TWI626256B - Catalyst composition and preparation method for synthesizing an amorphous copolyester - Google Patents

Abstract

The present disclosure provides a catalyst composition for synthesizing an amorphous copolyester comprising a titanate compound and a TiO ₂ /SiO ₂ coprecipitate, wherein the titanate compound and the TiO ₂ /SiO ₂ coprecipitate The weight ratio is 1:1 to 10:1. The present disclosure also provides a process for the preparation of an amorphous copolyester using the above catalyst composition.

Description

Catalyst composition for synthesizing amorphous copolyester and preparation method thereof

The disclosure relates to a catalyst composition for synthesizing an amorphous copolyester and a preparation method thereof.

The traditional polyester synthesis technology increases the molecular weight through a solid state polymerization process, but its color is generally grayish and yellowish, and is mostly used in general bottled containers. Most of the higher-priced cosmetics on the market are made of PETG (Polyethylene terephthalate glycol-modified) polyester. These PETG polyesters must not only have high molecular weight sufficient for injection blowing, but also have high transparency.

PETG is an amorphous copolyester that cannot pass through a solid state polymerization process to increase molecular weight. When a conventional metal solid phase catalyst (such as ruthenium) is used to catalyze the polycondensation reaction, the synthesized transparent polyester is slightly grayish; when the titanium liquid phase catalyst catalyzed polycondensation reaction, the synthesized polyester will be slightly yellow; When a polycondensation reaction is catalyzed by a titanium solid phase catalyst, a longer polymerization reaction time is required, and the molecular weight of the polyester is low.

Therefore, how to break through the limitations of traditional polyester synthesis technology, increase the molecular weight of PETG polyester, and solve the problem of polyester color ash and yellowing at the same time is an urgent problem to be solved.

An embodiment of the present invention provides a catalyst composition for synthesizing an amorphous copolyester comprising a titanate compound; and a TiO ₂ /SiO ₂ coprecipitate, wherein the titanate compound is co-precipitated with the TiO ₂ /SiO ₂ The weight ratio of the precipitate is from 1:1 to 10:1.

An embodiment of the present invention provides a method for preparing an amorphous copolyester, comprising mixing a monocarboxylic acid compound and a mono diol compound, wherein the dicarboxylic acid compound comprises terephthalic acid or dimethyl terephthalate, the second The alcohol compound comprises cyclohexanedimethanol and ethylene glycol; adding a catalyst composition as described above; performing an esterification reaction or a transesterification reaction, wherein the esterification reaction or the transesterification reaction has a reaction temperature of 160 ° C to 300 ° C, a reaction pressure of 0 kg / cm ² G to 5 kg / cm ² G; and a polycondensation reaction to form the amorphous copolyester, wherein the polymerization temperature of the polycondensation reaction is 180 ° C to 300 ° C, The reaction pressure is less than 1 Torr.

The above described features and advantages of the invention will be apparent from the following description.

The present disclosure provides a composite catalyst composition, which utilizes a novel catalyst composition of a liquid phase and a solid phase combination to catalyze a polycondensation reaction, and can increase the molecular weight of the polyester in an existing overall polymerization reaction system (weight average molecular weight Mw can be More than 20,000), at the same time solve the problem of gray or yellowish polyester color, and can reduce the amount of catalyst used and reaction time.

The present disclosure provides a catalyst composition for synthesizing an amorphous copolyester comprising a titanate compound; and a TiO ₂ /SiO ₂ coprecipitate, wherein the titanate compound and the TiO ₂ /SiO ₂ coprecipitate The weight ratio is 1:1 to 10:1.

The term "amorphous copolyester" as used in the present disclosure refers to a polyester which has no fixed melting point when scanned by differential scanning calorimetry (DSC). At present, the amorphous copolyester is mainly composed of 1,4-cyclohexanedimethanol monomer-polymerized copolyester polymer PETG, or is introduced isophthalic acid (IPA). The polymeric amorphous copolyester is polymerized, but is not limited thereto.

In one embodiment, the weight ratio of the titanate compound to the TiO ₂ /SiO ₂ coprecipitate is from 1:1 to 10:1, such as from 1:1 to 6:1. When the proportion of the titanate compound is too low, the reaction time may be long; when the proportion of the titanate compound is too high, the granule ester may be yellowish.

In one embodiment, the titanate compound comprises Titanium chelates, Titanium tetra-n-propoxide, Titanium tetraisopropanolate , N-butyl titanate, titanium isobutoxide or a combination thereof, but not limited thereto. The "titanate chelate" referred to in the present disclosure can be exemplified by bis(ethyl acetate) di-n-butoxy titanate (Nanjing Nengde Co., Ltd., product model: TCABEAT), di-triethanolamine diisopropyl Based titanate (Nanjing Nengde Company, product model: TCATE), bis(acetylacetonate) diisopropyl titanate (Nanjing Nengde Company, product model: TCAGBA) or bis(ethyl acetoacetate) titanic acid Diisobutyl ester (Nanjing Nengde Company, product model: TCAIBAY), but not limited to this.

In one embodiment, the TiO ₂ /SiO ₂ coprecipitate means that titanium dioxide (TiO ₂ ) and cerium oxide (SiO ₂ ) are formed by coprecipitation at a molar ratio of 1:1 to 10:1. The TiO ₂ /SiO ₂ coprecipitate can be obtained by conventional methods or commercially available. For the preparation of the conventional method, see Barringer, EA and Bowen, HK Formation, packing, and sintering of monodispersed TiO ₂ powders. Journal of the American Ceramic Society. 1982; 65: C199-C201 , the disclosure of which is incorporated herein by reference. However, the preparation method is not limited thereto. In one embodiment, the TiO ₂ /SiO ₂ coprecipitate has an average particle size of from 0.5 μm to 2 μm.

The present disclosure also provides a method for preparing an amorphous copolyester comprising mixing a dicarboxylic acid compound and a mono diol compound, wherein the dicarboxylic acid compound comprises Terephthalic acid (PTA) or terephthalic acid Dimethyl terephthalate (DMT), the diol compound comprises 1,4-cyclohexanedimethanol (CHDM) and ethylene glycol (Ethylene glycol, EG); a catalyst composition as described above is added; Esterification or transesterification, wherein the esterification reaction or the transesterification reaction has a reaction temperature of 160 ° C to 300 ° C and a reaction pressure of 0 kg / cm ² G to 5 kg / cm ² G; and performing a polycondensation reaction to form the amorphous copolyester, wherein the polymerization temperature of the polycondensation reaction is from 180 ° C to 300 ° C, and the reaction pressure is less than 1 Torr.

The "dicarboxylic acid compound" referred to in the present disclosure includes a dicarboxylic acid compound and an esterified product thereof, for example, a dicarboxylic acid ester compound. The unit "kg/cm ² G" of the reaction pressure of the esterification reaction or the transesterification reaction referred to in the present disclosure means a gauge pressure or a gauge pressure, indicating how much pressure is higher than atmospheric pressure. The unit Torr of the reaction pressure of the polycondensation reaction referred to in the present disclosure means an absolute pressure, and 1 Torr is defined as 1/760 of 1 standard atmospheric pressure.

In one embodiment, in the step of adding the catalyst composition as described above, it may be simultaneously added in the step of mixing the monocarboxylic acid compound and the mono diol compound, or in the esterification reaction or the transesterification reaction. After the steps are added, and are not limited to the order.

In one embodiment, when the dicarboxylic acid compound contains terephthalic acid, the esterification reaction is carried out; when the dicarboxylic acid compound contains dimethyl terephthalate, the transesterification reaction is carried out.

In one embodiment, the dicarboxylic acid compound may comprise, in addition to terephthalic acid or dimethyl terephthalate, isophthalic acid (IPA), naphthalene 2,6-dicarboxylic acid ( Naphthalene 2,6-dicarboxylic acid , 2,6-NDA), Dimethyl isophthalate (DMI), Dimethyl 2,6-naphthalenedicarboxylate, 2,6 -NDC) or a combination of the above, but not limited to this.

In one embodiment, the diol compound comprises from 20 mol% to 65 mol% of cyclohexanedimethanol and from 35 mol% to 80 mol% of ethylene glycol.

In one embodiment, the diol compound may further comprise diethylene glycol or 1,4-butanediol, in addition to cyclohexanedimethanol and ethylene glycol. 1,3-Propanediol, 2,2-Dimethyl-1,3-propanediol, or a combination thereof, but not limited thereto.

In one embodiment, the molar ratio of the dicarboxylic acid compound to the diol compound is from 1:1 to 1:2, such as from 1:1 to 2:3.

In one embodiment, the catalyst composition can be added in an amount from 40 ppm to 200 ppm, such as from 60 ppm to 150 ppm. In one embodiment, the titanate compound may be added in an amount of 30 ppm to 120 ppm, and the TiO ₂ /SiO ₂ coprecipitate may be added in an amount of 10 ppm to 70 ppm.

In one embodiment, in the method for preparing an amorphous copolyester, the method further comprises adding a phosphorus-containing compound as a heat stabilizer for the polyester, wherein the phosphorus-containing compound comprises triethyl phosphate. ), Trimethyl phosphate, Tributyl phosphate, Triphenyl phosphate, Triethyl phosphonoacetate, Phosphoric acid ), phosphorous acid or a combination of the above, but not limited thereto. In one embodiment, the phosphorus-containing compound may be added in an amount from 100 ppm to 500 ppm.

In one embodiment, the esterification or esterification reaction has a reaction temperature of from 160 ° C to 300 ° C and a reaction pressure of from 0 kg/cm ² G to 5 kg/cm ² G. When the reaction temperature is too low, the reaction time may be long; when the reaction temperature is too high, the ester particles may be yellowed.

In one embodiment, the polycondensation reaction has a reaction temperature of from 180 ° C to 300 ° C and a reaction pressure of less than 1 Torr, such as less than 0.1 Torr. When the reaction temperature is too low, the reaction time may be long; when the reaction temperature is too high, the ester particles may be yellowed. When the reaction pressure is too high, it may cause a long reaction time.

PETG Preparation example

Example 1 Composite catalyst composition

50.0 kg of PTA, 18.2 kg of EG, 14.1 kg of CHDM, 3.0 g of tetra-n-butyl titanate and 3.0 g of TiO ₂ /SiO ₂ coprecipitate (average particle size of about 1.2 μm) were added to the 200 L Pilot Plant The esterification reaction system is gradually heated to a temperature of about 180 ° C to 250 ° C and a pressure of about 2 kg / cm ² G for about 6 hours of esterification. Next, a vacuum was applied at a temperature of about 250 ° C to 280 ° C to gradually reduce the reaction pressure to 1 Torr or less, and a polycondensation reaction was carried out for about 171 minutes to complete the synthesis of the polyester reaction.

Next, the PETG polyester prepared in Example 1 was subjected to intrinsic viscosity (CANNON®-Ubbelohde glass capillary viscometer tested by ASTM D446 standard procedure) and gloss test (SA-2000 spectroscopic color difference by Nippon Denshoku Industries Co., Ltd.) The measurement is as shown in Table 1.

Example 2 Composite catalyst composition

50.0 kg of PTA, 18.2 kg of EG, 14.1 kg of CHDM, 3.0 g of tetra-n-butyl titanate and 0.5 g of TiO ₂ /SiO ₂ coprecipitate (average particle size of about 1.2 μm) were added to the 200L Pilot Plant The esterification reaction system is gradually heated to a temperature of about 180 ° C to 250 ° C and a pressure of about 2 kg / cm ² G for about 6 hours of esterification. Next, a vacuum was applied at a temperature of about 250 ° C to 280 ° C to gradually reduce the reaction pressure to 1 Torr or less, and a polycondensation reaction was carried out for about 184 minutes to complete the synthesis of the polyester reaction.

Next, the PETG polyester prepared in Example 2 was subjected to intrinsic viscosity (CANNON®-Ubbelohde glass capillary viscometer tested by ASTM D446 standard procedure) and gloss test (SA-2000 spectroscopic color difference by Nippon Denshoku Industries Co., Ltd.) The measurement is as shown in Table 1.

Comparative example 1 Titanium liquid catalyst

50.0 kg of PTA, 18.2 kg of EG, 14.1 kg of CHDM, and 15.0 g of tetra-n-butyl titanate were added to the esterification system of 200 L Pilot Plant, and the temperature was gradually raised to a temperature of about 180 ° C to 250 ° C and a pressure of about 2 The esterification reaction was carried out for about 5.2 hours at kg/cm ² G. Next, a vacuum was applied at a temperature of about 250 ° C to 280 ° C to gradually reduce the reaction pressure to 1 Torr or less, and a polycondensation reaction was carried out for about 116 minutes to complete the synthesis of the polyester reaction.

Next, the PETG polyester prepared in Comparative Example 1 was subjected to intrinsic viscosity (CANNON®-Ubbelohde glass capillary viscometer tested by ASTM D446 standard procedure) and gloss test (SA-2000 spectroscopic color difference by Nippon Denshoku Industries Co., Ltd.) The measurement is as shown in Table 1.

Comparative example 2 Titanium liquid catalyst

50.0 kg of PTA, 18.2 kg of EG, 14.1 kg of CHDM, 4.0 g of tetra-n-butyl titanate were added to the esterification system of 200 L Pilot Plant, and the temperature was gradually raised to a temperature of about 180 ° C to 250 ° C and a pressure of about 2 The esterification reaction was carried out for about 6 hours at kg/cm ² G. Next, a vacuum was applied at a temperature of about 250 to 280 ° C to gradually reduce the reaction pressure to 1 Torr or less, and a polycondensation reaction was carried out for about 181 minutes to complete the synthesis of the polyester reaction.

Next, the PETG polyester prepared in Comparative Example 2 was subjected to intrinsic viscosity (CANNON®-Ubbelohde glass capillary viscometer tested by ASTM D446 standard procedure) and gloss test (SA-2000 spectroscopic color difference by Nippon Denshoku Industries Co., Ltd.) The measurement is as shown in Table 1.

Comparative example 3 Titanium solid phase catalyst

50.0 kg of PTA, 18.2 kg of EG, 14.1 kg of CHDM, 2.7 g of TiO ₂ /SiO ₂ coprecipitate (average particle size of about 1.2 μm) was added to the esterification reaction system of 200 L Pilot Plant, and the temperature was gradually raised to about temperature. The esterification reaction was carried out at 180 ° C to 250 ° C under a pressure of about 2 kg/cm ² G for about 5.7 hours. Next, a vacuum was applied at a temperature of about 250 ° C to 280 ° C to gradually reduce the reaction pressure to 1 Torr or less, and a polycondensation reaction was carried out for about 205 minutes to complete the synthesis of the polyester reaction.

Next, the PETG polyester prepared in Comparative Example 3 was subjected to intrinsic viscosity (CANNON®-Ubbelohde glass capillary viscometer tested by ASTM D446 standard procedure) and gloss test (SA-2000 spectroscopic color difference by Nippon Denshoku Industries Co., Ltd.) The measurement is as shown in Table 1.

Comparative example 4 Titanium solid phase catalyst

50.0 kg of PTA, 18.2 kg of EG, 14.1 kg of CHDM, 1.5 g of TiO ₂ /SiO ₂ coprecipitate (average particle size of about 1.2 μm) was added to the esterification reaction system of 200 L Pilot Plant, and the temperature was gradually raised to about temperature. The esterification reaction was carried out at 180 ° C to 250 ° C under a pressure of about 2 kg/cm ² G for about 6 hours. Next, a vacuum was applied at a temperature of about 250 ° C to 280 ° C to gradually reduce the reaction pressure to 1 Torr or less, and a polycondensation reaction was carried out for about 303 minutes to complete the synthesis of the polyester reaction.

Next, the PETG polyester prepared in Comparative Example 4 was subjected to intrinsic viscosity (CANNON®-Ubbelohde glass capillary viscometer tested by ASTM D446 standard procedure) and gloss test (SA-2000 spectroscopic color difference by Nippon Denshoku Industries Co., Ltd.) The measurement is as shown in Table 1.

Table 1  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Liquid Catalyst (ppm) </td><td> Solid phase catalyst (ppm) </td><td> Polycondensation time (min) </td><td> IV (dL/g) </td><td> Color (brightness) L value </td> <td> Color (yellowness) b value</td><td> PETG result description</td></tr><tr><td> Example 1 </td><td> 60 </td>< Td> 60 </td><td> 171 </td><td> 0.73 </td><td> 67.33 </td><td> -1.04 </td><td> Good color, high molecular weight, reaction Short time</td></tr><tr><td> Example 2 </td><td> 60 </td><td> 10 </td><td> 184 </td><td> 0.75 </td><td> 67.85 </td><td> -2.14 </td><td> Good color, high molecular weight and short reaction time</td></tr><tr><td> Comparative example 1 </td><td> 300 </td><td> - </td><td> 116 </td><td> 0.67 </td><td> 64.54 </td><td> 3.35 < /td><td> Yellowish color and low brightness</td></tr><tr><td> Comparative Example 2 </td><td> 80 </td><td> - </td> <td> 181 </td><td> 0.76 </td><td> 57.67 </td><td> 0.52 </td><td> Yellowish color and low brightness</td></tr> <tr><td> Comparative Example 3 </td><td> - </td><td> 55 </td><td> 205 </td><td> 0.72 </td><td> 65.14 </td><td> -2.98 </td><td> Long reaction time and low brightness</td></tr><tr><td> Comparative Example 4 </ Td><td> - </td><td> 30 </td><td> 303 </td><td> 0.61 </td><td> 60.08 </td><td> -2.30 </td ><td> Long reaction time, low molecular weight, low brightness</td></tr></TBODY></TABLE>

As can be seen from Table 1, when only the titanium liquid phase catalyst composition (Comparative Example 1 and Comparative Example 2) was used, it was found that the color was yellowish and the brightness was low, although the amount of the catalyst used was increased. The reaction time is shortened, but the problem that the color is yellowish and the molecular weight is low and the brightness is low is still unsolvable. When only the titanium solid phase catalyst composition (Comparative Example 3 and Comparative Example 4) was used, it was found that the polymerization reaction time was long and the molecular weight was low, and it was not suitable for direct application to a production and processing product. However, the PETG synthesized by using the composite catalyst composition disclosed in the present invention has the characteristics of good transparency, good color and high molecular weight, and can effectively reduce the amount of catalyst used and shorten the reaction time in the preparation method.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

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Claims (12)

A catalyst composition for synthesizing an amorphous copolyester, comprising: a titanate compound; and a TiO ₂ /SiO ₂ coprecipitate, wherein the weight of the titanate compound and the TiO ₂ /SiO ₂ coprecipitate The ratio is 1:1 to 10:1. The catalyst composition of claim 1, wherein the titanate compound comprises a titanate chelate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate , tetraisobutyl titanate or a combination of the above. The catalyst composition of claim 1, wherein the TiO ₂ /SiO ₂ coprecipitate has a molar ratio of TiO ₂ to SiO ₂ of from 1:1 to 10:1. A method for preparing an amorphous copolyester, comprising: mixing a monocarboxylic acid compound and a mono diol compound, wherein the dicarboxylic acid compound comprises terephthalic acid or dimethyl terephthalate, and the diol compound comprises a ring Hexane dimethanol and ethylene glycol; adding the catalyst composition as claimed in claim 1; performing an esterification reaction or a transesterification reaction, wherein the esterification reaction or the transesterification reaction has a reaction temperature of 160 ° C Up to 300 ° C, a reaction pressure of 0 kg / cm ² G to 5 kg / cm ² G; and a polycondensation reaction to form the amorphous copolyester, wherein the polymerization temperature of the polycondensation reaction is 180 ° C to 300 ° C The reaction pressure is less than 1 Torr. The preparation method of claim 4, wherein the dicarboxylic acid compound further comprises isophthalic acid, naphthalene 2,6-dicarboxylic acid, dimethyl isophthalate, naphthalene 2,6-dicarboxylic acid Ester or a combination of the above. The preparation method of claim 4, wherein the diol compound further comprises diethylene glycol, 1,4-butanediol, 1,3-propanediol, neopentyl glycol or a combination thereof. The preparation method of claim 4, wherein the diol compound comprises 20 mol% to 65 mol% of cyclohexanedimethanol. The preparation method of claim 4, wherein the molar ratio of the dicarboxylic acid compound to the diol compound is from 1:1 to 1:2. The preparation method of claim 4, wherein the catalyst composition is added in an amount of from 40 ppm to 200 ppm. The preparation method of claim 9, wherein the TiO ₂ /SiO ₂ coprecipitate is added in an amount of 10 ppm to 70 ppm. The preparation method of claim 4, further comprising adding a phosphorus-containing compound comprising triethyl phosphate, trimethyl phosphate, tributyl phosphate, triphenyl phosphate, triethyl Phosphonic acid, phosphoric acid, phosphorous acid or a combination thereof. The preparation method of claim 11, wherein the phosphorus-containing compound is added in an amount of from 100 ppm to 500 ppm.