KR100803587B1 - How to recycle waste polyester to produce useful materials for industrial use - Google Patents

Abstract

The present invention is to prepare a polyester resin having a dimethyl 5-sulfoisophthalate sodium salt (abbreviated as DMSSIP) component having a function of depolymerizing waste polyester, and to add waste polyester to depolymerization to depolymerize waste polyester. Provided is a method for producing a polyester resin composition comprising a water-soluble polyester resin composition having a low softening point and a low melt viscosity by subjecting a softening point to a polycondensation reaction accompanied by an ester exchange reaction.

The polyester resin composition prepared according to the present invention is water-soluble and water-dispersible, and has a surface active function to make a resin solution dissolved in water, and to which a colorant, an additive, etc. is added, an electrophotographic, electronic recording developer, inkjet ink It can be used as a binder such as textile processing agent and coating agent as stock solution of resin aqueous solution. On the other hand, the solid resin relates to a method for producing a polyester resin, which is a raw material resin composition to be used as a toner for electrostatic image development, a powder paint, and an adhesive agent made by a pulverization method. According to the present invention, high value-added high-performance materials can be produced environmentally and economically by recycling waste resources.

Description

Recycling waste polyester to produce useful materials for industrial use {omitted}

The present invention generally refers to polyethylene terephthalate (hereinafter referred to as PET), in particular, dimethyl 5-sulfoisophthalate sodium salt which physically grinds waste PET molded articles, waste PET fibers, waste PET film and the like and depolymerizes. A polyester resin containing an alkali metal salt of sulfonic acid alkali metal salt of an aromatic dicarboxylic acid, which is abbreviated as DMSSIP), and a polyester resin composition which is capable of depolymerizing waste PET and carrying out polycondensation with an ester exchange reaction. It relates to a method for producing a polyester resin composition having good compatibility, solubility, and dispersibility.

Recently, polyester resins have excellent physical properties such as heat resistance, processability, transparency, and non-toxicity, compared to other resins, and thus are widely used in household goods and industrial products. On the other hand, many of these wastes have been generated, and their disposal has become a social problem and environmental problems are serious. Although these wastes are designated as recyclables by the Waste Management Act, they are only physically remelted to produce pictographs. Therefore, the quality of recycled products was not expected to meet the needs of consumers, and the amount of recycling was extremely limited.

The present inventors earnestly studied to solve the problem (1) polyester containing sulfonate alkali metal salt of aromatic dicarboxylic acid containing dimethyl 5-sulfoisophthalate sodium salt (abbreviated as DMSSIP) which functions as a depolymerization function. Preparing a resin; (2) adding a resin of step (1) to the waste polyester to depolymerize and polycondensation with an ester exchange reaction to prepare a polyester resin composition having a low softening point and a low melt viscosity; (3) preparing an aqueous solution composition obtained by dissolving the resin composition of step (2) in (A) water, (B) preparing a liquid composition dissolved in a water-compatible solvent, or (C) preparing a resin composition in a bulk state. It provides a method for producing a polyester resin composition characterized in that it comprises a step.

The present invention provides an electrophotographic developer, inkjet ink, powder coating, adhesive, water-soluble fiber processing agent, and a method for producing a resin composition for a coating containing a polyester resin composition obtained by recycling waste PET.

The present invention provides a polyester resin containing an alkali metal salt of sulfonic acid alkali metal salt of aromatic dicarboxylic acid, which comprises (1) dimethyl 5-sulfoisophthalate sodium salt (abbreviated as DMSSIP) having a depolymerization function: (2) Adding the resin of step (1) to the waste polyester to depolymerize and polycondensation accompanied with the ester exchange reaction to prepare a water-soluble polyester resin composition; And (3) the resin composition of step (2) is prepared from (A) an aqueous solution composition dissolved in water, (B) a liquid composition dissolved in a water-compatible solvent, or (C) a resin composition in a bulk state. It provides a method for producing a polyester resin composition comprising the step of.

DMSSIP used in polyester resins containing alkali metal salts of sulfonic acid alkali metal salts of aromatic dicarboxylic acids, including dimethyl 5-sulfoisophthalate sodium salt (abbreviated as DMSSIP), which has a depolymerization function which can be used in step (1) It is preferable to use 1-30 weight% with respect to monomer whole quantity.

Polybasic acids include phthalic anhydride, maleic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalate, dimethyl isophthalate, adipic acid, tetrahydrophthalic anhydride, trimellitic anhydride, trimellitic anhydride, pyromellitic anhydride, succinic acid and cyclohexane It is preferable to select from dicarboxylic acid and naphthalenedicarboxylic acid group, and to use it individually or in mixture in the quantity of 10 to 90 weight% with respect to monomer whole quantity. The polyhydric alcohols that can be used in step (1) are ethylene glycol, propylene glycol, diethylene glycol, 1,3-propendiol, 1,3-butanediol, neopentyl glycol, bisphenol A alkylene oxide adducts, trimethylolpropane , Glycerin, pentaerythritol and the like. These may be used alone or in combination. It is preferable to add these addition amounts in the quantity of 10 to 90 weight% with respect to monomer whole quantity. The polycondensation catalyst is a monobutyltin compound and the amount of the polycondensation catalyst is preferably used in an amount of 0.05 to 1.0% by weight based on the total amount of the monomers.

PET that can be used in step (2) is generally a polymer synthesized from terephthalic acid and ethylene glycol, it is preferable to use a chip physically pulverized various waste PET, such as waste PET molded articles, waste PET fibers, waste PET film.

The water affinity solvents usable in step (3) are alcohols, acetone, diacetone alcohol, dimethylformamide, dimethylacetamide, ethylcellsolve, butylcellsolve, tetrahydrofuran, N-methyl-2pyrrolidone, and the like. These can be used individually or in mixture. It is preferable to use 10 to 100% by weight based on the product of step (2).

The present invention is a polyester containing sulfonate alkali metal salts of aromatic dicarboxylic acid, including dimethyl 5-sulfoisophthalate sodium salt (abbreviated as DMSSIP), which is pulverized in a reactor and chipped into waste chips and depolymerizes. Add resin and depolymerize at 190 ~ 270 ℃. A polyester resin containing a water-soluble polyester resin composition having a softening point of 80 to 150 ° C. and a weight average molecular weight of 3,000 to 50,000 is produced. The polyester resin composition obtained by this invention is used as an electrophotographic developer, inkjet ink, powder coating, adhesive agent, water-soluble fiber processing agent, and binder resin composition for coating agents. For example, the produced polyester resin composition may be formed of an electrophotographic developer, an inkjet ink, a fiber processing agent, an adhesive, or a film coating agent in the state of an aqueous solution of a water-soluble polyester resin of 10 to 70% by weight of solids dissolved in water. It can be used as a binder. Alternatively, the resultant polyester resin composition may be used as a binder for an electrophotographic developer, an inkjet ink, an adhesive, or a film coating agent in the state of a polyester resin solution having a solid content of 10 to 70% by weight dissolved in a water-compatible solvent. The electrophotographic developer made using the polyester resin composition of the present invention is a toner made by a polymerization method or a pulverization method by adding a colorant, a charge agent, a mold release agent, and the like. Toner can be produced.

The inkjet ink made by using the polyester resin composition obtained in the present invention is a inkjet ink made by mixing a colorant, a water affinity solvent, a dispersant, a wetting agent, and dispersing with a high-speed disperser and filtering using a filter of 1 μm or less. It is possible to produce high quality inkjet inks that are vivid, permeable to the media and free of smearing.

Powder coating made by using the polyester resin composition obtained in the present invention is a powder coating of the present invention using a curing agent as an epoxy resin to form a coating film by mechanically pulverizing by adding a colorant, a curing agent, an anti-agglomerating agent and the like to form a coating film. The polyester resin for resin has a softening point of 95 ~ 105 ℃, glass transition temperature of 55 ℃ ~ 65 ℃, low melt viscosity, and low curing temperature of 180 ℃, so it has good flowability and has excellent coating appearance, heat resistance, chemical resistance, water resistance, solvent resistance. In accordance with the present invention, a powder coating having excellent weather resistance and adhesion is a powder coating characterized by low curing temperature and curing in a short time.

The hot melt adhesive produced using the polyester resin composition obtained by the present invention has good compatibility, low softening point, low melt viscosity, and thus has good adhesion to paper, textiles, leather, wood, plastics, metals, and the like. Can be.

The water-soluble fiber processing agent and the coating agent produced using the water-soluble polyester resin composition obtained by the present invention are excellent in adhesiveness, flexibility, permeability, and water resistance, and are also harmless to the human body and economical because they can be diluted and washed with water. Phosphorus products can be prepared. The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention.

<Production example 1>                     

Into a reactor equipped with a stirrer, a reflux cooler, a thermometer, and a nitrogen inlet, 400 g of dimethyl terephthalate, 50 g of DMSSIP, 100 g of neopentyl glycol, 200 g of bispentol Aethylene oxide adduct, and 0.5 g of butyl tin oxide were heated at 180 ° C. under a nitrogen stream. The reaction was carried out for 3 hours to confirm that the metaol leaked out to remove it, the temperature was raised to 220 ℃ to reduce the vacuum to remove the effluent while continuing the polycondensation reaction for 5 to 7 hours to prepare a polyester resin composition. This polyester resin composition is Tg 59 degreeC, softening point 101 degreeC, and weight average molecular weight 5,000.

<Production example 2>

Into a reactor equipped with a stirrer, a reflux cooler, a thermometer, and a nitrogen inlet, 200 g of dimethyl terephthalate, 200 g of dimethyl isophthalate, 45 g of DMSSIP, 160 g of ethylene glycol, and 0.5 g of butyl tin oxide were heated at 180 to 220 ° C. under nitrogen stream for 3 hours. After the reaction was carried out to remove the methanol, the bisphenol A propylene oxide was added to 100g of water and vacuum reduced at 230 ~ 250 ℃ to polycondensation reaction for 5 to 7 hours to prepare a polyester resin composition. This polyester resin composition is Tg 57 degreeC, softening point 103 degreeC, and weight average molecular weight 6,000.

<Example 1>

In a reactor equipped with a stirrer, a reflux cooler, a thermometer, and a nitrogen inlet, 200g of waste PET chips and 200g of <Production Example 1> were placed in a reactor and depolymerized at 200-250 ° C for 1 to 3 hours under nitrogen stream, followed by ester exchange. A polycondensation reaction is carried out to produce a polyester resin composition. This polyester resin composition is Tg 65 degreeC, softening point 115 degreeC, weight average molecular weight 11,000, outflow start temperature (Tfb) 121 degreeC, and outflow end point (Tend) 141 degreeC.

The electrostatic charge developing toner is prepared by the pulverization method using the resin composition as follows. 100 parts by weight of the resin composition, 35 parts by weight of magnetite, 3 parts by weight of carbon black (Degussa PRINTEX150T), charge control agent (BONTORN S-34)

1 part by weight and 2 parts by weight of canava wax were mixed with a Henschel mixer, kneaded with a melt kneader, pulverized and classified with a jet mill to prepare a toner having an average particle size of 8 to 10 탆. The toner was loaded into a cartridge for a commercially available laser printer (SLB3105V) and developed to produce a satisfactory image.

<Example 2>

Into a reactor equipped with a stirrer, a reflux cooler, a thermometer, and a nitrogen inlet, 100g of waste PET chips and 200g of <Production Example 1> were placed in a reactor example and depolymerized at 200-250 ° C for 1 to 3 hours under nitrogen stream, followed by ester exchange. A polycondensation reaction is carried out to produce a polyester resin composition. This polyester resin composition is Tg 61 degreeC, softening point 105 degreeC, weight average molecular weight 7,000, outflow start temperature (Tfb) 113 degreeC, and outflow end point (Tend) 129 degreeC.

200 g of the resulting resin composition and 600 g of water are mixed and heated to dissolve while stirring to form a water-soluble polyester resin aqueous solution.

Using the water-soluble polyester resin solution to produce a static charge developing toner by the polymerization method as follows.

100 parts by weight of aqueous resin solution, 5 parts by weight of carbon black (Degussa PRINTEX150T), 1 part by weight of charge control agent (Orient's BONTRON S-34), and 2 parts by weight of polyethylene wax were mixed and dispersed in a high-speed disperser and suspended in an aqueous solution containing a flocculating accelerator. The resulting particles were dried, and the obtained particles were dried three times by filtration and washing, and then the aggregated particle diameter was measured. The average particle diameter was 10 µm. An external additive (Degus Co., Ltd. R972) was added at a ratio of 1 part by weight based on 100 parts by weight of the dry particles, and mixed well with a Henschel mixer to form a toner. The obtained toner was formed by an image of a commercially available laser printer (Samsung Electronics ML6060), and as a result, it was possible to form a high-quality image with low temperature fixation and without contamination.

<Example 3>

In a reactor equipped with a stirrer, a reflux cooler, a thermometer, and a nitrogen inlet, 150g of waste PET chips and 200g of product were placed in a reactor and depolymerized at 200-250 ° C for 1 to 3 hours under nitrogen stream, followed by ester exchange. A polycondensation reaction is carried out to produce a polyester resin composition. This polyester resin composition is Tg 63 degreeC, softening point 109 degreeC, weight average molecular weight 8,500, outflow start temperature (Tfb) 119 degreeC, and outflow end point (Tend) 135 degreeC.

200 g of the resulting resin composition was mixed with 100 g of tetrahydrofuran and 300 g of water, followed by stirring to form a resin solution. Using the water-soluble polyester resin solution to prepare an inkjet ink as follows.

50 parts by weight of a resin solution, 20 parts by weight of carbon black (Degussa FW200) and 80 parts by weight of distilled water were mixed and milled with a sand mill for 30 minutes. (2) 1 part by weight of TRITONX-100, 5 parts by weight of diethylene glycol, and distilled water 100 parts by weight is added and diluted, and then filtered through a 0.5 μm Teflon membrane filter to prepare an ink. The obtained mink was loaded into a Canon BJC-2000SP printer and printed. There was no bleeding on the ground, the printing quality was excellent, and no ink was deposited even when left for a long time without nozzle clogging.

<Example 4>

200g of waste PET chips and 200g of product <Production Example 2> were placed in a reactor equipped with a stirrer, a reflux cooler, a thermometer, and a nitrogen inlet in a reactor and depolymerized for 1 to 3 hours at 200 to 250 ° C under nitrogen stream, followed by an ester exchange reaction. A polycondensation reaction is carried out to produce a polyester resin composition. This polyester resin composition is Tg 63 degreeC, the softening point 113 degreeC, the weight average molecular weight 10,000, the outflow start temperature (Tfb) 120 degreeC, and the outflow end point (Tend) 139 degreeC.

Using the resin composition to prepare a powder coating as follows.

100 parts by weight of the resin composition, 100 parts by weight of epoxy resin (EPICOTE 1050), 15 parts by weight of carbon black (FW200), 0.5 parts by weight of Modafilo, 0.5 parts by weight of Iganox in a melt kneader and pulverized with a jet mill It was confirmed that a high-quality coating surface having high gloss, heat resistance, water resistance, chemical resistance, and weather resistance was obtained by making a particle with a particle diameter powder and spraying it with an electrostatic sprayer for 10 minutes at 180 ° C.

<Example 5>

In a reactor equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, 150g of waste PET chips and 200g of product <Production Example 2> were placed in a reactor and depolymerized at 200-250 ° C for 1 to 3 hours under nitrogen stream, followed by ester exchange. A polycondensation reaction is carried out to produce a polyester resin composition. This polyester resin composition is Tg 61 degreeC, softening point 110 degreeC, weight average molecular weight 9,900, outflow start temperature (Tfb) 117 degreeC, and outflow end point (Tend) 137 degreeC.

Using the resulting resin composition to prepare a hot melt adhesive as follows.                     

100 parts by weight of the resin composition, 10 parts by weight of a plasticizer, and 5 parts by weight of ester wax were mixed in a mixer, kneaded in a melt kneader, and injected into chips to prepare a hot melt adhesive. The hot melt adhesive produced using the polyester resin composition obtained by the present invention has good compatibility, low softening point, low melt viscosity, and thus has good adhesion to paper, textiles, leather, wood, plastics, metals, and the like. Can be.

<Example 6>

Reactor example equipped with a stirrer, reflux cooler, thermometer, nitrogen inlet 100g of waste PET chip and 200g product of <Production Example 2> were put into the reactor and depolymerized at 200-250 ℃ for 1 to 3 hours under nitrogen stream, followed by ester exchange reaction A polycondensation reaction is carried out to produce a polyester resin composition. This polyester resin composition is Tg 45 degreeC, the softening point 109 degreeC, the weight average molecular weight 8,700, the outflow start temperature (Tfb) 112 degreeC, and the outflow end point (Tend) 127 degreeC.

250 g of this resin composition is mixed with 750 g of water and dissolved at 80 ° C. to prepare a water-soluble polyester resin composition. The water-soluble polyester resin solution is used as an adhesive, a fiber coating agent, and a film coating agent.

The polyester resin composition produced by recycling the waste PET according to the present invention is a functional polymer composition containing a water-soluble polyester resin, an electrophotographic developer, an inkjet ink, a powder coating, an adhesive, a water-soluble fiber processing agent, a resin composition for a coating agent, and the like. It can be used as an advanced new material, not only to create high added value, but also to solve environmental problems.

Claims (5)

(1) preparing a polyester resin containing a sulfonic acid alkali metal salt of an aromatic dicarboxylic acid comprising dimethyl 5-sulfoisophthalate sodium salt (abbreviated as DMSSIP) which functions as a depolymerization function; (2) adding the resin of step (1) to the waste polyester to depolymerize and polycondensation with an ester exchange reaction to prepare a water-soluble polyester resin composition; And (3) the resin composition of step (2) is prepared from (A) an aqueous solution composition dissolved in water, (B) a liquid composition dissolved in a water-compatible solvent, or (C) a resin composition in a bulk state. Method for producing a polyester resin composition comprising the step of. According to claim 1, wherein the resin having a depolymerization function of step (1) is 10 to 90% by weight of the sulfonic acid alkali metal salt of the aromatic dicarboxylic acid and 10 to polyhydric alcohol of 1 to 30% by weight based on the total amount of monomers It is a polyester resin produced | generated by reacting 90 weight%, The manufacturing method of the polyester resin composition characterized by the above-mentioned. The method of claim 1, wherein the resulting polyester resin composition is an electrophotographic developer, inkjet ink, fiber processing agent, adhesive, or film in the state of a water-soluble polyester resin aqueous solution of 10 to 70% by weight of solids dissolved in water. A method for producing a polyester resin composition, characterized in that used as a binder of the coating agent. The method of claim 1, wherein the resulting polyester resin composition is a binder of an electrophotographic developer, an inkjet ink, an adhesive, or a film coating agent in the state of a polyester resin solution having a solid content of 10 to 70% by weight dissolved in a water-compatible solvent. It is used for the manufacturing method of the polyester resin composition characterized by the above-mentioned. According to claim 1, wherein the polyester resin composition produced glass transition temperature (Tg) 30 ~ 80 ℃, softening point 80 ~ 150 ℃, weight average molecular weight 3,000 ~ 5,000, outflow start temperature (Tfb) 90 ~ 140 ℃, outflow A polyester resin composition having a termination temperature (Tend) of 100 to 150 DEG C, wherein the polyester resin composition is used as a grinding method toner, a hot melt adhesive, or a binder for powder coating.