KR20030088720A - Polyester resin composition, agent for modifying polyester resin and polyester resin mold - Google Patents

Abstract

An object of the present invention is to make a molded article of various shapes using a polyester resin as a material.

Melt-florate (MFR) by JISK7210 Table 1 and the conditions 4 to a polyester resin adds 20 g / 10min or less thickener, and increases melting | fusing point. In particular, for the regenerated polyester resin, a polymerizing agent having a functional group capable of reacting with the polyester resin is added, in addition to the thickener.

Description

Polyester resin composition, polyester resin modifier and resin molding {POLYESTER RESIN COMPOSITION, AGENT FOR MODIFYING POLYESTER RESIN AND POLYESTER RESIN MOLD}

The present invention relates to a polyester resin composition having an improved melt viscosity, a polyester resin modifier for modifying the melt viscosity of a polyester resin, and a resin molding comprising the polyester resin composition.

Since the polyester resin has a low melt viscosity, in extrusion or injection molding that does not include an extension process, a drawdown phenomenon occurs due to the weight of the melt falling down from the die of the extrusion machine or the nozzle of the injection molding machine due to its own weight. It was difficult. Therefore, the polyester resin is molded by extrusion molding, injection molding, or blow molding, which includes an extension step, which causes a problem that the molding shape is limited to a film shape, a fiber shape, and a container shape. That is, when the extension step is included, the molecular force of the polyester resin is oriented by the extension force and the melt viscosity becomes high, so that the drawdown phenomenon is less likely to occur.

Recently, attention has been paid to the recycling of scraps of polyester resin molded articles such as PET bottles, but since the polyester resin is made low molecular weight by heat treatment at the time of recycling, the melt viscosity becomes lower and the problem is more serious. Becomes And even if a molded article is produced, the molded article by the low molecular weight polyester resin has a large problem in use due to deterioration in mechanical strength.

Conventionally, in order to raise the melt viscosity of polyester resin, especially regenerated polyester resin, the means which aims at high molecular weight by adding resin which has a functional group which can react with polyester resins, such as an epoxy group, is proposed.

However, there is a problem in that such high molecular weight means has a high molecular weight limit, and in particular, in a regenerated polyester resin, sufficient melt viscosity for extrusion molding is not obtained.

1 is a graph showing the relationship between shear rate and melt viscosity of a sample using various thickeners and polymerizing agents.

2 is a graph showing the relationship between shear rate and melt viscosity of a sample to which modifier A is added in various amounts.

3 is a graph showing the relationship between shear rate and melt viscosity of a sample to which modifier B is added in various amounts.

4 is a graph showing the relationship between the molding temperature and the spiral length of the sample to which the modifier A is added in various amounts.

5 is a graph showing the relationship between the molding temperature and the spiral length of the sample to which the modifier B is added in various amounts.

The present invention provides a polyester resin composition comprising a polyester resin and a thickener of 20 g / 10 min or less in melt flow rate (MFR) according to JISK7210 Table 1, Condition 4 as a means for solving the conventional problems. will be.

It is preferable that 2-100 mass parts of said thickeners are added with respect to the mass part of polyester resin (100). Especially in the case of regenerated polyester resin, it is preferable to add a polymerizing agent having a functional group capable of reacting with the polyester resin. The thickener and the polymerizing agent are preferably mixed in a mass ratio of 1: 1 to 10: 1, and in general, the functional group of the polymerizing agent is preferably an epoxy group.

Furthermore, the present invention provides a polyester resin modifier containing a polymerizing agent having a MFR of 20 g / 10 min or less and a functional group capable of reacting with the polyester resin. It is preferable that the thickener is a polymer alloy of polypropylene and synthetic rubber, and it is preferable that the thickener and the polymerizing agent are mixed in a 6: 4-9: 1 mass ratio.

Moreover, it is providing the resin molding which consists of polyester resin composition. The resin molding is preferably produced by extrusion or injection molding, and the polyester resin composition of the resin composition may be extruded or injection molded without preliminary drying or degassing or removing moisture during molding. Do.

The present invention is described in detail below.

(Example)

[Polyester Resin]

The polyester resin of the present invention is a resin obtained by esterification of a divalent or higher polyhydric alcohol with a divalent or higher carboxylic acid, and is, for example, polyethylene terephthalate (PET) or polybutylene terephthalate.

The present invention is particularly useful for recycled polyester resins.

[Thickener]

The thickener of the present invention is to increase the melt viscosity of the polyester resin. As such a thickener, resin or elastomer which has a high melt viscosity is selected. Examples of the thickener include polyolefin resins or elastomers such as polyethylene, polypropylene, and ethylene-ethyl acrylate copolymer (EEA), styrene-butadiene-styrene block copolymer (SBS), and styrene-ethylene-butadiene-. Styrene-type elastomers, such as a styrene block copolymer (SEBS), or the polymer alloy of the said polyolefin resin, the said styrene-type elastomer, and / or synthetic rubber. As the synthetic rubber, for example, acrylic rubber, butyl rubber, ethylene-propylene rubber (EPR, EPDM), silicon rubber, urethane rubber, fluoride rubber, polysulfide rubber, graft rubber, butadiene rubber, isoprene rubber, chloroprene rubber, poly Isobutylene rubber, polybutene rubber, isobutene-isoprene rubber, acrylate-butadiene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), pyridine-butadiene rubber, styrene-isoprene rubber, acrylic Ronitrile-chloroprene rubber, styrene-chloroprene rubber, and the like.

As a thickener having a high thickening effect, there is a polymer alloy of polypropylene and the synthetic rubber. As the synthetic rubber, EPR, EPDM or SBR having good compatibility with polypropylene is preferable. In addition, when the polymer alloy is used as a thickener in a regenerated polyester resin, the resin does not cause yellowing or blocking in the case of pre-drying after extrusion water cooling.

Melt florate (MFR) of the thickener is 0.5 to 20 g / 10 minutes, preferably 0.5 to 10 g by a measuring method based on JISK7210 Table 1, Condition 4 (test temperature 190 ° C, test load 21.18 (N)). / 10 minutes, more preferably 0.5 to 5 g / 10 minutes, the thickener is usually 2 to 100 parts by mass, preferably 3 to 50 parts by mass, more preferably 10 to 10 parts by mass of the polyester resin (100) When the added amount of the thickener is less than 2 parts by mass, the thickening effect is not remarkable, and if it exceeds 100 parts by mass, the rigidity of the product may be lowered.

In the present invention, the thickener may be added not only to increase the melt viscosity of the polyester resin but also to improve heat resistance, impact resistance, dimensional stability, rigidity, and the like.

[Polymerizing agent]

In the present invention, a polymerizing agent is used especially for resins in which the melt viscosity is significantly lowered due to low molecular weight such as recycled polyester resin. As the polymerizing agent, a resin or elastomer having a functional group reacting with the polyester resin is used.

As a functional group reacting with the said polyester resin, an epoxy group, a carboxyl group, an isocyanate group, etc. are mentioned, for example, An epoxy group is preferable at the point which has high reactivity with polyester resin. As the resin or elastomer having such a functional group, styrene is grafted to an ethylene-based copolymer such as an ethylene-glycidyl methacrylate (GMA) copolymer, an ethylene-acrylic acid copolymer, an ethylene-vinyl isocyanate copolymer, or the ethylene-based copolymer. Polystyrene graft ethylene copolymers in which a styrene copolymer is grafted to a styrene copolymer, an epoxy group-containing SBS, an epoxy group-containing SEBS, an epoxy group-containing EEA, a carboxyl group-containing SBS, a carboxyl group-containing SEBS, and a carboxyl group-containing EEA. In addition, it is preferable that the difference of the sorbability parameter of the said polymerizing agent and a thickener is less than one.

The polymerizing agent is preferably selected to have a skeleton that is the same as the thickener used. For example, when the thickener is an olefin thickener such as polyethylene, EEA, EPR or EPDM, the polymerizing agent may be an olefin polymerizer such as ethylene-glycidyl methacrylate copolymer, ethylene-acrylic acid copolymer or ethylene-vinyl isocyanate copolymer. When the thickener is SBS or SEBS, SBS or SEBS polymerizer such as epoxy group-containing SBS or SEBS, carboxyl group-containing SBS or SEBS is selected. The polymerizing agent is usually added in an amount of 0.1 to 100 parts by mass, preferably 0.3 to 50 parts by mass, and more preferably 1.0 to 20 parts by mass with respect to 100 parts by mass of the polyester resin 100.

If the addition amount of the above-mentioned polymerizing agent is less than 0.1 parts by mass, the polymerization effect and the compatibilizing effect for the thickener are not sufficiently exhibited, and when added in excess of 100 parts by mass, the effect is saturated without a significant change.

It is preferable that the mixing ratio of the thickener mixed with the polyester resin and the polymerizing agent is usually 1: 1 to 10: 1 by mass. In other words, even if the amount of the polymerizing agent is less than that of the thickener, if the amount is more than 1/10 of the thickener, the polymerizing effect is sufficiently exhibited. However, when the amount is added in excess of the same amount as the thickener, the polymerizing effect is saturated, and the extrudability is also inhibited.

[Polyester Resin Modifier]

The thickener and the polymerizing agent may be mixed to prepare a polyester resin modifier. In this case, the mixing ratio of the thickener and the polymerizing agent is 1: 1 to 10: 1, preferably 6: 4 to 9: 1 parts by mass, as described above. Preferred thickeners as the modifier are polymer alloys of the polypropylene and synthetic rubber, and preferred synthetic rubbers are EPR, EPDM and SBR.

[Other components]

In the present invention, in order to further improve the heat resistance, impact resistance, dimensional stability, rigidity, etc. of the polyester resin composition, for example, styrene-isoprene rubber (SIR), styrene-ethylene copolymer, poly (α-methylstyrene) -poly Butadiene-poly (αmethylstyrene) copolymer (α-MeS-β-α-MeS), poly (αmethylstyrene) -polyisoprene-poly (α-methylstyrene) copolymer, butadiene-styrene copolymer (BS) , Ethylene-propylene-ethylidene copolymer, ethylene-vinyl acetate copolymer, ethylene-butene-1 copolymer, ethylene-propylene-ethylidenenorbornene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene- Propylene-1,4 hexadiene copolymer, ethylene-butene-1-ethylidenenorbornene copolymer, ethylene-butene-1-dicyclopentadiene copolymer, ethylene-butene-1-1, 4hexadiene copolymer , Acrylonitrile-chloroprene copolymer (NCR), styrene- Resins such as chloroprene copolymer (SCR) or elastomers, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, calcium sulfite, calcium phosphate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, magnesium oxide, titanium oxide, iron oxide, zinc oxide , Aluminum, silica, diatomaceous earth, roadmite, gypsum, talc, clay, asbestos, mica, glass fiber, calcium silicate, bentonite, white carbon, carbon black, iron powder, aluminum powder, stone powder, furnace slag, fly ash, Fillers such as cement and zirconia powder, flame retardants, antioxidants, anti-aging agents, ultraviolet absorbers, antistatic agents, crystallization accelerators, foaming agents, dyes, colorants such as pigments and the like may be added. The component may be added to the polyester resin modifier.

〔combination〕

The blending method of the above components is preferably a drive blend, and in particular, it is preferable to pelletize a mixture of a thickener and a polymerizing agent, and to injection molding by mixing the pellets with a pulverized product of a polyester resin, particularly a flake-shaped pulverized product. .

As described above, in the case of the polyester resin composition in which 3 parts by mass or more of a thickener and 1 part by mass or more of a polymerizing agent are added to the mass of the polyester resin 100 of the present invention, the composition contains water and the polyester Even if the resin is hydrolyzed during the regeneration or molding process to lower the molecular weight, the low molecular weight polyester resin is polymerized by the polymerizing agent and the melt viscosity is thickened by the thickener, so that preliminary drying is performed before molding, or Molding can be performed without performing deaeration moisture removal during molding.

Hereinafter, the present invention will be described in detail by way of examples. In addition, this invention is not limited only to the Example shown below.

[Example 1] (New Polyester Resin)

Using a polyethylene terephthalate resin (PET) in which the dicarboxylic acid unit is obtained from 100 mol% of terephthalic acid, the diol unit is from 98 mol% of ethylene glycol, and 2 mol% of diethylene glycol, and the ethylene prephthalate unit comprises 98 mol% of the precursor repeating unit. By blending Table 1, Thickener A (Low Density Polyethylene (LDPE): MFR 4.0 g / 10 min) and Thickener B (Reactor-TPO: Polypropylene-EPR Polymer Alloy, MFR 0.6 g / 10 min) were respectively driven and Melt viscosity was measured under conditions of a die diameter of 1 mm, measurement temperature of 270 ° C., and preheating time of 300 seconds using a capillary graph manufactured by Dongyang Seiki Co., Ltd., and barrel temperature of 260 to 270 ° C., mold temperature: surface of 25 to 35 ° C., injection Injection molding under a pressure of about 1000 kgf / cm 2 to prepare a plate of 175 mm x 12.7 mm and a thickness of 4 mm, and then process the plate to test pieces of 64 mm x 12.7 mm and notch depth of 2.54 mm (JISK7110). Side, impact resistance He said. The results are shown in Table 1.

According to Table 1, the melt viscosity (shearing rate of 1.22 × 10 ² × sec ⁻¹ ) of PET is increased to 5000 poise or more, which does not cause drawdown during extrusion, and the impact resistance is also improved by the addition of the thickener. It became.

[Example 2] (Regenerated Polyester Resin)

Using a PET bottle scavenger predryed at 150 ° C. for 4 hours, the thickener A, thickener B, thickener C (EEA, MFR 0.6 g / 10 min) and thickener D (SEBS, MFR 2.3 g / 10 min ) And the polymerizing agent A (epoxy group-containing SBS), the polymerizing agent B (styrene graft ethylene-GMA copolymer), and the polymerizing agent C (ethylene-GMA copolymer) were driven and injection molded under the same conditions as in the first embodiment. The same test pieces were made and physical properties were measured as in the first example. The results are shown in Table 2.

From Table 2, it is recognized that the addition of a thickener and a polymerizing agent increases the melt viscosity (shearing rate of 1.22 × 10 ² sec ⁻¹ ) and significantly improves the impact resistance even as the low molecular weight recycled polyester. . In addition, Sample Nos. 3, 4, and 10 using reactor TPO as a thickener also show no yellowing or blocking at the time of drying.

Melt viscosity was measured by changing the shear rate (sec- ¹ ) in various ways about the sample Nos. 1, 2, 3, 4, 6, 8 and 10. The results are shown in Table 3 and FIG. 1.

According to the results shown in Table 3 and FIG. 1, the sample Nos. 2, 3, 4, 6, 8, and 10 of the present invention all have a much higher melting point than sample No. 1, which is an additive-free regenerated PET, with a shear rate close to zero. The drawdown phenomenon of the polyester resin from the nozzle tip at the time of injection molding is prevented.

In addition, in the case of the shear rate near 10 ² s㏄ ⁻¹ corresponding to the shear rate at the time of extrusion molding, paint materials No. 2, 3, 4, 6, 8 and 10 are all higher than sample No. 1, It is anticipated that the draw down phenomenon of the molded product will be prevented and a release property can be obtained.

That is, in case of sample No. 2, 3, 4, 6, 8 and 10, when extruded by an extruder, the diameter is stable and the strand is smoothly obtained, but in sample No. 1, the strand diameter is not constant and the small diameter is obtained. Torn off at the part.

On the other hand, at a shear rate of 10 ³ sec ^-1 or more corresponding to the shear rate at the time of injection molding, the melt viscosity of sample No. 2, 3, 4, 6, 8, and 10 is all close to the melt viscosity of sample No. 1, and Good moldability is expected.

[Example 3]

A polyester modifier A was prepared by mixing 72.2% by mass of the thickener A (LDPE), 5,6% by mass of the thickener D (SEBS), and 22.2% by mass of the polymerizing agent A (epoxy group-containing SBS), and further, thickener B (reactor TPO). Polyester resin modifier B was prepared by mixing 75 mass% and polymerizing agent B (styrene graft ethylene-GMA copolymer) 25 mass%.

Regarding each of the modifier A and the modifier B, 5% by mass, 10% by mass, and 15% by mass were added to the recycled PET used in Example 2 to obtain the relationship between the shear rate and the melt viscosity. The results are shown in FIGS. 2 and 3.

2 and 3, it is expected that the addition of 5% by mass of the modifier A and the modifier B prevents the drawdown phenomenon, release property is possible, and injection molding is good.

Further, in the recycled PET to which the modifier A and the modifier B were added, injection molding was performed in a mold having a spiral cavity at a molding temperature of 260 to 280 ° C., and the spiral length in the cavity was measured. The results are shown in FIGS. 4 and 5.

4 and 5, even with the addition of 5% by mass of the modifier A and the modifier B, the spiral length is equal to or greater than that of no additives, and each sample melt exhibits good fluidity in the mold even with the addition of the modifiers A and B. It is recognized that injection molding is not inhibited but rather improved.

[Example 4]

As the thickener, thickener A (low density polyethylene (LDPE): MFR4.0 g / 10 min), thickener B (reactor TPO, MFR 0.6 g / 10 min), polymerizer A (epoxy group-containing SBS), polymerizer B ( Styrene graft ethylene-GMA copolymer EGMA-g-PS).

The thickener and the polymerizing agent are combined in the formulations of Tables 4 and 5, followed by roll mixing kneading, and then pulverized and pelletized to prepare a polyester resin modifier.

Each of the modifiers and the PET bottle waste pulverized product (recycled PET) are driven by the formulations shown in Tables 4 and 5, melt-kneaded in an extruder, extruded into a string from a nozzle, and cut into pellets in water to pelletize. did. Moreover, melt viscosity was measured on the conditions of the die diameter of 1 mm, the measurement temperature of 270 degreeC, and the preheating time of 300 second about each pellet sample using the capillary graph made by Dongyang Seiki Co., Ltd., without drying the pellet material of each compounding. The results are shown in Tables 4 and 5.

Cylinder temperature 210 to 255 ° C., screw; φ 30, biaxial in different directions, full flight, L / D = 25, open vent, 100 rpm, die; It extrusion-molded on the conditions of 3.5x15 mm, a ribbon die, and a breaker, and confirmed the drawdown (shape holding property of resin from the dice and sag down by self weight).

The results are shown in Tables 4 and 5.

[Comparative Example]

As the comparative example of the said Example, it carried out similarly to the said Example by the combination shown in Table 6, and the measurement of melt viscosity and the presence or absence of the drawdown phenomenon in the case of extrusion molding were confirmed. The results are shown in Table 6.

Sample No. 1 of the comparative example shown in Table 6 used recycled PET preliminarily dried in a constant temperature bath at 150 ° C for 4 hours.

Referring to the results shown in Tables 4 and 5, the drawdown phenomenon was prevented even in the resin composition of any of the examples in which preliminary drying was not performed (Samples No. 1 to No. 16).

In addition, the sample No. 2 of the comparative example which does not add the thickener and a polymerizer shown in Table 6, the sample No. 3 of the comparative example which is less than 3 mass parts, and the addition amount of a thickener is less than 3 mass parts, and also the equivalent amount of a polymerizing agent In Sample No. 4 of the comparative example below, preliminary drying was not carried out, so that a melt viscosity necessary for extrusion molding or the like was not obtained, and a remarkable drawdown phenomenon was observed.

In addition, in the case where 100 parts by mass or more of the thickener is added to the mass of regenerated PET (100 parts by mass (120 parts by mass in sample No. 5 of the comparative example, 300 parts by mass in sample No. 6 of the comparative example)), sufficient melting is required for extrusion molding and the like. Although the resin composition of the present invention has sufficient melt viscosity necessary for extrusion molding, it is sufficient to add more than 100 parts by mass of the thickener to 100 parts by mass of the recycled PET (polyester resin). It is not necessary, and rather, the addition of a large amount of thickener deteriorates the compatibility between the thickener and the polyester resin, and impairs the appearance of the appearance of the molded article (for example, a molded article formed using the reconstituted material of Sample No. 6 of the comparative example). Since a problem arises, it is not preferable to add much thickener.

The aesthetics of the external appearance of the molded product molded from the papermaking composition shown in the above example was good, and the impact resistance of the molded product was also sufficient. The molded article may be a foamed molded article.

The melt viscosity of the polyester resin is improved by the addition of the thickener of the present invention. Especially in the case of low molecular weight recycled polyester resins, the addition of a polymerizing agent significantly increases the melt viscosity, leading to a drawdown of the polyester resin from the nozzle tip during injection molding or a draw of the molded product during extrusion molding. Down phenomenon is prevented, injection molding is kept good, and impact resistance of the molding is also improved.

In addition, by performing extrusion molding or injection molding using a polyester resin composition containing both a thickener and a polymerizing agent, molding can be performed without preliminary drying of the polyester resin or suction dewatering before extrusion. In this case, the investment of equipment for the preliminary drying, the investment of equipment for a special extrusion machine with a vent hole, or the trouble or time of water removal is eliminated.

Therefore, in the present invention, the polyester resin moldings, which are conventionally limited to sheet, fiber and container shapes, can be molded into various shapes, and in particular, PET bottles used by the polyester resins used in the polyester resin composition of the present invention. In the case of regenerated resin, it is related to the improvement of a recycling rate.

Claims (12)

Polyester resin and the polyester resin composition characterized by the melt flow rate (MFR) according to JISK7210 Table 1, Condition 4 made of a thickener of 20 g / 10 minutes or less The method of claim 1, The said thickener is 2-100 mass parts with respect to 100 mass parts of polyester resins, The polyester resin composition characterized by the above-mentioned. A polyester resin composition is added to the polyester resin composition according to claim 1 or 2, further comprising a polymerizing agent having a functional group capable of reacting with the polyester resin. The method of claim 3, The thickener and the polymerizing agent is a polyester resin composition, characterized in that mixed in a 1: 1 to 10: 1 mass ratio. The method according to claim 3 or 4, Polyester resin composition, characterized in that the polyester resin is a recycled polyester resin. The method according to any one of claims 3 to 5, The functional group of the polymerizing agent is a polyester resin composition, characterized in that the epoxy group. A polyester resin modifier, characterized in that the MFR contains a thickening agent of 20 g / 10 min or less and a polymerizing agent having a functional group capable of reacting with the polyester resin. The method of claim 7, wherein The thickener is a polyester resin modifier, characterized in that the polymer alloy of polypropylene and synthetic rubber. The method according to claim 7 or 8, The thickener and the polymerizing agent is a polyester resin modifier, characterized in that the mixture in a 6: 4 to 9: 1 mass ratio. A resin molding comprising the polyester resin composition according to any one of claims 1 to 6. The method of claim 10, The resin molding is a resin molding, characterized in that produced by extrusion or injection molding. The method of claim 11, A resin molding comprising the polyester resin composition according to any one of claims 3 to 5, wherein the polyester resin composition is extruded or injected without preliminary drying or deaeration and water removal during molding. Resin molded article, characterized in that the molded.