JP2003292594A - Method for producing polyester resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the production of a polyester resin in a short time. <P>SOLUTION: This method for producing the polyester resin, comprising esterifying a saturated dibasic acid and an unsaturated polybasic acid with a glycol compound, is characterized by irradiating the reaction substance with microwaves to raise temperature and accelerate the esterification reaction. The method for producing the polyester, comprising depolymerizing waste PET materials with a glycol compound and the like, charging an unsaturated polybasic acid such as maleic anhydride into the depolymerization product, and heating the mixture, is characterized by irradiating the mixture with microwaves to heat the depolymerization product and the unsaturated polybasic acid and accelerate the esterification reaction. When the depolymerization product is obtained, the depolymerization product is irradiated with microwaves to lower the mol.wt. of the depolymerization product. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polyester resin.

[0002]

2. Description of the Related Art In the production of unsaturated polyester resins, saturated dibasic acids such as phthalic anhydride, unsaturated polybasic acids such as maleic anhydride and fumaric acid, and glycols such as ethylene glycol and propylene glycol. It is general that the unsaturated alkyd is produced by polycondensation with a class of compounds and is dissolved in a polymerizable vinyl monomer such as styrene.

In this conventional method, a saturated dibasic acid, an unsaturated polybasic acid and glycol are charged into a reaction kettle and heated to 80 to 90 ° C. while slowly flowing nitrogen gas into the reaction kettle, and then 1 Up to 150-160 over 1.5 hours
The temperature is raised to 18 ° C over 1 to 1.5 hours.
After removing the water of reaction by setting the temperature to 0 to 190 ° C. and maintaining this temperature for 2 to 2.5 hours, 6650 to 13300 Pa (50 to
While reducing the pressure to 100 mmHg), set the internal temperature to 190-200.
The temperature is kept at 30 ° C for 30 minutes to 2 hours until the desired acid value is reached, the internal temperature is lowered to 110 to 120 ° C, the polymerization inhibitor is added, and then a polymerizable monomer such as styrene is added. Therefore, assuming that the initial temperature rise takes 1 to 2 hours, the total reaction time is 8.5 hours to 10.5 hours. When isophthalic acid or dimethyl terephthalate is used, the synthesis time becomes longer. That is, it usually takes 15 to 16 hours when using isophthalic acid, and 12 to 14 hours when using a tere resin using dimethyl terephthalate.

In place of this dimethyl terephthalate component, recently, depolymerized polyethylene terephthalate resin (such as waste PET bottle flakes or waste PET bottle pellets described later) can be used.
These are commonly used as partial replacements for resin components. However, also in this case, the reaction time is generally the same as that described above, or it takes a long time to dissolve the waste PET bottle flakes, and thus it is generally necessary to take a longer time.

On the other hand, recently, in the so-called Container and Packaging Recycling Law, waste plastic bottles have become the object of recycling,
Collection is being promoted in each municipality. In that case, it is necessary to depolymerize the waste PET bottle flakes obtained by crushing the waste PET bottles and to re-synthesize the unsaturated polyester resin using the depolymerized product as a raw material.

More specifically, when an unsaturated polyester resin is produced from waste PET bottle flakes or pellets as a raw material, it is necessary to depolymerize the waste PET bottle flakes or pellets first. When depolymerizing the waste PET bottle flakes or pellets, an organotin-based catalyst or a titanium-based catalyst is used as a depolymerization catalyst, and an extruder is used in a short time while adding glycol to the polymer having an average molecular weight of 1500 or less. The technology to depolymerize oligomers
For example, it is already proposed in Patent Documents 1 to 3.

In this case, although the average molecular weight of the depolymerized oligomer of waste PET bottle flakes is preferably 800 or less, if the heating and the time are not sufficient, the depolymerization level of the oligomer, that is, the average molecular weight does not decrease. As a result, more time is required and sometimes even the quality of the final unsaturated polyester resin is adversely affected.

Further, when a regenerated unsaturated polyester resin is produced using the oligomer depolymerized to have an average molecular weight of 800 or less, esterification is carried out by adding an unsaturated polybasic acid such as maleic anhydride. However, this esterification reaction also requires some time.

[0009]

[Patent Document 1] Japanese Unexamined Patent Publication No. 11-60707

[0010]

[Patent Document 2] Japanese Patent Laid-Open No. 2000-7770

[0011]

[Patent Document 3] Japanese Patent Laid-Open No. 2002-332379

[0012]

As described above, when an unsaturated polyester resin is produced, the conventional esterification reaction in a reaction vessel is 8 if orthophthalic acid is used.
-10 hours, 15-16 when using isophthalic acid
Time, 12 to 14 hours when producing a tere unsaturated polyester resin using dimethyl terephthalate,
Both require a long time. This required time includes the time required for heating and the reaction time.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above problems and to manufacture a polyester resin in a short time.

[0014]

Means for Solving the Problems To achieve the above object, the present invention provides a method for esterifying a saturated dibasic acid, an unsaturated polybasic acid and glycols to synthesize a polyester resin, By irradiating the reactant with microwaves, the temperature is raised and the esterification reaction is promoted.

That is, the present invention "accelerates the heating of the reactant by irradiating the reactant with microwaves" and "irradiates the reactant with microwaves to accelerate the esterification reaction." The present invention aims to provide a method capable of efficiently producing a polyester resin.

In this way, the reaction can be completed in a short time, and for example, the reaction can be completed in about 1/3 to 1/4 of the time as compared with the conventional method. Further, the present invention, in the case of producing a polyester resin from waste pet material, by depolymerizing the waste pet material with glycols or the like, the unsaturated polybasic acid such as maleic anhydride is added to the depolymerized product. When the esterification reaction is carried out by heating, the microwaves are irradiated to raise the temperature of the depolymerized product and the unsaturated polybasic acid.

The present invention further reduces the molecular weight of the depolymerized product by irradiating the depolymerized product with microwaves when depolymerizing the waste pet material with glycols or the like to obtain the depolymerized product. is there.

Further, in the present invention, glycols are used for the waste pet material to depolymerize the waste pet material, and an unsaturated polybasic acid such as maleic anhydride is added to the depolymerized product to heat it for esterification. When carrying out the reaction, the esterification reaction is promoted by irradiating the reactant with microwaves.

That is, when producing a tere unsaturated polyester resin, it is possible to use waste PET materials such as waste PET bottle flakes and waste PET bottle pellets instead of the above-mentioned dimethyl terephthalate.
In this case, in detail, glycol is added to waste PET materials such as waste PET bottle flakes to obtain a polymerization degree of 800
An unsaturated polyester resin can be produced by preparing a depolymerized PET oligomer below and adding a predetermined amount of maleic anhydride to the mixture to cause an esterification reaction. In this reaction, when the depolymerization reaction is carried out by dissolving the waste pet material in glycol, conventionally, it takes 4 hours to
A reaction time of 6 hours is required.

According to the present invention, in this series of reactions, "the depolymerized product, that is, the pet oligomer is irradiated with microwaves to heat the irradiated object and accelerate the depolymerized reaction." When an unsaturated polybasic acid such as maleic anhydride is added to this to carry out an esterification reaction, the esterification reaction is accelerated by irradiating the reaction material with microwaves. " The total required time for manufacturing can be greatly reduced. These provide an extremely efficient method for producing a polyester resin.

Further, the present invention is to obtain an unsaturated polyester resin having a number average molecular weight of 3000 or more in the above. That is, according to the present invention, the polyester resin can be produced in a short time as described above, and the risk of gelation during the reaction can be reduced because the depolymerized product does not contain free glycol. Therefore, it is possible to easily obtain an unsaturated polyester resin having excellent performance and a number average molecular weight of 3000 or more.

Further, the present invention, in the above, when the depolymerization of waste pet material with glycols or the like to obtain a depolymerized product, using an extruder, or provided at the extruder and the exit of this extruder. Using a reactor, heating, melting and depolymerization reactions of waste pet material are carried out at once.

By doing so, the reaction can be promoted and an unsaturated polyester resin having a number average molecular weight of 3000 or more can be easily obtained.

According to the present invention, a tin-based catalyst such as dibutyltin oxide, a titanium-based catalyst such as isopropoxy titanate, or a zinc organic compound is added as a decomposition catalyst during depolymerization of the waste pet material. It is a thing.

By doing so, the reaction can be promoted and an unsaturated polyester resin having a number average molecular weight of 3000 or more can be easily obtained.

Further, in the present invention, polyethylene terephthalate is depolymerized in place of the waste pet material in the above.

Even in this case, similarly, an unsaturated polyester resin having a number average molecular weight of 3000 or more can be easily obtained.

Further, in the present invention, instead of irradiating the microwave in the above, the reaction is performed without irradiating the microwave.

That is, according to the present invention, an unsaturated polyester resin having a number average molecular weight of 3000 or more can be easily prepared if the reaction can be promoted by adjusting other conditions without irradiating the microwave. Obtainable.
For example, when producing a recycled unsaturated polyester resin using flakes or pellets of waste pet material as a main raw material, an organic acid compound such as dibutyltin oxide, isopropoxy titanate, or zinc is added as a decomposition catalyst when depolymerizing waste pet bottle flakes. Then, depolymerization with glycols using an extruder and a tubular reactor,
Using this depolymerized product (oligomer), an unsaturated polybasic acid such as maleic anhydride is added thereto, and if necessary, further microwave irradiation is carried out to accelerate the esterification reaction, thereby increasing the number average molecular weight. 3,000 or more (preferably 40
00 or more) of high molecular weight regenerated unsaturated polyester can be produced.

At this time, polyethylene terephthalate can be depolymerized in place of the waste pet material, which also makes it possible to easily obtain an unsaturated polyester resin having a number average molecular weight of 3000 or more.

Further, according to the present invention, the obtained high molecular weight unsaturated polyester having a number average molecular weight of 3000 or more may be blended with a monomer copolymerizable therewith.

[0032]

DETAILED DESCRIPTION OF THE INVENTION Microwaves are generally widely used in household microwave ovens. INDUSTRIAL APPLICABILITY The present invention utilizes a microwave having a frequency of 2450 MHz used in a household microwave oven for a direct heating method and a synthetic reaction accelerating method when producing an unsaturated polyester resin,
In addition, a method of accelerating the depolymerization reaction by adding glycols to waste pet materials such as waste PET bottle flakes, and when esterifying reaction by adding unsaturated polybasic acid such as maleic anhydride to the depolymerized product oligomer. It is used as a reaction promoting method.

As the heating / reaction method of each of the above-mentioned steps, heretofore, a method of heating not the reaction substance itself but the container containing the reaction substance by electric heat, or heating by circulating a heating medium such as heating oil Methods etc. were commonly used.

On the other hand, the inventors of the present invention can use it for directly irradiating the esterification reaction substance with microwaves to accelerate the reaction, and further, waste PET obtained by crushing a waste PET bottle. Direct heating of the reaction system by direct microwave irradiation of the components of the esterification reaction for the depolymerization of bottle flakes with glycols and the resynthesis of unsaturated polyester resin using the depolymerized product as a raw material Can be used in addition to the temperature rise of the reactants in the esterification reaction or depolymerization reaction, has a very large effect on the reaction itself,
The present invention has been completed by finding that microwaves can be used for promoting an esterification reaction and a depolymerization reaction.

In the present invention, 2450 MHz is generally used as the type of microwave, but the frequency is not particularly limited. A 915 MHz oscillator is used for food defrosting, which can also be used in the present invention.

As the reaction components for esterification, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, adipic acid, and hettic acid are used as saturated dibasic acid. , Tetrabromophthalic anhydride, etc. are considered, and the unsaturated polybasic acid may be maleic anhydride, fumaric acid, itaconic acid, etc.

As the glycols, ethylene glycol, propylene glycol, diethylene glycol,
Dipropylene glycol, polypropylene glycol,
Neopentyl glycol, 1,3 butanediol, 1,
4-butanediol, 1,6 hexanediol, hydrogenated bisphenol, bisphenol A propylene oxide adduct, dibromoneopentyl glycol, pentaerythritol diallyl ether, allyl glycidyl ether and the like can be mentioned. These have a chemically similar structure, and can be expected to have a heat-receiving effect as an object to be heated by microwave irradiation, or similarly to promote the esterification reaction.

When the polyester resin is produced according to the present invention, the generation of reaction water is observed by irradiating microwaves from the initial stage of heating, heating to 160 ° C., and further raising the temperature. However, by continuing the microwave irradiation while performing the water removal work and further continuing the work while reducing the pressure, the synthesis reaction can be completed in about 2.5 hours from the time of the generation of the reaction water to the desired acid value. it can.
Therefore, compared with the conventional method, about 1/3 to 1 / total as a whole.
It can be confirmed that the reaction can be completed in 4 hours, and that the effect of microwave irradiation is effective not only in simple heating but also in the esterification reaction itself.

In the case of this esterification reaction as well, it is possible to accelerate the reaction by irradiating microwaves in the same manner, and the reaction can be terminated in a short time. As a result, the produced alkyd component can be dissolved in a styrene monomer or the like to obtain the final unsaturated polyester resin.

Next, the number average molecular weight of the unsaturated polyester resin obtained according to the present invention will be described. It is known that unsaturated polyester resins having a number average molecular weight of 3,000 or more have very good physical properties such as corrosion resistance and may have the same performance as vinyl ester resins or epoxy resins, which are considered to be the best. Has been. However, the number average molecular weight of a general unsaturated polyester resin is about 1500 to 2500. Number average molecular weight 3
High molecular weight products of about 000 or more have not been practically used in practice. Because, there is a high risk of gelation during the synthesis reaction, and since the synthesis reaction requires a long time, technically,
This is because it has a cost problem.

On the other hand, with the enforcement of the so-called Container and Packaging Recycling Law, a large amount of recycled products of high-quality polyethylene terephthalate, that is, flakes of waste PET bottles, pellets or waste materials of PET films have been supplied. It is generally practiced in the past to depolymerize this with glycol or the like and then add α-β unsaturated polybasic acid to resynthesize the unsaturated polyester resin.

In the present invention, among unsaturated polyester resins using such waste pet materials and ordinary polyethylene terephthalate, those having a number average molecular weight of 3,000 or more are used.
Compared with the conventional method, it can be synthesized in an extremely short time. That is, the present invention, as described above, by adding a tin-based catalyst or titanium-based catalyst to the waste pet material or normal polyethylene terephthalate, using an extruder,
Alternatively, by using an extruder and a tubular reactor provided at the outlet of the extruder, depolymerization is performed with glycols, and if necessary, the reaction components are directly irradiated with microwaves to carry out the reaction. By significantly promoting it, as a whole, the number average molecular weight can be reduced to 30 in an extremely short time compared with the conventional one.
It is made possible to synthesize an unsaturated polyester resin of 00 or more.

The mixing ratio of each raw material according to the present invention is the same as that of a general unsaturated polyester resin, and propylene glycol can be used as the glycol and maleic anhydride or the like can be used as the unsaturated polybasic acid. This eliminates the need to use bisphenol A or the like contained as a component of the vinyl ester resin, eliminates the risk of environmental hormones, and can be utilized as an environment-friendly unsaturated polyester resin.

When recycling polyethylene terephthalate waste materials such as waste PET bottles, a depolymerization step is required. Conventionally, however, glycol is generally put into a reaction vessel for carrying out depolymerization to obtain polyethylene terephthalate. The depolymerization is carried out over a long period of time by introducing the waste material of. However, in this method, in addition to requiring a long time for the reaction, glycol remains in the depolymerized product, and the depolymerization level is insufficient, and polyethylene terephthalate having a number average molecular weight of several thousand is often mixed. It's a problem. On the other hand, in the case of a method in which glycols and a decomposition catalyst are added using an extruder based on the present invention and a decomposition reaction is carried out, a fixed amount of glycols is supplied to polyethylene terephthalate to cause a reaction to depolymerize ( There are no free glycols to make oligomers) and the depolymerization level is sufficiently homogeneous.

Next, the depolymerized oligomer thus prepared is reacted with an unsaturated acid such as maleic anhydride to cause an esterification reaction to produce an unsaturated polyester resin. In that case, basically, both the above-mentioned conventional method and the method based on the present invention can be adopted, but the reaction time or the behavior thereafter varies depending on which one is adopted.

That is, in the conventional method, the number average molecular weight is 1
A reaction time of about 8 hours or more is required in the esterification reaction for producing a general unsaturated polyester resin of 500 to 2500, and further, if an attempt is made to produce a high molecular weight unsaturated polyester resin, the risk of gelation is high, In practice, high molecular weight unsaturated polyester resins are difficult to manufacture. On the other hand, in the method based on the present invention, an esterification reaction with an oligomer produced by a method of quantitative addition of glycol using an extruder and a tubular reactor using a decomposition catalyst such as dibutyltin oxide for waste pet material When the reaction is carried out, the reaction can be carried out in a short time, and direct irradiation of the synthetic components with microwaves also has an extremely large accelerating effect for shortening the reaction time. In the case of manufacturing, it can be completed in about 1.5 hours. As the decomposition catalyst, tetraisopropoxy titanium, an organic acid salt of zinc or the like can be used in addition to the above-mentioned dibutyl tin oxide.

On the other hand, when a high molecular weight unsaturated polyester resin having a number average molecular weight of 3000 or more is produced by a conventional method which does not use the above-mentioned oligomer of polyethylene terephthalate, there is a large risk of gelation as described above. In reality, it is impossible to manufacture, and it takes 30 hours or more even if a special blending component is used, the profitability is poor, and in reality, almost no manufacturing is performed. On the other hand, in the present invention, the reaction can be completed in a short time of about 4 hours by the above series of methods. Further, in general, synthesis of a high molecular weight unsaturated polyester resin requires a deglycolization reaction in a high vacuum, but according to the present invention, it can be produced without requiring a high vacuum.

According to the present invention, this is because α-β, which occurs in the usual production of unsaturated polyester resin, has polyethylene terephthalate as a skeleton and does not contain free glycol in the depolymerized product. It is considered that this is because there is no risk of gelation due to the formation of a branched structure due to the polymerization of unsaturated bonds or the addition of glycol. Therefore, according to the present invention, it becomes possible to promote the increase in molecular weight while preventing gelation.

In other words, according to the present invention, the following [A]
A high molecular weight unsaturated polyester resin having a number average molecular weight of 3000 or more can be easily obtained in the state of having the advantages such as [D] to [D].

[A] Solution to Danger of Gelation The unsaturated polyester resin has an α-β unsaturated group in the molecule as compared with the saturated polyester represented by polyethylene terephthalate. Structurally different. Based on this unsaturated bond, a branched structure is generated in the polyester molecule as a result of polymerization or glycol addition, which is considered to cause gelation together with an increase in molecular weight. This makes the number average molecular weight of the conventional general unsaturated polyester resin approximately 2500 to 30.
It is considered that the reason for stopping at around 00. In contrast,
According to the present invention, polyethylene terephthalate as a component of saturated polybasic acid is glycolyzed to give a molecular weight of 1000.
It is used as an oligomer below, so to speak, it is a kind of polyester and does not contain free glycol,
Even if maleic anhydride is added, no branching occurs due to the molecular structure because there is no component that causes glycol addition. As a result, only linear polyester can be obtained, and high molecular weight can be obtained, and the risk of gelation is eliminated.

[B] Shortening of Synthesis Time According to the present invention, a catalyst such as dibutyltin oxide can be added in order to efficiently carry out depolymerization of waste polyethylene terephthalate. It is also effective in the synthesis step, and esterification can be realized in a short time.

Further, by directly irradiating the reaction component with microwaves, energy is directly applied to the hydroxyl group, which is one of the esterification reaction groups, so that the molecular motion becomes active and the esterification reaction can be carried out in a shorter time. Can be terminated.

[C] Environmental hormone-free component Known epoxy resin or vinyl ester resin having high toughness and high strength usually has bisphenol A or its reactive molecule in the molecule, Including the danger as a material.

In the present invention, an unsaturated polyester resin, which is a general blending component containing no bisphenol A, is made to have a high molecular weight, and the component is basically different from that of an epoxy resin or a vinyl ester resin. A free unsaturated polyester resin can be obtained.

[D] High Vacuum Equipment In order to make the unsaturated polyester resin have a high molecular weight, it is generally necessary to sufficiently carry out the deglycolization reaction in a high vacuum of 65.5 Pa (0.5 Torr) or less. It requires a special vacuum pump to realize the vacuum. On the other hand, in the present invention, the polymer has a sufficiently high molecular weight at a vacuum level of about 1.33 kPa (10 Torr), which is used in the usual esterification step, and therefore no problems in production occur.

[0056]

Example [Example A] Preliminary heating test using a household microwave oven Equipment used "NE-8500 manufactured by Matsushita Electric Industrial Co., Ltd." Rated voltage 100V Rated power consumption 990W Rated high frequency output 500W Microwave frequency 2450MHz Chamber size Width 300mm depth 305mm height 1
95 mm

Test Method Polypropylene glycol (48.7%) was added to waste PET bottle flakes (100% by mass), and dibutyltin oxide (catalyst) was added thereto (0.3%). Depolymerization was carried out at ℃ to obtain a waste PET bottle flake oligomer. Then, 350 g and 450 g of the waste PET bottle flake oligomer were placed in a 500 ml glass beaker, respectively, and subjected to microwave irradiation by the above equipment. As a result, the temperature rise data shown in the table below was obtained. The microwave heating efficiency by this method is as follows, and it was found to be effective as a direct heating method in the above-mentioned reactant system. That is, the heating efficiency showed a value of 80% or more at the initial stage and a value of 40% level even after the temperature was raised, whereby sufficient heating efficiency was confirmed. The heating efficiency is defined by the following formula.

Heating efficiency = amount of heat received energy to be heated / amount of microwave heating energy

[0059]

[Table 1]

Example B B-Depolymerization by Microwave Irradiation FIG. 1 shows a schematic configuration of a test apparatus. Here, 1 is an experimental reaction kettle capable of accommodating the reactant 2 inside,
A rotary stirring device 3 for stirring the reactant 2 is provided. Reference numeral 4 is a rotary drive source for the stirring device 3. Reference numeral 5 is a thermometer for measuring the temperature of the reactant 2. Reference numeral 6 denotes a microwave oscillator, which can irradiate the reaction target 2 inside the reaction vessel 1 with microwaves through the waveguide 7. That is, it is possible to directly irradiate the reaction target 2 with a microwave, rather than heating the reaction kettle 1 to indirectly heat the reaction target 2 therein. 8 is a vacuum suction path,
The inside of the reaction kettle 1 can be depressurized. Reference numeral 9 denotes a water removal conduit, which is provided with the condenser 10 so that the water inside the reaction vessel 1 can be discharged to the outside.

By weight ratio, waste PET bottle flakes 100
% Of propylene glycol and 0.3% of dibutyl oxide, which is a depolymerization catalyst, were charged into an extruder, and the waste PET bottle flakes had a molecular weight of 1500.
An oligomer depolymerized to a certain degree was prepared.

This oligomer is shown in FIG.
4.4 kg was put into the reaction kettle 1 for liter experiment, and while stirring by the stirrer 3, the microwave of the frequency of 2450 MHz from the microwave transmitter 6 was irradiated from the upper surface of the liquid surface of the reaction tank to carry out the depolymerization promotion experiment. It was Then, the microwave irradiation time from around 180 ° C. was 30 minutes, and as shown in the following table, the molecular weight could be reduced to about ½ of that before the reaction.

[0063]

[Table 2]

Equipment used: Microwave oscillator “TMG-491C” manufactured by Yamamoto Vinita Co., Ltd. 5 kW output 10 liter experimental kettle Internal volume 11536 cm ³ Cavity watt density = 5000/11536 = 0.43 W / cm ³

B-Depolymerization by Conventional Heating Method (Comparative Example) 4.1 kg of waste PET bottle flakes and 12.2 g of dibutyltin oxide as a reaction catalyst were mixed at 290 ° C. to 300 ° C.
The cylinder was put into an extruder with heating, and melted and kneaded. Then, this was put into a reaction tank heated to 250 ° C. and sufficiently stirred.

Then, propylene glycol was added little by little so that the internal temperature of the reaction tank did not drop below 200 ° C. This work required about 40 minutes.
After that, the reaction tank was kept at 200 ° C. and kept for 60 minutes, and then the content was sampled and the molecular weight was measured to obtain an average molecular weight of 800. The reaction was continued at 200 ° C. for 1 hour.
Then, the molecular weight decreased to 690.

As a result, the time required for depolymerization was 100 minutes to 220 minutes, which was three times or more that of Example B-.

Example C Esterification by Microwave Irradiation Example B-was placed in a 10 liter experimental reaction kettle 1 shown in FIG.
4.4 kg of depolymerized oligomer (180 ° C.) of waste PET bottle flakes with propylene glycol and 1.7 kg of maleic anhydride were added, and after stirring for 15 minutes,
A 5 kW microwave having a frequency of 2450 MHz was irradiated from the upper surface of the reaction solution, and the temperature was raised to 200 ° C. When the temperature was raised to 200 ° C., the generated water was discharged to the outside of the system by the condenser 10 and further 2660 Pa (20 Torr) by the vacuum pump.
And tried to remove water. After maintaining this state for 15 minutes, the acid value was measured and 79 was obtained. After maintaining the vacuum and temperature and irradiating microwaves for 15 minutes, 28 was obtained by measuring the acid value. After irradiating with microwave for further 15 minutes, the acid value was measured to obtain 13.6. At this point the microwave irradiation was terminated and the reaction was complete.

Next, 40% by mass of styrene monomer was added and mixed and stirred to produce an unsaturated polyester resin. As a result, an unsaturated polyester resin having a pale yellow appearance and a viscosity of 3.2 poise was obtained, which was an unsaturated polyester resin equivalent to the case of ordinary temperature heating. At this time, it took 45 minutes from the addition of the materials to the end of the alkyd reaction, but the decrease rate of the acid value was more rapid than that in the normal heating reaction, and it was clear that the esterification reaction proceeded rapidly. Met.

Equipment used: Microwave oscillator “TMG-491C” manufactured by Yamamoto Vinita Co., Ltd. Output 5 kW Frequency 2450 MHz 10 liters Experimental kettle Internal volume 11536 cm ³ Cavity watt density = 5000/11536 = 0.43 W / cm ³ Resin properties Curing properties Gelation 64 minutes Curing 97 minutes Exothermic temperature 129 ° C Barcol hardness 42 In addition, a resin concrete test piece (40 × 40 × 160 mm rectangular block, resin content 14%) was made with the obtained unsaturated polyester resin, and a bending test was performed. The performance was measured by. The results are shown in the table below.

[0071]

[Table 3]

C-Esterification by conventional heating methods
(Comparative Example) Example B-in the 10-liter experimental reaction kettle 1 shown in FIG.
The depolymerized oligomer (6090 g) is reacted and produced by the method of 1) and then maleic anhydride 2310 is added at 160 ° C.
g and charged. Since generation of water was observed at 10 minutes after the stirring at 180 ° C., drainage treatment was started by the condenser 10. In this state, 200 ℃ ~
The temperature was raised to 203 ° C. and the state was continued for 4 hours. At this time, a sample was taken to obtain an acid value of 48. 3990-
5320 Pa (30-40 Torr) vacuum state,
After continuing the reaction for 1 hour and 30 minutes, the acid value was measured.
At this time, an acid value of 28 was obtained. At this point, the reaction was deemed complete and heating was discontinued. After 45 minutes, 5600 g of styrene was added and stirred at 140 ° C. to produce a pale yellow unsaturated polyester resin.

From material input to completion of alkyd synthesis 5
It took 30 minutes.

Example D D-Esterification Reaction by Microwave Irradiation The following components were added to a 10 liter experimental reaction kettle 1 shown in FIG. 1 to synthesize an unsaturated polyester resin under microwave irradiation. Tried. That is, phthalic anhydride 240
A total of 6582 kg of 0 kg, 2592 kg of propylene glycol and 1590 kg of maleic anhydride was charged into the reaction kettle 1, and microwaves were directly irradiated to the raw material components from the beginning while flowing nitrogen gas, and the electric heater for heating the reaction kettle 1 was also simultaneously heated. Used to heat. At this time, 170 ℃
It took 30 minutes to reach. The temperature was maintained for 30 minutes, and the generation of water began, so the water removal was started by the condenser 10.

After that, microwave irradiation is performed for 30 minutes to 20
When the temperature was raised to 0 ° C. and the acid value was measured, it was 128. Next, while maintaining the temperature of 200 ° C while irradiating the microwave,
The state of decrease in acid value (reaction level) was confirmed. As shown in the table below, an acid value of 56
I was able to get According to this, alkyd having an acid value of 56 could be synthesized in 3 hours and 15 minutes by summing the heating and heat retention times from the beginning, and the following reaction system not irradiated with microwave of D- was used. It was possible to obtain an equivalent quality level with a reaction time of about 1/4.
That is, an unsaturated polyester resin having a pale yellow appearance and a viscosity of 2.6 poise was obtained. In the above, the vacuum treatment was performed after 2 hours and 30 minutes had passed from the beginning.

Equipment used: microwave oscillator “TMG-491C” manufactured by Yamamoto Vinita Co., Ltd. Output 5 kW Frequency 2450 MHz 10 liters Experimental kettle Internal volume 11536 cm ³ Cavity watt density = 5000/11536 = 0.43 W / cm ³

[0077]

[Table 4]

D-Esterification by conventional method Into a 10 liter experimental reaction kettle 1 shown in FIG. 1, the same components as in D- were charged, and 80 to 9 while flowing nitrogen gas.
Heat to 0 ° C. for 3 hours 15 minutes. At that point, the stirring became possible, and the stirring was started. It was further heated for 2 hours and 15 minutes and heated to 170 ° C. Since water was generated in this state, the water removal was started using the capacitor 10. Then, the mixture was heated for 2 hours, heated to 200 ° C., and the acid value was measured. After holding at 200 ° C for 1 hour and 30 minutes,
The vacuum process was started. As shown in the table below, the relationship between the holding time at 200 ° C. and the acid value is 51 after 4 hours and 30 minutes have passed, and it takes 12 hours if the total heat retention time from the beginning is taken. An alkyd of valence 51 could be synthesized.

Next, 40% of styrene monomer was added thereto and mixed and stirred to produce an unsaturated polyester resin. That is, an unsaturated polyester resin having a pale yellow appearance and a viscosity of 2.3 poise was obtained.

[0080]

[Table 5]

Example E Production of E-High Molecular Weight Unsaturated Polyester Resin (Part 1) Diptyltin oxide was previously prepared as a depolymerization catalyst in an amount of 0.8%.
112 g of waste PET bottle flakes with 3% by mass added
min and propylene glycol at a rate of 59 g / min were charged into the extruder 11 shown in FIG. 1 in the mold reactor 13
The mixture was allowed to pass for a period of time to produce a glycol depolymerized product of waste PET bottle flakes. The temperature is about 200 ℃ ~ 22
Maintained between 0 ° C. The obtained depolymerized oligomer is
It is a white wax at room temperature and has a number average molecular weight of 750 to 750.
It was 800. 12 kg of this depolymerized oligomer,
Maleic anhydride 4.8 kg at 200 ° C in the dissolved state
It was put into the reaction tank together with.

The internal temperature was immediately raised to 210 ° C. After maintaining this state in nitrogen gas for 30 minutes, irradiation with a microwave of 5 kW was performed, and it was confirmed that a large amount of water was produced. The pressure was gradually reduced and 2.66 kPa (20To) in 30 minutes.
rr). Furthermore, 1.33 to 2.66 kPa (10
Esterification was carried out for 3 hours under reduced pressure of ˜20 Torr). No gelation occurred. The following table shows the results of analysis of acid value, viscosity, and molecular weight (number average molecular weight Mn and weight average molecular weight Mw) at each reaction elapsed time.

This high molecular weight unsaturated polyester was once transferred to another container, styrene monomer was added at 50%,
A high molecular weight unsaturated polyester resin was used. Equipment used Extruder: Techno Bell KZW15 same-direction twin-screw extruder L / D = 75 Tube type reactor: Stainless steel tube Temperature conditions: 220-280 ° C Microwave oscillator: Yamamoto Vinita "TMG-491C" Output 5kW frequency 2450MHz

[0084]

[Table 6]

E--Production of High Molecular Weight Unsaturated Polyester Resin (Part 2) Using the depolymerized oligomer having a number average molecular weight of 750 to 800 obtained in E- above, 12 kg of this oligomer was added to
Maleic anhydride 4.8k at 200 ℃ in the molten state
It was put in the reaction tank together with g. Then, while passing nitrogen gas through this reaction tank, the temperature in the tank was set to 2 for 30 minutes.
It was kept at 20 ° C. Next, while discharging the reaction water out of the tank,
After 1 hour, the pressure is gradually reduced to 2.66 kPa.
Hold at (20Torr) for 1 hour, then 1.33kP
The reaction was carried out at a (10 Torr) for 4 hours. No gelation occurred. Acid value, viscosity for each reaction time at this time,
The results of molecular weight analysis are shown in Table 7.

This gives a number average molecular weight of 400 in 6 hours.
It was possible to obtain 0 or more. The total reaction time was about 6.5 hours, and a longer reaction time was required as compared with the case where the microwave of E- was irradiated, but the temperature of the reaction tank was kept high without irradiation of microwaves. By setting to, it was possible to synthesize a high molecular weight unsaturated polyester.

The product was transferred to another container and 50% of styrene monomer was added to obtain a high molecular weight unsaturated polyester resin.

[0088]

[Table 7]

E-Production of unsaturated polyester resin by conventional method In a 1 liter separable flask equipped with a stirrer, a reflux condenser, a thermometer and a gas introduction tube, 234 g of waste PET bottle flakes, 114 g of propylene glycol,
0.5 g of dibutyltin oxide was added, and glycol decomposition was carried out at 189 ° C. for 10 hours. As a result, the molecular weight of the oligomer was 1500.

After lowering the temperature to 160 ° C.,
140 g of maleic anhydride was added to the produced oligomer, and esterification was carried out at 200 ° C. to 210 ° C. for 3 hours. After that, 6.65 to 7.98 kPa (50 to 60 m
When the reaction was continued for 12 hours and 30 minutes under a reduced pressure of (mHg), the system gelled. After 1 hour of reduced pressure, the acid value was 29 and the number average molecular weight was about 3000.

It was presumed that the cause of gelation was that free propylene glycol remained even after the glycol decomposition was completed and this was added to the unsaturated bond of maleic anhydride to cause branching.

[0092]

As described above, according to the present invention, in the production of the polyester resin, by irradiating the reactant with microwaves, the heating of the reactant can be promoted and the esterification reaction thereof can be promoted. Therefore, the polyester resin can be efficiently produced.

According to the present invention, in the case of producing a polyester resin from waste pet material, the waste pet material is depolymerized with glycols and the like, and the depolymerized product is an unsaturated polybasic acid such as maleic anhydride. Are added and heated to carry out the esterification reaction, it is possible to raise the temperature of these depolymerized products and the unsaturated polybasic acid by irradiation with microwaves.

Further, according to the present invention, when the depolymerized waste pet material is depolymerized with glycols or the like to obtain a depolymerized product, the depolymerized product is irradiated with microwaves to lower the molecular weight of the depolymerized product. Is.

Further, according to the present invention, glycols are used in the depolymerized waste pet material to depolymerize the waste pet material, and an unsaturated polybasic acid such as maleic anhydride is added to the depolymerized product. When the esterification reaction is carried out by heating by heating, the esterification reaction can be promoted by irradiating the reactant with microwaves.

Therefore, according to the present invention, in a series of reactions, the pet oligomer which is a depolymerized product is irradiated with microwaves to heat the irradiated object and
Based on accelerating the depolymerization reaction and further accelerating the esterification reaction by irradiating the reaction substance with microwaves when an unsaturated polybasic acid such as maleic anhydride is added to the esterification reaction. In addition, it is possible to significantly reduce the total time required for producing the polyester resin from the waste pet material, and it is possible to produce the polyester resin extremely efficiently.

Further, according to the present invention, the polyester resin can be produced in a short time as described above, and the risk of gelation during the reaction can be reduced because the depolymerized product does not contain free glycol. Therefore, it is possible to easily obtain an unsaturated polyester resin having a number average molecular weight of 3000 or more, which has excellent performance.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a first test apparatus for carrying out the present invention.

FIG. 2 is a diagram showing a schematic configuration of a second test apparatus for carrying out the present invention.

[Explanation of symbols]

1 Reactor for experiment 2 Reactants 6 microwave transmitter 11 extruder 13 tube reactor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiro Iguchi             2-26 Ohama-cho, Amagasaki City, Hyogo Stock Association             Kubota Mukogawa Factory (72) Inventor Nobu Yoshimura             4-115-304 Hashimoto, Sagamihara City, Kanagawa Prefecture (72) Inventor Shinichi Otsuka             5-1-9 Harajuku, Shiroyama-cho, Tsukui-gun, Kanagawa Prefecture F-term (reference) 4F301 AA25 CA09 CA23 CA46 CA53                       CA61                 4G075 AA32 AA37 BA05 BB03 BD05                       CA02 CA26 CA51 CA54 DA18                       EA05 EB15 EB21 EC06 ED02                       FB02 FC20                 4J029 AA07 AB04 AB05 AD01 AE01                       BA03 BA05 BA08 BA09 BA10                       BD10 BF09 BF10 BF25 BF26                       CA06 CB04A CB05A CB06A                       CD03 CD04 CG05X GA13                       GA14 GA17 HA01 HB01 HB06                       KC01 KD02 KD11 KE03 KE13                       KG02 KG03

Claims (9)

[Claims] 1. When synthesizing a polyester resin by carrying out an esterification reaction using a saturated dibasic acid, an unsaturated polybasic acid and glycols, the reaction material is irradiated with microwaves to raise the temperature. At the same time, a method for producing a polyester resin, which comprises promoting an esterification reaction. 2. When producing a polyester resin from waste pet material, the waste pet material is depolymerized with glycols and the like, and an unsaturated polybasic acid such as maleic anhydride is added to the depolymerized product. A method for producing a polyester resin, which comprises heating these depolymerized products and an unsaturated polybasic acid by irradiating a microwave when the esterification reaction is carried out by heating. 3. When depolymerizing the waste pet material with glycols or the like to obtain a depolymerized product, the depolymerized product is irradiated with microwaves to reduce the molecular weight of the depolymerized product. Method for depolymerizing polyester resin. 4. A waste pet material is depolymerized by using glycols as the waste pet material, and an unsaturated polybasic acid such as maleic anhydride is added to the depolymerized product and heated to carry out an esterification reaction. In this case, a method for producing a polyester resin, which comprises accelerating an esterification reaction by irradiating a reaction material with microwaves. 5. The method for producing a polyester resin according to claim 2, wherein an unsaturated polyester resin having a number average molecular weight of 3000 or more is obtained. 6. When depolymerizing waste pet material with glycols or the like to obtain a depolymerized product, an extruder is used, or an extruder and a reactor provided at the outlet of this extruder are used. The method for producing a polyester resin according to claim 5, wherein the heating, melting and depolymerization reactions of the waste pet material are carried out all at once. 7. When depolymerizing the waste pet material, a tin catalyst such as dibutyltin oxide, a titanium catalyst such as isopropoxy titanate, or an organic compound of zinc is added as a decomposition catalyst. Item 7. A method for producing a polyester resin according to Item 5 or 6. 8. A method of depolymerizing polyethylene terephthalate instead of waste pet material.
The method for producing a polyester resin according to any one of 1 to 6 above. 9. The method for producing a polyester resin according to claim 5, wherein the reaction is carried out without irradiation of microwaves instead of irradiation of microwaves.