JPH0791373B2 - Copolyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a novel copolyester having high elastic modulus, high strength, high elongation and excellent heat resistance.

Further, the present invention relates to a copolyester which is excellent in moldability because it forms a thermotropic liquid crystal at the time of molding and can be used as a product such as a molding material, a film or a fiber.

[Conventional secret technique]

In recent years, regardless of whether it is a fiber, film or molded article,
There is an increasing demand for materials having excellent rigidity, strength, elongation and heat resistance. Polyesters have come to be widely used for general molded articles, but many polyesters are inferior in flexural modulus and flexural strength, and thus are not suitable for applications requiring high elastic modulus and high strength.

In recent years, liquid crystalline polyester has been attracting attention as a polyester suitable for applications requiring high elastic modulus and high strength. What attracted particular attention was WJ Jackson's publication of polyethylene terephthalate and acetoxybenzoic acid in Journal of Polymer Science Polymer Chemistry Edition Volume 14 (1976) p. 2043 and Japanese Patent Publication No. 56-18016. After the announcement of a thermal liquid crystal polymer consisting of and. Among them, Jackson says that the liquid crystal polymer is polyethylene terephthalate.
We reported that it exhibits more than twice the rigidity, more than four times the strength, and more than 25 times the impact strength, demonstrating new possibilities for highly functional resins.

[Problems to be Solved by the Present Invention]

However, the polymer of Jackson et al. Has the drawback of being very brittle and having low strength and elongation.

Therefore, we have previously found a copolyester that improves the ultimate (breaking) elongation of the Jackson et al. Polymer. (JP-A-60-186527) However, this improved copolyester also has a problem that the ultimate (breaking) elongation is low and the strength is low.

Furthermore, we have found a copolyester that suppresses the formation of insoluble and infusible particles. (JP-A-62-41221) However, this polyester may be inferior in heat resistance and may be unsuitable for engineering plastics.

Also, USP 4,035,356 discloses a polyester that improves abrasion resistance, but this polyester will also be mentioned later. Was likely to be generated. As a result, insoluble and infusible particles are likely to be formed, and thus the elongation at break of the obtained polymer tends to be low and fragile.

[Means for Solving the Object and Problems of the Invention]

Therefore, as a result of diligent study on polyester having high elastic modulus, high strength, high elongation at break and high heat resistance, a polymer having high elastic modulus, high strength, high elongation at break and improved heat resistance was found. The invention was reached.

That is, the gist of the present invention is to provide a terephthalic acid residue represented by the following formula (A): 20 to 45 equivalent%, Ethylene glycol residue represented by the following formula (B): 5 to 15
Equivalent percent, hydroquinone residue represented by -OCH ₂ CH ₂ O- (B) the following formula (C): 5 to 30 equivalent percent, A diol residue represented by the following formula (D): 5 to 20 equivalent% —O—R ¹ —O— (D) (wherein R ¹ is a divalent aromatic hydrocarbon group excluding 1,4 phenylene group or , —R ² —X—R ³ — group.

However, R ² and R ³ are divalent aromatic hydrocarbon groups, and X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, a hydrocarbon group, an ester group or a direct bond. ) An oxybenzoic acid residue represented by the following formula (E): 15 to 35 equivalent%, Oxyethoxybenzoic acid residue represented by the following formula (F): 4
Equivalent% or more And the equivalent number of each component is [A], [B], [C], [D], [E],
When represented by [F] (however, [B] and [E] do not include [F]), And And And the melt viscosity at 290 ° C. and 100 sec ⁻¹ is 30 poise or more. These copolyesters are characterized by exhibiting optical anisotropy in a specific melt phase.

To explain the present invention in detail, the features of the copolyester of the present invention are high rigidity, high strength, high elongation at break, and further excellent heat resistance.

In addition, the copolymerized polyester of the present invention exhibits liquid crystallinity and thus has excellent fluidity.

The copolyester of the present invention has the above-mentioned (A), (B),
It is composed of the components (C), (D), (E) and (F), and the composition of each component is such that (A) is 20 to 45 equivalent%, preferably 25 to 40.
Equivalent%, (B) 5 to 15 equivalent%, (C) 5 to 30 equivalent%, preferably 5 to 25 equivalent%, (D) 5 to 20 equivalent%,
(E) is 15 to 35 equivalent% and (F) is 4 equivalent% or more.
Furthermore, the equivalent number [A], [B], [C] of each component,
[D], [E] and [F] are represented by the following formula (1),
It satisfies (2) and (3). That is, the first feature of the present invention is Is to meet. By satisfying the above formula (1), it is possible to improve strength and elongation.

In that case, since the amount of (E) is large, the chain of (E) is likely to increase, which is likely to form crystals, and the voids at the interface between the crystal part and other amorphous parts increase, so that the strength, It is estimated that the elongation will decrease.

That is, It is considered that the formation of crystals suppresses the formation of crystals, and as a result, the strength and the elongation are improved due to the reduction of voids.

Furthermore, this provision Is preferred, and Is preferred.

The second feature is Is to meet.

Preferably, More preferably, Is.

When the component (F) does not satisfy the above formula (2), that is, when it is negligible with respect to the entire components, JP-A-62-
As also shown in 41221, the ultimate (break) elongation is very low.

When the component (F) satisfies the above formula (2), that is, when it is 4 equivalent% or more with respect to the total components, both strength and elongation are improved. It is presumed that this is because the component (F) has a role of imparting flexibility, and thus brings about a remarkable effect in improving the elongation.

The third feature is Is to meet. Preferably, And more preferably, It is.

At this time, this type of polyester has low heat resistance and is not preferable for use as an engineering plastic.

By satisfying the above condition, the heat resistance is improved, which is preferable for use as an engineering plastic.

That is, all of the above conditions (1), (2), and (3) must be satisfied in order to achieve high strength, high breaking elongation, and high heat resistance.

In order to obtain a higher molecular weight polymer, it is preferable to satisfy the following formula 0.9 ^[A] / ([B] + [C] + [D]) ^1.1 (4).

The copolyester of the present invention comprises the constituent components (A) to (F).

The constituent component of (D) is a general formula —O—R ¹ —O— (D) (wherein R ¹ is a divalent aromatic hydrocarbon group excluding 1,4 phenyl group or R ² —X—R ³ group). Indicates.

However, R ² and R ³ are divalent aromatic hydrocarbon groups, and X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, a hydrocarbon group, an ester group or a direct bond. ) Is a diol component represented by.

As the hydrocarbon group of X in the above formula, an alkylene group or an alkylidene group is preferable.

Specific examples of the residue of the aromatic dioxy compound represented by the formula (D) include, for example, resorcin, methylhydroquinone, t-butylhydroquinone, 2,5-di-t-butylhydroquinone, 2,6-di-t. -Butyl hydroquinone, methyl hydroquinone diacetate, t-butyl hydroquinone diacetate, 2,4,5-trimethylresorcin, 2,3,5-trimethylhydroquinone, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1, 6
-Dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-bis (4-
Hydroxyphenyl) propane, 2- (3-hydroxyphenyl) -2- (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4 ′
-Dihydroxydiphenyl, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ether, (4-hydroxyphenyl) -4-hydroxy Benzoate, 3,4'-
Examples thereof include residues such as dihydroxydiphenyl sulfone and 3,4′-dihydroxybenzophenone, but they are not necessarily limited to these, and these may be used as a mixture of two or more kinds.

Of these, resorcinol, 2,2-bis (4-hydroxyphenyl) propane, 4,4'-dihydroxyphenyl,
Bis (4-hydroxyphenyl) sulfide, bis (4
-Hydroxyphenyl) sulfone is particularly preferred.

By containing these constituents, surprisingly, the polymer obtained in the present invention exhibits optical anisotropy (indicates liquid crystallinity) in the melt phase, and is therefore excellent in moldability. Further, since the polymer is an efficient copolymer, voids are reduced, strength and elongation are improved, and further, the elastic modulus is high and the heat resistance is excellent.

For example, the complex elastic moduli ｜ E ^* ｜ at 40 ℃ and 80 ℃ measured with Vibron (110Hz) are ｜ E ^* ｜ ₄₀ , ｜ E ^* ｜ ₈₀
Then, And is | E ^* | ₄₀ 7.0 × 10 ¹⁰ dyne / cm ² | E ^* ｜ ₈₀ 5.0 × 10 ¹⁰ dyne / cm ² .

If the composition is selected, it can be │E ^* ｜ ₄₀ │E ^* ｜ ₈₀ 10.0 × 10 ¹⁰ dyne / cm ² .

Further, in terms of rheology, the melt viscosity is low and the moldability is very good.

The copolyester of the present invention can be manufactured by various manufacturing methods. For example, there may be a melt polymerization method, a solution polymerization method, an interfacial polymerization method, etc., but the melt polymerization method is preferable from the viewpoint of process simplicity.

The melt polymerization method can also be manufactured by various methods, but can be manufactured according to the methods described in JP-A-62-41220 and Japanese Patent Application No. 62-28697.

That is, the copolyester of the present invention is produced by reacting a polyester or oligoester with an oxycarboxylic acid to form a copolymer oligomer (first step), acylation (second step), and polymerization by deacetic acid (third step). However, the aromatic diol or aromatic diol and aromatic dicarboxylic acid are added by the end of the second stage. If necessary, an oxycarboxylic acid may be added.

To describe the production method in more detail, polyethylene terephthalate or oligoethylene terephthalate is used as the above-mentioned polyester or oligoester. Oygoethylene terephthalate is particularly preferable.

P-Hydroxybenzoic acid is used as the oxycarboxylic acid.

As the reaction method, the first step of contacting raw material polyethylene terephthalate or oligoethylene terephthalate with p-hydroxybenzoic acid and heating at 200 to 320 ° C. under normal pressure to form a copolymer oligomer, acylation by adding an acylating agent The second step is carried out, and the third step is polymerization at 250 to 340 ° C. under reduced pressure. In this case, acetic anhydride is preferably used as the sialylating agent in the second step.

Hydroquinone, HO—R ¹ —OH, and / or part of terephthalic acid, and / or part of p-hydroxybenzoic acid are added by the end of the second step. It is particularly preferable to add it at the end of the first stage, but it does not matter if it is added from the beginning.

The first reaction may be performed at any temperature in the range of 220 to 300 ° C, but is preferably 240 ° C to 290 ° C, and the reaction is carried out for 20 minutes to 5 hours.

The reaction is carried out until the residual amount of the oxycarboxylic acid compound is usually 70 mol% or less, preferably 50 mol% or less based on the charged amount.

The component (F) is produced during this reaction.

The amount of the acylating agent used in the second step is the same as the equivalent number to the constituents of the components (c), (D), and (E) of the raw materials added by the end of the second step, and is used in an amount equivalent to about 1.5 times. Preferably.

When acetic anhydride is used as the acylating agent, the acylation reaction is preferably carried out at 100 to 180 ° C.

The third stage polymerization is carried out at 250 to 340 ° C, especially 270 to 3
It is preferably carried out at 20 ° C. The time required for gradually reducing the pressure from 760 mmHg to 1 mmHg is 30 minutes or longer, preferably 60 minutes or longer, and it is particularly important to gradually reduce the pressure from 30 mmHg to 1 mmHg.

In the first step to the third step, it may be carried out without a catalyst, but if necessary, it is carried out in the presence of a catalyst.

As the catalyst used in the first step, the second step and the third step, a transesterification catalyst, a polycondensation catalyst, an acylation catalyst,
Decarboxylic acid catalysts are used, and these may be used as a mixture. The amount used is 5 to 5 relative to the polymer
The amount is 0000 ppm, preferably 50 to 5000 ppm.

The melt viscosity of the final product is 30 poise or more, preferably 50 poise or more and 5000 poise or less, and more preferably 100 poise or more and 2000 poise or less, as measured at 290 ° C. and 100 sec ⁻¹ .

Since the copolyester of the present invention can exhibit an optically anisotropic phase in the melt phase, the flowability is very good, and therefore the moldability is good and general melt molding such as extrusion molding, injection molding and compression molding is performed. It is possible to process into molded products, films, fibers and the like.

Since it has a particularly high flow, it is suitable for precision molded products and the like.

Further, at the time of molding, with respect to the copolyester of the present invention, glass fibers, fibers such as carbon fibers, talc, mica, fillers such as calcium carbonate, nucleating agents, pigments, antioxidants, lubricants, other stabilizers, difficult It is also possible to add a filler such as a flame retardant, an additive, a thermoplastic resin, or the like to give desired characteristics to the molded product.

It is also possible to create a composition that combines the characteristics of other polymers and the advantages of both of the copolyesters of the present invention by blending or alloying with other polymers.

〔Example〕

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

For the measurement of the melt viscosity in the examples, a capillary rheometer (manufactured by Intesco) was used, with a temperature of 290 ° C., a shear rate (γ) of 100 sec ⁻¹ , and a cylinder nozzle length / diameter = 30.

The infrared spectrophotometer used was Nicolet's 20DX BFT-IR. The polymer was either dissolved in hexafluoroisopropanol or a KBr disk was used as a test sample.

NMR used JNM-GX270 manufactured by JEOL. A test sample was prepared by dissolving the polymer in trifluoroacetic acid or hexafluoroisopropanol.

Molding was carried out using a 0.1 oz injection molding machine manufactured by Nippon Steel Co., Ltd. to prepare molded pieces.

As the vibron, Rheovibron manufactured by Toyo Baldwin Co., Ltd. was used, and the above molded piece was used at 110 Hz.

Tensile properties (tensile modulus, tensile strength, breaking elongation) were measured using TENSILON / UTM-IIIL manufactured by Toyo Baldwin. The Tg (glass transition temperature), which is a measure of heat resistance, is
Obtained from E ″ of Vibron.

Further 40 ° C. of Vibron, and 80 ° C. of the elastic modulus, respectively | E ^* | _40, | E ^* | ₈₀ and, the ratio | heat with ₈₀ values of _{^{| E * | 80 / | E}} * | 40 and | E ^* It was used as a measure of sex.

The optical anisotropy (liquid crystallinity) was observed using a polarization microscope with a hot stage.

Example 1 A glass polymerization tube equipped with a stirring blade, a nitrogen inlet, and a decompression port
-Hydroxybenzoic acid 44.2 (0.32 mol), polyethylene terephthalate oligomer (ηinh = 0.12dl / g) 30.7g
(0.16 mol) was charged, vacuum-nitrogen substitution was repeated 3 times, and finally, nitrogen was filled and placed under a nitrogen stream at a flow rate of 0.5 l / min. When the polymerization tube is immersed in an oil bath at 260 ° C, the contents will melt in about 30 minutes, so start stirring and continue to 2
Transesterification is performed for a period of time to produce a copolymerized oligomer.

After that, the temperature was lowered to 140 ° C in about 30 minutes, and hydroquinone 12.1 g (0.11 mol), resorcinol 12.1 g (0.11 mol),
26.6 g (0.16 mol) of terephthalic acid was added, then 97.1 g (0.95 mol) of acetic anhydride was added dropwise over 30 minutes, and stirring was continued for another 1 hour to carry out acylation. Then, the temperature of the oil bath is raised to 290 ° C. over 2 hours, 0.068 g of zinc acetate dihydrate is added, and decompression is gradually applied. And
Polymerization is performed for 1 hour and 30 minutes after the high vacuum of 0.3 mmHg is reached. The product is taken out by breaking the glass polymerization tube, made into chips, and then vacuum dried at 130 ° C. overnight. The obtained polymer was milky white and opaque. Raw material p-hydroxybenzoic acid,
The reaction rate of PET oligomer and hydroquinone is 100
%Met.

270MHz NMR (JNM-GX-270) manufactured by JEOL Ltd.
Was analyzed using trifluoroacetic acid as a solvent. Unit methylene proton and Β-methylene proton of 4.54ppm Alpha methylene broton, 7.40ppm The α-proton of the benzene ring of the unit and Benzene ring proton absorption, to 8.42ppm Β-proton on the benzene ring of the unit, to 8.22 ppm There was absorption of protons on the benzene ring of the unit. First
The ¹ H-NMR chart is shown in the figure.

In addition, this polymer was analyzed by JEOL NMR (JNR-GX-270) FT
When ¹³ C-NMR was measured using trifluoroacetic acid as a solvent using -NMR SPECTROMETER, it was found to be 151.0 ppm. * Absorption of carbon to 153.2ppm There was * absorption of carbon. FIG. 2 shows the ¹³ C-NMR chart.

As a result of quantifying them, (A), (C), and (D) show good agreement with the composition of the feed, and with respect to the preparation of hydroxybenzoic acid, the amount of the feed and (E) + (F) show good agreement, There was a good agreement between the amount of ethylene glycol component charged in the polyethylene terephthalate oligomer and (B) + (F).

As a result, terephthalic acid (A) 33.7 equivalent% ethylene glycol residue (B) 10.5〃 hydroquinone residue (C) 11.9〃 resorcinol residue (D) 11.3〃 oxybenzoic acid residue (E) 27.4〃 oxyethoxybenzoic acid The residue (F) was 5.2 〃.

That is, Met.

The tensile properties of this product were as follows: tensile modulus 73,000 kg / cm ² tensile strength 1,890 kg / cm ² breaking elongation 5.4% Tg 98 ° C.

It was | E ^* | ₄₀ = 13.0GPa | E ^* | ₈₀ = 10.5GPa. Melt viscosity at 290 ℃, 100sec ^-1 is 560
It was a poise and showed optical anisotropy at 290 ° C.

Examples 2 to 9 Polymerization was performed in the same manner as in Example 1 except that the composition of each component and the type of (D) were changed as shown in Table 1. Each composition and physical property value are shown in Table 1. From these results, in the range satisfying the above formulas (1), (2), and (3), the tensile properties (elastic modulus, strength, elongation at break) are excellent, and Tg exceeds 90 ° C. It was found that a product with excellent physical properties can be obtained.

Comparative Examples 1 to 10 Example 1 except that the composition of each component was changed as shown in Table 2.
A polymer was prepared as in. The measurement results of various physical properties are shown in Table 2. If at least one of the above formulas (1), (2), and (3) is not satisfied, the tensile properties such as tensile strength and elongation at break may be deteriorated, or Tg may be decreased (90 ° C or less). I was seen.

[Effect of the Invention] The copolyester of the present invention is a polymer having excellent liquidity and therefore excellent moldability and elastic modulus because it exhibits liquid crystallinity during melt molding. Moreover, since it is a tenacious polymer because it has excellent strength and elongation, it can be used as an alloy material or as a blend with glass fibers or carbon fibers. It also has excellent heat resistance. Therefore, it can be commercialized as a molding material, a film, or a fiber, and is particularly useful as a precision molding material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a ¹ H-NMR chart of the polymer obtained in Example 1. FIG. 2 is a ¹³ C-NMR chart diagram of the polymer obtained in Example 1.

Claims (1)

[Claims] 1. A terephthalic acid residue represented by the following formula (A): 20 to 45 equivalent%, Ethylene glycol residue represented by the following formula (B): 5 to 15
Equivalent percent, hydroquinone residue represented by -OCH ₂ CH ₂ O- (B) the following formula (C): 5 to 30 equivalent percent, A diol residue represented by the following formula (D): 5 to 20 equivalent%, -OR ¹ -O- (D) (wherein R ¹ is a divalent aromatic hydrocarbon group excluding 1,4 phenylene group) Or R ² —X—R ³ group, provided that R ² and R ³ are divalent aromatic hydrocarbon groups, X is an oxygen atom, a sulfur atom,
A sulfonyl group, a carbonyl group, a hydrocarbon group, an ester group or a direct bond is shown. ) An oxybenzoic acid residue represented by the following formula (E): 15 to 35 equivalent%, Oxyethoxybenzoic acid residue represented by the following formula (F): 4
Equivalent% or more, Is a copolyester consisting of [A], [B], [C],
When represented by [D], [E], and [F] (provided that [B],
[E] does not include [F]), And, And, And a polyester having a melt viscosity of 30 poise or more at 290 ° C. and 100 sec ⁻¹ .