JPH07216071A - Production of high-viscosity polyester elastomer - Google Patents

Abstract

PURPOSE:To obtain a high-viscosity polyester elastomer suitable for blow- molding, extrusion molding, etc., in high reproducibility by adding small amounts of an intramolecular acid anhydride of a tetracarboxylic acid and a cyclic iminoether compound to a polyester elastomer and reacting under melting. CONSTITUTION:This high-viscosity elastomer is produced by adding 0.1-3 pts.wt. of an intramolecular acid anhydride of a tetracarboxylic acid (preferably pyromellitic anhydride) and 0.2-5 pts.wt. of a cyclic iminoether compound of formula I (D and X are each a bivalent hydrocarbon group; the group of formula II is a 5 or 6-membered ring) to 100 pts.wt. of a polyester elastomer as a hard segment which contains a crystalline polyester having an aromatic dicarboxylic acid as a main acid component (preferably polytetramethylene terephthalate) and a polyether and/or a low-crystalline or amorphous polyester as a soft segment accounting for 10-50wt.% of the sum of the hard segment and the soft segment and reacting the components with each other under melting.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a high-viscosity polyester elastomer. More specifically, the present invention relates to a novel method for producing a highly viscous polyester elastomer suitable for blow molding, extrusion molding, etc. by adding a specific compound to a thermoplastic polyester elastomer and reacting it under melting.

[0002]

2. Description of the Related Art Thermoplastic polyester elastomers are
It has excellent moldability, heat resistance, mechanical properties, chemical resistance, etc. and is widely used as various molded products. However, when it is attempted to be applied to high-viscosity molding such as blow molding or extrusion molding, the viscosity of ordinary resins is insufficient and it cannot be used as it is.

Generally, the melt viscosity of a polyester elastomer can be adjusted by changing the degree of polymerization in the polymerization process, but it is difficult to produce a high viscosity polymer which can be blow-molded or extruded.
Not only is there a problem in terms of process and equipment that requires handling of ultra-high viscosity polymers, but in general, the polymerization reaction decreases in the latter stage of melt polymerization, and in some cases, the degree of polymerization decreases due to thermal decomposition. It's extremely difficult because of the problem.

Therefore, there has been proposed a method of increasing the viscosity of the polymer by adding various additives at an arbitrary stage after the polymerization, for example, at the time of molding. For example, JP-A-57-4961
No. 6, JP-A-57-92046 discloses a method of reacting a polyester with a specific cyclic iminoether compound. Further, JP-A-56-18617 describes a method in which a polyester is reacted with a dicarboxylic acid anhydride and a specific cyclic imino ether.

[0005]

However, these methods cannot raise the melt viscosity of the polyester elastomer to the extent applicable to blow molding and extrusion molding.

Therefore, an object of the present invention is to provide a novel method capable of producing a highly viscous polyester elastomer applicable to blow molding and extrusion molding with good reproducibility.

[0007]

The above-mentioned object of the present invention is as follows.
A crystalline polyester having an aromatic dicarboxylic acid as a main acid component as a hard segment, a polyether and / or a low crystalline or amorphous polyester as a soft segment, and the hard segment is a hard segment and a soft segment. 100 parts by weight of the polyester elastomer in the range of 10 to 50% by weight relative to the total amount, 0.1 to 3 parts by weight of a tetracarboxylic acid intramolecular acid anhydride, and a cyclic iminoether compound represented by the following formula (1): It can be achieved by a method for producing a high-viscosity polyester elastomer, which comprises adding 0.2 to 5 parts by weight and reacting under melting.

[0008]

[Chemical 2]

The manufacturing method of the present invention will be described in detail below.

The polyester elastomer used in the method of the present invention comprises a crystalline polyester having an aromatic dicarboxylic acid as a main acid component as a hard segment and a polyether and / or a low crystalline or amorphous polyester as a soft segment. Is a polymer that does.

Aromatic dicarboxylic acids constituting the crystalline polyester which is a hard segment include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid and methyl. Terephthalic acid, methyl isophthalic acid, etc. are exemplified, and among these, terephthalic acid, 2,6
-Naphthalenedicarboxylic acid is preferred. Further, within a range that does not impair the crystallinity of the polymer (for example, 20 mol% or less),
Some of these acid components include succinic acid, adipic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, and other aliphatic dicarboxylic acids; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; ε-oxycaproic acid,
It may be replaced with other carboxylic acid such as oxycarboxylic acid such as oxybenzoic acid and hydroxyethoxybenzoic acid. As the dicarboxylic acid component, only one kind may be used, or two or more kinds may be used in combination.

Examples of the diol component which constitutes the crystalline polyester which is the hard segment include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol and cyclohexanedimethylol. Of these, tetramethylene glycol is particularly preferable as the diol component. You may use together 2 or more types as such a diol component.

The polyester elastomer used in the method of the present invention comprises a polyether and / or an amorphous to low crystalline polyester as a soft segment.

As a preferred polyether, polyoxyalkylene glycol can be mentioned.
As such polyoxyalkylene glycol, for example, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytrimethylene glycol,
Examples thereof include polyoxytetramethylene glycol and copolymers thereof, and among these, polyoxytetramethylene glycol is particularly preferable. The average molecular weight of these polyoxyalkylene glycols is preferably 500 to 5000, and more preferably 600 to 4000.

The polyester constituting the soft segment is not particularly limited as long as it is a polyester having a low glass transition temperature and acting as a soft segment of the obtained polyester elastomer and is amorphous or low crystalline. Examples thereof include polyesters composed of the following dicarboxylic acid component and diol component.

Dicarboxylic acid components: succinic acid, adipic acid, suberic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, dimer acid, cyclohexanedicarboxylic acid, isophthalic acid and the like.

Diol component: ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentylene glycol, 3-methyl-1,5-pentanediol, 3,3-dimethyl-1,5- Pentanediol, octamethylene glycol, decamethylene glycol, dodecamethylene glycol, etc.

In the polyester elastomer used in the method of the present invention, when the soft segment is a polyether, the above-mentioned aromatic dicarboxylic acid, diol and polyoxyalkylene glycol can be produced by a conventionally known polymerization method, When the soft segment is polyester, the polyester constituting the hard segment and the polyester constituting the soft segment are separately produced by a conventionally known polymerization method, and these are kneaded under a melt condition to cause an ester-transesterification reaction. Can be manufactured by. The reaction temperature of this ester-transesterification reaction is preferably 200 to 300 ° C., more preferably 220 to 280 ° C., and the reaction time is preferably 15 minutes to 6 hours, more preferably 30 minutes to 4 hours.
It's about time.

The content of the hard segment in the polyester elastomer obtained by the above production method is
It is necessary to be 10 to 50% by weight based on the total amount of the hard segment and the soft segment. If the content of the hard segment is less than 10% by weight, the heat resistance of the obtained elastomer is insufficient, and if it is more than 50% by weight, the elastic properties are deteriorated, which is not preferable. The preferable content of the hard segment is 20 to 40% by weight.

In the method of the present invention, tetracarboxylic acid intramolecular anhydride and a specific cyclic iminoether compound are added to the above polyester elastomer and the reaction is carried out under melting.

Here, as tetracarboxylic acid intramolecular acid anhydride, pyromellitic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, butane-1,2,3,
4-tetracarboxylic dianhydride, 3,3 ', 4,4'-
Benzophenone tetracarboxylic acid dianhydride, 3,3 ′,
4,4'-diphenyltetracarboxylic dianhydride and the like can be exemplified. Of these, pyromellitic dianhydride is particularly preferable.

The amount of tetracarboxylic acid intramolecular acid anhydride added is 0.1 to 3 parts by weight, preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the polyester elastomer. If the amount added is outside this range, it will be difficult to produce the high-viscosity polyester elastomer aimed at by the present invention.

On the other hand, as the cyclic imino ether compound, a compound represented by the following formula (I) is used.

[0024]

[Chemical 3]

In the formula (1), X is a divalent hydrocarbon group, and specific examples thereof include ethylene, substituted ethylene, trimethylene and substituted trimethylene. As the substituent of the substituted ethylene or substituted trimethylene, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, and 5 to 5 carbon atoms
Examples thereof include a cycloalkyl group having 12 and an aralkyl group having 8 to 20 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl, isopropyl and the like. Examples of the aryl group include phenyl, naphthyl, diphenyl, and the like, and the following aryl groups may be used.

[0026]

[Chemical 4]

(Where R is --O--, --CO--, --S--,
―SO ₂ ―, ―CH ₂ ―, ―CH ₂ · CH ₂ ―, ―C
(CH ₃ ) ₂ —. ) Moreover, cyclohexyl can be illustrated as cycloalkyl.

Of these, ethylene and trimethylene are particularly preferable as X. The two X's in the formula (1) are preferably the same as each other, but they may be different groups.

D in the formula (1) is a divalent hydrocarbon group, and specific examples thereof include an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 12 carbon atoms, and 5 to 12 carbon atoms. And cycloalkenyl group, aralkylene group having 8 to 20 carbon atoms, and the like. More specifically, examples of the above alkylene group include methylene, ethylene, propylene, butylene, pentylene, hexamethylene, octamethylene, nonamethylene and decamethylene, and examples of the cycloalkylene group include cyclohexylene. Examples of the arylene group include phenylene, naphthylene, diphenylene and the following groups. This D may be the same hydrocarbon group as X described above or may be different.

[0030]

[Chemical 5]

(Where R'is --O--, --CO--, --S
―, ―SO ₂ ―, ―CH ₂ ―, ―CH ₂ · CH ₂ ―, ―
It is C (CH ₃ ) ₂ —. ) Also, in the formula (1),

[0032]

[Chemical 6]

The cyclic iminoether represented by the formula (5) forms a 5-membered ring or a 6-membered ring. A 5-membered ring is a compound called bisoxazoline and a 6-membered ring is a compound called bisoxazine. Specific examples thereof include the following compounds.

(I) Bisoxazolines: 2,2'-p
-Phenylenebis (2-oxazoline), 2,2'-m
-Phenylenebis (2-oxazoline), 2,2'-o
-Phenylene bis (2-oxazoline), 2,2'-p
-Phenylenebis (4-methyl-2-oxazoline),
2,2'-p-phenylene bis (4,4-dimethyl-2
-Oxazoline), 2,2'-m-phenylene bis (4
-Methyl-2-oxazoline), 2,2'-m-phenylenebis (4,4'-dimethyl-2-oxazoline),
2,2'-ethylenebis (2-oxazoline), 2,
2'-tetramethylene bis (2-oxazoline), 2,
2'-hexamethylenebis (2-oxazoline), 2,
2'-octamethylene bis (2-oxazoline), 2,
2'-decamethylene bis (2-oxazoline), 2,
2'-ethylenebis (4-methyl-2-oxazoline), 2,2'-tetramethylenebis (4,4-dimethyl-2-oxazoline), 2,2'-3,3'-diphenoxyethanebis ( 2-oxazoline), 2,2'-cyclohexylene bis (2-oxazoline), 2,2'-
Diphenylene bis (2-oxazoline).

(Ii) Bisoxazines: 2,2'-methylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-ethylenebis (5,6-dihydro-4)
H-1,3-oxazine), 2,2'-propylenebis (5,6-dihydro-4H-1,3-oxazine),
2,2'-butylene bis (5,6-dihydro-4H-
1,3-oxazine), 2,2'-hexamethylenebis (5,6-dihydro-4H-1,3-oxazine),
2,2'-p-phenylene bis (5,6-dihydro-4
H-1,3-oxazine), 2,2'-m-phenylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-naphthylenebis (5,6-dihydro-
4H-1,3-oxazine), 2,2'-p.p'-diphenylenebis (5,6-dihydro-4H-1,3-oxazine).

As the cyclic iminoether compound represented by the formula (I) used in the method of the present invention, 2,2'-m-phenylenebis (2-oxazoline) is particularly preferable.

The amount of the cyclic imino ether compound added is 0.2 to 100 parts by weight of the polyester elastomer.
It is 5 parts by weight, preferably 0.3 to 4 parts by weight. If the amount added is outside this range, it is difficult to obtain the high-viscosity polyester elastomer targeted by the present invention.

In the method of the present invention, both the above compounds are added to the polyester elastomer in the above amounts, and the reaction is carried out under melting.

The reaction conditions at that time may be any conditions as long as the polyester elastomer becomes a desired highly viscous material, and these conditions vary depending on the degree of polymerization of the polyester elastomer to be used, the type and amount of the compound to be added. The reaction temperature is preferably 200 to 300 ° C., more preferably 220 to 280 ° C., and the reaction time is preferably 30 seconds to 30 minutes, more preferably 1 to 20 minutes.

As the reaction method, the melting reaction may be carried out in a reactor having a stirring device, or the reaction may be carried out in a melt extruder such as an extruder. Further, a polyester elastomer obtained by dry blending the above compounds may be directly supplied to a molding machine and reacted in the molding machine to obtain a desired molded article.

Melt flow rate (MFR) of high viscosity polyester elastomer obtained by the method of the present invention
Is preferably 10 g / 10 minutes or less, more preferably 5
It is g / 10 minutes or less, and is suitable for blow molding and extrusion molding. Here, the MFR has a temperature of 230 ° C. and a load of 2.
It is a value measured under the condition of 16 g.

[0042]

According to the method of the present invention, the melt viscosity of a polyester elastomer can be increased to a desired viscosity in an extremely short time by using a melt extruder or the like.
Further, in the method of the present invention, the control of the reaction is easy, and even when the reaction is carried out in a molding machine to directly obtain a molded product, problems such as gelation do not occur, and stable molding can be performed with good reproducibility. it can.

Therefore, the method of the present invention can be preferably applied to molding which requires a high viscosity polymer such as blow molding and extrusion molding.

[0044]

The present invention will be described with reference to the following examples. "Parts" in the examples mean "parts by weight". The melt viscosity of the polymer is measured by using a melt indexer manufactured by Toyo Seiki Co., Ltd. according to JIS
According to K-7210, temperature 230 ℃, load 2.16g
It was measured under the conditions.

The reduced viscosity (ηsp / C) of the polymer is a phenol / tetrachloroethane mixed solvent (weight ratio 60/4).
In 0), the polymer concentration was 1.2 g / dl and the temperature was 35 ° C.

[Examples 1 to 4 and Comparative Example 1] The hard segment was polytetramethylene-2,6-naphthalate, the soft segment was polyoxytetramethylene glycol having an average molecular weight of 2000, and the proportion of the hard segment was all polymers. 30% by weight of polyester elastomer (ηsp / C = 2.90, MFR = 28
g / 10 minutes) 100 parts with pyromellitic dianhydride and 2,
Table 2 shows 2'-m-phenylene bis (2-oxazoline).
Were dry-blended in the amounts shown in Table 1 and melt-extruded using a 30 mmφ co-rotating extruder (PCM-30 manufactured by Ikegai Iron Works Co., Ltd.) at a polymer temperature of 240 ° C. and an average residence time shown in Table 1. Table 1 shows the melt flow rate (MFR) of the obtained polymer.

For comparison, Table 1 also shows the results when pyromellitic dianhydride and 2,2'-m-phenylenebis (2-oxazoline) were not added to the same polyester elastomer.

[0048]

[Table 1]

It can be seen from Table 1 that the melt viscosity of the polymer can be increased in an extremely short time by the method of the present invention, and that the polymer does not deteriorate or gel even if it stays for a relatively long time after being thickened. I understand.

Examples 5 to 8 and Comparative Example 2 The hard segment was polytetramethylene terephthalate, and the soft segment was isophthalic acid / sebacic acid in a molar ratio of 95/5.
Which is a crystalline polyester composed of a dicarboxylic acid component contained in 1. and hexamethylene glycol, and has a hard segment ratio of 30% by weight based on the total polymer (ηsp / C = 1.45, M
FR = 31 g / 10 min) 100 parts of various tetracarboxylic acid intramolecular acid anhydrides shown in Table 2 and 2,2'-m-
Phenylene bis (2-oxazoline) was dry-blended in the amount shown in Table 2 and melt-reacted with the residence time shown in Table 2 as in Example 1. The melt flow rate (MFR) of the obtained polymer is shown in Table 2.

For comparison, Table 2 also shows the results when the tetracarboxylic acid intramolecular anhydride and 2,2'-m-phenylenebis (2-oxazoline) were not added.

[0052]

[Table 2]

Claims (5)

[Claims] 1. A crystalline polyester containing an aromatic dicarboxylic acid as a main acid component as a hard segment, a polyether and / or a low crystalline or amorphous polyester as a soft segment, and the hard segment is a hard segment. And 100 parts by weight of the polyester elastomer in the range of 10 to 50% by weight based on the total amount of the soft segment and 0.1 to 3 parts by weight of tetracarboxylic acid intramolecular acid anhydride and the following formula (1). A method for producing a high-viscosity polyester elastomer, which comprises adding 0.2 to 5 parts by weight of a cyclic iminoether compound, and reacting under melting. [Chemical 1] 2. The method for producing a high-viscosity polyester elastomer according to claim 1, wherein the crystalline polyester constituting the hard segment is polytetramethylene terephthalate or polytetramethylene-2,6-naphthalate. 3. The polyether has an average molecular weight of 500-5.
It is polyoxyalkylene glycol of 000, The manufacturing method of the high viscosity polyester elastomer of Claim 1 characterized by the above-mentioned. 4. The method for producing a high-viscosity polyester elastomer according to claim 1, wherein the tetracarboxylic acid anhydride is pyromellitic dianhydride. 5. The cyclic imino ether compound is 2,2 ′.
-M-Phenylenebis (2-oxazoline) -The method for producing a high-viscosity polyester elastomer according to claim 1 or 4, wherein