CN108097194B

CN108097194B - Continuous production system for preparing aqueous polyurethane dispersion, continuous production process for aqueous polyurethane dispersion and application

Info

Publication number: CN108097194B
Application number: CN201711466121.5A
Authority: CN
Inventors: 赵伟国; 孙永建
Original assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd; Wanhua Chemical Guangdong Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd; Wanhua Chemical Guangdong Co Ltd
Priority date: 2017-12-28
Filing date: 2017-12-28
Publication date: 2020-08-28
Anticipated expiration: 2037-12-28
Also published as: CN108097194A

Abstract

The invention belongs to the technical field of continuous production of aqueous polyurethane dispersions, and provides a continuous production system for preparing an aqueous polyurethane dispersion, a continuous production process of the aqueous polyurethane dispersion and application of the aqueous polyurethane dispersion, wherein the continuous production process comprises the following steps: (1) polyisocyanate and oligomer polyol are put in a first tubular reactor VR1 to obtain a prepolymer I; adding oligomer polyol into VR1 in four parts; (2) the prepolymer I and a nonionic hydrophilic compound are put in a second tubular reactor VR2 to obtain a prepolymer II; adding non-ionic hydrophilic compound into VR2 in three parts; (3) diluting the prepolymer II and a solvent in VR 3; (4) diluting, adding hydrophilic chain extender and micromolecular diamine in VR 4; (5) the emulsion dispersion was carried out in VR 5. The process can realize the rapid and efficient continuous production of the aqueous polyurethane dispersion.

Description

Continuous production system for preparing aqueous polyurethane dispersion, continuous production process for aqueous polyurethane dispersion and application

Technical Field

The invention belongs to the technical field of continuous production of aqueous polyurethane dispersions, and particularly relates to a continuous production system for preparing an aqueous polyurethane dispersion, a continuous production process of the aqueous polyurethane dispersion and application of the aqueous polyurethane dispersion.

Background

The aqueous polyurethane dispersion takes water as a dispersion medium instead of an organic solvent, does not contain a volatile organic solvent (VOC), and is a tasteless, nontoxic, green and environment-friendly organic polymer material. The water is volatilized in the using process to form a polyurethane film, so that the film-forming material of the aqueous polyurethane dispersion has excellent physical and chemical properties which are equal to those of a polyurethane material.

The waterborne polyurethane material can be prepared into high-performance materials with different hardness and chemical resistance by adjusting a formula and a chemical modification mode, and can be widely applied to the fields of wood coatings, textile coatings, synthetic leather, plastic coatings, metal coatings, personal care, coating agents, adhesives, sealants, water-based ink and the like.

At present, the industrial production process of aqueous polyurethane dispersions is based on a batch process. The batch process refers to a process in which the processes of prepolymerization, dispersion and solvent removal are carried out in a reaction kettle step by step according to a time sequence after one-time feeding. However, the batch process has significant disadvantages in the production of aqueous polyurethane dispersions, in particular as follows: (1) the production efficiency is low, the vacancy rate of the device is high, and the production cost is high; (2) the production excessively depends on manual work, and the automation degree is low; (3) the quality fluctuation among product batches is large, and the defective rate is high.

The continuous production process of the aqueous polyurethane dispersion can effectively overcome the problems caused by intermittent production, and patent document CN102633971A discloses a continuous production process of the aqueous polyurethane dispersion based on the design of a double-screw reactor, wherein the continuous production process of the aqueous polyurethane dispersion adopts the processes of high-temperature prepolymerization at 120-200 ℃ and high-temperature dispersion at 90-150 ℃; for a water-based polyurethane system, high-temperature pre-polymerization can bring unpredictable side reactions, the macromolecular structure is uncontrollable, high-temperature dispersion can cause that the particle size control is very difficult when emulsion is dispersed, and the finished emulsion can be obtained only by cooling due to higher temperature of the whole process, and the production cost is high due to high process energy consumption. Patent document WO2017/009161a1 discloses a continuous dispersion device based on a static mixer, but does not mention a continuous production process of a prepolymerization process.

In addition, the simple tubular reactor has advantages for a liquid phase system with lower reaction viscosity, but the viscosity of the aqueous polyurethane prepolymer is gradually increased from low viscosity to high viscosity along with the reaction, if a proper internal member is not installed, the mixing effect and the reaction rate of the tubular reactor in continuous production are influenced, the molecular weight distribution of the product is very wide, the reaction rate is very slow, and the product performance is greatly reduced.

Disclosure of Invention

The invention aims to provide a continuous production system for preparing aqueous polyurethane dispersoid, a continuous production process of the aqueous polyurethane dispersoid and application thereof, aiming at the problems in the prior art, wherein the continuous production process can realize the rapid and efficient continuous production of a plurality of varieties of aqueous polyurethane dispersoids, completely realizes automation, and has low energy consumption, low production cost and stable product quality.

In order to achieve the above object, the present invention provides a continuous production system for producing an aqueous polyurethane dispersion, comprising:

a plurality of tubular reactors for reacting the reaction mass; the plurality of tubular reactors are sequentially connected in series with each other.

According to the continuous production system provided by the present invention, preferably, the continuous production system further comprises: the mixers are connected with the feed inlet of each tubular reactor and are used for uniformly mixing reaction raw materials and continuously injecting the reaction raw materials into the tubular reactors; the mixer is preferably a dynamic mixer with stirring or a static mixer without stirring.

According to the continuous production system provided by the present invention, preferably, the plurality of tubular reactors include a first tubular reactor VR1, a second tubular reactor VR2, a third tubular reactor VR3, a fourth tubular reactor VR4, a fifth tubular reactor VR5, a sixth tubular reactor VR6, and a seventh tubular reactor VR 7;

the first tubular reactor VR1 is a spherical tubular reactor with an inner baffle plate, the length-diameter ratio of the first tubular reactor VR1 is 10-500, and the pressure drop of an inlet and an outlet of the first tubular reactor VR1 is less than 0.05 Mpa; the inner baffle is arranged at the spherical diameter 1/4-1/2 close to the inlet of the spherical tubular reactor; preferably, a plurality of uniformly distributed circular holes are formed in the inner baffle, and the sum of the areas of the circular holes accounts for 25-78% of the total area of the inner baffle;

the second tubular reactor VR2 is a spherical tubular reactor with an inner baffle plate, the length-diameter ratio of the second tubular reactor VR2 is 10-500, and the pressure drop of an inlet and an outlet of the second tubular reactor VR2 is less than 0.05 Mpa; the inner baffle is arranged at the spherical diameter 1/4-1/2 close to the inlet of the spherical tubular reactor; preferably, a plurality of uniformly distributed circular holes are formed in the inner baffle, and the sum of the areas of the circular holes accounts for 37-83% of the total area of the inner baffle;

the length-diameter ratio of the third tubular reactor VR3 is 10-200;

the length-diameter ratio of the fourth tubular reactor VR4 is 10-200;

the length-diameter ratio of the fifth tubular reactor VR5 is 50-500, and the fifth tubular reactor VR5 is provided with an ultrasonic emulsification device;

the length-diameter ratio of the VR6 in the sixth tubular reactor is 10-200;

the length-diameter ratio of the seventh tubular reactor VR7 is 10-500.

The invention also provides a continuous production process of the aqueous polyurethane dispersion, which adopts the continuous production system to prepare the aqueous polyurethane dispersion, and the continuous production process comprises the following steps:

(1) the polyisocyanate and oligomer polyol are contacted in a first tubular reactor VR1 to carry out a first-step prepolymerization reaction to obtain a prepolymer I; wherein the oligomer polyol is added into the first tubular reactor VR1 simultaneously in four parts at four feed ports of the first tubular reactor VR1 respectively;

(2) the prepolymer I is contacted with a nonionic hydrophilic compound in a second tubular reactor VR2 for reaction to obtain a prepolymer II;

(3) diluting the prepolymer II and a solvent and/or an acrylate monomer in a third tubular reactor VR 3;

(4) carrying out chain extension reaction on the diluted prepolymer II, a hydrophilic chain extender and micromolecule diamine in a fourth tubular reactor VR4 to obtain a waterborne polyurethane ionomer;

(5) emulsifying and dispersing the waterborne polyurethane ionomer and deionized water in a fifth tubular reactor VR5 to obtain a waterborne polyurethane coarse emulsion; then removing the solvent to obtain the aqueous polyurethane dispersoid;

alternatively, the continuous production process comprises the steps of:

(1') contacting polyisocyanate with oligomer polyol in a first tubular reactor VR1 to carry out a first-step prepolymerization reaction to obtain a prepolymer I; wherein the oligomer polyol is added into the first tubular reactor VR1 simultaneously in four parts at four feed ports of the first tubular reactor VR1 respectively;

(2') reacting the prepolymer I with a hydrophilic chain extender and micromolecular dihydric alcohol in a second tubular reactor VR2 to obtain a prepolymer II;

(3') contacting the prepolymer II with a solvent and/or an acrylate monomer in a third tubular reactor VR3 for dilution;

(4') carrying out neutralization reaction on the diluted prepolymer II and a neutralizing agent in a fourth tubular reactor VR4 to obtain a waterborne polyurethane ionomer;

(5') contacting the waterborne polyurethane ionomer with deionized water in a fifth tubular reactor VR5 for emulsification and dispersion to obtain a waterborne polyurethane coarse emulsion; and then the aqueous polyurethane dispersoid is obtained after the solvent is removed.

According to the continuous process provided by the present invention, preferably, in step (1) or step (1'), the simultaneous feeding of the oligomer polyol in four portions into the first tubular reactor VR1 comprises: the mass of the oligomer polyol added in the first part accounts for 10-25% of the total added mass of the oligomer polyol, the addition amount of the second part accounts for 15-35% of the total added mass of the oligomer polyol, the addition amount of the third part accounts for 15-35% of the total added mass of the oligomer polyol, and the addition amount of the fourth part accounts for 30-50% of the total added mass of the oligomer polyol.

According to the continuous production process provided by the present invention, preferably, in step (2), the non-ionic hydrophilic compound is added to the second tubular reactor VR2 in three portions at the same time. More preferably, the simultaneous feeding of the non-ionic hydrophilic compounds into the second tubular reactor VR2 in three portions at three feed ports of the second tubular reactor VR2 respectively comprises: the mass of the nonionic hydrophilic compound added into the first part accounts for 15-50% of the total added mass of the nonionic hydrophilic compound, the addition amount of the second part accounts for 15-50% of the total added mass of the nonionic hydrophilic compound, and the addition amount of the third part accounts for 15-50% of the total added mass of the nonionic hydrophilic compound.

According to the continuous production process provided by the present invention, preferably, the continuous production process further comprises: contacting the aqueous polyurethane coarse emulsion with a rear chain extender to perform a rear chain extension reaction step and/or contacting the aqueous polyurethane coarse emulsion with an initiator to perform a polymerization reaction step; and then the water-based polyurethane dispersoid is obtained by decompressing and desolventizing.

Preferably, the post-chain extender is selected from one or more of isophorone diamine, butane diamine, ethylene diamine and 1, 6-hexamethylene diamine;

preferably, the initiators are sodium dithionite and tert-butyl hydroperoxide.

According to the continuous production process provided by the invention, preferably, in the step (1) or the step (1'), the polyisocyanate and the solvent are uniformly mixed in the first mixer M1 and then are injected into the first tubular reactor VR 1; the temperature of the raw materials mixed in M1 is 50-80 ℃;

in the step (2), the prepolymer I and the catalyst are uniformly mixed in a second mixer M2 and then injected into a second tubular reactor VR 2; or in the step (2'), the prepolymer I, a hydrophilic chain extender and micromolecule diol are uniformly mixed in a second mixer M2 and then injected into the second tubular reactor VR 2; the temperature of the raw materials mixed in M2 is 20-60 ℃;

in the step (3) or the step (3'), the prepolymer II and a solvent and/or an acrylate monomer are uniformly mixed in a third mixer M3 and then injected into a third tubular reactor VR 3; the temperature of the raw materials mixed in M3 is 20-60 ℃;

in the step (4), the diluted prepolymer II, a hydrophilic chain extender and micromolecule diamine are uniformly mixed in a fourth mixer M4 and then injected into a fourth tubular reactor VR 4; or in the step (4'), the diluted prepolymer II and the neutralizer are uniformly mixed in a fourth mixer M4 and then are injected into the fourth tubular reactor VR 4; the temperature of the raw materials mixed in M4 is 20-60 ℃;

in the step (5) or the step (5'), the waterborne polyurethane ionomer and deionized water are uniformly mixed in a fifth mixer M5 and then are injected into the fifth tubular reactor VR 5; the temperature of the raw materials mixed in the M5 is 5-30 ℃.

Preferably, the post-chain extension reaction step is: uniformly mixing the aqueous polyurethane coarse emulsion and a rear chain extender in a sixth mixer M6, and injecting the mixture into a sixth tubular reactor VR6 for rear chain extension reaction; the polymerization reaction comprises the following steps: and uniformly mixing the waterborne polyurethane coarse emulsion obtained by the post-chain extension reaction and an initiator in a seventh mixer M7, and injecting into a seventh tubular reactor VR7 for polymerization.

In each step, determining whether a catalyst needs to be added according to the reaction requirement; when the catalyst is required to be added, the catalyst and the reaction raw materials are mixed in a mixer corresponding to each reaction. The mass ratio of the addition amount of the catalyst to the corresponding prepolymer is 1: 100000-1: 1000.

Preferably, the catalyst is selected from dibutyltin dilaurate.

According to the continuous production process provided by the invention, preferably, the polyisocyanate is aliphatic diisocyanate or aromatic diisocyanate, and more preferably, one or more selected from hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate.

Preferably, the oligomer polyol is selected from one or more of polyester diol, polyether diol and polycarbonate diol. More preferably, the number average molecular weight of the polyester diol is 200-5000, and the polyester diol is selected from one or more of polybutylene adipate diol, neopentyl glycol adipate diol, polyhexamethylene glycol adipate diol, polycaprolactone diol, polyhexamethylene glycol phthalate diol and neopentyl glycol phthalate diol. More preferably, the polyether diol has a number average molecular weight of 200-5000, and is selected from one or more of polyoxypropylene diol, copolymerized diol of polyoxyethylene and polyoxypropylene, and polytetrahydrofuran diol. More preferably, the polycarbonate diol has the number average molecular weight of 200-5000, and is prepared by performing ester exchange reaction on carbonic diester and diol ester;

preferably, the non-ionic hydrophilic compound is a hydrophilic polyether compound containing a monofunctional or difunctional group reactive with isocyanate groups, more preferably selected from compounds containing a polyethoxy segment and having an ethylene oxide number of 12 to 75 per molecule, and having a molar mass of 500-3000 g/mol; in a preferred embodiment of the present invention, the nonionic hydrophilic compound is polyethylene glycol monomethyl ether.

Preferably, the small molecule diol is selected from one or more of ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, diethylene glycol, neopentyl glycol and cyclohexanedimethanol.

Preferably, the small molecule diamine is selected from one or more of isophoronediamine, butanediamine, ethylenediamine, 1, 6-hexanediamine, piperazine, 1, 4-diaminocyclohexane, bis- (4-aminocyclohexyl) methane, adipic acid dihydrazide and hydrazine.

Preferably, the hydrophilic chain extender is a dihydroxy compound containing a hydrophilic group, a diamino compound containing sulfonic acid, or a diamino compound containing a sulfonate salt. The hydrophilic group-containing dihydroxy compound is preferably selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid and dihydroxysuccinic acid; the sulfonic acid-containing diamino compound or sulfonate-containing diamino compound is preferably selected from one or more of N- (2-aminoethyl) -2-aminoethanesulfonic acid and alkali metal salts or ammonium salts thereof, N- (3-aminopropyl) -3-aminopropanesulfonic acid and alkali metal salts or ammonium salts thereof, and N- (2-aminoethyl) -3-aminopropanesulfonic acid and alkali metal salts or ammonium salts thereof.

Preferably, the neutralizing agent is selected from one or more of ammonia, ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, 2-amino-2-methyl-1-propanol, morpholine, N-methylmorpholine, dimethylisopropylamine, N-methyldiethanolamine, triethylamine, dimethylcyclohexylamine, ethyldiisopropylamine, sodium hydroxide, potassium hydroxide, lithium hydroxide and calcium hydroxide. Preferably, the solvent is selected from butanone and/or acetone.

Preferably, the acrylate monomer is a saturated acrylate monomer. The saturated acrylate monomer is preferably selected from one or more of methyl methacrylate, butyl acrylate and ethyl acrylate.

According to the continuous production process provided by the present invention, preferably, the process conditions of the first tubular reactor VR1 in step (1) or step (1') include: the reaction temperature is 60-140 ℃, the retention time is 0.2-6h, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the polyisocyanate to the oligomer polyol is 1: 15-1: 1; more preferably 1:8 to 1: 1.5.

The process conditions of the second tubular reactor VR2 in step (2) or step (2') include: the reaction temperature is 60-140 ℃, the retention time is 0.2-6h, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the polyisocyanate to the nonionic hydrophilic compound is 10: 1-3: 1, or the mass ratio of the polyisocyanate to the hydrophilic chain extender is 10: 1-2: 1, and the mass ratio of the polyisocyanate to the micromolecular diol is 25: 1-2: 1;

the process conditions of the third tubular reactor VR3 in step (3) or step (3') include: the reaction temperature is 20-60 ℃, the retention time is 5-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the prepolymer II to the solvent is 1: 0.25-1: 2, and the mass ratio of the prepolymer II to the acrylate monomer is 1: 0.5-1: 1.5;

the process conditions of the fourth tubular reactor VR4 in step (4) or step (4') include: the reaction temperature is 20-60 ℃, the retention time is 5-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the prepolymer II to the hydrophilic chain extender is 100: 1-20: 1, and the mass ratio of the prepolymer II to the small-molecular diamine is 120: 1-12: 1; or the mass ratio of the prepolymer II to the neutralizer is 120: 1-20: 1;

the process conditions of the fifth tubular reactor VR5 in step (5) or step (5') include: the reaction temperature is 5-30 ℃, the retention time is 5-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the waterborne polyurethane ionomer to the deionized water is 1: 0.4-1: 3.

Preferably, the process conditions of the sixth tubular reactor VR6 in the post-chain extension reaction step include: the reaction temperature is 10-40 ℃, the retention time is 2-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the aqueous polyurethane coarse emulsion to the rear chain extender is 500: 1-50: 1;

the process conditions of the seventh tubular reactor VR7 in the polymerization step include: the reaction temperature is 10-100 ℃, the retention time is 2-60 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the aqueous polyurethane crude emulsion obtained by the post-chain extension reaction to the initiator is 20000: 1-2000: 1.

The invention also provides the application of the continuous production process in the production of aqueous polyurethane by an acetone method, the production of aqueous polyurethane by a prepolymer method, the preparation process of aqueous polyurethane acrylate dispersoid and the preparation process of light-curable aqueous polyurethane acrylate dispersoid.

The invention also provides application of the aqueous polyurethane dispersion prepared by the continuous production process in wood coatings, textile coatings, synthetic leather, plastic coatings, metal coatings, personal care, coating agents, adhesives and sealants.

The principle of the continuous production process is as follows: the continuous production process of the waterborne polyurethane is carried out by adopting a continuous production system consisting of a multi-section tubular reactor, firstly, a two-section spherical tubular reactor containing an inner baffle is adopted as a pre-polymerization reactor of the waterborne polyurethane, in order to increase the mixing efficiency and reduce the pressure drop, the inner baffle with holes is implanted inside, and the mixing efficiency of the prepolymer under different viscosities can be greatly improved by implanting the inner baffle; the viscosity of the prepolymer continuously rises along with the reaction, and the pore diameter of the inner baffle is correspondingly adjusted; the viscosity in the reaction process can also be reduced by adding a proper amount of solvent; in order to obtain prepolymer with narrow molecular weight distribution, a process of adding oligomer polyol in four batches and adding nonionic hydrophilic compound in three batches is adopted.

The pressure in the invention is absolute pressure.

The technical scheme of the invention has the beneficial effects that:

1) the continuous production process of the waterborne polyurethane dispersoid adopts a continuous production system consisting of a multi-section tubular reactor, wherein a spherical tubular reactor containing inner baffles is used, and the inner baffles are uniformly distributed with a certain proportion of pore diameters, so that the tubular reactor has high-efficiency mixing capability and very low pressure drop; the energy consumption is low, the applicable range is wide, the production types are various, and the method can be used for producing aqueous polyurethane based on a prepolymer method and an acetone method, aqueous polyurethane acrylate dispersoid, light-curable aqueous polyurethane acrylate dispersoid and other various modified aqueous polyurethane dispersoids;

2) the continuous production process of the aqueous polyurethane dispersion is combined with the process of adding oligomer polyol in four parts and adding non-ionic hydrophilic compound in three parts, so that a prepolymer with narrow molecular weight distribution can be obtained, and the molecular weight distribution is 2.0-2.5; the aqueous polyurethane dispersion obtained therefrom has excellent initial strength and initial heat resistance when used in the direction of an adhesive.

The invention is a continuous production process of waterborne polyurethane and realizes full automatic control; the production efficiency is high, the product quality is stable, the application range is wide, and the method can be used for the production of aqueous polyurethane by an acetone method and a prepolymer method and the production of various modified aqueous polyurethane such as aqueous polyurethane acrylate dispersoid, light-curable aqueous polyurethane acrylate dispersoid and the like.

Drawings

FIG. 1 shows a process flow diagram for the continuous production of the aqueous polyurethane dispersions according to the invention.

FIG. 2 shows a schematic structural diagram of an inner baffle plate in the tubular reactor of the present invention.

The numbers in the above figures are illustrated as follows:

m1-first mixer, M2-second mixer, M3-third mixer, M4-fourth mixer, M5-fifth mixer, M6-sixth mixer, M7-seventh mixer, VR 1-first tubular reactor, VR 2-second tubular reactor, VR 3-third tubular reactor, VR 4-fourth tubular reactor, VR 5-fifth tubular reactor, VR 6-sixth tubular reactor, VR 7-seventh tubular reactor;

l1, L2, L3, L4, L5, L6, L7, L11, L12, L13, L14, L21, L22, and L23 are feed ports.

Detailed Description

In order that the technical features and contents of the present invention can be understood in detail, preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention have been described in the examples, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

The continuous production system used in the continuous production process of the aqueous polyurethane dispersion of each example is shown in FIG. 1. Wherein,

the first tubular reactor VR1 is a spherical tubular reactor containing 132 circular inner baffles, the length-diameter ratio is 290, and the pressure drop (related to the number of the inner baffles) of the inlet and the outlet is less than 0.05 Mpa. The inner baffle plate is arranged at the sphere diameter 1/3 close to the inlet of the spherical tubular reactor; a plurality of uniformly distributed circular holes are formed in the inner baffle, as shown in fig. 2; the sum of the areas of the circular holes accounts for 39 percent of the total area of the inner baffle plates.

The second tubular reactor VR2 is a spherical tubular reactor containing 84 circular inner separation blades, the length-diameter ratio of the second tubular reactor VR2 is 350, and the pressure drop of an inlet and an outlet of the second tubular reactor VR2 is less than 0.05 Mpa; the inner baffle plate is arranged at the sphere diameter 1/3 close to the inlet of the spherical tubular reactor; a plurality of uniformly distributed circular holes are formed in the inner baffle, as shown in fig. 2; the sum of the areas of the circular holes accounts for 50 percent of the total area of the inner baffle plates.

The length-to-diameter ratio of the third tubular reactor VR3 is 110;

the length-to-diameter ratio of the fourth tubular reactor VR4 is 150;

the length-diameter ratio of the fifth tubular reactor VR5 is 400, and the fifth tubular reactor VR5 is provided with an ultrasonic emulsifier;

the length-to-diameter ratio of the sixth tubular reactor VR6 is 130;

the length-to-diameter ratio of the seventh tubular reactor VR7 is 324.

In the present invention, the mixer connected to each tubular reactor is a static mixer without stirring.

First, the source of the reaction raw material

TDI, Hebei Cangzhou Dahua, Industrial products;

IPDI, degussa corporation, industrial;

PTMEG2000 (polytetrahydrofuran diol, Mn 2000), shanxi, san xie, a commercial product;

PBA2000 (polybutylene adipate glycol, Mn ═ 2000), Qingdao yutian, industrial;

PCL2000 (polycaprolactone diol, Mn 2000), Qingdao yutian, industrial;

PNA800 (poly neopentyl glycol adipate diol, Mn ═ 800), Qingdao yutian, industrial;

MPEG520, asian petrochemicals, industrial;

DMPA, boston, sweden, industrial;

BDO, Mitsubishi chemical, Industrial products;

catalyst (dibutyltin dilaurate (T12)), chemical engineering, industrial products of shanghai yutian;

MMA, a new chemical industry and an industrial product of Heilongjiang dragon;

BA, wanhua chemistry, industrial;

triethylamine, Zhejiang construction industry and industrial products;

ethylenediamine, yankee basf, industrial;

sodium N- (2-aminoethyl) -2-aminoethane sulfonate, winning from chemical and industrial products;

initiator (sodium dithionite, industrial product of West Longsu chemical, tert-butyl hydroperoxide, auxiliary agent of Lanzhou province, industrial product.

Second, testing method

1. Molecular weight (Mn) and molecular weight distribution index (Mw/Mn) measurements

The molecular weight and the distribution of the prepolymer were measured by a gel permeation chromatograph (GPC, Tosoh, model HLC-8220GPC, Japan), and the prepolymer was dissolved in tetrahydrofuran as a solvent, and tetrahydrofuran was used as a rinsing solvent at a solvent flow rate of 1ml/min at room temperature.

2. Initial Strength and initial Heat resistance test of Adhesives

1) The preparation process of the adhesive comprises the following steps: 100g of the aqueous polyurethane dispersion, 0.05g of BYK024 (Beck chemical) were mixed and stirred at 500rpm for 5min, 0.2g of Tego245 (digao) was added, stirring was continued for 5min, 0.15g of Vesmody U604 (Van Hua chemical) was added and stirring was continued at 600rpm for 10 min.

2) Preparation of test specimens

The resulting adhesive was coated on a substrate to obtain a composite material as a test specimen:

composite material	Substrate 1	Base material 2
			A	Rubber composition	Rubber composition
B	Canvas	Canvas
			C	PVC	PVC

The adhesive dispersion was first applied thinly using a brush to a 2.5cm wide and 15cm long strip of substrate and dried in an oven at 65 ℃ for 5 minutes, after which it was taken out and pressed at 30kg/cm2 for 10 seconds to give composite A.

Composite materials B and C were prepared in the same manner.

3) Testing the Peel Strength of the composite

The peel strength was measured with a GOTECH tensile machine at a peel rate of 200 mm/min.

Initial strength: and after pressing, directly testing the peel strength of the laminated board by a tensile machine.

Initial heat resistance: the prepared test piece is hung with a weight of 500 g and placed in an oven at 80 ℃, and the length of the test piece pulled apart within 30 minutes is tested.

Example 1 preparation of waterborne polyurethane by prepolymer method

Referring to fig. 1, 600 parts of TDI and 50 parts of acetone were pumped through a feed port L1, mixed completely in a first mixer M1 and preheated to 60 ℃, and then fed into a first tubular reactor VR1, 300 parts of PTMEG2000 (polytetrahydrofuran glycol, Mn ═ 2000) was pumped through a feed port L11, 550 parts of PTMEG2000 was pumped through a feed port L12, 550 parts of PTMEG2000 was pumped through a feed port L13, 600 parts of PTMEG2000 was pumped through a feed port L14, four parts of PTMEG2000 were simultaneously pumped, the pressure of VR1 was reduced to 0.04Mpa, the reaction temperature of VR1 was set to 85 ℃, and the residence time was 30 minutes; after the reaction in the first step is finished, the prepolymer I enters a second mixer M2, meanwhile, 120 parts of DMPA, 70 parts of BDO, 310 parts of acetone and 1 part of dibutyltin dilaurate catalyst are pumped into M2 through a feed inlet L2, the mixture is uniformly mixed and then enters a second tubular reactor VR2, the reaction temperature of VR2 is set to be 75 ℃, and the retention time is 1 hour; after the second step of reaction, the prepolymer II enters a third mixer M3, 1100 parts of acetone is pumped into M3 from a feed inlet L3, the mixture enters a third tubular reactor VR3 after preliminary mixing, the reaction temperature of VR3 is set to 35 ℃, and the retention time is 30 min; feeding the diluted prepolymer into a fourth mixer M4, pumping 73 parts of neutralizing agent triethylamine from a feed inlet L4, mixing, feeding into a fourth tubular reactor VR4, setting the reaction temperature of VR4 at 35 ℃, and keeping the reaction time for 10min to obtain the waterborne polyurethane ionomer; and (2) allowing the waterborne polyurethane ionomer to enter a fifth mixer M5, simultaneously pumping 4700 parts of deionized water into a feed inlet L5, mixing, allowing the mixture to enter a fifth tubular reactor VR5 with an ultrasonic emulsification device, setting the reaction temperature to be 15 ℃, allowing the residence time to be 20min, obtaining a waterborne polyurethane crude emulsion, allowing the waterborne polyurethane crude emulsion to enter a sixth mixer M6, simultaneously pumping 6 parts of ethylenediamine and 30 parts of water into a feed inlet L6, allowing the waterborne polyurethane crude emulsion to enter a sixth tubular reactor VR6, setting the reaction temperature of VR6 to be 25 ℃, allowing the residence time to be 10min, finally obtaining the waterborne polyurethane crude emulsion, and performing pressure reduction and solvent removal through a pressure reducer to obtain a carboxylate waterborne polyurethane dispersion without solvent and with the solid content of 30 wt%, wherein the dispersion is used for textile coating. The molecular weight and molecular weight distribution of the prepolymer II obtained are shown in Table 1, and the initial peel strength and initial heat resistance of the composite material sample obtained from the carboxylate type aqueous polyurethane dispersion are shown in Table 2. The parts added in the above reaction materials are parts by mass.

Example 2 preparation of waterborne polyurethane by acetone Process

Pumping 150 parts of HDI (hexamethylene diisocyanate), 140 parts of IPDI (isophorone diisocyanate) and 240 parts of acetone from a feed port L1, completely mixing and preheating the mixture in a first mixer M1 to 60 ℃, then feeding the mixture into a first tubular reactor VR1, pumping 400 parts of PBA2000 (polybutylene adipate glycol, Mn ═ 2000) from a feed port L11, pumping 500 parts of PBA2000 from a feed port L12, pumping 500 parts of PBA2000 from a feed port L13, pumping 700 parts of PBA2000 from a feed port L14, simultaneously pumping four parts of PBA2000, reducing the pressure of VR1 to 0.04MPa, setting the reaction temperature of VR1 to 85 ℃, and setting the residence time to 30 minutes; after the first-step reaction, the obtained prepolymer I enters a second mixer M2, 2 parts of dibutyltin dilaurate is pumped into M2 through a feed inlet L2 at the same time, the mixture enters a second tubular reactor VR2 after being uniformly mixed, 15 parts of MPEG520 is pumped into the second tubular reactor through a feed inlet L21, 15 parts of MPEG520 is pumped into the second tubular reactor through a feed inlet L22, 20 parts of MPEG520 is pumped into the second tubular reactor through a feed inlet L23, the reaction temperature of VR2 is set to 85 ℃, and the residence time is 1.5 hours; after the second step of reaction, the prepolymer II enters a third mixer M3, meanwhile, 3000 parts of acetone is pumped into M3 from a feed inlet L3, the mixture enters a third tubular reactor VR3 after being primarily mixed, the reaction temperature of VR3 is set to be 45 ℃, and the retention time is 30 min; the diluted prepolymer enters a fourth mixer M4, 31 parts of ethylenediamine, 32 parts of N- (2-aminoethyl) -2-aminoethane sodium sulfonate and 240 parts of deionized water are pumped into a feed inlet L4, the mixture enters a fourth tubular reactor VR4, the reaction temperature of VR4 is set to be 45 ℃, and the retention time is 25min, so that the waterborne polyurethane ionomer is obtained; the waterborne polyurethane ionomer enters a fifth mixer M5, 2600 parts of deionized water is pumped into a feed inlet L5, the mixture enters a fifth tubular reactor VR5 with an ultrasonic emulsification device after being mixed, the reaction temperature is set to be 20 ℃, the residence time is 20min, the waterborne polyurethane crude emulsion is obtained and enters a sixth mixer M6, 2 parts of ethylenediamine and 30 parts of water are pumped into the feed inlet L6 and enters a sixth tubular reactor VR6, the reaction temperature of VR6 is set to be 25 ℃, the residence time is 10min, the waterborne polyurethane crude emulsion is finally obtained, the pressure is reduced through a pressure reducer to remove the solvent, the sulfonate type waterborne polyurethane dispersion without the solvent and with the solid content of 50 wt% is obtained, and the dispersion is used for adhesives. The molecular weight and molecular weight distribution of the prepolymer II obtained are shown in Table 1, and the initial peel strength and initial heat resistance of the composite material sample obtained from the sulfonate-type aqueous polyurethane dispersion are shown in Table 2. The parts added in the above reaction materials are parts by mass.

Example 3 preparation of aqueous urethane acrylate Dispersion

Pumping 400 parts of HMDI, 400 parts of HDI, 10 parts of acetone and 1 part of dibutyltin dilaurate catalyst from a feed inlet L1, completely mixing in a first mixer M1, preheating to 80 ℃, then entering a first tubular reactor VR1, pumping 200 parts of PCL2000 (polycaprolactone diol, Mn ═ 2000) from a feed inlet L11, pumping 350 parts of PCL2000 from a feed inlet L12, pumping 350 parts of PCL2000 from a feed inlet L13, pumping 300 parts of PCL2000 from a feed inlet L14, simultaneously pumping four parts of PCL2000, reducing the pressure of VR1 to 0.03MPa, setting the reaction temperature of VR1 to 100 ℃, and keeping the reaction time to 1 hour; the prepolymer I obtained after the reaction in the first step enters a second mixer M2, at the same time, 120 parts of DMPA, 35 parts of NPG, 40 parts of BDO, 290 parts of acetone and 1 part of dibutyltin dilaurate catalyst are pumped into a second mixer M2 through a feed inlet L2, the mixture is uniformly mixed and then enters a second tubular reactor VR2, the reaction temperature of VR2 is set to be 110 ℃, and the residence time is 1 hour; after the second step of reaction, the obtained prepolymer II enters a third mixer M3, meanwhile, 1300 parts of acetone, 1000 parts of MMA and 800 parts of BA are pumped into the third mixer M3 through a feed inlet L3, and enter a third tubular reactor VR3 after primary mixing, wherein the reaction temperature of VR3 is set to 35 ℃, and the retention time is 30 min; the diluted prepolymer enters a fourth mixer M4, 90 parts of neutralizing agent triethylamine is pumped in from a feed inlet L4, the diluted prepolymer and the neutralizing agent triethylamine are mixed and then enter a fourth tubular reactor VR4, the reaction temperature of VR4 is set to be 35 ℃, the residence time is 10min, and the waterborne polyurethane ionomer is obtained; the waterborne polyurethane ionomer enters a fifth mixer M5, 4600 part of deionized water is pumped into a feed inlet L5, the mixture enters a fifth tubular reactor VR5 with an ultrasonic emulsification device, the reaction temperature is set to 15 ℃, the residence time is 20min, the obtained waterborne polyurethane crude emulsion enters a sixth mixer M6, 80 parts of hexamethylenediamine and 322 parts of water are pumped into a feed inlet L6, the mixture enters a sixth tubular reactor VR6 after being primarily mixed, the reaction temperature of VR6 is set to 30 ℃, and the residence time is 10 min; and then the aqueous polyurethane coarse emulsion enters a seventh mixer M7, 0.1 part of initiator is added from a feed inlet L7, the aqueous polyurethane coarse emulsion enters a seventh tubular reactor VR7 after primary mixing, the temperature of VR7 is set to be 50 ℃, the retention time is 30min, the aqueous polyurethane acrylate coarse emulsion is finally obtained, the solvent is decompressed and desolventized by a decompressor, the aqueous polyurethane acrylate dispersoid with the solid content of 40 percent and no solvent is obtained, and the dispersoid is used for wood lacquer. The molecular weight and molecular weight distribution of the prepolymer II are shown in Table 1, and the initial peel strength and initial heat resistance of the composite material sample obtained from the aqueous urethane acrylate dispersion are shown in Table 2. The parts added in the above reaction materials are parts by mass.

Comparative example 1 preparation of aqueous polyurethane Dispersion by prepolymer method

Referring to fig. 1, 600 parts of TDI and 50 parts of acetone were pumped from a feed port L1, mixed completely in a first mixer M1 and preheated to 60 ℃, and then fed into a first tubular reactor VR1, 2000 parts of PTMEG2000 (polytetrahydrofuran glycol, Mn 2000) was pumped from a feed port L11, the pressure of VR1 was reduced to 0.04Mpa, the reaction temperature of VR1 was set to 85 ℃, and the residence time was 30 minutes; after the reaction in the first step is finished, the prepolymer I enters a second mixer M2, meanwhile, 120 parts of DMPA, 70 parts of BDO, 310 parts of acetone and 1 part of dibutyltin dilaurate are pumped into M2 from a material port L2, the mixture is uniformly mixed and then enters a second tubular reactor VR2, the reaction temperature of VR2 is set to be 75 ℃, and the retention time is 1 hour; after the second step of reaction, the prepolymer II enters a third mixer M3, 1100 parts of acetone is pumped into M3 from a feed inlet L3, the mixture enters a third tubular reactor VR3 after preliminary mixing, the reaction temperature of VR3 is set to 35 ℃, and the retention time is 30 min; feeding the diluted prepolymer into a fourth mixer M4, pumping 73 parts of neutralizing agent triethylamine from a feed inlet L4, mixing, feeding into a fourth tubular reactor VR4, setting the reaction temperature of VR4 at 35 ℃, and keeping the reaction time for 10min to obtain the waterborne polyurethane ionomer; and (2) allowing the waterborne polyurethane ionomer to enter a fifth mixer M5, simultaneously pumping 4700 parts of deionized water into a feed inlet L5, mixing, allowing the mixture to enter a fifth tubular reactor VR5 with an ultrasonic emulsification device, setting the reaction temperature to be 15 ℃, allowing the residence time to be 20min, obtaining a waterborne polyurethane crude emulsion, allowing the waterborne polyurethane crude emulsion to enter a sixth mixer M6, simultaneously pumping 6 parts of ethylenediamine and 30 parts of water into a feed inlet L6, allowing the waterborne polyurethane crude emulsion to enter a sixth tubular reactor VR6, setting the reaction temperature of VR6 to be 25 ℃, allowing the residence time to be 10min, finally obtaining the waterborne polyurethane crude emulsion, and performing pressure reduction and solvent removal through a pressure reducer to obtain a carboxylate waterborne polyurethane dispersion without solvent and with the solid content of 30 wt%, wherein the dispersion is used for textile coating. The molecular weight and molecular weight distribution of the prepolymer II obtained are shown in Table 1, and the initial peel strength and initial heat resistance of the composite material sample obtained from the carboxylate type aqueous polyurethane dispersion are shown in Table 2. The parts added in the above reaction materials are parts by mass.

Comparative example 2 preparation of aqueous polyurethane Dispersion by acetone Process

Pumping 150 parts of HDI (hexamethylene diisocyanate), 140 parts of IPDI (isophorone diisocyanate) and 240 parts of acetone from a feed inlet L1, completely mixing in a first mixer M1, preheating to 60 ℃, then feeding into a first tubular reactor VR1, pumping 2100 parts of PBA2000 (polybutylene adipate glycol, Mn is 2000) from a feed inlet L11, reducing the pressure of VR1 to 0.04MPa, setting the reaction temperature of VR1 to 85 ℃, and setting the residence time to 30 minutes; after the reaction in the first step, the obtained prepolymer I enters a second mixer M2, 2 parts of dibutyltin dilaurate is pumped into M2 from a feed inlet L2 at the same time, the mixture enters a second tubular reactor VR2 after being uniformly mixed, 50 parts of MPEG520 is pumped from a feed inlet L21, the reaction temperature of VR2 is set to 85 ℃, and the retention time is 1.5 hours; after the second step of reaction, the prepolymer II enters a third mixer M3, meanwhile, 3000 parts of acetone is pumped into M3 from a feed inlet L3, the mixture enters a third tubular reactor VR3 after being primarily mixed, the reaction temperature of VR3 is set to be 45 ℃, and the retention time is 30 min; the diluted prepolymer enters a fourth mixer M4, 31 parts of ethylenediamine, 32 parts of N- (2-aminoethyl) -2-aminoethane sodium sulfonate and 240 parts of deionized water are pumped into a feed inlet L4, the mixture enters a fourth tubular reactor VR4, the reaction temperature of VR4 is set to be 45 ℃, and the retention time is 25min, so that the waterborne polyurethane ionomer is obtained; the waterborne polyurethane ionomer enters a fifth mixer M5, 2600 parts of deionized water is pumped into a feed inlet L5, the mixture enters a fifth tubular reactor VR5 with an ultrasonic emulsification device after being mixed, the reaction temperature is set to be 20 ℃, the residence time is 20min, the waterborne polyurethane crude emulsion is obtained and enters a sixth mixer M6, 2 parts of ethylenediamine and 30 parts of water are pumped into the feed inlet L6 and enters a sixth tubular reactor VR6, the reaction temperature of VR6 is set to be 25 ℃, the residence time is 10min, the waterborne polyurethane crude emulsion is finally obtained, the pressure is reduced through a pressure reducer to remove the solvent, the sulfonate type waterborne polyurethane dispersion without the solvent and with the solid content of 50 wt% is obtained, and the dispersion is used for adhesives. The molecular weight and molecular weight distribution of the prepolymer II obtained are shown in Table 1, and the initial peel strength and initial heat resistance of the composite material sample obtained from the sulfonate-type aqueous polyurethane dispersion are shown in Table 2. The parts added in the above reaction materials are parts by mass.

Comparative example 3 preparation of aqueous urethane acrylate Dispersion

Pumping 400 parts of HMDI, 400 parts of HDI, 10 parts of acetone and 1 part of dibutyltin dilaurate catalyst from a feed inlet L1, completely mixing in a first mixer M1, preheating to 80 ℃, then entering a first tubular reactor VR1, pumping 1200 parts of PCL2000 (polycaprolactone diol, Mn 2000) from a feed inlet L11, reducing the pressure of VR1 to 0.03MPa, setting the reaction temperature of VR1 to 100 ℃, and keeping the reaction time for 1 hour; the prepolymer I obtained after the reaction in the first step enters a second mixer M2, at the same time, 120 parts of DMPA, 35 parts of NPG, 40 parts of BDO, 290 parts of acetone and 1 part of catalyst are pumped into the second mixer M2 from a feed inlet L2, the mixture is uniformly mixed and then enters a second tubular reactor VR2, the reaction temperature of VR2 is set to be 110 ℃, and the residence time is 1 hour; after the second step of reaction, the obtained prepolymer II enters a third mixer M3, meanwhile, 1300 parts of acetone, 1000 parts of MMA and 800 parts of BA are pumped into the third mixer M3 through a feed inlet L3, and enter a third tubular reactor VR3 after primary mixing, wherein the reaction temperature of VR3 is set to 35 ℃, and the retention time is 30 min; the diluted prepolymer enters a fourth mixer M4, 90 parts of neutralizing agent triethylamine is pumped in from a feed inlet L4, the diluted prepolymer and the neutralizing agent triethylamine are mixed and then enter a fourth tubular reactor VR4, the reaction temperature of VR4 is set to be 35 ℃, the residence time is 10min, and the waterborne polyurethane ionomer is obtained; the waterborne polyurethane ionomer enters a fifth mixer M5, 4600 part of deionized water is pumped into a feed inlet L5, the mixture enters a fifth tubular reactor VR5 with an ultrasonic emulsification device, the reaction temperature is set to 15 ℃, the residence time is 20min, the obtained waterborne polyurethane crude emulsion enters a sixth mixer M6, 80 parts of hexamethylenediamine and 322 parts of water are pumped into a feed inlet L6, the mixture enters a sixth tubular reactor VR6 after being primarily mixed, the reaction temperature of VR6 is set to 30 ℃, and the residence time is 10 min; and then the aqueous polyurethane coarse emulsion enters a seventh mixer M7, 0.1 part of initiator is added from a feed inlet L7, the aqueous polyurethane coarse emulsion enters a seventh tubular reactor VR7 after primary mixing, the temperature of VR7 is set to be 50 ℃, the retention time is 30min, the aqueous polyurethane acrylate coarse emulsion is finally obtained, the solvent is decompressed and desolventized by a decompressor, the aqueous polyurethane acrylate dispersoid with the solid content of 40 percent and no solvent is obtained, and the dispersoid is used for wood lacquer. The molecular weight and molecular weight distribution of the prepolymer II are shown in Table 1, and the initial peel strength and initial heat resistance of the composite material sample obtained from the aqueous urethane acrylate dispersion are shown in Table 2. The parts added in the above reaction materials are parts by mass.

TABLE 1 molecular weights and molecular weight distributions of prepolymers II in examples and comparative examples

Prepolymer II	Molecular weight (Mn)	Molecular weight distribution (Mw/Mn)
			Example 1	3600	2.13
Example 2	4700	2.09
			Example 3	4400	2.24
Comparative example 1	3700	2.82
			Comparative example 2	4600	2.79
Comparative example 3	4400	3.01

TABLE 2 initial adhesion and initial heat resistance of composite test specimens made of the aqueous polyurethanes obtained in the examples and comparative examples

Summary of the results of the experiment obtained:

the comparison of the examples with the comparative examples shows that: according to the invention, by using a continuous production process of feeding in parts, the initial strength of the samples prepared from the waterborne polyurethane obtained in the examples 1-3 is obviously superior to that of the samples prepared from the waterborne polyurethane obtained in the comparative examples 1-3; the samples prepared from the waterborne polyurethane obtained in the examples 1-3 are shorter in pulling distance in a heat resistance test than the samples prepared from the waterborne polyurethane obtained in the comparative examples 1-3, which shows that the initial heat resistance is also remarkably improved.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A continuous production system for preparing an aqueous polyurethane dispersion, comprising:

a plurality of tubular reactors for reacting the reaction mass; the plurality of tubular reactors are sequentially connected in series with one another;

the plurality of tubular reactors comprises: a first tubular reactor (VR1), a second tubular reactor (VR2), a third tubular reactor (VR3), a fourth tubular reactor (VR4), a fifth tubular reactor (VR5), a sixth tubular reactor (VR6), and a seventh tubular reactor (VR 7);

the first tubular reactor (VR1) is a spherical tubular reactor with an inner baffle plate, the length-diameter ratio of the first tubular reactor is 10-500, and the pressure drop of an inlet and an outlet of the first tubular reactor is less than 0.05 Mpa; the inner baffle is arranged at the spherical diameter 1/4-1/2 close to the inlet of the spherical tubular reactor;

the second tubular reactor (VR2) is a spherical tubular reactor with an inner baffle plate, the length-diameter ratio of the second tubular reactor is 10-500, and the pressure drop of an inlet and an outlet of the second tubular reactor is less than 0.05 Mpa; the inner baffle is arranged at the sphere diameter 1/4-1/2 close to the inlet of the spherical tubular reactor.

2. The continuous production system of claim 1, further comprising: the mixers are connected with the feed inlet of each tubular reactor and are used for uniformly mixing reaction raw materials and continuously injecting the reaction raw materials into the tubular reactors;

the mixer is a dynamic mixer with agitation or a static mixer without agitation.

3. The continuous production system according to claim 1 or 2, characterized in that in the first tubular reactor (VR1), a plurality of uniformly distributed circular holes are formed in the inner baffle plate, and the sum of the areas of the circular holes accounts for 25-78% of the total area of the inner baffle plate;

in the second tubular reactor (VR2), a plurality of uniformly distributed circular holes are formed in the inner baffle, and the sum of the areas of the circular holes accounts for 37-83% of the total area of the inner baffle;

the length-diameter ratio of the third tubular reactor (VR3) is 10-200;

the length-diameter ratio of the fourth tubular reactor (VR4) is 10-200;

the length-diameter ratio of the fifth tubular reactor (VR5) is 50-500, and the fifth tubular reactor is provided with an ultrasonic emulsification device;

the length-diameter ratio of the sixth tubular reactor (VR6) is 10-200;

the length-diameter ratio of the seventh tubular reactor (VR7) is 10-500.

4. A continuous production process of an aqueous polyurethane dispersion, characterized in that the preparation of the aqueous polyurethane dispersion is carried out using the continuous production system as set forth in any one of claims 1 to 3, the continuous production process comprising the steps of:

(1) the polyisocyanate and oligomer polyol are contacted in a first tubular reactor (VR1) to carry out a first-step prepolymerization reaction to obtain a prepolymer I; wherein the oligomer polyol is simultaneously fed into the first tubular reactor (VR1) in four portions at four feed ports of the first tubular reactor (VR1), respectively;

(2) the prepolymer I is contacted with a nonionic hydrophilic compound in a second tubular reactor (VR2) to react to obtain a prepolymer II;

(3) diluting the prepolymer II and a solvent and/or an acrylate monomer in a third tubular reactor (VR 3);

(4) carrying out chain extension reaction on the diluted prepolymer II, a hydrophilic chain extender and micromolecule diamine in a fourth tubular reactor (VR4) to obtain a waterborne polyurethane ionomer;

(5) emulsifying and dispersing the waterborne polyurethane ionomer and deionized water in a fifth tubular reactor (VR5) to obtain a waterborne polyurethane coarse emulsion; then removing the solvent to obtain the aqueous polyurethane dispersoid;

alternatively, the continuous production process comprises the steps of:

(1') contacting polyisocyanate with oligomer polyol in a first tubular reactor (VR1) to perform a first-step prepolymerization reaction to obtain a prepolymer I; wherein the oligomer polyol is simultaneously fed into the first tubular reactor (VR1) in four portions at four feed ports of the first tubular reactor (VR1), respectively;

(2') reacting the prepolymer I with a hydrophilic chain extender and micromolecular dihydric alcohol in a second tubular reactor (VR2) to obtain a prepolymer II;

(3') contacting the prepolymer II with a solvent and/or an acrylate monomer in a third tubular reactor (VR3) for dilution;

(4') carrying out a neutralization reaction on the diluted prepolymer II and a neutralizing agent in a fourth tubular reactor (VR4) to obtain a waterborne polyurethane ionomer;

(5') contacting the waterborne polyurethane ionomer with deionized water in a fifth tubular reactor (VR5) to carry out emulsification and dispersion to obtain a waterborne polyurethane crude emulsion; and then the aqueous polyurethane dispersoid is obtained after the solvent is removed.

5. The continuous process of claim 4, wherein the simultaneous feeding of the oligomer polyol in four portions to the first tubular reactor (VR1) in step (1) or step (1') comprises: the mass of the oligomer polyol added in the first part accounts for 10-25% of the total added mass of the oligomer polyol, the addition amount of the second part accounts for 15-35% of the total added mass of the oligomer polyol, the addition amount of the third part accounts for 15-35% of the total added mass of the oligomer polyol, and the addition amount of the fourth part accounts for 30-50% of the total added mass of the oligomer polyol.

6. The continuous process according to claim 4, characterised in that in step (2) the non-ionic hydrophilic compound is fed simultaneously in three portions to the second tubular reactor (VR 2).

7. The continuous production process according to claim 6, wherein in step (2), the simultaneous addition of the non-ionic hydrophilic compound to the second tubular reactor (VR2) in three portions at three feed ports of the second tubular reactor (VR2) respectively comprises: the mass of the nonionic hydrophilic compound added in the first part accounts for 15-50% of the total added mass of the nonionic hydrophilic compound, the mass of the nonionic hydrophilic compound added in the second part accounts for 15-50% of the total added mass of the nonionic hydrophilic compound added in the second part, and the mass of the nonionic hydrophilic compound added in the third part accounts for 15-50% of the total added mass of the nonionic hydrophilic compound added in the third part.

8. The continuous production process according to any one of claims 4 to 7, further comprising: contacting the aqueous polyurethane coarse emulsion with a rear chain extender to perform a rear chain extension reaction step and/or contacting the aqueous polyurethane coarse emulsion with an initiator to perform a polymerization reaction step; and then the water-based polyurethane dispersoid is obtained by decompressing and desolventizing.

9. The continuous process of claim 8, wherein the post-chain extender is selected from one or more of isophoronediamine, butanediamine, ethylenediamine, and 1, 6-hexanediamine;

the initiator is sodium hydrosulfite and tert-butyl hydroperoxide.

10. The continuous process according to claim 8, wherein in step (1) or step (1'), the polyisocyanate and the solvent are mixed homogeneously in a first mixer (M1) and then injected into the first tubular reactor (VR 1);

in the step (2), the prepolymer I and the catalyst are uniformly mixed in a second mixer (M2) and then injected into a second tubular reactor (VR 2); or in the step (2'), the prepolymer I, a hydrophilic chain extender, micromolecule dihydric alcohol and a catalyst are uniformly mixed in a second mixer (M2) and then injected into the second tubular reactor (VR 2);

in the step (3) or the step (3'), the prepolymer II and a solvent and/or an acrylate monomer are uniformly mixed in a third mixer (M3) and then injected into the third tubular reactor (VR 3);

in the step (4), the diluted prepolymer II, a hydrophilic chain extender and micromolecule diamine are uniformly mixed in a fourth mixer (M4) and then injected into the fourth tubular reactor (VR 4); or in the step (4'), the diluted prepolymer II and the neutralizer are uniformly mixed in a fourth mixer (M4) and then are injected into the fourth tubular reactor (VR 4);

in the step (5) or (5'), the aqueous polyurethane ionomer and deionized water are uniformly mixed in a fifth mixer (M5) and then injected into the fifth tubular reactor (VR 5).

11. The continuous production process according to claim 10, wherein the post-chain extension reaction step is: uniformly mixing the aqueous polyurethane coarse emulsion and a rear chain extender in a sixth mixer (M6), and injecting the mixture into a sixth tubular reactor (VR6) for rear chain extension reaction;

the polymerization reaction comprises the following steps: uniformly mixing the waterborne polyurethane coarse emulsion obtained by the post-chain extension reaction and an initiator in a seventh mixer (M7), and injecting the mixture into a seventh tubular reactor (VR7) for polymerization;

the catalyst is selected from dibutyltin dilaurate.

12. The continuous production process according to any one of claims 4 to 7, 9 and 11,

the polyisocyanate is aliphatic diisocyanate or aromatic diisocyanate;

the oligomer polyol is selected from one or more of polyester diol, polyether diol and polycarbonate diol;

the non-ionic hydrophilic compound is a hydrophilic polyether compound containing mono-functional group or bifunctional group capable of reacting with isocyanate;

the small molecular diol is selected from one or more of ethylene glycol, propylene glycol, butanediol, hexanediol, diethylene glycol, neopentyl glycol and cyclohexanedimethanol;

the micromolecular diamine is selected from one or more of isophorone diamine, butanediamine, ethylene diamine, 1, 6-hexamethylene diamine, piperazine, 1, 4-diaminocyclohexane, bis- (4-aminocyclohexyl) methane, adipic acid dihydrazide and hydrazine;

the hydrophilic chain extender is a dihydroxy compound containing hydrophilic groups, a diamino compound containing sulfonic acid or a diamino compound containing sulfonate;

the neutralizing agent is selected from one or more of ammonia, ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, 2-amino-2-methyl-1-propanol, morpholine, N-methylmorpholine, dimethylisopropylamine, N-methyldiethanolamine, triethylamine, dimethylcyclohexylamine, ethyldiisopropylamine, sodium hydroxide, potassium hydroxide, lithium hydroxide and calcium hydroxide;

the solvent is selected from butanone and/or acetone;

the acrylate monomer is a saturated acrylate monomer.

13. The continuous production process according to claim 12,

the polyisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexyl methane diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate;

the number average molecular weight of the polyester dihydric alcohol is 200-5000, and the polyester dihydric alcohol is selected from one or more of polybutylene adipate dihydric alcohol, neopentyl glycol adipate dihydric alcohol, polyhexamethylene adipate neopentyl glycol ester dihydric alcohol, polyethylene glycol adipate dihydric alcohol, polycaprolactone dihydric alcohol, polyhexamethylene phthalate dihydric alcohol and neopentyl glycol phthalate dihydric alcohol;

the number average molecular weight of the polyether diol is 200-5000, and the polyether diol is selected from one or more of polyoxypropylene diol, copolymerized diol of polyoxyethylene and polyoxypropylene and polytetrahydrofuran diol;

the polycarbonate diol has the number average molecular weight of 200-5000, and is prepared by carrying out ester exchange reaction on carbonic diester and diol ester;

the non-ionic hydrophilic compound is selected from compounds containing polyethoxy chain segments and the number of ethylene oxide in each molecule is 12-75, and the molar mass is 500-3000 g/mol;

the dihydroxy compound containing hydrophilic groups is selected from one or more of dimethylol propionic acid, dimethylol butyric acid, dimethylol acetic acid and dihydroxy succinic acid;

the diamino compound containing sulfonic acid or the diamino compound containing sulfonate is selected from one or more of N- (2-aminoethyl) -2-aminoethanesulfonic acid and alkali metal salts or ammonium salts thereof, N- (3-aminopropyl) -3-aminopropanesulfonic acid and alkali metal salts or ammonium salts thereof, and N- (2-aminoethyl) -3-aminopropanesulfonic acid and alkali metal salts or ammonium salts thereof;

the saturated acrylate monomer is selected from one or more of methyl methacrylate, butyl acrylate and ethyl acrylate.

14. The continuous production process according to any one of claims 4 to 7, 9, 11, 13,

the process conditions of the first tubular reactor (VR1) in step (1) or step (1') include: the reaction temperature is 60-140 ℃, the retention time is 0.2-6h, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the polyisocyanate to the oligomer polyol is 1: 15-1: 1;

the process conditions of the second tubular reactor (VR2) in step (2) or step (2') include: the reaction temperature is 60-140 ℃, the retention time is 0.2-6h, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the polyisocyanate to the nonionic hydrophilic compound is 10: 1-3: 1, or the mass ratio of the polyisocyanate to the hydrophilic chain extender is 10: 1-2: 1, and the mass ratio of the polyisocyanate to the micromolecular diol is 25: 1-2: 1;

the process conditions of the third tubular reactor (VR3) in step (3) or step (3') include: the reaction temperature is 20-60 ℃, the retention time is 5-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the prepolymer II to the solvent is 1: 0.25-1: 2, and the mass ratio of the prepolymer II to the acrylate monomer is 1: 0.5-1: 1.5;

the process conditions of the fourth tubular reactor (VR4) in step (4) or step (4') include: the reaction temperature is 20-60 ℃, the retention time is 5-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the prepolymer II to the hydrophilic chain extender is 100: 1-20: 1, and the mass ratio of the prepolymer II to the small-molecular diamine is 120: 1-12: 1; or the mass ratio of the prepolymer II to the neutralizer is 120: 1-20: 1;

the process conditions of the fifth tubular reactor (VR5) in step (5) or step (5') include: the reaction temperature is 5-30 ℃, the retention time is 5-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the waterborne polyurethane ionomer to the deionized water is 1: 0.4-1: 3.

15. The continuous production process according to any one of claims 4 to 7, 9, 11, 13,

the process conditions of the sixth tubular reactor (VR6) in the post-chain extension reaction step include: the reaction temperature is 10-40 ℃, the retention time is 2-30 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the aqueous polyurethane coarse emulsion to the rear chain extender is 500: 1-50: 1;

the process conditions of the seventh tubular reactor (VR7) in the polymerization step include: the reaction temperature is 10-100 ℃, the retention time is 2-60 minutes, and the reaction pressure is 0.1-1 Mpa; the mass ratio of the aqueous polyurethane crude emulsion obtained by the post-chain extension reaction to the initiator is 20000: 1-2000: 1.

16. Use of the continuous process according to any one of claims 4 to 15 in the production of aqueous polyurethane by the acetone method, in the production of aqueous polyurethane by the prepolymer method, in the preparation of aqueous polyurethane acrylate dispersions and in the preparation of photocurable aqueous polyurethane acrylate dispersions.