JPS634588B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a highly viscous modified polyester elastomer. More specifically, the present invention relates to a method for easily and stably producing a high melt viscosity product using a polyester elastomer having a relatively low melt viscosity. Dicarboxylic acids, mainly terephthalic acid, or their ester-forming derivatives, low molecular weight glycols or their ester-forming derivatives, and molecular weights of 600 to 600.
Block copolymerized poly(ether ester) elastomer (hereinafter abbreviated as polyester elastomer) obtained from polyalkylene glycol No. 4000 is used in automobiles due to its good moldability, heat resistance, low temperature properties, oil resistance, etc. Widely used in electrical products. These molded articles are usually produced by an in-die extrusion method, a blow method, a profile extrusion method, or the like. Polyester elastomers are usually produced by melt polymerization. However, in order to prevent the decomposition of polyalkylene glycol, it is often carried out at relatively low temperatures, and due to the capacity of the equipment, the melt viscosity of the polymer obtained is sufficient for injection molding, but blow molding It is insufficient for use in extrusion methods and profile extrusion methods. As a method of increasing the melt viscosity of a polyester elastomer to the extent that blow molding or profile extrusion molding is possible, methods such as blending a polyepoxy compound or an ethylene copolymer having a carboxylic acid metal base in the side chain are known. There is (Japanese Patent Application Publication No. 51-143055
(Japanese Patent Application Laid-open No. 100495/1983). The method of blending an ethylene copolymer having a carboxylic acid metal group in the side chain requires at most 10 to 15% of the ethylene copolymer to be blended because the compatibility between the polyester elastomer and the ethylene copolymer is poor. %
Only a certain amount can be used, and it is not possible to obtain a product of sufficient viscosity. On the other hand, the method of increasing the viscosity by reacting the polyepoxy compound with the terminal group of the polyester elastomer requires a catalyst to promote the reaction. Nitrogen-containing compounds, phosphorus-containing compounds, metal salts, and the like are known as catalysts, but all of them cannot be used because they reduce the heat resistance of the polyester elastomer or have low catalytic activity. As a result of investigating catalysts that have strong catalytic activity and do not reduce the heat resistance of polyester elastomers, the present inventors found that carboxylic acid metal salts having 10 or more carbon atoms exhibit excellent performance, and proposed the above. . That is, the method involves melt-mixing a polyester elastomer, a diepoxy compound, and a metal salt of carboxylic acid in the presence of an appropriate stabilizer, but the high viscosity polyester elastomer obtained by such a method is The viscosity unevenness over time is relatively large, and due to unreacted epoxy compounds, the viscosity tends to change over time (thickening) during molding, and the uniformity of the wall thickness of the molded product may be lost. Furthermore, it was found that even when the waste generated during molding was recycled, the viscosity changed significantly, making it difficult to use it practically. As a result of intensive studies aimed at improving these drawbacks, the present inventors found that when melt-mixing a polyester elastic body, a diepoxy compound, and a metal salt of a carboxylic acid having 10 or more carbon atoms, a carboxylic acid metal is added to the side chain. By using an ethylene-based copolymer containing a base, the viscosity stability of the high-viscosity polyester elastomer is improved.Furthermore, by simultaneously using a mono- or polycarboxylic acid, the viscosity becomes more stable and operability is improved. The present invention was achieved by discovering that the moldability is improved. That is, the present invention provides a block copolymerized poly(ether ester) obtained from a dicarboxylic acid mainly including terephthalic acid or its ester-forming derivative, a low molecular weight glycol or its ester-forming derivative, and a polyalkylene glycol having a molecular weight of 600 to 4000. the elastic body 1
10 to 100 mmol of (A) diepoxy compound per kg,
(B) 2 to 35 mmol of a metal salt of group a or group a of the periodic table of carboxylic acids having 10 or more carbon atoms, and (C) 0.01 mmol of an ethylene copolymer having a carboxylic acid metal base in the side chain. This is a method for producing a highly viscous modified polyester elastomer characterized by melt-mixing ~0.2Kg. Further, the present invention provides that the block copolymerized poly(ether ester) elastomer contains (A), (B), and (C).
and (D) a method for producing a highly viscous modified polyester elastomer, characterized in that 0.005 to 0.95 mole of mono or polycarboxylic acid is melt-mixed with respect to 1 mole of (A). In the present invention, a high viscosity modified polyester elastic material is obtained by melt-mixing a diepoxy compound, a metal salt of a carboxylic acid having 10 or more carbon atoms, and an ethylene copolymer having a carboxylic acid metal base in the side chain to a polyester elastic material. The body has less unevenness in viscosity over time during manufacturing, and viscosity changes over time (thickening) during molding are less likely to occur. The polyester elastomer of the present invention is a block copolymerized poly(ether) produced from a dicarboxylic acid mainly including terephthalic acid or its ester-forming derivative, a low molecular weight glycol or its ester-forming derivative, and a polyalkylene glycol having a molecular weight of 600 to 4,000. ester) is an elastic body. At least 60 mol% of the dicarboxylic acid raw material for producing the polyester elastomer of the present invention is terephthalic acid or its ester-forming derivative. Examples of ester-forming derivatives of terephthalic acid include dilower alkyl terephthalic acid esters, dicycloalkyl esters, diaryl esters, dihydroxyalkyl esters, and the like. Dicarboxylic acid raw materials used in addition to the above raw materials include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, naphthalene dicarboxylic acid, 4,4'-bisbenzoic acid, and alkali metal salts of 3,5-dicarboxybenzenesulfonic acid;
and aliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, and dimer acid, or lower alkyl esters, cycloalkyl esters, aryl esters, and hydroxyalkyl esters thereof. These dicarboxylic acid raw materials may be a mixture of two or more kinds. Low molecular weight glycol raw materials include acyclic, alicyclic and aromatic glycols with a molecular weight of 250 or less and formable derivatives. Preferably, the number of carbon atoms is 2
~15 glycols. It is desirable that 60 mol% or more of the low molecular weight glycol raw material be one type of glycol selected from ethylene glycol, trimethylene glycol, and tetramethylene glycol. Glycols other than the above-mentioned glycols include glycols other than those used as main components among the above three types of glycols, or 1,2-propylene glycol, neopentyl glycol, hexamethylene glycol, cyclohexanedimethanol, or , hydroquinone, resorcinol, bisphenol A, tetrabromobisphenol A, and other hydroxyethyl compounds. These glycol raw materials may be a mixture of two or more types. Polyalkylene glycol raw materials include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random or blocked poly(ethylene-tetramethylene) glycol, random or blocked poly(propylene-tetramethylene) glycol, and these glycols and aromatic or aliphatic diols. Examples include condensates with. The number average molecular weight of polyalkylene glycol is
600-4000, preferably 600-3000. The method for producing the polyester elastic body of the present invention is not particularly limited. For example, a method may be used in which a reaction product obtained from a dicarboxylic acid or its ester and a low molecular weight glycol and a polyalkylene glycol is polycondensed under reduced pressure in the presence of a suitable catalyst (eg, a titanium compound). At this time, good results are often obtained by using a small amount of oxidative decomposition inhibitor to stabilize the polyalkylene glycol. The content of polyalkylene glycol in the polyester elastomer is generally 10 to 80% by weight. Within this range, the amount of polyalkylene glycol to be added is determined depending on the application. It is desirable that carboxylic acid groups account for 20% or more, preferably 30% or more of the terminal groups of the polyester elastomer based on the total amount of terminal groups. In order to increase the amount of carboxylic acid groups, it is effective to add and mix an intramolecular carboxylic acid anhydride such as phthalic anhydride in the latter stage of the polycondensation reaction or after the completion of the polycondensation reaction. The structure of the diepoxy compound used in the present invention is not particularly limited as long as it has two epoxy groups in the same molecule. Specifically, compounds represented by the following general formulas () to () can be mentioned as examples. [In the formula, R is an alkylene group with or without a side chain such as ethylene, propylene, tetramethylene, hexamethylene, 2,2-dimethyltrimethylene, etc., or a fat such as cyclohexene, 2,2-isopropylidene, biscyclohexyl, etc. cyclic group, o-
Phenylene, m-phenylene, p-phenylene,
Aromatic groups such as bisphenylene and 2,2-isopropylidene bisphenyl, general formula: (-R ¹ O) - _o R ¹ -
Polyether group represented by (R ¹ is 2 carbon atoms)
~6 alkylene group or phenylene group, n
represents an integer from 1 to 20. ) is shown. ] More specific examples of the diepoxy compounds represented by the above general formulas () to () include the compounds used in Examples. However, from the viewpoint of heat aging properties of the molded product, diepoxy compounds having an amine compound in the core are not preferred. Furthermore, glycidyl ethers of aromatic diols such as hydroquinone and bisphenol A have poor heat resistance and may have somewhat low thickening effects. The amount of the diepoxy compound used varies depending on the melt viscosity of the polyester elastomer required, but is 10 to 100 mmol per 1 kg of the polyester elastomer. If the amount is less than 10 mmol per kg of polyester elastomer, no thickening effect will be observed, and if it exceeds 100 mmol, the surface condition of the molded product will deteriorate, which is not preferable. In the present invention, a metal salt of group -a or -a of the periodic table of carboxylic acids having 10 or more carbon atoms is used as a reaction catalyst between the polyester elastomer and the diepoxy compound. Carboxylic acids having 10 or more carbon atoms include lauric acid, myristic acid, palmitic acid, stearic acid, linoleic acid, linolenic acid, oleic acid,
Examples include dodecanedicarboxylic acid and dimer acid. Particularly preferred is dimer acid. Dimer acid may contain monomer acid and trimer acid, which are by-products mixed in during the manufacturing process, as long as they account for 40% by weight or less of the total. These carboxylic acids are neutralized with metals from Group A or Group A of the Periodic Table of the Elements. Periodic Table of Elements - Group A metals are lithium,
Particularly preferred are sodium and potassium. Calcium and magnesium are particularly preferred as the metals of Group A of the Periodic Table of Elements. The above carboxylic acid is neutralized with these metals alone or in combination. Furthermore, when used as a catalyst, a mixture of these metal salts may be used. However, it is preferable that 90% or more of the carboxylic acid is neutralized. The amount of the above metal salt used is 1 kg of polyester elastomer.
2 to 35 mmol per portion. Further, preferable results can be obtained by using 0.05 to 0.8 mol per mol of the diepoxy compound used. Ethylene-based copolymers having carboxylic acid metal groups in their side chains are known, for example, from Canadian Patent No. 674595, but they are usually made by combining ethylene with an ethylenically unsaturated carboxylic acid such as acrylic acid or methacrylic acid. It is a copolymer neutralized with metals such as sodium, potassium, and zinc. These are commercially available, for example, as Surlyn R○ from DuPont or Himilan R○ from Mitsui Polychemicals. The amount used is 0.01 per kg of polyester elastic material.
~0.2Kg, preferably 0.02-0.12Kg. The ethylene copolymer has poor compatibility with the polyester elastomer, and when used in large amounts, layer separation occurs, deteriorating the surface condition and physical properties of the molded product. In the present invention, when a monocarboxylic acid and/or a polycarboxylic acid is used together with an ethylene copolymer, the viscosity is further stabilized and operability and moldability are improved. Specific examples of monocarboxylic acids include:
Benzoic acid, toluic acid, cumic acid, anisic acid, naphthoic acid, p-chlorobenzoic acid, p-bromobenzoic acid, phenyl acetic acid, naphthyl acetic acid, butyric acid, caproic acid, dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid,
Examples include linolenic acid and linoleic acid. The polycarboxylic acid is preferably a dicarboxylic acid or a tricarboxylic acid, and specifically, phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, benzophenodicarboxylic acid, trimellitic acid, adipic acid, azelaic acid, and sebacic acid. Examples include acid, dodecanedicarboxylic acid, dimer acid, trimer acid, and anhydrides and partially esterified products thereof. The amount used is 0.005 per mole of diepoxy compound.
~0.95 mol. The present invention has a polyester elastomer containing (A) a diepoxy compound, (B) a metal salt of group a or group a of the periodic table of carboxylic acids having 10 or more carbon atoms, and (C) a carboxylic acid metal base in the side chain. The ethylene copolymer and, if necessary, one or two types of (D) mono- or polycarboxylic acids are melt-mixed, and the mixing method includes a method of adding and mixing each compound to a polyester elastomer in a molten state; Alternatively, there are no particular limitations as long as the method allows uniform melt-mixing, such as a method in which polyester elastomer chips and each compound are mixed in advance at room temperature or at a temperature of 100° C. or lower and then heated and melt-mixed. In particular, after melting and reacting the polyester elastomer with (A) the diepoxy compound and (B) the carboxylate, (C)
More preferable results can be obtained by adding and melt-mixing the ethylene copolymer and (D) monocarboxylic acid or polycarboxylic acid. The melting and mixing temperature is preferably from 3°C higher than the crystalline melting point of the polyester elastomer to 260°C. The mixing time is about 30 seconds to 120 minutes and is determined by the mixing method and temperature. Even if pigments, various stabilizers, and additives are added at the same time during the mixing, the thickening effect of the present invention does not change. In the present invention, in the reaction between the polyester elastomer and the diepoxy compound, metal salts of monocarboxylic acids and/or dicarboxylic acids having 10 or more carbon atoms belonging to Group A or Group A of the Periodic Table of the Elements have high activity as catalysts and are highly active. A viscosity modified polyester elastomer is obtained, and by further using an ethylene copolymer having a carboxylic acid metal base in the side chain,
The viscosity stability is significantly improved, and by simultaneously using a mono- or polycarboxylic acid, the viscosity becomes more stable and the operability and moldability are improved. The present invention will be explained in detail below with reference to Examples, but the present invention is not limited to these Examples. In the Examples, "parts" simply indicate parts by weight, and the reduced specific viscosity, the amount of terminal carboxyl groups, and the melt index were measured according to the following procedure. (1) Reduced specific viscosity Measured under the following conditions. Solvent: Phenol/tetrachloroethane Weight ratio: 6/4 Concentration: 500 mg/25 ml Temperature: 30°C (2) Terminal carboxyl group content 100 mg of polyester elastomer and 10 ml of benzyl alcohol were placed in a container and dissolved at 200°C with stirring. The dissolution time was set to 2 minutes, 4 minutes, and 6 minutes,
After each solution was dissolved, the solution was cooled with water and diluted with 10 ml of chloroform. The amount of carboxyl groups at each dissolution time was obtained by titrating the solution with a 0.1N caustic soda and benzyl alcohol solution using phenolphthalene as an indicator. From these values, an extrapolated value at a dissolution time of 0 minutes was determined and determined as the amount of terminal carboxyl groups. (3) Melt index Measured at 230°C according to JIS K 6760 method. (4) Melting point The position of the peak obtained when the temperature was raised at 10°C/min using a differential thermal analyzer was defined as the melting point. Production Example 1 1,940 parts of dimethyl terephthalate, 1,350 parts of 1,4-butanediol, and 3.5 parts of tetrabutyl titanate were placed in a reactor, and a transesterification reaction was carried out. When the transesterification reaction has progressed to 95% or more, 1.
3,5-tris(4-hydroxy-3,5-di-
After adding and mixing 7.0 parts of t-butylbenzyl-2,4,6-trimethylbenzene and 1430 parts of polytetramethylene glycol having an average molecular weight of 1000, the mixture was transferred to an autoclave and subjected to a polycondensation reaction at 250°C for 140 minutes. The polytetramethylene glycol content in the obtained polyester elastomer chips was 40.6% by weight, the reduced specific viscosity was 1.85, and the amount of terminal carboxyl groups was:
The concentration was 73 mmol/Kg, and the melting point was 202°C. This is referred to as polyester elastic body A. Production Example 2 In the same manner as in Production Example 1, a polyester elastomer containing an isophthalic acid component of 25 mol% of the total acid component and a polytetramethylene glycol content of 35.0% by weight was obtained. Reduced specific viscosity is 1.91, terminal carboxyl group is 68
mmol/Kg, and the melting point was 173°C. This will be referred to as polyester elastic body B. Reference Example 1 Predetermined amounts of diethylene glycol diglycidyl ether, sodium stearate or disodium dimerate, and Irganox 1010 (Ciba Geigy) were added to polyester elastomer chips A and B.
After mixing using a drum tumbler, 40mm
Melt mixing was performed at 250°C using a φ extruder. The extrusion test was conducted at a discharge rate of 100 g/min for a total of 10 hours.
Sampling was performed every 30 minutes during the test, and the reduced specific viscosity and melt index were measured. Results first
As shown in the table, there are large variations during the process in both cases.

【table】

[Table] Example 1 After mixing and homogenizing the entire chips (a to c) obtained in Reference Example 1 using a drum tumbler,
Each was divided into four parts. Each was sprinkled with a predetermined amount of Himilan 1707 (Mitsui Polychemical) as a benzoic acid and ethylene copolymer, and extruded under the same conditions as in Reference Example 1 at a discharge rate of 50 g/min to form chips. Chips sampled every 30 minutes (1
The melt index of ~12) was measured. The results are shown in Table 2. When an ethylene copolymer is used, there is almost no variation during the process.

[Table] *marked: Reference material Example 2 Each chip (1 to 12) obtained in Example 1 was mixed and homogenized using a drum tumbler. This is 100
After drying at ℃ for 2 hours, it was extruded into chips under the same conditions as in Reference Example 1. The obtained chips are further dried,
Chip formation was repeated to obtain chips extruded twice and extruded four times in total. These chips were molded into No. 3 dumbbells with a thickness of 2 mm, and their strength and elongation were measured and compared with those before the extrusion test. The results are shown in Table 3. Chip number 2, 6, 10
It is difficult to use practically because the rate of decrease in strength and elongation is large and it is difficult to reuse the scrap resin. Example 3 Each chip (1 to 12) obtained in Example 1 was placed in an ampoule, dried under reduced pressure at 100°C overnight, and then
The tube was sealed in a nitrogen atmosphere of Hg. these at 240℃
After processing for 30 minutes, the polymers were rapidly cooled with liquid nitrogen, opened, and the reduced viscosity of each polymer was measured. The results obtained are shown in Table 3. Chip numbers 1, 5, and 9 had a large increase in viscosity, and it was difficult to obtain a uniform molded product due to the variation in viscosity within the molding machine.

[Table] *mark: Reference material

Claims (1)

[Scope of Claims] 1. Dicarboxylic acids mainly including terephthalic acid or ester-forming derivatives thereof, low molecular weight glycols or ester-forming derivatives thereof, and
A diepoxy compound (A) is added to a block copolymerized poly(ether ester) elastomer obtained from 600 to 4,000 polyalkylene glycol per 1 kg of the elastomer.
10 to 100 mmol, (B) 2 to 35 mmol of a metal salt of group a or group a of the periodic table of carboxylic acids having 10 or more carbon atoms, and (C) an ethylene system having a carboxylic acid metal base in the side chain. Copolymer 0.01~0.2
A method for producing a highly viscous modified polyester elastomer characterized by melt-mixing. 2 Claim 1, characterized in that (D) one or more mono- or polycarboxylic acids are melt-mixed in an amount of 0.005 to 0.95 mol per 1 mol of (A) diepoxy compound. 1. A method for producing a highly viscous modified polyester elastomer described in 1.