JPH0551612B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a block-graft copolymer useful as a functional polymer material such as a solid polymer electrolyte, and a method for producing the same. (Prior Art) Recently, organic conductors with electronic conductivity comparable to metals have been discovered, and some studies have already begun to consider their specific uses. However, although progress has been made in the development of ionic conductors, mainly inorganic crystals, glasses, and ceramics, organic polymer solids have not yet been put into practical use. Compared to inorganic ionic conductors, polymeric ones (i) have a lower specific gravity; (ii)
It has the following characteristics: (iii) flexible and thin films can be easily obtained; and (iv) relatively high ionic conductivity at room temperature. On the other hand, the required properties for general solid electrolytes, including polymer electrolytes, are (i) film-forming properties, (ii) high ionic conductivity, (iii) ionic ring ratio, and (iv) control of low water content. In particular, (ii) is emphasized. The mainstream of polymer materials currently being researched is matrix materials containing polyethylene oxide. (Problem to be solved by the invention) However, homopolyethylene oxide has a high degree of polymerization.
If it is less than 20, the cohesive force is too weak to form a film, and if it is more than 20, crystallization will begin and the performance as a solid electrolyte will deteriorate. Therefore, there is a limitation that the performance as a solid electrolyte cannot be improved with the currently available polymer materials. An object of the present invention is to provide a new highly functional polymeric material that solves this problem. (Means for Solving the Problems) The functional polymer material according to the present invention has the general formula () (Here, R ¹ is a hydrogen atom, a methyl group, or an ethyl group, R ² is a hydrogen atom or a methyl group, R ³ is a hydrogen atom, an alkyl group, an aryl group, an acyl group, or a silyl group, and n is 1 to 45 is an integer in the expression The number average molecular weight of the graft chain shown by is 45 or more
A block chain A of at least one polymer having a degree of polymerization of 10 or more and consisting of repeating units represented by (less than 2000); (Here, R ⁴ is a hydrogen atom, a methyl group, or an ethyl group, M is a formula -CH=CH ₂ , -C(CH ₃ )=CH ₂ ,
-COOCH ₃ or -COOC ₂ H ₅ , phenyl group, or substituted phenyl group) is a block chain B of at least one polymer having a degree of polymerization of 300 or more. It is a block-graft copolymer composed of the following, with a polymerization degree of 310 or more, in which the component ratio of block chain A to block chain B is 1:30 to 30:1. That is, the block-graft copolymer according to the present invention consists of the same or different repeating units represented by the general formulas () and (), respectively.
The block chains A and B of at least one polymer are, for example, A ¹ B ¹ , B ¹ A ¹ , B ¹ A ¹ B ¹ , B ¹ A ¹ B ² ,
They can be arbitrarily arranged as B ¹ A ¹ B ² A ¹ B ¹ . The polymerization degree of block chain A of the polymer is 10 or more, and the polymerization degree of B is 300 or more, and the component ratio of both block chains A and B is 1:30 to 30:1, so that the obtained block-graft copolymer The polymerization degree of the combination is 310 or more. Since the polymer block chain A functions as a polymer electrolyte, if the degree of polymerization is less than 10,
This polymer does not exhibit the characteristic microphase separation structure, and since the block chain B is a portion that maintains mechanical strength, if the degree of polymerization is less than 300, the mechanical strength of the polymer will decrease. Furthermore, if the component ratio of block chain A to block chain B is less than 1:30, the graft component will be too small and it will be difficult to maintain the function as a polymer electrolyte, and if it is more than 30:1, the graft component will not function as the main molecule of the block chain. This is because it becomes difficult to maintain mechanical strength. On the other hand, the block-graft copolymer of the present invention has the general formula () (wherein R ¹ is the same as above) and at least one block chain C of a polymer having a degree of polymerization of 10 or more; 1 degree of polymerization
Component ratio of block chain B of polymer of 300 or more is 1:
A block copolymer T having a polymerization ratio of 30 to 30:1 and having a polymerization degree of 310 or more is synthesized, and then the hydroxyl group of the side chain of this block copolymer T is added with the general formula RMe. (wherein R is t-butyl ether, diphenylethylene, benzyl, naphthalene, or cumyl group, and Me is sodium, potassium, or cesium atom) by reacting with it to carbanionize it,
Add to this the general formula () (Here, R ² is the same as above) to grow the graft chain by adding an alkylene oxide represented by the formula R ⁵ X (where R ⁵ is an alkyl group, aryl group, acyl group, It can be produced by adding a halogen compound represented by a silyl group (X is a halogen atom) to terminate polymerization. In addition, the block copolymer T as a main molecular chain consisting of block chains C and B used as a starting material is first made of 4-hydroxystyrene, 4-(1
For a monomer compound containing a residue represented by the general formula (), exemplified by -methylethenyl)phenol, the phenolic hydroxyl group is protected with a trialkyl group or a trialkylsilyl group. Synthesized from monomer compounds exemplified by vinyl compounds such as α-methylstyrene; diene compounds such as butadiene and isoprene; acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate; It can be obtained by polymerizing a block polymer having a repeating unit represented by the general formula () by a living anionic polymerization method and then hydrolyzing it with an acid or the like. Examples of initiators used in this polymerization include organometallic compound-based initiators such as n-butyllithium, sec-butyllithium, tert-butyllithium, and 2-methylbutyllithium. -Butyllithium is preferred. The amount used, together with the amount of the monomer compound charged, determines the molecular weight of the resulting polymer, and is therefore selected depending on the desired molecular weight. Since it is preferable that the degree of polymerization of the block chains C constituting the obtained block copolymer T is 10 or more, it is usually carried out in the reaction solution.
The concentration should be on the order of 10 ^-2 to ^{10 -4} mol/. Polymerization is generally carried out in an organic solvent, and examples of organic solvents that can be used include benzene,
Solvents for anionic polymerization such as toluene, n-hexane, and tetrahydrofuran are preferred. The appropriate concentration of the monomer compound to be subjected to polymerization in the reaction solution is 1 to 10% by weight, and the polymerization reaction is performed under a high vacuum with a pressure of 10 ^-5 Torr or less, or purified to remove harmful substances such as moisture. It is preferable to carry out the reaction under stirring at room temperature in an inert gas atmosphere such as argon or nitrogen. The elimination reaction of the protecting group can be easily carried out by dropping an acid such as hydrochloric acid or hydroiodic acid in a solvent such as dioxane, acetone, methyl ethyl ketone, or acetonitrile while heating. Carbanionization of the hydroxyl groups of the block copolymer T thus obtained is carried out by dissolving the block copolymer T in an anionic polymerization solvent such as tetrahydrofuran at a concentration of 1 to 30% by weight, preferably 1 to 10% by weight.
Add the organic alkali metal dissolved in a suitable solvent such as tetrahydrofuran to this, and then add the organic alkali metal dissolved in a suitable solvent such as tetrahydrofuran for 30 minutes at 0-25℃.
This is done by stirring for 4 hours. Examples of organic alkali metals used in this reaction include t-butoxypotassium, naphthalene potassium, diphenylethylene potassium, benzyl potassium, cumyl potassium, naphthalene sodium, and cumyl cesium. Among these, t-butoxypotassium is particularly preferred. preferable. To confirm this reaction, the product was reacted with trimethylsilyl chloride, then precipitated in methanol, purified, dried, and isolated.
This can be done by measuring the disappearance of hydroxyl groups and the amount of increase in trimethylsilyl groups by ¹ H-NMR, and it is possible to quantitatively understand the reaction of organic alkali metals to hydroxyl groups. It can also be confirmed by GPC that the block chains have not undergone cross-linking or decomposition reactions. Next, to the carbanionized block copolymer T, an alkylene oxide represented by the general formula (), such as ethylene oxide, propylene oxide, etc., is added in vapor or liquid form, and the mixture is heated at 0 to 80°C, depending on the amount, from 1 to 48°C. After stirring for a period of time, a block-graft copolymer can be obtained. The polymerization solution containing alkylene oxide is n-
Pour into hexane to precipitate, which can be isolated by filtering and drying. For characterization, the number average molecular weight is measured using a membrane osmometer, and the structure and composition are determined using infrared absorption spectroscopy and ¹ H-NMR, and the length and number of graft chains can be determined from the results. In addition, GPC can be used to determine whether the target product has been isolated and to estimate its molecular weight distribution. The polymerization of the block copolymer T which becomes the main molecular chain and the reaction for the growth of branch molecular chains thereof are usually carried out in an organic solvent. Examples of organic solvents that can be used for this are tetrahydrofuran, dioxane, tetrahydrofuran, etc. Solvents for anionic or ring-opening polymerization, such as pyran and benzene, are preferred. Compounds used to terminate polymerization include, for example, acids such as acetic acid; alkyl groups and aryl groups represented by the general formula R ⁵ halogenated compounds having a group, an acyl group, or a silyl group; and the like. Control of the length of the graft chain is determined by the number of moles of block chain C of the polymer contained in the block-graft copolymer, the amount of organic alkali metal at the time of carbanionization, and the amount of alkylene oxide. . That is, the amount of organic alkali metal should not exceed the number of moles of block chain C, and the length of the graft chain is expressed as number of moles of alkylene oxide/number of moles of organic alkali metal×molecular weight of alkylene oxide. For example, the length of the graft chain is the number average molecular weight.
To produce a block-graft copolymer of 2000, a block containing 7 x 10 ^-3 mol of block chain C is
Add organic alkali metal 5x to graft copolymer
After adding 10 ^-3 mol and performing carbanionization, 10 g of alkylene oxide may be added. Further, in order to produce a block-graft copolymer having a number average molecular weight of 45, all of the above-mentioned components may be used in equimolar amounts. Furthermore, those with a number average molecular weight of 45 to 2000,
This can be achieved by arbitrarily selecting an intermediate number of moles. (Examples) Hereinafter, specific embodiments of the present invention will be described in more detail based on Examples and Comparative Examples. In addition,
In the block copolymer in the example, each component is connected with "-b-". -p
-Hydroxystyrene-b-styrene). Example 1-1 [Poly(styrene-b-p-hydroxystyrene-b-styrene)...Synthesis of block copolymer T serving as the main molecular chain] Tetrahydrofuran 540 under high vacuum of 10 ^-5 Torr
1.1x of n-butyllithium as initiator in ml
10 ^-4 mol was charged. This mixed solution was kept at -78°C, 5.6 g of styrene diluted with 80 ml of tetrahydrofuran was added, and polymerization was carried out with stirring for 30 minutes. This reaction solution took on a red color. Next, 4.1 g of p-tert-butoxystyrene diluted with 90 ml of tetrahydrofuran was added and polymerized for 15 minutes with stirring. This solution also took on a red color. To this was added 5.6 g of styrene diluted with 80 ml of tetrahydrofuran, and polymerization was further carried out for 10 minutes while stirring. This solution also took on a red color. After the polymerization was completed, the reaction mixture was poured into methanol to precipitate the resulting polymer, which was then separated and dried to obtain 15.3 g of a white polymer. According to the ¹ H-NMR results, this is 73% styrene.
It was found to be a block copolymer consisting of 27% p-tert-butoxystyrene. Furthermore, the GPC solution curve showed a sharp single peak, confirming that it was a single polymer. n of this polymer is 14
It was ×10 ⁴ . Next, the block copolymer was dissolved in a mixed solvent of acetone and benzene, and dissolved at 30℃ using hydrogen iodide.
Poly(styrene-b-p-hydroxystyrene-b-
Styrene) was synthesized. In addition, styrene/in this poly(styrene-b-p-hydroxystyrene-b-styrene)
The ratio and molecular weight of p-hydroxystyrene/styrene can be arbitrarily selected based on the amount charged and the concentration of the initiator. Example 1-2 [Poly(styrene-b-p-hydroxystyrene-b-styrene)...carbanionization of block copolymer T serving as the main molecular chain with an organic alkali metal] Poly(styrene obtained in the previous example) -b-p-hydroxystyrene-b-styrene) was dissolved in 200 ml of tetrahydrofuran under high vacuum.
To this solution was added 0.07 mol of potassium t-butoxy at 25°C. After stirring this solution for 1 hour, 0.5 mol of trimethylsilyl chloride was added to react, and the reaction solution was poured into methanol to precipitate and separate the obtained polymer. When this polymer was analyzed by ¹ H-NMR, it was confirmed that potassium reacted with the hydroxyl groups, so that the hydroxyl group peak disappeared and the trimethylsilyl group peak increased. Also
From the GPC elution curve, it was confirmed that the molecular weight distribution was unchanged from before carbanionization, and that neither crosslinking nor decomposition reactions had occurred. In this example, carbanionization of the hydroxyl groups of the block copolymer proceeded completely quantitatively, and
This indicates that there are no side reactions such as main chain decomposition or crosslinking. Example 1-3 [Poly(styrene-
b-p-hydroxystyrene-b-styrene)
...Synthesis of block-graft copolymer from block copolymer T, which becomes the backbone molecular chain] Poly(styrene-b-
10g of p-hydroxystyrene (b-styrene)
was dissolved in 250 ml of tetrahydrofuran under high vacuum at 10 ⁻⁶ Torr. 8.3 x 10 ^-3 in this solution at 25℃
A mole of potassium t-butoxy was added. After stirring this solution for 1 hour, 1.66 g of ethylene oxide was added. This was kept at 65°C and stirred for 24 hours. Thereafter, acetic acid was added to stop the polymerization, and then the reaction mixture was poured into n-hexane to precipitate the polymer, which was separated and dried. The amount of polymer obtained was 11.6 g. This GPC elution curve is shown in FIG. 1, and the analysis results by ¹ H-NMR are shown in FIG. 2. The sharp single peak in the GPC elution curve confirmed that this was a single polymer. Further, n of this polymer was 16×10 ⁴ . From this ¹ H-NMR and Mn, it was found that the length of the graft chain was 200 and the composition of polyethylene oxide was 14%. Moreover, this IR spectrum is shown in FIG. FIG. 4 shows an electron micrograph of a film prepared by dissolving this block-graft copolymer in methyl ethyl ketone. From this, the phase of the trunk molecular chain (fine white streaks) and the phase of the branch molecular chains (black streaks)
It can be seen that these are microscopically separated. The absorption position in IR and ¹ H-NMR of this graft chain is IR (cm ^-1 ): C-O-C: 1115 cm ^-1 , ¹ H-
NMR (δ, ppm): OCH ₂ CH ₂ : 3.6 ppm. Examples 2 to 3 and Comparative Example 1 [Same as the previous example] The same procedures as in the previous example were performed except that the amount of ethylene oxide added and the polymerization conditions were changed as shown in Table 1, and the results were as shown in the table. Obtained.

【table】

[Synthesis of block-graft copolymer from poly(styrene-b-p-hydroxystyrene-b-styrene)... block copolymer T serving as the backbone molecular chain using propylene oxide]

Poly(styrene-b-
10g of p-hydroxystyrene (b-styrene)
was dissolved in 250 ml of tetrahydrofuran under high vacuum at 10 ⁻⁶ Torr. 0.02 mol of cumyl potassium was added to this solution, and after stirring at 25° C. for 1 hour, 6.3 g of propylene oxide was added. This was kept at 65°C and stirred for 24 hours, and trimethylsilyl chloride was added to stop the polymerization. After the polymerization was completed, the reaction mixture was poured into n-hexane to precipitate the polymer, which was separated and dried. The obtained polymer was white and weighed 16.3 g.
The n of this polymer is 23 x ¹⁰⁴ , and the GPC elution curve consists of a single sharp peak similar to that in Figure 1, confirming that this is a single polymer and making it ideal. It was found that grafting had taken place. IR of the grafted chain of this, ¹ H−
The absorption position in NMR is IR (cm ^-1 ): C-O-
C: 1115 cm ^-1 , ¹ H-NMR (δ, ppm):
OCH ₂ CH ₂ : 3.6 ppm. In addition, from the above n and ¹ H-NMR, it was found that the length of the graft chain was 315 and the composition of polypropylene oxide was 39%. Example 5 [Block copolymer: poly(styrene-b-p
-Hydroxystyrene-b-methyl methacrylate) and ethylene oxide] In the tetrahydrofuran of 1, as an initiator,
3.6×10 ^-5 mol of n-butyllithium was charged,
Keep this at -78℃ and add 5.2g of styrene, p.
10 g of -tert-butoxystyrene and 5.2 g of methyl acrylate were sequentially added, and after polymerization time of 3 hours, poly(styrene-b-p-tert-butoxystyrene-
b-methyl methacrylate) was obtained. Next, this block copolymer was dissolved in a mixed solvent of acetone and benzene, and hydrolyzed using hydrogen iodide to form a polyester containing 30 parts of styrene/40 parts of p-hydroxystyrene/30 parts of methyl methacrylate. (Styrene-b-p-hydroxystyrene-b-methyl methacrylate) was synthesized. From the results of ¹ H-NMR, GPC, and membrane osmotic pressure, this is 40% hydroxystyrene, and n is 20×10 ⁴
It was confirmed that 10g of this block copolymer was 10 ^-6 mm/Hg
Dissolved in 250 ml of tetrahydrofuran under high vacuum. To this solution was added 0.03 mol of potassium naphthalene at 25°C. After stirring this solution for 1 hour, 6.7 g of ethylene oxide was added. This at 65℃
After stirring for 24 hours, methyl bromide was added to stop the polymerization. After the polymerization was completed, the reaction mixture was poured into n-hexane, and the polymer was precipitated, separated, and dried. The obtained polymer was white in color and weighed 16.7 g. The n of this polymer is 33.4×10 ⁴ , and the GPC elution curve is similar to that in Figure 1, consisting of a single sharp peak, confirming that this is a single polymer, and that it is an ideal It was found that grafting had taken place. This IR spectrum is shown in FIG. IR and ¹ H-NMR of the grafted chain of this product
The absorption position in is IR (cm ^-1 ): C-O-C:
1115cm ^-1 , C=O: 1730cm ^-1 , C-CH ₃ : 1390,
1480cm ^-1 , ¹ H-NMR (δ, ppm): OCH ₂ CH ₂ :
3.6 ppm, α-methyl group: 1.2 ppm. In addition, from the above n and ¹ H-NMR, it was found that the length of the graft chain was 220 and the composition of polyethylene oxide was 40%. Example 6 [Block copolymer: poly(styrene-b-p
- Synthesis of block-graft copolymer from hydroxystyrene-b-butadiene and ethylene oxide] 1.0 x 10 ^-4 mol of n-butyllithium was charged as an initiator into 500 ml of tetrahydrofuran.
Keep this at -78℃ and add 5.6g of styrene, p.
- 7.0 g of butoxystyrene and 5.6 g of butadiene were added sequentially, and the polymerization time of styrene and p-tert-butoxystyrene was 1 hour each, butadiene was polymerized for 3 hours, and poly(styrene-b-p
-tert-butoxystyrene-b-butadiene) was obtained. Next, this block copolymer was dissolved in a mixed solvent of acetone and benzene, and hydrolyzed using hydrogen iodide. Poly(styrene) containing 35 parts of styrene/30 parts of p-hydroxystyrene/35 parts of butadiene was -bp-hydroxystyrene-b-butadiene) was synthesized. From the results of ¹ H-NMR, GPC, and membrane osmotic pressure, the composition of this p-hydroxystyrene is 30% by weight,
It was confirmed that Mn was 15×10 ⁴ . 10g of this block copolymer was 10 ^-6 mm/Hg
Dissolved in 250 ml of tetrahydrofuran under high vacuum. To this solution was added 0.02 mol of cumyl cesium. After stirring this solution at 25° C. for 2 hours, 4 g of ethylene oxide was added. This was stirred at 65°C for 24 hours, and acetic acid was added to stop the polymerization. After the polymerization was completed, the reaction mixture was poured into n-hexane, and the polymer was precipitated, separated, and dried. The obtained polymer was white in color and weighed 14 g. Since n of this polymer is 21×10 ⁴ and the GPC elution curve is similar to that in Figure 1 and consists of a single sharp peak, it is confirmed that this is a single polymer, and it is ideal. It was found that grafting had taken place. This IR spectrum is shown in FIG. The absorption position of this graft chain in IR and ¹ H-NMR is IR (cm ^-1 ):C-O-C:
1115cm ^-1 , -CH=CH ₂ :905, 990cm ^-1 , C=C:
1640cm ^-1 , ¹ H-NMR (δ, ppm): OCH ₂ CH ₂ :
3.6ppm, -CH= _CH2 : 5.4, 5.0ppm. In addition, from the above n and ¹ H-NMR, it was found that the length of the graft chain was 200, and the composition of polyethylene oxide was 29%. (Effect of the invention) The block-graft copolymer according to the invention has the following properties:
(1) With a block copolymer as the backbone molecule, amorphous polyalkylene oxide is concentratedly arranged in specific locations, and (2) the molecular structure is specified, allowing for precise microphase separation. Show the structure. Therefore, functions can be shared between the main molecular chain and the branch molecular chains. In particular, mechanical strength is achieved for the block chain (stem molecule), and by selecting amorphous polyalkylene oxide for the graft chain, complex formation properties when mixed with metal salts, high mobility of metal ions, etc. Because it can have the following functions, it becomes a functional polymer material with higher performance than conventional polymers containing polyalkylene oxide. usually,
The number average molecular weight of polyalkylene oxide is 2000
If this is exceeded, crystallization will begin and the high mobility of metal ions and the metal ion content cannot be increased, so block-graft copolymers with graft chains of such length cannot be used as solid polymer electrolytes. However, if the number average molecular weight of the present invention is
If it is less than 2,000, the polyalkylene oxide becomes liquid, which enables high mobility of metal ions and an increase in the content of metal ions, ensures high ionic conductivity, and provides properties as a solid electrolyte.

[Brief explanation of the drawing]

FIG. 1 to FIG. 4 each show Example 1 of the present invention.
FIGS. 5 and 6 are graphs showing the GPC elution curve, ¹ H-NMR spectrum, and IR spectrum, as well as electron micrographs, for the block-graft copolymer obtained in
Blocks obtained in Examples 5 and 6, respectively
1 is a graph showing an IR spectrum of a graft copolymer.

Claims (1)

[Claims] 1 General formula () (Here, R ¹ is a hydrogen atom, methyl group or ethyl group, R ² is a hydrogen atom or methyl group, R ³ is a hydrogen atom, alkyl group, aryl group, acyl group or silyl group, n is an integer from 1 to 45) , and in the formula The number average molecular weight of the grafted chain is 45 or more.
A block chain A of at least one polymer having a degree of polymerization of 10 or more and consisting of repeating units represented by (less than 2000); (Here, R ⁴ is a hydrogen atom, a methyl group or an ethyl group, M is a formula -CH=CH ₂ , -C(CH ₃ )=CH ₂ , -COOCH ₃ or -
A block chain B of at least one polymer having a degree of polymerization of 300 or more and consisting of a repeating unit represented by a group represented by COOC ₂ H ₅ , a phenyl group, or a substituted phenyl group. A block-graft copolymer having a polymerization degree of 310 or more and having a component ratio of A to block chain B of 1:30 to 30:1. 2 General formula () (In the formula, R ¹ is the same as above) and at least one block chain C of a polymer having a degree of polymerization of 10 or more, consisting of repeating units represented by the general formula () A block chain B of one type of polymer having a degree of polymerization of 300 or more is composed of a component ratio of 1:30 to 30:1,
The general formula RMe (where R is t-butyl ether, diphenylethylene, benzyl, naphthalene or cumyl group, and Me is a sodium, potassium or cesium atom) is added to the hydroxyl group of the block copolymer T having a degree of polymerization of 310 or more. The organic alkali metal represented by is reacted to form a carbanion, and this is given the general formula () (Here, R ² is the same as above) to grow the graft chain by adding an alkylene oxide represented by the formula R ⁵ X (where R ⁵ is an alkyl group, aryl group, acyl group, 2. The method for producing a block-graft copolymer according to claim 1, characterized in that the polymerization is stopped by adding a halogen compound represented by a silyl group and X is a halogen atom.