A halogen-containing flame retardant masterbatch with stable and efficient flame retardant effect and its preparation method

Abstract

The present invention relates to a halogen-containing flame retardant masterbatch with stable and efficient flame retardant effect and a preparation method thereof, which includes polyester resin, elastomer, halogen-containing flame retardant, flame retardant synergist, filler, anti-dripping agent, surface improver, lubricant and antioxidant. The present invention uses a special elastomer as a carrier, avoiding the situation of serious loss due to easy breaking of strips and more powder during extrusion granulation when only engineering plastics are used as carriers because there are more flame retardant powder. Also, a small amount of polyester is used as a carrier to enhance the compatibility between the masterbatch and polyester, and glass fiber during extrusion granulation to make flame retardant modified reinforcing materials, while improving the temperature resistance of the flame retardant masterbatch and reducing the yellowing of color caused by high temperature oxidation during the secondary extrusion granulation for preparing the flame retardant masterbatch.

Description

Technical Field

[0001] The present invention belongs to the field of modified plastics, and particularly relates to a halogen-containing flame retardant masterbatch with stable and high flame retardant effect and a preparation method thereof. Background Art

[0002] In the field of engineering plastics, especially crystalline polyester materials such as PBT and PET, due to their excellent electrical properties, mechanical strength, processability and electrical insulation properties, they are widely used as functional components of electrical components, such as the fan frames and blades of cooling fans, motor housings, relays, connectors, plug sockets, etc. And these functional components usually need to have flame retardant or glow wire and other properties. The modification means to endow engineering plastics with flame retardant properties is usually to blend and extrude polyester materials with flame retardants and flame retardant synergists. For example, CN202011477113 reports that PBT resin is mixed with a flame retardant, a flame retardant synergist and other additives, and the mixture is fed into a twin-screw extruder for extrusion granulation to obtain a flame retardant reinforced PBT material; CN202210046800 reports that components such as PBT resin, a flame retardant, and a flame retardant synergist are added to a mixer for mixing, and then the mixture is added to an extruder for extrusion granulation to obtain a flame retardant reinforced PBT composite material with a high glow wire ignition temperature. Although the functional materials obtained by this method have a flame retardant effect, because the flame retardant or flame retardant synergist is in a powder state during mixing, during the transportation process, due to the difference in bulk density between granular resins and processing aids and powdery flame retardants and flame retardant synergists, stratification occurs, resulting in unstable flame retardant performance of the material after extrusion granulation. To solve these problems, more amounts of flame retardants and flame retardant synergists need to be added during mixing, which leads to an increase in cost. When extruding by blending with a flame retardant masterbatch, the main components in the composite material are in a granular state during mixing, and there is no unstable flame retardant situation caused by the difference in bulk density. It can achieve the same flame retardant effect while relatively reducing the amount of flame retardant used. CN202210236062 discloses a carrier-free bromine-antimony flame retardant masterbatch using decabromodiphenylethane and antimony trioxide as flame retardants and PE wax as an adhesive, which is used in nylon 66 to obtain a flame retardant V-0; CN201910211920 reports a highly fluid bromine-phosphorus-based flame retardant masterbatch with a small amount of PBT resin as a carrier; CN202110514048 reports a high-concentration bromine-antimony-containing flame retardant masterbatch prepared by extrusion granulation using an engineering plastic as a carrier and a dispersant by heating and melting method. However, the flame retardant effects of the above prior arts are not stable. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a halogen-containing flame retardant masterbatch with stable and high flame retardant effect and a preparation method thereof, which solves the problem of unstable flame retardant effect in the prior art.

[0004] The present invention provides a halogenated flame retardant masterbatch with stable and efficient flame retardant effect, which comprises the following components by weight parts:

[0005]

[0006]

[0007] Among them, the elastomer is ethylene-methyl acrylate copolymer and / or ethylene-butyl acrylate copolymer.

[0008] Preferably, the elastomer is a mixture of ethylene-methyl acrylate copolymer and ethylene-butyl acrylate copolymer, and the weight ratio range of the two is 1:2 to 2:1.

[0009] The polyester resin is at least one of PBT resin with an intrinsic viscosity of 0.8-1.0 dl / g and PET resin with an intrinsic viscosity of 0.68-1.0 dl / g. The method for measuring the intrinsic viscosity is: according to the GB / T 14190-2017 standard, the capillary viscometer method is used for measurement. When the intrinsic viscosity is not within the above range, if the viscosity is too low, the mixed melt strength of the flame retardant masterbatch is insufficient, the flame retardant is unevenly dispersed and the extrusion cannot form a strip; if the viscosity is too high, due to the very high melt strength, it is difficult for the flame retardant to be evenly dispersed, affecting the flame retardant efficiency.

[0010] The content of methacrylic acid in the ethylene-methacrylic acid copolymer is 23-26%; the content of butyl acrylate in the ethylene-butyl acrylate copolymer is 33-37%. The methods for measuring the content of methacrylic acid and butyl acrylate are: the titration method is used for measurement, that is, a certain amount of copolymer is dissolved in toluene, a certain amount of potassium hydroxide ethanol solution is added, heated under reflux for 4 hours to completely saponify the sample, then cooled to room temperature, and then an ethanol aqueous solution is added, thymol blue indicator is dropped in, and titrated with 0.05mol·L -1 Sulfuric acid solution until the solution changes from blue to yellow as the end point, record the volume of sulfuric acid solution used, and calculate the content of methacrylic acid and butyl acrylic acid through the formula.

[0011] When the content of methacrylic acid and butyl acrylate is not within the above range, if the content is too low, the flame retardant and the flame retardant synergist will have insufficient viscosity of the mixed melt and uneven dispersion, resulting in poor flame retardant effect of the flame retardant masterbatch; if the content is too high, the melt viscosity is too high, and when the flame retardant masterbatch is extruded, the melt expands severely at the die orifice and is not easy to granulate.

[0012] The halogenated flame retardant is at least one of brominated epoxy resin, brominated polystyrene, and brominated polycarbonate; the flame retardant synergist is at least one of antimony trioxide and sodium antimonate; the anti-dripping agent is polytetrafluoroethylene.

[0013] The surface improver is a silicone masterbatch. The silicone content of the silicone masterbatch is 40-60%, and the carrier is low-density polyethylene.

[0014] The filler is ultrafine talcum powder, and the particle size range D50 is 0.4μm to 0.8μm.

[0015] Preferably, the elastomer is 15-18 parts; the surface improver is 0.5-5 parts.

[0016] In some preferred embodiments, the present invention provides a method for preparing the above-mentioned halogen-containing flame retardant masterbatch with stable and high flame retardant effect, including the following steps:

[0017] (1) Pre-dry the polyester resin, and after the drying treatment, mix the polyester resin with other components evenly and enter the premixer through a metering feeder to obtain a mixed material;

[0018] (2) Then send the mixed material into a twin-screw extruder, fully melt and plasticize, knead and mix, extrude through the die head, draw into strips, cool, and pelletize to obtain the one-step material of the halogen-containing flame retardant masterbatch;

[0019] (3) Pre-dry the above-mentioned one-step material of the flame retardant masterbatch, and then send the dried one-step material into the twin-screw extruder again, fully melt and plasticize, knead and mix, extrude through the die head, draw into strips, cool, pelletize, and dry to obtain the halogen-containing flame retardant masterbatch.

[0020] In some preferred embodiments of the present invention, a method of two-stage extrusion granulation is adopted to avoid the problem that due to the large amount of flame retardant powder, the flame retardant is unevenly distributed in the carrier due to the difference in the bulk density of the powder resin during the first extrusion granulation. The homogenization effect is achieved through the second granulation, further ensuring the stable and high flame retardant effect of the produced halogen-containing flame retardant masterbatch.

[0021] The present invention also provides an application of the halogen-containing flame retardant masterbatch with stable and high flame retardant effect in electronic and electrical devices such as heat dissipation components, connectors, plugs, switch panels, connectors, and relay housings.

[0022] The present invention also provides a modified material of halogen-containing flame retardant glass fiber reinforced polyester. The components of the modified material are in parts by weight and include the following components:

[0023]

[0024] The polyester resin is one or a mixture of two of PBT resin and PET resin, and the mixing ratio is 5:1 to 1:5. The intrinsic viscosity of PBT resin is 0.8-1.0 dl / g; the intrinsic viscosity of PET resin is 0.68-1.0 dl / g.

[0025] The toughening agent is at least one of EMA, EBA, and ethylene-acrylate-glycidyl methacrylate terpolymer.

[0026] The non-alkali glass fiber is a glass fiber with a diameter of 10-13 μm.

[0027] The antioxidant in the present invention is at least one of hindered phenol antioxidants and phosphite antioxidants, preferably a mixture of antioxidant 1010 and antioxidant 168, and the mass ratio of the two is 1-3:1-3; the lubricant is at least one of aliphatic carboxylic acid ester lubricants and polyolefin wax lubricants. The antioxidants and lubricants in the halogen-containing flame retardant masterbatch and the halogen-containing flame retardant glass fiber reinforced polyester modified material can be the same or different. The preparation method includes:

[0028] (1) Predry the polyester resin, and after uniformly mixing the dried polyester resin with other components in proportion, feed them into a premixer through a metering feeder to obtain a mixed material;

[0029] (2) Then feed the mixed material into a twin-screw extruder, fully melt and plasticize, knead and mix, extrude through the die head, draw into strips, cool, and pelletize to obtain the halogen-containing flame retardant glass fiber reinforced polyester modified material.

[0030] Beneficial effects

[0031] (1) The present invention uses a special elastomer as the carrier, avoiding the situation of easy breaking of the strip and a large amount of powder loss due to a large amount of flame retardant powder during extrusion and pelletizing when only using engineering plastics as the carrier; and uses a small amount of polyester as the carrier to strengthen the compatibility between the masterbatch and polyester and glass fiber during extrusion granulation to make the flame retardant modified reinforced material, while improving the heat resistance of the flame retardant masterbatch and reducing the yellowing of the color caused by high-temperature oxidation during the secondary extrusion granulation of the flame retardant masterbatch.

[0032] (2) The present invention applies the prepared flame retardant masterbatch to the glass fiber reinforced polyester material for flame retardant modification, successfully obtaining a stable flame retardant effect and a lower dosage ratio compared with using pure flame retardant and flame retardant synergist to obtain the same flame retardant effect, having an advantage in the comprehensive cost, and can obtain structural and functional components through molding processes such as injection molding, extrusion, and compression molding, and can be widely applied to fields such as cooling fans, motor housings, relays, and connectors in the electronic and electrical industries. Detailed Embodiments

[0033] The following further elaborates the present invention in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0034] Unless otherwise specified, the reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the technical field.

[0035] The raw materials used in the following examples and comparative examples are as follows:

[0036] A. PBT resin, A1: 1200-211M (Changchun Chemical Industry) with an intrinsic viscosity of 0.83 dl / g and A2: 1100-211M (Changchun Chemical Industry) with an intrinsic viscosity of 1.0 dl / g were respectively selected.

[0037] B. PET resin, B1: FG600 of Yizheng Chemical Fiber with an intrinsic viscosity of 0.68 dl / g and B2: BG80 of Yizheng Chemical Fiber with an intrinsic viscosity of 0.80 dl / g were respectively selected.

[0038] C. Elastomer, C1: EMA ethylene-methyl acrylate copolymer ELVALOY AC 1125 (methyl acrylic acid content 25%, DuPont); C2: EBA ethylene-butyl acrylate copolymer ELVALOY AC 34035 (butyl acrylate content 35%, DuPont); C3: EMA ethylene-methyl acrylate copolymer LOTRYL18MA02 (methyl acrylic acid content 18%, Arkema); C4: POE ethylene-butene copolymer ENGAGE 7467 (Dow Chemical); C5: a mixture of EMA ELVALOY AC 1125 and EBA ELVALOY AC 34035 with a mass ratio of 1:1; C6: ethylene-acrylate-glycidyl methacrylate terpolymer, grade LOTADER AX8900, Arkema were respectively selected.

[0039] D. Halogenated flame retardant, D1: brominated epoxy F-2100 (ICL of Israel); D2: brominated polystyrene BPS7010 (Tianyi Chemical); D3: brominated polycarbonate BC-58 (Chemtura) were respectively selected.

[0040] E. Flame retardant synergist: antimony trioxide E1: S-05N (Chenzhou Antimony Industry) and sodium antimonate E2: ATSA-62 (Chenzhou Antimony Industry) were respectively selected.

[0041] F. Filler, ultrafine talc powder with a D50 particle size of 0.65 μm was selected.

[0042] G. Anti-dripping agent, polytetrafluoroethylene was selected.

[0043] H. Lubricant, H1: polyolefin wax lubricant and H2: aliphatic carboxylic acid ester lubricant, PETS were selected.

[0044] I. Surface improvers, specifically, I1: silicone masterbatch, MB50-002 (Dow Corning) is selected; I2: other surface improver, EAA copolymer wax, A-C 540A (Honeywell) is selected.

[0045] J. Antioxidants, antioxidant 1010 and antioxidant 168 are selected and compounded in a 1:1 ratio.

[0046] K. Toughening agents, specifically, K1: EMA ethylene-methyl acrylate copolymer ELVALOY AC 1125 (DuPont); K2: EBA ethylene-butyl acrylate copolymer ELVALOY AC 34035 (DuPont); K3: ethylene-acrylate-glycidyl methacrylate terpolymer PTW (DuPont).

[0047] L. Glass fibers, specifically, L1: ECS13-4.5-534A (glass fiber diameter 13μm, Jushi Group); L2: HMG436S-10-4.0 (glass fiber diameter 10μm, Taishan Fiberglass Co., Ltd.).

[0048] The composite materials of each example and comparative example are prepared through the following process:

[0049] The preparation methods of the halogen-containing flame retardant masterbatch examples and comparative examples 8 and 9 are as follows:

[0050] (1) The polyester resin is pre-dried at 120 - 130°C for 4 - 5 hours;

[0051] (2) Prepare various raw materials according to the ratios in the table;

[0052] (3) The dried polyester resin and other raw materials are mixed evenly by a high-speed stirring mixer according to the ratio and then enter the premixer through a metering feeder to obtain a mixed material.

[0053] (4) The above mixed material is fed into a twin-screw extruder. The feeding rate of the twin-screw extruder is 300 - 450 kg / hour; the temperatures of each section of the screw of the twin-screw extruder from the feeding port to the head are 200 - 210°C, 210 - 220°C, 210 - 220°C, 220 - 230°C, 220 - 230°C, 230 - 240°C, 220 - 230°C, 220 - 230°C, 230 - 240°C respectively, and the screw speed is 200 - 300 rpm. Under the conveying and shearing actions of the twin-screw extruder, it is fully melted, plasticized, kneaded and mixed, extruded through the head, drawn into strips, cooled and pelletized to obtain the one-step material of the halogen-containing flame retardant masterbatch.

[0054] (5) Dry the above-mentioned one-step flame retardant masterbatch at 100 - 120 °C for 3 - 4 hours, and then feed the dried one-step material into the twin-screw extruder again. The feeding rate of the twin-screw extruder is 450 - 600 kg / hour. The temperatures of each section of the screw of the twin-screw extruder from the feeding port to the head are 200 - 210 °C, 210 - 220 °C, 210 - 220 °C, 220 - 230 °C, 220 - 230 °C, 230 - 240 °C, 220 - 230 °C, 220 - 230 °C, 230 - 240 °C respectively, and the screw speed is 200 - 300 rpm. Under the conveying and shearing action of the twin-screw extruder, it is fully melted, plasticized, kneaded and mixed, extruded through the head, strip-shaped, cooled, pelletized and dried to obtain a halogen-containing flame retardant masterbatch.

[0055] The preparation methods of the application examples and application comparative examples of the halogen-containing flame retardant masterbatch are as follows:

[0056] (1) Pre-dry the polyester resin at 120 - 130 °C for 4 - 5 hours;

[0057] (2) Prepare various raw materials according to the ratio in Table 2;

[0058] (3) Mix the polyester resin after drying treatment with the halogen-containing flame retardant masterbatch, toughening agent, antioxidant, alkali-free glass fiber, and lubricant evenly in a high-speed stirring mixer according to the ratio or separately enter the premixer through a metering feeder;

[0059] (4) Feed the above-mentioned mixed material into the twin-screw extruder. The feeding rate of the twin-screw extruder is 450 - 800 kg / hour. The temperatures of each section of the screw of the twin-screw extruder from the feeding port to the head are 220 - 230 °C, 230 - 240 °C, 203 - 240 °C, 240 - 250 °C, 250 - 260 °C, 240 - 250 °C, 240 - 250 °C, 230 - 240 °C, 230 - 240 °C respectively, and the screw speed is 250 - 400 rpm. Under the conveying and shearing action of the twin-screw extruder, it is fully melted, plasticized, kneaded and mixed, extruded through the head, strip-shaped, cooled, pelletized and dried, and finally packaged to obtain the glass fiber-reinforced polyester modified material particles with flame retardant effect.

[0060] The examples and comparative examples are tested by the following test methods or test standards:

[0061] (1) Dry the product obtained by extrusion and pelletization at 120 - 130 °C for 3 - 4 hours;

[0062] (2) Prepare test specimens by injection molding according to the corresponding standards;

[0063] (3) Test the flame retardant performance according to the UL 94-2020 standard;

[0064] (4) Inject the halogenated flame retardant masterbatch and the flame retardant masterbatch one-step material with the same components and the same weight parts into a square plate of 85mm×45mm×2.5mm, and use a Color Eye 7000A desktop spectrophotometer to perform color difference ΔE testing. Example 2 is used as the reference sample for color difference testing.

[0065] Table 1 Examples of halogenated flame retardant masterbatch (parts by weight)

[0066]

[0067]

[0068] Table 2 Comparative examples of halogenated flame retardant masterbatch (parts by weight)

[0069]

[0070]

[0071] Table 3-1 Application examples (parts by weight)

[0072]

[0073] Table 3-2 Application examples (parts by weight)

[0074]

[0075]

[0076] Table 4 Application comparative examples (parts by weight)

[0077]

[0078] The flame retardant grades of the halogen-containing flame retardant masterbatches prepared in Examples 1-15 are all V-0 to V-1, and the color difference is 0.1-0.7. The present invention uses a small amount of polyester resin, elastomer and a small amount of compounded surface improver, and through two passes of extrusion, it avoids large color fluctuations of the masterbatch and the flame retardant enhanced modified material using the masterbatch; if only the elastomer is used as the carrier and a small amount of surface modifier is compounded, after two extrusion granulations, the color difference change of the flame retardant masterbatch is greater than 2.5, and the color difference of the modified material is greater than 3.0 (Example 3 of Comparative Table 2, Application Example 3 of Comparative Table 4); if polyester and elastomer are used as the carrier without compounding the surface improver, after two extrusion granulations, the color difference change of the flame retardant masterbatch is greater than 2.0, and the color difference of the modified material is greater than 2.5 (Example 4 of Comparative Table 2); while using polyester, elastomer and a small amount of surface improver in combination, the color difference changes are reduced to below 0.8 and 0.6 respectively (see the test result comparison of Examples 2, 3, 4 and Comparative Examples 3, 5, 6 of the halogen-containing flame retardant masterbatch and Examples 2, 3, 4 and Application Comparative Examples 4, 5, 6 of the halogen-containing flame retardant masterbatch application). Thirdly, using the flame retardant masterbatch to prepare the flame retardant enhanced modified material requires less amounts of flame retardant and flame retardant synergist than the modified material obtained by directly using flame retardant, flame retardant synergist, resin, glass fiber, toughening agent and other additives through extrusion granulation to achieve the same flame retardant effect (see Application Example 4 and Application Comparative Example 7 of the halogen-containing flame retardant masterbatch).

Claims

1. A halogen-containing flame retardant masterbatch with stable and efficient flame retardant effect, characterized in that: By weight parts, it comprises the following components: 2 - 5 parts of polyester resin; 10 - 20 parts of elastomer; 55 - 65 parts of halogenated flame retardant; 10 - 15 parts of flame retardant synergist; 5 - 7.5 parts of filler; 0 - 2 parts of anti - dripping agent; 0.1 - 10 parts of surface improver; 0.5 - 1 part of lubricant; 0.1 - 0.3 parts of antioxidant; Among them, the elastomer is ethylene - methyl acrylate copolymer and / or ethylene - butyl acrylate copolymer; the polyester resin is at least one of PBT resin with an intrinsic viscosity of 0.8 - 1.0 dl / g and PET resin with an intrinsic viscosity of 0.68 - 1.0 dl / g; the surface improver is silicone masterbatch; the halogenated flame retardant masterbatch is obtained by two - stage extrusion.

2. The halogen-containing flame retardant masterbatch according to claim 1, wherein: The content of methyl acrylate in the ethylene - methyl acrylate copolymer is 23 - 26%; the content of butyl acrylate in the ethylene - butyl acrylate copolymer is 33 - 37%.

3. The halogen-containing flame retardant masterbatch according to claim 1, characterized in that: The halogenated flame retardant is at least one of brominated epoxy resin, brominated polystyrene, and brominated polycarbonate; the flame retardant synergist is at least one of antimony trioxide and sodium antimonate; the anti - dripping agent is polytetrafluoroethylene.

4. The halogen-containing flame retardant masterbatch according to claim 1, characterized in that: The filler is ultrafine talc powder; the antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants; the lubricant is at least one of aliphatic carboxylic ester lubricants and polyolefin wax lubricants.

5. The halogen-containing flame retardant masterbatch according to claim 1, characterized in that: The elastomer is 15 - 18 parts; the surface improver is 0.5 - 5 parts.

6. A preparation method of a halogenated flame retardant masterbatch with stable and high - efficient flame retardant effect as claimed in any one of claims 1 - 5, comprising the following steps: (1) Predry the polyester resin, and after uniformly mixing the dried polyester resin with other components in proportion, feed them into a premixer through a metering feeder to obtain a mixed material; (2) Then feed the mixed material into a twin - screw extruder, fully melt and plasticize, knead and mix, extrude through a die head, draw into strips, cool, and pelletize to obtain the one - step material of the halogenated flame retardant masterbatch; (3) Predry the above - mentioned one - step material of the flame retardant masterbatch, and then feed the dried one - step material into the twin - screw extruder again, fully melt and plasticize, knead and mix, extrude through a die head, draw into strips, cool, pelletize, and dry to obtain the halogenated flame retardant masterbatch.

7. An application of a halogenated flame retardant masterbatch with stable and high - efficient flame retardant effect as claimed in any one of claims 1 - 5 in electronic and electrical devices.

8. A modified material of halogen-containing flame-retardant glass fiber-reinforced polyester, characterized in that, The components of the modified material by weight parts comprise the following components: 45 - 55 parts of polyester resin; 14 - 18 parts of the halogenated flame retardant masterbatch as claimed in any one of claims 1 - 5; 0 - 5 parts of toughening agent; 15 - 35 parts of non - alkali glass fiber; 0.3 - 1 part of lubricant; 0.1 - 0.3 parts of antioxidant.

9. The modified material according to claim 8, wherein: The preparation method includes: (1) Predry the polyester resin, and after uniformly mixing the dried polyester resin with other components in proportion, feed them into a premixer through a metering feeder to obtain a mixed material; (2) Then feed the mixed material into a twin - screw extruder, fully melt and plasticize, knead and mix, extrude through a die head, draw into strips, cool, and pelletize to obtain a halogenated flame retardant glass fiber - reinforced polyester modified material.

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