Polyester composite material as well as preparation method and application thereof

Abstract

The invention provides a polyester composite material as well as a preparation method and application thereof, and the polyester composite material comprises the following components in parts by weight: 20-50 parts of polyester resin, 10-50 parts of glass fiber, 10-20 parts of a first flame retardant, 0.5-3 parts of a second flame retardant, 2-15 parts of a third flame retardant and 0.1-2 parts of a carbodiimide compound, the first flame retardant comprises a phosphorus flame retardant; the second flame retardant comprises a phosphorus-nitrogen flame retardant; the third flame retardant comprises a nitrogen flame retardant. According to the invention, the polyester composite material not only has a high glowing filament ignition temperature, but also can maintain good mechanical properties and long service life in harsh environments such as high temperature and high humidity, and the polyester composite material generates less mold scale in the processing process, and the obtained product has good apparent quality and good flame retardance. The performance requirements on materials in the fields of electronic and electrical components and the like are met.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a polyester composite material and a preparation method and application thereof. Background Art

[0002] Polyester is a polymer compound formed by polycondensation of diols or dibasic acids or polyols and polyacids; it has excellent physical and chemical properties and is widely used in packaging materials, building materials, electronic appliances, etc. Among them, polybutylene terephthalate (PBT) is a milky white, translucent to opaque, crystalline thermoplastic saturated polyester with excellent mechanical properties, electrical properties, heat resistance and processing properties, etc., and is widely used in the fields of electronic and electrical, new energy vehicles, and communication equipment.

[0003] With the development of automation, intelligence and integration of electronic and electrical components, in order to avoid overheating and active ignition of PBT materials due to poor contact, overload, short circuit, etc. during the use of electronic and electrical components, higher requirements are put forward for the glow wire ignition temperature (GWIT) and comparative tracking index (CTI) of PBT materials. The European Union International Electrotechnical Commission (IEC) organization proposed in the IEC60335 household and similar electrical appliance safety standard that the flame retardant properties of plastic parts used in long-term unattended electrical appliances must meet the UL94V0 level and the 750℃ glow wire contact material must not catch fire within 30s or the burning time is less than 5s, that is, the GWIT is greater than 750℃.

[0004] By adding flame retardants, the flame retardant properties of the material can be improved and the GWIT can be improved; however, on the one hand, the addition of flame retardants will affect the initial mechanical properties, moisture and heat aging resistance and processing properties of the material, among which the processing performance is manifested as the aggravation of mold deposit during the processing; on the other hand, the solutions in the prior art have little improvement in GWIT and need to be further improved.

[0005] Therefore, it is an urgent problem to be solved in this field to develop a polyester composite material with high glow-wire ignition temperature, excellent resistance to moisture and heat aging, less mold deposit during processing, good product appearance quality and long service life. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a polyester composite material and a preparation method and application thereof. The polyester composite material not only has a high glow-wire ignition temperature, but also can maintain good mechanical properties in harsh environments such as high temperature and high humidity, has a long service life, and generates less mold deposit during processing, and the obtained product has good apparent quality, meeting the performance requirements of materials in the fields of electronic and electrical components.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a polyester composite material, which comprises, by weight, 20 to 50 parts of polyester resin, 10 to 50 parts of glass fiber, 10 to 20 parts of a first flame retardant, 0.5 to 3 parts of a second flame retardant, 2 to 15 parts of a third flame retardant and 0.1 to 2 parts of a carbodiimide compound; the first flame retardant comprises a phosphorus-based flame retardant; the second flame retardant comprises a phosphorus-nitrogen-based flame retardant; and the third flame retardant comprises a nitrogen-based flame retardant.

[0009] In the present invention, a flame retardant with a specific composition is used, that is, a first flame retardant, a second flame retardant and a third flame retardant of specific types are compounded, so that the glow-wire ignition temperature of the polyester material can be effectively increased under the premise of ensuring low mold deposit; further, a carbodiimide compound with a specific content is compounded with the flame retardant to synergistically enhance the effect, ensure a high glow-wire ignition temperature, and at the same time, can alleviate the mold deposit problem of the polyester material during the processing process, and can also ensure that the obtained product has less or no floating fibers on the surface and has good apparent quality.

[0010] In the present invention, 20 to 50 parts of polyester resin can be, for example, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts or any range between the above values; preferably 27 to 43 parts.

[0011] In the present invention, 10 to 50 parts of glass fiber can be, for example, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50 parts or a range between any of the above values; preferably 23 to 41 parts.

[0012] In the present invention, 10 to 20 parts of the first flame retardant can be, for example, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, 15 parts, 15.5 parts, 16 parts, 16.5 parts, 17 parts, 17.5 parts, 18 parts, 18.5 parts, 19 parts, 19.5 parts, 20 parts or a range between any of the above values; more preferably 11.5 to 19.5 parts.

[0013] In the present invention, 0.5 to 3 parts of the second flame retardant can be, for example, 0.5, 0.52, 0.55, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 1, 1.02, 1.04, 1.06, 1.08 0.8 to 2 parts; more preferably 0.8 to 2 parts.

[0014] In the present invention, 2 to 15 parts of the third flame retardant can be, for example, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, 15 parts or a range between any of the above values; more preferably 5.7 to 10.8 parts.

[0015] In the present invention, if the content of the third flame retardant is too much, mold deposit will be aggravated during the injection molding process; if the content is too little, the glow-wire ignition temperature will be low.

[0016] In the present invention, 0.1 to 2 parts of the carbodiimide compound can be, for example, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 1.1 part, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts or a range between any of the above values; more preferably 0.7 to 1.5 parts.

[0017] In the present invention, if the content of the carbonized diamine compound is too much, the floating fibers on the surface of the product will be aggravated and the apparent quality will be poor; if the content is too little, the mold deposit will be aggravated during the injection molding process.

[0018] Preferably, the polyester resin comprises a polyester resin formed from a dibasic acid and a diol.

[0019] In the present invention, the dibasic acid includes an aliphatic dibasic acid and / or an aromatic dibasic acid, and the diol includes an aliphatic diol.

[0020] Preferably, the aliphatic dibasic acid includes C4-C20 aliphatic dibasic acid, and the C4-C20 aliphatic dibasic acid refers to an aliphatic dibasic acid having 4 to 20 carbon atoms, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or a range between any of the above values; illustratively, the C4-C20 aliphatic dibasic acid includes succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, etc.

[0021] Preferably, the aromatic dibasic acid includes at least one of terephthalic acid, phthalic acid, isophthalic acid or furandicarboxylic acid.

[0022] Preferably, the aliphatic diol includes C2-C20 aliphatic diol, and the C2-C20 aliphatic diol refers to an aliphatic diol having 2 to 20 carbon atoms, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or a range between any of the above values; illustratively, the C2-C20 aliphatic diol includes butanediol, pentanediol, hexanediol, nonanediol, decanediol and the like.

[0023] In the present invention, the polyester resin includes polybutylene terephthalate (PBT) and / or polyethylene terephthalate (PET).

[0024] Preferably, at 23° C., the intrinsic viscosity of the polyester resin is less than 1.4 dl / g.

[0025] In the present invention, the intrinsic viscosity of the polyester resin is tested with reference to GB / T 1632-1993 Determination of viscosity and intrinsic viscosity of dilute polymer solutions.

[0026] Preferably, the mass ratio of the first flame retardant, the second flame retardant and the third flame retardant is (10-18):1:(1-10), wherein the specific value in (10-18) can be, for example, 10, 10.2, 10.4, 10.6, 10.8, 11, 11.2, 11.4, 11.6, 11.8, 12, 12.2, 12.4, 12.6, 12.8, 13, 13.2, 13.4, 13.6, 13.8, 14, 14.2, 14.4, 14.6, 14.8, 15, 15.2, 15.4, 15.6, 15.8, 16, 16.2, 16.4, 16.6, 16.8, 17, 17.2, 17.4, 17.6, 17.8 7.6, 17.8, 18 or the range between any of the above values; the specific values ​​in (1-10) can be, for example, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, 5, 5.2, 5.4, 5.6, 5.8, 6, 6.2, 6.4, 6.6, 6.8, 7, 7.2, 7.4, 7.6, 7.8, 8, 8.2, 8.4, 8.6, 8.8, 9, 9.2, 9.4, 9.6, 9.8, 10 or the range between any of the above values; preferably (12-15):1:(5.8-7.8).

[0027] Preferably, the phosphorus-based flame retardant includes at least one of hypophosphite or phosphate compounds.

[0028] Preferably, the hypophosphite includes at least one of diethylaluminum hypophosphite, phenylaluminum hypophosphite, methylaluminum hypophosphite, diisobutylaluminum hypophosphite, methylethylaluminum hypophosphite, di-tert-butylaluminum hypophosphite or aluminum hypophosphite.

[0029] Preferably, the phosphate compound includes at least one of tributyl phosphate, trioctyl phosphate, triphenyl phosphate, resorcinol bis(diphenyl phosphate) or toluene diphenyl phosphate.

[0030] Preferably, the phosphorus-nitrogen flame retardant includes melamine polyphosphate and / or melamine phosphate.

[0031] Preferably, the nitrogen-based flame retardant includes at least one of melamine cyanurate, melamine borate and melamine; more preferably melamine cyanurate and / or melamine borate.

[0032] Preferably, the carbodiimide compound includes monomeric carbodiimide and / or polymeric carbodiimide.

[0033] Preferably, the monomeric carbodiimide includes at least one of dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-di(2,6-diisopropylphenyl)carbodiimide or 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride.

[0034] Preferably, the polymeric carbodiimide comprises aliphatic polymeric carbodiimide and / or aromatic polymeric carbodiimide; the number average molecular weight of the polymeric carbodiimide is 500 to 30,000.

[0035] In the present invention, the carbodiimide compound includes monomeric carbodiimide and polymeric carbodiimide, and the mass ratio of the monomeric carbodiimide to the polymeric carbodiimide is 1:(0.5-2); wherein the specific value in (0.5-2) can be, for example, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2 or a range between any of the above values; more preferably 1:(1.2-1.8).

[0036] Preferably, the polyester composite material further comprises 0.5 to 4 parts of toughening agent by weight, for example, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts or any range between the above values.

[0037] Preferably, the toughening agent includes at least one of nitrile rubber, polybutadiene rubber, ethylene-methyl acrylate-glycidyl methacrylate copolymer or methyl methacrylate-butadiene-styrene copolymer.

[0038] In the present invention, the polyester composite material may further be added with 0.5 to 10 parts of other additives according to actual needs; the other additives include but are not limited to compatibilizers, antioxidants, lubricants, antistatic agents, colorants, etc.

[0039] In the present invention, the amounts of the compatibilizer, antioxidant, lubricant, antistatic agent and colorant in the polyester composite material are independently 0.1 to 3 parts by weight.

[0040] In the present invention, the compatibilizer includes but is not limited to maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted polyolefin elastomer, glycidyl methacrylate grafted polyolefin elastomer, etc.; the antioxidant includes but is not limited to hindered phenol antioxidants (such as antioxidant 1010, antioxidant 1076, etc.), phosphite antioxidants (such as antioxidant 168), etc.; the lubricant includes but is not limited to silicone powder, N,N'-ethylene bis stearamide, pentaerythritol stearate, etc. The antistatic agent includes but is not limited to quaternary ammonium salt compounds.

[0041] In the present invention, the mass percentage of the polyester resin in the polyester composite material is ≥20%, preferably ≥30%.

[0042] In a second aspect, the present invention provides a method for preparing the polyester composite material according to the first aspect, the preparation method comprising:

[0043] The polyester resin, glass fiber, the first flame retardant, the second flame retardant, the third flame retardant, the carbodiimide compound and the optional toughening agent are mixed and extruded to obtain the polyester composite material.

[0044] Preferably, the extrusion temperature is 200-320°C, for example, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C or any range between the above values.

[0045] In a third aspect, the present invention provides an electronic and electrical component, comprising the polyester composite material described in the first aspect.

[0046] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] In the present invention, the polyester composite material adopts a flame retardant of a specific composition, that is, a specific type of first flame retardant, a second flame retardant and a third flame retardant are compounded, and a specific content of carbodiimide compounds are added to the flame retardants for compounding, so that the polyester composite material has both a high glow-wire ignition temperature and excellent resistance to moisture and heat aging, and the mold deposit problem of the polyester material in the processing process can be effectively alleviated, and it can also ensure that the obtained product has less floating fibers on the surface and good apparent quality. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0050] The materials used in the present invention can be purchased from the market. Unless otherwise specified, the materials used in the present invention are as follows:

[0051] PBT; purchased from Sinopec Yizheng Chemical Fiber Co., Ltd., brand GX112, intrinsic viscosity 0.82 dl / g.

[0052] Glass fiber: purchased from Jushi Co., Ltd., brand ECS13-03-834A, diameter 13 μm.

[0053] Diethylaluminum hypophosphite: purchased from Liaoning Jinfa Biomaterials Co., Ltd., brand name BEP-820H.

[0054] Phenyl aluminum hypophosphite: purchased from Henan Weitixi Chemical Technology Co., Ltd., the brand is PADP.

[0055] Aluminum hypophosphite: purchased from Wuhan Hanye Wuzhou Chemical New Materials Co., Ltd.

[0056] Melamine polyphosphate MPP: purchased from Budenheim Ibérica SLU, brand BUDIT 3141.

[0057] Melamine cyanurate (MCA) was purchased from Sichuan Fine Chemical Research and Design Institute.

[0058] Monomeric carbodiimide: N,N'-bis(2,6-diisopropylphenyl)carbodiimide, purchased from RASCHIG GmbH, with the brand name Stabilizer7000.

[0059] Polymeric carbodiimide: purchased from Shanghai Langyi Functional Materials Co., Ltd., brand HYMAX 213.

[0060] Epoxy resin: Bisphenol A diglycidyl ether, YD-019, Guodu Chemical Co., Ltd.

[0061] Toughening agent: methyl methacrylate-butadiene-styrene terpolymer, purchased from Kaneka, Japan, brand B564;

[0062] Melamine and triphenyl phosphate were commercially available.

[0063] Examples 1 to 17, Comparative Examples 1 to 7

[0064] Embodiments 1 to 17 and comparative examples 1 to 7 respectively provide a polyester composite material, and the formula of the polyester composite material is shown in Tables 1 to 5, in parts by weight; wherein, “ / ” indicates that the component is not included in the formula; M1 represents the mass ratio of the first flame retardant, the second flame retardant and the third flame retardant; the preparation method of the polyester composite material comprises: according to the ratio in the table, putting each component into a mixer and mixing until uniform to obtain a premix; then melt-mixing the obtained premix in the first section of the twin-screw extruder, and extruding and granulating to obtain a polyester composite material, wherein the extrusion temperature from zone one to the die head is 160°C-260°C-260°C-240°C-220°C-220°C-220°C-220°C-240°C-260°C, the main engine speed is 400rpm, and the feeding rate is 220kg / h.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069] Table 3

[0070]

[0071]

[0072] Table 4

[0073]

[0074] Table 5

[0075]

[0076]

[0077] Performance Testing

[0078] The polyester composite material was injection molded at a temperature of 230-290° C. The obtained product was subjected to the following performance tests.

[0079] (1) GWIT: Refer to IEC 60695-2-13 standard, the sample thickness is 3 mm;

[0080] (2) Resistance to wet heat aging: The initial tensile strength of the product was tested, recorded as L1; the product was then aged for 1008 h at 85°C and 85% humidity, and the tensile strength after aging was tested, recorded as L2; ​​and the tensile strength retention was calculated, recorded as L; L = L2 / L1 × 100%;

[0081] Among them, the tensile strength is tested according to the method specified in GB / T 1040.2-2022 "Determination of tensile properties of plastics Part 2: Test conditions for molded and extruded plastics", and the test speed is 10mm / min;

[0082] (3) Mold deposit: The obtained product was placed at a constant temperature of 120°C for 5 hours, and the TVOC (total volatile organic compound) content was tested according to the VDA277 standard; the lower the TVOC content, the less small molecular substances in the material, and the less mold deposit was generated during injection molding.

[0083] (4) Appearance: Observe whether there are floating fibers on the surface of the product; and divide it into three levels according to the percentage of floating fibers in the product area; among them, 0 means that the percentage of floating fibers in the product area is less than 0.5%; 1 means that the percentage of floating fibers in the product area is 0.5-2%; 3 means that the percentage of floating fibers in the product area is ≥2%.

[0084] The specific test results are shown in Table 6.

[0085] Table 6

[0086]

[0087] As can be seen from Table 6, the polyester composite material provided by the present invention adopts a flame retardant of a specific composition, that is, a specific type of a first flame retardant, a second flame retardant and a third flame retardant are compounded, and a specific content of a carbodiimide compound is added to the flame retardant for compounding, so that the polyester composite material has both a high glow-wire ignition temperature and excellent resistance to moisture and heat aging, and the mold deposit problem of the polyester material during processing can be effectively alleviated, and the surface of the obtained product can be ensured to have less floating fibers and good apparent quality; the polyester composite material GWIT ≥ 750 ° C; the initial tensile strength ≥ 80 MPa, after aging for 1008 h at a temperature of 85 ° C and a humidity of 85%, the tensile strength retention rate is ≥ 78%, the TVOC content is ≤ 200 μgC / g, the mold deposit is less, and the apparent quality is good.

[0088] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A polyester composite material, characterized in that: The polyester composite material comprises, by weight, 20 to 50 parts of polyester resin, 10 to 50 parts of glass fiber, 10 to 20 parts of a first flame retardant, 0.5 to 3 parts of a second flame retardant, 2 to 15 parts of a third flame retardant and 0.1 to 2 parts of a carbodiimide compound; The first flame retardant includes a phosphorus-based flame retardant; The second flame retardant includes a phosphorus-nitrogen flame retardant; The third flame retardant includes a nitrogen-based flame retardant.

2. The polyester composite material according to claim 1, characterized in that: The polyester resin includes a polyester resin formed by a dibasic acid and a diol; Preferably, the polyester resin includes polybutylene terephthalate and / or polyethylene terephthalate.

3. The polyester composite material according to claim 1 or 2, characterized in that: The mass ratio of the first flame retardant, the second flame retardant and the third flame retardant is (8-18):1:(1-10), preferably (12-15):1:(5.8-7.8).

4. The polyester composite material according to any one of claims 1 to 3, characterized in that: The phosphorus-based flame retardant includes at least one of hypophosphite or phosphate compounds; Preferably, the hypophosphite comprises at least one of diethyl aluminum hypophosphite, phenyl aluminum hypophosphite, methyl aluminum hypophosphite, diisobutyl aluminum hypophosphite, methylethyl aluminum hypophosphite, di-tert-butyl aluminum hypophosphite or aluminum hypophosphite; Preferably, the phosphate compound includes at least one of tributyl phosphate, trioctyl phosphate, triphenyl phosphate, resorcinol bis(diphenyl phosphate) or toluene diphenyl phosphate.

5. The polyester composite material according to any one of claims 1 to 4, characterized in that: The phosphorus-nitrogen flame retardant includes melamine polyphosphate and / or melamine phosphate; Preferably, the nitrogen-based flame retardant includes at least one of melamine cyanurate, melamine borate and melamine; more preferably melamine cyanurate and / or melamine borate.

6. The polyester composite material according to any one of claims 1 to 5, characterized in that: The content of the carbodiimide compound in the polyester composite material is 0.7 to 1.5 parts by weight; Preferably, the carbodiimide compound comprises monomeric carbodiimide and / or polymeric carbodiimide; Preferably, the carbodiimide compound comprises monomeric carbodiimide and polymeric carbodiimide, and the mass ratio of the monomeric carbodiimide to the polymeric carbodiimide is 1:(0.5-2); Preferably, the monomeric carbodiimide includes at least one of dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-di(2,6-diisopropylphenyl)carbodiimide or 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride.

7. The polyester composite material according to any one of claims 1 to 6, characterized in that: The polyester composite material further comprises 0.5 to 4 parts of a toughening agent in parts by weight; Preferably, the toughening agent includes at least one of nitrile rubber, polybutadiene rubber, ethylene-methyl acrylate-glycidyl methacrylate copolymer or methyl methacrylate-butadiene-styrene copolymer.

8. A method for preparing the polyester composite material according to any one of claims 1 to 7, characterized in that: The preparation method comprises: The polyester resin, glass fiber, the first flame retardant, the second flame retardant, the third flame retardant, the carbodiimide compound and the optional toughening agent are mixed and extruded to obtain the polyester composite material.

9. The preparation method according to claim 8, characterized in that: The extrusion temperature is 200-320°C.

10. An electronic and electrical component, characterized in that: The electronic and electrical component comprises the polyester composite material according to any one of claims 1 to 7.

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