JPS61166831A - Separation of aromatic polyester copolymer - Google Patents

Abstract

PURPOSE:To separate a polyester produced by contacting an alkaline aqueous solution of 1,1-bis(4-hydroxyphenyl)-1-phenylethane, etc. with an organic solvent solution of isophthalyl chloride, etc., by crushing the polyester after or simultaneous to gelation, and removing the solvent therefrom. CONSTITUTION:(A) An alkaline aqueous solution of a substance composed of 100-80(mol)% or 50-10% 1,1-bis(4-hydroxyphenyl)-1-phenylethane and 0-20% or 50-90% 2,2-bis(4-hydroxyphenyl)propane is made to react with (B) an organic solvent (preferably methylene chloride, etc.) solution of a substance composed of 100-75% or 0-30% terephthaloyl chloride and 0-25% or 100-70% isophthaloyl chloride. The obtained organic solvent solution of polyester is optionally washed and concentrated, and crushed after or simultaneous to gelation, and the organic solvent is removed to obtain powdery or granular polyester having high bulk density.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for isolating aromatic polyester copolymers. 1. Aromatic compound obtained from dihydric phenol containing 1-bis-(4-hydroxyphenyl)-1-phenylethane (hereinafter referred to as BP-A, CP) as a component and terephthalic acid chloride and/or isophthalic acid chloride The polyester copolymer is an aromatic polyester floride copolymer obtained from 2,2-bis-(4-hydroxyphenyl)-propane (hereinafter referred to as BPA), terephthalic acid chloride, and isophthalic acid chloride.
It is an organic solvent solution of an aromatic polyester copolymer obtained by interfacial polycondensation. However, there is no known method for easily and economically advantageously obtaining aromatic polyester copolymer powder or granules having a higher bulk density, which is problematic.

That is, an organic solvent solution of the aromatic polyester co-M itself obtained from a mixture of an alkaline aqueous solution of BPA, 30 to 70 mol% of terephthalic acid chloride, and 70 to 30 mol% of isophthalic acid chloride is washed and concentrated as necessary. It is known that it is possible to remove the organic solvent by crushing this after or simultaneously with gelation. However, even if an attempt was made to obtain a copolymer powder by the above method using BPA OP instead of BPA, it was found that the powder could not be obtained. Furthermore, even if gelation is attempted by adding methanol as a non-solvent, gelation does not substantially proceed and the result is a sticky mass. As a result of intensive studies on copolymer compositions that can be gelled in isolation methods, the present invention was achieved. That is, the present invention uses 100 to 80 mol% of BP-ACP and BP-ACP.
A aqueous alkaline solution of a substance consisting of ~20 mol% of AQ is brought into contact with an organic solvent solution of a substance consisting of 100-75 mol% of terephthalic acid chloride and 0-25 mol% of isophthalic acid chloride, or BP-A CP 5
Q - I Q mol% and BPA 50-90 mol%
An alkaline aqueous solution of a substance consisting of 100 to 70 mol% of isophthalic acid chloride and 0 terephthalic acid chloride
An organic solvent solution of an aromatic polyester produced by contacting with an organic solvent solution of a substance consisting of ~30 mol% is washed and concentrated as necessary, and after gelation or simultaneously pulverized, the organic The present invention relates to a method for isolating the aromatic polyester copolymer, which comprises removing the solvent.

In carrying out the present invention, organic solvents typically include hydrocarbons, hydrogens, halogenated hydrocarbons, and the like. Benzene, toluene, etc. are used, but it is particularly preferable to use a solvent for the produced polyester, and methylene chloride, 1,2-dichloroethane, 1,1,2-1-dichloroethane, tetrachloroethane, etc. are preferably used.
Methylene chloride is a typical example.

The interfacial polymerization reaction is carried out using an aqueous alkaline solution of bisphenols and an organic solvent solution of aromatic dicarboxylic acid chloride, but since the aqueous phase and organic phase are not substantially compatible, the polymerization reaction occurs near the interface between the two. progresses. It is usually carried out under vigorous stirring at room temperature and pressure. The aromatic polyester copolymer obtained by the polymerization reaction is dissolved in an organic solvent phase. On the other hand, the aqueous phase is mainly composed of alkali halides. A method such as static separation or separation using centrifugal force is used to separate the organic phase in which the polymer is dissolved and the aqueous phase.

The obtained aromatic polyester copolymer solution is mixed with water,
It is then washed by methods such as re-separation, countercurrent extraction, and filtration. This cleaning may be omitted or the degree of cleaning may be changed if necessary. In order to obtain a polymer with good properties, sufficient washing is preferred. Separation of the organic phase and the aqueous phase does not have to be carried out strictly; when both phases are mixed, that is, even when water is present, not only is there no adverse effect, but gelation may be promoted.

The polymerization reaction is usually carried out such that the concentration of the polymer produced is in the range of 3 to 20%, preferably in the range of 5 to 10%. The polymer solution is then concentrated to a polymer solubility of more than 25%, preferably 30 to 40%.

The polymer may be concentrated by simply stirring in an open system to evaporate the organic solvent, but usually a thin film evaporator or the like is used.

Since the boiling point of the organic solvent is low, normal pressure is sufficient, and it is preferable to carry out the process under increased pressure rather than reduced pressure.The reason is that increasing the pressure increases the boiling point of the organic solvent, making it possible to raise the operating temperature. As a result, the viscosity of the polymer solution decreases, making it possible to concentrate it to a considerably high concentration.

Of course, if the polymer concentration of the organic solvent solution of the aromatic polyester copolymer is as high as 30% or more before the concentration operation is performed, the concentration step is, of course, not necessary. In order to obtain such a highly concentrated polymer solution, the polymerization can be carried out at a high concentration using a reactor with a special stirring mechanism, or it can be carried out at a dilute concentration, and then a solid solution obtained by, for example, a stripping method can be used. There is a method in which aromatic polyester copolymer powder is added and dissolved therein. However, from an economic point of view, 5
It is often advantageous to carry out the polymerization at dilute concentrations, such as polymer concentrations of 1 to 1%, followed by concentration.

Furthermore, the concentration may be carried out using the equipment used in the subsequent pulverization step, in which case the concentration, kelization, and pulverization are performed in the same equipment. Polymer 1F
When 2i reaches 25% or more, gelation occurs simply by leaving the solution alone or subjecting it to a certain amount of time. This 5
Gelation means reaching a cake-like, mud-like, or soft solid state. This cake, slurry or solid material is pulverized using a suitable pulverizer. The suitable crusher differs somewhat depending on the polymer concentration of the gelled product, but a hammer mill or the like that is used for crushing ordinary hard solids cannot be used because it is extremely sticky. On the other hand, fine powder can be obtained by using a kneading machine such as a kneader. In particular, it is desirable to use a continuous kneader with a wing structure that allows normal kneading for a short time immediately after feeding, and then continues gentle kneading in order to obtain a fine powder. It is desirable to further distill off the organic solvent, and it is also possible to circulate air or nitrogen gas through the system to promote extrusion of the organic solvent.It is also possible to perform pulverization after gelation as described above. However, gelation and pulverization may be performed simultaneously.

It is also possible to add a non-solvent in the above operation. Non-solvents include methanol, ethanol,
Examples include alcohols such as isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; and hydrocarbons such as hexane, heptano, and cyclohexane. The non-solvent can be added by any method, such as adding it to a polymer solution that has been thoroughly washed after polymerization, or adding it after concentrating the polymer solution as described above. In addition, it is also possible to gel and crush the rice cake-like material that is produced when adding a non-solvent without separating it from the non-solvent, but any method such as isolating the rice cake-like material and gelling and pulverizing it is also possible. It is. The powder or granules thus obtained have a size of several meshes to several millimeters in diameter, and the polymer concentration is usually 50 to 70%. Thereafter, the organic solvent is further removed using a rotary dryer or a fluidized fluid dryer. Aromatic polyesters can be obtained as powders or granules. If moxibustion is necessary, this is further washed with water or methanol, hexane, xylene, etc., and then dried. The aromatic polyester copolymer thus obtained can then be pelletized by other well-known methods using an extruder or the like.

Alternatively, the aromatic polyester copolymer obtained by the method of the present invention, which can be redissolved in a solvent and used as a raw material for cast films or coating agents, can be used for polyethylene, polypropylene, polystyrene, A
Modification is possible by mixing BC@ fat, polymers of acrylic acid or their derivatives, polyethylene terephthalate, various rubbers, or copolymers of these, but one method for such modification is to convert the powder of the modified product into an aromatic compound. It can be dissolved or dispersed in an organic solvent solution of the polyester copolymer and incorporated into the gel when the aromatic polyester copolymer is gelled.

It is also possible to incorporate other inorganic powders such as glass powder as reinforcing materials into the gel body, as well as heat-resistant agents, light-resistant agents, antioxidants, and other additives for pigments. For example, the process is simple and economical compared to known polymer isolation methods, and the bulk density of the isolated aromatic polyester is large, which is advantageous for handling and subsequent steps such as pelletization. The quality of the products obtained therefrom is also good and has many advantages over known methods.

Next, the present invention will be explained in detail with reference to Examples.

Example 1 BP-AOP 116.05' (0,40m01),
Caustic saw 1”88.6 P (0.84 mol), P
-ta 0.58P (0,003mol), sodium sulfite 0.28? (0,0018m01) water 140
After dissolving at 0°C, keep the internal temperature at 25°C. 81.2 P of terephthalic acid dichloride (0.40 mO) dissolved in 700 m of methylene chloride is added with vigorous stirring via a dropping funnel.

Polymerize for about 4 hours while keeping the internal temperature at 25°C.

Next, after removing the supernatant liquid, dilute with 600ml of methylene chloride, add a small amount of water 1000cc1 hydrochloric acid to adjust the Pfi to 2, wash the polymer, thoroughly wash with water, remove the supernatant liquid, and dilute with methylene chloride containing the polymer. The solution was concentrated to a polymer concentration of 3Qwt% by distilling off some of the methylene chloride using a rotary evaporator, and the resulting mixture was transferred to a lab blast mill maintained at 50°C and heated at a rotation speed of 30 to 50 r, p, m. Smash. In about 15 minutes, the polymer is ground into a powder. To completely remove methylene chloride, vacuum dry at 120°C for 24 hours.5 The obtained polymer is 165.2P, yield 97.7%, ηSr/C1
,01 (η8P7C is C=0.55 in chloroform solvent
Example 2 Polymerization was carried out in the same manner as in Example 1, and after washing, the polymer was 8%
The polymer was concentrated to 20%, and methanol 300% was gradually added to solidify the polymer, and the cake-like polymer was ground in a lab blast mill in the same manner as in Example 1 and dried. .15&, yield 94.7%
, ηSp/C=0.91, and bulk density 0.41.

Examples 8 to 5, Comparative Examples 1 to 6 In the same manner as in Example 1, BP-ACP was used instead of BP-ACP.
ACP or/and BP, terephthalic acid chloride (T
PO) was replaced with TPC or/and IPC (isophthalic acid chloride), and interfacial polycondensation was carried out at the molar ratios shown in Table 1. After adding 2 to 5 mol % of t-butylphenol to the dihydric phenol as a molecular weight regulator, the polymer solution was thoroughly washed with water, and methanol was gradually added dropwise.

Addition of methanol 1 [400-500- becomes cake-like,
When stirring was continued gently, a fine powder was obtained after 2 to 3 hours (gelation). In Table 1, the mark Q indicates where gelation occurs. In Table 1, the mark X indicates the product that does not gel even after 10 hours of continued stirring after it has become cake-like.

The Tg- of the polymer was measured by DEC after vacuum drying the above polymer at 100° C. for one day and night.

Table 1

Claims (1)

[Claims] 1,1-bis-(4-hydroxyphenyl)-1-phenylethane 100-80 mol% and 2,2-bis-(
An alkaline aqueous solution of a substance consisting of 0 to 20 mol% of 4-hydroxyphenyl)-propane and 100 to 75 mol% of terephthalic acid chloride and 0 to 0 to 75 mol% of isophthalic acid chloride.
or 1,1-bis-(4-hydroxyphenyl)-
1-phenylethane 50-10 mol% and 2,2-bis-(4-hydroxyphenyl)-propane 50-90%
An organic solvent for an aromatic polyester copolymer produced by contacting an alkaline aqueous solution of a substance consisting of mol% with an organic solvent solution of a substance consisting of 100 to 70 mol% of isophthalic acid chloride and 0 to 30 mol% of terephthalic acid chloride. 1. A method for isolating an aromatic polyester copolymer, which comprises washing and concentrating a solution as necessary, and pulverizing the solution after or simultaneously with gelation to remove an organic solvent.