JPH02281043A - Polysiloxane having pyrrolidinium ring terminal - Google Patents

Abstract

PURPOSE:To obtain the subject polysiloxane suitable as material burying into organism or material of artificial organ by having pyrrolidinium rings at both molecular terminals and uniform molecular chain length. CONSTITUTION:The objective pyrrolidinium ring-terminated polysiloxane (e.g. compound expressed by formula II) is expressed by formula I (R is 1 to 4C alkyl or phenyl; R<1> is 1 to 4C alkyl; X is negative group; (p) and (q) are 10 to 2000; (a) is 3 to 6). Bis(hydroxydimethylsilylphenyl) ether expressed by formula III is reacted with organic lithium compound such as n-butyllithium to obtain dilithium salt and living anionic ring-opening reaction polymerization of hexamethylcyclotrisiloxane is performed using said dilithium salt as polymerization initiator to afford the objective polysiloxane.

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a polysiloxane having functionality at both ends, and more particularly to a novel polysiloxane having pyrrolidinium rings at both ends. [Technical background of the invention and its problems 1 A chain polydiorganosiloxane having functionality at both ends and having a uniform molecular weight can be made into a block copolymer with a uniform siloxane chain length by reacting with an organic monomer or polymer. A combined or crosslinked polymer can be obtained. The result is a polymeric material with controlled microdomain structure, which has unique properties such as blood compatibility, physiological properties such as affinity for a selected range of cells, and resistance to adhesive substances. Surface properties such as releasability can be utilized for various purposes. Conventionally, a method using diphenylsilanediol dilithium salt has been known as a method for obtaining a linear polyorganosiloxane having functionality at both ends (E, E, Bo
stik; AC3Poly+mer Preprin
t, Vol. 10, No. 2, p. 877, 1969), it is difficult to initiate the reaction quickly with this method, and furthermore, the molecular weight distribution of the obtained chain polyorganosiloxane is not uniform to a satisfactory level. Another method is to perform ring-opening polymerization of hexamethylcyclotrisiloxane using water as a reaction initiator in the presence of biscatechol organosiliconate or a lithium compound having a quaternary ammonium structure in the organic group bonded to the silicon atom. Although a method is known to
nce, Polymer (: hemistry, Vol. 14, No. 3, pp. 729-742 (1976), No. 7
43-7sg(19ys)), this method yields a polysiloxane with silanol groups at both ends,
Even if it is reacted with a herosilane compound such as dimethylchlorosilane, it is difficult to quantitatively introduce a 5t-H bond at both ends, and therefore it is not possible to quantitatively introduce any functional group at the ends. In addition, by ring-opening polymerization of hexamethylcyclotrisiloxane using an acetal-type lithium compound as a reaction initiator, a polysiloxane with a uniform molecular weight having a lithium oxy group at one end and a functional group at the other end was obtained. A method of obtaining a polysiloxane having functional groups at both ends by coupling with dimethyldichlorosilane is also known (P, M, Lefebvre et al.; Macroneo-1ecules, Vol. 10, No. 4, pp. 1171-872). , 1977), this method has the disadvantage that the reaction steps are complicated and the types of terminal functional groups are limited. As described above, no sufficiently effective method for obtaining a linear polyorganosiloxane having functionality at both ends and having uniform siloxane chain lengths has been known so far. The present inventors first performed ring-opening polymerization of hexaalkylcyclotrisiloxane using a dilithium salt of bis(hydroxydialkylsilylphenyl) ether as a reaction initiator, thereby creating a hexaalkylcyclotrisiloxane with functionality at both ends. It has been found that a linear polyorganosiloxane having one bisphenylene ether bond in the molecular chain and having uniform siloxane chain lengths can be obtained (Japanese Patent Application No. 63100/1983). In this case, the uniformity of the molecular chain length can be further increased by the presence of an alicyclic tertiary amine such as N-methylpyrrolidine [Patent Application No. 63-1238]
No. 41, H, Kazama, Y, Tezuka. Polymer Bulletin, Vol. 21, pp. 31-37 (1989)]. The present inventors have further obtained a hydroxyalkyl group-terminated polysiloxane with a uniform molecular chain length using the linear polysiloxane with a uniform siloxane chain length obtained by this method as a raw material (particularly Gansho 63-1906
No. 18), but for specific functional groups, such as nucleophilic functional groups such as carboxyl groups in organic polymers,
If it is possible to obtain a polysiloxane in which functional groups with greater reactivity exist at the molecular ends and the molecular chains are aligned, then by using this polysiloxane, block copolymers and crosslinked polymers can be made more reactive. can get well,
It is expected that polymer materials with controlled microdomain structures will be obtained. By the way, various polytetrahydrofurans having a cyclic quaternary ammonium salt structure at the end are known as polymers having such functional groups [Y, Tezuka
, E. J., Goethals, Makromol.
ekulareChea+ie, Volume 188, No. 783
-789 pages (1987)]. Polytetrahydrofuran with a star-like structure is also known, which has a similar functional group at the molecular end and an aromatic group at the center of the molecule [Y, Tezuka, E, J, Go
ethals. Makromolekulare Chemie, 1st
Volume 88, pages 791-797 (1987)],
However, for polysiloxanes, such cyclic quaternary
There are no known compounds with an ammonium salt structure as a terminal group. [Object of the Invention] An object of the present invention is to provide a polysiloxane having a pyrrolidinium ring bonded to a silicon atom via a carbon chain at both ends, particularly the above-mentioned polysiloxane having a uniform molecular chain length. Another object of the present invention is to provide a polysiloxane that has excellent reactivity with carboxyl groups and has uniform molecular chain lengths. As a result of extensive research to achieve the above object, the present inventors have discovered that a hexaalkylcyclotrisiloxane can be obtained by ring-opening polymerization of hexaalkylcyclotrisiloxane using dirithiram salt of bis(hydroxydialkylsilylphenyl)ether as a reaction initiator. It was discovered that a pyrrolidinium ring-terminated polysiloxane having a uniform molecular chain length can be synthesized using a linear polysiloxane having a uniform siloxane chain length as a raw material, and based on this knowledge, the present invention was completed.

[Structure of the invention]

That is, the present invention is based on the general formula (wherein R may be the same or different from each other and represents an alkyl group or a phenyl group having 1 to 4 carbon atoms, and R'
represents an alkyl group having 1 to 4 carbon atoms, X represents a negative group, p and q each represent an integer of 1O to 2.000, and a represents an integer of 3 to 6. ) is related to a pyrrolidinium ring-terminated polysiloxane. Hereinafter, the constituent elements of the present invention will be explained in detail. (Pyrrolidinium ring-terminated polysiloxane) The pyrrolidinium ring-terminated polysiloxane of the present invention has a bisphenylene ether structure at the center of the molecular chain, and the two phenylene groups are bonded to an ether oxygen atom and a silicon atom, respectively. Although the position of these bonds can be arbitrarily selected, the para position is preferred because raw materials are easily available and synthesis is easy. In the above-mentioned formula, in the two siloxane chains separated and bonded to each other via a bisphenylene ether structure, R is an alkyl group or a phenyl group having 1 to 4 carbon atoms, and may be the same or different from each other. Specific examples include methyl, ethyl, propyl, butyl, and phenyl groups, but among these, polysiloxane has the most advantageous characteristics such as ease of synthesis and flexibility and heat resistance. Methyl group is preferred because it represents well. p and q are each 10 to 2,000, preferably 10 to 200 for ease of synthesis, and when such polysiloxane is synthesized by living polymerization,
p and q are substantially equal. a is an integer from 3 to 6. When a is less than 3, the bonding point between both segments is susceptible to hydrolysis when it is made into a block copolymer with an organic polymer, and conversely, when a is more than 6, it is difficult to synthesize. Such atomic chains include trimethylene group, tetramethylene group, pentamethylene group, and hexamethylene group, among which trimethylene group (a=3) is preferred because of its ease of synthesis. R' is an alkyl group having 1 to 4 carbon atoms, a methyl group,
Examples include ethyl group, propyl group, butyl group, and methyl group is preferred because it is easy to synthesize and does not cause side reactions. X is a negative group, and corresponds to the cation of the nitrogen atom of the pyrrolidinium ring as an X-anion to form a pyrrolidinium salt. Specific examples of Examples include residues, among which a tosyl group is preferred because it is easy to synthesize. The polysiloxane of the present invention having a bisphenylene ether structure at the center of the molecule is produced by living polymerization into a substantially monodisperse state, in other words, with a weight average molecular weight Mw and a number average molecular weight Mn.
It is possible to obtain polysiloxanes with a ratio (M w /M n ) close to 1. The above ratio (
M w /M n ) is preferably 1.4 or less, more preferably 1.2 or less. (Production method) The pyrrolidinium ring-terminated polysiloxane of the present invention is produced, for example, as follows. First, bis(hydroxydimethylsilylphenyl) ether represented by the chemical formula is reacted with an organic lithium compound such as n-butyllithium to obtain a dilithium salt. Using this dilithium salt as a polymerization initiator, hexamethylcyclotrisiloxane was subjected to anionic ring-opening polymerization.
Obtain a polymer. This polymer is a dehydrated polydimethylsiloxane with a bisphenylene ether structure in the center of the molecule, and one lithium oxy group is bonded to each silicon atom at both ends of the molecule, and the molecular chain is long. (Japanese Patent Application No. 63-63100). In this case, by coexisting an alicyclic tertiary amine such as N-methylpyrrolidine, the length of the molecular chain can be changed. The uniformity can be further improved (Japanese Patent Application No. 123841/1983). The resulting polymer was reacted with dimethylchlorosilane to introduce a 5L-H bond at the molecular end, and then reacted with allyl alcohol in the presence of a platinum catalyst, resulting in a γ-hydroxypropyl group bonded to the terminal silicon atom. A γ-hydroxypropyl group-terminated polysiloxane represented by the following formula is obtained. This polysiloxane having a γ-hydroxypropyl group at the molecular end has a bisphenylene ether structure in the center, p and q are each 10 to 2.000, preferably 10 to 200, and the weight average molecular weight and number average molecular weight The ratio of is 1.4 or less, preferably 1.2 or less (
(Patent Application No. 1986-190618). This hydroxypropyl group-terminated polysiloxane is reacted with an acid chloride such as tosyl chloride or methanesulfonic acid chloride to obtain a polysiloxane having substituted sulfonic acid groups at both ends. In this case, if a chlorinated hydrocarbon such as methylene chloride or chloroform is used as a solvent, and triethylamine and 4-dimethylaminopyridine are allowed to coexist, the reaction can proceed efficiently. Although the reaction proceeds at room temperature, it may be heated as appropriate. For example, by reacting the tosyl group-terminated polysiloxane thus obtained with N-alkylpyrrolidine, a polysiloxane having a pyrrolidinium ring at the terminal can be obtained. Examples of N-alkylpyrrolidine include N-methylpyrrolidine, N-ethylpyrrolidine, and N-propylpyrrolidine, which are easy to react with and have few side reactions (
N-methylpyrrolidine is preferred because of its excellent yield. Methylene chloride, chloroform, 1, as a solvent
The reaction proceeds smoothly by using a chlorinated hydrocarbon such as 1.1-trichloroethane or an ether such as tetrahydrofuran. Although the reaction proceeds at room temperature, the reaction can proceed quantitatively by selecting chloroform, 1,1,1-trichloroethane, etc. as the solvent and heating it to 50 to 70°C. Here, for example, instead of bis(hydroxydimethylsilylphenyl) ether, a compound having a structure in which at least a part of its methyl group is replaced with an ethyl group, propyl group, butyl group, or phenyl group, or hexamethylcyclo Instead of part or all of trisiloxane, hexaethylcyclotrisiloxane or 1,3
．． Using other hexaorganocyclotrisiloxanes such as 5-trimethyl-1,3,5-tripropylcyclotrisiloxane, etc., or also replacing allyl alcohol with 1-buten-4-ol, l-hexene-6
- such as using other unsaturated alcohols such as
By appropriately changing each component used, it is possible to obtain a pyrrolidinium ring-terminated polysiloxane represented by the above general formula (where R, R', X, p, q and a are as described above) with good monodispersity. I can do it. The above reaction can be expressed as a reaction formula as follows. RR [Effects of the Invention] According to the present invention, it is possible to obtain a polysiloxane having pyrrolidinium rings at both ends, particularly a terminally functional polysiloxane with uniform molecular chain lengths. The pyrrolidinium ring-terminated polysiloxane of the present invention has excellent reactivity with nucleophilic functional groups such as carboxyl groups present at the terminals or side chains of various organic polymers.
Block copolymers and crosslinked polymers can be easily obtained. In this case, especially in the present invention, since the polysiloxane is a polysiloxane with uniform molecular chain length, the lengths of the siloxane segments in these block copolymers and crosslinked polymers are uniform, and a microdomain structure can be obtained with good control. Therefore, it has excellent biocompatibility, and has the advantage that the balance between biocompatibility and physical properties can be adjusted depending on the purpose of use. The copolymer using the pyrrolidinium ring-terminated polysiloxane of the present invention can be used as a biological implant material, an artificial organ material, etc. [Example J] Hereinafter, the present invention will be explained by reference examples and examples, but the present invention is not limited to these examples only. In these examples, unless otherwise specified, parts and percentages are It is based on weight. ! ! ! JLi (synthesis of polymerization initiator) 30 parts of bis[p-(hydroxydimethylsilyl)phenyl]ether was charged into a reaction vessel equipped with a water cooling jacket, a stirrer, and a dropping port, and degassed and dried nitrogen was introduced. Then, 622 parts of dry tetrahydrofuran was added and uniformly dissolved. While cooling the reaction vessel with water, 74 parts of an n-hexane solution containing 12.8 parts of n-butyllithium was slowly added dropwise, and the reaction was carried out for 2 hours. After the reaction was completed, tetrahydrofuran was distilled off under reduced pressure, and the solvent was evaporated after repeated decantation with dry fin-hexane in a nitrogen stream to obtain white solid bis(p-(hydroxydimethylsilyl)phenyl)ether dilithium. 26.1 parts of salt was obtained. The yield was 84% based on the theoretical amount. ! (Synthesis of terminal 5i-H polysiloxane) After degassing the reaction vessel and replacing it with nitrogen gas, dry tetrahydrofuran 3
55 parts of N-methylpyrrolidine, 164 parts of N-methylpyrrolidine, and 200 parts of hexamethylcyclotrisiloxane were charged and stirred to uniformly dissolve them. Next, bis[p-(hydroxydimethylsilyl)phenyl]ether dilithium salt 17 synthesized in Reference Example 1
．． A suspension obtained by dispersing 8 parts of tetrahydrofuran in 282 parts of dry tetrahydrofuran using ultrasonic waves was added, and the temperature was lowered to 2.
By stirring while maintaining the temperature at 1'C, the ring-opening polymerization of hexamethylcyclotrisiloxane was changed to 3'C.
After the reaction system became transparent after a certain period of time, 7.0 parts of dimethylchlorosilane was added and stirred to stop the polymerization reaction. The remaining residue was washed repeatedly with methanol, then dissolved in benzene, and then freeze-dried to obtain a colorless, transparent, and viscous polymer. The yield of the obtained polymer was 180 parts, which was 81% based on the theoretical amount. Using tetrahydrofuran as a carrier and monitoring with a differential refractometer, this polymer was measured by gel vermiacetone chromatography (GPC) using the refractive index as a parameter, as shown in Figure 1 (a). It showed a monodisperse peak at a number average molecular weight of 6,700. In addition, when IR and 'H-NMR were measured, the first
Characteristic absorption as shown in the table was obtained, and it was confirmed that it was polydimethylsiloxane having a phenylene group and a 5t-H bond in the molecule. (Leaving space below) 1 Table 11 ■U (Synthesis of -r-hydroxypropyl group-terminated polysiloxane) Polydimethyl having a bisphenylene ether structure in the molecule and a 5i-H bond at the end of the molecule synthesized in Reference Example 2 150 parts of siloxane was charged into a reaction vessel, and the vessel was degassed and replaced with nitrogen. After adding 433 parts of toluene and dissolving it uniformly, 392 parts of allylcoal and 6 parts of platinum charcoal (5% platinum content, manufactured by Nippon Engelhard) were added,
The reaction was carried out by stirring for 24 hours in a constant temperature bath set at 13°C. After the reaction was completed, the platinum charcoal was filtered off, toluene was distilled off under reduced pressure, and the mixture was washed repeatedly with methanol, and then freeze-dried from a benzene solution to purify 151 parts of a colorless transparent liquid reaction product. isolated. When the 'H-NMR and IR spectra of the obtained reaction product were measured, as shown in Table 2, no spectra attributed to 5L-H appeared, and -CH,- and -O
A spectrum attributed to H appeared, indicating that the hydrogen atom bonded to the silicon atom at the end of the molecule was completely converted to a γ-hydroxypropyl group. The yield of the obtained γ-hydroxypropyl group-terminated polysiloxane was almost quantitative with respect to the theoretical amount. A GPC chart using refractive index as a parameter showed monodispersity, and the number average molecular weight was 6,700. Table 115 Synthesis of A<-r-)-Cylpropyl group-terminated polysiloxane) Monodispersed polydimethylsiloxane having a bisphenylene structure in the molecule and a γ-hydroxypropyl group at the end of the molecule synthesized in Reference Example 3 (number average molecular weight 6,700) 1
After putting 20 parts into a reaction vessel, degassing and purging with nitrogen gas, 667 parts of dry methylene chloride was added and stirred to completely dissolve the polysiloxane. To this, 13.1 parts of 4-dimethylaminopyridine and 21.8 parts of triethylamine.
1 part, and then 20 parts of tosyl chloride, 5 parts, and heated to 15°C.
The reaction was carried out for 24 hours in a constant temperature bath. After the reaction, 330 parts of dichloromethane was distilled off under reduced pressure, and 1 part of n-hexane was added.
98 parts were added and filtration was performed in a nitrogen stream. The filtrate was poured into methanol at -10'C, washed repeatedly, dissolved in benzene, and frozen from the benzene solution to yield 76.1 parts of a clear colorless viscous oil. The 270 MHz 'H-NMR spectrum and IR spectrum of the obtained oil are shown in FIGS. 2 and 3. Further, the NMR δ values and IR characteristic absorptions are shown in Table 3 along with their attributions. Analysis of these measurement results revealed that the obtained polymer was a polydimethylsiloxane having a bisphenylene structure in the molecule and a γ-tosylpropyl group at the end of the molecule. In addition, GPC using the refractive index of the oil as a parameter showed excellent monodispersity as shown in Figure 1(b), and the number average molecular weight was 5% as shown in Figure 1(b).
It was almost the same as iH group-terminated polysiloxane. The yield is 60% based on the theoretical amount. (Leaving space below) a) b) b) Section C) d) Table e) f) g) Example 1 (synthesis of pyrrolidinium group-terminated polysiloxane) Synthesized in Reference Example 4, which has a bisphenylene structure in the molecule. , 40.0 parts of polydimethylsiloxane having a γ-tosylpropyl group at the end of the molecule was placed in a reaction vessel, degassed and replaced with nitrogen gas, and then 749 parts of chloroform was added and stirred to completely dissolve the polysiloxane. did. 5.
2 parts of N-methylpyrrolidine was added and reacted for 48 hours in a constant temperature bath at 50°C. After the reaction was completed, chloroform and unreacted N-methylpyrrolidine were distilled off under reduced pressure to give a brown color.
41.6 parts of a starch syrup-like polymer was obtained. 270 MHz measured on the resulting polymer
The H-NMR spectrum, IR spectrum, and GPC chart with ultraviolet absorption as parameters are shown in Figures 4, 5, and 1(c), respectively.
The δ value of R and the characteristic absorption of IH are shown in Table 4 along with their attributions. Analysis of these measurement results revealed that the obtained polymer was a polydimethylsiloxane having a bisphenylene structure in the molecule and an N-methylpyrrolidinium cation and a tosyl anion at the end of the molecule. The number average molecular weight obtained from GPC was almost the same as that of the S i -H group-terminated polysiloxane used, and the yield was almost quantitative with respect to the theoretical amount. The GPC chart showed an extremely narrow molecular weight distribution as shown in FIG. 1(C). Then, compared with a standard sample of polystyrene, the ratio of weight average molecular weight (M w ) to number average molecular weight (M n ) (M w / M n
) was 1.1 or less. (Margin below) Table 4

[Brief explanation of drawings]

Figure 1 is a GPC chart, (a) is the terminal 5L-
GPC charts of H polysiloxane, (b) a γ-tosylpropyl group-terminated polysiloxane, and (C) a pyrrolidinium ring-terminated polysiloxane. Figures 2 and 3 show 'H-NMR and IR spectra of γ-tosylpropyl group-terminated polysiloxane.
Figures 4 and 5 show 'H-NMR and IR spectra, respectively, of a pyrrolidinium ring-terminated polysiloxane. Applicant: Toshiba Silicone Corporation

Claims (1)

[Claims] 1. General formula▲ Numerical formula, chemical formula, table, etc.▼ (In the formula, R may be the same or different from each other and represents an alkyl group or phenyl group having 1 to 4 carbon atoms, R^
1 represents an alkyl group having 1 to 4 carbon atoms, X represents a negative group, p and q each represent an integer of 10 to 2,000, and a represents an integer of 3 to 6. ) Pyrrolidinium ring-terminated polysiloxane.