DD201473A1 - METHOD FOR PRODUCING REACTIVE CALCARATORY NON-CELL POLYURETHANE SYSTEMS - Google Patents

Abstract

The invention relates to a process for the preparation of reactive Kaltthaertender non-cellular polyurethane systems, which are processed by molding, brushing or spraying to polyurethane moldings, adhesives or coatings. The object of the invention is an economic process for the preparation of these polyurethane systems using minimal amounts of readily available catalyst and avoiding interfering side reactions. These polyurethane systems should be resistant to hydrolysis. The object is achieved by using a suitable catalyst. According to the invention, the object is achieved by reacting a catalyst mixture comprising from 0.001 to 1.0% by weight of an organic tin compound and an organic potassium salt, based on the polyol mixture used. The tin to potassium ratio is at least 0.1 to 1.0.

Description

Process for the preparation of reactive cold-curing non-cellular polyurethane systems

Field of application of the invention

The invention relates to a process for the preparation of reactive cold-curing non-cellular polyurethane systems which are processed by casting, brushing or spraying into polyurethane moldings, adhesives or coatings.

Characteristic of the known technical solutions

It is known that tertiary amines and organometallic compounds are used as catalysts. Within the group of organometallic catalysts for polyurethane systems, the tin compounds occupy a significant position. However, since tin compounds catalysed polyurethane systems are susceptible to hydrolysis due to the tin content, the aim is to find ways to achieve the required reactivity of the polyurethane system with the lowest possible catalyst use »

According to DD-PS 109 164 a process for accelerating the catalysed organotin compounds curing reaction of polyurethane systems is described, after which the reaction mixture of the acetoacetate synthesis is additionally added to the Hartungsgemisch. As a result, the reaction of organotin catalyzed polyurethane systems is additionally accelerated, the

Use amount of expensive tin catalyst significantly reduced and improves the aging resistance of polyurethane molding materials. However, since the described catalyst is not a pure product, no specific additional catalytic effect is possible. A further disadvantage is that the acceleration does not reach the desired level of reactivity due to the complexing effect of the remaining acetoacetic ester. Furthermore, according to DD-PS 109 165 discloses a method for accelerating the ζinnorganischen catalyzed curing reaction of polyurethane systems, after which substituted cyclic ketones are added. This invention makes it possible to substantially reduce the use amount of the tin catalyst for a constant gel time. A strong acceleration of the curing process of the polyurethane systems is to be noted, disadvantageous in this method is that organotin catalysts are used, which are complicated compounds, are technically difficult to access and thus preclude an economical production of reactive polyurethane systems. It is also known to use organic potassium salts, in particular potassium acetate. According to DD-PS 105 816 a process for the production of sprayable elastic polyurethane foams is described, after which an aqueous solution in particular of potassium acetate is optionally used in conjunction with known catalysts such as tertiary amines, triethylenediamine, dimethylcyclohexylamine and dimethylethanolamine, A disadvantage of this process according to the invention is that this catalyst alone or in the combination described is not suitable for cold-curing non-cellular polyurethane systems. The high catalyst content causes an increased susceptibility to hydrolysis. There are unwanted side reactions, such as carbon dioxide formation.

Furthermore, according to DE-OS 2,641,734 a two-component catalyst composition is known which consists of organic tin compounds and organic alkali compounds and is suitable for the production of hard or rigid cellular urethane-modified isocyanurate polymers. A disadvantage is that this composition is not used for the production of cold-curing

the non-cellular polyurethane systems is suitable, since the unwanted lifting reaction, such as carbodiimide formation with elimination of carbon dioxide occurs.

Object of the invention

The aim of the invention is an economical process for the production of reactive cold-curing non-cellular polyurethane systems, using "minimal amounts of readily available catalysts." Side reactions, such as the elimination of carbon dioxide, should be avoided. The reactive cold-curing noncellular polyurethane systems should be resistant to hydrolysis in the case of any specifically set reactivity.

Explanation of the essence of the invention

The object of the invention is to produce reactive cold-curing noncellular polyurethane systems with a suitable catalyst in accordance with the invention. According to the invention, the object is achieved by using a catalyst mixture consisting of an organic tin compound of the general formula

-C-R

^й Ь Ъ

о - σ - r "

or R-

η R ·) ^R -j

where R 1 and R _{2 are} different alkyl radicals and X is an oxygen or sulfur atom, and an organic potassium salt # The tin to potassium atomic ratio is at least 0.1 to 1.0. Based on the polyol used, 0.001 to 1.0 wt .-% catalyst mixture is added · Surprisingly, it was found that in the proposed composition according to the invention of the catalyst mixture

strongly synergistic catalytic effect occurs. This synergistic catalytic action begins even at low levels of the organic potassium salt. The content of organic potassium salt in the catalyst mixture is limited, despite continued synergistic catalytic action, However, for use in cold-curing non-cellular polyurethanes having a tin atom to potassium atom ratio of 0.1 to 1.0. A higher content of organic potassium salt leads to foaming of the polyurethane reaction mixture due to undesired lifting reactions.

Whereas in the known technical solutions the organic potassium salt, caused by the amount used, catalyzes the formation of isocyanurate and other foam-forming side reactions, a co-catalytic effect with respect to the tin catalyst used is achieved by the composition of the catalyst mixture according to the invention Catalyst concentration in the range of 0.001 to 1.0% by weight, based on the polyol mixture allows targeted control of the polyurethane reaction in such a way that it is possible to produce reactive cold-curing non-cellular polyurethane systems.

The organic potassium salt and the organic tin compound can either be added as a mixture to the polyol mixture or mixed individually with the polyol mixture for reaction.

For the process according to the invention, a polyol mixture is used which, besides the catalyst mixture according to the invention, contains known hydroxyl-containing substances, fillers and additives.

As hydroxyl-containing substances z. As polyether polyols, polyester polyols, hydroxyl-containing natural products and their reaction products, short-chain diols used as chain extenders and higher functional alcohols as crosslinking agents.

As usual fillers, for example, barite, kaolin and chalk are suitable. Common additives are the stabilizers commonly used in polyurethane chemistry, solvents, plasticizers, flame retardants, color pigments and desiccants. «

Lifting the polyol mixture polyisocyanates are used for the process according to the invention. Suitable polyisocyanates are all isocyanates known in polyurethane chemistry, which carry two or more isocyanate groups on an aliphatic, cycloaliphatic or aromatic radical. Mixtures of these polyisocyanates and reaction products with difunctional or polyfunctional hydroxyl-containing substances are also usable. However, preference is given to those Polyisocyanates, polyisocyanate mixtures and isocyanate-containing reaction products which are in the liquid state at room temperature.

The reactive cold-curing non-cellular polyurethane system prepared by the process according to the invention is processed in a known manner by casting, brushing or spraying into moldings, adhesives or coatings.

The reactive cold-curing non-cellular polyurethane system prepared by the process according to the invention is hydrolysis-stable. Undesirable carbon dioxide formation does not occur during production. The constituents of the catalyst mixture used are readily available, even small amounts causing the required reactivity and thus make the inventive method economically.

The invention will be explained with the following examples:

Embodiment 1

It is a polyol mixture consisting of 73 »4 parts by weight of a Polypropylenediols (OH number 56 mg KOH / g), 12.6 parts by weight of a polypropylene triol (OH number 435 mg KOH / g), 6.0 parts by weight a desiccant based on zeolite 50% in a polyether mixture (OH number 176 mg KOH / g) and from 8.0 parts by weight of dipropylene glycol. Using the above-mentioned polyol mixture, two polyol mixtures of a non-cellular polyurethane system are prepared by adding catalyst, wherein the one

1.0 mol% of bistributyltin oxide, component A 1, and the other 0.15% by weight of potassium acetate, component A 2. The amounts of catalyst used are such that both polyol mixtures have the same catalytic reactivity after addition of equivalent amounts of a diphenylmethane diisocyanate. By mixing these two polyol mixtures, any desired catalyst ratio can be established. By determining the reactivity occurring at the respective catalyst ratio after addition of equivalent amounts of the diphenylmethane diisocyanate 29 % NCO content, as shown in the table below, the synergistic catalytic activity described in the present invention can be determined · clarify

Reactivity means: duration of use as time between

Mixing of the polyol mixtures and the polyisocyanate and achievement of the gel state at tempered at 20 ⁰ C starting components and 150'g polyurethane system.

Mixture of the polyol. Comp. A 2 Content of catalyst (mVa1 / 100g) potassium acetate (mVal / 100g) nuclear ί K Reakti I (Weight parts) 3.36 (Wt .-%) _ relationship tivity - "3 Comp. A 1 - bistributyltin 3.02 _ 0.15 Sn: (Sec) t (Weight parts) 10 (Gene.-*) 2.69 0,015 0.31 : 1.0 180 100 20 1.0 2.35 0,030 0.46 ι 1.0 122 90 30 0.9 2.02 0,045 0.61 20.1: : 1.0 93 80 40 0.8 1.68 0,060 0.76 8.7 s t 1.0 80 70 50 0.7 1.34 0,075 0.92 5.1! ι 1.0 76 60 60 0.6 1.01 0,090 1.07 3,3 y , 1.0 76 50 70 0.5 0.67 0.105 1.22 2.2: ι 1.0 72 40 80 0.4 0.34 0,120 1.38 1.4 years ι 1.0 83 30 90 0.3 - 0.135 1.53 0,9 ' i 1.0 93 20 100 0.2 0,150 0.5 ι 120 10 0.1 0.2 180 - -

8 embodiment 2

The procedure is analogous to Example 1 except that instead of 1.0% by weight of bistributyltin oxide 1.0% by weight of bistributyltin sulfide, component A 3 "and instead of 0.15% by weight of potassium acetate, 0.025% by weight of potassium acetate, component A 4 »used. The following results are obtained in the reactivity measurement, which are shown in the following table to illustrate the occurring synergistic effect.

Mixture of polyol mixtures Comp. Δ 4 Content of catalyst (mVal / 100g) potassium acetate (mVal / 100g) nuclear : K Reakti (Weight Тіѳ) 3.27 (Wt .-%) - relationship tivity Comp. A 3 mm Bistributylzinnsulfit 2.94 ·. 0.03 sn (Sec) (Weight parts) 10 (Ge "· -SS) 2.62 0.0025 0.05 , 1 650 100 20 1.0 2.29 0.0050 0.08 ί 1 518 90 30 0.9 1.96 0.0075 0.10 98 s 1 480 80 40 0.8 1.64 0.0100 0.13 52.4 i ! 1 446 70 50 0.7 1.31 0.0125 0.15 28.6 years 1 422 60 60 0.6 0.98 0.0150 0.18 19.6! : 1 415 50 70 0.5 0.65 0.0175 0.20 12.6 s , 1 434 40 80 0.4 0.33 0.0200 0.23 8,7 ι , 1 445 30 90 0.3 - 0.0225 0.26 5.4: ί 1 460 20 100 0.2 0.0250 3,2 years 540 10 0.1 1.4 years 650 - -

Embodiment 3

It is a polyol mixture consisting of 70.0 parts by weight of a polypropylene triol, OH number 435 mg KOH / g, 24.0 parts by weight of castor oil, OH number 160 mg KOH / g and from 6.0 parts by weight of a drying agent 50% zeolite based in a polyether mixture, OH number 176 mg KOH / g. Using the abovementioned polyol mixture, two polyol mixtures are prepared analogously to working examples 1 and 2, one polyol mixture containing 0.2% by weight of dibutyltin diacetate, component A 5 'and the other 0.3% by weight of potassium acetate, component A 6 Contains catalyst and both polyol mixtures after addition of equivalent amounts of the crude product of diphenylmethane diisocyanate, KCO content 31 % _{t have} the same catalytic reactivity «

By mixing the polyol mixtures and reactivity measurements using the respective polyol mixture and equivalent amounts of the crude product of the diphenylmethane diisocyanate, the following results summarized in the table below are obtained, which also illustrate the synergistic effect that occurs *

Mixture of the polyol. I Comp. A 6 Content of catalyst (mVal / 100g) potassium acetate (mVal / ΙΟσ g) nuclear Reakti (Parts by weight) 0.57 (Wt .-%) mm relationship tivity Comp. A 5 dibutyltin 0.51 _ 0.31 Qy * * (Weight parts) 10 (Wt .-%) 0.46 0.03 0.61 OH < 100 20 0.20 0.40 0.06 0.92 240 90 30 0.18 0.34 0.09 1.22 1.6: 180 80 40 0.16 0.28 0.12 1.53 0.8 i 155 70 50 0.14 0.23 0.15 1.84 0.4 · 114 60 60 0.12 0.17 0.18 2.14 0.3 y 95 50 70 0.10 0.11 0.21 2.44 0.2. 87 40 80 0.08 0.06 0.24 2.76 0.1 s 92 30 90 0.06 - 0.27 3.06 0.08 y 109 20 100 0.04 0.30 0.04: 135 10 0.02 0.02. 157 - 240 > TC ί 1 ; 1 ί 1 ί 1 : 1 , 1 , 1 ί 1 : 1

The atomic ratios tin to potassium foaming of the polyurethane system.

0.08 to 1 cause the disturbing

- 12 Embodiment 4

780 g of a polypropylene-polyethylene triol, OH number 35 mg KOH / g, 50 g of a zeolite-based dry agent 50% in a polyether mixture, OH number 176 mg KOH / g, 50 g butanediol-1,4, 15 g of iron oxide yellow and 100 g of kaolin filler are mixed with 2 g of dibutyltin diacetate and 1.5 g of potassium acetate, wherein the atomic ratio of tin to potassium is 0.38 to 1, after adding 256 g of the crude product of diphenylmethane diisocyanate, KCO content 31%, A highly reactive cold-curing noncellular polyurethane system is formed, which can be processed into a vertical coating with appropriate quantity use with a two-component polyurethane processing machine with injection unit. The reactivity is about 25 seconds. In order to achieve the same reactivity when using customary catalysts, the following amounts of catalyst are required at the stated polyol amounts: 45 g of triethylenediamine, 33% in dipropylene glycol or 8 g of dibutyltin diacetate.

Embodiment 5

553 g of a polypropylene diol, OH number 56 mg KOH / g, 50 g of a polypropylene triol, OH number 435 mg KOH / g, 60 g of a zeolite-based desiccant 50% in a polyether mixture, OH number 176 mg KOH / g, 20 g of dipropylene glycol, 15 g of iron oxide yellow and 300 g of kaolin filler are mixed with 1.2 g of dibutyltin diacetate and 0.4 g of potassium acetate, wherein the atomic ratio of tin to potassium is 0.85 to 1.

Hach addition of 200 g of the crude product of diphenylmethane diisocyanate, UCO content 31 % _f is formed an elastic cold-curing non-cellular polyurethane system with a reactivity of about 3 minutes.

In order to achieve the same reactivity when using conventional catalysts, the following amounts of catalyst are required at the indicated amounts of polyol: 20 g of triethylenediamine, 33% strength in dipropylene glycol or 3 g of dibutyltin diacetate.

Claims (1)

- 13 claim of invention 1 "Process for the preparation of reactive cold-curing non-cellular polyurethane systems which are formed from a polyol mixture consisting of known hydroxyl-containing substances, fillers, additives, catalysts and from a polyisocyanate under normal conditions, characterized in that a catalyst mixture is used, consisting of an organic tin compound 'of the general formula ti T? * D О - О - R ₂ j I Sn "or R- - Sn - χ - Sn - Щ ^ O - C - R ₂ wherein R ₁ and Rp are different alkyl radicals and X is an oxygen or sulfur atom, and an organic potassium salt wherein the atomic ratio of tin to potassium is at least 0.1 to 1.0 and 0.001 to 1.0 weight percent catalyst mixture be added to the polyol mixture.