JPH03167226A - Block copolymer - Google Patents

Abstract

PURPOSE:To obtain a block copolymer having the characteristic properties of both an addition polymerization polymer and a polycondensation polymer by incorporating a specified segment and a segment comprising a poly(meth) acrylic ester in it. CONSTITUTION:During or after polymerizing a segment A selected from among a polyester, a polyamide(imide), a polyimide and a polyurethane, hydroxyl groups or amino groups are introduced into either or both ends of the segment A, and during or after polymerizing a segment B comprising a poly(meth)acrylic ester, a carboxyl group is introduced into either end of the segment B. The hydroxyl groups or amino groups introduced into either or both ends of segment A are reacted with the carboxyl group introduced into either end of the segment B to obtain the title copolymer in which the segments are bonded through an ester bond, an amide bond or an imide bond to form A-B or B-A-B.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a novel block copolymer.

(Prior technology) There have been attempts to utilize block copolymerization as a method for combining polymeric materials with different properties to express new functions. A method to obtain a block copolymer by kneading and cutting molecules by shearing force to generate radicals, a method for producing a polyether block copolymer by polymerizing ethylene oxide in the presence of polypropylene oxide, terephthalic acid and ethylene glycol In addition to this, a method for producing a block copolymer in which polyoxyethylene is present and co-condensed is known.

(Problem to be solved by the invention) However, with conventional methods, the combination of polymeric materials is limited, and only block copolymers of addition polymers or polycondensates can be obtained, and block copolymers with unique performance cannot be obtained. There has been a strong desire to combine polymers with different functions in order to obtain

(Means for Solving the Problems) In view of this situation, the present inventors believe that if a block copolymer having both segments of an addition polymerization polymer and a polycondensation polymer can be obtained, it will have an unprecedented function. As a result of intensive studies considering the use of the block copolymer as a polymer material, we succeeded in obtaining such a block copolymer and arrived at the present invention.

That is, the gist of the present invention is that the general formula AB or B-・A-
B, segment A is selected from polyester, polyamide, polyimide, polyamideimide, and polyurethane, and segment B is composed of one or more poly(meth)acrylic esters. .

Segment A in the block copolymer of the present invention includes polyesters such as polyethylene terephthalate, polybutylene terephthalate, and wholly aromatic polyesters, nylon 6, nylon 6-6, nylon 11, and nylon 12.
, nylon 6-10, polyamides such as poly p-phenylene terephthalamide, poly m-phenylene isophthalamide, biromellitic anhydride, diphenyl ether 3,
4, 3°, 4-tetracarboxylic anhydride, diphenylmethane 3,4.3°. Aromatic polyimides such as polyimides made from tetracarboxylic anhydrides such as 4°-tetracarboxylic anhydride, diphenylbroban 3, 4, 3°, 4°-tetracarboxylic anhydrides, and aromatic diamines;
Polyamideimide made from trimellitic acid and aromatic diamine, polyamideimide made from combination of pyromellitic anhydride and dicarboxylic acid such as isophthalic acid and aromatic diamine, diphenylmethane diisocyanate, tolylene diisocyanate, Polyurethane made from a diisocyanate such as hexamethylene diisocyanate and a diol polyol at both ends such as polyethylene glycol or polypropylene glycol, or a diic acid polyester at both ends from a glycol such as ethylene glycol, brobylene glycol or 1,4-butanediol. can be used.

The poly(meth)acrylic acid ester as segment B has the general formula (1) R2 (wherein R1 represents an alkyl group having 1 to 18 carbon atoms, a fluorinated alkyl group, or a cyclohexyl group, and R2 represents hydrogen or a methyl group. ) is preferred, and examples of such poly(meth)acrylic esters include methyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl methacrylate, , 2.
2-trifluoroethyl methacrylate, octafluoropentyl methacrylate, fluorodecyl methacrylate, 2, 2. Examples include 2-trifluoroethyl acrylate.

In the block copolymer of the present invention, a hydroxyl group or an amino group is introduced into one or both ends of segment A during or after polymerization, and a carboxylic acid group is introduced into one end of segment B during or after polymerization. , a block compound formed by bonding via an ester bond, an amide bond, or an imide bond by a reaction between a hydroxyl group or an amino group introduced at one or both ends of segment A and a carboxylic acid group introduced at one end of segment B. It is a polymer.

The degree of polymerization of each segment of the block copolymer of the present invention may be determined depending on the intended use, and is not limited by molecular weight.

In the block copolymer of the present invention, segment A and segment B are separately polymerized, and in the polymerization of segment A, diol or diamine is used in excess to introduce a hydroxyl group or an amino group at both ends. By partially using a monool, monoamine, monocarboxylic acid, dicarboxylic acid monoester, etc. during polymerization, it is possible to obtain a polymer having a hydroxyl group or an amino group at one end. When the polymer is polyimide or polyamideimide, one end can be obtained by partially using phthalic anhydride.

Polymerization of segment B is preferably carried out by ionic polymerization or group transfer polymerization because a carboxylic acid or acid anhydride group is introduced into one end of the segment B at or after the completion of polymerization. It is more preferable to carry out the polymerization by a group transfer polymerization method because it is relatively easy to control the polymerization degree, molecular weight distribution, and composition. This group transfer polymerization method is a polymerization method disclosed in JP-A-58-13603, in which living polymerization is carried out at room temperature using an initiator such as silyl ketene acetal. Suitable for polymerizing acid esters. In the case of anionic living polymerization, a hydroxyl group can be introduced into segment B by using trimethylsilyloxy, monochloroalkane (alkanes include ethane, broban, etc.), and this and dicarboxylic acid monohalide, trimellitic anhydride halide, etc. A carboxylic acid group can be introduced at the terminal by reaction with Furthermore, a hydroxyl group can be introduced at the end by radical polymerization using a chain transfer agent such as 2-mercabutoethanol, and a carboxylic acid group can be introduced by reacting this with dicarboxylic acid monohalide or the like.

When the group transfer polymerization method is used in the production of segment B of the present invention, the polymerization conditions, polymerization cocatalyst, polymerization solvent, etc. described in the publication can be used under similar conditions. After polymerization using [2-methyl-1-[2-(trimethylsiloxy)ethoxy]-1-bropenyl)oxy]trimethylsilane as an initiator, the trimethylsilyl group at the polymerization initiation terminal is removed to terminate the polymerization. This is preferable because a hydroxyl group remains at the end. Methods for introducing a carboxylic acid or acid anhydride to one end of segment B include introducing an acid anhydride group by reacting the hydroxyl group at this end with trimellitic anhydride monoacid chloride, succinic anhydride, glutaric anhydride, and anhydride. Introduction of a carboxylic acid group by reaction with phthalic acid or terephthalic acid monomethyl ester can be mentioned.

A block copolymer can be obtained by mixing segment A and segment B thus obtained in a suitable solvent, for example, dimethylacetamide, and heating if necessary.

Depending on the intended use, various additives such as stabilizers and colorants may be added to the block copolymer of the present invention.

(Example) The present invention will be further explained below using Examples.

Reference Example 1 5 equipped with an argon introduction tube, a stirrer, a thermocouple, and a drying tube
After sufficiently drying the inside of the 00mβ flask and purging it with argon, 11.0 g of bis(4-aminophenyl) ether and 178 g of dry dimethylacetamide were added to it, and while stirring this solution, 1 ml of biromellitic anhydride was added at room temperature.
1.0 g was added dropwise over 2 to 3 minutes. The temperature of the reaction system rose to 38°C due to the addition of the acid anhydride, but returned to room temperature in about 30 minutes. Stirring was continued for another 2 hours at room temperature to obtain a polyamic acid solution with an intrinsic viscosity of 0.7 dg/g (30°C).

Reference example 2 5 equipped with an argon introduction pipe, a stirrer, a thermocouple, and an exhaust pipe
After thoroughly drying the inside of the flask and purging it with argon, add 250mj of tetrahydrofuran to it.
? ．． 0.04 molar acetonitrile solution of trisdimethylaminosulfonium bifluoride 5.0 mj2,
[(2-methyl-1-[2-( }limethylsiloxy)
EthoxyJ-1-bropenyl)oxy]trimethylsilane2. 2. Add Og and stir while being careful not to let the temperature of the reaction system exceed 50°C.
2- 67g of trifluoroethyl methacrylate in 10
It was dripped over several minutes.

After the dropwise addition was completed, stirring was continued until the temperature of the reaction system became 30° C. or lower, and then 1 Omj2 of methanol was added to stop the polymerization. As a result, the trimethylsilyl group at the polymerization initiation terminal was removed, and a hydroxyl group was formed at the polymer terminal.

The obtained solution was dropped into hexane to precipitate the polymer, and the precipitate was dried to obtain a polymer as a white powder. The molecular weight of this polymer was approximately 12,000.

18.6 g of this polymer and 20 g of dry tetrahydrofuran
0 mβ was placed in a 500 mg reaction vessel which had been sufficiently purged with argon, and while stirring under water cooling, 4.3 g of trimellitic anhydride 2. triethylamine was added.
When 0 g was added, a white solid (triethylamine hydrochloride) was immediately precipitated, so this was filtered off, and the solution after filtration was added dropwise to hexane to precipitate the polymer. It was dried, and this was poured into 200 ml of methanol. After stirring and purifying the mixture, it was filtered and dried to obtain a white powdery polymer having an acid anhydride at its terminal.

Example 1 90 g of the dimethylacetamide solution of the polyamic acid obtained in Reference Example 1 and a solution of 1 g of the polymer obtained in Reference Example 2 dissolved in 9 g of dry dimethylacetamide were mixed, and then stirred at about 100 ° C. for 4 hours. A brown copolymer solution was obtained.

The fact that this was a block copolymer was confirmed by NMR after reprecipitating the polymer with methanol.

When this polymer was coated on a transparent conductive glass substrate and heat treated at 250°C for 2 hours, the polyamic acid was dehydrated and ring-closed, forming poly2, 2. 2-} A thin film of a block copolymer having both segments of trifluoroethyl methacrylate and polyimide was obtained. This substrate was aligned by rubbing both sides with cotton cloth, and using this, the cell gap was set to 2.3 μm, and the ferroelectric liquid crystal (
A ferroelectric liquid crystal cell was created by injecting CS-1014) manufactured by Chisso ■. Apply voltage to this cell with a pulse width of 1
When m S % pulse height was applied at ±40 V and its memory property was evaluated, it showed good bistability.

(Effects of the Invention) Since the block copolymer of the present invention is composed of an addition polymerization segment and a polycondensation segment, it has both the characteristics of an addition polymerization polymer and the characteristics of a polycondensation polymer.
It is a useful material in the fields of paints and various functional films.

Claims (1)

[Claims] 1) Represented by the general formula A-B or B-A-B, segment A is selected from polyester, polyamide, polyimide, polyamideimide, and polyurethane, and segment B is one type of poly(meth)acrylic ester. A block copolymer consisting of the above.