JPS60233044A - Production of polyisocyanate - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as an isocyanate component without causing the coagulation and blocking, free from the restrictions in the material of the reactor nor the reaction temperature, in high yield and purity, by reacting a mixture of a specific triamino compound and hexamethylenediamine with phosgene. CONSTITUTION:A triamino compound having three primary amino groups which are not bonded directly to the aromatic ring is made to react with phosgene to obtain the corresponding triisocyanate compound. In the above process, a mixture of said triamino compound and hexamethylenediamine is reacted with phosgene. The reaction is carried out preferably using e.g. 1,8-diamino-4-aminomethyl- octane, etc. as the triamino compound, at a weight ratio of the triamino compound to hexamethylenediamine of 5:95-90:10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a triincyanate compound having six incyanato groups in one molecule that are not directly bonded to an aromatic ring.

[Conventional technology]

Conventionally, incyanato group is aromatic B! It is known that polyisocyanates that are not directly bonded to J can be used as raw materials for producing non-yellowing polyurethane resins with excellent weather resistance. Representative products of these non-yellowing polyisocyanates include hexamethylene diinocyanate, 2,2.4
- or 2,4.4-) Limethylhexamethylene diisocyanate, isophorone diisocyanate, 1.4-
Examples include diisocyanatocyclohexane, bis(incyanatomethyl:2)shiffhexane, and xylylene diincyanate, but these have a pungent odor at room temperature and are difficult to handle safely due to toxicity to the human body. Yes. Furthermore, since diincyanates are difunctional, when used as a crosslinking agent for polyurethane resins, the crosslinking density is often too low. Therefore, ``These cycyanates are used as adducts derived by polymerizing and polyfunctionalizing them by reacting with so-called adducting agents such as triols such as trimethy4-propane, water, and tert-butanol. It is being However, since these are polymer mixtures, they have a high viscosity and require dilution with a solvent for handling, and their incyanate group content is inevitably reduced.

Against this background, in recent years, non-yellowing trifunctional incyanate compounds have been developed that have very low viscosity because they are monomers, and have extremely low vapor pressure at room temperature, so they are less irritating and less toxic. Development is underway.

These triisocyanates are, for example, JP-A-55-3
27, JP-A-55-167269, JP-A-56-615
41, JP-A No. 56-127341, etc., all of them are produced by the reaction of the corresponding triamino compound with phosgene (phosgenation reaction). Generally, in the phosgenation reaction of amines, amine hydrochloride is prepared in an inert solvent with 6
Hydrochloride method to form incyanate by reacting with phosgene at 0 to 260°C, or reaction of amine with phosgene at below 40°C, preferably below 8°C to form a mixture of carbamyl plide and amine hydrochloride. There are two methods: cold and hot two-step process to obtain incyanate, which is then heated to 60 to 260° C. under phosgene blowing. However, although the former hydrochloride method has the advantage of being able to obtain incyanate in a relatively high yield in the laboratory, it requires the synthesis and purification of an intermediate called amine hydrochloride; It has many disadvantages in industrial processes, such as the fact that it is usually solid and its handling is complicated.

Therefore, in the case of producing incyanate by the phosgenation reaction of amines, industrially, it is common to prioritize the advantages in terms of process and equipment, and to adopt a two-step cold/hot process. In fact, diincyanates such as those exemplified in Hikari are usually manufactured and supplied industrially by a two-step cold and hot process without any problems.

However, when converting a triamino compound (hereinafter simply referred to as triamine), which has three primary amine 7 groups in one molecule that are not directly bonded to an aromatic ring, to triincyanate by reacting with phosgene, the above-mentioned cold and heat two-step When trying to adopt this method, the slurry-like solid produced by the cold phosdenization reaction at a temperature of 60°C or higher starts to aggregate and eventually becomes lumpy, so the reaction does not proceed smoothly and the reaction is forced to continue. Even if the process is completed, the amount of tar-like polymeric substances and insoluble solids generated increases unnecessarily, and the critical triisocyanate yield cannot be increased. Another drawback is that the triisocyanate produced by such a reaction contains many impurities. Examples of impurities include those in which one of the three incyanates is replaced with chlorine, and so-called hydrolyzable chlorine. Triincyanate having a high hydrolyzable chlorine content is usually preferably 500 ppm or less, since polyurethane resin produced using it has a drawback in weather resistance.

The unique difficulty of this triamine phosgenation reaction is that
This problem can be solved to some extent by using the hydrochloride method or the so-called carbamate method as described in JP-A-52-122348.

However, the hydrochloride method has major problems in terms of equipment and process as described above, and the carbamate method also requires a gas component other than phosgene called carbon dioxide, which complicates the equipment and increases the heat-cooling ratio. Requires heat and multiple steps,
Furthermore, it has the disadvantage that it takes a relatively long time to complete the reaction.

In addition, as a measure to avoid agglomeration of the reaction contents in such a phosgenation reaction of triamine, it has been proposed to conduct the reaction in a reactor made of a water-repellent material at least in the low-temperature reaction section. (Unexamined Japanese Patent Publication No. 57-123158) However, the use of such a special reactor has many problems in terms of complication and high cost of the equipment.

[Problem that the invention seeks to solve]

In other words, when producing triincyanate through the phosgenation reaction of triamine, a two-stage cold and hot process, which is the easiest to adopt industrially, avoids agglomeration of solids and achieves high yield and high purity.
Furthermore, the development of a technology capable of manufacturing with high productivity without being limited to special reactor materials has been an attractive challenge for the industry.

[Means and effects for solving the problems] As a result of intensive research to achieve the above-mentioned problems in the phosgenation reaction of triamine, the present inventors surprisingly found that in the coexistence of hexamethylene diamine, He discovered that all of the problems could be solved by carrying out the phosgenation reaction of triamine, and was busy completing the present invention.

That is, in the present invention, when producing a corresponding triincyanate compound by reacting a triamino compound having three primary amino groups in one molecule that are not directly bonded to an aromatic ring with phosgene, the triamino compound and The present invention provides a manufacturing method characterized by reacting a mixture of hexamethylene diamine with phosgene.

According to the method of the present invention, the cold-thermal two-step phosdenization reaction of triamine proceeds as a uniform white slurry without agglomeration in any reactor material or temperature range. , which eventually transforms into a homogeneous clear solution within a relatively short time. Furthermore, the yield of the final product, triincyanate, is much higher than in the case where hexamethylene diamine is not present, and a highly purified product is obtained. Furthermore, the yield of hexamethylene diinocyanate produced at the same time is sufficiently high, making it an extremely excellent process as an industrial method for producing triisocyanate.

Although there is a prior art related to phosgenation of a mixture of two or more amines (Japanese Patent Application Laid-Open No. 48-48419),
This technique is aimed at the economical advantage of avoiding duplication of dosage, and does not mention anything about the phosgenation reaction of triamino compounds.

The triamino compound having three primary amino groups in one molecule that is not directly bonded to an aromatic ring and used as a raw material in the present invention is, for example, 1,8-diamino-4-aminomethyloctane, 1.6. 11-) riaminoundecane, 1
, 2.3-) Liaminozolopas 1.3.5-) Lis(aminomethyl)benzene, 1.3.5-) Lis(aminomethyl)cyclohexane, 2-Aminomethyl-3-(3-
Aminozolovir)-5-7minomethyl-bicyclo[2
,2゜1]-hebutane, 2-aminomethyl-3-(3-
aminozolopyl)-6-amitsumethyl-bicyclo-[2
,2,1] -hebutane, 1.4- (or 1.3-)
Bis(aminomethyl)-2-(3-aminozolovir)-
Cyclohexane, 1.4-(or 1.3-)bis-(
Examples include aminomethyl)-1-(6-aminozorobyl)-cyclohexane, 1-aminomethyl-2-(3-aminozorobyl)-4(or 5)-(2-aminoethyl)-cyclohexane, and the like.

These triamines are mixed with hexamethylene diamine and subjected to the phosgenation reaction, but the mixing ratio (triamine) = (hexamethylene diamine) weight ratio is 5 = 95 ~
90:10 is preferred. If the amount of triamine is too small, it will be difficult to separate the triincyanate compound after the reaction, and if the amount of hexamethylene diamine is too small, the agglomeration of the reaction contents will be insufficiently suppressed. stomach.

Hereinafter, the method of the present invention will be explained in order of steps.

In the low-temperature phosgenation reaction, which is the first step of the method of the present invention, a mixture of triamine and hexamethylene diamine is usually prepared in the presence of an inert solvent under relatively low-temperature conditions (usually 60%
The reaction is carried out at a temperature of 0.degree. C. or below, preferably -10 to 10.degree. The amount of phosgene used is at least equimolar, usually at least twice the mole relative to the amino group. As the inert solvent, tetralin, decalin, chlorobenzene, 0-dichlorobenzene, trichlorobenzene and the like are commonly used from the viewpoint of being inert to phosdanes and incyanate groups and having a relatively high boiling point. The low temperature phosphatization process usually requires 1 to 6 hours depending on the reaction temperature to complete the reaction.

Next, the temperature of this low-temperature phosgenation reaction product is raised in order to transfer it to a high-temperature phosgenation reaction. In the conventional phosgenation reaction of triamine using a cold two-step method, the contents agglomerate at this stage of temperature rise, making it impossible to stir the system, but according to the method of the present invention, such agglomeration is completely avoided. No, the system remains a homogeneous slurry.

The high-temperature phosgenation reaction is usually carried out at a temperature of 100 to 260° C. while supplying phosgene into the system, and the carbamyl chloride produced in the low-temperature phosgenation step is thermally decomposed and converted into incyanate. When the reaction is completed, the system becomes a homogeneous transparent liquid, and according to the method of the present invention, the time required for the high-temperature phosdenization step to complete the reaction is usually 1 to 15 hours, depending on the heating temperature.

The above reaction process is applicable to both batch and continuous reaction methods.

After the reaction is completed, the phosgene remaining in the system is purged with an inert gas such as nitrogen, the solvent is recovered, and the products triisocyanate and hexamethylene diisocyanate are separated by an appropriate method. As a separation method, vacuum distillation using the difference in boiling point between triisocyanate and hexamethylene diisocyanate is preferred.

The triincyanate and hexamethylene diisocyanate thus obtained are each effectively used as an incyanate component to be a raw material for polyurethane resins and the like.

Hereinafter, the content of the present invention will be explained more specifically using Examples.

Example 1 Orthodichlorobenzene 400I was charged into a glass reactor equipped with a stirrer, thermometer, condenser and gas blowing tube, and after cooling to 0°C, Phosdan 515I was introduced and dissolved. Into this thing 600g of orthodic tetrabenzene
50.9 of 1,8-diamino-4-aminomethyloctane and 5011 of hexamethylene diamine dissolved in the solution were added to the bottom of the reactor with stirring over 2 hours while keeping the internal temperature of the reactor below 5°C, and the addition was completed for 1 hour. Stirring continued. The system became a highly fluid white slurry. After that, the temperature was raised to 140℃ over about 1 hour while blowing phosdan, and the temperature was increased to 140℃.
The supply of phosphor was continued for 5 hours while maintaining the temperature. During this time, the reaction system remained in a highly fluid slurry state, and finally turned into a yellow transparent liquid with no solids remaining. After blowing nitrogen gas into the reaction solution to remove residual phosgene, orthodichlorobenzene as a solvent was distilled off under reduced pressure, and a small amount (91%) of tar was removed using a thin film evaporator.

The obtained incyanate mixture was rectified under reduced pressure to obtain hexamethylene diisocyanate as a fraction with a boiling point of 126° C./10 μHg. ! i+ (yield 96%) and boiling point 19
62.9 (yield: 85%) of 1,8-diynecyanato-4-ynecyanatomethyloctane was obtained as a fraction at 3°C/3 mHg. The purity of the obtained hexamethylene diisocyanate as determined by gas chromatography rough analysis (hereinafter referred to as Go
linear purity) is 99% or more, hydrolyzable chlorine content is 1
50ppm.

The GO purity of 1,8-diisocyanato-4-incyanatomethyloctane was 98% (2% low boiling impurities x hydrolyzable chlorine content 380 ppm).

Example 2 1.8-diami/-4-aminomethyloctane at 75%.
9. The reaction was carried out in the same manner as in Example 1 except that hexamethylene diamine was changed to 25y. The reaction system maintained a highly fluid slurry state over the entire temperature range as in Example 1, and finally became a yellow transparent liquid. Purification was carried out in the same manner as in Example 1, and 35I hexamethylene diisocyanate □ (yield 96%) and 901 1,8-diynecyanato-4-ynecyanatomethyloctane (yield 8%) were purified.
3%). Hexamethylene diisocyanate □
GO purity is over 99%, hydrolyzable chlorine content is 140%
The Go purity of ppms 1 s 8-diisocyanato-4-incyanatomethyloctane was 97%, and the hydrolyzable chlorine content was 450 ppm.

Example 3 1.8-diamino-4-aminomethyloctane at 251
．． The reaction was carried out in the same manner as in Example 1 except that hexamethylene diamine was changed to 75 g. Reaction System I As in Example 1, the reaction system remained in a highly fluid slurry state over the entire temperature range, and after 3 hours and 30 minutes at 140°C, the solid matter disappeared and a pale yellow transparent liquid was formed. Purification was carried out in the same manner as in Example 1 to obtain 105.9 hexamethylene diine cyanide) (
JIX ratio 97%). 5I! 1,8-diynecyanato-4-ynecyanatomethyloctane (yield 9%)
I got it. G of the obtained hexamethylene diincyanate
O-line purity 99% or more, hydrolyzable chlorine content 180p
The Go line purity of pms 1 , 8-diincyanato-4-incyanatomethyloctane was 98.5%, and the hydrolyzable chlorine content was 290 ppm.

Comparative Example 1 Orthodichloropene f' was added to the same reactor as in Example 1:
/ 400.1/ was prepared and cooled to 0°C, then phosgene 2
60I was introduced and dissolved. 1,8-diamino-4- dissolved in 600 g of heorthodixolbenzene
50g of aminomethyloctane was added to the bottom of the reactor while stirring for 2 hours while keeping the internal temperature below 5℃, and after the dropwise addition, 1
Stirring was continued for an hour.

The system was in a highly viscous slurry state. After that, the temperature was raised while blowing phosgene, and when the reaction solution reached about 70°C, agglomeration of the slurry-like solids began to occur, and the glutinous solids got entangled in the stirring device and eventually turned into lumps. It became impossible to stir. The temperature continued to rise while stirring was stopped, and when the temperature of the reaction solution reached approximately 160°C, the lumps began to separate, so stirring was restarted and the solids were broken off by shearing force while phosgene was heated at 145°C for 8 hours. continued to supply. The resulting liquid was dark brown and some solid suspended matter remained.

After removing residual phosgene with nitrogen, orthodichlorobenzene was removed under reduced pressure. The obtained concentrate was processed in a thin film evaporator.31. It was separated into a black tar component of f and a pale yellow distilled incyanate component. The distillate was rectified under reduced pressure to obtain 38 g (yield 52%) of 1,8-diisocyanato-4-incyanatomethyloctane. The GO line purity of this product is 96%.
(low-boiling impurities 7%), hydrolyzable chlorine content is 2000
It was ppm.

Example 4 Monochlorobenzene 400I was placed in the same reactor as Example 1.
After cooling to 0° C., 480 g of phosgene was introduced and dissolved. Monochlorobenzene 600I into this thing
! 1,6.11-)riaminoundecane dissolved in 5
0I and 50.9 g of hexamethylene diamine were added to the reactor under stirring over a period of 2 hours while keeping the internal temperature below 5° C., and stirring was continued for 1 hour after the dropwise addition was completed. The system was a slightly yellow slurry with fluidity. Thereafter, the temperature was raised to the solvent reflux temperature K over about 1 hour while blowing phosgene, and the reaction was continued for 7.5 hours under the solvent reflux condition. During this time, the reaction system maintained a highly fluid slurry state and finally became a light brown transparent liquid. The same purification procedure as in Example 1 was added to 6
9.9 hexamethylene diincyanate (95% yield)
) and 1,6 as a fraction with a boiling point of 208°C/2wn Hg
．． 11-) Riin cyanatoundecane 58g (yield 84
%) was obtained.

The obtained hexamethylene diinocyanate had an aa line purity of 99% or more, a hydrolyzable chlorine content of 150 ppm, and a G of 1.6.11-triisocyanatoundecane.
O-line purity 97%, hydrolyzable chlorine content 440 pp
It was m.

Comparative Example 2 A reaction was carried out in exactly the same manner as in Example 4 except that the amount of phosgene was 220y and hexamethylene diamine as an amine component was not added. The solid content began to aggregate and form lumps. After stopping stirring and raising the temperature to the reflux temperature of the solvent, stirring was restarted, but although some lumps separated, they were not dispersed. The reaction was continued for 10 hours while the solvent was refluxed and phosgene was blown into the solution, but a large amount of solid matter remained.

1,6°11 obtained by the same purification procedure as in Example 4
- The yield of triisocyanatoundecane was only 22%.

Patent applicant: Asahi Kasei Industries, Ltd. Procedural amendment ζ Hakusei) June 2nd, 1980 Mr. Manabu Shiga, Commissioner of the Patent Office ■Display of incident 1983 Patent Application No. 88374 2. Name of the invention Method for producing polyisocyanate 3. Person who makes corrections Relationship to the incident: Patent applicant 1-2-6-4 Dojimahama, Kita-ku, Osaka-shi, Osaka Prefecture, subject to amendment “Detailed description of the invention” column in the specification 5. Contents of correction

Claims (3)

[Claims] (1) When producing a corresponding triisocyanate compound by reacting a triamino compound having six primary amino groups in one molecule that are not directly bonded to an aromatic ring with phosgene, the triamino compound and hexamethylene A production method characterized by subjecting a mixture of siacines to a phosphor reaction. (2) The method according to claim 1, wherein the triamino compound is 1,8-diamino-4-aminomethyloctane. (3) The method according to claim 1, wherein the ratio of hexamethylene diamine to triamino compound is from 5:95 to 90:10.