CN114478934B

CN114478934B - Polymer polyol preparation method and system thereof and obtained polymer polyol

Info

Publication number: CN114478934B
Application number: CN202011145713.9A
Authority: CN
Inventors: 杨正勇; 朱建海
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Filing date: 2020-10-23
Publication date: 2024-06-28
Anticipated expiration: 2040-10-23

Abstract

The invention discloses a preparation method and a system of polymer polyol and the obtained polymer polyol, wherein the preparation method comprises the following steps: and adding the reaction mixed solution into a reaction kettle through a reducing dripping nozzle for reaction, wherein the inner diameter of the dripping nozzle gradually becomes smaller along the flowing direction of the reaction mixed solution, and the reaction mixed solution comprises basic polyether polyol, an initiator, a chain transfer agent, an unsaturated monomer and a macromer. According to the invention, the continuous production process is optimized, the feed inlet entering the reaction system is improved, the material lifting flow rate entering the reaction kettle is quickly and fully mixed with the reaction material through the reducing drip nozzle, the blockage problem of the drip inlet of the reaction and the non-ideal reaction in the reaction process are reduced, and the solid content and the stability of the product are improved.

Description

Polymer polyol preparation method and system thereof and obtained polymer polyol

Technical Field

The invention belongs to the field of polymer polyol preparation, and particularly relates to a polymer polyol preparation method and system and an obtained polymer polyol.

Background

The polymer polyol is obtained by grafting vinyl monomers to a base polyether polyol by free radical in situ polymerization. Polymer polyols are mainly used for the production of polyurethane flexible foams. Polyurethane foam materials made from polymer polyols are largely divided into slabstock foam and molded foam. Polyurethane slabstock foam is used in carpets, furniture, and bedding. Polyurethane molded foams are used mainly in the automotive and aircraft industries. Polyurethanes prepared using polymer polyols can improve the properties, particularly hardness and load carrying capacity, of flexible polyurethane foams.

A problem commonly encountered in the manufacture of polymer polyols, i.e. systems in which the polymer is stably dispersed in the base polyol, is to obtain a polymer polyol having both a relatively high solid polymer content and a sufficiently low viscosity for easy handling. The production processes for polymer polyols are now generally batch, semi-batch and continuous processes. The polymer polyol produced by the semi-batch process has high monomer conversion rate, but has larger viscosity, especially has obvious viscosity increase in a formula with high styrene and high solid content, and influences the transportation and the use of the product. The continuous process is suitable for large-scale production of single polymer polyol, the product quality is stable, and the viscosity of the product is lower than that of the product prepared by the semi-continuous process under the same solid content.

The formula of the synthetic polymer polyol has more patents, but for the relatively few processes, such as patent CN101333288A, a polymer polyol single removal process is introduced, and a filling stripping tower is adopted to solve the problem of higher residual monomers; patent CN109705281A describes a process for improving the conversion rate by adding an initiator in series connection of three kettles, so that the monomer content in the product is further reduced; patent CN209405714U describes a polymer polyol purification system also for reducing the monomer content of the polymer polyol, whereas there are relatively few patents for the reaction process stages.

The continuous production process of the polymer polyol is early in development, but the continuous production process of the polymer polyol is rarely operated for a long period in the actual production process, because the conventionally used monomer styrene and acrylonitrile process schemes are not well controlled, non-ideal polymerization often occurs, the blocking phenomenon occurs, the actual solid content is lower, the blocking mainly occurs at the feed inlet of a reaction system, the junction of a high-temperature reaction material and a low-temperature mixed solution is arranged at the feed inlet of the reaction system, if the control is improper, the explosion polymerization of the monomer in the mixed solution occurs, so that a pipeline is blocked, the product is unstable, and even if the ideal reaction is not obtained more in normal production, the phenomena of lower actual solid content, poor stability and the like occur.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a preparation method of polymer polyol, in particular to a preparation method of polymer polyol, which optimizes the continuous production process, uses two or more reaction kettles with stirring, improves a feed inlet entering a first reaction kettle, enables the entering material to be fully mixed with the reaction material rapidly by lifting the flow rate through a reducing dropping nozzle (similar to a truncated cone shape or a wine bottle shape), reduces the blocking problem of the feed inlet of the reaction and the non-ideal reaction in the reaction process, and improves the solid content and the stability of products.

It is an object of the present invention to provide a process for producing a polymer polyol, comprising: the reaction mixed solution is introduced (or introduced) into the reaction kettle for reaction through a feed inlet, a dropping nozzle (in a round table shape or a wine bottle shape) with a variable diameter is arranged on the feed inlet, and the inner diameter of the dropping nozzle is gradually reduced along the flowing direction of the reaction mixed solution.

In a preferred embodiment, the ratio of the largest inner diameter to the smallest inner diameter of the drop nozzle is not less than 3, preferably not less than 5, more preferably not less than 8.

For example, the ratio of the maximum inner diameter to the minimum inner diameter of the dropping nozzle is 2 to 15, preferably 3 to 10. Wherein, the ratio of the maximum inner diameter to the minimum inner diameter of the dripping nozzle can also be called as the inlet-outlet aperture ratio of the dripping nozzle.

In a further preferred embodiment, the aspect ratio of the length of the dropping nozzle to its maximum inner diameter is 30 to 4, preferably 25 to 4, more preferably 24 to 8 (e.g., 10 to 20).

In a preferred embodiment, one end of the dropping nozzle is connected to the feed port, and the other end is connected to a transfer pump for injecting the reaction mixture into the feed port through the dropping nozzle, i.e., for transferring the reaction mixture.

In a further preferred embodiment, the feed inlet is arranged on the reaction vessel and/or on an external circulation pipeline of the reaction vessel, preferably on an external circulation pipeline of the reaction vessel.

In a preferred embodiment, the reaction mixture comprises a base polyether polyol, an initiator, a chain transfer agent, an unsaturated monomer, and a macromer.

In a further preferred embodiment, the temperature of the reaction mixture is controlled to 25 ℃ or less, preferably 20 ℃ or less, more preferably 16 ℃ or less, before entering the feed inlet.

In a preferred embodiment, the chain transfer agent is selected from at least one (or at least two) of benzene, toluene, ethylbenzene, xylene, hexane, isopropanol, n-butanol, 2-butanol, ethyl acetate, butyl acetate, and mercaptans.

In a further preferred embodiment, the chain transfer agent is used in an amount of 4 to 10% by weight based on the total weight of unsaturated monomer, macromer and base polyether polyol.

In a preferred embodiment, the unsaturated monomer is selected from at least one of aliphatic conjugated dienes, vinylidene aromatic monomers, ethylenically unsaturated nitriles, ethylenically unsaturated amides, vinyl esters.

Preferably, the aliphatic conjugated diene is selected from butadiene and/or isoprene; and/or the vinylidene aromatic monomer is selected from at least one of styrene, alpha-methyl styrene, (tertiary butyl) styrene chlorostyrene, cyanostyrene, and bromostyrene; and/or the ethylenically unsaturated nitrile is selected from methacrylonitrile, and the ethylenically unsaturated amide is selected from at least one of acrylamide, methacrylamide, N-dimethylacrylamide, N- (dimethylaminomethyl) acrylamide; and/or the vinyl ester is selected from at least one of ethyl acetate, vinyl ether, vinyl ketone, vinyl and vinylidene halide.

In a further preferred embodiment, the unsaturated monomer is selected from at least one of vinylidene aromatic monomers and ethylenically unsaturated nitriles.

In a still further preferred embodiment, the unsaturated monomer is selected from the group consisting of mixtures of styrene and acrylonitrile, wherein the mass ratio of styrene to acrylonitrile is from 2:3 to 4:1, preferably from 2:1 to 3:1.

In a preferred embodiment, the base polyether polyol is a polyether polyol obtained by ring-opening polymerization of an epoxy compound, having a number average molecular weight of 500 to 20000, preferably 2000 to 6000, and a hydroxyl functionality of 1 to 8, preferably 3 to 6.

In a further preferred embodiment, the ethylene oxide segment is present in the base polyether polyol in an amount of from 5 to 25% by weight.

In a still further preferred embodiment, the base polyether polyol is used in an amount of 40 to 80%, preferably 45 to 60% by weight based on the total weight of unsaturated monomer, macromer and base polyether polyol.

In a preferred embodiment, the initiator is selected from organic peroxides and/or fatty azo compounds.

In a further preferred embodiment, the initiator is selected from at least one of hydrogen peroxide, di-tert-butyl peroxide, tert-butyldiethyl acetate, tert-butyl peroctoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy, tert-butyl peroxypivalate, tert-amyl peroxypivalate, tert-butyl peroxy-2-ethylhexanoate, lauroyl peroxide, cumene hydroperoxide, azobisisobutyronitrile and dimethyl azobisisobutyrate, preferably from at least one of azobisisobutyronitrile, dimethyl azobisisobutyrate and tert-butyl peroxy-2-ethylhexanoate.

In a still further preferred embodiment, the initiator is used in an amount of 0.1 to 0.8%, preferably 0.2 to 0.5% by weight based on the total weight of unsaturated monomer, macromer and base polyether polyol.

In a preferred embodiment, the macromer is a modified polyether polyol containing unsaturated reactive bonds, preferably derived from the reaction of at least a trifunctional polyether polyol with an ethylenically unsaturated compound. Preferably, the ethylenically unsaturated compound is selected from at least one of an acid anhydride compound containing an unsaturated reaction bond, an acrylic acid ester compound, and an isocyanate compound containing an unsaturated reaction bond, more preferably from at least one of methyl methacrylate, ethyl methacrylate, maleic anhydride, 3-isopropenyl- α, α -dimethylbenzyl isocyanate, and hydroxyethyl methacrylate.

Where an anhydride compound having an unsaturated reactive bond (e.g., maleic anhydride) is used, it is also necessary to carry out the end-capping treatment with an epoxy compound (e.g., ethylene oxide).

In a further preferred embodiment, the macromer is used in an amount of 2 to 9%, preferably 3 to 8%, based on the total weight of unsaturated monomer, macromer and base polyether polyol.

In a preferred embodiment, the temperature of the reaction is above 90 ℃, preferably 95-130 ℃.

In a preferred embodiment, the residence time of the reaction mixture in the reaction vessel is greater than 20 minutes, preferably greater than 30 minutes (e.g., greater than 45 minutes), most preferably greater than 60 minutes.

The residence time is the volume of the reaction kettle divided by the dropping flow rate, so the dropping flow rate can be controlled according to the residence time.

In a preferred embodiment, the reaction is followed by a dealkylation treatment to obtain the polymer polyol.

In a further preferred embodiment, the unreacted monomers are removed using falling film evaporation or a flash tank, preferably a flash tank.

In a preferred embodiment, the polymer polyol obtained by the process has a solids content of 20 to 60% by weight.

In a further preferred embodiment, the polymer polyol obtained by the process comprises: 30ppm or less of an unsaturated monomer (preferably 10ppm or less of acrylonitrile and 20ppm or less of styrene) and 10ppm or less of a chain transfer agent.

The polymer polyol obtained by the method has higher solid content, long-period operation and good product dispersibility.

The second object of the present invention is to provide a polymer polyol obtained by the method according to one of the objects of the present invention.

The polymer polyol comprises: 30ppm or less of an unsaturated monomer (preferably 10ppm or less of acrylonitrile, 20ppm or less of styrene), and 10ppm or less of a chain transfer agent; and/or the polymer polyol has a solids content of 20 to 60wt%.

It is a further object of the present invention to provide a system for preparing a polymer polyol, preferably for carrying out the preparation method according to one of the objects of the present invention, wherein the system comprises a mixing subsystem, a reaction subsystem and a stripping subsystem connected in sequence, wherein a dropping nozzle (in the shape of a truncated cone or a wine bottle) with an inner diameter gradually decreasing is provided at a feed inlet (in a flow direction of a reaction mixture) of the reaction subsystem for adding the reaction mixture to the reaction subsystem.

In a preferred embodiment, the compounding subsystem includes a first compounding pot and a second compounding pot.

In a preferred embodiment, stirring means and cooling means (preferably serpentine cooling coils) are provided independently of each other in said first and second compounders.

Wherein the temperature of the reaction mixture is controlled to be less than or equal to 25 ℃, preferably less than or equal to 20 ℃, more preferably less than or equal to 16 ℃ by utilizing the serpentine cooling coil.

In a preferred embodiment, the reaction subsystem comprises two first and second reaction kettles in series.

In a further preferred embodiment, an external circulation line is provided on each reactor.

In a still further preferred embodiment, the dripping nozzle is disposed at a feed inlet of the first reaction kettle, preferably, the feed inlet is disposed on the first reaction kettle and/or on an external circulation pipeline of the first reaction kettle, and more preferably, on the external circulation pipeline of the first reaction kettle.

In the invention, the feeding port connected with the variable-diameter dropper is preferably arranged on the outer circulation pipeline of the first reaction kettle, so that the flow rate of the feeding reaction mixed solution is increased to form a high-speed injection state after passing through the nozzle, and a high-flow-rate cold material is obtained. The high-temperature material is circulated in the outer circulation pipeline, so that the sprayed high-flow-rate cold material is quickly taken away by the high-temperature material when contacting with the high-temperature material circulated in the outer circulation pipeline, and the problem of blockage of a feed inlet is effectively avoided.

In a preferred embodiment, the stripping subsystem is a falling film evaporator or flash tank for removing unreacted monomers.

In a further preferred embodiment, the aspect ratio of the length of the dropping nozzle to the maximum inner diameter thereof is 30 to 4, preferably 25 to 4, more preferably 24 to 8.

The endpoints of the ranges and any values disclosed in the present invention are not limited to the precise range or value, and the range or value should be understood to include values close to the range or value. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein. In the following, the individual technical solutions can in principle be combined with one another to give new technical solutions, which should also be regarded as specifically disclosed herein.

Compared with the prior art, the invention has the following beneficial effects: according to the invention, the continuous production process is optimized, the feed inlet entering the reaction kettle is improved, the material lifting flow rate entering the feed inlet is enabled to be fully mixed with the reaction material through the reducing dropping nozzle, the blocking problem of the reaction feed inlet and the non-ideal reaction in the reaction process are reduced, and the solid content and the stability of the product are improved.

Drawings

Fig. 1 shows a schematic diagram of the system according to the invention, wherein the external circulation line is not shown in fig. 1.

1: A blending subsystem; 1-1: a first mixing kettle; 1-2: a second compounding tank (feed tank);

2: a reaction subsystem; 2-1: a first reaction kettle; 2-2: a second reaction kettle;

3: a dripping nozzle; 4: a sheet stripping subsystem; 5: a polymer polyol product.

In fig. 1, a feed port is connected with a reaction subsystem (specifically, the feed port can be arranged on a reaction kettle therein and/or arranged on the external circulation pipeline), wherein all reaction mixed liquid (comprising basic polyether polyol, an initiator, a chain transfer agent, an unsaturated monomer and a macromer) is uniformly mixed in a first mixing kettle 1-1 with stirring and then transferred to a second mixing kettle (a feed tank) 1-2, the mixed solution is continuously conveyed into the reaction subsystem through the feed port of the reaction subsystem 2 by a feed pump from the second mixing kettle (the feed tank) 1-2, the feed port is connected with a reducing drip nozzle 3, materials in the first reaction kettle 2-1 in the reaction subsystem overflows into the second reaction kettle 2-2 through a pipeline, the pressure in the second reaction kettle enters a stripping subsystem 4 through an overflow regulating valve of an outlet, and a polymer polyol product 5 is obtained through the removal of the monomer.

FIG. 2 shows a schematic structural view when fed in an external circulation line of the first reaction tank;

2-11: an outer circulation pipeline of the first reaction kettle; 2-12: an external circulation pump; 3: a dripping nozzle; 6-a feed inlet; 7-reaction mixture.

Fig. 3 shows a schematic flow of material using the system of fig. 2.

7-Reaction mixture (high pressure fluid); 8-fluid ejected by a reducing dropper; 9-low pressure fluid.

When the feed inlet connected with the reducing nozzle is arranged in the external circulation pipeline of the first reaction kettle, the flow speed of the feed reaction mixed liquid 7 rises after passing through the nozzle, and a high-speed injection state (namely 8 in fig. 3) appears at a contact point, so that the feed reaction mixed liquid is a high-flow-speed cold material. The outer circulation pipeline circulates flowing high-temperature materials (low-pressure fluid), so that when the sprayed high-flow-rate cold materials contact the high-temperature materials flowing in the outer circulation pipeline, the high-flow-rate cold materials are quickly taken away by the flowing high-temperature materials, and the problem of blockage of a feed inlet is effectively avoided.

The system has higher solid content and better product stability for synthesizing high solid content polymer polyol, and can realize long-period operation.

Detailed Description

The invention is described in detail below with reference to the drawings and the specific embodiments, it is necessary to point out that the following embodiments are only for further description of the invention and are not to be construed as limiting the scope of the invention, and some insubstantial modifications and adaptations of the invention by those skilled in the art based on the present disclosure remain within the scope of the invention.

In addition, the specific features described in the following embodiments may be combined in any suitable manner without contradiction. The various possible combinations of the invention are not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention can be made, so long as the concept of the present invention is not deviated, and the technical solution formed thereby is a part of the original disclosure of the present specification, and also falls within the protection scope of the present invention.

The raw materials used in examples and comparative examples, if not particularly limited, are all as disclosed in the prior art, and are, for example, available directly or prepared according to the preparation methods disclosed in the prior art.

The main raw materials are as follows:

acrylonitrile: an industrial grade;

Styrene: an industrial grade;

isopropyl alcohol: an industrial grade;

Azobisisobutyronitrile: an industrial grade;

Base polyether polyol: the trifunctional polyether polyol has a number average molecular weight of 3000, a hydroxyl value of 56mgKOH/g and an ethylene oxide content of 8.1%, and mainly contains secondary hydroxyl group end caps, GEP-560S.

Macromer M-356: 1mol of polyether polyol C and 1mol of maleic anhydride are subjected to esterification reaction at 100-130 ℃ for 2 hours, then are reacted with 3mol of ethylene oxide, the reaction temperature is 100-130 ℃ and the reaction time is 5 hours, so that polyether ester containing unsaturated double bonds, namely a macromolecular monomer M-356, is obtained, the unsaturation degree is 0.050meq/g, and the hydroxyl value is 33.5mgKOH/g;

radical initiator: dimethyl azodiisobutyrate, V601.

[ Example 1]

A process for continuously preparing a polymer polyol using the system shown in fig. 1 (using the feed arrangement of fig. 2):

1. 31 parts of styrene, 13 parts of acrylonitrile, 3 parts of macromer, 3 parts of isopropanol, 49.7 parts of basic polyether polyol and 0.3 part of dimethyl azodiisobutyrate are uniformly mixed in a first mixing kettle, and the temperature of the mixed solution is reduced to below 16 ℃ through a serpentine cooling coil.

2. And (3) transferring the reaction mixed solution into a second mixing kettle for standby, and introducing cooling solution into a serpentine cooling coil pipe of the second mixing kettle to keep the temperature of the second mixing kettle below 16 ℃.

3. And (3) pumping the reaction mixed liquid from the second mixing kettle by using a conveying pump, conveying the reaction mixed liquid into the reaction kettle, and controlling the flow rate through frequency conversion of the pump. The reaction kettle comprises a first reaction kettle and a second reaction kettle, and a feed inlet is arranged on an outer circulation pipeline of the first reaction kettle.

4. Before entering the feed inlet, the caliber of the outlet end is controlled by a reducing dripping nozzle, the caliber of the discharge outlet is 3 times smaller than that of the feed inlet (the caliber ratio of the inlet to the outlet of the dripping nozzle is 3) by using tetrafluoro material in the dripping nozzle, and the reaction mixed solution enters the first reaction kettle from the external circulation pipeline through the dripping nozzle.

5. The residence time in the first reactor was controlled to 60min by adjusting the flow.

6. The temperature in the first reaction kettle is controlled at 120 ℃, and the reaction pressure is 0.4MPa.

7. The reaction materials in the first reaction kettle overflow to the second reaction kettle through a pipeline, the reaction is continued in the second reaction kettle, the reaction temperature is controlled at 120 ℃, and the pressure of the reaction system is controlled at 0.4MPa through a regulating valve at the outlet of the second reaction kettle.

8. The reaction material of the second reaction vessel overflowed to a flash tank to remove unreacted monomers, and pure polymer polyol was obtained, and the product performance is shown in table 1.

[ Example 2]

1. 21 parts of styrene, 8 parts of acrylonitrile, 3 parts of macromer, 3 parts of isopropanol, 64.7 parts of basic polyether polyol and 0.3 part of dimethyl azodiisobutyrate are uniformly mixed in a first mixing kettle, and the temperature of the mixed solution is reduced to below 16 ℃ through a serpentine cooling coil.

2. And (3) transferring the mixed solution into a second mixing kettle for standby, and introducing cooling liquid into a serpentine cooling coil pipe of the second mixing kettle to keep the temperature of the second mixing kettle below 16 ℃.

5. The residence time in the first reactor was controlled to 45min by adjusting the flow rate.

[ Example 3]

4. Before entering the feed inlet, the caliber of the outlet end is controlled by a reducing dripping nozzle, the caliber of the discharge outlet is reduced by 5 times compared with that of the feed inlet (the caliber ratio of the inlet to the outlet of the dripping nozzle is 5) by using a tetrafluoro material to prepare the dripping nozzle, and the reaction mixed solution enters the first reaction kettle from the external circulation pipeline through the dripping nozzle.

5. The residence time in the first reactor was controlled to 60min by adjusting the flow rate.

[ Example 4]

4. Before entering the feed inlet, the caliber of the outlet end is controlled by a reducing dripping nozzle, the caliber of the discharge outlet is reduced by 8 times compared with that of the feed inlet (the caliber ratio of the inlet to the outlet of the dripping nozzle is 8) by using a tetrafluoro material to prepare the dripping nozzle, and the reaction mixed solution enters the first reaction kettle from the external circulation pipeline through the dripping nozzle.

[ Example 5]

4. Before entering the feed inlet, the caliber of the outlet end is controlled by a reducing dripping nozzle, the caliber of the discharge outlet is reduced by 10 times compared with that of the feed inlet (the caliber ratio of the inlet to the outlet of the dripping nozzle is 10) by using tetrafluoro material in the dripping nozzle, and the reaction mixed solution enters the first reaction kettle from the external circulation pipeline through the dripping nozzle.

[ Example 6]

A method for continuously preparing a polymer polyol using the system shown in fig. 1 (self-tapping into a kettle):

4. Before entering the feeding hole, the caliber of the outlet end is controlled by a reducing dripping nozzle, the caliber of the discharging hole is 3 times smaller than that of the feeding hole (the caliber ratio of the inlet to the outlet of the dripping nozzle is 3) by using tetrafluoro material to prepare the material in the dripping nozzle, and the reaction mixed solution enters the first reaction kettle through the dripping nozzle.

Comparative example 1

A method for continuously preparing a polymer polyol using the system shown in fig. 1:

4. Before entering the feed inlet, the caliber of the outlet end is controlled by a reducing dripping nozzle, the caliber of the discharge outlet is reduced by 15 times compared with that of the feed inlet (the caliber ratio of the inlet to the outlet of the dripping nozzle is 15) by using a tetrafluoro material to prepare the dripping nozzle, and the reaction mixed solution enters the first reaction kettle from the external circulation pipeline through the dripping nozzle.

5. The residence time in the first reactor was controlled to 30min by adjusting the flow rate.

Wherein too high a feed pressure of comparative example 1 resulted in experimental failure.

Comparative example 2

2. And (3) transferring the reaction mixed solution into a second mixing kettle for standby, and feeding cooling solution into a serpentine cooling coil of the second mixing kettle to keep the temperature of the second mixing kettle below 16 ℃.

4. Before entering the feed inlet, the reaction mixed liquid directly enters the first reaction kettle through the feed inlet arranged on the outer circulation pipeline by not arranging a dripping nozzle.

8. The reaction material of the second reaction vessel overflowed to a flash tank to remove unreacted monomers, and pure polymer polyol was obtained, and the product performance is shown in table 2.

[ Comparative example 3]

4. Before entering the first reaction kettle, the reaction mixed solution directly enters the first reaction kettle through a feed inlet arranged on the first reaction kettle by not arranging a dripping nozzle.

Table 1:

in Table 1, the in-out caliber ratio refers to the ratio of the maximum inner diameter to the minimum inner diameter of the dropping nozzle; the length-diameter ratio refers to the length-diameter ratio of the dripping nozzle and the maximum inner diameter of the dripping nozzle.

Table 2:

The invention has been described in detail in connection with the specific embodiments and exemplary examples thereof, but such description is not to be construed as limiting the invention. It will be understood by those skilled in the art that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, and these fall within the scope of the present invention. The scope of the invention is defined by the appended claims.

Claims

1. A method of preparing a polymer polyol comprising: introducing the reaction mixed solution into a reaction kettle through a feed inlet for reaction, wherein the feed inlet is arranged on an outer circulation pipeline of the reaction kettle, a reducing dripping nozzle is arranged on the feed inlet, and the inner diameter of the dripping nozzle gradually becomes smaller along the flowing direction of the reaction mixed solution; before the reaction mixed solution enters the feed inlet, controlling the temperature of the reaction mixed solution to be less than or equal to 20 ℃;

the ratio of the maximum inner diameter to the minimum inner diameter of the dripping nozzle is more than or equal to 3; the length-diameter ratio of the length of the dripping nozzle to the maximum inner diameter of the dripping nozzle is 30-4.

2. The method according to claim 1, wherein,

The ratio of the maximum inner diameter to the minimum inner diameter of the dripping nozzle is more than or equal to 5.

3. The method according to claim 1, wherein,

The length-diameter ratio of the length of the dripping nozzle to the maximum inner diameter of the dripping nozzle is 25-4.

4. The method according to claim 1, wherein,

One end of the dropping nozzle is connected with the feeding hole, the other end of the dropping nozzle is connected with the delivery pump, and the delivery pump is used for delivering the reaction mixed solution.

5. The method of claim 1, wherein the reaction mixture comprises a base polyether polyol, an initiator, a chain transfer agent, an unsaturated monomer, and a macromer.

6. The method according to claim 5, wherein the chain transfer agent is at least one selected from the group consisting of benzene, toluene, ethylbenzene, xylene, hexane, isopropyl alcohol, n-butanol, 2-butanol, ethyl acetate, butyl acetate and mercaptans.

7. The process according to claim 6, wherein the chain transfer agent is used in an amount of 4 to 10% by weight based on the total weight of the unsaturated monomer, the macromer and the base polyether polyol.

8. The method according to claim 5, wherein the unsaturated monomer is at least one selected from the group consisting of aliphatic conjugated dienes, vinylidene aromatic monomers, ethylenically unsaturated nitriles, ethylenically unsaturated amides and vinyl esters.

9. The method according to claim 8, wherein the unsaturated monomer is at least one selected from the group consisting of vinylidene aromatic monomers and ethylenically unsaturated nitriles.

10. The method of claim 8, wherein the unsaturated monomer is selected from the group consisting of a mixture of styrene and acrylonitrile.

11. The method according to claim 5, wherein the base polyether polyol is a polyether polyol obtained by ring-opening polymerization of an epoxy compound, and has a number average molecular weight of 500 to 20000 and a hydroxyl functionality of 1 to 8.

12. The process according to claim 11, wherein the ethylene oxide content by weight in the base polyether polyol is 5 to 25%.

13. The method of claim 11, wherein the base polyether polyol is used in an amount of 40 to 80% by weight based on the total weight of the unsaturated monomer, the macromer and the base polyether polyol.

14. The method according to claim 5, wherein the initiator is selected from organic peroxides and/or fatty azo compounds.

15. The method according to claim 14, wherein the initiator is at least one selected from the group consisting of hydrogen peroxide, di-t-butyl peroxide, t-butyl diethyl acetate, t-butyl peroctoate, t-butyl peroxyisobutyrate, t-butyl peroxide, t-butyl peroxypivalate, t-amyl peroxypivalate, t-butyl peroxy-2-ethylhexanoate, lauroyl peroxide, cumene hydroperoxide, azobisisobutyronitrile and dimethyl azobisisobutyrate.

16. The method according to claim 14, wherein the initiator is at least one selected from the group consisting of azobisisobutyronitrile, dimethyl azobisisobutyrate and t-butyl peroxy-2-ethylhexanoate.

17. The method of claim 14, wherein the initiator is used in an amount of 0.1 to 0.8% based on the total weight of the unsaturated monomer, the macromer and the base polyether polyol.

18. The method of claim 17, wherein the initiator is used in an amount of 0.2 to 0.5% based on the total weight of the unsaturated monomer, the macromer and the base polyether polyol.

19. The method according to claim 5, wherein the macromer is a modified polyether polyol having an unsaturated reactive bond.

20. The method of claim 19, wherein the macromer is derived from reacting at least a trifunctional polyether polyol with an ethylenically unsaturated compound.

21. The method of claim 20, wherein the ethylenically unsaturated compound is selected from at least one of methyl methacrylate, ethyl methacrylate, maleic anhydride, 3-isopropenyl- α, α -dimethylbenzyl isocyanate, and hydroxyethyl methacrylate.

22. The method of claim 19, wherein the macromer is present in an amount of 2 to 9% by weight based on the total weight of the unsaturated monomer, macromer, and base polyether polyol.

23. The method of claim 22, wherein the macromer is present in an amount of 3 to 8% by weight based on the total weight of the unsaturated monomer, macromer, and base polyether polyol.

24. The method according to any one of claims 1 to 23, wherein,

The temperature of the reaction is above 90 ℃; and/or

The residence time of the reaction mixture in the reaction kettle is more than 20 minutes.

25. The method of claim 24, wherein the process comprises,

The temperature of the reaction is 95-130 ℃; and/or

The residence time of the reaction mixture in the reaction kettle is more than 30 minutes.

26. The method of claim 24, wherein the polymer polyol is obtained by performing a dealkylation treatment after the reaction.

27. The process of claim 26 wherein unreacted monomers are removed using falling film evaporation or flash tanks.

28. Polymer polyol obtained by the production process according to any one of claims 1 to 27,

The method comprises the following steps: less than 30ppm of unsaturated monomer, less than 10ppm of chain transfer agent; and/or

Wherein the solids content is 20-60wt%.

29. A system for carrying out the preparation method according to any one of claims 1 to 27, wherein the system comprises a mixing subsystem, a reaction subsystem and a sub-subsystem which are sequentially connected, wherein a dripping nozzle with gradually smaller inner diameter is arranged at a feed inlet of the reaction subsystem and is used for adding a reaction mixed solution into the reaction subsystem; the mixing subsystem comprises a first mixing kettle and a second mixing kettle, wherein a stirring device and a cooling device are respectively and independently arranged in the first mixing kettle and the second mixing kettle; the reaction subsystem comprises two first reaction kettles and two second reaction kettles which are connected in series, an external circulation pipeline is arranged on each reaction kettle, the dripping nozzle is arranged at a feed inlet of the first reaction kettle, and the feed inlet is arranged on the external circulation pipeline of the first reaction kettle; the ratio of the maximum inner diameter to the minimum inner diameter of the dripping nozzle is more than or equal to 3; the length-diameter ratio of the length of the dripping nozzle to the maximum inner diameter of the dripping nozzle is 30-4.

30. The system of claim 29, wherein the system further comprises a controller configured to,

The stripping subsystem is a falling film evaporator or a flash tank and is used for removing unreacted monomers.

31. The system of claim 29, wherein the system further comprises a controller configured to,

The ratio of the maximum inner diameter to the minimum inner diameter of the dripping nozzle is more than or equal to 5; and/or