JP2002317035A - Method for producing alkyd resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a transparent alkyd resin scarcely producing foreign materials or causing filtration residues by which the distilling off of an alcohol component can be suppressed during production of the resin and the alkyd resin is stably produced in a short time using a recycled polyester resin. SOLUTION: This method for producing the alkyd resin having 5-70% oil length comprises dissolving the recycled polyester resin(PES) and a first polybasic acid component in a mixture or a reactional product of an alcohol component of a <=3-valent polyhydric alcohol and a >=4-valent alcohol in 0.005-20 weight ratio thereof with a first lipid component, depolymerizing the recycled PES in the presence of a depolymerizing catalyst, then adding a second lipid component and a second polybasic acid component, carrying out esterifying reaction and producing the alkyd resin. The amount of the compounded first polybasic acid component is <=2 mol based on 1 mol of the <=3-valent polyhydric alcohol and <=0.5 mol based on 1 mol of the total of the alcohol components and the recycled PES is used in an amount of 5-40 wt.% based on the total of the whole components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing an alkyd resin using a polyester resin recovered and recycled from waste materials such as waste plastic bottles.

[0002]

2. Description of the Related Art Conventionally, the use of terephthalic acid as a dibasic acid, which is a raw material for producing an alkyd resin, is more expensive than the use of phthalic acid or phthalic anhydride. Normally, terephthalic acid was not used in the production of the alkyd resin or was used in a small amount even if it was used because it became turbid or foreign substances were easily generated.

Further, in recent years, disposal of waste has become a problem, and research on utilization of waste plastic bottles by recycling and the like has been conducted.

A method for producing an alkyd resin by using a polyester resin recovered and recycled from waste such as a waste plastic bottle is described in, for example, JP-A-11-228733. The method is a method of depolymerizing and transesterifying the recovered polyester resin with an alkyd resin oligomer having a molecular weight of 5,000 or less and having a hydroxyl group. However, in this method, a step of previously synthesizing the alkyd resin oligomer is required, and the amount of the alcohol component at the time of depolymerization is small, so that the recovered polyester resin is difficult to sufficiently depolymerize, and it is difficult to depolymerize. There is a problem that it takes time, and when the alkyd resin finally obtained is filtered, many filtration residues are generated.

Japanese Patent Application Laid-Open No. 6-9923 discloses a reaction comprising reacting an alcohol with polyethylene terephthalate in the presence of a catalyst, and subsequently reacting the reaction product with an acid and / or an acid anhydride. Non-aqueous coating compositions containing the product are described. However, in producing a reaction product, first, in the presence of a catalyst, an alcohol is reacted with polyethylene terephthalate,
The alcoholysis reaction of polyethylene terephthalate is performed.At this time, it is necessary to distill alcohol such as ethylene glycol together with the condensed water, and to add the distilled alcohol to the system. There are problems such as an increase and an increase in manufacturing time.

An object of the present invention is to use a polyester resin recovered from waste and regenerated, which is transparent, hardly generates foreign matter and has little filtration residue, and can suppress the distillation of alcohol during the alcoholysis reaction, and An object of the present invention is to provide a method for producing an alkyd resin which can be performed in a short time.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, this time, a mixture or an esterified product of an alcohol component containing a polyhydric alcohol or more and an oil or fat, The present inventors have found that the above object can be achieved by dissolving a polyester resin and a predetermined amount of a polybasic acid recovered from waste and regenerating a predetermined amount of polybasic acid, and then adding the remaining polybasic acid component to carry out an esterification reaction to complete the present invention. It led to.

That is, the present invention is selected from alcohol components, fats and oils and fatty acids in which the former / latter weight ratio of a polyhydric alcohol having a valency of 3 or less to an alcohol having a valency of 4 or more is in the range of 0.005 to 20. In a mixture or a reaction product with at least one kind of first lipid component, a regenerated polyester resin mainly containing terephthalic acid recovered from waste and regenerated and a first polybasic acid component are dissolved and depolymerized. A method for producing an alkyd resin by depolymerizing in the presence of a catalyst, and then subjecting it to an esterification reaction by adding a second lipid component and a second polybasic acid component, which are at least one selected from fats and oils and fatty acids, The amount of the first polybasic acid component is 2 mol or less based on 1 mol of the trihydric or lower polyhydric alcohol and 0.5 mol or less based on the total of 1 mol of the alcohol component. And the amount of the regenerated polyester resin is 5 to 40% by weight based on the total of the regenerated polyester resin, the alcohol component, the first and second lipid components, and the first and second polybasic acid components. The present invention provides a method for producing an alkyd resin having an oil length of 5 to 70%.

The present invention also provides a coating composition containing the alkyd resin produced by the above method. Hereinafter, the production method of the present invention will be described in detail.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A recycled polyester resin (hereinafter sometimes abbreviated as “recycled PES”) which is used in the method of the present invention and is mainly made of terephthalic acid recycled from wastes is used as a resource. Polyester products such as polyethylene terephthalate (eg, PET bottles) collected for recycling, polyethylene terephthalate, industrial waste, and polyethylene terephthalate and polybutylene terephthalate made mainly of terephthalic acid And the like. Polyester resins recycled from scraps generated during the production of parts and the like are included, and recycled polyethylene terephthalate is particularly preferred. This regenerated PES is usually used in the form of chips or pulverized material.

In the method of the present invention, first, a mixture or a reaction product of an alcohol component containing an alcohol having a valency of 4 or more and a polyhydric alcohol having a content of 3 or less and at least one lipid component selected from fats and oils and fatty acids is used. In addition, the reproduction P
The ES and the first polybasic acid component are dissolved, and depolymerization is performed in the presence of a depolymerization catalyst.

Examples of the alcohol having a valency of 4 or more in the alcohol component include alcohols having a valency of 4 or more such as diglycerin, triglycerin, pentaerythritol, dipentaerythritol, and sorbitol. This is preferred from the viewpoint of curing and drying properties of the coating film when the obtained alkyd resin is used as a coating material. Examples of the trihydric or lower polyhydric alcohol include, for example, trimethylolpropane, trimethylolethane,
Trihydric alcohols such as glycerin; for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6- Hexanediol, 1,4-dimethylolcyclohexane and the like can be mentioned, and among them, glycerin, ethylene glycol, diethylene glycol and triethylene glycol are mixed with the above-mentioned tetravalent or higher alcohol (for example, pentaerythritol). It is suitable from the viewpoints of depolymerizability at the time of use and the ability to dissolve a high melting point tetravalent or higher alcohol at a low temperature.

In the above alcohol component, the mixing ratio of the trihydric or lower polyhydric alcohol to the tetrahydric or higher alcohol is 0.005 to 20, preferably 0.02 to 10, more preferably 0.02 to 10 by weight. Is preferably in the range of 0.05 to 5 in view of the depolymerization property of the regenerated PES and the drying property of the obtained alkyd resin.

The fat or oil which is one of the first lipid components mixed or esterified with the alcohol component is a triglyceride of a fatty acid, and specific examples thereof include soybean oil, safflower oil, linseed oil, and tall oil. Examples include oil, coconut oil, palm kernel oil, castor oil, dehydrated castor oil, fish oil, tung oil and the like. As the fats and oils, drying oils or semi-drying oils having an iodine value of 90 or more are preferable, and soybean oil and tall oil are particularly preferable.

The fatty acid which is one of the first lipid components mixed or reacted with the alcohol component includes, for example,
Soybean oil fatty acids, safflower oil fatty acids, linseed oil fatty acids,
Tall oil fatty acids, coconut oil fatty acids, palm kernel oil fatty acids, castor oil fatty acids, dehydrated castor oil fatty acids, fish oil fatty acids, tung oil fatty acids, and the like. As the fatty acid, drying oil fatty acids or semi-dry oil fatty acids having an iodine value of 90 or more are preferable, and soybean oil fatty acids and tall oil fatty acids are particularly preferable.

The mixing ratio of at least one first lipid component selected from the above fats and oils and fatty acids is usually 5 to 5 based on the sum of the first lipid component and the first lipid component described below.
It is preferably in the range of 80% by weight, preferably in the range of 10 to 60% by weight, from the viewpoints of the curability and pigment dispersibility of the paint when the obtained alkyd resin is made into a paint, and the toughness of the resulting coating film. It is.

In the method of the present invention, the reaction product of the alcohol component and the first lipid component includes both a reaction product by a normal esterification reaction and a reaction product by a transesterification reaction. When an alcohol component is reacted with a fatty acid, an esterification reaction usually occurs. When an alcohol component is reacted with a fat or oil, a transesterification reaction usually occurs.

The reaction between the alcohol component and the first lipid component can be suitably carried out by a method known per se in the presence of an esterification reaction catalyst such as zinc acetate, litharge, dibutyltin oxide and the like.

The amount of the regenerated PES mixed in the mixture or the reaction product of the alcohol component and the first lipid component is determined by the amount of the regenerated PES, the alcohol component, the first lipid component, and the first polybasic acid component. Suitably, it is in the range of 7 to 80% by weight, preferably 10 to 70% by weight, based on the total. Here, "the regenerated PES, the alcohol component, and the first
The sum of the lipid component and the first polybasic acid component ”means that when the regenerated PES is blended in the reaction product, the regenerated PES is reconstituted into the sum of the alcohol component and the first lipid component, which are the raw materials of the reaction product. PE
It means the total amount of S and the first polybasic acid component.

[0020] In the mixture or reaction product of the alcohol component and the first lipid component, the first component to be blended together with the regenerated PES.
As the polybasic acid component, polybasic acids usually used as an acid component constituting an alkyd resin can be used in the same manner, for example, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and anhydride. Maleic acid,
Succinic anhydride, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid,
Dibasic acids such as diphenylmethane-4,4'-dicarboxylic acid, fumaric acid, adipic acid, and sebacic acid; tribasic or higher polybasic acids such as trimellitic anhydride, pyromellitic anhydride, trimesic acid, and methylcyclohexentricarboxylic acid And the like. Among them, one or a combination of two or more of phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride and trimellitic anhydride is preferable.

The amount of the first polybasic acid component is 2 mol or less, preferably 0.1 to 1 mol, based on 1 mol of the trivalent or less alcohol, and the total amount of the alcohol component is 1 to 1 mol. 0.5 mol or less, preferably 0.
The amount is in the range of 01 to 0.3 mol.

In the method of the present invention, the regenerated PES is used in the presence of a depolymerization catalyst which is a catalyst for accelerating the depolymerization of the regenerated PES.
The ES is depolymerized. Representative examples of the depolymerization catalyst include, for example, monobutyltin hydroxide, dibutyltin oxide, monobutyltin-2-ethylhexanoate, dibutyltin dilaurate, stannous oxide, tin acetate,
Examples thereof include zinc acetate, manganese acetate, cobalt acetate, calcium acetate, lead acetate, antimony trioxide, tetrabutyl titanate, and tetraisopropyl titanate. The amount of these depolymerization catalysts used depends on the above-mentioned recycled PE
Usually, 0.005 parts by weight based on 100 parts by weight of S, alcohol component, first lipid component and first polybasic acid component in total.
It is preferred that it is in the range of ５5 parts by weight.

In the method of the present invention, (1) a mixture of an alcohol component and a first lipid component, a regenerated PES and a first polybasic acid component are mixed and dissolved to perform depolymerization, or (2) The reaction product of the alcohol component and the first lipid component, the regenerated PES, and the first polybasic acid component may be mixed and dissolved to perform depolymerization.

The conditions for depolymerizing the regenerated PES are not particularly limited as long as the depolymerization can be performed using a depolymerization catalyst. For example, an alcohol component heated to 80 to 220 ° C. A regenerated PES and a first polybasic acid component are added to a mixture of a mixture or a reaction product with a lipid component and a mixture of a depolymerization catalyst, and the mixture is heated to, for example, 140 to 2.
Dissolution and depolymerization at 60 ° C. can be mentioned.

In the method of the present invention, after the regenerated PES is dissolved and depolymerized, at least one of a second lipid component and a second polybasic acid component selected from fats and oils and fatty acids is added thereto. In addition, an alkyd resin is obtained by an esterification reaction. In the present invention, the "esterification reaction" includes not only a normal esterification reaction,
"Transesterification" is also intended to be included.

In the above-mentioned esterification reaction, the second lipid component blended with the second polybasic acid component includes:
Those which can be used as the first lipid component can be similarly used.

By blending the second lipid component during the esterification reaction, the amount of the first lipid component mixed or reacted with the alcohol component before the depolymerization reaction can be reduced. Can be performed efficiently. The amount of the second lipid component in the esterification reaction is such that the total amount of the first lipid component and the second lipid component is such that the oil length of the obtained alkyd resin is 5 to 70.
%, Preferably within a quantitative range of 30 to 70%, from the viewpoints of the drying properties of the coating film and the physical properties of the coating film in the case of a dried coating film.

In the esterification reaction performed after the depolymerization reaction of the regenerated PES, the second polybasic acid component used together with the second lipid component is usually used as an acid component constituting an alkyd resin. Polybasic acids can be used, for example, phthalic anhydride, isophthalic acid,
Terephthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, naphthalenedicarboxylic acid, 4,4'-
Biphenyldicarboxylic acid, diphenylmethane-4,4 '
-Dibasic acids such as dicarboxylic acid, succinic acid, fumaric acid, adipic acid, sebacic acid, and maleic anhydride; trivalent or higher polybasic acids such as trimellitic anhydride, pyromellitic anhydride, trimesic acid, and methylcyclohexene carboxylic acid Acids; lower alkyl esters of these dibasic acids or tribasic or higher polybasic acids; Of these, dibasic acids and lower alkyl esters thereof are preferred.

Recycled PE constituting the alkyd resin
The regenerated PES is used in an amount of 5 to 40% by weight, in particular 10 to 35% by weight, based on the sum of S, alcohol component, first and second lipid components and first and second polybasic acid components. Is preferred.

Further, the equivalent number of carboxyl groups of the first polybasic acid component and the second polybasic acid component is 0.5 to 1.0 with respect to 1 equivalent of the hydroxyl group of the alcohol component.
Preferably, it is in the range of 0.6 to 0.99 from the viewpoints of water resistance and physical properties of the dried coating film. The above "carboxyl group of polybasic acid component"
In the case where the polybasic acid component is a lower alkyl ester of a polybasic acid, it is converted to a carboxyl group generated by hydrolyzing the ester.

The esterification reaction for obtaining the alkyd resin can be carried out under esterification reaction conditions known per se. For example, the second polybasic acid component and the second After blending the lipid components of 2, the esterification reaction (dehydration, condensation or transesterification) is carried out at a temperature of about 180 to 260 ° C. for about 3 to 10 hours in the presence of an esterification reaction catalyst. Can be. Examples of the esterification reaction catalyst include those exemplified as the depolymerization catalyst. The amount of the esterification reaction catalyst is preferably in the range of 0.005 to 5% by weight based on the above system.

In the production of alkyd resin, recycled PES
By adding a small amount of a phosphorus compound to the product after depolymerization of the above and performing an esterification reaction, the resulting alkyd resin can be suppressed from being colored. Examples of the phosphorus compound include phosphoric acid, phosphorous acid, and hypophosphorous acid; and alkyl esters or phenyl esters of these acids (for example, trimethyl phosphite, trimethyl phosphate, triphenyl phosphite, triphenyl phosphate, and the like). And the like.

After the completion of the esterification reaction, the alkyd resin is
Usually, it can be taken out as it is after cooling, but it can be taken out by diluting it with an organic solvent in order to improve filterability and handling workability. The type of the organic solvent,
There is no particular limitation as long as it can dissolve the alkyd resin.

The alkyd resin obtained by the method of the present invention has excellent solubility in an organic solvent and can be dissolved in a weak solvent such as mineral spirits despite containing a terephthalic acid component. It is useful as a resin binder in a coating composition. In recent years, alkyd resins that can be dissolved in a weak solvent have been used more and more, and alkyd resins obtained by the method of the present invention are suitable for this purpose.

The alkyd resin obtained by the method of the present invention has an oil length of 5 to 70%, particularly 30 to 70%; a number average molecular weight of 1,000 to 12,000, particularly 1,500 to 1,
0000; hydroxyl value is 10 to 150 mgKOH / g,
Especially 15 to 130 mg KOH / g; acid value is 1 to 50 mg
It is preferably in the range of KOH / g, especially 3 to 20 mg KOH / g.

The alkyd resin obtained by the method of the present invention, which uses a drying oil or a semi-drying oil as a fat or oil, has excellent oxidative drying properties, and can be suitably used as a resin for a room temperature-curable paint. When used as a cold-setting resin, the drying property can be improved by using a metal compound dryer such as cobalt naphthenate, zirconium naphthenate and lead naphthenate together. The alkyd resin obtained by the method of the present invention, in particular, an alkyd resin having a short oil length, an alkyd resin obtained by using a saturated fatty acid as a fatty acid, reacts with an amino resin such as a melamine resin, a polyisocyanate compound, and a hydroxyl group such as an epoxy compound. It can be suitably used as a resin for thermosetting paints in combination with a curing agent having a property. The coating composition containing the alkyd resin obtained by the method of the present invention can be produced by a method known per se, except that the alkyd resin is used as at least a part of the resin binder.

[0037]

The present invention will be described more specifically with reference to the following examples. Hereinafter, “parts” and “%” are based on weight, respectively.

Example 1 149 parts of pentaerythritol, 30 parts of ethylene glycol and 260 parts of soybean oil fatty acid were charged into a reactor equipped with a thermometer, a stirrer, a heating device and a rectification column, and the temperature was raised to 140 ° C. with stirring. did. 5.0 parts of dibutyltin oxide, 5.0 parts of zinc acetate, 150 parts of recycled polyethylene terephthalate (recycled PET) and 30 parts of phthalic anhydride were charged therein, and then the temperature was raised to 235 ° C.
The depolymerization of the regenerated PET was performed while keeping the time. Alcohol was not distilled off in this step. Next, temperature 180
℃ 180, phthalic anhydride 180 parts and soybean oil fatty acid 2
After charging 61 parts, the temperature was raised to 180 ° C., the temperature was raised to 240 ° C. over 3 hours while dehydrating, and maintained at the same temperature for 1 hour, 50 parts of xylene was added for reflux, and the dehydration condensation reaction was further performed at the same temperature. Was done. Then cool and mineral spirits 62
The dilution was carried out by adding 0 parts to obtain an alkyd resin solution having a nonvolatile content of about 60%.

Example 2 119 parts of pentaerythritol, 30 parts of ethylene glycol, 170 parts of soybean oil fatty acid and 92 parts of soybean oil were charged into a reactor equipped with a thermometer, a stirrer, a heating device and a rectification column, and stirred. The temperature was raised to 140 ° C. 5.0 parts of dibutyltin oxide, 5.0 parts of zinc acetate, 150 parts of recycled polyethylene terephthalate (recycled PET) and 30 parts of phthalic anhydride were charged therein, and then heated to 235 ° C. and maintained at the same temperature for 2 hours. Then, depolymerization of the recycled PET was performed. Alcohol was not distilled off in this step.
Next, the mixture was cooled to a temperature of 180 ° C, and 177 parts of phthalic anhydride was added.
Charged 177 parts of soybean oil fatty acid and 92 parts of soybean oil, 18
After the temperature was raised to 0 ° C., the temperature was raised to 240 ° C. over 3 hours while dehydrating, and maintained at the same temperature for 1 hour, 50 parts of xylene was added for reflux, and a dehydration condensation reaction was performed at the same temperature. Then, the mixture was cooled and diluted by adding 610 parts of mineral spirits to obtain an alkyd resin solution having a nonvolatile content of about 60%.

Example 3 89 parts of pentaerythritol, 30 parts of ethylene glycol and 270 parts of soybean oil were charged into a reactor equipped with a thermometer, a stirrer, a heating device and a rectification column, and stirred.
The temperature was raised to 40 ° C. 5.0 parts of litharge and 5.0 parts of zinc acetate were charged therein, and the temperature was raised to 230 ° C.
The transesterification reaction of soybean oil was performed while keeping the time. Next, the mixture is cooled to a temperature of 180 ° C., charged with 150 parts of recycled polyethylene terephthalate (recycled PET) and 30 parts of phthalic anhydride, and then heated to 235 ° C. and kept at the same temperature for 2 hours to depolymerize the recycled PET. Was. Alcohol was hardly distilled off in this step. Next, the mixture was cooled to a temperature of 180 ° C., 207 parts of phthalic anhydride and 270 parts of soybean oil were charged, and the temperature was raised to 180 ° C.
After the temperature was raised to 0 ° C. and maintained at the same temperature for 1 hour, 50 parts of xylene was added for reflux, and a dehydration condensation reaction was further performed at the same temperature. Then, the mixture was cooled and diluted by adding 610 parts of mineral spirits to obtain an alkyd resin solution having a nonvolatile content of about 60%.

Example 4 An alkyd resin solution having a nonvolatile content of 60% was obtained in the same manner as in Example 1 except that 2.0 parts of trimethyl phosphate was added after depolymerization of the recycled PET.

Comparative Example 1 149 parts of pentaerythritol, 30 parts of ethylene glycol and 260 parts of soybean oil fatty acid were charged into a reactor equipped with a thermometer, a stirrer, a heating device and a rectification column, and the temperature was raised to 140 ° C. with stirring. did. After 5.0 parts of dibutyltin oxide, 5.0 parts of zinc acetate, and 150 parts of recycled polyethylene terephthalate (recycled PET) were charged therein,
Heated to 235 ° C and kept at the same temperature for 2 hours to make recycled PET
Was depolymerized. In this step, distillation of about 1.5 parts of ethylene glycol other than the condensed water was observed. Then temperature 1
After cooling to 80 ° C., 210 parts of phthalic anhydride, 261 parts of soybean oil fatty acid, and 1.5 parts of ethylene glycol (distilled alcohol-corrected portion) were charged, and the temperature was raised to 180 ° C. Temperature up to ℃
After keeping for a time, 50 parts of xylene was added for reflux, and a dehydration condensation reaction was further performed at the same temperature. Then, the mixture was cooled and diluted by adding 620 parts of mineral spirits to obtain an alkyd resin solution having a nonvolatile content of about 60%.

Comparative Example 2 A reactor equipped with a thermometer, stirrer, heating device and rectification column was charged with 119 parts of pentaerythritol, 30 parts of ethylene glycol, 170 parts of soybean oil fatty acid and 92 parts of soybean oil, and stirred. The temperature was raised to 140 ° C. 5.0 parts of dibutyltin oxide, 5.0 parts of zinc acetate and 150 parts of recycled polyethylene terephthalate (recycled PET) were charged therein, and the temperature was raised to 235 ° C. and maintained at the same temperature for 2 hours to dissolve the recycled PET. Polymerization was performed. In this step, distillation of about 1.5 parts of ethylene glycol other than the condensed water was observed. Next, the mixture was cooled to a temperature of 180 ° C.
Parts, 177 parts of soybean oil fatty acid, 92 parts of soybean oil and 1.5 parts of ethylene glycol (distilled alcohol-corrected part), heated to 180 ° C., and dehydrated for 2 hours over 3 hours.
After the temperature was raised to 40 ° C. and maintained at the same temperature for 1 hour, 50 parts of xylene was added for reflux, and a dehydration condensation reaction was performed at the same temperature. Then, the mixture was cooled and diluted by adding 610 parts of mineral spirits to obtain an alkyd resin solution having a nonvolatile content of about 60%.

Comparative Example 3 89 parts of pentaerythritol, 30 parts of ethylene glycol and 273 parts of soybean oil were charged into a reactor equipped with a thermometer, a stirrer, a heating device, and a rectification column, and stirred while stirring.
The temperature was raised to 40 ° C. 5.0 parts of litharge and 5.0 parts of zinc acetate were charged therein, and the temperature was raised to 190 ° C.
The transesterification reaction of soybean oil was performed while keeping the time. No alcohol was distilled off in this step. Next, the temperature was cooled to 180 ° C., and 150 parts of recycled polyethylene terephthalate (recycled PET) was charged.
The temperature was raised to the same temperature and maintained at the same temperature for 2 hours to depolymerize the recycled PET. In this step, distillation of about 1.5 parts of ethylene glycol other than the condensed water was observed. Next, the mixture was cooled to a temperature of 180 ° C., and 237 parts of phthalic anhydride, 273 parts of soybean oil, and ethylene glycol (distilled alcohol corrected component)
Charge 1.5 parts, raise the temperature to 180 ° C,
After the temperature was raised to 240 ° C. over a period of time and maintained at the same temperature for 1 hour, 50 parts of xylene was added for reflux, and a dehydration condensation reaction was further performed at the same temperature. Then, the mixture was cooled and diluted by adding 610 parts of mineral spirits to obtain a nonvolatile content of about 60%.
Alkyd resin solution was obtained.

In each of Comparative Examples 1 to 3, when ethylene glycol (distilled ethylene glycol-corrected component) was not added, the resin had a high molecular weight, and Gardner of an alkyd resin solution having a nonvolatile content of about 60% was used. both the viscosity becomes Z ₅ or more high viscosity was achieved, there is no practical difficulty handling.

[0046]

[Table 1]

Test Examples 1 to 4 and Comparative Test Examples 1 to 3 Production of Paint Composition and Preparation of Test Coated Plate Nonvolatile content 60 obtained in Examples 1 to 4 and Comparative Examples 1 to 3 above.
% Alkyd resin solution (166.7 parts) and 5% cobalt naphthenate solution (0.6 parts) and 12% zirconium naphthenate solution (2.5 parts) were mixed to obtain each clear paint.

Each of the obtained clear paints was applied to a tin plate so as to have a dry film thickness of 100 μm, and the touch drying time and the curing drying time when allowed to stand still in a room at a temperature of 20 ° C. and a humidity of 60% RH. Was measured. The hardness of the cured and dried coating film was measured with a Koenig pendulum hardness meter. The test results are shown in Table 2 below.

[0049]

[Table 2]

As is clear from Table 2 above, Examples 1 to
In each test example of the clear paint using the alkyd resin solution of No. 4, the test results of the touch drying time and the hardening and drying time of the paint and the hardness of the hardened and dried coating film were as follows. The result was equivalent to the result in each comparative test example of the paint. That is, according to the present invention, the target alkyd resin can be produced without adding ethylene glycol for correcting the distilled ethylene glycol during the production of the alkyd resin.

[0051]

According to the production method of the present invention, it is possible to suppress the distillation of alcohol during the alcoholysis reaction of regenerated PES by using the polyester resin recovered from waste.
It is possible to produce an alkyd resin which is transparent and has little generation of foreign substances and little filtration residue in a short time and stably.
The method of the present invention can be used for recycling waste pet bottles and the like in order to utilize waste.

The alkyd resin obtained by the method of the present invention can be suitably used as a resin for thermosetting paint oil in combination with a resin for cold-setting paint or a curing agent. The alkyd resin obtained by the method of the present invention can be a transparent and non-turbid resin despite containing a terephthalic acid component, and can be dissolved in a weak solvent such as mineral spirits. is there. For this reason, it can be suitably used as a coating resin for applications requiring repaintability.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4J029 AA01 AB04 AD01 AD02 AD03 AD04 CB03A CB04A CB05A CB06A CB10A CC05A FB01 FC02 FC03 FC04 FC05 FC07 FC08 JE162 4J038 DD121 DD131 DD141 DD151 HA216 HA286 HA296 JC00 LA0227

Claims (9)

[Claims] An alcohol component having a former / latter weight ratio of a polyhydric alcohol having a valency of 3 or less and an alcohol having a valency of 4 or more within a range of 0.005 to 20, and at least one selected from fats and oils and fatty acids. In a mixture or a reaction product with a certain first lipid component, a regenerated polyester resin whose main raw material is terephthalic acid recovered from waste and regenerated, and a first polybasic acid component are dissolved, and the mixture is dissolved in the presence of a depolymerization catalyst. A method of producing an alkyd resin by adding a second lipid component, which is at least one selected from fats and oils and fatty acids, and a second polybasic acid component, followed by an esterification reaction, The compounding amount of the first polybasic acid component is 2 mol or less based on 1 mol of the above-mentioned trihydric or lower polyhydric alcohol and 0.5 mol or less based on 1 mol of the total of the alcohol components. The use of the regenerated polyester resin in an amount of 5 to 40% by weight based on the total of the raw polyester resin, the alcohol component, the first and second lipid components, and the first and second polybasic acid components. Characteristic oil length 5
A method for producing ７０70% alkyd resin. 2. A reaction product of an alcohol component and a lipid component,
2. The method according to claim 1, wherein the alcohol component and the lipid component are mixed and dissolved, and reacted in the presence of a catalyst. 3. The method according to claim 1, wherein the regenerated polyester resin is used in an amount of 7 to 80% by weight based on the total of the regenerated polyester resin, the alcohol component and the first lipid component. Manufacturing method. 4. The method according to claim 1, wherein the blending ratio of the polyhydric alcohol having a valency of 3 or less and the alcohol having a valency of 4 or more in the alcohol component is in the range of 0.02 to 10 in terms of the former / the latter weight ratio. Item 4. The production method according to any one of Items 1 to 3. 5. The method according to claim 1, wherein the alcohol having a valency of 4 or more is pentaerythritol. 6. The method according to claim 1, wherein the trivalent or lower polyhydric alcohol is at least one alcohol selected from ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and glycerin. The manufacturing method as described. 7. The polybasic acid charged into the system together with the recycled polyester resin is phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride,
7. It is one or a combination of two or more of succinic anhydride and trimellitic anhydride.
The production method according to any one of the above. 8. The method according to claim 1, wherein the recycled polyester resin is recycled polyethylene terephthalate or recycled polybutylene terephthalate. 9. A coating composition containing an alkyd resin produced by the production method according to any one of claims 1 to 8.