JPH01254209A - Hollow yarn type module structural body - Google Patents

Abstract

PURPOSE:To obtain the title module structural body which is excellent in heat resistance durable to repeated steam sterilization and chemical resistance and capable of utilization in various fields by utilizing heat resistant engineering plastic which is high in thermal deformation temp., rigid and stable in hydrolytic property as a housing member. CONSTITUTION:A housing is formed of heat resistant engineering plastic such as polysulfone which has glass transition temp. not lower than 150 deg.C and hydrolytic stability of physical properties holding rate not lower than 80% after continuous exposure to hot water for 1500hours. A hollow yarn porous membrane made of PP is bundled and charged in this housing and both end parts are fixed while utilizing the substance obtained by mixing a polyamine- base curing agent with epoxy resin as a potting material. This hollow yarn type module structural body made by such a way has high strength and can be utilized for all fields such as medical fields and foodstuff fields and also industrial fields.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a heat-resistant material that is suitable for purifying and separating liquids or gases, aeration into liquids, degassing from liquids, etc. The present invention relates to a hollow fiber type module structure with excellent durability, chemical resistance, and mechanical properties.

[Prior art and problems to be solved by the invention] In conventional hollow fiber module structures, the housing is made of metal or made of resin such as polycarbonate, vinyl chloride, acrylic resin, ABS resin, etc. There are many examples of this. If the housing is made of metal, there are disadvantages such as the resulting module structure being heavy, expensive, and difficult to mass produce.Also, if the housing is made of general-purpose resin, it has poor heat resistance and durability. It has drawbacks such as poor chemical properties and weak mechanical properties.

On the other hand, as a botting material for fixing a porous hollow fiber membrane to a housing, a polyurethane-based material is often used because of its ease of molding and good sealing properties. However, polyurethane-based botting materials have the disadvantage that their range of use is narrow in terms of heat resistance, chemical resistance, and solvent resistance.

[Means for Solving the Problems] Therefore, the present inventors have developed a material that has a high heat distortion temperature, is rigid, has little creep, and has stable hydrolyzability as a housing member for a conventional hollow fiber type module structure. By using this method, it is possible to obtain a module structure that has excellent heat resistance and chemical resistance that can withstand repeated steam sterilization, and has high strength and can be used in all fields such as the industrial field, the medical field, the food field, etc. We have discovered what we can do and have arrived at the present invention.

That is, the present invention provides a heat-resistant engineering method for manufacturing a plurality of porous hollow fiber membranes with hydrolytic stability having a glass transition temperature of 150° C. or higher and a physical property retention rate of 80% or higher after continuous exposure to hot water for 1500 hours. The plurality of porous hollow fiber membranes are loaded into a housing made of plastic, and both ends of the plurality of porous hollow fiber membranes are sealed to the housing using an epoxy resin (here, "tight" means sealing liquid and gas). A hollow fiber type module structure is provided.

In the present invention, a heat-resistant engineering plastic having a glass transition point (Tg) of 150°C or higher and a hydrolytically stable property retention rate of 80% or higher after continuous exposure to hot water for 1500 hours is used as the housing member. It has a major feature in its use.

Here, the physical property retention rate defined as a measure of hydrolytic stability is the ratio (%) of mechanical properties (tensile strength) to the original value when immersed in hot water at 96°C for 1500 hours.
), and as a test method for hydrolytic stability, a tensile test piece (5 x 0.5 x 0.125 inches) was subjected to a tensile test based on the ASTM (American Society for Testing and Materials) standard. The test piece was continuously immersed in 96°C hot water for 1500 hours, and the ratio to the value obtained in a tensile test was taken as the physical property retention rate.

Typical examples of heat-resistant engineering plastics having such characteristics include polysulfone, polyethersulfone, polyetherimide, polyallylsulfone, and the like.

If the glass transition point (Tg) is less than 150°C, or if the property retention rate after 1500 hours of continuous hot water exposure is less than 80%, it is not heat resistant.
Moreover, it cannot sufficiently withstand repeated high-pressure steam sterilization.

Incidentally, the retention of physical properties of polysulfone after continuous exposure to hot water for 1500 hours is approximately 100%, and polyethersulfone, polyetherimide, and polyallylsulfone also exhibit retention of physical properties of 90 to 100%, respectively. On the other hand, polycarbonate has a physical property retention rate of 50% or less and cannot be used in the present invention.

In addition, the heat-resistant engineering plastics mentioned above meet the UL standard at a continuous use temperature of 160°C, have good steam resistance, have good long-term creep resistance, and have excellent mechanical and electrical properties. It is something that exists. Furthermore, it can withstand acids and alkalis at high temperatures.

Next, as the porous hollow fiber membrane used in the present invention, one made of a crystalline thermoplastic polymer that can be melt-formed is preferably used. In other words, in the past, membranes made of cellulose resins (cellulose acetate, cuprammonium cellulose, acetyl cellulose), polymethyl methacrylate, polyacrylonitrile, polyvinyl alcohol, etc. were mainly used using wet spinning methods, but There are problems in the medical field because sterilization is difficult, and there are also problems in terms of strength and chemical resistance, so separation of liquids used in manufacturing processes in the chemical industry, petrochemical industry, pharmaceutical industry, electronic material industry, etc. , it could not be used for purification treatment, etc.

From this point of view, in the present invention, a melt-formable crystalline thermoplastic polymer, particularly a melt-formable crystalline thermoplastic polymer having a degree of crystallinity of 60% or more, is dry melt-spun,
When a hollow fiber membrane made porous by a physical stretching method is used, it has excellent heat resistance, strength, and chemical resistance, and can be suitably used in the above fields.

Examples of crystalline thermoplastic polymers that can be melt-formed include polypropylene, olefin resins such as poly4-methylpentene-1, polyvinylidene fluoride, polytetrafluoroethylene, and tetrafluoroethylene copolymers. A typical example is fluororesin.

These thermoplastic polymers can be copolymerized or mixed with other materials to the extent that the properties of the thermoplastic polymer are not substantially adversely affected.

The above-mentioned porous hollow fiber membrane can be manufactured by a conventionally known method, for example, JP-A-60-139807, JP-A-60-139807;
As shown in Japanese Patent No. 139808, there is an extraction method in which a material to be eluted is mixed with a material to form a film, and then the substance to be eluted is eluted from the membrane to form a porous membrane. After spinning, it can be produced by a stretching method in which it is stretched in a specific temperature range and/or in a specific medium to make it porous.

Next, a description will be given of a botting material for loading the porous hollow fiber membrane into the housing and fluidly fixing both ends of the hollow fiber membrane to the housing.

Polyurethane resin is conventionally used as the botting material due to its ease of molding and good sealing properties.

However, polyurethane-based botting materials often have problems in that they are sensitive to heat, easily hydrolyzed, and have poor chemical resistance, particularly to solvents.

Therefore, in the present invention, it has excellent heat resistance and chemical resistance,
Epoxy resin is used as the ink material with few problems in mechanical properties and good durability.

Furthermore, considering that the curing temperature is high and curing takes time, a botting material prepared by mixing a polyamine curing agent with an epoxy resin is preferably used.

Among the polyamine curing agents used in the present invention, polyamide curing agents are particularly preferably used because they have the following characteristics.

Polyamide hardeners are usually liquid at room temperature, and can be mixed with epoxy resins without the need for heat.Additionally, if slightly heated (approximately 50 to 100 degrees Celsius), the viscosity of the mixture becomes extremely low. , the adhesion with the porous hollow fiber membrane becomes good, and the end sealability becomes excellent. In this case, it is more effective if the viscosity of the polyamide curing agent is 70 voices or less, preferably 50 voices or less at a temperature of 75°C. If this viscosity becomes too high, the fluidity during botting will deteriorate, making it impossible for the botting material to penetrate into the bundle of hollow fiber membranes, and the adhesion with the hollow fiber membranes will be poor, resulting in a seal. Defects are more likely to occur.

Polyamide curing agents have a lower curing temperature than aromatic polyamine or acid anhydride curing agents (from room temperature to
00°C), and the curing time is short (about 20 to 80 minutes).

In addition, polyamide curing agents not only have extremely low toxicity and irritation when mixed with epoxy resins, but also have been approved by the US FDA as a curing agent for epoxy resins that can be used in food and pharmaceutical applications. It has been approved and can be used in an extremely wide range of applications, including food and pharmaceuticals as well as water purifiers.

Furthermore, compared to conventional polyurethane resin botting materials,
Its solvent resistance, chemical resistance, and duck resistance have been greatly improved, making it possible to be applied to acid/alkaline solutions and organic solvents (alcohols, esters, ketones, etc.), and it can be repeatedly sterilized using high-pressure steam. It also has sufficient durability.

Specific examples of the polyamide curing agent explained above include:
Examples include dimer acid, which is a dimer of linoleic acid, and condensation products of fatty acids and polyamines (trade names: Persamide (manufactured by Henkel) and Zenamide (manufactured by Henkel)).

Next, the type of epoxy resin to be mixed with the polyamide curing agent is not particularly limited, and examples thereof include glycidyl ether, glycidyl ester, glycidyl amine,
Aliphatic epoxide, fatty epoxide type, etc. are used. Among the above, glycidyl type epoxy resins are common, and among them, those that are liquid at room temperature, such as glycidyl ether type and glycidyl ester type epoxy resins, are particularly preferably used.

Examples of the glycidyl ether type include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, polypropylene glycol diglycidyl ether, -thyl, etc., and examples of the glycidyl ester type include phthalic acid diglycidyl ester, Examples include dimer acid diglycidyl ester.

The polyamide curing agent and the epoxy resin are mixed at room temperature or, if necessary, heated to 50 to 100°C. The curing temperature can be determined as needed within the range of room temperature to about 120°C, but generally higher temperatures will lower the viscosity during mixing and shorten the curing time, but on the other hand, too high a temperature. 50 to 100℃, as the pot life is extremely short.
It is preferable to decide within a range of degrees.

In the present invention, the method of botting (fixing) both ends of the porous hollow fiber membrane to the housing is to store the hollow fiber bundle while applying centrifugal force in the longitudinal direction of the hollow fiber bundle, and to place the bottling in the loaded housing. A rotary centrifugal molding method may be used, in which the botting material is injected into the housing, or a static molding method may be used, in which the botting material is injected into the housing while the hollow fiber bundle is loaded and left in the housing.

[Examples] Hereinafter, the present invention will be explained in detail based on Examples, but
The present invention is not limited to these examples.

(Example) Inner diameter 45m (φ), outer diameter 52+us (φ), length 38
Inside the polysulfone housing with an inner diameter of 32071 mm
2400 polypropylene porous hollow fiber membranes (trade name: Nishikutan, manufactured by Ube Industries, Ltd.) having a thickness of 55 pm and a length of 300 mm were bundled and loaded, and both ends were fixed with a botting material. As the botting material, a glycidyl ether type epoxy resin (product name: Ebicoat 828, manufactured by Yuka Shell Epoxy ■) and a polyamide resin curing agent (product name: Persamide 125, manufactured by Henkel Hakusui ■) were used in a weight ratio of 65: 35. The mixture was mixed at a temperature of 75° C. and cured for about 1 hour after injection of the botting material. Next, the central part of the end of the hollow fiber membrane bundle tightly fixed with the botting material was cut at right angles to the length direction of the fiber ends to form an opening.

Chemical resistance, heat resistance, and high pressure steam sterilization tests were conducted on the hollow fiber type module structure manufactured as described above, consisting of a polypropylene porous hollow fiber membrane loaded in a polysulfone housing and a cured epoxy resin. The test conditions and results are shown in Table 1.

(Comparative example) A hollow fiber module structure was produced under the same conditions as in the example except that polycarbonate was used as the housing and polyurethane resin was used as the potting material.
This hollow fiber module structure was tested for chemical resistance, heat resistance, and high pressure steam sterilization. The results are shown in Table-1.

(Hereinafter, blank space) [Effects of the Invention] As explained above, the hollow fiber type module structure of the present invention has a housing with a glass transition temperature of 150°C or higher and a property retention rate after continuous exposure to hot water for 1500 hours. It is made of heat-resistant engineering plastics with a hydrolytic stability of 80% or more, and both ends of the porous hollow fiber membrane are fixed with epoxy resin, so it has excellent heat resistance and chemical resistance. Due to its strength, it can be used in all fields such as industrial, medical, and food fields.

Claims (1)

[Claims] (1) Multiple porous hollow fiber membranes with a glass transition temperature of 15
The plurality of porous hollow fibers are loaded into a housing made of heat-resistant engineering plastics having hydrolytic stability with a physical property retention rate of 80% or more after continuous exposure to hot water at 0° C. or higher for 1500 hours. A hollow fiber type module structure characterized in that both ends of a membrane are fluid-tightly fixed to the housing with an epoxy resin.