JPH06222056A - Serum separating medium containing dicyclopentadien based copolymer - Google Patents

Abstract

PURPOSE:To obtain a practically quite useful serum separating medium in which temporal fluctuation of objective components to be measured is suppressed during separating operation without causing any physical or chemical variation. CONSTITUTION:The inventive serum separating medium principally comprises a dicyclopentadien based copolymer having number-average molecular weight of 200-10,000 containing 20-98mol.% of unit derived from dicyclopentadien, 2-50mol.% of unit derived from olefin and/or alkylvinylether, and 0-30mol.% of unit derived from other monomer having unsaturated ethylene linkage which can be copolymerized.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood separating agent using a dicyclopentadiene copolymer. More specifically, when separating a serum component and a blood clot component coexisting in blood or a plasma component and a blood cell component by utilizing the difference in their specific gravities, by imparting an intermediate specific gravity between the two components, The present invention relates to a blood separating agent which can be used for the purpose of facilitating the separation operation of these two components by forming a partition wall between them. Conventionally, various compounds have been known as a separating agent used in such a separating operation. For example, silicone oil (JP-A-54-2120 etc.), acrylic polymer oil (JP-A-54-63797 etc.), chlorinated polybutene oil (JP-A-57-9718 etc.), α-
Olefin / maleic acid diester copolymer
2-199644, etc.) or a cyclopentadiene oligomer (JP-A-1-295163, etc.) as a main component, and silica or clay as a thixotropic agent for adjusting specific gravity or viscosity or maintaining shape It is known that inorganic fine particles are added. On the other hand, recently, drug therapy has been actively carried out in clinical practice, and therefore, there is a growing need to measure the blood concentration of the drug accurately and quickly. Separation agents are being used more and more often because they can perform blood separation treatment easily and quickly. [0004] However, these oil-based blood separating agents have insufficient affinity with thixotropic agents, and therefore heat treatment, long-term storage, or centrifugation operation. Under these conditions, phase separation may occur and the physical properties of the gel may deteriorate the function of the partition wall, and the separation of oil components may easily contaminate the separated components. There is a problem that decomposition products are easily generated and the separated components are easily contaminated. Further, when a compatible oil is mixed in order to adjust the specific gravity and the viscosity, due to the difference in affinity with the thixotropic agent, a change with time in the properties of the blood separating agent occurs, and thermal stability is improved. It has the drawback of being bad, and
When an oil having a low specific gravity is mixed, it has a drawback that the separated components are easily contaminated. Further, when the separating agent contains a volatile component having a low molecular weight, the inner wall of the vacuum blood collection tube becomes water repellent, which causes a problem such as slow blood coagulation. Further, when a conventional blood separating agent is used, for example, in hospital pharmacy vol. 12, No. 6,401 (19
86), as previously reported in Kyushu Pharmaceutical Bulletin No. 40, 39 (1986), etc., the problem that the drug component contained in serum decreases with time due to the effect of the blood separating agent used. There is. This is because the drug component to be measured is absorbed by the blood separating agent due to the influence of the blood separating agent used during the blood separating operation, and the blood concentration thereof decreases over time. The cyclopentadiene oligomer described above is excellent in terms of drug adsorption, but has a drawback that it contains a large amount of volatile components when used in a vacuum blood collection tube. Therefore, it is not appropriate to use a conventional blood separating agent for the purpose of measuring the blood concentration of a certain drug, and there has been a strong demand for the development of a blood separating agent that improves these points. [0007] An object of the present invention is to provide a practically excellent blood separating agent which does not have these drawbacks. As a result of intensive studies to achieve such an object, the present inventors have found that a copolymer containing a specific dicyclopentadiene and an olefin and / or an alkyl vinyl ether as essential components is extremely excellent in practical blood separation. The present invention has been reached by finding that it can be used as an agent. That is, the gist of the present invention is that a unit derived from dicyclopentadiene (a) is 20 to 98 mol%, an olefin having 6 to 20 carbon atoms and / or an alkyl vinyl ether having 2 to 20 carbon atoms in an alkyl group ( 2 to 50 mol% of units derived from b), and (a) above,
A dicyclopentadiene copolymer having a number average molecular weight of 200 to 10,000 and containing 0 to 30 mol% of units derived from a monomer (c) having a copolymerizable ethylenically unsaturated bond other than (b). The blood separating agent contains coalesced as a main component. The present invention will be described in detail below. The dicyclopentadiene corresponding to the monomer (a) in the present invention has the following structural formula: It is represented by The monomer (b) in the present invention is an olefin having 6 to 20 carbon atoms and / or an alkyl vinyl ether having 2 to 20 carbon atoms in the alkyl group. As the olefin, α-olefin, propylene oligomer and isobutylene oligomer are suitable. The α-olefin is a straight-chain or low-branch hydrocarbon having a carbon-carbon double bond at its terminal, and specifically, those obtained by low-polymerizing ethylene are preferably used. Is used by separating α-olefin having a predetermined carbon number from the reaction product by means such as distillation. When the carbon number of the α-olefin exceeds 20, the resulting copolymer becomes solid at room temperature, which is not preferable. When it is less than 6, complicated operations such as reaction under pressure during synthesis of the copolymer are required. It is not preferable because it is necessary. As the propylene oligomer, propylene dimer, propylene trimer, propylene tetramer, propylene pentamer and propylene hexamer obtained by low-polymerizing propylene are preferably used. As the isobutylene oligomer, diisobutylene, triisobutylene, tetraisobutylene, and pentaisobutylene obtained by low-polymerizing isobutylene are preferably used.
In the present invention, the olefin having 6 to 20 carbon atoms may be used alone or as a mixture thereof.
Alkyl vinyl ether has 2 to 20 carbon atoms
Is a vinyl ether of an alkyl group having a straight or branched chain of, specifically, ethyl vinyl ether,
Propyl vinyl ether, isopropyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, sec-butyl vinyl ether, cyclohexyl vinyl ether, hexyl vinyl ether, 2
-Ethylhexyl vinyl ether, octyl vinyl ether, lauryl vinyl ether, myristyl vinyl ether, palmityl vinyl ether, stearyl vinyl ether are preferably used. In the present invention, the alkyl vinyl ether having 2 to 20 carbon atoms may be used alone or as a mixture thereof. When the number of carbon atoms of the alkyl group of the alkyl vinyl ether exceeds 20, the resulting copolymer becomes a solid at room temperature, which is not preferable, and when it is less than 2, complicated reactions such as reaction under pressure during synthesis of the copolymer are required. It is not preferable because it requires various operations. The alkyl group of the alkyl vinyl ether preferably has 6 to 18 carbon atoms. The copolymer of the present invention contains 20 to 80 mol% of units derived from the monomer (a) and the monomer (b).
2 to 50 mol% of units derived from Among them, the unit derived from the monomer (a) and the unit derived from the monomer (b) are each 30 to 90 mol%.
And 5 to 40 mol% are preferable. Within this range, the copolymer of the present invention has a monomer (a) having a large specific gravity.
The specific gravity can be adjusted in a wide range by adjusting the copolymerization molar ratio of the monomer (b) having a low specific gravity and the carbon number of the monomer (b). Therefore, in order to use the copolymer of the present invention as a blood separating agent, the copolymerization molar ratio and the carbon number of the monomer may be adjusted so as to obtain a desired specific gravity. In addition to the units derived from the monomers (a) and (b) described above, the copolymer of the present invention has an ethylenic group which is copolymerizable with the units (a) and (b). The unit derived from the monomer (c) having an unsaturated bond is contained in the copolymer in an amount of 0 to 30 mol%, preferably 0 to 20.
It is also possible to contain it by mol%. The monomer (c) is not particularly limited as long as it is a compound having an ethylenically unsaturated bond other than the monomers (a) and (b) above, and examples of the compound having one ethylenically unsaturated bond include: Examples thereof include styrene, indene, isobutylene, piperylene, alkylallyl ether, norbornene and the like. As the monomer (c), a monomer that does not have a highly polar group such as an ester group or an amide group is particularly preferable. The copolymer of the present invention can be obtained by copolymerizing the above-mentioned monomers (a) and (b) and, if necessary, the monomer (c) at a desired polymerization ratio. Although various methods can be applied as the polymerization method, a cationic polymerization method is preferably used. Specifically, for example, the monomers (a) and (b) and optionally (a) and (b) are added to the reactor.
Other than the above, a monomer (c) having a copolymerizable ethylenically unsaturated bond is charged all at once, and a cationic polymerization catalyst is added all at once or continuously or in a divided manner in the presence or absence of a solvent to perform cationic polymerization. There is a method of doing. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, alicyclic hydrocarbons such as cyclohexane and ethylcyclohexane, aliphatic hydrocarbons such as hexane and heptane, methylene chloride and carbon tetrachloride. And halogenated hydrocarbons such as 1,2-dichloropropane. Protonic acids and Lewis acids are used as the cationic polymerization catalyst. As the protic acid, sulfuric acid, hydrochloric acid, perchloric acid, methanesulfonic acid,
Examples include trifluoromethanesulfonic acid, chlorosulfonic acid, trifluoroacetic acid, trichloroacetic acid and the like. As the Lewis acid, aluminum chloride, aluminum bromide,
Metal halides such as tin chloride, titanium chloride, iron chloride, boron trifluoride and boron trifluoride complex (eg ethyl ether, ester, acetic acid, or phenol complex),
And organometallic compounds in which some chlorine of aluminum chloride is substituted with methyl or ethyl groups. Especially, a boron trifluoride complex is preferable when obtaining a liquid copolymer. The catalyst amount is usually 0.5 to 10% by weight based on the monomer. When a metal halide catalyst is usually used,
A trace amount of water serving as a cation source, alcohol, fatty acid, ether, alkyl halide and the like are used as a cocatalyst. The polymerization reaction is usually carried out at about -70 to 150 ° C. The termination of the cationic polymerization is carried out by adding a polymerization inhibitor such as methanol to the reaction system, and then adding an alkaline aqueous solution to this to neutralize the catalyst and remove it by washing with water. Thereafter, the unreacted monomer, the solvent and the like are removed by distillation to obtain the intended copolymer. The number average molecular weight of the obtained copolymer is usually 200 to
It is about 10,000. Moreover, the viscosity is 1,000 to
It is about 1,500,000 cP. The molecular weight can be appropriately adjusted by using a chain transfer agent together or by appropriately adjusting the type and amount of the solvent, the polymerization temperature and the like. The copolymer of the present invention may be further hydrogenated after the copolymerization reaction. Hydrogenation tends to improve the hue of the copolymer and increase the chemical stability of the copolymer. The copolymer of the present invention is useful as a blood separating agent used for separating components in blood. In this case, from the viewpoint of the specific gravity of the blood component to be separated or the separation operation, the specific gravity of the copolymer at a temperature of 25 ° C. is 1.00 to 1.08, preferably 1.028 to
1.060 and viscosity of 1,000-1,500,00
0 cP, preferably 10,000 to 400,000 c
Those in the range of P are preferably used. If the viscosity is too low, the storage stability of the obtained separating agent is poor, and the separating agent is apt to move due to gravity or the like at high temperature, which makes it difficult to maintain the shape, which is not preferable. On the other hand, if the viscosity is too high, the handling and dispensing operation to the blood collection tube are not easy due to the high viscosity. Also, the floatability is insufficiently secured and the separation performance is poor. The copolymer of the present invention can be used as it is as a blood separating agent, but it is used as a main component and is used as a blood separating agent for the purpose of adjusting specific gravity or viscosity as necessary. Various additives can be blended for the purpose of maintaining the shape. Such compounding agents include inorganic fine powders such as silica, bentonite, titanium oxide, alumina, and talc, or polymer fine powders such as polystyrene powder and polyurethane powder, and the compounding amount thereof is 100 parts by weight of the copolymer. On the other hand, it is usually in the range of 0 to 20 parts by weight. Further, the blood separating agent of the present invention usually preferably contains a gelling agent in order to maintain a stable non-flowing state before and after the centrifugation operation. As a gelling agent,
For example, glutamic acid amide, hydrogenated castor oil, organic gelling agents such as dibenzylidene sorbitol, hydrophobic silica,
An inorganic gelling agent such as an aliphatic amine derivative of smectite clay may be used. The blending ratio of these gelling agents is usually in the range of 0.1 to 20 parts by weight with respect to 100 parts by weight of the polymer. If the amount of the gelling agent added is too small, the strength of the separating agent may be insufficient during the blood separation operation, so that the partition wall may flow, and the separating agent may not function sufficiently. Further, the shape retention of the separating agent is insufficient TP, and the storage stability tends to be insufficient. On the other hand, if there is too much gelling agent, the fluidity will be insufficient, which makes it difficult to ensure the floatability of the separating agent during centrifugation, and the fluidity of the separating agent will be insufficient. Deterioration occurs. The blood separating agent of the present invention must have a specific gravity intermediate between serum components and blood clot components or plasma components and blood cell components. Therefore, the specific gravity at 25 ° C. is 1.
It is preferably in the range of 028 to 1.060. For example, in the case of a blood separation tube containing a blood separation agent at the bottom, the greater the difference in specific gravity between the blood clot component or blood cell component and the blood separation agent, the greater the floatability of the separation agent during centrifugation, which is preferable. However, if the specific gravity is less than 1.028, a part of the separating agent having a small specific gravity may be separated in the serum or plasma component after centrifugation, which is not preferable. The blood separating agent containing the specific copolymer of the present invention is particularly inactive to blood. That is, there is no risk of causing phenomena such as blood adsorption and elution, it does not contain volatile components, and it is stable over time. In addition, since the polarity is low, the adsorption and solubility of the drug contained in serum are low, the measured value of the drug is not adversely affected, and a more accurate test value can be obtained. In order to use the blood separating agent of the present invention, it is generally used by preliminarily accommodating it in the bottom of a vacuum or non-vacuum blood collection tube. EXAMPLES The present invention will now be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. Example 1 (Production of Copolymer) In a 2 liter flask, dicyclopentadiene 300 was added.
g, an α-olefin having 12 carbon atoms (trade name dialene 1
2, Mitsubishi Kasei Co., Ltd. registered trademark) 300 g, toluene 60
Charge 0g in a batch, heat to 100 ° C under nitrogen atmosphere,
Next, while maintaining the temperature, 18 g of boron trifluoride etherate (BF ₃ .Et ₂ O) was continuously added, and the temperature was kept at the same temperature for 4 hours to carry out a copolymerization reaction. After completion of the reaction, the mixture was cooled, 200 cc of methanol was added to terminate the polymerization, and 300 cc of an aqueous 10% alkali solution was added to neutralize the catalyst. This was washed with water using a separating funnel until the aqueous layer became neutral, and then 160% under reduced pressure (6 mmHg).
Copolymer 188 by distilling off the solvent and unreacted monomer at ℃
g was obtained. The obtained copolymer had a viscosity of 240,000 cP at 25 ° C., a specific gravity of d ₄ ²⁵ 1.054, and a number average molecular weight (measured by gel permeation chromatography and converted into polystyrene) of 280. . Example 2 (Production of Copolymer) In a 2 liter flask, dicyclopentadiene 200 was added.
g, propylene tetramer 200 g and toluene 400
g at a time, heated to 70 ° C. under a nitrogen atmosphere, and then, while maintaining this temperature, 12 g of boron trifluoride etherate (BF ₃ · Et ₂ O) was continuously added while paying attention to heat generation. Further, the temperature was kept at the same temperature for 4 hours to carry out a copolymerization reaction. After completion of the reaction, the reaction mixture was cooled and 100 cc of methanol was added to terminate the polymerization, and 300 cc of a 5% alkaline aqueous solution was added to neutralize the catalyst. This was washed with a separating funnel until the aqueous layer showed neutrality. Then, under reduced pressure (6 mmH
The solvent and unreacted monomers were distilled off at 160 ° C. to obtain 203 g of a polymer. The obtained copolymer has a temperature of 25 ° C.
In a viscosity of 120,000, a specific gravity d ₄ ^{2 5}
1.043, the number average molecular weight (measured by gel permeation chromatography and converted into polystyrene) was 260. Comparative Example 1 (Production of Acrylic Polymer) 240 g of toluene was charged into a 1 liter flask and heated to 100 to 110 ° C. under a nitrogen atmosphere, and then butyl acrylate 36 was added thereto while maintaining the temperature.
A mixture of 0 g and t-butylperoxyoctoate (3.6 g) was added over 5 hours, and after the addition, aging was carried out at the same temperature for 2 hours. After completion of the reaction, toluene and unreacted monomers were distilled off under reduced pressure (6 mmHg) to give an acrylic polymer 3
57 g were obtained. The polymer obtained is pale yellow and transparent at 25 ° C.
At a viscosity of 65,000 cP and a specific gravity of d ₄ ²⁵ 1.
It was 042. Test Example 1 (Evaluation of Drug Adsorption) Each of the polymers obtained in Examples 1 and 2 and Comparative Example 1 was evaluated by the following method. About 1.5 g of each polymer was placed in a test tube having a constant diameter, 1 cc of bovine serum containing a drug at a constant concentration was added thereto, and the mixture was allowed to stand at 25 ° C. After 72 hours, only bovine serum was collected and the amount of drugs (phenytoin and lidocaine) contained therein was measured by the fluorescent immuno-antibody method. The ratio of the drug concentration in the bovine serum after standing for 72 hours to the drug concentration in the original bovine serum was determined and defined as the drug residual rate.
The drug residual rate is 80% or more as ○, 70-80% as Δ,
70% or less was defined as x. The results are shown in Table 1. Also, for comparison, Separation Agent A, which is currently marketed as a serum separation agent, is used.
(A substance containing silicon as a main component and gelled with silica fine particles) and a separating agent B (a substance containing polyester as a main component and gelled with silica fine particles), and further as a comparative example 2 a cyclopentadiene oligomer. EC
R-327 (Tonex brand name, specific gravity 1.03
6, viscosity 168,000 cP / 25 ° C, number average molecular weight 2
The same evaluation was carried out using a thermal polymerization product of 20, cyclopentadiene). [Table 1] Test Example 2 (Evaluation of Volatile Components) Volatile components of the polymers of Examples 1 and 2 and Comparative Examples 1 and 2 were measured by the following method. 100 g of the polymer was placed in a flask, heated to 150 ° C. under a nitrogen atmosphere, the volatile components were distilled off under a reduced pressure of 6 mmHg, and the weight% of the distillate was calculated. The results are shown in Table-2. [Table 2] Although Examples 1 and 2 and Comparative Example 1 do not contain a volatile component, the cyclopentadiene oligomer of Comparative Example 2 contains a volatile component. Examples 3 to 4 (Production of Separation Agent) 100 parts by weight of the copolymer obtained in Example 1 and 0.2 part by weight of Gelol D (a condensate of sorbitol and benzaldehyde, manufactured by Shin Nippon Rika Co., Ltd.) Put in a flask 16
Gelol D was dissolved by stirring at 0 ° C. for 2 hours and cooled to prepare a blood separating agent (Example 3). Similarly, the copolymer 100 obtained in Example 2 was used.
A blood separating agent was produced from 1 part by weight and 0.2 part by weight of Gelol D (Example 4). Each of these blood separating agents had an appropriate thixotropic property, showed fluidity by applying a stress such as a centrifugal force, and formed a gel in a normal standing state. Test Example 3 (Serum Separation Test) About 1.5 g of each blood separating agent prepared in Examples 3 to 10 was used.
The whole blood sample was placed in the bottom of a blood collection tube of cc and collected, and left to stand. After blood coagulation proceeded and the blood was separated into serum and blood clot, centrifugation was performed at 3000 rpm for 10 minutes, and a gel of the blood separation agent was formed between the blood serum and the blood clot for any of the blood separation agents. Serum could be easily removed from the blood collection tube by decantation. Since the blood separating agent of the present invention has a hydrocarbon-based polymer as a main component, it does not cause any physical or chemical change, and changes with time in the components to be measured during the blood separating operation. It is particularly advantageous as a blood separating agent for a vacuum blood collection tube because it has a small amount and contains almost no volatile component, and is extremely useful in practice.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mariko Kimura             Three, Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture             Ryokasei Co., Ltd.

Claims (1)

Claims: 1. A unit derived from dicyclopentadiene (a) 20 to 98 mol%, an olefin having 6 to 20 carbon atoms and / or an alkyl vinyl ether having 2 to 20 carbon atoms in the alkyl group. Units 2-50 derived from (b)
A number average molecular weight of 2 containing mol% and 0 to 30 mol% of a unit derived from a monomer (c) having a copolymerizable ethylenically unsaturated bond other than the above (a) and (b).
A blood separating agent containing a dicyclopentadiene-based copolymer of 00 to 10,000 as a main component. 2. The blood separating agent according to claim 1, wherein the dicyclopentadiene-based copolymer is a copolymer obtained by copolymerization in the presence of a cationic polymerization initiator.