JPS5884845A - Acrylonitrile-based polymer composition for forming - Google Patents

Abstract

PURPOSE:To obtain titled composition of outstanding water permeability and formability, with high selective material separation performance, suitable for forming hollow fiber, etc., comprising an acrylonitrile-based polymer and a specific acrylonitrile-based block copolymer. CONSTITUTION:The objective composition comprising (1) 5-50wt% of an acrylonitrile-based polymer of an acrylonitrile content >=40wt% and (2) 50-95wt% of a block copolymer composed of (A) a segment consisting of at least 80wt% of acrylonitrile and a copolymerizable vinyl monomer (e.g., acrylamide) (B) a second segment consisting of at least 20wt% of a non-cyano (pref. carboxyl) functional group-contg. vinyl monomer other than acrylonitrile (e.g., acrylamide) and a copolymerizable vinyl monomer (pref. acrylonitile).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel moldable acrylonitrile base composition. More specifically, it relates to a polymer composition containing a specific block copolymer as a basic component and a mixture of acrylonitrile, acrylonitrile, and acrylonitrile. The object of the present invention is to provide a polymer composition with excellent moldability that can be used to mold hollow fibers or flat membranes having universal separation ability.

Conventional bacteria. Cellulose 7- is used to separate particulate matter such as viruses, kumbaku or colloidal substances.
Cellulose-based hollow fibers or flat membranes such as Tate, Cubrohan, etc. have been used, but such hollow delicate or flat membranes have the disadvantage of having low water permeability and being susceptible to clogging. In addition, hollow TIIILI has low water permeability.
It was necessary to increase the area of contact between the flat membrane and the octopus housing, which inevitably led to a larger device and reduced operability, resulting in an economic disadvantage.

On the other hand, hollow fibers or flat membranes made of acrylonitrile polymer have been proposed to improve the water permeability, which is a drawback of these cellulose-based hollow fibers or flat membranes. Problems such as the reduction of clogging are being brought to light, but in the field of medical applications such as artificial organs, especially artificial kidneys, we are trying to separate 5 and 1 to obtain adequate water permeability. It is extremely unsatisfactory in terms of selective separation ability, which allows useful substances other than the substances 1 to pass through, and to separate 6 of the alkaline substances, and various improvements are being considered. However, hollow fibers or flat membranes that satisfy both water permeability and selective separation ability have not been obtained; however, they are in the form of lumps.

In view of these drawbacks, the present inventors have investigated the copolymerization composition and degree of polymerization of acrylonitrile-based polymers with each vinyl monomer, or the block copolymers containing acrylonitrile as a product component, and their copolymer compositions with vinyl monomers. As we proceeded with a detailed study of the composition, etc., we found that certain blocks consisting of segments mainly composed of acrylolotrile and segments containing more than a certain percentage of vinyl monomers other than acrylonitrile were given a specific mixture. By subjecting a mixed polymer composition of an acrylonitrile-based mixture to hollow fiber or flat film molding, a molded product having excellent water permeability and a high selectivity of about 11ffi after loosening can be obtained. thing,
1. This polymer composition can be spun at a high take-up speed during molding, particularly when forming a hollow wire using a wet method or a wet method. The present invention was completed after discovering that it has excellent moldability that could not be expected with conventional Chiko, and after conducting extensive studies on the WPIIa process.

That is, the present invention provides a segment tAJ containing 80% by weight or more of acrylonitrile and a segment (B) containing 201% or more of a vinyl monomer other than acrylonitrile.
This is a 7-acrylonitrile polymer composition for molding consisting of ABallBall block 50-95% by weight, which consists of ABallBall block 50-95% by weight, and 5-5obJ11% acrylonitrile-based polymer having an acrylonitrile content of 401% by weight or more.

Generally, it is known that when a block copolymer is bath-dissolved in a solvent to form a solution or melted, phase separation occurs due to differences in the affinity between each segment or the affinity between each segment and the dissolving material. However, it was unavoidable that this would lead to a decrease in moldability, which in turn would lead to a decrease in the performance of the mold.

However, in the case of an uninvented polymer composition consisting of a specific mixing ratio of a co-monomer of ABm blocks and an acrylonitrile polymer, which will be explained in the comments below, phase separation occurs when this is dissolved in a solvent to form a bath liquid. By combining an ABfi block copolymer with a specific composition and structure and a specific mixing ratio with an acrylonitrile monomer, the phase separation is extremely fine and stable. Therefore, it is presumed that it has achieved extremely excellent moldability that could not be expected from conventional techniques. Furthermore, this If#different phase separation phenomenon and MuBat
By combining with specific segment components constituting the block group copolymer, it is possible to simultaneously achieve grade A water permeability and excellent selective separation ability, which could not be achieved with conventional acrylonitrile polymers. It is thought that it provides a membrane.

The mixing ratio of the AB type Pronk co-tetrapolymer and the 2-acrylonitrile-based 1 polymer constituting the polymer composition of the present invention is 1
This is an important element. The mixing ratio of hbmy lock copolymer, which is the basic component, is 50%), acrylonitrile type 1
When the amount of coalescence is 50'N or more, a moderate water permeability can be obtained when formed into a hollow aim or a flat membrane, but the selective separation ability, which is the most important aspect of the present invention, may be reduced. cause.

On the other hand, when the mixing ratio of the ABII block copolymer is 95% by weight or more, although the selective separation ability shows a high value,
This results in a decrease in water permeability and, in particular, a decrease in moldability, making it impossible to fully achieve the object of the present invention. Therefore, in the polymer composition of the present invention, it is important that the weight of the basic components of the mm and mm blocks is 50 to 9 s and the acrylonitrile polymer is 5 to 50 s.

Segments (5) and (B) of the BW block copolymer, which are the basic components in the polymer composition of the present invention, are the most important elements except that they are as shown below. The segment body) is a portion that mainly plays a role of exhibiting high water permeability attrition together with the acrylonitrile polymer, which is the other component of the polymer composition of the present invention, and
For this purpose, it is essential to contain acrylonitrile up to 80% by weight, and if the amount is less than 801%, sufficient water permeability is sufficient.
Therefore, it becomes difficult to achieve the object of the present invention. The remaining 20. l [If less than 31%, there is no problem in introducing copolymerization components other than acrylonitrile and there are no restrictions, but usually one or two vinyl monomers copolymerizable with acrylonitrile are used as appropriate. Specific examples of the vinyl monomers selected and used include acrylamide, methacryl agide, N-methylacrylamide, N-ethylmethacrylamide, and maleimide.

Allyl alcohol, methallyl alcohol, /-human p-xyethyl methacrylate, methallyl amine /.

I-aminoethyl methacrylate, acrylic acid.

Methacrylic acid, itaconic acid, methyl acrylate.

Methyl methacrylate, ethyl methacrylate.

Examples include, but are not limited to, -monomethylacrylonitrile, g-cyanoacrylonitrile, vinyl acetate, vinyl chloride, vinylitine chloride, and styrene.

In order to impart a high degree of selective separation ability to the molded product for separating substances, which is the main objective of the present invention, it is necessary to
m-block copolymer and segment (BJ) in which the compositional components constituting BJ are cyano groups other than acrylonitrile, such as hydroxyl group, carboxyl group, 7-mido group, imido group, amino group, methyl ester group, ethyl ester group, etc. Vinyl monomers having functional groups other than groups (both 2 and 2)
Among the above-mentioned functional groups, carboxyl groups, hydroxyl groups, and amide groups are required to be contained in an amount of 0 weight or more.

Those having a methyl ester group are preferred. Specifically, acrylamide, methacrylamide, allyl alcohol, methallyl alcohol, and acrylic acid.

Examples include methacrylic a, methyl acrylate, methyl methacrylate, etc., but are not limited to these. These vinyl monomers other than acrylonitrile are 1
m or 28 i or more may be more than sufficient to achieve the objective of the present invention, but if it is less than 201 i, it becomes impossible to maintain a high degree of selective separation ability, and the objective of the present invention cannot be achieved.

The remaining components are not particularly limited, and may be monomers including acrylonitrile that are copolymerizable with the above-mentioned vinyl monomers; It is better to use 7-acrylonitrile.

In the ABfi block copolymer consisting of (segment body) and (BJ) which are the basic components of the polymer composition of the present invention, there is no difference even if the composition ratio of acrylonitrile is the same in each segment (5) and (B). In this case, using the same vinyl monomers other than acrylonitrile in each segment (A) and 1B) may improve selective separation efficiency, although this does not impede the achievement of the purpose of the present invention. This is undesirable because it reduces the laxity of Bl, and it is necessary to use different vinyl monomers other than acrylonitrile in the segmented product and Bl.

The degree of integration of the ABli Pro 1 and Tsuku copolymers of the present invention is useful even if the segments (A) and (B) are combined to the extent of oligomers, but problems such as falling off during molding may occur and crystallization may occur. The intrinsic viscosity (η
It is preferable to set it as high molecular weight of 0.5 or more in 1oh).

To synthesize the ABII block copolymer of the present invention that satisfies the above requirements, a conventional block copolymer synthesis method is used.
1 is an ionic polymerization technique, a functional group having a condensation reactivity at the end is a segmented product having a hydroxyl group, an amino group, etc.) and (Bl is a bifunctional incyanate, such as tolylene diisocyanate) + 4+4'- Techniques of condensation and bonding using bifunctional reagents such as diincyanatodiphenylmethane, terephthalyl chloride and inphthalyl chloride, or polymerization ropes containing two types of peroxide groups with different activities, such as dicyclohexanone peroxide. It can be synthesized by a radical synthesis technique such as a two-stage polymerization method, etc., or by a combination of these techniques. In general, it is difficult to completely integrate the entire polymerization system into ABW block copolymers using such polymerization techniques, and the resulting polymer often contains polymers other than block copolymers. In order to separate only the block copolymer from the Mix 1 coalescence, mix IIs of the Mix 1 coalescence, such as dimethylformamide, N-methyl-2-pyrrolidone, etc., with a non-solvent such as water, acetone, methanol, etc. What is necessary is to carry out fractional precipitation using a solvent. Further, if the polymer other than the block copolymer in the mixed polymer is an acrylonitrile polymer described later, it is not necessary to separate and take out only the block copolymer, and the mixed polymer can be used as is. The component other than the AIG block copolymer in the polymer composition of the present invention is an acrylonitrile polymer, and any acrylonitrile polymer or acrylonitrile copolymer containing 40 weight or more of acrylonitrile may be used. If a polymer with an acrylonitrile content of less than 40% by weight is used, the moldability will deteriorate and 12! This is undesirable because it significantly deteriorates the mechanical properties of the resulting hollow delicate or flat membrane molded product. In order to obtain the acrylonitrile polymer, vinyl monomers copolymerizable with acrylonitrile may be combined by a conventional polymerization method, preferably radical polymerization. Specifically, the vinyl monomer to be used may be selected from vinyl monomers other than acrylonitrile used in the production of the AB type block copolymer described above, or 2 or more monomers (although not necessarily). The acrylonitrile used in the Aflll block copolymer does not need to be the same as the vinyl monomer other than IJl.

The polymer composition of the present invention can be generally prepared as a solution of an ABM block copolymer and an acrylonitrile-based polymer in a common bath and subjected to molding into hollow fibers or flat membranes by a conventional method. To dissolve in a common am, the ABII block copolymer and the acrylonitrile-based one are combined in advance at a predetermined ratio, and then added to a solvent and dissolved with stirring, or a solution in which each is dissolved separately has a predetermined composition. The AB type block copolymer may be mixed in such a way that the polymer is mixed in such a way that the copolymer has a predetermined composition. Coalescence and acrylonitrile) Sufficient stirring is required to uniformly mix the IJ-ru system 1 coalescence. As a common material for making the Mukuro #I case, there is no particular problem if it is an S section that can dissolve both the AH block copolymer and the acrylonyl-IJ polymer, but usually acrylic is used. Dimethylpolamide, dimethylacetamide, N-
One or more mixed solvents such as organic solvents such as methyl-2-pyrrolidone and dimethyl sulfoxide, and inorganic solvents such as nitric acid, rhodan soda aqueous solution, and zinc chloride aqueous solution are used.

The obtained solution is generally observed as a transparent homogeneous solution, but it can be observed using a differential interference microscope, etc. It was observed that the solution was loose and stable, exhibiting a slight phase separation. These solutions may contain, for example, oxidizing fat-blocking agents, l
Il! Addition of various additives such as a fuel agent or a matting agent does not adversely affect the achievement of the object of the present invention.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto, and in the Examples, the term "weight" means "weight" unless otherwise specified.

Measurement of the water permeability of hollow *pongee made of the acrylonitrile polymer composition of the preparation invention was carried out using hollow fibers with an outer diameter of P31K pre-glued and bonded at both ends with resin as shown in Figure 1. and 200 between the injection side and the outflow negative
■ Calculate the permeation amount of physiological saline per unit time by taking the Hg pressure difference, and divide the effective area of the inner wall of the hollow fiber by the calculated value to obtain the value per unit area (aJ/Hr Lee s
mHg).

The inulin passage rate is measured by the following procedure, in which the reaction product produced from the fruit is heated in an acidic solution of hydrochloric acid, and the absorbance is measured by reacting it with thiobarbylic acid.

After dissolving 1.00i of inulin in 2011jlC of physiological saline, add 980jlj of serum or bovine blood to bring the total volume to 1000ml.
IIj is adjusted to 1001v/d7 bath solution '1 of inulin. (This solution is used as the serum source solution.) This redundant liquid was used as the water permeability test and ljlm, and the centrifuged device IjL1
f! :Using 2001111Hg between injection negative and outflow force
After one hour, the serum solution that comes out through the hollow fiber wall is collected and the amount of inulin is determined. 30d80.-11111017.5 for 1 volume of liquid
) to I N -B, 80° and 'n Seisui 500a
3 volumes of the solution containing j and 0.166 N-NaOH
The supernatant liquid obtained by adding S volume and mixing is used.

1.016 N of this supernatant and 1.016 N of physiological saline.
Add NaOHO,1- and heat treatment at 98℃ for 15 minutes. After cooling, add 3 red IW solution prepared by dissolving thiobarbiculic acid (1.00) in 11,500U of 35% concentrated salt, and heat at 83℃ Heat treatment was performed for 5 minutes, and after cooling to room temperature, absorption analysis was performed, and the inulin passage rate was determined from the value at 435 nm using the following formula.

(Reference example) Synthesis of ABIIB lock copolymer Acrylonitrile containing dicyclohexanone peroxy 312 f, lauryl sulfate, which is represented by the following formula, is suspended in deionized water 300011j containing lauryl sulfate, and Rongalite is suspended in this. 7.2? In addition, the temperature was raised to 40°C to start the second polymerization. Polymerization was carried out for 2 hours while stirring the reaction system and controlling the temperature so as not to exceed 40°C. When a small amount of the system was taken out and the remaining amount of acrylonitrile was measured by gas chromatography, it was found that 111% of the charged acrylonitrile AF11 had been polymerized. Next, 2,001 liters of methyl acrylate was added to the polymerization reaction system for the 2nd R polymerization, and the temperature in the system was maintained at 70° C. and the mixture was stirred for 3 hours to carry out polymerization.

The resulting suspension was filtered, washed with water, and dried to give a white / Polymer 446 was obtained.

In this polymer, polyacrylonitrile produced in the polymerization of the IR, polymethyl acrylate produced in the 3'2R, and the target acrylonitrile are segment components, and methyl acrylate is the segment component.
Contains Mu811 block copolymer, approximately 5,000
514 of acetone was added to dissolve only the polymethyl acrylate, and the operation of separating was repeated three times to remove it. By this operation, the polymer weight became 31 (169).As a result of analysis by fractional precipitation method using a mixed solvent of dimethylformamide and acetone, which is a part of this polymer, it was found that polyacrylonitrile was 46.5%, AB [block copolymer] Combine 53
．． It was found that it contained 5%. AB obtained by separation
The intrinsic viscosity of the block copolymer was 1.83.

Example 1 An hBWB lock copolymer having acrylonitrile polymerized and fractionated by the method of the reference example as the segment body) and methyl acrylate as the segment (B) is 11
The mixture was mixed with an acrylonitrile polymer consisting of acrylonitrile/methyl acrylate=92/8 so as to have a composition of 1. Next, these polymer compositions were dissolved in 70% nitric acid solution Sa such that the total polymer concentration was 16% and 1%, and the polymer compositions were dissolved in a conventional hollow fiber spinning fi device to obtain a circle of 200 microns and an outer diameter of 300 microns. A hollow fiber was obtained by spinning in a 30% nitric acid aqueous solution. These characteristics of the hollow fibers are listed in Table 10 below, and the hollow fibers made of the polymer composition of the present invention were gratified to have excellent water permeability and a high degree of selective separation ability.

Example 2.3 Synthesis of an ABII block combination in which acrylonitrile is used as a segment (AJ acid component) and acrylic acid is used as a segment (B) component, and segment (4) is synthesized by the same two-stage polymerization method as in the reference example. A block copolymer containing acrylonitrile segment (B) and acrylamide as a component was synthesized. After completion of the two-way polymerization, y
! In order to remove the polyacrylic acid and polyacrylamide that were mainly polymerized in the 2nd JR polymerization, each was washed with a large amount of overflowing water, and then fractional precipitation was performed with a DMF/aqueous melt rope to obtain only the desired ABII block copolymer. was collected and deposited. The intrinsic viscosity of these AB type block copolymers and the composition of the segment (B) component in the ABII block copolymer were as shown in Table 2.

These AB! ! Polyacrylonitrile (intrinsic viscosity: 1.21) was mixed with the block copolymer so as to have the composition shown in Table 3, and then the polymer composition of the present invention was mixed so that the total polymer membership was 19.5%. 11 [K] of 65% nitric acid was dissolved in the solution. All of the obtained solutions were opaque and homogeneous solutions with microphase separation.

These solutions were kept at 0°C and had an outer diameter of 045cm and an inner diameter of 0,1
Using the annular spinneret (2), 111 parts of water was introduced into the solution *1-1 from the outside of the annular spinneret, and the solution was encapsulated in the can liquid and discharged. The discharge linear velocity of the solution at this time was 16 ml/ml, and this solution passed through a space of about 99 ml/ml, was introduced into water at room temperature, and was then raised onto a take-up roll for ms. It was found that the moldability of the hollow fibers formed in this way and the performance of the obtained hollow fibers were extremely excellent.

Example 4 ABII block copolymerization of random copolymers with different ratios of acrylonitrile/methyl acrylate in segment (81') and acrylonitrile (segment pseudo) component in the same manner as in the reference example above. Similar to the reference example, only the AB type block copolymer was spouted out from a mixed solvent of dimethylformamide and acetone, and the composition analysis and intrinsic viscosity were determined as shown in Table 4.

Table 4 The ABII block copolymer obtained in Experiment N13 was added to the acrylonitrile/methyl acrylate/methallylsulfone compound with jlII of 92.5/'7.010.5.
: Acrylonitrile copolymer consisting of I (intrinsic viscosity 1
．． 18) was mixed so as to have a weight of 15 based on the total polymer, and then a hollow fiber having an outer diameter of 300 μm and an inner diameter of 200 μm was produced using the same spinning method and equipment as in Example 3.

The performance of the obtained hollow fibers is as follows: water permeability: 499 IILL/
Hr.

-2■Hg and inulin passage rate of 716%, which is extremely high, and it has been demonstrated that the performance is far superior to that of hollow fibers obtained from conventional acrylonitrile copolymers.

t FiAm's easy lI! Akira? Figure 1 is an apparatus for measuring the water permeability and inulin passage rate of hollow fibers obtained from the polymer composition of the present invention, where l indicates the inlet of the spreading solution, 2 indicates the outlet of the treatment solution, and 4. is a hollow fiber bundle, and both ends are boted with i/M1iI (
5 and 6). 3 indicates the outlet of the liquid filtered through the hollow fiber wall.

Patent applicant: Asahi Kasei Industries, Ltd. Figure 1

Claims (1)

[Claims] An ABg block copolymer consisting of 80% by weight or more of acrylonitrile segment) and 20% by weight or more of a vinyl monomer other than acrylonitrile:/l [BI] An acrylonitrile-based polymer composition for molding, comprising 5 to 50 μm of acrylonitrile-based 1-merite having an acrylonitrile content of b'4ON11% or more.