JPH06145464A - Amphoteric polymer gel, amphoteric polymer gel membrane and their production - Google Patents

Abstract

PURPOSE:To provide the subject polymer gel useful for a biocompatible material and a functional membrane for separation, etc., composed mainly of a mixture of a specific graft copolymer having a basic group and a specific graft copolymer having an acidic group and exhibiting a specific swelling behavior depending on a variation in a pH value. CONSTITUTION:The objective polymer gel is composed mainly of a mixture of (A) a graft copolymer having a water-soluble main chain with a basic group such as vinylpyridine, and a water-insoluble side chain and (B) a graft copolymer having a water-soluble main chain with an acidic group such as (meth)acrylic acid and a water-insoluble side chain at an A/B ratio of preferably 10/90-90/10. An amphoteric-ion polymer get membrane is produced by dissolving the polymer gel in a solvent such as DMF and casting the soln. in the form of a film.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a water-absorbing material composed of a novel crosslinkable polymer, particularly a biocompatible material, a functional separation membrane, an ion-permeable membrane, an artificial muscle, an artificial eye, a drug delivery system, a mechanochemical. The present invention relates to a zwitterionic polymer gel, a zwitterionic polymer gel film that can be used for materials, sensors, switches, memory elements, ion exchange resins, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Up to now, there have been reports on water-absorbing materials composed of many crosslinkable polymers. For example, a collection of polymer articles, Vol. 39, No. 4, pp. 187 (19
82), a hydrogel film obtained by copolymerizing 2-hydroxymethacrylate and reactive polystyrene having a polymerizable double bond at the terminal and forming a film of the copolymer exhibits anticoagulant properties. It is disclosed. In addition, a collection of polymer articles, Vol. 46, No. 10, pp. 603 (1
989) discloses that a zwitterionic polymer gel can be obtained by repeatedly freezing and thawing a mixed aqueous solution of polyacrylic acid, polyallylamine hydrochloride and polyvinyl alcohol.

[0003]

However, since the above-mentioned hydrogel film is a nonionic polymer gel, it shows no change in the swelling behavior under acidic or alkaline conditions. Further, in order to produce the above-mentioned zwitterionic polymer gel, a very complicated and laborious process of repeatedly freezing and thawing is required, and there is a drawback that the production is difficult.
In general, polymer gels cannot be redissolved in a solvent due to cross-linking by a chemical bond, so that it is difficult to regenerate or re-form a film.

[0004]

According to the present invention, a graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water and a water-soluble graft copolymer having an acidic group are used. There is provided a zwitterionic polymer gel based on a graft copolymer mixture of a graft copolymer consisting of a main chain and side chains that are insoluble in water.

Further, according to the present invention, a graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water, and a water-soluble main chain having an acidic group and a water-soluble main chain There is provided a zwitterionic polymer gel membrane containing as a main component a mixture of both graft copolymers of a graft copolymer having side chains that are insoluble in.

Furthermore, according to the present invention, in producing a zwitterionic polymer gel membrane, a graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water, and A zwitterion characterized in that both graft copolymers of a main chain having an acidic group and a water-soluble main chain and side chains insoluble in water are dissolved in a solvent, and then a film is formed by a casting method. Provided is a method for producing a polymeric gel film.

Next, the present invention will be described in more detail.

The graft copolymer used in the present invention means a graft copolymer having a water-soluble main chain having a basic group and a side chain insoluble in water, and a water-soluble main chain having an acidic group. It is a graft copolymer consisting of chains and side chains that are insoluble in water. The average molecular weight (weight average) is not particularly limited as long as it has film-forming properties, but it is preferably 10,000 to 7,000,000, and more preferably 50,000 to 2,000,000. If it is less than 10,000, the film formability may be poor,
On the other hand, if it exceeds 7,000,000, synthesis may be difficult. The molecular weight of the side chain is 1,000 to 20.
10,000 is preferable, but more preferably 2,000 to
It is 50,000. When it is less than 1,000, the zwitterionic polymer gel film tends to be dissolved when it is attempted to swell in water, and when it exceeds 200,000, it may be difficult in synthesis.

The polymerizable monomer used in the main chain of the water-soluble graft copolymer of the present invention having an acidic group is exemplified by one having a carboxylic acid group, a sulfonic acid group and a phosphoric acid group. You can Specifically, (meta)
Acrylic acid, itaconic acid, maleic acid, glutaconic acid,
Aconitic acid, citraconic acid, mesaconic acid, fumaric acid,
Tiglic acid, crotonic acid, muconic acid, isocrotonic acid,
3-butenoic acid, cinnamic acid, abietic acid, maleic anhydride, itaconic anhydride, styrene sulfonic acid, 2- (meth) acrylamido-2-methyl-1-propane sulfonic acid, vinyl sulfonic acid, or their substitution products or Examples thereof include derivatives. Examples of the polymerizable monomer used in the main chain of the water-soluble graft copolymer of the present invention having a basic group include those having an amino group. Specifically, vinyl pyridine, N,
N-dimethylaminoethyl (meth) acrylate, N,
N-dimethylaminopropyl (meth) acrylamide,
N, N-diethylaminoethyl (meth) acrylate,
N, N-diethylaminopropyl (meth) acrylamide, vinylcarbazole, vinylimidazole, (4-
Vinylbenzyl) dimethylamine, allylamine, t-
Butylaminoethyl (meth) acrylate, or a substitution product or derivative thereof can be used.

Monomers forming side chains insoluble in water include methyl (meth) acrylate and ethyl (meth).
Acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-butyl (meth)
Acrylate, isobutyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate, glycidyl (meth)
Acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2,3-dibromopropyl (meth) acrylate, vinyl acetate, styrene, α-methylstyrene, 2,2-bis [(meth) acryloyloxypolyethoxy. Phenyl] propane, 2,2'-bis [4
Examples include-(3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane, (meth) acrylonitrile, acrolein, or their substitution products or derivatives.

As the method for synthesizing the graft copolymer in the present invention, a method using a redox reaction (initiator such as cerium salt), a method using a polymer containing a peroxide group, a method using a polymer containing a diazo group, and a dual method Examples thereof include a method using a polymer having a bond, a method using a mercapto group, a method using a polymer containing an acid generating group, a method using a macromonomer, and a method using a condensation reaction between polymers. Further, as the (co) polymerization reaction method, known radical polymerization, ionic polymerization, photopolymerization and the like can be used.

The resulting graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water and a water-soluble main chain having an acidic group and a water-insoluble main chain In order to obtain a mixture of both graft copolymers having a certain side chain, it is desirable to take a predetermined amount of each graft copolymer and dissolve it in a suitable solvent.
In this case, the mixing ratio of both graft copolymers is not particularly limited and may be an amount as necessary according to the application, but considering the characteristics as a zwitterionic polymer gel, the molar ratio is The basic group-containing monomer / acidic group-containing monomer is preferably 1/99 to 99/1, more preferably 10/90 to 90/10. When the amount of the basic group-containing monomer or the acidic group-containing monomer is less than 1, the characteristics of the zwitterionic polymer gel are lost and the polymer gel tends to be a cation or anionic polymer gel. The solvent is not particularly limited as long as it can dissolve a mixture of both graft copolymers and can form a film by a casting method, but is preferably N, N-dimethylformamide or N-methylformamide. , N, N-diethylformamide, dimethylsulfoxide, methanol, ethanol, propanol, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, tetrahydrofuran, chloroform, methylene chloride, ether, benzene, toluene, xylene, acetonitrile, and mixed solutions thereof. can give. It is desirable to pour this solution onto a suitable substrate to evaporate the solvent. The substrate is not particularly limited, but if Teflon is used as the substrate, the film can be easily peeled off. The temperature at the time of evaporation of the solvent is not particularly limited, but is preferably 0 to 300 ° C, more preferably 10 to 100 ° C. After the solvent is evaporated, a treatment such as vacuum drying may be further performed depending on the case. Below 0 ° C, the evaporation of the solvent is very slow, which is uneconomical. On the other hand, if the temperature exceeds 300 ° C, the polymer may be modified by oxidation or the like, which is not preferable. By the above operation, the zwitterionic polymer gel film of the present invention can be prepared. The novel zwitterionic polymer gel film of the present invention thus prepared can be freely controlled in thickness depending on the concentration of the solution or the amount of the solution poured onto the substrate. 3 shows a change in swelling behavior with a change in pH.

[0013]

The zwitterionic polymer of the present invention obtained as a mixture of both the specific graft copolymer having a basic group and water-soluble and the specific graft copolymer having an acidic group and water-soluble. Since the gel exhibits a unique swelling behavior with a change in pH, it is a water-absorbing material, particularly a biocompatible material, a functional separation membrane, an ion permeable membrane, an artificial muscle, an artificial eye, a drug delivery system, a mechanochemical material, It can be applied to sensors, switches, memory elements, ion exchange resins, etc. Further, the zwitterionic polymer gel of the present invention can be formed into a film by a very simple casting method as compared with the conventional method. In addition, according to the present invention, it is possible to introduce any basic group or acidic group segment, and in some cases, three or more basic group or acidic group segments. Further, although the polymer gel has hitherto been unable to be regenerated or reused, the polymer gel of the present invention can be re-dissolved by selecting a solvent and further re-filming is possible.

[0014]

EXAMPLES Next, reference examples and examples will be specifically described. The molecular weight represents a weight average molecular weight measured by GPC (gel permeation chromatography).

[0015]

[Reference Example 1] Macromonomer (number average molecular weight = 6,000) which is a polymer of styrene and has a methacrylate at one end
0) 1 g, acrylic acid 1 g, 2,2′-azobisisobutyronitrile 0.05 g and N, N-dimethylformamide 15 g were put in a sealed tube, and after degassing operation, the tube was sealed, and the temperature was 60 ° C.
It was polymerized for 12 hours. The polystyrene reduced molecular weight of the obtained polymer by GPC was 408,000.

[0016]

[Reference Example 2] Macromonomer (number average molecular weight = 6,000) which is a polymer of styrene and has a methacrylate at one end
0) 1 g, methacrylic acid 1 g, 2,2′-azobisisobutyronitrile 0.05 g and N, N-dimethylformamide 15 g were put in a sealed tube, and after degassing, the tube was sealed.
Polymerization was performed at 12 ° C for 12 hours. The polystyrene reduced molecular weight of the obtained polymer by GPC was 358,000.

[0017]

[Reference Example 3] Macromonomer having a styrene polymer and a methacrylate at one end (number average molecular weight = 6,000)
0) 1 g, N, N-dimethylaminoethyl acrylate 1 g, 2,2′-azobisisobutyronitrile 0.00
5 g and 5 g of ethyl acetate were placed in a sealed tube, degassed, sealed and polymerized at 60 ° C. for 12 hours. G of the obtained polymer
Polystyrene conversion molecular weight by PC is 488,000
Met.

[0018]

[Reference Example 4] 1 g of a macromonomer (number average molecular weight = 6,000) of a polymer of methylmethacrylate whose one end is methacrylate, 1 g of acrylic acid, 0.05 g of 2,2'-azobisisobutyronitrile and 15 g of N, N-dimethylformamide was placed in a sealed tube, degassed, sealed, and polymerized at 60 ° C. for 12 hours. GP of the polymer obtained
The polystyrene reduced molecular weight according to C was 381,000.

[0019]

[Reference Example 5] 1 g of a macromonomer (number average molecular weight = 6,000) of a polymer of methylmethacrylate having a methacrylate at one end, 1 g of N, N-dimethylaminoethyl methacrylate, 2,2'-azobisiso Butyronitrile (0.005 g) and ethyl acetate (5 g) were placed in a sealed tube, and after deaeration, the tube was sealed and polymerized at 60 ° C. for 12 hours. The polystyrene reduced molecular weight of the obtained polymer by GPC was 328,000.

The following experiments were carried out using the graft copolymers obtained from Reference Examples 1, 2, 3, 4 and 5, and the swelling degree in water at pH = 2, 6, 10 was measured.

[0021]

Example 1 0.3 g of the polymer of Reference Example 1 and 0.3 g of the polymer of Reference Example 3 were dissolved in 6 ml of N, N-dimethylformamide, and this solution was dropped onto a 5 cm square Teflon plate. It was left at 50 ° C. for 24 hours. The film was peeled from the Teflon plate and vacuum dried at 50 ° C. for 24 hours. The film thickness was 120 μm. The swelling degree is shown in Table 1. Here, the degree of swelling means that the obtained film is immersed in water having a predetermined pH at 25 ° C.
After immersing and swelling for 24 hours, the weight is measured, and is obtained according to the equation 1.

[0022]

[Table 1]

[0023]

[Equation 1]

[0024]

[Example 2] 0.35 g of the polymer of Reference Example 1 and Reference Example 3
0.15 g of the polymer of Example 1 was dissolved in 6 ml of N, N-dimethylformamide, and this solution was added dropwise onto a 5 cm square Teflon plate and left at 50 ° C. for 24 hours. The film was peeled from the Teflon plate and vacuum dried at 50 ° C. for 24 hours. The film thickness was 90 μm. The swelling degree is shown in Table 2. Here, the degree of swelling means that the obtained film is immersed in water having a predetermined pH condition.
The weight is measured after immersion and swelling at 5 ° C. for 24 hours, and is determined according to Equation 1.

[0025]

[Table 2]

[0026]

Example 3 0.1 g of the polymer of Reference Example 1 and 0.2 g of the polymer of Reference Example 3 were dissolved in 6 ml of N, N-dimethylformamide, and this solution was added dropwise to a 5 cm square Teflon plate. It was left at 50 ° C. for 24 hours. The film was peeled from the Teflon plate and vacuum dried at 50 ° C. for 24 hours. The film thickness was 70 μm. The swelling degree is shown in Table 3. Here, the degree of swelling is obtained by immersing the obtained film in water having a predetermined pH state at 25 ° C. for 24 hours to swell the film, and then measuring the weight, and is determined according to the formula 1.

[0027]

[Table 3]

[0028]

Example 4 0.3 g of the polymer of Reference Example 2 and 0.3 g of the polymer of Reference Example 3 were dissolved in 6 ml of N, N-dimethylformamide, and this solution was dropped onto a 5 cm square Teflon plate. It was left at 50 ° C. for 24 hours. The film was peeled from the Teflon plate and vacuum dried at 50 ° C. for 24 hours. The film thickness was 150 μm. The swelling degree is shown in Table 4. Here, the degree of swelling means that the obtained film is immersed in water having a predetermined pH at 25 ° C.
After immersing and swelling for 24 hours, the weight is measured, and is obtained according to the equation 1.

[0029]

[Table 4]

[0030]

Example 5 0.3 g of the polymer of Reference Example 4 and 0.3 g of the polymer of Reference Example 5 were dissolved in 6 ml of N, N-dimethylformamide, and this solution was dropped on a 5 cm square Teflon plate. It was left at 50 ° C. for 24 hours. The film was peeled from the Teflon plate and vacuum dried at 50 ° C. for 24 hours. The film thickness was 110 μm. The swelling degree is shown in Table 5. Here, the degree of swelling means that the obtained film is immersed in water having a predetermined pH at 25 ° C.
After immersing and swelling for 24 hours, the weight is measured, and is obtained according to the equation 1.

[0031]

[Table 5]

[0032]

Example 6 A film obtained in the same manner as in Example 1 was
It was dissolved in 8 ml of N-dimethylformamide, and this solution was dropped on a 5 cm square Teflon plate, and the solution was added at 50 ° C. for 24 hours.
Left for hours. The film was peeled from the Teflon plate and vacuum dried at 50 ° C. for 24 hours. The film thickness was 100 μm.
The swelling degree is shown in Table 6. Here, the degree of swelling is obtained by immersing the obtained film in water having a predetermined pH state at 25 ° C. for 24 hours to swell the film, and then measuring the weight, and is determined according to the formula 1.

[0033]

[Table 6]

Claims (3)

[Claims] 1. A graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water, and a water-soluble main chain having an acidic group and insoluble in water. A zwitterionic polymer gel containing a graft copolymer mixture of a side chain and a graft copolymer as a main component. 2. A graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water, and a water-soluble main chain having an acidic group and insoluble in water. A zwitterionic polymer gel film containing, as a main component, a mixture of both graft copolymers having a side chain. 3. In producing the zwitterionic polymer gel membrane according to claim 2, a graft copolymer comprising a water-soluble main chain having a basic group and a side chain insoluble in water, and an acidic group. Having a water-soluble main chain and a water-insoluble side chain, both graft copolymers are dissolved in a solvent, and then a film is formed by a casting method. Method for producing molecular gel film.