FI68407C - FOERFARANDE FOER FRAMSTAELLNING AV POLYURETAN GENOM ANVAENDNING AV POLYMERMODIFIERADE POLYOLER SAMT FRAMSTAELLNING AV POLYMERMODIFIERADE POLYOLER - Google Patents

Description

68407

This invention relates to a process for the preparation of polyurethanes using polymer-modified polyols and to the preparation of polymer-modified polyols.

Polyurethane foam is prepared by reacting a polyol with a polyisocyanate in the presence of a blowing agent and usually one or more other additives.

It is known to use preformed polymer-modified polyols (i.e., polyols containing other polymeric material) in the polyurethane formation reaction to modify the physical properties of the resulting foam as desired. For example, GB 1,501,172 describes the use of polyol dispersions obtained in polyaddition reactions of a polyisocyanate with primary amines, secondary amines, hydrazines or hydrazides; and GB Patent 1,482,213 describe the use of polyols having a polymeric material obtained by polymerizing ethylene-unsaturated monomers dispersed and also copolymerized in situ by polymerization.

The invention thus relates to a process for the preparation of polyurethane, in which the isocyanate is reacted with a polymer-modified polyol preformed by polymerizing an alkanolamine with an organic polyisocyanate in the presence of a polyol.

The process is characterized in that the alkanolamine 30 is reacted at least for the most part polyfunctionally with the isocyanate in a molar ratio of 1.0: 0.5 to 1.0: 1.6 and the polyol acts at least for the most part as an unreacted carrier in the preformation step of said polymer-modified polyol.

In the process of the invention, an alkanolamine, meaning an organic compound having one of 2 68407 or more hydroxyl groups (-OH groups) and one or more primary, secondary or tertiary amine groups (-NH 2 »= NH or -N), acts as a poly as an optional reactant (having one or more reactive hydrogen atoms) and forming a polyaddition product with a polyisocyanate (meaning a compound having at least two isocyanate groups). When the alkanolamine is a primary or secondary amine, it has alcohol and amine groups containing active hydrogen atoms, all of which hydrogen atoms can be reactive with isocyanate. When the alkanolamine is a tertiary amine, it has several alcohol groups, all of whose active hydrogen atoms can be reactive with the isocyanate. In all cases, all 15 or only some of the reactive hydrogen atoms may actually react. It is believed that in the polyaddition reaction, straight and / or branched chains are formed when the isocyanate and hydroxyl groups combine to form urethane bonds (-NH-CO-O-) and when the isocyanate and amine groups combine to form urea-bond (-NH-C0-NH- n-CO-NH-). The resulting polyaddition product can be blended and / or chemically combined (by copolymerization) with a polyol; as used herein, the term polymer-modified polyol refers to both physical and chemical combinations and mixtures thereof, although it is believed that in most cases the process of the invention results in a predominantly physical combination. Such a physical combination may be a solution or permanent dispersion of the polyaddition product in the polyol, depending on the starting materials used. In particular, the alkanol-30 amine used, as well as the polyol, may determine the physical form of the polymer-modified polyol.

In the process of the invention, the alkanolamine and isocyanate are preferably mixed in a molar ratio of about 1.0: 0.5 to 1.0: 1.5 in the presence of a polyether polyol having a molecular weight of 200 to 10 G00 (especially 2800 to 7000) and the total amount of reacted alkanolamine and polyisocyanate. The amount of 68407 is 1-35% by weight based on the weight of the polyol.

Any suitable alkanolamine or combination of alkanolamines may be used as the alkanolamine in the process of the invention; the alkanolamine may be a primary, secondary or tertiary alkanolamine such as monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butylamine, N-butylamine Diisopropanolamine, triisopropanolamine, N-methylisopropanolamine, N-ethylisopropanolamine, N-propylisopropanolamine, but are not limited thereto. As used herein, the term alkanolamine also refers to substituted alkanolamines, and thus it is possible to use, for example, primary and secondary alkanolamines having a halogen substituent on the nitrogen atom, or secondary or tertiary alkanolamines having a halogen substituent on the alkyl group; . In a particularly preferred embodiment, triethanolamine is used as the alkanolamine.

As the organic polyisocyanate, any suitable polyisocyanate can be used, such as the aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates known to be used in the polyisocyanate / polyol reaction to form a polyurethane (see e.g.

Suitable commercially available polyisocyanates include 2,4- and 2,6-toluene diisocyanates and mixtures of these isomers (commonly referred to as TDI), polyphenylpolymethylene polyisocyanates of the type obtained by condensing aniline with formaldehyde and then phosgenating (generally designated MDI). ), and polyisocyanates containing carbodiimide groups, urea-35 groups, allophate groups, isocyanate groups, urea groups or biuret groups (commonly referred to as polyisocyanates).

68407

Any suitable polyols can be used, for example polyether polyols having a molecular weight of 200 to 10,000 and the use of which in the polyurethane-forming polyisocyanate / polyol reaction is described, for example, in GB 1 482 213. Such known polyether polyols can be obtained, for example, by the reaction of alkylene oxides. with compounds containing an active hydrogen atom, the molecular weight of the reaction product depending on the amount of alkylene oxide used in the reaction.

It is also to be understood that not all alcohol / amine groups of the alkanolamine used in the polyaddition reaction of the invention need to react with the isocyanate under all conditions, and that the alkanolamine may thus in some cases react monofunctionally and thus act as a chain terminator.

The polyaddition reaction of the invention can be catalyzed, if desired, using catalysts commonly used in polyurethane polyisocyanate / polyol formation reactions. For example, organometallic compounds such as stannous octoate and dibutyltin dilaurate and / or amines such as triethylenediamine can be used. The amount of catalyst used may be relatively small compared to the amount normally used in the polyurethane formation reaction; for example, it may be of the order of 0.02% rather than 0.2% of the total amount of polyol, although higher amounts may be used if desired.

It may not be necessary to use a catalyst in the reaction with the primary or secondary alkanolamine, but its use in the reaction of tertiary alkanolamines, such as in the reaction of triethanolamine, is preferred.

The molecular weight of the polyaddition product can be adjusted by varying the relative amount of alkanolamine and the relative proportion of polyisocyanate. Although, for example, a molar ratio of alkanolamine to polyisocyanate of 1.0: 0.5 to 1.0: 1.5 is preferred, and especially equivalent molar ratios are particularly preferred, it is also possible to use a higher amount of isocyanate if a higher the higher viscosity or no-5 higher gelation usually resulting from the amount of isocyanate can be unduly allowed. Thus, the upper limit of the ratio may optionally be about 1.0: 1.55 or 1.0: 1.6. When the amount of isocyanate is reduced, the molecular weight of the polyaddition product decreases and at the same time its viscosity decreases. In general, the alkanolamine / organic poly-10 isocyanate ratio is preferably 1.0: 0.8 to 1.0: 1.1.

Although the concentration of reacted alkanolamine and isocyanate (and thus the concentration of the polyaddition product) in the polyether polyol may vary within wide limits, it should generally be from 1 to 35% by weight, preferably from 3 to 30% by weight. When a certain concentration of polyaddition product is desired (e.g., for the production of polyurethane foams with certain optimum properties, a concentration of, for example, about 10% by weight * is required), it can be obtained by appropriately selecting reactants to obtain the desired concentration directly or by subsequent dilution of the formed polyaddition product. polyether polyols.

The temperature at which the reactants can be mixed with one another can be 0 ° C or lower, but it is still above the melting point and can even be up to 150 ° C. Preferably, the reactants are stirred at room temperature or just above their melting points, up to 70 ° C. Optionally, the reactants can also be mixed below their melting points.

The reaction is exothermic, and the observed temperature rise depends on the weight ratio of the polyaddition product prepared to the polyether polyol.

The more efficiently the reactants are mixed, the finer the particle size of the dispersion is obtained (when preparing a 6 68407 dispersion) and the lower the viscosity is obtained. Although conventional batch preparation can be used, in which one of the reactants, an alkanolamine or a polyisocyanate, is first dissolved or dispersed in the polyether polyol and then the other is added to the maximum mixing zone, continuous addition of reactants can also be used. In the latter case, the reactants are pumped at controlled rates and mixed simultaneously, or the second reactant may first be mixed with the polyether polyol and the second reactant may be added and then mixed.

The polyether polyol dispersion can be used either immediately after the reaction or only later. For example, a polyether polyol containing a polyaddition product can be fed from a controlled in-line coupled mixing unit where the reaction takes place directly to the mixing head of a known type of polyurethane manufacturing machine. When the reaction of the alkanolamine with the polyisocyanate is relatively slow, an intermediate tank can be used between such a mixing unit on the production line and the polyurethane mixing head, which gives additional time to complete the reaction.

The polyaddition product is used to make polyurethane foam. When the product is in the form of a permanent polyol dispersion, i.e. a dispersion which does not separate or at least remains as a dispersion during mixing with other foam-forming ingredients, the dispersed polyaddition product is particularly effective as a filler in the production of a highly resilient easy-to-work foam. and at the same time as a cell wall breaker.

When the product is in the form of a polyol solution, it can potentially be used to form polymeric materials having properties different from those of products made with polyol dispersions.

In general, when the polyaddition product is in the form of a permanent dispersion, it can be used with such soft.

7 68407 for the production of semi-rigid and hard polyurethane foams with improved properties, such as higher hardness, and for the production of highly resilient, non-shrinking foams well known in the industry because the polyol dispersed in the polyaddition product has the ability to open cell walls. In addition, the dispersions are suitable for the production of elastomers, coatings and coatings made of, for example, polyurethane.

When the dispersion is used for the production of polyurethane, the properties of the polyol dispersed in the polyurethane production process, in particular its hydroxyl number and functionality, are selected in a known manner, taking into account the type of polyurethane to be produced. For example, in the preparation of elastomers, the polyether poly-15 is preferably linear, i. difunctional, and has a hydroxyl number of the order of 30-170. For the production of foams, the polyether polyol is selected in a known manner to give a flexible, semi-flexible or hard foam. For example, polyether polyols having a hydroxyl number of 20 to 80 and having 2 to 4 hydroxyl groups per molecule, for example "ICI Polyol PBA 1233", are used for the preparation of flexible foams. If desired, polyether polyol blends can also be used.

Organic polyisocyanates suitable for use in the preparation of polyurethane have been described previously; they may be of the same type as the organic polyisocyanates described above in connection with the alkanolamine reaction.

To prepare the foams, a blowing agent is added to the reaction mixture. Examples of suitable blowing agents 30 are water which reacts with the polyisocyanate to form carbon dioxide and inert volatile liquids which evaporate as a result of the exothermic reaction or, when using a mechanical flotation process, volatilize under reduced pressure. Examples of such liquids are halogenated hydrocarbons having a boiling point at normal pressure of at most 100 ° C, preferably at most 50 ° C, in particular chlorofluorocarbons such as trichlorofluoromethane and dichlorodifluoromethane, and also chlorinated hydrocarbons such as dichloromethane. The amount of blowing agent is selected in a known manner, taking into account the desired density of the foam to be produced. In general, 0.005 to 0.3 moles of gas per 100 g of reaction mixture is a suitable amount.

If desired, the density of the foam produced can be increased by overpacking, i. by foaming the reaction mixture into a closed mold having a volume smaller than the volume of the foam formed by the reaction mixture in the free space would be. In general, the composition of the polyurethane foam-forming reaction mixture should be such that the ratio of isocyanate myrrh to active hydrogen atoms is substantially 0.9: 1 to 1.2: 1, but higher ratios may be used if desired.

When preparing a polyurethane foam, it must usually be stabilized, i.e., cell formation must be controlled by the addition of a foam stabilizer or cell formation regulator, such as a polysiloxane-polyalkylene oxide block copolymer, which may contain direct carbon-silicon-organic linkers or carbon-pin linkages. between them. Suitable for use in the preparation of "highly resilient" polyurethane foam are dimethylsilicone oils or their low molecular weight modifications, for example "Theodore Goldschmidt AG Silicone 25 B8616".

Depending on the type of polyurethane to be produced, a single-batch, prepolymer or pseudopolymer process can be used.

The components of the reaction mixture 30 used to make the polyurethane can be mixed in any suitable manner, for example, with the equipment described in the literature used for this purpose. If desired, some of the components may be premixed to limit the number of component streams required in the final mixing step. Often, a two-stream system is suitably used, with one stream containing the polyisocyanate or prepolymer and the other all the other components of the reaction mixture.

68407

The invention is illustrated by the following example, in which all parts are parts by weight and all percentages are by weight. Unless the temperature of the reactants is mentioned, their temperature is room temperature.

5 The abbreviations used in the examples have the following meanings.

Polyether A:

A polyether derived from glycerol and propylene oxide containing 15% ethylene oxide and having a hydroxyl number of 35 with a primary hydroxyl number of about 75%.

Polyether B:

A polyether derived from trimethylolpropane and propylene oxide having an OH number of 34 adjusted to 34 with ethylene oxide with a primary OH value of 80%.

Polyether C:

Polyether derived from glycerol and propylene oxide and ethylene oxide, having an OH number of 47 with a primary OH group content of less than 5%.

20 Polyether D:

Linear polypropylene glycol having an OH number of 56 and containing secondary hydroxyl groups.

Example 1 900 g of polyether A were mixed at 20 ° C with 48.7 g of triethanolamine (20 ° C) under high power mixing conditions, and 51.2 g of 2,4- and 2.6- -toluene diisocyanate mixture (80:20). 0.3 g of dibutyltin dilaurate catalyst was then added, whereby due to the rapid reaction, the temperature of the mixture rose to 30 minutes from the addition of the catalyst from 20 ° C to 37 ° C.

The reaction mixture was cooled to give a stable dispersion containing 10% solids with a viscosity at 16 ° C of 1600 cP.

35,300 g of the product obtained above were placed in a beaker to which 7.8 g of water, 3 g of diethanolamine, 0.21 g of bis (2-dimethylaminoethyl) ether and 1.5 g of "Golschmidt Silicone B8612" were added. The mixture was stirred and the temperature was adjusted to 22 ° C. Dibutyl 5-tin dilaurate was then added and the mixture was stirred for 10 seconds, to which was added 117 g of a mixture of 2,4- and 2,6-toluene diisocyanate (80:20). After 5 seconds, the mixture was poured into a mold and the mixture began to swell. 105 seconds after the end of mixing, an itchy-10 nucleated high-elastic foam having the following properties was obtained: 3

Density, kg / m 34 CLD, g / cm2 (1) 28

Elasticity,% (2) 63 15 (1) Compression resistance with 40% deformation (2) Sphere rebound%.

Example 2 920 g of polyether A were added at 20 ° C to a beaker, to which 32.1 g of diethanol-20 amine at 30 ° C were then added at room temperature with mechanical stirring. 47.9 g of a mixture of 2,4- and 2,6-toluene diisocyanate (80:20) were added to the vortex of the mixture over 30 seconds. A white stable dispersion was obtained and the temperature rose from 20 ° C to 37 ° C over 30 seconds during the addition of the isocyanate. The polyaddition product contained isocyanate and alkanolamine in a molar ratio of 0.9: 1.0, and the final product contained 8.0% polyaddition product in polyether polyol; the viscosity of the final product at room temperature was acceptable.

300 g of the product obtained above were placed in a beaker, to which were then added with stirring 7.8 g of water, 3 g of diethanolamine, 0.21 g of bis (2-dimethylaminoethyl) ether and 1.5 g of "Goldschmidt Silicone B 8616", the temperature being adjusted 22 ° C. 0.75 g of dibutyltin dilaurate was then added, stirred for 10 seconds and 117 g of a mixture of 2,4- and 2,6-toluene diisocyanate (80:20) were added. After 5 seconds, the mixture was poured into a mold and expansion began. 105 seconds after the end of mixing, a non-shrinkable high resilience foam had formed having properties similar to the product of Example 1.

Example 3 (comparative example)

A foam was prepared by a method similar to Example 2, but substituting 300 g of polyether-10 polyol (polyether A) in the polyether polyol (300 g) and using only 100 g of isocyanate. The mixture swelled to a foam as in Example 2; however, the resulting foam shrank and its properties could not be measured.

Example 4 A polyaddition product of a polyether polyol was prepared using polyether A as in Example 2, and the mixture was formed as a foam as in Example 2, except that all of the dibutyltin dilaurate was replaced with 0.6 g of stannous octate. A high resilience foam with properties similar to the product obtained in Example 1 was obtained.

Example 5

The polyaddition product was prepared and foamed as in Example 2, but using polyether B instead of polyether 25 A. The resulting dispersion in polyether-polyol was stable, had a solids content of 8% and had an acceptable viscosity at room temperature. The resulting foam did not shrink and had similar properties to the product of Example 1.

30 Example 6

A polyaddition product of polyether A was prepared as in Example 2, but with an isocyanate / alkanolamine molar ratio of 1.1: 1.0 and a total solids content of 8%. The product obtained had a high viscosity of 35, 2500 cP, at 25 ° C, but was still useful.

12 68407

Flotation according to Example 2 produced a high resilience non-shrinking foam.

Example 7 (comparative example)

Polyether A polyaddition product 5 was prepared as in Example 2, except that the isocyanate / alkanolamine molar ratio was 0.45: 1.0 and the total solids content was 8%. Foaming as in Example 2 gave a foam which shrank. Its properties could not be measured.

10 Example 8

A polyaddition product was prepared from 920 g of polyether A (20 ° C) mixed with 24.5 g of diethanolamine (30 ° C) and then with vigorous stirring 55.5 g of crude MDI. A poly-15 adduct in the polyether polyol with a solids content of 8%, a viscosity at 25 ° C of over 3000 cP, but still usable, was obtained.

The product was foamed as in Example 2 to give a non-shrinkable high resilience foam.

20 Example 9

A stable dispersion was prepared for polyether C at 20 ° C by adding 80.24 g of diethanolamine (30 ° C) to 800 g of polyether C with high speed stirring and continuing to stir when 25,119.75 g 2 was added to the mixture. A mixture of 4- and 2,6-toluene diisocyanate (80:20), which was added over 1 minute. The temperature rose to 29 ° C. The cooled product had an acceptable viscosity at room temperature and a solids content of 20%.

30 Example 10

A stable dispersion was prepared as in Example 9 using polyether D instead of polyether C. The resulting polyaddition compound in polyether D had an acceptable viscosity at room temperature and a solids content of 20%.

68407 13

The stable dispersions produced in Examples 1, 2, 5-10 are of the non-ionic type, i. dispersions contain covalent polymeric substances without ionizable groups. Dispersions were prepared virtually without water (and do not include water or other ionizable media). The small amounts of water generally contained in commercial polyols and other starting materials may be acceptable, although in general the presence of water is undesirable and should be kept to a minimum. The water content should not exceed 1% by weight, and most preferably the water content should be considerably lower, for example less than 0.1%, although it is to be understood that in some circumstances the process of the invention may be applied even at water contents above 3%.

In carrying out the process according to the invention, the polyols may be triols containing predominantly primary hydroxyl groups, since such polyols are particularly useful starting materials for the preparation of polyurethane foams. Since the production of polymer-modified polymers by the process according to the invention, in particular the production of the dispersions shown in the examples, involves the reaction of an isocyanate mainly or entirely with an alkanolamine, the polyol being a substantially or completely unreacted carrier, it should be noted that any suitable polyol can be used. are affected by the requirements of the polyurethane formation reaction carried out in the next step, in which the polymer-modified polyol is used. Thus, for example, polyols which are triols and / or diols having primary and / or secondary hydroxyl groups or other polyols of suitable structure can be used.

Claims (17)

A process for the preparation of a polyurethane, in which an isocyanate is reacted with a polymer-modified polyol 5 preformed by polymerizing an alkanolamine with an organic polyisocyanate in the presence of a polyol, characterized in that the alkanolamine is reacted at least for the most part with 0.5 molar isocyanate -1.0: 1.6 and the polyol acts at least for the most part as an unreacted carrier in the preforming step of said polymer modified polyol. Process according to Claim 1, characterized in that a polyether polyol having a molecular weight of 200 to 10,000 is used in the preforming step of said polymer-modified polyol, and the total amount of reacted alkanolamine and polyisocyanate is 1 to 35% by weight, based on the weight of the polyol. Process according to Claim 2, characterized in that the alkanolamine and the isocyanate are reacted in a molar ratio of 1: 0.8 to 1: 1.1. Process according to Claim 2 or 3, characterized in that the total amount of reacted alkanolamine and polyisocyanate is from 3 to 30% by weight, based on the weight of the polyol. Process according to Claim 2, 3 or 4, characterized in that the total amount of alkanolamine and polyisocyanate is more than 10% by weight, based on the weight of the polyol, and after polymerization of the alkanolamine and isocyanate, polyol is added to dilute the polymer-modified polyol. Process according to one of Claims 1 to 5, characterized in that the alkanolamine is triethanolamine. Process according to one of Claims 1 to 6, characterized in that the polyisocyanate used in the preformation of the polymer-modified polyol is an aromatic diisocyanate. 15 68407 Process according to one of Claims 1 to 7, characterized in that a catalyst is added to the mixture of alkanolamine and polyisocyanate in order to catalyze the polymerization reaction between them. Process according to Claim 8, characterized in that the catalyst is an organometallic compound or an amine. Process according to one of Claims 1 to 9, characterized in that the preformed polymer-modified polyol is in the form of a permanent dispersion. Process according to one of Claims 1 to 10, characterized in that the preformed polymer-modified polyol is nonionic. Process according to any one of claims 1 to 11, characterized in that the alkanolamine is reacted with an organic polyisocyanate in the preformation step of said polymer-modified polyol so that practically no water is present. Process according to one of Claims 1 to 12, characterized in that the polyol contains essentially primary hydroxyl groups. Process according to one of Claims 1 to 13, characterized in that the isocyanate which is reacted with the polyol is the same as that used in the preformation step of the polymer-modified polyol. 14 68407 Process according to one of Claims 1 to 14, characterized in that the polyurethane-forming reaction between the isocyanate and the polyol is carried out in the presence of a blowing agent to form a polyurethane foam material. A process for preparing a polymer-modified polyol for use in a process according to any one of claims 1 to 15, wherein the alkanolamine is polymerized with an organic polyisocyanate in the presence of a polyol, characterized in that the alkanolamine is triethanolamine and is reacted at least substantially with an isocyanate. and the polyol acts at least primarily as an unreacted carrier. A process for preparing a polymer-modified polyol for use in a process according to any one of claims 1 to 15, wherein the alkanolamine is polymerized with an organic polyisocyanate in the presence of a polyol containing predominantly primary hydroxyl groups, characterized in that the alkanolamine is reacted at least predominantly polyfunctionally with isocyanate. and the polyol acts at least primarily as an unreacted carrier. 17 Patentkrav 684 0 7