A polymer lightweight automobile mask and its production process

Abstract

The invention relates to the technical field of polymer materials, and discloses a polymer lightweight automobile mask and a production process thereof. The polyene-based nitrogen-phosphorus-silicon flame retardant contains nitrogen-phosphorus-silicon synergistic flame retardant elements. The synergistic effect of phosphorus and nitrogen causes an oxidation reaction in the matrix when the material burns to produce non-combustible volatile substances, and forms a stable foam layer on the surface of the material to isolate heat from entering the interior of the material and prevent further combustion. The organic silicon in the carbon layer helps to form a continuous and dense silicate protective layer, significantly improves the oxygen index of the material, and enhances the flame retardant effect. The skeleton of the polyene-based nitrogen-phosphorus-silicon flame retardant is a six-membered ring of alternating single and double phosphorus-nitrogen bonds, has the same rigidity as a benzene ring, forms a dense network structure after chemical cross-linking, improves the compatibility of the entire system, thereby enhancing the impact strength and bending strength of the material, and improves the aging resistance of the material, and can be promoted for use on automobile masks.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a polymer lightweight automobile face mask and a production process thereof. Background Art

[0002] Cars are the most common means of transportation. Many countries regard the automobile industry as an important pillar industry. With the continuous development of the automobile industry, the automobile industry is facing three major problems: energy, pollution and safety. Among them, energy is the most prominent. Energy conservation has become the core issue of the development of the automobile industry: lightweight and energy saving have always been the research topics of the automobile industry. Energy saving is first to improve the economy of automobile fuel, and reducing the weight of the car is one of the important measures. Data show that for every 100kg reduction in automobile mass, fuel consumption per 100 kilometers can be reduced by 0.7L, and for every 10% reduction in automobile weight, fuel efficiency can be improved by 5.5%. Therefore, lightweight design is the key research content of the current automobile industry, and engineering plastics are one of the important directions of lightweight application research.

[0003] Automobile masks include engine cylinder head covers, radiator covers, headlight reflector covers, air deflectors and water tank covers, etc. In the prior art, they are generally made of metal materials such as thin steel plates, cast aluminum alloys and composite steel plates, but they have problems such as heavy weight, poor corrosion resistance, and easy warping and deformation. At the same time, the heat resistance of general engineering plastics cannot meet the working temperature requirements of automobile masks; with the advent of the lightweight era, the requirements for the performance stability of automotive products are gradually increasing. Among them, unsaturated polyester sheet molding compounds are widely used in many fields such as rail transit, new energy vehicles, electrical engineering and chemical industry due to their light weight, high strength, corrosion resistance and low cost. In particular, their application in high-speed rail vehicles, intercity buses and new energy vehicles has shown explosive growth, and these applications all require flame retardancy.

[0004] Unsaturated polyester sheet molding compound is a composite material with excellent comprehensive performance and has been widely used in many fields. However, the limiting oxygen index of its base material unsaturated polyester resin is only 19.6%, which is a flammable product. It will produce a lot of smoke and toxic gases when burning, which limits the application of unsaturated polyester sheet molding compound. In order to give the resin the flame retardant requirements, there are two commonly used methods: one is to add flame retardant materials, such as hydrated aluminum hydroxide, antimony trioxide and phosphate solvent-based flame retardants, but there are often problems such as poor compatibility with the resin or affecting the mechanical properties of the resin; the other is the synthesis of reactive flame retardant resin, introducing flame retardant elements into the polymer molecular skeleton, the flame retardant effect is stable and the mechanical properties of the product are greatly improved compared with the former; the reactive flame retardant currently produced in China is mainly halogen flame retardant, which releases a lot of smoke or toxic gas when burning, causing a significant impact on the environment and personal safety; therefore, the development of a flame retardant, heat-resistant and lightweight automotive mask has become a hot topic of current research. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a polymer lightweight automobile mask and a production process thereof, which has the effects of weight reduction, flame retardancy, heat resistance, light weight and energy saving.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A polymer lightweight automobile mask comprises the following components in parts by weight: 100 parts of ethylene unsaturated polyester resin, 90-120 parts of calcium carbonate filler, 20-30 parts of carbon fiber, 5-25 parts of polyene nitrogen phosphorus silicon flame retardant, 0.05-0.1 parts of hydroquinone, 1.5-3 parts of initiator, 1-2.5 parts of internal mold release agent, 25-35 parts of low shrinkage additive, 2-6 parts of thickener and 2-4 parts of pigment.

[0008] The production process of the polymer lightweight automobile mask is as follows: add vinyl unsaturated polyester resin, polyene nitrogen phosphorus silicon flame retardant, inhibitor, initiator and low shrinkage additive into a high-speed mixer, stir at a speed of 1500-2000r / min for 5-10min, add calcium carbonate filler, thickener, internal release agent and pigment, continue stirring for 10-20min to obtain uniformly dispersed unsaturated polyester paste, use polyethylene film as a diaphragm, and evenly impregnate the polyester paste on carbon fiber with a length of 10-15mm, thicken and mature at 40-55℃ for 16-32h to obtain a lightweight prepreg, and then place the lightweight prepreg in a metal mold with a heating temperature of 75-90℃, keep warm at 5-10MPa for 15-30min, tear off the film, and obtain a polymer lightweight automobile mask.

[0009] Preferably, the initiator is any one of tert-butyl perbenzoate, benzoyl peroxide, and dicumyl peroxide.

[0010] Preferably, the internal mold release agent is zinc stearate, the low shrinkage additive is vinyl acetate, and the thickener is toluene diisocyanate.

[0011] Preferably, the production process of the polyene-based nitrogen-phosphorus-silicon flame retardant is:

[0012] Step (1), under a nitrogen atmosphere, add 4-ethynylanisole and tetrahydrofuran to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, dropwise add n-butyllithium solution at -70°C, stir for 30-50min, add dimethylvinylchlorosilane, stir to react, after the reaction is completed, add deionized water and ethyl acetate to extract, concentrate the organic phase, and separate by column chromatography to obtain ethynylanisole silane.

[0013] Step (2), under a nitrogen atmosphere, add ethynylanisole silane and dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78 ° C, add boron tribromide dropwise, react at 20-35 ° C for 16-24h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane.

[0014] Step (3), under a nitrogen atmosphere, add ethynylphenol silane, sodium hydride and tetrahydrofuran to a reaction flask, stir evenly, add hexachlorocyclotriphosphazene, stir to react, after the reaction is completed, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant.

[0015] Preferably, in step (1), the ratio of 4-ethynylanisole, n-butyllithium solution, and dimethylvinylchlorosilane is 1 mol: (1.2-1.5) mol: (1.05-1.15) mol.

[0016] Preferably, in step (1), the reaction temperature is 20-35° C. and the reaction time is 5-12 h.

[0017] Preferably, in step (2), the ratio of ethynylanisole silane to boron tribromide is 1 mol:(1.2-1.5) mol.

[0018] Preferably, in step (3), the ratio of ethynylphenol silane, sodium hydride and hexachlorocyclotriphosphazene is (6.5-7.5) mol: (8-12) mol: 1 mol.

[0019] Preferably, in step (3), the reaction temperature is 60-75° C. and the reaction time is 8-16 h.

[0020] By adopting the above technical solution, the beneficial effects of the present invention are:

[0021] The invention firstly reacts 4-ethynylanisole with dimethylvinylchlorosilane under the action of n-butyl lithium to obtain ethynylanisole silane, then removes the methoxy group by boron tribromide to obtain ethynylphenol silane, and then reacts with hexachlorocyclotriphosphazene under the action of sodium hydride to obtain a polyene nitrogen phosphorus silicon flame retardant, and finally initiates polymerization of vinyl unsaturated resin, polyene nitrogen phosphorus silicon flame retardant and other additives, and obtains a high-molecular lightweight automobile face mask after thickening, aging and compression molding. The high-molecular-weight automobile face mask is suitable for automobile engine cylinder head cover, radiator cover, headlight reflector cover, deflector cover and water tank face mask.

[0022] The vinyl unsaturated ester resin molecular chain contains unsaturated double bonds and active carboxyl groups, which can be decomposed by the initiator to obtain primary free radicals, activate the vinyl ester resin molecular chain and the double bonds with the polyolefin nitrogen phosphorus silicon flame retardant, and a chain reaction occurs between the activated double bonds, so that the linear resin molecular chains are cross-linked to form a three-dimensional network structure; the thickener toluene diisocyanate can react chemically with the carboxyl group to form an interlaced network structure for thickening. The new bonds formed by the chemical reaction are difficult to break, and the structure contains carbon-carbon triple bonds. During the curing process, cross-linking forms a dense three-dimensional network structure, which can be further cured at high temperature. After curing, the surface of the polymer will gradually form high-temperature resistant silicon carbon and other inorganic substances, which slow down the thermal decomposition of the organic components inside the material. As the silane content increases, more and more high-temperature resistant inorganic substances are formed, and the aging resistance is further improved.

[0023] Polyene-based nitrogen-phosphorus-silicon flame retardants contain nitrogen-phosphorus-silicon synergistic flame retardant elements. The synergistic effect of phosphorus and nitrogen causes the matrix to undergo an oxidation reaction when the material burns to produce non-combustible volatile substances, such as carbon dioxide, nitrogen oxides, etc., which can quickly form a stable foam layer on the surface of the material, isolating heat from entering the interior of the material and preventing further combustion. The organic silicon in the carbon layer helps to form a continuous and dense silicate protective layer, significantly improving the oxygen index of the material, reducing the smoke and corrosive gases produced during combustion, protecting the substrate under the carbon layer from damage, and improving the flame retardant effect. At the same time, the polyene-based nitrogen-phosphorus-silicon flame retardant can produce chemical crosslinking with unsaturated polyester to form a dense three-dimensional network structure, so that the flame retardant is stably present in the resin matrix, is not easy to migrate and precipitate, and has good flame retardant and long-lasting performance.

[0024] The skeleton of the polyolefinic nitrogen-phosphorus-silicon flame retardant is a six-membered ring of alternating single and double phosphorus-nitrogen bonds, which has a certain rigidity like a benzene ring. The multiple olefinic unsaturated bonds in its structure are chemically bonded with the unsaturated bonds in the unsaturated polyester to form a dense cross-linked network structure. At the same time, the isocyanate group of toluene diisocyanate and the carboxyl group of the unsaturated polyester can react chemically to form a relatively stable chemical bond, which improves the compatibility of the entire system, thereby enhancing the impact strength and bending strength of the material, and can be promoted for use on automotive masks. DETAILED DESCRIPTION

[0025] The following content provides different embodiments or examples, so that those skilled in the art can implement it with reference to the description text. Of course, these are merely examples, and are not intended to limit the present invention. The endpoints and any value of the scope disclosed in the present invention are not limited to this accurate scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article.

[0026] Vinyl unsaturated polyester resin, produced by Sichuan Dongcai Technology Group Co., Ltd.

[0027] 4-Ethynylanisole, CAS number is 768-60-5.

[0028] Dimethylvinylchlorosilane, CAS number is 1719-58-0.

[0029] Hexachlorocyclotriphosphazene, CAS number is 940-71-6.

[0030] Example 1

[0031] Step (1), under nitrogen atmosphere, add 20mmol of 4-ethynylanisole and 180mL of tetrahydrofuran to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, add 26mmol of 2.5mol / L n-butyllithium solution at -70°C, stir for 45min, add 22mmol of dimethylvinylchlorosilane, react at 25°C for 10h, add deionized water and ethyl acetate for extraction, concentrate the organic phase, separate by column chromatography, and obtain ethynylanisole silane. The preparation reaction formula is as follows:

[0032]

[0033] Step (2), under nitrogen atmosphere, add 15mmol of ethynylanisole silane and 150mL of dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78°C, add 210mmol of boron tribromide dropwise, react at 25°C for 18h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane. The preparation reaction formula is as follows:

[0034]

[0035] Step (3), under nitrogen atmosphere, add 70mmol of ethynylphenol silane, 100mmol of sodium hydride and 125mL of tetrahydrofuran to the reaction flask, stir evenly, add 10mmol of hexachlorocyclotriphosphazene, react at 65°C for 12h, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant. The preparation reaction formula is as follows:

[0036]

[0037] Step (4), add 100g of vinyl unsaturated polyester resin, 5g of polyolefin nitrogen phosphorus silicon flame retardant, 0.06g of hydroquinone, 2.5g of tert-butyl perbenzoate, and 30g of vinyl acetate into a high-speed mixer, stir at a speed of 1800r / min for 9min, add 110g of calcium carbonate filler, 2g of toluene diisocyanate, 1.5g of zinc stearate and 3g of pigment, continue stirring for 15min, obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, evenly impregnate the polyester paste on 25g of carbon fiber with a length of 12mm, thicken and mature at 45°C for 24h to obtain a lightweight prepreg, then place the lightweight prepreg in a metal mold with a heating temperature of 85°C, keep warm at 8MPa for 25min, tear off the film, and obtain a polymer lightweight automotive mask.

[0038] Example 2

[0039] Step (1), under a nitrogen atmosphere, 35mmol of 4-ethynylanisole and 175mL of tetrahydrofuran were added to a reaction flask equipped with a thermometer and a dropping funnel, and after stirring, 42mmol of a 2.5mol / L n-butyllithium solution was added dropwise at -70°C, stirred for 30min, 36.75mmol of dimethylvinylchlorosilane was added, and the mixture was reacted at 35°C for 5h, deionized water and ethyl acetate were added for extraction, and the organic phase was concentrated and separated by column chromatography to obtain ethynylanisole silane.

[0040] Step (2), under a nitrogen atmosphere, add 30 mmol of ethynylanisole silane and 240 mL of dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78 ° C, add 36 mmol of boron tribromide dropwise, react at 35 ° C for 16 h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane.

[0041] Step (3), under a nitrogen atmosphere, add 162.5 mmol of ethynylphenol silane, 200 mmol of sodium hydride and 250 mL of tetrahydrofuran to a reaction flask, stir evenly, add 25 mmol of hexachlorocyclotriphosphazene, react at 75 ° C for 8 h, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant.

[0042] Step (4), add 100g of vinyl unsaturated polyester resin, 10g of polyolefin nitrogen phosphorus silicon flame retardant, 0.05g of hydroquinone, 1.5g of benzoyl peroxide and 255g of vinyl acetate into a high-speed mixer, stir at a speed of 2000r / min for 5min, add 90g of calcium carbonate filler, 3g of toluene diisocyanate, 2.5g of zinc stearate and 4g of pigment, continue stirring for 10min to obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, evenly impregnate the polyester paste on 30g of carbon fiber with a length of 15mm, thicken and mature at 55°C for 16h to obtain a lightweight prepreg, then place the lightweight prepreg in a metal mold with a heating temperature of 90°C, keep warm at 10MPa for 15min, tear off the film, and obtain a polymer lightweight automobile mask.

[0043] Example 3

[0044] Step (1), under a nitrogen atmosphere, 12 mmol of 4-ethynylanisole and 120 mL of tetrahydrofuran were added to a reaction flask equipped with a thermometer and a dropping funnel, and after stirring, 18 mmol of a 2.5 mol / L n-butyllithium solution was added dropwise at -70 ° C, stirred for 50 min, 12.6 mmol of dimethylvinylchlorosilane was added, and the mixture was reacted at 20 ° C for 12 h, deionized water and ethyl acetate were added for extraction, and the organic phase was concentrated and separated by column chromatography to obtain ethynylanisole silane.

[0045] Step (2), under a nitrogen atmosphere, add 8 mmol of ethynylanisole silane and 96 mL of dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78 ° C, add 12 mmol of boron tribromide dropwise, react at 20 ° C for 24 h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane.

[0046] Step (3), under a nitrogen atmosphere, add 32.5 mmol of ethynylphenol silane, 40 mmol of sodium hydride and 50 mL of tetrahydrofuran to a reaction flask, stir evenly, add 5 mmol of hexachlorocyclotriphosphazene, react at 60 ° C for 16 h, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant.

[0047] Step (4), add 100g of vinyl unsaturated polyester resin, 15g of polyolefin nitrogen phosphorus silicon flame retardant, 0.1g of hydroquinone, 3g of diisopropylbenzene peroxide and 28g of vinyl acetate into a high-speed mixer, stir at a speed of 1500r / min for 10min, add 120g of calcium carbonate filler, 5g of toluene diisocyanate, 2.5g of zinc stearate and 4g of pigment, continue stirring for 20min to obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, evenly impregnate the polyester paste on 20g of carbon fiber with a length of 10mm, thicken and mature at 40°C for 32h to obtain a lightweight prepreg, then place the lightweight prepreg in a metal mold with a heating temperature of 75°C, keep warm at 5MPa for 30min, tear off the film, and obtain a polymer lightweight automobile mask.

[0048] Example 4

[0049] Step (1), under a nitrogen atmosphere, 15 mmol of 4-ethynylanisole and 135 mL of tetrahydrofuran were added to a reaction flask equipped with a thermometer and a dropping funnel, and after stirring, 20.4 mmol of a 2.5 mol / L n-butyllithium solution was added dropwise at -70 ° C, stirred for 35 min, 17.4 mmol of dimethylvinylchlorosilane was added, and the mixture was reacted at 30 ° C for 9 h, deionized water and ethyl acetate were added for extraction, and the organic phase was concentrated and separated by column chromatography to obtain ethynylanisole silane.

[0050] Step (2), under a nitrogen atmosphere, add 9 mmol of ethynylanisole silane and 100 mL of dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78 ° C, add 12.2 mmol of boron tribromide dropwise, react at 25 ° C for 24 h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane.

[0051] Step (3), under a nitrogen atmosphere, add 45.5 mmol of ethynylphenol silane, 65 mmol of sodium hydride and 78 mL of tetrahydrofuran to a reaction flask, stir evenly, add 6.5 mmol of hexachlorocyclotriphosphazene, react at 70 ° C for 12 h, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant.

[0052] Step (4), add 100g of vinyl unsaturated polyester resin, 20g of polyolefin nitrogen phosphorus silicon flame retardant, 0.08g of hydroquinone, 2g of initiator tert-butyl perbenzoate and 30g of vinyl acetate into a high-speed mixer, stir at a speed of 1600r / min for 8min, add 110g of calcium carbonate filler, 5g of toluene diisocyanate, 1.6g of zinc stearate and 3.5g of pigment, continue stirring for 16min to obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, evenly impregnate the polyester paste on 26g of carbon fiber with a length of 13mm, thicken and mature at 50°C for 24h to obtain a lightweight prepreg, then place the lightweight prepreg in a metal mold with a heating temperature of 85°C, keep warm at 8MPa for 20min, tear off the film, and obtain a polymer lightweight automotive mask.

[0053] Example 5

[0054] Step (1), under a nitrogen atmosphere, add 25mmol of 4-ethynylanisole and 150mL of tetrahydrofuran to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, then dropwise add 35mmol of a 2.5mol / L n-butyllithium solution at -70°C, stir for 45min, add 28.5mmol of dimethylvinylchlorosilane, react at 35°C for 10h, add deionized water and ethyl acetate for extraction, concentrate the organic phase, and separate by column chromatography to obtain ethynylanisole silane.

[0055] Step (2), under a nitrogen atmosphere, add 18 mmol of ethynylanisole silane and 200 mL of dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78 ° C, add 22.5 mmol of boron tribromide dropwise, react at 30 ° C for 20 h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane.

[0056] Step (3), under a nitrogen atmosphere, add 102 mmol of ethynylphenol silane, 135 mmol of sodium hydride and 180 mL of tetrahydrofuran to a reaction flask, stir evenly, add 15 mmol of hexachlorocyclotriphosphazene, react at 70 ° C for 15 h, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant.

[0057] Step (4), add 100g of vinyl unsaturated polyester resin, 25g of polyolefin nitrogen phosphorus silicon flame retardant, 0.1g of hydroquinone, 3g of benzoyl peroxide and 35g of vinyl acetate into a high-speed mixer, stir at a speed of 2000r / min for 10min, add 100g of calcium carbonate filler, 6g of toluene diisocyanate, 2.5g of zinc stearate and 3g of pigment, continue stirring for 15min to obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, evenly impregnate the polyester paste on 25g of carbon fiber with a length of 15mm, thicken and mature at 45°C for 25h to obtain a lightweight prepreg, then place the lightweight prepreg in a metal mold with a heating temperature of 85°C, keep warm at 9MPa for 25min, tear off the film, and obtain a polymer lightweight automobile mask.

[0058] Comparative Example 1

[0059] Step (1), under nitrogen atmosphere, add 70mmol of 4-vinylphenol, 100mmol of sodium hydride and 125mL of tetrahydrofuran to a reaction flask, stir evenly, add 10mmol of hexachlorocyclotriphosphazene, react at 65°C for 12h, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a product with the structural formula: Polyene nitrogen phosphorus flame retardant.

[0060] Step (2), add 100g of ethylene unsaturated polyester resin, 5g of polyolefin nitrogen phosphorus flame retardant, 0.06g of hydroquinone, 2.5g of tert-butyl perbenzoate, and 30g of vinyl acetate into a high-speed mixer, stir at a speed of 1800r / min for 9min, add 110g of calcium carbonate filler, 2g of toluene diisocyanate, 1.5g of zinc stearate and 3g of pigment, continue stirring for 15min, obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, uniformly impregnate the polyester paste on 25g of carbon fiber with a length of 12mm, thicken and mature at 45°C for 24h to obtain a lightweight prepreg, then place the lightweight prepreg in a metal mold with a heating temperature of 85°C, keep warm at 8MPa for 25min, tear off the film, and obtain a car mask.

[0061] Comparative Example 2

[0062] 100g of vinyl unsaturated polyester resin, 5g of ethynylphenol silane (prepared by Example 1), 0.06g of hydroquinone, 2.5g of tert-butyl perbenzoate, and 30g of vinyl acetate were added to a high-speed mixer, and stirred at a rotating speed of 1800r / min for 9min. 110g of calcium carbonate filler, 2g of toluene diisocyanate, 1.5g of zinc stearate and 3g of pigment were added, and stirring was continued for 15min to obtain a uniformly dispersed unsaturated polyester paste. A polyethylene film was used as a diaphragm, and the polyester paste was evenly impregnated on 25g of carbon fiber with a length of 12mm. The mixture was thickened and matured at 45°C for 24h to obtain a lightweight prepreg. The lightweight prepreg was then placed in a metal mold with a heating temperature of 85°C, and kept warm at 8MPa for 25min. The film was torn off to obtain a car mask.

[0063] Comparative Example 3

[0064] Add 100g of vinyl unsaturated polyester resin, 0.06g of hydroquinone, 2.5g of tert-butyl perbenzoate, and 30g of vinyl acetate into a high-speed mixer, stir at a speed of 1800r / min for 9min, add 110g of calcium carbonate filler, 2g of toluene diisocyanate, 1.5g of zinc stearate and 3g of pigment, continue stirring for 15min to obtain a uniformly dispersed unsaturated polyester paste, use a polyethylene film as a diaphragm, and evenly impregnate the polyester paste on 25g of carbon fiber with a length of 12mm, thicken and mature at 45°C for 24h to obtain a lightweight prepreg, and then place the lightweight prepreg in a metal mold with a heating temperature of 85°C, keep it warm at 8MPa for 25min, tear off the film, and obtain a car mask.

[0065] Limiting oxygen index (LOI) test: According to GB / T 2406-1993 standard, the limiting oxygen index of the material is tested using a limiting oxygen index tester, and the test specimen specification is 100mm×6.5mm×3.2mm.

[0066] Vertical burning performance (UL-94) test: According to GB / T 2408-2008 standard, the vertical burning performance of the material is tested using a vertical burning tester, and the test specimen specification is 125mm×10mm×5mm.

[0067] Table 1 Flame retardant performance test

[0068] LOI(%) UL-94 Example 1 27.4 V-0 Example 2 30.2 V-0 Example 3 35.1 V-0 Example 4 37.2 V-0 Example 5 37.6 V-0 Comparative Example 1 25.5 V-0 Comparative Example 2 22.8 V-1 Comparative Example 3 19.6 V-2

[0069] It can be seen from the test results in the above table that with the increase of the content of the polyene-based nitrogen-phosphorus-silicon flame retardant, the flame retardant performance of the automobile mask is gradually enhanced. The limiting oxygen index in Example 5 is 37.6%, and the vertical combustion grade is V-0, which belongs to the flame retardant material level; this is because the polyene-based nitrogen-phosphorus-silicon flame retardant contains nitrogen-phosphorus-silicon synergistic flame retardant elements. The synergistic effect of phosphorus and nitrogen causes the matrix to undergo an oxidation reaction when the material burns to produce non-combustible volatile substances, such as carbon dioxide, nitrogen oxides, etc., which can quickly form a stable foam layer on the surface of the material, isolating heat from entering the material, and preventing further combustion; the organic silicon in the carbon layer helps to form a continuous and dense silicate protective layer, significantly improves the oxygen index of the material, reduces the smoke and corrosive gases generated during combustion, protects the substrate under the carbon layer from damage, and improves the flame retardant effect; at the same time, the polyene-based nitrogen-phosphorus-silicon flame retardant can be chemically cross-linked with the unsaturated polyester to form a dense three-dimensional network structure, so that the flame retardant is stably present in the resin matrix, is not easy to migrate and precipitate, and has good flame retardant and durable performance.

[0070] Comparative Example 1 does not contain silicon element, but contains phosphorus and nitrogen alternating structure, has a certain flame retardant effect, and its limiting oxygen index is 25.5%; Comparative Example 2 does not contain phosphorus and nitrogen flame retardant elements, only contains silicon element, has general flame retardant performance, and its vertical combustion grade is V-1; Comparative Example 3 does not contain any flame retardant elements, and its limiting oxygen index is only 19.6%, which belongs to the level of flammable materials.

[0071] Bending strength test: According to GB / T 2567-2008 standard, the bending performance was tested using a bending testing machine, the indenter movement speed was 2 mm / min, and the sample specification was 80 mm × 10 mm × 4 mm.

[0072] Impact strength test: According to GB / T 1043-1993 standard, an impact testing machine is used to test the unnotched impact performance. The sample specification is 80mm×10mm×4mm, and the impact energy is 15J.

[0073] Table 2 Mechanical properties test

[0074] Bending strength(MPa) <![CDATA[Impact strength (kJ / m 2 )]]> Example 1 210.82 105.42 Example 2 218.65 108.95 Example 3 230.61 112.23 Example 4 235.14 115.65 Example 5 226.08 110.04 Comparative Example 1 209.36 105.83 Comparative Example 2 202.31 103.26 Comparative Example 3 195.62 98.34

[0075] From the test results in the above table, it can be seen that with the increase of the content of polyolefin nitrogen phosphorus silicon flame retardant, the mechanical properties of the car mask are gradually enhanced. This is because its skeleton is a six-membered ring of alternating single and double phosphorus nitrogen, which has a certain rigidity like the benzene ring. The multiple olefin unsaturated bonds in its structure are chemically bonded with the unsaturated bonds in the unsaturated polyester to form a dense cross-linked network structure. At the same time, the isocyanate group of toluene diisocyanate and the carboxyl group of the unsaturated polyester can react chemically to form a relatively stable chemical bond, which improves the compatibility of the entire system, thereby enhancing the impact strength and bending strength of the material.

[0076] Aging resistance test: The prepared automobile mask is placed in an aging box at 175°C for 180 hours, the bending performance is tested using a bending tester, and the bending strength change amplitude is calculated.

[0077] Table 3 Aging resistance test

[0078]

[0079]

[0080] From the test results in the above table, it can be seen that with the increase of the content of polyene nitrogen phosphorus silicon flame retardant, the aging resistance of the car mask is gradually enhanced. After the aging test of 175℃×180h, the change value of the bending strength is not large. This is because the structure of polyene nitrogen phosphorus silicon flame retardant contains carbon-carbon double bonds and carbon-carbon triple bonds, which can produce chemical cross-linking with unsaturated resins and can be further cured at high temperatures. After curing, the surface of the polymer will gradually form high-temperature resistant silicon carbon and other inorganic substances, which slow down the thermal decomposition of the organic components inside the material. With the increase of silane content, more and more high-temperature resistant inorganic substances are formed, which further improves its aging resistance.

[0081] The preferred embodiments of the present disclosure are described in detail above, but the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

Claims

1. A production process for a polymer lightweight automobile face mask, characterized in that: The polymer lightweight automobile mask comprises the following components in parts by weight: 100 parts of ethylene unsaturated polyester resin, 90-120 parts of calcium carbonate filler, 20-30 parts of carbon fiber, 5-25 parts of polyene nitrogen phosphorus silicon flame retardant, 0.05-0.1 parts of hydroquinone, 1.5-3 parts of initiator, 1-2.5 parts of internal mold release agent, 25-35 parts of low shrinkage additive, 2-6 parts of thickener and 2-4 parts of pigment; The production process of the polymer lightweight automobile mask is as follows: adding vinyl unsaturated polyester resin, polyolefin nitrogen phosphorus silicon flame retardant, hydroquinone, initiator and low shrinkage additive into a high-speed mixer, stirring at a speed of 1500-2000 r / min for 5-10 minutes, adding calcium carbonate filler, thickener, internal release agent and pigment, and continuing stirring for 10-20 minutes to obtain uniformly dispersed unsaturated polyester paste, using polyethylene film as a diaphragm, uniformly impregnating the polyester paste on carbon fibers with a length of 10-15 mm, thickening and ripening at 40-55° C. for 16-32 hours to obtain a lightweight prepreg, and then placing the lightweight prepreg in a metal mold with a heating temperature of 75-90° C., keeping the heat at 5-10 MPa for 15-30 minutes, tearing off the film, and obtaining a polymer lightweight automobile mask; The production process of the polyene-based nitrogen-phosphorus-silicon flame retardant is as follows: Step (1), under a nitrogen atmosphere, add 4-ethynylanisole and tetrahydrofuran to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, then dropwise add n-butyllithium solution at -70°C, stir for 30-50 minutes, add dimethylvinylchlorosilane, stir to react, after the reaction is completed, add deionized water and ethyl acetate to extract, concentrate the organic phase, and separate by column chromatography to obtain ethynylanisole silane; Step (2), under a nitrogen atmosphere, add ethynylanisole silane and dichloromethane to a reaction flask equipped with a thermometer and a dropping funnel, stir evenly, cool to -78°C, drop boron tribromide, react at 20-35°C for 16-24h, add methanol to quench, extract with deionized water and ethyl acetate, concentrate the organic phase, and dry to obtain ethynylphenol silane; Step (3), under a nitrogen atmosphere, add ethynylphenol silane, sodium hydride and tetrahydrofuran to a reaction flask, stir evenly, add hexachlorocyclotriphosphazene, stir to react, after the reaction is completed, cool and filter, wash with deionized water, and concentrate the filtrate to obtain a polyene nitrogen phosphorus silicon flame retardant.

2. The production process of polymer lightweight automobile face mask according to claim 1, characterized in that: The initiator is any one of tert-butyl perbenzoate, benzoyl peroxide and dicumyl peroxide.

3. The production process of polymer lightweight automobile face mask according to claim 1, characterized in that: The internal mold release agent is zinc stearate, the low shrinkage additive is vinyl acetate, and the thickener is toluene diisocyanate.

4. The production process of the polymer lightweight automobile mask according to claim 1 is characterized in that: In the step (1), the ratio of 4-ethynylanisole, n-butyllithium solution and dimethylvinylchlorosilane is 1 mol: (1.2-1.5) mol: (1.05-1.15) mol.

5. The production process of polymer lightweight automobile face mask according to claim 1, characterized in that: In the step (1), the reaction temperature is 20-35° C. and the reaction time is 5-12 h.

6. The production process of polymer lightweight automobile face mask according to claim 1, characterized in that: In the step (2), the ratio of ethynylanisole silane to boron tribromide is 1 mol: (1.2-1.5) mol.

7. The production process of polymer lightweight automobile face mask according to claim 1, characterized in that: In the step (3), the ratio of ethynylphenol silane, sodium hydride and hexachlorocyclotriphosphazene is (6.5-7.5) mol: (8-12) mol: 1 mol.

8. The production process of polymer lightweight automobile face mask according to claim 1, characterized in that: In the step (3), the reaction temperature is 60-75° C. and the reaction time is 8-16 h.

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