JPS5921886B2 - Method for producing polyester block copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for producing a polyester block copolymer.

Generally, when it is desired to impart a high degree of functionality to a polymer, the polymer is often made up of a wide variety of constituent components, and the method used is to randomly polymerize each constituent component.

However, since random polymers generally have poor thermal properties, it is difficult to obtain useful polymers. In such case,
One useful method is to produce block polymers. For example, a method of block copolymerizing hydrophobic, high-melting point crystalline polyethylene terephthalate with hydrophilic polyoxyethylene glycol to impart hydrophilicity and improving dyeability, or a method of block copolymerizing hydrophobic, high-melting point crystalline polyester with polyoxytetramethylene glycol. There is a method in which softness is imparted by block copolymerizing. However, when producing a head polymer consisting of polyesters, a randomization reaction occurs in addition to a blocking reaction, so it is necessary to suppress or prevent the randomization reaction.

As such a method, a method of adding a phosphorus compound is known (see Japanese Patent Publication No. 46-35500). However, according to the research conducted by the present inventors, the effect of suppressing and preventing the randomization reaction by adding a phosphorus compound is greatly influenced by the catalyst present in the system when the head nokization reaction is allowed to proceed. , For example, when the catalyst used is antimony trioxide, which is usually used for polymerization of polyethylene terephthalate, it is virtually impossible to suppress or prevent the randomization reaction by adding a phosphorus compound. In the case of titanate esters, it has become clear that the addition of a phosphorus oxifusic acid compound suppresses and prevents the randomization reaction particularly markedly.

That is, the present invention melt-mixes at least one aromatic polyester selected from the group consisting of polytrimethylene terephthalate, polytetramethylene terephthalate, and poly(5-hexamethylene terephthalate) and an aliphatic polyester, and at least increases the degree of blocking of the polyester. In a method for producing a block copolymer, the reaction is carried out in the presence of a titanium-based catalyst, and after the reaction is substantially completed, a sufficient amount of a phosphorus acid compound to deactivate the action of the catalyst is added. This is a method for producing a polyester block copolymer, which is characterized in that the polyester block copolymer is added.

The aromatic polyester used in the method of the present invention is an aromatic polyester selected from the group consisting of polytrimethylene terephthalate, polytetramethylene terephthalate, and polyhexamethylene terephthalate, and the aromatic polyester is obtained by copolymerizing a small proportion of a third component. Includes what has been caused.

Examples of the third component include isophthalic acid, naphthalenedicarboxylic acid (2,6-, 2,7-, 1,4-dicarboxylic acid is particularly preferred), diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyldicarboxylic acid, and diphenyldicarboxylic acid. Aromatic dicarboxylic acids such as sulfonic acid, diphenyl ether dicarboxylic acid, etc.; Aromatic oxyacids such as β-hydroxyethoxybenzoic acid; Fats such as adipic acid, sebacic acid, decanedicarboxylic acid, azelaic acid, ε-monocaprolactone, etc. Group carboxylic acids: ethylene glycol, propylene glycol, pentamethylene glycol, decamethylene glycol, cyclohexane-1,4-dimethanol, neopentylene glycol, diethylene glycol, triethylene glycol, tricyclodecane dimethylol, 2,2-bis β - Glycols such as hydroxyphenylpropane and the like can be mentioned. Moreover, an aliphatic polyester is one in which the main acid component is an aliphatic acid component.

Examples of acid components include succinic acid, adipic acid,
Azelaic acid, sebacic acid, decanedicarboxylic acid, etc. can be mentioned. Specific examples of glycol components include:
It is the same as that exemplified for the glycol component of the aromatic polyester. Therefore, two or more of these may be used in combination, or, for example, a small proportion of an aromatic acid component such as the above-mentioned terephthalic acid may be copolymerized. Further, homopolymers comprising an oxyacid component such as ε-caprolactone or copolymers having this as a component are also included in the aliphatic polyester.
The above-mentioned aromatic polyesters and aliphatic polyesters may be further combined with trifunctional or higher functional polyfunctional compounds such as trimesic acid, trimethylolpropane, pentaerythritol, or o-benzoylbenzoic acid, toluic acid, methoxypolyoxyethylene glycol, octyl It may also be a polyester obtained by copolymerizing one or more monofunctional compounds such as alcohol to a substantially linear extent.

In the present invention, polytetramethylene terephthalate is used as the hard segment polyester because the polyester block copolymer produced exhibits particularly excellent elastic properties, oil resistance, cold resistance, etc., and can be used for various purposes. , polytrimethylene terephthalate, and polyhexamethylene terephthalate, and aliphatic polyesters such as polyethylene adipate, polytetramethylene adipate, polyhexamethylene adipate, and polyethylene sebacate are used as the polyester of the soft segment. preferable.

In the present invention, first, the above-mentioned aromatic polyester and aliphatic polyester are melt-mixed and subjected to a blocking reaction.

This blocking reaction is carried out in the presence of a titanium catalyst. The use of a titanium-based catalyst not only allows this blocking reaction to proceed smoothly, but also sufficiently suppresses and stops the polymer randomization reaction even after the thermal history that occurs after the desired blocking reaction is completed. So that
There is an advantage that the catalytic action can be very easily deactivated by the phosphorus oxy compound. The advantage of using a titanium-based catalyst is as described above, and it has industrial significance in that a stable product can be obtained using the polyester block copolymer obtained by the method of the present invention. For example, when an antimony trioxide catalyst is used instead of a titanium-based catalyst, it is virtually impossible to deactivate or suppress the catalytic action by adding a phosphorous acid compound, and therefore it is difficult to produce products using this. When attempting to obtain a product, it is impossible to obtain a product with stable properties because the blocking reaction proceeds to various degrees due to differences in thermal history.

Examples of titanium-based catalysts include titanate esters, titanyl oxalate, titanium halides, hydrolysates of titanium halides, titanium hydroxide, and titanium oxide hydrates.

Specific examples of these include propyl titanate,
Examples include butyl titanate, titanyl oxalate, calcium titanyl oxalate, potassium titanyl oxalate, titanium tetrachloride, a reaction product of titanium tetrachloride and hexanediol, a reaction product of titanium tetrachloride and water, and the like. These titanium-based catalysts are preferably used in an amount of about 0.001 to 0.5 mol%, particularly about 0.003 to 0.1 mol%, per repeating unit of the entire aromatic polyester and aliphatic polyester used in the reaction.

In order to make a titanium-based catalyst exist in the reaction system, aromatic polyester and/or produced using a titanium-based catalyst are usually used.
Alternatively, a method using an aliphatic polyester may be used, but a titanium-based catalyst may be further added at the time of melt reaction and mixing, if necessary. As mentioned above, the method of the present invention is carried out in the presence of a titanium-based catalyst, and it is preferable not to include a catalyst whose catalytic activity cannot be deactivated even by the addition of a phosphorus compound such as antimony trioxide. However, even in the presence of a catalyst whose catalytic activity cannot be deactivated or suppressed by a phosphorus compound, as in the case where one polyester is a polyester produced using antimony trioxide as a catalyst during production, titanium-based catalysts cannot be used. It has become clear that the objects of the present invention can be substantially achieved when the above-described preferred ranges are present. It has also become clear that in such cases it is preferable to use a titanium-based catalyst in an amount of about 50% or more of the amount of active catalyst present in the system.
In the blocking reaction, the type of polyester to be reacted,
Although it varies depending on various conditions such as the terminal group concentration, reaction temperature, and moisture content in the reaction system, it is generally carried out at 150°C for 5 to 120 minutes.
Above, it is carried out especially at a temperature of 200° C. or higher, particularly 230° C. or higher, which is higher than the melting point of the polyester.

For the above-mentioned most preferred combination of aromatic polyester and aliphatic polyester, a temperature of 230°C or more and less than 260°C is optimal. The atmosphere during the melt-mixing in which the blocking reaction is carried out may be under increased pressure, reduced pressure, or normal pressure, and in any case, an inert atmosphere is preferable.

The blocking reaction is generally carried out for 5 to 120 minutes and is substantially completed, but to confirm more specifically, the polymer is sampled from the system as the reaction progresses and its softening point and elastic recovery rate are measured. This can be done appropriately by checking in advance.

In addition, it has become clear that the point at which the softening point reaches its maximum value generally coincides with the point at which the reaction system becomes transparent, so in practical terms, the point at which the reaction system becomes transparent can also be used for judgment. It is valid. These points coincide with the point at which the blocking reaction is substantially completed. The elastic recovery rate is preferably determined by a value of 50% or more after 20% elongation and 5 minutes of relaxation.
The method of the present invention is then carried out by adding a phosphorous acid compound into the reaction system.

The phosphorus compound acts to substantially deactivate the catalytic activity of the titanium-based catalyst present in the reaction system, and at the stage where the blocking reaction has progressed appropriately, it maximizes the progress of the subsequent randomization reaction. This has the effect of suppressing stoppage to a limited extent. The phosphorus oxy acid compound having the above action is a compound having a free hydroxyl group (-0H) bonded to a phosphorus atom, and specific examples of such phosphorus oxy acid compounds are as follows. For example, preferred specific examples include inorganic acids such as orthophosphoric acid, phosphorous acid, and hypophosphorous acid, methylphosphinic acid, ethylphosphinic acid, isobutylphosphinic acid, benzylphosphinic acid, phenylphosphinic acid, and cyclohexyl Phosphinic acid, 4-methylphenylphosfuonic acid, etc., methylphosfunic acid, ethylphosfuonic acid, isopropylphosfuonic acid, isobutylphosfuonic acid, benzylphosfuonic acid, phenylphosfuonic acid, cyclohexyl Phosphonic acids such as phosphonic acid and 4-methylphenylphosphonic acid, and partial esters of alkyl, cycloalkyl, aryl, and aralkyl having 1 to 20 carbon atoms such as methyl, ethyl, propyl, cyclohexyl, phenyl, and benzyl; can include partial metal salts of these sodium, potassium, calcium, magnesium, etc. These preferable compounds can be summarized as compounds represented by the following formulas [1] and partial esters or partial salts thereof. [In the formula, R1 is a hydrogen atom or a monovalent hydrocarbon residue such as an alkyl group, cycloalkyl group, aralkyl group, or aryl group having 20 or less carbon atoms] [In the formula, R2 and R3 are each independently the above-mentioned A group selected from the group consisting of the same groups as R1] Among these phosphorus compounds, those in the form of oxyacid are particularly preferred because they have a particularly large effect and are effective in small amounts.

Moreover, since it is used in a molten state, it is more preferable to use one with a high boiling point and high decomposition point. Moreover, these phosphorusoxy acid compounds are also used as a mixture. The amount of the phosphorus oxyacid compound is sufficient to deactivate the titanium-based catalyst, and it is usually effective to use one or more compounds per titanium atom. The addition of the phosphoric acid compound may be carried out all at once or in two or more times. In this system, other additives such as oxidation stabilizers, light stabilizers, ultraviolet absorbers,
Optical brighteners, matting agents, lubricants, antistatic agents, flame retardants, flame retardant aids, fungicides, pigments, reinforcing agents, fillers, etc. can be used without any problems. Of course, these may be included in advance during the production of each polyester. It is also possible to use compounds that have two or more of these functions at the same time.
For example, a suitable example is a stabilizer for a phosphoric acid that functions as the phosphoric acid compound. It is also possible to mix it with other polymers than polyester, such as polystyrene, polyethylene, various rubbers, polycarbonate, etc. The time for mixing with the phosphoric acid compound depends on the mixing method, but generally it can be completed in a very short time. For example, it is preferable to carry out the reaction within about 5 minutes to 90 minutes, particularly within 60 minutes, both from the viewpoint of suppressing undesirable side reactions of the polymer and from an economical point of view. This reaction can be carried out either continuously or batchwise. For example, the titanium-based catalyst can be deactivated by passing a pre-melted mixture into an extruder together with a phosphorus oxyacid compound, or by feeding the phosphorus compound directly into a reaction vessel where the blocking reaction is carried out batchwise.
There is a method to take it out after it is deactivated. Stable block polymers obtained by such a reaction method, for example, those having soft segments made of aliphatic polyester and hard segments made of aromatic polyester are highly useful as elastomers from a practical standpoint. Next, the present invention will be explained by giving examples.

All parts by weight of the middle part of the example were ashes, and ηSp/c was 35 at a concentration of 1.2 g/11 in orthochlorophenol.
Reduced viscosity measured at °C Example 1 and Comparative Example 1 (1) 194 parts of dimethyl terephthalate, 140 parts of tetramethylene glycol, 0.102 parts of butyl methanoate (
0.03 mol%/acid component) was stirred and heated under an inert atmosphere to carry out a transesterification reaction.

A liquid mainly consisting of methanol distilled at a reaction temperature of 200°C was taken, and when the distilled methanol reached almost the theoretical amount, the pressure in the system was gradually reduced and the temperature was raised to 240°C.

Finally, the pressure in the system was reduced to a highly reduced pressure of 0.5 mL Hg or less, and the polymerization was completed. ηSp/c of the polytetramethylene terephthalate obtained here=1.05
, the softening point was 225.5°C. This polymer will be referred to as Polymer A. (2) On the other hand, dimethyl adipate 348
272.8 parts of ethylene glycol and 0.204 parts of butyl titanate were treated in the same manner as above to obtain polyethylene adipate.

This product was ηSp/c-0155. This polymer will be referred to as Polymer B. (3) After drying, the polymer A5O part and the polymer B1OO part were melted and mixed under a high vacuum of 0.5I1H9 or less at 240°C. Initially, it was opaque due to layer separation, but it became transparent after about 50 minutes.
At that point, 0.1 mol % of phosphorous acid was added based on the total acid components of both polymers A and B, and the mixture was stirred for 20 minutes under an inert atmosphere at normal pressure to obtain a polyester block copolymer. This will be referred to as Polymer C. Table 1 shows the change in softening point when the obtained polyester block copolymer was further melted at 240 DEG C. in an inert atmosphere.

In Comparative Example 1, which is also listed, the melting and mixing reaction was carried out for about 7 hours under almost the same conditions as Example 1 except that phosphorous acid was not used.
The polymer obtained after 0 minutes was designated as Polymer C'.

In addition, the above polyesters C and C' were subjected to JI at a cylinder temperature of 190°C, a mold temperature of 60°C, and a cooling time of 30 seconds.
Molded according to SK-6301.

Polymer C' did not solidify under the same conditions and a molded article could not be obtained. The molded article obtained from Polymer C exhibited a tensile strength of 102 kg/C77ll, a tensile elongation of 760%, and a tear strength of 63k9/CTrL. Examples 2 to 4 and Comparative Examples 2 to 4 Polymer A produced by methods (1) and (2) of Example 1
Using Polymer B and Polymer B, the polymer A5O portion and the polymer BlOO portion were subjected to a block reaction according to the method (3) of Example 1, using various phosphorus compounds listed in Table 2.

Even after being left at 240°C for 60 minutes, the softening point remained almost unchanged from when it was taken out.

Examples 5 to 9 and Comparative Examples 5 to 9 (1) In the same manner as the method (1) of Example 1, ηSp/
Polytetramethylene terephthalate with c-1.45 (referred to as Polymer A1), polytetramethylene terephthalate with η Sp/c-1.10 (referred to as Polymer A2),
Polytrimethylene terephthalate with η Sp/c=1.15 (referred to as polymer A3) and η Sp/c−1,
65 polyhexamethylene terephthalate (Polymer A
4) was manufactured.

(2) In the same manner as the method (2) of Example 1, η Sp
/CO. Polytetramethylene adipate of 95 (referred to as Polymer B1), polyhexamethylene adipate of η Sp/c-0.85 (referred to as Polymer B2), η Sp
/c-1,05 polyethylene adipate (polymer B
2) was manufactured.

Claims (1)

[Claims] 1. A method for producing a polyester block copolymer by melt-mixing at least one aromatic polyester selected from the group consisting of polytrimethylene terephthalate, polytetramethylene terephthalate, and polyhexamethylene terephthalate and an aliphatic polyester and causing a blocking reaction. A polyester block characterized in that the reaction is carried out in the presence of a titanium-based catalyst, and after the reaction is substantially completed, a sufficient amount of a phosphorous acid compound to deactivate the action of the catalyst is added. Method for producing copolymers.