Flame-retardant polyester resin composite composition and molded articles produced thereby

Abstract

To provide a flame-retardant polyester resin composite composition which is excellent in balanced mechanical properties and hydrolysis resistance, and a molded article manufactured from the same.SOLUTION: A flame-retardant polyester resin composite composition contains 40 to 60 wt.% of (A) a polyester resin, 10 to 50 wt.% of (B) a glass fiber which is surface-treated with a sizing composition containing a film formation agent containing a polyurethane resin and an epoxy resin and a silane coupling agent containing aminosilane and epoxy silane, 10 to 30 wt.% of (C) a flame retardant having a phosphorus content of 20 wt.% or more and a nitrogen content of 5 wt.% or less, wherein when being measured in a 3:2 mixed solvent of phenol to o-dichlorobenzene at 25°C (weight reference), intrinsic viscosity of the polyester resin is 0.8 to 1.1 dl / g, or when being measured at 250°C and a load of 2.16 kg, a melting index of the polyester resin is 10 to 80 g / 10 min.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a flame-retardant polyester resin composite composition and a molded product produced therefrom. Specifically, the present invention relates to a flame-retardant polyester resin composite composition having an excellent balance of mechanical properties and hydrolysis resistance, and a molded product produced therefrom.

Background Art

[0002] Polyester is a synthetic resin excellent in mechanical strength, heat resistance, transparency, and gas barrier properties, and is widely used as a material for beverage containers, packaging films, audio and video films, etc. Further, polyester is also widely used as a material for medical fibers, tire cords, building materials, etc.

[0003] In order to improve the mechanical or thermal properties of polyester, a filler such as glass fiber may be used together (see Patent Document 1). By the way, although the mechanical properties and heat resistance of a polyester resin composition reinforced with glass fiber are improved, there is also a problem that the color easily changes at high temperatures.

[0004] Also, there have been attempts to add a flame retardant to a polyester resin to improve flame retardancy and to improve the adhesive strength with other members (see Patent Document 2).

[0005] On the other hand, since polyester resin is likely to undergo hydrolysis in a high-temperature and high-humidity environment, its scope of application is limited.

[0006] Therefore, there is a demand for the development of a flame-retardant polyester resin composite composition having an excellent balance of mechanical properties and hydrolysis resistance.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

[0008] The object of the present invention is to provide a flame-retardant polyester resin composite composition that exhibits excellent balance of mechanical properties and hydrolysis resistance.

[0009] Another object of the present invention is to provide a molded article manufactured from the flame-retardant polyester resin composite composition. [Means for solving the problem]

[0010] In one embodiment of the present invention to achieve the above objective, a flame-retardant polyester resin composite composition is provided, comprising, based on the total weight of the composition, (A) 40 to 60% by weight of polyester resin, (B) 10 to 50% by weight of glass fibers surface-treated with a sizing composition comprising a film-forming agent containing polyurethane resin and epoxy resin and a silane coupling agent containing aminosilane and epoxysilane, and (C) 10 to 30% by weight of a flame retardant having a phosphorus content of 20% by weight or more and a nitrogen content of 5% by weight or less, wherein the intrinsic viscosity of the polyester resin is 0.8 to 1.1 dl / g when measured in a mixed solvent of phenol and o-dichlorobenzene in a 3:2 (by weight) ratio at 25°C, or the melt index of the polyester resin is 10 to 80 g / 10 min when measured at 250°C under a 2.16 kg load.

[0011] In a specific example of the present invention, the polyester resin (A) content may be 45 to 55% by weight, the surface-treated glass fiber (B) content may be 20 to 35% by weight, and the flame retardant (C) content may be 15 to 25% by weight.

[0012] In a specific example of the present invention, the polyester resin (A) may include at least one selected from the group consisting of polybutylene terephthalate (PBT) and polyethylene terephthalate (PET).

[0013] In specific examples of the present invention, the flame-retardant polyester resin composite composition may further contain one or more additives (D) selected from the group consisting of antioxidants, weather stabilizers, mold release agents, dispersants, neutralizing agents, antiblocking agents, reinforcing agents, fillers, antistatic agents, lubricants, slip agents, nucleating agents, additional flame retardants, pigments, and dyes.

[0014] In a specific example of the present invention, the flame-retardant polyester resin composite composition may further contain, based on 100 parts by weight of the composition, one or more antioxidants selected from the group consisting of pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene and tris(2,4-di-t-butylphenyl)phosphite in an amount of 0.05 to 0.3 parts by weight.

[0015] In a specific example of the present invention, the flame-retardant polyester resin composite composition may further contain, based on 100 parts by weight of the composition, one or more lubricants selected from the group consisting of pentaerythritol tetrastearate and N,N'-ethylenedistearamid in an amount of 0.1 to 0.5 parts by weight.

[0016] Another embodiment of the present invention provides a flame-retardant polyester resin composite molded article manufactured by molding the flame-retardant polyester resin composite composition.

[0017] In a specific example of the present invention, the flame-retardant polyester resin composite molded article can satisfy the V0 standard when measured by the UL94 test method based on a thickness of 0.75 mm.

[0018] In a specific example of the present invention, the tensile strength after maintaining a flame-retardant polyester resin composite molded product of an ISO standard test piece at a temperature of 85°C and a relative humidity of 85% for 1000 hours can exhibit 85% or more of the initial tensile strength.

[0019] In a specific example of the present invention, the flame-retardant polyester resin composite molded product can be an automotive part or an electric and electronic part.

Effects of the Invention

[0020] The flame-retardant polyester resin composite composition according to a realization example of the present invention is excellent in the balance of mechanical properties and hydrolysis resistance.

[0021] The polyester resin composite molded product according to a realization example of the present invention can be usefully used for automotive parts and electric and electronic parts that may generate heat.

Modes for Carrying Out the Invention

[0022] Hereinafter, the present invention will be described in more detail. The flame-retardant polyester resin composite composition according to an implementation example of the present invention contains, based on the total weight of the composition, (A) 40 to 60% by weight of a polyester resin, (B) 10 to 50% by weight of glass fibers surface-treated with a sizing composition containing a film-forming agent containing a polyurethane resin and an epoxy resin and a silane coupling agent containing an aminosilane and an epoxysilane, and (C) 10 to 30% by weight of a flame retardant having a phosphorus content of 20% by weight or more and a nitrogen content of 5% by weight or less.

[0023] (A) Polyester resin The flame-retardant polyester resin composite composition according to an implementation example of the present invention contains a polyester resin (A).

[0024] In a specific example of the present invention, the polyester resin (A) may contain at least one selected from the group consisting of polybutylene terephthalate (PBT) and polyethylene terephthalate (PET). That is, the polyester resin (A) may contain either one or both of polybutylene terephthalate (PBT) and polyethylene terephthalate (PET).

[0025] Incidentally, polybutylene terephthalate (PBT) may be prepared by subjecting 1,4-butanediol and terephthalic acid or dimethyl terephthalate to an esterification reaction or a transesterification reaction, and then subjecting the product to polycondensation. Polyethylene terephthalate (PET) may be prepared by subjecting ethylene glycol and terephthalic acid or dimethyl terephthalate to an esterification reaction or a transesterification reaction, and then subjecting the product to polycondensation.

[0026] Further, when measured in a 3:2 (by weight) mixed solvent of phenol and o-dichlorobenzene at 25 °C, the intrinsic viscosity of the polyester resin (A) is 0.8 to 1.1 dl / g, or when measured at 250 °C under a load of 2.16 kg, the melt index of the polyester resin (A) is 10 to 80 g / 10 min. When the intrinsic viscosity or melt index of the polyester resin (A) belongs to this range, the flame-retardant polyester resin composite composition can have appropriate processability and exhibit excellent mechanical properties.

[0027] The flame-retardant polyester resin composite composition according to an implementation example of the present invention contains the polyester resin (A) at a content of 40 to 60% by weight based on the total weight of the composition. Preferably, the flame-retardant polyester resin composite composition may contain the polyester resin (A) at a content of 45 to 55% by weight based on the total weight of the composition. When the content of the polyester resin (A) is less than 40% by weight, the mechanical properties and processability of the molded product may deteriorate, and when it exceeds 60% by weight, the processability and impact strength of the molded product may deteriorate.

[0028] (B) Surface-treated glass fiber A flame-retardant polyester resin composite composition according to one embodiment of the present invention includes glass fibers (B) whose surface is treated with a sizing composition. Specifically, the flame-retardant polyester resin composite composition according to one embodiment of the present invention includes glass fibers (B) whose surface is treated with a sizing composition which includes a film-forming agent comprising a polyurethane resin and an epoxy resin, and a silane coupling agent comprising an aminosilane and an epoxysilane. The glass fibers (B) whose surface is treated with the sizing composition can play a role in improving the mechanical strength and hydrolysis resistance of the flame-retardant polyester resin composite composition.

[0029] The glass fiber (B) surface-treated with a sizing composition used in a flame-retardant polyester resin composite composition according to one embodiment of the present invention may be, but is not limited to, that disclosed in Patent Document 1.

[0030] A flame-retardant polyester resin composite composition according to one embodiment of the present invention contains 10 to 50% by weight of glass fibers (B) surface-treated with a sizing composition, based on the total weight of the composition. Preferably, the flame-retardant polyester resin composite composition may contain 10 to 40% by weight, more preferably 20 to 35% by weight of glass fibers (B) surface-treated with a sizing composition, based on the total weight of the composition. When the content of glass fibers (B) surface-treated with a sizing composition satisfies the above range, the flame-retardant polyester resin composite composition may exhibit excellent mechanical properties and hydrolysis resistance.

[0031] (C) Flame retardant A flame-retardant polyester resin composite composition according to one embodiment of the present invention contains a flame retardant (C). Specifically, the flame retardant (C) is a phosphorus-based flame retardant or a phosphorus-nitrogen-based flame retardant having a phosphorus content of 20% by weight or more and a nitrogen content of 5% by weight or less.

[0032] In a specific example of the present invention, the flame retardant (C) may include at least one phosphorus-based flame retardant or phosphorus nitrogen-based flame retardant selected from flame retardants that combine polyphosphate-based and melamine-based materials.

[0033] The flame-retardant polyester resin composite composition according to an embodiment of the present invention contains flame retardant (C) in an amount of 10 to 30% by weight, based on the total weight of the composition. Preferably, the flame-retardant polyester resin composite composition may contain flame retardant (C) in an amount of 15 to 25% by weight, based on the total weight of the composition. When the content of flame retardant (C) satisfies the above range, the flame-retardant polyester resin composite composition can exhibit excellent flame retardancy as well as excellent mechanical properties and hydrolysis resistance.

[0034] (D) Additives The flame-retardant polyester resin composite compositions according to the embodiment of the present invention may further contain conventional additives, without departing from the scope of the present invention. For example, the flame-retardant polyester resin composite compositions according to the embodiment of the present invention may further contain, but are not limited to, one or more additives (D) selected from the group consisting of antioxidants, weather stabilizers, mold release agents, dispersants, neutralizing agents, antiblocking agents, reinforcing agents, fillers, antistatic agents, lubricants, slip agents, nucleating agents, additional flame retardants, pigments, and dyes.

[0035] In specific examples of the present invention, the flame-retardant polyester resin composite composition may further contain an antioxidant to improve its heat resistance stability. The antioxidant can be a phenolic antioxidant, a phosphorus-based antioxidant, or the like. Specifically, one or more antioxidants selected from the group consisting of pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and tris(2,4-di-t-butylphenyl)phosphite may be used.

[0036] Furthermore, the flame-retardant polyester resin composite composition may contain an additional 0.05 to 0.3 parts by weight of the antioxidant based on 100 parts by weight of the composition. If the antioxidant content is less than 0.05 parts by weight, it is difficult to ensure long-term heat resistance stability. On the other hand, if the antioxidant content exceeds 0.3 parts by weight, the heat resistance stability will not improve further, and the economic efficiency of the product may decrease, which is undesirable.

[0037] In specific examples of the present invention, the flame-retardant polyester resin composite composition may further contain a lubricant. Specifically, the flame-retardant polyester resin composite composition may further contain, based on 100 parts by weight of the composition, one or more lubricants selected from the group consisting of pentaerythritol tetrastearate and N,N'-ethylenedistearamid in an amount of 0.1 to 0.5 parts by weight.

[0038] There are no particular limitations on the method for preparing the flame-retardant polyester resin composite composition of the present invention. Methods for preparing polyester resin compositions known in the art to which the present invention belongs can be used as is or with appropriate modifications. The resin components and compounds described above can be freely selected and mixed in any desired order without any special restrictions on the order.

[0039] To give a specific example, the required amount of each resin and compound mentioned above can be mixed for 1 to 2 hours in a kneader such as a Hensel mixer, kneader, roll, or Banbury mixer, and then melted and kneaded at a temperature of 200°C to 270°C using a single-screw / twin-screw extruder to prepare a pelletized polyester resin composition.

[0040] Another embodiment of the present invention provides a flame-retardant polyester resin composite molded article manufactured by molding a flame-retardant polyester resin composite composition.

[0041] There are no particular limitations on the method for producing molded articles from the flame-retardant polyester resin composite composition according to the embodiment of the present invention, and methods known in the art to which the present invention belongs can be used. For example, a flame-retardant polyester resin composite molded article can be produced by molding the flame-retardant polyester resin composite composition according to the embodiment of the present invention using conventional methods such as injection molding, extrusion molding, or casting molding. Preferably, the molded article can be produced by injection molding the flame-retardant polyester resin composite composition.

[0042] In a specific example of the present invention, the flame-retardant polyester resin composite molded article can satisfy the V0 standard when measured by the UL94 test method based on a thickness of 0.75 mm.

[0043] In a specific example of the present invention, the tensile strength of a flame-retardant polyester resin composite molded product of an ISO standard test specimen after being maintained at a temperature of 85°C and a relative humidity of 85% for 1000 hours may be 85% or more of the initial tensile strength.

[0044] In specific examples of the present invention, flame-retardant polyester resin composite molded articles can be used in automotive parts and electrical and electronic components.

[0045] (Examples) The present invention will be described in more detail below with reference to examples and comparative examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not limited thereto.

[0046] (Examples 1 and 2, Comparative Examples 1-6) The following resins and compounds were used in the quantities shown in Table 1.

[0047] A polyester resin was mixed with glass fibers surface-treated with a sizing composition, a phosphorus-based flame retardant, and additives. The mixture was melted and mixed in a twin-screw extruder (75 mm, L / D 1:44) to produce resin composition pellets by pelletizing the continuous resin composite. The resin composition pellets were then dried in a dryer at 120°C for 4 hours, and test injection-molded specimens were produced using an Ankel 180-ton injection molder.

[0048] In this process, pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate) and 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene were used as antioxidants, and ethylenebisstearamide was used as a lubricant.

[0049] -A1: Polybutylene terephthalate (Kanghui Co., Ltd., KH2100, intrinsic viscosity 1.0 dl / g) -A2: Polyethylene terephthalate (Lotte Chemical Co., Ltd., BCN-80, intrinsic viscosity 0.85 dl / g) -B1: Glass fiber surface-treated with a sizing composition (KCC Corporation, CS329) -B2: Glass fiber (KCC, CS321) -C1: Phosphorus-based flame retardant (phosphorus content 23% by weight, nitrogen content 0% by weight) -C2: Phosphorus nitrogen-based flame retardant (phosphorus content 21% by weight, nitrogen content 15% by weight) -C3: Phosphorus-nitrogen-based flame retardant (phosphorus content 19% by weight, nitrogen content 10% by weight) -C4: Phosphorus-zinc flame retardant (phosphorus content 19% by weight, nitrogen content 0% by weight) -C5: Phosphorus-nitrogen-based flame retardant (phosphorus content 23% by weight, nitrogen content 5% by weight) -C6: Aromatic brominated flame retardant (bromine content 50% by weight) and antimony trioxide (antimony trioxide 90% by weight) -D1: Hydrolysis inhibitor (carbodiimide) -D2: Hydrolysis inhibitor (ethylene-glycidyl methacrylate)

[0050] [Table 1]

[0051] (Example test) The flame-retardant polyester resin composite compositions obtained in each example and comparative example, and the test specimens produced therefrom, were tested by the following method.

[0052] (1) Density Measurements were taken in accordance with ISO 1183.

[0053] (2) Tensile strength Measurements were taken in accordance with ISO 527. The test specimens were prepared according to Type A, and the test speed was 50 mm / min.

[0054] (3) Flexural modulus and flexural strength Measurements were taken in accordance with ISO 178. The specimen size was 80 mm × 10 mm × 4.0 mm, the span length was 60 mm, and the test speed was 2 mm / min.

[0055] (4) Izod impact strength Measurements were taken at room temperature according to ISO 180, Type A. The test specimens were 80 mm × 10 mm × 4.0 mm, and notched specimens were used.

[0056] (5) Heat distortion temperature (HDT) Measurements were taken in accordance with ISO 75. The test specimen size was 80 mm × 10 mm × 4.0 mm, and the stress load was set to 0.45 MPa.

[0057] (6) Hydrolysis resistance The rate of change in tensile strength was measured after maintaining the material for 1000 hours at a temperature of 85°C and a relative humidity of 85%.

[0058] (7) Flame retardant Measured according to the UL94 test method.

[0059] [Table 2]

[0060] As can be seen from Tables 1 and 2 above, molded articles produced from the flame-retardant polyester resin composite compositions of the examples belonging to the scope of the present invention exhibited excellent mechanical properties, hydrolysis resistance, and flame retardancy.

[0061] On the other hand, in Comparative Example 1, which used an aromatic bromine-based flame retardant and antimony trioxide, flame retardancy decreased. In Comparative Example 2, which used a flame retardant with a nitrogen content outside the range of the present invention, flame retardancy and hydrolysis resistance decreased. In Comparative Example 3, which used a flame retardant with a nitrogen content outside the range of the present invention and untreated glass fibers, hydrolysis resistance decreased. In Comparative Example 4, which used a zinc phosphorus-based flame retardant and untreated glass fibers, flexural modulus, hydrolysis resistance, and flame retardancy decreased significantly. In Comparative Examples 5 and 6, which used untreated glass fibers and a hydrolysis inhibitor, flexural modulus and flame retardancy decreased.

[0062] Molded articles produced from flame-retardant polyester resin composite compositions according to examples within the scope of the present invention have excellent balance of mechanical properties and hydrolysis resistance, and can therefore be usefully used in automotive parts and electrical and electronic components.

Claims

1. Based on the total weight of components (A) to (C), (A) 40-60% by weight of polyester resin, (B) 10 to 50% by weight of glass fibers surface-treated with a sizing composition comprising a film-forming agent containing polyurethane resin and epoxy resin and a silane coupling agent containing aminosilane and epoxysilane, (C) Contains 10 to 30% by weight of a flame retardant having a phosphorus content of 20% by weight or more and a nitrogen content of 5% by weight or less. A flame-retardant polyester resin composite composition wherein the intrinsic viscosity of the polyester resin is 0.8 to 1.1 dl / g when measured in a 3:2 (by weight) mixed solvent of phenol and o-dichlorobenzene at 25°C, or the melt index of the polyester resin is 10 to 80 g / 10 min when measured at 250°C under a 2.16 kg load.

2. The polyester resin (A) content is 45 to 55% by weight, The content (B) of the surface-treated glass fibers is 20 to 35% by weight. The flame-retardant polyester resin composite composition according to claim 1, wherein the content of the flame retardant (C) is 15 to 25% by weight.

3. The flame-retardant polyester resin composite composition according to claim 1, wherein the polyester resin (A) comprises at least one selected from the group consisting of polybutylene terephthalate (PBT) and polyethylene terephthalate (PET).

4. The flame-retardant polyester resin composite composition according to claim 1, further comprising one or more additives (D) selected from the group consisting of antioxidants, weather stabilizers, mold release agents, dispersants, neutralizing agents, antiblocking agents, reinforcing agents, fillers, antistatic agents, lubricants, slip agents, nucleating agents, additional flame retardants, pigments, and dyes.

5. The flame-retardant polyester resin composite composition according to claim 4, further comprising, based on 100 parts by weight of components (A) to (C) in total, one or more antioxidants selected from the group consisting of pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene and tris(2,4-di-t-butylphenyl)phosphite, in an amount of 0.05 to 0.3 parts by weight.

6. The flame-retardant polyester resin composite composition according to claim 4, further comprising 0.1 to 0.5 parts by weight of one or more lubricants selected from the group consisting of pentaerythritol tetrastearate and N,N'-ethylenedistearamid, based on a total of 100 parts by weight of components (A) to (C).

7. A flame-retardant polyester resin composite molded article manufactured by molding a flame-retardant polyester resin composite composition according to any one of claims 1 to 6.

8. A flame-retardant polyester resin composite molded article according to claim 7, which satisfies the V0 standard when measured by the UL94 test method with a thickness of 0.75 mm as the standard.

9. The flame-retardant polyester resin composite molded article according to claim 7, wherein the tensile strength of the flame-retardant polyester resin composite molded article of an ISO standard test specimen after being maintained at a temperature of 85°C and a relative humidity of 85% for 1000 hours is 85% or more of the initial tensile strength.

10. A flame-retardant polyester resin composite molded article according to claim 7, which is an automotive part or an electrical / electronic component.

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