A toughening modifier for PBT resin, modified PBT resin and a method for preparing the same

Abstract

The application provides a toughening modifier of PBT resin, modified PBT resin and a preparation method thereof. The preparation method of the toughening modifier of PBT resin comprises the following steps: preparing an emulsion by taking a mixture containing lipophilic polymerizable monomers as a dispersed phase and water as a continuous phase; and performing polymerization reaction on the obtained emulsion to obtain the toughening modifier of PBT resin. The toughening modifier of PBT resin is a reactive modifier, and can be applied to a PBT / glass fiber composite system, so that the impact toughness of PBT is improved, and better tensile strength is maintained.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a toughening modifier for PBT resin, a modified PBT resin, and a method for preparing the same. Background Technology

[0002] Polybutylene terephthalate (PBT) is a highly crystalline polymer with advantages such as creep resistance and good dimensional stability. PBT resin is often modified by filling it with glass fiber / inorganic fillers. The resulting modified PBT typically has poor toughness. The main reasons for this decrease in toughness include the inherent toughness of the PBT resin itself and the interfacial compatibility between the resin and the glass fiber / inorganic filler.

[0003] To improve the toughness of PBT, reactive toughening agents can be used to modify it. Commonly used reactive toughening agents for PBT include ethylene / octene copolymer grafted with maleic anhydride, polyethylene / vinyl acetate copolymer grafted with maleic anhydride, polyethylene-butyl acrylate-glycidyl methacrylate polymer, and styrene-acrylonitrile-maleic anhydride copolymer. However, these toughening agents can lead to a decrease in tensile strength during PBT modification. For example, Chinese patent document CN112048160A discloses a composite toughening agent obtained by combining a polyolefin-modified toughening agent and a polymeric elastomer grafted copolymer toughening agent (in a 1:1 ratio). When the composite toughening agent content is 85%, the material's impact toughness increases by 71%, but the tensile strength decreases by 12%. This indicates that while the addition of toughening agents effectively improves the toughness of PBT, it also reduces tensile strength.

[0004] Therefore, there is an urgent need to develop a toughening modifier for PBT resin that can improve the impact toughness of PBT while maintaining better tensile strength. Summary of the Invention

[0005] The purpose of this invention is to provide a toughening modifier for PBT resin, a modified PBT resin, and a method for preparing the same, so as to solve the technical problem that the existing toughening modifiers for PBT resin cause a decrease in tensile strength when improving the impact toughness of PBT.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A method for preparing a toughening modifier for PBT resin includes the following steps:

[0008] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was then subjected to a polymerization reaction to obtain a toughening modifier for PBT resin.

[0009] Preferably, the lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers;

[0010] Optionally, the vinyl monomer is one or more selected from methyl methacrylate, methyl acrylate, butyl acrylate, and styrene;

[0011] More preferably, the vinyl monomer is a mixture of methyl methacrylate and styrene;

[0012] More preferably, the vinyl monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio.

[0013] Optionally, the epoxy-containing polymerizable monomer is glycidyl acrylate.

[0014] Preferably, the dispersed phase further includes: polyether diol, isocyanate, chain extender, and catalyst.

[0015] Preferably, the polyether diol is one or more of PPG200 and PPG330;

[0016] More preferably, the polyether diol is PPG200.

[0017] Optionally, the isocyanate is one or more selected from toluene diisocyanate, isoflurone diisocyanate, and diphenylmethane diisocyanate;

[0018] More preferably, the isocyanate is diphenylmethane diisocyanate.

[0019] Optionally, the chain extender is one or more of butylene dimethacrylate, ethylene dimethacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate;

[0020] More preferably, the chain extender is a mixture of butylene dimethacrylate and hydroxyethyl acrylate;

[0021] More preferably, the chain extender is a mixture of butylene dimethacrylate and hydroxyethyl acrylate in a 1:1 mass ratio.

[0022] Optionally, the catalyst is one of dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate;

[0023] More preferably, the catalyst is dimethylaminoethyl methacrylate.

[0024] Optionally, the dispersed phase accounts for 74-90% of the mass percentage of the emulsion;

[0025] Preferably, the dispersed phase accounts for 80-85% of the mass percentage of the emulsion.

[0026] Preferably, in the dispersed phase, the mass ratio of the vinyl monomer, the epoxy-containing polymerizable monomer, the polyether diol, the isocyanate, the chain extender, and the catalyst is 60:(7-13):10:8:(3-5):0.5.

[0027] Preferably, the continuous phase further includes an emulsifier; the emulsifier is one or more of sodium dodecyl sulfate, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer.

[0028] More preferably, the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a 1:1 mass ratio.

[0029] Preferably, the mass ratio of the emulsifier to the lipophilic polymerizable monomer is (0.8-1.5):100.

[0030] Preferably, the dispersed phase further includes an initiator; the initiator is one or more of azobisisobutyronitrile and azobisisoheptanenitrile.

[0031] More preferably, the initiator is azobisisobutyronitrile (AIBN).

[0032] Preferably, the mass ratio of the initiator to the lipophilic polymerizable monomer is (0.5-1.0):100.

[0033] Preferably, the polymerization reaction is carried out at 55-65°C for 4-6 hours, followed by a reaction at 75-85°C for 1-3 hours.

[0034] More preferably, the polymerization reaction is carried out at 60°C for 5 hours, followed by a reaction at 80°C for 2 hours.

[0035] Preferably, the method for preparing the toughening modifier of PBT resin further includes: adding a demulsifier to the mixture after polymerization reaction to demulsify, then filtering, washing, and drying to obtain the toughening modifier of PBT resin.

[0036] The present invention also provides a toughening modifier for PBT resin obtained by the preparation method of the toughening modifier for PBT resin.

[0037] The present invention also provides a modified PBT resin containing a toughening modifier of the PBT resin.

[0038] Preferably, the modified PBT resin comprises the following raw materials: a toughening modifier for PBT resin, PBT resin, and a filler;

[0039] Preferably, the mass ratio of the toughening modifier, PBT resin, and filler in the PBT resin is 100:5:30.

[0040] Preferably, the filler is glass fiber.

[0041] The present invention also provides a method for preparing modified PBT resin, comprising the following steps: mixing the toughening modifier of the PBT resin with PBT resin and filler evenly, and extruding and granulating to obtain the modified PBT resin.

[0042] The above-described solution of the present invention has at least the following beneficial effects:

[0043] (1) The method for preparing the toughening modifier of PBT resin of the present invention includes the following steps: preparing an emulsion using a mixture containing lipophilic polymerizable monomers as the dispersed phase and water as the continuous phase; and subjecting the obtained emulsion to a polymerization reaction to obtain the toughening modifier of PBT resin. The lipophilic polymerizable monomer is one or more of vinyl monomers and epoxy-containing polymerizable monomers. The toughening modifier of PBT resin is a reactive modifier that can be applied to PBT / glass fiber composite systems, improving the impact toughness of PBT while maintaining better tensile strength. The epoxy groups in the molecular structure of the toughening modifier of PBT resin facilitate reaction with hydroxyl groups on the glass fiber surface, improving interfacial compatibility.

[0044] (2) The method for preparing the toughening modifier of PBT resin of the present invention, wherein the vinyl monomer is one or more of methyl methacrylate, methyl acrylate, butyl acrylate, and styrene. The epoxy-containing polymerizable monomer is glycidyl acrylate. The dispersed phase further includes: polyether diol, isocyanate, chain extender, and catalyst, and the dispersed phase also includes an initiator. The present invention adopts a concentrated emulsion polymerization method, using the lipophilic polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst as the dispersed phase, and water as the continuous phase. The dispersed phase is added dropwise to the aqueous phase and mixed to obtain a concentrated emulsion. At the same time, the initiator is added to the dispersed phase to undergo a polymerization reaction, thereby preparing the PBT toughening modifier. In the polymerization reaction system, the polyurethane segments grafted by the chemical reaction of the hydroxyl groups in the acrylate segments with the isocyanate groups form chemical bonds with the acrylate molecular segments, giving the material high elasticity. During the toughening process of PBT resin, it can better absorb the energy brought by impact, thereby effectively improving the toughness of PBT resin. Adding it to PBT resin can effectively improve the toughness of PBT resin without reducing tensile strength and flexural modulus.

[0045] (3) The method for preparing the toughening modifier for PBT resin of the present invention, wherein the vinyl monomer is a mixture of methyl methacrylate and styrene; and the epoxy-containing polymerizable monomer is glycidyl acrylate. The toughening modifier for PBT resin has a styrene-acrylate copolymer as the main chain, and introduces epoxy active groups through glycidyl acrylate, while simultaneously introducing polyurethane segments. The hydroxyl groups of hydroxyethyl acrylate condense with isocyanate to generate acrylate-grafted polyurethane segments. On the one hand, the introduction of styrene enhances the strength of the modifier; on the other hand, the toughening effect is controlled by the acrylate / polyurethane ratio, and interfacial compatibilization is achieved through epoxy groups. The toughening modifier for PBT resin prepared in this way, when applied to toughening PET resin, exhibits a good balance of rigidity and toughness, and is suitable for the modification of polyester materials such as PBT.

[0046] (4) The method for preparing the toughening modifier of PBT resin of the present invention, wherein the polymerization reaction is carried out at 55-65℃ for 4-6 hours, and then at 75-85℃ for 1-3 hours. Free radical polymerization can be completed at low temperature, and then the polyurethane synthesis can be completed by raising the temperature. The reaction conditions are mild. Detailed Implementation

[0047] Unless otherwise specified in the embodiments of this invention, the conditions shall be performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products. The following only provides some of the reagents used in the embodiments of this invention; different manufacturers and models of raw materials do not affect the implementation of the technical solution or the achievement of the technical effect of this invention.

[0048] Example 1

[0049] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0050] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 60°C for 5 hours, and then at 80°C for 2 hours to induce polymerization. A demulsifier was added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0051] The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers. The vinyl monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio. The epoxy-containing polymerizable monomer is glycidyl acrylate.

[0052] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, catalysts, and initiators; the mass ratio of the vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, and catalysts is 60:13:10:8:5:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomers is 0.8:100.

[0053] The polyether diol is PPG200. The isocyanate is diphenylmethane diisocyanate. The chain extender is a mixture of butylene dimethacrylate and hydroxyethyl acrylate in a 1:1 mass ratio. The catalyst is dimethylaminoethyl methacrylate. The initiator is azobisisobutyronitrile.

[0054] The continuous phase comprises water and an emulsifier; the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a 1:1 mass ratio. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.2:100.

[0055] The dispersed phase accounts for 85% of the mass percentage of the emulsion.

[0056] The demulsifier is a methanol solution of sodium chloride. The amount of the demulsifier used is 8% of the mass of the emulsion.

[0057] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0058] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0059] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0060] As a specific implementation of this embodiment, the method for preparing the modified PBT resin includes the following steps:

[0061] The toughening modifier of PBT resin is mixed evenly with PBT resin and filler in a high-speed mixer. After being mixed evenly, the mixture is drawn into strands by a twin-screw extruder at 240-260°C and then granulated by water cooling in a water bath to obtain plastic granules. The plastic granules are dried at 110°C for 6 hours and then injection molded at 250-270°C to obtain the final product.

[0062] Example 2

[0063] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0064] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 55°C for 4 hours, and then at 85°C for 3 hours to induce polymerization. A demulsifier was added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0065] Wherein, the lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers; the vinyl monomer is methyl acrylate; and the epoxy-containing polymerizable monomer is glycidyl acrylate.

[0066] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, catalysts, and initiators; the mass ratio of the vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, and catalysts is 60:7:10:8:5:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomers is 0.5:100.

[0067] The polyether diol is PPG330; the isocyanate is toluene diisocyanate; the chain extender is ethylene glycol dimethacrylate; the catalyst is diethylaminoethyl methacrylate; and the initiator is azobisisoheptanenitrile.

[0068] The continuous phase comprises water and an emulsifier; the emulsifier is sodium dodecyl sulfate. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.1:100.

[0069] The dispersed phase accounts for 74% of the mass percentage of the emulsion;

[0070] The demulsifier is a methanol solution of sodium chloride. The amount of the demulsifier used is 8% of the mass of the emulsion.

[0071] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0072] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0073] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0074] Example 3

[0075] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0076] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 65°C for 6 hours, and then at 75°C for 1 hour to induce polymerization. A demulsifier was added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0077] The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers; the vinyl monomer is methyl methacrylate. The epoxy-containing polymerizable monomer is glycidyl acrylate.

[0078] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, catalysts, and initiators; the mass ratio of the vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, and catalysts is 60:13:10:8:4:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomers is 1.0:100.

[0079] The polyether diol is a mixture of PPG200 and PPG330 in a mass ratio of 1:2; the isocyanate is isoflurone diisocyanate; the chain extender is hydroxypropyl acrylate; the catalyst is diethylaminoethyl methacrylate; and the initiator is azobisisobutyronitrile.

[0080] The continuous phase comprises water and an emulsifier; the emulsifier is a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.5:100.

[0081] The dispersed phase accounts for 90% of the mass percentage of the emulsion;

[0082] The demulsifier is a methanol solution of sodium chloride. The amount of the demulsifier used is 8% of the mass of the emulsion.

[0083] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0084] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0085] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0086] Example 4

[0087] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0088] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 60°C for 5 hours, and then reacted at 75°C for 3 hours to allow the emulsion to undergo a polymerization reaction, thus obtaining a toughening modifier for PBT resin.

[0089] Wherein, the lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers; the vinyl monomer is styrene; and the epoxy-containing polymerizable monomer is glycidyl acrylate.

[0090] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, catalysts, and initiators; the mass ratio of the vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, and catalysts is 60:10:10:8:3:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomers is 0.8:100.

[0091] The polyether diol is PPG200. The isocyanate is diphenylmethane diisocyanate; the chain extender is a mixture of butylene dimethacrylate and ethylene dimethacrylate in a 1:1 mass ratio; the catalyst is dimethylaminoethyl methacrylate; and the initiator is azobisisobutyronitrile.

[0092] The continuous phase comprises water and an emulsifier; the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a mass ratio of 1:3. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 0.8:100.

[0093] The dispersed phase accounts for 82% of the mass percentage of the emulsion;

[0094] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0095] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0096] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0097] Example 5

[0098] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0099] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 60°C for 5 hours, and then at 80°C for 3 hours to induce polymerization. A demulsifier was added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0100] The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers. The vinyl monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio. The epoxy-containing polymerizable monomer is glycidyl acrylate.

[0101] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, catalysts, and initiators; the mass ratio of the vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, and catalysts is 60:13:15:12:3:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomers is 0.8:100.

[0102] The polyether diol is PPG200. The isocyanate is diphenylmethane diisocyanate. The chain extender is a mixture of butylene dimethacrylate and hydroxyethyl acrylate in a 1:1 mass ratio. The catalyst is dimethylaminoethyl methacrylate. The initiator is azobisisobutyronitrile.

[0103] The continuous phase comprises water and an emulsifier; the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a 1:1 mass ratio. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.2:100.

[0104] The dispersed phase accounts for 85% of the mass percentage of the emulsion.

[0105] The demulsifier is a methanol solution of sodium chloride. The amount of the demulsifier used is 8% of the mass of the emulsion.

[0106] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0107] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0108] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0109] As a specific implementation of this embodiment, the method for preparing the modified PBT resin includes the following steps:

[0110] The toughening modifier of PBT resin is mixed evenly with PBT resin and filler in a high-speed mixer. After being mixed evenly, the mixture is drawn into strands by a twin-screw extruder at 240-260°C and then granulated by water cooling in a water bath to obtain plastic granules. The plastic granules are dried at 110°C for 6 hours and then injection molded at 250-270°C to obtain the final product.

[0111] The preparation method of the toughening modifier for PBT resin in this embodiment is the same as that in Example 1. Example 5 differs from Example 1 only in that it increases the polyurethane content and extends the polymerization reaction time by 1 hour. Specifically, the mass ratio of the vinyl monomer, epoxy-containing polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 1 is 60:13:10:8:3:0.5, and the reaction conditions are 60°C for 5 hours, followed by a reaction at 80°C for 2 hours. The mass ratio of the vinyl monomer, epoxy-containing polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 5 is 60:13:15:12:3:0.5, and the reaction conditions are 60°C for 5 hours, followed by a reaction at 80°C for 3 hours.

[0112] Example 6

[0113] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0114] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 60°C for 5 hours and then at 80°C for 2 hours to induce polymerization. A demulsifier was added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0115] The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers. The vinyl monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio. The epoxy-containing polymerizable monomer is glycidyl acrylate.

[0116] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, catalysts, and initiators; the mass ratio of the vinyl monomers, epoxy-containing polymerizable monomers, polyether diols, isocyanates, chain extenders, and catalysts is 60:13:10:8:3:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomers is 0.8:100.

[0117] The polyether diol is PPG200. The isocyanate is diphenylmethane diisocyanate. The chain extender is a mixture of butylene dimethacrylate and ethylene glycol dimethacrylate in a 1:1 mass ratio. The catalyst is dimethylaminoethyl methacrylate. The initiator is azobisisobutyronitrile.

[0118] The continuous phase comprises water and an emulsifier; the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a 1:1 mass ratio. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.2:100.

[0119] The dispersed phase accounts for 85% of the mass percentage of the emulsion.

[0120] The demulsifier is a methanol solution of sodium chloride. The amount of demulsifier used is 8% of the emulsion content.

[0121] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0122] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0123] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0124] As a specific implementation of this embodiment, the method for preparing the modified PBT resin includes the following steps:

[0125] The toughening modifier of PBT resin is mixed evenly with PBT resin and filler in a high-speed mixer. After being mixed evenly, the mixture is drawn into strands by a twin-screw extruder at 240-260°C and then granulated by water cooling in a water bath to obtain plastic granules. The plastic granules are dried at 110°C for 6 hours and then injection molded at 250-270°C to obtain the final product.

[0126] The preparation method of the toughening modifier for PBT resin in this embodiment is the same as that in Example 1. Compared with Example 1, the amount of chain extender used in Example 6 is reduced. Specifically, the mass ratio of vinyl monomer, epoxy-containing polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 1 is 60:13:10:8:5:0.5. The mass ratio of vinyl monomer, epoxy-containing polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 6 is 60:13:10:8:3:0.5.

[0127] Example 7

[0128] The method for preparing the toughening modifier for PBT resin in this embodiment includes the following steps:

[0129] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 60°C for 5 hours, and then at 80°C for 2 hours to induce polymerization. A demulsifier was added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0130] The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers. The vinyl monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio. The epoxy-containing polymerizable monomer is glycidyl acrylate.

[0131] The dispersed phase comprises: vinyl monomer, polyether diol, isocyanate, chain extender, catalyst, and initiator; the mass ratio of the vinyl monomer, polyether diol, isocyanate, chain extender, and catalyst is 60:10:8:5:0.5. The mass ratio of the initiator to the lipophilic polymerizable monomer is 0.8:100.

[0132] The polyether diol is PPG200. The isocyanate is diphenylmethane diisocyanate. The chain extender is a mixture of butylene dimethacrylate and hydroxyethyl acrylate in a 1:1 mass ratio. The catalyst is dimethylaminoethyl methacrylate. The initiator is azobisisobutyronitrile.

[0133] The continuous phase comprises water and an emulsifier; the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a 1:1 mass ratio. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.2:100.

[0134] The dispersed phase accounts for 85% of the mass percentage of the emulsion.

[0135] The demulsifier is a methanol solution of sodium chloride. The amount of demulsifier used is 8% of the emulsion content.

[0136] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0137] The method for preparing the modified PBT resin described in this embodiment includes the following steps:

[0138] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0139] As a specific implementation of this embodiment, the method for preparing the modified PBT resin includes the following steps:

[0140] The toughening modifier of PBT resin is mixed evenly with PBT resin and filler in a high-speed mixer. After being mixed evenly, the mixture is drawn into strands by a twin-screw extruder at 240-260°C and then granulated by water cooling in a water bath to obtain plastic granules. The plastic granules are dried at 110°C for 6 hours and then injection molded at 250-270°C to obtain the final product.

[0141] The preparation method of the toughening modifier for PBT resin in this embodiment is the same as that in Example 1. The dispersed phase in Example 7 does not contain epoxy-based polymerizable monomers. Specifically, the mass ratio of the vinyl monomer, epoxy-based polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 1 is 60:13:10:8:5:0.5. The mass ratio of the vinyl monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 7 is 60:10:8:5:0.5.

[0142] Comparative Example 1

[0143] The preparation method of the toughening modifier for PBT resin in this comparative example includes the following steps:

[0144] An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was first reacted at 60°C for 5 hours to induce polymerization. A demulsifier was then added to the mixture after polymerization to demulsify it. The mixture was then filtered, washed, and dried to obtain a toughening modifier for PBT resin.

[0145] The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers. The vinyl monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio. The epoxy-containing polymerizable monomer is glycidyl acrylate.

[0146] The dispersed phase comprises: vinyl monomers, epoxy-containing polymerizable monomers, and an initiator; the mass ratio of the vinyl monomers to the epoxy-containing polymerizable monomers is 60:13. The mass ratio of the initiator to the lipophilic polymerizable monomers is 0.8:100.

[0147] The polyether diol is PPG200. The isocyanate is diphenylmethane diisocyanate. The chain extender is a mixture of butylene dimethacrylate and hydroxyethyl acrylate in a 1:1 mass ratio. The catalyst is dimethylaminoethyl methacrylate. The initiator is azobisisobutyronitrile.

[0148] The continuous phase comprises water and an emulsifier; the emulsifier is a mixture of sodium dodecyl sulfate and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) in a 1:1 mass ratio. The mass ratio of the emulsifier to the lipophilic polymerizable monomer is 1.2:100.

[0149] The dispersed phase accounts for 85% of the mass percentage of the emulsion.

[0150] The demulsifier is a methanol solution of sodium chloride. The amount of demulsifier used is 8% of the emulsion content.

[0151] The toughening modifier for PBT resin prepared by the method described in this embodiment can be used for toughening modification of PBT resin. The modified PBT resin of this embodiment contains the toughening modifier for PBT resin, specifically comprising the following raw materials: toughening modifier for PBT resin, PBT resin, and filler; wherein the mass ratio of PBT resin, toughening modifier for PBT resin, and filler is 100:5:30; and the filler is glass fiber.

[0152] The preparation method of the modified PBT resin described in this comparative example includes the following steps:

[0153] The toughening modifier of the PBT resin is mixed evenly with the PBT resin and filler, and then extruded and granulated to obtain the final product.

[0154] As a specific implementation of this comparative example, the preparation method of the modified PBT resin includes the following steps:

[0155] The toughening modifier of PBT resin is mixed evenly with PBT resin and filler in a high-speed mixer. After being mixed evenly, the mixture is drawn into strands by a twin-screw extruder at 240-260°C and then granulated by water cooling in a water bath to obtain plastic granules. The plastic granules are dried at 110°C for 6 hours and then injection molded at 250-270°C to obtain the final product.

[0156] This comparative example uses the same raw materials and preparation method as Example 1, the only difference being that the dispersed phase of Comparative Example 1 does not contain the polyether diol, isocyanate, chain extender, or catalyst. Specifically, the mass ratio of the vinyl monomer, epoxy-containing polymerizable monomer, polyether diol, isocyanate, chain extender, and catalyst in Example 1 is 60:13:10:8:5:0.5. The mass ratio of the vinyl monomer and epoxy-containing polymerizable monomer in Comparative Example 1 is 60:13.

[0157] Effect Comparison

[0158] To verify the technical effectiveness of the toughening modifier for PBT resin described in this invention, the following experiments were conducted:

[0159] The toughening modifiers of PBT resins prepared in Examples 1-7 and Comparative Example 1 were used to prepare modified PBT resins according to the preparation method in Example 1. The prepared modified PBT resins were made into samples, placed in a desiccator for 12 hours, and then tested as follows:

[0160] Tensile strength / elongation at break: Tested according to ASTM D-638 standard, sample size 165×13×3.2mm. 3 Tensile tests were conducted at a speed of 20 mm / min.

[0161] Flexural strength / modulus: Tested according to ASTM D-790 standard, sample size 127×12.7×3.2mm. 3 The speed is 5 mm / min.

[0162] Notched impact strength: Tested according to ASTM D-256 standard, the sample size for the notched impact test is 64×12×3.2mm. 3 The notch machining radius is 0.25mm and the angle is 45°.

[0163] The results of the experiment are as follows:

[0164]

[0165] A comparison of Examples 1-7 with Comparative Example 1 shows that the toughening modifier for PBT resin described in this invention can effectively improve the rigidity and impact toughness of PBT materials. A comparison of Examples 1 and 5 with Comparative Example 1 shows that the polyurethane portion of the toughening modifier for PBT resin significantly improves the tensile strength and notched impact strength of PBT materials. A comparison of Examples 1 and 6 shows that the chain extender, by controlling the ratio of soft to hard segments in the polyurethane chain, has a significant impact on the tensile strength of PBT materials. A comparison of Examples 1 and 7 shows that the addition of epoxy polymerizable monomers also slightly improves the tensile strength and notched impact strength.

[0166] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A method for preparing a toughening modifier for PBT resin, characterized in that, Includes the following steps: An emulsion was prepared using an oleophilic polymerizable monomer as the dispersed phase and water as the continuous phase. The emulsion was then subjected to a polymerization reaction to obtain a toughening modifier for PBT resin. The lipophilic polymerizable monomer is a mixture of vinyl monomers and epoxy-containing polymerizable monomers; The dispersed phase also includes: polyether diol, isocyanate, chain extender, and catalyst; The continuous phase also includes an emulsifier; The dispersed phase accounts for 74% of the mass percentage of the emulsion. 90%.

2. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The vinyl monomer is one or more of methyl methacrylate, methyl acrylate, butyl acrylate, and styrene.

3. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The epoxy-containing polymerizable monomer is glycidyl acrylate.

4. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The polyether diol is one or more of PPG200 and PPG330.

5. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The isocyanate is one or more of toluene diisocyanate, isoflurone diisocyanate, and diphenylmethane diisocyanate.

6. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The chain extender is one or more of butylene dimethacrylate, ethylene dimethacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate.

7. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The catalyst is one of dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate.

8. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The emulsifier is sodium dodecyl sulfate or polyethylene oxide. Polypropylene oxide One or more of the following: polyethylene oxide triblock copolymers.

9. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The dispersed phase also includes an initiator; the initiator is one or more of azobisisobutyronitrile and azobisisoheptanenitrile.

10. The method for preparing the toughening modifier for PBT resin according to claim 1, characterized in that, The polymerization reaction is first carried out at 55 Reaction 4 at 65℃ 6 hours, then at 75 Reaction 1 at 85℃ 3h.

11. The toughening modifier of PBT resin obtained by the preparation method of the toughening modifier of PBT resin according to any one of claims 1 to 10.

12. A modified PBT resin, characterized in that, A toughening modifier containing the PBT resin of claim 11.

13. A method for preparing a modified PBT resin, characterized in that, The process includes the following steps: mixing the toughening modifier of PBT resin as described in claim 11 with PBT resin and filler evenly, and then extruding and granulating the mixture to obtain the final product.

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