JP3376389B2 - Polyester block copolymer and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to the excellent low-temperature characteristics, the hue is good, a method of manufacturing a further polyester block copolymer及 patron excellent in elastic recovery.

[0002]

2. Description of the Related Art It is well known that a polyester block copolymer having an aromatic polyester as a hard segment and an aliphatic polyether as a soft segment is used in various applications as a so-called polyester elastic body. However, there is a problem that these polyester elastic bodies are insufficient in heat resistance and weather resistance.

The present inventors have already proposed a polyester copolymer having a soft segment of a polyester composed of an aromatic dicarboxylic acid and polyoxyethylene glycol, in order to improve such problems.

[0004]

The above-mentioned polyester copolymer having a soft segment of a polyester composed of an aromatic dicarboxylic acid and polyoxyethylene glycol is a polyester copolymer using a conventional aliphatic polyether as a soft segment. Although it is superior in heat resistance and elastic recovery as compared with, the glass transition temperature was higher than that of the conventional polyester copolymer, and the low temperature characteristics were not high. In addition, it was not always sufficient because the hue was bad due to the coloring caused by the decomposition of polyoxyethylene glycol.

An object of the present invention is to provide a polyester block copolymer excellent in low temperature characteristics, hue and elastic recovery.

[0006]

The present invention provides a terephthalic acid component in an amount of 50 mol% or more based on the total dicarboxylic acid component, and an oligooxyethylene glycol component composed of 2 to 5 oxyethylene units based on the total dicarboxylic acid component. 60 ~
97 mol% and polyoxyalkylene glycol having a molecular weight of 300 to 2000 are added to the total dicarboxylic acid component of 40
20 to 80% by weight of a soft segment (A) composed of 3 to 3 mol% of a polyether ester, and a hard segment (B) 8 composed of polytetramethylene terephthalate having a tetramethylene terephthalate unit content of 60 mol% or more.
It is a polyester block copolymer composed of 0 to 20% by weight, and is a polyester block copolymer having a glass transition temperature of 0 ° C. or lower and excellent in low temperature characteristics and hue.

The polyester block copolymer of the present invention comprises a soft segment (A) and a hard segment (B).

[Soft segment] Soft segment (A) constituting the polyester block copolymer of the present invention
The terephthalic acid component as the dicarboxylic acid component is 50 mol% or more with respect to the total dicarboxylic acid component, and the oligooxyethylene glycol component having 2 to 5 oxyethylene units as the diol component is 60 to 97 with respect to the total dicarboxylic acid component. It is a polyether ester composed of 40% to 3% by mol of a polyoxyalkylene glycol component having a molecular weight of 300 to 2000.

The soft segment (A) may contain an acid component other than terephthalic acid as a copolymerization component in a proportion of less than 50 mol%, preferably less than 20 mol%, based on the total acid component, and is copolymerizable. Examples of such components include aromatic dicarboxylic acids other than terephthalic acid, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids and the like.

Examples of aromatic dicarboxylic acids include isophthalic acid, phthalic acid and naphthalenedicarboxylic acid, examples of aliphatic dicarboxylic acids include linear dicarboxylic acids having 8 to 12 carbon atoms, and examples of alicyclic dicarboxylic acids include cyclohexane. Mention may be made of dicarboxylic acids.

The oligooxyethylene glycol having 2 to 5 oxyethylene units used as the diol component is, for example, diethylene glycol, triethylene glycol or tetraethylene glycol, or a mixture thereof. When the number of oxyethylene units is less than 2, the elastic recovery property is lowered. Further, when the number of oxyethylene units exceeds 5, the heat resistance decreases.

The oligooxyethylene glycol composed of 2 to 5 oxyethylene units used as the diol component is 60 to 97 mol% based on the total dicarboxylic acid component. If it is less than 60 mol%, the elastic recovery property is lowered.

The polyoxyalkylene glycol having a molecular weight of 300 to 2000 is, for example, polyoxytetramethylene glycol or polyoxyethylene glycol, preferably polyoxytetramethylene glycol having a molecular weight of 500 to 2000 and polyoxyethylene having a molecular weight of 300 to 1500. It is ethylene glycol. These may be used as a mixture.

The polyoxyalkylene glycol having a molecular weight of 300 to 2000 is 40 to 3 mol%, preferably 30 to 3 mol% based on the total dicarboxylic acid component. Three
If it is less than mol%, the glass transition temperature of the polyester block copolymer cannot be made sufficiently low, and not only the low temperature characteristics cannot be improved but also the hue cannot be improved. Also,
If it exceeds 40 mol%, the effect of improving the low temperature characteristics is small, the heat resistance is lowered, and the compatibility is lowered.

Other than the above, a copolymerization component may be used in the range of 20 mol% or less for the diol component of the soft segment. The copolymerizable component has 2 to 12 carbon atoms.
The aliphatic glycol, polyoxyalkylene glycol and the like can be mentioned.

The soft segment (A) has a melting point of the polyester consisting only of the components constituting the soft segment, preferably 100 ° C. or lower, more preferably 50 ° C. or lower, and particularly preferably amorphous polyester. It is a thing.

[Hard segment] The hard segment (B), which is another component of the polyester block copolymer, comprises 6 units of tetramethylene terephthalate.
It comprises 0 mol%, preferably 70 mol% or more of polyester as a component. The smaller the proportion of the copolymerization component is, the higher the melting point is, which is preferable.

In the hard segment (B), an aromatic dicarboxylic acid containing a benzene ring other than terephthalic acid, an aromatic dicarboxylic acid containing a naphthalene ring, an aliphatic dicarboxylic acid having 4 to 12 carbon atoms, and tetramethylene glycol other than Aliphatic glycols having 2 to 12 carbon atoms, alicyclic glycols such as cyclohexanedimethanol and the like may be copolymerized. The copolymerization component is 40 mol%, preferably 30 mol% or less.

The copolymerization component constituting the hard segment (B) has a melting point of the polyester comprising the units constituting the hard segment (B) is 160 ° C., preferably 1
A copolymerization ratio of 70 ° C. or higher is desirable for maintaining good crystallinity.

[Polyester Copolymer] The weight ratio of the soft segment (A) to the hard segment (B) constituting the polyester block copolymer of the present invention is 2
0:80 to 80:20, preferably 50:50 to
It is 75:25. When the weight ratio of the soft segment (A) and the hard segment (B) is out of the above range, the elastic recovery property is lowered.

Further, the intrinsic viscosity of the polyester block copolymer of the present invention is preferably 0.6 or more, and when it is less than 0.6, the mechanical strength of the obtained polyester block copolymer is lowered, which is not preferable.

The polyester block copolymer of the present invention has a glass transition temperature of 0 ° C. or lower. Glass transition temperature is 0
If the temperature exceeds ℃, the impact strength and the like at a low temperature are deteriorated, which is not preferable.

[Additives] In the above polyester block copolymer, a branching agent, a sulfonate compound for imparting cationic dyeability, a phosphorus compound for imparting flame retardancy, and Other copolymerization components may be copolymerized, and pigments, dyes, fillers, flame retardants, stabilizers, antioxidants, light stabilizers, chain extenders and the like may be contained.

[Manufacturing Method] The soft segment (A) in the polyester block copolymer of the present invention is preferably obtained by polycondensation at a temperature of 240 to 270 ° C. during its manufacture. If the polycondensation temperature exceeds 270 ° C., the resulting polyester block copolymer will be inferior in terms of hue. It is presumed that this is because the decomposition of polyoxyethylene glycol, which is a constituent of the soft segment, is promoted. When the polycondensation temperature is lower than 240 ° C, not only the polycondensation reaction rate becomes slow and the reaction time becomes long, but also the degree of polymerization of the polyester constituting the soft segment (A) becomes low, resulting in a polyester block copolymerization The strength of coalescence decreases.

The polyester block copolymer of the present invention is produced by preparing a polyester constituting the soft segment (A) and a polyester constituting the hard segment (B), and then melt-mixing at a temperature of 230 to 260 ° C. under reduced pressure. It is preferable to carry out a transesterification reaction and terminate the reaction at a temperature of 2 to 60 ° C. lower than the melting point of the polyester constituting the hard segment (B). This is because if the transesterification reaction is carried out at a temperature lower than 230 ° C., the polyester (B) is difficult to dissolve, and if it is carried out at a temperature higher than 260 ° C., it is difficult to stop the reaction.

The apparatus used for melt mixing in the production is preferably a reaction vessel or a reaction extruder capable of melt mixing under reduced pressure.

Also, in melt mixing, "degree of reaction" and "state of reaction stop" are important points. The former can be appropriately changed depending on what kind of properties the polymer is desired to have, but the reaction conditions therefor are the type of polyester comprising the soft segment (A) and the polyester comprising the hard segment (B), Amount, molecular weight, etc.
Since it depends on various factors such as temperature and catalyst, it is difficult to determine uniquely. Therefore, in practice, the reaction conditions under which the desired polyester block copolymer can be obtained will be found out after the polymer, composition, equipment, etc. to be used have been determined.

When the transesterification reaction is carried out, the melting point (Tm _AB of the polyester block copolymer obtained is
It is important that the reaction is carried out until the temperature (° C) is lower than the melting point (Tm _B (° C)) of the polyester comprising the hard segment (B) by 2 to 60 ° C.

When the amount of decrease in melting point is less than 2 ° C., the transesterification reaction does not proceed sufficiently, and the obtained polymer is a polyester composed of a soft segment (A) and a hard segment (B) rather than a block copolymer. It exhibits the properties as a mixture of the polyesters and does not exhibit sufficient elastic recovery performance. On the other hand, when the melting point lowering amount exceeds 60 ° C., the transesterification reaction proceeds too much, the chain length of the polyester comprising the hard segment (B) of the resulting polymer becomes too short, the crystallinity decreases, and the elastic recovery occurs. It is not desirable because the performance becomes insufficient and becomes substantially equivalent to that of the random copolymer.

The termination of the reaction does not always cause a problem when the polyester block copolymer after the reaction is immediately molded, but, for example, when the chips are once formed and then melted again to form a molded product. Since the transesterification reaction further progresses during remelting and the properties of the polyester block copolymer change, it is desirable to stop the transesterification reaction. As a method of stopping this reaction, it is preferable to use a method of deactivating the catalyst. For example, a titanium or tin catalyst is used as a transesterification reaction catalyst, and phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid and derivatives thereof. Can be used to deactivate the catalytic activity. The deactivator is preferably added in an amount that is equimolar or more to the metal such as the titanium compound or tin compound of the catalyst.

The method for deactivating this catalytic activity is carried out at a temperature of 26.
If the melting point of the polyester composed of the hard segment (B) exceeds 260 ° C, the effect is reduced at 0 ° C or higher, so that it is possible to perform reaction and molding at a low temperature by using a solvent, a plasticizer or the like in advance. It is desirable to keep it.

The intrinsic viscosity of the polyester block copolymer thus obtained (in orthochlorophenol at 35 ° C.)
Is preferably 0.4 or more, more preferably 0.
It is 6 or more. As the intrinsic viscosity, a polyester having a high intrinsic viscosity is used as the polyester consisting of the soft segment (A) and the polyester consisting of the hard segment (B) used in the transesterification reaction, and both polymers are decomposed during the transesterification reaction and the degree of polymerization is increased. Can be achieved by reacting under conditions that do not decrease If the reaction temperature during the transesterification reaction is too high, thermal decomposition will occur, and if water, glycol components, etc. coexist in the reaction atmosphere, hydrolysis, glycol decomposition, etc. will occur, resulting in an intrinsic viscosity of the polyester block copolymer. Is not desirable because it decreases.

[0033]

EXAMPLES The present invention will be described in more detail below with reference to examples. Various characteristics were measured as follows. As the differential scanning calorimeter, Model 2910 manufactured by DuPont was used. Intrinsic viscosity: Determined from solution viscosity measured at 35 ° C in orthochlorophenol. Melting point: The temperature was measured at 20 ° C./min using a differential scanning calorimeter, and the temperature was determined from the apex of an endothermic peak corresponding to melting of crystals. Glass transition temperature: The polyester block copolymer was once melted using a differential scanning calorimeter and then rapidly cooled to 10 ° C.
The temperature was measured again at a temperature of 1 / min. Hue: Determined by Z-Σ80 manufactured by Nippon Denshoku Co., Ltd.

Example 1 Dimethyl terephthalate 100
Parts by weight, triethylene glycol 70 parts by weight, polyoxytetramethylene glycol (average molecular weight 650) 10
An ester exchange reaction was carried out using 0 part by weight of titanium tetrabutoxide as a catalyst, followed by a polycondensation reaction at 265 ° C. under high vacuum to obtain a polyester having an intrinsic viscosity of 0.97. 95 parts by weight of dry chips of polybutylene terephthalate having an intrinsic viscosity of 1.02 obtained by polycondensation separately with this polyester are melt-mixed and 250 ° C., 1 mmHg
Was transesterified under high vacuum for 60 minutes, and then phenylphosphonic acid (1.5 moles relative to titanium tetrabutoxide) was added to obtain a polyester block copolymer. The polyester block copolymer obtained had an intrinsic viscosity of 1.10 and a melting point of 202 ° C. Table 1 shows the glass transition temperature and the results of color measurement.
As shown in Table 1, this polyester block copolymer has a greatly lowered glass transition temperature and an improved hue.

Comparative Example 1 Dimethyl terephthalate 100
By weight, 93 parts by weight of triethylene glycol is subjected to transesterification reaction using titanium tetrabutoxide as a catalyst, and then polycondensation reaction is performed at 265 ° C. under high vacuum.
A polyester having an intrinsic viscosity of 0.72 was obtained. Then, a transesterification reaction with polybutylene terephthalate was carried out in the same manner as in Example 1 to obtain a polyester block copolymer having an intrinsic viscosity of 0.90 and a melting point of 180 ° C. As shown in Table 1, the properties of this polyester block copolymer are higher in glass transition temperature and poor in hue as compared with Example 1.

[Comparative Example 2] The composition of the same soft segment as in Comparative Example 1 was used, and the polycondensation temperature was set to 255 in order to improve the hue.
C. and the polyester block copolymerization was performed in the same manner as in Comparative Example 1 except that the weight ratio of the soft segment (A) to the hard segment (B) was changed from 70:30 to 75:25 in order to lower the glass transition temperature. Got united. The polyester block copolymer obtained has a glass transition temperature,
Although the hue is slightly improved, it is significantly inferior to that of Example 1.

Example 2 The same as Example 1 except that 100 parts by weight of dimethyl terephthalate, 85 parts by weight of triethylene glycol, and 47 parts by weight of polyoxytetramethylene glycol (average molecular weight 1000) were used as the composition of the soft segment. To obtain a polyester block copolymer. The properties of the obtained polyester block copolymer are shown in Table 1.

[Examples 3 and 4] Polyester block copolymers were obtained in the same manner as in Example 1. The composition and reaction conditions are shown in Table 1.

[Examples 5 and 6] A polyester block copolymer was obtained in the same manner as in Example 1 except that polyoxyethylene glycol (average molecular weight 400) was used instead of polyoxytetramethylene glycol in Example 1. It was The properties of the obtained polyester block copolymer are shown in Table 1.

[0040]

[Table 1]

As is clear from the above results, the glass transition temperature can be lowered by copolymerizing the specific polyoxyalkylene glycol with the soft segment, and the improvement of low temperature characteristics can be expected. Also, from the viewpoint of hue, it is apparent that the quality is significantly improved as compared with the polyester block copolymer in which polyoxyalkylene glycol is not copolymerized.

[0042]

The polyester block copolymer of the present invention can remarkably improve low temperature properties. In addition, in terms of hue as well, a polyester block copolymer having excellent appearance and heat resistance can be obtained because it is significantly improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (5)

(57) [Claims] 1. A terephthalic acid component is 50 mol% or more based on the total dicarboxylic acid component, an oligooxyethylene glycol component consisting of 2 to 5 oxyethylene units is 60 to 97 mol% and a molecular weight based on the total dicarboxylic acid component. Thirty
20 to 80% by weight of the soft segment (A) composed of 40 to 3 mol% of polyether ester based on all dicarboxylic acid components of 0 to 2000 of polyoxyalkylene glycol, and 60 mol% or more of tetramethylene terephthalate units. A polyester block copolymer comprising a polytetramethylene terephthalate hard segment (B) in an amount of 80 to 20% by weight, the polyester block copolymer having a glass transition temperature of 0 ° C. or lower and excellent in low temperature characteristics and hue . 2. A polyoxyethylene polyester block copolymer of alkylene glycol according to claim 1 is a polyoxytetramethylene glycol having a molecular weight of 500 to 2000 weight <br/> case body. 3. The polyester block copolymer according to claim 1, wherein the polyoxyalkylene glycol is a polyoxyethylene glycol having a molecular weight of 300 to 1500 . Upon wherein the soft segments (A) polycondensing the polyester block copolymer according to claim 1, characterized in that the polycondensation temperature 240 to 270 ° C.
The method of production. 5. The melting point of the polyester block copolymer for producing a polyester block copolymer by melt-mixing the polyester comprising the soft segment (A) and the polyester comprising the hard segment (B) and subjecting them to transesterification reaction. The method for producing a polyester block copolymer according to claim 1, wherein the reaction is terminated at a point of 2 to 60 ° C. lower than the melting point of the polyester composed of the hard segment (B).