KR20190033993A - Polyester resin composition - Google Patents

Abstract

The present invention relates to a polyester resin composition, which exhibits excellent releasability and mechanical properties, comprising: 60 to 80 wt % of a polyester resin including a dicarboxylic acid-derived repeating unit and a diol-derived repeating unit; and 0.01 to 2 parts by weight of a nitride-based inorganic nucleating agent and 0.1 to 5 parts by weight of a high-density polyethylene-based organic nucleating agent, with respect to 100 parts by weight of a mixture.

Description

[0001] POLYESTER RESIN COMPOSITION [0002]

The present invention relates to a polyester resin composition which exhibits improved crystallization speed and exhibits excellent releasability and mechanical properties.

Polyester resins are widely used as textile materials for reinforced plastics, paints, films, molding resins, and garments because of their excellent mechanical strength and elastic strength.

Among various polyester resins, polycyclohexylene dimethylene terephthalate (PCT) is a high heat resistant plastic material having excellent heat resistance, discoloration resistance, and chemical resistance, and is a filler for mechanical properties such as glass fiber Has been applied to household appliances such as LED reflector, connector, dish container, baking frame, electric, electronic parts and automobile parts.

However, despite this excellent physical properties, the PCT material is susceptible to mold release failure if the crystallization speed is slow and it is not sufficiently cooled during injection molding. In addition, when a sufficient cooling time is provided for prevention of mold release defects, the entire molding cycle is delayed. This can hinder the application of PCT materials to a variety of applications because it can reduce the productivity of injection molding or component manufacturers.

It is an object of the present invention to provide a polyester resin composition which exhibits improved crystallization speed and exhibits excellent releasability and mechanical properties.

It is still another object of the present invention to provide a molded article produced using the polyester resin composition and exhibiting excellent releasability and mechanical properties.

In order to achieve the above object, the inventor of the present invention has succeeded in manufacturing a polyester resin composition having improved crystallization speed, excellent releasability and mechanical properties, and succeeded in producing the polyester resin composition. It can be applied to a variety of electric / electronic products or automobile connectors, switches, relays, jacks, IC sockets, AC parts, presser sensors or housings which require excellent releasability and mechanical properties along with rapid crystallization speed. Completed.

Hereinafter, a polyester resin composition according to a specific embodiment of the present invention and a molded article produced using the same will be described in detail.

Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, the configurations shown in the embodiments described herein are merely the most preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In this specification, the terms "comprising," "comprising," or "having ", and the like are intended to specify the presence of stated features, But do not preclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof.

As used herein, a "polyester" is a synthetic polymer prepared by polycondensation of one or more carboxylic acids with one or more diol compounds, including "copolyesters".

In the present specification, the term "repeating unit" means a unit structure having a functional group derived from a diol or a functional group derived from a carboxylic acid bonded through a carbonyloxy group.

In the present invention, an inorganic nucleating agent having an excellent effect of improving the crystallization rate in the production of a polyester resin composition using a polyester resin and a filler, and a combination of an organic nucleating agent capable of compensating mechanical properties and releasability of the resin composition upon use of the inorganic nucleating agent By using it, the crystallization rate can be increased and the mechanical properties and releasability can be simultaneously improved.

Specifically, the polyester resin composition according to one embodiment of the present invention is a polyester resin composition,

(i) 60 to 80% by weight of a polyester resin comprising a dicarboxylic acid-derived repeating unit containing terephthalic acid and a diol-derived repeating unit containing 1,4-cyclohexanedimethanol; And (ii) from 20 to 40% by weight of the filler,

(iii) 0.01 to 2 parts by weight of a nitride-based inorganic nucleating agent, and 0.1 to 5 parts by weight of high density polyethylene (HDPE) as an organic nucleating agent of 0.92 g / cm ³ or more.

Hereinafter, each component constituting the polyester resin composition will be described in detail.

(i) Polyester resin

In the polyester resin composition according to one embodiment of the present invention, the polyester resin is a polyester resin obtained by polymerizing a dicarboxylic acid-based compound containing terephthalic acid and a diol compound containing 1,4-cyclohexanedimethanol Polyester copolymer comprising a repeating unit derived from a dicarboxylic acid compound containing terephthalic acid and a repeating unit derived from a diol compound containing 1,4-cyclohexanedimethanol.

Specifically, in the polyester resin, the repeating unit derived from a dicarboxylic acid-based compound may be a repeating unit derived from a dicarboxylic acid or an ester thereof.

The dicarboxylic acid may specifically be an aromatic dicarboxylic acid having 8 to 20 carbon atoms or an aliphatic dicarboxylic acid having 4 to 20 carbon atoms. More specifically, terephthalic acid (TPA), isophthalic acid (IPA ) Or 2,6-naphthalenedicarboxylic acid (2,6-NDA).

The dicarboxylic acid ester compound may be an aromatic dicarboxylic acid having 8 to 20 carbon atoms or an ester of an aliphatic dicarboxylic acid having 4 to 20 carbon atoms. More specifically, dimethyl terephthalate (DMT) Dimethyl isophthalate (DMI), or dimethyl 2,6-naphthalenedicarboxylate (2,6-NDC).

In the polyester resin composition according to an embodiment of the present invention, the polyester resin can be produced by controlling the kind and content of the dicarboxylic acid-based compound used in the production thereof, thereby improving the mechanical properties, heat resistance, electrical insulation and impact resistance And can exhibit more improved characteristics.

Specifically, in the polyester resin, the repeating unit derived from the dicarboxylic acid-based compound may contain 80 mol% or more of the repeating unit derived from terephthalic acid or its ester compound based on 100 mol% of the repeating unit derived from the dicarboxylic acid-based compound. In this case, when applied to a polyester resin composition, it exhibits improved electrical insulation and molding processability, and can maintain excellent initial mechanical properties even in a high temperature and high humidity environment, and exhibits excellent crystallinity at low temperature molding.

More specifically, the polyester resin may contain a repeating unit derived from a dicarboxylic acid-based compound as a repeating unit represented by the following formula (1), wherein at least 80 mol% of the repeating unit may be a repeating unit derived from terephthalic acid, as is to be Ar ¹ is a 1,4-phenylene group in the repeating unit of formula I:

[Chemical Formula 1]

In the above formula (1), Ar ¹ is a substituted or unsubstituted arylene group having 6 to 18 carbon atoms.

Considering the remarkable effect of improving the mechanical properties, heat resistance, electrical insulation and impact resistance of the dicarboxylic acid-based compound and controlling the content thereof, in the polyester resin, the repeating unit derived from the dicarboxylic acid- 80 to 100 mol% of repeating units derived from terephthalic acid or its ester compound; And 0 to 20 mol% of recurring units derived from isophthalic acid or its ester compound.

On the other hand, in the polyester resin, the repeating unit derived from a diol compound may include a repeating unit derived from 1,4-cyclohexane dimethanol.

Since the repeating unit derived from 1,4-cyclohexane dimethanol contains a cyclic structure having a carbon number of 6, it has excellent electrical insulation as compared with a resin containing a phenylene group having a non-covalent electron in a molecular chain such as a polycarbonate resin, As a result, when applied to a polyester resin composition comprising the polyester resin, the electrical insulation can be greatly improved.

The repeating unit derived from 1,4-cyclohexane dimethanol is contained in an amount of 5 mol% or more, specifically 5 to 100 mol%, more specifically 60 mol% or more, based on 100 mol% of the repeating units derived from the diol compound constituting the polyester resin To 100 mol%. When included in the above-mentioned content range, electrical insulation and heat resistance can be greatly improved while maintaining excellent mechanical properties of the polyester resin composition.

In the above polyester resin, the repeating unit derived from the diol compound may be a repeating unit derived from 1,4-cyclohexane dimethanol described above, and may be a repeating unit derived from a diol compound such as ethylene glycol, diethylene glycol, 1,4-butanediol, Or neopentyl glycol, and other repeating units derived from a diol-based compound.

Specifically, the polyester resin includes a repeating unit represented by the following formula (2), wherein R ¹ in the following formula (2) is cyclohexylenedimethylene and u is 0, with a repeating unit derived from a diol compound % Of repeating units derived from a diol compound, and repeating units derived from ethylene glycol, which can further improve the impact resistance of the polyester resin, are contained in an amount of 5 mol% or more, more specifically 60 to 100 mol% It can be included in the negative amount:

(2)

In Formula 2,

R ¹ is a substituted or unsubstituted, linear, branched or cyclic alkylene group having 1 to 10 carbon atoms,

R ² is a substituted or unsubstituted, linear or branched alkylene group having 1 to 10 carbon atoms,

Y is -O-, -NH- or -S-,

u is an integer of 0 or 1.

More specifically, the polyester resin may be a polycyclohexylenedimethylene terephthalate resin prepared by polycondensation of terephthalic acid and 1,4-cyclohexane dimethanol, and a part of 1,4-cyclohexane dimethanol Ethylene glycol is copolymerized in an amount of not more than 1 mol% based on 100 mol% of the repeating units derived from the diol compound, or the content of isophthalic acid in the terephthalic acid is not more than 20 mol% based on 100 mol% of repeating units derived from dicarboxylic acid ≪ / RTI >

The polycyclohexylenedimethylene terephthalate resin has a crystallization speed much faster than that of polyethylene terephthalate (PET), although it is later than polybutylene terephthalate (PBT), has high heat resistance while being capable of injection molding, and has relatively high price competitiveness Potential application possibilities are very high. Except for the liquid crystal polymer, the polymer has the highest melting point among the existing polyester resins, has a low water absorption rate as compared with the polyacrylate (PA) polymer, and is excellent in discoloration resistance due to heat. Accordingly, when the polyester resin composition according to the present invention includes the polycyclohexylenedimethylene terephthalate resin as the polyester resin, the heat resistance and the mechanical strength can be greatly improved while maintaining the impact strength.

In order to exhibit more excellent effects in terms of releasability, mechanical properties, heat resistance, impact resistance, electric conductivity and the like through control of the type and content of constituent components and polymerization conditions, Weight average molecular weight, glass transition temperature and the like can be controlled. Specifically, in order to improve the above-mentioned effect, the polyester resin may have an intrinsic viscosity of 0.50 to 1.2 dl / g converted from a viscosity measured at 35 ° C after dissolving in a solvent o-chlorophenol (OCP). When having an intrinsic viscosity within the above-mentioned range, there is no fear of deterioration of mechanical properties due to an appropriate molecular weight, and excellent blending efficiency and moldability can be exhibited. In consideration of the remarkable effect in improving the releasability and the mechanical properties according to the intrinsic viscosity control of the polyester resin, more specifically not less than 0.50 dl / g and not more than 0.80 dl / g, more specifically not more than 0.60 dl / To 0.70 dl / g.

The polyester resin is a polyester resin which satisfies the above-mentioned intrinsic viscosity condition and has a weight average molecular weight (Mw) of 10,000 to 100,000 g / mol and a glass transition temperature of 0 to 200 ° C, more specifically 80 to 120 ° C . In the present invention, the weight average molecular weight (Mw) is a value measured in terms of standard polystyrene measured by gel permeation chromatography (GPC) and the glass transition temperature (Tg) is measured by Differential Scanning Calorimetry (DSC) .

The polyester resin may be contained in an amount of 60 to 80% by weight based on the total weight of the polyester resin composition, and may be included in an amount of 60 to 70% by weight in consideration of the excellent effect of improving the polyester content in the polyester resin composition have.

(ii) filler

The filler serves to improve the impact resistance of the polyester resin composition and can be used without particular limitation as long as it is usually used in the production of a polyester resin composition. The polyester resin composition according to an embodiment of the present invention may include an inorganic filler.

Specific examples of the inorganic filler include glass fiber, carbon fiber, boron fiber, glass bead, glass flake, talc, carbon black, clay, mica, wollastonite, calcium titanate whisker, aluminum borate whisker aluminum boric acid whisker, zinc oxide whisker, or calcium whisker. Any one or a mixture of two or more thereof may be used.

The form of the filler is not particularly limited. However, considering the remarkable improvement effect of the use of the filler and the shape control, among the above-mentioned inorganic fillers, glass fiber, wollastonite, calcium titanate whisker ) Or an aluminum boric acid whisker can be used. More specifically, it is possible to improve the moldability and to improve the mechanical properties such as the tensile strength, the bending strength and the bending elastic modulus of the molded article and the heat distortion temperature A glass fiber can be used in view of improving the heat resistance of the glass fiber.

When glass fiber is used as the filler, a glass fiber in the form of a filament, a thread, a fiber or a whisker may be used. The glass fibers may have an average length of 0.1 to 20 mm, 0.3 to 10 mm or 3 to 5 mm, and an aspect ratio ([L (average length of fibers) / D (average fiber diameter) To 2000, or from 30 to 1000. < RTI ID = When the aspect ratio condition described above is satisfied, it is possible to exhibit a better mechanical strength improvement effect.

The filler may be included in an amount of 20 to 40% by weight based on the total weight of the polyester resin composition. When it is contained within the above-mentioned content range, it is possible to exhibit an excellent mechanical property improving effect without worrying about lowering of moldability. More specifically, the filler may be included in an amount of 20 to 30% by weight based on the total weight of the polyester resin composition.

(iii) Nucleating agent

In general, the nucleating agent acts as nuclei for crystallization during molding of the polyester resin composition, thereby improving the crystallization speed of the resin composition and improving the heat resistance and injection moldability of the polyester resin composition. Among them, the inorganic nucleating agent has an excellent effect of improving the crystallization rate of the polyester resin composition, but it has a disadvantage of increasing the brittleness of the resin composition and lowering the mechanical strength. In addition, the organic nucleating agent has excellent mechanical property and releasability improving effect, but the effect on the crystallization speed improvement is insignificant.

On the other hand, in the present invention, a nitride-based inorganic nucleating agent having a better effect of improving the crystallization rate and an organic nucleating agent of high-density polyethylene (HDPE) having a better mechanical property and a releasing property improving effect are mixed and used at an optimum ratio, The speed can be improved, and at the same time the releasability and the mechanical properties can be improved.

Specifically, as the inorganic nucleus agent, a nitride-based inorganic nucleus agent having high thermal conductivity and high stability at a high temperature among various inorganic nucleating agents and having an excellent crystallization speed improving effect when applied to a polyester resin composition can be used.

Specifically, the nitride-based inorganic nucleating agent may be a non-metallic element such as boron (B) or silicon (Si); Amphoteric elements such as aluminum (Al); Or a nitride containing a transition metal such as titanium (Ti), tantalum (Ta), vanadium (V), chromium (Cr), molybdenum (Mo), tungsten (W) or niobium (Nb) is boron nitride (BN), aluminum nitride (AlN), silicon nitride (Si ₃ N _4), titanium nitride (TiN), tantalum nitride (TaN, Ta ₂ N), nitride, vanadium (VN), chromium nitride (CrN, Cr ₂ N), molybdenum nitride (Mo ₂ N), niobium nitride (NbN) or tungsten nitride (WN, W ₂ N). Any one or a mixture of two or more of them may be used.

Among them, a boron nitride-based compound having an excellent effect of improving the crystallization rate of the polyester resin composition and having excellent compatibility with high-density polyethylene can be used. Examples of the boron nitride include hexagonal boron nitride, cubic boron nitride, and pyrolytic boron nitride (PBN), and any one or a mixture of two or more of them may be used. As the boron nitride-based inorganic nucleating agent, commercially available IND-11 (TM) (manufactured by Spear New Materials) may be used.

The inorganic nucleating agent may be included in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the mixture containing the polyester and the filler. If the content of the inorganic nucleating agent is less than 0.01 parts by weight, the effect of improving the crystallization rate with the presence of the inorganic nucleating agent is insignificant. If the content is more than 2 parts by weight, the mechanical strength of the resin composition may be deteriorated.

On the other hand, as the organic nucleating agent, a high-density polyolefin-based resin can be used. More specifically, the organic resin is excellent in mechanical property and releasability improvement effect due to its low adhesion with metal and impact- High-density polyethylene excellent in surface property improving effect in the production of a molded article can be used.

In the present invention high density polyethylene, the measured density according to ASTM D1505 0.92 g / cm ³ ≪ / RTI > Density polyethylene has a density of 0.92 to 1.0 g / cm 3, more specifically 0.95 to 1.0 g / cm 3, still more specifically 0.96 to 0.98 g / cm 3, Of polyethylene. When the above-mentioned density range is satisfied, excellent mechanical properties and releasability improving effects can be exhibited. If the density of the high-density polyethylene is 0.92 g / cm < ³ > , The crystallization temperature is lowered and the effect of improving the crystallization rate can not be obtained.

As the high-density polyethylene, a product prepared by directly using a conventional polymerization reaction to meet the above-mentioned conditions may be used, or a commercially available product such as Yuzex 7200 (manufactured by SK General Chemicals) may be used.

The organic nucleating agent may be included in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the mixture including the polyester and the filler. If the content of the polyolefin-based organic nucleating agent is less than 0.1 part by weight, the effect of improving the mechanical strength and releasability is insignificant. If the amount exceeds 5 parts by weight, the crystallization synergistic effect is insignificant, and the polyester resin, especially the PCT resin, The mechanical properties of the resin composition deteriorate and appearance defects occur.

More specifically, in the polyester resin composition according to one embodiment of the present invention, the inorganic nucleating agent and the organic nucleating agent are mixed at a weight ratio of 1: 2 to 1:20, more specifically, May be included in a weight ratio of 1: 5 to 1:10. When used in the above-mentioned weight ratio, the crystallization speed and the mechanical properties and the releasability improving effect can be improved by the use of different kinds of nucleating agent combination.

(iv) Other additives

The polyester resin composition according to one embodiment may further include an impact modifier in order to complement or enhance the physical properties of the polyester resin composition together with the above-mentioned components.

Specifically, the impact modifier may impart toughness to the polyester resin composition to improve the tensile strength. Examples of such impact modifiers include unsaturated nitrile-diene rubber-aromatic vinyl graft copolymer, alkyl methacrylate-diene rubber-aromatic vinyl graft copolymer, alkyl methacrylate-silicone / alkyl acrylate graft copolymer, Or an ethylene-alkyl acrylate-glycidyl methacrylate copolymer, and any one or a mixture of two or more thereof may be used. In view of the excellent compatibility with the polyester resin composition and the effect of improving the tensile strength of the resin composition, the impact modifier is more preferably an ethylene-alkyl acrylate-glycidyl methacrylate copolymer , More specifically, random terpolymers obtained by polymerizing ethylene, acrylic ester and glycidyl methacrylate under high pressure can be used. Commercially available impact reinforcements include Elvaloy (TM) PTW from DuPont.

When the above-mentioned impact modifier is further included, it may be contained in an amount of 10% by weight or less, more specifically 0.1 to 10% by weight, more specifically 0.1 to 5% by weight based on the total weight of the mixture including the polyester resin and the filler have.

In addition to the impact modifier, the polyester resin composition according to one embodiment may further contain an antioxidant, a pigment, a lubricant, an antioxidant, a plasticizer, a coloring inhibitor, a matting agent, a deodorant, a flame retardant, a weathering additive, an antistatic agent, An additive such as an ultraviolet absorber, an antistatic agent,

The antioxidant suppresses the yellowing of the polymer resin, thereby improving the appearance of the polymer resin composition and the molded article, and inhibiting oxidation or pyrolysis. Examples of the antioxidant include a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, a hindered amine-based light stabilizer, and the like, and a compound containing a monomer having a phenolic antioxidant and a phosphorus- Type antioxidant may be used.

In the polyester resin composition according to one embodiment of the present invention, the antioxidant may be a phenol-based first antioxidant and a second phenol-based antioxidant which are excellent in the prevention of coloring and deterioration of physical properties of a molded article due to heat or oxidation, A mixture of a phenol-based first antioxidant and a phosphorus-based second antioxidant in a weight ratio of 2: 1 to 1: 2, or 1: 1 to 1: 2, may be used .

Examples of the phenolic antioxidant include 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) Bis [3- (3,5-di-tert-butyl-4-hydroxy-benzyl) Phenyl] propionamido] hexane), 1,6-bis [3- (3,5-di (tert-butyldimethylsilyloxy) butyl-4-hydroxyphenyl) propionamido] propane), tetrakis [methylene ((1,1- Methyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane) Any one or a mixture of two or more may be used. Commercially available phenolic antioxidants include AO-60 (TM) from ADEKA.

Specific examples of the phosphorus-based second antioxidant include phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triethylphosphonoacetate, bis (2,6-di-tert- butyl-4-methylphenyl) pentaerythritol Di-phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4- (2,4-di-tert-butylphenyl) pentraerythritol-di-phosphite, and any one or a mixture of two or more thereof may be used. Commercially available phosphorus antioxidants include Doverphos S9228 (TM) and the like.

If the content of the antioxidant in the polyester resin composition is too high, the mechanical properties, particularly the heat resistance and the like, of the polymer resin composition may be lowered. Therefore, when the antioxidant is further contained, It may be contained in an amount of not more than 10 parts by weight based on 100 parts by weight of the mixture. In consideration of the improvement of the appearance characteristics of the polymer resin composition and the molded article due to the addition of the antioxidant and the effect of preventing oxidation or pyrolysis without worrying about deterioration of mechanical properties, To 5 parts by weight, or 0.1 to 1 part by weight, or 0.1 to 0.5 part by weight.

Examples of the pigments include carbon black, titanium oxide, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, lithopone (BaSO ₄ .ZnS), white lead (2PbCO 3 揃 Pb Calcium, alumina, boron nitride and the like, and any one or a mixture of two or more of them may be used. When the pigment is further included, it may be included in an amount of 10 parts by weight or less, more specifically 0.01 to 5 parts by weight based on 100 parts by weight of the mixture including the polyester resin and the filler.

In addition, the lubricant can be used for stably dispersing a filler, a pigment or the like in the resin composition and for easily releasing the resin composition. Examples of such activator include metal stearate lubricants, amide lubricants, paraffin lubricants, and ester lubricants, and any one or a mixture of two or more thereof may be used. More specifically, N, N'-ethylene bis (stearamide) and the like can be used. When the above-mentioned lubricant is further included, it may be included in an amount of 10 parts by weight or less based on 100 parts by weight of the mixture including the polyester resin and the filler, and more specifically 0.1 to 5% by weight.

More specifically, the polyester resin composition according to one embodiment of the present invention, in consideration of excellent compatibility with the above-mentioned polyester resin, filler and nucleating agent, stable expression of excellent mechanical properties, and effect of improving releasability, The antioxidant may further include a phenolic antioxidant and a phosphorus-based antioxidant in a ratio of 2: 1 to 1: 2, or 1: 1 to 1: 2 By weight. At this time, the types of the impact modifier and the antioxidant are as described above.

The polyester resin composition according to one embodiment of the present invention may further comprise 60 to 80% by weight of a polycyclohexylenedimethylene terephthalate resin as the polyester resin, and as boron nitride and 0.01 to 2 parts by weight of an organic nucleating agent mixture as the boron-based inorganic nucleating agent based on 100 parts by weight of a glass fiber containing 20 to 40% by weight in terms of the filling material than 0.92 to 1.0g / cm ^3, particularly 0.95 to And 0.1 to 5 parts by weight of 0.98 g / cm ^{3 of} high density polyethylene, wherein the weight ratio of the organic nucleating agent to the inorganic nucleating agent (= organic nucleating agent / inorganic nucleating agent) is 5 to 10 and further comprises the impact modifying agent and the antioxidizing agent The antioxidant may include a phenol-based antioxidant and a phosphorus-based antioxidant in a weight ratio of 2: 1 to 1: 2.

More specifically, the polyester resin composition according to one embodiment comprises 60 to 70% by weight of polycyclohexylenedimethylene terephthalate resin as the polyester resin, 20 to 30% by weight of glass fiber as the filler, Specifically 0.1 to 10% by weight of an ethylene-alkyl acrylate-glycidyl methacrylate copolymer, wherein 100 parts by weight of the mixture comprising the polyester resin, the filler and the impact modifier is 0.01 to 5 parts by weight, 2.0 parts by weight of an organic nucleating agent of 0.92 to 1.0g / cm ^3, more specifically from 0.95 to 0.98g / cm ³ comprising a high density polyethylene, 0.1 to 5 parts by weight, the weight ratio of the organic nucleating agent for the inorganic nucleating agent (= organic nucleating agent / An inorganic nucleating agent) of 5 to 10 and a phenol-based first antioxidant and a phosphorus-based second antioxidant in a weight ratio of 2: 1 to 1: 2, As shown in Fig.

The polyester resin composition according to one embodiment of the present invention having the above composition can be produced by blending the above components with the optimum content described. At this time, blending of the respective components can be performed according to a conventional method, and a blending device may be used if necessary.

Specifically, the polyester resin composition may be prepared by putting a polyester resin, a filler, a nucleating agent and optionally one or more other additives in a mixing device, a mixer, or a tumbler under the above-mentioned content conditions, and then mixing the mixture through a twin-screw extruder have. At this time, the resins for forming the polyester resin composition may preferably be used in a sufficiently dried state.

The polyester resin composition according to one embodiment of the present invention contains an inorganic nucleating agent having an excellent crystallization rate improving effect and an organic nucleating agent capable of improving mechanical strength and releasability in an optimal amount to improve crystallization speed, Can be improved at the same time.

Specifically, the polyester resin composition has a crystallization temperature of 250 DEG C or higher, more specifically 255 DEG C or higher, and a cooling time of 20 seconds or less, more specifically 15 seconds or less in the injection step. The polyester resin composition preferably has a tensile strength of 1000 kg / cm 2 or more, more specifically 1100 kg / cm 2 or more as measured by D638, a flexural strength of 1400 kg / cm 2 or more, more specifically 1600 kg / And an impact strength of not less than 90 J / m, more specifically not less than 95 J / m as measured according to ASTM D256, and has excellent mechanical properties.

Accordingly, it can be useful for manufacturing various electric / electronic products or automobile connectors, switches, relays, jacks, IC sockets, AC parts, presser sensors, or housings that require a high crystallization speed and good releasability and mechanical properties have.

Specifically, the polyester resin composition is molded by various molding methods such as injection molding, extrusion molding, extrusion blow molding, extrusion blow molding or profile molding, and post-processing such as thermoforming using the same, Or a film or the like.

Accordingly, according to another embodiment of the present invention, a molded article produced using the polyester resin composition may be provided.

The molded article may be subjected to various molding methods such as injection molding, extrusion molding, extrusion blow molding, injection blow molding and profile extrusion molding, and post-processing such as thermoforming using the molding method .

The specific shape and size of the molded article may vary depending on the application, and examples thereof may be, for example, a shape such as a sheet, a container, or a pellet.

The polyester resin composition according to the present invention exhibits improved crystallization speed and exhibits excellent releasability and mechanical properties. Accordingly, it can be useful for manufacturing various electric / electronic products or automobile connectors, switches, relays, jacks, IC sockets, AC parts, presser sensors, or housings that require a high crystallization speed and good releasability and mechanical properties have.

Best Mode for Carrying Out the Invention Hereinafter, the function and effect of the present invention will be described in more detail through specific examples of 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.

≪ Production of polyester resin composition >

Each compound used in the preparation of the resin composition according to the examples and comparative examples is as follows:

Polyester resin (A): polycyclohexylenedimethylene terephthalate (PCT) (intrinsic viscosity 0.65 dl / g) obtained by condensation polymerization of terephthalic acid (TPA) and 1,4-cyclohexanedimethanol (CHDM)

Polyester resin (B): Polyethylene terephthalate (PET) (intrinsic viscosity of 0.8 dl / g) obtained by condensation polymerization of ethylene glycol (EG) and terephthalic acid (TPA)

Filler: glass fiber (T-187H ™, manufactured by NEG)

The inorganic nucleating agent (A): boron nitride (IND-11 ™, manufactured by Spear New Materials)

(B): Sodium salt of montanic acid (Licomont NaV101, manufactured by Clariant)

Organic nucleating agent (A): High density polyethylene (HDPE) (Yuzex 7200 ™, manufactured by SK General Chemicals) (density measured according to ASTM D1505: 0.968 g / cm ³ )

Organic nucleating agent (B): low density polyethylene (LDPE) (density measured according to ASTM D1505 0.915g / cm ³⁾

First Oxidation Stabilizer: Phenolic Oxidation Stabilizer (AO-60 ™, manufactured by ADEKA)

Second Oxidation Stabilizer: Phosphorus Oxidation Stabilizer (S9228 (TM), Doverphos)

(E / nBA / GMA) copolymer (Elvaloy (TM) PTW, manufactured by Du Pont) was used as the impact modifier: ethylene / n-butyl acrylate / glycidyl methacrylate

≪ Production of polyester resin composition >

Example 1

Based on 100 parts by weight of a mixture of 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fiber as a filler and 3% by weight of an impact modifier, (Φ: 40 mm, L / D = 44), 0.2 part by weight of a stabilizer, 0.2 part by weight of a phosphorus-based second oxidative stabilizer, 0.1 part by weight of an inorganic nucleating agent (A) and 1.0 part by weight of an organic nucleating agent To prepare pellets of a polyester resin composition.

Example 2

Based on 100 parts by weight of a mixture of 69% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fiber as a filler and 1.0% by weight of an impact modifier, 0.2 parts by weight of a stabilizer, 0.2 part by weight of a phosphorus-based second oxidative stabilizer, 0.1 part by weight of an inorganic nucleating agent (A) and 2.0 parts by weight of an organic nucleating agent (A) were uniformly kneaded using a twin screw extruder (Φ: 40 mm, L / D = 44) And kneaded and extruded to prepare pellets of a polyester resin composition.

Comparative Example 1

Based on 100 parts by weight of a mixture containing 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fibers as a filler and 3% by weight of an impact modifier, 0.2 part by weight of the stabilizer and 0.2 part by weight of the phosphorus-based second oxidative stabilizer were uniformly kneaded and extruded using a twin-screw kneading extruder (Φ: 40 mm, L / D = 44) to prepare a pellet of a polyester resin composition.

Comparative Example 2

Based on 100 parts by weight of a mixture containing 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fiber as a filler and 3% by weight of an impact modifier, , 0.2 part by weight of the phosphorus-based second oxidative stabilizer, and 2.0 parts by weight of the organic nucleating agent (A) were homogeneously kneaded and extruded using a twin screw extruder (Φ: 40 mm, L / D = 44) .

Comparative Example 3

Based on 100 parts by weight of a mixture containing 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fibers as a filler and 3% by weight of an impact modifier, 0.2 part by weight of a stabilizer, 0.2 part by weight of a phosphorus-based second oxidative stabilizer and 0.5 part by weight of an inorganic nucleating agent (A) were uniformly kneaded and extruded using a twin screw extruder (?: 40 mm, L / D = 44) Pellets were prepared.

Comparative Example 4

, 10 weight% of polyethylene terephthalate (PET) as a polyester resin (B), 30 weight% of glass fiber as a filler, and 50 weight% of an impact modifier (A) (A) and 0.1 part by weight of an organic nucleating agent (A) were added to 100 parts by weight of a mixture containing 100 parts by weight of a phenol based antioxidant, And uniformly kneaded and extruded using a kneading extruder (?: 40 mm, L / D = 44) to prepare a pellet of a polyester resin composition.

Comparative Example 5

Based on 100 parts by weight of a mixture containing 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fibers as a filler and 3% by weight of an impact modifier, 0.2 parts by weight of a stabilizer, 0.2 part by weight of a phosphorus-based second oxidizing stabilizer, 0.1 part by weight of an inorganic nucleating agent (A) and 6.0 parts by weight of an organic nucleating agent (A) were uniformly kneaded using a twin screw extruder (Φ: 40 mm, L / D = 44) And kneaded and extruded to prepare pellets of a polyester resin composition.

Comparative Example 6

Based on 100 parts by weight of a mixture of 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fiber as a filler and 3% by weight of an impact modifier, (Φ: 40 mm, L / D = 44), 0.2 part by weight of a stabilizer, 0.2 part by weight of a phosphorus-based second oxidative stabilizer, 0.1 part by weight of an inorganic nucleating agent (B) and 1.0 part by weight of an organic nucleating agent To prepare pellets of a polyester resin composition.

Comparative Example 7

Based on 100 parts by weight of a mixture of 67% by weight of polycyclohexylenedimethylene terephthalate (PCT) as a polyester resin (A), 30% by weight of glass fiber as a filler and 3% by weight of an impact modifier, (Φ: 40 mm, L / D = 44), 0.2 part by weight of a stabilizer, 0.2 part by weight of a phosphorus-based second oxidative stabilizer, 0.1 part by weight of an inorganic nucleating agent (A) and 1.0 part by weight of an organic nucleating agent To prepare pellets of a polyester resin composition.

<Experimental Example: Measurement of Physical Properties of Polyester Resin Composition>

The pellets prepared in Examples 1 and 2 and Comparative Examples 1 to 7 were injection-molded at an injection temperature of 285 ° C using an injection machine, and then the injection-molded specimens were subjected to a test under the conditions of 23 ± 2 ° C. and 50 ± 5% relative humidity , And the physical properties of each were measured in the following manner. The results are shown in Table 1 below.

1) Tensile Strength and Flexural Strength: A test specimen was prepared in accordance with ASTM D 638, and tensile strength and flexural strength were measured using a universal testing machine (Zwick Roell Z010).

2) Impact strength: A test specimen was prepared in accordance with ASTM D256, and the impact strength was measured using an impact tester (Yasuda).

3) Heat resistance: A test specimen was prepared in accordance with ASTM D648, and heat resistance was measured using a heat distortion temperature measuring device (HDT tester, Toyoseiki).

4) Crystallization temperature: The crystallization temperature of the polymer was measured using a differential scanning calorimeter (DSC, DSC 8000, manufacturer: PerkinElmer). Specifically, the polymer was heated to 310 DEG C, held for 5 minutes, cooled to 30 DEG C, and then increased in temperature. At this time, the temperature rising rate and the falling rate were adjusted to 10 ° C / min, respectively. The crystallization temperature was defined as the crystallization temperature at the maximum point of the exothermic peak from the curve appearing while decreasing the temperature.

5) Cooling Time (Injection Process): The shortest time (injection cooling time) during which the composition injected into the ASTM tensile specimen mold solidified during the preparation of the specimen using the polyester resin composition was stably separated from the mold was measured.

division unit Example Comparative Example One 2 One 2 3 4 5 6 7 Seal
burglar 3.2mm kg / cm ² 1290 1200 1230 1260 1160 1280 1200 1210 1250 curve
burglar 6.4mm kg / cm ² 1830 1770 1630 1790 1680 1660 1670 1710 1770 Shock
burglar 3.2mm J / m 110 90 100 120 85 115 132 95 105 Heat resistance 1.8 MPa ℃ 253 250 250 246 257 230 222 247 249 Tc Crystallization temperature ℃ 257 258 250 247 254 - 251 247 254 Cooling
time Injection process second 11 12 25 18 15 38 17 18 29

As a result, it was found that the polyester resin compositions of Examples 1 and 2, in which an inorganic nucleating agent and an organic nucleating agent were mixed, exhibited substantially the same mechanical properties as those of Comparative Example 1 in which no nucleating agent was used, Respectively. In comparison with Comparative Example 2 in which only the organic nucleating agent was used alone, the effect was somewhat reduced in terms of mechanical strength, but the crystallization temperature and crystallization rate were greatly increased. On the other hand, when compared with Comparative Example 3 using only an inorganic nucleating agent, the crystallization temperature and speed showed almost the same level of results, but they were more excellent in terms of mechanical properties. From the above results, it can be seen that the mixing ratio of the inorganic nucleating agent and the organic nucleating agent can increase the crystallization speed and simultaneously improve the mechanical properties and the releasability.

Also, in Comparative Example 4 using a mixture of different kinds of polyester resins such as PET, the moldability was largely lowered as the PCT content condition was not satisfied, and it was confirmed that the heat resistance was lowered due to the PET used together .

In addition, when HDPE was used in an excessive amount as in Comparative Example 5, the effect of improving the crystallization rate was insignificant, the heat resistance was greatly lowered, and a flow mark (flow mark) was generated in appearance.

Comparative Example 6 in which an inorganic nucleating agent of a conventional montmethane metal salt was used in combination with a high density polyethylene type organic nucleating agent and Comparative Example 7 in which a low density polyethylene type organic nucleating agent was used in place of a high density polyethylene type organic nucleating agent was used in place of the nitride type inorganic nucleating agent , The crystallization temperature was lowered and the cooling time was greatly increased as compared with Examples 1 and 2. From this, it can be confirmed that a better crystallization rate improving effect can be obtained by using a combination of a nitride-based inorganic nucleating agent and a high-density polyethylene-based organic nucleating agent.

On the other hand, when comparing Examples 1 and 2, the polyester resin composition of Example 1 further including an impact modifier showed the same level of crystallization temperature and speed as in Example 2, but the impact modifier The mechanical properties including tensile strength were improved by the increased amount.

Claims (13)

60 to 80% by weight of a polyester resin comprising a dicarboxylic acid-derived repeating unit containing terephthalic acid and a diol-derived repeating unit containing 1,4-cyclohexanedimethanol; And
For 100 parts by weight of the mixture comprising 20 to 40% by weight of filler,
0.01 to 2 parts by weight of a nitride-based inorganic nucleating agent, and 0.92 g / cm ³ And 0.1 to 5 parts by weight of the high-density polyethylene-based organic nucleating agent.
The method according to claim 1,
Wherein the inorganic nucleating agent and the organic nucleating agent are contained in a weight ratio of 1: 2 to 1:20.
The method according to claim 1,
Wherein the inorganic nucleating agent comprises at least one selected from the group consisting of boron nitride, aluminum nitride, silicon nitride, titanium nitride, tantalum nitride, vanadium nitride, chromium nitride, molybdenum nitride, niobium nitride, and tungsten nitride. Polyester resin composition.
The method according to claim 1,
Wherein the inorganic nucleating agent comprises boron nitride.
The method according to claim 1,
Wherein the organic nucleating agent is a high-density polyethylene having a density of 0.95 to 1.0 g / cm &lt; ^{3 &} gt ;.
The method according to claim 1,
Wherein the polyester resin is a polycyclohexylene dimethylene terephthalate resin.
The method according to claim 1,
Wherein the polyester resin has an intrinsic viscosity of 0.50 to 1.2 dl / g.
The method according to claim 1,
Wherein the filler comprises an acicular filler.
The method according to claim 1,
A colorant, a lubricant, a light stabilizer, a transesterification inhibitor, a coupling agent, a chain extender, a UV stabilizer, a coloring inhibitor, a matting agent, a deodorant, a flame retardant, a weathering additive, Wherein the polyester resin composition further comprises at least one additive selected from the group consisting of an antistatic agent, a releasing agent, an ion exchanger, and a light absorber.
10. The method of claim 9,
The impact modifier may be an unsaturated nitrile-aromatic vinyl copolymer, an unsaturated nitrile-aromatic vinyl-glycidyl (meth) acrylate copolymer, an unsaturated nitrile-aromatic vinyl-maleic anhydride copolymer, an ethylene-acrylate-glycidyl methacrylate (Meth) acrylate-grafted vinyl copolymer, a halogen-substituted vinyl copolymer, an aromatic vinyl-aromatic maleimide-maleic anhydride copolymer, an aromatic vinyl-unsaturated nitrile- A polyester resin composition comprising at least one compound selected from the group consisting of an aromatic maleimide copolymer, an aromatic vinyl-α-methyl aromatic vinyl copolymer and an aromatic vinyl-unsaturated nitrile-α-methyl aromatic vinyl copolymer .
The method according to claim 1,
An impact modifier, and an antioxidant,
Wherein the antioxidant comprises a phenol-based antioxidant and a phosphorus-based antioxidant in a weight ratio of 2: 1 to 1: 2.
The method according to claim 1,
To 100 parts by weight of a mixture comprising 60 to 80% by weight of a polycyclohexylenedimethylene terephthalate resin as the polyester resin and 20 to 40% by weight of glass fibers as the filler,
0.01 to 2 parts by weight of boron nitride as the inorganic nucleating agent and 0.1 to 5 parts by weight of high density polyethylene as an organic nucleating agent of 0.92 to 1.0 g / cm 3, wherein the weight ratio of the inorganic nucleating agent to the organic nucleating agent is 1: 5 to 1:10 ,
An impact modifier, and an antioxidant,
Wherein the antioxidant comprises a phenol-based antioxidant and a phosphorus-based antioxidant in a weight ratio of 2: 1 to 1: 2.
A molded article comprising the polyester resin composition according to any one of claims 1 to 12.