JPS61130307A - Recovery of chlorosulfonated polyolefin - Google Patents

Abstract

PURPOSE:To obtain a polymer low in a residual solvent content, by feeding a chlorosulfonated polyolefin solution containing a powdered inorganic compound to an extruder having a function of devolatilization. CONSTITUTION:At least 0.005pt.wt., per 100pts.wt. polymer, powdered inorganic compound (e.g., TiO2) comprising 100-mesh or smaller is added to a solution comprising a chlorosulfonated polyolefin and a volatile organic solvent (e.g., CCl4), and the mixture is fed from a feed tank 5 through a pump 6 to an extruder 1 having a function of devolatilization and kneaded with heating, while the solvent is being volatilized from vents 7-9 to recover the polymer. In this way, a solid rubber is obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to the production of chlorosulfonated polyolefin, and more specifically to the so-called drying process in which a solid rubber is produced by recovering a polymer component from a solution of chlorosulfonated polyolefin. Regarding the method.

(Prior Art) As a method of recovering a polymer component from a solution of chlorosulfonated polyolefin and obtaining a solid polymer, a method of removing the solvent using a drum dryer has conventionally been used (for example, U.S.P.
2,923,979).

Also, in recent years, efficient new technology using an extruder has been developed (for example, Japanese Patent Application Laid-Open No. 123201/1983).

(Problems to be solved by the invention) Although the method using an extruder is efficient as a method for recovering chlorosulfonated polyolefin, the range of optimal operating conditions is relatively narrow, and recovery may be difficult depending on the type of raw material and operating conditions. In some cases, the amount of solvent remaining in the polymer increases. In order to reduce the amount of residual solvent, it may be necessary to operate at low capacity or under conditions that deteriorate physical properties, which is a problem.

(Means for Solving the Problems) As a result of research into a method for solving these problems and easily reducing the amount of residual solvent, the inventors of the present invention discovered that a solution of chlorosulfonated polyolefin can be extracted from a chlorosulfonated polyolefin solution using an extruder having a devolatilizing function. When recovering polyolefin, it is possible to suppress the decrease in performance and physical properties and efficiently reduce the amount of residual solvent by adding at least 0.005 parts by weight of a powdered inorganic substance to 100 parts by weight of the polymer. The inventors have discovered that this is possible and have arrived at the present invention.

The chlorosulfonated polyolefin solution referred to herein is a solution containing a chlorosulfonated polyolefin and a volatile organic solvent, and the volatile organic solvents include carbon tetrachloride, trichloromethane, dichloromethane, and tetrafluoride. Methanebenzene, etc. The solution is usually ethylene.

After dissolving so-called polyolefin, which is a homopolymer or copolymer obtained by polymerizing olefins such as propylene, 1-butene, and The sulfonated polyolefin solution may be condensed if necessary, or octadecyl 3-(3,5-
Jitter 7 Yariputyl-4-hydroxyphenyl)-propinate, Pentaerys IJ f Rutetrakis (
Phenolic compounds such as 3-(3,5-di-ter-7-yarybutyl-4-hydroquinophenyl)globiochete, 2,6-theta-yarybutyl-4-methylphenol, epoxy compounds such as glycidyl ether type of bisphenol A, dibutyl It is obtained by adding tin-based compounds such as tin malate and dibutyl tin laurate.

In this specification, the powdered inorganic substances are powders of metal oxides, metal salts, ceramics, etc., and are preferably substances that do not deteriorate the properties of rubber. Specific examples include magnesium 7,
Metal oxides such as titanium, lead, and silicon, magnesium, and calcium.

Carbonates or sulfates of metals such as barium, clay.

Natural products such as talc and pumice, and brick powder can be chewed.

The smaller the particle size of these powders, the greater the effect per amount added. The upper limit of the particle size is not particularly limited, but is usually 100 mesh or less, preferably 30 mesh.
It is 0 mets/yu or less. Although even a small amount of these powdered inorganic substances is added to the foil, the effect of reducing the residual solvent is given, but it is usually at least 0.0 parts by weight per 100 parts by weight of the polymer.
A favorable effect is observed when 0.05 parts by weight is added.

The upper limit of the amount added is not clear as it varies depending on the type of powder used, particle size, etc., but if the improvement effect is saturated at about 0.5 to 5 parts by weight based on 100 parts by weight of the polymer content. There are many.

The extruder with a devolatilizing function used in the present invention is an extruder equipped with a vent machine for discharging vapors such as solvents generated by volatilization inside the extruder to the outside of the system. It has functions such as feeding, stirring, mixing, kneading, exhausting, and extruding dry rubber. Normally, the base extruder has an opening in the barrel, etc. as necessary, and auxiliary pumps are used to move the material in and out, and part of the screw is a model with a different feeding effect. stirring, mixing, crosstalk,
Functions such as surface renewal and pressure sealing can be added.

(Function) When recovering a polymer from a chlorosulfonated polyolefin solution using an extruder to make a solid polymer, dispersing an inorganic substance in the polymer improves heat capacity and thermal conductivity, and prevents the generation of localized high-temperature areas. It prevents heat and has a shoulder effect.

It can be said that these actions suppress the deterioration of the polymer and promote efficient desolvation.

In addition, air accompanying the additive expands during drying, foams the polymer, renews the surface, and increases the specific surface area, thereby promoting devolatilization.

(Examples) 1) Examples and Comparative Examples Solid rubber was obtained using the apparatus conceptually shown in Figure 1.

In the figure, extruder 1 is a self-cleaning biaxial co-rotating three-vent type extruder with an L/D of about 41.

In the figure, 13, 14, 15. Each region is independent in terms of internal pressure, and the gas phase portion of 14.15 is under reduced pressure.

A single-screw extruder with an L/D of approximately 5, indicated by 2 in the figure, is connected to the tip of the twin-screw extruder, and the internal gas phase communicates with the area 15 in the figure.

2) A chlorosulfonated polyolefin solution as a raw material was obtained by the following method.

Density 0.957±0.0 in glass lined reaction vessel
02 f/cC, melt index 6,7±0.2 900 parts by weight of carbon tetrachloride was charged to 100 parts by weight of polyethylene, and after pressurization, the polyethylene was dissolved at 100°C, and pyridine o, o o s±0. 0 after adding 001 parts by weight
．． α of 2%.

α'-Azobisisobutyronitrile 22 parts by weight of sulfuryl chloride was added at a constant rate over 4 hours using carbon tetrachloride as a catalyst, reacted with polyethylene, and then degassed by blowing in nitrogen gas. Polymer content is 13.5-14.
A 2% chlorosulfonated polyolefin solution was obtained.

The content of sulfur and chlorine in this polymer is 1.0 each.
They ranged from 8 to 1.35% and from 35.1 to 35.4%. After adding the additives shown in Table 1 to this solution, flash concentration was performed to obtain a polymer solution having a polymer content of about 20 to 60%.

The solid polymer was recovered by the following method.

The barrel temperature of the twin-screw extruder was set at 100-170°C, the vent internal pressure was set at 200-10 Torr, and the barrel temperature of the vacuum single-screw extruder was operated at 40-60°C to obtain the polymers shown in Table 1.

The amount of residual solvent in the recovered polymer was approximated and evaluated by the following measurement. The recovered rubber was shredded into particles of about 1 m, and the weight loss on heating at 110'c x 1 hour was measured.

Example-1 The content of sulfur and chlorine in the polymer is 1.18 each
%, 35.2%, 0.5 parts by weight of rutile titanium oxide with an average particle size of 0.37 μm was added to 100 parts by weight of the polymer, and the extruder conditions shown in Table 1 were used. The polymer was recovered.

The heating loss of the obtained polymer was measured and was 1.0.
At 21%, the color tone of the sb polymer was uniform with little change.

Comparative Example-1 A polymer was recovered under substantially the same conditions as in Example-1 except that titanium oxide was removed.

The heating loss of this polymer is 0.40%.Example-1
It was quite inferior.

Comparative Example 2 A polymer with a heating loss of 0.23% was obtained in the same manner as Comparative Example 1 except that the extruder conditions were changed.

This polymer was accompanied by a strong acidic odor, had a brownish color, and had a greater degree of deterioration than that of Example-1.

Example-2 The content of sulfur and chlorine in the polymer is each 1.08
%, using a rubber solution of 35.1%, with a polymer content of 1
After adding 1.5 parts by weight of calcium carbonate having an average particle size of 1.74 μm to 00 parts by weight, the polymer was recovered. The loss on heating of this polymer was 0.18%.

Comparative Example 3 A polymer was recovered by operating under almost the same conditions as in Example 2 except for excluding calcium carbonate.

The heating loss of this polymer was 0.31'X, and Example-
It was inferior to the second one.

Example-3 The content of sulfur and chlorine in the polymer is 1.35
%, 35.4 x Tochi6 Le*! J Use a matrix solution and add pumice powder (32μ) to 100 parts by weight of polymer.
0.2 parts by weight of 0.2 parts by weight of 0.5 m or less) was added, and a polymer with a heating loss of 0.28% was recovered.

Example-4 0.2 parts by weight of pumice powder of Example-3 was mixed with brick powder (32 μm
(below) The polymer was operated under almost the same conditions as in Example 3, except that the amount was changed to 0.01 part by weight, and a polymer having a heating loss of 0.41% was recovered.

Comparative Example 4 A polymer was recovered by operating under almost the same conditions as in Example 3, except for excluding the additive.

The heating loss of this polymer was 0.64%, and Example-1
It was inferior to 3 and 4 and I was disappointed.

(Effects of the Invention) The method according to the present invention can easily reduce the amount of residual bath medium in the polymer with little deterioration in the recovered dry rubber. Further, the addition of a small amount of titanium oxide or the like has the effect of controlling the color tone of the recovered polymer and also has the effect of making the appearance of the polymer uniform.

[Brief explanation of drawings]

Figure 1 shows one of the extruders used to carry out the method of the present invention.
FIG. 2 is a conceptual diagram showing an example. 1... Biaxial rotating extruder, 2... Single-screw extruder, 3
... Electric motor, 4... Electric motor, 5... Raw material tank, 6.
... Raw material supply pump, 7... Devolatilization vent, 8... Devolatilization vent, 9... Devolatilization vent, 10... Dry rubber,
11... Solvent recovery system (including vacuum source), 12... Solvent recovery system (including vacuum source), 13... Heating region, 14
...Vent area-1,15...Vent area-2゜Patent applicant Denki Kagaku Kogyo Co., Ltd. Procedural amendment January 17, 1985 Manabu Shiga, Commissioner of the Patent Office Indication of case 1 1988 patent Application No. 252012 2 Name of the invention Method for recovering chlorosulfonated polyolefin 3 Person making the amendment Relationship to the case Patent applicant 4 Detailed description of the invention in the specification subject to the amendment 5 Contents of the amendment (1) Description "Tsukuromethane. Tetrafluoride methane/" on page 3, line 9 is corrected to "dichloromethane. Tetrafluoride methane, pen." (2) "Vent Isoki" on page 5, line 9 of the specification is changed to "Function" is corrected. (3) "Use" on page 5, line 14 of the specification is corrected to "use". (4) "Seltzke IJ Jungian property" on page 6, line 12 of the specification is corrected to "self-cleaning property". (5) "Charcoal tetrachloride solution" on page 7, lines 9 to 10 of the specification is corrected to "carbon tetrachloride solution." (6) “Flashu concentrate” on page 7, line 18 of the specification
is corrected to "flash concentration."

Claims (1)

[Claims] When recovering chlorosulfonated polyolefin from a chlorosulfonated polyolefin solution using an extruder with a devolatilizing function, at least 0%
．． A method for recovering chlorosulfonated polyolefin, characterized in that 0.05 parts by weight of a powdered inorganic substance is present.