JPH06306039A - Paraphenylene diisocyanate and production of isocyanate group-terminated prepolymer using the same - Google Patents

Abstract

(57) [Summary] [Structure] 1-20 mm x 1-20 m using a breaker
Flakes in the range of m × 0.1 to 2 mm, 3 to 10
mm × 3 to 10 mm × 0.2 to 1 mm is contained in 90% or more of the whole, or the average particle diameter is 1 to 10 using a granulator.
mm range, with a total particle size range of 2-5 mm of 9
PPD characterized by containing 0% or more of particles
And a method for producing an isocyanate-terminated prepolymer by reacting the PPDI with a liquid polyether polyol at room temperature. [Effects] By using flakes or particles of PPDI, dimer formation during melting is suppressed, and a high quality urethane elastomer is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to paraphenylene diisocyanate and a method for producing an isocyanate group-terminated prepolymer using the same.

[0002]

2. Description of the Related Art Polyurethane elastomers utilize their properties such as oil resistance, abrasion resistance, chemical resistance, cold resistance, toughness, etc. to make rolls for industrial parts, solid tires, anti-vibration materials, shoe materials, etc. Is used for. Polyurethane lastomers can be prepared by reacting an organic diisocyanate, a long-chain polyol and a chain extender at the same time, or by reacting an organic diisocyanate and a long-chain polyol, and adding a chain extender to the obtained isocyanate end group prepolymer. The way to get it is done. As the organic diisocyanate,
Conventionally, aromatic diisocyanates such as tolylene diisocyanate, (TDI) diphenylmethane diisocyanate (MDI), and paraphenylene diisocyanate (hereinafter abbreviated as PPDI) have been used. In particular, the polyurethane elastomer using PPDI forms a dense hard segment due to the simple molecular structure of PPDI and good symmetry, and the phase separation between the hard segment and the soft segment is very good. Compared with the polyurethane elastomers of, the elasticity, heat resistance and compression set are excellent. However, PPDI is solid at room temperature, has sublimability, is difficult to handle, and it is difficult to obtain a polyurethane elastomer having a certain quality.

[0003]

When using PPDI, it is necessary to melt PPDI. Since the melting point is as high as 95 ° C., it requires a large amount of energy and also takes time. Further, when heated near the melting point for a long time, a dimer is produced, which causes deterioration of purity and turbidity. Furthermore, PPD
I has a strong sublimation property, and when it is charged into a reaction kettle in the form of a nodule (hereinafter abbreviated as a block) and melted, the sublimated substance is recrystallized and attached in the upper space of the kettle. Since the reaction of isocyanate, including the synthesis of isocyanate-terminated prepolymer, requires stoichiometric rigor, it is difficult to obtain a certain quality if PPDI that remains attached to the upper part of the reaction vessel and does not participate in the reaction remains. Is.

Since PPDI has a high melting point, strict heat retention is required when the liquid is charged through a pipe connected to the reaction kettle. Manual charging of PPDI includes a method of heating the PPDI of the block in the oil can to 100 ° C. or higher to melt it, or a method of crushing the PPDI of the block in the oil can with a hammer before charging. ,
Since PPDI has a sublimation property, it has a strong odor and is difficult to have a good working environment. As a countermeasure against this, it has been considered that a prepolymer is obtained by injecting PPDI and an active hydrogen-containing compound into a multi-screw extruder with a quantitative feeder and continuously reacting them (Japanese Patent Laid-Open No. 64-69618).
No.), the quantitative feeder was insufficient in quantitativeness and accuracy, and it was difficult to always obtain a prepolymer having a constant quality.

[0005]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention is 1 to 20 mm using a flaker
It is a flake in the range of x1 to 20 mm x 0.2 to 2 mm and contains 3 to 10 mm x 3 to 10 mm x 0.2 to 1 mm in an amount of 90% by weight or more of the whole, or an average particle diameter using a granulator. Is in the range of 1 to 10 mm, and 90% by weight or more of the total particles are contained in the particle diameter range of 2 to 5 mm, and a method of producing the PPDI which is liquid polyether at room temperature. The present invention relates to a method for producing an isocyanate group-terminated prepolymer reacted with a polyol.

The present invention will be further described in detail. The flaker used in the present invention is a flakes made by scraping off a thin film-like solid, which is obtained by bringing a substance in a molten state into contact with the surface of a rotating drum, or by flowing it onto a rotating belt to solidify by cooling with a scraper. It is a device for forming. The flaker includes a drum type, a belt type, a table type and the like, and the drum type is more preferable. In addition, the granulator used in the present invention is a granular solid that is cooled and solidified by dropping a molten droplet through a nozzle or by injecting granular droplets formed by spraying into a rotating drum or belt. Is a device for obtaining.

The flakes obtained from the flaker are 3 to 10
If the size of mm × 3 to 10 mm × 0.2 to 1 mm is 90% by weight or more, it is easy to use, and if it is smaller than this size, problems such as scattering are likely to occur, and if it is too large, melting takes time and handling is difficult. 90% by weight or more of particles having a particle size of 2 to 5 mm obtained from a granulator are easy to use. If the particles are smaller than this size, problems such as scattering are likely to occur like flakes. Is difficult. The machine for processing with a breaker or granulator is used with a nitrogen seal so as not to absorb moisture in the air. Further, for the obtained flakes or particles of PPDI, a filling container having no moisture permeability is used.

In the production of the isocyanate group-terminated prepolymer according to the present invention, first, a liquid polyether polyol is charged into a reaction kettle at room temperature, and then the mixture is agitated while passing nitrogen gas, and flakes or granular PPDI is added to gradually increase the kettle temperature. The temperature rises to. The rate of temperature rise is determined by the production amount, but P
As the PDI amount increases, the temperature gradually rises, and the reaction is completed in about 2 hours after reaching 80 ° C. The internal temperature of the reaction kettle is 100 ° C
Be careful not to exceed this value because side reactions will occur.

The term "liquid at room temperature" as used herein means a liquid having a viscosity of 5 to 35 ° C. and 10,000 mPa · s or less. It is necessary to heat and melt a polyol that is solid at room temperature, such as polytetramethylene ether glycol, in advance. In this case, since the internal temperature of the reaction vessel is already high when PPDI is charged, PPDI easily sublimes. Generally, the method for producing an isocyanate group-terminated prepolymer is a method in which an organic isocyanate is first charged into a reaction kettle, the temperature is raised to the reaction temperature, and then a long-chain polyol is added. This conventional method is PP
When applied to DI, a large amount of sublimated PPDI adheres to the upper part of the reaction kettle, causing various troubles.

The polyether polyol which is liquid at room temperature used in the present invention may be a short molecule active hydrogen compound to which an alkylene oxide is added. For example, polypropylene polyether polyol,
Examples include polyethylene polypropylene polyether polyol. The molecular weight of the polyether polyol is 2
The number of functional groups is preferably 00 to 10,000 and the number of functional groups is preferably 2 to 4.

[0011]

EFFECT OF THE INVENTION Flake or granular PP which is easy to handle
By using DI, dimer generation during melting is suppressed and a high quality urethane elastomer can be obtained. Also,
Since the melting time is short, sublimation of PPDI is small, and a stoichiometrically strict reaction can be performed. Furthermore, since the working time is short, the working environment can be improved.

[0012]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Production of PPDI Flakes Production Example 1 As shown in FIG.
Heat to 0-110 ° C and feed the melted PPDI. 100 to 1 in contact with the PPDI liquid surface of this saucer 1
The small drum 2 heated to 10 ° C. is rotated at 50 to 60 rpm to uniformly deposit PPDI on the drum surface. Further, the surface temperature of another large drum 3 whose distance from the small drum 2 is set within 1 mm is kept at 50 to 60 ° C. and 10 rpm.
While rotating below, on the surface of the large drum 3, the small drum 1
Large drum 3 by contacting with the liquid layer of PPDI inside
Make a thin film of PPDI on the surface. This PPDI solidifies during rotation and is scraped off by another fixed scraper 4 before making one rotation. In this way, flakes of PPDI are obtained and stored in the filling container 5. 92% by weight of the flakes were 3-10 mm x 3-10 mm x 0.2-1 mm.

Production Example 2 of PPDI Particles Production Example 2 FIG. 2 is a perspective view of a granulating apparatus, which shows a granulator 1, a stainless belt 2, and a filling container 3. FIG. 3 shows a sectional view of a granulator for explaining the principle. The fixed inner cylinder 4 in the granulator 1 as shown in FIG. 3 is heated to 100 to 110 ° C., and the melted PPDI is fed to the raw material supply pipe 5 passing through the inside. PPDI is extruded from the plurality of holes 8 of the rotating outer cylinder 7 at 40 to 100 rpm through the plurality of nozzle bars 6 attached to the main pipe. Extruded molten PPD
I dropped onto a movable stainless steel belt 2 kept at 40 to 50 ° C., which was installed below 40 to 50 mm, to obtain cooled PPDI during the movement of the belt. Collect in 3. 96% by weight of the particles had a particle size of 3 to 5 mm.

Reference Example 1 PPDI distilled from a rectification column by the production of PPDI
Was cooled to 110 ° C., filled in a petroleum can, and allowed to cool as it was to obtain a block of PPDI. P of this block
PDI (1 kg) was completely melted in a nitrogen atmosphere at a temperature of 110 ± 1 ° C., and flakes and particles obtained by the above-described production example were evaluated. The results are shown in Table 1.

[0016]

[Table 1]

Reference Example 2 The flakes of PPDI obtained in Example 1 (10 kg) were placed in a bag and beaten from the outside to further finely pulverize. The preparation from this crushed flakes was dusty and had a strong odor.
76% by weight of these flakes are 1-5 mm x 1-5 mm x
It was 0.2-1 mm.

Application Example 1 of Production of Isocyanate-Terminated Prepolymer Polymer polypropylene liquid glycol (PP-2000, manufactured by Sanyo Kasei Co., Ltd., molecular weight) at room temperature in a 100-liter reaction kettle equipped with a stirrer, a thermometer, and a nitrogen seal tube. 2000) 43.1 mol was charged, and then the flakes PPDI obtained in Example 1 were stirred by passing nitrogen gas.
86.2 mol was charged and reacted at 80 ° C. for 2 hours.
The maximum temperature during the reaction reached 85 ° C. The NCO content of the synthesized prepolymer was 3.5%. The appearance of the obtained prepolymer was transparent. When the inside of the kettle was inspected after the reaction, a slight white spot was found at the top of the kettle.

Application Example 2 In the same reaction vessel as in Application Example 1, 86.2 mol of PPDI of the flakes obtained in Example 1 was heated and melted at 110 ° C. for 6 hours with stirring while nitrogen gas was passed through, and then charged at room temperature. , Liquid polypropylene polyether glycol (PP-2000 manufactured by Sanyo Chemical Industries, molecular weight 2000) 43.
1 mol was charged and reacted at 80 ° C. for 2 hours. The maximum temperature during the reaction reached 90 ° C. The NCO content of the synthesized prepolymer was 3.4%. The appearance of the obtained prepolymer was cloudy. After inspecting the inside of the kettle after the reaction, the upper part of the kettle was sublimated from PPDI and the whole surface was white.

Comparative Example 1 PPD of a petroleum canning block was placed in the same reaction kettle as in Application Example 1.
I. 86.2 mol was melted by heating at 110 ° C for 12 hours, then charged, and then stirred while passing nitrogen gas, and preheated to 80 ° C.
43.1 mol of liquid polycaprolactone polyol (molecular weight 2000) heated to the above was charged and reacted at 80 ° C. for 2 hours. The maximum temperature during the reaction reached 95 ° C. The NCO content of the synthesized prepolymer was 3.3%. The appearance of the obtained prepolymer was cloudy. After inspecting the inside of the kettle after the reaction, the upper part of the kettle was sublimated from PPDI and the whole surface was white.

[Brief description of drawings]

FIG. 1 is a view showing a flaker manufacturing apparatus.

[Explanation of symbols]

 1 PPDI saucer 2 Small drum 3 Large drum 4 Scraper 5 Filling container

FIG. 2 is a perspective view showing a granulating device.

[Explanation of symbols]

 1 Granulator 2 Stainless belt 3 Filling container

FIG. 3 is a sectional view of a granulator.

[Explanation of symbols]

 2 Stainless belt 4 Fixed inner cylinder 5 Raw material supply pipe 6 Nozzle bar 7 Rotating outer cylinder 8 hole

Front page continued (72) Inventor Akihiro Yamane 4530 Kaisei-cho, Shinnanyo-shi, Yamaguchi Japan Polyurethane Industry Co., Ltd. Nanyo Plant

Claims (2)

[Claims] 1. A flaker is used for 1 to 20 mm × 1 to 20
Flake in the range of mm × 0.1 to 2 mm, 3-1
90% by weight or more of 0 mm × 3 to 10 mm × 0.2 to 1 mm is contained, or the average particle diameter is 1 using a granulator.
The method for producing para-phenylenediisocyanate is characterized in that it is in the range of 10 mm and 90% by weight or more of the particles are contained in the particle diameter range of 2-5 mm. 2. A method for producing an isocyanate group-terminated prepolymer, which comprises reacting the paraphenylene diisocyanate according to claim 1 with a liquid polyether polyol at room temperature.