JPH0593053A - Liquid crystalline polyester and its production - Google Patents

Abstract

(57) [Summary] [Structure] A liquid crystalline polyester comprising a dicarboxylic acid unit, a diol unit and an oxybenzoic acid unit, in which the sequence is controlled so that the number of oxybenzoic acid chains is small. [Effect] Compared with conventional polyester, mechanical properties are improved and moldability is facilitated. The mechanical properties were further improved by further containing m-oxybenzoic acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel liquid crystalline polyester having a more alternately controlled sequence and a method for producing the same. The liquid crystalline polyester of the present invention has a high elastic modulus, a high tensile strength, a bending strength, an impact strength and the like, and further has a high elongation, and thus has toughness. It is superior not only to mechanical properties but also to heat resistance.
The liquid crystal polyester of the present invention can exhibit these characteristics because it forms a thermotropic liquid crystal at the time of molding and the sequence is controlled more alternately. Further, it has a feature that it shows high fluidity even at a lower temperature side than the conventional one with the same composition and the same composition ratio. Therefore, it is very useful as a product such as a molding material, a film, and a fiber.

In particular, the molding material is suitable for automobile parts, electric and electronic parts, thin molded products and precision molded products. In addition, since the difference between the solid heat-resistant temperature and the temperature at which it can be sufficiently melted is small, there is an advantage in polymerization that it can be polymerized at a low temperature despite its high heat resistance.

[0003]

2. Description of the Related Art In recent years, there has been an increasing demand for materials having excellent rigidity, strength, elongation and heat resistance, regardless of whether they are fibers, films or molded products. Polyester has been widely recognized as a general molded product. However, many polyesters are inferior in flexural modulus and flexural strength, and thus are not suitable for use in which high elastic modulus and high strength are required.

In recent years, liquid crystalline polyester has been attracting attention as a polyester suitable for applications requiring high elastic modulus and high strength. The Journal of Polymer Science
Polymer Chemistry Edition Volume 14 (197
6 years) 2043 pages, USP3,778,410, USP
3,804,805 and Japanese Patent Publication No. 56-18016. J. Only after Jackson et al. Announced a thermal liquid crystal polymer composed of polyethylene terephthalate and acetoxybenzoic acid. Among them, Jackson et al. Found that this liquid crystal polymer has a rigidity of 5 times or more that of polyethylene terephthalate.
It was reported that it exhibits more than double the strength and more than 25 times the impact strength, and shows a new possibility for high performance resin.

However, the polymer of Jackson et al. Has the drawback of being very brittle and having low strength and elongation. It is considered that this is mainly because the ratio of the chain of p-oxybenzoic acid units represented by the following formula is very large.

[0006]

[Chemical 11]

Further, it is considered that the melting point, the softening point, etc. vary depending on the ratio of the chain. On the other hand, there are many reports on molding processing conditions using the polymer of Jackson et al. (For example, JA Cuculo et al., Jour.
nal of Polymer Science. Ph
physical Edition 26 179 (198)
8)) According to this report, the higher the molding temperature, the higher the elastic modulus, and the reason for this is that unmelted material exists on the low temperature side and gives defects to the higher-order structure of the molded product. .. (This indicates that the liquid crystal state is only partially taken.) This is probably because the sequence and its distribution, and the composition distribution are widely distributed, that is, the non-uniformity is large. ..

This means that unless the molding temperature is raised for the heat resistance of the solid, high-performance physical properties cannot be exhibited, and the original liquid crystallinity is not sufficiently exhibited unless the temperature is high. It is shown that, on the low temperature side, that is, near the melting start point and a temperature slightly higher than the melting start point, the fluidity also deteriorates, making it impossible to perform thin molding, which is a characteristic of liquid crystalline polymers.

[0009]

The present applicants have previously found a copolyester which improves the elongation at break of the polyester developed by Jackson et al.
0-186527). The idea there is to reduce the chain of p-oxybenzoic acid units described above,
This is the origin of the attempt to reduce the chain.

However, JP-A-60-186527
According to the production method in JP-A No. 60-186525 and a production method as disclosed in JP-A-60-186525, only a random polymer can be produced even though the first step is made so that p-oxybenzoic acid is not chained. There was a large difference between the temperature at which the temperature was low and at which the heat resistance when solid was maintained, and the temperature at which it could flow sufficiently.

According to Japanese Unexamined Patent Publication (Kokai) No. 64-26632, the liquid crystalline polyester obtained by the above-mentioned method by Jackson et al. Is a polymer having a high blocking property formed by block-polymerizing p-oxybenzoic acid (the above-mentioned. It is said that it was attempted to improve the physical properties by randomizing by a two-step polymerization method because the physical properties and the like are deteriorated by the formation of high chain fraction).

However, according to additional tests, the polyester produced by this method also has a high heat resistance, but has a high melt viscosity and considerably deteriorates fluidity, and its mechanical properties such as strength and elongation are not so good. This is p-
This is probably because oxybenzoic acid was polymerized only randomly.

Further, Japanese Patent Laid-Open No. 2-45524 discloses a method of adding p-hydroxybenzoic acid and acetic anhydride or p-acetoxybenzoic acid continuously or in a divided manner. Polyethylene terephthalate constitutional unit shown below

[0014]

[Chemical formula 12]

When the ratio of is 80:20 (molar ratio), H
DT is only 150 ℃, melt viscosity at 318 ℃ is 77
Only 0 Poise and a method which is less favorable than the method according to JP-A-64-26632 are obtained (JP-A-2-4552).
(See the description in Example 1 of No. 4). Furthermore, we have found a copolyester which suppresses the formation of insoluble and infusible particles (Japanese Patent Laid-Open No. 62-42121).

However, this polyester may be inferior in heat resistance and may be unsuitable for engineering plastics. Also, USP 3,8
No. 90,256 discloses a polyester that improves abrasion resistance, and this polyester is also disclosed in Japanese Examined Patent Publication No. 56-18.
Because of the same method as in No. 016, a chain of p-oxybenzoic acid units was likely to be formed. Therefore, insoluble and infusible particles are likely to be formed, and thus the breaking elongation of the obtained polymer tends to be low and fragile.

In many cases, the heat resistance was poor because the amount of the copolymerization component was too large. Further, according to the above-mentioned US Pat. No. 3,804,805 by Jackson et al., There is an example in which an m-oxybenzoic acid unit is introduced, but according to additional tests, the heat resistance is poor and the mechanical properties are not sufficient. Further, JP-A-62-267323, 62-285916, 63-09.
9227 and the like also describe that it contains an m-oxybenzoic acid unit, but this method is essentially USP 3,804,8.
Only a polymer similar to the polymer of No. 05 is obtained, and the heat resistance and mechanical properties are not sufficient.

Japanese Unexamined Patent Publication (Kokai) No. 52-121095 describes a method using diphenyl carbonate. However, this method can only produce the same characteristics as those described above, and the heat resistance and mechanical characteristics are not sufficient. .. In addition, JP-A-63-
In 317524, a method of improving elongation and improving anisotropy of physical properties in a system using an aliphatic diol other than ethylene glycol, etc. is considered. Regarding the method for further improving the effect (especially improvement of elongation),
No suggestions have been made.

Therefore, the present inventors mainly

[0020]

[Chemical 13]

A liquid crystal polyester comprising the constitutional unit of
In addition, it has high tensile strength, bending strength, impact strength, etc., high elongation at break and excellent heat resistance, and also excellent heat resistance in solid state, but when it starts flowing, it has very good fluidity by just raising it to a slightly high temperature. (In order to do so, if it is in a solid state and shows heat resistance up to a certain temperature T _1, and if it shows very excellent fluidity at the temperature at T ₂ , T ₁ is as high as possible,
₂ -T ₁ may be as small as possible. ), Therefore, it is excellent in moldability, and even if it is a copolymer, it exhibits high crystallinity in the solid state to improve mechanical properties, improve hydrolysis resistance, filler, etc. I think that there is a system that can be able to significantly improve the mechanical properties and thermal properties when mixed with
We thought that it was to control the sequence and compositional distribution, and more specifically, to make the alternate sequence as described later.

As a result, a method for producing a liquid crystalline polyester having the above characteristics was found (Japanese Patent Application No. 2-91640).
issue). However, the polyester of Japanese Patent Application No. 2-91640 has not yet had sufficient mechanical properties.

[0023]

Accordingly, the inventors of the present invention have made earnest studies to develop a polyester having better mechanical properties than the above polyester, and as a result, m-, which is a Kink component, has been added.
Oxybenzoic acid unit

[0024]

[Chemical 14]

We have found that the strength and the elongation at break are further improved by introducing the above-mentioned substances, and have reached the present invention. That is: 1) Statistical alternating oxybenzoic acid units. 2) Introducing a m-oxybenzoic acid unit as a Kink component, particularly as a Kink component. The present invention was reached by combining these two elements.

That is, the gist of the present invention is the following formula (1):
A dicarboxylic acid unit represented by

Embedded image —CO—R ¹ —CO— (1) (In the formula, R ¹ represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.) A diol represented by the following formula (2) unit,

Embedded image —OCH ₂ CH ₂ O— (2) and an oxybenzoic acid unit represented by the following formula (3)

[0027]

[Chemical 17]

Is a polyester (formula (3) represents a unit of the following formula (4) or a unit of (5)),
A liquid crystalline polyester which satisfies the following conditions (1) to (3).

[0029]

[Chemical 18]

The above structural units (1), (2),
The number of moles of each of (3), (4), and (5) [1],
[2], [3], [4], and [5] satisfy the following formulas (I) and (II).

## EQU6 ## 0.65 ≦ [3] / ([1] + [3]) ≦ 0.88 (I) 0.02 ≦ [5] / ([4] + [5]) ≦ 0.15 ( II) Of the oxybenzoic acid units represented by formula (3),
An oxybenzoic acid unit in which a diol unit represented by the formula (2) is present next to the carbonyl group (—CO—) side is (3-1),

[0031]

[Chemical 19]

Then, the number of moles of (3-1) is [3-1]
Then, the following formula (III)

[0033]

[Equation 7]

R ₃ defined by 0 ≦ r ₃ ≦ 0.
It should be in the range of 88. The solution viscosity measured in p-chlorophenol / o-dichlorobenzene (30 ° C., concentration: 0.5 g / dl) is 0.4 dl / g or more. Incidentally, statistically alternating oxybenzoic acid units means that p-oxybenzoic acid units are statistically alternating (that is, the fraction of the chain of p-oxybenzoic acid units is smaller than random) in the true sense. However, since the amount of the m-oxybenzoic acid unit component is smaller than that of the p-oxybenzoic acid unit, the amount of the chain containing the m-oxybenzoic acid unit as shown below is extremely small.

[0035]

[Chemical 20]

Also, in terms of analysis, these chains are linked to the above-mentioned p
Since it is not possible to distinguish it from the chain of the oxybenzoic acid unit at this time, these are collectively expressed as the following general formula.

[0037]

[Chemical 21]

That is, the fact that the above-mentioned oxybenzoic acid units (3) are alternating roughly corresponds to the fact that the p-oxybenzoic acid units are alternating.
Hereinafter, the present invention will be described in detail. The characteristic feature of the liquid crystalline polyester of the present invention is that it has high strength and high elongation at break, so it is a tough polymer, and further has the same composition and heat resistance in a very excellent solid state in the same composition ratio. Further, since the above-mentioned T ₂ −T ₁ is extremely small, it has a characteristic that it can be molded at a low temperature, and in general, it is said that molding at a low temperature, that is, a temperature slightly higher than the melting point is superior in mechanical properties. It has characteristics.

Further, since these liquid crystalline polyesters show high crystallinity in the solid state, they are characterized in that they are improved in hydrolysis resistance and, when mixed with a filler or the like, mechanical properties and thermal properties can be improved. The reason why such a liquid crystalline polyester has been developed is that it was studied based on the following ideas.

That is, in producing a polymer mainly composed of a dicarboxylic acid unit, a diol unit, a p-oxybenzoic acid unit and a m-oxybenzoic acid unit, it is achieved by minimizing the number of chains of the p-oxybenzoic acid unit. I thought I could do it. JP-A-60-186527, which is an improvement of the conventional liquid crystalline polyester of Jackson et al.,
In JP-A-64-26632 and JP-A-2-45524, although the heat resistance and the mechanical properties are improved, they are random in that the p-oxybenzoic acid unit was block-wise present in the polymer. It was only done, and its randomness was qualitative, and its measure of randomness was not quantified.

The present inventors cannot satisfy all the above-mentioned physical properties if the above components are randomly present in the polymer, and that they can be achieved by allowing them to exist statistically alternately. Found. That is, the liquid crystalline polyester of the present invention has the following formula (III)

[0042]

[Equation 8]

When the parameter r ₃ (sequence generation ratio) defined by is used, r ₃ is 0 ≦ r ₃ ≦
It is necessary to satisfy 0.88.

Here, {([3] -2 × [2]) /
When [3]} is set to [A], r ₃ is preferably [A] ≦ r ₃ ≦ 0.85, and more preferably,

[A] + 0.2 × [2] / [3] ≦ r ₃ ≦ 0.83, particularly preferably [A] + 0.4 × [2] / [3] ≦ r ₃ ≦ 0. 80, most preferably [A] + 0.6 × [2] / [3] ≦ r ₃ ≦ 0.76.

However, as described above, [3]> 2 × [2]
For, although the right to the [A] ≦ r _3, considering the error of the calculated, more preferably keep the [A] -0.03 ≦ r _3. The meanings of these are described below. Regarding the derivation of the formula (V), see B. Volme
rt, Polymer Chemistry; Spr
inger-Verlag: NY 1973P. 117
~ P. It carried out based on the description of 123.

To specifically describe the meaning of the above formula, next to the carbonyl side of the sequence of the oxybenzoic acid unit represented by the formula (3), a dotted line is shown in the following formulas (a) and (b). As described above, it is considered that two different types of units can be connected. The following formula (a) shows a case where the above-mentioned oxybenzoic acid unit is a chain, and the following formula (b)
Is the same as the oxybenzoic acid unit (3-1) in which a diol unit is present next to the carbonyl group side.

[0047]

[Chemical formula 22]

In the formulas (a) and (b), if the number of moles of the unit corresponding to the underlined portion is [a], [b],
[3] ≈ [a] + [b] (where [3] = [4] +
[5]). However, there are terminal groups, etc., or the acid anhydride bond represented by the following formula in the main chain

[0049]

[Chemical formula 23]

Or

Embedded image Since there may be a bond represented by —CO—R ¹ —CO—O—CH ₂ CH ₂ O—, the right and left sides of the above formula are not necessarily equal. In addition, the expression that actually has meaning is

[0051]

[Equation 10]

However, in the analytical method for determining r ₃ described later, [a] = [4] − [b] is assumed because [b] and [3] are obtained instead of [a]. The formula (IV) is represented by the formula (III) described above for convenience.
The ratio of (1), (2) and (3) will be described later,
In the formula (III), the value obtained by the NMR method of the product after amine decomposition was adopted.

The ratios of (1), (2) and (3) can be determined by a gas chromatography method after methanol decomposition, and show good agreement with the NMR method. Next, the meaning of r ₃ will be described. Generally, there is a concept of a monomer reactivity ratio at the time of producing a polymer copolymer. In that case, there are two kinds of monomers M ₁ and M ₂ , and the probability that the monomer M ₁ enters next to the active species to M ₁ * is W _11, and the concentration of M ₁ and M ₂ is [M
₁ ] and [M ₂ ], the following general formula

[0054]

[Equation 11]

It is represented by (Where R ₁ = k ₁₁ / k
₁₂ ; k ₁₁ is a reaction rate constant in which M ₁ enters next to ˜M ₁ *.
k ₁₂ is a reaction rate constant in which M ₂ enters next to ˜M ₁ *). Therefore, R ₁ is the ratio of reaction rate constants in which M ₁ or M ₂ enters after next to ˜M ₁ *. In general, W ₁₁ may be obtained by analyzing a polymer, and in the case of vinyl compound chain polymerization, R ₁ may be obtained from the monomer consumption (or composition ratio in the polymer).

In the case of the reaction system of the present invention, since it is a sequential reaction and it is necessary to consider side reactions such as transesterification, the monomer reactivity ratio R ₁ immediately determines the composition and sequence of the polymer. It's not a thing, but it's possible to think in a similar way. That is, the reactivity ratio of the monomer is unknown, but if W ₁₁ can be determined from the polymer,
It is thought that it can determine the generation rate of the sequence. That is, W ₁₁ is [M ₁ −M ₁ ] / [M
₁ ] can be replaced. (Note that [M ₁ -M _1]
It indicates the concentration with M ₁ next to M _1. ) Then, the present inventors newly named r ₃ as the sequence generation ratio, and expressed the same as the above equation.

[0057]

[Equation 12]

Was used to define r ₃ . In the above formula, [a] / [3] represents the ratio of the oxybenzoic acid units represented by the general formula (3) to the chain represented by the general formula (a), that is, the probability. ing.

In consideration of the above matters, and as described above, from the analytical problem, it is assumed that [a] = [3]-[b], and the above equation (III) is obtained, whereby r ₃ is calculated. Did
[B] = [3-1]). In addition, in this case, originally, r ₃ should be calculated based on the ratio of the chains of p-oxybenzoic acid, but the chain of oxybenzoic acids containing m-oxybenzoic acid is at present the p-oxybenzoic acid Is difficult to distinguish analytically from the chain of p-oxybenzoic acid, and the proportion of the chain containing m-oxybenzoic acid is considered to be extremely low due to the small amount of m-oxybenzoic acid units. The chain ratio was replaced with the chain ratio of oxybenzoic acid represented by the general formula (a) to calculate r ₃ .

[3]-[3-1] / in the formula (III)
[3] represents the ratio of the above-mentioned oxybenzoic acid unit (3) excluding the unit having the structure represented by the formula (3-1), that is, the probability. here,
Regarding the structure shown below, the unit forming the structure (3-1) is considered to be an underlined part, that is, twice.

[0061]

[Chemical 25]

When r ₃ > 1, (3) has a block-like sequence with respect to (2), and the larger the value of r ₃ , the higher the blocking property. That is, it means that the ratio of the chain of oxybenzoic acid units becomes large. r ₃ ≈ 1
(3) has a random sequence with respect to (2), which means that the ratio of the oxybenzoic acid chain in the polymer to (3) is the sum of (3) and (2) as the total composition. It means that it is almost the same as the composition ratio of (3) at the time.

When r ₃ <1, the chain ratio of oxybenzoic acid becomes smaller. That is, (3) means alternating with (2), and it means that the smaller r ₃ is, the more alternating. When r ₃ = 0, it means that a chain of oxybenzoic acid is not formed. However, when the ratio of (3) increases, that is, [3]>
When 2 × [2], r ₃ is substantially

## EQU13 ## r ₃ ≧ {[3] -2 × [2]} / [3].

[0064]

When r ₃ = {[3] -2 × [2]} / [3], it can be said to be an ideal alternating copolymer in a sense. From the opposite side, when r ₃ > 1,

Embedded image It means that the fraction of the sequence of —CO—R ¹ —CO—O—CH ₂ CH ₂ —O— (14) is large, and r ₃ ≈
When it is 1, it means that the sequence of (14) is only a statistically random fraction, and when r ₃ <1, it means that the sequence of (14) is decreasing.

That is, the conventional liquid crystal polyester having the same composition and composition ratio is (1)
It can be said that the sequence of 4) is increasing. This is because it is difficult to reduce the sequence (14) by the conventional manufacturing method. An oxybenzoic acid unit in which an oxybenzoic acid unit is present next to the ether side of the oxybenzoic acid unit (3-2), which cannot be measured due to analytical problems, and a dicarboxylic acid of (1) next to the ether side Oxybenzoic acid unit in which the unit exists (3-3)

[0066]

[Chemical 27]

[3-2]
[3-3],

[0068]

[Equation 15]

Since r ₁ defined by is r ₃ ≈r ₁ , the polymer of the present invention can be said to be a polymer satisfying 0 ≦ r ₁ ≦ 0.88. In this case r
_{With 1} > 1, (3) has a block-like sequence with respect to (1), and the larger the r ₁ value, the higher the blockiness. That is, it means that the ratio of (3-2) becomes large.

When r ₁ ≈1, (3) has a random sequence with respect to (1), and the ratio of (3-2) to (3) in the polymer is (3) and (1). It means that it is the same as the composition ratio of (3) when () is the entire composition. Further, when r ₁ <1, the ratio of (3-2) becomes smaller. That is, (3) means alternating with (1), and it means that the smaller r ₁ is, the more alternating. When r ₁ = 0, (3-2) means not generated.

In the case of the liquid crystalline polyester of Jackson et al., The fact that (3) is blocky with respect to (1) means that V. A. Nicel
y, et al. (Macromoleculecu
les 20 573 (1987)). In terms of the method of the present invention, Nicoly et al.

[0072]

[Equation 16]

It is judged whether or not it is a block by whether or not m is larger than 1 using the equation The meaning of this is to judge whether the ratio of (3-2) is larger or smaller than the composition ratio of (3) when (3) and (1) are taken as a whole, but the polymer of Jackson et al. m = 1.
3 and proved to be blocky. (However, they are {([1] + [3]) / [3]}
Only measured up to ≤0.7. We have
{([1] + [3]) / [3]}> 0.7 was also measured, but it was still blocky. ) JP-A-60-186
527, JP-A 64-26632, and JP-A 2-45.
No. 524 and the like are also random. This is clear from the comparative example described in Japanese Patent Application No. 23-91640.

Incidentally, JP-A 64-26632 and JP-A-2
No. -45524 is a system in which m-oxybenzoic acid units are included. In addition to the system of the present invention, there is an example in which the difference in the melt between the completely alternating system and the non-alternating system is examined (SI Stupp et al., Ma.
cromolecules 21 1228 (198
8)).

Certainly, in the alternating system, the width of transition from solid to liquid crystal is narrow. However, since the alternating system in this paper synthesizes monomers sequentially, it is very difficult to synthesize the monomers, and the mechanical properties of the synthesized products have not been investigated. Now, returning to the present theory, in the present invention, the above r ₃
Needs to satisfy 0 ≦ r ₃ ≦ 0.88, and by satisfying this,
The liquid crystalline polyester of the present invention has the following features.

1. Has high tensile strength and bending strength. 2. Has high impact strength. 3. It has a high elongation at break. 4. Higher heat resistance than other polymers with the same composition and composition ratio. 5. The molding temperature can be lowered because T ₂ -T ₁ is small. 6. Molded products at lower temperatures have better mechanical properties. 7. The apparent activation energy of melt viscosity is small. 8. High crystallinity. 9. Good hydrolysis resistance. 10. The effect of mixing the filler and the like is remarkable.

In particular, the physical properties of the polymer of the present invention are far superior to those of the conventional ones in the balance between mechanical properties and thermal properties. In addition, the fact that the molding temperature can be lowered despite the high heat resistance also means that the polymerization temperature during manufacturing can be lowered, meaning that a polymer with good heat resistance can be manufactured using conventional manufacturing equipment. To do. R ¹ of the dicarboxylic acid unit represented by the structural unit (1) represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and specifically,

[0078]

[Chemical 28]

[0079] (- X- is -O -, - S -, - SO 2 -,
—CH ₂ —, —C (CH ₂ ) ₂ — and the like) and the like. These may be used alone or may be mixed to form a copolymer. Of these, (a), (b), (c), (d) or (e) are preferred. When used alone, (a), (c) and (d) are preferred, with (a) or (c) being particularly preferred. Even when used as a mixture, at least one unit is (a),
It is preferable to be selected from (c) and (d), and the total of these should occupy 50% or more, particularly preferably 66% or more in terms of the molar ratio of R ¹ . Three or more of these may be used, but up to two are preferred.

Preferred mixed systems are combinations of (a) and (b), (a) and (c), (a) and (d), (d) and (b), and (d) and (c). Etc. can be mentioned. In the present invention, the ratio of the number of moles [1] and [3] of the units of the above general formulas (1) and (3) is as shown in {[3]
If / ([1] + [3]) = [B] is set, it is necessary to satisfy [B] ≧ 0.65 because of manufacturing problems. That is, in the manufacturing method of the present invention,

[0081]

[Chemical 29]

[B] ≧ 2/3 inevitably when not adding
Becomes However, the liquid crystalline polyester of the present invention can of course be produced by a method other than the production method of the present invention. However, also in that case, it is necessary to satisfy [B] ≧ 0.65. That is, [B] <
When it is 0.65, the heat resistance is lowered, which is not preferable. From the viewpoint of heat resistance, [B] ≧ 0.68 is preferable, and [B] ≧ 0.70 is more preferable. On the other hand, the upper limit is
[B] ≦ 0.88. If it is more than this, the absolute value of the chain of p-oxybenzoic acid units increases, which is not preferable.

That is, in the present invention, 0.65 ≦
[B] ≦ 0.88 is preferable, and 0.68 is more preferable.
≦ [B] ≦ 0.86, particularly preferably 0.70 ≦
[B] ≦ 0.85, most preferably 0.75 ≦ [B] ≦
It is 0.85. The ratio of [1] and [2] increases the degree of polymerization,

## EQU17 ## 0.80 ≦ [1] / [2] ≦ 1.2, preferably 0.85 ≦ [1] / [2] ≦ 1.15, more preferably 0.90 ≦ [1] /[2]≦1.10.

In order to improve the hydrolysis resistance,

[Equation 18] 0.80 ≦ [1] / [2] ≦ 1.0 is preferable.

It is preferable that 1.0 ≦ [1] / [2] ≦ 1.2.

Next, regarding the ratio of [4] and [5],
If {[5] / ([4] + [5])} = [C],
0.02 ≦ [C] ≦ 0.15, more preferably 0.
02 ≦ [C] ≦ 0.13, particularly preferably 0.02 ≦
[C] ≦ 0.08. From the viewpoint of heat resistance and crystallinity, it is preferable that the content of [5] is small. From the viewpoint of strength and elongation, [5] is preferable.

When [C] <0.02, the strength and elongation are not improved, which is not preferable, and when [C] ≧ 0.02, the strength and elongation are rapidly improved. On the other hand, [C] ≧ 0.1
No. 5 is not preferable as a molding material because the Vicat softening point is significantly lowered. The polyester in the present invention contains almost no ether component represented by the following formula described in JP-A-60-186527.

[0087]

[Chemical 30]

With a large amount of such an ether component,
The heat resistance referred to in the present invention is significantly lowered, and the crystallinity is also lowered, which is not preferable. However, even if a small amount of this ether component is present, the number of moles is not included in [3].

Here, how to obtain r ₃ will be described. This could not be determined from the NMR of conventional polymers. Therefore, the inventors of the present invention have made a diligent study and found a method for obtaining r ₃ . That is, when the liquid crystalline polyester of the system of the present invention is reacted with a primary amine, surprisingly, the ester bond of the above formula (b) is not selectively cleaved and the bond remains and other ester bonds (for example, Formula (a) above
Was found to be cleaved. By utilizing this, the sequence of the liquid crystalline polyester of the present invention can be analyzed.

This method will be described in more detail. For example, the liquid crystalline polyester of the present invention was crushed, and the crushed sample was treated with a large excess of n-propylamine at 40 ° C. for 90 minutes. Using AM-500 manufactured by BRUKER, analysis and quantification are carried out by 500 MHz ¹ H-NMR. ¹
H-NMR measurement is performed using deuterated methanol or a mixed solvent of deuterated DMSO and deuterated methanol or deuterated trifluoroacetic acid as a solvent, and the amount of the component (b) is quantified. Since the ratio of (1), (2), and (3) can be obtained by using the identified peak intensities, r ₃ was calculated using this. According to this method, information on the -CO- side sequence of the compound (3) can be obtained.

The composition ratios of (1), (2) and (3) were measured by enlarging FIGS. 1 and 2. The error is
When [1] / [3] = 20/80 (molar ratio), 20 ±
It is 0.5 / 80 ± 0.5. In this amine decomposition method, (a) and (3) are not known, but (3) and (b) are distinguished from each other. Therefore, r ₃ is exactly [3]-
It is expressed using [b].

As described above, it is considered that the more alternating polyester is uniform not only in the sequence but also in composition distribution. For example, according to the data of Vibron shown in FIGS. 2 and 3, E ′ = 3 is used as a measure of heat resistance.
A temperature showing × 10 ¹⁰ dyne / cm ² is taken, and this is taken as T ₁
And (E 'indicates the storage elastic modulus) Next, E' = 5.times.10 as the lowest temperature at which the fluid can sufficiently flow.
^As a temperature showing ⁹ dyne / cm ² , this is T _2, and
Assuming that T ₂ −T ₁ = a, only the polyester of the present invention has 0 ≦ a ≦ 90 ° C. as apparent from the figure. 0 ≦ a ≦ 85 ° C., more preferably 0 ≦ a ≦ 80 ° C.
Is to meet. The fact that a is small means that the flow temperature is low although the heat resistance in the solid state is high.

Further, in terms of mechanical characteristics, when R ^{1 in} (1) is a 1,4-phenylene group, [3] / [1] ≈80 / 2
When it is set to 0, the liquid crystalline polyester of the present invention is improved in breaking elongation and strength (tensile, bending) by about 20% or more, and a (T ₂ −T ₁ ) is smaller than that of the conventional liquid crystalline polyester. Means that it has heat resistance and can be molded at a low temperature, and at that time, since the whole is melted, its melt viscosity is extremely low. This corresponds to the fact that the sequences are alternating, that is, the value of r ₃ is small.

The fact that the structure (especially the higher-order structure) does not remain after melting indicates that the state of the structure change due to temperature change is indicated by a small angle X.
It can be clarified by tracing by the line scattering method (in addition, the change of the crystal structure can be clarified by the wide angle X-ray scattering method described below). Next, it is expected that the crystallinity will be improved in the case of the same composition ratio by the sequence becoming more alternating (that is, by making it more uniform). The degree of this can be grasped from DSC and X-ray scattering.

The presence or absence of crystals and the size and type of crystals can be compared with each other from ΔH at Tc in DSC and from the peak intensity and the value of 2θ in X-rays. In particular, when the composition ratio is the same, if molding is performed under the same molding conditions, if there is a difference in the primary structure, particularly in the sequence, it is considered that the two analysis methods can clearly show the difference. For example, when a rod is made, its wide-angle X-ray is measured, and the scattering pattern in the equatorial direction, meridian direction, etc. is examined, the polymer of the present invention has a crystalline lattice of more than that of a conventional polymer having the same composition and composition ratio. It is considered that the size is small and the spacing between crystal molecules is small.

The solution viscosity η _inh of the liquid crystalline polyester obtained in the present invention can be determined as follows.
As a solvent, p-chlorophenol / o-dichlorobenzene = 1/1 (wt ratio) was dissolved at room temperature to give a concentration of 0.5 g /
It is set to dl and measured at 30 ° C. (Calculated by the following formula.)

Η _inh = ln (t / t ₀ ) /0.5 t ₀ : Falling speed (sec) of blank (solvent only) t: Falling speed (sec) at concentration of 0.5 g / dl The polyester has a characteristic that the melt viscosity becomes small and the fluidity is improved at the same composition and composition ratio, in view of the degree of polymerization (considering the solution viscosity described above as a measure). When η _inh is less than 0.4, the mechanical properties are not good, which is not preferable. More preferably η _inh ≧
0.5, more preferably η _inh ≧ 0.6, most preferably η _inh ≧ 0.7. Further, the liquid crystal polyester of the present invention can be measured for solution viscosity by this method. That is, it is considered that the polymer having a long chain (3) does not exist because it can be dissolved substantially completely. Also, the composition distribution seems to be more uniform.

The liquid crystalline polyester obtained in the present invention is phenol / 1,1,2,2, tetrachloroethane = 1 /
It seems that there is almost nothing that is fairly uniform and has a long chain (3) because it also dissolves in a 1 wt ratio and hexafluoroisopropanol. Next, the manufacturing method will be described.

For producing a polyester satisfying 0 ≦ r ₃ ≦ 0.88, a conventional method, that is, Japanese Patent Publication No.
6-18016, JP 58-87125, JP 60-186525, JP 64-26632, JP 2-45524, JP 62-267323,
JP-A-62-285916, JP-A-63-09922
It cannot be achieved by the method of No.7.

As a method for producing a polyester in which r ₃ satisfies the above range, the present inventors separate the p-oxybenzoic acid unit at the time of the raw material in order to make it difficult to form a chain of p-oxybenzoic acid. I.e.

[0100]

[Chemical 31]

It was thought that the above should be used. That is, as in the present invention, the diol component is

Embedded image When -OCH ₂ CH ₂ O- (2) is used, transesterification or acidolysis reaction generally occurs actively at high temperature, and as a result, the chain of p-oxybenzoic acid becomes a block or randomly. Was supposed to be. However, unexpectedly, it was difficult to transesterify the component (2). That is, the polymer according to the method of Jackson et al. Or JP-A-62-267323 is

Embedded image Since the component of —CO—R ¹ —CO—OCH ₂ CH ₂ O— remains, the ratio of the above (a) increases. Other methods have attempted to cause transesterification and acidolysis even a little.

In the present invention, the fact that transesterification of the —OCH ₂ CH ₂ O— component is unlikely to occur unexpectedly at high temperatures is intended to be used conversely. Hereinafter, the manufacturing method of the present invention will be described more specifically. In the present invention, first,
2-ethylenebis-4-hydroxybenzoate and / or 1,2-ethylenebis-4-acetoxybenzoate and a predetermined dicarboxylic acid (HOOC-R ¹ -CO
OH), and further m-hydroxybenzoic acid and /
Or m-acetoxybenzoic acid, optionally 1,2
-Ethylenebis-3-hydroxybenzoate and /
Alternatively, 1,2-ethylenebis-3-acetoxybenzoate is added, and acetic anhydride is optionally added, and in some cases, p-hydroxybenzoic acid and / or p-hydroxybenzoic acid is added.
-Add acetoxybenzoic acid and perform acetylation and the like at 100 to 170 ° C. The reaction time is 5 minutes to 3 hours, preferably 20 minutes to 1.5 hours. The amount of acetic anhydride is preferably about the same as the amount of hydroxyl groups in the raw material and about 1.5 times. That is, with acetic anhydride as (16), the number of moles of each component is [6] = [6-1] + [6-2],

[9]
= [9-1] + [9-2], [16], {[16]
/ (2 × [6] +

[9])} = [D], 1.0
≦ [D] ≦ 1.5, particularly preferably 1.1 ≦ [D] ≦
It is 1.4.

Also, when only a raw material containing no hydroxyl group is used, a small amount of acetic anhydride may be used. In this case, there is an advantage that the polymerization rate becomes high. The ratio of (6), (7) and (8) is {([6] + [7]) /, where the number of moles of each component is [6], [7] and [8].
[8]} = [E], 0.85 ≦ [E] ≦ 1.1
5 is preferable, and 0.9 ≦ [E] ≦ 1.1 is particularly preferable.

Next, (6-2), (7-2), (9-
The ratio of 2) and (10-2) is

[0105]

[Equation 21]

It is It is preferable to charge (6-2) or (7-2) than to charge (9-2) or (10-2) because the physical properties of the produced polymer are improved and the polymerization rate is increased. If the above value exceeds 0.3, heat resistance is lowered and liquid crystallinity is lowered, so that fluidity is deteriorated, which is not preferable.

The ratio between (9) and (10) is

(22) 0 ≦ (

[9] + [10]) / ([6] + [7]) ≦ 6,
Preferably, 0.5 ≦ (

[9] + [10]) / ([6] + [7]) ≦
4, more preferably 1 ≦ (

[9] + [10]) / ([6] + [7]) ≦ 3. The reaction can be carried out without a catalyst, and a catalyst may be added if necessary.

Thereafter, the temperature is raised to start polymerization. 220 polymerization
Polymerization is carried out at ˜340 ° C., preferably at 260˜320 ° C. It is particularly preferable to carry out at 265 to 300 ° C. Most preferably, it is 265 to 280 ° C. It also has the advantage that it can be polymerized at low temperature in spite of its heat resistance. The time required for gradually reducing the pressure from 760 mmHg to 1 mmHg is 30 minutes or more, preferably 60 minutes.
It is carried out for more than a minute, especially from 30mmHg to 1mm
It is important to gradually reduce the pressure to Hg.

At the time of polymerization, it is possible to carry out without a catalyst, but if necessary, it is carried out in the presence of a catalyst. As the catalyst to be used, an ester exchange catalyst, a polycondensation catalyst, an acylation catalyst and a decarboxylic acid catalyst are used, and these may be used as a mixture. Preferred catalysts are Ti (OBu) ₄ , B
uSnOOH, Sn (OAc) ₂ , Sb ₂ O ₃ , Fe
(Acac) ₃ , Zn (OAc) ₂ , Co (OA
c) ₂ , NaOAc, KOAc and the like. The amount used is 5 to 50,000 ppm, preferably 50 to 5,000 ppm, based on the polymer.

The polymerization time may be 10 hours or less, but it is preferably 7 hours or less. Most preferably, it is performed within 1 to 4 hours. Although this polymerization has the advantage that it can be carried out at a low temperature, it has the advantage that it can be easily extracted even at a low temperature and that no trouble occurs during the extraction. This too seems to be based on the fact that the sequence is controlled more alternately.

The production method of the present invention and JP-A-63-3175.
As for the difference from the method described in JP-A No.
The inventors of No. 3-317524 do not think that the physical properties can be improved only by ethylene glycol as the aliphatic glycol as described above, and it is said that C ₃ or more is improved because it is difficult for transesterification and acidolysis reaction to occur. Says. In addition, they are the prior applications of the present inventors (JP-A-60-18).
6525) and believes that acidolysis can be sufficiently carried out by using ethylene glycol in this method.
From the beginning, we have not considered improving physical properties with ethylene glycol alone.

As described above, the present inventors did not sufficiently perform transesterification and acidolysis even in the case of ethylene glycol, and therefore, in production, the chain of p-oxybenzoic acid units should be reduced from the beginning. This is very different from the inventor of JP-A-63-317524, which believes that transesterification and acidolysis are sufficiently performed in the case of ethylene glycol.

The liquid crystalline polyester of the present invention exhibits optical anisotropy in the molten phase. In particular, when melting is started, the solid part almost disappears only by slightly raising the temperature from the melting start temperature, and almost all can be in a liquid crystal state, so it has a characteristic that the fluidity is far better than conventional polyester with η _inh . Therefore, it has good moldability and can be subjected to general melt molding such as extrusion molding, injection molding and compression molding, and can be processed into molded products, films, fibers and the like.

Regarding the melt viscosity, the polyester of the present invention generally exhibits a low melt viscosity because it exhibits liquid crystallinity. For example, the melt viscosity at 275 ° C and 10 ³ sec ^-1 is 5
000 poise or less, preferably 30 to 3000 poise, more preferably 100 to 2500 poise. The same η
_{Regarding inh} , the melt viscosity at 275 ° C. of the present invention has the lowest value.

Further, the small value of the ratio of the melt viscosity at 275 ° C. and the melt viscosity at 290 ° C. is also a feature of the present invention. Since it has a high flow, it is suitable for precision molded products. For example, it can be used for automobile parts, parts for information materials such as compact disks and floppy disks, and parts for electronic materials such as connectors and IC sockets.

Further, at the time of molding, the copolymer polyester of the present invention is mixed with fibers such as glass fiber and carbon fiber, fillers such as talc, mica and calcium carbonate, nucleating agents, pigments, antioxidants, lubricants and other stabilizers. It is also possible to add fillers and additives such as agents and flame retardants, and thermoplastic resins to give desired properties to the molded article. It is also possible to blend with other polymers or alloy to create compositions that combine the characteristics of other polymers with the advantages of both of the copolyesters of the invention.

[0117]

The present invention will be described in more detail below.
The present invention is not limited to the following examples unless it exceeds the gist. The melt viscosity in the examples was measured using a Shimadzu flow tester with a shear rate of 100.
0 sec ⁻¹ , cylinder nozzle length / diameter = 20 was used.

The optical anisotropy (liquid crystallinity) was observed using a polarizing microscope with a hot stage. Molding was carried out using a 0.1 oz injection molding machine manufactured by Nippon Steel Co., Ltd. to prepare molded pieces. Also, a molded piece was prepared for the HDT measurement using a 2.5 oz injection molding machine manufactured by Toshiba Machine. As the vibron, a leo vibron manufactured by Toyo Baldwin Co., Ltd. was used.
Molded pieces of oz were used under 110 Hz.

The tensile properties (tensile elastic modulus, tensile strength, elongation at break) were measured for the above 0.1 oz molded product using TENSILON / UTM-III L manufactured by Toyo Baldwin. The DSC was measured using TA2000 manufactured by DuPont. Powder is used as the sample, and the temperature is raised to 350 ° C. at a rate of 20 ° C./min, left for 5 minutes and then 20 ° C./m
The temperature was lowered to 20 ° C. in. After leaving it for another 5 minutes, 2
The temperature was raised to 350 ° C at 0 ° C / min. The charts of the temperature decreasing process and the second temperature increasing process are illustrated.

Vicat softening temperature is based on Toyo Seiki's automatic HD.
Using a T measuring device, the sample is the temperature at which the needle penetrates 1 mm at a temperature rising rate of 50 ° C./hr using the runner portion of the 0.1 oz molded piece. The Izod impact strength was measured with a notch in accordance with the ASTM-D256 standard.

The tensile elongation at break was 0.
The 1 oz molded piece (dumbbell piece) has a lower elongation and a considerably lower strength than the ASTM molded piece. Therefore, it can be said that the molded piece having an elongation of 3.5% or more is a fairly tenacious polymer. If it is less than 3.0%, it can be said that the polymer is considerably brittle.

Reference Example 1 [Synthesis of 1,2-ethylenebis-4-hydroxybenzoate] p-Hydroxybenzoic acid and ethylene glycol were added to xylene to obtain p-hydroxybenzoic acid / ethylene glycol =
Charged so as to be 2/1 (molar ratio), p-as a catalyst
Toluenesulfonic acid was charged. This was heated to the reflux temperature of xylene and reacted. After the reaction was completed, the unreacted portion was washed with water and removed to obtain highly pure 1,2-ethylenebis-4-hydroxybenzoate. The structure is
^It was confirmed by ¹ H-NMR.

[0123] were synthesized on the basis of Reference Example 2 [1,2-ethylene bis -3-hydroxybenzoate] Polymer Chemistry 30 572 (1973). That is, it was synthesized by transesterification of methyl m-hydroxybenzoate and ethylene glycol, and the structure was ¹
It confirmed using 1 H-NMR.

<Example 1> 4,9.1 g (0.163 mol) of 1,2-ethylenebis-4-hydroxybenzoate was added to a glass polymerization tube equipped with a stirring blade, a nitrogen inlet and a pressure reducing port.
After charging 27.0 g (0.163 mol) of terephthalic acid, 39.3 g (0.284 mol) of p-hydroxybenzoic acid and 5.6 g (0.041 mol) of m-hydroxybenzoic acid, N ₂ -vacuum substitution was carried out, Furthermore, 83.0 g (0.
(813 mol), and the system was heated to 140 ° C. with stirring and kept at 140 ° C. for 1 hour. Then, the temperature was raised to 275 ° C over 1.5 hours, and when the temperature reached 275 ° C, depressurization was started.

The pressure was reduced to 10 mmHg in the first hour,
10mmHg to 0.3mmHg over 1.5 hours
I chose Polymerization was carried out at 0.3 mmHg for 30 minutes, and the torque was sufficiently increased at that time, so the polymerization was terminated. Then, the polymer was extracted from the bottom of the polymerization tube by allowing it to stand still and restoring the pressure. The extractability was very good.

After the chips were formed, they were vacuum dried at 120 ° C. overnight. This polymer had an η _inh of 1.17 and a melt viscosity of 750 poise at 275 ° C. (Tables 1, 2,
3) This polymer had r ₃ = 0.80. still,
FIG. 1 shows an NMR chart after amine decomposition used for determining r ₃ = 0.80. Also, various mechanical properties are shown in Tables 1, 2,
It was as shown in 3.

Further, FIG. 2 shows various vibron charts including the first embodiment. What is shown in the figure is that of the first embodiment. Vibron T ₁ is 175 ℃, T ₂ is 250 ℃
And a = T ₂ −T ₁ = 75 ° C., which is smaller than that of the conventional polymer having the same composition ratio. Among the mechanical properties, the tensile strength at break was a very high value of 2.480 kg / cm ² . The breaking elongation was 4.6%, which was higher than that of the comparative example having the same composition ratio. That is, as described above, when it is 3% or less, it feels brittle, whereas the polymer of the present invention has a considerable tenacity. Also, the melt viscosity is low for η _inh compared to the comparative example. The temperature dependence of the melt viscosity was 750 poise at 275 ° C. and 430 poise at 290 ° C., which was small.

<Examples 2 to 10> Example 1 except that the kinds of raw materials, the charging ratio and the polymerization conditions were changed as shown in Table 1.
I went the same way. That is, the polymerization temperature was reached for 1.5 hours after the acetylation, and when the polymerization temperature was reached, depressurization was started. The pressure was reduced to 10 mmHg in the first hour and then to less than 1 mmHg for 1.5 hours. Therefore, when the polymerization time is 2.5 hours or more, the final pressure is 1 mmH.
When it is less than g and less than 2.5 hours, the pressure at that time becomes the final pressure and is 1 mmHg or more.

Tables 1, 2, and 3 summarize the results of measuring the polymerization conditions and various physical properties of Examples 1 to 10. Examples 5 and 6 will be described in some detail. In Example 5, as in Example 1, a glass polymerization tube was polymerized as shown in Tables 1, 2, and 3. R ₃ = 0 the polymer is r ₃ = 0.78 (Fig.
The NMR chart for 78 is shown. ) And η _inh
= 1.36, melt viscosity of 275 ° C. 1580 poise, 2
The strength of the molded piece at 75 ° C. was 2,580 kg / cm ^2, which was a very high value. The breaking elongation was 4.4%, which was a very high value and was tenacious.

In Example 6, S on the 50 times scale of Example 5 was used.
This was carried out using a US 20 liter autoclave. This polymer has r ₃ = 0.78 and η
_When the temperature was changed and molding was carried out at a melt viscosity of 1500 poise at _inh = 1.32 and 275 ° C., the values shown in Tables 1, 2, and 3 were obtained. From this result, the lower the molding temperature, the elastic modulus,
It shows that the strength and elongation are high.

Further, ASTM pieces were prepared and the flexural modulus, flexural strength, Izod impact strength and HDT were also measured. The vibron chart of this polymer is shown in FIG. T ₁ = 18
The temperature was 0 ° C., T _{2 was} 259 ° C., and the value a was 79 ° C., which was small. A DSC chart is shown in FIG. T _m = 260.
It showed a clear melting point at 4 ° C.

70 parts by weight of this polymer was further kneaded with 30 parts by weight of glass fiber in a biaxial kneader and then AS
TM pieces were prepared and the physical properties were measured in the same manner. The results are shown in Table 3.
Also described in. Further, FIG. 4 shows an NMR chart diagram after amine decomposition for determining r ₃ in Example 4.

[0133]

[Table 1]

[0134]

[Table 2]

[0135]

[Table 3]

[0136]

[Table 4]

Comparative Example 1 A compound was prepared according to the method described in JP-B-56-18016. That is, polyethylene terephthalate / p-acetoxybenzoic acid / m-acetoxybenzoic acid was used as a raw material, and the final composition ratio was made equal to that in Example 5. (Table 4,
(See 5)

Comparative Example 2 It was produced according to the method described in JP-A-62-285916. That is, polyethylene terephthalate / acetic anhydride and p-hydroxybenzoic acid / m-hydroxybenzoic acid were used as raw materials so that the final composition ratio was equal to that in Example 5. (See Tables 4 and 5)

COMPARATIVE EXAMPLE 3 It was produced according to the method described in JP-A No. 52-121095. That is, polyethylene terephthalate / p-hydroxybenzoic acid / m-hydroxybenzoic acid / diphenyl carbonate was used as a raw material, and the final composition ratio was made equal to that in Example 5. (See Tables 4 and 5)

Comparative Example 4 It was produced according to the method described in JP-A-60-186525. The final composition ratio was made equal to that in Example 5.
(See Tables 4 and 5)

Comparative Example 5 According to the method described in JP-A No. 64-26632, m-acetoxybenzoic acid was added to carry out two-step polymerization. The composition ratios are shown in Tables 4 and 5.

Comparative Example 6 The procedure of Example 1 was repeated except that [5] / ([4] + [5]) was set to 0.0125. The results are shown in Tables 4 and 5.

[0143]

[Table 5]

[0144]

[Table 6]

[0145]

EFFECTS OF THE INVENTION Since the sequence of the liquid crystalline polyester of the present invention is controlled in an alternating manner, its mechanical properties are higher than those of conventional polyesters having the same composition and the same composition ratio.
Excellent thermal properties. That is, the strength is high, the elongation is high, and the lower the molding temperature is, the better the physical properties are. Further, since it has high crystallinity, it has a clear melting point and exerts a strengthening effect on glass fibers and the like. Further, it has a high HDT, and since it flows at a low temperature for its heat resistance, it has an advantage that the polymerization temperature can be lowered. Further, there is an advantage that the polymerization temperature can be lowered. Further, even if the polymerization temperature is lowered, there is an advantage that it can be extracted from the bottom of the polymerization tank.

The liquid crystalline polyester of the present invention exhibits optical anisotropy in the molten phase. In particular, when melting is started, the solid portion is almost eliminated by raising the temperature a little from the melting start temperature, and almost all of them can be in one liquid crystal state. Therefore, the fluidity is much better than that of the conventional polyester. The liquid crystalline polyester of the present invention,
Since it has a high flow, it is suitable for precision molded products.
For example, it can be used for automobile parts, parts for information materials such as compact disks and floppy disks, and parts for electronic materials such as connectors and IC sockets. It is also used as a film or a sensor, and is most suitable for a film.

[Brief description of drawings]

FIG. 1 shows the results of Example 1 after amine decomposition to determine r ₃ .
^{It is a} < ¹ > H-NMR chart figure.

FIG. 2 is a diagram showing vibron data of Example 1 and Example 6.

3 is a DSC chart diagram of the polymer obtained in Example 6. FIG.

4 shows an NMR chart after amine decomposition for determining r ₃ in Example 4. FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ikuyuki Sakata 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd.

Claims (6)

[Claims] 1. A dicarboxylic acid unit represented by the following formula (1): ## STR1 ## --CO--R ¹ --CO-- (1) (wherein, R ¹ is a divalent fragrance having 6 to 18 carbon atoms). Group hydrocarbon group.) A diol unit represented by the following formula (2), a —OCH ₂ CH ₂ O —... (2) and an oxybenzoic acid unit represented by the following formula (3): ] (Formula (3) represents a unit of the following formula (4) or a unit of (5)) and is a liquid crystalline polyester characterized by satisfying the following conditions (1) to (4). [Chemical 4] The above structural units (1), (2), (3), (4),
The number of moles of (5) [1], [2], [3],
[4] and [5] satisfy the following formulas (I) and (II). ## EQU1 ## 0.65 ≦ [3] / ([1] + [3]) ≦ 0.88 (I) 0.02 ≦ [5] / ([4] + [5]) ≦ 0.15 ( II) Of the oxybenzoic acid units represented by formula (3),
An oxybenzoic acid unit having a diol unit represented by the formula (2) adjacent to the carbonyl group (—CO—) side is represented by (3-1), Then, assuming that the number of moles of (3-1) is [3-1], the following formula (III) R ₃ defined by is within the range of 0 ≦ r ₃ ≦ 0.88. The solution viscosity measured in p-chlorophenol / o-dichlorobenzene (30 ° C., concentration: 0.5 g / dl) is 0.4 dl / g or more. 2. The molar ratio of the unit of the formula (1) and the unit of the formula (3) is in the range of 0.7 ≦ [3] / ([1] + [3]) ≦ 0.85. The liquid crystalline polyester according to claim 1, wherein the liquid crystalline polyester is present. 3. A compound represented by the following formula (6) and / or (7) as a starting material: A dicarboxylic acid represented by the following formula (8): HOOC-R ¹ -COOH (8) (wherein R ¹ represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms) and The method for producing a liquid crystalline polyester according to claim 1, wherein acetic anhydride is reacted as necessary to perform polycondensation in a molten state. 4. A compound represented by the following formula (9) and / or (10) as a starting material: 4. The method for producing a liquid crystalline polyester according to claim 3, wherein: 5. A compound of formula (9) is a compound of formula (9-1) and / or formula (9-2): The compound of the formula (10) is a compound represented by the formula (10-1) and / or the formula (10-2): And (9-1), (9-2), (10-1), (1
0-2), the number of moles of each [9-1], [9-2], [1]
0-1] and [10-2] satisfy the following equation: ([9-2] + [10-2]) / ([9-1] + [10-1]) ≦ 0.35 The method for producing a liquid crystalline polyester according to claim 4, wherein 6. [9-1], [9-2], [10-
1] and [10-2] satisfy the following equation: ([9-2] + [10-2]) / ([9-1] + [10-1]) ≦ 0.25 The method for producing a liquid crystalline polyester according to claim 5, which is characterized in that.