JPH05287067A - Production of modified polyester - Google Patents

Abstract

PURPOSE:To produce a stable modified polyester which has a high m.p. and thermal characteristics unchangable even when it dwells long at high temp. in a molding machine during molding by adding at least one compd. selected from specific compds. to a mixture of at least two different polyesters when these polyesters are melt mixed. CONSTITUTION:At least one compd. selected from the group consisting of a monoepoxy compd. of formula I (wherein R<1> is an org. group having no primary alcoholic hydroxyl group), a carbodiimide compd. of formula II (wherein R<2> and R<3> are each an arom. hydrocarbon group), and an oxazolone compd. of formula III (wherein R<4>, R<5>, and R<6> are each an arom. hydrocarbon group) is added to a mixture of at least two different polyesters in the process for producing a modified polyester by melt mixing the polyesters. The modified polyester has a high m.p. and undergoes no change in thermal characteristics even when it dwells long at a high temp. in a molding machine during molding.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a modified polyester by melt-mixing two or more different polyesters.

[0002]

2. Description of the Related Art As one of methods for imparting a high function to polyester, there is a method in which a component other than the polyester constituent component (hereinafter referred to as a modifying component) is copolymerized with the polyester. This method is usually performed by adding a modifying component having an ester-forming functional group to the reaction system before the completion of the polycondensation reaction of the polyester. In this method, since the modifying component is randomly copolymerized in the molecular chain, there is a drawback that the melting point of the obtained polyester is significantly lowered when the copolymerization rate is increased.

Therefore, it has been proposed to obtain a modified polyester having a high melting point by melt-mixing the polyester and a polyester (homopolyester or copolyester) containing a modifying component as at least a part of its constituent components. For example, a method of melt mixing polyethylene terephthalate and an aliphatic polyester to improve flexibility and dyeability (Japanese Patent Publication No. 45-21596 and Japanese Patent Publication No. 54-127963), polyethylene terephthalate and a sulfonate compound are copolymerized. There is a method of melting and mixing the above polyester to improve hydrophilicity and dyeability (JP-A-50-123925, JP-A-53-86833).

However, these methods also differ.
When two or more kinds of polyesters are melt-mixed, a transesterification reaction proceeds between polyester molecular chains and within the molecular chains.
Therefore, the thermal characteristics of the modified polyester are likely to change while two or more different polyesters are melt-mixed, so that the range of conditions under which the modified polyester having the same thermal characteristics can be produced is extremely narrow, and industrial production There is a problem that is difficult. In order to solve such a problem, it is necessary to stop or suppress the transesterification reaction that proceeds when two or more different polyesters are melt mixed. By stopping or suppressing the transesterification reaction, it becomes possible to obtain a modified polyester having a high melting point and being thermally stable.

As this method, Japanese Patent Publication No.
The publication proposes to add organic and inorganic phosphorus compounds when two or more polyesters are melt mixed. However, such a phosphorus compound has not only a small effect of suppressing the transesterification reaction, but also the addition of the phosphorus compound has a problem that the hydrolysis resistance of the obtained modified polyester is lowered. Further, JP-A-52-29892 proposes to add a carboxylic acid ester, a carbonic acid ester or a carbonate compound when two or more kinds of polyesters are melt mixed. However, these compounds not only have a small effect of suppressing the transesterification reaction, but when the compound is added,
There are problems that toxic phenols and the like are by-produced and that the polymer is colored yellow. In addition, JP-A-51-1
Japanese Patent No. 11895 proposes to add a lactam compound when melt-mixing two or more kinds of polyesters. However, the lactam compound not only has a small effect of suppressing the transesterification reaction, but also has a problem that the polymer is easily colored brown by adding the lactam compound.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention effectively stop the transesterification reaction which proceeds when two or more polyesters having different color and hydrolysis resistance of the polymer are melt mixed. The present invention has been completed as a result of extensive studies on a method capable of suppressing.

[0007]

The above-mentioned object of the present invention is to provide the following (A) when a modified polyester is produced by melt-mixing two or more different polyesters.
It can be solved by a method for producing a modified polyester, which comprises adding one or more compounds selected from the group of (B) and (C). (A) General formula

[Chemical 4] Monoepoxy compound represented by (B) General formula

[Chemical 5] A carbodiimide compound (C) represented by the general formula

[Chemical 6] Oxazoline compound represented by: The feature of the method of the present invention is that two or more different polyesters are used. The different polyester means that the polyester itself is different, and the kind and content of the constituent components of the polyester, the average molecular weight of the polyester, and the like are different.

First, as the first polyester as the base polymer, the type of polyester used is not limited, but the modified polyester obtained has excellent dyeing properties and flexibility while maintaining high melting point and high crystallinity. From the viewpoint of exhibiting the function, it is preferable to use an aromatic homopolyester, and it is particularly preferable to use an aromatic homopolyester selected from polyethylene terephthalate, polytetramethylene terephthalate, polyethylene naphthalate, and polycyclohexanedimethylene terephthalate.

Next, in the present invention, as the second and subsequent polyesters, the following (1) or (2) can be adopted. (1) The polyester used in the first is a homopolyester in which at least one of the constituent components is different. For example, when polyethylene terephthalate is used as the first polyester, polyethylene isophthalate, polyethylene naphthalate, polyethylene adipate, polytetramethylene terephthalate, etc. may be mentioned.

(2) A copolyester in which a modifying component is copolymerized with the first base polymer. For example, when polyethylene terephthalate is used as the first base polymer, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid,
Dicarboxylic acid components such as adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-propylene glycol, tetramethylene glycol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polytetramethylene glycol, 1,4 Examples thereof include polyethylene terephthalate obtained by copolymerizing one or more diol components such as cyclohexanedimethanol, bisphenol A or an ethylene oxide adduct thereof.
Incidentally, the copolymerization rate of the modifying component in the above-mentioned copolyester is not particularly limited, but from the viewpoint that the obtained modified polyester can exhibit excellent functions such as dyeability and flexibility while maintaining high melting point and high crystallinity. , 10 mol% or more with respect to the total acid components constituting the copolyester 1
Less than 00 mol%, more preferably 20 mol% or more 10
It is less than 0 mol%.

The mixing ratio of two or more different polyesters in the present invention is arbitrary, but since the modified polyester obtained has a high melting point and high crystallinity,
It is preferable to use 50% by weight or more of the aromatic homopolyester with respect to the modified polyester obtained.

In the present invention, two or more different polyesters described above are melt mixed. As a method of melt-mixing, two or more different polyesters are open batch type kneading devices such as roll mixers, closed batch type kneading devices such as Banbury mixers and kneaders, single-screw, twin-screw and multi-screw screws. Type continuous kneading apparatus, 1-axis and 2-axis disk type continuous kneading apparatus, 1-axis and 2-axis rotor type continuous kneading apparatus, or known methods such as melt mixing using a melt kneader such as a static kneader The method of can be adopted. The two or more polyesters may be mixed in advance in a solid state such as chips, or may be supplied to the above-mentioned melt-kneader without being mixed, and melt-mixed, or the melt-kneader described above in a separately melted state. And may be melt mixed.

In the present invention, the temperature at which two or more different polyesters are melt-mixed varies depending on the type of polyester used for melt-mixing, but is generally a temperature above the melting point of the polyester and below the decomposition temperature. The time for melt-mixing two or more different polyesters in the present invention varies depending on the heat resistance of the polyester used for melt-mixing and the like, but is generally 0.1 to 120 minutes.

Further, in the present invention, the atmosphere in which two or more different polyesters are melt-mixed may be any of pressurized, normal pressure and reduced pressure, and generally, reduced pressure or an inert gas atmosphere is used.

In the present invention, when two or more kinds of different polyesters described above are melt-mixed, one or more kinds of compounds selected from the group consisting of the monoepoxy compound, the carbodiimide compound and the oxazoline compound represented by the above general formula are used. Need to be added.

Examples of the compound represented by the above general formula are as follows. In the monoepoxy compound represented by the general formula (A), R ¹ is an organic residue containing no primary alcoholic hydroxyl group. The number of carbon atoms in R ¹ is 1
-30 is preferable. Specific examples of the compound include styrene oxide, allylbenzene oxide, and octene-1.
-Oxide, cyclohexyl ethylene oxide, 1,2
-Epoxy-4-phenylbutane, 1,2-epoxy-
3-methyl-4-phenylbutane, methyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, glycidyl lauryl ether, epifluorohydrin, epichlorohydrin, epibromohydrin, 1,2-epoxy-3,3,3. 3-trichloropropane etc. are mentioned.

In the carbodiimide compound represented by the general formula (B), R ² and R ³ are aromatic hydrocarbon groups and may be the same or different. In addition, R ² ,
The carbon number in R ³ is preferably 6 to 30. Specific examples of the compound include N, N'-bis (o-tolyl) carbodiimide, N, N'-bis (2,6-diethylphenyl)
Examples thereof include carbodiimide and N, N'-bis (2,6-diisopropyl) carbodiimide.

In the oxazoline compound represented by the general formula (C), R ⁴ , R ⁵ R and R ⁶ are hydrogen, or an aliphatic, alicyclic or aromatic hydrocarbon group, and even if they are the same. May be different. The carbon number in R ⁴ , R ⁵ and R ⁶ is preferably 0 to 30. Examples of specific compounds include 2-oxazoline, 2-methyl-2-oxazoline, 2-phenyl-2-oxazoline, 2,5-dimethyl-2-oxazoline, 5-methyl-2-phenyl-2.
-Oxazoline, 2,4-diphenyl-2-oxazoline, 2,5-diphenyl-2-oxazoline and the like can be mentioned. The above compounds may be used in combination of two or more kinds.

The amount of the above-mentioned compound added is not particularly limited, but is preferably 0.01 to 10% by weight, based on the total weight of the two or more polyesters to be mixed, because the transesterification reaction can be effectively suppressed. It is particularly preferably 0.05 to 5% by weight. If it is less than 0.01% by weight, the transesterification reaction tends to be difficult to be suppressed,
If it exceeds, the effect of suppressing the transesterification reaction will reach the ceiling and it will not only be economical, but also the excessive amount of the compound will remain in the polymer, which may cause volatilization during molding or bleed out on the surface of the molded product. Tend.

In the present invention, the timing of addition of the above compounds is not particularly limited. It may be added in advance to one or more of the polyesters to be melt-mixed, or may be added at the same time as the start of melt-mixing of two or more different polyesters, or between the start of melt-mixing and the end of melt-mixing. Since the transesterification reaction of two or more different polyesters can be effectively suppressed, it is preferable to melt-mix the polyester to which the compound has been added in advance. In the present invention, the above-mentioned compound may be added once or divided into two or more times, or the compound may be previously dispersed or dissolved in an appropriate medium and added.

The modified polyester obtained by the method of the present invention contains a matting agent, an antioxidant, a light stabilizer, an ultraviolet absorber, an optical brightener and an antistatic agent at the same time as or at a different stage from the addition of the above-mentioned compounds. Agents, flame retardants, antibacterial agents, deodorants, reinforcing materials, pigments, other polymer compounds, etc. may be contained.

In the method of the present invention, it is not clear why the transesterification reaction which proceeds when two or more different polyesters are melt-mixed can be suppressed by adding the above-mentioned compound, but the compound is a polyester. It easily reacts with the terminal carboxyl group that promotes the transesterification reaction, and is considered to suppress the transesterification reaction that proceeds during melt mixing of the polyester. It is conventionally known that the above-mentioned compound reacts with polyester and has an action of suppressing thermal decomposition and hydrolysis of the polyester, but in the present invention, the compound is different.
It is fundamentally different from the conventional findings in that it has the effect of suppressing the transesterification reaction that proceeds in a polyester melt mixing system of at least one kind.

[0023]

EXAMPLES The present invention will now be described in more detail by way of examples. The physical properties in the examples were measured as follows. A. Intrinsic viscosity (η) As an orthochlorophenol solution, it was measured at 25 ° C. B. Melting point (Tm) Differential scanning calorimeter (DSC4 type manufactured by Perkin Elmer)
Was measured at a temperature rise rate of 20 ° C./min. When there are two or more melting peaks, the peak temperature on the high temperature side was taken as the melting point. C. Color tone (b value) It was measured using a color computer (SM-3 type manufactured by Suga Test Instruments Co., Ltd.). The higher the b value, the more yellow-brown it is. D. Hydrolysis resistance (Δη) Pellets (3 mm square) were placed in a pressure pot at 130 ° C. for 24 hours.
It was obtained by hydrothermal treatment for a period of time and examining the change Δη in the intrinsic viscosity. The smaller Δη, the better the hydrolysis resistance.

Reference Example 1 (Synthesis of Polyethylene Terephthalate) To 5000 parts by weight of dimethyl terephthalate and 3200 parts by weight of ethylene glycol, 2 parts by weight of manganese acetate tetrahydrate and 2 parts by weight of antimony trioxide were added, and the mixture was heated to 140 at normal pressure.
To 240 ° C. and transesterification was performed while distilling off methanol. After transesterification,
2.5 parts by weight of trimethyl phosphate was added, and the degree of vacuum and the temperature were gradually raised to 285 ° C. and 0.5 mmHg.
Polycondensation reaction was carried out for 4 hours at η = 0.65, Tm = 2
Polyethylene terephthalate having 55 ° C., b value = 1.5 and Δη = 0.31 was obtained.

Reference Example 2 (Synthesis of Polyethylene Isophthalate) Using 5,000 parts by weight of dimethyl isophthalate and 3200 parts by weight of ethylene glycol, the same operation as in Reference Example 1 was carried out, η = 0.64, Tm = 247 ° C., b value = 1.
4, polyethylene isophthalate with Δη = 0.30 was obtained.

Reference Example 3 (Synthesis of Polyethylene Adipate) Using 5,000 parts by weight of dimethyl adipate and 3600 parts by weight of ethylene glycol, the same operation as in Reference Example 1 was performed, and polyethylene having η = 0.66 and Tm = 55 ° C. I got an adipate.

Reference Example 4 (Synthesis of ethylene terephthalate-ethylene isophthalate copolymer) 2000 parts by weight of dimethyl terephthalate, 3000 of dimethyl isophthalate
Parts by weight, using 3200 parts by weight of ethylene glycol,
Perform the same operation as in Reference Example 1 ,. An ethylene terephthalate-ethylene isophthalate copolymer having η = 0.65 was obtained.

Example 1 Polyethylene terephthalate 200 synthesized in Reference Example 1
After sufficiently drying 0 part by weight, 20 parts by weight of glycidyl lauryl ether was supplied to a twin-screw extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.), and 280 ° C.
Melt kneading with a residence time of 2 minutes, η = 0.65, Tm
= 250 ° C, b value = 1.5, and Δη = 0.31 was obtained. Similarly, 2000 parts by weight of polyethylene isophthalate synthesized in Reference Example 2 and 20 parts by weight of glycidyl lauryl ether were melt-kneaded, and η = 0.
64, Tm = 247 ° C., b value = 1.4, Δη = 0.30
Polyester B of was obtained.

85 parts by weight of polyester A and 15 parts by weight of polyester B (addition amount of glycidyl lauryl ether: 1% by weight based on the total weight of the polyester before addition of glycidyl lauryl ether) were sufficiently dried and then fed to a twin-screw extruder. Melt mixing was performed at 280 ° C. for a residence time of 2 minutes, η = 0.65, Tm = 253 ° C., b value =
A modified polyester of 1.5 and Δη = 0.31 was obtained. When the modified polyester was melt-held at 280 ° C. for 30 minutes and 60 minutes, Tm was 252 ° C.,
The temperature was 251 ° C., and there was almost no decrease.

Comparative Example 1 85 parts by weight of polyethylene terephthalate synthesized in Reference Example 1 and 15 parts by weight of polyethylene isophthalate synthesized in Reference Example 2 were thoroughly dried and fed to a twin-screw extruder at 280 ° C. for a residence time. Two minutes of melt mixing was performed. The physical properties of the obtained modified polyester are η = 0.65,
Tm = 252 ° C., b value = 1.5, Δη = 0.31. When this modified polyester was melt-held at 280 ° C. for 30 minutes and 60 minutes, the Tm was 23.
The temperature dropped to 3 ° C and 220 ° C.

Examples 2 to 6 The same operation as in Example 1 was carried out except that the mixing ratio of polyester A and polyester B was changed. Table 1 shows the obtained modified polyester η, Tm, b value, Δη, and Tm when these modified polyesters were melt-held at 280 ° C. for 30 minutes and 60 minutes. All modified polyesters showed almost no decrease in melting point due to melt holding.

[0032]

[Table 1] Examples 7 to 13 Operations were performed in the same manner as in Example 1 except that the type of compound to be added and the addition amount were changed. Table 2 shows η, Tm, b value, Δη of the obtained modified polyester, and Tm when these modified polyesters were melt-held at 280 ° C. for 30 minutes and 60 minutes. All modified polyesters showed almost no decrease in melting point due to melt holding.

[0033]

[Table 2] Comparative Example 2 The same operation as in Example 1 was performed except that triphenyl phosphite was used instead of glycidyl lauryl ether. Η, Tm, b of the obtained modified polyester
Value, Δη, and these modified polyesters at 280 ° C
Table 2 shows Tm when melt-held for 30 minutes and 60 minutes. Δη of the obtained modified polyester is 0.4
4 and the hydrolysis resistance was considerably lowered.

Comparative Example 3 The procedure of Example 1 was repeated except that diphenyl terephthalate was used instead of glycidyl lauryl ether. Η, Tm, b of the obtained modified polyester
Value, Δη, and these modified polyesters at 280 ° C
Table 2 shows Tm when melt-held for 30 minutes and 60 minutes. The b value of the obtained modified polyester is 7.0.
And was colored yellow.

Comparative Example 4 The same operation as in Example 1 was carried out except that N, N'-bisterephthaloylcaprolactam was used instead of glycidyl lauryl ether. Table 2 shows η, Tm, b value, Δη of the obtained modified polyester, and Tm when these modified polyesters were melt-held at 280 ° C. for 30 minutes and 60 minutes. The modified polyester thus obtained had ab value of 14.2 and was colored brown.

Examples 14 to 17 The same operations as in Example 1 were carried out except that the melt mixing time of polyester A and polyester B was changed. Table 3 shows η, Tm, b value, Δη of the obtained modified polyester, and Tm when these modified polyesters were melt-held at 280 ° C. for 30 minutes and 60 minutes. All modified polyesters showed almost no decrease in melting point due to melt holding.

[0037]

[Table 3] Example 18 85 parts by weight of the polyester A prepared in Example 1 and 15 parts by weight of polyethylene isophthalate synthesized in Reference Example 2 were sufficiently dried and then fed to a twin-screw extruder to obtain 2
Melt mixing was performed at 80 ° C. for a residence time of 2 minutes. The physical properties of the obtained modified polyester are η = 0.65 and Tm = 25.
At 3 ° C., b value = 1.5 and Δη = 0.31. The modified polyester is further treated at 280 ° C. for 30 minutes and 60
Tm when melted and held for 2 minutes is 252 ° C and 25
The temperature was 1 ° C., and there was almost no decrease.

Example 19 85 parts by weight of polyethylene terephthalate synthesized in Reference Example 1 and 15 parts by weight of polyethylene isophthalate synthesized in Reference Example 2 were thoroughly dried, and then 1 part by weight of glycidyl lauryl ether (total weight of polyester to be mixed) 1% by weight) to a twin-screw extruder and melt-mixed at 280 ° C. for a residence time of 2 minutes. The physical properties of the obtained modified polyester are η = 0.65, Tm
= 252 ° C, b value = 1.5, and Δη = 0.31.
When the modified polyester was melt-held at 280 ° C. for 30 minutes and 60 minutes, the Tm was 251 each.
C. and 250.degree. C., which hardly decreased.

Example 20 2000 parts by weight of polyethylene adipate synthesized in Reference Example 3 was thoroughly dried and then fed to a twin-screw extruder together with 20 parts by weight of glycidyl lauryl ether.
Melt kneading was carried out at 280 ° C. for a residence time of 2 minutes to obtain polyester C. 85 parts by weight of polyester A and 15 parts by weight of polyester C (amount of glycidyl lauryl ether added:
(1% by weight based on the total weight of the polyester before the addition of glycidyl lauryl ether) is sufficiently dried, and then the mixture is fed to a twin-screw extruder and melt-mixed at 280 ° C. for a residence time of 2 minutes to obtain η = 0.65. , Tm = 253 ° C., b value = 1.5, and Δη = 0.31 were obtained.
When the modified polyester was melt-held at 280 ° C. for 30 minutes and 60 minutes, the Tm was 252, respectively.
C. and 251.degree. C., and there was almost no decrease.

Comparative Example 5 85 parts by weight of polyethylene terephthalate synthesized in Reference Example 1 and polyethylene adipate 15 synthesized in Reference Example 3
After sufficiently drying parts by weight, the mixture was fed to a twin-screw extruder and melt-mixed at 280 ° C. for a residence time of 2 minutes.
= 0.65, Tm = 252 ° C., b value = 1.5, Δη =
A modified polyester of 0.31 was obtained. When the modified polyester was melt-held at 280 ° C. for 30 minutes and 60 minutes, the Tm was lowered to 230 ° C. and 218 ° C., respectively.

Example 21 2000 parts by weight of the ethylene terephthalate-ethylene isophthalate copolymer synthesized in Reference Example 4 was sufficiently dried, and then, together with 20 parts by weight of glycidyl lauryl ether, it was supplied to a twin-screw extruder and retained at 280 ° C. Melt kneading was carried out for 2 minutes to obtain polyester D. The same operation as in Example 1 was carried out using 85 parts by weight of polyester A and 15 parts by weight of polyester D synthesized in Reference Example 1, η = 0.65, Tm = 253 ° C., b value = 1.5, Δ
A modified polyester having η = 0.31 was obtained. When the modified polyester was melt-held at 280 ° C. for 30 minutes and 60 minutes, the Tm was 252 ° C. and 252 ° C., respectively, and there was almost no decrease. Comparative Example 6 85 parts by weight of polyethylene terephthalate synthesized in Reference Example 1 and 15 parts by weight of ethylene terephthalate-ethylene isophthalate copolymer synthesized in Reference Example 4 were sufficiently dried and then fed to a twin-screw extruder at 280 ° C. Melt mixing for a residence time of 2 minutes, η = 0.65, Tm =
A modified polyester was obtained at 251 ° C., b value = 1.5, Δη = 0.31. This modified polyester is further heated at 280 ° C.
The Tm was lowered to 244 ° C. and 236 ° C. when melt-held at 30 minutes and 60 minutes, respectively.

Example 22 85 parts by weight of polyethylene terephthalate synthesized in Reference Example 1 and 15 parts by weight of polyethylene isophthalate synthesized in Reference Example 2 were sufficiently dried and then fed to a twin-screw extruder at 280 ° C. for a residence time. Melt mixing was performed for 2 minutes to obtain a polyester having Tm of 252 ° C. When this polyester was melt-held at 280 ° C. for 5 minutes,
The Tm dropped to 248 ° C. 50 parts by weight of this polyester having Tm = 248 ° C. and 0.5 parts by weight of glycidyl lauryl ether were fed to a twin-screw extruder to obtain 280
Melt kneading was carried out at a temperature of 2 minutes for η = 0.65.
A modified polyester having Tm = 247 ° C., b value = 1.6 and Δη = 0.31 was obtained. Further, the Tm when melt-held at 280 ° C for 30 minutes or 60 minutes is 246 ° C, 246 ° C.
And almost did not decrease.

[0043]

The modified polyester obtained by the method of the present invention has a high melting point and is stable in that its thermal characteristics do not change even if it stays at a high temperature during molding for a long time.
It can be widely used in fibers, films, resins and other fields.

Claims (1)

[Claims] 1. When producing a modified polyester by melt-mixing two or more different polyesters, one or more compounds selected from the following groups (A), (B) and (C) are added. A method for producing a modified polyester, comprising: (A) General formula: A monoepoxy compound (B) represented by the general formula: A carbodiimide compound (C) represented by the general formula: An oxazoline compound represented by