阅读说明：本技术 聚氨酯预聚物的连续制备 (Continuous preparation of polyurethane prepolymers ) 是由 D·博德曼 C·欣克 N·施利贝 J-M·德赖索尔纳 H·韦塔克 H·瓦格纳 J·艾伯丁 于 2020-03-29 设计创作，主要内容包括：本发明涉及在具有活塞流的停留时间反应器中制备聚氨酯预聚物的连续方法以及这些预聚物用于制备聚氨酯的用途。(The present invention relates to a continuous process for preparing polyurethane prepolymers in a residence time reactor with plug flow and to the use of these prepolymers for preparing polyurethanes.)

1. A continuous process for preparing a polyurethane prepolymer, the process comprising reacting

a) Di-or polyisocyanates with

b) Compounds having isocyanate-reactive hydrogen atoms, optionally in the presence of

c) Catalysts, additives, auxiliaries and/or additive substances

Reaction in a residence time reactor with plug flow, wherein the value of at least one physical property of the product leaving the residence time reactor is checked periodically or continuously and, in the event of deviations from predetermined target values, the temperature and/or flow rate of the reactants entering the residence time reactor and/or the flow rate through the residence time reactor and/or the temperature of the residence time reactor is adjusted.

2. The process according to claim 1, wherein adiabatic reaction conditions are established in the residence time reactor, and wherein the temperature and/or flow rate of the reactants entering the residence time reactor and/or the flow rate through the residence time reactor is adjusted in case of a deviation from a predetermined target value.

3. The process of claim 1 or 2, wherein the flow rate through the residence time reactor is adjusted by controlling the delivery of reactants into the residence time reactor.

4. A process according to any one of claims 1 to 3, wherein the composition of the product leaving the residence time reactor is determined by NIR spectroscopy.

5. The process of any one of claims 1 to 4, wherein the temperature of the reactants entering the residence time reactor is from 40 ℃ to 150 ℃.

6. The process according to any one of claims 1 to 5, wherein the residence time in the residence time reactor is from 5 to 15 minutes.

7. An apparatus for the continuous preparation of polyurethane prepolymer, the apparatus comprising:

a. a residence time reactor with plug flow;

b. a heat exchanger connected upstream of the residence time reactor;

c. at least one means for conveying a stream through the residence time reactor;

d. at least one reactor for periodically or continuously measuring the product leaving the residence time

Means for at least one physical property of the stream;

e. for controlling the temperature of the heat exchanger and at least one flow path for the feed material

Means for passing the throughput of the means for residence time reactor.

8. The apparatus of claim 7, further comprising f) a heat exchanger connected downstream of the residence time reactor.

9. The apparatus according to claim 7 or 8, further comprising g) at least one mixing device arranged upstream of the residence time reactor.

10. The device according to claim 9, further comprising h) means for temperature control of the mixing device and/or for temperature control of the material stream fed into the mixing device.

11. Computer system for controlling the continuous preparation of polyurethane prepolymers by the process according to any one of claims 1 to 6, said computer system comprising at least:

an interface unit configured to periodically or continuously take from the residence time reactor and input as input parameter at least one physical property of the product leaving the residence time reactor,

-a processor configured to compare the periodically or continuously obtained at least one physical property of the product exiting the residence time reactor with a predetermined target value for the at least one physical property stored and available in a database communicatively connected to the processor and to dynamically adjust the temperature and/or flow rate of the reactants entering the residence time reactor and/or the flow rate through the residence time reactor and/or the temperature of the residence time reactor by suitable control in case of deviations from the predetermined target value.

12. Computer system according to claim 11, configured to be connected with the device according to any of claims 7 to 10 by a wireless and/or wired connection, and to at least semi-automatically obtain and input at least one physical property of the product exiting the residence time reactor and the temperature and/or flow rate of the reactants entering the residence time reactor and/or the flow rate through the residence time reactor and/or the temperature of the residence time reactor through the interface unit.

13. The computer system of claim 11 or 12, wherein the processor implements a self-learning algorithm thereon for automatically comparing at least one physical property of the product exiting the residence time reactor with a predetermined target value for the at least one physical property, and for automatically controlling and dynamically adjusting the temperature and/or flow rate of reactants entering the residence time reactor and/or the flow rate through the residence time reactor and/or the temperature of the residence time reactor during the reaction by the interface unit, wherein the algorithm is configured to optimize the process for preparing the polyurethane prepolymer by dynamically adjusting the one or more temperatures and/or the one or more flow rates.

14. Computer program product which, when loaded into a memory unit of a processing unit, in particular a memory unit of a computer system according to any one of claims 11 to 13, and executed by at least one processor, in particular a processor of a computer system according to any one of claims 11 to 13, in a method according to any one of claims 1 to 6, periodically or continuously acquires and compares at least one physical property of the product leaving the residence time reactor with a predetermined target value and dynamically adjusts the temperature and/or flow rate of the reactants entering the residence time reactor and/or the flow rate through the residence time reactor and/or the temperature of the residence time reactor in the event of a deviation from the predetermined target value.

15. Computer-implemented method for controlling the preparation of polyurethane prepolymers, in particular as part of the method according to any one of claims 1 to 6, comprising at least:

-receiving data in real time of at least one physical property of the product exiting the residence time reactor,

-comparing the data with predetermined target values of at least one physical property stored and available in a database, and

-dynamically adjusting by control the temperature and/or flow rate of reactants entering the residence time reactor and/or the flow rate through the residence time reactor and/or the temperature of the residence time reactor in case of deviations from the specified target values.

Examples

Raw materials

Isocyanate 1: 4,4' -diphenylmethane diisocyanate (4,4' -MDI) having a molar mass of 250.26g/mol and an NCO content of 33.5% ((4, 4' -MDI))ME,BASF SE)；

Isocyanate 2: carbodiimide-modified 4,4 '-diphenylmethane diisocyanate (4,4' -MDI), NCO: 29.5%, (MM 103,BASF SE)；

Isocyanate 3: 1:1 mixture of 4,4 '-diphenylmethane diisocyanate (4,4' -MDI) and 2,4 '-diphenylmethane diisocyanate (2,4' -MDI) having a molar mass of 250.26g/mol and 33.5% (NCO)MI,BASF SE)；

Isocyanate 4: polymeric isocyanates (MDI) consisting of 2,2' -diphenylmethane diisocyanate, 2,4' -diphenylmethane diisocyanate and 4,4' -diphenylmethane diisocyanate, NCO: 31.5%, (M20S,BASF SE)；

Polyol 1: polyether alcohols having an OH number of about 104 and consisting of propylene glycol and propylene oxide (MW: about 1070 g/mol);

polyol 2: dipropylene glycol (DPG) with an OH number of 840 (MW: 134 g/mol);

polyol 3: tripropylene glycol (TPG) with an OH number of 582 (MW: 183 g/mol);

polyol 4: a polyether alcohol having an OH number of about 55 and consisting of propylene glycol and propylene oxide (MW: about 2000 g/mol);

polyol 5: trimethylolpropane (TMP) with an OH number of 1235 (MW: 134 g/mol);

polyol 6: polytetrahydrofuran (pTHF; polytetramethylene ether glycol, PTMEG) having an OH number of about 56 (MW: about 2000 g/mol);

polyol 7: a polyesterol having an OH number of about 60 and consisting of adipic acid, monoethylene glycol, diethylene glycol and glycerol (MW: about 2500 g/mol);

polyol 8: polyether alcohols having an OH number of about 30 and consisting of propylene glycol, propylene oxide and ethylene oxide (MW: about 3400 g/mol);

polyol 9: a polyether alcohol having an OH number of about 27 and consisting of glycerol, propylene oxide and ethylene oxide (MW: about 5200 g/mol);

10 of polyol: polyether alcohols having an OH number of about 28 and consisting of glycerol, propylene oxide and ethylene oxide (MW: about 5400 g/mol);

polyol 11: a polyether alcohol having an OH number of about 250 and consisting of dimethylaminopropylamine and propylene oxide (MW: about 450 g/mol);

polyol 12: a polyether alcohol having an OH number of about 630 and consisting of pentaerythritol and ethylene oxide (MW: about 360 g/mol);

polyol 13: polyether alcohol having an OH number of about 42 and consisting of glycerol, propylene oxide and ethylene oxide (MW: about 3500g/mol)

Chain extender 11, 4-butanediol;

additive 1: diethylene glycol bischloroformate;

additive 2 silicone stabilizer (DABCO DC 193, Evonik IndustriesAG);

additive 3 Black paste: (Black paste N, Covestro AG);

additive 4 Silicone stabilizer (Dow)57Additive，Dow Corning Corp.)；

Additive 5 emulsifier based on maleic acid half ester, olefin copolymer and bis (2-propylheptyl) phthalate;

additive 6 water;

catalyst 1 triethylenediamine end-capped with sebacic acid;

catalyst 2 dimethylethanolamine;

catalyst 3 bis (2-dimethylaminoethyl) ether;

potassium acetate catalyst 4 in monoethylene glycol;

catalyst 5N, N-trimethyl-N-hydroxyethyl-bis (aminoethyl ether).

All percentages are by weight unless explicitly stated otherwise.

Measurement of physical Properties

The following properties of the prepolymer/polyurethane obtained were determined by the following method:

determination of molecular weight:

the number average molecular weight was determined in accordance with DIN 55672-2. Calibration is performed herein using PMMA.

Determination of NCO value:

determination of the NCO content according to EN ISO 11909: primary and secondary amines react with isocyanates to form substituted ureas. The reaction proceeds quantitatively in excess amine. At the end of the reaction, the excess amine was titrated potentiometrically with hydrochloric acid.

Measurement of hydroxyl value:

the hydroxyl number is determined in accordance with DIN 53240 (1971-12).

And (3) viscosity measurement:

unless otherwise stated, viscosity is measured at 25 ℃ using a Brookfield CAP2000 instrument with plate/cone measurement geometry (PK 100; e.g.using a PK 11 ℃ cone with a diameter of 28mm and a cone angle of 1 ℃ C.) at a shear rate of 401/s in accordance with DIN EN ISO 3219 (1994).

And (3) mechanical testing:

the properties of the resulting polyurethanes were determined by the specified methods:

density: DIN EN ISO 1183-1, A

Hardness (Shore A/D): DIN ISO 7619-1 or ASTM D2240

Tensile strength/elongation at break: DIN 53504

Tear propagation resistance: DIN ISO 34-1, B (b)

Rebound resilience: DIN 53512

Compression set: ASTM D395

The glass transition temperature Tg is determined by differential scanning calorimetry (DIN EN ISO 11357-1 at 20K/min).

Preparation of the prepolymer

Method 1 for producing PU (polyurethane) prepolymer (comparative example)

The corresponding isocyanate and additive 1 were first charged at 50 ℃ into a 50kg reactor with a nitrogen blanket and a stirrer and the corresponding polyol was added at this temperature. The reaction mixture was heated to 70-80 ℃. The reaction mixture was stirred at 80 ℃ for 2 hours and then pumped out at a temperature of RT (═ room temperature) to 60 ℃ into a storage vessel without further treatment.

Method for producing PU prepolymer 2 (invention)

The corresponding isocyanate (or isocyanate mixture) is mixed with additive 1 at 50 ℃ in a storage tank to give the final isocyanate component and premixed with the corresponding polyol (or polyol mixture) by means of a short static mixer unit. The reaction mixture was brought to the appropriate reaction temperature by a plate heat exchanger and then pumped to an adiabatic residence time reactor. A static mixer with double jacket was used as adiabatic residence time reactor with plug flow. A precisely metered stream of reactants is captured by a mass flow meter and used as a benchmark for control of the metered stream. The reaction mixture was converted to the final product in 10 minutes in a tube reactor/residence time reactor and then cooled to about 60 ℃ by means of a further plate heat exchanger and transferred to a suitable storage vessel. The reaction curve was monitored using an NIR probe (the NIR probe was located at the end of the residence time reactor downstream of the plate heat exchanger) and the starting temperature was adjusted according to figures 1 and 2.

Data for the inventive and comparative examples are summarized in tables 1-4 below.

TABLE 1

TABLE 2

Prepolymer numbering	1	2d	3	4
						Comparative example 1a	Example 1c	Comparison 2	Example 2
Isocyanate 1[ wt.%]	73.9	73.9
					Isocyanate 2[ wt.%]	4.2	4.2
Isocyanate 3[ wt.%]			36.2	36.2
					Polyol 1[ wt.%]	14.4	14.4
Polyol 2[ wt.%]	5.0	5.0
					Polyol 3[ wt.%]	2.5	2.5
Polyol 4[ wt.%]			63.7	63.7
					Additive 1[ wt.%]	0.02	0.02	0.01	0.01
Reaction/initiation temperature [ deg.C]	80	80	80	120
					Flow rate [ kg/min ]]	-	2	-	2
Reaction/residence time [ min ]]	120	10	120	10
					NCO[％]	20.4	20.2	9.4	9.7

TABLE 3

TABLE 4

Prepolymer numbering	9	10
				Comparison 5	Example 5
Isocyanate 2[ wt.%]	67.0	67.0
			Isocyanate 3[ wt.%]	6.0	6.0
Polyol 7[ wt.%]	27.0	27.0
			Additive 1[ wt.%]	0.003	0.003
Reaction/initiation temperature [ deg.C]	85	100
			Flow rate [ kg/min ]]	-	2
Reaction/residence time [ min ]]	100	10
			NCO[％]	22.8	22.4

Production of molded articles using selected PU prepolymers

The production of the polyurethane moldings is carried out by converting the corresponding polyol component (a) with the corresponding isocyanate component (B). Data for the inventive and comparative examples are summarized in tables 5 and 6 below.

Table 5.Application tests (flexible molded foams) using prepolymer 1 (comparative) and prepolymer 2d (inventive).

Table 6.Application tests (flexible molded foams) using prepolymer 5 (comparative) and prepolymer 6 (inventive).

List of reference numerals

1. 1a storage vessel (e.g. tank, IBC, bucket) for the reactants

2.2 a mixing device for premixing (static or dynamic)

3. 3a Heat exchanger (e.g. heated by oil, water or steam)

4 mixing device (static or dynamic mixing unit)

5 Heat exchanger

6 plug flow reactor

7 heat exchanger

8 product container (bucket, IBC, tank truck or storage tank)