Thermoplastic resin composition and automobile interior parts manufactured therefrom

Abstract

The present invention relates to a thermoplastic resin composition and an automobile interior part manufactured from the same. The thermoplastic resin composition according to the present invention has improved heat resistance and impact resistance by changing the materials used in a manner different from that of the conventional ones, and has an effect of providing excellent product reliability and appearance quality by satisfying a balance of physical properties such as mechanical properties and fluidity.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Korean Patent Application No. 10-2022-0124048 filed on September 29, 2022 and Korean Patent Application No. 10-2023-0082468 refiled on June 27, 2023 based thereon, and all contents disclosed in the documents of the Korean patent application are incorporated as part of this specification.

[0002] The present invention relates to a thermoplastic resin composition and an automobile interior part manufactured from the same, and more particularly to a thermoplastic resin composition and an automobile interior part manufactured from the same, which have improved heat resistance and impact resistance due to changes in raw materials used, and which satisfy a balance of physical properties such as mechanical properties and fluidity, thereby providing excellent product reliability and appearance quality. [Background technology]

[0003] Materials used for automotive interior parts so far have included acrylonitrile-butadiene-styrene resin (ABS), composite resins made by mixing polycarbonate resin (PC) and acrylonitrile-butadiene-styrene resin (ABS), composite resins made by mixing polycarbonate resin (PC) and acrylate-styrene-acrylonitrile resin (ASA), and composite resins made by mixing polycarbonate resin (PC) and polybutylene terephthalate resin (PBT). These materials have excellent physical properties and are used in a variety of automotive interior parts.

[0004] Recently, due to environmental concerns, the use of waste products made from polyethylene terephthalate resin (hereinafter referred to as "PET resin") for processing into various plastic products has been considered.

[0005] Taking PET bottles as an example, the number has increased by 2.5 billion, or about 100,000 tons, but the recycling measures for these are limited to collecting them and recycling them into beverage bottles or fibers or packaging materials.

[0006] However, although PET resin is classified as a polyester resin like PBT, it is known that it has a higher crystallization temperature than PBT, leading to poor moldability and relatively unstable mechanical properties such as dimensional change.

[0007] Therefore, when PET resin is added, the physical properties mentioned above are inevitably poor compared to PBT, and it is necessary to develop a technology that can resolve this issue. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Publication No. 10-2016-0060907 (Publication date 2016.05.31) Summary of the Invention [Problem to be solved by the invention]

[0009] In order to solve the above-mentioned problems of the conventional art, the present invention aims to provide a thermoplastic resin composition which is economical since it can be used as an unpainted product by changing the materials used, and which has improved heat resistance and impact resistance, and satisfies a balance of physical properties such as mechanical properties and fluidity, thereby providing excellent product reliability and appearance quality.

[0010] Another object of the present invention is to provide an automobile interior part using the above thermoplastic resin composition.

[0011] The above and other objects of the present invention can be achieved by the present invention described below. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides a thermoplastic resin composition comprising: i) 44 to 56 weight % of a polybutylene terephthalate resin; ii) 8 to 17 weight % of a polyethylene terephthalate resin; iii) 12 to 20 weight % of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1 to 2.2 weight % of a carboxy-reactive epoxy resin; and v) 10 to 35 weight % of glass fibers containing SiO2, CaO and Al2O3, wherein the SiO2 content is 50 weight % or more and the Al2O3 content is greater than the CaO content.

[0013] II) In the above I), the intrinsic viscosity of the polybutylene terephthalate resin i) may be 0.45 to 0.85 dl / g.

[0014] III) In the above I) or II), the intrinsic viscosity of the polyethylene terephthalate resin ii) may be 0.5 to 0.9 dl / g.

[0015] IV) In the above I) to III), the polyethylene terephthalate resin ii) may be a recycled polyethylene terephthalate resin.

[0016] V) In the above I) to IV), the above iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer may contain 40 to 80% by weight of a conjugated diene compound, 10 to 40% by weight of an aromatic vinyl compound, and 1 to 20% by weight of a (meth)acrylate compound.

[0017] VI) In the above I) to V), the particle size of the above iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer may be 0.2 to 0.4 μm.

[0018] VII) In the above I) to VI), the iv) carboxy-reactive epoxy resin may be one or more selected from ethylene-n-butyl acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-acrylic acid ester-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-dimethacrylate-glycidyl methacrylate copolymer, ethylene-acrylate-glycidyl methacrylate copolymer, and ethylene-vinyl acetate-glycidyl methacrylate copolymer.

[0019] VIII) In the above I) to VII), the above iv) carboxy-reactive epoxy resin may contain 1 to 15% by weight of a monomer derived from glycidyl methacrylate.

[0020] IX) In the above I) to VIII), the intrinsic viscosity of the polybutylene terephthalate resin i) may be smaller than the intrinsic viscosity of the polyethylene terephthalate resin ii).

[0021] X) In the above I) to IX), the ii) polyethylene terephthalate resin may contain recycled resin from mineral water bottles.

[0022] XI) In the above I) to X), the recycled resin from mineral water bottles may be formed into pellets by extruding waste mineral water bottles.

[0023] XII) In the above I) to XI), the polyethylene terephthalate resin ii) may have a melting point of 250 to 256°C.

[0024] XIII) In the above I) to XII), the thermoplastic resin composition may contain one or more additives (vi) selected from a polyethylene-based lubricant, a hydrolysis suppression aid, and a phenolic antioxidant.

[0025] XIV) In any of I) to XIII), the thermoplastic resin composition may have a flexural strength of 140 MPa or more, measured on a 4 mm test piece using SPAN64 in accordance with ISO 178 at a speed of 2 mm / min, and a flexural modulus of 5000 MPa or more.

[0026] The present invention also provides XV) a thermoplastic resin composition comprising: i) 44 to 56 weight % of a polybutylene terephthalate resin; ii) 8 to 17 weight % of a polyethylene terephthalate resin; iii) 12 to 20 weight % of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1 to 2.2 weight % of a carboxy-reactive epoxy resin; and v) 10 to 35 weight % of glass fibers containing SiO2, CaO and Al2O3, wherein the SiO2 content is 50 weight % or more and the Al2O3 content is higher than the CaO content; and wherein the intrinsic viscosity of the i) polybutylene terephthalate resin is lower than the intrinsic viscosity of the ii) polyethylene terephthalate resin.

[0027] The present invention also provides XVI) a method for producing a thermoplastic resin composition, comprising the steps of feeding i) 44 to 56 weight % of a polybutylene terephthalate resin; ii) 8 to 17 weight % of a polyethylene terephthalate resin; iii) 12 to 20 weight % of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1 to 2.2 weight % of a carboxy-reactive epoxy resin; and v) 10 to 35 weight % of glass fibers containing SiO2, CaO and Al2O3, wherein the SiO2 content is 50 weight % or more and the Al2O3 content is greater than the CaO content; into an extruder, and melt-kneading and extruding the resulting mixture.

[0028] XVII) In the above XVI), the step of melt-kneading and extruding the thermoplastic resin composition can be carried out at an extrusion temperature of 250 to 300° C., an F / R (flow ratio) of 10 to 55 kg / hr, and a screw rotation speed of 150 to 600 rpm.

[0029] XVIII) In the above-mentioned XVI) to XVII), a step of injecting the thermoplastic resin composition at an injection temperature of 240 to 280°C and a mold temperature of 40 to 80°C can be included.

[0030] The present invention also relates to a process for producing a polyester fiber material, comprising: XIX) a step of feeding i) 44-56% by weight of a polybutylene terephthalate resin; ii) 8-17% by weight of a recycled polyethylene terephthalate resin; iii) 12-20% by weight of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1-2.2% by weight of a carboxy-reactive epoxy resin; and v) 10-35% by weight of glass fiber, which contains SiO2, CaO and Al2O3, the SiO2 content of which is 50% by weight or more and the Al2O3 content of which is greater than the CaO content; into an extruder, and melt-kneading and extruding the resulting mixture, XX) The present invention provides a method for producing a thermoplastic resin composition, characterized in that the intrinsic viscosity of the polybutylene terephthalate resin in i) is smaller than the intrinsic viscosity of the polyethylene terephthalate resin in ii) above.

[0031] The present invention also provides XXI) an automobile interior part which is produced by containing the above-mentioned thermoplastic resin composition.

[0032] XXII) In the above XXI), the automobile interior part may be a vehicle electronics body control module housing. Effect of the Invention

[0033] The thermoplastic resin composition according to the present invention can be molded into automobile interior parts.

[0034] In addition, the automobile interior parts manufactured from the thermoplastic resin composition according to the present invention have improved heat resistance and impact resistance, and satisfy a balance of physical properties such as mechanical properties and fluidity, and at the same time, have excellent moldability, which has the effect of improving the appearance quality.

[0035] Therefore, the thermoplastic resin composition according to the present invention can be applied to the field of automobile interior parts, including the housing of a vehicle electronic device Body Control Module, which is required as an automobile interior material. [Brief description of the drawings]

[0036] [Figure 1] 1 is a process flow chart showing a process for producing recycled polyethylene terephthalate resin used in the examples described below. [Diagram 2] Photographs showing virgin PET resin (left side) and recycled resin from waste mineral water bottles (right side) obtained by the process of Fig. 1. Here, PET resin refers to virgin resin made by the DMT method, which is a transesterification reaction between dimethyl terephthalate (DMT) and ethylene glycol (EG) known in the art. BEST MODE FOR CARRYING OUT THEINVENTION

[0037] In the following, the present invention will be described in more detail to facilitate understanding of the present invention.

[0038] The terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meaning, but should be interpreted in a meaning and concept that corresponds to the technical idea of ​​the present invention, taking into consideration that the inventor can appropriately define the concept of the term in order to explain the invention in the best possible manner.

[0039] In this description, the meaning of "comprise" may be defined as "produced by polymerization comprising", "polymerized comprising", or "comprises as a unit derived from", unless otherwise defined.

[0040] Unless otherwise specified, all numbers, values ​​and / or expressions expressing amounts of ingredients, reaction conditions, polymer compositions and formulations used in this description should be understood in all cases to be modified by the term "about" since such numbers are inherently approximations that reflect, among other things, various uncertainties of measurement that arise in obtaining such values. Also, when numerical ranges are disclosed in this description, such ranges are continuous and include all values ​​from the minimum value to said maximum value, inclusive, unless otherwise specified. Furthermore, when such ranges refer to integers, they include all integers from the minimum value to said maximum value, inclusive, unless otherwise specified.

[0041] In this description, when a range is recited for a variable, the variable is understood to include all values ​​within the recited range, including the recited endpoints of the range. For example, the range "5-10" is understood to include not only the values ​​5, 6, 7, 8, 9, and 10, but also any subranges such as 6-10, 7-10, 6-9, 7-9, etc., and any value between the integers that are valid within the recited range, such as 5.5-8.5, and 6.5-9, etc. Also, the range 10-30% is understood to include values ​​such as 10%, 11%, 12%, 13%, etc., and all integers up to and including 30%, as well as any value between the integers that are valid within the recited range, such as 10.5%, 15.5%, 25.5%, etc.

[0042] As used herein, the term "hydrolysis stabilizer", unless otherwise specified, refers to a material that is stable against hydrolysis and thus can improve mechanical properties, etc., even under conditions where hydrolysis may occur.

[0043] In this description, the flow index may be the Melt Flow Index measured at 260° C. under a load of 5 kg according to ISO 1133, unless otherwise specified.

[0044] The present inventors have confirmed that an automobile interior part manufactured using a thermoplastic resin composition containing a specific weight percent of polybutylene terephthalate resin and polyethylene terephthalate resin, a hydrolysis stabilizer in which a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer and a carboxy-reactive epoxy resin are mixed, and glass fiber with an excessive SiO2 content, has improved heat resistance and impact resistance, satisfies a balance of physical properties such as mechanical properties and fluidity, and provides excellent product reliability and appearance quality. Thus, the present inventors have completed a material for an automobile interior part as an unpainted product that has excellent moldability and appearance quality while satisfying a balance of physical properties such as mechanical properties and fluidity as in the present invention.

[0045] thermoplastic resin composition The thermoplastic resin composition according to one embodiment of the present invention comprises: i) 44-56 wt% of polybutylene terephthalate resin; ii) 8-17 wt% of polyethylene terephthalate resin; iii) 12-20 wt% of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1-2.2 wt% of a carboxy-reactive epoxy resin; and v) 10-35 wt% of glass fiber comprising SiO2, CaO and Al2O3, wherein the SiO2 content is 50 wt% or more and the Al2O3 content is greater than the CaO content.

[0046] In one embodiment of the present invention, i) polybutylene terephthalate resin and ii) polyethylene terephthalate resin are crystalline materials that impart moldability to a thermoplastic resin composition containing the same and impart chemical resistance to an automobile interior part manufactured using the same.

[0047] i) Polybutylene terephthalate resin The polybutylene terephthalate resin i) is a crystalline resin and prevents the penetration of chemicals from the outside, while improving the flowability of a thermoplastic resin composition containing the resin during injection molding due to its crystallized structure, thereby providing excellent appearance quality.

[0048] In one embodiment of the present invention, the polybutylene terephthalate resin i) may be a polybutylene terephthalate resin obtained by direct esterification or transesterification of 1,4-butanediol with terephthalic acid or dimethyl terephthalate to obtain a polybutylene terephthalate resin.

[0049] The polybutylene terephthalate resin (PBT) may have a repeating unit represented by the following Chemical Formula 1.

[0050] [ka]

[0051] In the above chemical formula, m is the average degree of polymerization in the range of 50-200.

[0052] In one embodiment of the present invention, in order to increase the impact strength of the thermoplastic resin composition, a copolymer in which the polybutylene terephthalate resin is copolymerized with an impact improving compound such as polytetramethylene glycol, polyethylene glycol, polypropylene glycol, aliphatic polyester, aliphatic polyamide, etc., or a modified polybutylene terephthalate resin in which the polybutylene terephthalate resin is mixed with the impact improving compound may be used.

[0053] In one embodiment of the present invention, the intrinsic viscosity of the polybutylene terephthalate resin measured in accordance with ASTM D2857 may be, for example, 0.45 to 0.85 dl / g, 0.45 to 0.77 dl / g, or 0.55 to 0.75 dl / g. If the intrinsic viscosity is too low outside the above range, the physical property reinforcing effect is reduced, so there is a drawback that the effect of improving chemical resistance is small, and if the intrinsic viscosity is too high, there is a drawback that moldability is reduced, so that problems may occur in the appearance of parts.

[0054] In this description, unless otherwise specified, the intrinsic viscosity is a value obtained by completely dissolving a sample to be measured in a methylene chloride solvent at a concentration of 0.05 g / ml, filtering the solution through a filter, and measuring the filtrate at 20° C. using an Ubbelohde viscometer.

[0055] The polybutylene terephthalate resin i) may have a weight average molecular weight of, for example, 10,000 to 80,000 g / mol, 20,000 g / mol to 100,000 g / mol, 30,000 g / mol to 90,000 g / mol, 40,000 g / mol to 80,000 g / mol, or 50,000 g / mol to 70,000 g / mol. Mechanical properties can be improved within the above range.

[0056] Specifically, the weight average molecular weight is measured by preparing a sample with a compound concentration of 1 wt% by putting tetrahydrofuran (THF) and the compound in a 1 ml glass bottle, filtering the standard sample (polystyrene) and the sample through a filter (pore size 0.45 μm), and injecting the sample into a GPC injector to obtain the molecular weight and molecular weight distribution of the compound by comparing the elution time of the sample with the calibration curve of the standard sample. In this case, the Infinity II 1260 (Agilient) can be used as a measuring device, and the flow rate can be set to 1.00 mL / min and the column temperature to 40.0° C.

[0057] The content of the polybutylene terephthalate resin i) may be, for example, 44 to 56% by weight, specifically 45 to 52% by weight, preferably 46 to 52% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives. If it is less than the above range, there is a drawback that cracks occur in an automobile interior part manufactured using a thermoplastic resin composition containing the resin, and if it exceeds the above range, there is a drawback that the rigidity and heat resistance properties of an automobile interior part manufactured using a thermoplastic resin composition containing the resin are reduced.

[0058] The polybutylene terephthalate resin (i) has an intrinsic viscosity greater than that of the polyethylene terephthalate resin (ii). small It may also be something.

[0059] The method for producing the polybutylene terephthalate resin is not particularly limited as long as it is a polymerization method commonly used in the technical field to which the present invention belongs, and if it meets the definition of the polybutylene terephthalate resin according to the present invention, it may be commercially purchased and used.

[0060] ii) Polyethylene terephthalate resin According to one embodiment of the present invention, ii) the material contains polyethylene terephthalate resin, thereby achieving the physical properties required for BCM parts.

[0061] The polyethylene terephthalate resin ii) is not particularly limited as long as it is a normal polyethylene terephthalate resin.

[0062] The polyethylene terephthalate resin ii) may have a repeating unit represented by the following chemical formula 2 as a basic structure.

[0063] [ka]

[0064] In the above chemical formula, n represents an integer of 1 or more, for example, an integer of 40 to 160.

[0065] In one embodiment of the present invention, the polyethylene terephthalate resin ii) is a (co)polymer copolymerized or modified with an impact improving compound, or is used in the form of a copolymer containing an impact improving compound or an environmentally friendly compound, thereby increasing the impact strength of the thermoplastic resin composition.

[0066] The impact modifying compound may be, by way of example only, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, aliphatic polyesters, aliphatic polyamides, and the like.

[0067] The environmentally friendly compound may be, for example, 1,4-cyclohexanedimethanol, or isophthalic acid.

[0068] In one embodiment of the present invention, the intrinsic viscosity of the polyethylene terephthalate resin ii) measured in accordance with ASTM D2857 may be 0.5 dl / g or more, 0.5 to 0.9 dl / g, or 0.6 to 0.9 dl / g. If the intrinsic viscosity is too low outside the above range, the effect of reinforcing physical properties decreases, so that the effect of improving chemical resistance may be small, and if the intrinsic viscosity is too high, the moldability may decrease, causing problems in the appearance of parts.

[0069] The weight average molecular weight of the polyethylene terephthalate resin ii) may be, for example, 5,000 to 80,000 g / mol, or 10,000 to 60,000 g / mol. When the weight average molecular weight satisfies the above range, the hydrolysis resistance and the injection deviation can be improved.

[0070] The ii) polyethylene terephthalate resin may have a melting point of 250°C or higher, specifically 250 to 256°C. In this case, the melt flow index of the thermoplastic resin composition can be improved, which is preferable for improving moldability.

[0071] The polyethylene terephthalate resin (ii) may have a crystallization temperature (Tm) of 250°C or higher, specifically, 250 to 258°C. In this case, the melt flow index of the thermoplastic resin composition can be improved, which is preferable for improving moldability.

[0072] In the present description, the melting point can be measured using methods known in the art, for example, a differential scanning calorimeter (DSC) can be used to measure the heat absorption peak.

[0073] The content of the ii) polyethylene terephthalate resin may be 8 to 17% by weight, preferably 9 to 17% by weight, more preferably 9 to 16% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If the content is less than the above range, cracks may occur in an automobile interior part manufactured using a thermoplastic resin composition containing the same, and if the content exceeds the above range, the rigidity and heat resistance of an automobile interior part manufactured using a thermoplastic resin composition containing the same may be reduced.

[0074] The method for producing the polyethylene terephthalate resin is not particularly limited as long as it is a polymerization method commonly used in the technical field to which the present invention belongs, and if it meets the definition of the polyethylene terephthalate resin according to the present invention, it may be commercially purchased and used.

[0075] The polyethylene terephthalate resin (ii) may contain recycled polyethylene terephthalate resin.

[0076] As an example, the ii) polyethylene terephthalate resin may include a recycled resin from mineral water bottles. The mineral water bottle may be, but is not limited to, a resin containing polyethylene terephthalate, which may be polyethylene terephthalate produced by condensation polymerization of terephthalic acid and ethylene glycol.

[0077] The recycled resin from mineral water bottles may be formed into pellets by extruding waste mineral water bottles.

[0078] The mineral water bottle recycled resin can be obtained, for example, by treating PET bottles into flakes according to the process flow chart shown in FIG. 1, which will be described later.

[0079] FIG. 1 below is a process flow chart showing the process of extruding waste mineral water bottles to produce recycled polyethylene terephthalate resin used in the examples.

[0080] According to the following Fig. 1, a sorting process is carried out to classify waste mineral water bottles into colored and colorless transparent bottles. The sorting can be carried out visually, where the colored bottles are mainly green.

[0081] The sorted waste mineral water bottles are crushed using a cutting machine. It is preferable to wash around 200 kg prior to the crushing process, and then carry out the drying and flaking process.

[0082] The pulverized material can be finely pulverized to a size within a range of, for example, 3 to 5 mm, specifically, 3.5 to 5 mm. In this case, by increasing the surface area of ​​the pulverized material, the efficiency of the subsequent drying process can be increased and the efficiency of blending with a thickener can also be improved.

[0083] The pulverized material is secondarily dried and then flaked.

[0084] The secondary drying is a process of removing moisture from the pulverized material and blending a thickener, and may be performed by a method of performing a dehumidification treatment after preliminary drying, if necessary.

[0085] The pre-drying is a step of heating the pulverized material within a range of 120 to 140° C. so that the moisture content of the pulverized material becomes about 1000 ppm, and a thickener is added simultaneously with or after the pre-drying.

[0086] Specifically, the pulverized material and thickener are placed in a friction dryer controlled at 140°C and 50 rpm, and heated air at 120 to 140°C is continuously passed through while retaining the material for about 2 hours until the moisture content of the pulverized material reaches 1000 ppm.

[0087] In this description, ppm is by weight unless otherwise specified.

[0088] The thickener is not limited as long as it is a compound that does not melt and undergoes a thickening reaction under the temperature conditions described above (e.g., 140°C) and the temperature conditions of the dryer described below (e.g., 165°C). As an example, a carbodiimide-based thickener can be used.

[0089] Examples of the carbodiimide-based thickeners include carbodiimide and polycarbodiimide, and the thickener is added by appropriately adjusting the mixing ratio with the ground material depending on the intrinsic viscosity suitable for the target product.For example, the thickener can be added at 0.75% by weight or less, or at 0.25 to 0.75% by weight, based on a total of 100% by weight of the mixture of ground material and thickener.

[0090] The dehumidification treatment is a step of obtaining an additional dried material by dehumidifying the (preliminary) dried material so that the moisture content is less than 50 ppm in order to prevent hydrolysis of the resin.

[0091] As an example of the dehumidification treatment, the additional drying material may be fed into a dryer hopper in the form of high-temperature hot air and retained for about 5 hours at a temperature of 165°C and a dew point of -60 to -40°C until the moisture content becomes less than 50 ppm.

[0092] The flake processing involves breaking the material into flakes of around 5 mm using an optical flake sorter.

[0093] It can then be extruded at an extrusion temperature of 200-270°C to form pellets.

[0094] Specifically, in the extrusion step, a thickener may be added to the flakes, and the mixture may be melted at the melting temperature of the thickener and formed into pellets.

[0095] The thickener has a lower melting temperature than the thickener added to the pre-dried material and melts at about the drying temperature of 140° C. and the secondary drying temperature of 165° C. If the thickener is added together with the pre-dried material, it will melt and pre-drying and dehumidification will not be possible, so it is added separately.

[0096] The amount of the thickener used can be appropriately adjusted to provide a recycled polyethylene terephthalate resin having an intrinsic viscosity required for a target product. For example, the amount may be within a range of 0.1 to 0.75% by weight based on the total weight of the melt.

[0097] The thickener may be an oxazoline-based thickener, and examples thereof include oxazoline and 1,3-phenylenebisoxazoline.

[0098] The extrusion step can be carried out, for example, by feeding the flakes and a thickener into an extruder and melt-extruding at a melt temperature of 275 to 280° C. and a maximum melt pressure of about 110 bar.

[0099] The obtained molten extrudate may be passed through a 20 micron SUS (Steel Use Stainless) filter at a vacuum level of 10 mbar to remove foreign matter, and then cooled and cut.

[0100] The cooling and cutting can be carried out using commonly used equipment.

[0101] As an example, using a pelletizer, the molten extrudate discharged from a SUS filter can be formed into spheres with a diameter of 2.8 mm using circulating water at 90°C under conditions of a die plate temperature of 320°C and a blade rotation speed of 3,200 rpm.

[0102] If the obtained molding result retains residual heat of 140°C or more, the surface of the molding result may recrystallize. For example, surface recrystallization may occur during the course of passing through an in-line crystallizer equipped with a vibrating conveyor for about 15 minutes.

[0103] The surface crystallization can prevent the raw materials from sticking together and agglomerating.

[0104] The surface-recrystallized molding product can be compounded with talc, coupling agents, glass fibers, etc., as necessary, to process it into a recycled polyethylene terephthalate resin.

[0105] The recycled polyethylene terephthalate resin may be 8 to 17% by weight, preferably 9 to 17% by weight, more preferably 9 to 16% by weight, based on 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. By adjusting the content of the recycled PET resin within the above range, the mechanical properties of the polyester composition can be improved, and a thermoplastic resin composition having an excellent balance with injection properties can be obtained.

[0106] (Hydrolysis stabilizer) According to one embodiment of the present invention, iii) a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer and iv) a carboxy-reactive epoxy resin can be used in combination as a hydrolysis stabilizer to achieve hydrolysis stability properties.

[0107] In this description, the weight % of a unit, monomer, block, etc. in a polymer can refer to the weight % of the monomer from which it is derived.

[0108] In addition, in this description, the weight percentage of a unit, monomer, block, etc. in a polymer can be measured by a measurement method commonly used in the technical field to which the present invention belongs. Alternatively, the content of an input monomer can be defined as the content of a unit, etc. in a produced polymer, assuming that all monomers are polymerized.

[0109] iii) (Meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer In the present invention, iii) the (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer not only complements the heat resistance properties but also provides excellent impact resistance to an automobile interior part manufactured from a thermoplastic resin composition containing the same.

[0110] The (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer iii) may be a graft copolymer.

[0111] The graft copolymer may, for example, contain 40 to 80% by weight of a conjugated diene compound, 10 to 40% by weight of an aromatic vinyl compound, and 1 to 20% by weight of a (meth)acrylate compound.

[0112] Specifically, the graft copolymer may contain 50 to 70% by weight of a conjugated diene compound, 20 to 35% by weight of an aromatic vinyl compound, and 1 to 15% by weight of a (meth)acrylate compound.

[0113] The graft copolymer may preferably contain 55 to 65% by weight of a conjugated diene compound, 25 to 35% by weight of an aromatic vinyl compound, and 5 to 15% by weight of a (meth)acrylate compound.

[0114] If the content of the conjugated diene compound is too low, falling outside the above range, the impact resistance may decrease, whereas if the content of the conjugated diene compound is too high, the rigidity (elastic modulus) may decrease.

[0115] In addition, if the content of the (meth)acrylate compound is too low outside the above range, the rigidity is improved but the impact resistance may decrease, whereas if the content of the (meth)acrylate compound is too high, the rigidity complementing effect may decrease.

[0116] The (meth)acrylate compound contained in the iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer may be at least one selected from common (meth)acrylate compounds that can be used in the technical field to which the present invention pertains, such as methacrylate and acrylate, and is preferably methacrylate.

[0117] The conjugated diene compound contained in the (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer iii) may contain, for example, butadiene, but is not limited to those containing only a specific conjugated diene compound.

[0118] The aromatic vinyl compound contained in the iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer may be, for example, one or more selected from styrene, α-methylstyrene, α-ethylstyrene, and p-methylstyrene, and styrene is preferred.

[0119] The (iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer is characterized by being polymerized from components within the above-mentioned specific content range, and preferably contains an appropriate amount of (meth)acrylate component, thereby favorably improving heat resistance, and may further contain a separate alkyl acrylate component different from the (meth)acrylate component, if necessary.

[0120] The (iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer can be used as a powder having a particle size of 0.2 to 0.4 μm, preferably 0.25 to 0.35 μm, and more preferably 0.2 to 0.35 μm. In this case, there is an effect of providing improved impact strength and improved ejectability.

[0121] In this description, the particle size can be measured by a known method for measuring the size of particles, and in particular, it can be measured using a nitrogen gas adsorption method and a BET analysis device (Micromeritics' Surface Area and Porosity Analyzer ASAP 2020 device). More specifically, 0.3 g to 0.5 g of a sample can be added to a tube, pretreated at 100° C. for 8 hours, and then measured at room temperature using an ASAP 2020 analysis device. The same sample can be measured three times to obtain an average value.

[0122] The (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer (iii) may have a weight average molecular weight of, for example, 10,000 to 180,000 g / mol, 20,000 g / mol to 150,000 g / mol, 30,000 g / mol to 120,000 g / mol, 50,000 g / mol to 120,000 g / mol, or 80,000 g / mol to 120,000 g / mol. Mechanical properties can be improved within the above range.

[0123] The content of the iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer may be 12 to 20% by weight, preferably 12 to 19% by weight, more preferably 12 to 18% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If it is less than the above range, the impact resistance of an automobile interior part manufactured using a thermoplastic resin composition containing it may be weakened, and if it exceeds the above range, the flowability of the thermoplastic resin composition containing it may be poor, and the rigidity and heat resistance of an automobile interior part manufactured using the thermoplastic resin composition may be deteriorated.

[0124] iv) Carboxy-reactive epoxy resins According to one embodiment of the present invention, iv) carboxy-reactive epoxy resin can provide impact resistance to the automotive interior parts manufactured using the thermoplastic resin composition described herein while improving the chemical resistance.

[0125] The iv) carboxy-reactive epoxy resin may be, for example, an epoxy-functional (meth)acrylic copolymer formed from an epoxy-functional (meth)acrylic monomer and an alkylene.

[0126] In this description, unless otherwise specified, "(meth)acrylic" includes both acrylic and methacrylic monomers, and "(meth)acrylate" includes both acrylate and methacrylate monomers.

[0127] Specific examples of the epoxy-functional (meth)acrylic monomers can include species containing 1,2-epoxy groups, including glycidyl acrylate and glycidyl methacrylate.

[0128] Specific examples of the iv) carboxy-reactive epoxy resin may be one or more selected from ethylene-n-butyl acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-acrylic acid ester-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-dimethacrylate-glycidyl methacrylate copolymer, ethylene-acrylate-glycidyl methacrylate copolymer, and ethylene-vinyl acetate-glycidyl methacrylate copolymer.

[0129] The iv) carboxy-reactive epoxy resin may be, for example, a copolymer containing 1-15 wt% or 3-10 wt% of glycidyl methacrylate monomer, 60-74 wt% or 63-74 wt% of ethylene monomer, and 20-30 wt% or 25-30 wt% of n-butyl acrylate. If the content of the glycidyl methacrylate monomer is too high, it may be insufficient to improve the impact resistance and chemical resistance of an automobile interior part manufactured using a thermoplastic resin composition containing the same.

[0130] The content of the iv) carboxy-reactive epoxy resin may be 0.1 to 2.2 wt%, preferably 0.5 to 2.2 wt%, and more preferably 1 to 2.2 wt%, based on the total 100 wt% of all components constituting the composition, including (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If the content of the carboxy-reactive epoxy resin is too high outside the above range, there is a problem of gas generation in the injection product on the surface of an automobile interior part manufactured using a thermoplastic resin composition containing the same, which is disadvantageous in that it impairs the appearance quality.

[0131] The total content of the iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer and iv) carboxy-reactive epoxy resin may be 15.1 to 20 wt%, preferably 15.2 to 19 wt%, more preferably 15.3 to 18 wt%, based on the total 100 wt% of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If used in excess outside the above range, the appearance quality of the injection molded product may be impaired on the surface of an automobile interior part manufactured using a thermoplastic resin composition containing the same, and if used in an inappropriately small amount, it is difficult to provide impact resistance and to provide an effect of inhibiting the transesterification reaction.

[0132] v) Glass Fiber In one embodiment of the present invention, the thermoplastic resin composition includes v) glass fiber, thereby improving physical properties of the thermoplastic resin composition, and thereby improving tensile strength and flexural strength of a molded product manufactured from the thermoplastic resin composition.

[0133] The v) glass fiber may be of a type that reinforces the rigidity of a molded article produced using the thermoplastic resin composition and improves mechanical properties.

[0134] The v) glass fiber may, for example, contain 50 to 65% by weight of silica, 15 to 32% by weight of alumina, and 12 to 22% by weight of calcium oxide. When glass fibers contained within the above ranges are used, a thermoplastic resin composition having an excellent balance of chemical resistance, mechanical properties, and heat resistance can be obtained.

[0135] More preferably, the v) glass fiber contains 50-60% or 50-55% by weight of silica, 15-27% or 15-22% by weight of alumina, and 13-25% or 13-20% by weight of calcium oxide. In this case, a thermoplastic resin composition having an excellent balance of physical properties such as processability, specific gravity, and mechanical properties can be obtained, and a molded product having high heat resistance, high rigidity, and high toughness can be provided from the thermoplastic resin composition.

[0136] The v) glass fiber may be a glass fiber having a circular cross section or a flat cross section, and when it has the above-mentioned range and cross section, high rigidity, light weight, and appearance quality can be ensured.

[0137] When the aspect ratio (L / D) of the v) glass fiber, which is the ratio of the average length (L) to the average diameter (D), is, for example, 1:1 to 1:4, specifically 1:1 to 1:3, and more specifically 1:1 to 1:2, it can provide the thermoplastic resin composition of the present invention with high strength and high toughness, as well as improved elongation and surface appearance quality. When the aspect ratio is, for example, 1:3 to 1:4, and more specifically, about 1:4, it can provide a molded product that is advantageous in terms of flatness, deformation, and orientation, as well as high strength and high toughness.

[0138] In this description, the average diameter and average length can be measured using a scanning electron microscope (SEM). Specifically, 20 inorganic fillers are selected using a scanning electron microscope, and the diameter and length of each are measured using an icon bar capable of measuring the diameter, and then the arithmetic average is calculated.

[0139] The average diameter may be, for example, 10 to 13 μm, specifically, 10 to 11 μm, and the average length may be, for example, 2.5 to 6 mm, specifically, 3 to 4 mm. When the above-mentioned ranges are satisfied, there is an effect of improving the processability and improving the tensile strength of a molded product produced by molding the thermoplastic resin composition of the present invention.

[0140] In one embodiment of the present invention, the v) glass fiber may be used together with other inorganic fibers, and the inorganic fibers are at least one selected from natural fibers including carbon fibers, basalt fibers, kenaf, and hemp.

[0141] The glass fibers v) may be treated with a sizing agent during fiber production or post-treatment. Examples of such sizing agents include lubricants, coupling agents, and surfactants.

[0142] The lubricant is used to allow the glass fibers to form good strands, and the coupling agent enables good adhesion between the glass fibers and the base resin. When appropriately selected in consideration of the types of base resin and glass fibers, the coupling agent can impart excellent physical properties to the thermoplastic resin composition.

[0143] The coupling agent may be directly applied to the glass fiber or may be added to an organic matrix, and the content of the coupling agent must be appropriately selected so that the performance of the coupling agent can be fully exhibited.

[0144] The coupling agent may be an amine-based, acrylic-based, or silane-based agent, and it is preferable to use a silane-based agent.

[0145] Examples of the silane system include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β-(3,4-epoxyethyl)γ-aminopropyltrimethoxysilane.

[0146] The v) glass fiber may be, for example, 10 to 35% by weight, preferably 10 to 32% by weight, more preferably 10 to 28% by weight, and even more preferably 15 to 25% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If it is less than the above range, cracks may occur in an automobile interior part manufactured using a thermoplastic resin composition containing this, and if it exceeds the above range, the rigidity and heat resistance of an automobile interior part manufactured using a thermoplastic resin composition containing this may be reduced.

[0147] Additives The thermoplastic resin composition according to an embodiment of the present invention may further include a suitable additive (vi) for improving its flowability.

[0148] The additive vi) may be, for example, at least one selected from the group consisting of a lubricant, a heat stabilizer, and a hydrolysis inhibitor.

[0149] The lubricant is not particularly limited as long as it can ensure the ease of removal and flowability of an injection screw used to manufacture an automobile interior part from a thermoplastic resin composition containing the lubricant.

[0150] As an example of the lubricant, a polyethylene wax can be used.

[0151] The lubricant may be, for example, 0.01 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.1 to 2% by weight, even more preferably 0.1 to 1% by weight, and most preferably 0.1 to 0.5% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If the content of the lubricant is too high outside the above range, problems with appearance such as unevenness may occur on the surface of an automobile interior part manufactured using a thermoplastic resin composition containing the lubricant, which may impair the appearance quality.

[0152] The heat stabilizer is not particularly limited as long as it can prevent deterioration of an automobile interior part manufactured using a thermoplastic resin composition containing the heat stabilizer due to high temperatures.

[0153] The heat stabilizer is not particularly limited as long as it can ensure the above properties, but preferably, a high phenolic antioxidant can be used.

[0154] The phenol-based antioxidant may include a hindered phenol-based stabilizer having a crystallization temperature (Tm) of 110 to 130° C., and specific examples thereof include tetrakis[ethylene-3-(3,5-di-t-butyl-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, or a combination thereof.

[0155] The heat stabilizer may be, for example, 0.01 to 5% by weight, preferably 0.01 to 3% by weight, and more preferably 0.01 to 2% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If the content of the heat stabilizer is too high, problems with appearance such as unevenness may occur on the surface of an automobile interior part manufactured using a thermoplastic resin composition containing the same, which may impair the appearance quality.

[0156] The hydrolysis inhibitor according to the present invention may be of various known types, provided that it does not adversely affect the thermoplastic resin composition of the present invention. Among commercially available substances, inorganic phosphate compounds such as sodium monophosphate having the chemical formula NaH2PO4 may be used.

[0157] The hydrolysis suppression auxiliary may be, for example, 0.01 to 5% by weight, preferably 0.01 to 3% by weight, and more preferably 0.01 to 2% by weight, based on the total 100% by weight of all components constituting the composition (i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, v) glass fiber, and vi) additives described below. If the content of the hydrolysis suppression auxiliary is too high outside the above range, problems with appearance such as unevenness may occur on the surface of an automobile interior part manufactured using a thermoplastic resin composition containing the same, which may impair the appearance quality.

[0158] The thermoplastic resin composition may have a heat distortion temperature under high load of 180° C. or higher, specifically 184 to 190° C., as measured in accordance with ISO 75 using a test piece described below.

[0159] In this description, the high load heat distortion temperature can be measured under a high load of 1.82 MPa in accordance with ISO 75.

[0160] Method for producing thermoplastic resin composition The method for producing the thermoplastic resin composition of the present invention will be described below. In the description of the method for producing the thermoplastic resin composition of the present invention, all of the contents of the thermoplastic resin composition described above are included.

[0161] As an example, a method for producing a thermoplastic resin composition described herein includes the steps of feeding i) 44 to 56 weight % of polybutylene terephthalate resin; ii) 8 to 17 weight % of polyethylene terephthalate resin; iii) 15 to 28 weight % of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1 to 2.2 weight % of a carboxy-reactive epoxy resin; and v) 10 to 35 weight % of glass fibers containing SiO2, CaO, and Al2O3, wherein the SiO2 content is 50 weight % or more and the Al2O3 content is greater than the CaO content, into an extruder, and melt-kneading and extruding the mixture.

[0162] The melt-kneading step may include, for example, other additives as described above.

[0163] The melt-kneading and extruding steps may be performed using at least one selected from the group consisting of a single screw extruder, a twin screw extruder, and a Banbury mixer, and preferably a twin screw extruder, which may be used to uniformly mix the composition and then extrude the mixture to obtain, for example, a pellet-shaped thermoplastic resin composition. In this case, the deterioration of mechanical properties and thermal properties may be prevented, and plating adhesion and appearance quality may be excellent.

[0164] The step of producing pellets using the extrusion kneader can be performed, for example, at an extrusion temperature of 250 to 300° C., a feed rate (Flow ratio, F / R) of 10 to 59 kg / hr, and a screw rotation speed of 200 to 390 rpm, and preferably at an extrusion temperature of 250 to 280° C., an F / R of 10 to 40 kg / hr, and a screw rotation speed of 220 to 300 rpm.

[0165] After extruding the thermoplastic resin composition, a step of injecting the composition at an injection temperature of 240 to 280°C, specifically 250 to 270°C, a mold temperature of 40 to 80°C, specifically 50 to 70°C, and an injection speed of 10 to 50 mm / sec, specifically 10 to 30 mm / sec may be included.

[0166] Further, an automobile interior part containing the thermoplastic resin composition of the present invention will be described. In describing the automobile interior part containing the thermoplastic resin composition of the present invention, all of the contents of the thermoplastic resin composition described above are included.

[0167] Automotive interior parts The thermoplastic resin composition of the present invention can be effectively used for automobile interior parts that require moldability, mechanical properties, high load heat resistance, and chemical resistance through sufficient complementation between components.

[0168] The automobile interior parts can be manufactured by a method commonly used in the art. For example, a melt-kneaded product, pellets, or a sheet (plate) molded therefrom of the thermoplastic resin composition according to the present invention can be used as a raw material to apply molding methods such as injection molding, injection compression molding, extrusion molding (sheet casting), press molding, pressure molding, hot bending molding, compression molding, calendar molding, and rotational molding.

[0169] The thermoplastic resin composition of the present invention can be produced by melt kneading and extruding pellets using, for example, a twin-screw extruder (φ40, L / D:42, equipped with SM Platek) set at 250 to 300°C or 250 to 280°C at 200 to 390 rpm or 250 to 280 rpm, feeding i) polybutylene terephthalate resin, ii) polyethylene terephthalate resin, iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, iv) carboxy-reactive epoxy resin, and v) glass fiber into the main inlet at a feed rate (Flow ratio, F / R) of 10 to 59 kg / hr or 30 to 40 kg / hr, and feeding vi) additive into the side inlet at a feed rate of 10 to 59 kg / hr or 10 to 20 kg / hr.

[0170] The pellets can be fed into an injection molding machine to produce automobile interior parts.

[0171] In order to indirectly confirm the physical properties of the manufactured automobile interior parts, the pellets are injected into an injection molding machine (ENGEL, 80 tons) at an injection temperature of 260°C, a mold temperature of 60°C, and an injection speed of 30 mm / sec to manufacture ISO standard test pieces.

[0172] The produced test piece may have a melt flow rate of, for example, 30 g / 10 min or more, specifically 30 to 36 g / 10 min, measured at 260° C. under a load of 5 kg in accordance with ISO 1133.

[0173] In addition, the test piece has an Izod notch impact strength of 10 kJ / m2 or less, as measured at 23°C in accordance with ISO 180 / 1A, for example. 2 The above is a specific example of 11 to 12 kJ / m 2 may be also possible.

[0174] The test piece may have a tensile strength of, for example, 90 MPa or more, specifically 90 to 99 MPa, measured in accordance with ISO 527 at a speed of 50 mm / min.

[0175] In addition, the bending strength of a 4 mm test piece measured at a speed of 2 mm / min using SPAN64 in accordance with ISO 178 may be, for example, 140 MPa or more, specifically 140 to 144 MPa, and the bending modulus of elasticity may be, for example, 5000 MPa or more, specifically 5000 to 5150 MPa.

[0176] The automotive interior part may specifically be a vehicle electronics Body Control Module housing, but is not limited to a particular type.

[0177] That is, the thermoplastic resin composition according to one embodiment of the present invention is characterized by comprising specific weight percents of polybutylene terephthalate resin, polyethylene terephthalate resin, (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer, carboxy-reactive epoxy resin, and glass fiber in which SiO2 is in an excess amount. Automotive interior parts manufactured from the composition have the advantages of improved heat resistance and impact resistance as a result of changing the materials used from conventional materials, and of satisfying a balance of physical properties such as mechanical properties and fluidity, thereby providing excellent product reliability and appearance quality.

[0178] In the description of the thermoplastic resin composition, the production method thereof, and the automobile interior part of the present invention, other conditions, equipment, etc. that are not explicitly described can be appropriately selected within the range commonly used in the art, and it is clearly stated that there are no particular limitations.

[0179] The present invention may, however, be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein.

[0180] [Example] Examples 1 to 4 and Comparative Examples 1 to 9 The raw materials used in the examples are as follows. (A) Polybutylene terephthalate resin (PBT) A-1) PBT, intrinsic viscosity (IV) 0.7dl / g A-2) PBT, intrinsic viscosity (IV) 0.8dl / g (B) Polyethylene terephthalate resin (PET: homopolymer), intrinsic viscosity (IV) 0.8 dl / g recycled PET resin: corresponds to the white chip in Figure 2 (right side) obtained by processing mineral water bottles according to the process flow chart in Figure 1 below. (C) (Meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer C1) Methacrylate-butadiene-styrene copolymer (particle size 0.3 μm, methyl methacrylate 15% by weight, butadiene 80% by weight, styrene 5% by weight, weight average molecular weight 103,000 g / mol) C2) Acrylonitrile-styrene-butyl acrylate copolymer (25% by weight acrylonitrile, 34% by weight styrene, 41% by weight butyl acrylate, weight average molecular weight 130,000 g / mol) C3) Acrylonitrile-butadiene-styrene copolymer (10% by weight acrylonitrile, 60% by weight butadiene, 30% by weight styrene, weight average molecular weight 78,000 g / mol) D) Ethylene / n-butyl acrylate / glycidyl methacrylate resin (65% by weight of ethylene, 28% by weight of n-butyl acrylate, 7% by weight of glycidyl methacrylate) (E) Glass fiber: average length 3 mm, average diameter 10 μm E-1) Glass fiber containing 48% by weight of silica, 12% by weight of alumina, 35% by weight of calcium oxide, and 5% by weight of other components including MgO E-2) Glass fiber containing 44% by weight of silica, 14% by weight of alumina, 36% by weight of calcium oxide, and 6% by weight of other components including MgO E-3) Glass fiber containing 52% by weight of silica, 18% by weight of alumina, 16% by weight of calcium oxide, and 14% by weight of other components including MgO (Additives) F) Lubricant (polyethylene wax) LDPE wax G) Hydrolysis inhibitor (ester exchange inhibitor): Sodium monophosphate, chemical formula NaH2PO4 H) Heat stabilizer (high phenolic antioxidant): Pentaerythritol tetrakis[(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)]

[0181] The raw materials of the thermoplastic resin composition shown in Table 1 below were mixed and extruded to produce a thermoplastic resin composition having a uniform dispersion in the form of pellets. The pellets were then heated and injected into a mold, and cooled to produce parts. Through an injection process, test specimens that can be used as automobile interior parts were prepared.

[0182] Specifically, the components shown in Table 1 below are mixed in a mixer, and then extruded for 1 to 3 minutes at 250 rpm using a twin-screw extruder (φ40, L / D: 42, equipped with SM Platek) set at 260°C, while feeding the components into the main inlet at a feed rate of 39 kg / hr and feeding additives into the side inlet at a rate of 11 kg / hr, to produce thermoplastic resin composition pellets.

[0183] The produced pellets were dried in a convection oven at 80°C for at least 4 hours, and then injected into an injection molding machine (ENGEL, 80 ton) at an injection temperature of 260°C, a mold temperature of 60°C, and an injection speed of 30 mm / sec to prepare ISO test specimens.

[0184] [Table 1]

[0185] For reference, the total weight % of the raw materials used in Table 1, A-1 to H, is 100% by weight.

[0186] Experimental Example 1: Evaluation of physical properties of automobile interior part test pieces The physical properties of the automobile interior part test pieces produced in Examples 1 to 4 and Comparative Examples 1 to 9 were evaluated. The evaluation methods were as follows. -Melt Flow Rate: According to ISO 1133 (260℃, 5kg) -Impact strength (IZOD): according to ISO 180 / 1A (Notched, 23°C) - Tensile strength and elongation: according to ISO 527 (50mm / min) -Flexural strength, flexural modulus: According to ISO 178 (4mm, SPAN64, speed 2mm / min) - Heat distortion temperature (HDT): According to ISO 75 (high load 1.82 MPa)

[0187] The results measured according to the above evaluation criteria are shown in Table 2 below.

[0188] [Table 2]

[0189] Referring to Table 2, it can be seen that the thermoplastic resin compositions of Examples 1 to 4 according to the present invention have high impact strength, flexural modulus, high load heat distortion temperature, and hydrolysis resistance retention rate, and therefore the automobile interior parts manufactured using the same basically satisfy physical properties such as impact strength, tensile strength, and flexural strength, while also providing excellent chemical resistance and high load heat resistance properties, and reducing the degree of gas generation during injection, thereby providing both product reliability and appearance quality. In addition, it was confirmed that Comparative Example 1, in which an excessive amount of polybutylene terephthalate resin is used outside the appropriate range, had a low flow index compared to Examples 1 to 4, and therefore had poor processability, and the tensile strength, flexural strength, and flexural modulus were significantly deteriorated.

[0190] Moreover, it was confirmed that Comparative Example 2, in which an extremely small amount of polybutylene terephthalate resin was used, was somewhat inferior in impact strength and heat distortion temperature when compared with Examples 1-4.

[0191] In addition, it can be seen that Comparative Example 3 and Comparative Example 4, which use glass fibers with less than 50% by weight of SiO2, have deteriorated tensile strength, flexural strength, flexural modulus, impact strength, and heat distortion temperature, etc., when compared with Examples 1 to 4.

[0192] Moreover, it is clear that Comparative Example 5, which does not use a carboxy-reactive epoxy resin, is inferior in tensile strength, flexural strength, flexural modulus, and heat resistance when compared with Examples 1 to 4.

[0193] Moreover, it can be seen that Comparative Example 6, in which an ASA resin was used instead of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound, had deteriorated impact strength and heat resistance properties when compared with Examples 1 to 4.

[0194] In addition, it can be seen that Comparative Example 7, in which ABS resin was used instead of the (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound, had deteriorated tensile strength, flexural strength and heat resistance properties compared with Examples 1 to 4.

[0195] Moreover, it is understood that Comparative Example 8, in which a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound was used in an amount less than the appropriate range, had deteriorated impact strength compared with Examples 1 to 4.

[0196] In addition, it was confirmed that Comparative Example 9, in which a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound was used in an amount less than the appropriate range, had deteriorated fluidity and flexural modulus, and was poor in tensile strength, flexural strength, and heat resistance, when compared with Examples 1 to 4.

[0197] Additionally, the same procedures as in Example 1 were repeated, except that the recycled PET resin in Example 1 was replaced with virgin PET, and the fluidity, tensile strength, tensile elongation, flexural strength, flexural modulus, impact strength, and heat distortion temperature were measured for the test specimens obtained. At this time, the white chip shown in the left diagram of Figure 2 below was used as the virgin PET.

[0198] As a result, the fluidity was 34 g / 10 min, the tensile strength was 99 MPa, the tensile elongation was 3.9%, the bending strength was 144 MPa, the bending modulus was 5070 MPa, and the impact strength was 11.4 kJ / m 2 The heat distortion temperature was measured to be 185° C., and it was found that the thermoplastic resin compositions provided physical properties equivalent or similar to those of the thermoplastic resin compositions of Examples 1 to 4.

[0199] That is, the thermoplastic resin composition according to an embodiment of the present invention includes a specific weight percent of polybutylene terephthalate resin, polyethylene terephthalate resin, a hydrolysis stabilizer in which a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer and a carboxy-reactive epoxy resin are mixed, and glass fiber containing an excess amount of SiO2. Therefore, an automobile interior part manufactured from the composition has improved heat resistance and impact resistance, and satisfies a balance of physical properties such as mechanical properties and fluidity, thereby providing excellent product reliability and appearance quality. In particular, even if recycled polyethylene terephthalate resin is used as the polyethylene terephthalate resin, there is an advantage in that the physical properties are sufficiently improved.

Claims

1. i) 44 to 56% by weight of polybutylene terephthalate resin; ii) 8 to 17% by weight of a polyethylene terephthalate resin; iii) 12 to 20% by weight of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1 to 2.2 wt. % of a carboxy-reactive epoxy resin; v) SiO 2 , CaO and Al 2 O 3 The SiO 2 The content is 50% by weight or more, and Al 2 O 3 10 to 35% by weight of glass fibers, the content of which is greater than the CaO content; The thermoplastic resin composition, wherein the iv) carboxy-reactive epoxy resin is at least one selected from ethylene-n-butyl acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-acrylic acid ester-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-dimethacrylate-glycidyl methacrylate copolymer, ethylene-acrylate-glycidyl methacrylate copolymer, and ethylene-vinyl acetate-glycidyl methacrylate copolymer.

2. The thermoplastic resin composition according to claim 1, wherein the intrinsic viscosity of the polybutylene terephthalate resin is 0.45 to 0.85 dl / g, and the intrinsic viscosity of the polyethylene terephthalate resin is 0.5 to 0.9 dl / g.

3. The thermoplastic resin composition according to claim 1, wherein the ii) polyethylene terephthalate resin is a recycled polyethylene terephthalate resin.

4. The thermoplastic resin composition according to claim 1, wherein the iii) (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer comprises a graft copolymer containing 40 to 80% by weight of a conjugated diene compound, 10 to 40% by weight of an aromatic vinyl compound, and 1 to 20% by weight of a (meth)acrylate compound.

5. The thermoplastic resin composition according to claim 1, wherein the iv) carboxy-reactive epoxy resin contains 1 to 15% by weight of a monomer derived from glycidyl methacrylate.

6. The thermoplastic resin composition according to claim 1, wherein the intrinsic viscosity of the polybutylene terephthalate resin (i) is smaller than the intrinsic viscosity of the polyethylene terephthalate resin (ii).

7. The thermoplastic resin composition according to claim 1, wherein the polyethylene terephthalate resin (ii) comprises recycled mineral water bottle resin.

8. The thermoplastic resin composition according to claim 1, further comprising one or more additives selected from a polyethylene-based lubricant, a hydrolysis suppression aid, and a phenolic antioxidant.

9. 2. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a flexural strength of 140 MPa or more and a flexural modulus of 5000 MPa or more, the flexural strength and the flexural modulus being measured on a 4 mm test piece using SPAN 64 according to ISO 178 at a speed of 2 mm / min.

10. i) 44 to 56% by weight of polybutylene terephthalate resin; ii) 8 to 17% by weight of polyethylene terephthalate resin; iii) 12 to 20% by weight of a (meth)acrylate compound-conjugated diene compound-aromatic vinyl compound copolymer; iv) 0.1 to 2.2% by weight of a carboxy-reactive epoxy resin; and v) SiO 2 , CaO and Al 2 O 3 The SiO 2 The content is 50% by weight or more, and Al 2 O 3 10 to 35% by weight of glass fiber having a content greater than the CaO content; and feeding the glass fiber into an extruder, melt-kneading and extruding the glass fiber; The method for producing a thermoplastic resin composition, wherein the iv) carboxy-reactive epoxy resin is at least one selected from the group consisting of ethylene-n-butyl acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-acrylic acid ester-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-dimethacrylate-glycidyl methacrylate copolymer, ethylene-acrylate-glycidyl methacrylate copolymer, and ethylene-vinyl acetate-glycidyl methacrylate copolymer.

11. The method for producing a thermoplastic resin composition according to claim 10, wherein the intrinsic viscosity of the polybutylene terephthalate resin (i) is smaller than the intrinsic viscosity of the polyethylene terephthalate resin (ii).

12. An automotive interior part manufactured containing the thermoplastic resin composition described in claim 1.

13. 13. The automotive interior part of claim 12, wherein the automotive interior part is a vehicle electronics Body Control Module housing.

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