DE2261545A1 - PROCESS FOR MANUFACTURING RIGID FOAM - Google Patents

Description

B esc lire ibu η g to the patent application

Shell Internationale Research Maatschappij, H.V., 's-Gravenbage 2076, Hiederlande "concerning:

Process for the production of rigid foams.

The invention relates to an approach which can be used in the production of isocyanurate-containing foams suitable and a process for the production of such foams.

It is known that isocyanurate-containing foams can be prepared by using an organic polyisocyanate a polyol, in the presence of a catalyst which is capable of isocyanate groups to isocyanurate rings to trimerize and a propellant. As a primerization catalyst is used in known processes. dissolved in certain polyols, and trichlorofluoromethane as a blowing agent.

However, when carrying out such

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drive in practice the problem that it is annoying, prepare a miscible solution containing the polyol, the trichlorofluoriaethane and the potassium acetate. Han can Although the potassium acetate dissolves in certain polyols, the mixture separates "when trichlorofluoroethane is added. Of course, certain difficulties arise when processing such immiscible solutions. One way of overcoming this disadvantage is that the Trichlorfluonnethan with the organic polyisocyanate added and the immiscible components only immediately before the preparation of the isocyanurate-containing Brings foams into contact. However, this solution means an undesirable restriction in handling the procedural components.

Surprisingly it has now been found that ann in the presence of a diol containing at least one secondary hydroxyl group, a miscible solution of one or more polyols, potassium acetate and trichlorofluoromethane produce k.

According to the invention contains a liquid miscible solution which is suitable for the production of isocyanurate-containing foams suitable

(a) potassium acetate,

(b) a diol with an average molecular weight of at least 100 and at least one secondary hydroxyl group in the molecule,

(c) a polyol different from the diol (b), and

(d) trichlorofluoromethane,

with the proviso that component (a) has a solubility in component (c) of at least 10 g / l at 25 ° C.

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Suitable diols with an average molecular weight of at least 100 and at least one secondary hydroxyl group in the molecule (hereinafter referred to as "secondary diols") include polyoxypropylene glycols of various molecular weights such as dipropylene glycol, tripropylene glycol and tetrapropylene glycol; 1,3-butanediol; 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol and 2-methyl-2,4-pentanediol (hexylene glycol); 1,2-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol and 33-hexanediol and mixtures from these diols. Diols with an average molecular weight of less than 500, which are a single, are preferred have secondary and a single primary hydroxyl group.

Suitable polyols as distinct from secondary diols (hereinafter referred to as "polyols") include those belonging to the following classes of polyols: polyether polyols, Polyester polyols; Polyether-polyester polyols; Polyester amide polyols or condensation products of mines or alkanolamines and an alkylene oxide such as ethylene oxide or propylene oxide. However, potassium acetate must have a solubility of at least 25 G in the polyol concerned 10 g / l. Preferred polyols are the polyether polyols, which can be produced by reacting one or more alkylene oxides, e.g. ethylene oxide, propylene oxide, Styrene oxide or epichlorohydrin, with an alkane polyol, e.g. an alkylene diol or a polyalkylene polyol (e.g. ethylene glycol, glycerine, pentaerythritol, sucrose or Sorbitol); or with an alkylene oxide polymer or copolymer (e.g. a block copolymer or a random copolymer). Other suitable polyols are made by reacting one or more of the above polyols with less than the stoichiometric amount of an organic Polyisocyanates. Particularly preferred polyols are those

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309 829/1021.

obtained by reacting a triol, such as glycerine, with propylene oxide.

Polyols with an average molecular weight are particularly suitable from 200 to 10,000.

The weight ratio of secondary di-oil to polyol can be in the miscible solution can vary within wide limits, but is usually in the range from 5: 1 to 1: 5 preferably from 1: 2 to 1: 5.

The amount of potassium acetate can also vary between wide limits and can be, for example, 0.5 to 20, preferably 2.5 to 7.5 parts by weight, calculated on 100 parts by weight of secondary diol plus polyol. The amount of potassium acetate present in the liquid miscible solution is limited by the degree of its solubility in the diol, polyol and trichlorofluoromethane. The potassium acetate is preferably dissolved in the polyol, if necessary with heating. Before adding the secondary diol and the trichlorofluoromethane to the mixture, any undissolved potassium acetate is filtered off.

The amount of trichlorofluoromethane in the liquid mixture can vary widely, for example from 50 to 300 parts by weight per 100 parts by weight of secondary diol plus polyol.

According to another aspect of the invention is a method of making rigid isocyanurate-containing foams (Rigid foams), characterized in that the above-described liquid miscible solution under foaming conditions umsotzt with an organic polyisocyanate.

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Suitable organic polyisocyanates include monoaryl polyisocyanates and polyaryl polyisocyanates, such as, for example, the polyaryl polyalkylene polyisocyanates. Examples of monoaryl polyisocyanates are toluene-2,4-diisocyanate and toluene-2,6-diisocyanate and mixtures thereof (for example in a ratio of 80:20 or 65:35) in-phenylene diisocyanate and p-phenylene diisocyanate. Examples of Polyarylpolyisocyanate are naphthalene-1,5-diisocyanate, diphenylmethyl-4,4-diisocyanate ^1, 3-methyldiphenylmethane-4,4 diisocyanate -'-- and diphenyl-4,4'-diisocyanate.

A particularly suitable polyaryl polyisocyanate is crude diphenylmethane diisocyanate, made by phosgenation of crude. Diphenylmethanediamines, which can be obtained by reacting aromatic amines, such as aniline-ochloraniline and o-toluidine, with formaldehyde and hydrochloric acid. If aniline is used as the aromatic amine, the product is a mixture of diphenyl-4,4 ¹ -diisocyanate, diphenyl-2,4-diisocyanate and related polyisocyanates of higher molecular weight and higher functionality, such as the tri- and tetra-isocyanates The proportions of these components in the mixture change with the proportions of formaldehyde and aniline in the preparation of the crude diphenylmethane polyamines. Suitable weight ratios of aniline to formaldehyde are 4: 1 to 4: 1.5.

Suitable crude diphenylmethanedixocyanates contain about 30 to 90, preferably 40 to 65 wt .-> o polyisocyanate with a functionality of more than 2. The difunctional material comprises substantial proportions of diphenylmethane-4,4 ¹ -diisocyanate, the proportions of the above components can can also be varied by adding some diphenyl

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4,4'-diamine from the crude diphenylmethane diamine starting material or some diphenylmethane-4-, 4'-diisocyanate from your raw diphenylmethane diisocyanate product removed.

The amount of organic polyisocyanate that is present with the liquid miscible solution is implemented, can vary within wide limits, but in general each equivalent on active hydroxyl groups of the polyol 2 to 10, preferably 3 to 7 equivalents of isocyanate groups of the organic Polyisocyanates used.

The liquid miscible solution and / or the organic polyisocyanate, which are used to form rigid polyisocyanurate foams, further additives can be used contain.

Suitable additives are fillers such as chalk and clay; Antioxidants; Flame retardants such as trichloroethyl phosphate; Silicone oils, such as siloxane-oxyalkylene copolymers. Usual polyurethane catalysts such as amines (e.g. triethylenediamine and triethylamine), which the reaction between hydroxyl and isocyanate groups catalyzing can also be present.

The liquid miscible solution and the organic polyisocyanate can be reacted under foaming conditions and you get molded pieces, panels or laminates made of or with foam. The trichlorofluoromethane component the liquid miscible solution is allowed to evaporate, so that the reaction mixture is foamed. The heat of reaction may just be enough to get the trichlorofluoromethane to evaporate or you can add additional heat to the reaction mixture.

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The rigid isocyanurate-containing foams (rigid foams) obtained by the process according to the invention ^ have good properties even at high temperatures, do not ignite and are particularly suitable for insulating material and components.

In the examples which illustrate the invention in more detail, A represents a glycerol-initiated propylene oxide adduct, prepared by basic catalysis, which has an average molecular weight of about 300; Polyol B is discontinued glycerine-initiated propylene oxide adduct with about j> - wt .-% internal random ethylene oxide and about 10 % By weight of external ethylene oxide, the percentages being based on the total weight of ethylene and propylene oxide. are related; Polyol 0 is a glycerine-initiated propylene oxide adduct produced by basic catalysis which has an average molecular weight of about 3,000 and a hydroxyl number of about 56 mg KOH / g.

The solubility of potassium acetate in polyols A and B at 25 ° G is higher than 10 g / l.

B is ρ ie 1 1

At tree temperature, one approach (Type A) was made from the following Components manufactured:

Polyol A 20 parts by weight potassium acetate 0.25 "

Trichlorofluoro-

methane 17

The approach was heterogeneous.

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Then four more batches were made at room temperature, in which diols with at least one secondary hydroxyl group are incorporated according to the invention in batches of type A was. The approaches had the following composition:

Tabel

Components 1 approaches 2 (Weight Parts 4th 10 18th 20th Polyol A. 5 - 3 - Propylene glycol 10 Polypropylene glycol - 10 - - (MW 250; - - '4 Hexylene glycol 0 .25 0, 4th 0.5 Potassium acetate 21 17th _ 21 Trxchlorofluoromethane 5 0.25 11

All four approaches were well miscible solutions; no heterogeneity could be observed.

For comparison, three more were used when the temperature was low Prepared batches in which diols and a triol were incorporated in batches of type A that were not secondary Had hydroxyl group. The comparative approaches are shown in Table II:

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226154fr

TABLE II

Carrion sets (parts by weight)

ÄUÜiJJ UJJ. CXl \ J CJJ. 5 6th 7th Polyol A. 15th 20th 20th Monoethylene glycol 7th - : - 1,4-butanediol - 10 - Glycerin - , - 8th Potassium acetate 0.4 0.5 0.5 Trichlorofluoromethane 15th 20th 20th

All three approaches were heterogeneous. Example 2

The following components became one at room temperature Approach (type B) produced:

Polyol A 20 parts by weight of polyol B. 10 "potassium acetate 0.25" Trichlorofluoro-

methane 22 "

The approach was heterogeneous.

Now “three further batches were prepared at room temperature, in which the batch of type B diols, with min.

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at least one secondary hydroxyl group were incorporated, the approaches had the following composition:

T A Components BELLE III 9 10 Polyol A. 15th 20th Polyol B 10 10 Tripropylene glycol Approaches (parts by weight) _ - Polypropylene glycol
(MW 250) 8th 10 Hexylene glycol 20th - 5 Potassium acetate 9 0.25 0.5 Trichiorfluoromethane 8th 17th 20th _ - 0.5 24

All three approaches were uniform, mixable solutions without any heterogeneity.

For comparison purposes, three further batches were prepared at room temperature, in which a batch of type B Diols and a triol were incorporated, which are not secondary Had hydroxyl groups. These approaches are shown in Table IV.

TABLE IV:

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TABLE IV

Approaches (parts by weight)

11 12th 13th Polyol A. 10 10 20th Polyol B 10 10 20th Monoethylene Glycpl - - - 1, ^ =: butanaiol - Glycerin - - 9 Potassium acetate 0.25 0.25 0.5 Trichlorofluoromethane 10 11 19th

All three approaches were heterogeneous. Example 5

At room temperature, two approaches from the in Table V specified components manufactured.

IABE LLE V

Approaches (parts by weight) Components ■

14 15 '

Polyol G 18 20

polyethylene glycol 8 2.5

Hexylene ^ lycol - 8

Potassium acetate 0.25 0.5

Trichlorofluoromethane 20 20

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Cure the approach that is a di-oil with a secondary hydroxyl group (Batch 15) contained, was a uniform solution without heterogeneity.

Example 4

By mixing the following components under foaming conditions a rigid, isoeyanurathaitiger foam was produced:

Liquid miscible solution 1 73 parts by weight silicone oil (L534O) 1 "

raw diphenylmethanedixocyanate 100 "

The rigid foam had a good, fine cell structure and showed a satisfactory behavior at high temperatures.

Example 5

By mixing the following components under foaming conditions A rigid foam containing isocyanurate was produced:

Liquid miscible solution 2 45.5 parts by weight Silicone oil (SF1066) 1.0 "

crude diphenylmethane diisocyanate 100.0. ".

The rigid foam had a good fine cell structure and showed a satisfactory behavior at high temperatures.

PATENT ACTION:

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Claims (9)

PATENT CLAIMS Process for the production of rigid isocyanurate-containing Foams by reacting an organic polyisocyanate with a polyol in the presence of potassium acetate as a trimerization catalyst and of trichlorofluoromethane as a propellant, characterized in that that the polyisocyanate is reacted with a uniform liquid solution which consists of (a) potassium acetate, (b) a diol with an average molecular weight of at least 100 and one or more secondary ones Hydroxyl groups in the molecule, (c) a polyol different from the diol (b), and (d) trichlorofluoromethane, wherein one uses a polyol (c) where the potassium acetate (a) at 25 ⁰ C of at least 10 g has a solubility / l. 2. The method according to claim 1, characterized in that there is a diol (b) with a mean Molecular weight less than 500 used. 3. Method according to claim 1 or 2, characterized in that g e k e η η draws that one uses a diol (b) with only a single secondary hydro ^ lgruppe. g e k e η η - 4. The method according to claim 3, characterized in that the diol (b) is polyoxypropylene glycol used. 309829/1021 5. The method according to any one of claims 1 to 4t thereby characterized in that a glycerine-initiated propylene oxide adduct is used as polyol (c) 6. The method according to any one of claims 1 to 5 »thereby characterized in that in the starting solution the weight ratio of the diol (b) to the polyol (c) is the same Is 1: 5 to 5: 1. 7. The method according to any one of claims 1 to 6, characterized characterized in that the potassium acetate (a) used in a proportion of 0.5 to 20 parts by weight per 100 parts by weight of diol (b) plus polyol (c) 8. The method according to any one of claims 1 to 7 _f, characterized in that the trichlorofluoromethane (d) is used in a proportion of 50 to 300 parts by weight per 100 parts by weight of diol (b) plus polyol (c). 9. The method according to any one of the preceding claims, characterized in that the starting solution with crude diphenylmethane diisocyanate as the polyisocyanate implements. 309829/1021