CN117924657A

CN117924657A - Benzenediisocyanate composition, preparation method and application thereof

Info

Publication number: CN117924657A
Application number: CN202410015461.XA
Authority: CN
Inventors: 尚永华; 王鹏飞; 成兆坤; 朱付林; 朱岳栋; 牛康宁; 李建峰; 石滨
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2024-01-03
Filing date: 2024-01-03
Publication date: 2024-04-26

Abstract

The invention relates to a benzene diisocyanate composition, a preparation method and application thereof, wherein the benzene diisocyanate composition comprises benzene diisocyanate and 5-6000ppm of a compound shown as a formula (1),The benzene diisocyanate composition provided by the invention has excellent stability.

Description

Benzenediisocyanate composition, preparation method and application thereof

Technical Field

The invention belongs to the technical field of isocyanate, and particularly relates to a benzene diisocyanate composition, a preparation method and application thereof.

Background

The p-phenylene diisocyanate is generally obtained by reacting phenylenediamine with phosgene (phosgene), is an aromatic diisocyanate with simple structure and high regularity, and has wide application in high-performance elastomer materials.

The reaction activity of the p-phenylene diisocyanate is high, and the polyurethane elastomer prepared from the p-phenylene diisocyanate has good heat resistance, but because the storage stability is poor, more dimers are generated in the high-temperature and room-temperature storage process, and the downstream elastomer performance is influenced, so that the application of the p-phenylene diisocyanate in the elastomer field is seriously influenced.

Accordingly, there is a need in the art to provide a storage-stable phenylene diisocyanate and a process for preparing the same.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide a phenylene diisocyanate composition. The phenylene diisocyanate composition has excellent stability, and the prepared polyurethane elastomer has excellent mechanical properties.

To achieve the purpose, the invention adopts the following technical scheme:

The present invention provides a benzene diisocyanate composition comprising benzene diisocyanate and 5 to 6000ppm (e.g., 8ppm、10ppm、15ppm、20ppm、30ppm、50ppm、60ppm、100ppm、150ppm、200ppm、220ppm、250ppm、300ppm、320ppm、350ppm、400ppm、450ppm、500ppm、1000ppm、1500ppm、2000ppm、2500ppm、3000ppm、3500ppm、4000ppm、4500ppm、5000ppm、5500ppm、5800ppm, etc.), preferably 10 to 2000ppm of a compound represented by the formula (1);

The researchers of the invention find that when the benzene diisocyanate composition contains 5-6000ppm of the compound of formula (1), the compound has excellent stability, especially the PPDI can still keep excellent stability after contacting air, thereby reducing the difficulty of customers in the use process, and the prepared elastomer has excellent mechanical properties. A content of less than 5ppm or more than 6000ppm may deteriorate stability.

The phenylene diisocyanate composition of the present invention includes 95wt.% or more of the phenylene diisocyanate.

In the present invention, the phenylene diisocyanate composition is referred to as PPDI composition, the phenylene diisocyanate is referred to as PPDI, and the compound represented by the chemical formula (1) is referred to as PPAI.

Preferably, the benzene diisocyanate comprises any one or a combination of at least two of 1, 2-benzene diisocyanate, 1, 3-benzene diisocyanate, 1, 4-benzene diisocyanate, 1, 5-benzene diisocyanate, preferably 1, 4-benzene diisocyanate and/or 1, 3-benzene diisocyanate, more preferably 1, 4-benzene diisocyanate;

preferably, the compound represented by the formula (1) includes, but is not limited to, any one or a combination of at least two of the following compounds:

In the present invention PPAI may be produced as a by-product in the production of PPDI or may be added artificially to obtain the desired content.

In the present invention, the content of PPAI can be measured by analysis by gas chromatography.

Another object of the present invention is to provide a method for preparing the xylylene diisocyanate composition, which comprises:

(1) An isocyanate process:

a. Mixing phenylenediamine with phosgene in the presence of a solvent;

b. Reacting phenylenediamine with phosgene in a cold reaction unit to form an intermediate reactant comprising isocyanate, aminoacyl chloride, hydrochloride, phenylenediamine and phosgene;

c. The intermediate reactant produced in the cold reaction unit is isocyanated in the hot reaction unit to obtain a reaction product containing the benzene diisocyanate and the compound represented by formula (1).

Wherein the intermediate reactant obtained in carrying out reaction b comprises less than 5% of phenylenediamine, preferably less than 4%, based on the molar amount of the phenylenediamine fed. The lower limit of the phenylenediamine content of the intermediate reactant obtained in the reaction b is not particularly required, but the phenylenediamine content is controlled to be more than 0.1% in consideration of the cost of industrial production.

(2) Solvent separation and purification steps: removing the solvent from the reaction product obtained in the step (1), refining the removed solvent to obtain a recycled solvent, and returning the recycled solvent to the reaction system of the step (1);

(3) And (3) a separation procedure: and (3) separating and purifying the desolventizing reaction product obtained in the step (2) to obtain the benzene diisocyanate composition.

The isocyanation process of step (1) may be referred to as phosgenation, and the isocyanation reaction is phosgenation.

Specific examples of the phosgenation method include a method in which phenylenediamine is directly reacted with phosgene (also referred to as a cold-hot two-stage phosgenation method), a method in which hydrochloride obtained by reacting phenylenediamine with hydrochloric acid (hydrogen chloride) is reacted with phosgene in a reaction solvent (also referred to as an amine hydrochloride phosgenation method), and the like, and an amine phosgenation method is preferable.

Preferably, the phosgenation of the amine is carried out by means of a two stage of cryo-and thermo-phos-genation. The luminescence process comprises the following steps: in the presence of a reaction solvent, phenylenediamine and phosgene are mixed and subjected to a luminescence reaction to obtain phenylenediamine cooling liquid. The actual obtained slurry in the cold light process is a slurry containing phenylenediamine, phenylenediamine hydrochloride, phenylenediamine chloride and a very small amount of benzene diisocyanate, and the slurry is directly applied to the isocyanate process.

Preferably, the phenylenediamine comprises any one or at least two of 1, 2-phenylenediamine, 1, 3-phenylenediamine, 1, 4-phenylenediamine, and 1, 5-phenylenediamine.

Preferably, the luminescence process specifically includes: and (3) introducing phosgene into a reaction solvent, adding a reaction solvent amine solution containing phenylenediamine, stirring and mixing the phosgene and the amine solution, and carrying out a luminescence reaction to obtain the phenylenediamine cooling liquid.

Preferably, the content of phenylenediamine in the amine solution is 1.0wt.% or more, such as 4wt.％、5wt.％、6wt.％、7wt.％、8wt.％、9wt.％、10wt.％、11wt.％、12wt.％、13wt.％、14wt.％、15wt.％、16wt.％、17wt.％、18wt.％、19wt.％、20wt.％, etc., preferably 5.0wt.% or more.

Preferably, the content of phenylenediamine in the amine solution is 50wt.% or less, preferably 30wt.% or less.

Preferably, the photochemical temperature in the photochemical step is at least 0deg.C, for example, at 5 ℃,10 ℃, 20 ℃, 25 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃,90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, etc., preferably at least 20deg.C.

Preferably, the luminescence temperature in the luminescence process is 130 ℃ or lower, preferably 80 ℃ or lower, more preferably 60 ℃ or lower.

Preferably, the chill-photochemical process is performed under normal pressure or under pressure.

The pressure (gauge pressure) in the chill-stage is preferably 0.01MPaG or more, more preferably 0.02MPaG or more.

The pressure (gauge pressure) in the chill-stage is preferably 1.0MPaG or less, more preferably 0.5MPaG or less, and still more preferably 0.4MPaG or less.

Preferably, the molar amount of phosgene is 4 times or more, preferably 6 times or more, more preferably 8 times or more the molar amount of phenylenediamine.

Preferably, the molar amount of phosgene is 50 times or less, preferably 40 times or less, more preferably 20 times or less the molar amount of phenylenediamine.

Because the phenylenediamine has smaller solubility in solvents such as chlorobenzene, dichlorobenzene, toluene and the like, a layer of intermediate reactants (such as hydrochloride, carbamoyl chloride and the like) can be formed on the surfaces of amine particles in the reaction process of the amine and the phosgene, so that the further reaction of the phosgene and the amine is hindered, the conversion rate of the amine is low, the molar content of the amine in the reaction solution generated by the cold reaction unit is high, and the content of PPAI generated by the hot reaction unit is finally higher.

Preferably, the molar content of phenylenediamine in the cold reaction process can be adjusted by controlling the mixing intensity of the reactor, and a mixing device having a grinding function for solids in the reaction liquid, preferably a homogenizing pump, a grinding pump, a pulverizing pump, a colloid mill, a gear tooth type dispersing machine, and more preferably a mixing device having a fluted disc type dispersing structure, such as a homogenizing pump, a grinding pump, is preferably used.

Preferably, the toothed disc has a toothed disc gap of 500 μm or less, more preferably 200 μm or less.

Preferably, the residence time of the reaction solution by grinding using a mixing device is 1min or more, preferably 5min or more.

Preferably, the residence time of the reaction liquid by grinding using a mixing device is 180min or less, preferably 120min or less.

Preferably, the step (1) specifically includes: phosgene is introduced into phenylenediamine to carry out luminescence reaction; and continuously introducing phosgene into the luminescence reaction liquid to perform thermal reaction, so as to obtain a reaction product containing the benzene diisocyanate and the compound shown in the formula (1).

When the isocyanate reaction is carried out using a phenylenediamine chilled liquid with phosgene, a target content of the compound of formula (1) can be obtained by controlling the reaction conditions. The content of PPAI in the phenylene diisocyanate composition may be adjusted by adding PPAI to the phenylene diisocyanate composition.

Preferably, the molar amount of phosgene is 50 times or less, preferably 40 times or less, more preferably 30 times or less the molar amount of phenylenediamine.

Preferably, the reaction temperature in the isocyanate process is 80 ℃ or higher, preferably 100 ℃ or higher.

Preferably, the reaction temperature in the isocyanate-forming process is 180 ℃ or less, preferably 170 ℃ or less, more preferably 160 ℃ or less.

Preferably, the isocyanate reaction time is 1h or more, preferably 3h or more.

Preferably, the isocyanate reaction time is 25 hours or less, preferably 20 hours or less.

Preferably, the isocyanation reaction is carried out under normal pressure or under pressurized conditions.

The pressure (gauge pressure) of the isocyanation reaction is preferably 0MPaG or more, more preferably 0.0005MPaG or more, still more preferably 0.001MPaG or more, still more preferably 0.003MPaG or more, particularly preferably 0.01MPaG or more, particularly preferably 0.02MPaG or more, and most preferably 0.03MPaG or more.

The pressure (gauge pressure) of the isocyanation reaction is preferably 0.6MPaG or less, preferably 0.4MPaG or less, more preferably 0.2MPaG or less.

Preferably, the isocyanate process is a batch process or a continuous process, preferably a continuous process.

Preferably, the isocyanatoprocess may be a batch or continuous process. In the continuous step, the slurry (phenylenediamine cold reaction solution) produced in the cold reaction unit is continuously fed from the cold reaction unit to a different thermal reaction unit from the cold reaction unit, the phenylenediamine cold reaction solution is reacted with phosgene in the thermal reaction unit, and the reaction solution (reaction substance) is continuously withdrawn from the thermal reaction unit. The number of reaction kettles in the continuous process is not particularly limited, and may be, for example, two, three, four, five or more.

If necessary, the reaction product of the isocyanate-based process may be subjected to a degassing step, a solvent separation step and a purification step, and the residual phosgene and the gas such as hydrogen chloride produced as a by-product may be removed from the reaction product by a known degassing column. In the solvent separation and purification step, the reaction solvent is distilled off from the reaction solution by a known distillation column. Most of the solvent is returned to the isocyanate processing step after refining.

In the present invention, examples of the reaction solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as octane and decane, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylcyclohexane, and halogenated aromatic hydrocarbons such as chlorotoluene, chlorobenzene, dichlorobenzene, dibromobenzene, and trichlorobenzene. The reaction solvent may be used alone or in combination of 2 or more. Among the reaction solvents, halogenated aromatic hydrocarbons are preferable, and chlorobenzene and dichlorobenzene are more preferable.

If necessary, the tar removal step may be performed on the solvent-removed reaction product. The tar component is removed from the reaction solution using a known tar removal device such as a short-path evaporator. The reaction substance from which tar components were removed in the tar removal step was referred to as an intermediate substance.

The intermediate may be purified, if necessary, by an industrial separation technique such as distillation and crystallization, without any particular limitation.

Preferably, the rectification is carried out in a rectification column.

Preferably, the rectification column comprises a plate rectification column or a packed rectification column.

In a preferred embodiment of the present invention, the proportion of PPAI can be adjusted to the above range by controlling the reaction conditions and the separation conditions. The content of PPAI in the PPDI composition may be adjusted by adding PPAI to the PPDI composition.

Preferably, the theoretical plate number of the rectifying column is 1 or more, preferably 2 or more.

Preferably, the theoretical plate number of the rectifying column is 60 or less, preferably 40 or less.

Preferably, the top pressure of the rectifying column is 0.1kPa or more, preferably 0.15kPa or more.

Preferably, the top pressure of the rectifying column is 4kPa or less, preferably 2.5kPa or less.

Preferably, the reflux ratio of the top of the rectifying column is 0.01 or more, preferably 0.1 or more.

Preferably, the reflux ratio at the top of the rectifying column is 30 or less, preferably 20 or less.

In a preferred embodiment of the present invention, the method for producing a xylylene diisocyanate composition described above can be carried out, for example, by using the flow chart shown in fig. 1. As shown in fig. 1, the reactor mainly comprises a luminescence unit, and in an isocyanate unit to be described later, a continuous thermal luminescence unit (carried out in a thermal luminescence reactor) is carried out, and the conversion of phenylenediamine is adjusted by appropriately adjusting the batch of the toothed disc, the residence time of the mixing equipment in the cold reaction unit, etc., thereby adjusting the production amounts of the phenylenediisocyanate and PPAI. And a phosgene removal unit and a solvent removal unit are arranged behind the photochemical kettle, the phosgene and the solvent are removed from the reaction solution, a heavy component removal unit is arranged behind the solvent removal unit, the tar removal procedure is carried out on the reaction product of the solvent removal, and the reaction product is distilled in a refining unit to obtain the final product. In the rectification separation described later, the content of PPAI in the xylylene diisocyanate composition is adjusted by appropriately adjusting the reflux ratio at the top of the column or the like.

Specifically, first, a reaction solvent is charged into a luminescence reactor. Then, phosgene was continuously supplied to the bottom of the cryogenically chemical reactor through a phosgene supply line at the above-described supply ratio. The amine solution in which phenylenediamine is dissolved in the reaction solvent is continuously supplied to the top of the luminescence reactor through an amine supply line. Then, while maintaining the inside of the luminescence reactor at the above luminescence temperature and luminescence pressure, the reaction substance in the luminescence reactor is introduced into a polishing pump by a pump to be polished and circulated back to the cold reaction reactor. Thus, a slurry comprising phenylenediamine hydrochloride, phenylenediamine acid chloride, phenylenediamine, and a small amount of a phenylene diisocyanate is produced.

Then, a slurry containing phenylenediamine hydrochloride, phenylenediamine acid chloride, phenylenediamine and a small amount of a diisocyanate is continuously fed to the top of the thermal photooxidation reactor through a luminescence liquid feeding line. That is, while continuously supplying phosgene and an amine solution to the autoclave, a slurry containing phenylenediamine hydrochloride, phenylenediamine chloride, phenylenediamine and a small amount of a diisocyanate is continuously taken out of the autoclave and transferred to the thermal autoclave.

Next, phosgene was continuously supplied to the top of the thermal-phosgenation reactor in the above-described supply ratio by way of an insertion tube. Then, the slurry and phosgene were stirred and mixed while maintaining the inside of the thermal reactor at the above-mentioned reaction temperature and reaction pressure (step 1 isocyanate-based step). Thus, the phenylenediamine cooling agent reacts with phosgene to produce, as a main component, phenylenediisocyanate and, as a by-product, PPAI.

Thus, the cold light treatment step and the isocyanate treatment step are continuously performed.

Then, a reaction solution containing a xylylene diisocyanate, PPAI, a reaction solvent, and the like is produced. The sum of residence times in the isocyanate process is within the above range.

Next, the above-mentioned photochemical reaction liquid is continuously fed to the middle of the column of the dephosgene column through a reaction material feed line. The photochemical liquid is separated into a gas containing phosgene, hydrogen chloride, and the like, and a liquid degassing substance containing xylylene diisocyanate, PPAI, a reaction solvent, and the like by a decarbonylation column (degassing step).

Next, the deaerated matter is continuously fed into the column of the desolventizing column through the deaerated matter feed line. Then, the reaction solvent was distilled off from the degassed material by means of a desolventizing column (solvent separation and purification step) to obtain a desolventized material containing xylylene diisocyanate and PPAI.

Next, the desolventizing substance is continuously fed to the upper portion of the tar remover through the desolventizing substance feed line. Then, the tar component is removed from the desolventized material by a tar remover to obtain an intermediate product containing the xylylene diisocyanate and PPAI (tar removing step).

Next, the intermediate matters are continuously fed into the column of the rectifying column through the intermediate matters feeding line. Then, the low boiling substances are distilled off from the intermediate quality under the conditions of the rectification step described above (bottom temperature, top pressure, bottom reflux ratio, top reflux ratio and residence time), and the xylylene diisocyanate composition is recovered from the lower part of the middle of the column.

Thus, a xylylene diisocyanate composition comprising xylylene diisocyanate and PPAI can be continuously produced.

It is still another object of the present invention to provide a modified composition of a xylylene diisocyanate composition, which is a modified composition obtained by modifying a xylylene diisocyanate composition according to one of the objects, wherein the modified xylylene diisocyanate in the modified composition contains any one or a combination of at least two of the following groups (a) to (e): (a) isocyanurate groups, (b) uretdione groups, (c) biuret groups, (d) urethane groups, (e) urea groups, (f) iminooxadiazinedione groups, (g) allophanate groups, (h) uretonimine groups, or (i) carbodiimide groups.

The phenylene diisocyanate composition can be modified by a person skilled in the art according to need by a known method to obtain a phenylene diisocyanate modified composition, which is suitably used as a polyisocyanate component and an active hydrogen group-containing component as a raw material of a polyurethane resin.

More specifically, the modified phenylene diisocyanate having the functional group (isocyanurate group) of (a) is a trimer of phenylene diisocyanate, and is obtained, for example, by reacting a phenylene diisocyanate composition in the presence of a known isocyanurate catalyst to isocyanurate the phenylene diisocyanate therein.

The modified xylylene diisocyanate having the functional group (allophanate group) of the above (b) can be obtained by further reacting a xylylene diisocyanate composition with an alcohol in the presence of a known allophanatization catalyst.

The modified xylylene diisocyanate containing the functional group (biuret group) of the above (c) can be obtained by further reacting a xylylene diisocyanate composition with, for example, water, tertiary alcohol (for example, t-butanol, etc.), secondary amine (for example, dimethylamine, diethylamine, etc.), etc., in the presence of a known biuretizing catalyst.

The modified xylylene diisocyanate containing the functional group (urethane group) of the above (d) can be obtained by reacting the xylylene diisocyanate composition with a polyol component (for example, trimethylolpropane, etc.).

The modified xylylene diisocyanate containing the functional group (ureido) of the above (e) can be obtained by reacting the xylylene diisocyanate composition with water, a polyamine component (described later) or the like.

The modified xylylene diisocyanate (asymmetric trimer) containing the functional group (iminooxadiazinedione group) of the above (f) can be obtained by reacting a xylylene diisocyanate composition in the presence of a known iminooxadiazinedione catalyst to cause iminooxadiazinedione (e.g., trimerization) of the xylylene diisocyanate.

The modified xylylene diisocyanate having the functional group (uretdione group) of the above (g) can be obtained by a method of heating a xylylene diisocyanate composition at about 90℃to 200℃or by reacting it in the presence of a known uretdione catalyst to uretdione (e.g., dimerize) the xylylene diisocyanate.

The modified xylylene diisocyanate having the functional group (uretonimine group) of the above (h) can be obtained by reacting a xylylene diisocyanate composition in the presence of a known carbodiimidization catalyst to form a carbodiimide group and then adding a xylylene diisocyanate to the carbodiimide group.

The modified xylylene diisocyanate having the functional group (carbodiimide group) of the above (i) can be obtained by reacting a xylylene diisocyanate composition in the presence of a known carbodiimide catalyst.

The phenylene diisocyanate-modified composition may contain at least 1 functional group of the above (a) to (i), or may contain 2 or more functional groups. Such a xylylene diisocyanate-modified composition can be produced by appropriately combining the above-mentioned reactions. In addition, the phenylene diisocyanate-modified composition may be used alone or in combination of 2 or more.

The fourth object of the present invention is to provide a polyurethane resin obtained by reacting the phenylene diisocyanate composition of one of the objects with an active hydrogen group-containing substance or by reacting the modified composition of the third object with an active hydrogen group-containing substance.

Examples of the active hydrogen group-containing substance include a polyol component (component mainly containing a polyol having 2 or more hydroxyl groups), a polythiol component (component mainly containing a polythiol having 2 or more mercapto groups (thiol groups)), and a polyamine component (compound mainly containing a polyamine having 2 or more amino groups).

Specifically, the polyurethane resin can be suitably used for applications such as inks, transfer foils, adhesives, gels, elastomers, foams, adhesives, liquid-curable sealing materials, RIM molded articles, micro-foam polyurethanes, various microcapsules, optical materials, aqueous resins, thermosetting resins, active energy ray (e.g., electron beam, ultraviolet ray, etc.) curable resins, artificial and synthetic leather, setting powders, robot members, moving members, medical care materials, base resins of Carbon Fiber Reinforced Plastics (CFRP), transparent rubbers, transparent hard resins, waterproof materials, films, sheets, pipes, plates, speakers, sensors, organic electroluminescent members, solar power generation members, robot members, wearable members, sporting goods, leisure goods, medical goods, nursing goods, house components, acoustic members, lighting members, chandeliers, outdoor lamps, packages, vibration/shock/vibration absorbing members, soundproof members, daily necessities, sundry goods, bumpers, sleeping wares, stress absorbing materials, stress relieving materials, automobile interior and exterior parts, conveyor members, automatic members, vibration-proof members, sundry equipment, office equipment, and health care equipment.

The fifth object of the present invention is to provide an elastomer material comprising the polyurethane resin of the fourth object.

Examples of the elastomer include a cast polyurethane elastomer (CPU), a thermoplastic polyurethane elastomer (TPU), a thermosetting polyurethane elastomer (TSU), and a millable polyurethane elastomer.

The elastomer comprises soft segments formed by the reaction of a phenylene diisocyanate with a high molecular weight polyol, and hard segments formed by the reaction of a phenylene diisocyanate with a low molecular weight polyol and/or a low molecular weight polyamine.

Compared with the prior art, the invention has the following beneficial effects:

The benzene diisocyanate composition provided by the invention contains 5-6000ppm of the compound shown in the formula (1) and has excellent stability.

Drawings

FIG. 1 is a flow chart of the preparation of a phenylene diisocyanate composition in an embodiment of the present invention;

Detailed Description

The method for measuring the relevant test in the invention is as follows:

1. Molar content of phenylenediamine

And (3) taking the reaction liquid (mass A), carrying out suction filtration, washing a filter cake for 2-3 times by using dichloromethane, drying the filter cake (mass B), placing the filter cake in tetrahydrofuran, stirring to fully dissolve the phenylenediamine, filtering and drying to obtain the filter cake (mass C), wherein the mass C minus the mass B is the mass of the phenylenediamine, and the mass C is the molar content of the phenylenediamine compared with the total amount of the phenylenediamine.

2. Structure confirmation and content ratio of Compound PPAI

The structure determination of PPAI was performed by GCMS.

Derivatizing a reaction solution containing PPAI: one drop of the reaction solution was mixed with 600uL of acetonitrile, 300uL of bis (trimethylsilyl) trifluoroacetamide, 100uL of pyridine, and heated at 70℃for 30min, to be tested.

Instrument: agilent 8890

The testing method comprises the following steps: (1) chromatography column: DB-5 (30 m.times.0.25 mm.times.0.25 μm); (2) sample injection amount: 1 μl; (3) split ratio: 1/50; (4) sample inlet temperature: 280 ℃; (5) temperature programming: keeping the temperature at 50 ℃ for 2min, heating to 80 ℃ at 5 ℃/min, heating to 280 ℃ at 15 ℃/min, and keeping the temperature for 15min; transmission line temperature: 300 ℃.

Analysis results: the peak with molecular weight 206 in the mass spectrum is the derivative PPAI, and the structure is as follows:

Analysis was performed by gas chromatography under the following conditions, and the content of the compound PPAI was obtained by normalizing the area values of the obtained gas chromatogram.

Instrument: agilent 7890

(1) Chromatographic column: DB-5 (30 m.times.0.25 mm.times.0.25 μm); (2) sample injection amount: 0.5. Mu.L; (3) split ratio: 1/30; (4) sample inlet temperature: 260 ℃; (5) column flow rate: 1.5mL/min; (6) temperature programming: maintaining 1min at 100deg.C, heating to 280 deg.C at 10deg.C/min, and maintaining for 20min; (7) FID detector temperature: 280 ℃; (8) hydrogen flow rate: 40mL/min, air flow rate: 400mL/min.

3. Content ratio of Benzenediisocyanate

The PPDI having a purity of 99mol% in the examples described below was used as a standard substance, and was analyzed by gas chromatography under the following conditions by the internal standard method.

Instrument: agilent 7890

(II) raw materials and sources

TABLE 1 raw material information

Reagent name	Manufacturer' s	Purity of
			Para-phenylenediamine	An Nuo A	＞99.0％
Chlorobenzene (Chlorobenzene)	Inock	Analytical grade
			Polycaprolactone diol (molecular weight 2000)	Daxie celluloid (brand 220N)	Industrial grade
1, 4-Butanediol	Inock	Analytical grade

To facilitate understanding of the present invention, examples are set forth below. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

Unless otherwise specified, "parts" and "%" are based on mass.

Examples 1 to 7 and comparative examples 1 and 3

The above examples and comparative examples each provide a PPDI composition, the specific composition of which is detailed in table 2.

The preparation method of the PPDI composition is as follows:

PPDI compositions were made using the procedure shown in fig. 1. Specifically, 800 parts by mass of chlorobenzene was charged into a luminescence reactor shown in FIG. 1. Next, the luminescence temperature in the luminescence reactor was adjusted to 50℃and the luminescence pressure (gauge pressure) in the luminescence reactor was adjusted to 0.06MPaG. Then, 150 parts by mass of phosgene was introduced into the autoclave via a phosgene supply line, and a mixed solution (amine solution) of 150 parts by mass of PPDA and 1050 parts by mass of chlorobenzene was introduced into the autoclave via an amine supply line. Thus, a PPDA chill slurry was prepared.

Next, phosgene was continuously blown into the autoclave through the phosgene supply line at a supply rate of 100 parts by mass/hr, and an amine solution having a PPDA concentration of 7.5wt.% was continuously charged into the autoclave through the amine supply line at a supply rate of 1000 parts by mass/hr, while the reactants were fed to the polishing pump through the actinic liquid feed line and circulated back to the autoclave through the actinic liquid feed line in accordance with the gap and residence time of the fluted disc shown in table 2, and PPDA actinic liquid was fed into the one autoclave through the actinic liquid feed line.

Next, phosgene was continuously introduced into the thermal-phosgenation reactor. Table 2 shows the reaction temperature and reaction pressure (gauge pressure) of the reactor and the ratio of phosgene supply to 1mol of PPDA.

Thus, a reaction product containing PPDI was produced by reacting a PPDA cooling liquid with phosgene to produce PPDI. In addition, a part of the unreacted phosgene is condensed by a condenser into an photochemical kettle.

Next, the photochemical reaction liquid was continuously fed into the dephosgene column. The reaction mass is then degassed in a dephosgene column. Next, the deaerated matter is discharged from the deaeration tower through a deaerated matter transporting line, and is continuously transported into the deaeration tower. Thus, 120 parts by mass of a desolvation material having a concentration of 95wt.% of PPDI was prepared.

Next, the desolventizing substance is discharged from the desolventizing column through a desolventizing substance delivery line, and the desolventized solvent is purified by a solvent purifying column and then reused.

The solvent refining column was packed with a packing material corresponding to 10 theoretical plates, and the operating conditions thereof were as follows:

Bottom temperature: 80-130 DEG C

Overhead temperature: 60-120deg.C

Overhead pressure: as shown in Table 2

Overhead reflux ratio: as shown in Table 2

Residence time: 0.5-5h

Continuously conveying the solvent-removed material into a tar remover. Then, the desolventizing substance is subjected to tar removal in a tar remover to prepare an intermediate substance. The content ratios of chlorobenzene (MCB), PPDI and PPAI in the intermediate materials are shown in Table 2.

Next, the intermediate matters were continuously fed into the rectifying column by a feed rate of 100 parts by mass/hr. The rectifying column was packed with a packing material having a theoretical plate number of 5. The light components are then removed from the top of the column in a rectification column from which the PPDI composition product is withdrawn.

The rectification conditions in the rectification column are as follows:

Bottom temperature: 110-130 DEG C

Overhead temperature: 100-110 DEG C

Overhead pressure: 0-1.5KPa

Residence time: 1-5h

The recovery rate and the overhead reflux ratio in the rectification step are shown in Table 2.

Thereby, a PPDI composition was produced. The ratio of PPDI to PPAI in the PPDI composition is shown in Table 2.

Comparative example 2

To the intermediate material obtained in example 1 was added PPAI to a content of 1.3%, and a PPDI composition of comparative example 2 was prepared under the same photochemical, concentration and separation conditions as in example 1.

TABLE 2 conditions and results for examples 1-7 and comparative examples 1-3

Stability test

The PPDI compositions of the above examples and comparative examples were evaluated for thermal stability testing, as follows:

the initial NCO content (NCO%) of the PPDI compositions of the above examples and comparative examples was measured by titration (HG/T2409-92). First, N-butylamine in excess of the theoretical NCO content was added and allowed to react, and the residual excess N-butylamine was analyzed with a 0.1N hydrochloric acid reagent. The results are shown in table 3 below.

The PPDI compositions of the above examples and comparative examples were placed in transparent glass bottles, the glass bottles were filled with nitrogen gas and sealed, and then each was stored at 50 ℃ for 30 days to obtain a stored composition, and NCO% of the stored composition was measured in the same manner as described above. 4g of the composition was dissolved in 16g of tetrahydrofuran, and the solution phenomenon was visually observed. The results are shown in table 3 below.

TABLE 3 application Effect data of PPDI compositions

As shown in Table 3, the stability of the PPDI composition can be effectively improved by controlling the PPAI content in the PPDI composition to be within 5-6000ppm, and the PPAI content is lower than 5ppm (comparative example 3) and higher than 6000ppm (comparative examples 1 and 2), so that the stability performance is inferior to that of the PPDI composition provided by the invention.

The applicant states that the detailed method of the present invention is illustrated by the above examples, but the present invention is not limited to the detailed method described above, i.e. it does not mean that the present invention must be practiced in dependence upon the detailed method described above. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of raw materials for the product of the present invention, addition of auxiliary components, selection of specific modes, etc., falls within the scope of the present invention and the scope of disclosure.

Claims

1. A benzene diisocyanate composition, characterized in that the benzene diisocyanate composition comprises benzene diisocyanate and 5 to 6000ppm of a compound represented by formula (1);

2. The xylylene diisocyanate composition according to claim 1, wherein the mass content of the compound represented by the formula (1) is 10 to 2000ppm.

3. The phenylene diisocyanate composition according to claim 1, characterized in that the phenylene diisocyanate comprises any one or at least two combinations of 1, 2-phenylene diisocyanate, 1, 3-phenylene diisocyanate, 1, 4-phenylene diisocyanate, 1, 5-phenylene diisocyanate, preferably 1, 4-phenylene diisocyanate and/or 1, 3-phenylene diisocyanate, more preferably 1, 4-phenylene diisocyanate;

preferably, the phenylene diisocyanate composition comprises 95wt.% or more of phenylene diisocyanate;

4. a process for preparing the xylylene diisocyanate composition according to any one of claims 1 to 3, which comprises:

(1) An isocyanate process:

a. Mixing phenylenediamine with phosgene in the presence of a solvent;

c. isocyanating the intermediate reactant generated by the cold reaction unit in the hot reaction unit to obtain a reaction product containing the benzene diisocyanate and the compound shown in the formula (1);

Wherein the intermediate reactant obtained in carrying out reaction b comprises less than 5% of phenylenediamine, preferably less than 4%, based on the molar amount of the phenylenediamine fed;

5. The method of claim 3 or 4, wherein the phenylenediamine comprises any one or a combination of at least two of 1, 2-phenylenediamine, 1, 3-phenylenediamine, 1, 4-phenylenediamine, and 1, 5-phenylenediamine; and/or the reaction solvent is selected from aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, halogenated aromatic hydrocarbons, nitrogen-containing compounds, ethers, ketones, fatty acid esters, and aromatic carboxylic acid ester solvents.

6. A modified composition of a xylylene diisocyanate composition, characterized in that the modified composition is a xylylene diisocyanate composition according to any one of claims 1 to 3 or a modified composition obtained by modifying a xylylene diisocyanate composition produced by the production method according to any one of claims 4 to 6, wherein the modified xylylene diisocyanate in the modified composition contains any one or a combination of at least two of the following groups (a) to (e): (a) isocyanurate groups, (b) uretdione groups, (c) biuret groups, (d) urethane groups, (e) urea groups, (f) iminooxadiazinedione groups, (g) allophanate groups, (h) uretonimine groups, or (i) carbodiimide groups.

7. Polyurethane resin, characterized in that it is obtained by reacting the xylylene diisocyanate composition according to any one of claims 1 to 3 or the xylylene diisocyanate composition produced by the production method according to any one of claims 4 to 5 and/or the modified composition according to claim 6 with a substance containing an active hydrogen group.

8. An elastomeric material comprising the polyurethane resin of claim 7.