RU2537002C1 - Method of obtaining triblockcopolymers of methacrylic monomers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method includes successive radical polymerisation of three monomers in presence of catalyst, whereas catalyst applied is complex compound of ruthenium with carborane fragment, initiator, whereas initiator applied is carbon tetrachloride, and activator. As monomers methylmethacrylate, isoboronylmethacrylate and tret-butylmethacrylate are applied. As activator isopropylamine is applied, and as catalyst 3,3-{[1',1'-diphenyl-6'-phenyl-6'-(6',8-µ-(o-phenylene))]-1',6'-diphosphohexane}-3-chlorine-closo-3,1,2-dicarbollylruthenium is applied.

EFFECT: obtaining copolymers of required composition with low polydispersity with application of lower catalyst concentrations.

2 cl, 3 ex, 1 dwg

Description

The present invention relates to methods for producing organic macromolecular compounds, namely to the production of triblock copolymers of methacrylic monomers by methods of "live" (controlled) radical polymerization, which can be used in microlithography to obtain the basis of photoresistive compositions of printed circuit boards, diffraction gratings.

Polymerization in the “live” chain mode is an effective way to obtain polymers with a clearly defined intramolecular structure and certain molecular weight values. Its main advantage over conventional radical polymerization is the ability to obtain finely dispersed homo- and copolymers, as well as grafted and block copolymers.

One of the most effective ways of carrying out “living” radical polymerization is to carry out a process using an atom transfer polymerization mechanism using transition metal compounds as catalysts [Macromolecules, v.28, p.1721 (1995); J. Am. Chem. Soc. V. 117, p. 5614 (1995)].

Acrylic triblock copolymers are known (US 5264527 A, C08F 4/00, C08F 293/00, C08F 297/00, C08F 122/40, C08F 122/00, C08F 297/08, C08F 4/48, publ. 11/23/1993 g) and ABC polymers of triblockmetal acrylate (US 5219945 A, C08F 297/02, C08F 293/00, C08F 297/00, C08L 53/00, publ. 06/15/1993), their preparation by live ion polymerization for the production of elastomeric products. The advantage of this method is the preparation of finely dispersed copolymers. The main disadvantage is that the method of live anionic polymerization is taken as the basis, which is characterized by the complexity of the implementation, the need for thorough degassing and drying of the starting materials from traces of moisture.

The closest in technical essence and the result to the claimed invention is a method for producing polymethyl methacrylate, protected by patent for invention RU 2348655 C1, C08F 20/18, C08F 4/00, publ. 03/10/2009, adopted for the closest analogue (prototype).

The prototype method is carried out by "live" radical polymerization in the presence of ruthenium complex compounds with carborane ligands as a catalyst, carbon tetrachloride as an initiator and tert.-butylamine as an activator. The polymerization of methyl methacrylate is carried out in the mass of monomer at 80 ° C with a molar ratio of the components of the catalyst: initiator: amine: MMA equal to 1: 2: 4: 600. This method provides efficient production of a homopolymer. Monomer conversion exceeds 80% in 2-3 hours.

The disadvantages of this method is the high concentration of the used catalyst, which determines the high cost of the final product and necessitates the subsequent purification of the polymer, as well as the applicability of this method only to obtain homopolymers.

The objective of the invention is to provide a new method for producing triblock copolymers of methacrylic monomers by controlled radical polymerization.

The technical result from the use of the present invention is to reduce the concentration of the catalyst, as well as optimizing the process of obtaining highly dispersed high molecular weight compounds based on block copolymers.

This object is achieved by the fact that in the method for producing a triblock copolymer of methacrylic monomers, comprising sequential radical polymerization of three monomers in the presence of a catalyst, a complex compound of ruthenium with a carboran fragment is used, an initiator using carbon tetrachloride, and an activator, as monomers use methyl methacrylate, isobornyl methacrylate and tert.-butyl methacrylate, isopropylamine is used as an activator, and as a catalyst mash use 3.3 - {[1 ′, 1′-diphenyl-6′-phenyl-6 ′ - (6 ′, 8-µ- (o-phenylene))] - 1 ′, 6′-diphosphagexane} -3 Chloro-Closo-3,1,2-dicarbolylruthenium; the process is carried out at 80 ° C, and the catalyst, initiator, activator and monomer are taken in a molar ratio of 1: (10 ÷ 50) :( 2 ÷ 4) :( 1000 ÷ 10000).

In accordance with the invention, the synthesis of triblock copolymers is carried out in three stages as follows.

At the first stage, a polymethyl methacrylate-based macroinitiator is obtained. To do this, prepare a composition of carbon tetrachloride, isopropylamine, methyl methacrylate and ruthenium catalyst, mixing the components in a certain proportion. The resulting mixture was thoroughly mixed, degassed and placed in a thermostat heated to 80 ° C. The polymerization is carried out for 2-8 hours, which allows to provide a product with a conversion of 30-80%, depending on the ratio between the components of the system and the time of the process. The resulting polymer is purified by reprecipitation and drying under reduced pressure (in vacuum).

In the second stage, the synthesis of a block copolymer based on the obtained macroinitiator and isobornyl methacrylate is carried out. To do this, a portion of the catalyst synthesized in the first stage of the macroinitiator is placed in the reaction vessel and poured with a pre-prepared solution of the amine in isobornyl methacrylate. The resulting mixture was stirred, degassed and polymerized and the block copolymer was isolated in a manner analogous to the synthesis of a macroinitiator.

In the third stage, the synthesis of a triblock copolymer is carried out. The block copolymer obtained in the second stage is placed in the reaction vessel, the catalyst, and the prepared solution of amine in tert-butyl methacrylate is poured. After this, polymerization and polymer isolation are carried out.

The most optimal ratio between isopropylamine and ruthenium catalyst is (2 ÷ 4): 1. A further increase in the amine concentration does not lead to an improvement in molecular weight characteristics or an increase in the rate of the process. With a molar ratio of [amine]: [catalyst] less than 2: 1, the polymerization of methyl methacrylate proceeds at a lower rate.

In the synthesis of block copolymers in accordance with the invention, the molar ratio between the ruthenium catalyst, macroinitiator, amine and grafted monomer is 1: (10 ÷ 50) :( 2 ÷ 4) :( 1000 ÷ 6000). The specified ratio allows to obtain finely dispersed block copolymers with the desired values of the lengths of the blocks.

The use of ruthenium carborane complexes together with isopropylamine provides the efficient production of triblock copolymers. A positive effect is achieved due to the interaction of amine and ruthenacarborane in the reaction system, leading to the formation of a ruthenium compound that catalyzes the polymerization process. When implementing the invention, there is a decrease in the concentration of the used catalyst in comparison with the prototype by 10 times. Thus, the use of the proposed ruthenacarborane catalyst allows the process to be carried out with a ratio between the catalyst and monomer equal to 1: (1000 ÷ 10000), which allows to reduce the cost of the catalyst and subsequent purification of the finished product.

The triblock copolymers obtained in accordance with the present invention have a number average molecular weight of from 40,000 to 120,000 and a polydispersity coefficient in the range of 1.4-1.7. The block structure of the copolymers leads to a higher resolution of photoresist compositions compared to compositions based on the statistical copolymers currently in use.

The following are examples of specific implementation of the alleged invention:

Example 1

1. Prepare a solution of isopropylamine in methyl methacrylate with a concentration of 0.04 mol%. 3.325 ml of a 0.1 M solution of carbon tetrachloride in toluene and 14 ml of a solution of isopropylamine in methyl methacrylate at room temperature are added to 9.22 mg (1.3 x 10 ^-5 mol) of compound 1. The molar ratio between the catalyst, initiator, activator and monomer in the resulting mixture is 1: 25: 4: 10000. The mixture thus prepared is degassed. The polymerization is carried out without air, in a hermetically sealed vessel at a residual pressure of (2-5) × 10 ^-2 mm RT. pillar. The reaction temperature is 80 ° C, the time is 5 hours. At the end of the reaction, the reaction mixture is dissolved in 5 ml of methylene chloride and planted in 100 ml of stirred hexane. The resulting polymer precipitate was separated by filtration and dried in vacuo to obtain polymethyl methacrylate in a yield of 37%. According to the analysis carried out by gel permeation chromatography, the polymer is characterized by M _n = 19800, PDI = 1.45.

2. 1 mg (1.44 × 10 ^-6 mol) of compound 1 and 113.5 mg (1.43 × 10 ^-4 mmol) of the synthesized polymethylmethacrylate initiator are placed in a reaction vessel. A solution of isopropylamine in isobornyl methacrylate with a concentration of 0.03 mol% is prepared. The prepared solution of the amine in the monomer is poured into the reaction vessel and stirred until the macroinitiator is completely dissolved. The molar ratio between the catalyst, macroinitiator, activator and monomer in the resulting mixture is 1: 40: 4: 1250. The mixture thus prepared is degassed. The polymerization is carried out without air, in a hermetically sealed vessel at a residual pressure of (2-5) × 10 ^-2 mm RT. pillar. The reaction temperature is 80 ° C, the time is 20 minutes At the end of the reaction, the reaction mixture was dissolved in 2 ml of methylene chloride and poured into 50 ml of stirred isopropyl alcohol. The resulting polymer precipitate was separated by filtration and dried in vacuo to give a block copolymer in 10% yield. According to the analysis performed by gel permeation chromatography, the polymer is characterized by Mn = 33100, PDI = 1.33.

3. 3.4 mg (4.9 × 10 ^-6 mol) of compound 1 and 65.5 mg (2 × 10 ^-6 mol) of PMMA-b-PIBMA diblock copolymer acting as a macroinitiator are placed in the reaction vessel. A solution of isopropylamine in tert-butyl methacrylate with a concentration of 0.04 mol% is prepared. The prepared solution of the amine in the monomer is poured into the reaction vessel and stirred until the macroinitiator is completely dissolved. The molar ratio between the catalyst, macroinitiator, activator and monomer in the resulting mixture is 1: 40: 4: 3150. The polymerization is carried out without air, in a hermetically sealed vessel at a residual pressure of (2-5) × 10 ^-2 mm RT. pillar. The reaction temperature is 80 ° C, the time is 5 hours. At the end of the reaction, the reaction mixture is dissolved in 2 ml of methylene chloride and a stirred mixture of isopropylamine and water (1: 4) is poured into 100 ml. The resulting polymer precipitate was separated by filtration and dried in vacuo to give the desired triblock copolymer in 30.5% yield. According to the analysis carried out by gel permeation chromatography, the polymer is characterized by Mn = 91600, PDI = 1.4.

Example 2

The polymethylmethacrylate macroinitiator in the first stage is obtained analogously to example 1, but in the second stage, the process is carried out for 40 minutes, obtaining a diblock copolymer with a yield of 15%. According to the analysis performed by gel permeation chromatography, the polymer is characterized by Mn = 35500, PDI = 1.33.

In the third step, the reaction time is 2.5 hours. The result is a polymer with Mn = 54300, PDI = 1.39.

Example 3

The polymethylmethacrylate macroinitiator in the first stage is obtained analogously to example 1, but in the second stage, the process is carried out for 50 minutes, obtaining a copolymer with a yield of 17%). According to the analysis performed by gel permeation chromatography, the polymer is characterized by Mn = 38900, PDI = 1.49.

At the third stage, the reaction time is 6 hours. A triblock copolymer was obtained with a yield of 49%, Mn = 121700, PDI = 1.67.

As can be seen from the above examples, the use of systems based on carborane complexes of ruthenium and isopropylamine allows the targeted production of finely dispersed triblock copolymers based on methyl methacrylate, isobornyl methacrylate and tert-butyl methacrylate. At the same time, it is possible to use the catalyst in a concentration of 10 times less compared to the prototype.

Figure 1 shows the structural formula of the used ruthenium carborane complex (compound 1).

Claims (2)

1. The method of producing tribloxopolymer of methacrylic monomers, comprising sequential radical polymerization of three monomers in the presence of a catalyst, which is a complex compound of ruthenium with a carboran fragment, an initiator, which is carbon tetrachloride, and an activator, characterized in that methyl methacrylate is used as monomer , isobornyl methacrylate and tert.-butyl methacrylate, isopropylamine is used as activator, and 3.3- { [1 ′, 1′-diphenyl-6′-phenyl-6 ′ - (6 ′, 8-µ- (o-phenylene))] - 1 ′, 6′-diphosphagexane} -3-chloro-closos-3, 1,2-dicarbolriluthenium. 2. The method according to claim 1, characterized in that the process is carried out at 80 ° C, and the catalyst, initiator, activator and monomer are taken in a molar ratio of 1: (10 ÷ 50) :( 2 ÷ 4) :( 1000 ÷ 10000) .

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