JPH0643495B2 - Linear thermotropic copolymer consisting of aromatic azomethine type mesogenic units and polysiloxane spacers and process for their preparation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to an essentially linear thermotropic group consisting of aromatic azomethine (CH = N) type mesogen units and diorganopolysiloxane bent spacer (chain) units. Regarding copolymers. The present invention further relates to two processes for preparing the above copolymers from mesogen monomers and α, ω-bis (hydro) diorganopolysiloxanes, each of which is α, ω-substituted by a group containing an ethylenic double bond.

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION A linear thermotropic polymer containing mesogenic units separated by a bent spacer is compared with a polymer in which mesogenic units are directly linked to each other via a non-mesogenic rigid binding medium. Lower phase transition temperatures (especially glass transition temperature Tc and clarificatio where the intermediate phase becomes anisotropic)
n) There is interest in having a temperature Tc).

Linear thermotropic copolymers are known that contain the following as spacers: Polymethylene groups (A. Roviello et al., J. Polym. Sci., Pol.
ym.Lett.Ed. 13 , 455, (1975)), diorganopolysiloxane group (IUPA by C. Aguilera et al.
C Macro, Florence Preprints, 3 , 306, (1980)), mixing of aliphatic and polysiloxane groups (BW Jo et al.
Eur. Pol. J., 18 , 223, (1982).

Thermotropic polyesters containing diorganopolysiloxane spacers are of particular interest because they have a much lower phase transition temperature than thermotropic polymers of the same type where the spacers are polymethylene groups (C. Aguilera et al. Makromol. Chem. 184 , 253, (1983)). However, careful examination of the molecular weights (n) obtained with these thermotropic polyesters of the prior art reveals that they have been treated with low molecular weight (on the order of 3000-4000 g / mol) thermotropic oligomers, such molecular weights It turns out that it is not suitable for use as an engineering plastic.

The applicant company operating in this technical field has 4
Higher molecular weight (more than 000 g / mol, reaching 10,000 g / mol and exceeding 10,000 g / mol (
has developed an essentially linear thermotropic copolymer comprising a diorganopolysiloxane spacer with n), which forms the first subject of the invention,
The above molecular weights make the thermotropic copolymers well suited for use as engineering plastics.

More specifically, the present invention is in the first subject matter an essentially linear thermotropic copolymer consisting of mesogenic units and flexible diorganopolysiloxane spacers, the formula of which in their structure: [In the formula, the symbols A are the same, and each is a single bond or -O-, The symbol B ₁ represents a group of —CH═N— or —N═CH—, while the symbol B ₂ is different from B ₁ and represents a —N═CH— group (B
₁ is -CH = N-) or -CH = N- group (B ₁
Represents -N = CH-), and the symbol D is a group of the following formula: (In the formula, y is an integer in the range of 0 to 2, and the symbol E is a single bond or -CH = N-, -N = CH when y = 1.
-, Or And when y = 2, a single bond, Or In which R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and are monovalent selected from linear or branched alkyl groups containing 1 to 12 carbon atoms. Hydrocarbon groups of (by at least one chlorine, bromine or fluorine atom with respect to these groups or
Optionally substituted by a CN group); at least one alkyl and / or alkoxy group containing 1 to 4 carbon atoms or a phenyl group optionally substituted by at least one chlorine atom, the symbol X being An integer in the range 2 to 8 and the symbol n
Is an integer or a fraction in the range of 0 to 50].

As a thermotropic copolymer which is a preferred representative example of the present invention, in the formula (I), the symbols A are the same, a single bond or —O—, The symbol B ₁ represents a group of —CH═N— or —N═CH—, while the symbol B ₂ is different from B ₁ from a group of —N═CH— (B
₁ is -CH = N-) or -CH = N- group (B ₁
Is -N = CH-), and symbol D is a group of the following formula: (In the formula, y is an integer in the range of 0 to 2, and the symbol E is a single bond or -CH = N-, -N = CH when y = 1.
-, Or , And a single bond when y = 2, Or R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and each represents a linear or branched alkyl group containing 1 to 6 carbon atoms or a phenyl group. Is an integer of 2 or 3, and the symbol n may be one containing a repeating unit of the formula (I) in the structure, which is an integer or a fraction in the range of 1 to 30.

The most preferred embodiment of the present invention, a thermotropic copolymer, may include those containing in the structure a repeating unit of the formula (I) satisfying the following conditions: A is a single bond, B ₁ is -N = CH-, and B is
₂ is -CH = N-, D has the above meaning in relation to formula (I), each of R ₁ to R ₆ is the same or different,
1. a linear alkyl or phenyl group containing 1 to 3 carbon atoms, wherein x is 2 and n is in the range 1 to 30; A is And B ₁ is —CH═N— and B ₂ is —N═CH.
Is −, D has the above meaning in relation to the formula (I), and R _{1 to} R ₆ are
2. each represents a linear alkyl group or a phenyl group, which is the same or different and contains 1 to 3 carbon atoms, x is 2 and n is in the range of 1 to 30; A is -O-, B ₁ is -CH = N-, B
₂ is -N = CH-, D has the above meaning in relation to formula (I), R _{1 to} R ₆ are each the same or different and are linear alkyl containing 1 to 3 carbon atoms. A group or a phenyl group, x is 3 and n is in the range 1-30.

Specific thermotropic copolymers, which are highly preferred embodiments of the invention, include, for example, those containing in the structure repeating units of formula (I) which satisfy the following conditions: A is -O-, B ₁ is -CH = N-, B
₂ is -N = CH-, and D is _4. R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are methyl groups, x is 3 and n is in the range 1-20. A is -O-, B ₁ is -CH = N-, B
₂ is -N = CH-, and D is _5. R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are methyl groups, x is 3 and n is in the range 1-20. A is -O-, B ₁ is -CH = N-, B
₂ is -N = CH-, and D is Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are methyl groups, x is 3 and n is in the range 1-20.

4000 g of the thermotropic copolymer according to the invention
/ Mol higher, for example 10,000 to 20000 g /
It has a number average molecular weight n that can reach values as high as the molar range. Copolymers with such a molecular weight exhibit mechanical properties that can be used in the field of engineering plastics.

Another characteristic of the copolymers according to the invention is that they form a liquid crystal (mesophase) phase without risk of thermal decomposition, depending on the structure of the copolymer, for example at an average temperature of 50 ° C to 270 ° C. It is to be. The configuration relative to ambient temperature (23 ° C.) and the temperature spanned by the anisotropy zone (the range that can be indicated by the difference in Tc-Tg in the case of amorphous copolymers) can be conveniently adjusted, especially by the following various structural parameters.

It is observed that the attribute of the symbol D shown in formula (I); for example, increasing the number of phenyl groups results in increasing the value of the phase transition temperature.

The length n of the flexible polysiloxane spacer shown in formula (I); for example, increasing n value is observed to result in decreasing phase transition temperature values.

Siloxane spacer dispersity (see below for method of making copolymers according to the invention); for example, polydispersity reduces the value of the phase transition temperature relative to the phase transition temperature produced by the use of monodisperse siloxane spacers. It is observed that you can.

The present invention is also a first process for the preparation of essentially linear thermotropic copolymers, wherein these copolymers have the formula (I) in which B ₁ is -CH = N- and B ₂ is -N = CH-. ) Is included in the structure of the repeating unit, which is the second method of the present invention.
Form the subject of.

More specifically, this method is characterized in that it comprises the following steps (a) and (b): (a) a method known per se, (i) a difunctional compound of the formula: (Wherein the symbols x and A have the general or preferred meanings indicated above in relation to formula (I)) and, (ii) the diamine compound of the following _{formula; H 2 N-D-NH} 2 ( IV), wherein the symbol D has the general or preferred meanings given above in relation to formula (I), and then from the reaction mixture by methods known per se. By separating the resulting mesogen precursor monomer of formula (II) in pure form, the formula: Where the symbols x, A and D have the general or preferred meanings given above in relation to formula (I)
-Synthesizing a disubstituted mesogen precursor monomer, and (b) operating under anhydrous conditions in an oxygen-free inert atmosphere and in the presence of a hydrosilylation catalyst, (iii) Α, ω-bis (hydro) diorganopolysiloxane of Where R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and n have the general or preferred meanings given above in relation to formula (I), and (iv) At the end of step (a), the formula (I
Reacting the mesogen precursor monomer of I), then And / or by carrying out the polyhydrosilylation reaction by separating the desired thermotropic copolymer from the reaction mixture in a manner known per se, immediately after the complete disappearance of CH ₂ ═CH—. To synthesize the desired thermotropic copolymer.

The present invention is also a second method of making thermotropic copolymers, wherein these copolymers have a B ₁ of --N.
═CH— and B ₂ is —CH═N—, to a method applied when it comprises a repeating unit of formula (I) in its structure, which forms the third subject of the invention. .

More specifically, this method comprises the steps (a ′) and
(b ') is included: (a') (v) a bifunctional compound of the formula: Where the symbols x and A have the general or preferred meanings given above in relation to formula (I), and (vi) an aromatic dialdehyde of the formula: OHC-D-CHO (VIII ), Wherein the symbol D has the general or preferred meanings given above in relation to formula (I), in a manner known per se, and then from the reaction mixture By isolating the resulting mesogen precursor monomer of formula (VI) in pure form by a method known per se, the formula: Where the symbols x, A and D have the general or preferred meanings given above in relation to formula (I)
-Synthesizing a disubstituted mesogen precursor monomer and (b) operating under anhydrous conditions in the absence of oxygen and in the presence of a hydrosilation catalyst, (iii) α, ω-bis (hydro) diorganopolysiloxane; Where R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and n have the general or preferred meanings given above in relation to formula (I), and (vii ) At the end of the previous step (a ′), the formula (V
Reacting with the mesogen precursor monomer of I) and then from the reaction mixture in a manner known per se,
After the functional group -Si-H and / or CH 2 ₌ CH- completely disappeared immediately, by separating the desired thermotropic copolymer, running poly hydrosilylation reaction synthesis of the desired thermotropic copolymer To do.

The above steps (a) and (a ′) are carried out in bulk with 0.5 mol of the diamine reactant (ii) or 1 mol of the difunctional reactant (i) or (v), for example from 50 ° C. to 150 ° C. At ℃, for example, 2
It can be carried out by heating for 0 minutes to 1 hour.

The procedure is preferably carried out in the presence of an organic liquid which is a solvent for the starting reactants, but in the amount of reactants as indicated above, but which is a non-solvent for the desired mesogen precursor monomer to the extent of 0-23 ° C. carry out. From this viewpoint, it is preferable to use a saturated aliphatic monoalcohol containing 1 to 4 carbon atoms, alone or in combination, and particularly preferably methanol. In this case, the temperature of the imino reaction advantageously corresponds to the boiling point of the solvent used and the length of the reaction is, for example:
Between 20 minutes and 5 hours. The reaction is over and 0
After cooling to a temperature on the order of 23 ° C., the mesogen precursor monomer in the form of a crystalline precipitate can be recovered by filtration and if necessary purified by recrystallization.

The bifunctional reactants (i) and (v) of formula (III) and formula (VII) are known products which can be easily prepared. For example, Is obtained by the condensation reaction of 4-hydroxybenzaldehyde and allyl bromide, 4-hydroxybenzaldehyde is obtained by the same type of reaction with acryloyl chloride.

In steps (b) and (b '), formula (II) or formula (VI)
The polyhydrosilylation reaction of the mesogen precursor monomer of can be carried out in a heterogeneous mixture and without solvent.

The operations are preferably carried out in a homogeneous mixture by adding the starting reactants to a solvent or solvent mixture common to the reactants and the desired copolymer, paying attention to the concentration of the reactants. That is, (iii) and (iv) on the one hand, and (iii) and (iv) on the other hand
(vii) is greater than or equal to 5% by weight and more precisely 6 to 30% or more, expressed in g of reactants per 100 cm ³ of solvent, depending on the solubility of the reactants. The solvent used must be anhydrous, and suitable solvents include tetrahydrofuran, benzene, chlorobenzene,
Mention may be made of toluene and acetonitrile.

The polyhydrosilylation reaction is generally carried out at 20 ° C to
It is carried out at a temperature of 120 ° C, preferably at a temperature of 60 ° C to 100 ° C. Mesogen precursor monomer (iv) or (vii)
In 1 of reactant (iii) containing a -Si-H group.
Used in an amount equal to 1 mol per mol. Use the amounts of reactants (iii) and (iv or vii) such that the molar ratio of reactants (iii) / reactants (iv or vii) is in the range, for example, 0.90 / 1 to 1.1 / 1. Does not leave the realm of the present invention.

The α, ω-bis (hydro) organopolysiloxane (iii) of the formula (V) used is a well known product in the silicone industry and in some cases (fully alkylated compounds) is commercially available. ing. They are, for example, French A1-2,486,952 and French A5-2,05.
No. 8,988. If these products are not commercially available, they may be chain polymerized, for example, by cationically polymerizing a suitable α, ω-bishydroxylated diorganopolysiloxane oil and then using reagents such as dihydrotetraalkyldisiloxane. It can be produced by a transfer reaction. In these compounds of formula (V), when n is larger than 1, it is treated as a compound having a polymerizable structure, and a single polymer species (so-called monodisperse structure, in which n is an integer) or It is possible to have any of the mixtures of polymerizable species of the same chemical structure with different numbers of repeating units (so-called polydisperse structures, where n is often a fraction).

For hydrosilylation catalysts it is possible in particular to use the following compounds, in particular elemental platinum, hexachloroplatinic acid in the hydrated form or else elemental platinum and α, ω-bis (vinyl) diorgano. Complexes based on siloxane type ligands, eg metal carbonyls such as cobalt carbonyl or nickel carbonyl. A preferred catalyst of the present invention is a complex based on hexachloroplatinic acid or the elemental platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, commonly referred to as the Karsted catalyst. It is a catalyst. The amount of catalyst used is the following ratio: Is generally in the range of 0.05 × 10 ^{−4 to} 20 × 10 ⁻⁴ and preferably in the range of 0.2 × 10 ^{−4 to} 5 × 10 ⁻⁴ .

The catalyst can be introduced into the reaction mixture either in its naturally occurring form or in the form of a suspension or solution in a suitable diluent or solvent. In the case of the preferred catalyst consisting of hexachloroplatinic acid, it is generally used in the form of a solution of a saturated aliphatic monoalcohol, for example isopropanol. In the case of the preferred catalysts which consist of platinum-based complexes of the elements, they are generally used in the form of solutions of hydrocarbons, for example benzene, toluene, cyclohexane or n-hexane.

In order to actually carry out step (b) or (b '), first charge the reactants (iv) or (vii), then the optionally chosen solvent into the reactor and stir the reactants as described above. Heat to the adopted temperature within the temperature range. Then the catalyst is added. Next, the bis (hydro) siloxane reactant (iii)
Can be introduced into the stirred and heated reactants, optionally in the form of a solution of one and / or other solvent which can be used, in which case the reactants can be selected at the same time as the selected solvent or starting reactants. It is advantageous to include one of the selected solvents which can be used). This introduction is carried out gradually, for example over a period of 30 minutes to 15 hours. The introduction of the bis (hydro) siloxane reactant (iii) is preferably carried out while at the same time ensuring that dry and oxygen-free nitrogen is distributed to the reactants. When the introduction of the reactant (iii) is completed, -Si-H and / or
Alternatively, the reaction mixture is further maintained at the selected temperature conditions, for example on the order of 1 to 10 hours, until the CH ₂ ═CH-functional group has completely disappeared. At the end of the reaction, when the desired copolymer is obtained in solution, it can be precipitated by adding a non-solvent or a mixed non-solvent to the reaction mixture and the precipitated copolymer can be separated. The copolymer can also be obtained by removing the solvent from the reaction mixture by vacuum distillation.

We have especially used the method (first and second) in which the reactant (iv) or (vii) (somegen precursor monomer) has the formula (II or VI) in which the symbol A represents an oxygen bridge. Process) in the structure of the desired copolymer, unsuitable repeat units of the formula: (Wherein the symbols x, B ₁ , D, B ₂ , R ₁ to R ₆ and n have the meanings given above in relation to formula (I)), which is the position of the secondary reaction leading to the repeating unit become. These unsuitable units are Functional group Reactant (iv) or (vii) by cleavage through bond formation
Can be obtained as a result of rearrangement of the ether bond introduced by: Inappropriate units of formula (IX), when they are optionally formed, do not exceed 10 mol% relative to the sum of the units of formula (I) + units of formula (IX).

Specific examples of the present invention are shown below, but the present invention is not limited thereto.

In these examples, the thermotropic copolymers according to the invention were fixed, in particular by spectroscopic studies (infrared absorption and proton and C ¹³ nuclear magnetic resonance). Molecular value of these copolymers; number average molecular weight n, polydispersity (PI
= W / n) and the number average degree of polymerization DPn, especially by steric exclusion chromatography, in a variety of consistent calibrations (including tetrahydrofuran solvent, polystyrene)
Was used to determine. The thermotropic property is 99
00 Differential thermal analysis (DSC) with a DuPont instrument containing a DSC910 module integrated with a central processing unit
Measured by It was observed by means of a polarizing microscope incorporating a heating stage capable of identifying the phase properties present and examined by means of X-ray diffraction.

Examples Two series of thermotropic copolymers containing repeating units of the formula below in their structure are described in these examples: (In the formula, in the first series, D is And n is 1, 2, 3, 4, 4.3, 5, 6.8 and 15
(Examples 3 to 10), and in the second series, D is And n is 1, 2, 3, 4 and 6.8 (Examples 11 to 15)) These copolymers were obtained by using the manufacturing method previously referred to as the first method And by starting with a suitable combination of (iv).

The reaction product (iii) is various α, ω-bis (hydro) of the following formula.
Contains diorganopolysiloxane: (N is the following value, n = 1, n = 2, n = 3, n = 4,
Corresponding to n = 4.3, n = 5, n = 6.8 and n = 15).
Corresponding oligosiloxanes with n values equal to 1, 2, 3, 4 and 5 are monodisperse species, with n values of 4.3, 6.8 and 1
The corresponding oligosiloxane equal to 5 is a polydisperse species.

In the following, each oligosiloxane reactant (iii) is designated by the symbol Hn, where n is the symbol n in formula (XI).
Has a value of.

Formula (iv) is a symbol of the following formula M1: And M2: Containing two mesogen precursor monomers represented by

In the following, the first series of eight copolymers are represented by: H1M1, H2M1, H3M1, H4M1, H4.3.
Represented by M1, H5M1, H6.8M1 and H15M1. For the second series of five copolymers, the expressions H1M2, H2M2, H3M2, H4M2 and H6.8M
Shown by 2.

Example 1 Preparation of mesogen precursor monomer according to the procedure of step (a) of the first method according to the present invention.

The p- allyloxybenzaldehyde 20 g (0.1235 mol) is dissolved in methanol 300 cm ³ in the glass reactor. Such a reactor has a capacity of 500 cm ³ and is equipped with a heating system using a heat transfer medium, a magnetic stirrer system, a dropping funnel and a reflux condenser. Then 6.67 g (0.0617 mol) of p-phenylenediamine are added and the mixture is heated under reflux of methanol for 2 hours. At the end of this time, the reaction mixture is cooled to 0 ° C. and the precipitate formed, which is the reaction product, is collected by filtration. The product is then purified by recrystallisation from 500 cm ³ of chlorobenzene. Thus 20.22 g of product was recovered and the structure after spectroscopic studies (infrared absorption and proton and C ¹³ nuclear magnetic resonance) was consistent with formula M1 above. This operation is repeated as many times as necessary to be able to serve the desired amount of monomer M1.

Example 2 Somemegen precursor monomer M2 is prepared according to the present invention according to the procedure of step (a) of the first method.

7.45 g (0.0459 mol) of p-allyloxybenzaldehyde was added to a volume 5 equipped with the equipment as described in Example 1.
It is dissolved in 200 cm ³ of methanol glass reactor of 00cm ^3. Then, 4,4'-diaminodiphenyl 4g (0.0
217 mol) and the mixture is added to 1 under reflux of methanol.
Heat for half an hour. After this time, the reaction mixture is cooled to 0 ° C. and the precipitate formed, which is the reaction product, is collected by filtration. Then purified by recrystallization of the product from chlorobenzene of 350 cm ^3.
Thus 10.6 g of product was recovered and the structure after spectroscopic studies (infrared absorption and proton and C ¹³ nuclear magnetic resonance) was consistent with formula M2 above. This operation is repeated as many times as necessary to serve the desired amount of monomer M2.

Examples 3-10 According to the operation of step (b) of the first method according to the present invention, a first series of thermotropic copolymers, H1M1, H2.
M1, H3M1, H4M1, H4.3M1, H5M1, H
6.8M1 and H15M1 are produced.

1. Equipment: The operation is 250 cm ³ equipped with a heating system using a heat transfer medium, a magnetic stirring system, a suitable funnel, a reflux condenser and a system for dispersing dry oxygen-free nitrogen.
In a glass reactor of.

2. General procedure: First 3.96 g (0.01 mol) of monomer M1 and 60 cm ³
Of anhydrous toluene is charged to the reactor. Turn on the stirrer and heat the reactants to a temperature of 85 ° C. Then the catalyst is added. The catalyst is a Kirsted catalyst, 1
It is an n-hexane solution having a concentration of 0% (expressed by the weight g of elemental platinum with respect to the volume cm ³ of the solution). 6 microliters of this solution is injected with a syringe (ratio: number of gram atoms of element Pt / number of moles of Hn oligosiloxane is 3 × 10 5
^-4 ).

A solution was achieved in which dry oxygen-free nitrogen was dispersed in the reactants and a solution containing 0.01 mol of α, ω-bis (hydro) oligosiloxane Hn and 20 cm ³ of anhydrous toluene was stirred for 4 hours. Pour continuously into material. The temperature is maintained at 85 ° C. After pouring is complete, the reaction mass is kept stirring at 85 ° C. for a further 8 hours.

The desired copolymer HnM1 was obtained by removing toluene while heating to 85 ° C. and continuously reducing the pressure from atmospheric pressure to 1 Pa. The product obtained is an orange solid.

3. Results for Examples 3-10: In Table 1 below, the amounts of reactants and products and various parameters given by steric exclusion chromatography are reported for each copolymer prepared.

In Table 2 below, the value of the phase transition temperature measured by DSC and the nature of the existing phase observed using a polarization microscope are reported for each copolymer prepared.

Examples 11-15 According to the operation of step (b) of the first method according to the method of the present invention, the second series: H1M2, H2M2, H3M2, H4M.
2 and H6.8 M2 thermotropic copolymers are prepared.

1. Equipment See Examples 3-10.

2. General procedure Similar to that used for Examples 3 to 10, but here 4.72 g (0.01 mol) of monomer M2 are introduced.

3. Results of Examples 11-15 In Table 3 below, the amounts of reactants and products and the various parameters given by steric exclusion chromatography are reported respectively for the copolymers prepared.

In Table 4 below, the value of the phase transition temperature observed by DSC and the nature of the existing phase observed using a polarization microscope are reported for each of the prepared copolymers.

Claims (10)

[Claims] 1. An essentially linear thermotropic copolymer consisting of mesogenic units and flexible diorganopolysiloxane spacers, the repeating units of the formula: [In the formula, the symbols A are the same, and each is a single bond or -O-, The symbol B ₁ represents a group of —CH═N— or —N═CH—, while the symbol B ₂ is different from B ₁ and represents a —N═CH— group (B
₁ is -CH = N-) or -CH = N- group (B ₁
Represents -N = CH-), and the symbol D is a group of the following formula: (In the formula, y is an integer in the range of 0 to 2, and the symbol E is a single bond or -CH = N-, -N = CH when y = 1.
-, Or And when y = 2, a single bond, Or And R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and are linear or branched alkyl groups containing 1 to 12 carbon atoms, A monovalent hydrocarbon group selected from the above alkyl groups that can be substituted by one chlorine, bromine or fluorine atom or by a -CN group; at least one alkyl and / or alkoxy group containing 1 to 4 carbon atoms or at least one A phenyl group optionally substituted by one chlorine atom, the symbol X is an integer in the range 2-8, and the symbol n
Is an integer or fraction in the range of 0-50]. 2. In the formula (I), the symbols A are the same, a single bond or --O--, The symbol B ₁ represents a group of —CH═N— or —N═CH—, while the symbol B ₂ is different from B ₁ from a group of —N═CH— (B
₁ is -CH = N-) or -CH = N- group (B ₁
Represents -N = CH-), and the symbol D is a group of the following formula: (In the formula, y is an integer in the range of 0 to 2, and the symbol E is a single bond or -CH = N-, -N = CH when y = 1.
-, Or , And a single bond when y = 2, Or R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and each represents a linear or branched alkyl group containing 1 to 6 carbon atoms or a phenyl group. The copolymer according to claim 1, wherein the structure contains the repeating unit formula (I) in which the symbol X is an integer of 2 or 3, and the symbol n is an integer or a fraction in the range of 1 to 30. 3. B ₁ is -CH = N- and B ₂ is -N = C.
A process for producing a copolymer according to claim 1 or 2 which comprises in its structure a repeating unit of formula (I) which is H-, characterized in that it comprises the following steps (a) and (b): (A) in a manner known per se, (i) a bifunctional compound of the formula: (Where the symbols x and A have the meanings given in claim 1 or 2 in relation to formula (I)), and (ii) a diamine compound of the formula: H ₂ N-D-NH ₂ (IV (In the formulae, the symbol D is the formula 1 or 2 in relation to the formula (I).
Of the formula (II), and then separating the mesogen precursor monomer of formula (II) obtained in a pure state from the reaction mixture by methods known per se. : (Wherein the symbols x, A and D have the meanings given in claim 1 or 2 in relation to the formula (I)), by the group having an ethylenic double bond, α,
synthesizing a ω-disubstituted mesogen precursor monomer,
And (b) operating under anhydrous conditions in an oxygen-free inert atmosphere and in the presence of a hydrosilylation catalyst, (iii) α, ω-bis (hydro) diorganopolysiloxane of the following formula: Siloxane; (Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and n have the meaning indicated in claim 1 or 2 in relation to the formula (I)), (iv) At the end of step (a), the formula (I
Reacting the mesogen precursor monomer of I), then And / or immediately after the CH ₂ ═CH-functional group has completely disappeared,
The desired thermotropic copolymer is synthesized by carrying out a polyhydrosilylation reaction by separating the desired thermotropic copolymer from the reaction mixture. 4. B ₁ is -N = CH- and B ₂ is -CH =
A process for the preparation of a copolymer according to claim 1 or 2 which comprises in its structure a repeating unit of formula (I) which is N-, characterized in that it comprises the following steps (a ') and (b'): (a ′) (v) a bifunctional compound represented by the following formula; (Wherein the symbols x and A have the meanings given in claim 1 or 2 in relation to formula (I)), and (vi) an aromatic dialdehyde of the formula: OHC-D-CHO (VIII) (In the formulae, the symbol D is defined in relation to the formula (I).
With the meanings given above) in a manner known per se, and then by a method known per se, the formula (V
By separating the mesogen precursor monomer of I) from the reaction mixture in a pure state, the formula: (Where the symbols x, A and D have the meanings given in claim 1 or 2 in relation to formula (I))
Synthesizing a disubstituted mesogen precursor monomer, and (b ') operating under anhydrous conditions in an oxygen-free inert atmosphere and in the presence of a hydrosilation catalyst, (iii) Α, ω-bis (hydro) diorganopolysiloxane of Where R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and n have the general or preferred meanings given above in relation to formula (I), and (iv ) At the end of said step (a ′) reacting with the mesogen precursor monomer of formula (VI) obtained in pure form, then from the reaction mixture in a manner known per se. And / or CH 2 ₌ CH- after functional group completely disappeared immediately, by separating the desired thermotropic copolymer, synthesis of the desired thermotropic copolymer is running poly hydrosilylation reaction. 5. An organic liquid in which the first step (a or a ') is a solvent for the starting material but a non-solvent for the desired mesogen precursor monomer at a temperature on the order of 0.degree. C. to 23.degree. 5. The process according to claim 3 or 4, which is carried out in the presence of and operating at a temperature corresponding to the boiling point of the solvent used. 6. The first step (a or a ') is carried out using 0.5 mol of diamine reactant (ii) or dialdehyde (vi) per mol of difunctional reactant (i) or (v). The method of claim 5, wherein the method is performed as follows. 7. The second step (b or b ') is carried out by adding a solvent or mixed solvent common to the reactants and the desired copolymer to the starting reactants, the concentration of the reactants being the weight of the reactants per 100 cm ³ of solvent. Process according to any one of claims 3 to 6 carried out in a homogeneous medium by noting that it is equal to at least 5%, expressed as g. 8. The second step (b or b ') is performed at 20 ° C. to 120 ° C.
8. The method of claim 7 carried out in the temperature range of ° C. 9. Mesogen precursor monomer (iv) or (vii)
To 9. A process according to claim 7 or 8 which is used in an amount equal to 1 mol per mol of the reactant containing. 10. In fact, in the second stage (b or b ') first the reactants (iv) or (vii) are charged to the reactor used, then the catalyst is added thereto, and A process according to any one of claims 7 to 9 wherein the bis (hydro) siloxane reactant (iii) is gradually introduced into the stirred and heated reactant.