CN110511163A

CN110511163A - Photochemical reaction prepares the method for polyisocyanates and prepares the method for waterborne polyurethane resin

Info

Publication number: CN110511163A
Application number: CN201910822858.9A
Authority: CN
Inventors: 俞勇; 尚永华; 李建峰; 郭耀允; 王腾飞; 李文滨; 孙烨; 王峤; 刘德刚; 黎源
Original assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd
Priority date: 2019-09-02
Filing date: 2019-09-02
Publication date: 2019-11-29
Anticipated expiration: 2039-09-02
Also published as: CN110511163B

Abstract

The invention belongs to the technical fields of waterborne polyurethane resin, more particularly to a kind of photochemical reaction prepares the method for polyisocyanates and prepares the method for waterborne polyurethane resin, the method for preparing waterborne polyurethane resin includes the following steps: that waterborne polyurethane resin will be obtained comprising the raw material progress polymerization reaction of polyisocyanates, oligomer polyol, chain extender and hydrophilic agent；Wherein, content≤0.045wt% of the Benzophenone class impurity in the polyisocyanates.The present invention can be effectively improved the anti-yellowing property of product, be also reduced due to leading to the underproof harm of downstream product there are this kind of impurity in product by the content of Benzophenone class impurity in control polyisocyanates preparation process.

Description

Photochemical reaction prepares the method for polyisocyanates and prepares waterborne polyurethane resin Method

Technical field

The invention belongs to the technical fields of waterborne polyurethane resin more particularly to a kind of photochemical reaction to prepare polyisocyanates Method and the method for preparing waterborne polyurethane resin.

Background technique

Polyurethane is outstanding one of the synthetic resin of comprehensive performance.Due to its synthon is wide in variety, reaction condition is mild, It is single-minded, controllable, and be formulated that adjustment leeway is big and its microstructure feature of high molecular material, can be widely used for coating, binder, Foamed plastics, synthetic fibers and elastomer, it has also become one of essential material of people's food, clothing, housing and transportation；Moreover, its Body has just formd the material family of a multi items, multi-series, forms complete polyurethane industrial system, this is other Not available for resin.

With the reinforcement of people's environmental consciousness and environmental regulation, the research of environment-friendly type aqueous polyurethane, exploitation day Benefit is taken seriously, and application is constantly expanded to the fields such as coating, binder by leather finishing agent, gradually captures solvent type The market of polyurethane.In water-base resin, aqueous polyurethane is still the representative of outstanding resin, is that modern water-base resin is studied One of hot spot.

It is studied according to researcher in this field, the chlorinity in polyisocyanates will affect the resistance to of waterborne polyurethane resin Xanthochromia performance, in some instances it may even be possible to directly result in the jaundice of waterborne polyurethane resin, while it is living to the reaction of sectional interest to be possible to meeting Property has adverse effect on.Therefore, it has to be controlled the chlorinity in polyisocyanates in this field.

Polyisocyanates is caused the higher reason of chlorinity occur and have much to need to avoid using different methods.Specially Sharp file US 5364958 disclose it is a kind of prepare Isocyanate method, with hot HCl gas to removing phosgene after reaction solution into Row heat treatment, to achieve the purpose that reduce product color number.Patent document EP 0581100 is it is also proposed that a kind of prepare light isocyanic acid The method of ester is added thereto chemical reducing agent that is, after phosgenation and before removal solvent, obtains light-coloured prods.Patent document CN00809301.6 provides a kind of method by bromide in control phosgene, iodide content and realizes isocyanates having light color Preparation.Patent document EP 0561225 also discloses a kind of method for preparing isocyanates having light color, wherein in the light of corresponding amine After gasification resulting isocyanates under the pressure of 1-150bar and 100-180 DEG C at a temperature of carry out hydrogenation treatment, obtain Isocyanates having light color product.Patent document EP 0546398 and EP 0446781 is reached by being pre-processed to raw material amine Reduce the purpose of the color number of isocyanates made from phosgenation reaction.The method that the former provides is before amine carries out phosgenation to it Acidification, the method that the latter provides are pre-processed with hydrogen to it before amine carries out phosgenation, and acidified or hydrogen is located in advance Amine after reason is reacted with phosgene again, finally obtains the isocyanates of light color.

Above prior art preparation polyisocyanates, although referring to many reduction isocyanates colorations and chlorinity Method, but fail clearly be which kind of impurity result in polyisocyanates chlorinity is higher or yellowish, this gives Certain uncertainty is brought in actual application.If can clearly cause polyisocyanates jaundice or chlorinity inclined On the basis of high specific dopant species, the concrete scheme solved the problems, such as is proposed, to realize the low color number of polyisocyanates, low chlorine The purpose of content, it will there are more directive significances to light polyisocyanates is prepared.

Summary of the invention

The method of polyisocyanates is prepared the object of the present invention is to provide a kind of phosgenation reaction and is prepared aqueous poly- The method of urethane resin prepares the content of Benzophenone class impurity during polyisocyanates by controlling light phosgenation, can be effective Ground improves the anti-yellowing property of product, also reduces due to leading to the underproof danger of downstream product there are this kind of impurity in product Evil.

To achieve the goals above, technical scheme is as follows:

In one aspect of the invention, a kind of method that phosgenation reaction prepares polyisocyanates is provided, including is walked as follows It is rapid: polyamines and excessive phosgene being subjected to phosgenation reaction, the crude product containing polyisocyanates is obtained, then to the thick production Object is post-processed, and the polyisocyanates is obtained；The method uses molten during preparing the polyisocyanates Agent includes that aromatic solvent (for example, in a step of the method or multiple steps, has used aromatic solvent；Fragrance The use of race's solvent can be in the stage of reaction, be also possible in post-processing stages),

In the polyisocyanates Benzophenone class impurity content≤0.045wt% (for example,≤0.04wt% ,≤ 0.03wt% ,≤0.02wt%), preferably≤0.035wt%, more preferably≤0.025wt%.

The method provided according to the present invention, it is preferable that in described the step of being in contact there are aromatic solvent and phosgene, Its process conditions is controlled to limit the content of Benzophenone class impurity in the polyisocyanates；The process conditions packet of control It includes: Contact Temperature≤180 DEG C of control aromatic solvent and phosgene,

(1) when the Contact Temperature of aromatic solvent and phosgene is 165 DEG C -180 DEG C, control contact duration≤2h, preferably ≤1h；(2) when the Contact Temperature of aromatic solvent and phosgene is 150 DEG C -165 DEG C, control contact duration≤4h, preferably≤ 2h；(3) when the Contact Temperature of aromatic solvent and phosgene is less than 150 DEG C, time of contact is unrestricted；

And when the Contact Temperature of aromatic solvent and phosgene is 150 DEG C -180 DEG C, control contacts total duration≤4h, excellent Choosing≤2h.

In the present invention, " when the Contact Temperature of aromatic solvent and phosgene is less than 150 DEG C, time of contact is unrestricted " is Refer to, since the generation of Benzophenone class impurity when the Contact Temperature of aromatic solvent and phosgene is less than 150 DEG C is very slow, Er Qiezhuan Change that rate is lower, the Benzophenone class impurity of generation is also not enough to cause the Benzophenone class impurity content in final polyisocyanate product More than defined range；The time of contact of phosgene and aromatic solvent when therefore, to less than 150 DEG C is not limited.

In some instances, the method that phosgenation reaction prepares polyisocyanates specifically comprises the following steps:

A) polyamines and excessive phosgene are subjected to phosgenation reaction, during preparing the polyisocyanates (for example, Including the stage of reaction and/or post-processing stages) solvent that uses includes aromatic solvent, it obtains containing aromatic solvent, polyisocyanate The crude product of cyanate and phosgene；Reaction end gas (predominantly phosgene, hydrogen chloride, a small amount of aromatic solvent and minimal amount of mesh Mark product) absorbed with aromatic solvent after obtain the aromatic solvent containing phosgene；

B) crude product for obtaining step a) carries out the processing of removing phosgene and aromatic solvent, isolated polyisocyanic acid Ester crude product and aromatic solvent containing phosgene；

C) by the aromatic solvent containing phosgene obtained by step a) and step b) phosgene and aromatic solvent separate, The phosgene and aromatic solvent isolated, which return in step a), to be recycled；

D) the polyisocyanates crude product for not containing phosgene obtained in step b) is refined, obtains the polyisocyanic acid Ester；

The technique for the step of (for example, in above-mentioned steps a)~step c)) control is in contact there are aromatic solvent and phosgene Condition so that in the polyisocyanates Benzophenone class impurity content≤0.045wt% (for example,≤0.04wt% ,≤ 0.03wt% ,≤0.02wt%), preferably≤0.035wt%, more preferably≤0.025wt%.

In some embodiments, step a) may also include that during post-processing to crude product using fragrance Race's solvent, for example, carrying out cooling absorption using the gaseous state crude product that aromatic solvent generates reaction in gas phase phosgenation reaction Processing.

The routine operation for being absorbed as this field of reaction end gas.In some embodiments, the reaction tail of step a) The specific absorption pattern that gas is absorbed with aromatic solvent can be operated by the way of absorption tower, used in tail gas absorption Aromatic solvent can be consistent with aromatic solvent used in reaction process.Aromatic solvent used in tail gas absorption into Entering can be used refrigerant before absorption tower and is cooled down, and recommend cooling temperature higher than the freezing point temperature of used aromatic solvent 2-20℃.Tail gas can also be cooled down before reaction end gas enters absorption tower, and be contained after absorption tower absorption processing The aromatic solvent of phosgene；It can also be directly entered tail gas absorber without cooling, it is molten to finally obtain the aromatic series containing phosgene Agent.

Phosgene is carried out to gained crude product and aromatic solvent subtractive process is the routine operation of this field.Some specific In embodiment, gained crude product is carried out the process that phosgene and aromatic solvent remove by step b), can use Chinese patent Apply for method disclosed in CN107652208A；It is preferred that at 50-180 DEG C, more preferably 60-150 DEG C, absolute pressure 0.01- It is removed under 0.1MPa.For example, the material containing phosgene, which can choose, to be more than or equal to 150 DEG C and is being less than in entire subtractive process Under conditions of equal to 180 DEG C and residence time≤1h.

The process separated to phosgene and aromatic solvent is the routine operation of this field.In some specific embodiments In, step c) by the aromatic solvent containing phosgene phosgene and the process that separates of aromatic solvent use the side of rectifying column Formula, tower top obtain the phosgene of purity >=97%, and tower reactor obtains the aromatic solvent of phosgene content≤0.01%, and using the two as Raw material returns in the system of step a) (recycling).Pressure in separation process is absolute pressure 0.01-0.2MPa, tower reactor Temperature is 50-180 DEG C, and preferably 60-150 DEG C, tower top temperature is 0-50 DEG C, preferably 5-30 DEG C.

The process refined to polyisocyanates crude product is the routine operation of this field.In some specific embodiments In, this field public affairs can be used without containing the process that the polyisocyanates crude product of phosgene refines in gained in step b) by step d) Know that technology removes the small molecules such as solvent, monomer in each step；It is, for example, possible to use the modes such as rectifying, distillation, crystallization carry out it is pure Change and refines.

A small amount of chlorine is inevitably had for light phosgenation prepares the technique of isocyanates, in the final products of acquisition to deposit In.On the one hand remaining chlorine will lead to the jaundice of isocyanate-monomer itself；On the other hand, depositing due to these impurity containing chlorine Leading to the big ups and downs of reaction during downstream application, it could even be possible to will lead to downstream product (for example, water-base resin) It is unqualified.For this reason, it may be necessary to control the chlorinity in isocyanate products.

However, light phosgenation is prepared in the technique of isocyanates, it is many to lead to exist the miscellaneous qualitative factor of chlorine, remaining chlorine Source and type also can be very much.In the common process of this field, usually use the separation means for disregarding cost (as repeatedly Rectifying etc.) dechlorination, although being also able to achieve the reduction of chlorinity and color number, being also constantly present certain chlorine can not be removed, this master If since its boiling point and polyisocyanates are caused by.It is found by present inventor after further studying, contains chlorine A part of source of the benzophenone impurity as residual chlorine in product, by controlling such impurity content in certain model Enclose, for example, content≤0.045wt% of Benzophenone class impurity, may be implemented chlorinity in polyisocyanate product≤ 0.02% or even chlorinity≤0.01%, and then promote the anti-yellowing property of polyisocyanate product and downstream product.

Inventor has found that during light phosgenation prepares polyisocyanates, if made in preparation process Solvent is aromatic solvent (for example, phenyl ring class solvent), then solvent can react at the time of contact and generate with phosgene Benzophenone substance containing chlorine causes to generate impurity in final polyisocyanate product.And the benzophenone substance containing chlorine As a part of source of residual chlorine in polyisocyanic acid ester products, the control of yield just seems critically important.By preventing or dropping The probability or yield that benzophenone substance in low polyisocyanates preparation process containing chlorine generates, can effectively promote polyisocyanate cyanogen The yellowing resistance of acid esters product.

In some examples, in the step of there are aromatic solvent and phosgene contact, the phosgene and aromatic solvent are connect Touching can occur to react as follows:

The aromatic solvent can be indicated by chemical structural formula shown in formula (II), it may be assumed that

Wherein, the R in formula (II) is selected from H, Cl or CH₃。

The impurity of benzophenone of the gained containing chlorine, can be indicated by chemical structural formula shown in formula (I) after reaction, That is:

Wherein, the R in formula (I) is selected from H, Cl or CH₃。

By applicant's the study found that temperature reaches 150 DEG C in the step of contacting there are aromatic solvent and phosgene Or more under conditions of can react and generate Benzophenone class impurity.Due to the Benzophenone class impurity and polyisocyanates of generation Relatively, conventional rectifying means cannot achieve the separation of the two to boiling point.It is efficiently separated to realize, it is necessary to a large amount of Separation equipment and investment, and a large amount of product can be brought to lose.Therefore, if the generation stage in such impurity controls it System can avoid impurity effect properties of product.

By the applicant's further study show that, when the Contact Temperature of aromatic solvent and phosgene is at 165 DEG C -180 Between DEG C and when duration≤1h of control contact, the content of Benzophenone class impurity in finally obtained polyisocyanates≤ 0.035wt%；When the Contact Temperature of aromatic solvent and phosgene is between 165 DEG C -180 DEG C and the when a length of 1- of control contact When 2h, the content of Benzophenone class impurity is 0.025-0.045wt% in finally obtained polyisocyanates；When aromatic solvent and The Contact Temperature of phosgene is between 165 DEG C -180 DEG C and when the duration > 2h of contact, benzene first in finally obtained polyisocyanates The content of ketone impurity can be in 0.045wt% or more.When the Contact Temperature of aromatic solvent and phosgene 150 DEG C -165 DEG C it Between and when duration≤2h of control contact, in finally obtained polyisocyanates the content of Benzophenone class impurity be≤ 0.025wt%；When the Contact Temperature of aromatic solvent and phosgene is between 150 DEG C -165 DEG C and the when a length of 2- of control contact When 4h, the content of Benzophenone class impurity is 0.035-0.045wt% in finally obtained polyisocyanates；As the duration > of contact When 4h, the content 0.045wt% or more of the Benzophenone class impurity in finally obtained polyisocyanates.

When the Contact Temperature of aromatic solvent and phosgene is less than 150 DEG C, the generation of Benzophenone class impurity is very slow, and And conversion ratio is lower, the Benzophenone class impurity of generation is also not enough to cause the Benzophenone class impurity in final polyisocyanate product Content is more than defined range；Therefore, time of contact is unrestricted.

When 180 DEG C of Contact Temperature > of aromatic solvent and phosgene, although can be conducive to generate Benzophenone class impurity, If the contact duration of the two is extremely short (such as≤60s, preferably≤30s), the Benzophenone class impurity generated in the short time is also not enough to lead Causing the Benzophenone class impurity content in final polyisocyanate product is more than defined range.

Therefore, in phosgenation reaction system, Contact Temperature≤180 DEG C of aromatic solvent and phosgene are preferably controlled, it is excellent ≤ 165 DEG C of choosing, more preferably≤150 DEG C.Wherein, when the Contact Temperature of aromatic solvent and phosgene is at 165 DEG C -180 DEG C, control Contact duration≤2h；When the Contact Temperature of aromatic solvent and phosgene is at 150 DEG C -165 DEG C, control contact duration≤4h；When When the Contact Temperature of aromatic solvent and phosgene is less than 150 DEG C, time of contact is unrestricted；Also, work as aromatic solvent and light The Contact Temperature of gas is at 150 DEG C -180 DEG C, control contact total duration≤4h, preferably≤2h.When aromatic solvent and phosgene At 180 DEG C of Contact Temperature >, control contact duration≤60s, preferably≤30s.Under such control process conditions, can effectively it prevent Or reduce the probability that Benzophenone substance generates, that is, it can effectively reduce the benzophenone impurity in polyisocyanates product containing chlorine Content.

In the present invention, " contact duration " refers to that aromatic solvent and phosgene are being set in specific temperature point or temperature range Residence time in standby and/or pipeline:

(1) if this method is batch process, contact duration (t) is the stop in specific temperature point or temperature range Time；

(2) if this method is continuous process, contact duration (t) is the equipment in specific temperature point or temperature range And/or the volume flow of the stream stock comprising phosgene and aromatic solvent in the effective volume (V) of pipeline and equipment and/or pipeline The ratio between (Q), calculation formula are as follows:

T=V/ (Q), wherein Q=Q1+Q2+Q3.

The volume flow of aromatic solvent containing phosgene in the stream stock of aromatic solvent and/or absorption phosgene of the Q1- containing phosgene Amount；

The volume flow of Q2- polyamines and/or polyamines salt；

The volume flow of Q3- isocyanates.

In the present invention, " contact total duration " refers to control in each specific temperature point or each specific range of temperatures Total adduction duration of " contact duration ".

Phosgenation reaction of the invention can be carried out using technology category known in the art.The side provided according to the present invention Method, in some examples, the phosgenation reaction is selected from gas phase phosgenation reaction, liquid phase phosgenation reaction or anti-at salt phosgenation It answers.

For example, the phosgenation reaction can carry out in the gas phase, i.e., gas phase phosgenation reacts, and for details, reference can be made to China Patent application CN 102260194A, CN 105214568A.In some embodiments, the step of gas phase phosgenation reacts is wrapped It includes: 1) polyamines gasifying to form polyamines air-flow, polyamines drop is contained in the polyamines air-flow；2) it removes and contains in the polyamines air-flow Polyamines drop, obtain the polyamines air-flow for being substantially free of polyamines drop；3) by the polyamines air-flow for being substantially free of polyamines drop It carries out gas phase phosgenation with phosgene to react, gained reaction product passes through liquid inert medium (for example, aromatic solvent) and/or lazy Property medium and the mixture of isocyanates be quickly cooled to 100-140 DEG C in gas injection absorption plant, obtain isocyanates Crude product.Meanwhile the polyamines drop contained in polyamines air-flow is removed using heater；For example, the specific structure of heater used can Referring to corresponding contents disclosed in Chinese patent document CN 105214568A.The temperature of gas phase phosgenation reaction is, for example, 200- 550 DEG C (e.g., 250 DEG C, 300 DEG C, 320 DEG C, 380 DEG C, 420 DEG C, 500 DEG C), preferably 250-400 DEG C；The pressure of reaction is 0.01-1MPa (e.g., 0.05MPa, 0.08MPa, 0.2MPa, 0.5MPa, 0.8MPa), preferably 0.03-0.3MPa.In some tools In the mode of body, the mixed gas (reaction product) after phosgene is reacted with polyamines can be with a kind of liquid inert medium (for example, virtue Fragrant race's solvent) and/or the mixture of inert media and isocyanates carry out absorption cooling.Due to reaction mixture gas temperature compared with Height, therefore it is required that reaction mixture gas body is absorbed by the mixture of liquid inert medium and/or inert media and isocyanates Temperature≤180 DEG C after cooling, preferably≤165 DEG C, more preferably≤150 DEG C.Here the cooling of reaction mixture gas body absorbed Journey can be counted as the moment completion that reaction mixture gas body is contacted with cooling absorbing medium, and the time is extremely short, and this field is general Think it for≤30s.Therefore, in the step that aromatic solvent and phosgene contact, the Contact Temperature of the two be can be understood as It is temperature after cooling.When the Contact Temperature of the two is at 165 DEG C -180 DEG C, control contact duration≤2h；When the contact of the two Temperature is at 150 DEG C -165 DEG C, control contact duration≤4h；When the Contact Temperature of the two is less than 150 DEG C, time of contact not by Limitation.With the restriction of this process conditions, generated to prevent or reduce the benzophenone impurity containing chlorine.Liquid inert medium is selected All inert fluids for being suitable for preparing isocyanates, preferably aromatic solvent, more preferably chlorobenzene, m-dichlorobenzene, neighbour two One of chlorobenzene, paracide and chlorotoluene are a variety of.

For example, the phosgenation reaction can also carry out in the liquid phase, that is, liquid phase phosgenation reaction, for details, reference can be made to Chinese patent document CN 103319372B.In some embodiments, liquid phase phosgenation reaction is carried out in two steps: 1) cold reaction, Temperature is 0-100 DEG C, preferably 40-70 DEG C；Pressure is absolute pressure 0.1-1MPa；By polyamines and aromatic solvent (can be selected from chlorobenzene, One of dichloro-benzenes, o-dichlorohenzene, paracide and chlorotoluene are a variety of) it is hybridly prepared into after solution and hyperstoichiometry Phosgene is reacted, and reaction time can be 2-120min, preferably 5-45min.2) thermal response, temperature are 60-180 DEG C, It is preferred that 110-165 DEG C, more preferable 120-150 DEG C；Pressure is absolute pressure 0.1-1MPa；With chlorobenzene, m-dichlorobenzene, o-dichlorohenzene, right One of dichloro-benzenes and chlorotoluene or it is a variety of be solvent, reacted with the phosgene of hyperstoichiometry, reaction time can Think 0.5-5h.In the step that aromatic solvent and phosgene contact, when the Contact Temperature of the two is at 165 DEG C -180 DEG C, Control contact duration≤2h；When the Contact Temperature of the two is at 150 DEG C -165 DEG C, control contact duration≤4h；When connecing for the two When touching temperature less than 150 DEG C, time of contact is unrestricted.With the restriction of this process conditions, to prevent or reduce the hexichol containing chlorine Ketone class impurity generates.

For example, the phosgenation reaction can also carry out in hydrogen chloride and/or carbon dioxide, that is, at salt phosgenation Reaction, for details, reference can be made to Chinese patent document CN 105218422B, CN107337615A.In some embodiments, at salt light The step of gasification reaction are as follows: 1) hydrogen chloride and/or carbon dioxide and polyamines carry out salt-forming reaction, the chlorination in atent solvent The molar equivalent ratio of amino is 1-2.5:1, preferably 1.2-2:1, amino in the carbon dioxide and polyamines in hydrogen and polyamines Molar equivalent ratio is 0.5-5:1, preferably 0.6-3:1, and the mass ratio of atent solvent and polyamines is 25-5:1, preferably 20-5: 1；The temperature of salt-forming reaction is 0-50 DEG C, and preferably 5-30 DEG C, pressure is absolute pressure 0.1-1MPa, preferably absolute pressure 0.2- 0.5MPa；Reaction time is 1-15min, preferably 5-10min.After step 1) salt-forming reaction, gained hydrochloride or 2) reaction solution of carbonate, which enters step, carries out phosgenation reaction with phosgene；Reaction temperature is 100-170 DEG C, preferably 110- 165 DEG C, more preferable 120-150 DEG C；Reaction pressure is absolute pressure 0.1-1MPa, preferably absolute pressure 0.2-0.5MPa；With metachemistry meter The phosgene of amount is reacted, and reaction time can be 1-5h.Atent solvent therein is selected from chlorobenzene, m-dichlorobenzene, neighbour One of dichloro-benzenes, paracide and chlorotoluene are a variety of.It is somebody's turn to do what atent solvent (i.e. aromatic solvent) and phosgene contacted In step, when the Contact Temperature of the two is at 165 DEG C -180 DEG C, control contact duration≤2h；When the Contact Temperature of the two is 150 At DEG C -165 DEG C, control contact duration≤4h；When the Contact Temperature of the two is less than 150 DEG C, time of contact is unrestricted.With this The restriction of process conditions generates to prevent or reduce the benzophenone impurity containing chlorine.

The method that the phosgenation reaction provided according to the present invention prepares polyisocyanates, in some examples, the polyamines choosing From m-xylene diamine, p dimethylamine, 1,3- hexamethylene dimethylamine, 1,4- hexamethylene dimethylamine, 1,4- butanediamine, 1,6- hexamethylene diamine, Isosorbide-5-Nitrae-diaminocyclohexane, diamino-dicyclohexyl methane are (for example, industrial goods H12MDA, is comprising 4,4- diamino, two ring The mixture of hexyl methane, 2,4- diamino-dicyclohexyl methane, 2,2- diamino-dicyclohexyl methane etc.), toluenediamine, Asia Methyldiphenylamine (for example, 2,2'- methylene dianiline (MDA)s, 4,4'- methylene dianiline (MDA)), isophorone diamine, phenylenediamine, naphthalene two Amine, 1,8- octamethylenediamine, 1,10- decamethylene diamine, 1,12- diamino dodecane, 1,5- pentanediamine, cyclohexane diamine, hexahydrotoluene One of diamines, tetramethyl-para-phenylene diamine and dimethyl diphenyl diamines are a variety of, are preferably selected from m-xylene diamine, 1,3- hexamethylene Dimethylamine, 1,4- butanediamine, 1,5- pentanediamine, 1,6- hexamethylene diamine, diamino-dicyclohexyl methane, isophorone diamine, toluene One of diamines, phenylenediamine and naphthylenediamine are a variety of.

In some examples, shown in the chemical structural formula of the aromatic solvent such as formula (II):

Wherein, the R in formula (II) is selected from H, Cl or CH₃；

The aromatic solvent is preferably selected from chlorobenzene, o-dichlorohenzene, m-dichlorobenzene, paracide, m-chlorotoluene, adjacent chloromethane One of benzene and p-chlorotoluene are a variety of.

The method that the phosgenation reaction provided according to the present invention prepares polyisocyanates, in a specific embodiment, in institute It states in method, the aromatic solvent is as the medium in the phosgenation reaction and/or as the medium in the post-processing Carry out using.For example, when preparing polyisocyanates using gas phase phosgenation reaction, gained after gas phase phosgene is reacted with gas phase polyamines Reaction product carries out the post-processing of cooling absorption by aromatic solvent.

In some examples, the Benzophenone class impurity is the benzophenone substance containing chlorine, chemical structural formula such as formula (I) It is shown:

Wherein, the R in formula (I) is selected from H, Cl or CH₃；

In some embodiments, the benzophenone substance containing chlorine is selected from 1,1'- dichloro benzophenone, 2, 2'- dichloro benzophenone, 3,3'- dichloro benzophenone, 1,2'- dichloro benzophenone, 2,3'- dichloro benzophenone, 1,2,1', Tetra- chlorobenzophenone of 2'-, 2,3,2', tetra- chlorobenzophenone of 3'-, 1,2,2', tetra- chlorobenzophenone of 3'-, 1,3,1', 3'- tetrachloro Benzophenone, 2,4,2', tetra- chlorobenzophenone of 4'-, 1,3,2', tetra- chlorobenzophenone of 4'-, 1,4,1', tetra- chlorodiphenyl first of 4'- Ketone, the chloro- 1,2'- dimethyl benzophenone of 1,2'- bis-, the chloro- 3,3'- dimethyl benzophenone of 2,2'- bis-, 1,2'- bis- chloro- 2, 3'- dimethyl benzophenone, the chloro- 3,3'- dimethyl benzophenone of 1,1'- bis-, the chloro- 4,4'- dimethyl hexichol first of 2,2'- bis- One of ketone, the chloro- 3,4'- dimethyl benzophenone of 1,2'- bis- and the chloro- 4,4'- dimethyl benzophenone of 1,1'- bis- are more Kind.

In the second aspect of the invention, a kind of method preparing waterborne polyurethane resin is provided, is included the following steps:

Polymerization reaction will be carried out comprising the raw material of polyisocyanates, oligomer polyol, chain extender and hydrophilic agent, obtains water Property polyurethane resin；

Wherein, the polyisocyanates is to be prepared through phosgenation reaction, and preparing the polyisocyanates Solvent used in process includes aromatic solvent；The content of Benzophenone class impurity in the polyisocyanates≤ 0.045wt% (for example,≤0.04wt% ,≤0.03wt% ,≤0.02wt%), preferably≤0.035wt%, more preferably≤ 0.025wt%.

In the method for preparing waterborne polyurethane resin, if polyisocyanates raw material used is by phosgenation reaction system It is standby to obtain, then by the Benzophenone class impurity content in control polyisocyanates, it can effectively improve gained aqueous polyurethane The anti-yellowing property of product, and polyisocyanates caused reaction big ups and downs during downstream application can also be reduced.

The method provided according to the present invention, in some examples, the Benzophenone class impurity is the benzophenone object containing chlorine Matter, shown in chemical structural formula such as formula (I):

Wherein, the R in formula (I) is selected from H, Cl or CH₃；

In some embodiments, the benzophenone substance containing chlorine is for example selected from 1,1'- dichloro first Ketone, 2,2'- dichloro benzophenone, 3,3'- dichloro benzophenone, 1,2'- dichloro benzophenone, 2,3'- dichloro benzophenone, 1, Tetra- chlorobenzophenone of 2,1', 2'-, 2,3,2', tetra- chlorobenzophenone of 3'-, 1,2,2', tetra- chlorobenzophenone of 3'-, 1,3,1', 3'- Four chlorobenzophenones, 2,4,2', tetra- chlorobenzophenone of 4'-, 1,3,2', tetra- chlorobenzophenone of 4'-, 1,4,1', tetra- chlorodiphenyl of 4'- Ketone, the chloro- 1,2'- dimethyl benzophenone of 1,2'- bis-, the chloro- 3,3'- dimethyl benzophenone of 2,2'- bis-, 1,2'- bis- chloro- 2, 3'- dimethyl benzophenone, the chloro- 3,3'- dimethyl benzophenone of 1,1'- bis-, the chloro- 4,4'- dimethyl hexichol first of 2,2'- bis- One of ketone, the chloro- 3,4'- dimethyl benzophenone of 1,2'- bis- and the chloro- 4,4'- dimethyl benzophenone of 1,1'- bis- are more Kind.

In some preferred embodiments, the polyisocyanates prepares polyisocyanic acid by phosgenation reaction as described above The method of ester is prepared.

Catalyst commonly used in the art can be added in polymerization process and accelerate polymerization.In some examples, the polymerization Reaction can add one of organic tin, organo-bismuth class, cycloalkanes salt or a variety of as the catalyst to promoting its polymerization anti- It answers.

In some examples, the oligomer polyol (its relative molecular weight≤20000) is selected from polycaprolactone glycol (PCL), polyester-diol, polycarbonate glycol, polytetramethylene ether diol (PTMEG), polyadipate -1,4- butyl glycol ester diol With one of polyhexamethylene adipate glycol or a variety of.The polyester-diol is preferably 2- methyl-1,3-propanediol (MPD), neopentyl glycol (NPG), 2,2,4- trimethyl -1,3- pentanediol (TMPD), 2- ethyl -2- butyl -1,3- propylene glycol (BEPD), 1,4 cyclohexane dimethanol (1,4-CHDM), adipic acid, hexahydrophthalic anhydride (HHPA), 1,4 cyclohexanedicarboxylic acid (1,4- CHDA), polyester-diol derived from azelaic acid (AZA) or M-phthalic acid (IPA).

In some examples, the chain extender is polyfunctionality alcohol compound and/or polyfunctionality aminated compounds (example Such as, degree of functionality 2,3,4,5), be preferably selected from ethylene glycol, diglycol (diethylene glycol (DEG)), 1,2-PD, a contracting dipropyl Glycol, 1,4- butanediol (1,4-butanediol, BDO), 1,6-HD (HD), trimethylolpropane (TMP), castor oil, One in ethylenediamine (EDA), hydrazine, hexamethylene diamine, isophorone diamine, making methylpentamethylenediamine diamine, diethylenetriamines and triethylene tetramine Kind is a variety of.

In some examples, the hydrophilic agent is hydrophilic chain extender, is preferably selected from dihydromethyl propionic acid (DMPA), dihydroxy first Base butyric acid (DMBA), 1,4- butanediol -2- sodium sulfonate, diethanol amine, triethanolamine, N methyldiethanol amine (MDEA), N- second Base diethanol amine (EDEA), N- propyl diethanol amine (PDEA), N butyl diethanol amine (BDEA), dimethylethanolamine, bis- (2- Ethoxy) one of aniline (BHBA), bis- (2- hydroxypropyl) aniline (BHPA) and N methyldiethanol amine (MDEA) or a variety of.

During preparing aqueous polyurethane emulsion, solvent can not be used, but solvent also can be used.The raw material When carrying out polymerization reaction in a solvent, the solvent is selected from water, acetone, butanone, n,N-Dimethylformamide and N- methylpyrrole One of alkanone (NMP) is a variety of.

In the method for preparing waterborne polyurethane resin, the concrete operation step and process conditions being related to are art technology Personnel are known, and which is not described herein again.For example, specifically refer to Chinese patent document CN 104829811A, CN 107602803A, Corresponding contents disclosed in CN 102875736A etc..

Compared with the existing technology, the beneficial effect of technical solution of the present invention is:

The present invention is connect in the method that phosgenation reaction prepares polyisocyanates by control phosgene and aromatic solvent Process conditions are touched, content≤0.045wt% of Benzophenone class impurity in gained polyisocyanate product can be effectively improved The anti-yellowing property of polyisocyanate product can be such that the color number of the polyisocyanates obtained stablizes in 15Hazen hereinafter, even 10Hazen or less.Meanwhile can also by chloride content≤200ppm of finally obtained polyisocyanate product, even≤ 100ppm.In addition, also reducing anti-due to causing during downstream application in polyisocyanates there are Benzophenone class impurity The big ups and downs answered, it could even be possible to will lead to the unqualified of downstream product.Contained using low Benzophenone class impurity obtained by the present invention The polyisocyanates of amount is that the anti-yellowing property of waterborne polyurethane resin made from raw material is also significantly improved.

Specific embodiment

In order to technical characteristic and content of the invention is understood in detail, it is described in more detail below of the invention excellent Select embodiment.Although describing the preferred embodiment of the present invention in embodiment, however, it is to be appreciated that can be in a variety of manners Realize the present invention without that should be limited by the embodiments set forth herein.

H₁₂MDA (4,4'- diamino-dicyclohexyl methane): market purchasing, trade names are Wanamine H₁₂MDA；

IPDA: market purchasing, trade names are Wanamine IPDA；

1,3-BAC: market purchasing, manufacturer are Mitsubishi gas Co., Ltd.；

Phosgene: self-control, purity >=95%, referenced patent file CN104415770A；

O-dichlorobenzene solution: outsourcing meets professional standard HG/T 3602-2010；

Chlorobenzene: outsourcing meets standard GB/T/T 2404-2014；

Oligomer polyol, PTEMG (polytetramethylene ether diol): market purchasing, the limited public affairs of Shanxi three-dimensional group share Department, trade names: PTEMG-1800；

Dibutyl tin laurate: market purchasing, traditional Chinese medicines reagent, purity >=95%；

NEP (N- ethyl pyrrolidone): market purchasing, traditional Chinese medicines reagent, purity >=95%；

DMPA (2,2- dihydromethyl propionic acid): market purchasing, traditional Chinese medicines reagent, purity >=95%；

TEA (triethylamine): market purchasing, traditional Chinese medicines reagent, purity >=95%；

EDA (diethylamine): market purchasing, traditional Chinese medicines reagent, purity >=95%.

Following test method is used in each preparation example of the present invention, embodiment and comparative example:

(1) Benzophenone substance, which does impurity quantitative analysis, in polyisocyanates is carried out in gas-chromatography, gas phase color Spectrum analysis condition is as follows:

Chromatographic column: Agilent HP-5 (specification 30m*0.32mm*0.25mm)；Injector temperature: 280 DEG C；Split ratio: 30:1；Column flow: 1.5ml/min；Column temperature: 100 DEG C, retain and be increased to 260 DEG C with 15 DEG C/min after 0.5min, keep 8min； Detector temperature: 280 DEG C；H₂Flow: 35ml/min.

(2) analysis of the chloride content in polyisocyanates is using side mentioned by standard GB/T/T12009.1-1989 Method.

(3) analysis of the chromaticity index in polyisocyanates is using method mentioned by standard GB/T/T605-2006.

(4) yellowing resistance of aqueous polyurethane emulsion product can be tested: aqueous polyurethane emulsion be poured into glass mold, room Film is removed from glass mold after temperature film forming 48h, is put into 80 DEG C of baking ovens, is toasted 12h, obtain dry polyurethane film.With The color value b of color difference meter (liking beautiful color X-Rite528 type) test gained polyurethane film, then polyurethane film is put into 150 DEG C of baking ovens 0.5h is toasted, the color value b of resin film after toasting is tested with color difference meter and tests color difference △ E.

Polyisocyanates preparation example 1

A) using heater disclosed in the embodiment 1 of Chinese patent application CN105214568A, by diamines H₁₂MDA is carried out Gasify and be heated to 355 DEG C, under the protection of nitrogen, connects with the gaseous phosgene for being heated to 355 DEG C via respective feed pipe It is added in reactor continuously and carries out phosgenation reaction；The pressure of reaction is absolute pressure 0.05MPa, and the temperature of reaction is 360 DEG C；Its In, H₁₂The inlet amount of MDA is 800Kg/h, and the inlet amount of gaseous phosgene is 3000Kg/h；Gas is passed through using o-dichlorobenzene solution Resulting mixed gas quickly (time of contact is 10s or so) is cooled to 100 DEG C after device for ejecting and absorbing will react, and is contained Product H₁₂The crude product of MDI, phosgene and o-dichlorobenzene solution；Reaction end gas, which enters after tail gas absorber, uses -35 DEG C of adjacent dichloro Benzole soln absorbs, and obtains the o-dichlorobenzene solution containing phosgene.

B) crude product for obtaining step a) carries out the processing of removing phosgene and o-dichlorobenzene solution, adjacent dichloro in crude product Benzole soln and excessive phosgene are removed at 168 DEG C, absolute pressure 0.1MPa, the isolated H without containing phosgene₁₂MDI is slightly produced Product and o-dichlorobenzene solution containing phosgene；

Controlling residence time of the o-dichlorobenzene solution containing phosgene at 168 DEG C in subtractive process is 1h.

C) step a) reaction end gas obtains the o-dichlorobenzene solution containing phosgene after absorbing, with gained after step b) subtractive process O-dichlorobenzene solution containing phosgene enters the separation that rectifying column carries out phosgene and o-dichlorobenzene solution；Separation process is exhausted in pressure Press that 0.125MPa, column bottom temperature are 155 DEG C, tower top temperature carries out under conditions of being 15 DEG C, obtain phosgene that purity is 98% and The o-dichlorobenzene solution of phosgene content < 0.001%, the phosgene and o-dichlorobenzene solution isolated return in step a) into Row is recycled；

In the separation process of phosgene and o-dichlorobenzene solution, o-dichlorobenzene solution of the control containing phosgene stops at 155 DEG C Staying the time is 1h.

D) H of phosgene will not be contained obtained in step b)₁₂MDI crude product is purified by way of rectifying, exhausted H is obtained under 0.5KPa, 150-160 DEG C of boiling ranges of pressure₁₂MDI (dicyclohexyl methyl hydride diisocyanate) product.

In whole process, the o-dichlorobenzene solution containing phosgene is 1h in 150-165 DEG C of residence time, at 165-180 DEG C Residence time be 1h；And control its total residence time≤2h between 150 DEG C -180 DEG C.

Gained H₁₂The yield of MDI product is 97%, the purity 99.5% of product.In products obtained therefrom, the hexichol containing chlorine is generated (it is 1,2,1', tetra- chlorobenzophenone of 2'-, 2,3,2', tetra- chlorobenzophenone of 3'-, 1,2,2', 3'- tetrachloro two to ketone class impurity Benzophenone) total content be 0.01wt%.

Polyisocyanates preparation example 2

The phosgenation reaction of step a) uses liquid phase phosgenation reaction, discloses referring to Chinese patent document CN103319372B Reaction kettle in using following steps carry out:

1) cold reaction: by H₁₂MDA is configured to the solution that mass content is 15% by solvent of o-dichlorohenzene, and is preheating to 40 DEG C, the liquid phosgene with -5 DEG C is passed into progress liquid phase phosgenation reaction in the reaction kettle containing o-dichlorobenzene solution simultaneously；Its In, H₁₂The inlet amount of MDA is 400Kg/h, and the inlet amount of cold reaction phosgene is 1500kg/h, and cold reaction temperature is controlled at 60 DEG C, Residence time is 5min；

2) thermal response: temperature control is at 155 DEG C and the residence time is 2h, exists in o-dichlorobenzene solution and excess phosgene Under reacted, obtain containing product H₁₂The reaction solution (crude product) of MDI, phosgene and o-dichlorobenzene solution；

Reaction end gas is absorbed after entering tail gas absorber with -30 DEG C of o-dichlorobenzene solution, obtains the adjacent dichloro containing phosgene Benzole soln.

B) reaction solution for obtaining step a) carries out the processing of removing phosgene and o-dichlorobenzene solution, adjacent dichloro in reaction solution Benzole soln and excessive phosgene are removed at 155 DEG C, absolute pressure 0.05MPa, obtain the H without containing phosgene₁₂MDI crude product and O-dichlorobenzene solution containing phosgene；

In subtractive process, controlling residence time of the o-dichlorobenzene solution containing phosgene at 155 DEG C is 1h.

C) reaction end gas obtains the o-dichlorobenzene solution containing phosgene after absorbing in step a), with step b) subtractive process gained O-dichlorobenzene solution containing phosgene enters the separation that rectifying column carries out phosgene and o-dichlorohenzene；Separation process is absolute pressure in pressure 0.125MPa, column bottom temperature are 145 DEG C, and tower top temperature carries out under conditions of being 15 DEG C, obtain phosgene and light that purity is 98% The o-dichlorobenzene solution of Gas content < 0.001%, the phosgene and o-dichlorobenzene solution isolated are returned in step a) and are carried out It is recycled.

In whole process, control the o-dichlorobenzene solution containing phosgene 150-165 DEG C residence time be 3h, 165 DEG C- Residence time between 180 DEG C is 0h；And controlling its total residence time between 150 DEG C -180 DEG C is 3h.

Gained H₁₂The yield of MDI product is 96%, the purity 99.5% of product.In products obtained therefrom, the hexichol containing chlorine is generated (it is 1,2,1', tetra- chlorobenzophenone of 2'-, 2,3,2', tetra- chlorobenzophenone of 3'-, 1,2,2', 3'- tetrachloro two to ketone class impurity Benzophenone) total content be 0.008wt%.

Polyisocyanates preparation example 3

The phosgenation reaction of step a) is used at salt phosgenation reaction, with reference to the reality of Chinese patent document CN105218422B It applies in tank reactor disclosed in example 1 and is carried out using following steps:

1) it is previously added 1000Kg o-dichlorohenzene in salt-forming reaction kettle as reaction dissolvent, opens circulating pump and stirring, Hydrogen chloride compressed gas enters reactor by premixer with the speed of 50mol/min, after stirring 15min, by H₁₂MDA and neighbour The mixed liquor of dichloro-benzenes is warming up to 30 DEG C by feed preheater, after being come into full contact with the flow velocity of 335Kg/h and hydrogen chloride gas Salt-forming reaction；It is cooled down using outer circulation cooling water, removes part reaction heat, circulating fluid flow rate is in 5m³/ h or so, reaction solution Temperature maintains 30-45 DEG C, after feeding 3h, stops H₁₂The charging of the mixed liquor of MDA and o-dichlorohenzene, continues to be passed through HCl gas 30min。

2) H for obtaining step 1)₁₂MDA hydrochloride slurry is transferred in photochemical reaction kettle, this photochemical reaction kettle has light Gas air inlet pipe, vapor condensation reflux and stirring；Photochemical reaction kettle is heated up, while opening stirring, is led to after temperature reaches 60 DEG C Enter phosgene, phosgene charging rate is 50mol/min, 145 DEG C of reaction temperature, stops phosgene charging after reaction solution clarification, obtains Contain product H₁₂MDI, phosgene and o-dichlorohenzene at salt photochemical reaction liquid (crude product)；

B) reaction solution for obtaining step a) carries out the processing of removing phosgene and o-dichlorobenzene solution, adjacent dichloro in reaction solution Benzole soln and excessive phosgene are removed at 145 DEG C, absolute pressure 0.04MPa, obtain the H without containing phosgene₁₂MDI crude product and O-dichlorobenzene solution containing phosgene.

C) o-dichlorobenzene solution of the gained containing phosgene after reaction end gas absorbs in step a) takes off degassing procedure institute with step b) The o-dichlorobenzene solution that phosgene must be contained enters the separation that rectifying column carries out phosgene and o-dichlorohenzene；Separation process is absolute pressure in pressure 0.125MPa, column bottom temperature are 165 DEG C, and tower top temperature carries out under conditions of being 15 DEG C, obtain phosgene and light that purity is 98% The o-dichlorobenzene solution of Gas content < 0.001%, the phosgene and o-dichlorobenzene solution isolated are returned in step a) and are carried out It is recycled；

In the separation process of phosgene and o-dichlorobenzene solution, o-dichlorobenzene solution of the control containing phosgene stops at 165 DEG C Staying the time is 1h.

In whole process, residence time of the o-dichlorobenzene solution containing phosgene between 150 DEG C -165 DEG C is 0h, controls it It is 1h in 165 DEG C -180 DEG C of residence times；And controlling its total residence time between 150 DEG C -180 DEG C is 1h.

Gained H₁₂The yield of MDI product is 96%, the purity 99.5% of product.In products obtained therefrom, the benzene first containing chlorine is generated (it is 1,2,1', tetra- chlorobenzophenone of 2'-, 2,3,2', tetra- chlorobenzophenone of 3'-, 1,2,2', tetra- chlorodiphenyl of 3'- to ketone impurity Ketone) total content be 0.015wt%.

Polyisocyanates preparation example 4

Step a) the process referring to described in polyisocyanates preparation example 1 as above for preparing polyisocyanates carries out, different Place is, in step a), using 1,3-BAC (1,3- hexamethylene dimethylamine) by preparing HXDI (1,3- ring at salt light phosgenation Own diformazan based isocyanate).The process of step a) are as follows:

1) it is previously added 1000Kg chlorobenzene in salt-forming reaction kettle as reaction dissolvent, opens circulating pump and stirring, chlorination Hydrogen compressed gas enters reactor by premixer with the speed of 50mol/min, after stirring 15min, by 1,3-BAC (1,3- Hexamethylene dimethylamine) with the mixed liquor of chlorobenzene 30 DEG C are warming up to by feed preheater, with the flow velocity and hydrogen chloride gas of 235Kg/h Come into full contact with rear salt-forming reaction；It is cooled down using outer circulation cooling water, removes part reaction heat, circulating fluid flow rate is in 5m³/h Left and right, reacting liquid temperature maintain 30-45 DEG C, and after feeding 3h, the mixed liquor for stopping 1,3-BAC and chlorobenzene is fed, and continue to be passed through HCl gas 30min.

2) obtain step 1) 1,3-BAC hydrochloride slurry are transferred in photochemical reaction kettle, this photochemical reaction kettle has Phosgene air inlet pipe, vapor condensation reflux and stirring；Photochemical reaction kettle is heated up, while opening stirring, after temperature reaches 60 DEG C It is passed through phosgene, phosgene charging rate is 50mol/min, 145 DEG C of reaction temperature, stops phosgene charging after reaction solution clarification, obtains To containing product HXDI (dicyclohexyl methyl hydride diisocyanate), phosgene and chlorobenzene at salt photochemical reaction liquid (crude product)；

Reaction end gas is absorbed after entering tail gas absorber with -20 DEG C of chlorobenzene solution, obtains the chlorobenzene solution containing phosgene.

B) reaction solution for obtaining step a) carries out the processing of removing phosgene and chlorobenzene solvent, chlorobenzene and excess in reaction solution Phosgene removed at 168 DEG C, absolute pressure 0.1MPa, obtain the HXDI crude product without containing phosgene and chlorobenzene containing phosgene be molten Liquid；

In subtractive process, controlling residence time of the chlorobenzene solution containing phosgene at 168 DEG C is 1h.

C) step a) reaction end gas obtains the chlorobenzene solution containing phosgene after absorbing, and contains phosgene with step b) subtractive process gained Chlorobenzene solution enter rectifying column carry out phosgene and chlorobenzene solution separation；Separation process is absolute pressure 0.125MPa, tower in pressure Bottom temperature is 155 DEG C, tower top temperature carries out under conditions of being 15 DEG C, obtains phosgene and phosgene content < that purity is 98% 0.001% chlorobenzene solution, the phosgene and chlorobenzene solution isolated, which return in step a), to be recycled；

In the separation process of phosgene and chlorobenzene solution, residence time of chlorobenzene solution of the control containing phosgene at 155 DEG C is 1h。

D) the HXDI crude product for not containing phosgene obtained in step b) purify by way of rectifying, In HXDI (dicyclohexyl methyl hydride diisocyanate) product is obtained under absolute pressure 0.5KPa, 140-150 DEG C boiling range.

In whole process, chlorobenzene solution of the control containing phosgene is 1h in 150-165 DEG C of residence time, controls it in 165- 180 DEG C of residence time is 1h；And control its total residence time≤2h between 150 DEG C -180 DEG C.

The yield of gained HXDI product is 96.5%, the purity 99.65% of product.In products obtained therefrom, the benzene containing chlorine is generated (it is 1,1'- dichloro benzophenone, 2,2'- dichloro benzophenone, 3,3'- dichloro benzophenone, 1,2'- bis- to ketone class impurity Chlorobenzophenone, 2,3'- dichloro benzophenone) total content be 0.013wt%.

Polyisocyanates preparation example 5

A) using heater disclosed in the embodiment 1 of Chinese patent application CN105214568A, diamines IPDA is carried out Gasify and be heated to 355 DEG C, under the protection of nitrogen, connects with the gaseous phosgene for being heated to 355 DEG C via respective feed pipe It is added in reactor continuously and carries out phosgenation reaction；The pressure of reaction is absolute pressure 0.05MPa, and the temperature of reaction is 360 DEG C；Its In, the inlet amount of IPDA is 800Kg/h, and the inlet amount of gaseous phosgene is 3000Kg/h；Gas injection is passed through using chlorobenzene solution Resulting mixed gas quickly (time of contact is 10s or so) is cooled to 100 DEG C after absorption plant will react, and obtains containing product The crude product of IPDI, phosgene and chlorobenzene solution；Reaction end gas is absorbed after entering tail gas absorber with -25 DEG C of chlorobenzene solution, is obtained To the chlorobenzene solution containing phosgene.

B) crude product for obtaining step a) carries out the processing of removing phosgene and chlorobenzene solvent, chlorobenzene and excess in crude product Phosgene removed at 168 DEG C, absolute pressure 0.1MPa, obtain the IPDI crude product without containing phosgene and chlorobenzene containing phosgene be molten Liquid；

C) step a) reaction end gas obtains the chlorobenzene solution containing phosgene after absorbing, and contains phosgene with step b) subtractive process gained Chlorobenzene solution enter rectifying column carry out phosgene and chlorobenzene solution separation；Separation process is absolute pressure 0.125MPa, tower in pressure Bottom temperature is 155 DEG C, and tower top temperature carries out under conditions of being 15 DEG C, obtains phosgene and phosgene content < that purity is 98% 0.001% chlorobenzene solution, the phosgene and chlorobenzene solution isolated, which return in step a), to be recycled；

D) the IPDI crude product for not containing phosgene obtained in step b) purify by way of rectifying, In IPDI (isophorone diisocyanate) product is obtained under absolute pressure 0.5KPa, 140-150 DEG C boiling range.

The yield of gained IPDI product is 97.5%, the purity 99.75% of product.In products obtained therefrom, the benzene containing chlorine is generated (it is 1,1'- dichloro benzophenone, 2,2'- dichloro benzophenone, 3,3'- dichloro benzophenone, 1,2'- bis- to ketone class impurity Chlorobenzophenone, 2,3'- dichloro benzophenone) total content be 0.009wt%.

The preparation comparative example 1 of polyisocyanates

Comparative example process referring to described in polyisocyanates preparation example 1 as above carries out.The method for preparing polyisocyanates In, the difference is that:

B) crude product for obtaining step a) carries out the processing of removing phosgene and o-dichlorobenzene solution, adjacent dichloro in reaction solution Benzole soln and excessive phosgene are removed at 168 DEG C, absolute pressure 0.1MPa, obtain the H without containing phosgene₁₂MDI crude product and O-dichlorobenzene solution containing phosgene；

In the subtractive process of step b), control the o-dichlorobenzene solution containing phosgene 168 DEG C at a temperature of the residence time be 2h。

C) step a) reaction end gas obtains the o-dichlorobenzene solution containing phosgene after absorbing, and contains with obtained by step b) subtractive process The o-dichlorobenzene solution of phosgene enters the separation that rectifying column carries out phosgene and o-dichlorobenzene solution；Separation process is absolute pressure in pressure 0.125MPa, column bottom temperature are 155 DEG C, and tower top temperature carries out under conditions of being 15 DEG C, obtain phosgene and light that purity is 98% The o-dichlorobenzene solution of Gas content < 0.001%, the phosgene and o-dichlorobenzene solution isolated are returned in step a) and are carried out It is recycled；

In the separation process of phosgene and o-dichlorobenzene solution, temperature of the o-dichlorobenzene solution containing phosgene at 155 DEG C is controlled The lower residence time will be 3h.

In whole process, control the o-dichlorobenzene solution containing phosgene 150-165 DEG C residence time be 3h, control its 165-180 DEG C of residence time is 2h；And controlling the total residence time between 150 DEG C -180 DEG C is 5h.

H₁₂The yield of MDI product is 97%, the purity 99.5% of product.In products obtained therefrom, the benzophenone containing chlorine is generated Class impurity be 1,2,1', 2'-, tetra- chlorobenzophenone, 2,3,2', 3'-, tetra- chlorobenzophenone, 1,2,2', 3'-, tetra- chlorobenzophenone, The total content of impurity is 0.065wt%.

The preparation comparative example 2 of polyisocyanates

Comparative example process referring to described in polyisocyanates preparation example 2 as above carries out.The method for preparing polyisocyanates In, the difference is that:

B) reaction solution (crude product) obtained step a) carries out the processing of removing phosgene and solvent o-dichlorohenzene, reaction solution In excessive phosgene removed at 155 DEG C, absolute pressure 0.05MPa, obtain the H without containing phosgene₁₂MDI crude product and contain phosgene O-dichlorohenzene；

In the subtractive process of step b), controlling the residence time at 155 DEG C of the o-dichlorohenzene containing phosgene is 3h.

In whole process, controlling residence time of the o-dichlorobenzene solution containing phosgene between 150-165 DEG C is 5h, control Its residence time between 165 DEG C -180 DEG C is 0h；And it controls its total residence time between 150 DEG C -180 DEG C and is 5h。

H₁₂The yield of MDI product is 96%, the purity 99.5% of product.In products obtained therefrom, the benzophenone containing chlorine is generated Class impurity be 1,2,1', 2'-, tetra- chlorobenzophenone, 2,3,2', 3'-, tetra- chlorobenzophenone, 1,2,2', 3'-, tetra- chlorobenzophenone, The total content of impurity is 0.05wt%.

The preparation comparative example 3 of polyisocyanates

Comparative example process referring to described in polyisocyanates preparation example 3 as above carries out.The method for preparing polyisocyanates In, the difference is that:

In the separation process of the phosgene and o-dichlorobenzene solution of step c), the o-dichlorobenzene solution containing phosgene is controlled 165 The residence time is 2.5h at DEG C.

In whole process, controlling residence time of the o-dichlorobenzene solution containing phosgene between 150 DEG C -165 DEG C is 0h, control Making its residence time between 165-180 DEG C is 2.5h, and controls its total residence time between 150 DEG C -180 DEG C and be 2.5h。

H₁₂The yield of MDI product is 96%, the purity 99.5% of product.In products obtained therefrom, the benzophenone containing chlorine is generated Class impurity be 1,2,1', 2'-, tetra- chlorobenzophenone, 2,3,2', 3'-, tetra- chlorobenzophenone, 1,2,2', 3'-, tetra- chlorobenzophenone, The total content of impurity is 0.07wt%.

The preparation comparative example 4 of polyisocyanates

C) o-dichlorobenzene solution of the gained containing phosgene after reaction end gas absorbs in step a) takes off degassing procedure institute with step b) The o-dichlorobenzene solution that phosgene must be contained enters the separation that rectifying column carries out phosgene and o-dichlorohenzene；Separation process is absolute pressure in pressure 0.15MPa, column bottom temperature are 185 DEG C, and tower top temperature carries out under conditions of being 15 DEG C, obtain phosgene and phosgene that purity is 98% The o-dichlorobenzene solution of content < 0.001%, the phosgene and aromatic solvent isolated, which return in step a), to be recycled It uses；

In the separation process of phosgene and o-dichlorobenzene solution, o-dichlorobenzene solution of the control containing phosgene stops at 185 DEG C Staying the time is 1h.

In whole process, controlling residence time of the o-dichlorobenzene solution containing phosgene between 150 DEG C -165 DEG C is 0h, Residence time between 165-180 DEG C is 0h, but its total residence time in the case where 180 DEG C of > is 1h.

H₁₂The yield of MDI product is 96%, the purity 99.5% of product.In products obtained therefrom, the benzophenone containing chlorine is generated Class impurity be 1,2,1', 2'-, tetra- chlorobenzophenone, 2,3,2', 3'-, tetra- chlorobenzophenone, 1,2,2', 3'-, tetra- chlorobenzophenone, The total content of impurity is 0.085wt%.

The preparation comparative example 5 of polyisocyanates

Comparative example process referring to described in polyisocyanates preparation example 5 as above carries out.The method for preparing polyisocyanates In, the difference is that:

B) crude product for obtaining step a) carries out the processing of removing phosgene and chlorobenzene solution, in reaction solution chlorobenzene solution and Excessive phosgene is removed at 168 DEG C, absolute pressure 0.1MPa, obtains the IPDI crude product without containing phosgene and the neighbour containing phosgene Dichlorobenzene solution；

In the subtractive process of step b), controlling residence time of the chlorobenzene solution containing phosgene at 168 DEG C is 2h.

In the separation process of phosgene and chlorobenzene solution, residence time of chlorobenzene solution of the control containing phosgene at 155 DEG C is 3h。

In whole process, chlorobenzene solution of the control containing phosgene is 3h in 150-165 DEG C of residence time, controls it in 165- 180 DEG C of residence time is 2h；And controlling the total residence time between 150 DEG C -180 DEG C is 5h.

The yield of gained IPDI product is 97.5%, the purity 99.75% of product.In products obtained therefrom, two containing chlorine are generated (it is 1,1'- dichloro benzophenone, 2,2'- dichloro benzophenone, 3,3'- dichloro benzophenone, 1,2'- to Benzophenone class impurity Dichloro benzophenone, 2,3'- dichloro benzophenone) total content be 0.059wt%.

Through detecting, in above-mentioned polyisocyanates preparation example and comparative example in each technological parameter and polyisocyanate product The total content of benzophenone containing chlorine, the content of chlorine, the test result of coloration see the table below 1.

Table 1

It can be seen that in the preparation process of polyisocyanates from data in upper table, by controlling the aromatic series containing phosgene The residence time of solvent (150-180 DEG C) at high temperature, to reach the chloro Benzophenone in control polyisocyanate product The content of class impurity, so targetedly and effectively reduce the chlorinity in polyisocyanate product, effectively improve production The anti-yellowing property of product can also be reduced due to causing downstream product underproof there are the impurity of chloro Benzophenone class in product Harm.

The embodiment 6 of waterborne polyurethane resin:

1) by polyalcohol PTEMG 46.45g, the polyisocyanates H as obtained by preparation example 1₁₂MDI95g, organic tin are urged Four with feed opening, condenser pipe, thermometer and stirring are added in agent dibutyl tin laurate (0.05g is dissolved in 5g acetone) In mouth bottle, 85 DEG C of reaction temperature, speed of agitator 250rpm are set, reacts about 40min, until NCO reaches theoretical value 8.94%, is stopped Heating.

2) be added 30g acetone, be cooled to 60 DEG C hereinafter, successively sequence be added NEP 10g, DMPA9.5g, be warming up to 70 DEG C, Speed of agitator 250rpm reacts about 4h, until NCO reaches theoretical value 2.41%, antioxidant 1010 is added and the adjusting of 50g acetone is added The viscosity of system.

3) be cooled to 40 DEG C hereinafter, and be added 7.1g TEA neutralization, stirring 10min obtain performed polymer.

4) performed polymer is poured into dispersion cup, 275g deionized water is poured slowly under 1200rpm revolving speed and is dispersed, in system Emulsion-stabilizing after be slowly added to the EDA aqueous solution of 25g mass fraction 10%, continue to disperse 1min.

5) de- acetone, absolute pressure 5KPa, water-bath temperature are carried out to the lotion after stable dispersion obtained by step 4) with Rotary Evaporators Under the conditions of 35 DEG C of degree, acetone treatment 1h is taken off, the translucent aqueous polyurethane emulsion of blueing light is obtained.To gained aqueous polyurethane emulsion Product, which carries out yellowing resistance, to be tested, and color difference △ E is 0.3.

The embodiment 7 of waterborne polyurethane resin:

The preparation process of waterborne polyurethane resin side referring to described in the embodiment 6 of waterborne polyurethane resin in the present embodiment Method, the difference is that: used polyisocyanates raw material is that the IPDI as made from the preparation example 5 of polyisocyanates is (different Isophorone diisocyanate).The yellowing resistance of gained aqueous polyurethane emulsion product can be tested, color difference △ E is 0.2.

The comparative example 5 of waterborne polyurethane resin:

The preparation process of waterborne polyurethane resin side referring to described in the embodiment 6 of waterborne polyurethane resin in this comparative example Method, the difference is that: used polyisocyanates raw material is as made from the preparation comparative example 1 of polyisocyanates H₁₂MDI product.The yellowing resistance of gained aqueous polyurethane emulsion product can be tested, color difference △ E is 3.5.

The comparative example 6 of waterborne polyurethane resin:

The preparation process of waterborne polyurethane resin side referring to described in the embodiment 6 of waterborne polyurethane resin in this comparative example Method, the difference is that: used polyisocyanates raw material is resulting by the preparation comparative example 5 of polyisocyanates IPDI.The yellowing resistance of gained aqueous polyurethane emulsion product can be tested, color difference △ E is 4.2.

It can be tested as the yellowing resistance to waterborne polyurethane resin it is found that using polyisocyanates made from the application method (total content≤0.015wt% of Benzophenone class impurity therein) is applied to downstream process, aqueous poly- ammonia obtained as raw material The anti-yellowing property of ester resin is also significantly improved.And using the preparation comparative example products therefrom of polyisocyanates as raw material Applied to downstream process, the anti-yellowing property of waterborne polyurethane resin obtained is poor.

Various embodiments of the present invention are described above, above description is exemplary, and non-exclusive, and It is not limited to disclosed each embodiment.Without departing from the scope and spirit of illustrated each embodiment, for this skill Many modifications and changes are obvious for the those of ordinary skill in art field.

Claims

1. a kind of method that phosgenation reaction prepares polyisocyanates includes the following steps: to carry out polyamines and excessive phosgene Phosgenation reaction obtains the crude product containing polyisocyanates, then post-processes to the crude product, obtains the polyisocyanate Cyanate；The solvent that the method uses during preparing the polyisocyanates includes aromatic solvent, and feature exists In,

Content≤0.045wt% of Benzophenone class impurity, preferably≤0.035wt% in the polyisocyanates, more preferably ≤ 0.025wt%.

2. the method according to claim 1, wherein there are the steps that aromatic solvent and phosgene are in contact described In rapid, its process conditions is controlled to limit the content of Benzophenone class impurity in the polyisocyanates；The technique item of control Part includes: Contact Temperature≤180 DEG C for controlling aromatic solvent and phosgene,

(1) when the Contact Temperature of aromatic solvent and phosgene is 165 DEG C -180 DEG C, control contact duration≤2h, preferably≤1h； (2) when the Contact Temperature of aromatic solvent and phosgene is 150 DEG C -165 DEG C, control contact duration≤4h, preferably≤2h；(3) When the Contact Temperature of aromatic solvent and phosgene is less than 150 DEG C, time of contact is unrestricted；

And when the Contact Temperature of aromatic solvent and phosgene is 150 DEG C -180 DEG C, control contact total duration≤4h, preferably≤ 2h。

3. method according to claim 1 or 2, which is characterized in that the phosgenation reaction be selected from gas phase phosgenation reaction, Liquid phase phosgenation reaction or at salt phosgenation reaction.

4. method according to any one of claim 1-3, which is characterized in that

The polyamines is selected from m-xylene diamine, p dimethylamine, 1,3- hexamethylene dimethylamine, 1,4- hexamethylene dimethylamine, 1,4- fourth two Amine, 1,6- hexamethylene diamine, 1,4- diaminocyclohexane, diamino-dicyclohexyl methane, toluenediamine, methylene dianiline (MDA), different Buddhist That ketone diamines, phenylenediamine, naphthylenediamine, 1,8- octamethylenediamine, 1,10- decamethylene diamine, 1,12- diamino dodecane, 1,5- pentanediamine, ring One of hexane diamine, hexahydrotoluene diamines, tetramethyl-para-phenylene diamine and dimethyl diphenyl diamines are a variety of, are preferably selected from M-xylene diamine, 1,3- hexamethylene dimethylamine, 1,4- butanediamine, 1,5- pentanediamine, 1,6- hexamethylene diamine, diaminocyclohexyl first One of alkane, isophorone diamine, toluenediamine, phenylenediamine and naphthylenediamine are a variety of；And/or

Shown in the chemical structural formula of the aromatic solvent such as formula (II):

Wherein, the R in formula (II) is selected from H, Cl or CH₃；

The aromatic solvent be preferably selected from chlorobenzene, o-dichlorohenzene, m-dichlorobenzene, paracide, m-chlorotoluene, ortho-chlorotolu'ene and One of p-chlorotoluene is a variety of；And/or

The Benzophenone class impurity is the benzophenone substance containing chlorine, shown in chemical structural formula such as formula (I):

Wherein, the R in formula (I) is selected from H, Cl or CH₃；

The benzophenone substance containing chlorine is for example selected from 1,1'- dichloro benzophenone, 2,2'- dichloro benzophenone, 3,3'- Dichloro benzophenone, 1,2'- dichloro benzophenone, 2,3'- dichloro benzophenone, 1,2,1', tetra- chlorobenzophenone of 2'-, 2,3, Tetra- chlorobenzophenone of 2', 3'-, 1,2,2', tetra- chlorobenzophenone of 3'-, 1,3,1', tetra- chlorobenzophenone of 3'-, 2,4,2', 4'- tetra- Chlorobenzophenone, 1,3,2', tetra- chlorobenzophenone of 4'-, 1,4,1', tetra- chlorobenzophenone of 4'-, the chloro- 1,2'- diformazan of 1,2'- bis- Base benzophenone, the chloro- 3,3'- dimethyl benzophenone of 2,2'- bis-, the chloro- 2,3'- dimethyl benzophenone of 1,2'- bis-, 1,1'- Two chloro- 3,3'- dimethyl benzophenones, the chloro- 4,4'- dimethyl benzophenone of 2,2'- bis-, the chloro- 3,4'- dimethyl of 1,2'- bis- One of benzophenone and the chloro- 4,4'- dimethyl benzophenone of 1,1'- bis- are a variety of.

5. method according to any of claims 1-4, which is characterized in that in the method, the aromatic series is molten Agent as in the phosgenation reaction medium and/or as the medium in the post-processing carry out using.

6. a kind of method for preparing waterborne polyurethane resin, includes the following steps:

Polymerization reaction will be carried out comprising the raw material of polyisocyanates, oligomer polyol, chain extender and hydrophilic agent, obtained aqueous poly- Urethane resin；It is characterized in that,

The polyisocyanates is to be prepared through phosgenation reaction, and use during preparing the polyisocyanates Solvent include aromatic solvent；

Content≤0.045wt%, the preferably≤0.035wt% of Benzophenone class impurity in the polyisocyanates, more preferably For≤0.025wt%.

7. according to the method described in claim 6, it is characterized in that, the Benzophenone class impurity is the benzophenone object containing chlorine Matter, shown in chemical structural formula such as formula (I):

Wherein, the R in formula (I) is selected from H, Cl or CH₃；

8. method according to claim 6 or 7, which is characterized in that the polyisocyanates passes through as in claim 1-5 Described in any item methods are prepared.

9. method a method according to any one of claims 6-8, which is characterized in that

The oligomer polyol be selected from polycaprolactone glycol, polyester-diol, polycarbonate glycol, polytetramethylene ether diol, One of polyadipate -1,4- butyl glycol ester diol and polyhexamethylene adipate glycol are a variety of；The polyester-diol is excellent It is selected as 2- methyl-1,3-propanediol, neopentyl glycol, 2,2,4- trimethyl -1,3- pentanediol, 2- ethyl -2- butyl -1,3- the third two Derived from alcohol, 1,4 cyclohexane dimethanol, adipic acid, hexahydrophthalic anhydride, 1,4 cyclohexanedicarboxylic acid, azelaic acid or M-phthalic acid Polyester-diol；And/or

The chain extender is polyfunctionality alcohol compound and/or polyfunctionality aminated compounds, is preferably selected from ethylene glycol, a contracting Diethylene glycol, 1,2- propylene glycol, dipropylene glycol, 1,4- butanediol, 1,6-HD, trimethylolpropane, castor oil, second One of diamines, hydrazine, hexamethylene diamine, isophorone diamine, making methylpentamethylenediamine diamine, diethylenetriamines and triethylene tetramine are more Kind；And/or

The hydrophilic agent is hydrophilic chain extender, is preferably selected from dihydromethyl propionic acid, dimethylolpropionic acid, 1,4-butanediol -2- Sodium sulfonate, diethanol amine, triethanolamine, N methyldiethanol amine, N- ethyldiethanolamine, N- propyl diethanol amine, N- butyl Diethanol amine, dimethylethanolamine, bis- (2- ethoxy) aniline, one in bis- (2- hydroxypropyl) aniline and N methyldiethanol amine Kind is a variety of.

10. the method according to any one of claim 6-9, which is characterized in that described in the raw material carries out in a solvent When polymerization reaction, the solvent is selected from one of water, acetone, butanone, n,N-Dimethylformamide and N-Methyl pyrrolidone Or it is a variety of.