JPH05295095A - Polyester block copolymer and its production - Google Patents

Abstract

PURPOSE:To provide the subject copolymer excellent in light resistance and chlorine resistance, and high in elastic recovery and melting point. CONSTITUTION:The objective polyester block copolymer made up of (A) polycarbonate-ester copolymer segments with 4-12C aliphatic diols mutually linked through carbonate linkages and ester linkages and (B) polyester segments each composed of an aromatic dicarboxylic acid as the main acid component and tetramethylene glycol, etc., as the main glycol component. In this case, the segment A is such that 10-70mol% of its structural units consists of ester linkages with the main acid component being an aromatic dicarboxylic acid such as isophthalic acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polyester block copolymer and a method for producing the same. More specifically, it relates to a polyester block copolymer having a polycarbonate segment as a soft segment, which is suitable for producing elastic yarns, and a method for producing the same.

[0002]

2. Description of the Related Art Heretofore, spandex has been generally used as an elastic yarn, and polyester has only begun to be used for some applications. Spandex
It can be said that it occupies this position due to its good elastic recovery performance.

However, spandex also has various drawbacks, which limits its use. For example, it cannot be dyed together with polyester because it has poor wet heat resistance, it turns yellow when exposed to light, it has poor chlorine resistance, and it is limited in applications such as swimwear.

In order to improve these drawbacks, various studies have been made for a long time to use polyester as a raw material for elastic yarns, but none of them has been put into practical use other than polyether ester elastomers having improved wet heat resistance. This is because the elastic yarn using the obtained polymer is inferior in the performance of spandex. In particular, the problem is that the elastic performance is poor. If this point can be improved, it is considered that the goodness of polyester can be exhibited and the drawbacks of spandex can be improved.

In particular, light resistance, chlorine resistance, etc. are often determined by so-called soft components, and therefore, new components different from the soft components currently used in spandex are demanded.

From this point of view, the present inventors previously proposed a polyester block copolymer having a soft segment of polyester containing phthalic acids and a long-chain diol as main components (Japanese Patent Laid-Open No. 4-33919). .. However, it has been found that this soft component also becomes hard at low temperatures such as below freezing and is difficult to use as a soft component.

On the other hand, as a soft component of polyurethane,
Aliphatic polycarbonate is known as a soft component of polyurethane having excellent light resistance and chlorine resistance. Using this polycarbonate as a soft component, if a polyester block copolymer using an aromatic polyester as a hard component is produced, light resistance, chlorine resistance, it is thought that an elastic body excellent in cold resistance may be obtained, Although tested, it was difficult to obtain a block copolymer having a recovery rate of 80% or more after 200% elongation and a melting point of 180 ° C. or more.

[0008]

From the above viewpoints, the present invention is a block copolymer of an aliphatic polycarbonate type soft component and an aromatic polyester hard component, which is excellent in elastic recovery and has a high melting point. A novel polyester block copolymer and a method for producing the same are provided.

[0009]

Means for Solving the Problems The present inventors have used an aliphatic polycarbonate ester obtained by copolymerizing an aromatic polyester as a soft component and an aromatic polyester as a hard component to cause a transesterification reaction between them. Then, they have found that a polyester block copolymer having a high melting point and excellent elastic recovery can be obtained, and the present invention has been accomplished.

That is, according to the present invention, a polycarbonate ester copolymer part (A) in which an aliphatic diol having 4 to 12 carbon atoms is bonded by a carbonate bond and an ester bond, and an aromatic dicarboxylic acid as a main acid component, A polyester block copolymer comprising a polyester moiety (B) having a melting point of 170 ° C. or higher, the main component being at least one glycol selected from the group consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol and cyclohexanedimethanol. A polyester block copolymer characterized in that 10 to 70 mol% of the constituent units of the polycarbonate ester copolymer part (A) are mainly composed of ester bonds having an aromatic dicarboxylic acid as an acid component. so That.

One component constituting the polyester block copolymer of the present invention is a polycarbonate ester copolymer portion (A) in which an aliphatic diol having 4 to 12 carbon atoms is bound by a carbonate bond and an ester bond.
Is.

Examples of the aliphatic diol having 4 to 12 carbon atoms include linear or branched diols having 4 to 12 carbon atoms, and among them, primary diols having 4 to 12 carbon atoms are preferable. Used. Preferred aliphatic diols include, for example, 1,6-hexanediol, 1,
Mention may be made of 10-decanediol and 3-methyl-1,5-pentanediol. If the number of carbon atoms of the aliphatic diol exceeds 13, it is difficult to obtain, and the reaction between the polycarbonate ester copolymer (A ′) and the polyester (B ′) described later becomes difficult, and the obtained block The elastic recovery performance of the copolymer also deteriorates, which is not preferable.

In the present invention, the ester bond of the polycarbonate ester copolymer portion (A) occupies 10 to 70 mol%, preferably 20 to 50 mol% of the constitutional unit of the polycarbonate ester copolymer (A), and mainly It is necessary for the aromatic dicarboxylic acid to be composed of an ester bond having an acid component. If the ester bond content is less than 10 mol%, it is difficult to obtain a block copolymer having a high melting point, while if it exceeds 70 mol%, the low-temperature properties deteriorate.

The aromatic dicarboxylic acid is not particularly limited, but examples thereof include phthalic acids and naphthalene dicarboxylic acids. In particular, aromatic dicarboxylic acids capable of obtaining a polymer having low crystallinity, that is, a non-linear polymer are preferable, and among them, isophthalic acid is most often used. These may be used in combination of two or more.

Here, "mainly" means at least 70.
Mol%, preferably 80 mol% or more is composed of an aromatic dicarboxylic acid component, and the sum of other aliphatic dicarboxylic acid and acid components such as oxycarboxylic acid is 30 mol% or less of all acid components,
It is preferably 20 mol% or less.

As the diol component constituting the polycarbonate ester copolymer part (A), other diol components may be copolymerized in addition to the aliphatic diol. The amount of such a copolymerization component is preferably less than 30 mol% of the diol component, preferably 20 mol% or less.

The component constituting the other block of the polyester block copolymer of the present invention comprises an aromatic dicarboxylic acid as a main acid component and is selected from the group consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol and cyclohexanedimethanol. A polyester portion (B) having a melting point of 170 ° C. or higher, which comprises at least one selected glycol as a main glycol component.

Examples of the aromatic dicarboxylic acid used in the polyester portion (B) include terephthalic acid,
Examples thereof include 2,6-naphthalenedicarboxylic acid and 4,4′-diphenyldicarboxylic acid. These may be used in combination of two or more.

As the glycol component, at least one glycol selected from the group consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol and cyclohexanedimethanol is used. Of these combinations, a system in which the aromatic dicarboxylic acid is terephthalic acid and the glycol is tetramethylene glycol is often used.

As used herein, the term "mainly" means that other acid components may be copolymerized in an amount of 30 mol% or less, preferably 20 mol% or less, based on the total acid components.

Since the polyester block copolymer of the present invention has a polyester block having a melting point of 170 ° C. or higher, preferably 180 to 240 ° C., it can be heat set at a high temperature after being made into a fiber, for example. It has the advantage that it can be used at high temperatures under extremely low loads.

The polyester block copolymer of the present invention described above is, for example, a polycarbonate ester copolymer (A ') or a polycarbonate ester copolymer (A') consisting of the above-mentioned polycarbonate ester copolymer portion (A) or polyester portion (B) alone. The polyester (B ') is produced by melt reaction.

The polycarbonate ester copolymer (A ') is produced by combining the aliphatic diol having 4 to 12 carbon atoms with a carbonate bond and an ester bond.

For example, as one method, an aromatic dicarboxylic acid or its ester-forming derivative is reacted with an aliphatic diol to obtain a diol ester of an aromatic dicarboxylic acid, and then a carbonic acid ester such as diphenyl carbonate.
Examples include a method of adding methyl carbonate, ethyl carbonate and the like and reacting them to obtain a high molecular weight polycarbonate ester.

As another method, a conventional polyester is produced from an aliphatic polycarbonate having a low molecular weight such as polycarbonate diol for producing polyurethane, an aliphatic diol and an aromatic dicarboxylic acid or an ester-forming derivative thereof. The same method as can be used. At this time, when the aromatic dicarboxylic acid is used in the acid state, carbon dioxide gas is generated rather than the carbonate and the amount of the carbonate bond is not constant in many cases. Therefore, it is better to use the ester form.

As the polycarbonate ester copolymer (A '), one having an intrinsic viscosity of 0.5 or more, preferably 0.7 or more is used. When the intrinsic viscosity is less than 0.5, the intrinsic viscosity of the obtained polyester block copolymer is also low, and the strength of the obtained fiber is low.
This is because it is necessary to use other means such as a chain extender to increase the intrinsic viscosity.

On the other hand, the polyester (B ') can be produced by a method similar to the production of ordinary polyester,
An intrinsic viscosity of 0.5 or more, preferably 0.7 to 1.3 is used.

In the present invention, the block is prepared by reacting the polycarbonate ester copolymer (A ') having an intrinsic viscosity of 0.5 or more and the polyester (B') having a melting point of 170 ° C. or more, produced as described above. A copolymer is used, and the weight ratio of the polycarbonate ester copolymer (A ') to the polyester (B') is 30:70 to 90: 1.
The ratio is 0, preferably 50:50 to 85:15.

When the amount of the polycarbonate ester copolymer (A ') is less than that, the effect as a block copolymer is small and, for example, the elastic recovery ability is insufficient or the flexibility is deteriorated. On the other hand, if the amount is larger than this, the crystallinity becomes insufficient and molding becomes difficult. Especially when it is made into fibers, it is 70:30 to 90:10, preferably 75:25 to 85:15. Outside this range,
This is because the fiber does not have sufficient elastic recovery ability.

In the present invention, the polycarbonate ester copolymer (A ') and the polyester (B') having such a weight ratio are melt-reacted. The extent to which this melting reaction is carried out is very important, but it is not uniquely determined. However, it is necessary that the melting point of the finished polyester block copolymer is 2 to 50 ° C. lower than the melting point of the original polyester (B ′),
Particularly in the case of fibers, it is desirable that the elastic recovery rate of the fibers is 85% or more, preferably 90% or more after being stretched by 200%, and it is desirable that the fibers are not fused even by heat treatment at 130 ° C.

When the melting point is lower than 2 ° C., the reaction does not proceed sufficiently, and the obtained polymer is not a block copolymer but a polycarbonate ester copolymer (A ′) and a polyester (B ′). Of the mixture, and does not show sufficient elastic recovery performance. on the other hand,
When the melting point decrease exceeds 50 ° C., the reaction proceeds too much, the length of the polyester part (B) of the resulting block copolymer becomes too short, the crystallinity decreases, and the elastic recovery performance is insufficient. And is substantially equivalent to the random copolymer, which is not desirable.

Since this condition depends on the polymer composition, the intrinsic viscosity of each polymer, the type and amount of the catalyst, the reaction temperature, the pressure, etc., the reaction time can be changed by keeping these constant, and It can be determined by looking for conditions under which the polymer is obtained.

As another method of determination, there is a method in which the reaction is carried out in the absence of an additive such as a matting agent that makes the polymer opaque, and the time when the reaction becomes transparent is used as a standard. This method is a preferable method because the end point of the reaction can be determined correspondingly even if the conditions change. Generally, the end point is set within 5 minutes from the time when it becomes transparent.

Such a blocking reaction can be carried out by any of batch and continuous methods. For example, a method of polymerizing a polycarbonate ester copolymer (A ') and adding and reacting a separately polymerized polyester (B') when the intrinsic viscosity is increased, a method of polycarbonate ester copolymer (A ') and polyester (B ') is polymerized and fed to a continuous reactor for reaction.

The conditions for this reaction are usually 230 to 260.
It is carried out at normal pressure or reduced pressure at 0 ° C. This is because the polyester (B ') is difficult to melt at a temperature lower than this temperature, and it is difficult to stop the reaction at a temperature higher than this temperature. However, in the case where the reaction product can be immediately cooled as in the continuous reaction, the reaction temperature can be further increased.

After completion of the reaction, it is preferable to add an acid such as phosphoric acid or phosphorous acid to stop the reaction in order to suppress deterioration of physical properties due to reaction in the subsequent spinning. The addition amount of this acid is generally 1 to 10 times the molar amount of the catalyst metal used.

The intrinsic viscosity (at 35 ° C. in orthochlorophenol) of the polyester block copolymer thus obtained is 0.6 or more, preferably 0.8 to 2.0.

The polyester block copolymer of the present invention comprises a branching agent, a sulfonate compound for imparting cationic dyeability, a phosphorus compound for imparting flame retardancy,
Other copolymerization components may be copolymerized,
Pigments, dyes, fillers, flame retardants, stabilizers and the like may be contained.

[0039]

EXAMPLES The present invention will be described in more detail with reference to the following examples. In the examples, "part" means "part by weight". Further, various characteristics were measured as follows. The intrinsic viscosity was determined from the viscosity measured in orthochlorophenol at 35 ° C. Melting point (° C.) Using a differential scanning calorimeter, the temperature was measured at the apex of an endothermic peak corresponding to the melting of the crystal, which was heated at 20 ° C./min. Elastic recovery rate (%) When stretched at 1,000% / min and reached a predetermined elongation (L ₀ ), immediately returned at the same rate and the stress reached 0,
Immediately again, the tensile force was calculated to obtain the elongation (L) at the point where stress appears, and the elongation was calculated by the following formula. Elastic recovery rate = [(L ₀ −L) / L ₀ ] × 100

Example 1 To 97 parts of dimethyl isophthalate (50 mol% / diol) and 118 parts of hexamethylene glycol, 0.1 part of titanium tetrabutoxide was added and reacted by heating to distill off almost theoretical amount of methanol. did. Next, 107 parts of diphenyl carbonate was added thereto, the phenol distilled at 250 ° C. was removed, and after 0.5 hours, the inside pressure was gradually reduced, and after maintaining the pressure of 0.5 mmHg for 10 minutes, a small amount of When diphenyl carbonate (addition amount: 0.3 part) was added, the viscosity increased. The intrinsic viscosity of the obtained polymer (A ') was 0.96.

On the other hand, polytetramethylene terephthalate (B ') having an intrinsic viscosity of 1.05, which is separately prepared by a conventional method.
65 parts of the product (melting point 223 ° C.) dried at 140 ° C. for 6 hours was prepared and added to the polymer (A ′), and 0.5
As a result of reacting at 250 ° C. for 40 minutes under reduced pressure of mmHg (A ′ / B ′ = 75/25), the polymer became transparent. After adding 0.2 part of phosphorous acid, it was taken out into a chip shape. did.

The polyester block copolymer thus obtained had an intrinsic viscosity of 0.99, a melting point of 196 ° C., and had an elastic recovery rate after elongation of 200% measured at room temperature of 91%. Also, the same elastic recovery rate measured at 0 ° C is 90%.
Met.

Comparative Example 1 118 parts of hexamethylene glycol and 0.1 part of titanium butoxide were added with 210 parts of diphenyl carbonate, and the same procedure as in Example 1 was followed by adding diphenyl carbonate.
A polymer (A ') having an intrinsic viscosity of 1.07 was obtained.

The same polytetramethylene terephthalate (B ') as in Example 1 was added thereto (A' / B '= 75 /
25), the mixture was reacted at 250 ° C., and when it became transparent, 0.2 part of phosphorous acid was added and taken out.

This polymer has an intrinsic viscosity of 1.06 and a melting point of 1
At 62 ° C, the elastic recovery rate after 200% elongation at room temperature in the filament form was 75%.

Comparative Example 2 146 parts of dimethyl isophthalate (75 mol% / diol), the amount of diphenyl carbonate was changed to 53 parts, and the amount of polytetramethylene terephthalate was 82 parts (A '/ B' = 75 / In the same manner as in Example 1 except that the step 25) was performed, a block copolymer was obtained by reacting until transparent.

This block copolymer has an intrinsic viscosity of 0.9.
7, the melting point was 203 ° C., the elastic recovery rate after 200% elongation at room temperature was 90%, which was good, but the elastic recovery rate at 0 ° C. reached only 45%.

Example 2 165 parts of dimethyl isophthalate, 29 parts of dimethyl terephthalate, and 191 parts of decamethylene glycol were transesterified with 0.3 part of dibutyltin diacetate, and almost the theoretical amount of methanol was distilled off. To this reaction product, 300 parts of polyhexamethylene carbonate having a molecular weight of about 2,000, which was synthesized from hexamethylene glycol and dimethyl carbonate by a conventional method, was added, and the pressure was gradually reduced at 250 ° C. under a reduced pressure of 0.5 mmHg. After reacting for 2 hours, a polycarbonate ester copolymer (A ′) having an intrinsic viscosity of 1.05 [carbonate / ester = 67: 33
(Molar ratio)] was obtained.

180 parts of polytetramethylene terephthalate (B ') (intrinsic viscosity 0.91, melting point 223 ° C.), which was separately synthesized with this polymer (A') by a conventional method and dried (A '/ B' = 75 /) 25) was added and the reaction was continued until it became transparent, 0.2 parts of phenylphosphonic acid was added to deactivate the catalyst, and the product was taken out.

The block copolymer thus obtained has an intrinsic viscosity of 1.02, a melting point of 195 ° C., an elastic recovery rate after room temperature elongation of 200% of 89%, and that at 0 ° C. is 8%.
It was 7%.

Examples 3 to 5 Polycarbonate ester copolymers (A ') having different composition ratios were produced in the same manner as in Example 2, and these and various polyesters (B') were A '/ B. ′ = 70/3
The reaction was carried out at a ratio of 0 (part). Intrinsic viscosity, melting point, 200% at room temperature and 0 ° C. of the obtained block copolymer
The elastic recovery rate after stretching is shown in Table 1.

[0052]

[Table 1]

[0053]

INDUSTRIAL APPLICABILITY The polyester block copolymer of the present invention is a thermoplastic elastic body excellent in light resistance, chlorine resistance, hydrolysis resistance and mildew resistance, and is used in various fields such as fibers, films and resins. Can be used.

Further, while maintaining high elastic recovery performance as an elastic body, it has a high melting point, and particularly, the weight ratio of the polycarbonate ester copolymer portion (A) and the polyester portion (B) is 85/15 to 60/40. Such a soft material has a large effect and is suitable for manufacturing elastic yarn.

Claims (2)

[Claims] 1. A polycarbonate ester copolymer part (A) in which an aliphatic diol having 4 to 12 carbon atoms is bonded by a carbonate bond and an ester bond, and an aromatic dicarboxylic acid as a main acid component, ethylene glycol, triglyceride A polyester block copolymer comprising a polyester moiety (B) having a melting point of 170 ° C. or higher, which comprises at least one glycol selected from the group consisting of methylene glycol, tetramethylene glycol and cyclohexanedimethanol as a main glycol component. A polyester block copolymer, characterized in that 10 to 70 mol% of the constituent units of the copolymer part (A) are mainly composed of ester bonds having an aromatic dicarboxylic acid as an acid component. 2. A polycarbonate ester copolymer (A ') having an intrinsic viscosity of 0.5 or more, which is formed by binding an aliphatic diol having 4 to 12 carbon atoms by a carbonate bond and an ester bond, and an aromatic dicarboxylic acid. Melt-mixing with a polyester (B ') having a melting point of 170 ° C or higher and a main acid component of which is at least one glycol selected from the group consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol and cyclohexanedimethanol. Then, the polyester block copolymer is reacted until the melting point becomes lower than the melting point of the polyester (B ') by 2 to 50 ° C.