JP2990437B2 - Flexible polyester-polyether elastomers, compositions and keypads - Google Patents

Description

The present invention relates to a polyester-polyether elastomer excellent in flexibility and moldability, and more particularly, to a rubber-like flexibility as compared with a conventional polyester-polyether elastomer. Has injection molding capability and excellent dimensional stability,
The present invention relates to an elastomer suitable for molding materials such as electric parts and mechanical parts.

Polyester-polyether elastomer is positioned as a material having an elastic modulus intermediate between that of plastic and rubber, and is used in various applications for molding because of its excellent physical properties, durability and moldability. However, in recent years, more flexible elastomers have been demanded mainly for applications such as keypads of electric and electronic parts. The present invention can provide materials suitable for these applications.

Furthermore, in the present invention, it is possible to provide a highly flexible elastomer having significantly improved heat aging resistance and light resistance and improved discoloration due to heat and light, and retains its initial properties even under severe use conditions. It became possible.

[Conventional technology and its problems]

Copolymer elastomers in which polytetramethylene glycol (hereinafter, referred to as PTMG) is used as a soft segment and an ester chain mainly containing butylene terephthalate units is used as a hard segment are known. In order to obtain a highly flexible elastomer with this copolymer, it is necessary to copolymerize PTMG at a high rate, so that the crystallinity of the hard segment is significantly reduced, and as a result, the crystallization speed during injection molding is slow. This leads to a significant extension of the cycle. In particular, this tendency is remarkable in a composition having a Shore hardness of 35 D or less, and in extreme cases, the crystallinity of the hard segment required to maintain the properties as an elastomer cannot be secured. Furthermore, high-rate copolymerization of PTMG is expensive and economically disadvantageous.

On the other hand, it is known to produce a highly flexible elastomer by using poly (propylene oxide) glycol (hereinafter, referred to as EO-PPG) capped with ethylene oxide as another soft segment (for example, Japanese Patent Application Laid-Open No.
55-147546). In the case of EO-PPG, the affinity for butylene terephthalate with the hard segment is better than that of PTMG, and the average molecular weight of the soft segment can be increased as compared with the case of PTMG. Therefore, the blockiness of the copolymer is improved, and relatively good crystallinity is maintained even in a polymer composition that provides high flexibility. Further EO-PPG
Also has the advantage of being cheaper than PTMG.

However, an elastomer using EO-PPG easily absorbs water because it contains a polyoxyethylene unit. In particular, a highly flexible elastomer intended by the present invention has a remarkable increase in water absorption. For this reason, dimensional change due to water absorption is large, and it cannot be used for precision parts such as electric parts. Furthermore, EO-PPG has poor polymerization reactivity with a butylene terephthalate unit, and it is extremely difficult to obtain a practically desired level of polymerization in high-rate copolymerization. A branching agent must be added, and only an elastomer having poor mechanical properties can be obtained.

Further, EO-PPG is easily oxidatively deteriorated due to its structure, and even an elastomer using EO-PPG is significantly deteriorated and colored under severe conditions such as high temperature and exposure to ultraviolet rays. In order to improve this point, JP-A-55-147546 recommends the use of a phenolic antioxidant containing an amide group and an amine light stabilizer (hindered amine) having steric hindrance. However, according to the study of the present inventors, it has been clarified that when these stabilizers are applied to a highly flexible elastomer as aimed at by the present invention, remarkable coloring of the elastomer is caused instead.

[Problems to be solved by the invention]

A first object of the present invention is to provide a polyester having a high degree of flexibility such as a Shore hardness of 35D or less and free from the above-mentioned disadvantages, that is, having good crystallinity, moldability, polymerization reactivity, and a small dimensional change due to water absorption. -To obtain a polyether elastomer.

Further, a second object of the present invention is to significantly improve heat aging resistance, light resistance, and discoloration resistance so that such an elastomer can be used even under severe conditions.

[Means for solving the problem]

The present invention has found that the above-mentioned problems can be solved only when PTMG and EO-PPG are used in combination at a specific ratio as soft segments. That is, the first problem described above is that “terephthalic acid, isophthalic acid and / or phthalic acid,
4-butanediol, polytetramethylene glycol,
It is composed of a copolymer containing poly (propylene oxide) glycol capped with ethylene oxide as a main component, and the composition ratio of each component is represented by the following formulas (I) to (I).
A flexible polyester-polyether elastomer for molding, characterized by satisfying V).

65≤ [PTMG] + [PPG] ≤85 (I) 25≤ [PPG] ≤60 (II) 0.5 [PA] + [PTMG] +5/3 [PPG] ≤115 (III) 0≤ [PA] ≤15 (IV) Here, [PPG], [PTMG], and [PA] are as follows.

[PPG]: Weight% of the total unit of the repeating unit composed of poly (propylene oxide) glycol and dicarboxylic acid capped with ethylene oxide [PTMG]: Within the total polymer of the repeating unit composed of polytetramethylene glycol and dicarboxylic acid % By weight [PA]: isophthalic acid and / or mol% mol% mol% of all acid components of phthalic acid ”.

The second problem is that the polyester-polyether elastomer further contains a hindered phenol-based antioxidant and a hindered amine-based light stabilizer having no amide group in the molecule. The problem can be solved at once with a composition mainly composed of a flexible polyester polyether elastomer for molding.

First, the soft segments constituting the elastomer of the present invention will be described.

PTMG having a number average molecular weight of 800 to 2500 is preferably used. If the number average molecular weight is smaller than this range, the crystallinity of the elastomer is reduced, and if it is larger, phase separation tends to occur. A more preferred range of the number average molecular weight is 1200 to 2200. It is desirable that the molecular weight distribution be as sharp as possible.

EO-PPG is a poly (propylene oxide) glycol obtained by addition polymerization of ethylene oxide to the terminal, and preferably has a total average molecular weight of 1500 to 3000 and an ethylene oxide unit content of 20 to 35% by weight of the whole. . If the average molecular weight and ethylene oxide content are smaller than these ranges, the polymerization reactivity tends to decrease,
Conversely, when it is large, the water absorption of the obtained elastomer tends to be excessive. A particularly preferred range for the ethylene oxide content is 25 to 35% by weight.

Next, the composition ratio of each component, which is the main feature of the present invention, will be described. If the composition ratio does not satisfy the formulas (I) to (IV), the effect of the present invention cannot be obtained.

The formula (I) relates to the amount of a soft component for imparting a high degree of flexibility targeted by the present invention. When [PTMG] + [PPG] is smaller than the formula (I), the high flexibility intended by the present invention cannot be obtained, and such a relatively hard type elastomer can be obtained by a conventional technique without using the present invention. It is possible to respond. On the other hand, if the value is larger than the formula (I), the moldability is remarkably reduced due to the decrease in crystallinity, and the mechanical limit, particularly the elastic limit in a high temperature range, is reduced so that rubber elasticity is not developed. A more preferred range of the formula (I) is 65 to 80% by weight.

If [PPG] is smaller than the formula (II), it is not possible to obtain a highly flexible elastomer having good moldability, and if it is larger, the water absorption becomes excessive no matter how the composition of other components is changed. No practical elastomer is obtained. Also (I
If it is larger than the formula (I), the polymerizability is remarkably reduced, and a polymer having a sufficient degree of polymerization cannot be obtained.

Also, when the left side of the formula (III) is larger than the right side, the water absorption is also high. The left side is an index of the sum of the water absorption of EO-PPG itself and the increase in water absorption due to the decrease in crystallinity due to isophthalic acid and / or phthalic acid or PTMG copolymerization. This can be interpreted as indicating that it needs to be suppressed.

Further, by copolymerizing isophthalic acid and / or phthalic acid, a more flexible elastomer can be obtained. However, when [PA] is larger than the formula (IV), the crystallinity is also remarkably reduced, and in a high temperature region, This results in lowering of the elastic limit. [PA]
Is more preferably 0 ≦ [PA] ≦ 10.

The present invention has a great effect when applied to the production of an elastomer having a Shore hardness of 35D or less.

In the present invention, a small amount of components other than the above-mentioned components can be copolymerized as long as the physical properties and moldability of the elastomer are not impaired. Other copolymerization components include, as an acid component, naphthalenedicarboxylic acid, 5-sodium sulfo-isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dodecandionic acid, aromatic and alicyclic such as p-oxybenzoic acid. , Aliphatic dicarboxylic acids, oxycarboxylic acids, and diol components such as ethylene glycol, propylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and ethylene oxide and propylene oxide adducts of bisphenols. However, the present invention is not limited to these.

It is preferable to use a small amount of a branching agent in the polymerization of the elastomer of the present invention. The branching agent is an ester-forming compound having a functionality of 3 to 6, and the amount of the branching agent is preferably in the range of 0.9 to 6 equivalents, more preferably in the range of 1.5 to 5 equivalents, per 100 mol of aromatic dicarboxylic acid. Good. If the amount is less than this range, the polymerization reactivity may be insufficient. If the amount is more than this range, the basic properties as an elastomer such as a decrease in elongation at break may be impaired.

Representative compounds that can be used as a branching agent include polycarboxylic acids, and specific examples thereof include trimellitic acid, hemimellitic acid, pyromellitic acid, trimesic acid, and 1,1,2,2-
Examples include ethanetetracarboxylic acid, 1,3,5-pentanetricarboxylic acid, and 1,2,3,4-cyclopentanetetracarboxylic acid. These may be used as they are or in the form of their lower alkyl esters, acid anhydrides and the like.

Another typical compound that can be used as a branching agent is a polyol. Specific examples include glycerin, trimethylolpropane, pentaerythritol, 1,2,6
-Hexanetriol, sorbitol, 1,1,4,4-tetrakis (hydroxymethyl) cyclohexane, tris (2-hydroxyethyl) isocyanurate and the like.

Polyfunctional oxycarboxylic acids can also be used as another branching agent, and specific examples include malic acid, citric acid, tartaric acid, 3-hydroxyglutaric acid, and 4- (β-hydroxyethyl) phthalic acid.

Among these, the most preferred branching agents are trimellitic acid, trimesic acid, and lower alkyl esters and acid anhydrides thereof, trimethylolpropane, and tris (2-hydroxyethyl) isocyanurate.

Next, improvement of the heat aging resistance, light resistance and discoloration resistance under severe conditions of the present elastomer will be described.

In the present invention, heat aging resistance of the elastomer, light resistance,
In order to improve discoloration resistance, it is particularly preferable to use a hindered phenol-based antioxidant having no amide group in the molecule and a hindered amine-based light stabilizer as stabilizers. For a stabilizer having both a hindered phenol group and a hindered amine group in the same molecule, the stabilizer alone may be used.

Specific examples of hindered phenolic antioxidants containing no amide group in the molecule include triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6 -Hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) ) Propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3
-(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester,
3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, bis or tris (3-tert-butyl-6-methyl-4-hydroxyphenyl) And propane. Among them, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] and 1,6-hexanediol-bis (3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-
(t-butyl-4-hydroxybenzyl) benzene and the like are preferably used.

Specific examples of the hindered amine light stabilizer include dimethyl-1- (2-hydroxyethyl) -4-succinate.
Hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] ｝ ｛(2,2,6,6
-Tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl) ) -2-n-Butylmalonic acid, bis (1,2,2,
6,6-pentamethyl-4-piperidyl), N, N'-bis (3-aminopropyl) and 2,4-bis [N-butyl-N
-(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, 1-
[2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- [3-
(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl)
Sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, butanetetracarboxylic acid or an oligoester of butanetetracarboxylic acid and a diol is 1,2,2,6,6-pentamethyl- 4-hydroxypiperidine or a compound at least partially esterified by 2,2,6,6-tetramethyl-4-hydroxypiperidine, 4-hydroxy-2,2,6,6-tetramethyl-
And ethylene oxide adduct of 1-ethanol piperidine. Of these, particularly preferred is poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl} (2,2,6, 6−
Tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl) Bis-n-butylmalonate (1,2,2,6,
6-pentamethyl-4-piperidyl), N, N'-bis (3
-Aminopropyl) and 2,4-bis [N-butyl-N-
(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate.

The content of each of these stabilizers is preferably about 0.1 to 3% by weight. In practice, the amount should be appropriately adjusted depending on the environmental conditions in which the molded article is used. Where the content
Less than 0.1% by weight has little stabilizing effect, while 3% by weight
If the ratio exceeds the range, problems such as bleeding out to the surface of the molded article occur.

Further, various additives and modifiers can be added to the elastomer of the present invention depending on the use. For example, there are pigments, ultraviolet absorbers, terminal blocking agents, thickeners, antistatic agents, crystallization accelerators, reinforcing materials, release agents, flame retardants, plasticizers, and the like.

Next, a method for producing the elastomer of the present invention will be described.

The copolymer of the present invention may employ a known method for producing a polyester-polyether copolymer, except that the polymer composition falls within the range satisfying the formulas (I) to (IV). That is, an aromatic dicarboxylic acid or its ester-forming derivative and 1,4-butanediol, polyether glycol are esterified or transesterified at 180 ° C. to 240 ° C. under a diol component excess to form a low polymer, Further
Excess 1,4-butanediol is distilled off under high vacuum at 220 ° C. to 250 ° C. to polymerize to a predetermined degree of polymerization.

Here, transesterification and esterification are carried out at normal pressure, reduced pressure,
It can be carried out under either pressure. On the other hand, regarding the timing of adding the polyether glycol, first, a low polymer is formed from the aromatic dicarboxylic acid and 1,4-butanediol, and then mixed with the polyether glycol to obtain a polymer. It can also be subjected to condensation.

In addition, these reactions may be performed in a batch system, or may be performed entirely or partially continuously. The polycondensation may be performed by a method such as thin film polymerization.

As the catalyst for the transesterification or esterification reaction and the polycondensation reaction, conventionally known catalysts can be used. Typical examples include titanium compounds and tin compounds, such as tetraalkyl titanates, reaction products of tetraalkyl titanates with alkylene glycols, partial hydrolysates of tetraalkyl titanates, titanium hexaalkoxide metal salts, and titanium compounds. Titanium compounds such as carboxylate and titanyl compounds, and tin compounds such as dialkyltin oxide, dialkyltin sulfide, monoalkylhydroxytin oxide, trialkyltin hydroxide and triaryltin hydroxide, and mixtures thereof are used.

In the reaction, the branching agent may be added at any stage before the start of the polycondensation, but is preferably before the transesterification or esterification reaction.

The step of adding the hindered phenol-based antioxidant and the hindered amine-based light stabilizer not containing an amide group in the present invention may be carried out at any time during the production of the polymer, that is, from the start of the transesterification or esterification reaction to the end of the polycondensation. Also, any stage from the time of molding, that is, from the time of drying the pellet to the completion of melt molding, is possible.
Further, a master pellet method may be used.

One of the preferable methods for adding the stabilizer is to add the stabilizer at any stage from the start of the transesterification or esterification reaction to the end of the polycondensation reaction. The reason is that in the melt polymerization, particularly in the batch polymerization method, thermal decomposition is likely to occur when the copolymer is discharged from the reaction vessel after the completion of the polymerization, and the addition of the stabilizer of the present invention by the end of the polycondensation in these polymerization processes This is because thermal decomposition can be suppressed efficiently.

In the present invention, even when the addition of an antioxidant or a light stabilizer is performed at the time of molding after production of a polymer, a stabilizer such as a hindered phenol is used until the completion of polycondensation in order to suppress thermal decomposition in the polymerization process described above. It is desirable to add a small amount to the mixture. The amount of the heat stabilizer to be added for this purpose varies depending on the polycondensation conditions, but is usually from 0.01 to 0.01 per unit weight of the finally obtained polyester elastomer.
The range is 2.0% by weight, preferably 0.05 to 1.0% by weight.

Since the polyester polyether elastomer of the present invention or a composition mainly containing this elastomer has a modulus of elasticity closer to that of rubber than a conventional polyester polyether elastomer, a molded article obtained by injection-molding the same is: It is very useful for electric and electronic components such as keypads and push buttons, especially as keypads.

[Examples] The present invention will be described in more detail with reference to Examples.

The Shore hardness, water absorption and melt viscosity (melt index) in the present invention were measured by the following methods.

<Shore hardness>: Measured according to ASTM-D2240 using a Shore hardness meter type D.

<Water absorption>: Measured according to ASTM-D570.

<Melt index (MI)>: 10 at 190 ° C under a load of 2160 g according to ASTM-D1238.
The amount of polymer passed per minute was measured.

Further, as a sample for measuring the Shore hardness and the water absorption, a sample obtained by punching a 1 mm thick JIS No. 2 dumbbell from a sheet obtained by melt-pressing a polymer and rapidly cooling to 60 ° C. was used.

In addition, as for evaluation of moldability, when injection molding a JIS No. 2 dumbbell at a mold temperature of 60 ° C., the shortest molding time which can be molded without any problem from the mold releasability and the appearance of the molded product was examined.

 The heat resistance and light resistance were evaluated by the following methods.

<Heat discoloration resistance>: The JIS No. 2 dumbbell (2 mm thick) obtained by injection molding is treated in a gear oven manufactured by Tabai Seisakusho Co., Ltd. at 120 ° C. for 96 hours, and the color tone (YI value) of the test piece is subjected to a suga test. Machine
Measured with an SM color computer. The discoloration resistance was evaluated based on the difference (ΔYI) of the YI value before and after the heat treatment.

<Light resistance>: Inject JIS No. 2 dumbbell (2mm thick) by injection molding in a fade meter (black panel temperature: 83 ° C) manufactured by Suga Test Instruments Co., Ltd. for 192 hours, and change color tone before and after treatment of the test piece (ΔY
It was evaluated by I) and by observing the presence or absence of cracks on the test piece surface.

Example 1 The following raw materials were charged into an esterification reactor equipped with a stirrer and a rectification column.

Terephthalic acid 41.8 kg Trimellitic anhydride 338.0 g 1,4-butanediol 40.8 kg Tetrabutyl titanate 27.7 g Mono n-butylhydroxytin oxide 16.0 g After the addition was completed with stirring, the temperature was gradually raised. Distillation of water as a reaction product started, and after 3 hours and 30 minutes, distillation of almost the theoretical amount of water was completed.

After adding 288 g of tetrabutyl titanate to the reaction mixture, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene is used as a heat stabilizer. (CIBA-GEIGY “Irganox” 1330)
60 g (0.1% by weight based on the polymer produced) were added.

Next, 73.2 kg of PTMG (number average molecular weight of about 1400) and EO-PPG (number average molecular weight of about 215
0, ethylene oxide content 33% by weight) After transferring to a polymerization reactor containing 32.7 kg, the polymerization temperature was maintained at 245 ° C, and
The degree of vacuum was 0.9 mmHg or less in 0 minutes. After the polymerization reaction was continued for 3 hours and 25 minutes, the stirring was stopped, and the polymer was extruded into water in a strand form from the discharge port at the bottom of the reactor under the pressure of nitrogen gas.

 Next, this was cut into chips of uniform size.

Further, after drying, press molding was performed to evaluate each physical property. Table 1 shows the results. In addition, the symbol of the acid component in a table | surface is as follows, respectively.

TPA: terephthalic acid IPA: isophthalic acid OPA: phthalic acid Examples 2 and 3 and Comparative Examples 1 and 2 The evaluation results of those polymerized and molded in the same manner as in Example 1 except that the polymer composition was changed are summarized in Table 1. Was. As shown in Comparative Example 1, when [PPG] is below the range of the formula (II), the moldability is deteriorated. On the other hand, as shown in Comparative Example 2, when the range is above the range of the formula (II), the polymerizability and the water absorption are deteriorated. .

Examples 4, 5, 6 and Comparative Examples 3, 4 Evaluation results of the polymerized and molded products in the same manner as in Example 1 except that the polymer composition was changed are summarized in Table 2. In the compositions deviating from the formula (III) as in Comparative Examples 3 and 4, Examples 4 and
It can be seen that the water absorption is higher than that of 5,6.

Examples 7 and 8 and Comparative Example 5 Table 3 summarizes the results of evaluation of those polymerized and molded in the same manner as in Example 1 except that the polymer composition was changed. From Comparative Example 5, it can be seen that when [PA] exceeds the range of the formula (IV), the moldability is significantly deteriorated.

Example 9 In Example 2, as a stabilizer to be added after the esterification reaction was completed, a stabilizer A: 800 g (0.5% by weight based on the produced polymer) of "Irganox" 1330, and a stabilizer E: poly [$ 6- (1,1,3,3-tetramethylbutyl) imino-1,
3,5-triazine-2,4-diyl {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) Imino II] (CIBA-GEIGY "CHIMASSORB" 944LD) 800g
(0.5% by weight based on the polymer produced) Polymerization was carried out in the same manner as in Example 2 except that the elastomer was used in combination to obtain an elastomer.
Further, drying and injection molding were performed according to a conventional method, and the obtained dumbbell was evaluated for heat resistance and light resistance. As shown in Table 4, the discoloration due to heat and light was small, and no crack was observed.

Examples 10 and 11 Polymerization, molding and evaluation of heat and light resistance were carried out in the same manner as in Example 9 except that the stabilizer to be added was changed as shown in Table 4. It can be seen that when hindered phenol and hindered amine are not used together, thermal degradation and light degradation are remarkable under severe conditions such as the evaluation conditions.

Example 12 Stabilizer B: N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide) ("Irganox" 1098, CIBA-GEIGY) Polymerization, molding and evaluation were carried out in the same manner as in Example 9 except that a combined system of "CHIMASSORB" 944LD was used. Table 4 shows the results
Shown in It can be seen that when a hindered phenol containing an amide group is used, coloring by heat or light is remarkable.

Examples 13, 14, and 15 The same procedure as in Example 9 was carried out except that the stabilizer to be added was changed as shown in Table 4. In each case, the discoloration was small, and good heat resistance and light resistance were obtained.

 Each stabilizer described in the table has the following structure.

Stabilizer C: 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (CIBA-GEIGY “Irganox” 259) Stabilizer D: triethylene glycol -Bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] (CIBA-GEIGY "Irganox" 245) Stabilizer F: N, N'-bis (3-aminopropyl) 2,4-bis [N-
Butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate (CIBA-GEIGY "CHIMASSORB" 119FL) Stabilizer G : Bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate (CIBA-GEIGY “TINUVIN” 144) [Effects of the Invention] (1) Highly flexible elastomers, which could not be achieved due to poor moldability or poor dimensional stability due to water absorption, in the prior art using PTMG or EO-PPG alone as a soft segment, Can be easily obtained by applying the present invention.

(2) By using PTMG and EO-PPG at a specific ratio, the advantages of not only the combination effect but also the advantages of both are expressed dominantly, and effects that cannot be obtained by themselves can be obtained. That is, even if the total amount of the soft segments is significantly increased from the range that can be achieved by the conventional technology, the copolymer retains good crystallinity and injection moldability, and the dimensional change due to water absorption is at a level at which there is no practical problem. Can be suppressed.

(3) As compared with the case where EO-PPG alone is used as the soft segment, the polymerizability is improved, and as a result a copolymer having a high degree of polymerization is obtained. Also, the mechanical properties are greatly improved.

(4) Since the elastomer obtained by the present invention has an elastic modulus closer to that of rubber than the conventional polyester-polyether elastomer, the conventional polyester-polyether elastomer such as an electric / electronic part such as a keypad or a push button is not used. It can be applied to applications that could not be used.

(5) Because it can impart more excellent heat aging resistance and light resistance, and has little change in color due to heat and light, it can be used under severe conditions or when it is colored in a pale color due to design requirements. It can also be applied to design parts that dislike discoloration.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiromitsu Ishii 9-9 Oe-cho, Minato-ku, Nagoya-shi, Aichi Nagoya Office, Toray Industries, Inc. (56) References JP-A-62-235325 (JP, A) JP-A-62-235319 (JP, A) JP-A-54-118451 (JP, A) JP-A-52-44869 (JP, A) JP-A-55-147546 (JP, A) JP-A-51-144489 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C08G 63/00-63/91 C08L 67/00-67/08 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A copolymer comprising terephthalic acid, isophthalic acid and / or phthalic acid, 1,4-butanediol, polytetramethylene glycol, poly (propylene oxide) glycol capped with ethylene oxide as a main component. A flexible polyester polyether elastomer for molding, wherein the composition ratio of each component satisfies the following formulas (I) to (IV). 65≤ [PTMG] + [PPG] ≤85 (I) 25≤ [PPG] ≤60 (II) 0.5 [PA] + [PTMG] +5/3 [PPG] ≤115 (III) 0≤ [PA] ≤15 (IV) Here, [PPG], [PTMG], and [PA] are as follows. [PPG]: Weight% of the total unit of the repeating unit composed of poly (propylene oxide) glycol and dicarboxylic acid capped with ethylene oxide [PTMG]: Within the total polymer of the repeating unit composed of polytetramethylene glycol and dicarboxylic acid % By weight [PA]: mol% of isophthalic acid and / or phthalic acid in all acid components 2. A copolymer comprising terephthalic acid, isophthalic acid and / or phthalic acid, 1,4-butanediol, polytetramethylene glycol, poly (propylene oxide) glycol capped with ethylene oxide as a main component. And the composition ratio of each component satisfies the above formulas (I) to (IV) and further contains a hindered phenol-based antioxidant and a hindered amine-based light stabilizer having no amide group in the molecule. A composition mainly composed of a flexible polyester polyether elastomer for molding. 3. A keypad obtained by injection-molding the polyester polyether elastomer according to claim 1 or 2 or a composition containing the elastomer as a main component.