JPH09309946A - Aromatic polyester with branched aliphatic side chains - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] The problem to be solved by the present invention is to provide excellent water repellency and low surface energy useful as a coating film or film.
To obtain an aromatic polyester having branched aliphatic side chains having solid surface characteristics such as. SOLUTION: The main chain has a wholly aromatic polyester structure, and an aliphatic side chain having a branched structure is bonded to at least a part of the aromatic ring in the main chain, which is solvent-soluble and / or heat-meltable. An aromatic polyester having a branched aliphatic side chain.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating film, a film,
The present invention relates to an aromatic polyester having a branched aliphatic side chain having excellent solid surface properties and having solvent solubility and / or heat melting property, which is useful in fields such as molding materials.

[0002]

2. Description of the Related Art An aromatic polyester obtained by partially introducing p-hydroxybenzoic acid into polyethylene terephthalate by a transesterification reaction exhibits a melt liquid crystallinity (Journal of Polymer Science).
ce, Chemistry Edition, Volume 14,
(Page 2043, 1976), it has become known that an aromatic polyester having a proper main chain rigidity generally exhibits a melt liquid crystallinity.

Until recently, some aromatic liquid crystal polyesters having a melted liquid crystallinity have been commercialized, and due to the strong self-cohesive force of the molecular chain and the high fluidity based on the liquid crystallinity, they have been used as engineering plastics as self-reinforced polymers. Widely used in the field. On the other hand, these aromatic liquid crystalline polyesters exhibiting liquid crystallinity are generally poor in miscibility with other polymers in melt kneading as a result of strong self-cohesive force, and necessary for blending with other polymers through a solution. It is also poor in solvent solubility. Therefore, there have been many restrictions on blending such aromatic polyesters with other polymers, and a sufficient composite effect has not always been obtained.

In recent years, studies on aromatic polymers having an aliphatic side chain have been reported on aromatic polyesters and aromatic polyamides (for example, Angew. Chem. In.
t. Ed. Engl. 28, 253, 1989 or Macromokecules, 26, 1595
P., 1993), they show that, for example, aromatic polyesters have both solvent solubility and melt liquid crystallinity by bonding a linear alkyl side chain to an aromatic ring,
It has been reported that it takes a unique self-aggregation morphology that becomes clear by X-ray measurement (for example, Polymer
Journal, 24, 1119, 1992).
However, little attention was paid to physical properties such as those mechanical properties, and no report was made.

On the other hand, there have been many cases in which introduction of an aliphatic side chain or a fluorine-containing side chain into a flexible polymer such as an acrylic resin has been conventionally examined. For example, the main chain is polyacrylate or polymethacrylate ( Polymer, 33, 131
Page 6, 1992, Macromolecules,
26, 6694, 1993),

Aliphatic polyester (Macromole
, 27, 1928, 1994), and polysiloxane (Liquid Crystal, 7).
Volume, 669 pages, 1990, Liquid Crys
Tal, Vol. 16, 223, 1994).

Up to now, an example in which a fluorine-containing side chain has been introduced into a flexible aromatic polyester having a specific structure in which the main chain has an aromatic ring and an aliphatic chain (Liquid Cr
ystal, vol. 18, p. 347, 1995), but no particular attention is paid to physical properties other than morphology and liquid crystallinity, and there is no study example on a wholly aromatic polyester having a rigid main chain. There have been no cases where aromatic polyesters have been investigated for side chains containing dialkylsiloxane.

[0008]

The problem to be solved by the present invention is to have a branched aliphatic side chain having solid surface properties such as excellent water repellency and low surface energy, which is useful as a coating film or film. To obtain an aromatic polyester.

[0009]

Means for Solving the Problems As a result of earnest research to obtain an aromatic polyester having excellent surface properties, the present inventors have found that an aliphatic side chain having a specific side chain structure or side chain substitution form. It was found that an aromatic polyester obtained by bonding to an aromatic ring in the main chain has solvent solubility, heat melting property or melt liquid crystallinity, and shows excellent solid surface properties such as water repellency and low surface energy. The present invention has been completed.

That is, according to the present invention, the main chain has an aromatic polyester structure, and an aliphatic side chain having a branched structure is bonded to at least a part of aromatic rings in the main chain. And / or an aromatic polyester having a heat melting property.

Further, the aromatic polyester of the present invention is characterized in that the terminal of the aliphatic side chain is particularly a neopentyl group or an isopropyl group,
The main chain has an aromatic polyester structure and has 4 to 3 carbon atoms
A solvent-soluble and / or heat-meltable aromatic polyester in which one aliphatic side chain of 0 is bonded per repeating structural unit of the main chain is included.

The aromatic polyester of the present invention has a main chain having an aromatic polyester structure, and one or more aliphatic side chains are bonded to all aromatic rings in the main chain. And / or heat-melting aromatic polyester, and aromatic polyester characterized in that the aromatic polyester is a copolymer in the main chain structure and / or side chain substitution. Furthermore, the aromatic polyester of the present invention,
At least a part of the aromatic polyester structure constituting the main chain particularly includes an aromatic polyester having a metaphenylene ring. Further, the aromatic polyester of the present invention includes an aromatic polyester having a liquid crystallinity.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic polyesters having an aliphatic side chain in the present invention include those having a branched side chain, those having one aliphatic side chain per repeating structural unit, and all of the main chains. Examples thereof include those in which an aliphatic side chain is bonded to the aromatic ring, and aromatic polyester copolymers having an aliphatic side chain.

Here, as the aliphatic side chain having a branched structure, it is essential that one or more branches are contained in the side chain, and one or more tertiary or quaternary carbons are included in the side chain. Those having the terminal side or in the middle are used. In particular,
Examples thereof include those in which one side chain is branched into two chains, three chains, etc., and those in which the end of the aliphatic side chain is a neopentyl group or isopropyl group.

Those having a branched structure in the side chain exhibit superior solid surface characteristics with the same carbon number, that is, high water contact angle and low surface free energy, as compared with those having a linear structure. Further, the higher the degree of branching at the side chain end, the better the solid surface characteristics. For example, in the case of Examples 1 and 2 and Comparative Example 1 in which the aliphatic side chains having 5 carbon atoms have different side chain terminal methyl groups due to branching, the surface property measurement results of the solid film are shown in FIG. Shown in.

FIG. 1 is a diagram showing the relationship between the number of side chain terminal methyl groups and the surface free energy γ (mN / m). The number of methyl groups on the side chain terminal in FIG. 1 is specifically, 1 is-(CH ₂ ) ₄ -CH ₃
A 2 - a _{(CH 2) 2 -CH (CH} 3) 2, 3 is a _{-CH 2 -C (CH 3) 3} . It can be seen from FIG. 1 that the higher the degree of branching, the lower the surface free energy.

It is essential that the aliphatic side chain contained in each repeating structural unit in the present invention has 4 or more carbon atoms, preferably 4 to 30 carbon atoms, and has a straight chain structure. Alternatively, a branched structure is used.
When the carbon number is 3 or less, the solvent solubility and / or the heat melting property are poor and the handling is difficult. Further, if the carbon number exceeds 30, it becomes difficult to perform quantitative synthesis.

Compared to those containing two or more aliphatic side chains per repeating structural unit, those containing only one aliphatic side chain can be used without a longer aliphatic side chain significantly deteriorating the characteristics of the main chain. In many cases, it is effective in developing excellent surface properties and mechanical properties.

On the other hand, when the aliphatic side chains are substituted on all the aromatic rings in the present invention, the number of carbon atoms in the side chains is not necessarily limited, but the solvent solubility, the heat melting property and the surface characteristics of the solid film make it possible. Preferably has 2 or more carbon atoms. Those having an aliphatic side chain on all aromatic rings of the main chain, particularly those having two or more side chains on all aromatic rings have good surface properties even if the number of carbon atoms in the side chain is small. Or has excellent solvent solubility.

The main chain aromatic polyester structure in the present invention includes a wholly aromatic polyester structure consisting only of an aromatic ring and an ester bond, and an aromatic polyester structure containing an aliphatic chain in a part of the main chain. This includes a case where at least a part or all of the aromatic ring of the main chain is a metaphenylene ring. Further, those having an aromatic polyester structure exhibiting a liquid crystallinity only in the main chain are also included.

For example, those containing a metaphenylene ring in the main chain and those containing an aliphatic chain have, in addition to excellent surface characteristics,
The solvent solubility and heat melting property can be controlled more widely, and a high molecular weight aromatic polyester can be obtained. Further, when the meta isomer monomer is used, it is excellent in cost and production yield.

As the aromatic polyester in the present invention, in addition to homopolymers having a repeating chemical structure, plural kinds of aromatic monomers are used, or the main chain has a different bonding property such as paraphenylene ring or metaphenylene ring. A copolymer obtained by using an aromatic ring is also included. Further, a copolymer obtained by using a plurality of types of aliphatic side chains having different side chains and different structures or by using an unsubstituted monomer together is also used.

On the other hand, as one kind of the aromatic polyester copolymer having an aliphatic side chain, it is also possible to use one in which an amide bond or an ether bond is partially introduced into the ester bond of the main chain. Copolymerization in the main chain and / or side chain as described above can control and improve the surface characteristics of the obtained aromatic polyester, as well as control the melting temperature and the liquid crystallinity, and mechanical properties and solvent dissolution. It is effective in improving the compatibility and the miscibility with other polymers.
In any of the copolymers, the copolymerization ratio and block property, and the copolymerization ratio of the main chain portion and the side chain portion are not particularly specified as long as they have solvent solubility and / or heat melting property.

In the present invention, the bonding mode of the aromatic ring and the aliphatic chain is not particularly limited, and for example, an ether bond (—O—)
Or an ester bond (-COO-), or the one directly bonded to an aromatic ring. In the present invention, the carbon contained in the above-mentioned bond connecting the main chain and the side chain is not included in the carbon number of the side chain.

General formulas 1 to 4 are shown as examples of the chemical structure of the aromatic polyester having an aliphatic side chain in the present invention.

General formula 1

[0027]

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General formula 2

[0029]

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General formula 3

[0031]

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General formula 4

[0033]

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(X or X ₁ or X in the general formulas 1 to 4)
₂ represents an ether bond or an ester bond, R
Or R ₁ or R ₂ represents the same or different alkyl group,
Ar and Ar ¹ are the same or different aromatic rings, n and m
Represents the number of repeating units. )

Aromatic polyesters which do not exhibit solvent solubility in organic solvents or heat melting properties do not belong to the present invention. In addition, those that show only heat melting property and do not have solvent solubility are often inferior in solid surface properties because molding conditions are limited because they cannot be formed into a coating film or film by a method using a solution. . On the other hand, those exhibiting melted liquid crystallinity have excellent characteristics because they can be easily melt-molded and orientation is controlled.

The aromatic polyester having an aliphatic side chain according to the present invention is a solid having more excellent water repellency and lower surface free energy than those having a linear aliphatic side chain conventionally synthesized. It is particularly excellent in the surface properties of films, coating films or molded products.

[0037]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 0.1 mol of pyromellitic dianhydride and 0.2 mol of neopentyl alcohol were stirred in a dry inert gas atmosphere while slowly raising the temperature to 150 ° C. and stirring for 45 minutes. Held After cooling, 300 mL of a toluene / acetone mixed solution was added, and the mixture was stirred for 12 hours and then filtered. The filtrate was washed with hexane to obtain a para-dicarboxylic acid monomer having two aliphatic side chains.

To 0.05 mole of the obtained monomer, 10 times mole of thionyl chloride and 80 mL of tetrahydrofuran were added, and the mixture was refluxed at 80 to 90 ° C. for 20 minutes, and then tetrahydrofuran and excess thionyl chloride were removed to obtain the above-mentioned product. Monomer chloride was obtained.

0.04 mol of 4,4'-biphenol and twice its equivalent amount of triethylamine were added to tetrahydrofun 30.
While vigorously stirring the solution dissolved in mL, a solution prepared by dissolving monophenol in an equimolar amount with biphenol in tetrahydrofuran was added dropwise. After the solution became viscous and the reaction was completed, the solution was added to 500 mL of methanol to precipitate a polymer, which was then filtered, and dissolved and reprecipitated using a tetrahydrofuran solvent and methanol, and finally with methanol. After washing, it was dried to obtain a polymer.

By the above method, R ₁ = R ₂ =
CH ₂ C (CH ₃ ) ₃ , X = ester bond, Ar = 4
An aromatic polyester having 2 aliphatic side chains per repeating unit structure, which is 4′-biphenyl, was obtained. In ¹ H-NMR measurement of the obtained polymer, main chain hydrogen was observed at 7.4 ppm, 7.7 ppm and 8.3 ppm, and side chain hydrogen was observed at 1.0 ppm and 4.1 ppm.

The obtained polymer was dissolved in chloroform and N-methylpyrrolidone. In addition, it is 25
It became a molten liquid crystal at 0 ° C. (Tm) and became an isotropic melt at 315 ° C. (Ti). Polymer-0.1 g, chloroform 1
After dissolving in 0 ml, it was cast on a glass substrate and a polymer film was obtained by a solvent casting method. The film was vacuum dried at room temperature.

The obtained film was transparent and homogeneous, and its surface characteristics were measured by a contact angle measuring device (F, manufactured by Kyowa Interface Science Co., Ltd.).
ACE contact angle meter CA-X type) was used to measure water, diiodomethane, and ethylene glycol. The water contact angle was 90.6 degrees, and the surface free energy was 37.5 mN.
Was / m.

(Examples 2 and 3) Neopentyl alcohol
Aliphatic side chain having a branched structure in the side chain in the same manner as in Example 1 except that isopropyl alcohol (Example 2) and 2 ethyl 1-butanol (Example 3) are used in place of the vinyl group. An aromatic polyester having

All the obtained polymers were dissolved in chloroform. Further, in the temperature rising heating, a molten liquid crystal is formed at 162 ° C. (Example 2) and 174 ° C. (Example 3), respectively.
It became an isotropic melt at 22 ° C. (Example 2) and 212 ° C. (Example 3). After dissolving 0.1 g of each polymer obtained in 10 ml of chloroform, it was cast on a glass substrate and a film of each polymer was obtained by a solvent casting method. The film was vacuum dried at room temperature. Both films obtained were translucent and homogeneous. Table 1 shows the results of measuring the surface characteristics of the film.

[0046]

[Table 1]

Comparative Example 1 Example 1 was repeated except that 1-pentanol was used instead of neopentyl alcohol.
An aromatic polyester having an aliphatic side chain with a linear structure was obtained in the same manner as in. The obtained polymer was dissolved in chloroform and N-methylpyrrolidone. Further, in the heating by heating, it became a molten liquid crystal at 215 ° C. and became an isotropic melt at 249 ° C. Polymer-0.1 g chloroform 10 ml
Then, it was cast on a glass substrate and a polymer film was obtained by a solvent casting method. The film was vacuum dried at room temperature. The obtained film was transparent and homogeneous, and the results of its surface property measurement are shown in Table 1.

(Example 4) While stirring 0.1 mol of trimellitic anhydride and 0.1 mol of 1-hexadecanol in a dry inert gas atmosphere, slowly raise the temperature to 150 ° C and stir for 45 minutes. , Held. After cooling, 200 mL of acetone was added, and the mixture was stirred for 12 hours and then filtered. The filtered product was washed with methylene chloride to obtain a para-form dicarboxylic acid monomer in which one aliphatic side chain having 16 carbon atoms was introduced into the para-phenylene ring.

10 moles of thionyl chloride and 80 mL of tetrahydrofuran were added to 0.05 mole of the obtained monomer, the mixture was refluxed at 80 to 90 ° C. for 20 minutes, and then the tetrahydrofuran and excess thionyl chloride were removed. Of chloride was obtained. A solution prepared by dissolving 0.02 mol of 4,4'-biphenol and twice its equivalent amount of triethylamine in 30 mL of tetrahydrofun, while strongly stirring the solution, and dissolving an equivalent amount of biphenol and monomer chloride in tetrahydrofuran. Was dripped.

After the solution became viscous and the reaction was completed, the solution was added to 500 mL of methanol to precipitate the polymer, which was then filtered and dissolved and reprecipitated using a tetrahydrofuran solvent and methanol. The polymer was washed with methanol and dried to obtain a polymer. By the above method,
In the general formula 2, R = (CH ₂ ) ₁₅ CH ₃ , X = ester bond,
An aromatic polyester having one aliphatic side chain per repeating unit structure with Ar = 4,4′-biphenyl was obtained.

Here, the side chain is bonded to the main chain aromatic ring by an ester bond. The polymer obtained was chloroform, N-
Dissolved in methylpyrrolidone. Also, in heating by heating, 2
It became a molten liquid crystal at 30 ° C. (Tm) and became an isotropic melt at 260 ° C. (Ti). After dissolving 0.1 g of the polymer in 10 ml of chloroform, the polymer was cast on a glass substrate to obtain a film by a solvent casting method. The film was vacuum dried at room temperature. The resulting film was translucent and homogeneous.
As a result of measuring the surface characteristics of the film, the water contact angle was 89.
At 8 degrees, the surface free energy was 35.9 mN / m.

Example 5 Using 1-dodecanol instead of neopentyl alcohol and toluene /
A chloride of a para-form dicarboxylic acid monomer having two side chains having 12 carbon atoms was obtained in the same manner as in Example 1 except that methylene chloride was used instead of the acetone mixed solution.

On the other hand, diethyl 2,5-dihydroxyterephthalate was used as the diole monomer. A solution prepared by dissolving 0.02 mol of the above-mentioned monomer chloride in tetrahydrofuran was prepared by adding 0.02 mol of the above-mentioned diol monomer and 2 times its equivalent amount of triethylamine to tetrahydrofunn 30.
The solution dissolved in mL was added dropwise with vigorous stirring. After the solution became viscous and the reaction was completed, the solution was heated to 500 m.
The polymer was precipitated by adding it to L of methanol, followed by filtration, repeating dissolution and reprecipitation using a tetrahydrofuran solvent and methanol, and finally washing with methanol and drying to obtain a polymer.

By the above method, R in the general formula 3 is obtained.₁= (C
H_Two)₁₁CH_Three, R_Two= CH_TwoCH_Three, X ₁= X_Two= Ester
Bonding, aliphatic side chains attached to all aromatic rings in the main chain
Has 4 aliphatic side chains per repeating unit structure
Aromatic polyester was obtained. The polymer obtained is black.
It was dissolved in loform, acetone and N-methylpyrrolidone.
0.1 g of the polymer was dissolved in 10 ml of chloroform.
After casting, cast it on a glass substrate and cast it by the solvent casting method.
A film of the limer was obtained. The film is dried at room temperature
Was. The obtained film is transparent and homogeneous, and its surface characteristics
As a result, the water contact angle was 96.1 degrees, and the free surface
The energy was 35.5 mN / m.

Example 6 Two aliphatic side chains of the same length were introduced into all the aromatic rings in the main chain in the same manner as in Example 5, except that ethanol was used instead of 1-dodecanol. , In the general formula 3, R ₁ = R ₂ = CH ₂ CH ₃ , X ₁ = X ₂ =
An aromatic polyester, which is an ester bond, was synthesized.
The obtained polymer was dissolved in chloroform, acetone and N-methylpyrrolidone. In addition, the temperature rises to 257
It became a molten liquid crystal at ℃ (Tm) and became an isotropic melt at 319 ° C (Ti).

0.1 g of the polymer was added to 10 ml of chloroform.
After dissolving in ml, it was cast on a glass substrate to obtain a polymer film by a solvent casting method. The film was dried at room temperature. The obtained film was transparent and homogeneous, and its surface characteristics were measured. As a result, the water contact angle was 88.5 degrees and the surface free energy was 47.1 mN / m.

Example 7 0.1 mol of pyromellitic dianhydride and 0.2 mol of 1-dodecanol were slowly heated to 150 ° C. while stirring in a dry inert gas atmosphere, and kept stirring for 45 minutes. After cooling, 300 mL of dichloromethane was added, and the mixture was stirred for 12 hours and then filtered. The filtered product was washed with dichloromethane several times to obtain a para-form dicarboxylic acid monomer into which two C12 aliphatic side chains were introduced.

After the solvent is distilled off from the filtrate, it is washed with an acetone / hexane mixed solution and separated. This was repeated several times, and the solvent was finally distilled off from the filtrate, followed by washing with hexane to obtain a meta-form dicarboxylic acid monomer having two aliphatic side chains having 12 carbon atoms. To each of the resulting monomers, 0.05 mol of thionyl chloride and 8 mol
Add 0 mL of tetrahydrofuran at 80-90 ° C for 2
After refluxing for 0 minutes, tetrahydrofuran and excess thionyl chloride were removed to obtain chlorides of the para-form monomer and meta-form monomer.

0.04 mol of 4,4'-biphenol and twice its equivalent amount of triethylamine were added to tetrahydrofun 30.
While vigorously stirring the solution dissolved in mL, 0.016 mol of para-form monomer-chloride and 0.0-form of meta-form monomer-chloride.
A solution prepared by dissolving 04 mol in 10 mL of tetrahydrofuran was added dropwise. After the solution becomes viscous and the reaction is complete,
The solution was added to 500 mL of methanol to precipitate a polymer, which was then filtered, repeatedly dissolved and reprecipitated using a tetrahydrofuran solvent and methanol, and finally washed with methanol and dried to obtain a polymer.

By the above method, R ₁ = R ₂ =
(CH ₂ ) ₁₁ CH ₃ , X ₁ = X ₂ = ester bond, and n /
(M + n) = 0.2 and Ar = Ar '= 4,4'-
An aromatic polyester copolymer which is biphenyl was obtained. The obtained polymer was dissolved in chloroform. Also, when heated to a temperature of 85 ° C (Tm), it becomes a liquid crystal and melts.
It became an isotropic melt at 3 ° C (Ti).

0.1 g of polymer was added to 10 m of chloroform.
After dissolving in 1 l, it was cast on a glass substrate to obtain a polymer film by a solvent casting method. The film was dried at room temperature. The obtained film was homogeneous and transparent, and its surface characteristics are shown in Table 1.

Example 8 0.01 mol of para-form dicarboxylic acid monomer chloride having an aliphatic side chain having 12 carbon atoms and 0.01 mol of meta-form dicarboxylic acid monomer chloride.
In the same manner as in Example 7 except that a mole is used, R
₁ = R ₂ = (CH ₂ ) ₁₁ CH ₃ , X ₁ = X ₂ = ester bond,
And n / (m + n) = 0.5, Ar = Ar ′ =
An aromatic polyester copolymer which is 4,4′-biphenyl was obtained.

The obtained polymer was dissolved in chloroform, acetone and N-methylpyrrolidone. Further, in the heating by heating, it becomes an isotropic melt at about 60 ° C. (Ti), but before that, a temperature range showing optical anisotropy was observed. The polymer-0.
After dissolving 1 g in 10 ml of chloroform, the solution was cast on a glass substrate and a polymer film was obtained by a solvent casting method. The film was dried at room temperature. The obtained film was homogeneous and transparent, and its surface characteristics are shown in Table 1.

Example 9 In the same manner as in Example 7 except that 1-pentanol was used as the alcohol and n / (n + m) = 0.75, R ₁ =
R ₂ = (CH ₂ ) ₄ CH ₃ , X ₁ = X ₂ = ester bond, and n / (m + n) = 0.75, Ar = Ar ′ = 4.
An aromatic polyester copolymer which is 4'-biphenyl was obtained. The obtained polymer is chloroform, acetone, N.
-Dissolved in methylpyrrolidone and 4
It became an isotropic melt at 8 ° C. (Ti) and showed no liquid crystallinity.

0.1 g of the polymer was mixed with 10 ml of chloroform.
After dissolving in ml, it was cast on a glass substrate and a polymer film was obtained by a solvent casting method. The film was dried at room temperature. The obtained film was homogeneous and transparent, and its surface characteristics are shown in Table 1.

(Example 10) Use of 1-octanol as an alcohol, n / (n + m) = 1.0 (that is, all meta-dicarboxylic acid monomers are used as side chain-containing monomers). Otherwise in the same manner as in Example 7, R ₂ = (CH ₂ ) ₇ CH ₃ , X ₂ = ester bond, and n / (m + n) = 1 (that is, m = 0) in General Formula 4, and Ar An aromatic polyester with '= 4,4'-biphenyl was obtained.

The obtained polymer was dissolved in chloroform, acetone, and N-methylpyrrolidone, and became an isotropic melt at 48 ° C. (Ti) by heating at elevated temperature, showing no molten liquid crystallinity. After dissolving 0.1 g of the obtained polymer in 10 ml of chloroform, it was cast on a glass substrate and a polymer film was obtained by a solvent casting method. The film was dried at room temperature. The obtained film was homogeneous and transparent, and its surface characteristics are shown in Table 1.

[0068]

EFFECT OF THE INVENTION Aromatic in which an aliphatic side chain is bonded to an aromatic ring of the main chain, which is characterized in that the branched structure and the number of side chain bonds, the main chain structure and the side chain substitution are copolymers according to the present invention Polyester has solvent solubility, heat melting property or melt liquid crystal property,
It has excellent solid surface characteristics, especially high contact angle with water and low surface energy.

[Brief description of drawings]

FIG. 1 Number of side chain terminal methyl groups and surface free energy γ
It is a figure which shows the relationship with (mN / m).

Claims (7)

[Claims] 1. A solvent-soluble and / or heat-meltable resin, wherein a main chain has a wholly aromatic polyester structure, and an aliphatic side chain having a branched structure is bonded to at least a part of aromatic rings in the main chain. Aromatic polyester having branched aliphatic side chains with properties. 2. The aromatic polyester having a branched aliphatic side chain according to claim 1, wherein the terminal of the aliphatic side chain is a neopentyl group or an isopropyl group. 3. A branched aliphatic side chain having 4 to 30 carbon atoms,
The aromatic polyester having a branched aliphatic side chain according to claim 1, wherein one or more units are bonded per repeating structural unit of the main chain. 4. The branched aliphatic side chain according to claim 1, wherein one or more aliphatic side chains are bonded to all aromatic rings in the main chain. Aromatic polyester. 5. The main chain structure and / or the branched aliphatic side chain is
An aromatic polyester having a branched aliphatic side chain according to any one of claims 1 to 4, which is a copolymer. 6. The aromatic polyester having a branched aliphatic side chain according to any one of claims 1 to 4, which has a metaphenylene ring in at least a part of the main chain structure. 7. The aromatic polyester having a branched aliphatic side chain according to any one of claims 1 to 4, which exhibits a melt liquid crystallinity.