JPS5918413B2 - Polyester manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing polyester.

The purpose is to provide a new method for producing linear polyester with excellent stability and transparency. Generally, in the production of polyester, it is necessary to use a catalyst in order to carry out the esterification reaction, transesterification reaction, and polycondensation reaction within a practically sufficient time, and many catalysts have been proposed for this purpose. .

However, in many of the known metal compound catalysts for esterification and transesterification reactions, trivalent and/or pentavalent phosphorus compounds are usually added as stabilizers to thermally decompose the polymer during the high-temperature polycondensation reaction. It is known (for example, the specifications of British Patent Nos. 588833 and 588834, Japanese Patent Publication No. 32-6897, etc.). However, these phosphorus compounds may impair the hydrolysis resistance of the resulting polyester, react with catalysts containing certain metal ions to produce insoluble compounds, or reduce certain polymerization catalysts. It has the disadvantage of worsening the color tone of polyester.

As a result of intensive studies by the present inventors to eliminate these drawbacks, the present inventors found that as a stabilizer in the polyester manufacturing process,
The present inventors have discovered that these drawbacks can be solved by adding a crown ether compound instead of a phosphorus compound, and have thus arrived at the present invention.

That is, the present invention is characterized in that at least one crown ether compound is added when producing a linear polyester through an esterification reaction and/or transesterification reaction using at least one catalyst, and then a polycondensation reaction. This is a method for producing polyester.

In the method of the present invention, the polyester is a substantially linear polyester, including (a polyester composed of a dicarboxylic acid and a dihydroxy compound, (2) a linear homopolyester such as a polyester composed of an oxycarboxylic acid, etc.); Although the main target is copolyester,
Branching agents such as glycerin, pentaerythritol, dipentaerythritol, sorbitol, butane-1,2,4-tricarboxylic acid, trimellitic acid, pyromellitic acid, 5-oxyisophthalic acid, 2,5
- Trifunctional or higher polyfunctional compounds, such as dioxyterephthalic acid, and monofunctional compounds, such as benzoic acid, O-benzylbenzoic acid, and methoxypolyalkylene glycol, also have polymers that are substantially linear. They may be copolymerized within a certain range.

The dicarboxylic acid components constituting the polyester (1) include (a) succinic acid, glutaric acid, adipic acid,
aliphatic dicarboxylic acids such as pimelic acid, sebacic acid, decamethylene dicarboxylic acid, bicyclohexane dicarboxylic acid, bicyclohexyl-4,4'-dicarboxylic acid,
cyclobutane-1,3-dicarboxylic acid, decalin 2,
Alicyclic dicarboxylic acids such as 6-dicarboxylic acids, ←→
Phthalic acid, isophthalic acid, terephthalic acid, methyl terephthalic acid, methyl isophthalic acid, chlorterephthalic acid, bromiterephthalic acid, dichloroterephthalic acid, diprometerephthalic acid, 5-chloroisophthalic acid, 5-bromiisophthalic acid, 1,5 -dichloronaphthalene-2,6-dicarboxylic acid, 1,5-dibromnaphthalene-2,6-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid , tetralin-1,5-dicarboxylic acid, tetralin-2,6-dicarboxylic acid, biphenyl-4,4'
-dicarboxylic acid, biphenyl-3,4-dicarboxylic acid,
1,2,3,4,5,6-hexahydrobiphenyl-4
, dicarboxylic acid, diphenylsulfone-4,4'-
dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenyl ketone-4,4'-dicarboxylic acid,
Aromatic dicarboxylic acids such as diphenooxyethane-4,4'-dicarboxylic acid and the like can be mentioned.

Dihydroxy compound components include (a) ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, octamethylene glycol,
Aliphatic glycols such as decamethylene glycol and neopentylene glycol; (b) Alicyclics such as cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, decalin-2,6-dimethanol, tricyclodecane dimethanol, etc. Glycol, ←→ Hydroquinone, bisphenol A) 3,3',5,5'-tetrachlorobisphenol A) 3,3',5,5'-tetrabromobisphenol A) 3,3! ,5,5'-tetrachloro4,4'-
Dioxybiphenylsulfone, 3,i,5,5/-tetrabromo-4,4'-dioxybiphenylsulfone, 4
, 4'-dioxybiphenyl, 4,4'-dioxybiphenylsulfone, 1,1-bis(p-oxyphenyl)
Aromatic dioxy compounds such as cyclohexane, item 1,
4-bis(β-hydroxyethoxy)benzene, 4,4
'-Bis(p-β-hydroxyethoxyphenyl)-sulfone, 2,2-bis(p-β-hydroxyethoxyphenyl)-propane, 2,2-bis(4-β-hydroxyethoxyphenyl)-3,5- dichlorophenyl)propane, 2
, 2-bis(4-β-hydroxyethoxy-3,5-dibromphenyl)propane, 1,1'-bis(4-β-
Aliphatic glycols containing an aromatic nucleus such as hydroxyethoxy 3,5-dichlorophenyl) sulfone, 1,1'-bis(4-β-hydroxyethoxy 3,5-dibromphenyl) sulfone, etc., polyethylene glycol ,
Examples include polyether glycols such as polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, and the like.

The oxycarboxylic acid component constituting the polyester in (2) above includes (g) aliphatic oxycarboxylic acids such as ω-oxycaproic acid, ω-oxyundecanoic acid, etc.;
p-oxybenzoic acid, p-2-hydroxyethoxybenzoic acid, p-(p-2-hydroxyethoxy)
Aromatic oxycarboxylic acids such as phenyl-benzoic acid and the like can be mentioned.

The above-mentioned polyester can be produced by, for example, 1) reaction of dicarboxylic acid and/or lower alkyl ester or aryl ester thereof with a dioxy compound, 2) reaction of oxycarboxylic acid and/or lower alkyl ester or aryl ester thereof, and 3) diglycol of dicarboxylic acid. Reaction of ester and dicarboxylic acid, 4) Reaction of a low polymer obtained by reaction of dicarboxylic acid or oxycarboxylic acid and ethylene oxide or ethylene carbonate, 5) Reaction of dicarboxylic acid halide and dioxy compound, 6) Dicarboxylic acid It is produced by a conventionally known method such as reaction of an aromatic dioxy compound such as hydroquinone diacetate with a lower fatty acid ester.

For the initial esterification and/or transesterification reaction of the polyester, a conventionally known catalyst containing metal ions is used.

For example, calcium acetate, zinc acetate, manganese acetate, cobalt acetate, sodium acetate, nickel acetate, lead acetate, uranium acetate, lithium acetate, cerium acetate, lead oxide, antimony oxide, magnesium oxide, zinc oxide, tetrabutyl titanate, potassium titanate. , titanium oxalate, etc., but are not limited to these. Examples of the crown ether compound used in the present invention include the following compounds (* indicates a carbon atom, O indicates an oxygen atom, and hydrogen atoms are omitted.

). However, it goes without saying that the invention is not limited to these compounds.

One or more of these crown ether compounds are selected and used depending on the polyester manufacturing conditions (temperature, time, pressure, etc.), the catalyst used, etc.

For example, aliphatic polyesters are produced at relatively low temperatures, so the heat stability of crown ether compounds is not a big issue, but aromatic polyesters are produced at relatively high temperatures, so crown ether compounds with excellent heat stability are It is necessary to choose an ether compound. It is believed that the crown ether compound of the present invention can stabilize and make polyester transparent by trapping the metal atoms of the catalyst used in the esterification reaction and/or the transesterification reaction within or between the molecules. There is a certain correlation between the metal ion radius and the ether ring radius of the catalyst used.

For example, when trapping a metal ion within a molecule, the closer the radius of the ether ring and the radius of the metal ion, the easier it is to trap, and if the ether ring is too large than the metal ion, the metal ion will slip through. Hard to get trapped. Therefore, it is necessary to select an appropriate raw ether compound depending on the type of metal of the catalyst used. For example, Ca, Zn, Mn, Li, Ce, CO
In the catalyst system containing metals such as
, XXX, XXX, XL, XV, XVI, XVII, X
XII, K. K, XL, XLMI, XX, etc. are preferable.

The crown ether compound in the present invention is added to the reaction system in the esterification reaction step, the transesterification reaction step, and/or the polycondensation reaction step of polyester production.

However, if it is added when the reaction rate of the esterification reaction and/or the transesterification reaction is less than 50%, it is not preferable because the polycondensation reaction may be difficult to proceed depending on the reaction system. Furthermore, if it is added at the final stage of the polycondensation reaction, the effects of the present invention will not be fully achieved. Therefore, it is preferable to add the crown ether compound from the time when the reaction rate of esterification reaction and/or transesterification reaction is 50% or more until the middle stage of polycondensation, and especially from the time when the reaction rate is 90% or more until the early stage of polycondensation. It is preferable to wait until. The addition may be done all at once or in portions. The amount of the crown ether compound added is 40 mol% or more, preferably 80 mol% or more, based on the metal atoms of the catalyst used.

The upper limit of the amount added is not particularly limited, but if it is added in an unnecessarily large amount to the polyester, it may impair the physical properties of the polyester, so it is not more than 10% by weight, especially not more than 5% by weight, based on the polyester. is preferred.
The crown ether compound of the present invention has an excellent effect of stabilizing and clarifying polyester when used in place of a phosphorus compound, which is a known stabilizer for polyester. It can also be used in combination with phosphorus compounds.

In this case, it is necessary to suppress the amount of the phosphorus compound used to less than 50 mol% of the metal atoms in the catalyst used. According to the method of the present invention, a polyester having excellent stability, particularly excellent hydrolysis resistance, can be easily produced.

Furthermore, in systems where the catalyst reacts with the phosphorus compound to form an insoluble precipitate, the transparency of the polyester is improved since the addition of the phosphorus compound is not necessary. Furthermore, excellent effects such as polyester with excellent color tone can be obtained. Examples are given below to illustrate specific examples of the present invention, but the present invention is not limited thereto.
In the examples, all parts indicate parts by weight, and the intrinsic viscosity of the polymer was calculated from the value measured at 35°C in orthochlorophenol. Example 1, Comparative Example 1 97 parts of dimethyl terephthalate, 6 parts of ethylene glycol
5.1 parts of zinc acetate dihydrate and 0.055 parts of zinc acetate dihydrate were charged into a reactor equipped with a rectification column, and the transesterification reaction was carried out at 160 to 220°C. When almost the theoretical amount of methanol had been distilled out (the reaction rate was approximately 100%), Tribenzo 18-Crown-6 (Compound of the above XL) 0.21 part (206% based on the metal atom of the catalyst, 0.22% by weight based on the polymer)
(B) 0.041 part of phosphorous acid was added, and 0.044 part of antimony trioxide was added to each, and a polycondensation reaction was carried out at 2700C for 110 minutes.

Each of the obtained polymers was melted at 275°C and 0.5 m
Spun by discharging from a spinneret with a hole diameter of 7nφ, and heating at 90°C.
The fibers were stretched 4 times with a pin, and then heat-treated to a fixed length at 180° C. to obtain polyester fibers (untreated in Table 1). A portion of the obtained fibers was treated in a free state in water at 120° C. for 4 days (after 4 days in water at 120° C. in Table 1). Table 1 shows the performance of each fiber. It can be seen that the polyester of the present invention has excellent hydrolysis resistance (strength retention) compared to the case where a conventional phosphorus stabilizer is used.

Examples 2 to 6 Polymerization and yarn spinning were carried out in exactly the same manner as in Example 1, except that each compound shown in the upper row of Table 2 was used instead of Compound XL.

The hydrolysis resistance (strength retention after 4 days in water at 120° C.) of the obtained fibers is as shown in the lower row of the same table. It can be seen that the polyester produced by the method of the present invention has excellent hydrolysis resistance. Example 7 97 parts of dimethyl terephthalate, 6 parts of ethylene glycol
5.1 parts of calcium acetate monohydrate and 0.098 parts of calcium acetate monohydrate were charged into a reactor equipped with a rectification column, and the transesterification reaction was carried out at 160 to 220°C. When almost the theoretical amount of methanol had been distilled out (the reaction rate was (about 100%), Jso ZU (4) Tribenzo 18-crown-6 (metallic compound of the above XL) 0.96 parts (1.0% by weight based on the polymer, 470 mol (Ff) based on the metal atoms of the catalyst) )) added, (
B) 0.041 parts of phosphorous acid (1 part per metal atom of the catalyst)
00 mol 0) was added to each system, and 0.044 part of antimony trioxide was added to each system to carry out the polycondensation reaction at 270°C.
It lasted 110 minutes.

Both of the obtained polymers had an intrinsic viscosity of 0.65.
When each of these polymers was formed into a 50 micron thick raw film by a conventional method and the turbidity was measured, (4)
is 1.040! ! , (The day was 1.8160 ri.

From this, it can be seen that the turbidity when using the crown ether compound is about half that when using the phosphorus compound, and the transparency is excellent. Note that the turbidity is expressed as a percentage of the diffuse transmittance to the total transmittance.

Claims (1)

[Claims] 1 Performing an esterification reaction and/or transesterification reaction between a dicarboxylic acid and/or its ester-forming derivative and a dihydroxy compound and/or its ester-forming derivative using a catalyst containing at least one kind of metal ion, followed by polycondensation. When manufacturing linear polyester through
A method for producing polyester, which comprises adding at least one crown ether compound.