JP2003160679A - Method for producing composite polymer material - Google Patents

Abstract

(57) [Problem] To provide a method for producing a composite polymer material which is free from strength deterioration due to remaining radicals and no adverse effect due to elution of remaining monomers. SOLUTION: After a radical is generated in a polymer material and then a graft chain is introduced by contacting with a vinyl compound, T _M -5 ° C. ≧ T ° C. ≧ 60 ° C. (T _M is the crystal melting point of the polymer material. A cleaning method including a hot water treatment step at a temperature (T ° C.) represented by the following formula:

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to uses in medicine, medical care, food such as contact with biological systems and separation and purification of proteins, and
The present invention relates to a method for producing a composite polymer material obtained by introducing a graft chain following a radical-forming reaction into a polymer material used for various electronic materials and the like.

[0002]

2. Description of the Related Art In recent years, membranes and non-woven fabrics in which graft chains are introduced with the generated radicals as starting points have been used for various purposes such as filtration and adsorption. In the case of the composite polymer material obtained by generating radicals by the treatment with plasma, the treatment with the reactive gas, or the treatment with the actinic ray, and graft-polymerizing a specific monomer, the radicals and the monomers remain. There is concern about the impact. For example, when a material that has undergone a graft polymerization reaction is used in the fields of food and medical care, it is conceivable that the radicals remaining in the material and the remaining monomers may adversely affect the living body. Further, there is concern that the strength may be reduced due to the main chain breaking by the residual radicals. Furthermore, in the case of materials used in a clean environment such as electronics and biotechnology, there is a concern about the influence of elution of residual substances.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a composite polymer material which is free from strength deterioration due to residual radicals and adverse effects due to elution of residual monomers.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that after introducing a graft chain following a radical-forming reaction, the crystal melting point of the polymer material is 5 By carrying out washing including a hot water treatment step at a temperature lower than 60 ° C. and higher than 60 ° C., it is possible to sufficiently wash residual monomers and the like after the graft polymerization reaction and prevent deterioration of strength due to radicals. The present invention has been completed and the present invention has been completed.

That is, according to the present invention, [1] a radical is generated in a polymer material and then a graft chain is introduced by contacting with a vinyl compound, and then a temperature (T) represented by the following formula (1) ℃) hot water treatment step including washing, a method for producing a composite polymer material, T _M −5 ° C. ≧ T ° C. ≧ 60 ° C. (1) (where T _M is the polymer material) It represents a crystal melting point, and T represents a hot water treatment temperature.) [2] The polymer material is irradiated with ionizing radiation of 10 kGy or more and 500 kGy or less to generate radicals in the polymer material [1. [3] The method for producing a composite polymer material according to [2], [3] The method for producing a composite polymer material according to [2], wherein the ionizing radiation is a γ ray or an electron beam, [4] The molecular material is a porous material [1], [ Method for producing a composite polymeric material according to] or [3], [5] [1], [2],
A composite polymer material obtained by the method for producing a composite polymer material according to [3] or [4].

The present invention will be described in detail below. In the method for producing a composite polymer material of the present invention, a radical is generated in the polymer material, and then a graft chain is introduced by contacting with a vinyl compound, and then at 60 ° C. or higher and the crystal of the polymer material is used. The hot water treatment is carried out at a temperature (T ° C) lower than the melting point (T _M ° C) by 5 ° C. As the resin used for the polymer material in the present invention, polyethylene,
Polypropylene resin, polyolefin resin such as poly 4-methyl 1-pentene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, polyester resin such as polycyclohexylene dimethylene terephthalate resin, nylon 6 , Nylon 66, nylon 610, nylon 612, nylon 11, nylon 1
2, polyamide resin such as nylon 46, polyvinylidene fluoride resin, ethylene / tetrafluoroethylene resin,
Examples thereof include fluororesins such as polychlorotrifluoroethylene resin, and thermoplastic resins such as polyphenylene ether resin and polyacetal resin.

In the present invention, it is preferable to use polyethylene, polypropylene, or polyvinylidene fluoride, which is generally applicable to graft polymerization, as the polymer material. The amount of radicals generated in the polymer material is preferably 200 × 10 ¹⁵ / g or more, more preferably 5
It is not less than 00 × 10 ¹⁵ / g. As a method for generating radicals, for example, treatment with plasma generated by corona discharge or glow discharge, treatment with active gas represented by ozone, mercury lamp, fluorescent lamp, xenon lamp, metal halide lamp, tungsten lamp, tungsten. Incandescent lamp,
Treatment with actinic rays such as ultraviolet rays and ionizing radiation can be used. Among them, the treatment with actinic rays is preferable, and among the actinic rays, ionizing radiation is preferable. What is ionizing radiation?
Radiation that is capable of causing ionization by interacting with substances, such as α rays, β rays, and γ emitted by radioactive decay.
Ray, X-ray, proton beam, electron beam, π-meson, μ-meson, and neutron beam that can obtain the same or higher energy by an accelerator. In the present invention, it is more preferable to use γ-rays or electron beams that are industrially suitable for mass production, and γ-rays that can generate radicals uniformly are particularly preferable.

In the present invention, the irradiation dose of ionizing radiation is preferably 10 kGy or more and 500 kGy or less, and 20 kGy or less.
Gy or more and 200 kGy or less are more preferable. 10 kG
An irradiation dose of y or more and 500 kGy or less is preferable because an effective amount of radicals can be generated and the strength of the material after irradiation does not deteriorate. Further, this effect is more remarkable as the specific surface area of the porous material is larger. In the present invention, a radical is generated in the polymer material and then contacted with the vinyl compound to carry out the graft polymerization. As a method of graft polymerization,
The method is roughly divided into a pre-irradiation method in which radicals are generated and then brought into contact with a monomer, and a simultaneous irradiation method in which radicals are generated in a state in which the radicals are brought into contact with each other. In the present invention, any method can be applied, but the liquid phase pre-irradiation method is the most preferable method.

The vinyl compound used in the present invention is a monomer or polymer having a vinyl group, and an organic compound having a reactive group capable of being cleaved and polymerized by a reaction with a radical. For example: Acrylic acid and its derivatives such as acrylamide, N, N, -dimethylacrylamide, acrylonitrile, methyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 4-hydroxybutyl. Acrylate, and 1,4-butanediol diacrylate; Methacrylic acid, such as glycidyl methacrylate, and suitable derivatives thereof; Vinyl carboxylate derivatives, such as vinyl acetate, N-vinyl acetamide, and N.
Vinylpyrrolidone; vinylsulphonic acids and their alkali metal salts, such as sodium vinylsulphonate; alkenylarylsulphonic acids and their alkali metal salts, such as styrene sulphonic acid and sodium styrenesulphonate; vinyl ethers such as vinyl methyl ether, Vinyl ethyl ether, vinyl glycidyl ether, diethylene glycol divinyl ether, and vinyl-n-butyl ether; vinyl ketone, such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl-n-propyl ketone; vinyl amine, such as N-vinyl pyrrolidine; , A polyalkylene compound having a vinyl group, an acrylic group, or a methacrylic group, for example, ethoxytetraethoxyethyl acrylate, or Toxytetraethoxyethyl methacrylate, n-propoxide decaethyleneoxyethyl vinyl ether, polyethylene glycol monoacrylate, poly (ethylene / propylene) glycol monomethacrylate, and allyloxyoctapropyleneoxyethanol; sugar derivatives such as vinyl-substituted arabinose or acryloylated hydroxy. Propyl cellulose; polyalkylene glycol having a functional group, such as triethylene glycol diacrylate and tetraethylene glycol diallyl ether.
In addition, styrene, chloromethylstyrene, styrenesulfonic acid, etc. are also included as derivatives of styrene. It is preferable to use a water-soluble vinyl compound.

In the present invention, after the introduction of the graft chain,
Cleaning including a hot water treatment step is performed. The hot water treatment step is
That is, the polymer material is immersed in hot water at a temperature (T ° C.) that satisfies T _M −5 ° C. ≧ T ° C. ≧ 60 ° C. (where TM represents the crystal melting point of the polymer material). Hot water temperature (T ° C)
Is preferably a temperature satisfying T _M −10 ° C. ≧ T ° C. ≧ 80 ° C., more preferably a temperature satisfying T _M −10 ° C. ≧ T ° C. ≧ 100 ° C. If hot water treatment is performed at a temperature of 60 ° C. or higher, the effects of deactivating radicals and removing residual monomers can be exhibited, and the temperature is 5 ° C. or lower than the melting point of the polymer material, that is, T ° C. ≦ T. _When hot water treatment is performed at _M- 5 ° C, there is no risk of causing changes in the shape and physical properties of the polymer material. The amount of water used for the hot water treatment is such that the polymer material can be completely immersed, and is preferably 5 times or more, more preferably 10 times or more, and particularly preferably 20 times or more the weight of the polymer material. Is.
If the washing is performed with an amount of hot water that is 5 times or more the weight of the polymer material, the polymer material can usually be completely immersed, and a satisfactory washing effect can be obtained.

The immersion time is preferably 1 minute or more, more preferably 5 minutes to 1 hour. If the immersion time is too long, the polymer material may deteriorate, and if it is too short, the effect is not sufficient. In addition, repeating the above-mentioned treatment a plurality of times is a preferable embodiment because it is possible to obtain higher effects in deactivating radicals in the polymer material, preventing strength deterioration, and washing the monomer. When the hot water treatment is repeated a plurality of times, the total immersion time is preferably 1 hour or less.

In the present invention, the above treatment method can be generally applied to polymer materials, but the effect is remarkable especially in porous materials. The porous material is a material containing a penetrating void of 10% or more in volume in a polymer material, and examples of the porous material include a polymer sintered body, a foam, a nonwoven fabric, and a filtration membrane. There are various types of polymeric porous membranes such as dialysis membranes.
In particular, applying the method of the present invention to a polymer porous membrane is effective in the production of ultrapure water and the filtration of chemicals in the electronics field where elution is a problem, and when used in food-related or medical applications. Is effective in preventing elution of harmful substances.

Particularly, in medical and medical applications such as dialysis membranes and membranes used for filtration of plasma fractionated preparations, not only the remaining eluate is removed, but also the remaining radicals are extinguished, and the influence of the radicals on the living body. It is also effective in preventing Furthermore, the effect of preventing the strength deterioration of the porous material due to the disappearance of radicals can be expected.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to Examples. The test methods shown in the examples are as follows. (1) Measurement of Crystal Melting Point It was measured by differential scanning calorimetry (hereinafter referred to as DSC). Differential scanning calorimeter (Seiko Denshi SSC-
5,000) at a temperature range of 30 to 300 ° C. and a temperature rising rate of 10 ° C./min, the peak top of the endothermic peak of the polymer material was determined, and the temperature was defined as the crystal melting point (° C.).

(2) Measurement of residual radical amount Electron spin resonance (ESR) device (JEOL Co., Ltd.)
ES-FE2GX), sample amount about 0.05g
Was filled in an ESR sample tube and the amount of radicals (spin number / g) remaining in the composite polymer material was measured. (3) Tensile breaking strength, tensile breaking elongation Tensile testing machine (Autograph A manufactured by Shimadzu Corporation)
G-A type), the length of the test piece is 100 mm, the distance between the chucks (mark line distance) is 50 mm, the pulling speed is 200 mm /
A tensile test was performed under the test conditions of a measurement temperature of 23 ± 2 ° C. The sample used is one month after the preparation.
The breaking strength (N / m ² ) and the breaking elongation (%) were calculated from the breaking load (N), the breaking elongation (mm) and the cross-sectional area (m ² ) according to the following equations. Tensile breaking strength (N / m ² ) = breaking load / cross-sectional area tensile breaking elongation (%) = breaking elongation / distance between chucks × 10
0 (4) Quantification of eluate After graft polymerization reaction, it was washed once with 500 ml of ethanol and autoclaved (BS-manufactured by Tomy Industries Co., Ltd.).
Model 235) was used to perform hot water treatment at a predetermined temperature. Then, using the same apparatus again, washing with hot water at 121 ° C., washing water is appropriately diluted, hydrochloric acid is added to adjust the pH to 2 or less, and then nitrogen gas is aerated to remove inorganic carbon components. did. This solution is used as a measuring solution, and TOC Engineering TOC meter 65 manufactured by Toray Engineering Co.
The amount of carbon was determined using Form 0 and the amount of residual monomer was analyzed. The standard value of the eluate test based on the dialysis-type artificial kidney device approval standard is 100 ppm.

[0016]

Example 1 Polyvinylidene fluoride resin (SOLVAY
Manufactured by SOLEF1012, crystal melting point 178 ° C) 40w
After stirring and mixing a composition consisting of t% and triphenyl phosphate 60 wt% at 70 ° C. with a Henschel mixer,
It is cooled and put into powder form from the hopper.
It melt-mixed at 210 degreeC using the mm twin screw extruder. Then, while flowing tri (2-ethylhexyl) phosphate heated at 120 ° C inside the hollow at a rate of 7 mL / min, it was hollow from the spinneret consisting of an annular orifice with an inner diameter of 0.8 mm and an outer diameter of 1.2 mm. It was extruded into a filament, cooled and solidified in a water bath adjusted to 40 ° C., and wound on a cassette. Then, triphenyl phosphate was extracted and removed with ethanol, and the attached ethanol was removed by drying, and then heat treatment was performed at 130 ° C. for 1 hour in a fixed length fixed state to obtain a hollow fiber-shaped porous polymer material. The thickness of the obtained polymer material is 40 μm,
The maximum pore size was 36 nm and the porosity was 60%. This polymer material was cut into a length of 25 cm and bundled into 400 pieces was subjected to a hydrophilic treatment by a radiation graft polymerization method. In a nitrogen atmosphere, γ-rays with a dose of 100 kGy were irradiated using cobalt 60 as a radiation source. The radical amount at this time was measured by ESR, and it was 2630 × 10 ¹⁵ / g.

After filling this membrane in a reaction vessel, the inside of the reaction vessel was evacuated to 13 Pa or less and left at room temperature for 15 minutes.
Next, 0.78 vol% hydroxypropyl acrylate (manufactured by Tokyo Kasei Co., Ltd.) and 2.04 vol% polyethylene glycol dimethacrylate (Aldrich).
Co., Ltd., number average molecular weight 875), 25 vol% t-butyl alcohol (manufactured by Junsei Chemical Co., Ltd.), and 72.1.
A monomer solution containing 8 vol% distilled water was bubbled with nitrogen to remove dissolved oxygen from the monomer solution. This graft reaction solution was suction-introduced into a degassed reaction vessel and reacted at a reaction temperature of 40 ° C. for 2 hours. After the reaction, the product was taken out of the container, washed once with 500 ml of ethanol, subsequently immersed in 100 ml of distilled water, and subjected to hot water treatment at 121 ° C. for 20 minutes in an autoclave (BS-235 type manufactured by Tomy Industries Co., Ltd.). went. As a result, as shown in Table 1,
In the obtained composite polymer material, the radicals disappeared below the detection limit, and the strength and elongation after 1 month were higher than those of the comparative examples, and the residual monomer amount in the material after washing was 15 pp.
It was as low as m.

[0018]

Example 2 A hollow fiber-shaped porous polymer material was obtained in the same manner as in Example 1 except that the hot water treatment temperature was 105 ° C. As shown in Table 1, the radical amount was 5 × 1 as in Example 1.
It disappeared to 0 ¹⁵ / g, the strength and elongation of the material could be maintained, and the amount of residual monomer after washing was 22 ppm.

[0019]

Example 3 A hollow fiber-shaped porous polymer material was obtained in the same manner as in Example 1 except that the hot water treatment temperature was 80 ° C. Table 1
As described above, the radical amount disappeared to 50 × 10 ¹⁵ / g, the strength and elongation of the material were higher than those of the comparative examples, and the residual monomer amount after washing was 32 ppm.

[0020]

[Comparative Example 1] A hollow fiber-shaped porous polymer material was obtained in the same manner as in Example 1 except that distilled water at 25 ° C was used as the hot water treatment. The breaking strength and elongation were measured 1 month after the preparation of the sample. As a result, as shown in Table 1, the obtained polymer material after the graft polymerization reaction had 281 x radicals.
As much as 10 ¹⁵ / g remains, both strength and elongation are lower than those of the examples. Further, the amount of residual monomer after washing was 940 ppm, which was about 60 times that in Example 1. From the above, it was found that a large amount of radicals are present, the strength is deteriorated, and the cleaning is insufficient.

[0021]

[Table 1]

[0022]

EFFECTS OF THE INVENTION According to the present invention, residual radicals after graft polymerization can be deactivated following a radical generation reaction, strength and elongation can be maintained, and residual monomers after graft polymerization reaction can be sufficiently removed. A safe composite polymer material can be provided.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F073 AA05 BA06 BA07 BA08 BA15                       BA23 BA24 BA27 BA29 BA34                       CA41 EA11 FA01 FA03                 4F074 AA17 AA24 AA26 AA38 AA57                       AA66 AA71 AA77 AA97 CD11                       CD17 DA44 DA59

Claims (5)

[Claims] 1. A radical is generated in a polymer material, and then a graft chain is introduced by contacting with a vinyl compound, and then a temperature (T) represented by the following formula (1)
C.) The method for producing a composite polymer material, which comprises performing washing including a hot water treatment step. T _M −5 ° C. ≧ T ° C. ≧ 60 ° C. (1) (In the formula, T _M represents the crystalline melting point of the polymer material, and T represents the hot water treatment temperature.) 2. Polymer material of 10 kGy or more, 500 k
The method for producing a composite polymer material according to claim 1, wherein the polymer material is irradiated with an ionizing radiation of Gy or less to generate radicals. 3. The method for producing a composite polymer material according to claim 2, wherein the ionizing radiation is γ ray or electron beam. 4. The method for producing a composite polymer material according to claim 1, 2 or 3, wherein the polymer material is a porous material. 5. A composite polymer material obtained by the method for producing a composite polymer material according to claim 1, 2.