JPS587651B2 - Method for producing graft polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a graft polymer in which a chlorosulfonated polyolefin is used as a backbone polymer and a polyoxyalkylene chain is used as a branch polymer.

More specifically, the invention relates to the treatment of chlorosulfonated polyolefins, especially chlorosulfonated polyethylene, dissolved in an inert organic solvent, with polyalkylenes, glycols, especially polyethylene glycols having a hydroxyl group at at least one end in the presence of an aqueous alkaline solution. The present invention relates to a method for producing the above-mentioned graft polymer, which comprises reacting the graft polymer.

Chlorosulfonated polyethylene has long been known as an elastomer with extremely excellent weather resistance, and is produced industrially.

Since this polymer contains a sulfonyl chloride group (S02Cl) as a crosslinking point, various attempts have been made to modify this polymer by taking advantage of its reactivity.

For example, attempts have been made to hydrolyze this into sulfonic acid and use it as an ion exchange resin.

[B. Bikson et al., Polymer 20,
215 (1979)].

In addition, research has been conducted on methods for converting sulfonyl chloride groups into sulfonamide groups by reaction with ammonia, and then converting the sulfonamide groups into various functional groups. A. 01sen
et al., J. PolymerSci. A-I7, 191
3, 1921, 1927 (1969)).

Many of these reactions are carried out using film-like polymers.

On the other hand, attempts have been made to graft polymerize styrene onto a chlorosulfonated polyethylene skeleton using a cationic polymerization mechanism using a sulfonyl chloride group as an active site and a special Lewis acid as a melting medium (Y. Minou
ra et al., J. Polymer Sci, Snake,
9 6 1 (1 9 76) J. P. kenne
dy, Appl. Polymer Symposia
1 9 7 7, 30].

The present invention is completely different from these and other conventional methods for improving chlorosulfonated polyethylene, and provides a new graft copolymer through a condensation reaction between polymers as described above.

Furthermore, by grafting branch polymers consisting of hydrophilic polyoxyalkylene chains onto the skeleton of chlorosulfonated polyethylene, which is inherently lipophilic, a graft copolymer with unique properties that is expected to have various special uses can be produced. It is possible to obtain a combination.

The chlorosulfonated polyolefin used in the process of the invention typically has an SO2
and Cl2 [for example, Takemoto et al., Koka, 66, 192
5 (1963)) and generally contain a significant amount of -CI groups in addition to -SO2C1 groups.

The content of these groups can be varied widely by appropriate selection of reaction conditions.

In particular, chlorosulfonated polyethylene, under the trade name Hypalon, has an S content of 1.4-1.0% and a CI content of 2.
Between 5 and 36% of famous brands are industrially produced and commercially available.

In the method of the present invention, these commercially available products are included.
All types of chlorosulfonated polyolefins can be used.

The polyalkylene glycols (also referred to as polyalkylene oxides) used in the present invention are typically produced by ring-opening polymerization or copolymerization of alkylene oxides such as ethylene oxide, propylene oxide, and have a variety of molecular weights and/or ) are commercially available.

In the present invention, any compound derived from alkylene oxide and having at least a hydroxyl group at the l-terminus may be used, but in order to provide a large graft side chain with hydrophilicity, polyethylene glycol is used. It is preferable to use

As the solvent for the chlorosulfonated polyolefin, any inert organic solvent that is substantially incompatible with water may be used, but in general, carbon tetrachloride, chloroform, 1,2-dichloroethane, etc. , 1・1・1
- It is preferred to use halogenated hydrocarbons such as trichloroethane.

Is the alkaline aqueous solution you use based on alkali metals? Preferably, aqueous solutions of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are used.

The process of the present invention is generally carried out by mixing a solution of a chlorosulfonated polyolefin, an aqueous alkali solution and a polyalkylene glycol in any order and stirring under heat.

Therefore, the concentration of the polymer solution must be selected to provide a solution of a viscosity that allows sufficient agitation under the reaction conditions.

Further, it is preferable to use the polyalkylene glycol in an amount such that about the same mole or more of hydroxyl groups are present per SOCl group present in the polymer used.

Although the amount of base used can vary widely,
Generally, it is desirable to use the polyalkylene glycol in excess of the equivalent amount of hydroxyl groups in the polyalkylene glycol used.

Although the amount of water used to dissolve the base is arbitrary, it is usually used in such an amount that the polyalkylene glycol used is completely dissolved and the reaction mixture forms a homogeneous emulsion through its emulsifying action. .

The reaction temperature used is from room temperature to the boiling point of the solvent used, but a temperature of 40 to 80°C is usually convenient.

-SO2C present in chlorosulfonated polyethylene
It is well known that the l group undergoes hydrolysis in the presence of a strong alkali to produce a sulfonic acid group, and the product is considered for use as an ion exchange resin.

In the method of the present invention, the sulfonyl chloride group is not only hydrolyzed to generate a sulfonic acid group, but also
The condensation with polyalkylene glycols to give graft copolymers seems rather surprising.

It is known that polyoxyalkylene chains, especially polyoxyethylene chains, have a scavenging effect on metal cations, especially alkali metal ions, and that the terminal hydroxyl group plays a major role in this effect [for example, Yanagida et al. , oil chemistry 28
, 8 (1979)).

In the case of the reaction of the present invention, the polyalkylene glycol traps alkali metal cations in the aqueous phase and migrates to the interface between the aqueous phase and the organic phase, or even into the organic phase, thereby dechlorinating the sulfonyl chloride groups. It can be considered that condensation occurs due to the accompanying terminal hydroxyl groups to give a graft polymer.

The presence of polyoxyalkylene craft chains in the products of the present invention can be seen in the infrared absorption spectra of products subjected to repeated precipitation purification or prolonged methanol extraction. This can be confirmed by the presence of absorption.

As mentioned above, the product of the present invention exhibits properties significantly different from that of the backbone polymer, chlorosulfonated polyolefin, due to the presence of hydrophilic polyoxyalkylene chains.

For example, the latter have almost no water absorption, whereas the products of the invention exhibit water absorption properties that vary within a wide range, depending on the type, molecular weight and content of the polyoxyalkylene graft chains.

Solutions of the products of the invention also have excellent film-forming and spinnability and can provide films and filaments with remarkable elasticity.

In view of these properties, the products of the present invention have useful applications as new membrane materials, elastic yarns, etc.

Furthermore, by utilizing the cation trapping effect of the polyoxyalkylene chain as described above, it is also possible to apply it to separation processes and catalytic reactions.

Next, the present invention will be explained in more detail based on examples.

Example 1 Chlorosulfonated polyethylene (
Add 2 g of Hypalon 40) manufactured by Showa Denko ■ and 40 cc of 2-dichloroethane and stir to dissolve.

Commercially available polyethylene glycol 6000 (molecular weight: about 6000) 12 dissolved in a 1% aqueous sodium hydroxide solution is added to this flask and stirred well, and the mixture immediately becomes a homogeneous emulsion.

The mixture is stirred for 3 hours while being heated to 60°C, and then poured into a large amount of methanol to precipitate the product, which is then neutralized using dilute hydrochloric acid.

The precipitate is filtered, thoroughly washed with methanol and water, and then dried under vacuum to obtain 2.3 g of product.

This product is estimated to contain approximately 18% polyoxyethylene chains by infrared absorption spectroscopy.

The chlorine content is 30.7%, and the water absorption rate for 72 hours is 25%.

The raw material Hypalon 40 has a chlorine content of 36.2%, a sulfur content of about 1%, and a water absorption rate of 1% or less.

Examples 2 to 6 Commercially available polyethylene glycol 600, 1000, 2000, 40 instead of polyethylene glycol 60000
The products shown in Table 1 are obtained in the same manner as in Example 1, except that 00 and 20000 are used.

(The table also includes the results of Example 1.

) Table 1 Example number Polyethylene Cl content Water absorption rate Grafting rate Glycol (%) (%)
*(%)**2 60.0
34.0 11 8.0
3 1000 33.8
13 8, 54
2000 33.0 1
8 14.05 40
00 32.3 22
16.51 6000 3.0
．． 7 25 16.56
20000 29.5 4
2 24.5* Weight increase rate (%) after 72 hours immersion in water ** Polyoxyethylene chain content determined from infrared absorption spectrum Examples 7 to 12 Hypalon 20 (chlorine content: 29%) instead of Hypalon 40
．． The products shown in Table 2 were obtained in exactly the same manner as in Example 1, except that 8%, sulfur content of about 1.4% and absorption of about 1% were used.

Table 2

Claims (1)

[Claims] 1. A chlorosulfonated polyolefin, which is characterized by reacting a chlorosulfonated polyolefin dissolved in an inert organic solvent that is incompatible with water with a polyalkylene glycol having a hydroxyl group at at least one terminal in the presence of an alkaline aqueous solution. A method for producing a graft copolymer having a trunk polymer and polyoxyalkylene chains as branch polymers.