KR102545381B1 - Process of Vinylester resins for eco-friendly corrosion resistance pultrusion using recycled polyethyleneterephthalate flake - Google Patents

Abstract

The present invention relates to a method for producing a vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes, and more specifically, by reacting recycled polyethylene terephthalate (recycled PET) flakes, glycol, and a first polyhydric base acid to achieve glycolysis (Glycolysis) to prepare a polyol; A second step of preparing a monobasic acid for vinyl ester resin by reacting an acrylic monomer and a second polybasic acid with the polyol prepared in the first step; A third step of preparing an epoxy resin-modified vinyl ester resin oligomer by reacting an epoxy resin with the monobasic acid prepared in the second step; and a fourth step of preparing a vinyl ester resin by diluting the epoxy resin-modified vinyl ester resin oligomer prepared in the third step with a vinyl monomer. Disclosed is a method for producing a vinyl ester resin for use.

Description

Manufacturing method of vinyl ester resins for eco-friendly corrosion resistance pultrusion using recycled polyethylene terephthalate flakes

The present invention relates to a method for producing an eco-friendly, corrosion-resistant vinyl ester resin for pultrusion molding using recycled polyethylene terephthalate flakes.

PET is a semi-crystalline polymer and has excellent physical properties such as thermal stability, transparency, and strength compared to its price, and has many uses in various fields such as films, beverage bottles, and fibers, and accounts for 60 to 70% of the global plastic market today. As of 2009, PET production is 54 million tons/year, growing by about 7% annually. However, the global recovery rate of waste PET products is only about 25%, and the remaining amount is disposed of by incineration or landfill, which not only causes environmental pollution but also causes economic losses.

PET has high crystallinity and high melting point, so it is used not only as a fiber but also as a film, bottle, and injection molded material. In particular, the characteristics of PET used for bottles include light weight, high strength, high strength, excellent transparency, gas permeability, chemical resistance, and hygiene and safety of food due to high quality maintenance of contents.

Recycling of PET has increased interest mainly due to its widespread use in the packaging of polymer bottles. Currently, consumption of PET worldwide reaches 13 million tons. Accordingly, it is very important from an economic as well as an environmental point of view to convert waste polyester discarded after use into a chemical raw material again.

There are two main ways to recycle waste polyester. Physical recycling is to use polyester clips or flakes, and chemical recycling is to recover polyester raw materials through chemical reactions. Among them, chemical recycling is known as the most economically and environmentally preferable method.

PET is a semi-crystalline thermoplastic polymer used in textile manufacturing, packaging films, bottles, electrical insulators, etc., and can be produced in two ways: by condensation of TPA and EG or by reaction of DMT and EG. Both methods are polymerized into PET via the monomer BHET (bis(hydroxyethyl)terephthalate). Various PET chemical decomposition methods have been developed with the goal of recovering TPA, DMT, and BHET, which are raw materials that can be reproduced into pure polyester. Looking at the recycling method of PET, a method of making crystal pellets by compression molding PET by a condensation reaction from ethylene glycol and terephthalic acid or terephthalic acid methyl ester, and a method of making PET with monoethylene glycol and monoethylene glycol through the reverse reaction of depolymerization, hydrolysis or methane decomposition of monomers. There is a method of depolymerization with terephthalic acid or terephthalic acid methyl ester.

In relation to this, Korea Patent Publication No. 10-2011-0010173 discloses a method for producing bis(2-hydroxyethyl) terephthalate using waste polyethylene terephthalate, wherein waste polyethylene terephthalate is pulverized, followed by a supercritical corresponding process ( Supercritical glycolysis) discloses a method for producing polyester bis(2-hydroxyethyl) terephthalate, which is a polyester raw material, and the following Korean Patent No. 10-0353151 discloses a glycolysis reaction of recycled polyethylene terephthalate A method for preparing a saturated polyester by performing a step of preparing an intermediate and a step of condensing the intermediate and an aromatic dibasic acid is disclosed.

However, in these patents, the vinyl ester resin technology produced by applying PET has not yet been developed, and in general, vinyl ester resin is one of corrosion-resistant and thermosetting resins, which are dissolved in styrene by reacting unsaturated carboxylic acids with epoxy resin. It is a resin with excellent corrosion resistance, good mechanical strength, and high elongation.

The use of vinyl ester resin is similar to unsaturated polyester resin in its curing method and molding method, and its workability is easy and good. It has excellent physical properties such as overcuring, so it is widely used as an ultraviolet light and electronic curing paint.

Accordingly, the inventors of the present invention, focusing on the above technical issues, prepared a vinyl ester resin using polyethylene terephthalate flakes recycled through a material recycling process, confirmed that they had physical properties and corrosion resistance for pultrusion molding, and completed the present invention.

Korean Patent Publication No. 10-2011-0010173 Korean Patent Registration No. 10-0353151

Therefore, the present invention has as a technical solution to provide a method for producing a vinyl ester resin for pultrusion molding using recycled polyethylene terephthalate flakes.

In order to solve the above technical problem, the present invention,

A first step of preparing a polyol by glycolysis by reacting recycled polyethylene terephthalate (recycled PET) flakes, glycol, and a first polybasic acid;

A second step of preparing a monobasic acid for vinyl ester resin by reacting an acrylic monomer and a second polybasic acid with the polyol prepared in the first step;

A third step of preparing an epoxy resin-modified vinyl ester resin oligomer by reacting an epoxy resin with the monobasic acid prepared in the second step; and

A fourth step of diluting the epoxy resin-modified vinyl ester resin oligomer prepared in the third step with a vinyl monomer to prepare a vinyl ester resin; characterized in that it comprises,

Provided is a method for producing a vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes.

Preferably, in the present invention, in the first step, 300 to 430 parts by weight of recycled polyethylene terephthalate flakes, 280 to 370 parts by weight of glycol, and 280 to 340 parts by weight of a first polybasic acid are mixed with 0.08 to 0.13 parts by weight of a metal salt catalyst. After reaction, glycolysis is performed to prepare a polyol having a hydroxyl value of 110 to 150,

The glycol is at least one selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and neopentyl glycol,

The metal salt catalyst is characterized in that at least one selected from zinc acetate, antimony trioxide (Sb2O3), tin oxalate (SnC2O4) and monobutyltin oxide (C4H10O2Sn).

In the present invention, in the second step, 60 to 80 parts by weight of an acrylic monomer, 80 to 90 parts by weight of a second polybasic acid, and 0.20 to 280 parts by weight of an amine-based catalyst are added to 210 to 280 parts by weight of the polyol prepared in the first step. 0.30 parts by weight and 0.05 to 0.07 parts by weight of a polymerization inhibitor were added and reacted to prepare a monobasic acid having an acid value of 120 to 150,

The acrylic monomer is 2-methoxyethyl methacrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate t-butyl methacrylate sec- Butyl methacrylate, pentyl methacrylate, 2-ethylhexyl methacrylate, 2-ethylbutyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, n- at least one selected from octyl methacrylate, isooctyl methacrylate, isononyl methacrylate, lauryl methacrylate, tetradecyl methacrylate, and trimethylolpropane trimethacrylate (TMPTMA);

The amine-based catalyst is at least one selected from triethylamine, ethyltrimethylammonium bromide, dimethylbenzylamine, and di-n-butylamine,

The polymerization inhibitor is characterized in that at least one selected from hydroquinone, toluhydroquinone, methylhydroquinone and p-benzoquinone.

In the present invention, in the third step, 200 to 250 parts by weight of an epoxy resin is added to the monobasic acid prepared in the second step and reacted to prepare an epoxy resin-modified vinyl ester resin oligomer,

In the fourth step, after adding 0.08 to 0.1 parts by weight of a polymerization retardant to the epoxy resin-modified vinyl ester resin oligomer prepared in the third step, diluted with 370 to 410 parts by weight of a vinyl monomer,

The epoxy resin is at least one selected from bisphenol a-type epoxy resin, bisphenol F-type epoxy resin, novolak-type epoxy resin and alicyclic epoxy resin,

The vinyl monomer is styrene, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, ethyl hexaacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, propyl ( meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tertiary-butyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acryl It is characterized in that it is at least one selected from the group consisting of late, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate.

In the present invention, the first polybasic acid and the second polybasic acid are characterized in that at least one selected from phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride and adipic acid.

The method for producing an eco-friendly, corrosion-resistant vinyl ester resin for pultrusion molding using recycled polyethylene terephthalate flakes according to the present invention increases the molecular weight of the vinyl ester resin by preparing acrylic acid with PET-modified polyol, and improves the corrosion resistance structure and toughness in the molecule by the PET component. It is not only environmentally friendly because it can be improved to produce vinyl ester resin, but also has excellent mechanical properties and toughness, so it has the advantage of recycling resources.

According to the present invention, the viscosity is low, and it has excellent impregnability with glass fibers and carbon fibers, and excellent mechanical properties.

Furthermore, the recycled vinyl ester resin is a pultrusion-molded reinforced plastic that is used as a corrosion-resistant REBAR for structures that can replace reinforcing bars in concrete structures. As a polymer resin, which is a raw material for excellent carbon fiber composites, recycled vinyl ester resin has the advantage of being widely used as an industrial material.

1 is a flowchart showing a manufacturing process of a method for manufacturing a vinyl ester resin for pultrusion molding using recycled polyethylene terephthalate flakes according to the present invention.

The present invention will be described in detail with reference to the drawings below.

1 is a flowchart showing a manufacturing process of a method for manufacturing a vinyl ester resin for pultrusion molding using recycled polyethylene terephthalate flakes according to the present invention.

Referring to Figure 1, the method for producing a vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes of the present invention is a glycolysis by reacting recycled polyethylene terephthalate (recycled PET) flakes, glycol and a first polybasic acid ( Glycolysis) to prepare a polyol; A second step of preparing a monobasic acid for vinyl ester resin by reacting an acrylic monomer and a second polybasic acid with the polyol prepared in the first step; A third step of preparing an epoxy resin-modified vinyl ester resin oligomer by reacting an epoxy resin with the monobasic acid prepared in the second step; and a fourth step of preparing a vinyl ester resin by diluting the epoxy resin-modified vinyl ester resin oligomer prepared in the third step with a vinyl monomer.

That is, in the present invention, in the production of vinyl ester resin for glass fiber reinforced plastics produced by pultrusion, industrial waste polyethylene terephthalate oligomer and PET generated from household goods are pulverized and recycled PET flakes as main raw materials to obtain vinyl ester resin It's about how to make it. In particular, the present invention reacts glycol and polybasic acid on recycled PET flakes to obtain polyol, improves the working environment and mechanical properties of pultrusion molded reinforced plastics by using reactive acrylic monomers with low odor and fire risk, and epoxy resin It is characterized by imparting strong acid resistance and oxidation resistance by reacting and denaturing, and realizing strong acid resistance and corrosion resistance by diluting with a vinyl-based monomer.

The following steps are divided into more detailed descriptions.

First, a first step is a step of preparing a polyol by reacting recycled polyethylene terephthalate (recycled PET) flakes, glycol, and a first polybasic acid to perform glycolysis. Preferably, 300 to 430 parts by weight of recycled polyethylene terephthalate flakes, 280 to 370 parts by weight of glycol, and 0.08 to 0.13 parts by weight of a metal salt catalyst are mixed with 280 to 340 parts by weight of a first polybasic acid, followed by heating and mixing in a nitrogen atmosphere. It is reacted at 215 ~ 225 ℃ to produce a polyol having a hydroxyl value of 110 ~ 150 by glycolysis.

At this time, the recycled polyethylene terephthalate may be flakes or fine chips obtained by pulverizing polyethylene terephthalate generated when discarding household goods after use, and may be at least one selected from among them. It is preferable that the amount used be 300 to 430 parts by weight. If the amount is less than 300 parts by weight, the hydroxyl value of the polyol of the vinyl ester resin increases, the content of the epoxy resin reacting increases, the viscosity of the vinyl ester resin decreases, the fiber impregnability improves, but the PET content is low, so the cost of the resin increases, This is because when it exceeds 430 parts by weight, the viscosity of the vinyl ester resin is too high, the fiber impregnability is poor, and the price of the resin is lowered, but the mechanical strength is lowered.

In addition, the glycol may be at least one selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and neopentyl glycol, and may contain 280 to 370 parts by weight. The viscosity of the polyol is compatible, and the glycol may be selected and included by adjusting the weight within the above weight range so that the hydroxyl value is 110 to 150.

Most preferably, it is good to mix diethylene glycol, neopentyl glycol, propylene glycol and a polybasic acid. Specifically, the amount used is preferably mixed with 160 to 200 parts by weight of diethylene glycol, 100 to 130 parts by weight of neopentyl glycol, 20 to 40 parts by weight of propylene glycol, and 280 to 340 parts by weight of a polybasic acid.

In this case, 160 to 200 parts by weight of diethylene glycol is mixed. This is because if diethylene glycol is less than 160 parts by weight, the compatibility of the resin is excellent, but the decomposition time of PET is prolonged, and if it exceeds 200 parts by weight, the compatibility of the resin is lowered, and problems such as cloudiness and reddening of color at high temperatures occur. .

In addition, 100 to 130 parts by weight of neopentyl glycol is mixed. Neopentyl glycol has good reactivity and improves the water resistance of the resin, so it is mainly used as a raw material for SMC of water-resistant unsaturated polyester resin. When the amount exceeds 130 parts by weight, the price of the resin and the viscosity of the polyol increase, resulting in a problem in that the viscosity of the resin increases in the second stage reaction.

In addition, propylene glycol is mixed in 20 to 40 parts by weight. In order to control the viscosity of the polyol and the hydroxyl value of the polyol, 20 to 40 parts by weight are added at the end of the reaction. If it is less than 20 parts by weight, the viscosity of the polyol increases, and if it exceeds 40 parts by weight, the viscosity decreases, but the hydroxyl value increases.

In addition, the polybasic acid is a saturated polybasic acid and may be selected from phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride and adipic acid. The amount used is 280 to 340 parts by weight. If it is less than 280 parts by weight, the final hydroxyl value is low, the viscosity of the polyol is low and the molecular weight is small, and if it exceeds 340 parts by weight, the hydroxyl value is high, the reaction time is long, and the viscosity is high, so it is too hard and There is a problem that it takes a lot of time to melt and use.

In addition, as the metal salt catalyst, one or more types may be selected from among zinc acetate, antimony trioxide (Sb2O3), tin oxalate (SnC2O4), and monobutyltin oxide (C4H10O2Sn). The amount used is preferably 0.08 to 0.13 parts by weight. This is because when the amount is less than 0.08 parts by weight, glycolysis does not occur well, and when the amount exceeds 0.13 parts by weight, internal foaming due to overreaction occurs.

As described above, after putting appropriate amounts of recycled polyethylene terephthalate flakes, glycol, polybasic acid and metal salt catalyst into a reactor, heating and mixing in a nitrogen atmosphere, reacting in a stable state at 215 to 225 ° C for 3 hours to glycolize recycled polyethylene terephthalate to glycol can get angry At this time, polyols of ethylene glycol, diethylene glycol, dipropylene glycol, terephthalic acid, and polybasic acid may be produced by glycol sheath. Furthermore, when the reaction temperature is less than 215 ° C, the reaction time for glycolysis becomes longer, and when it exceeds 225 ° C, the color of the unsaturated polyester resin turns brown, so it is important to react within the above range.

In addition, the reaction may be terminated at a value of 110 to 150 by measuring the hydroxyl value of the reaction product by glycolysis of the recycled polyethylene terephthalate.

Next, the second step is a step of preparing a monobasic acid for vinyl ester resin by reacting the polyol prepared in the first step with an acrylic monomer and a second polybasic acid. Specifically, 210 to 280 parts by weight of the polyol prepared in the first step, 60 to 80 parts by weight of an acrylic monomer, 80 to 90 parts by weight of a second polybasic acid, 0.20 to 0.30 parts by weight of an amine catalyst, 0.05 to 0.05 parts by weight of a polymerization inhibitor 0.07 part by weight is added, the temperature is raised to 110 ° C, and the reaction is performed for 1 hour to produce a monobasic acid having an acid value of 120 to 150 for vinyl ester resin. In the second step, a polybasic acid and an acrylic monomer are reacted with the PET polyol produced in the first step to produce a monobasic acid for vinyl ester resin.

At this time, it is included in 210 to 280 parts by weight of the product polyol produced by the reaction in the first step. If it is less than 210 parts by weight, the amount of PET used is low, so price competitiveness is lowered, and the content of the reacting epoxy resin is increased to increase the viscosity There is a problem, and in the case of more than 280 parts by weight, the price competitiveness is increased, but the content of maleic anhydride and reactive monomers reacting increases, which increases the risk of cracking during curing and gelation during reaction.

In addition, as the second polybasic acid, unsaturated dibasic acids such as maleic anhydride and fumaric acid may be selectively used. The amount used is 80 to 90 parts by weight, and when less than 80 parts by weight, the content of the PET polyol and the content of the acrylic monomer in the first step are lowered, so that the unsaturated content is lowered during curing of the vinyl ester resin, so the strength of the resin is lowered, and the strength of the resin is lowered when the vinyl ester resin is cured. In case of curing the resin, cracks due to heat generation may occur due to the high unsaturated content participating in the reaction. More preferably, as an embodiment of the present invention, maleic anhydride, which does not generate water by reacting with glycol during the reaction, was used.

In addition, the acrylic monomer is a reactive monomer, 2-methoxyethyl methacrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate t-butyl meth Acrylate sec-butyl methacrylate, pentyl methacrylate, 2-ethylhexyl methacrylate, 2-ethylbutyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, 2-methoxyethyl methacrylate rate, n-octyl methacrylate, isooctyl methacrylate, isononyl methacrylate, lauryl methacrylate, tetradecyl methacrylate, and trimethylolpropane trimethacrylate (TMPTMA). . In one embodiment of the present invention, 2-hydroxyethyl acrylate (2-HEA) having a low molecular weight was selected in consideration of the viscosity of the vinyl ester resin.

At this time, the amount used is 60 to 80 parts by weight of acrylic monomer. If less than 60 parts by weight, the strength of the resin is lowered due to the low unsaturated content participating in the reaction. Cracks may occur due to

In addition, in order to promote the reaction between the polyol produced in the first step and the second polybasic acid, the reaction temperature was raised to 110 ° C., and 0.05 to 0.07 parts by weight of a polymerization inhibitor and 0.20 to 0.30 parts by weight of an amine catalyst were added and reacted.

At this time, as the polymerization inhibitor, at least one selected from among hydroquinone, toluhydroquinone, methylhydroquinone, and p-benzoquinone may be mixed and used, and storage stability of the unsaturated polyester resin when the input amount is less than 0.05 parts by weight It is difficult to store for a long period of time due to the lowering, and when it exceeds 0.07 parts by weight, the gelation time becomes longer and the work efficiency decreases.

In addition, the amine-based catalyst may be one or more selected from triethylamine, ethyltrimethylammonium bromide, dimethylbenzylamine, and di-n-butylamine, and when the amount of the added amount is less than 0.20 parts by weight, the reaction time becomes longer and 0.30 parts by weight If it exceeds the part, the reaction rate is very fast and heat is generated severely, resulting in a problem in that acrylic acid storage stability is lowered.

In addition, the acid value of the vinyl ester resin monobasic acid product may be measured and the reaction may be terminated at a value of 120-150. Furthermore, if the reaction temperature is 115 ° C or higher, the unsaturated base acid and the unsaturated group of the reactive monomer react with each other, increasing the risk of gelation during synthesis.

Next, in the third step, an epoxy resin is reacted with the monobasic acid prepared in the second step to prepare an epoxy resin-modified vinyl ester resin oligomer, and the monobasic acid prepared in the second step is reacted with an epoxy resin. A step of preparing an epoxy resin-modified vinyl ester resin oligomer by adding 200 to 250 parts by weight and reacting, which is a step of improving mechanical and chemical properties by using an epoxy resin. Specifically, epoxy resin is a resin that is used in various fields such as surface coating, electrical insulation, laminated structures, construction, and adhesives because of its excellent heat resistance, chemical resistance, solvent resistance, adhesiveness, and abrasion resistance, and excellent electrical and mechanical properties. At this time, the epoxy resin may be selected from one or more of bisphenol-a-type epoxy resin, bisphenol-F-type epoxy resin, novolak-type epoxy resin, and alicyclic epoxy resin. Accordingly, bisphenol a-type vinyl ester resin has the advantages of excellent chemical resistance, heat resistance, corrosion resistance and hardness, fast curing speed, and relatively low price, and when mixed with novolak-type vinyl ester resin, it has excellent corrosion resistance, super heat resistance, and high It has a heat distortion temperature and has excellent mechanical properties so that it does not break.

In the present invention, 150 to 180 parts by weight of a low viscosity bisphenol a-type epoxy resin and 50 to 70 parts by weight of a medium viscosity bisphenol a-type epoxy resin were added to prepare an epoxy resin-modified vinyl ester resin at 100 to 110 ° C.

In the case of less than 150 parts by weight of low-viscosity type bisphenol-a epoxy resin, the viscosity of the resin becomes too high due to the relatively large number of epoxy resins of medium viscosity during synthesis, and in the case of more than 180 parts by weight, the resin viscosity decreases and the impregnation property is improved, but the resin viscosity is low. There is a problem that the stickiness of the surface becomes severe during hardening.

Also preferably, in the third step, the epoxy resin reacts at 100 to 110° C., including the catalyst and the polymerization inhibitor, and 0.30 to 0.50 parts by weight of an amine-based catalyst may be added as the catalyst. At this time, the amine-based catalyst may be at least one selected from triethylamine, ethyltrimethylammonium bromide, dimethylbenzylamine, and di-n-butylamine, and when the catalyst amount is less than 0.30 parts by weight, the reaction time becomes longer and 0.5 parts by weight In the case of exceeding a part, the reaction rate is very fast and severe heat generation occurs, resulting in a problem in that acrylic acid storage stability is lowered.

In addition, as the polymerization inhibitor, at least one selected from among hydroquinone, toluhydroquinone, methylhydroquinone, and p-benzoquinone may be mixed and used, and the amount of the polymerization inhibitor is preferably 0.05 to 0.07 parts by weight.

Finally, the fourth step is a step of preparing a vinyl ester resin by diluting the epoxy resin-modified vinyl ester resin oligomer prepared in the third step with a vinyl monomer. Specifically, 0.08 to 0.10 parts by weight of a room temperature stable polymerization retardant is added to the epoxy resin-modified vinyl ester oligomer prepared in the third step, and then diluted with 370 to 410 parts by weight of a vinyl monomer to prepare a vinyl ester resin.

The vinyl monomer is a reactive diluent, styrene, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, ethyl hexaacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate Late, propyl(meth)acrylate, n-butyl(meth)acrylate, iso-butyl(meth)acrylate, tertiary-butyl(meth)acrylate, lauryl(meth)acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate, and at least one member may be selected from the group consisting of, more preferably styrene, methyl methacrylate, 2-hydroxyethyl methacryl It is good to choose among rates.

The diluted vinyl monomer is included according to the viscosity of the resin. If it is less than 370 parts by weight, the viscosity of the resin increases and the impregnability of the fiber decreases. If it exceeds 410 parts by weight, the resin viscosity decreases and the impregnability improves, but the viscosity of the resin is too Since it is lowered and the resin flows down during pultrusion, it is preferably included in 370 to 410 parts by weight.

As described above, while sequentially passing through the first to fourth steps, an eco-friendly, corrosion-resistant vinyl ester resin for pultrusion molding can be manufactured using recycled polyethylene terephthalate flakes.

Hereinafter, the present invention will be described in more detail with examples, but this is presented for explanation only, and the present invention is not limited to these examples.

<Example 1>

1) 170g of diethylene glycol, 109g of neopentyl glycol, 25g of propylene glycol, 406g of PET chips, 290g of phthalic anhydride, and 0.13g of zinc acetate were put into a 2L reactor as catalysts, and the temperature was raised to 190℃ while supplying nitrogen. The temperature was raised to 215 ° C. over 4 hours while gradually raising and stirring. While maintaining the temperature, the acid value was measured and when the solid acid value was 30 or less and the hydroxyl value (OHv) was 130 or less, the temperature was cooled to 100 ° C or less to prepare PET polyol.

2) 247 g of the prepared PET polyol, 60 g of 2-hydroxyethyl acrylate (2-HEA), 83 g of maleic anhydride, 0.25 g of an amine catalyst (triethylamine), and 0.06 g of toluhydroquinone were mixed and the temperature was raised to 105 ° C. It was reacted for 1 hour while maintaining the temperature by raising the temperature so that the acid value was 140 or less.

3) When the acid value is below 140, while maintaining the temperature at 105℃, 167g of epoxy resin YD-128 (Kukdo Chemical) and 54g of YD-011 (Kukdo Chemical) are divided into 5 times and added over 2 hours, and maintained at 105℃ for 2 hours. When the reaction was abnormal and the acid value was measured and the acid value was less than 15, 0.1 g of toluhydroquinone was added and mixed.

4) When the acid value was 15 or less, 379 g of styrene monomer and 0.09 methylhydroquinone were added and diluted to prepare a vinyl ester resin by further adjusting the styrene monomer while maintaining the temperature at 60° C. or less.

<Example 2>

In this example, it was prepared in the same manner as in Example 1, but with 160 g of diethylene glycol, 105 g of neopentyl glycol, 24 g of propyl glycol, 424 g of PET chips, 282 g of phthalic anhydride, and 0.14 g of zinc acetate, the PET polyol acid value was 30. Hereinafter, a hydroxyl value (OHv) of 114 was prepared, and 270 g of PET polyol, 58 g of 2-hydroxyethyl acrylate (2-HEA), 81 g of maleic anhydride, 0.23 g of triethylamine, and 0.06 g of toluhydroquinone contained vinyl with an acid value of 140 or less. After preparing acrylic acid, 162 g of epoxy resin YD-128 and 51 g of YD-011 were added to 367 g of styrene monomer and 0.09 methylhydroquinone in a vinyl ester oligomer having an acid value of 15 or less, and diluted to further adjust the styrene monomer to prepare a vinyl ester resin.

<Example 3>

In this example, in the same manner as in Example 1, 193 g of diethylene glycol, 126 g of neopentyl glycol, 30 g of propyl glycol, 315 g of PET chips, 335 g of phthalic anhydride, 0.08 g of zinc acetate, PET polyol acid value of 30 or less, Hydroxyl value (OHv) 141 was prepared, and 213 g of PET polyol, 63 g of 2-hydroxyethyl acrylate (2-HEA), 88 g of maleic anhydride, 0.26 g of triethylamine, and 0.07 g of toluhydroquinone were used to obtain vinyl-containing acrylic acid having an acid value of 140 or less. 400 g of styrene monomer and 0.10 g of methylhydroquinone were added to a vinyl ester oligomer having an acid value of 15 or less with 175 g of epoxy resin YD-128 and 56 g of YD-011, and diluted to further adjust the styrene monomer to prepare a vinyl ester resin of Example 2. .

<Comparative Example 1>

After putting 118g of epoxy resin YD-128 and 38.09g of YD-011 in a reactor and raising the temperature to 100℃ while supplying air, 0.6g of 2-methylimidazole amine catalyst and 0.20g of polymerization inhibitor hydroquinone (HQ-S) were added to the reactor. put in A temperature of 100 ° C. 100 g of methacrylic acid (MAA) was slowly added over 2 hours, and the reaction was carried out paying attention to exotherm.

When the addition of methacrylic acid was completed, the reaction was stopped when the acid value became 15 or less while maintaining the temperature at 105° C., and diluted with 390 g of styrene monomer. A vinyl ester resin was prepared by further adjusting the styrene monomer.

<Test Example>

Test methods and measurement results such as mechanical properties of the vinyl ester resin according to Examples 1 to 3 and Comparative Example 1 are shown in Table 1 below.

Example
One Example
2 Example
3 comparative example
One Test Methods Polyol OHv 124 112 145 - ASTM D 4274, E222 Potentiometric Measurement viscosity
(POISE) 4.7 4.9 5.3 5.0 Measured at 25°C with a Brockfield LVT viscometer Non-volatile content
(%) 61 62 60 61 Melt the resin in a toluene/methanol solution in an oven at 107°C and volatilize for 1 hour, then convert the remaining amount into percentage (%) resin acid value
(KOH mL/g) 10.8 11.5 10.0 9.0 Measured with KOH solution gelation time
(minute) 7 6 8 6 Measured based on 1% of curing agent in a 50℃ thermostat resin barcol hardness
(Barcol) 39 40 42 39 Based on 1% curing agent, measured by curing at 50℃ and then curing at 80℃ for 2 hours Laminated Barcol Hardness
(Barcol) 47 46 48 47 After stacking three layers of glass fiber mat (#450), curing at 50℃, and then curing at 80℃ for 2 hours, measurement tensile strength
(MPa) 50 49 49 47 ASTM D-638 flexural strength
(MPa) 100 99 105 99 ASTM D-638 elongation
(%) 3.3 3.2 2.0 2.2 ASTM D-638 Storage at 60℃
(Day) 10 9 8 8 Measure the gelation time of the resin while keeping it in a temperature-controlled oven for a certain period of time 105℃ storage
(hour) 1.5 1.5 One 1.0 Measure the gelation time of the resin while keeping it in a temperature-controlled oven for a certain period of time

As can be seen in Table 1, it was confirmed that the vinyl ester resin according to Examples 1 to 3 of the present invention has excellent mechanical properties and elongation equal to those of the vinyl ester resin according to Comparative Example 1. That is, when according to the method of the present invention, a vinyl ester resin is prepared using PET flake as a main raw material, but it can exhibit physical properties equal to or better than those of a vinyl ester resin using a new material.

As such, the present invention reacts glycol and polybasic acid on recycled PET flakes to obtain polyol, improves the working environment and mechanical properties of pultrusion molded reinforced plastics by using reactive acrylic monomers with low odor and fire risk, and reacts epoxy resin It is possible to produce vinyl ester resin, which is an unsaturated polyester resin for glass fiber reinforced plastics manufactured by pultrusion molding, by imparting strong acid resistance and oxidation resistance by denaturation, and by diluting with a vinyl monomer to impart strong acid resistance and corrosion resistance. .

The above description is only illustrative of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (5)

A first step of preparing a polyol by glycolysis by reacting recycled polyethylene terephthalate (recycled PET) flakes, glycol, and a first polybasic acid;
A second step of preparing a monobasic acid for vinyl ester resin by reacting an acrylic monomer and a second polybasic acid with the polyol prepared in the first step;
A third step of preparing an epoxy resin-modified vinyl ester resin oligomer by reacting an epoxy resin with the monobasic acid prepared in the second step; and
A fourth step of diluting the epoxy resin-modified vinyl ester resin oligomer prepared in the third step with a vinyl monomer to prepare a vinyl ester resin; characterized in that it comprises,
Manufacturing method of vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes. According to claim 1,
In the first step, 300 to 430 parts by weight of recycled polyethylene terephthalate flakes, 280 to 370 parts by weight of glycol, and 280 to 340 parts by weight of a first polybasic acid are mixed with 0.08 to 0.13 parts by weight of a metal salt catalyst, followed by reaction and glycolysis. A polyol having a hydroxyl value of 110 to 150 is prepared,
The glycol is at least one selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and neopentyl glycol,
Characterized in that the metal salt catalyst is at least one selected from zinc acetate, antimony trioxide (Sb2O3), tin oxalate (SnC2O4) and monobutyltin oxide (C4H10O2Sn),
Manufacturing method of vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes. According to claim 1,
In the second step, 60 to 80 parts by weight of an acrylic monomer, 80 to 90 parts by weight of a second polybasic acid, 0.20 to 0.30 parts by weight of an amine-based catalyst, 210 to 280 parts by weight of the polyol prepared in the first step, polymerization inhibition Adding 0.05 to 0.07 parts by weight and reacting to prepare a monobasic acid having an acid value of 120 to 150,
The acrylic monomer is 2-methoxyethyl methacrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate t-butyl methacrylate sec- Butyl methacrylate, pentyl methacrylate, 2-ethylhexyl methacrylate, 2-ethylbutyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, n- at least one selected from octyl methacrylate, isooctyl methacrylate, isononyl methacrylate, lauryl methacrylate, tetradecyl methacrylate, and trimethylolpropane trimethacrylate (TMPTMA);
The amine-based catalyst is at least one selected from triethylamine, ethyltrimethylammonium bromide, dimethylbenzylamine, and di-n-butylamine,
Characterized in that the polymerization inhibitor is at least one selected from hydroquinone, toluhydroquinone, methylhydroquinone and p-benzoquinone,
Manufacturing method of vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes. According to claim 1,
In the fourth step, a polymerization retardant is added to the epoxy resin-modified vinyl ester resin oligomer prepared in the third step, and then diluted with a vinyl monomer.
The epoxy resin is at least one selected from bisphenol a-type epoxy resin, bisphenol F-type epoxy resin, novolak-type epoxy resin, and alicyclic epoxy resin,
The vinyl monomer is styrene, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, ethyl hexaacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, propyl ( meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tertiary-butyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acryl It is characterized in that at least one selected from the group consisting of late, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate,
Manufacturing method of vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes. According to claim 1,
Characterized in that the first polybasic acid and the second polybasic acid are at least one selected from phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride and adipic acid,
Manufacturing method of vinyl ester resin for pultrusion using recycled polyethylene terephthalate flakes.

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