JPH0527458B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing plasma-polymerized membrane-coated particles having selective adsorption properties for amino acids. (Prior Art) Compounds with optical activity are extremely important in natural organic compounds, and life is built on optically active substances. In addition, pharmaceuticals, agricultural chemicals, product additives, fragrances,
It is becoming very important in chemical and industrial fields related to living things such as feed. In order to separate these optically active substances, there is an application to optical resolution agents that utilize optically active substances. Particularly important are optically active polymers. Optically active polymers include proteins, polysaccharides, and the like, and many of the polymers involved in living organisms are optically active. However, synthetic polymers do not have optical activity unless they are specifically synthesized. Therefore, optically active polymers have been synthesized by various methods. For example, JP-A-60-67504 discloses a method using an optically active polymerization catalyst using an optically active polymerization catalyst consisting of a specific asymmetric ligand compound and an anionic initiator compound. Shows how to synthesize polymers. Furthermore, a method for polymerizing optically active monomers is disclosed in JP-A-51-81891. Other methods have also been proposed, such as fixing optically active compounds to polymers and making them insoluble. Problems remain with these methods, such as the extremely difficult and low-yield process of introducing a functional group into an optically active compound, the use of a special polymerization catalyst, and the use of only monomers with double bonds. (Problems to be Solved by the Invention) The purpose of the present invention is to polymerize and immobilize optically active camphor using a simpler process;
The present invention also proposes a method for producing plasma-polymerized membrane-coated particles that can be immobilized on a wider range of carriers and have selective adsorption properties for amino acids. (Means for Solving the Problems) The method of the present invention is characterized in that D camphor is activated in low-temperature plasma and brought into contact with fine particles to form a plasma polymerized film on the surface of the fine particles. The camphor used in the present invention is not particularly limited, and may be any camphor having optical activity.
Alternatively, camphor derivatives having optical activity may be used. D-camphor is preferred. Camphor or camphor derivatives usually have a high boiling point and a low vapor pressure at room temperature. When camphor or camphor derivatives have sublimation properties, they are preferably vaporized by sublimation. However, if the vapor pressure is low, it is necessary to increase the vapor pressure by heating. As the heating method, any of heater heating, high-frequency heating, far-infrared heating, or laser heating may be used, but it is important to perform heating so that decomposition does not occur due to heating. The plasma used in the present invention refers to a so-called low-temperature plasma, and the ionized gas plasma can be generated by any of the known methods for generating such a plasma. For example, in ``Applied Techniques of Plasma Chemistry'', edited by JR Hollahan and AT Bell, Wiley, New York 1974 and in ``Plasma Chemistry of Polymers'', edited by M Shen, Detzker New York, 1976. That is, the monomer can be placed under vacuum between parallel plate electrodes connected to a high frequency generator, and the plasma can be generated using the parallel plates either outside or inside the vacuum chamber. Alternatively, an electric field may be created by an external induction coil to generate a plasma of ionized gas, or a plasma may be generated by placing oppositely charged electrodes spaced apart directly into a vacuum chamber. Depending on the plasma polymerization conditions, the plasma polymerized product can be in the form of grease (liquid), film (membrane), or particle (powder).
In order to obtain a film-like polymer,
Plasma polymerization conditions are selected appropriately. Plasma polymers are usually formed as a thin film on sheets, fibers, or particulates of paper, glass, silica gel, polymers, etc. Among these, those with a large surface area are preferred, and silica gel fine particles with a particle size of 0.1 mm or less are particularly preferred. The plasma polymerized product of D camphor of the present invention can be prepared using organic solvents such as alcohol, ether, pyridine, chloroform, acetone, benzene, formic acid,
It has no solubility in dimethylformamide etc.
It can be seen that it is a crosslinked polymer. However, the swelling property in organic solvents changes depending on the polymerization conditions. It is difficult to identify the structure and chemical structure of plasma polymers. IR, NMR, X-ray,
A tentative evaluation can be made by measuring with an electron microscope or the like and measuring the optical rotation. Primary between monomer and polymer (chemistry)
The structural relationship changes depending on the type of monomer and plasma polymerization conditions. It is necessary to select conditions in which most of the typical chemical structure of the monomer, such as the asymmetric center, remains. Monomers whose chemical structures are easily destroyed by general polymerization methods, light and heat, etc. are also difficult to retain their primary structure by plasma polymerization. Generally, plasma polymerization of D camphor is carried out for usually 1 minute or more, preferably 10 minutes or more, and a method of applying high frequency waves in pulses is also preferable. It is preferable to combine methods such as reducing the plasma polymerization time, lowering the plasma output, lowering the degree of vacuum, or lowering the temperature of the substrate. Regarding plasma output, the structure of monomers with high output tends to be damaged, but if the output is lowered too much, polymerization will not proceed sufficiently and the residual rate of monomer will increase, or the molecular weight of the product will not be high enough and it will dissolve in solvent etc. or Therefore, it is important to determine the output based on these considerations. The high frequency output in the case of polymerization of D camphor is usually 10 to 300 W, preferably 50 to 300 W.
It is 200W. Naturally, the high frequency output must be selected appropriately depending on the intended use. The degree of vacuum also shows the same tendency and effect as the output; when the degree of vacuum decreases, the progress of polymerization is insufficient and the physical properties of the polymer are not sufficient. On the other hand, if the degree of vacuum is too high, the energy of the plasma becomes too high, resulting in a polymer with almost no monomer structure remaining, or a film or powder with an extremely high degree of crosslinking, which may cause the inside of the polymer to be It becomes difficult for substances to enter and exit, and even if the properties of the monomer remain, the performance of the polymer cannot be expressed. Vacuum level is normal
It is 10 ^-5 to 10 ² Torr, preferably 10 ^-4 to 10 Torr, and more preferably 10 ^-3 to 1 Torr. The temperature of the substrate has little to do with the essential mechanism of plasma polymerization, but when the substrate temperature is high and the molecular weight and crosslinking of the polymerization product is low, the product will vaporize and be dispersed. Furthermore, when the substrate temperature is low, unactivated monomers adhere and solidify due to diffusion due to the temperature gradient, resulting in a decrease in polymerizability. (Effects of the Invention) The method of the present invention replaces conventional methods for producing optically active polymers, which are complicated and special, and which can only be applied to specific optically active compounds, by directly and in one step producing monomers. It is an extremely effective method from an engineering standpoint in that it can be polymerized through plasma polymerization. The plasma polymer of D camphor obtained using silica gel as a carrier has selective adsorption properties for amino acids, and the carrier on which the plasma polymer is formed can be arbitrarily selected, making it extremely useful for producing optical resolution materials, etc. . The present invention will be explained in more detail below with reference to Examples. Example 1 Figure 1 shows the plasma polymerization apparatus used this time. 1 is the radio frequency (RF) power supply, here 13.56MHz
A high frequency power source was used. The high frequency generated in 1 is passed through a matching box 2 to an electrode 4 with a diameter of 10 cm in a reaction vessel 3. When a high frequency is applied between the electrode 4 and the grounded pair of electrodes 5, plasma is generated inside the reaction vessel. 5.0 g of D-camphor 6, 6' are placed in the monomer containers on the left and right sides of the electrode, and the amount of monomer supplied to the plasma is varied by changing the pressure with the exhaust control valve 7. The gas or other monomer that generates the plasma is 17-1
It can be supplied from 9. 2.0 g of porous silica (particle size 4 to 32 μm) 20 was placed in a glass container 21 and placed between the electrodes. D-camphor is sublimated under reduced pressure, and when the pressure within the reaction vessel becomes constant, a high frequency voltage is applied to the electrodes to generate D-camphor plasma.
The high frequency output was 100 W, and polymerization was repeated 5 times for 60 minutes. Silica was taken out between each batch and stirred with a spatula. D-camphor plasma was generated near the upper and lower electrodes, and the silica was colored light brown.
Monomer feed rate is 47 mg/min. After polymerization, the silica was taken out, stirred and washed overnight with acetone, filtered and dried under reduced pressure to obtain a sample. The amount of polymer deposited was 3.9% by weight based on the silica. 200mg of this silica fine particles is 2.4×10 ^-2 M/D
and L-tryptophan aqueous solution were placed in 8 ml of each, stirred for 3 hours, and the amount of adsorption was measured. The amount of adsorption was 6.3 x 10 ^-6 M for the D form, and 27.3 x for the L form.
There is adsorption of 10 ^-6 M, and the adsorption amount of L isomer to D isomer.
It had a selective adsorption property of 4.3 times. The amount of adsorption was determined by diluting the tryptophan solution 200 times and determining the amount from the absorption peak at 28/nm using ultraviolet absorbance method. Example 2 Using the same method as Example 1, high frequency output 100W,
Plasma polymerization was carried out under reduced pressure of 0.4 Torr and at the vacuum degree and polymerization time shown in Table 1 to obtain plasma polymerized silica. Thereafter, washing and drying were performed in the same manner as in Example 1, and then the adsorption amounts of D and L tryptophan were measured. Table 1 shows the results.

[Table] In both cases, selective adsorption was observed for L-form and D-form.

[Brief explanation of the drawing]

Figure 1 shows a straight-tube type plasma polymerization apparatus.
is a radio frequency (RF) power source, 3 is a glass reaction vessel,
4 represents the upper electrode, 5 represents the lower electrode, 6 and 6' represent D-camphor, and 20 represents fine particles.

Claims (1)

[Claims] 1. Activating D camphor in low temperature plasma,
A method for producing plasma-polymerized film-coated particles having selective adsorption properties for amino acids, the method comprising forming particles coated with a plasma-polymerized film on the surface of the microparticles by contacting them with the microparticles. 2. The method according to claim 1, wherein the D camphor is vaporized and introduced into the low-temperature plasma. 3. The method according to claim 1, wherein low-temperature plasma is generated at a vacuum degree of 10 ^-5 to ^{10 2} Torr. 4. The method according to claim 4, wherein the fine particles are silica gel with a particle size of 0.1 mm or less.