TWI554544B - Polyester, methods for manufacturing the same and methods for manufacturing a polyester sheet - Google Patents

Description

Polyester, manufacturing method thereof and method for producing polyester sheet

This invention relates to polyesters and polyester sheets containing the polyester, more particularly to diacids and diols used in the formation of polyesters.

Polyester materials are widely used in industrial or residential applications, but there are still many areas to be improved, such as when processing into sheets or shot into bottles, often due to crystal defects during processing steps. It is easy to cause whitening of the material, which in turn affects the properties of light transmission, mechanical properties, etc., and the above problems are exacerbated as the thickness of the sheet increases or the use temperature increases. In addition, the health needs of heat and non-toxicity in the use of people's livelihood are also on the rise.

The above considerations of polyester include (1) high heat resistance, deformation deformation is not easy in the use environment; (2) good optical characteristics, that is, light transmittance is high, transparency is good; (3) good tensile strength and processing (4) Good heat hydrolysis resistance; (5) No harmful substances such as bisphenol A. In summary, it is urgent to apply a non-crystalline polyester material having the above properties to a new generation of transparent plastic.

The polyester provided by an embodiment of the present invention is obtained by copolymerizing a diacid and a diol, wherein the diacid comprises: 1 mole of terephthalic acid, dialkyl terephthalate, or a combination thereof; The diol is composed of a mole of cyclobutanediol and b mole of 1,4-cyclohexanedimethanol, wherein a+b=1, 0.35 a 0.9, and 0.1 b 0.65, the 1,4-cyclohexanedimethanol is composed of 70 to 100 mol% of trans-1,4-cyclohexanedimethanol and 0 to 30 mol% of cis-1,4-cyclohexanedimethanol.

A method for producing a polyester according to an embodiment of the present invention comprises mixing 1,4-cyclohexanedimethanol with a reaction accelerator, and performing the reaction at 200 ° C to 280 ° C for 0.5 hour to 2 hours to obtain 1,4. a product of isomerization of cyclohexanedimethanol; a mixture of a mole of cyclobutanediol, b moles of 1,4-cyclohexanedimethanol isomerization, and 1 mole of a mixture of terephthalic acid, dialkyl terephthalate, or a combination thereof, wherein a+b=1, 0.35 a 0.9, and 0.1 b 0.65; heating the mixture to give a polyester.

A method for producing a polyester sheet according to an embodiment of the present invention comprises: melt-extruding the polyester to form a polyester sheet.

The polyester provided by one embodiment of the present invention is formed by reacting a diacid with a diol, wherein the diacid comprises: 1 mole of terephthalic acid (TPA), dialkyl terephthalate ( Dialkyl terephthalate) such as dimethyl terephthalate (DMT), or a combination thereof. The diol is a cyclopentanediol such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol (2,2,4,4-tetramethyl-). 1,3-cyclobutanediol (CBDO) and b-molar 1,4-cyclohexanedimethanol (1,4-CHDM). The ranges of a and b above are as follows: a+b=1, 0.35 a 0.9 (for example 0.4 a 0.7), and 0.1 b 0.65 (for example 0.3 b 0.6), the 1,4-cyclohexanedimethanol is from 70 mol% to 100 mol% (for example, 75 mol% to 90 mol%) of trans-1,4-cyclohexanedimethanol (trans-1,4-cyclohexanedimethanol, trans-1,4-CHDM) and 0 mol% to 30 mol% (for example, 10 mol% to 25 mol%) of cis-1,4-cyclohexanedimethanol (cis-1,4-CHDM) ) composed of. If the content of trans-1,4-cyclohexanedimethanol is too low, the ratio of heat hydrolysis is high, the tensile yield strength and bending strength are low, and the heat resistance is low. If the content of the cyclobutanediol is too low, the heat resistance is low.

In an embodiment of the invention, 0.5 of the above polyester a/b 9. The 1,4-cyclohexanedimethanol is from 70 mol% to 100 mol% of trans-1,4-cyclohexanedimethanol (trans-1,4-CHDM) and 0 mol. %~30 mol% of cis-1,4-cyclohexanedimethanol (cis-1,4-CHDM). If the ratio of a/b is too low, the heat resistance is low. If the ratio of a/b is too high, the tensile yield strength is low.

In one embodiment of the invention, the diacid is dimethyl terephthalate, the diol is a mole of cyclobutanediol, and b moles of 1,4-cyclohexanedimethanol. The copolymerization product of the above diacid and diol is as shown in Formula 1, wherein a+b=1, 0.35 a 0.9, and 0.1 b 0.65:

The above 1,4-cyclohexanedimethanol is composed of 70 mol% to 100 mol% of trans-1,4-cyclohexanedimethanol and 0 mol% to 30 mol% of cis-1,4-cyclohexanedimethanol. If the stereostructure is exhibited, the copolymerization product of the above diacid and diol is as shown in Formula 2, wherein b1+b2=b, 2.33 B1/b2: (Formula 2)

In one embodiment of the invention, the diacid is dimethyl terephthalate, the diol is a mole of cyclobutanediol, and b moles of trans-1,4-cyclohexanedimethanol. The copolymerization product of the above diacid and diol is as shown in Formula 3, wherein a+b=1, 0.35 a 0.9, and 0.1 b 0.65:

The above polyester can be obtained by a two-stage reaction (such as esterification and polycondensation) of the diacid and the diol, and the polycondensation step can be catalyzed by a suitable catalyst, and the catalyst content is about 25 ppm to 500 ppm of the reactant. In one embodiment of the present invention, the catalyst in the polycondensation step may be a tin catalyst, a lanthanide, a gallium, an aluminum, a titanium, a lanthanide, or a combination of the above. For example, the catalyst can be dibutyltin oxide and tetrabutyl titanate.

In one embodiment of the present invention, 1,4-cyclohexanedimethanol is mixed with a reaction accelerator, and isomerization reaction is carried out at about 200 ° C to 280 ° C for about 0.5 hour to 2 hours to obtain 1,4- The product of isomerization of cyclohexanedimethanol, i.e., the above-mentioned 1,4-cyclohexanedimethanol containing 70 to 100 mol% of trans-1,4-cyclohexanedimethanol. It is to be noted that the above-mentioned method of preparing 1,4-cyclohexanedimethanol of 70-100 mol% of trans-1,4-cyclohexanedimethanol is not limited thereto.

Next, a mixture of a mole of cyclobutanediol, b moles of 1,4-cyclohexanedimethanol isomerized product, and 1 mole of terephthalic acid, terephthalic acid The dialkyl ester, or a combination thereof, is formed to form a mixture, and the mixture is further heated to carry out an esterification reaction at 180 ° C to 240 ° C for about 2 hours to 5 hours, followed by a polycondensation reaction at 250 ° C to 300 ° C for about 2 hours to 5 hours. In the hour, after two stages of esterification and polycondensation, a polyester is synthesized, wherein a+b=1, 0.35 a 0.9, and 0.1 b At 0.65, the intrinsic viscosity of the polyester was measured by a Ubbelohde viscometer of about 0.4 dL/g to 0.8 dL/g. If the intrinsic viscosity of the polyester is too high, it may be difficult to process the fluidity. If the intrinsic viscosity of the polyester is too low, the mechanical properties may be poor and the material may be easily broken.

In an embodiment of the present invention, the reaction accelerator may be selected from the group consisting of ruthenium, osmium, iridium, osmium, a hydroxide of the above element, an oxide of the above element, and an alcoholate of the above element.

In an embodiment of the present invention, the reaction accelerator may be selected from the group consisting of barium hydroxide, barium hydroxide, barium hydroxide, barium hydroxide, barium hydroxide, barium ethoxide, hydrazine hydrate, hydrazine ethoxide, hydrazine hydride, hydrazine hydrate, methanol hydrazine. a group consisting of cerium oxide, cerium oxide, cerium oxide, cerium oxide and cerium oxide. In an embodiment of the invention, the reaction promoter may be ammonia water.

In one embodiment of the present invention, the product of isomerization of the above 1,4-cyclohexanedimethanol may be further purified by recrystallization, and the recrystallization may be, for example, heated at about 50 ° C to 100 ° C. 0.5~1 hour, melt into liquid and take it out to room temperature (for example, about 20 °C ~ 40 °C), add solvent (such as ethyl acetate or methyl ethyl ketone) to stir to dissolve the solid product, then cool down to precipitate white needle Crystallization, vacuum filtration under vacuum to obtain the product of isomerization of purified 1,4-cyclohexanedimethanol, which can be analyzed by mass spectrometry (GC chromatography) to obtain its trans-1,4-cyclohexanedimethanol. The content. In some embodiments of the present invention, the content of trans-1,4-cyclohexanedimethanol in the product of isomerization of 1,4-cyclohexanedimethanol is greater than or equal to about 70% or even greater than or equal to about 98%, cis- The content of 1,4-cyclohexanedimethanol is about 30% or less and about 2% or less. In summary, the present invention provides a method for increasing the content of trans-1,4-cyclohexanedimethanol.

After synthesizing the above polyester, the above polyester is dehumidified and dried. Because the high moisture content in the high temperature process will cause polymer degradation, it may have adverse effects on the physical properties of subsequent materials. If the circulating airflow is used for dehumidification and drying, the drying treatment condition is that the temperature is set at about 70. °C~80°C, more than 36 hours. If it is dried under vacuum, the treatment conditions are set to about 60 ° C to 70 ° C for about 4 hours to 8 hours. Then, it is melted and extruded by a twin screw extruder. The processing temperature of the melt processing is about 220 ° C to 270 ° C, the screw rotation speed is about 200 rpm to 800 rpm, and finally melted and extruded through a T-die through a casting wheel (casting) The drum is given a uniform thickness of polyester foil (also known as a polyester sheet), and the temperature of the cast film is usually lower than the glass transition temperature (Tg) to ensure rapid cooling of the polymer during melting.

The above polyester has excellent heat resistance and tensile strength, and has the effects of resistance to heat hydrolysis and easy molding, and the polyester sheet has high transparency in addition to the aforementioned advantages, and can reduce mechanical strength due to low heat resistance and crystallization. And the problem of low total light transmittance, and no harmful substances such as bisphenol A, the above polyester and polyester sheets can be applied to various domestic applications requiring heat resistance, tensile strength or transparent materials.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

[Production of Isomerization of 1,4-Cyclohexane Dimethanol]

Example a

1,4-cyclohexanedimethanol (C0479 from Tokyo Chemical Industry Co., Ltd., which has 68.8% of trans-1,4-CHDM and 31.2% of cis-1,4-CHDM) was heated to melt, taking 144 The mixture was mixed with 0.036 mole of 50% aqueous solution of ruthenium hydroxide (RbOH) (reaction accelerator), and subjected to isomerization reaction at 200 ° C for 0.5 hour to form a solid product, which was sampled for GC analysis, and the results were ascertained from the GC results. The content of trans-1,4-cyclohexanedimethanol of the product of isomerization of 1,4-cyclohexanedimethanol of a is shown in Table 1.

Example b~h

The conditions other than the kind of the reaction accelerator were the same as those of Example a, and the reaction accelerators used in Examples b to h were sequentially 50% aqueous solution of cesium hydroxide (CsOH) and 50% cesium hydroxide (Sr(OH). ₂ ) aqueous solution, 50% aqueous solution of barium hydroxide (Ba(OH) ₂ ), 45% aqueous solution of cerium hydroxide (Sr(OH) ₂ .8H ₂ O) containing water of crystallization, 45% of water containing crystal water An aqueous solution of barium hydroxide (Ba(OH) ₂ .8H ₂ O), barium oxide (BaO), and a 28% aqueous solution of ammonia water were sampled for GC analysis, and the results of GC were found to be 1 and 4 of Examples b~h. - The content of trans-1,4-cyclohexanedimethanol of the product of isomerization of cyclohexanedimethanol, as shown in Table 1.

Comparative example a~c

The conditions other than the kind of the reaction accelerator were the same as those in Example a, and the reaction accelerators used in Comparative Examples a to c were pyridine, 1,8-diazabicyclo[5.4.0] eleven. Alkyl-7-ene (1,8-diazabicyclo [5.4.0] undec-7-ene), and ethanolamine.

As can be seen from Table 1, in Examples a to h, compared with Comparative Example ac, the use of an alkali metal hydroxide and an alkaline earth metal hydroxide can form a higher high trans isomer than the use of an organic base. ~h It is known that the alkali metal hydroxide and alkaline earth metal hydroxide can reach the equilibrium concentration of isomerization within 0.5 hours at 200 ° C, and the trans-1,4-CHDM content of Example a can be increased from 68.8% to 78.9. %, other examples b~h CHDM The content of trans isomer can be increased from 68.8% to 72.3~79.2%.

[Production of Purification of Isomerization of 1,4-Cyclohexane Dimethanol]

The product of isomerization of 1,4-cyclohexanedimethanol of Example a was heated to melt to a liquid state, and taken out and naturally cooled to room temperature. 300 g of the isomerized product of 1,4-cyclohexanedimethanol was weighed in a 27.5 ° C water bath, and 600 ml of ethyl acetate was added thereto to stir to completely dissolve the solid to obtain a solution.

The solution was cooled to precipitate white acicular crystals, and the crystals were vacuum filtered at 4 ° C to obtain white needle crystals and a colorless transparent filtrate. The transparent filtrate was added ethyl acetate (ethyl acetate) and recrystallized again in a cold water bath at 12 ° C to combine white. Needle crystal, dry weighing knot The crystals were sampled and subjected to GC analysis. From the GC results, the product of the isomerization of 1,4-cyclohexanedimethanol of Example a was found to have a content of trans-1,4-cyclohexanedimethanol of 98.5%.

【Polyester Synthesis】

Example 1

194 g of dimethyl terephthalate (DMT) as a diacid monomer, 115.2 g of 1,4-cyclohexanedimethanol (1,4-CHDM) and 50.4 g of 2,2,4,4 -Tetramethyl-1,3-cyclobutanediol (CBDO) is a diol monomer, adding about 250ppm dibutyltin oxide and 150ppm tetrabutyl titanate as catalyst, at 200-230 ° C The esterification reaction is carried out for about 4 hours, followed by a polycondensation reaction at 280-290 ° C for about 4 hours. After two-stage esterification and polycondensation, a copolyester PCTM ₃₅ -70 is synthesized, and the essence is measured by a Ubbelohde viscometer. The viscosity is 0.664 dL/g.

Example 2~23

Except for the molar ratio and type of the diol monomer, the other conditions were the same as in Example 1, and the molar ratios and types of the diol monomers of Examples 2 to 23 are shown in Table 2. The intrinsic viscosity of the copolyesters synthesized in Examples 2 to 23 is shown in Table 2.

Comparative example 1

194 g of dimethyl terephthalate (DMT) is used as a diacid monomer, 71.3 g of ethylene glycol (EG) is a diol monomer, and a content of about 250 ppm of dibutyltin oxide and 150 ppm of tetrabutyltitanium is added. The acid ester is a catalyst, and the esterification reaction is carried out at 200-230 ° C for about 4 hours, followed by polycondensation at 280-290 ° C for about 4 hours, and after two-stage esterification and polycondensation, a copolyester is synthesized. (PET), the intrinsic viscosity measured by a Ubbelohde viscometer was 0.741 dL/g.

Comparative example 2

194 g of dimethyl terephthalate (DMT) is used as a diacid monomer, and 165.6 g of 1,4-cyclohexanedimethanol (1,4-CHDM) is a diol monomer, and the content is about 250 ppm. The butyl tin oxide and 150 ppm tetrabutyl titanate are used as a catalyst, and the esterification reaction is carried out at 200-230 ° C for about 4 hours, followed by polycondensation at 280-290 ° C for about 4 hours, and two-stage esterification. After the polycondensation, the copolyester PCT-70 was synthesized, and the intrinsic viscosity was 0.723 dL/g as measured by a Ubbelohde viscometer.

Comparative example 3

194 g of dimethyl terephthalate (DMT) as a diacid monomer, 122.4 g of 1,4-cyclohexanedimethanol (1,4-CHDM) and 43.2 g of 2,2,4,4 -Tetramethyl-1,3-cyclobutanediol (CBDO) is a diol monomer, adding about 250ppm dibutyltin oxide and 150ppm tetrabutyl titanate as catalyst, at 200-230 ° C The esterification reaction is carried out for about 4 hours, followed by polycondensation at 280-290 ° C for about 4 hours. After two-stage esterification and polycondensation, a copolyester PCTM ₃₀ -70 is synthesized, and the essence is measured by a Ubbelohde viscometer. The viscosity was 0.662 dL/g.

Comparative Example 4~6

Except for the molar ratio and type of the diol monomer, the other conditions were the same as in Example 1, and the molar ratios and types of the diol monomers of Comparative Examples 4 to 6 are shown in Table 2. Comparative example The intrinsic viscosity of the 4~6 synthetic copolyester is shown in Table 2.

It can be seen from Table 2 that changing the ratio of cis/trans isomer of 1,4-cyclohexanedimethanol and changing the content of 2,2,4,4-tetramethyl-1,3-cyclobutanediol can be changed. The glass transition temperature and crystallinity of the polymer can synthesize a highly heat-resistant amorphous polymer, and the glass transition of Examples 1 to 23 The changing temperature is higher than PET. It can be seen from Examples 1 to 23 that in the same molar ratio of 1,4-cyclohexanedimethanol, the proportion of trans-1,4-cyclohexanedimethanol is increased, and the conversion temperature of the polyester glass can be increased ( Tg). It can be seen from Examples 1 to 23 that a specific ratio of 2,2,4,4-tetramethyl-1,3-cyclobutanediol and a high proportion of trans-1,4-cyclohexanedimethanol are contained. 1,4-cyclohexanedimethanol as a monomeric polyester forms an amorphous polymer (no melting point (Tm)), which can effectively improve the transparency of polyester and reduce the melting process. Crystallization problem.

As can be seen from Table 2, the total light transmittance of the polyesters of Examples 1 to 23 was higher than the total light transmittance of PET in Comparative Example 1. The total light transmittance of the polyesters of Examples 1 to 23 was higher than that of the polyesters of Comparative Examples 2 to 6.

[Making Polyester Sheets]

Examples 24 to 46

100 parts by weight of the polyesters of Examples 1 to 23 were weighed separately, dried in a hot air circulating oven at 70 ° C, dried for 24 hours, and then melted and extruded by a twin-screw extruder. The processing temperature of the melt processing was 220 ° C to 280. °C, the screw speed was about 500 rpm, and it was melted and extruded through a T-die to obtain a transparent sheet of uniform thickness, and the temperature of the mold wheel was set to 70 °C.

The tensile properties and flexural strength of the sheets of Examples 24 to 46 were measured as shown in Table 3. The sheets of Examples 27 to 31 and Examples 37 to 46 were tested for hydrolyzability at 250 ° C, and the results are shown in Table 4.

It can be seen from Table 3 and Table 4 that changing the ratio of cis/trans isomer of 1,4-cyclohexanedimethanol and changing the content of 2,2,4,4-tetramethyl-1,3-cyclobutanediol It can change the heating and hydrolysis properties of the polyester. It can be seen from Table 4 that the hydrolyzed polyester is heated at the same temperature and at the same time. The degree of hydrolysis of the polyesters of Examples 5 to 8 was lower than that of the polyester of Example 4, and the degree of hydrolysis of the polyesters of Examples 15 to 18 was lower than that of the polyester of Example 14, and Examples The degree of hydrolysis of the polyester of 20 to 23 is also lower than that of the polyester of Example 19.

In summary, the polyester of the present invention has good mechanical strength and heat resistance, and is required for the use of a transparent material such as a heat-treated packaging material (Tg>100 ° C) and high temperature sterilization, which requires high heat resistance. It has transparency, heat resistant temperature, mechanical strength and resistance to heat hydrolysis.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

Claims (10)

a polyester obtained by copolymerizing a diacid with a mono diol, wherein the diacid comprises: 1 mole of terephthalic acid, dialkyl terephthalate, or a combination thereof; the diol system Consisting of a mole of cyclobutanediol and b mole of 1,4-cyclohexanedimethanol, wherein a+b=1, 0.35 a 0.9, and 0.1 b 0.65, the 1,4-cyclohexanedimethanol is composed of 70 to 100 mol% of trans-1,4-cyclohexanedimethanol and 0 to 30 mol% of cis-1,4-cyclohexanedimethanol. The polyester as described in claim 1 has the following chemical structure: For example, the polyester described in claim 1 or 2, wherein 0.5 a/b 9. The polyester as described in claim 1 has the following chemical structure: Where b1+b2=b, 2.33≦b1/b2. The polyester as described in claim 1 has the following chemical structure: A method for producing a polyester, comprising: mixing 1,4-cyclohexanedimethanol with a reaction accelerator, and performing the reaction at 200 ° C to 280 ° C for 0.5 hour to 2 hours to obtain a 1,4-cyclohexane. a product of isomerization of alkane dimethanol; a mixture of a mole of cyclobutanediol, a product of isomerization of b moles of 1,4-cyclohexanedimethanol, and 1 mole of terephthalic acid Formic acid, dialkyl terephthalate, or a combination thereof, to give a mixture, wherein a+b=1, 0.35 a 0.9, and 0.1 b 0.65, the product of isomerization of the 1,4-cyclohexanedimethanol is from 70 to 100 mol% of trans-1,4-cyclohexanedimethanol and 0 to 30 mol% of cis-1,4-cyclohexane. Composition of dimethanol; heating the mixture to obtain a polyester. The method for producing a polyester according to claim 6, wherein the reaction accelerator is selected from the group consisting of ruthenium, osmium, iridium, osmium, a hydroxide of the above element, an oxide of the above element, and an alcoholization of the above element. a group of objects. The method for producing a polyester according to claim 6, wherein the reaction accelerator is selected from the group consisting of barium hydroxide, barium hydroxide, barium hydroxide, barium hydroxide, barium ethoxide, barium ethoxide, cesium methoxide, ethanol. A group consisting of hydrazine, methanol hydrazine, ethanol hydrazine, methanol hydrazine, ethanol hydrazine, cerium oxide, cerium oxide, cerium oxide and cerium oxide. A method of producing a polyester according to claim 6, wherein the method The reaction accelerator is ammonia. A method for producing a polyester sheet comprising: melt-extruding the polyester as described in claim 1 to form a polyester sheet.