CS229503B1 - Method for the producing hard polyurethanizokyanuratic foams - Google Patents

Description

The invention relates to a process for the production of isocyanurals ^; modified polyurethanes, in particular polyurethane isocyanurate foams of polyesterpolyols based on by-products from petrochemical production, or mixtures thereof with polyetherpolyols, or other, mainly organic, compounds having at least one in the molecule. one active hydrogen.

It is known to prepare isocyanurate foams in terms of the structure encompassing the isocyanurate rings formed by the trimerization of isocyanates. Chair characteristic iso. the cyanurate ring is its high thermal and hydrolytic stability. However, foams prepared by trimerization of the isocyanates themselves have very low mechanical stress resistance. These will be improved, in particular by reducing extremely high friability, through the modification of isocyanurate foams by urethane bonds (U.S. Pat. Nos. 2,979,485 and 2,993,870).

Tosocyanurates containing polyurethane linkages are also prepared by trimerization of isocyanate-terminated urethane prepolymer [J. Cell. Plastic. 1, 85 (1965)].

At present, the more commonly used method of preparing foams in one step is relatively well known. Preparation of polyether polyol-modified isocyanurate foams with a mol. weighing less than 300 is the basis of Belgian patent 680,380.

Use of polyol with mol. a weight greater than 300 is again the subject of French patent 1,518,165. Other similar processes for the preparation of urethane-modified isocyanurate foams are also known [J. Cell. Plastic. 4,248 (1968); J. C.I. Plastic. Seipt./Okt. 203 (1970); J. Cell. Plastic. Mar./apr. 91 (1970); Belgian Patent 723,151).

The disadvantage, however, is the limited resources of starting materials, respectively. their costly production, which is an obstacle to further expansion of polyurethane isocyanurate production.

According to the present invention, the process for producing rigid polyurethane isocyanurate foams by reacting at least one aliphatic or aromatic dl- to polyisocyanate with a polyol in the presence of urethane and / or isocyanurate catalysts and other auxiliaries such as stabilizers is such that the polyol used consists of part or all of polyesterpol. prepared by esterification, polyesterification or re-esterification of the acid component formed from tasil or the complete distillation residue from the production of terephthalic acid and / or dimethyl terephthalate and the di-tetraol-based alcohol component.

An advantage of the production method according to the invention is that the above-mentioned polyester polyol from the distillation residues from the production of terephthalic acid and / or dimethyl terephthalate alone, optionally together with other compounds containing more than one active hydrogen per molecule, without is simple to produce polyurethane-iso-cyanurate foams. As other polyols, polyester polyols from pure starting materials and / or polyether polyols or other compounds may be used.

Suitable polyespheepolyols are also products based on dicarboxylic acids and / or their anhydrides with divalent or polyhydric alcohols. Adipic acid is suitable for their preparation, furthermore they can be dicarboxylic acids: oxalic, malonic, succinic, glutaric, cork or azelaic. Then unsaturated dicarboxylic acids, e.g. matelnovine, fumaric, itaconic or phthalic anhydride and maleic anhydride. Among the polyhydric alcohols, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, and other polypropylene glycols, butylene glycols or polybutylene glycols are suitable.

Further, glycerol, hexane | triol, butanetriol, trimethylolpropane, trm] octylolithane, tol, mannitol or sorbitol and other known polyhydric alcohols.

Suitable polyether polyols, which can be used to produce blends with polyester polyol based on the distillation residues from the production of dimethyl terophthalate or terephthalic acid, are known. They are the products of the reaction of polyhydric alcohols, polycarboxylic acids or polyvalent phenols with a low-molecular-weight 1,2-epoxy compound which contains one molecule per molecule, such as e.g. propylene oxide. Examples of low-molecular 1,2-epoxy compounds are ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, N, N-epoxyhexane, ethyl 2,3-optooctane, epichlorohydrin. epibromohydrin, ·. styrene oxide, glycidyl ether, metylglycidyléter, phenyl lglycidyléter, butylglyctdylsulfid, glycidyl dyimetyl ^ sulifón, glycidylmetlkryláť, glycidyl acrylate, ₁ glycídylbollzcáť -glycldylacetát, "glycidyiokt ^ oic acid, or glccidylsorbát gtycidytalyifiaiát. How ^:. epoxides used for. preparation of polcétorpolyols! most suitable are compounds which are formed. a hydrocarbon, an ether, a sulfide, a sulfone or an ester with a moncepoxy group and containing up to 18 carbon atoms per molecule. In particular, polyetherpolyols based on non-isomeric alkyl oxides are used to prepare the rigid pdyurethane foam. Further, they may be polyesteramides or mixtures thereof with polyesters prepared by known processes from polyhydric acids, alcohols, optionally amines, further known polymers (NSR Pat. 1,105,156) or polylycotalc (NSR Pat. 1039,744 and 1045,095).

Many organic di-polyisocyanates are suitable as the flavoring component according to the invention, e.g. aryl benzyl or naphthalene series aryl radicals which are more active and less toxic than aliphatic diisocyanates.

Such are: 2,44 toluene diisocyanate, 2,6-toluene diisocyanate and mixtures thereof. Other isocyanates can be used, e.g.

phenylene diisocyanate, alpha-naphthalenediisocyanate, 4-toluene diisocyanate, n-hexylene diisocyanate, methylene bis (4- (phenylene isocyanate), 3'-ditoluene-4,4'-diisocyanate, 4,4'-methanediphenyldiocyanate) 'methoxy-4,4-difenyléndiizokyanát,

1,5-naiftalenediisocyanate, 2,4-chlorophenylemidisocyanate, hexameitylenediisocyanate,

1.3-cyclopentylene diisocyanate,

1,2-cyclohexylenediisocyanate,

1.4- cyklahexyléndiizokyanát, cyklopeintylidéndiizokyanát, cyklohexylidéndiizakyanát, p-phenylene diisocyanate, m-phenylene diisocyanate, 4,4 & apos dilfenylpropándiizokyanát, l-methyl-2,4-phenylene diisocyanate, ^4.4 tons -difenyléndiizakyanát,

1.2- propylene diisocyanate,

1,2-butylene diisocyanate, ethylidene diisocyanate, propylidene diisocyanate, butylidene diisocyanate,

1.3.5- Triisocyanatebenzol

2.4.6- Triisocyanate-toluene

2,4,6-4-trisocyanochlorobenzene ₁ 4,4 ^< , 4'-triphenyl-methanitriisocyanate, polymethylene polyphenylisocyanate or mixtures thereof.

High molecular weight polyisocyanates are the liquid reaction products of diisocyanates and polyhydroxy compounds or polyamines. In addition, polyisothiocyanates or mixtures of polyilyl isocyanates may be used. Technical unpurified or crude polyisocyanates, e.g. crude methylene bis (4-phenylisocyanate) mixture.

In addition, in some cases, a prepolymer, a product after partial reacting of the polyether polyol or mixtures thereof with diisocyanates, is suitable as an isocyanate component. Selection of the type of diisocyanate used, resp. % of the polyisocyanate, depends on the properties of the starting materials and the desired properties of the product.

The nature and amount of excipients, which include activators, stabilizers, emulsifiers, blowing agents, solvents, quenching agents, fillers and the like, have a considerable influence on the properties of rigid polyurethane isocyanurate foams.

Many compounds can be used as activators for the polyurethane reaction (J. H. Saunders and C. Frish in Polyurethanes, translation: Khimija polyurethanes, Izdatelstvo "Khimija", Moscow 1968).

Among the known compounds, in particular tertiary amines, e.g. N, N‘ -dimethylcyclohexylamine, dimethylethanolamine, triethylenediamine, dimethylaniline, pyridine, ethylphorpholine, quinoline and the like, or organometallic compounds such as dibutyltin laurate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltan tin disulfide, dimethyl tin disulfonate, dimethyl tin disulfonate, dimethyl tin disulfonate, dimethyl tin disulfide;

When using unrefined residues from the production of dimethyl terephthalate or terephthalate acid, it is necessary to take into account the catalytic influence of the metals present, in particular the salts of manganese, cobalt, chromium, molybdenum, iron and other metals.

The effect of the catalysts is often increased by the correct selection of the amounts of the individual components, with a synergistic effect, in particular using tin salts and tertiary amines. By suitably selecting the concentration, type and ratio of the catalysts, not only the reaction of the hydroxyl group with the isocyanate, but also the formation and properties of the foam can be influenced.

Trimerization catalysts suitable for the preparation of polyurethane isocyanurate foams are known and extensively described in the patent literature. They include tertiary amines (Germany Pat. No. 951161; US Pat. 2,993,870; V. Brit. Pat. 856,372), trialkylphosphines [Hofman, A. W., Jahresbe 349 (1958); Ber. 3, 761 (1870)}, organic onium compounds, ethylenimines, metal carboxylates, basic catalysts including alkali and alkaline earth oxides, their hydroxides, carbonates, alcoholates and phenolates, alkali salts of enolizable compounds, tin, antimony, Friedel- Criaft catalysts and alkali metal chelates.

Combinations of target-amine catalysts are well known (U.S. Pat. Nos. 3,180,846, 3,168,483, 3,179,626, 3,179,628, 3,154,522, 2,993,870,

146 219; NSR pat. 1013,869), as well as organic onium compounds (V. Brit. Pat. 837,120 and U.S. Pat. 3,010,963) and other catalysts [V. Brit. pat. 809 809, 1 155 768; Hofmanu A. W. Ber. 18, 764 (1886), Frenzel W., Ber. 21, 411 (1888); US Pat. 2,801,244].

Examples of basic catalysts include alkali or alkaline earth metal oxides, their hydroxides, carbonates, alcoholates (U.S. Pat. No. 809,809).

The practical application of these catalysts, however, are only those which at 0.1 to 10% by weight, allow the trimerization of isocyanates, at a temperature of 20 DEG C. and the conversion of the conceived, ¹ min 10 exceeds 85 to 90% by weight. Such catalysts include, in particular, 2,4,6-tris- (dimethylaminomethyl) phenol, 2,4,6-tris (diethylaminomethyl) phenol, N, N'N'-tris (dimethylaminomethyl 1-dimethylamino) drothiazine, hydroxide potassium, sodium hydroxide, potassium acetate, and combinations of a tertiary amine with an alkaline salt.

Low molecular weight diols such as ethylene glycol, diethylene glycol, propylene glycols, and 1,4-butylene glycol are used as the starters of the urethane reaction, or as a solvent for the trimerization catalyst.

The concentration of the catalytic system is selected so that the start time, the growth time of the foam and the loss of tack meet the requirements, i. j. The start time ranges from 8 to 20 s, the growth time is 15 to 90 s, the tack loss is 18 to 180 s.

Of the available blowing agents, compounds are generally used which, upon heating or conversion with the isocyanate, release gaseous compounds. Low molecular weight liquids and water are preferably used in foaming. The heat of reaction and the reaction of water with the diisocyanate cause foaming of the mixture to form a sufficiently stable foam which maintains its form until the mass gels.

Suitable low molecular weight liquids are fluorochlorohydrocarbons having a boiling point of between about 20 ° C and about 50 ° C or mixtures thereof, e.g. trichlorofluoromethane, trichlorofluoroethane, dichlormonofluoromethane, monochloroethane, monochloronofluoroethane, difluoromonochloroethane or ¹ difluorodichloroethane,

However, compounds with a boiling point of from -50 ° C to 110 ° C, and possibly higher boiling points, can also be used (U.S. Pat. No. 2,865,869).

The stabilizers ensure the formation, size and uniformity of the foam cells. They are organosilanes, e.g. mixed polysiloxane-polyoxyalkylene polymers - (U.S. Pat. No. 2,834,748 -a and 2,917-480 ').

The importance of emulsifiers is to: - improve the solubility of the reaction components or auxiliary substances. Many emulsifiers, such as dioctyl phthalate, dibutylphthalate and the like are suitable.

Flame retardants (bis-haloalkyl) -phosphate, in particular bis (2-chloroethyl ethyl) -phosphate, bis (2-bromomethylphosphate), 2 (bromo-2-methylphosphate), 2 (2-bromomethylphosphate), 2, and 2 can be added to the polyurethane isocyanurate foams prepared according to the invention. Inorganic substances which also function as fillers and dyes, such as ammonium phosphates, sodium borate, antimony trioxide, may also be used as flame retardants. also organic polymeric substances such as polyvinyl chloride powder.

The process according to the invention can be carried out by a known process by pouring or spraying on conventional equipment used to produce polyurethane compositions. Depending on the type of foaming device, the method of dosing the individual components is chosen.

An advantage of the process according to the invention is the processing of the polyol component on the basis of secondary, economically underutilized raw materials to give full-value polyurethane isocyanurate foams having very good properties, in particular at elevated temperatures.

Further details of the process according to the invention as well as further advantages are apparent from the examples.

EXAMPLE

And 30 g of the polyester polyol prepared lransesterilfikáciou 1500 g - distillation residues from the production of dim ^ etyMeroitalátu, 1460 -g diethylene glycol and 250 g of ^L -Pen taerytritolu, the hydroxyl content - 410 mg - KOH / / g, was added 1.7 g of silicone - stabilizer Tegostab B 1903, - 0.7 g of dimethylcyclohexylamine, 0.07 g of dibutyltin dilaurate, 1.4 g of 50 pera, a solution of potassium acetate in ethylene glycol, 0.7 g of - 2,4,6-ΐlis (dimethylaminomethylphenol) and 11,2 g ШеЫбй ^ гmethane as blowing agent. In a paper-waxed glass, this polyol component is mixed with 131.9 grams of crude 4,4'-diisocyanatodiphenylmethane, commercially designated Desmodur 44 V. The resulting foam has a start time of 17, a growth time of 45 seconds and a tack of 47 seconds, bulk density 38 4 kg / m ³ , - friability 17% and according to ASTM 1692 is self-extinguishing.

Example 1 - a d 2

To 30 g of a 1: 1 weight ratio of polyester polyol and polyether polyol (mixed with the polyester polyol produced according to Example 1 and polyapolyol Slovaprop T-450, obtained oxypropylacious sucrose) with a hydroxyl group concentration of 416.0 mg KOH / g was added 2 g Togostab B-1903 silicone stabilizer, 0.9 grams of dimethylcyclohexylamine, 0.09 g of di-butyl tin dilaurate, 1.7 g of a 50% solution of potassium acetate in ethylene glycol, 0.8 g of 2,4,6-tris (dimethylaminomethyl) of phenol and 16.4 g of trichlorofluoromethane as blowing agent.

This polyol component is mixed with 185 g of crude 4,4‘-diisocyanatodiphenylmethane at a ratio of - NCO-: —OH = 6: -1. This results in a fine-grained foam with a uniform structure, with foaming times: start time 25 s, growth time 90 s, tack loss 95 s. The bulk density of the foam is 39.6 kg / m 3 friability -26% and -in accordance with ASTM 1692, the foam is non-flammable.

EXAMPLE 1 a d 3

To 30 g of a mixture of polyesterpolyols (polyesterpolyol prepared according to example 1 and polyesterpolyol obtained by the reaction of adipic acid, ethylene glycol and i.e. methyl ethylpiperidine with a hydroxyl number of 420 mg KOH / g in a weight ratio of 2: 1) is added 1, 2. 7 grams of stabilizer - Tegostab B 1903, 0.7 g of dimethylcyclohexylamine, 0.07 g of dibutyltin dilaurate, 1.4 g of a 50% potassium acetate solution in ethylene glycol, 0.7 g of 2,4,6-tris ( dimelylaminomethyl) phenol, 11.2 g of a blowing agent - trichlonfluoromethane and

6.6 g of tris-2-chloroethyl phosphate as a flame retardant. This polyol component is mixed with

131.9 g of crude 4,4'-diisocyanatodiphenylmethane at a mole ipomer of —NCO:: —OH = 4: 1. A foam having characteristic times: starting time 19 s, growth time 50 s, loss of tack 62 s, bulk density 40.4 kg / m ³ , friability according to ASTM C-421 is obtained.

Claims (1)

SUBJECT Process for producing rigid polyurethane isocyanurate foams by reacting at least one aliphatic or aromatic di- and polyisocyanate with a polyol in the presence of urethane and / or isocyanurate catalysts and my excipients as stabilizers, characterized in that the polyol used is VYNALEZU consists. partly or wholly of polyester polyol obtainable by esterification, polyesterification or re-esterification of the acid component consisting in part or wholly of the distillation residue from the production of terephthalic acid and / or dimethyl terephthalate and / or the di-tetraol-based alcohol component.