvent; Ratio of amine to phosgene; Are the phosgenation products of a toluene heating temperature and duration of heating during diamine or of ρ, ρ'-diaminodiphenylmethane, z. B. 50 of the reaction and the distillation and amount of m-tolylene diisocyanate, in particular the 2,4- and volatile aromatic diisocyanate, from which the 2,6-isomer, or mixtures thereof, and Me-phosgenation product is distilled off.
ethylene bis (4-phenyl isocyanate). Other volatile aro- The flame retardants in the phosgenation pio-

matic diisocyanates are m- and p-phenylene products of aromatic diamines reduce the required diisocyanate, Chlorophenylene diisocyanate, 1,5-naph- 55 borrowed amount of flame retardants that the foam thalin diisocyanate and 3,3'-dimethyl-4,4'-diphenyl- makes self-extinguishing after ignition, considerably, methane diisoeyanate, which can be obtained by phosgenation. The claimed process enables dis Herder corresponding diamines. position of rigid polyurethane foams of good quality

The phosgenation product of the aromatic di- flame retardancy, without the use of larger amounts of amine with a content of volatile aromatic 60 flame retardants, as they are otherwise necessary and the diisocyanates of 50 to 90% can by themselves or frequently have a deterioration in other properties with one or more volatile aromatic
Diisocyanates of other origin used v / earth,
until the total amount of volatile aromatic diisocyanates is 40 to 90 percent by weight superior to the total 65: higher melting point, which in itself is a mass. The phosgenation products improve the strength of the flanim; lower thermematic diamines are mixtures of volatile aromatic diisocyanates with relatively non-cursory

distillation residues obtained from known processes, because these are formed by pyrolysis of the non-volatile dissolved polyisocyanates. thats why

avoid.

The concentration of non-volatile solutes including that in the phosgenation

of the foam. The foams obtained in this way boiled comparable, from distilled aromatic Diisocyanates obtained in the following ;! Points

conductivity; higher
higher dimensional stability.

Compression strength

At least one equivalent of isocyanate groups is usually required to produce the new foams per equivalent of active hydrogen in the polyol, preferably about 1.03 to 1.05 isocyanate equivalents per equivalent of active hydrogen used. Generally is the excess of isocyanate groups not greater than 20% of the stoichiometrically required amount.

Polyols from a large class of polyfunctional derivatives are:

IO

a) polyfunctional polyesters, reaction product of adipic acid, phthalic anhydride and trimethylolpropane with low acid number (below 10) and high hydroxyl number (above 400), the is practically anhydrous, sebacin, glutar, '"phthal, halophthal, hydrogenated phthal, Succinic, fumaric and maleic acid esters with polyols such as ethylene glycol, glycerine, sorbitol and polypropylene glycol,

b) polyfunctional polyester amide made from tetraethylene diamine or ethanolamine with terminal OH groups,

c) polyfunctional polyethers with several OH groups (presumably general formula

R.
I. O- / CH ₂ -CH- -H (OHW 1 R ¹

in which R is a polyester radical, R ^{1 is} hydrogen, methyl or phenyl, X 1 to 5. Y i to iO and Z is 1 to 9 or 0). Such polyethers contain three to ten OH groups which react with isocyanate groups and have a hydroxyl number of about 200 to 750, preferably 370 to 620.

Flame retardants to be used usually contain halogen (especially chlorine and / or Bromine) and / or phosphorus, e.g. B. diallyl styrene phosphonate; Diallyl phenyl phosphonate, allyl ester halogenated « organic acids, e.g. B. tetrachlorophthalic acid, dibromophthalic acid and dibromosuccinic acid; tris (2,3-dibromopropyl) phosphate; tris (2,3-di- chlorpropyO-pliüsphat; Tris (chloroethyl) phosphate; Bis- / i-chloroethyl vinyl phosphonate.

Preferred polyethers with flame retardant properties contain !! Halogen and / or phosphorus as part of the polyether molecule. Examples of such preferred polyethers are the reaction products of epichlorohydrin with a polyol such as glycerine or sorbitol. With these polyethers on their own or in a mixture with non-reactive flame retardants Flameproof rigid polyurethane foams are obtained by the claimed process.

The flame retardants described vary in their effect, with some 5 files per 100 parts of polyurethane cause a good flame retardancy, while with bovine 25 or more parts per 100 parts Po !, ^r u: -th; i! I nr> - 'i-- \ are. Bringing in large mengu; - ', ^. "aii'-kwsffihigcr flame retardants affect the isocyanate conversion (foam formation) and essential properties of the polyurethane foams, in particular dimensional stability, resistance to crushing and heat resistance. The flame retardant migrates into the foam and thereby causes shrinkage or deformation, what is accelerated at elevated temperatures.

In the production of rigid polyurethane foams, the polyaddition of aromatic Polyisocyanate to the polyol in the presence of various auxiliaries (blowing agents, activators or Catalysts, dispersants or emulsifiers) take place.

Propellants are carbon dioxide, fluorinated saturated aliphatic hydrocarbons or theirs Mixtures, e.g. B. monofluorotrichloromethane; Dichlorodifluoromethane; Monochlorotrifluoromethane; Trichlorotrifluoroethane; Dichloro - ^ - fluoroethane; Tetrachlorodifluoroethane; 1,1 - difluoroethane; 1,1,1 - dichlorofluoroethane.

Activators or catalysts are:

1. tertiary amines, such as triethylamine, N-methylmorpholine, Triethylenediamine, Ν, Ν, Ν ', Ν'-tetra methyl-1,3-butanediamine;

2. Tertiary amines containing hydroxyl groups that are capable of crosslinking the polyurethane are compounds the general formula

X,

N - (CH ₂ ) ,, - (NH - [CH ₂ ] _} .) _M - N

wherein Xi, X-2, X: t and Xi can be the same or different and the group H- (O-alkyleneL-. wherein ζ is an integer from 1 to 4 and »alkylene is a divalent tliphatically saturated hydrocarbon radical (1 to 10 C Atoms) is, bed ^{r <} i'tcn, vvtiiie! But one of the groups Xi, X *,. '■ ..,' nd Xi can be an alkyl radical with up to 20 carbon atoms; η an integer of 1 to 10, preferably 2 or 3, m = 0 or an integer from 1 to 3 and y is an integer from 1 to 10; examples of these compounds are tetra (hydroxyethyl) ethyenediamine; tetra (hydroxypropyO -älhylenediarnine;
the ; oxidation product of propylene oxide and diethylethylene; and N-coco- (N, N ', N' trihydroxyethyl) ethylenediamine; 3. Organotin compounds of the general formula

R,

Sn

wherein CH ^ X is an alkali radical (1 to 18 C atoms); Ri, R2 and K: s each is an alkane radical (1 to 18 carbon atoms), hydrogen, halogen or a hydrocarbon group and Ri, R _: > and R: s are identical or different with the further »VIiiiichkr-ii. that two terms form the :: i: group Ri, ■ .. ;; * κ! R _; j together sow ;; rsic- ^! or tail; vein inside; li ^ i.ipicle Ph "these known organ compounds are" letramethyltin, tetra-ti-buty iinti, tetraoctyltin, dimethyldioctyltin. Triethyltin chloride, dioctyltin dichloride, di-n-butyltin dichloride, dilauryltin difluoride, 2-ethylhexyltin triiodide, din-octyltin oxide, di-η butyltin diluaurate, di-n-butyltin diacetate, di-n-monobutyltin-bis (octyltin), bis (2-butyltin) di-octyltin 2 - ethyl

hexanoate), tri-n-butyltin acetonate and dibutyltin diacetate;

4. organic tin salts, such as stannous octoate and stannooleate.

These catalysts can be used alone or in mixtures of two or more of these substances will.

Examples of known dispersants or emulsifiers are polyethylene phenol ethers, mixtures of Polyalcohol carboxylic acid esters, oil-soluble sulfonates and siloxane-oxyalkylene block copolymers. For Emulsifiers suitable for the claimed process are the siloxane-oxyalkylene block copolymers the general formula

/ O - (R ₂ SiO) _p - (C _n H _2n O), - R "
R '- Si ^ - O - (R ₂ SiO), - (C _n H ₂ ,, O) .. - R "

- (R ₂ SiO), - (C _n H _2n O), - R "

where R, R 'and R "are alkyl radicals (1 to 18 carbon atoms), p, q and r are integers from 2 to 15 and - (C" H2 "O) ₌ a polyoxyalkylene block, preferably a polyoxyethylene-polyoxypropylene block with 10 to 50 on each of the two oxyalkylene building blocks, are described in U.S. Patent 2,834,748, and their use in the manufacture of polyurethane foams is the subject of Belgian patents 582 362 and 582 363.

In addition to the abovementioned commonly used auxiliaries, the known ones may be rigid Polyurethane foams still contain crosslinking agents, auxiliary blowing agents and pigments.

example 1

35

45

50

Rigid polyurethane foams were made as follows:

A. First, make a mixture of the following ingredients:

100 parts of a polyether made by reacting epichlorohydrin with a Mixture of glycerine and sorbitol, with a hydroxyl number of about 450,

0.4 parts of dimethylethanolamine,

0.4 parts of dibutyltin dilaurate,

1.0 part of a siloxane-oxyalkylene block copolymer,

8.33 parts pentakis (hydroxypropyl) diethylene

triamine and
30.0 parts of trichloromonofluoromethane.

This mixture is worked through thoroughly at room temperature and it becomes 81.7 parts a distilled mixture of 20% 2,6- and 80% 2,4-ToJuylen -diisocyanat added. The reaction mass is vigorously stirred for 15 to 30 seconds, in poured into a mold and allowed to stand at room temperature for about 16 to 24 hours.

B. The same mixture as in Part A is made with 100 parts of a toluenediamine phosgenation product with an isocyanate equivalent weight of 106.1 and a content of about 70 to 75% volatile toluene diisocyanate mixed.

C. The procedures of Parts A and B are repeated except that the aromatic polyisocyanate is used 123.4 parts of a phosgenation product of ρ, ρ'-diaminodiphenylmethane with an isocyanate equivalent weight of 131.4 and a content of about 80% of volatile methylene bis (4-phenyl isocyanate) be used.

D. A rigid foam is produced according to the procedure described in C with the deviation, that the phosgenation product of p, p'-diaminodiphenylmethane has an isocyanate equivalent weight of about 143 and a volatile aromatic diisocyanate content of about 70%.

All four foams were tested for flame retardancy according to ASTM flame test D-1692 checked. The results are summarized in Table I:

Table I.

Burning rate,

cm / min

Deletion time, seconds ..
Self-extinguishing

foam

7.5
79
no

Yes

0 Yes

It turns out that rigid polyurethane foams made with a chlorine-containing polyether and pure aromatic Diisocyanate are not flame retardant. Foams made with the same chlorine-containing Polyethers and a phosgenation product of an aromatic diamine are not only flame retardant, but also self-extinguishing. That surprising improvement is presumably of attendance one or more compounds of unknown constitution in the phosgenation product of the aromatic diamine used to make foams B, C and D.

Example 2

100 parts of a polyether, which contained a reaction product of cane sugar and propylene oxide, with a hydroxyl number of 600 and a viscosity of 1600 ocP at 25 ⁰ C,
2 parts siloxane-oxyalkylene block copolymer

merisat,

1.5 parts of dibutyltin dilaurate,
1.5 parts of distilled dimethyl-hexadecylamine,
20 parts of tri- (chloroethyl) phosphate,
45 parts of trichloromonofluoromethane

are mixed together until a homogeneous emulsion is formed. Then 116 parts become one Toluylenediamine phosgenation product with an isocyanate equivalent weight of 105.3 and one Volatile toluene diisocyanate content of about 75% added. The mass obtained becomes 15 to Stirred vigorously for 30 seconds and then poured into a mold, allowed to rise to full height and set aside and allowed to stand at room temperature for 16 to 24 hours. A sample of the The resulting rigid foam, when tested according to ASTM D-1692, has a burning rate of 5.0 cm / min and is self-extinguishing.

A similar foam is made with 96 parts of distilled toluene diisocyanate and on Flame resistance tested. This foam has a burn rate of 6.9 cm / min and is not self-extinguishing.

Example 3

A series of rigid polyurethane foams is made as described in Example 2 using distilled toluene diisocyanate, but produced by varying the amount of the flame retardant (Foam I). These foams are rated for their flammability according to ASTM D-1692 with a

Sample of the prepared according to Example 2 using the phosgenation product of tolylenediamine Foam compared. In addition, a corresponding, but using 40 parts Tri- (chloroethyl) phosphate produced foam included in this comparison. The results are compiled in Table II:

Table II

Foams i 20th 25th 30th 35 40 95 37 20th 15th 10 *) 3.2 1.4 0.6 0.3 no Yes Yes Yes Yes

Foams II

Parts of tri- (chloroethyl) phosphate

Deletion time, seconds

From the 2.54 cm mark
burned distance, cm

Self-extinguishing

20th 10

1.3
Yes

40

*) Sample completely consumed.
**) Sample does not ignite.
II made with the toluenediamine phosgenation product.

It can be seen that foam I with 20 parts of flame retardant burns completely after ignition, while foam II extinguishes itself with the same amount of flame retardant. they show also that to get a self-extinguishing foam with a comparable extinguishing time when using To obtain distilled toluene diisocyanate, twice the amount of the flame retardant is necessary than when using the phosgenation product of tolylenediamine.

B e i s ρ i e 1 4

A crude toluenediamine phosgenation product with a content of about 75% volatile toluene diisocyanate (80% 2,4-isomer and 20% 2,6-isomer) is obtained by phosgenation of a toluenediamine mixture in the presence of monochlorobenzene and distilling off the solvent from the crude reaction product at atmospheric pressure manufactured. It is made by distilling off 39 percent by weight of toluene diisocyanate 3.2 mm Hg concentrated. The concentrated product has an isocyanate equivalent weight of 139 and contains about 59% volatile toluene diisocyanate. There are two mixtures of concentrated Phosgenation product and pure toluene diisocyanate produced:

Ge
mix Weight percent
concentrated
Phosgenation
product Weight percent
pure toluene
diisocyanate % volatile
Toluene
diisocyanate A.
B. 23.1
28.6 76.9
71.4 87
83

Three polyether blends are prepared as in Example 2 and one of these blends is made with 96 parts of toluene diisocyanate, the second with 106 parts of mixture A and the third with 102 parts Mixture B implemented.

The foams produced in this way are tested for their flammability in accordance with ASTM D-1692. The results:

1. The foam produced with pure toluene diisocyanate burns completely in 95 seconds.

2. The foam produced with mixture A extinguishes in 58 seconds and the sample burns up to 6.8 cm from the 2.54 cm mark.

3. The foam produced with mixture B extinguishes in 25 seconds and the sample burns up to 2.1 cm from the 2.54 cm mark.

Example5

It shows the production of flame-retardant rigid polyurethane foams using a flame retardant, which contains groups which react with polyisocyanate. The toluene-n-diamine used 5 phosgenation product has an isocyanate equivalent weight of about 106.3 and a volatile content Toluene diisocyanate of about 75 percent by weight.

909 529/306

Table III

10

Foam, parts B. C. 60 70 30th 20th 10 5 1 1 0.2 0.3 2.0 1.5 35 35 0 90.2 118.2 0 8th 70 0.6

Premix
Polyether as in example 2

Phosphorus-containing polyol

Glycerin

Siloxane-oxyalkylene block copolymer

Stannous octoate

Dimethylhexadecylamine (distilled) Trichloromonofluoromethane

Isocyanate

Toluene diisocyanate

Toluylenediamine phosgenation product ...

Flame Test Results (ASTM D-1692) Extinguishing Time, Seconds

Distance burned away from the 2.54 cm mark, cm

60 30 10

35

98 0

75 ** \ 70 20

0.3 1.5 35

0 111.2

20th

2.2

*) Hydroxyl number 212, acid number 1, water content 0.1, functionality 2, phosphorus content 12% and viscosity 2500 cP at 25 ° C. **) The sample burns completely after ignition.

These data show that the tolylenediamine phosgenation product gives a strong polyurethane foam surprising flame resistance.

B e i s ρ i e 1 6

Rigid polyurethane foams are made as described above and using the following Components manufactured. The toluene phosgenation product was essentially the same as that of Example 5.

Example 7

In the same manner as described above, rigid foams were prepared using reaction masses of the following composition. The tolylenediamine phosgenation product of this example was essentially the same as that in the example 5 used.

Polyether (hydroxyl number 475)

Chlorinated diphenol

"Silicone" X-520

Dibutyltin dilaurate

»Quadrol« *)

Dimethylethanolamine

Tolylenediamine phosgenation product

Antimony trioxide

Trichloromonofluoromethane

Foam A parts

100

11 1.0 0.8

10.0 0.2

115 20 40

Foam B parts

108 12 1.6 0.7 0.0 0.0

0 24 30

45

55 polyether (hydroxyl number 464) ..

"Silicone" X-520

Dibutyltin dilaurate

"Halowax" 1014 *)

Antimony trioxide

Dimethylethanolamine

Tolylenediamine phosgenation product

Toluene diisocyanate

Trichloromonofluoromethane

Foam A parts

75 0.75 0.6 15.0 15.0 0

55 25

Foam B parts

75 0.75 0.6 15.0 15.0 1.0

70.0 0 25

*) N, N, N ', N'-Tetra (2-hydroxypropyl) ethylenediamine.

Foam A shrunk 1 to 2 ^liters per cent, was friable, had good cellular structure, and did not melt when ignited. Its flame resistance was good.

Foam B had a shrinkage of 3%, had a moderately good cell structure, was friable and melted when ignited. Its flame resistance was only moderate, worse than that by foam A.

*) A chlorinated naphthene, product of Koppers Chem. Co.

Foam A, made using pure toluene diisocyanate, melted when ignited became and had poor flame retardancy. Foam B, made using the toluenediamine phosgenation product, did not melt when ignited and had good flame resistance.

This shows that the flame resistance of rigid polyurethane foams improves to a surprising degree can be distilled if in place of

aromatic polyisocyanates the phosgenation products of aromatic polyamines used became.

Claims (1)

Claim: Process for making rigid polyurethane foams by reacting a polyol with a organic polyisocyanate in the presence of a Propellant and a flame retardant, characterized in that the polyol in a manner known per se with the phosgenation product of an aromatic diamine is reacted, this product being 40 to 90 percent by weight of volatile aromatic Diisocyanate contains and at least one equivalent of isocyanate groups per equivalent of active Hydrogen is used.