KR20060128493A - A preparing method of alkyd resin using waste pet - Google Patents

Abstract

Provided is a method for preparing alkyd resin using waste PET, which produces alkyd resin with physical properties equal to conventional alkyd resin prepared without using waste PET, recycles waste resources effectively, and prevents environmental pollution. The method for preparing alkyd resin using waste PET comprises the steps of: adding 0.1-5 parts by weight of a catalyst selected from lithium hydroxide, zirconium hydroxide, or butyltin oxide, 40-50 parts by weight of liquid multivalent alcohol, and a part of fatty acid to 100 parts by weight of waste PET, and then heating the admixture to 240Œ5‹C to obtain hydrolysate; adding 35-55 parts by weight of polybasic acid and the remaining fatty acid to the hydrolysate to be reacted at 240Œ5‹C, and cooling the resultant. The total fatty acid used in both the hydrolysis step and the reaction step is added in an amount of 80-120 parts by weight.

Description

A preparing method of alkyd resin using waste PET

The present invention relates to a method for producing alkyd resin using waste PET, and more particularly, to obtain a hydrolyzate by hydrolyzing waste PET used as a beverage container or other product, and using the hydrolyzate to form an alkyd resin. It relates to a manufacturing method.

Generally, polyethylene terephthalate (PET) is one of polyester resins formed by polymerization of terephthalic acid and ethylene glycol, and PET consumption is currently 13 million tons worldwide. Among them, 9.5 million tons are used in the textile industry, 2 million tons for audio and video tape production, and 1.5 million tons for various types of packaging such as bottles.

However, as the amount of PET used increases, the waste PET that is discarded is also increasing, which causes a serious environmental problem because waste PET takes a long time to naturally decompose. Accordingly, there is a demand for a method for efficiently recycling waste PET.

PET recycling technologies generally practiced to date include material recycling, chemical recycling, and energy recycling.

The material recycling method is to remove foreign substances from waste PET, crush, wash and shape them into flakes or pearllets and use them as raw materials for plastic production. Chemical recycling is used to remove hydrocarbons from waste PET and recover hydrocarbon oils through crushing, pyrolysis, gas purification, condensation, etc., and to use them as raw materials or fuels in the chemical industry. In addition, energy recovery is to generate gas by pyrolyzing waste PET or to manufacture solid fuel and use it as a substitute fuel.

As another method of the chemical recycling method related to the present invention, PET is a copolymer of ethylene glycol and terephthalic acid, and when hydrolyzed, the PET is decomposed into ethylene glycol and terephthalic acid and used as an alternative raw material thereof. In particular, polyesters obtained by reacting polybasic acids with polyhydric alcohols and fatty acids are called alkyd resins, and are widely used in paints and coatings of buildings, bridges, and the like. It becomes possible.

However, PET has a problem in that the softening point is very high and is hardly dissolved in an organic solvent, so that hydrolysis is not easy. For this reason, a method of hydrolyzing by heat treatment at high temperature has been proposed, but the softening point of PET is too high, so that the hydrolysis efficiency is lowered. Accordingly, there is a demand for a method that can effectively hydrolyze waste PET and replace it with a raw material of alkyd resin.

Accordingly, the present invention is to solve the above-described problems, to efficiently hydrolyze waste PET at a lower temperature to obtain a hydrolyzate, and to provide a method for producing an alkyd resin using the hydrolyzate. have.

The present invention to achieve the above object

In the manufacturing method of alkyd resin which makes polyhydric alcohol, polyhydrochloric acid, and a fatty acid react,

To the waste PET, a catalyst selected from lithium hydroxide, zirconium hydroxide, or butyltin oxide, liquid polyhydric alcohol and fatty acid is added, and then heated to 240 ± 5 ° C. A hydrolysis step of obtaining a hydrolyzate; It provides a method for producing alkyd resin using waste PET, characterized in that it comprises a; and adding a polybasic acid and the residual amount of fatty acid to the hydrolyzate and reacted at 240 ± 5 ℃ and cooled.

Hereinafter, the present invention will be described in more detail.

In order to manufacture alkyd resin using waste PET, the present invention firstly adds a catalyst, a liquid polyhydric alcohol and a fatty acid to waste PET, and then undergoes a hydrolysis step of obtaining hydrolyzate by heating to 240 ± 5 ° C.

Here, the waste PET includes various PET products collected for recycling, including beverage containers, and is preferably used to be crushed to a predetermined size in order to facilitate the hydrolysis reaction. The particle size does not need to be limited, but the smaller the particle size, the faster the hydrolysis rate. Therefore, it is preferable to grind to a size of 10 to 20 cm 2 in consideration of the reaction rate.

The catalyst added in the hydrolysis step serves to shorten the hydrolysis time to be selected from lithium hydroxide (Lithiume hydroxide), zirconium hydroxide (Zirconium hydroxide) or butyltin oxide (Butyltin oxide) It is good to use.

The catalyst is added to 0.1 to 5 parts by weight based on 100 parts by weight of waste PET, when the addition amount is less than 0.1 parts by weight based on waste PET, there is a problem that the productivity of the hydrolysis reaction is prolonged and the productivity decreases. If the amount exceeds 5 parts by weight, the hydrolysis time is shortened, but the esterification time is also shortened, which makes it difficult to manage the end point of the reaction by tracking the acid value or viscosity. Therefore, the catalyst is preferably added within the above range. .

It is difficult to hydrolyze only the catalyst to hydrolyze the PET, since the waste PET and the catalyst are solid, so the reactivity is not effective, so that no effective hydrolysis occurs. Therefore, in the present invention, the liquid polyhydric alcohol and fatty acid are added together with the catalyst to be heated, and when the liquid polyhydric alcohol and fatty acid are added together with the catalyst to be heated, the waste PET has a melting point due to hydrolysis of alcohol. It melts at much lower temperatures, leading to hydrolysis. At this time, the more the addition amount of the liquid polyhydric alcohol, the lower the melting temperature, efficient hydrolysis proceeds. Hydrolysis is completed in about 1-2 hours at 240 ± 5 ℃.

The liquid polyhydric alcohol may be used to select those used in the process of preparing a common alkyd resin. Examples of liquid polyhydric alcohols include ethylene glycol, polyethylene glycol, 1,3-butylene glycol, propylene glycol, polypropylene glycol, butylene glycol, hexanediol, neopentyl glycol, octane diol, butyl ethyl propane diol, bisphenol A Selected from hydrogenated bisphenol A, bisphenol F, glycerin, trimethol ethane, trimetholpropane, tris hydroxy methyl amino methane sorbitol.

The liquid polyhydric alcohol is preferably added 40 to 50 parts by weight with respect to 100 parts by weight of waste PET, there is a problem of acid value or viscosity when the amount of the polyhydric alcohol added in the liquid is less than 40 parts by weight, the addition amount exceeds 50 parts by weight If there is a problem in the resin performance, it is preferable to add a liquid polyhydric alcohol within the above range.

In the hydrolysis reaction step, the fatty acid is added together with the liquid polyhydric alcohol to proceed the hydrolysis reaction, and if necessary, the fatty acid may be added in the reaction step described later. When the fatty acid is added with the polyhydric alcohol in the hydrolysis reaction step, hydrolysis is completed in about 1 hour at 240 ± 5 ° C. As the fatty acid is added or the amount of fatty acid is added in the hydrolysis reaction step, the reaction The time becomes long. This is because the hydrolysis reaction of PET does not occur effectively because fatty acids cause ester reaction with liquid polyhydric alcohol and lack alcohol content. Therefore, the fatty acid can be selectively added in the hydrolysis reaction step and the reaction step to control the reaction time, and in the hydrolysis reaction step, the reaction time can be controlled by controlling the addition amount.

The fatty acid is preferably added so that the total amount added to 80 to 120 parts by weight based on 100 parts by weight of waste PET, when the addition amount is less than 80 parts by weight, there is a rapid reaction problem, when the addition amount exceeds 120 parts by weight of low viscosity Since there is a problem, it is preferable to add a fatty acid within the above range.

The fatty acid may be selected from those added in the manufacture of a common alkyd resin, for example, selected from palm oil, palm oil, castor oil, castor oil fatty acid, palm oil fatty acid, palm oil fatty acid, linseed oil, soybean oil, cottonseed oil, forest oil Can be used.

After adding catalyst and liquid polyhydric alcohol and fatty acid to waste PET as above, PET is hydrolyzed to terephthalic acid and ethylene glycol when heated to 240 ± 5 ℃, and some of the produced hydrolyzate is reacted with fatty acid. Will generate

At this time, in order to promote the hydrolysis reaction, pentaerythritol is preferably added in an amount of 5 to 20 parts by weight based on 100 parts by weight of waste PET. This pentaerythritol lowers the melting temperature of the waste PET and shortens the hydrolysis time. When the amount of the pentaerythritol is less than 5 parts by weight based on 100 parts by weight of waste PET, the effect is insignificant, and the amount of addition exceeds 20 parts by weight. If there is a problem in that the overall alcohol content to increase the resin performance, it is good to add pentaerythritol within the above range.

When the hydrolysis step is completed as described above, polybasic acid and the remaining fatty acid are added to the hydrolyzate to react at 240 ± 5 ° C. and then cooled.

Here, the polybasic acid may be selected from those used in the manufacture of a common alkyd resin, for example, adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, azeline acid, sebacic acid, tetrahydro phthalic anhydride, At least one selected from hexahydro phthalic anhydride, tetrabromic phthalic anhydride, hept anhydride, hymic anhydride, maleic anhydride, fumaric acid, methyl cyclohexene tricarboxylic anhydride and pyromellitic anhydride can be used.

The polybasic acid is preferably added 35 to 55 parts by weight based on 100 parts by weight of waste PET, when the addition amount of the polybasic acid is less than 35 parts by weight, there is a viscosity gloss problem, if the addition amount exceeds 55 parts by weight of high viscosity Since there is a problem, it is preferable to add a polybasic acid within the above range.

The remaining amount of fatty acid is added and reacted with the polybasic acid. The fatty acid does not need to be added when the total amount is added in the hydrolysis step as described above, and when the part is added in the hydrolysis step, the remaining amount may be added. If the fatty acid is not added in the hydrolysis step, the whole amount can be added. This may be done selectively, but as described above, the total amount of fatty acids may be 80 to 120 parts by weight based on 100 parts by weight of waste PET.

In addition to fatty acids, other additives such as monoacid can be further added for the purpose of molecular weight control, as in the conventional alkyd resin production method. As monoacid, those selected from benzoic acid, butyl tert-butyl benzoic acid, rosin acid, etc. Can be used. The other additive is preferably added 0.15 to 0.25 parts by weight based on 100 parts by weight of waste PET.

As described above, after the polybasic acid and the fatty acid are added to the hydrolyzate obtained in the hydrolysis step and reacted at 240 ± 5 ° C., an alkyd resin is prepared. As the reaction proceeds, the viscosity gradually increases, and the base value gradually decreases. . Therefore, the reaction is terminated when the desired viscosity or base value is reached while measuring the base value and the viscosity.

Alkyd resins prepared in this way have high viscosity and are difficult to handle, so they can be diluted with a solvent. The solvents used for dilution can be selected from those used as diluents in the manufacture of conventional alkyd resins. For example, xylene or methanol Can be used. In addition, a separate filtration process may be performed to filter foreign substances generated in the reaction process, and the alkyd resin thus prepared may be used for various purposes, and may be particularly useful for room temperature drying paints mainly based on alkyd resins. .

Alkyd resins produced by recycling waste PET as described above have the same physical properties as alkyd resins produced by a general method without using waste PET, and accordingly, in the present invention, waste PET can be recycled to contribute to preventing environmental pollution. In addition, there is a useful advantage to reduce the waste of resources by efficiently recycling waste resources.

Hereinafter, the present invention will be described in more detail with reference to the following examples, which are only presented to aid the understanding of the present invention, but the present invention is not limited thereto.

<Example 1>

20 parts by weight of PET ground to 10-20 cm 2, 0.04 parts by weight of lithium hydroxide, 20 parts by weight of soybean oil, and 9 parts by weight of glycerin are placed in a reactor and heated to 240 ± 5 ° C. for hydrolysis. After the reaction was cooled to 100 ° C., 5 parts by weight of terephthalic acid, 0.7 parts by weight of maleic anhydride, and 3 parts by weight of benzoic acid were added, and the reaction temperature was gradually raised to react at 240 ± 5 ° C. for 5 hours. The base value was 8.2 mgKOH / g. It was. After the reaction was completed, the reaction temperature was lowered to 100 ° C., 35 parts by weight of xylene was added, and 3.8 parts by weight of methanol was added at 60 ° C. to dilute the reaction.

In this case, the time required for hydrolysis and the physical properties (total solid content, viscosity, acid value) of the prepared alkyd resin are shown in Table 1 below.

<Example 2>

23 parts by weight of PET ground to 10-20 cm 2, 0.04 parts by weight of lithium hydroxide and 10 parts by weight of glycerin were placed in a reactor and heated at 240 ± 5 ° C. for hydrolysis. When the hydrolysis was completed, the reaction mass was returned to 100 ° C. After cooling, 23 parts by weight of soybean oil, 6 parts by weight of terephthalic acid, 0.9 parts by weight of maleic anhydride, 4 parts by weight of benzoic acid, and 0.04 parts by weight of benzoic acid were added, and the reaction temperature was gradually raised to react at 240 ± 5 ° C. for 5 hours. Thin 8.3 mgKOH / g. After the reaction was completed, the reaction temperature was lowered to 100 ° C., 35 parts by weight of xylene was added, and 3.8 parts by weight of methanol was added at 60 ° C. to dilute the reaction.

In this case, the time required for hydrolysis and the physical properties (total solid content, viscosity, acid value) of the prepared alkyd resin are shown in Table 1 below.

<Example 3>

20 parts by weight of PET ground to 10-20 cm2, 0.04 parts by weight of lithium hydroxide, 18 parts by weight of soybean oil, 10 parts by weight of glycerin, and 2 parts by weight of pentaerythritol were placed in a reactor and heated at 240 ± 5 ° C. When the hydrolysis was completed, the reaction product was cooled to 100 ° C., and then 5 parts by weight of terephthalic acid, 0.7 parts by weight of maleic anhydride and 3 parts by weight of benzoic acid were added, and the reaction temperature was gradually raised to react at 240 ± 5 ° C. for 5 hours. The base value at this time was 8.1 mgKOH / g. After the reaction was completed, the reaction temperature was lowered to 100 ° C., 35 parts by weight of xylene was added, and 3.8 parts by weight of methanol was added at 60 ° C. to dilute the reaction.

In this case, the time required for hydrolysis and the physical properties (total solid content, viscosity, acid value) of the prepared alkyd resin are shown in Table 1 below.

Comparative Example 1

19 parts by weight of soybean oil, 12 parts by weight of pentaerythritol, 10 parts by weight of glycerin, 14 parts by weight of terephthalic acid, 2 parts by weight of maleic anhydride, 6 parts by weight of benzoic acid and 0.04 parts by weight of an additive were added to the reactor, followed by 3 hours at 240 ± 5 ° C. The base value was 8.0 mg KOH / g. After the reaction was completed, the reaction temperature was lowered to 100 ° C., 35 parts by weight of xylene was added, and 3.8 parts by weight of methanol was added at 60 ° C. to dilute the reaction.

division Hydrolysis time Solid content (%) Viscosity (cps) Base value (mgKOH / g) Example 1 90 minutes 60 ± 2 22 ± 5 8.2 Example 2 120 minutes 60 ± 2 20 ± 5 8.3 Example 3 70 minutes 60 ± 2 25 ± 5 8.1 Comparative Example 1 - 60 ± 2 20 ± 5 8.0

As shown in Table 1, in Examples 1 to 3 in which alkyd resins were prepared using waste PET within the preferred range of the present invention, hydrolysis time was short and other physical properties of Comparative Example 1 which prepared alkyd resins in a general manner. It can be confirmed that it has similar physical properties to.

Experimental Example

Maleic acid resin was added to the alkyd resins prepared in Examples 1 to 3 and Comparative Example 1 to prepare a naturally-dried paint. The physical properties (hardening time, workability, coating strength, coating gloss) of the coating thus prepared were evaluated according to the method described in KS M 5601 and the results are shown in Table 2 below.

division Curing time Water resistance Glossiness Workability Example 1 8 hours clear. 94% Good Example 2 8 hours clear 90% Good Example 3 8 hours clear 92% Good Comparative Example 1 8 hours clear 93% Good

As shown in Table 2, in the case of the paint prepared using the alkyd resin prepared according to the present invention, it can be seen that the physical properties of the paint prepared using the alkyd resin prepared by the general method are similar.

As can be seen in Table 1 and Table 2 when the waste PET is recycled according to the present invention to produce alkyd resin has the same physical properties as the alkyd resin prepared by the general method, thus recycling the waste PET as in the present invention Therefore, when manufacturing alkyd resin, waste resources can be efficiently recycled, thus reducing waste of resources, and in particular, it is useful to contribute to preventing environmental pollution.

As described above, the present invention efficiently hydrolyzes waste PET at low temperature to obtain a hydrolyzate, and when the alkyd resin is prepared using the hydrolyzate, it is equivalent to a conventional alkyd resin prepared without using waste PET. It can be seen that it has physical properties, and thus, when producing alkyd resin as in the present invention using waste PET, it is possible to efficiently utilize waste resources, and there is a useful effect that can contribute to the prevention of environmental pollution.

Claims (5)

In the manufacturing method of alkyd resin which makes polyhydric alcohol, polyhydrochloric acid, and a fatty acid react, To the waste PET, a catalyst selected from lithium hydroxide, zirconium hydroxide, or butyltin oxide, liquid polyhydric alcohol and fatty acid is added, and then heated to 240 ± 5 ° C. A hydrolysis step of obtaining a hydrolyzate; A reaction method of adding polybasic acid and the residual amount of fatty acid to the hydrolyzate and reacting at 240 ± 5 ° C. and then cooling the reaction product to produce alkyd resin using waste PET. The method according to claim 1, The catalyst is added 0.1 to 5 parts by weight based on 100 parts by weight of waste PET, 40 to 50 parts by weight of liquid polyhydric alcohol, 35 to 55 parts by weight of polybasic acid and the total amount of fatty acids added in the hydrolysis step and the reaction step. A method for producing an alkyd resin using waste PET, characterized in that it is added so as to be 80 to 120 parts by weight. The method according to claim 1 or 2, The method for producing alkyd resin using waste PET, characterized in that 5 to 20 parts by weight of pentaerythritol is further added to 100 parts by weight of waste PET in the hydrolysis step. The method according to claim 3, The waste PET is a method for producing alkyd resin using waste PET, characterized in that the pulverized to a size of 10 ~ 20 ㎠. An ambient temperature drying paint, comprising alkyd resin produced by the production method of claim 1 as a main ingredient.