DD148460A3 - METHOD FOR PRODUCING STABLE POLYURETHANE SOLUTIONS - Google Patents

Abstract

The invention relates to a method for improving the reproducible continuous production of polyurethane solutions, in particular for the production of coating compositions, adhesives and paints. The aim of the invention is to produce polyurethane solutions which are characterized in that secondary reactions are largely avoided during the synthesis, which results in a viscosity which can be reproduced in a small fluctuation range. Solutions reflects. The main cause of the present state of the art lies in the different reactivity of the polyols and the secondary reactions of the polyurethane synthesis to be derived therefrom. The cause of the different reactivity of the polyols and the polyol components lies in the metal ion content of the polyols and leads to significant viscosity fluctuations of the polyurethane solutions. This is prevented by the polyester or polyether alcohols or the polyol component prior to processing into polyurethane solutions a solution of * diketone and a ketone having a tertiary carbon atom adjacent to the carboxyl group o. Complexing agent such as 2,2'-dipyridile, 2,2 ' -Dichinolin, Salzylaldoxim, o.Mischung. from above mentioned Loesg. u. be added to said complexing agents.

Description

195 139 - «-

Title of the invention

Process for the preparation of stable polyurethane solutions

Field of application of the invention

The invention relates to a process for improving the reproducibly continuous production of polyurethane solutions, in particular for the production of polyurethane coating compounds, adhesives and coatings,

Characteristics of the known technical solutions

Polyurethane solutions are prepared by polyaddition of organic hydroxyl and isocyanate containing components in the presence of solvents. Depending on the desired end product are unbranched or branched polyester or polyether with different Molekulargev / light, chain extenders such as iithylene glycol, butanediols, hexanediol and diamines, and diisocyanates such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, 'hexamethylene diisocyanate. and isophorone diisocyanate used. The solvents used are ethyl glycol acetate,

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Toluene, xylene, ethyl acetate, dimethylformamide, tetrahydrofuran, Dieliloräthan, methyl ethyl ketone, acetone, cyclohexanone in JFrage.

In addition, oxidation, staining and hydrolysis stabilizers or similar stabilizers may be added.

In the production of polyurethane solutions, it is important to achieve certain viscosity ranges depending on polymer properties. It is a condition that no post-reactions take place in these products under storage conditions over a longer period. These adverse reactions are evidenced by such undesirable phenomena as viscosity increase to unprocessability and crosslinking reactions manifested by the formation of compact gel-like masses.

It is possible, by addition of acidic substances such as organic acid halides or alkyl phosphates, to neutralize the alkali metal content which can be detected and catalytically active in each polyol and which can already cause the abovementioned undesired effects during the synthesis, and thus to inhibit these reactions. However, the acidic additives, which must be added in larger amounts, usually have a negative effect on the mechanical properties of the end products, in particular the hydrolysis resistance.

It is apparent from DT-OS 169 484 2 that polyurethane-polyurea polymers are stabilized with betaine salt soluble in dimethylformamide. However, the addition of the betaine salt has no influence on the secondary reactions occurring during the synthesis, since it is not able to influence the kinetics of the reactions determined by the high concentration of the reactants.

19 5 13 9 -S-

It is also known that undesirable high viscosities can be counteracted by substances which act as chain terminators. Canadian Patent 888781 proposes blending primary alcohols into the reaction mixture during the reaction. A disadvantage has been found that thus the allophanate formation can not be suppressed and no defined molecular structure occurs. Based on this, DT-OS 2323 393 recommends using sterically hindered secondary alcohols as more effective chain terminators. But even these secondary alcohols are unable to trap secondary reactions. In addition, it has been observed that although the viscosities are not subject to extreme scattering, they generally do not meet the requirements of technological processing.

Z Jei ₁ ei e r invention

The aim of the invention is to provide polyurctane solutions which are characterized in that secondary reactions are largely avoided during the synthesis, which is reflected in a viscosity of the solutions that is reproducible in a small range of fluctuation.

Loan of the invention

The object of the invention is to produce stable polyurethane solutions with reproducible viscosities by largely avoiding secondary reactions during the synthesis.

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According to the invention the object is achieved in that the polyester or Polyätheralkoholon or the hydroxyl-containing component before processing into polyurethane solutions 50 to 500 ppm of a solution of (3-diketone, preferably acetylacetone, and a ketone having a carboxyl group adjacent tertiary carbon atom of the general formula

R ₂

• R ₁ --CH.J 5 -CoHf-, -CoHi ₇

RCCR ₀ '· * ^ä > * '

^Ί Hi ^ R ₀ -CHo

OR ₂ ^ά *

preferably methyl isobutyl ketone or propyl isobutyl ketone, in a ratio of 3 to 5: 1 are added or 10 to 150 ppm, preferably 20 to 70 ppm, complexing agents of the following type are added;

Nitrogen-containing heterocycles with the - perroene moiety

"U - C - C - II = ti Ii

preferably 2,2'-dipyridyl

- Cuproing grouping

I «Il

-C = H-C-C- IT = C-

I l

C C

Preferably 2,2'-dichinoline

- Te _r roingruppierung

'I' Il

C = ITC-C-IT

preferably terpyridine

13 9-9-

or oximes of the general formula

C = IT OH OH

wherein R ₁ - HS _a lizylaldoxim or R ₁ - CH ₃ o-Hydroxyacetophenonoxim preferably be used

or Antidioxime with the general formula

Tj ΛΙ / Ί "DTy Λ * ΤΤΓ *TJ

R ₁ -OCR ₁ R ₁ -CH ₃ , -C ₆ H ₅ ,

It Il ^J

HO - N N - OH 0

preferably diacetyldioxime

or 30 to 1,300 ppm, preferably 50 to 400 ppm of a mixture of a solution consisting of a p-diletonone _; preferably acetylacetone, and a ketone having a tertiary carbon atom adjacent to the carboxyl group of the general formula

I Xi ₁ "UIl ₃ , -Ogilc, -Kj- ^ Xr-,

^GH 3

Preferably methyl isobutyl ketone or Propylisobutylketonjim ratio 3 to 5: 1 and complexing agents, such as 2,2'-dipyridyl, 2,2'-dichloro, terpyridine, SaIi-, zylaldoxim or o-IIydroxyacetophenonoxim or Diacetyldioxim be added. The mixing ratio of solution to complexing agents is 50: 1 to 1:10, preferably 30: 1 to 1: 4.

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With these substances according to the invention, largely all secondary reactions caused by contaminants caused by raw materials are contained, such as, in particular, by masking of the heavy metal ions of different valence states. It is conceivable that metal ions which interfere with the synthesis of one polyurethane system do not cause analogous effects in the other system. With the agents according to the invention, it is possible to set specific, specific, according to application · a constant reactivity.

Particularly advantageous is the use of the agents according to the invention in polyester alcohols having a molecular weight of 800 to 3,000 and polyether alcohols having a molecular weight of 1,000 to 5,000, which are prepared by known methods and from the usual raw materials. Can be carried out at temperatures up to 150 ⁰ G, the addition of the active compounds according to the invention to the polyol or hydroxyllialtigen component, either immediately after the preparation of the polyols or before 7 / Further processing of the same, or of the hydroxyl component for the polyurethane solution. Furthermore, it is possible to add the active compounds according to the invention to the individual reaction stages in the preparation of polyurethane solutions by the prepolymer method.

Example I

The invention will be explained in more detail below with reference to some embodiments:

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example 1

a) 2β parts of a polyester alcohol based on adipic acid, butanediol-1, 4 and ethylene glycol having the average Molekulargeiircht of 2,000 and the OH number 56 are liomogeriisiert with 35.4 parts Dich.lorath.an and thereby heated to 95 ° C. At this temperature, the addition of 2.88 parts of tolylene diisocyanate (pure, isomer ratio 80:20). After Zudocierung of 0.0078 parts of dibutyltin dilaurate, the reaction mixture is left for 2 hours at 120 ⁰ C and again added 35.4 parts of dichloroethane at room temperature and the reaction mixture was cooled to 110 ⁰ C. This is followed by the addition of 0.428 parts of 1,6-hexanediol. Subsequently, the components are allowed to react for 1 hour at 110 ⁰ C and diluted with 50 parts of solvent. 10 different batches of polyester alcohol give the following result in terms of the viscosity of the solution:

cP (20 ⁰ C) 6ί 21,300 cP (20 ⁰ C) 7: 7400 8: 17 200 9 29 600 10 16 800

b) analogously to a, but the polyester alcohol before processing 30 ppm of dipyridyl, based on the polyester alcohol in the solvent or directly added to the polyester alcohol. There were meas entcP (20 ⁰ C) 6 following viscosities of 30 wipe solution: 22,000 cP (20 ⁰ C)

7: 18 900. 8: 20 800. 9: 21 700. , 10: 19 700

Batch 1: 1 6 300 2: 1 1 000 3: 2 500 4: 1 8th 700 5: 7 100

charge 1: 18 500 2: 19 700 3: 21 100 4: 19 000 5: 21 500

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c) analogously to a, but 100 ppm of a mixture of an acetylacetone / ethyl isobutyl ketone solution (ratio 4: 1) and 2,2'-dipyridil in a ratio of 2: 1, based on polyester alcohol, are added to the polyester alcohol before processing. Misc viscosities of the 30/50 solution were measured:

charge

1: 15 300 cP (20 ^U C) 2: 16 700 3: 18 200 4: 1 6 800 5: 19 500 6: 22 200 7 :, 15 100 8th: 20 200 24 600 10: 17 050

After addition of the erfindungsgenäßen substances according to b) and c) gives products which meet the required viscosities.

Example 2

a) 150 parts of a PolyesteralkohoIes based on adipic acid, 1,4-butanediol and ethylene glycol are mixed with 20 parts of xylene and brought to 90 ⁰ C. Thereafter, 0.08 parts of dibutyltin dilaurate are added and well homogenized; At 90 ⁰ C (neat, isomer ratio 80: 20) the addition of 17.5 parts of toluene diisocyanate is carried out and it is the Re _a ktionsgemisch 2 72 hours at 150 ⁰ C stirred. Hach cooling to 100 ⁰ C wird.Durther addition of 0.04 parts of dibutyltin dilaurate and 15 minutes of homogenization.

195 139

· Hach the 2.3 parts of 1,6-hexanediol were added, rapid heating is carried out at 120 ⁰ C, with 2 hours stirring raui3. After cooling the mixture to 80 ⁰ C, slowly 400 parts of xylene and 2 parts of silicone oil are added.

7 different polyester batches give the following viscosities of the 1: 6 solution:

Batch 1: 150. cP (20 ° C)

1: 1 150 2: Ί 270 3: 830 4: 170 5: 050 6: 80 7: 120

b) analog a, but the polyester alcohol before the. Processing 45 ppm Salicylaldoxira, based on polyester alcohol added. The following viscosities of the 16% solution were measured:

Batch 1: 780 cP (20 ^° C)

2: 850

3: 870

4: 1 200

5: 1 200

6: 800

7: 920

c) analogously to a, but the polyester alcohol 300 ppm of a solution of acetylacetone and ethyl isobutyl ketone in the ratio + 3.5: 1, based on. Polyester alcohol added. The following viscosities of the 16% solution were measured:

195 139 - *> -

charge

1 : 1 570 cP (20 ⁰ C) 2: 1 640 3: 900 4: 210 5: 150 6: 630

7: 820

Addition of the substances according to the invention according to b) and c) gives products which correspond to the required viscosity ranges.

Example 3

a) 175 parts of a polyester alcohol based on adipic acid and 1,6-hexanediol are mixed with 40 parts of toluene and heated to 80 ⁰ C with the addition of 0.03 parts of dibutyltin dilaurate. Thereafter, 18.5 parts of tolylene diisocyanate (pure, isomer ratio 80: -20) are added. After exceeding the maximum temperature is stirred for 2 hours at 120 ⁰ C, then cooled to 90 ⁰ C and 2.7 parts of 1,6-hexanediol added by rapid heating to 120 ⁰ C and v / eiterer addition of 40 parts of toluene and 0.022 parts Dibutyltin dilaurate is obtained a reaction mixture, which is stirred for 2 hours at 120 ⁰ C. This is followed by the addition of 585 parts of methyl ethyl ketone, wherein the temperature should not fall below 60 ⁰ C. Examination of 10 batches of polyester alcohol gives the following viscosities at a solids content of 20 % of the solution:

Batch 1: 730 oP (20 ⁰ C)

2: 560

3: 3 500

4: 980

195139 -Ή-

5: 1 200 cP (20 ⁰ O) 6: 1 980 7: 720 8th: 450 9: 2 000 10: 1 120

b) analogously to a, but are added to the polyester alcohol 50 ppm of 2,2'-dichinoline, based on polyester alcohol. The following viscosities of the solution were measured:

charge

1 : 1 600 cP (20 ^υ 0) 2: ' 1 550 3: 1 700 4: 1 920 5: 2 100 6: 2 180 7: 1 570 8th: 1 480 9: 2 200 10: 1 970

c) analog a, but the polyester alcohol 300 ppm of a solution of acetylacetone and methyl isobutyl ketone in the ratio. 5: 1 »based on polyester alcohol added. The following viscosities of the 20 S & Lgen solution were measured:

charge

1: 1 500 c? (20 ^U C) 2: CVJ 100 3: 1 730 4: 1 920 5: 1 600

19 5 13 9 -. * -

6: 2 150 7: 1 690 8th: 2 000 9: 1 850 10: 1 790

cp (20 ^° C)

After addition of the substances according to the invention according to b) and c), products are obtained which correspond to the required viscosity ranges »

Example 4

a) 300 parts of a polyester alcohol based on adipic acid, 1,4-butanediol and iithylenglykol having the average molecular weight of 2,000 and the OH number 56 are mixed with 39 parts of butyl acetate and 0.048 parts of dibutyltin dilaurate and brought to 95 ⁰ G. Hit room temperature, 34 parts of toluene diisocyanate (pure, isomer ratio SO : 20) are added to this mixture and homogenized for 20 minutes. With stirring, the reaction mixture is left for 1 hour at 115 to 118 ⁰ C. Thereafter, v / eitere 39 parts of butyl acetate and 0.036 parts of dibutyltin dilaurate are added and the reaction mixture is stirred for 1 hour at 105 to 110 ⁰ C again. Then 3.92 parts of diethylene glycol are added and stirred for 3 hours at 110 ⁰ C, wherein a total of 540 parts of ethyl acetate are added in portions.

10 different batches of polyester alcohol show the following final viscosity of the 35% solution:

Batch 1: 110,000 cP (20 ^° C.)

1: 110 000 2: 7Q 000 3: 15 000 4: 35 000 5: 95 000

19 5 1 39 6: 40 000 7: 20 000 8th: 25 000 9: 68 000 10: 28 000

kb

cp (20 ^° C)

b) analogously to a, but 180 ppm of a mixture of a solution of acetylacetoneAlisisobutyiketon (ratio 4: 1) and 2,2'-dipyridil in the ratio 5: 1 based on polyester alcohol are added to the polyester alcohol before processing.

The following viscosities of the 30% solution were measured:

Batch 1: 20,000 cP (20 ^° C.)

2: 24 600

3: 32,000

"4: 44,000

5: 28,000

6: 37,000

7: 40,000

8: 30,000

9: 42,000

10: 31 500

Addition of the substances according to the invention according to b) gives products which correspond to the required viscosity ranges.

Example 5

a) 247 parts of ethyl glycol acetate and 247 parts of xylene are presented. To this is added 229 parts of isophorone diisocyanate. This mixture is heated to 70 ⁰ C and with stirring 272 parts of a batch

19 5 13 9

Polyester alcohol based on adipic acid / lleopentylglycol / trimethylolpropane with the average molecular weight 'of. about 1 000 and the OH number 210 added. The entire reaction is approximately 4 hours, with the last 2 hours the PoIyurethanlösung is maintained at 110 ⁰ C. 8 different polyester alcohol batches have the following final viscosities at a pesticide content of 50 % :

charge

1: 80 CP (20 ^U C) 2: 90 3: 250 4: 150 5: 280 6: 70 7: 110 8th: 200

b) analogously, but 60 ppm of 2,2'-dipyridyl, based on polyester alcohol, are added to the polyester alcohol before processing. The following viscosities of the 50% solution were measured:

Batch 1: 120 cP (20 ^° C.)

1: 1 20 2: 1 20 3: 1 60 4: 1 70 5: 1 SO 6: 1 30 7: 1 40 8th: 1 70

19 5 13 9 ~ ^ΛΒ ~

c) analogously to a, but 200 ppm of a mixture of a solution of acetylacetone / methyl isobutyl ketone (ratio 4.5: 1) and salicylaldoxime in the ratio 3: 1, based on polyester alcohol added to the polyester alcohol prior to processing. The following viscosities of the 50% solution were measured:

cp (20 ^° C)

charge 1: 120 2: 130 3: 150 4: 130 5: 170 6: 150 7: 150

8: 130

After addition of the substances according to the invention according to b) and c), products are obtained which correspond to the required viscosity ranges.

Example 6

a) Each 133 parts of iithylglykolacetat and xylene are presented. 150 parts of a polyether alcohol based Gljyzerin / Ethylene oxide / propylene oxide having the OH number and the average molecular weight of 3,500 and parts of a polyether alcohol based on glycerol and propylene oxide having the OH number 440 and the average molecular weight of 400 v / earth added and by

, Stirring is achieved a good homogeneity. Thereafter, 570 parts of a modified toluene diisocyanate are added at room temperature and the reaction mixture is brought to 80 to 90 ⁰ C and

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Kept at this temperature for 2 hours. Then it is cooled and drained,

6 different Polyätherchargen result in the following result in terms of the viscosities of the 50 / Sigen solution:

cp (20 ^° C)

charge 1: 220 2: 370 3: 400 ace 380 5: 250 6: 300

b) analogously to a, but the polyether alcohols before processing 250 ppm of a mixture of a solution of acetylacetoneAlisisobutylketon (ratio 4: 1) and 2,2 '-Dipyridil in the ratio 6: 1, based on polyether alcohol added. The following viscosities of the 50% solutions were measured:

Batch 1: 280 cP (20 ^° C)

1 : 280 2: 340 3ϊ 350 4: 320 5: 300 6: 300

flat addition of the substances according to the invention according to b) gives products which correspond to the required viscosity ranges.

Claims (1)

1 S 5 1 3 9 invention claim H. A process for the production of stable polyurethane ¹ solutions, characterized in that the polyester or Polyätheralkoholen or the hydroxyl-containing component prior to processing into polyurethane solutions 50 to 500 ppm of a solution of beta-diketone, preferably acetylacetone, and a ketone with one of the carboxyl adjacent tertiary carbon atom of the general formula ^R 2 j ^ R ₁ -CH ₃ or -C ₂ H ₅ or -C ₃ H ₇ R ₁ - C - C - R ₀ - p ¹ Il I ^{2 R} 2 preferably methyl isobutyl ketone or propyl isobutyl ketone, in a ratio of 3 to 5: 1 are added, or 10 to 150 ppm complexing agents, such as nitrogen-containing heterocycles with Ferroingruppierung = N - C - C - IT = K II preferably 2,2'-dipyridyl, or with Cuproingruppierung Il -C = N-C-C-N = C- 1 ι C C preferably 2,2'-dichinoline, or with aero-grouping I Il Il Il Il I Il U preferably terpyridine, are added, or Oximes with the general formula 19 5 13 9 -H8- ^R 1 C = H - OH R ₁ -H or CH ₃ 'OH preferably salicylaldoxime or o-hydroxyacetophenone oxime, are added, Antioxime with the general formula R.J - C - C - R ^ R - -CHo, -Cz-Hp-, HO - N N - OH 0 Preferably Diacetyldioxim be added, or 30 to 1,300 ppm of a mixture of a solution consisting of a fi-diketone, preferably acetylacetone, and a ketone having a tertiary carbon atom of the general formula adjacent to the carboxyl group R - C - C - Rp R ^. - CH-i j "" ^ ρ ^ ζ """C- ^ Hy OR ₂ 'R ₂ -CH ₃ preferably methyl isobutylbutyl ketone or propyl isobutyl ketone, in a ratio of 3 to 5: 1> and complexing agents such as 2,2'-dipyridile, 2,2'-dichinoline, terpyri-ηη, salicylaldoxime, o-hydroxyacetophenone oxime or diacetyldioxime, wherein the Higchungsverhältnis of solution to complexing agents 50 : 1 to 1: 10, to be added.