JPS60120719A - Manufacturing method of aromatic polyester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved process for making improved copolyesters. More particularly, the present invention provides starting materials aromatic dicarboxylic acids, dihydroxyphenol and p
- A method for producing an oxybenzoyl polyester of a hydroxybenzoic acid compound.

It is known that polyester resins of this type can be produced by moderate polymerization methods including suspension polymerization and bulk polymerization.

Of these, the bulk polymerization method is probably the most desirable from an economic point of view. However, because aromatic polyesters have higher melting points than aliphatic polyesters such as polyethylene terephthalate, relatively high temperatures are required to keep them molten. Therefore, the polymers often become colored and their performance deteriorates.

Furthermore, it has been experienced that it is difficult to obtain constant melting characteristics of resins even from different lots. Obviously, changes in melting conditions are undesirable in industrial operations;
This results in less efficient operations and undesirable variations in the moldings.

Therefore, much effort has been devoted to the development of methods to provide polyester molding materials which eliminate the above-mentioned drawbacks and which make it possible to obtain products with favorable and uniform appearance and properties.

According to the present invention, it is possible to consistently produce polymers with extremely low degree of discoloration and excellent thermal stability that could not be obtained by conventional bulk polymerization.

One object of the present invention is to provide a method for producing aromatic polyesters having extremely low degree of discoloration and excellent thermal stability.

It is a further object of the present invention to provide an improved process for the consistent and economical production of aromatic polyesters of good quality.

It is still a further object of the present invention to provide polyesters having reproducible melting points and crystallization temperatures.

Other aspects of the invention and its applicability will become apparent from the detailed description below. It is believed, however, that various changes and modifications within the spirit and embodiments of the invention will become apparent to those skilled in the art from the following description, so that the following detailed description and specific examples are not included herein. It is to be understood that, while indicating preferred embodiments of the invention, the description is given by way of example only. According to the invention, salts, in particular alkaline earth metal salts or alkali salts and preferably It has now been found that, by an improved process characterized by the addition of potassium sulfate, a method is provided for obtaining polyester resins which overcome the problems encountered in the implementation of the conventional process and which do not exhibit the above-mentioned disadvantages in use. It was done.

The wholly aromatic polyester to which the production method of the present invention is applied consists of one or more combinations of repeating units of the following formula.

where X is O, S, O, NH or SO, 1 C-, n is Oi or l, and the integer of the repeating part present 'I) 4- q+ r+ 8 + t +
The sum of u ranges from about 3 to about 800.

The combination of the above units is formula 1. n,? / and vg carbonyl group and formula 1. J Contains a bond with the oxy group of ① and ②.

In the most common combination, all units of the above formula can be present in a single copolymer. A simple example would be a homopolymer with units l and ■.

Other combinations include mixtures of the units ■ and ■, ■ and ■, m and v, v and ■, and l and ■.

The position of the functional group is preferably the para (1,4) position.

They can also be in meta positions with respect to each other. Regarding the naphthalene moiety, the most preferred position of the functional group is 1
, 4.1.5 and 2.6. Groups of this type can also be in meta position with respect to one another.

The symbols 7'l'71rl'l' and U are integers and represent the number of repeating moieties present in the polymer.

Total number (7) + q+ r +s + t +u)
can vary from 3 to 800 and, if present, the ratio q/r, q/i t/r, t/i i', lO, the most preferred ratio being 10/10 and more. Ru.

formula! Examples of substances from which repeating moieties of can be obtained are p-hydroxybenzoic acid, phenyl parahydroxybenzoate, p-acetoxybenzoic acid and inbutyl-p-acetoxybenzoate.

Among those from which repeating moieties of Formula I can be derived are terephthalic acid, inophthalic acid, diphenyl terephthalate, diethylisophthalate, methylethyl terephthalate and inbutyl half ester of terephthalic acid. Compounds from which the repeating moiety 2) is obtained include p, 7)'-bisphenol, p+ p'-oxybis-phenol, 4I4
'-Dihydroxybenzophenone, resorcinol and hydroquinone are present. It will become clear that these materials are also suitable as repeating parts of formulas (1) to (2).

An example of a monomer represented by 2 is 6-hydroxy-1
-naphthoic acid, 5-acetoxy-1-naphthoic acid and phenyl-5-hydroxy-1-naphthonic acid. Monomers representing formula V include 1°4-naphthalenedicarboxylic acid, IL5-7taledicarboxylic acid and 2,6-naphthalenedicarboxylic acid. Diphenyl esters and dicarbonyl chlorides of these acids can also be used.

Examples of representative monomers in 2) are 1,4-dihydroxynaphthalene, 2,6-dihydrosinaphthalene and 1,5-dihydroxynaphthalene.

Particularly preferred for use in the practice of this invention are oxybenzoyl polyester-based plastic materials.

Oxybenzoyl polyesters useful in this invention generally have repeating units of formula (1).

where p is the order of magnitude from about 3 to about 600.

One preferred type of oxybenzoyl polyester is wherein R' is selected from the group consisting of benzoyl, lower alkanoyl or preferably hydrogen, and R2 is hydrogen, benzyl, lower alkyl or preferably phenyl and necessarily, and p is from 3 to 600, preferably 3
This is a type of expression (■) that is an integer from 0 to 200. The value of p corresponds to a molecular weight of about 1000 to 72000, preferably 3500 to 25000. The synthesis of these polyesters is known as “Hydroxybenzoic acid-based polyesters” (“PoLyesters Ba5e”).
d on Elldrowy-banzoic Ac1
No. 619.577, now abandoned, filed March 1, 1967, herein incorporated by reference. This application is referenced in US Pat. No. 3,668,300.

Another preferred type of oxybenzoyl polyester is (K) where X is 10 or -SO,-, m is 0 or 1, n is 0 or 1, and p: γ = 10 :15
to 15:10, p:q=1:xoo to 100:1,
p+q -1-r = a to 600, preferably 20
It is a copolyester of repeating units of formulas (1), (2) and (2), which are from 200 to 200. The carbonyl group in the repeating part of formula l or ■ is represented by formula 1'
It is bonded to the oxy group of the repeating moiety of formula I or ■, and the oxy group of the repeating moiety of formula I or ■ is bonded to the oxy group of the repeating moiety of formula I or ■. Or it is bonded to the carbonyl group of the repeating part of m.

The preferred copolyester is (X) It has a repeating unit of formula X.

The synthesis of this type of polyester is known as "p-oxybenzoyl copolyester"("p-0zybenzoylC").
U.S. Pat.

Bulk condensation of aromatic polyesters is described in the patent literature and broadly includes an alkanoylation step in which the appropriate gadicarboxylic acid, hydroxybenzoic acid and diol are reacted with an acid anhydride, and the reaction product of the first step is polycondensed. a prepolymerization step to form a prepolymer and then heating the prepolymer to form a polycondensate with a desired degree of polymerization.

The polyesters useful in this invention can be chemically modified by various means such as incorporating into the polyester tri- or higher functional reactants such as trimesic acid or cyanuric acid chloride or monofunctional reactants such as benzoic acid. You can also. The benzene ring in these polyesters is preferably unsubstituted, but can be substituted with non-interfering substituents, examples of which include:
Other halogens such as chlorine or bromine, lower alkoxy such as methoxy, and lower alkyl such as methyl are included.

Salts can be organic or inorganic salts.

However, it is preferable to use alkaline earth metal salts. More particularly, salts such as aluminum acetate, calcilanoacetate, calcium sulfate, copper acetate, magnesium acetate, magnesium prephthalate, potassium acetate, potassium chloride, potassium phosphate, sodium acetate, sodium sulfate and potassium bisulfate may be used. I can do it.

Although it is contemplated that the salt may be added at any stage of production, it is particularly effective when added with the monomer charge and provides significantly superior properties in articles molded from oxybenzoyl polyester resins. It was discovered that

The salt can be added as a solid or as a solution at a temperature above the melting point of the salt. It is also possible to add the salt as a solution if the formulation is carried out at low temperatures.

Generally, salt is added over a range of about 25.0 ppm to about 500 ppm.

The exact mechanism by which the processability of polyester and the appearance and properties of articles molded from polyester are significantly improved by the addition of the salts described above is not completely understood. However, it has been observed that when the above-mentioned salts are used during the polyester processing step, the persistence of the peak height of repeated endothermic transitions and the achievement of a constant exothermic transition is significantly and substantially improved.

It is known that aromatic oxybenzoyl polyester polymers exhibit an endothermic transition corresponding to the melting point of polyester. Upon cooling, an exothermic transition or crystallization occurs. If a strong exotherm is observed, the transition can be described as reversible.

The observations and results listed in the table below indicate that the addition of a salt such as potassium sulfate significantly improved the reversibility of peaks detected by differential scanning calorimetry or DSC.

In measuring the duration of the peak height, the endotherms of the second and second heating cycles are recorded on the same scale. Measure the distance from the baseline to the peak and divide the height of the first period peak by the height of the second period peak and multiply by 100. This value is expressed as a "percent persistence value".

When measuring the endotherm for salt-free aromatic oxybenzoyl polyesters, it is difficult to determine the onset of the transition at the second period peak and the width or broadening of the heating curve makes it difficult to measure the peak. becomes.

Therefore, the temperature change between the onset of the transition and the peak is of a gradual nature and exhibits a heating curve in the form of a gentle slope or rounded hill. Such peaks are described herein, particularly in the Examples, as broad or diffuse peaks.

The second period peak obtained when a salt is incorporated in the treatment of aromatic polyester according to the present invention is sharp and clear due to the well-defined temperature curve, in which case the transition onset temperature and peak maximum temperature can be easily measured. be done.

It is to be understood that the following examples illustrate the invention but do not in any way limit the invention, which has the embodiments defined in the appended claims.

Example 1 4.4'-dihydroxybiphenyl 268 bond, p-
396 pounds of hydroxybenzoic acid, 238 pounds of terephthalic acid
Bond and acetic anhydride 690 bond were charged into the reaction tank.

The reactor was flushed with nitrogen and the reactants were heated to reflux temperature with stirring and continued heating for a minimum of 3 hours. The temperature of the reaction mixture was then raised to 315°C and distillation was started without reflux and continued for about 5 hours. At this point distearyl pentaerythritol diphosphite FO, 7t bond was added and after 10 minutes the viscous melt (conversion 93.34 based on distillate yield) was transferred to an insulated stainless steel pan. The solution was injected into the solution and allowed to cool under a nitrogen atmosphere. Next, it was taken out and crushed (particle size <1
．． 2 fights, 80% < 0.5 attacks). The yield of prepolymer after milling was 90%.

The prepolymer was further polymerized in the solid state by shaking in a rotary heating vessel. The prepolymer was heated at 23°C/
The mixture was heated from ambient temperature to 365° C. at a rate of 100 hr and cooled immediately. The resulting polymer was obtained as a free-flowing powder.

Example 2 The procedure of Example 1 was repeated using exactly the same materials and procedures, with the only exception that 57 g of potassium sulfate was added to the reaction vessel along with the monodisperse charge.

DSC (differential scanning thermal scanning:
The endothermic and exothermic peaks of the total temperature) were measured and are shown in the i@1 table below.

Table 1 1) SC endothermic peak DSC exothermic start Example 1 41O weak* 366 355 Example 2 42
1 419 381 381 *The peaks recorded were of a broad and diffuse shape, showing no sharp and distinct peaks.

Example 3 4.4'-dihydroxybiphenyl 204. O,! i
'(1,o 9s mol), p-hydroxy-benzoic acid 3
oi, ig (zis mole), tev 7 taA/acid 181
．． 1 g (1,09 mol) and acetic anhydride s 26.61/
(5.t58 mol) was charged into a reaction vessel, placed under nitrogen atmosphere and heated to reflux temperature with stirring, which continued for a minimum of 3 hours. Distillation was then started without reflux and continued for approximately 5 hours, during which time the temperature of the reaction mixture was increased to 31 °C.
The temperature was raised to 5°C. At this point, 0.76 g of distearylpentaerythritol diphos 7i) was added and after 10 minutes the viscous melt (933% conversion based on distillation yield) was filtered into an aluminum foil lined tube. The mixture was poured into a heated stainless steel beaker and kept at 30°C. The prepolymer was kept at 300°C for 20 hours under nitrogen atmosphere, then taken out, allowed to cool and ground (particle size <
12 degrees; 80 degrees (o, s m). The yield of prepolymer after pulverization was 90 fj.

The prepolymer was polymerized in the solid state by shaking the prepolymer in a rotating aluminum drum in a furnace under a nitrogen atmosphere.The prepolymer was heated from 204°C to 354°C and held at the higher temperature for 1 hour. Upon cooling, the resulting prepolymer was obtained as a free-flowing powder.

Example 4 The method of Example 1 is repeated using exactly the same materials and procedures, with the only difference being that, along with the monomer charge, 0.067 ml of potassium sulfate! i' was added to the reaction vessel.

The DEC (Differential Scanning Calorimeter) endothermic peaks for the first and second heating cycles are measured and listed in the table below along with the percent duration of the endothermic peak height.

Table 3 Example 3 34 422 417* Example 4 107 416429 * The peaks recorded were of a broad, diffuse shape and showed no sharply defined peaks.

Similar comparisons were made with several other polyesters, with the comparisons prepared according to the method of Example 1 and the potassium sulfate containing polyesters prepared according to the method of Example 2. The results are shown in the table below.

Example 5 0 27 414 412*Example 6110
71 414 422 Example 7 0 40 418
417*Example 8110 75 422 426* The peaks recorded were in a broad, diffused form and did not exhibit sharp, well-defined peaks.

As shown above, the salt-containing polyesters exhibited significantly improved percent persistence values of endothermic peak height.

A comparison between the comparison prepared according to Example 1 and the salt-containing polyester prepared according to Example 2 is shown in Table 2. In Examples 10, 12, 16°20 and 22, the same comparative material was used;
Polyesters 5.19 and 21 are listed separately for more direct comparison.

Example 9 Aluminum acetate 98 5° Example 10
Comparison 0 22 Example 11 Calcium acetate 152 35 Example 12
Comparison 022 Example 13 Copper acetate 84 84 Example 14 Comparison 032 Example 15 Magnesium acetate 126 86 Example 1
6 Comparison 0 22 Example 17 Potassium chloride 100 70 Example 18
Comparison 0 18 Example 19 Sodium acetate 73 38 Example 20
Comparison 0 22 Example 21 Sodium sulfate 73 38 Example 22
Comparison 0 22 Even when salts such as calcium sulfate, magnesium terephthalate, potassium acetate, potassium phosphate, and potassium bisulfate are used in place of the salts specifically listed in Table 2,
Similarly significantly improved percent persistence values were obtained compared to the comparators with broad or diffuse second period peaks.

Example 23 4.4′-dihydroxy-biphenyl 344.5 bonds, p-hydroxybenzoic acid 514.0 bonds, terephthalic acid 309.0 bonds, acetic anhydride 8960 bonds and potassium sulfate 57.0 g were charged into a reaction vessel. . It was placed under a nitrogen atmosphere and heated to reflux temperature with stirring for a minimum of 3 hours. Distillation was then started without reflux and continued for about 5% while increasing the temperature of the reaction mixture to 315°C. At this point, distearyl pentaerythritol diphosphite 416. (l) was added and after 10 minutes the viscous melt (93.3% conversion based on distillate yield) was poured into an insulated stainless steel pan, placed under nitrogen atmosphere and allowed to cool. Then it was taken out and crushed (particle size: 1.2m).
, 80% capacity).

The prepolymer was further polymerized in the solid state by shaking in a rotary heating vessel under nitrogen. The prepolymer was heated from ambient temperature to 365° Ct and immediately cooled. The resulting polymer was obtained as a free-flowing powder.

As for the characteristic values of the polymer, the second and second endothermic peaks were at 416° and 418°, and the first and second exothermic points were at 377° and 379°.

Example 24 A series of 65 experiments were conducted using 93 ppm of potassium sulfate based on the final polymer to prepare a polyester according to the method of Example 23. The average onset of heat generation in the first cycle was measured to be 3778°, and the average onset of heat generation in the second cycle was measured to be 3784°. The proximity of these points 7 is extremely important with respect to consistency and reproducibility in injection molding operations. The products obtained by injection molding of polyester were of high quality.

In the table above, the amount of salt used is ppm in the final polymer.
It is a standard.

In the above examples and the appended claims, the term "advancing" is to be understood as polymerization in the solid state.

Patent Applicant: Dart Industries, Inc.

Claims (1)

[Claims] 1. Generating a prepolymer by thermally condensing a precursor;
A method for producing an aromatic polyester by a method comprising thereafter further polymerizing said prepolymer to produce a polymer of a desired degree of polymerization, wherein a salt is incorporated during the reaction operation prior to completion of polymerization. A method characterized by: 2 Polyester is represented by the following formula, where X is O, S, O, NH or SO. 1 C-, and n is 0 or l, and the integer p0q+γ0g-1-t- in the repeating part of the above formula
2. The method of claim 1, comprising repeating portions selected from the group consisting of one or more of the following, wherein the sum of 1-u is from about 3 to about 800. 3. The method according to claim 2, wherein the salt is added in an amount of 25 to 500 ppm. 4. The method according to claim 2, wherein the salt is an organic salt. 5. The method according to claim 2, wherein the salt is an inorganic salt. 6. The method according to claim 2, wherein the salt is an alkali metal salt. 74. The method according to claim 2, wherein the salt is an alkaline earth metal salt. 8. The method according to claim 3, wherein the salt is potassium sulfate. 9. The method according to claim 3, in which the addition of salt is carried out together with the introduction of a single substance. A patent in which the IO salt is selected from the group consisting of aluminum acetate, calcium acetate, calcium sulfate, copper acetate, magnesium acetate, magnesium terephthalate, potassium acetate, potassium chloride, potassium phosphate, sodium acetate, sodium sulfate, and potassium bisulfate. Claim 1
The method described in section.