KR101420793B1 - Method for producing molded object of polyesters resin and molded object of polyesters resin - Google Patents

Abstract

The present invention relates to a polyester resin molded article in which the content of acetaldehyde and formaldehyde is reduced and a method for producing the same. The method for producing a polyester resin molded article of the present invention is a method for producing a polyester resin molded article, which comprises mixing a composite metal oxide containing at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti) Reacting the dicarboxylic acid component and the glycol component to form a polyester resin in the presence of the catalyst composition containing the polyester resin; And molding the polyester resin. Further, the resin molded article of the present invention contains less than 3 ppmw of an aldehyde-based compound.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing a polyester resin molded article,

The present invention relates to a method for producing a polyester resin molded article and a polyester resin molded article. More particularly, the present invention relates to a process for producing a polyester resin molded article and a polyester resin molded article, which can provide an environmentally friendly resin molded article containing a trace amount of an aldehyde compound (Aldehydes) and having no toxicity to human body.

Polyester has excellent mechanical and chemical properties and is widely used in applications such as beverage filling containers and medical applications, packaging materials, sheets, films, and automobile molded products . In particular, polyethylene terephthalate is widely used for the production of food containers such as drinking water containers and food packaging materials. However, acetaldehyde and formaldehyde are generated as additives in the polycondensation process, and it is not preferable to drink through a product containing the same. In particular, the acetaldehyde present in the drinking water bottle slowly flows out and mixes with the contents to adversely affect the flavor and aroma of the product to be ingested. Trace amounts of acetaldehyde may not generally have a significant effect on the taste and flavor of beverages, but the presence of trace amounts of acetaldehyde in non-carbonated beverages, such as simple mineral beverages, has a tendency to adversely affect the taste and flavor of the beverage . In addition, the formaldehyde present in the bottle is a toxic substance strictly regulated in developed countries by causing cancer-like diseases in vivo even in a very small amount. Therefore, many researches have been conducted to suppress the formation of aldehyde-based substances such as acetaldehyde and formaldehyde which are formed in the polycondensation process.

The antimony-based catalyst is a representative material for polycondensation of polyethylene terephthalate used for producing food containers such as bottles. However, in the case of food containers made of antimony catalysts, a large amount of acetaldehyde and formaldehyde are produced as adducts in the polycondensation process. Therefore, catalyst systems using other metals are continuously being developed for the manufacture of polyesters (J. Environ. Monit. 2006, 8, 288) because of toxicity problems associated with the use of antimony and environmental concerns. Despite its attempts to apply antimony-free catalysts such as titanium (Ti) or aluminum (Al) catalysts, the problem of formation of acetaldehyde and formaldehyde during polycondensation or product molding Is still a significant problem. For example, U.S. Patent Publication No. 2007/0191582 discloses a method of reducing acetaldehyde in a polycondensation process using a combination of antimony and tin (Sn). For the same purpose, Korean Patent Publication 2009/0114375 uses aluminum and titanium, and US Patent Publication No. 2010/0048783 proposes a method using titanium.

However, the method using a combination of antimony and tin is not a useful method because it causes environmental toxicity problems before reducing acetaldehyde. In the case of an open patent using an aluminum system and a titanium system, the production of acetaldehyde and formaldehyde is reduced However, it does not solve the fundamental problem.

Therefore, the development of catalysts for the development of eco-friendly vessels that do not affect the taste and flavor of beverages and that are not toxic to humans by minimizing the production of acetaldehyde and formaldehyde during polyester polycondensation process and product molding process Various manufacturing methods are still required.

An object of the present invention is to provide a process for producing a polyester resin molded article in which the content of acetaldehyde and formaldehyde is reduced.

The present invention also provides a polyester resin molded article in which the content of acetaldehyde and formaldehyde is reduced.

The present invention relates to a composite metal oxide, zinc (Zinc), and zinc (Zn) based compound containing at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) Reacting a decarboxylic acid component and a glycol component in the presence of a catalyst composition containing a phosphorus (P) -based compound to form a polyester resin; And molding the polyester resin. The present invention also provides a method for producing a polyester resin molded article.

Further, the present invention provides a polyester resin molded article comprising an aldehyde-based compound at less than 3 ppmw.

Hereinafter, a method for producing a polyester resin molded article and a polyester resin molded article according to a specific embodiment of the present invention will be described in detail.

According to one embodiment of the present invention, there is provided a catalyst composition comprising a composite metal oxide comprising at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti) Reacting the dicarboxylic acid component and the glycol component to form a polyester resin; And a step of molding a polyester resin.

It is known that phosphorus compounds which act as heat stabilizers and antioxidants can be used in the polyester polymerization process. Previously known catalysts for polyester synthesis have lower catalytic activity when used with phosphorus compounds The use amount of the phosphorus compound is limited. The use of such conventional catalysts for synthesizing polyester fails to sufficiently increase the addition amount of the phosphorus compound, so that the methyloxy radical, which is a pre-step material of formaldehyde, can not be controlled in the polycondensation process, and consequently, It is known that formaldehyde, which is a carcinogenic substance harmful to human body, is produced in the merging process. In the case of the antimony-based catalyst previously used for polyester synthesis, a large amount of acetaldehyde is produced, which has a toxic environment-toxic effect, which is problematic in the production of molded articles such as food storage containers.

Accordingly, the present inventors have made efforts to improve a polyester polycondensation process, which has been pointed out as a problem in the above-mentioned conventional polyester molding process, and a catalyst which produced acetaldehyde and formaldehyde in the process of molding the product, The presence of a catalyst composition containing a composite metal oxide, a zinc-based compound, and a phosphorus-based compound, containing at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti) The inventors confirmed that the polyester resin molded product produced under the above conditions contains a trace amount of acetaldehyde and formaldehyde, and completed the invention.

The catalyst composition comprising a composite metal oxide, a zinc-based compound, and a phosphorus-based compound containing at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti) And a glycol component to form an ester monomer or an oligomer, and can also act as a catalyst for the polycondensation reaction of such an esterification reaction product.

Further, the composite metal oxide, the zinc compound, and the phosphorus compound can be introduced at any stage of the polyester polymerization. For example, according to one embodiment of the present invention, the composite metal oxide, the zinc-based compound, and the phosphorus compound may be added to any stage of esterification reaction or polycondensation reaction in the form of a composition containing all three components This is possible. Specifically, the composite metal oxide may be added to the esterification reaction step, and the zinc compound and the phosphorus compound may be introduced into the polycondensation step. In this case, a polyester having reduced acetaldehyde and formaldehyde contents can be produced more effectively .

According to an embodiment of the present invention, the step of forming the polyester resin may include a step of forming a composite metal oxide containing at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti) Esterification reaction of the dicarboxylic acid component and the glycol component; And a step of polycondensing a product of the esterification reaction by adding a zinc-based compound and a phosphorus compound.

Meanwhile, the composite metal oxide may include at least one element selected from the group consisting of aluminum (Al), and magnesium (Mg) together with titanium (Ti). Preferably, the composite metal oxide includes titanium (Ti) and aluminum (Al), or may include titanium (Ti) and magnesium (Mg), and more preferably titanium (Ti) And magnesium (Mg).

The amount of the titanium (Ti), aluminum (Al), and magnesium (Mg) to be used in the composite metal oxide is not particularly limited but may be a composite metal containing titanium (Ti), aluminum (Al), and magnesium The amount of Ti may be 0.5 to 5 times the sum of the amounts of Al and Mg, and the ratio of Al: Mg may be 2: 1 to 1: 2 have. Preferably, the ratio of Ti: Al: Mg can be from about 10: 1: 1 to about 1: 1: 1.

The content of the titanium (Ti) element in the composite metal oxide may be about 10 ppmw or less, for example about 2 to about 10 ppmw, preferably about 4 to about 5 ppmw, relative to the polyester resin formed . In order to produce a polyester having reduced acetaldehyde and formaldehyde content, it is preferable to use about 10 ppmw or less based on the titanium element content.

The titanium-based catalyst compound used in the conventional polyester production method usually uses at least 10 ppmw or more of a titanium element based on the final polyester resin, and when the polycondensation is attempted using less than 10 ppmw of the titanium element, There is a problem that the reaction time is prolonged and a polyester having a low viscosity is produced. However, when the titanium content is high, the color of the polyester product is shifted to the yellow side, which may be inadequate for commercial use, and the catalytic activity is excessively high, so that many by-products including formaldehyde can be produced during the polymerization.

According to an embodiment of the present invention, the composite metal oxide may be represented by the following Chemical Formula 1 or Chemical Formula 2.

[Chemical Formula 1]

(2)

In Formula 2, n is an integer of 2 to 20.

Alternatively, the composite metal oxide may be a titanium alkoxide of the following formula (III), an aluminum alkoxide of the following formula (IV), and a coprecipitate of a magnesium alkoxide of the following formula (5).

(3)

Ti (OR ¹⁾ ₄

[Chemical Formula 4]

Al (OR ²⁾ ₃

[Chemical Formula 5]

Mg (OR ³⁾ ₂

In the formulas (3), (4) and (5), R ¹ , R ² and R ³ may be the same or different and each is a straight or branched alkyl group (Alkyl) having 1 to 20 carbon atoms, An alkenyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms Arylalkyl) or an alkylaryl group having 7 to 20 carbon atoms (Alkylaryl).

The composite metal oxide can be obtained through the steps of Schemes 1 to 3 below.

First, Titanium alkoxide represented by Chemical Formula 3 and Aluminum alkoxide represented by Chemical Formula 4 are mixed in water and an ethanol solvent as shown in the following Reaction Scheme 1, It can be made into an oligomer form.

[Reaction Scheme 1]

다음에, 하기 반응식 2에 따라 상기 반응식1의 생성물에 상기 화학식 5로 표시되는 마그네슘 알콕사이드를 투입함으로써 티타늄(Ti)-알루미늄(Al)-마그네슘(Mg)-산소가 교호적으로 결합되며 안정한 육각형을 이루는 금속 알콕사이드 구조가 형성될 수 있다.

Next, a titanium hexa-aluminum (Al) -magnesium (Mg) -oxy bond is alternately bonded by injecting the magnesium alkoxide represented by the above formula (5) into the product of the above reaction formula 1 according to the following Reaction Scheme 2, The resulting metal alkoxide structure can be formed.

[Reaction Scheme 2]

Alkyl and oxygen are alternately linked with each other as shown in the following Reaction Scheme 3 by replacing functional groups and alcohol groups bonded to titanium and aluminum by hydrolysis by adding water to the reactant of Reaction Scheme 2, A single molecule or an oligomer of the composite metal oxide forming the hexagonal ring of the composite metal oxide may be produced.

[Reaction Scheme 3]

The products according to Reaction Schemes 1 to 3 can be referred to as coprecipitates because they are obtained by precipitating titanium alkoxide, aluminum alkoxide, and magnesium alkoxide in the form of complex oxides by adding a solvent of water and ethanol.

As described above, the titanium alkoxide, the aluminum alkoxide, and the magnesium alkoxide are dissolved in the presence of ethanol according to Reaction Schemes 1 to 3, and water mixed with ethanol at room temperature is added thereto. Can be easily obtained.

The composite metal oxide can be produced by a relatively simple method, and is stable in moisture and easy to store. Unlike the antimony-based catalyst, the metal complex oxide has a relatively low metal self-toxicity and is unlikely to cause human and environmental problems.

The zinc-based compound refers to a compound containing zinc (Zn), and examples thereof include zinc acetylacetate, zinc oxide, zinc peroxide, zinc sulfide, Zinc carbonate, Zinc hydroxide, Zinc halogenation, zinc metal, or a mixture thereof. However, the present invention is not limited thereto.

The catalytic activity of the composite metal oxide can be further improved and the polymerization time can be shortened by the inclusion of the zinc-based compound, and the thermal decomposition time is reduced, and zinc is selectively involved in the polymerization and acetaldehyde And formaldehyde.

The content of the zinc-based compound contained in the catalyst composition is about 10 to about 300 ppmw, preferably about 20 to about 300 ppmw based on the zinc (Zn) element content in the zinc-based compound, About 200 ppmw can be used. Addition of a zinc-based compound in the above range is preferable from the viewpoint of increasing the viscosity in the polyester polymerization and shortening the polycondensation time to produce a polyester of excellent product. As the content of the zinc compound increases, the reaction time and viscosity increase effect may be improved. However, when the amount of the zinc compound is excessively used, the color of the produced polyester may deteriorate and the crystallization speed may be lowered in the solid phase polymerization.

The zinc-based compound acts as a cocatalyst to supplement the activity of the composite metal oxide used as a catalyst in polyester polymerization do. More specifically, according to the present invention, a polycondensation reaction can be performed even when a small amount of the composite metal oxide catalyst is used by using a zinc-based compound together with a composite metal oxide catalyst. It is also possible to obtain a product having a high viscosity with a short reaction time. Therefore, the polycondensation reaction time is shortened, resulting in shorter pyrolysis time for the resulting polyester, and the addition product is reduced because it is selectively involved in the polymerization in the polycondensation process. As a result, the final formed polyester will contain significantly reduced acetaldehyde and formaldehyde. Also, it can be added at any stage of the polycondensation process, is easy to use because it is soluble in glycol components at room temperature, and does not react with composite metal oxides, phosphorus compounds, and other additives, It can be added to the reactor, which is convenient for the application of the process.

The phosphorus compound refers to a compound containing phosphorus (P), and includes, for example, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, phosphoric acid, , Phenylphosphine, 2-carboxyethylphenyl phosphinic acid, or a mixture thereof, but the present invention is not limited thereto.

The phosphorus compound can prevent generation of a pre-step material that directly generates acetaldehyde by reducing pyrolysis during the polymerization reaction of the polyester, and also can prevent generation of methyloxy radical, a pre-stage material for forming formaldehyde . In addition, the phosphorus compound prevents the yellowing of the polyester formed by inhibiting the formation of the colorbody, thereby maintaining the original color of the molded article of the present invention.

The content of the phosphorus compound contained in the catalyst composition is about 5 to about 50 ppmw, preferably about 10 to about 40 ppmw, based on the phosphorus (P) element content in the phosphorus compound, Can be used. Addition of the phosphorus compound in the above range is preferable from the viewpoint of increasing the viscosity in the polyester polymerization and preventing the pyrolysis to produce a polyester in which the content of acetaldehyde and formaldehyde is reduced.

The phosphorus compound serves as a heat stabilizer to reduce pyrolysis of the polyester. More specifically, it inhibits the generation of acetaldehyde generated by the reverse reaction in which the molecular chain is shortened due to the heat applied to the esterification exchange reaction and the polycondensation reaction, the reaction heat generated additionally and the frictional heat generated by stirring, or the decomposition reactions . It also inhibits addition products with radicals and strong bonds with the resulting radicals to inhibit the formation of formaldehyde in the final formed polyester.

Unlike the antimony-based catalyst and the conventional composite metal oxide, the polycondensation using the catalyst composition exhibits high activity within a short reaction time even in a small amount and can be selectively polymerized. Thus, polyesters containing less aldehyde-based materials such as acetaldehyde and formaldehyde, which are harmful to the environment and the human body, can be produced. In addition, the polyester produced by using the catalyst composition of the present invention is excellent in physical properties such as viscosity and color, and is useful for mass production of polyester, especially in the production of molded articles such as drinking water bottles, fiber plastics and food packaging materials using polyethylene terephthalate And can be applied commercially advantageously.

In the presence of a catalyst composition comprising a composite metal oxide comprising at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti), a zinc-based compound and a phosphorus compound, The step of reacting an acid component and a glycol component to form a polyester resin may be carried out by liquid phase polymerization or solid phase polymerization.

More specifically, first, the dicarboxylic acid component and the glycol component are esterified.

According to an embodiment of the present invention, the 'dicarboxylic acid component' may be a dicarboxylic acid such as terephthalic acid, an alkyl ester thereof (monomethyl, monoethyl, dimethyl, diethyl or dibutyl ester) Lower alkyl esters) and / or their acid anhydrides, which react with the glycol component to form a dicarboxylic acid moiety, such as a terephthaloyl moiety, can do. Specifically, there can be mentioned terephthalic acid, oxalic acid, malonic acid, azelaic acid, fumaric acid, pimelic acid, Suberic acid, isophthalic acid, dodecane dicarboxylic acid, naphthalene dicarboxylic acid, biphenyldicarboxylic acid, 1,4 1,3-Cyclohexane dicarboxylic acid, 1,3-Cyclohexane dicarboxylic acid, Succinic acid, Glutaric acid, ), Adipic acid, sebacic acid, 2,6-naphthalene dicarboxylic acid, 1,2-norbornane dicarboxylic acid ( Dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, acid, 1,3-cyclobutane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 5-sodium sulfoisophthalic acid, , 5-potassium sulfoisophthalic acid, 5-lithium sulfoisophthalic acid, or 2-sodium sulfoterephthalic acid, but the present invention is not limited thereto. And other dicarboxylic acids not exemplified above may be used as long as they do not impair the object of the present invention. Preferably, terephthalic acid may be used as the dicarboxylic acid component.

According to one embodiment of the present invention, examples of the glycol component include ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 1,3 Butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, neopentyl glycol, Propylene glycol, diethylene glycol, triethylene glycol, 1,2-cyclohexane diol, 1,3-cyclohexane diol, 1,3-cyclohexane diol, Cyclohexane diol, propane diol, 1,6-hexane diol, neopentyl glycol, tetramethylcyclobutane diol, 1,4-cyclohexane diol, 1,4-cyclohexane diol, 1,4-cyclohexane diethanol, 1,10-decamethylene glycol, 1,12-dodecane But are not limited to, dodecane diol, polyoxyethylene glycol, polyoxymethylene glycol, polyoxytetramethylene glycol, or glycerol, and the like. And other glycols can be used within the scope of not impairing the object of the present invention. Preferably, ethylene glycol may be used as the glycol component.

According to one embodiment of the present invention, the step of esterifying the dicarboxylic acid component and the glycol component is carried out at a temperature of about 100 to about 300 캜, preferably about 130 to about 280 캜, at a temperature of about 1 to about 6 Hour, preferably about 2 to about 5 hours.

In the next step, the product of the esterification reaction is polycondensed.

The polycondensation of the product of the esterification reaction is preferably carried out at a temperature of from about 200 to about 300 DEG C, preferably from about 260 DEG C to about 290 DEG C and from about 30 to about 0.1 torr for from about 1 to about 3 hours, Can be carried out by reacting for about 1 hour to about 2 hours. Therefore, since the polycondensation time can be remarkably shortened compared with the case of using the conventional catalyst, the productivity is improved.

As described above, the polyester may be formed by liquid phase polymerization, and the formed polyester has an intrinsic viscosity From about 0.50 to about 0.70 dL / g, preferably from about 0.62 to about 0.70 dL / g.

The product of the liquid phase polymerization can be subjected to solid state polymerization at a temperature of 80 DEG C or more for 1 hour or more under reduced pressure vacuum at 1 torr or less. More specifically, vacuum polymerization can be carried out under a reduced pressure of 0.1 to 1 torr, and solid phase polymerization can be carried out stepwise at 100 to 300 DEG C for 10 to 30 hours.

As described above, the polyester can be formed by solid-state polymerization, and the polyester formed at this time has an intrinsic viscosity From about 0.80 to about 1.0 dL / g, preferably from about 0.82 to about 1.0 dL / g.

In the method for producing a polyester resin molded article of the present invention, toners may be further added to improve the hue of the resin molded article to be produced. Examples of the coloring agent include cobalt acetate, cobalt acetylacetonate, cobalt benzoylacetonate, cobalt hydroxide, cobalt bromide, cobalt chloride, cobalt acetate, Cobalt iodide, Cobalt fluoride, Cobalt cyanide, Cobalt nitrate, Cobalt sulfate, Cobalt selenide, and the like. But are not limited to, compounds including cobalt such as cobalt phosphate, cobalt oxide, cobalt thiocyanate, or cobalt propionate.

The addition amount of the coloring agent can be added in an amount of about 150 ppmw or less, for example, about 30 to about 150 ppmw, and preferably about 60 to about 100 ppmw, based on the final polyester resin. It is known that the cobalt compound itself has a certain degree of catalytic activity. However, if an excessive amount of the cobalt compound is added to such an extent that the catalytic effect can be exerted, the residual metal in the polyester may increase, leading to toxicity and brightness decrease. Therefore, when added in the above range, an additive substance such as acetaldehyde and formaldehyde is produced in a very small amount in the polyester, Can be minimized.

Further, in the step of adding the cobalt compound in the present invention, the step of esterifying the dicarboxylic acid component and the glycol component during the polymerization reaction or the step of polycondensation of the product of the esterification reaction may be carried out at any stage Do. Further, other cobalt-based compounds may be used within the range not impairing the object of the present invention, and the use thereof may be excluded depending on the purpose of producing the polyester.

Next, a method of molding the polyester resin is presented.

The step of molding the polyester resin may be carried out by various molding methods such as a compression molding method, a transfer molding method, a laminated molding method, an injection molding method, an extrusion molding method, a blow molding method, A calender molding, a gas molding, an insert mold, or a vacuum molding process. The method or apparatus available in such a molding step may be used without limitation as long as it is known to be usable for the production of plastic molded articles. For example, in the case of producing a drinking water plastic bottle from the polyester resin prepared above, a blow molding method can be used.

The step of molding the polyester resin may further include a step of forming a preform of the resin molded article using the polyester resin. In the step of forming a preform of such a resin molded article, the formed polyester resin is dried to remove moisture, and the polyester resin from which moisture has been removed may be injection molded or extruded to prepare a preform suitable for the final product. The final product can be provided by applying the preform to the above-described molding method.

The polyester resin obtained by the process according to the present invention may contain less than 3 ppmw of an aldehyde-based compound. More specifically, it may contain acetaldehyde of less than 1 ppmw and 1 ppmw of formaldehyde of less than 1 ppmw, based on the weight of the polyester resin.

The prepared molded product may be an environmentally friendly container which does not affect the taste and flavor and is not toxic in the human body when the content of acetaldehyde and formaldehyde is reduced and used as a food storage container. Specific examples thereof include drinking water bottles, food packaging materials, and fibrous plastics.

According to another embodiment of the invention, a polyester resin molded article containing less than 3 ppmw of an aldehyde-based compound can be provided.

The polyester resin molded article of the present invention may contain less than 3 ppmw of an aldehyde-based compound. The aldehyde-based compound means a carbon compound having a formyl group (-CHO), and specific examples thereof include acetaldehyde and formaldehyde. Preferably, the polyester resin molded article of the present invention may contain less than 1 ppmw of acetaldehyde and less than 1 ppmw of formaldehyde.

On the other hand, the polyester resin molded article of the present invention includes a composite metal oxide containing at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and titanium (Ti) In the presence of a catalyst composition, by the above-described method for producing a polyester resin molded article.

On the other hand, the polyester resin molded article may further contain 5 to 50 ppmw of a phosphorus compound based on the phosphorus (P) element content in the phosphorus compound with respect to the weight of the polyester resin molded article. Such a phosphorus compound may be derived from the catalyst composition used in the above-described method for producing a polyester resin molding.

As described above, even when the specific composite metal oxide is used together with the phosphorus compound, the activity is not significantly lowered, and the phosphorus compound added to reduce the generation of the aldehyde-based compound during the production of the polyester resin molding The usage can be greatly increased. Therefore, the resin molded product obtained by the above-mentioned method of producing a polyester resin molded article contains or substantially does not contain an aldehyde compound in a very low content, and contains a phosphorus compound in a high content as compared with a previously known polyester resin molded article .

The polyester resin molded article may further contain 10 to 300 ppmw of a zinc-based compound based on the zinc (Zn) element content of the zinc-based compound with respect to the weight of the polyester resin molded article. Such a zinc-based compound may be derived from the catalyst composition used in the polyester resin molding production method described above.

The polyester resin molded article having the above characteristics can be used as an environmentally friendly container which does not affect the taste and flavor and is not toxic to human body when acetaldehyde and formaldehyde contents are reduced as food storage containers. Specifically, the polyester resin molded article may be used as a drinking water bottle, a food packaging material, a fibrous plastic, or the like, and is preferably used as a drinking water bottle.

According to the present invention, there can be provided a process for producing an environmentally friendly resin molded article which contains a trace amount of an aldehyde-based compound and is free from toxicity to human body, and such polyester resin molded article.

Hereinafter, the present invention will be described in more detail with reference to examples according to the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

Experimental conditions

In the examples, the synthesis of the composite metal oxide was carried out in air and a general synthesis method was used. As a reaction solvent for synthesis, an alcohol type solvent was used. But are not limited to, titanium isopropoxide, aluminum isopropoxide, magnesium methoxide, cobalt acetate, triethyl phosphate, terephthalic acid, and ethylene Ethylene glycol was used without any purification process.

[ Manufacturing example  1: Preparation of composite metal oxide]

45 mL (151.9 mmol) of titanium isopropoxide and 5 g (24.5 mmol) of aluminum isopropoxide were dissolved in 70 mL of ethanol by heating. Magnesium methoxide (6-7 wt% in methanol, 25 mL) was slowly added thereto using a syringe. Next, 25 g of distilled water and 20 mL of ethanol were mixed, and the diluted solution was slowly added dropwise at room temperature (23 ° C) over 30 minutes.

The mixture was stirred for 1 hour, and the resulting white precipitate was filtered using a glass filter. The collected solid was extracted in air and the residue was washed with distilled water (30 mL x 2) and washed again with ethanol (30 mL x 2) Respectively.

The product was dried in vacuo at 70-80 DEG C for 6 hours to give 19.7 g of composite metal oxide.

[ Example  One]

1. Liquid Phase Polymerization Step

Terephthalic acid (14.5 Kg, 87.3 mol), monoethylene glycol (6.42 Kg, 105.75 mol), isophthalic acid (0.448 Kg, 3 mol) Mg complex metal oxide (200 mg) was added to the reactor and heated with stirring to raise the temperature to 250 ° C at room temperature. The tower temperature sensor connected to the reactor to measure distillate generated during the reaction was heated at 250 ° C to 135 ° C , The reaction was stopped and the BHET (Bis-hydroxyethylene terephthalate) produced by the esterification reaction was moved through the tube to the polycondensation reactor.

Then, zinc acetate (Zn (OAc) ₂ , 6.91 g) and triethyl phosphate (TEP, 1.2 g) were dissolved in 100 g of monoethylene glycol and dissolved in a polycondensation reactor. The pressure of the polycondensation reactor was adjusted to 28 torr The pressure was gradually reduced to 0.4 torr over 1 hour and the temperature was raised from 250 占 폚 to 280 占 폚. The reaction was terminated when the temperature inside the reactor was lowered and the reactor was maintained without any change and the stirrer speed inside the reactor was lowered and no change was observed at the time when the polycondensation reaction was completed.

The obtained polyethylene terephthalate (PET) resin had an intrinsic viscosity of 0.62 dL / g and a number average molecular weight of 17,000 to 22,000 g / mol.

After completion of the reaction, the reaction product was pulverized through a pelletizer through cooling water, and 13 Kg of a transparent polyethyleneterephthalate resin in the form of a chip was obtained.

2. Solid phase polymerization step

1. The polyethylene terephthalate resin obtained in the liquid phase polymerization step was dried in air to remove moisture. (2 hours and 50 minutes), 170 占 폚 (2 hours), 225 占 폚 (8 hours), and cooling at a reduced pressure (0.2 to 0.5 torr) (10 hours) for 23 hours and 50 minutes.

After completion of the reaction, a polyethylene terephthalate resin having a crystalline structure in the form of a white solid compound and having an intrinsic viscosity of 0.84 dL / g and a number average molecular weight of 32,000 to 35,000 g / mol was obtained.

3. Polyethylene Terephthalic Preform ( Preform ) Produce

2. The polyethylene terephthalate resin obtained in the solid phase polymerization step was dried at 150 ~ 160 ° C for 4 ~ 5 hours by using a water drier to completely remove moisture in the polyethylene terephthalate. The resin with moisture removed is placed in an injection molding machine (model: HUSKY) and automatically transferred to a screw rpm 1 to 3 at a temperature of about 265 to 300 ° C. to put the resin into the preform mold. The resin is cooled for 9 to 15 seconds, 20 ~ 25 bar) to prepare preforms.

4. Polyethylene Terephthalic Bottle ( Bottle ) Produce

Using a bottle manufacturing machine (model: Erontier), the preforms were fixed to the preform at a fixed temperature of 70-80 ^° C and a pressure of 5 ~ 8 Kgf / cm ² . After putting, the preform was automatically turned along the lane and received heat. At this time, the preform rotation speed was 8.4 seconds, and the preform was subjected to three stages of air pressure (primary: 11, secondary: 40, tertiary: 7 Kgf / cm ² ) in the mold. In the mold, the thickness of the bottle was determined by the pressure applied to the preform, and the thickness of the bottle was determined based on the intensity of air blown at the same time.

[ Comparative Example  One]

1. Liquid Phase Polymerization Step

In Example 1, a polyethylene terephthalate liquid resin was produced in the same manner as in Example 1, except that Ti / Si catalyst was used instead of Ti / Al / Mg composite metal oxide of Production Example 1 and zinc acetate was not included And the number average molecular weight was 15,450 ~ 20,000 g / mol.

2. Solid phase polymerization step

1. A polyethylene terephthalate solid state resin was prepared using the liquid resin prepared in the liquid phase polymerization step under the same conditions as in the solid phase polymerization step 2 of Example 1, and the number average molecular weight was 28,700-30,100 g / mol.

3. Polyethylene Terephthalic Preform ( Preform ) Produce

2. Using the solid resin obtained in the solid-phase polymerization step, a preform applicable to drinking water bottles was formed in the same manner as in the production of the preform of Example 1 above.

4. Polyethylene Terephthalic Bottle ( Bottle ) Produce

Using the preform obtained in the production of the preform of No. 3, a bottle applicable for drinking water was manufactured in a bottle molding machine in the same manner as the bottle production of Example 1.

[ Comparative Example  2]

1. Liquid Phase Polymerization Step

In the same manner as in Example 1 except that the Sb (OAc) ₃ catalyst was used instead of the Ti / Al / Mg composite metal oxide of Production Example 1 and zinc acetate was not contained, the polyethylene terephthalate liquid resin And the number average molecular weight was 16,950 ~ 21,500 g / mol.

2. Solid phase polymerization step

1. A polyethylene terephthalate solid-state resin was prepared using the liquid resin prepared in the liquid phase polymerization under the same reaction conditions as in Example 1, and the number average molecular weight was 30,400 to 34,100 g / mol.

3. Polyethylene Terephthalic Preform ( Preform ) Produce

2. Using the solid phase resin obtained in the solid phase polymerization step, the preforms applicable to drinking water bottles were formed in the same manner as in the production of the preforms of Example 1.

4. Polyethylene Terephthalic Bottle ( Bottle ) Produce

Using the preform obtained in the production of the preform of No. 3, a bottle applicable for drinking water was manufactured in a bottle molding machine in the same manner as the bottle production of Example 1.

The catalyst compositions and contents of Example 1 and Comparative Examples 1 and 2 are shown in Table 1 below.

division Catalyst composition PET reference element
Content (ppmw) Example 1 Ti / Al / Mg + Zn (OAc) ₂ + TEP Ti = 5, Al = 0.25, Mg = 0.22,
Zn = 119.20, P = 34 Comparative Example 1 Ti / Si + TEP Ti = 5, Si = 0.50, P = 34 Comparative Example 2 Sb (OAc) ₃ + TEP Sb = 253, P = 34

< Experimental Example >

[How to measure]

1. Intrinsic Viscosity (IV)

Phenol and 1,1,2,2-tetrachloroethanol were mixed in a weight ratio of 6: 4 to 100 mL of the reagent, and 0.4 g of a polyester resin to be measured And the solution is transferred to a Ubbelohde viscometer for 90 minutes. The solution is kept in a 30 ° C thermostat for 10 minutes, and the falling seconds of the solution can be obtained by using a viscometer and an aspirator. The number of drops of the solvent was also found by the same method, and then R.V. Value and I.V. Values were calculated. In the following equation, C represents the concentration of the sample.

[Equation 1]

R.V. = Samples falling in water / solvent drops in seconds

[Equation 2]

IV = 1/4 (RV-1) / C + 3/4 (in RV / C)

2. Concentration of Carboxylic end group (CEG, -COOH)

0.5 g of the polyester resin to be measured having a size of 4 mm was placed in a 100 mL dissolution tube and 25 mL of an ortho-chlorophenol solvent was added and dissolved at 100 DEG C for 1 hour to prepare a sample. The sample was titrated with 0.02 M KOH methanol solution and measured. The number of carboxyl groups is referred to as carboxylic group equivalents / 10 ⁶ g (or mmol / Kg) of polymer.

3. Concentration of hydroxyl end (Diethylene glycol, DEG, -OH)

0.5 g of a polyester resin of 4 mm in size to be measured was placed in a 100 mL dissolution tube, and 25 mL of an ortho-chlorophenol solvent was added and dissolved at 100 DEG C for 1 hour to prepare a sample. An excess amount of adipic acid (50 mL) was added to the sample and reacted at 100 DEG C for 1 hour to replace the terminal hydroxyl group with the terminal carboxyl group. After removing the extra adipic acid, the difference between the terminal carboxyl group amount of the substituted sample and the terminal carboxyl group amount of the non-substituted sample was calculated.

4. Polyethylene terephthalate resin color (Color = L, a, b)

50 g of the polyester resin to be measured was removed from the air and put in a colorimeter model SA-2000, and the color was measured ten times to standardize the average value.

The L, a, and b color systems are used internationally as a basis for polyester color evaluation. These color values are one of the color systems for standardizing color measurements and describe recognizable colors and color differences. In this system, L is the brightness factor and a and b are the color measurement numbers. In general, the b value indicating the yellow / blue balance is an important figure in the manufacture of drinking water containers and food packaging materials. Positive b value means yellow discoloration and negative value means blue discoloration. Positive a value means red discoloration and negative value means green discoloration. The L value is a numerical factor indicating the brightness and is a very important value such as the b value in the manufacture of containers such as drinking water containers and food packaging materials.

5. Analysis of acetaldehyde and formaldehyde content (ppmw)

The polyester product to be measured was made into a small piece and was frozen in liquid nitrogen, followed by pulverization with a freezing pulverizer (model: JFC-300) and filtering with a syringe filter (25-mesh) . To this, 2.5 mL of distilled water was added, and the tube was pierced. Then, the tube was poured into a 120 ^o C oven for about 1 hour to extract acetaldehyde and formaldehyde. The extracted material is kept in the freezer for 20 minutes and thawed for about 10 minutes at room temperature. The solution is filtered with a 0.45 μm filter, then 0.2 mL of derivatized solution (0.02 g 2,4-Dinitrophenylhydrozine, 2 mL phosphoric acid) 17.8 mL of distilled water was mixed to obtain 60 ^o C for 15 min to dissolve). The two solutions were mixed well and allowed to stand for about 30 minutes. The solution was analyzed by HPLC (High Performance Liquid Chromatography). HPLC conditions were as follows: Column-YMC-Pack A-302 ODS, temperature -40 ^° C, mobile phase-55% Acetonitrile and 45% min, pressure -116 bar, injection amount -10 uL, detection wavelength -UV 360 nm and analysis time -12 minutes. Acetaldehyde and formaldehyde concentrations were determined from the previously prepared calibration curve formulas.

[ Experimental Example  One]

The time required for the esterification reaction (the time taken to complete the reaction after the initiation of the catalyst injection in the slurry state) of Example 1 and Comparative Examples 1 and 2, the polycondensation time (time taken to complete the reaction after the start of the polycondensation reaction) The intrinsic viscosity of the resulting polyester was measured and is shown in Table 2 below.

division Esterification reaction time Polycondensation time Type of polymerization Intrinsic viscosity
(Unit: dL / g) Example 1 3 hours 10 minutes 1 hour 30 minutes Liquid phase polymerization 0.62 Solid state polymerization 0.84 Comparative Example 1 3 hours 45 minutes 2 hours 30 minutes Liquid phase polymerization 0.60 Solid state polymerization 0.72 Comparative Example 2 3 hours and 30 minutes 2 hours 10 minutes Liquid phase polymerization 0.61 Solid state polymerization 0.81

[ Experimental Example  2]

Color (L, a, b), CEG concentration, and DEG concentration of Example 1 and Comparative Examples 1 and 2 were measured and shown in Table 3 below.

division Type of polymerization Color CEG concentration
(Unit: mmol / Kg) DEG concentration
(Unit: wt%) L a b Example 1 Liquid phase polymerization 53.9 0.35 -5.59 22.8 2.22 Solid state polymerization 79.0 -0.59 -4.58 21.3 2.15 Comparative Example 1 Liquid phase polymerization 50.7 0.7 -1.0 24.9 3.82 Solid state polymerization 73.4 -0.5 -0.7 26.5 3.89 Comparative Example 2 Liquid phase polymerization 52.8 0.25 -1.5 27.0 3.16 Solid state polymerization 78.4 -0.2 -1.1 28.5 2.54

Referring to Tables 2 and 3, in the case of producing polyethylene terephthalate using the catalyst composition of the present invention, the time required for the esterification reaction was 3 hours and 10 minutes, and the time required for the polycondensation reaction was 1 hour and 30 minutes, The physical properties of the polyethylene terephthalate formed were different from each other, but all of them were capable of obtaining polyethylene terephthalate having generally good physical properties.

Also, the polyethylene terephthalate obtained by the liquid phase polymerization showed a viscosity of 0.62 dL / g, and the polyethylene terephthalate obtained by the solid phase polymerization showed a good viscosity of 0.84 dL / g.

[ Experimental Example  3]

The contents of acetaldehyde and formaldehyde in the bottles prepared in Example 1 and Comparative Examples 1 and 2 were measured and are shown in Table 4 below.

division Acetaldehyde content (unit: ppmw) Formaldehyde content (unit: ppmw) Example 1 0.8 0.3 Comparative Example 2 12.5 5.6 Comparative Example 3 24.3 2.7

Referring to Table 4, the final bottle was prepared and analyzed for aldehyde-based compounds. As a result, it was confirmed that acetaldehyde and formaldehyde were significantly reduced in Example 1 as compared with Comparative Examples 1 and 2. Accordingly, it is expected that one molded article of the polyester resin of the above-mentioned embodiment can contain an extremely small amount of acetaldehyde and formaldehyde to produce an environmentally friendly container which does not affect the taste and flavor of the beverage and is not toxic to the human body. On the other hand, it was confirmed that the contents of acetaldehyde and formaldehyde were too high in the bottles of Comparative Examples 1 and 2, and the use thereof as a food storage container would be detrimental to both the environment and the human body.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of example, It will be understood that the invention may be practiced within the scope of the claims.

Claims (20)

In the presence of a catalyst composition comprising at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and a composite metal oxide comprising titanium (Ti), a zinc compound, and a phosphorus compound, dicarboxylic acid Reacting the component and the glycol component to form a polyester resin; And
And molding the polyester resin.
The method according to claim 1,
The step of forming the polyester resin comprises:
Esterifying the dicarboxylic acid component and the glycol component in the presence of at least one element selected from the group consisting of aluminum (Al) and magnesium (Mg) and a composite metal oxide containing titanium (Ti); And
Adding the zinc-based compound and the phosphorus compound to the product of the esterification reaction, and polycondensing the polyester resin molded product.
The method for producing a polyester resin molded article according to claim 1, wherein the composite metal oxide comprises titanium (Ti), aluminum (Al), and magnesium (Mg).
The method of claim 3,
Wherein the composite metal oxide is represented by the following Formula 1 or 2:
[Chemical Formula 1]

(2)

In Formula 2, n is an integer of 2 to 20.
The method of claim 3,
Wherein the composite metal oxide is a coprecipitate of a titanium alkoxide represented by the following formula (3), an aluminum alkoxide represented by the following formula (4), and a magnesium alkoxide represented by the following formula (5)
(3)
Ti (OR ¹⁾ ₄
[Chemical Formula 4]
Al (OR ²⁾ ₃
[Chemical Formula 5]
Mg (OR ³⁾ ₂
In the above formulas (3), (4) and (5)
R ¹ , R ² and R ³ may be the same or different and each represents a hydrogen atom, a linear or branched alkyl group (Alkyl) having 1 to 20 carbon atoms, a linear or branched alkenyl group having 2 to 20 carbon atoms, A cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, (Alkylaryl).
The method according to claim 1,
Wherein the zinc-based compound comprises at least one selected from the group consisting of zinc acetate, zinc oxide, zinc peroxide, zinc sulfide, zinc carbonate, zinc hydroxide, zinc halide and zinc metal.
The method according to claim 1,
Wherein the phosphorus compound is at least one selected from the group consisting of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, phosphoric acid, phenylphosphine, and 2-carboxylethylphenylphosphinic acid Way.
3. The method of claim 2,
Wherein the esterification reaction is carried out at a temperature of 100 to 300 占 폚 for 1 to 6 hours.
3. The method of claim 2,
Wherein polycondensation of the product of the esterification reaction is carried out at a temperature of 200 to 300 DEG C and a reduced pressure of 30 to 0.1 torr for 1 to 3 hours.
The method according to claim 1,
Wherein the content of the titanium (Ti) element contained in the composite metal oxide is 2 to 10 ppmw relative to the polyester resin to be formed.
The method according to claim 1,
Wherein the content of the zinc-based compound contained in the catalyst composition is 10 to 300 ppmw based on the zinc (Zn) element content of the zinc-based compound relative to the weight of the polyester resin.
The method according to claim 1,
Wherein the content of the phosphorus compound contained in the catalyst composition is 5 to 50 ppmw based on the phosphorus (P) element content in the phosphorus compound based on the weight of the polyester resin.
The method according to claim 1,
Wherein the step of molding the polyester resin is carried out by compression molding, transfer molding, lamination molding, injection molding, extrusion molding, blow molding, calender molding, gas molding, insert molding or vacuum molding.
The method according to claim 1,
Wherein the polyester resin has an intrinsic viscosity of 0.80 to 1.0 dL / g when formed by solid phase polymerization.
The method according to claim 1,
Wherein the polyester resin molded article comprises less than 1 ppmw of acetaldehyde and less than 1 ppmw of formaldehyde.
16. A polyester resin molded article produced by the method according to any one of claims 1 to 15 and containing less than 3 ppmw of an aldehyde-based compound.
17. The method of claim 16,
Less than 1 ppmw of acetaldehyde and less than 1 ppmw of formaldehyde.
17. The method of claim 16,
Further comprising 5 to 50 ppmw of a phosphorus compound based on the phosphorus (P) element content in the phosphorus compound based on the weight of the polyester resin molding.
17. The method of claim 16,
Further comprising 10 to 300 ppmw of zinc-based compound based on the content of zinc (Zn) element contained in the zinc-based compound with respect to the weight of the polyester resin molded article.
17. The method of claim 16,
Wherein the polyester resin molded article is a drinking water bottle.