JPH04493B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a novel polyarylate with excellent heat resistance. More specifically, the present invention relates to a novel polyarylate with excellent heat resistance and flame retardancy obtained from an aromatic diol containing a phosphorus atom and an aromatic dicarboxylic acid. BACKGROUND ART Polyarylates have been known as heat-resistant polymers. For example, 4-hydroxybenzoic acid homopolymer or copolymer (Sumitomo Chemical, trade name Econol), or bisphenol A
A polymer consisting of , terephthalic acid, and isophthalic acid (Unitika, trade name U Polymer) was proposed in the past, and is now commercially available. Such polymers inherently have (1) relatively high melting points or decomposition temperatures below their melting or softening points;
Poor moldability. (2) Poor color tone. (3) Poor transparency. (4) Insufficient heat resistance. (5) Poor flame retardancy. It had the following drawbacks. Problems to be Solved by the Invention The main purpose of the present invention is to provide a heat-resistant polyarylate that is particularly suitable for plasma spray coatings and molded products used at high temperatures, and has good heat resistance and high flame retardancy. An object of the present invention is to provide a new heat-resistant polyarylate having the following properties. As a result of intensive research into new heat-resistant polyarylates that do not have the above-mentioned problems, the present inventors discovered that phosphorus-containing polyarylates having repeating units with a specific structure have extremely excellent properties. reached. Means for Solving the Problems The present invention has the following configuration. That is, the present invention is a heat-resistant polyarylate consisting of repeating units represented by the following structural formula () and having an average degree of polymerization of 10 to 300. (However, R1, R2, and R3 are selected from halogen atoms and lower alkyl groups having 1 to 8 carbon atoms. Also, n ₁ and n ₂ are each 0 to 4, and n ₃ is 0 to 3.
represents an integer. ) Actions and Effects The average degree of polymerization (n) of the heat-resistant polyarylate of the present invention is 10 to 300, preferably 30 to 200, most preferably
Must be between 50 and 150. If the average degree of polymerization is less than 10, various physical, mechanical, and chemical property values including the above-mentioned heat resistance will be poor. On the other hand, if the average degree of polymerization is greater than 300, the melt viscosity becomes too high and fluidity etc. are impaired. R1, R2, and R3 include halogen atoms such as chlorine atom and bromine atom, and carbon atoms of 1 to 1, such as methyl group, ethyl group, propyl group, hexyl group, and octyl group.
Among them, halogen atoms are preferred. The method for producing the heat-resistant polyarylate of the present invention includes an aromatic dicarboxylic acid having an appropriate functional group capable of forming a repeating unit having a predetermined structure by condensation, or an ester-forming derivative thereof, and an aromatic diol group. This can be accomplished by utilizing various ester formation methods in which phosphinic acid or its ester-forming derivatives are reacted. Examples of the aromatic dicarboxylic acid or its ester-forming derivative effective in such an ester-forming reaction include a free dicarboxylic acid group, a dicarboxylic acid ester group, or a dicarboxylic acid halide group,
On the other hand, examples of phosphinic acid having an aromatic diol group or its ester-forming derivative include free dihydroxyl group, diacyloxy group,
A phosphinic acid compound having a diaryloxy group or the like is preferably used. Examples of aromatic dicarboxylic acids used in the production of the polyarylate of the present invention include terephthalic acid,
Examples include isophthalic acid and phthalic acid, among which terephthalic acid (abbreviated as TPA) and isophthalic acid (abbreviated as IPA) are particularly preferably used. A mixture of the above aromatic dicarboxylic acids may be used if necessary. On the other hand, examples of phosphinic acid (abbreviated as HCA) having an aromatic diol group used in the production of the polyarylate of the present invention include the following formulas (), ()
(abbreviated as p-HCA and o-HCA, respectively). As an example, aromatic dicarboxylic acid represented by the following formula () and aromatic dicarboxylic acid represented by the following formula ()
The heat-resistant polyarylate of the present invention can be produced by condensing HCA with a carboxylic acid ester derivative under high temperature and high vacuum. (However, R is a group of the same kind or a different kind, and each is a lower alkyl group having 1 to 8 carbon atoms.) In addition, a carboxylic acid ester derivative of HCA represented by the above formula () (for example, an acetate ester derivative p -HCA-2A) can be produced by esterifying HCA represented by the above formula () in a corresponding carboxylic acid anhydride (for example, acetic anhydride) under reflux. On the other hand, HCA used in the production of the polyarylate of the present invention can be produced, for example, by reacting a phosphinic acid represented by the following formula () with a corresponding benzoquinone in a suitable solvent such as ethyl cellosolve. When producing the heat-resistant polyarylate of the present invention, the molar ratio of the aromatic dicarboxylic acid and the carboxylic acid ester derivative of HCA is usually 0.8 to 1.2, particularly 0.9 to 1.1, and optimally equimolar. preferable. In addition, a catalyst is usually used in the condensation reaction, but
In order to obtain the polyarylate of the present invention, one or more compounds selected from, for example, various metal compounds or organic sulfonic acid compounds are used. Such metal compounds include antimony, titanium, germanium, tin, zinc, aluminum,
Compounds such as magnesium, calcium, manganese and cobalt are used, while organic sulfonic acid compounds such as sulfosalicylic acid and o-sulfobenzoic anhydride are used, while dimethyltin malate (abbreviated as CS) is used. It is particularly suitable for use. The amount of the catalyst added is usually 1×10 ^-5 per mole of the structural unit of polyarylate.
~1×10 ⁻² mol, preferably 5×10 ⁻⁵ to 5×10 ⁻³
mol, optimally from 1×10 ⁻⁴ to 1×10 ⁻² mol. In addition, the temperature conditions and reaction time of the condensation reaction are usually 4 to 12 hours at 180 to 400°C under normal pressure, especially
Preferably, the temperature is 250-360°C for 6-10 hours, optimally 280-320°C for 8-10 hours. Further under reduced pressure (usually 0.01-10torr) 180-400℃
for 4 to 12 hours, especially at 250 to 400℃ for 6 to 10 hours,
Optimally, the temperature is preferably 280-400°C for 8-10 hours. According to the present invention, (1) Decomposition does not occur even when used at high temperatures. (2) Preferred glass transition temperature range (150-230℃)
It falls within the preferred melting point temperature range (280-420°C) and has excellent heat resistance. (3) Excellent color tone and transparency. (4) Excellent flame retardancy. A new polyarylate having excellent physical properties as a heat-resistant polymer can be obtained. Further, the polyarylate according to the present invention is particularly useful as a material for films, fibers, and molded products used in applications requiring heat resistance and flame retardancy. Hereinafter, the present invention will be explained in more detail using Examples. In addition, the average degree of polymerization of the polymer referred to in the present invention is
By dividing the number average molecular weight measured at a temperature of 39°C using gel permeation chromatography (Toyo Soda HLC801A model) using a chloroform solution containing 2.5% hexafluoroisopropanol as the solvent by the molecular weight of the repeating unit. It's what I asked for. Further, the glass transition temperature and melting point were measured using a differential calorimeter (Model DSC-2, manufactured by PerkinElmer). On the other hand, the novel polyarylate according to the present invention is
It was identified by infrared absorption spectrum, NMR spectrum, glass transition temperature, and elemental analysis. Example 1 p-HCA represented by the above formula () was produced by reacting phosphinic acid represented by the above formula () with p-benzoquinone at a temperature of 90° C. in an ethyl cellosolve solvent. P-HCA represented by the above formula () and acetic anhydride are charged in a molar ratio of 1:4 into an esterification reactor, and diacetate, i.e., p-HCA-2A, is produced by esterification under reflux in acetic anhydride. did. P-HCA-2A and TPA were charged in a 1:1 molar ratio to a condensation reactor, and dimethyl tin maleate (CS) was added as a catalyst at 1 x 10 ^-4 mol per mol of polyarylate structural unit, and the mixture was placed in a nitrogen atmosphere. Lower normal pressure
The reaction was carried out at 280°C for 8 hours with mixing. The esterification reaction rate was approximately 95% based on the weight of distilled acetic acid. This reaction product was further reacted at 320°C under a reduced pressure of 0.1 torr, and the temperature was finally raised to 340°C for a total of 10 hours of condensation. During this time, the product went from a molten state to a solid state. In addition, during the reduced pressure reaction, the raw material p-HCA-2A
However, no sublimation of TPA was observed. The obtained polyarylate was a crystalline polymer with an average degree of polymerization of 73, a melting point of 392°C, and excellent color tone.
When this was molded into a string shape at 420°C, it was found to have good transparency, a glass transition point of 190°C, and good heat resistance. In addition, when the fire source was moved away from the fire after it was ignited, the fire extinguished immediately, and it had good flame retardant properties. In addition, when this polyarylate was analyzed by infrared absorption spectrum, NMR spectrum, and elemental analysis, the following results were obtained.
It was confirmed that it was a polyarylate having a repeating unit with the following structure. In other words, in the infrared absorption spectrum, it is 1780k.
Absorption based on C=O of aromatic dicarboxylic acid ester is observed at 736k and 782k, and absorption of para-substituted aromatics at 736k and 782k
Absorption of symmetric trisubstituted aromatics was observed at 880k. Furthermore, in the NMR spectrum, no absorption of hydrogen atoms of methyl groups (1.5 ppm and 2.3 ppm) based on the raw material acetate ester was observed. According to the results of elemental analysis, C = 68.6% (theoretical value 68.7
%), H=3.40% (theoretical value 3.33%), P=6.79% (theoretical value 6.82%). Example 2 O-HCA represented by the above formula () was produced by reacting phosphinic acid represented by the above formula () with o-benzoquinone at a temperature of 90° C. in an ethyl cellosolve solvent. o-HCA represented by the above formula () and acetic anhydride were charged in a molar ratio of 1:4 into an esterification reactor,
Diacetate, o-HCA-2A, was prepared by esterification in acetic anhydride under reflux. o-HCA and TPA in a molar ratio of 1 in the condensation reactor
Add 1 x 10 ^-4 mol of dimethyltin maleate (CS) as a catalyst to 1 mol of polyarylate structural unit at 280°C under nitrogen atmosphere at normal pressure.
The mixture was allowed to react while being mixed for 8 hours. Based on the weight of distilled acetic acid, the esterification reaction rate was approximately 93%. This reaction product was further reacted at 280°C under a reduced pressure of 0.1 torr, and the temperature was finally raised to 360°C for a total of 10 hours of condensation. In addition, during the reduced pressure reaction, the raw material o-HCA-2A
However, no sublimation of TPA was observed. The obtained polyarylate was an amorphous polymer with an average degree of polymerization of 58, a glass transition temperature of 189°C, and excellent color tone and transparency. This polymer was molded into a barb shape at 330°C, and when the barb was ignited and the fire source was moved away, it immediately extinguished, indicating that it had good flame retardant properties. Furthermore, when this polyarylate was analyzed by infrared absorption spectrum, NMR spectrum, and elemental analysis, the following results were obtained, confirming that it was a polyarylate having a repeating unit with the following structure. In other words, in the infrared absorption spectrum, it is 1780k.
Absorption based on C=O of aromatic carboxylic acid ester is observed in 736k and 781k, and para-substituted aromatic absorption is observed in 736k and 781k.
Absorption of asymmetric trisubstituted aromatics was observed at 878k. Furthermore, in the NMR spectrum, no absorption of hydrogen atoms of methyl groups (1.5 ppm and 2.3 ppm) based on the raw material acetate ester was observed. According to the results of elemental analysis, C = 68.8% (theoretical value 68.7
%), H = 3.38% (theoretical value 3.33%), P = 6.77%
(Theoretical value: 6.82%). The results of Example 1 and Example 2 are shown in Table 1.

[Table] Examples 3 to 4 Experiments were conducted in the same manner as in Example 1 except that other aromatic dicarboxylic acids shown in Table 2 were used instead of TPA. A quality polymer was obtained. This polymer was molded into a barb shape at 330°C, and when the barb was ignited and the fire source was moved away, it immediately extinguished, indicating that it had good flame retardant properties. The results are listed in Table 2.

[Table] Examples 5 to 6 Experiments were conducted in the same manner as in Example 2, except that other aromatic dicarboxylic acids shown in Table 3 were used instead of TPA, and the color tone, transparency, and flame retardance were An excellent amorphous polymer was obtained. The results are listed in Table 3.

[Table] Reference Examples 1-2 As reference examples, the characteristic values of polyethylene terephthalate and U polymer (Unitika, trade name U-100) are shown in Table 4.

[Table] Polyethylene terephthalate has good color tone and transparency, but when the tegus was ignited, it continued to burn until it burned out even if the fire source was moved away. Further, it can be seen that the Tg is lower than that of the polymer of the present invention, and the heat resistance is inferior. In addition, the U polymer has a brown color, and when the flame source is ignited and the fire source is moved away, the U polymer continues to burn for several seconds, indicating that the flame retardance is slightly inferior to that of the polymer of the present invention. In addition, Econol (Sumitomo Chemical Co., Ltd., trade name
E2000) has excellent heat resistance with a heat distortion temperature of 293°C, but once ignited it continues to burn for several seconds, indicating that its flame retardance is slightly inferior to that of the polymer of the present invention.

Claims (1)

[Scope of Claims] 1. A heat-resistant polyarylate consisting of repeating units represented by the following structural formula () and having an average degree of polymerization of 10 to 300. (However, R1, R2, and R3 are selected from halogen atoms and lower alkyl groups having 1 to 8 carbon atoms. Also, n ₁ and n ₂ are each 0 to 4, and n ₃ is 0 to 3.
represents an integer. )