JPS6037134B2 - Manufacturing method of polyester elastic body - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing polyester elastomer.

More specifically, the present invention relates to a method for producing a block copolymerized polyester elastomer having good transparency, using an aromatic polyester component as a hard component and an aliphatic polyester component as a soft component. As a polyester elastic body, polyether ester, which has a polyether component as a soft component and an aromatic polyester component as a hard component, is well known.

However, since such polyether ester elastic bodies have ether bonds in their molecules, they are susceptible to deterioration such as oxidative deterioration and photodegradation, and therefore cannot be said to be a desirable polymer.

However, a further disadvantage is that when formed into a film or the like, moisture permeation is extremely large.

This drawback becomes a major problem when the polyether ester is used for food packaging or medical equipment such as blood bags. On the other hand, a block copolymerized polyester elastomer containing an aromatic polyester component as a hard component and an aliphatic polyester component as a soft component is known as an ether bond-free polyester elastomer.

However, this polyester elastomer is usually opaque;
It has a drawback that it is difficult to use in the above-mentioned applications that require transparency. As a result of intensive research to develop a transparent polyester elastomer with low moisture permeability, the present inventor discovered that a fat that is transparent and flexible at around room temperature can be used as a soft component of a block copolymerized polyester elastomer. The present invention was achieved based on the finding that the above object can be achieved by using a group polyester.

That is, in the present invention, when assembling a block copolymerized polyester elastomer by reacting an aromatic polyester and an aliphatic polyester, 75 to 95% of the total repeating units of the aromatic polyester contain terephthalic acid and carbon atoms. Using a polyester consisting of repeating units of esters with 2 to 6 linear aliphatic glycols, the aliphatic polyester is made of an aliphatic dicarboxylic acid as the main acid component, and a linear aliphatic glycol having 2 to 6 carbon atoms is used. Using a polyester whose main glycol component is flexible at 0°C and whose parallel light transmittance is 70% or more when formed into a sheet with a thickness of 0.2, This is a method for producing a polyester elastomer having a softening point of 100° C. or higher, characterized in that the reaction is carried out until the elongation recovery rate after elongation by 20% and relaxation for 5 minutes becomes 50% or more under a melting lamp.

The aromatic polyester used in the present invention is...
It is a copolymerized polyester composed of terephthalic acid, a linear aliphatic glycol having 2 to 6 carbon atoms, and a third component.

Examples of aliphatic glycols mentioned above include ethylene glycol, trimethylene glycol, tetramethylene glycol, bentamethylene glycol, hexamethylene glycol, and the like.

Examples of the third component include dicarboxylic acids other than terephthalic acid, glycols other than linear aliphatic glycols having 2 to 6 carbon atoms, oxycarboxylic acids, and the like.

More specifically, for example, isophthalic acid, naphthalenedicarboxylic acid (2,6-1,2,7-1,1,4-dicarboxylic acid is particularly preferred), diphenylcarboxylic acid, diphenoxychetanedicarboxylic acid, diphenylsulfonedicarboxylic acid, Dicarboxylic acids such as diphenyl ether dicarboxylic acid; propylene glycol, decamethylene glycol,
Glycols such as cyclohexane-1,4-dimethanol, neobenzene glycol, diethylene glycol, triethylene glycol, tricyclodecane dimethylol, 2,2-bis-8-hydroxyphenylpropane, etc., do-oxycarboxylic acid, p-oxybenzoic acid , oxycarboxylic acids such as 8-hydroxyethoxybenzoic acid and the like. These can be used alone or in combination of two or more. The copolymerization ratio of the third component varies slightly depending on the type, but is 5 to 25 mol%, based on the total of the brewing component and glycol component that make up the polyester.
Preferably it is 7 to 20 mol%.

If the copolymerization ratio of the third component is less than 5 mol %, the resulting elastic body will have poor transparency and a reduced elastic recovery rate, and if it exceeds 25 mol %, it will stick during molding or have reduced heat resistance. For example, when isophthalic acid is used as the third component, a polyester consisting of about lo mol% isophthalic acid, about 40 mol% terephthalic acid, and about 50 mol% linear aliphatic glycol (e.g., tetramethylene glycol) It can be a preferred aromatic polyester. Furthermore, when another glycol is used as the third component, the glycol escapes during the polymerization reaction, so it goes without saying that the above ratio is not the charged composition but the content in the resulting polymer. For producing such an aromatic polyester, a commonly used polyester production method such as a melt polymerization method can be used.

Examples of melt polymerization methods include transesterification of lower alkyl esters of dicarboxylic acids such as dimethyl esters with glycols, esterification reactions of dicarboxylic acids and glycols, and the like. There is a method of forming a polymer and polymerizing the glycol ester and/or its low polymer. Further, the aliphatic polyester used in the present invention is a polyester that is flexible (glass transition temperature is 0° C. or lower) and transparent at 0°C.

Regarding aliphatic polyester, transparent refers to one with a parallel light transmittance of 70% or more when made into a sheet with a thickness of 0.2. The sheet was heated and compressed to 20 picoC on a hot plate to a thickness of 0.2mm, and after being left at 0°C for 2 hours, the sheet was sandwiched between glass plates and then measured. The main ingredients of the polyester are aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and decanedicarboxylic acid.

In addition, as the glycol component, the aliphatic glycols listed as the glycol component of aromatic polyester are mainly targeted. Most polyesters made from the combination of aliphatic dicarboxylic acids and glycols usually have low glass transition temperatures, but are crystalline and opaque at 0°C. However, if it becomes opaque, it is possible and necessary to make it transparent by forming a copolymer using two or more dicarboxylic acids or glycols. Moreover, as the dicarboxylic acid and/or glycol to be copolymerized, the above-mentioned aromatic dicarboxylic acids, aromatic diols, etc. can also be used. For example, the use of isophthalic acid as a copolymerization component is particularly preferred because it increases the compatibility with the aromatic polyester, speeds up the melt-mixing reaction, and makes the resulting polymer transparent.
Furthermore, as the aliphatic polyester, polyesters obtained from oxycarboxylic acids such as -caprolactone, -oxycarboxylic acid, etc., which are flexible and transparent at 0°C, can also be used.
Representative examples of the aromatic polyester and aliphatic polyester mentioned above include the following.

Aromatic polyesters include polyesters of terephthalic acid and two glycols selected from the group consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol, and hexamethylene glycol, mixed acid components of terephthalic acid and isophthalic acid, and ethylene. Polyesters with glycol or trimethylene glycol or tetramethylene glycol, etc.; as aliphatic polyesters, one or more aliphatic dicarboxylic acids selected from the group consisting of adipic acid, sebacic acid, azelaic acid and decanedicarboxylic acid and ethylene glycol Examples include polyesters of one or more glycols selected from the group consisting of , trimethylene glycol, tetramethylene glycol, and hexamethylene glycol and isophthalic acid (ratio of less than 40 mol % of the brewing ingredients).

Aromatic polyesters and aliphatic polyesters such as those described above may further be used in combination with trimesic acid, trimethylolpropane,
One or more polyfunctional compounds of trifunctional or higher functionality, such as bentaerythritol, or monofunctional compounds, such as o-benzoylbenzoic acid, toluic acid, methoxypolyoxyethylene glycol, octyl alcohol, are combined to a substantially linear extent. It may also be a polymerized polyester.

The copolymerization ratio (weight ratio) of these aliphatic polyesters and aromatic polyesters varies depending on the purpose to be used, but is generally 10:90 to 90:10, preferably 2.
The ratio is 80 to 85 to 15.

40:6, especially when used for applications that require flexibility.
0 to 85 to 15 preferably 5 to 50 to 75 to 25
is used. If the proportion of aliphatic polyester exceeds the above range, the softening point will be lowered, which is not preferable, and
If the amount of aromatic polyester exceeds the above range, flexibility will decrease, which is not preferable. The method of the present invention is carried out by melt-mixing the aromatic polyester and aliphatic polyester as described above and causing a blocking reaction. The blocking reaction is preferably carried out in the presence of a titanium catalyst. When using a titanium-based catalyst, not only does the blocking reaction proceed smoothly, but it is also possible to sufficiently suppress and stop the randomization reaction even after the thermal history that occurs after the desired blocking reaction is completed. Thus, there is an advantage that the catalytic action can be extremely easily deactivated or suppressed by the phosphorus compound. Examples of titanium-based catalysts include titanate esters, titanyl oxides, titanium halides, hydrolysates of titanium halides, titanium hydroxide, and titanium oxide hydrates.

Specific examples of these include propyl titanate,
Butyl titanate, titanyl post acid, titanyl calcium post acid, titanyl potassium post acid, titanium tetrachloride, reaction products of titanium tetrachloride and hexanediol, reaction products of titanium tetrachloride and water, etc. These titanium-based The catalyst is about 0.001 to 0.5 mol%, especially 0.003 mol%, based on the total repeating unit of the two or more polyesters used in the reaction.
It is preferable to use it in an amount of about 0.1 mol %.

The presence of a titanium-based catalyst in the reaction system is usually carried out by a method using two or more types of polyester produced using a titanium-based catalyst, but if necessary, a titanium-based catalyst may be further added during melt reaction mixing. It's okay.

Examples of catalysts other than the titanium-based catalysts include polymerization catalysts used in the production of polyester, such as antimony-based catalysts such as antimony trioxide, germanium-based catalysts such as germanium dioxide and germanate metal salts, tin-based catalysts such as tin acetate, etc. can be used.

The usage of these catalysts is also the same as that of titanium-based catalysts. The blocking reaction varies depending on various conditions such as the type of two or more polyesters to be reacted, their terminal group concentration, reaction temperature, and moisture content in the reaction system, but generally it takes 5 to 120 minutes and 150 minutes.
The heating is carried out at a temperature of 0° C. or higher, particularly 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 two or more types of polyesters, a temperature of 230 to 26,000 degrees is optimal. The atmosphere during the molten rope frame for the blocking reaction is pressurized,
Either under reduced pressure or normal pressure may be used, and in either case, it is preferable to use an inert atmosphere.

Generally, the flocculation reaction is substantially completed after being carried out for 5 to 120 minutes, but to confirm this 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 researching the method in advance.

In addition, it has been revealed 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 it is useful to judge the point at which the reaction system becomes transparent. It is effective for These points correspond to the points at which the blocking reaction has substantially ended. The elastic recovery rate is preferably determined by a value of 50% or more after 20% elongation and 5 minutes of relaxation.
In order to stop the flocculation reaction, a method of lowering the temperature, a method of adding a reaction terminator such as a phosphorus compound, etc. can be employed. For example, when the blocking reaction is carried out continuously, the blocked polymer discharged after the reaction is generally cooled with water. Preferred specific examples of phosphorus compounds that can be used as reaction terminators include inorganic acids such as orthophosphoric acid, phosphorous acid, and hypophosphoric acid, methylphosphinic acid, ethylphosphinic acid, inbutylphosphinic acid, and benzylphosphinic acid. Phosphinic acid, phenylphosphinic acid, cyclohexylphosphinic acid, 4-methylphenylphosphinic acid, etc., methylphosphinic acid, ethylphosphinic acid, isopropylphosphinic acid, inbutylphosphinic acid, penzyl Phosphonic acids such as phosphonic acid, phenylphosphonic acid, cyclohexylphosphonic acid, and 4-methylphenylphosphonic acid, and alkyl and cycloalkyl having 1 to 20 carbon atoms such as methyl, ethyl, propyl, cyclohexyl, phenyl, benzyl, etc. , aryl, aralkyl esters and partial esters, as well as their metal salts such as sodium, potassium, calcium and magnesium, or ammonium salts, phosphine oxides such as triethylphosphine oxide and triphenylphosphine oxide, Examples include phosphines such as tributylphosphine, triphenylphosphine, tribenzylphosphine, and tricyclohexylphosphine. These preferred compounds are summarized as compounds represented by the following formulas [1] to [N] and their esters or salts. Formula [1] [In the formula, R is a hydrogen atom or a monovalent hydrocarbon group such as an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group having 20 or less carbon atoms] Formula [D] [In the formula, R2 and R3 are each independently a group selected from the group consisting of the same groups as the above R. [Machi] [In the formula, R4, R5, and R6 are each independently selected from the group consisting of the same groups as the above R. Formula [W] [In the formula, R7, R8, and R9 are each independently selected from the group consisting of the same groups as R] Among these phosphorus compounds, those in the form of oxyacid are It is particularly preferred because its effects are large and it is effective even with a small amount.

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. These phosphorus compounds can also be used as a mixture. The amount of the phosphorus compound is, for example, 0.9 or more phosphorus atoms per titanium atom, preferably 0.9 or more. It is effective to use one or more needles, particularly preferably one or more. The neighboring compound may be added at once or in two or more times. This system may contain other additives such as oxidation stabilizers, light stabilizers, ultraviolet absorbers, optical brighteners, matting agents, lubricants, antistatic agents, anti-static agents, etc. Refueling agents, chick combustion aids, antifungal agents, pigments,
Strengthening 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 containing the above-mentioned function as a phosphorus compound. The blocking reaction in the present invention can be carried out in a continuous method, a batch method, or any other method, but in order to stop the reaction when a reaction terminator is not used, it is preferable to cool the reaction as far away as possible. In order to obtain a homogeneous block copolymer, it is preferable to carry out the reaction in a continuous or multi-stage reactor system.

The block copolymerized polyester obtained according to the method of the present invention can be made into films, tubes, and other various molded products by molding methods such as injection molding, blow molding, and extrusion molding.

At the time of molding, rapid cooling is a preferred molding method because the transparency, which is the object of the present invention, is particularly enhanced. In the present invention, additives such as other polymers, inorganic substances, nucleating agents, pigments, dyes, etc. can be added to the block copolymerized polyester as necessary.

The block copolymerized polyester obtained according to the method of the present invention is an extremely useful material for films, tubes, etc. for medical devices, food packaging or food transportation, and industrial molded products such as gears, rolls, hoses, etc.

Next, the present invention will be explained by giving examples.

All figures in the middle part of the example represent parts by weight, and sp/c is 1.2 hours/35°C at that concentration in orthochlorophenol.
This is the reduced viscosity measured at In addition, the parallel light bran transmittance was measured using a Poick integrating sphere microturbidity meter. Example 1 (1' 155 parts of dimethyl terephthalate, 3 bags of dimethyl isophthalate (10 mol%/total components), 190 parts of tetramethylene glycol, and 0.1 $ of butyl titanate
A transesterification reaction was carried out by heating the mixture under an inert gas atmosphere.

The reaction was carried out while extracting a liquid mainly composed of methanol produced at a reaction temperature of 200°C, and when the extracted methanol reached approximately 95% of the theoretical amount, the pressure inside the system was gradually reduced.
And it overflowed to 240qo.

Finally, the pressure in the system was reduced to a highly reduced pressure of 0.5 days or less, and polymerization was carried out. The obtained aromatic polyester paste sp/c was 1.42. This polyester will be referred to as Polymer A. [21 On the other hand, 24 parts of dimethylazibate, 116 parts of dimethyl isophthalate (15 parts
(mol%/total components), 396 parts of tetramethylene glycol, and 0.2 parts of butyl titanate were reacted in the same manner as above to obtain an aliphatic polyester.

This material had a sp/c value of 1.23, and remained transparent and very sticky candy-like even when cooled to 0°C. This polyester will be referred to as Polymer B. After drying 40 parts of the above polymer A and 6 parts of polymer B, 0.5
It was melted under a high vacuum below 100 Hz.

The reaction system was opaque immediately after the polymer dissolved, but became transparent after about 2 minutes. It became. After reacting for an additional 5 minutes, the polymer was removed and rapidly cooled. The obtained polymer was molded into a film with a thickness of 0.2.

The film is transparent (parallel light transmittance 73%),
When soaked in boiling water for 1 hour, it was opaque immediately after being taken out, but became transparent again as it dried. 11
The material dried in a dryer at 0° C. for 1 hour showed the same transparency as that before soaking in weaving water.

Further, the same reaction as above was carried out, and after the reaction system became transparent, the reaction was continued for an additional 5 minutes, and then 0.1 part of phosphorous acid was added.

Subsequently, the polymer was taken out. The obtained polymer was heated to 180
JI by injection molding at a molding temperature of 4000 °C and a mold temperature of 4000 °C.
A No. 3 dumbbell of S6301 was created, and tensile test and 2
The elongation recovery rate after 0% elongation and relaxation for 5 minutes was determined. As a result, the tensile strength was 135k9/ground and the elongation was 42.
0%, showing an elongation recovery rate of 77%. The softening point measured by the needle penetration method was 17,300. Comparative examples 1 to 3
In the production of polymers A and B of Example 1, respectively:
Example 1 except that dimethyl terephthalate or dimethyl adibate is used instead of dimethyl isophthalate.
Proceed in the same manner as above to remove the polymer. ．． ·Obtained.

The obtained homopolymers are referred to as Polymer A' and Polymer B', respectively. Polymer B' was flexible but shape-retentive and opaque. Example 1 was repeated using Polymer A' or B' instead of Polymer A or B. A plating reaction was performed. Table 1 shows the parallel light transmittance of the obtained block copolymer film having a thickness of 0.2 mm.

Table 1 Comparative Example 4 In Example 1, the melt-mixing reaction was stopped before it became transparent, or was continued for an additional 3 hours after it became transparent.

The obtained polymer was as follows. Before becoming transparent (after one melting period): Elongation recovery rate 20%. After it became transparent, it was allowed to react for an additional 3 hours: it could not be molded and its softening point was about 80°C.

Examples 2 to 4 Various aromatic polyesters and aliphatic polyesters shown in Table 2 were melt-blocked to obtain floc copolymers.

Claims (1)

[Claims] 1. When reacting aromatic polyester and aliphatic polyester to produce a block copolymerized polyester elastomer, (A) 75 to 95% of the total repeating units of the aromatic polyester are terephthalic acid and carbon atoms having 2 to 6 carbon atoms. Using a polyester consisting of repeating units of ester with a linear aliphatic glycol, (B) the aliphatic polyester has an aliphatic dicarboxylic acid as the main acid component, and the main glycol component is a linear aliphatic glycol having 2 to 6 carbon atoms. (C) Melting the aromatic polyester and the aliphatic polyester while stirring, A method for producing a polyester elastomer having a softening point of 100° C. or higher, characterized in that the reaction is carried out until the elongation recovery rate after stretching by 20% and relaxing for 5 minutes becomes 50% or higher.