JPS6336612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a main chain consisting of a chlorinated polyolefin skeleton and a polyoxyalkylene graft chain are produced by reacting a chlorosulfonated polyolefin with a polyalkylene oxide having a primary amino group at at least one end. to obtain a reaction product containing a grafted polymer consisting of 2
The present invention relates to a method for producing a polymer composition having high water absorption, which is characterized by treatment with a polyfunctional isocyanate compound having the above isocyanate group or a polyfunctional epoxy compound having two or more epoxy groups. .

The present inventors have previously discovered that the main chain of a chlorinated polyolefin is produced by the reaction of a chlorosulfonated polyolefin with a polyalkylene oxide having a primary amino group as a terminal group, and the polyolefin is bonded to the main chain through a sulfonamide bond. We have discovered a method for producing a graft polymer consisting of oxyalkylene graft chains (Japanese Patent Publication No. 33608/1983).

This graft polymer is a hydrophobic backbone polymer mainly composed of a chlorinated polyolefin structure that has its own elastomer nature.
Due to the grafting of highly hydrophilic polyalkylene oxide chains, it exhibits interesting properties as a water-absorbing elastomer.
New medical materials, waterproof materials, coating compositions,
It is expected to be used as a membrane material.

However, in this method, a considerable proportion of the aminated polyalkylene oxide used in the reaction remained unreacted, and the amount of polyalkylene oxide bound was often quite low compared to the amount used. Particularly when commercially available chlorosulfonated polyethylene with a low content of sulfonyl chloride groups is used as a raw material, the achieved grafting ratio (expressed by the weight ratio of branch polymer to trunk polymer) is only about 30% at most. . Associated with this is the problem that the water absorption rate and water absorption rate when the graft polymer is brought into contact with water are not large enough for applications such as medical materials or waterproof materials. .

As a result of extensive studies to overcome this problem, the present inventor has developed a reaction product of chlorosulfonated polyolefin and aminated polyethylene oxide,
By treating with a polyfunctional isocyanate compound having two or more isocyanate groups or a polyfunctional epoxy compound having two or more epoxy groups, the amount of aminated polyalkylene oxide bonded can be significantly increased. Accordingly, the hydrophilicity, particularly the water absorption rate and water absorption rate, of the resulting polymer composition can be significantly improved compared to the reaction product without such treatment. I discovered that.

Thus, the present invention provides a graft polymer comprising a main chain comprising a chlorinated polyolefin skeleton and a polyalkylene oxide graft chain by reacting a chlorosulfonated polyolefin with a polyalkylene oxide having a primary amino group at at least one end. and then treating it with a polyfunctional isocyanate compound having two or more isocyanate groups or a polyfunctional epoxy compound having two or more epoxy groups. A method of making a combined composition is provided.

The first step of the method of the present invention is the step of producing a graft polymer, which is carried out in exactly the same manner as in the above-mentioned Japanese Patent Publication No. 59-33608.

That is, it is carried out by dissolving the chlorosulfonated polyolefin and the aminated polyalkylene oxide in a suitable inert organic solvent, and stirring the mixture preferably under heating for a suitable period of time.

The chlorosulfonated polyolefin used as a reaction raw material in this case is selected from olefin polymers such as polyethylene, polypropylene or ethylene-propylene copolymer, which have a sufficiently high molecular weight to exhibit properties as a plastic or an elastomer. These polymers are synthesized according to known methods and usually contain a relatively small amount of sulfonyl chloride groups as well as a relatively large amount of chlorine bonded by substitution with hydrogen; It can be said that the skeleton consists essentially of chlorinated polyolefin. In this case, the chlorine content and the sulfur content (corresponding, of course, to the content of sulfonyl chloride groups)
can be changed by changing the reaction conditions, but especially in chlorosulfonated polyethylene, which is industrially produced as a synthetic rubber with excellent weather resistance, the chlorine content is 20 to 40% and the sulfur content is 1. ~1.5% is normal. In the present invention it is advantageous to use such commercially available products.

In the first step of the present invention, the polyalkylene oxide having a primary amino group at the end used as another reaction raw material is ethylene oxide,
It can be synthesized by known methods from polyalkylene glycols synthesized by ring-opening polymerization or copolymerization of alkylene oxides such as propylene oxide and butylene oxide. A variety of them are commercially available with molecular weights of 1,000 and primary amino functionality close to 2. In view of the high degree of hydrophilicity desired for the final composition, in the present invention, the terminal amino acids of such commercially available aminated polyethylene oxides or ethylene oxide-propylene oxide copolymers containing relatively large amounts of ethylene oxide units are preferred. It is preferred to use compounds.

The ratio of both components used is arbitrary, for example 0.1
A ratio of aminated polyalkylene oxide to chlorosulfonated polyolefin of ~2.0:1 can be used; however, considering the balance between water absorption and physical properties of the final composition, a ratio on the order of 0.5 to 1.0:1 may be used. desirable.

Any solvent may be used as long as it dissolves both reaction components and is inert to the reaction. It is usually advantageous to use aromatic or halogenated hydrocarbons. The amount of solvent used must be at least such that under the reaction conditions sufficient agitation of the reaction mixture is possible.

The reaction temperature is conveniently between room temperature and the boiling point of the solvent used.

The reaction product of the first stage thus obtained is treated with a polyfunctional isocyanate or an epoxy compound in the second stage of the method of the invention.

This treatment may be carried out using a solution obtained by isolating and recovering the reaction product from the reaction mixture of the first stage according to a conventional method and redissolving it. It is preferable to carry out the reaction by adding the above-mentioned polyfunctional compound directly to the reaction mixture of the first stage without isolating it. However, in this case, it goes without saying that the solvent used in the first step must be inert to these polyfunctional compounds.

The polyfunctional isocyanate compound used in the present invention is a compound having two or more isocyanate groups in the molecule, and examples include various diisocyanates or polyisocyanates commonly used in the production of polyurethane. However, it may also be a prepolymer containing terminal isocyanate groups obtained by reacting a polyether polyol or a polyester polyol with an excess of diisocyanate.

The polyfunctional epoxy compound used in the present invention is a compound containing two or more epoxy groups in the molecule, and is a low molecular weight compound such as ethylene glycol diglycidyl ether, diethylene glycol dicrycidyl ether, glycerol polyglycidyl ether, etc. Examples include polyepoxy compounds, but as long as they are soluble in the solvent used, epoxy resins having epoxy groups at both ends, which are produced by polycondensation of general bisphenols and epichlorohydrin, are used. be able to.

There is no particular limit to the amount of these polyfunctional isocyanates and epoxy compounds used, but in order to achieve good results, all amino groups present in the aminated polyalkylene oxide used in the first step reaction must be It is preferred to use an amount such that at least equimolar moles of isocyanate or epoxy functional groups are present.

In the first step of the method of the present invention, as described above, the aminated polyalkylene oxide reacts with the sulfonyl chloride group in the chlorosulfonated polyolefin to give a graft chain with a sulfonamide linkage. Since aminated polyalkylene oxides often have amino groups at both ends, amino groups are still present at the free ends of this graft chain (some aminated polyalkylene oxides have amino groups at both ends). It is also possible that it is reacting with the sulfonyl chloride group). In a preferred embodiment of the process of the present invention, the reaction mixture of the first stage is directly subjected to the second stage treatment, which contains, in addition to the graft polymer, a significant proportion of unreacted polymer. Aminated polyalkylene oxides are present. The polyfunctional isocyanate added according to the invention reacts with the amino group at the end of the graft chain and the amino groups at both ends of the free aminated polyalkylene oxide to form a urea bond, or further reacts with the urea bond and the sulfonamide The active hydrogens still present in the grafting groups react to form biuret crosslinks, thus generally forming interpenetrating polymer networks.
It is thought that by forming a complex network structure called a polymer network, most of the unreacted free aminated polyalkylene oxide is fixed and insolubilized. Similarly, in the case of polyfunctional epoxy compounds, the epoxy group reacts with the active hydrogens in the various amino groups and other groups as mentioned above, resulting in ring-opening additions, forming a network structure and forming unresolved epoxy groups. It is believed that fixation of the reactive aminated polyalkylene oxide is achieved.

To carry out the second stage of the process according to the invention, it is preferable to redissolve the reaction product of the first stage, either directly or optionally isolated, in the reaction mixture that has completed the reaction of the first stage. A polyfunctional isocyanate or epoxy compound, preferably diluted with an inert organic solvent, is added to the solution obtained by stirring thoroughly. In this case, in order to avoid gelation or an excessive increase in viscosity of the reaction mixture, it is advantageous to previously lower the temperature of the solution to about room temperature or below before adding the polyfunctional compound. After stirring thoroughly to ensure uniform mixing, a film-like polymer composition can be obtained by casting the reaction mixture and evaporating the solvent, or by coating, impregnating, or other operations using the reaction mixture as it is. It can also be used for subsequent evaporation of the solvent.

In order to achieve sufficient fixation of the free aminated polyalkylene oxide as described above, it is preferable to subject the polymer composition after evaporation of the solvent to heat treatment under appropriate conditions. The heating temperature and heating time at that time are related to various factors such as the reactivity of the polyfunctional compound used, so it cannot be determined unconditionally, but it can be determined by referring to the chemistry of polyurethane or by conducting simple experiments. It can be easily determined by repeating.

In the above, as the second step of the method of the present invention, a method is described in which the solution of the graft reaction product of the first step is subjected to the second step treatment.
The second step of the process of the invention consists in simply immersing the polymer film obtained from the grafting reaction mixture by means such as casting or coating into a solution of the polyfunctional isocyanate or epoxy compound used according to the invention. It can also be done by doing. The solvent used in this case is
Any solvent may be used as long as it is an inert solvent for the polyfunctional compound and does not dissolve the polymer film, but solvents that do not excessively swell the polymer film, such as diethyl ether and diisopropyl, may be used. ether, g-n
- Preference is given to using aliphatic ether solvents such as butyl ether. In addition, when using a water-soluble polyepoxy compound as a polyfunctional compound,
Water may also be used as a solvent. Conditions such as the concentration of the polyfunctional compound in the solution used for dipping, the temperature of the solution and the dipping time depend on many factors, especially the thickness of the polymer film to be dipped, the reactivity of the polyfunctional compound used, and the use of activators. However, by repeating simple experiments, it is possible to determine the conditions under which desired results can be achieved. It is preferable that the film taken out from the immersion liquid is washed if necessary, dried, and further subjected to the same heat treatment as described above.

The polymer compositions obtainable according to the invention have very high water absorption rates and water absorption rates, as is clear from the following examples and figures. Furthermore, it exhibits good properties as a crosslinked elastomer not only in a dry state but also in a water-absorbed state. Based on these facts, the polymer composition produced according to the present invention can be used as a biocompatible medical material,
A wide range of applications may be found in the fields of waterproofing materials, coating agents, sealants, coating compositions, separation membrane materials, etc.

Next, the present invention will be further explained with reference to Examples.

Example 1 3 g of commercially available chlorosulfonated polyethylene (Hypalon 40, Showa Neoprene Co., Ltd.) was dissolved in 30 ml of dichloroethane and heated to 60° C. with stirring. 3 g of aminated polyethylene oxide (molecular weight approx.
4000, total amine value approximately 19mgKOH/g, Sanyo Chemical Co., Ltd.)
solution was added all at once and stirring at 60°C was continued for 6 hours. While stirring was continued, heating was stopped and the temperature of the reaction mixture was lowered to room temperature. Approximately 10 ml of a sample of this reaction mixture was taken and poured onto a glass plate, and the solvent was completely evaporated at room temperature to obtain a dry film (this will be referred to as Film A).

0.5 ml of hexamethylene diisocyanate and 3 drops of triethylamine were added to the remaining reaction mixture while stirring. After stirring for several minutes, the entire amount was poured onto a glass plate, and the solvent was completely evaporated at room temperature to obtain a dry film (this will be referred to as film B). A sample of Film B was heated in an electric dryer at 60° C. for 8 hours (this is referred to as Film C).

Some samples of each of films A, B, and C
Soaked in distilled water at room temperature for 10 days. The ratio of the dry weight of films A, B, and C after immersion to the weight before immersion was 62.2%, 88.2%, and 89.9%, respectively.
It was hot. The weight loss is thought to be mainly due to the elution of unreacted, unbound polyethylene oxide. The three film samples were re-immersed in distilled water at room temperature. The water absorption rate expressed as weight increase rate was determined for sample films A, B, and C after 1 hour, respectively.
36.6%, 100.1%, 112.6%, and after 72 hours, it seems that equilibrium swelling has been reached.
They were 40.9%, 106.6%, and 121.6%. The dry film after this re-soaking showed almost no decrease in weight compared to before re-soaking.

Some samples of Films A and C were extracted in boiling ethanol for 24 hours to remove unreacted aminated polyethylene oxide. FIG. 1 shows the relationship between water absorption and immersion time when these film samples were immersed in distilled water at room temperature.

The above results show that the sample treated with diisocyanate according to the present invention has an increased amount of bound polyethylene oxide and a correspondingly significant increase in water absorption compared to the untreated sample. This clearly shows that the effect becomes more pronounced when heat treatment is applied.

Example 2 A sample of film A from Example 1 was immersed in a solution containing 0.2 ml of xylylene diisocyanate in 10 ml of diisopropyl ether for 20 hours at room temperature. The sample film taken out was washed with acetone and methanol, further washed with water, and then dried. After this sample was immersed in distilled water at room temperature, the water absorption rate was 112.2%.

Example 3 3 g of chlorosulfonated polyethylene was dissolved in 30 ml of dichloroethane and heated to 60° C. with stirring. Into this stirred solution was 3 g of aminated polyethylene oxide (molecular weight approximately 4000, total amine value approximately 25 mg KOH/g, Toray Industries, Inc.) in 20 ml dichloroethane.
The solution was added all at once and stirring was continued for 6 hours while heating to 60°C. The temperature of the reaction mixture was lowered to room temperature while stirring, and a sample of about 10 ml of this mixture was taken out and poured onto a glass plate, and the solvent was evaporated at room temperature to obtain a dry film (this will be referred to as film D). . While stirring the remaining reaction mixture,
0.2 ml of ethylene glycol diglycidyl ether was added thereto. After stirring for several minutes to mix thoroughly, the entire amount was poured onto a glass plate and the solvent was completely evaporated at room temperature to obtain a dry film (this will be referred to as E). Film E was heat treated at 70°C for 8 hours. Some samples of films D and E were extracted in boiling ethanol for 28 hours. FIG. 2 shows the relationship between water absorption and immersion time when these samples were dried and then immersed in distilled water at room temperature.

From this figure, it is clear that the sample treated with a diepoxy compound according to the present invention and further subjected to heat treatment exhibits a significant increase in both water absorption rate and water absorption rate compared to the sample not treated with a diepoxy compound. .

[Brief explanation of the drawing]

FIG. 1 shows the water absorption curve of a film of a polymer composition treated with a diisocyanate in accordance with the present invention in comparison to an untreated film. FIG. 2 shows the water absorption curve of a film of a polymer composition treated with a diepoxy compound in accordance with the present invention in comparison with an untreated film.

Claims (1)

[Claims] 1. A reaction product obtained by reacting a chlorosulfonated polyolefin with a polyalkylene oxide having a primary amino group at least at one end, and a polyfunctional isocyanate compound having two or more isocyanate groups or two or more 1. A method for producing a water-absorbing polymer composition, which comprises treating it with a polyfunctional epoxy compound having an epoxy group.