JP5070672B2 - Solid xylylenediamine in containers, method for producing the same, and method for storing xylylenediamine - Google Patents

Description

  The present invention relates to a container-containing solid xylylenediamine, a method for producing the same, and a method for storing xylylenediamine. Since the solid xylylenediamine in a container of the present invention is excellent in storage stability, it is industrially useful. Xylylenediamine is a compound useful as a raw material for polyamide resins, curing agents and the like, and as an intermediate raw material for isocyanate compounds and the like.

  It is known that amines are easily deteriorated by light, heat, oxygen, etc., and cause deterioration such as coloring and odor through storage. In particular, xylylenediamine is a benzylamine, unlike aromatic amines such as diaminotoluenes and aliphatic amines such as hexamethylenediamine and isophoronediamine. In addition, the deammonia reaction tends to proceed remarkably. Conventionally, when preserving xylylenediamine, the air in the container is replaced with an inert gas such as nitrogen gas, and then sealed, and stored such as to avoid the effects of light, heat, etc. It is normal. However, even if such a treatment is performed, a satisfactory effect is still not obtained.

  As a technique for stably storing xylenediamine, a method of adding an unsaturated compound having a terminal double bond such as 1-butene, 1-hexene, and styrene is described (see Patent Document 1). However, this method leads to a decrease in purity due to the addition of additives to the product, and there is a possibility that inconvenience may occur due to the unsaturated compound added when the product is used.

  In addition, it is described that ammonia odor odor due to deterioration of polyamine during storage can be suppressed by enclosing a liquid made of aliphatic polyamine in an airtight container in a substantially oxygen-free state (see Patent Document 2). However, according to the study by the present inventors, a drum can or 20L can (Ito Can) that is usually used as an industrial container for xylylenediamine is used. Even when filling was performed while being distributed, the xylylenediamine after storage was deteriorated in color. As estimated by the present inventors, the effort to achieve anaerobic state by nitrogen substitution in normal industrial production does not sufficiently achieve oxygen purge. It is probable that this was not achieved. When the present inventors actually investigated the oxygen concentration in the gas phase part of the 20 L can after filling when the 20 L can was filled with xylylenediamine, the container was preliminarily purged with nitrogen and nitrogen was further circulated. However, despite the xylylenediamine filling, the presence of about 500 to 2000 ppm of oxygen was observed in the gas phase. Further, when the oxygen concentration in the gas phase portion of the 20 L can after storage was investigated, an oxygen concentration higher than that at the time of filling was detected in some cases. That is, air leakage was suspected throughout the storage period. Therefore, in order to store xylylenediamine in a substantially oxygen-free state, special consideration is required when filling the container or selecting a container and packing that does not leak oxygen, and this is usually carried out industrially. It seems that careful consideration is not enough.

Although not related to the preservation method of aromatic amines containing aromatic rings such as xylylenediamine, coloring aromatic amines by storing aromatic amines in a sealed state in the presence of an oxygen scavenger and desiccant It is described that the quality can be maintained without doing (see Patent Document 3). In general, water is necessary for an oxygen scavenger to exert its effect, and therefore, a decrease in quality due to transfer of water to amines is assumed. In order to prevent this, the coexistence of a desiccant has been proposed, but it is considered that the moisture necessary for the function of the oxygen scavenger is not sufficiently maintained. High-purity amines are extremely hygroscopic, exhibiting an equivalent absorption rate compared to common desiccants such as silica gel, activated carbon, molecular sieves, and anhydrous calcium chloride, and are perfect using desiccants. It is virtually impossible to completely prevent moisture absorption, i.e. transfer of moisture to the diamine.
Further, since there is a concern about deformation of the container due to volume reduction of the gas phase portion in the container due to oxygen absorption, a pressure resistant container that can withstand negative pressure is required. Furthermore, gas barrier properties are also required for the packing of the lid in order to keep the container airtight. Therefore, the container suitable for this document must be very versatile.
Japanese Patent Publication No.46-21857 Japanese Patent Laid-Open No. 10-81651 JP 2002-193897 A

  An object of the present invention is to provide a xylylenediamine excellent in storage stability that does not cause quality deterioration such as coloring even after long-term storage and a method for producing the same, and a method for storing xylylenediamine. It is.

  As a result of intensive studies, the present inventors have found that solid xylylenediamine in a container that has been solidified in a container after being filled in a liquid form is extremely excellent in storage stability, can prevent coloring during storage, and can be used for a long time. The present invention has been found out that it can be stably stored.

That is, the present invention relates to the following.
(1) A liquid xylylenediamine having a hue of APHA of 20 or less in a container and then solidified in the container, and then solidified in the container. The hue measured as is APHA as 20 or less.
(2) The solid xylylenediamine in a container according to (1), wherein the oxygen concentration in the gas phase portion in the container is 0.01 to 21 vol%.
(3) The solid xylylenediamine in a container according to (1), wherein the xylylenediamine is metaxylylenediamine.
(4) The solid xylylenediamine in a container according to (1), wherein the xylylenediamine is a mixture of metaxylylenediamine and paraxylylenediamine having a freezing point of 30 ° C. or less.
(5) A liquid xylylenediamine having a hue of APHA of 20 or less is charged in a container, and then cooled to solidify the xylylenediamine in the container. Manufacturing method.
(6) The method for producing a solid xylylenediamine in a container according to (5), wherein after replacing the gas phase portion in the container with an inert gas, the xylylenediamine is solidified in the container.
(7) The method for producing a solid xylylenediamine in a container according to (5), wherein xylylenediamine is solidified within 10 days after filling the container.
(8) A liquid xylylenediamine having a hue of 20 or less as APHA is filled in a container, and the liquid xylylenediamine is solidified in the container by cooling to form a solid xylylenediamine. A method for storing xylylenediamine, wherein the amine is stored in a container while maintaining a solid state.
(9) The method for preserving xylylenediamine according to (8), wherein the oxygen concentration in the gas phase in the container is 0.01 to 21 vol%

  The solid xylylenediamine in a container provided in the present invention is extremely excellent in storage stability, and its color deterioration is extremely small even in an environment where oxygen is present, for example, in the air. In the present invention, an inexpensive general-purpose container that is industrially used can be used, and it is not necessary to thoroughly reduce the oxygen concentration, and is simple and economical. Therefore, the industrial significance of the present invention is great.

  Hereinafter, the present invention will be specifically described. The xylylenediamine in the present invention is metaxylylenediamine, paraxylylenediamine and a mixture thereof. The freezing point of metaxylylenediamine is 14 ° C, and the freezing point of paraxylylenediamine is 63 ° C. The freezing point of a mixture of metaxylylenediamine and paraxylylenediamine depends on its composition and ranges from 2 ° C to 63 ° C. In particular, metaxylylenediamine or a mixture of metaxylylenediamine and paraxylylenediamine having a freezing point of 30 ° C. or lower is suitable for the present invention.

The container-like solid xylylenediamine of the present invention is produced by filling a container with liquid xylylenediamine having a hue of 20 or less as APHA and then cooling to solidify the xylylenediamine in the container. When the APHA of liquid xylylenediamine used as a raw material for solid xylylenediamine in a container exceeds 20, the degree of coloration of the produced solid xylylenediamine in a container is high, and sufficient quality cannot be obtained. In order to maintain the APHA of liquid xylylenediamine at 20 or less, the following formula:
0 <a × b × exp (0.07 × T) <2000
(Wherein, a is the average oxygen concentration (vol%) of the storage atmosphere, b is the number of days (days) until it is solidified in the container after being taken out of the production process, and T is the average temperature (° C.).)
It is preferable to control the storage history of xylylenediamine until it is solidified in the container after being taken out of the production process so as to satisfy the above condition.

  The xylylenediamine filled in a container in a liquid form is preferably solidified as soon as possible, preferably solidified within 10 days after filling the container, more preferably within 5 days, and within 3 days. It is particularly desirable to be. The temperature at which xylylenediamine is solidified is not particularly limited. However, for example, it is desirable that the temperature be not higher than (freezing point of xylylenediamine-5 ° C.) in order to solidify as quickly as possible. Liquid xylylenediamine can be cooled and solidified by placing the container in a place where the temperature is lower than the freezing point, such as in a temperature-controlled room, refrigerator, or outdoor in a cold region, immersing the container in a water bath or oil bath, etc. A cooling means such as sprinkling ice into a container is arbitrarily selected.

  The solid xylylenediamine in a container coagulated in the container of the present invention has a hue of 20 or less as APHA, which is measured as a liquid after being stored in a solid state and melted. The storage period is preferably 5 to 1500 days, more preferably 30 to 800 days. If APHA after storage for the above period is 20 or less, it can be suitably used for many applications. When APHA is measured by melting solid xylylenediamine in a container solidified in a container and measuring APHA, it is preferable that the gas phase part of the container does not deteriorate the color of liquid xylylenediamine in the operation from melting to measurement. Is replaced with an inert gas such as nitrogen and heated to melt the xylylenediamine, and the measurement is performed immediately. The APHA measurement method is described in ASTM-D-1209 and ASTM-D-5386. Specific methods for measuring APHA include a method by visual comparison with a standard sample and a method using a commercially available color difference meter, and either method may be used.

  Various containers can be used as the container used in the present invention, and cans, bottles, containers, tanks and the like made of metal, plastic, glass and the like can be mentioned. The solid xylylenediamine in a container of the present invention exhibits excellent storage stability even in an environment where oxygen is present in the gas phase, unlike the liquid xylylenediamine, and thus has high airtightness without air leakage. There is no need to use special containers or special packing with high gas barrier properties, and inexpensive general-purpose containers such as drum cans, oil cans, tank trucks, bulk containers, and stationary tanks that are commonly used in industry can be used suitably. .

  The container-containing solid xylylenediamine of the present invention is surprisingly excellent in storage stability as compared with liquid xylylenediamine, and its color deterioration is extremely small even in an environment where oxygen is present. This feature is extremely advantageous when handling xylylenediamine. Since liquid xylylenediamine is easily deteriorated by oxygen in the air, it is necessary to replace the air in the container with an inert gas such as nitrogen before storing it, but it is sealed and stored. This requires a long inert gas replacement process using a large amount of inert gas, and also requires a container with a special material and structure that is highly airtight and does not leak air during storage. For this reason, it is not easy and economical to implement industrially. On the other hand, the solid xylylenediamine in a container of the present invention is significantly less deteriorated in color even in the presence of oxygen, so that the gas phase in the container is filled with an inert gas such as nitrogen in particular. There is no need to keep air, and air may be used.

  However, since liquid xylylenediamine is easily deteriorated by oxygen, the liquid xylylenediamine is filled in the container and then solidified, and after the solid xylylenediamine contained in the container is melted, the liquid xylylenediamine is further liquid in the container. In order to avoid deterioration during the period of holding the liquid, the gas phase is previously replaced with an inert gas that does not contain oxygen and does not react with xylylenediamine, such as nitrogen, argon, helium, etc. It is preferable when the period for holding xylylenediamine is long. The oxygen concentration in the gas phase portion in the container is preferably 0.01 to 21 vol%, more preferably 0.01 to 1 vol%, and particularly preferably 0.01 to 0.3 vol%.

  Utilizing the high storage stability of the solid xylylenediamine in a container according to the present invention, a new method for storing xylylenediamine is provided. That is, after filling a container with liquid xylylenediamine having a hue of 20 or less as APHA, the container is cooled to produce solid xylylenediamine in a container, and stored in the state of solid xylylenediamine in a container. Thus, xylylenediamine can be stably stored.

  According to this method, when oxygen is present in the gas phase portion in the container, xylylenediamine can be preferably stored even when the gas phase portion is air, which is extremely advantageous. For example, in a place where there is no inert gas supply facility (for example, when xylylenediamine is used as a curing agent for epoxy resin at a construction site), when xylylenediamine contained in a container is used, but the remainder is generated, the present invention By applying this storage method, it is possible to prevent the excessive xylylenediamine from being deteriorated and to store it stably.

  The oxygen concentration in the gas phase in the container when stored in the state of solid xylylenediamine in a container is preferably 0.01 to 21 vol%, more preferably 0.01 to 1 vol%, and particularly preferably 0.01. -0.3 vol%. For the deterioration of liquid xylylenediamine, it is advantageous that the oxygen concentration in the gas phase in the container is low. However, when xylylenediamine is stored by the method of the present invention, xylylenediamine is present in liquid form. Since the period is short, there is no need to pursue a particularly strict oxygen-free state, and the presence of oxygen of about 0.01 vol% does not matter. According to the study by the present inventors, it is easy to reduce the oxygen concentration to about 1 to 0.3 vol% when attempting to reduce the oxygen concentration in the gas phase in the container by introducing an inert gas into the container. However, when the oxygen concentration is lowered, the efficiency of substitution by introducing an inert gas is lowered, and particularly when trying to obtain an extremely low oxygen concentration of less than 0.01 vol%, it is not impossible, but a very large amount A long-term replacement operation using an inert gas is required. In the present invention, the presence of about 0.01 vol% oxygen is not a problem, so even if the gas phase in the container is replaced with an inert gas, the amount of inert gas used and the time for the replacement treatment are not affected. The burden can be kept small, which is advantageous.

  In the preservation method of the present invention, it is necessary to control the temperature so that the solid xylylenediamine contained in the container maintains a solidified state. The temperature is not particularly limited as long as the xylylenediamine is solidified. For example, it is efficient and desirable to maintain the temperature within a range from −20 ° C. to (freezing point of xylylenediamine—1 ° C.). Further, the temperature at which xylylenediamine is maintained in a solidified state need not be constant. If the temperature is below (freezing point of xylylenediamine-1 ° C.), the xylylenediamine filled in the storage container may be stored outdoors, but in direct sunlight or the like (freezing point of xylylenediamine-1 Care must be taken not to raise the container temperature to a temperature exceeding (° C).

  In producing the solid xylylenediamine in a container of the present invention, it is important to solidify the xylylenediamine after filling the container. As described above, when it is necessary to replace the gas phase part with an inert gas such as nitrogen in advance, when the coagulated xylylenediamine is crushed and filled with flaky xylylenediamine, the gas contained is This is unfavorable because it increases the number of inconveniences, such as taking time for this replacement or not being able to perform sufficient replacement.

  The use of xylylenediamine is an epoxy resin curing agent, a polyamide raw material, an isocyanate raw material, etc., and for these uses, it is usually used in liquid form. When the coagulated xylylenediamine is melted and used, it is desirable to melt it in the container, leave the container in a place with a temperature higher than the freezing point, immerse the container in a warm water bath, oil bath, etc. Melting means such as contacting the container and spraying steam on the container is arbitrarily selected. The heating temperature at this time is preferably as low as possible, desirably melting at a temperature lower than (freezing point + 120 ° C.), more preferably a temperature lower than (freezing point + 60 ° C.), and further preferably a temperature lower than (freezing point + 40 ° C.). . When the gas in the gas phase contains oxygen or air, it is desirable to replace the gas phase with an inert gas such as nitrogen in advance.

  Since metals such as cobalt, copper, rhodium, zinc and iron adversely affect the storage stability of xylylenediamine, the total amount of cobalt, copper, rhodium, zinc and iron in xylylenediamine is 0.005% by weight. Or less, more preferably 0.0005% by weight or less.

The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to these examples.
The coloring was evaluated by the hue (APHA) measured by the method described in ASTM-D-1209.

<Example 1>
Under an air atmosphere, a brown glass bottle having a capacity of 0.5 L was filled with 0.4 L of liquid metaxylylenediamine (APHA5 or less, freezing point 14 ° C.) at 25 ° C. The stopper was capped and immediately stored in a constant temperature bath at 2 ° C. Metaxylylenediamine was solidified when visually confirmed after 2 hours from putting in the thermostat. After storage at 2 ° C. for 1 month (30 days), the glass bottle containing metaxylylenediamine was taken out of the thermostatic bath and melted in a water bath at 40 ° C., and then APHA was measured. APHA was 5 or less, and coloring during storage was not recognized.

<Example 2>
Under an air atmosphere, a 0.5 L brown glass bottle was filled with 0.4 L of a liquid meta / para mixed xylylenediamine (meta / para = 7/3 (molar ratio), APHA 5 or less, freezing point 8 ° C.) at 25 ° C. The stopper was capped and immediately stored in a constant temperature bath at 2 ° C. As a result of visual confirmation after 2 hours from putting in the thermostatic bath, xylylenediamine was solidified. After storage at 2 ° C. for 1 month (30 days), the glass bottle containing xylylenediamine was taken out of the thermostatic bath, and xylylenediamine was melted in a 40 ° C. water bath, and then APHA was measured. APHA was 5 or less, and coloring during storage was not recognized.

<Example 3>
A metal 20 L can was filled with 18 L of liquid metaxylylenediamine (APHA 5 or less, freezing point 14 ° C.) at 25 ° C. After the nitrogen substitution process in which nitrogen was blown into the gas phase for 1 minute, the lid was quickly capped. Thereafter, the container containing metaxylylenediamine was held in an environment having a temperature of 5 ° C. or higher and 13 ° C. or lower. Two days later, metaxylylenediamine was solidified as confirmed by shaking the container. It was stored in a solid state at 5 ° C. or higher and 13 ° C. or lower for 2 months (60 days). After storage for 2 months, APHA was measured after melting metaxylylenediamine in a 40 ° C. water bath. APHA was 5 or less, and coloring during storage was not recognized. At this time, the oxygen concentration in the gas phase was 0.15 vol%.

<Example 4>
Under an air atmosphere, a brown glass bottle having a capacity of 0.5 L was filled with 0.4 L of liquid paraxylylenediamine (APHA5 or less, freezing point 63 ° C.) at 80 ° C. After nitrogen substitution treatment in which nitrogen was blown into the gas phase for 1 minute, the stopper was capped and immediately stored in a constant temperature bath at 2 ° C. When visually confirmed after 2 hours from putting in the thermostat, paraxylylenediamine was solidified. After storage at 2 ° C. for 1 month (30 days), the glass bottle containing paraxylylenediamine was taken out of the thermostatic bath, and paraxylylenediamine was melted in an 80 ° C. water bath, and then APHA was measured. APHA was 5 or less, and coloring during storage was not recognized.

<Comparative Example 1>
Under an air atmosphere, a brown glass bottle having a capacity of 0.5 L was filled with 0.4 L of liquid metaxylylenediamine (APHA5 or less, freezing point 14 ° C.) at 25 ° C. After stoppering, APHA was measured after storage in liquid state at room temperature (25 ° C.) for 1 month (30 days). APHA was 60, and it was considerably colored yellow.

<Comparative example 2>
Under an air atmosphere, a 0.5 L brown glass bottle was filled with 0.4 L of a liquid meta / para mixed xylylenediamine (meta / para = 7/3 (molar ratio), APHA 5 or less, freezing point 8 ° C.) at 25 ° C. After stoppering, APHA was measured after storage in liquid state at room temperature (25 ° C.) for 1 month (30 days). APHA was 50, and it was considerably colored yellow.

<Comparative Example 3>
A metal 20 L can was filled with 18 L of liquid metaxylylenediamine (APHA 5 or less, freezing point 14 ° C.) at 25 ° C. After the nitrogen substitution process in which nitrogen was blown into the gas phase for 1 minute, the lid was quickly capped. It was stored in a liquid state at 20-30 ° C. for 2 months (60 days). When APHA was measured after storage for 2 months, APHA was 25 and clear coloring was observed. At this time, the oxygen concentration in the gas phase was 0.15 vol%.

<Example 5>
A metal 20 L can was filled with 18 L of liquid metaxylylenediamine (APHA 5 or less, freezing point 14 ° C.) at 25 ° C. After the nitrogen substitution process in which nitrogen was blown into the gas phase for 1 minute, the lid was quickly capped. The container containing metaxylylenediamine was immediately stored in a thermostatic bath at 2 ° C. Metaxylylenediamine was coagulated when confirmed by touching the container one day after placing in the thermostatic bath. After storage at 2 ° C. for 6 months (180 days), after melting metaxylylenediamine in a 40 ° C. water bath, APHA was measured. APHA was 5 or less, and coloring during storage was not recognized. At this time, the oxygen concentration in the gas phase was 0.15 vol%.

  The xylylenediamine stored in the present invention is useful as a raw material for polyamide resins, curing agents and the like, and as an intermediate raw material for isocyanate compounds and the like.

Claims (3)

After filling the container with liquid xylylenediamine having a hue of 20 or less as APHA, the container is cooled to solidify the xylylenediamine in the container to produce a solid xylylenediamine in the container. A method for preserving xylylenediamine, which is preserved in the state of rangeamine, wherein xylylenediamine is metaxylylenediamine or a mixture of metaxylylenediamine and paraxylylenediamine having a freezing point of 30 ° C or lower, A method for storing xylylenediamine, which comprises coagulating xylylenediamine within 10 days after filling into a container and storing it in a temperature range from -20 ° C to 1 ° C lower than the freezing point of the xylylenediamine. After replacing the gas phase in the vessel with an inert gas, featuring a solidifying the xylene re diamine in a container, storage method xylylenediamine according to claim 1, wherein.   The method for preserving xylylenediamine according to claim 1, wherein the oxygen concentration in the gas phase portion in the container is 0.01 to 21 vol%.