JPH02281042A - Polysiloxane having carboxyalkyl group terminal - Google Patents

Abstract

PURPOSE:To obtain the subject polysiloxane having excellent reactivity with amino group, imino group and hydroxyl group by comprising molecular chains having uniform length and bonding carboxyalkyl group to one or both of terminal silicon atoms of the molecules. CONSTITUTION:The objective carboxyalkyl group-terminated polysiloxane is expressed by formula I [R is 1 to 4C alkyl or phenyl; R<1> is monofunctional hydrocarbon or group expressed by formula II (X is 0 or 1; (q) is 10 to 2000; (a) is 3 to 6); (p) is 10 to 2000] and has <=1.4 ratio (Mw/Mn) of weight-averaged molecular weight(Mw) to number-averaged molecular weight (Mn).

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a carboxyalkyl group-terminated polysiloxane, and more particularly to a novel polysiloxane in which the length of the molecular chains is uniform and a carboxyalkyl group is bonded to one or both terminal silicon atoms. .

[Technical background of the invention and its problems]

Chain polysiloxanes with uniform molecular chain lengths and reactive functional groups at one or both ends can be made into graft copolymers, block copolymers, or crosslinked polymers by reacting with various organic polymers. is obtained, resulting in a copolymer with uniform length of siloxane segments. Such copolymers result in polymeric materials with controlled microdomain structure, and their unique properties, such as blood compatibility, physiological properties such as affinity for a selected range of cells, right and adhesive properties. Surface properties such as releasability to substances can be utilized for various purposes. The present inventors have developed a polysiloxane having a hydroxyalkyl group at one end [H, Kazas+a, Y . Tezuka, Ni, Is+ai; Po1y+se
Journal, Vol. 19, pp. 1091-1100 (1987)] and polysiloxanes having hydroxyalkyl groups on both sides (Japanese Patent Application No. 190618/1987) were synthesized. However, polysiloxanes that have specific functional groups, such as functional groups that have greater reactivity toward amino groups, imino groups, and hydroxyl groups in organic polymers, are present at the molecular ends and have uniform molecular chain lengths. If it can be obtained, block copolymers, crosslinked polymers, etc. can be obtained with good reactivity using the polysiloxane, and it is expected that a polymer material with a controlled microdomain structure can be obtained. Incidentally, polysiloxanes in which a carboxyalkyl group is bonded to the silicon atom at the end of the molecule or in the molecule are known. For example, dimethylchlorosilane (
By cohydrolyzing this cyanopropyl silane with other desired chlorosilanes, a siloxane chain is formed and the cyano group is carboxylated, resulting in a carboxyalkyl group-containing polysiloxane. However, by such conventional methods, polysiloxanes having carboxyalkyl groups at the terminals and having uniform molecular chain lengths cannot be obtained. [Object of the Invention] An object of the present invention is to provide a polysiloxane having a carboxyalkyl group at one or both ends and having a uniform molecular chain length. Another object of the present invention is to provide a polysiloxane that has excellent reactivity with amino groups, imino groups, and hydroxyl groups and has uniform molecular chain lengths. [Structure of the Invention] That is, the present invention provides - a mathematical formula (wherein R may be the same or different from each other,
Represents an alkyl group or phenyl group having 1 to 4 carbon atoms, and R
1 represents a monovalent hydrocarbon group or group, p and q each represent an integer of 10 to 2,000, X represents 0 or 1, and a represents an integer of 3 to 6). , and the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw/
The present invention relates to a carboxyalkyl group-terminated polysiloxane having Mn) of 1.4 or less. The present invention will be explained in detail below. (Carboxyalkyl group-terminated polysiloxane) The carboxyalkyl group-terminated polysiloxane of the present invention is a chain polysiloxane having a carboxyalkyl group at one or both ends. In the case of a chain polysiloxane having a carboxyalkyl group at one end, a monovalent hydrocarbon group R' is present at the other end. In this case, R' is an alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, dichloropentyl group, cyclohexyl group, etc. Examples include cycloalkyl groups such as 2-phenylethyl and 2-phenylpropyl groups; aryl groups such as phenyl and tolyl groups; alkenyl groups such as vinyl and allyl groups. However, among these, a butyl group is preferred because the raw material lithium compound is easy to obtain and handle and has high reactivity. In the case of a linear polysiloxane having carboxyalkyl groups at both ends, one bisphenylene ether structure (-CsH4-0-CJ-) may exist in the center of the molecule (
In other words, X may be O or 1, but it is better to control the polysiloxane with uniform molecular chain length (because it is easier to obtain, it is better to have a bisphenylene ether structure, that is, X is 1). Preferable, those two]
The 22lene group is bonded to an ether oxygen atom and a silicon atom, respectively. Although the positions of these bonds can be selected arbitrarily, discrete positions are preferred because raw materials are easily available and synthesis is easy. In the formula, R is an alkyl group having 1 to 4 carbon atoms or a phenyl group in a single siloxane chain or two siloxane chains separated from each other and bonded via a bisphenylene ether structure; may be the same or different from each other, specific examples include methyl group, ethyl group, propyl group, butyl group and phenyl group,
Among these, methyl group is preferred because it is easy to synthesize and best exhibits the characteristics of polysiloxane, such as flexibility and heat resistance. p and q are each 10 to 2,0001, preferably 10 to 200 from the viewpoint of ease of synthesis, and since the synthesis of such polysiloxane is by living polymerization, p and q are substantially equal, p or q is less than 10 or 2,
Polysiloxanes exceeding 000 are monodisperse (difficult to synthesize) by living polymerization. In this case, the bonding point of both segments is easily subject to hydrolysis, and conversely, it is difficult to synthesize those where a is more than 6. Such atomic chains include trimethylene group, tetramethylene group, pentamethylene group, etc. and hexamethylene groups, among which trimethylene group (a = 3) is preferred because of its ease of synthesis.Also, the weight average molecular weight (Mw) and number average molecular weight ( The ratio (M w / M n ) of Mn) is 1.4 or less, preferably 1.2 or less, indicating substantially monodispersity; when this ratio exceeds 1.4, the carboxyalkyl of the present invention It is not possible to provide superior biocompatibility to graft copolymers, block copolymers, and crosslinked polymers with organic polymers, which is a characteristic of group-terminated polysiloxanes, and the above ratio M w / M n ) is a value determined by comparing the number average molecular weight determined from a gel vermicin chromatography (GPC) chart and a standard sample of polystyrene. (Production method) The carboxyalkyl group-terminated polysiloxane of the present invention is
For example, it is manufactured as follows. When producing a polysiloxane in which a carboxyalkyl group is present at one end, a monovalent hydrocarbon lithium compound R'Li is used as a reaction initiator.As eR', the above-mentioned groups are exemplified; , butyl group is preferred. When producing a polysiloxane having carboxyalkyl groups at both ends, a dilithiated product of diphenylsilanediol may be used as a reaction initiator, but in order to make the ratio of weight average molecular weight to number average molecular weight close to 1, teeth,
For example, it is preferable to use a compound having diorganohydroxysilyl groups on both sides of a bisphenylene ether structure as a starting material. Examples of such compounds include bis[p-(hydroxydimethylsilyl)phenyl 1 ether, bisCm- (Hydroxydimethylsilyl)phenyl 1 ether, bis

Examples include [p-(hydroxymethylphenylsilyl)phenyl) ether, bis[m-(hydroxydiphenylsilyl)phenyl]ether, etc., but because of ease of handling and reactivity, two methyls are added to each silicon atom. It is preferable to have a group bonded to it.
It is reacted with an organolithium compound such as butyllithium to form a dilithium salt, which is used as a reaction initiator. A chain polysiloxane can be obtained by carrying out the anionic ring-opening polymerization of hexaorganocyclotrisiloxane using such various reaction initiators. Depending on the type of reaction initiator used, if you are aiming for a polysiloxane in which a bisphenylene ether structure is introduced into the molecule and carboxyalkyl groups are present at both ends, a polysiloxane with a bisphenylene ether structure is preferable. It is preferable because it has excellent uniformity of one molecular chain. As the hexaorganocyclotrisiloxane, hexamethylcyclotrisiloxane is most preferable from the viewpoint of reactivity and the properties of the obtained polysiloxane.
1-limethyl-1.3.5-tripropylcyclotrisiloxane, phenylpentamethylcyclotrisiloxane,
Other cyclic trisiloxanes such as 1.1-diphenyl-3,3,5,5-tetramethylcyclotrisiloxane may be used; the ring-opening polymerization reaction proceeds at or around room temperature in a nitrogen stream. After the living anion ring-opening polymerization has progressed, ω-(diorganochlorosilyl)monocarboxylic acid triorganosilyl ester is added as a reaction terminator, for example, 30 to
It is heated to 80° C. to remove the lithium atom at the end of the molecule and introduce a carboxyalkyl group. The polymer into which carboxyalkyl groups have been introduced by the termination reaction is injected into a large amount of methanol to precipitate, and after repeated washing with methanol, low boiling point components are removed by heating under reduced pressure, and the desired carboxyalkyl groups are removed. The terminal polysiloxane can be isolated. i Naoshige-Sarawata 11 The above-mentioned reaction terminator can be produced as follows. That is, alkenyl acetic acid is reacted with triorganochlorosilane in the presence of an amine to obtain alkenyl acetic acid triorganosilyl ester. Examples of alkenyl acetic acids include vinyl acetic acid, allyl acetic acid, l
Examples of the amine include -butenyl acetic acid and l-pentenyl acetic acid, with vinyl acetic acid being preferred because of its good reactivity. Examples of the amine include triethylamine and pyridine. Examples of triorganochlorosilane include trimethylchlorosilane, dimethylisopropylchlorosilane, and dimethylchlorosilane.
Examples include tert-butylchlorosilane, dimethylphenylchlorosilane, triethylchlorosilane, etc.
Among them, trimethylchlorosilane is preferred because of its ease of availability and reactivity. The reaction may be carried out at or around room temperature; for example, a solvent and an amine are added to alkenyl acetic acid, triorganochlorosilane is added dropwise under water cooling, and then the temperature is returned to room temperature or slightly warmed, or reflux is carried out near the boiling point of the solvent. Examples include ethers such as diethyl ether, diisopropyl ether, and tetrahydrofuran; and hydrocarbons such as n-pentane, n-hexane, cyclohexane, petroleum ether, and gasoline. After the reaction is completed, the solvent and amine are distilled off, and the alkenyl acetic acid triorganosilyl ester is isolated by distillation under reduced pressure. The alkenyl acetate triol and ganosilyl ester thus obtained can be reacted with diorganochlorosilane to obtain a reaction terminator. Examples of diorganochlorosilane include dimethylchlorosilane, diethylchlorosilane, methylphenylchlorosilyl, diphenylchlorosilane, etc., but dimethylchlorosilane is preferred because it is easily available and has good reactivity. This can be carried out in the presence of a catalyst and with slight heating, but care must be taken as the reaction occurs rapidly. Examples of platinum-based catalysts include platinum carbon, etc. From the zero reaction product, ω-
The (diorganochlorosilyl)monocarboxylic acid triorganosilyl ester can be isolated. Such terminators include 3-(dimethylchlorosilyl)butyric acid trimethylsilyl ester, 3-(dimethylchlorosilyl)butyric acid dimethylisopropylsilyl ester, 3-(dimethylchlorosilyl)butyric acid dimethyl-ter
t-Butylsilyl ester, 3-(dimethylchlorosilyl)butyric acid dimethylphenylsilyl ester, 3-(diethylchlorosilyl)butyric acid trimethylsilyl ester, 3
-(methylphenylchlorosilyl)butyric acid trimethylsilyl ester, 3-(diphenylchlorosilyl)butyric acid trimethylsilyl ester; and the corresponding 4-substituted valerate, 5-substituted cabroate, 6-
Examples include substituted enanthate esters. [Effects of the Invention] The present invention provides a polysiloxane having a carboxyalkyl group at one or both ends and having a uniform molecular chain length. The polysiloxane of the present invention has excellent reactivity with amino groups, imino groups, hydroxyl groups, etc. present at the ends or side chains of various organic polymers, so it can easily be used to form graft copolymers, block copolymers, or cross-linked polymers. Polymers can be 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 obtained using the polysiloxane of the present invention is
It is useful as biological implant material, artificial organ material, etc. [Examples] The present invention will be explained below by reference examples and examples, but the present invention is not limited to these examples. In these examples, unless otherwise specified, parts and percentages are It is based on weight. (Synthesis of bifunctional polymerization initiator) 30 parts of bis[p-(hydroxydimethylsilyl)phenyl]ether was charged into a reaction vessel equipped with a water-cooled jacket, a stirrer, and a dropping port, and degassed. After introducing dry nitrogen, 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 completion of the reaction, tetrahydrofuran was distilled off under reduced pressure, and the mixture was heated under a nitrogen stream. After repeated decantation using dry n-hexane, the solvent was evaporated to obtain 26.1 parts of bis[p-(hydroxydimethylsilyl)phenyl]ether dilithium salt as a white solid. The yield was 84% based on the theoretical amount. 11. (Synthesis of reaction terminator) Vinyl acetate trimethylsilyl ester 44 was placed in a reaction vessel equipped with a reflux tube and a three-way cock, degassed, and then purged with nitrogen.
．． Take 2 parts, add 52.9 parts of dimethylchlorosilane, and further add 0.26 parts of platinum carbon containing 5% platinum, and slowly raise the temperature in an oil bath with stirring. The reaction occurred rapidly at ℃.After refluxing for 2 hours, vacuum distillation was performed under a nitrogen stream to obtain a boiling point of 77-78.
37.2 parts of a colorless and transparent oil having a temperature of C/3 Torr was obtained. This oil was subjected to IH-NMR measurement at 270 MHz, and the spectrum shown in FIG. 1 was obtained. The δ values and their assignments are shown in Table 1. This confirmed that the obtained oil was 3-(dimethylchlorosilyl)butyric acid trimethylsilyl ester. The yield was 53% based on the theoretical amount. Table 1 a) b) c) d) e) 11
■U (Synthesis of reaction terminator) In a reaction vessel similar to that used in Reference Example 2, under a nitrogen stream, io and o parts of allyl acetic acid trimethylsilyl ester,
11.0 parts of dimethylchlorosilane and 0.26 parts of platinum carbon containing 5% platinum were added, heated to 45°C in an oil bath to start the reaction, and the reaction was carried out for 2 hours at the reflux temperature of dimethylchlorosilane. After the reaction was completed, vacuum distillation was performed under a nitrogen stream to obtain 7.2 parts of a colorless and transparent oil with a boiling point of 94° C./4 Torr. This oil was subjected to 'H-NMR measurement at 270 MHz, and the spectrum shown in FIG. 2 was obtained. The δ values and their attributions are shown in Table 2. This revealed that the obtained oil was 4-(dimethylchlorosilyl)valeric acid trimethylsilyl ester. The yield was 46% based on the theoretical amount. Table 2 a) b) c) d) e)
f) Pour hexamethylcyclotrisiloxane into a reaction vessel that has been degassed twice and replaced with nitrogen gas, add and dissolve tetrahydrofuran, and add n-butyllithium previously dissolved in n-hexane. In addition, polymerization was initiated. 2
After stirring at 0°C for 3 hours, 3-(dimethylchlorosilyl)butyric acid trimethylsilyl ester synthesized in Reference Example 2 was added as a reaction terminator, and immediately transferred to a constant temperature bath at 50°C, and the reaction was continued for 2 hours. I did it. After the reaction was completed, the product solution was poured into a large amount of methanol to precipitate the polymer, which was then washed with methanol and heated to remove low-boiling components to obtain a colorless and transparent viscous oil. . The composition ratio of the raw materials used and the yield of the oily substance were as shown in Table 3. For these oils, 270 MHz '
H-NMR and IR spectra and GPC charts were obtained. 'H-NMR of the polymer obtained in Example 1
GPC charts using the spectrum, IR spectrum, and refractive index as parameters are shown in FIGS. 3 to 5, respectively. 'H-NMR δ value and IR characteristic absorption,
They are shown in Table 4 along with their attributions. Analysis of these measurement results confirmed that the obtained oil was polydimethylsiloxane having a 3-carboxypropyl group at one end. Table 3 shows the yield of polysiloxane based on the theoretical amount and the calculated value and the value determined from GPC for the number average molecular weight. When these carboxyl group-terminated polysiloxanes were subjected to GPC again after being left for one month, the same chart was obtained and the stability was good. It exhibited a narrow molecular weight distribution, and the ratio of weight average molecular weight (M w ) to number average molecular weight (Mn) (Mw/M n ) was 1.1 or less compared to a standard sample of polystyrene. Table 3 (blank below) (blank below) a) b) Section C) d) Table d) c) e) f) (blank below) Same reaction as used in Example 1 Hexamethylcyclotrisiloxane was placed in a container, and tetrahydrofuran and N-methylpyrrolidine were added and uniformly dissolved. To this was added a suspension of bis[p-(hydroxydimethylsilyl)phenyl]ether dilithium salt synthesized in Reference Example 1 in n-hexane, and polymerization was carried out at 20°C for 3 hours. Then, 3- synthesized in Reference Example 2 was used as a reaction terminator.
(Dimethylchlorosilyl)butyric acid trimethylsilyl ester was added and after the reaction was completed at 50° C. for 1 hour, purification was carried out in the same manner as in Example 1 to obtain a colorless and transparent viscous oil. The composition ratio of the raw materials used and the yield of the polymer were as shown in Table 5. These polymers were analyzed in the same manner as in Example 1. The 'H-NMR spectrum and IR spectrum of the oil obtained in Example 4 are shown in Figures 6 and 7, respectively.
GPC charts using R, I) and UV as parameters are shown in Figures 8(a) and (b).
Table 6 shows the δ values and characteristic absorptions of IR along with their attributions. From these analysis results, it was confirmed that the obtained oil was polydimethylsiloxane having bisphenylene ether bonds in the molecule and 3-carboxypropyl groups bonded to silicon atoms at both ends. Table 5 shows the yield of the polymer based on the theoretical amount and the calculated value and the value determined from GPC for the number average molecular weight. When these carboxyl group-terminated polysiloxanes were left to stand for one month and then subjected to GPC again, exactly the same charts were obtained, indicating good stability. As shown in Figure 8, the GPC charts show extremely sharp and narrow molecular weight distributions, and the weight average molecular weight (Mw) compared to the polystyrene standard sample.
)/number average molecular weight (Mn) ratio was 1.1 or less. Table a) Section b) C) d) G1 Table d) DI. e) Mouth f) Real JLf 2-Dan 4-(dimethylchlorosilyl)valeric acid trimethylsilyl ester synthesized in Reference Example 3 was used as a reaction terminator instead of 3-(dimethylchlorosilyl)butyric acid trimethylsilyl ester. The polymer was synthesized in the same manner as in Example 2 and Example 3 except for the above. A similar analysis was also conducted. The amount of reaction terminator used and the yield of polymer are shown in Table 7.
-NMR spectra, IR spectra, and GPC charts using refractive index as parameters are shown in Figs. Shown in the table. From these analysis results, the obtained polymer is. It was confirmed that it was polydimethylsiloxane with a 4-carboxybutyl group bonded to one end. Table 7 shows the yield of the polymer based on the theoretical amount and the calculated value and the value determined from GPC for the number average molecular weight. When these carboxyl group-terminated polysiloxanes were left to stand for one month and then subjected to GPC again, exactly the same charts were obtained, indicating good stability. As shown in Figure 11, the GPC chart shows a very sharp and narrow molecular weight distribution, and the weight average molecular weight (Mw)/number average molecular weight (Mn) ratio compared to the polystyrene standard sample is 1.1. It was below. Table 7 a) b) C) d) d) c) e) f) g) Island island

[Brief explanation of drawings]

Figure 1 shows the 'H-NMR spectrum of the reaction terminator obtained in Reference Example 2, Figure 2 shows the 'H-NMR spectrum of the reaction terminator obtained in Reference Example 3, and Figures 3 to 5 show the oily substance obtained in Example 1. 'H-NMR and IR spectra, as well as GPC charts,
Figures 6 and 7 show 'H-' of the oily substance obtained in Example 4.
NMR and IR spectra, Figure 8 shows the GPC chart of the oil obtained in Example 5, Figures 9 to 11 show the 'H-NMR and IR spectra of the polymer obtained in Example 7, and A GPC chart is shown. 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,
Represents an alkyl group or phenyl group having 1 to 4 carbon atoms, and R
^1 represents a monovalent hydrocarbon group or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ groups, p and q each represent an integer from 10 to 2,000, x represents 0 or 1, and a represents 3. A carboxyalkyl group-terminated polysiloxane having a weight average molecular weight (Mw) to a number average molecular weight (Mn) ratio (Mw/Mn) of 1.4 or less.