A glass fiber composite material for manufacturing special shoe tips and a preparation method thereof

Abstract

The present application relates to the technical field of special toe cap materials, and in particular to a glass fiber composite material for manufacturing special toe caps and a preparation method thereof. A glass fiber composite material for manufacturing special toe caps is made by hot pressing multiple layers of glass fiber prepregs; the glass fiber prepregs are made of the following raw materials in percentage by mass: 60-65wt% glass fiber mesh cloth, 24-28% thermosetting resin composition, 3-4% low shrinkage resin, 0.15-2% initiator, 0.2-0.3% cross-linking agent, 4-6% heat-resistant reinforcing monomer, 0.4-0.6% thickener, 0.25-0.35% defoaming agent, and 0.8-1.2% release agent. The special safety toe cap prepared by using the glass fiber composite material provided in the present invention is not only light in texture, meeting the lightweight design requirements of safety shoes, but also has excellent compressive strength and impact strength, meeting the requirements of European standard EN 22568, standard CSA, and American standard ASTM.

Description

Technical Field

[0001] The present application relates to the technical field of special shoe toe materials, and in particular to a glass fiber composite material for manufacturing special shoe toes and a preparation method thereof. Background Art

[0002] Safety shoes are a type of safety footwear designed specifically for industrial and labor environments. They can effectively prevent injuries from heavy objects and punctures from sharp objects, protecting toes from injury. They are suitable for a variety of working environments such as construction sites, metallurgy, chemical synthesis, and pharmaceuticals, providing workers with all-round safety protection.

[0003] Safety shoes are often equipped with special toe caps, which can be categorized as either metal or non-metallic. Metal toes are typically made of steel, with a rare exception of special aluminum alloys. Steel toes are the mainstream metal toe option, as they are simple to process and relatively inexpensive to produce. Special aluminum alloy toes, while lightweight, are relatively expensive to produce, limiting their use.

[0004] Plastic toe caps can be categorized as thermoplastic and thermosetting, depending on the resin matrix. Thermoplastic toe caps offer a simpler production process and lower costs compared to thermosetting toe caps, but their relatively low compressive strength limits their application. While the dense three-dimensional mesh structure of thermosetting toe caps provides excellent compressive strength, they have low impact strength, are prone to brittle cracking, and have a relatively short service life, which inadvertently increases the production cost of safety shoes.

[0005] In order to solve the problem that the toe of existing safety shoes cannot meet the three requirements of impact resistance, compressive strength and lightness at the same time, the inventor provides a glass fiber composite material for manufacturing special toe and a preparation method thereof. Summary of the Invention

[0006] In order to solve the technical bottleneck of the above-mentioned technology that the impact strength, compressive strength and lightweight cannot be achieved simultaneously, the present invention provides a glass fiber composite material for manufacturing special shoe heads and a preparation method thereof.

[0007] The present invention provides a glass fiber composite material for manufacturing special shoe toes, which is achieved through the following technical solutions:

[0008] A glass fiber composite material used for manufacturing special shoe toes is made by hot pressing multiple layers of glass fiber prepreg;

[0009] The glass fiber prepreg is made of the following raw materials in percentage by weight: 60-65 wt% of glass fiber mesh, 24-28 wt% of thermosetting resin composition, 3.0-4.0 wt% of low shrinkage resin, 0.15-2.0 wt% of initiator, 0.20-0.30 wt% of cross-linking agent, 4.0-6.0 wt% of heat-resistant reinforcing monomer, 0.4-0.6 wt% of thickener, 0.25-0.35 wt% of defoaming agent, and 0.8-1.2 wt% of release agent;

[0010] The glass fiber mesh is surface-modified with a silane coupling agent, then impregnated with an interface modification resin, and dried and cured. The interface modification resin is an isocyanate-modified hydroxypropyl acrylate resin.

[0011] The thermosetting resin composition at least includes acrylate resin and hydroxyacrylate resin.

[0012] The plastic-steel special shoe head prepared by the present invention is not only light in texture, meeting the lightweight design requirements of shoe products, but also has excellent compressive strength and impact strength, and has a relatively wide range of applications. It can be applied to safety shoes, labor protection shoes, work shoes, hiking shoes and other shoe products.

[0013] Preferably, the glass fiber prepreg is made of the following raw materials in the following mass percentages: 63-64wt% of glass fiber mesh cloth, 26-27wt% of thermosetting resin composition, 3.2-3.5wt% of low shrinkage resin, 0.18-2.0wt% of initiator, 0.24-0.26wt% of cross-linking agent, 4.0-4.2wt% of heat-resistant reinforcing monomer, 0.5-0.54wt% of thickener, 0.30-0.32wt% of defoaming agent, and 1.0-1.1wt% of release agent.

[0014] Optimizing the formula of the thermosetting resin composition can ensure the compressive strength, impact strength, and lightweight design requirements of the plastic-steel special shoe head, while also optimizing the production cost of the plastic-steel special shoe head and improving the product's market competitiveness.

[0015] Preferably, the thermosetting resin composition is composed of propyl methacrylate, polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000, and hydroxyl-terminated polysiloxane modified with side chain acrylate with a number average molecular weight of 800-2000.

[0016] Preferably, the mass ratio of the propyl methacrylate, polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000, and the side chain acrylate-modified hydroxyl-terminated polysiloxane with a number average molecular weight of 800-2000 is (80-100):(5-30):(5-20).

[0017] By optimizing the composition of the thermosetting resin composition, the compressive strength of the plastic-steel special shoe head can be ensured while further optimizing and improving the impact strength of the plastic-steel special shoe head.

[0018] Preferably, the side chain acrylate modified hydroxyl-terminated polysiloxane includes γ-methacryloxypropylmethyldimethoxysilane, dimethoxymethylpropylsilane, methylphenyldimethoxysilane, and trimethoxy(methyl)silane as the end cap.

[0019] Preferably, the molar ratio of the γ-methacryloxypropylmethyldimethoxysilane, dimethoxymethylpropylsilane and methylphenyldimethoxysilane is (1-2):5:(1-2).

[0020] By adopting the above technical solution, the heat resistance and stability of plastic-steel special shoe heads can be improved, thereby expanding the application scope of plastic-steel special shoe heads. The thermosetting resin composition can be flexibly designed according to the actual application scenarios to meet the usage requirements of different application scenarios, thereby enhancing the core competitiveness of the enterprise.

[0021] Preferably, the preparation method of the side chain acrylate modified hydroxyl terminated polysiloxane is as follows:

[0022] 10 parts by weight of γ-methacryloxypropylmethyldimethoxysilane, 0.05-0.20 parts by weight of hydroquinone as a polymerization inhibitor and 20-30 parts by weight of an aqueous solution were mixed evenly, acid was added to adjust the pH to 5-6.5, and alcoholysis reaction was carried out at 40-60° C. for 15-60 minutes to obtain a silanol mixture A;

[0023] 10 parts by weight of dimethoxymethylpropylsilane and 20-30 parts by weight of an aqueous solution were mixed evenly, acid was added to adjust the pH to 5-6.5, and alcoholysis reaction was carried out at 40-60° C. for 15-60 minutes to obtain a silanol mixture B;

[0024] 10 parts by weight of methylphenyldimethoxysilane and 20-30 parts by weight of an aqueous solution were mixed evenly, acid was added to adjust the pH to 5-6.5, and alcoholysis reaction was carried out at 40-60° C. for 15-60 minutes to obtain a silanol mixture C;

[0025] Transfer the silanol mixture B to a three-necked flask, heat it to 35-45°C in a water bath, and simultaneously add silanol mixture A and silanol mixture C dropwise with magnetic stirring at 80-160rpm. The dropping speed of silanol mixture A is 1-5mL / min, and the dropping speed of silanol mixture C is 1-5mL / min. After the addition of silanol mixture A and silanol mixture C is completed, the temperature is maintained at 35-45°C for 60-90min, and then dimethoxydimethylsilane and acid are added to adjust the pH to 5-6 and carry out end-capping reaction for 5-10min. After adding alkali solution to adjust the pH to 7, the mixture is dehydrated in a water separator, and the obtained liquid is subjected to vacuum fractionation to remove the hydrolyzed silane monomer that does not participate in the reaction to obtain side chain acrylate-modified hydroxyl-terminated polysiloxane.

[0026] Preferably, the molar ratio of hydrolyzed γ-methacryloxypropylmethyldimethoxysilane in silanol mixture A, hydrolyzed dimethoxymethylpropylsilane in silanol mixture B, and hydrolyzed methylphenyldimethoxysilane in silanol mixture C is (1-4):10:(1-2).

[0027] The preparation method of the side chain acrylate modified hydroxyl-terminated polysiloxane provided in the present invention is relatively simple and has relatively low operational difficulty. It can be synthesized in a laboratory or commissioned to an enterprise for industrial batch production and customization.

[0028] By adopting the above technical solution, the compressive strength and impact resistance of the plastic-steel special shoe toe can be improved.

[0029] Preferably, the crosslinking agent is at least one of tripropylene glycol diacrylate, trimethylolpropane triacrylate, HDI trimer curing agent, and pentaerythritol triacrylate.

[0030] By adopting the above technical solution, the compressive strength and impact resistance of the plastic-steel special shoe toe can be improved.

[0031] Preferably, the low shrinkage resin is polycaprolactone NPG200.

[0032] Preferably, the heat-resistant reinforcing monomer is at least one of styrene and diphenylethylene.

[0033] By adopting the above technical solution, the high temperature resistance performance of the plastic steel special shoe head can be improved.

[0034] Preferably, the initiator is at least one of benzoyl peroxide BPO, tert-butyl peroxy 2-ethylhexanoate TBPO, azobisisobutyronitrile AIBN, tetraisopropyl titanate, and dibutyltin dilaurate.

[0035] Preferably, the initiator is a composition of benzoyl peroxide (BPO) and tetraisopropyl titanate.

[0036] The tetraisopropyl titanate composition can catalyze the polyurethane reaction of organic matter containing -NCO groups and organic matter containing active -OH groups, meeting the requirement of pre-curing into a gel film state to obtain a thermosetting resin composition film in step 2, thereby improving the overall processing performance; benzoyl peroxide BPO meets the high-temperature-induced double bond polymerization reaction in the hot pressing molding stage in step 4, and hot curing molding is used to produce high-quality plastic steel special shoe heads.

[0037] Preferably, the thickener is at least one of magnesium oxide, fumed silica, organic bentonite, and montmorillonite.

[0038] By adopting the above technical solution, the viscosity of the thermosetting resin composition can be adjusted, which facilitates the preparation of the finished glass fiber prepreg in the later preparation process stage and helps improve the overall processing performance.

[0039] Preferably, the defoamer is BASF Efka PB 2720 defoamer or BYK 051N defoamer.

[0040] By adopting the above technical solution, an excellent degassing treatment is achieved, which can improve the density of the plastic-steel special shoe head, and further improve the compressive strength and impact resistance of the plastic-steel special shoe head.

[0041] Preferably, the release agent is at least one of stearate, molybdenum disulfide, talc powder, and mica powder.

[0042] By adopting the above technical solution, it is convenient to achieve rapid demoulding after the heat curing and hot pressing molding is completed, thereby improving the overall processing performance, and helping to improve the surface finish of the plastic steel special shoe head and enhance the product appearance.

[0043] The present invention provides a method for preparing a glass fiber composite material for manufacturing special shoe toes, which is achieved through the following technical solutions:

[0044] A method for preparing a glass fiber composite material for manufacturing special shoe toes comprises the following steps:

[0045] Step 1: Pre-treatment of glass fiber mesh cloth; and simultaneously preparing a thermosetting resin composition;

[0046] Step 2: uniformly mixing accurately measured amounts of a thermosetting resin composition, a low-shrinkage resin, an initiator, a cross-linking agent, a heat-resistant reinforcing monomer, a thickener, a defoaming agent, and a release agent to obtain a film-forming slurry; uniformly coating the obtained film-forming slurry on the surface of a release paper; and pre-curing the film-forming slurry on the surface of the release paper until the film-forming slurry is in a gel film state, thereby obtaining a thermosetting resin composition film sheet;

[0047] Step 3: attaching two sheets of the obtained thermosetting resin composition film to the upper and lower surfaces of the glass fiber prepreg to prepare the glass fiber prepreg, and curing the glass fiber prepreg at 40-50° C. for 36-48 hours;

[0048] Step 4: Cut the aging treated glass fiber prepreg to obtain a finished glass fiber prepreg in the shape of a forming mold. The finished glass fiber prepreg is stacked into a preformed toe by a manual lamination method. After hot pressing, the preformed toe is demoulded, trimmed, and polished to obtain a finished plastic steel toe. The hot pressing parameters are as follows: first pressurize to 10-20 MPa at 0.5-1 MPa / s, hold the pressure at a hot pressing temperature of 120-130°C for 60±5s, then pressurize to 30-40 MPa at 2-2.5 MPa / s, and hold the pressure at a hot pressing temperature of 140-160°C for 120±5s.

[0049] The preparation method of the present invention is relatively simple, has low operational difficulty, and is easy to implement in industrial batch production.

[0050] Preferably, the pretreatment preparation method of the glass fiber mesh in step 1 is as follows: first, spray a methacryloxysilane aqueous solution on the surface of the glass fiber mesh, wherein the concentration of methacryloxysilane in the methacryloxysilane aqueous solution is 4-8wt%, and the spraying amount is 5-40g / m 2 Then put it into the oven for drying at a temperature of 50-70°C and a drying time of 5-10 minutes. Finally, apply isocyanate-modified hydroxypropyl acrylate resin on the surface of the methacryloxysilane-modified glass fiber mesh cloth with a coating amount of 5-50g / m 2 , pre-cured and formed at 60-75℃ for 15-20min, then compounded with release paper and rolled up to obtain the finished glass fiber mesh cloth.

[0051] The grafting of methacryloxysilane on the surface of the glass fiber mesh cloth improves the compatibility with the isocyanate-modified hydroxypropyl acrylate resin, so that the isocyanate-modified hydroxypropyl acrylate resin is evenly coated on the surface of the methacryloxysilane-modified glass fiber mesh cloth. The -NCO group in the isocyanate-modified hydroxypropyl acrylate resin reacts with the active -OH group exposed on the surface of the glass fiber mesh cloth to form a polyurethane reaction. The -NCO group in the isocyanate-modified hydroxypropyl acrylate resin reacts with the terminal hydroxyl group -OH group in the methacryloxysilane oligomer to form a polyurethane reaction. After pre-curing and molding at 60-75°C for 15-20 minutes, it is in a gel state and composited with the release paper.

[0052] The preparation method of the finished glass fiber prepreg in the present invention is relatively simple, which is convenient for batch production and reduces the production cost of the finished glass fiber prepreg. The prepared finished glass fiber prepreg is convenient for subsequent processing and use, thereby improving the production efficiency of plastic steel special shoe heads and the quality stability of products in the same batch.

[0053] In summary, this application has the following advantages:

[0054] 1. The plastic-steel special shoe toe prepared by the present invention is not only light in texture, meeting the lightweight design requirements of shoe products, but also has excellent compressive strength and impact resistance.

[0055] 2. The preparation method of the present invention is relatively simple, has low operational difficulty, and is easy to implement in industrial batch production.

[0056] 3. The plastic-steel safety shoe toe made of the glass fiber composite material provided in the present invention has a higher weight ratio. Compared with the steel toe, when the strength is equivalent, the weight of the plastic-steel safety shoe toe is about 50% of that of the steel toe, which reduces the total weight of the safety shoe as a whole, is conducive to the lightweight design of the safety shoe, and meets the needs of hiking shoes.

[0057] 4. The plastic-steel safety shoe toe product of the present invention has a high degree of design freedom. According to different designed molds, plastic-steel shoe toes with uneven thickness and streamlined shapes can be produced, and the surface finish is high, and the appearance is more ornamental.

[0058] 5. The plastic-steel safety shoe toe made of the glass fiber composite material provided by the present invention has the advantages of good insulation safety, impact resistance, high and low temperature resistance, corrosion resistance, and chemical stability.

[0059] 6. The preparation process of the present invention is a thermosetting process, the material is non-toxic, and it conforms to the trend of green environmental protection.

[0060] 7. The plastic-steel safety shoe toe made of the glass fiber composite material provided by the present invention is a non-metallic material, is non-conductive, has good insulation performance, can pass airport security inspection, and expands its application range.

[0061] 8. The plastic-steel safety shoe toe made of the glass fiber composite material provided by the present invention has a relatively wide range of applications and can be applied to safety shoes, labor protection shoes, work shoes, hiking shoes and other footwear products. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 Schematic diagram of the product structure of the glass fiber plastic steel toe cap prepared in Example 1 of the present invention.

[0063] Figure 2 This is a process flow chart of the glass fiber plastic steel toe cap in Example 1 of the present invention. DETAILED DESCRIPTION

[0064] In order to further understand the inventiveness and technical advancement of the present invention, the preferred embodiments of the present invention are discussed in detail below with reference to examples and comparative examples. It should be noted that this specific embodiment is merely an explanation of the technical solution of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make modifications to this embodiment as needed without contributing to creativity, but as long as they are within the scope of the claims of the present invention, they are protected by patent law. Example

[0065] A glass fiber composite material used for manufacturing special shoe toes is obtained by stacking multiple layers of glass fiber prepreg cloth into a preformed prefabricated shoe toe by a manual lamination method. The prefabricated shoe toe is hot-pressed, then demoulded, trimmed, and polished.

[0066] The glass fiber prepreg contained in the glass fiber composite material glass fiber plastic steel toe cap can ensure that the glass fiber plastic steel toe cap has excellent compressive strength and impact strength, and meets the requirements of lightweight design. The density of the glass fiber composite material used to manufacture special toe cap is less than 2.2g / cm 3 In the above-mentioned glass fiber composite material, the bonding strength between the glass fiber mesh and the thermosetting resin composition matrix is particularly important, and the bonding strength determines the compressive strength and impact strength of the glass fiber safety shoe toe product.

[0067] To this end, the inventors developed a glass fiber mesh cloth with a special surface treatment. Specifically, the glass fiber mesh cloth is first surface-modified with a silane coupling agent, then impregnated with an interface-modifying resin, and dried and cured. The interface modification resin is an isocyanate-modified hydroxypropyl acrylate resin. At medium and low temperatures (60-80°C) and the action of tetraisopropyl titanate and / or dibutyltin dilaurate, the -NCO group of the isocyanate-modified hydroxypropyl acrylate resin reacts with the active hydroxyl group -OH in the thermosetting resin composition to produce a polyurethane group -NH-CO- connecting molecular unit to complete the initial connection with the thermosetting resin composition. In the subsequent thermoforming process, at high temperatures (100-140°C) and with at least one of benzoyl peroxide BPO, tert-butyl peroxide 2-ethylhexanoate TBPO, and azobisisobutyronitrile AIBN as an initiator, the double bonds of the isocyanate-modified hydroxypropyl acrylate resin undergo double bond polymerization reaction with the double bonds in the thermosetting resin composition, thereby effectively improving the crosslinking density of the polymer and further improving the compressive strength and impact strength of the glass fiber safety shoe toe product.

[0068] Isocyanate-modified hydroxypropyl acrylate resin is made of HDI isocyanate and hydroxypropyl methacrylate.

[0069] The fiberglass mesh is EWR600, with a weight of 600g / m 2 .

[0070] The specific preparation method of the glass fiber mesh cloth refers to the preparation method of the glass fiber mesh cloth in Example 1.

[0071] The thermosetting resin composition has a significant impact on the density, compressive strength and impact strength of the fiberglass safety shoe toe. The present invention optimizes the design of the thermosetting resin composition.

[0072] Specifically, the thermosetting resin composition is composed of propyl methacrylate, polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000, and side chain acrylate-modified hydroxyl-terminated polysiloxane with a number average molecular weight of 800-2000.

[0073] The compound use of polyethylene glycol methyl ether methacrylate can improve the impact strength of plastic-steel special shoe heads, and enhance the toughness and impact rebound recovery performance of plastic-steel special shoe heads.

[0074] The hydroxyl-terminated polysiloxane modified with side chain acrylate can improve the impact strength of the plastic-steel special shoe head, improve the toughness and impact rebound recovery performance of the plastic-steel special shoe head, and also improve the high-temperature resistance of the plastic-steel special shoe head.

[0075] Preferably, the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000, and side chain acrylate-modified hydroxyl-terminated polysiloxane with a number average molecular weight of 800-2000 is (80-100):(5-30):(5-20). The mass ratio of the total mass of polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000 and side chain acrylate-modified hydroxyl-terminated polysiloxane with a number average molecular weight of 800-2000 to propyl methacrylate is (25-50):100.

[0076] The glass fiber prepreg is made of the following raw materials in the following mass percentages: 60-65wt% of glass fiber mesh cloth, 24-28wt% of thermosetting resin composition, 3.0-4.0wt% of low shrinkage resin, 0.15-2.0wt% of initiator, 0.20-0.30wt% of cross-linking agent, 4.0-6.0wt% of heat-resistant reinforcing monomer, 0.4-0.6wt% of thickener, 0.25-0.35wt% of defoaming agent, and 0.8-1.2wt% of release agent.

[0077] The fiberglass mesh is new fiberglass mesh or recycled fiberglass mesh.

[0078] The crosslinking agent in the glass fiber prepreg formula will affect the overall crosslinking density of the composite material. Preferably, the crosslinking agent is at least one of tripropylene glycol diacrylate, trimethylolpropane triacrylate, HDI trimer curing agent, and pentaerythritol triacrylate.

[0079] In order to improve the production efficiency of glass fiber composite materials, tripropylene glycol diacrylate, trimethylolpropane triacrylate and pentaerythritol triacrylate contained in the crosslinking agent are photosensitive monomers, which facilitate pre-curing into a gel film state in step 2 of the processing stage to obtain a thermosetting resin composition film.

[0080] The -NCO group in the HDI trimer curing agent contained in the crosslinking agent can undergo a polyurethane reaction with the -OH group in the propyl methacrylate in the thermosetting resin composition to generate a polyurethane group -NH-CO- linked molecular unit, which is convenient for pre-curing into a gel film state during the processing stage to obtain a thermosetting resin composition film.

[0081] The low shrinkage resin is polycaprolactone NPG200, which improves the low shrinkage of the hot pressing molding of the plastic steel toe.

[0082] The heat-resistant reinforcing monomer is at least one of styrene and stilbene, preferably styrene.

[0083] The initiator is at least one of benzoyl peroxide BPO, tert-butyl peroxy 2-ethylhexanoate TBPO, azobisisobutyronitrile AIBN, tetraisopropyl titanate, and dibutyltin dilaurate.

[0084] The initiator is prepared by compounding benzoyl peroxide BPO and tetraisopropyl titanate.

[0085] The thickener is at least one of magnesium oxide, fumed silica, organic bentonite, and montmorillonite. Preferably, the thickener is magnesium oxide, which has a good thickening effect while optimizing the overall production cost.

[0086] The defoamer is BASF Efka PB 2720 defoamer or BYK 051N defoamer.

[0087] The release agent is at least one of stearate, molybdenum disulfide, talc powder and mica powder.

[0088] The side chain acrylate modified hydroxyl terminated polysiloxane is mainly prepared from γ-methacryloxypropylmethyldimethoxysilane, dimethoxymethylpropylsilane and methylphenyldimethoxysilane.

[0089] The side chain acrylate modified hydroxyl-terminated polysiloxane has the effect of improving the impact strength of glass fiber safety shoe heads in thermosetting resin compositions. The improvement in impact strength is mainly reflected in the optimization of toughness and impact rebound recovery performance. In addition, it can also improve the high temperature resistance of glass fiber safety shoe heads.

[0090] The structural formula of the side chain acrylate modified hydroxyl terminated polysiloxane is as follows:

[0091] , wherein the molar ratio of a:b:c is 5:(1-2):(1-2). That is, in the preparation of the side-chain acrylate-modified hydroxyl-terminated polysiloxane, preferably, the molar ratio of γ-methacryloxypropylmethyldimethoxysilane, dimethoxymethylpropylsilane, and methylphenyldimethoxysilane is (1-2):5:(1-2).

[0092] Controlling the amount of methylphenyldimethoxysilane added can adjust the number of benzene rings on the polysiloxane side chain, thereby improving the heat resistance and compressive strength of the plastic steel toe cap.

[0093] Controlling the addition amount of γ-methacryloyloxypropylmethyldimethoxysilane can adjust the number of γ-methacryloyloxy groups on the polysiloxane side chains, that is, control the double bond content, and further control the cross-linking density of the three-dimensional network structure of the formed cured product. This can improve the heat resistance and compressive strength of the fiberglass safety shoe head while also giving it good impact strength, allowing the fiberglass safety shoe head to meet the requirements of European standard EN22568, CSA standard, and American standard ASTM.

[0094] The amount of side chain acrylate modified hydroxyl-terminated polysiloxane added to the thermosetting resin composition should not be too much. Excessive addition of side chain acrylate modified hydroxyl-terminated polysiloxane will result in excessive crosslinking density of the three-dimensional network structure of the formed cured product, increased brittleness and decreased toughness, and deviation in impact toughness.

[0095] See also Figure 2 A method for preparing a glass fiber composite material for manufacturing a special shoe toe comprises the following steps:

[0096] Step 1: Pretreatment and preparation of glass fiber mesh;

[0097] Simultaneously preparing a thermosetting resin composition;

[0098] Step 2: placing accurately measured thermosetting resin composition, low shrinkage resin, heat-resistant reinforcing monomer, thickener, defoamer, and release agent in a reaction kettle, stirring and degassing for 30-45 minutes under nitrogen protection, adding initiator and cross-linking agent after degassing to obtain film-making slurry, and evenly coating the obtained film-making slurry on the surface of release paper, and pre-curing the film-making slurry on the surface of the release paper until the film-making slurry is in a gel film state, thereby obtaining a thermosetting resin composition film sheet;

[0099] Step 3: Compounding the two obtained thermosetting resin composition films on the upper and lower surfaces of the glass fiber prepreg to prepare the glass fiber prepreg, and subjecting the glass fiber prepreg to curing treatment at 40-50° C. for 36-48 hours;

[0100] Step 4: Cut the aging treated glass fiber prepreg to obtain the finished glass fiber prepreg in the shape of the forming mold. The finished glass fiber prepreg is stacked into a preformed toe cap by manual lamination. After hot pressing, the preforms are demoulded, trimmed, and polished to obtain the finished plastic steel toe cap. The hot pressing parameters are as follows: first pressurize at 0.5-1MPa / s to 10-20MPa, hold the pressure at a hot pressing temperature of 120-130℃ for 60±5s, then pressurize at 2-2.5MPa / s to 30-40MPa, hold the pressure at a hot pressing temperature of 140-160℃ for 120±5s to obtain the glass fiber safety toe cap. For details about the actual product of glass fiber safety toe cap, please refer to Figure 1 .

[0101] Preparation Example 1: The preparation method of side chain acrylate modified hydroxyl terminated polysiloxane is as follows:

[0102] Step 1: 23.3 g of γ-methacryloxypropylmethyldimethoxysilane KH572 (CAS No.: 3978-58-3), 0.12 g of polymerization inhibitor - hydroquinone (CAS No.: 123-31-9) and 50 g of aqueous solution were mixed evenly, 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 6.0, and the mixture was subjected to alcoholysis reaction at 45°C for 30 min to obtain KH572 hydrolysis to obtain silanol mixed solution A;

[0103] 14.8 g of dimethoxymethylpropylsilane (CAS No. 18173-73-4) was mixed evenly with 30 g of aqueous solution, and 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 6.0. The dimethoxymethylpropylsilane was subjected to alcoholysis at 45°C for 30 min to obtain silanol mixture B.

[0104] 18.2 g of methylphenyldimethoxysilane (CAS No. 3027-21-2) was mixed evenly with 40 g of aqueous solution, and 0.1 mol / L dilute hydrochloric acid was added to adjust the pH value to 6.0. The mixture was subjected to alcoholysis reaction at 45°C for 30 min to obtain silanol mixture C.

[0105] Step 2: 224.0 g of silanol mixture B was transferred to a 1000 ml three-necked flask, heated in a water bath to 40 ° C, and 73.3 g of silanol mixture A and 58.2 g of silanol mixture C were added dropwise at 120 rpm under magnetic stirring. The dropping rate of silanol mixture A was 1.8 mL / min, and the dropping rate of silanol mixture C was 1.5 mL / min. After the addition of silanol mixture A and silanol mixture C was completed, the reaction was continued at 40 ° C for 60 min, and then 3.1 g of dimethoxydimethylsilane (CAS No. 1112- 39-6) The mixture was stirred magnetically at 120 rpm for 2 min, and the pH was adjusted to 5.5 by adding 0.1 mol / L dilute hydrochloric acid. The end-capping reaction was carried out for 400 s. Then, the pH was adjusted to 7 by adding 0.1 mol / L aqueous NaOH solution. The resulting liquid was poured from the three-necked flask into a water separator for dehydration. The dehydrated polysiloxane mixture was poured into a three-necked flask equipped with a rectifying head for vacuum fractionation to remove low-boiling point materials (hydrolyzed silane monomers that did not participate in the reaction) to obtain a side-chain acrylate-modified hydroxyl-terminated polysiloxane.

[0106] The number average molecular weight of the prepared side chain acrylate-modified hydroxyl-terminated polysiloxane was measured by vapor pressure (gas phase) osmosis. The number average molecular weight of the side chain acrylate-modified hydroxyl-terminated polysiloxane was 720, and the molecular weight distribution width parameter D=1.24.

[0107] In step 2, what needs to be controlled is the addition amount of silanol mixture A and silanol mixture C. The limiting conditions are as follows: the molar ratio of hydrolyzed γ-methacryloxypropylmethyldimethoxysilane in silanol mixture A, hydrolyzed dimethoxymethylpropylsilane in silanol mixture B, and hydrolyzed methylphenyldimethoxysilane in silanol mixture C is 1:5:1.

[0108] Preparation Example 2 differs from Preparation Example 1 in that: Step 2: 224.0 g of silanol mixture B was transferred to a 1000 ml three-necked flask, heated in a water bath to 40° C., and 146.6 g of silanol mixture A and 58.2 g of silanol mixture C were added dropwise at 120 rpm under magnetic stirring. The dropping rate of silanol mixture A was 1.8 mL / min, and the dropping rate of silanol mixture C was 1.5 mL / min. After the addition of silanol mixture A and silanol mixture C was completed, the reaction was continued at 40° C. for 75 min, and then 3.1 g of dimethoxydimethylsilane (C AS No. 1112-39-6) was magnetically stirred at 120 rpm for 2 minutes, 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 5.5, and the end-capping reaction was carried out for 400 seconds. Then, 0.1 mol / L aqueous NaOH solution was added to adjust the pH to 7. The resulting liquid was poured from the three-necked flask into a water separator for dehydration. The dehydrated polysiloxane mixture was poured into a three-necked flask equipped with a rectifying head for vacuum fractionation to remove low-boiling point materials (hydrolyzed silane monomers that did not participate in the reaction), thereby obtaining a side-chain acrylate-modified hydroxyl-terminated polysiloxane.

[0109] The number average molecular weight of the prepared side chain acrylate-modified hydroxyl-terminated polysiloxane was measured by vapor pressure (gas phase) osmosis. The number average molecular weight of the side chain acrylate-modified hydroxyl-terminated polysiloxane was 885, and the molecular weight distribution width parameter D=1.27.

[0110] In step 2, what needs to be controlled is the addition amount of silanol mixture A and silanol mixture C. The limiting conditions are as follows: the molar ratio of hydrolyzed γ-methacryloxypropylmethyldimethoxysilane in silanol mixture A, hydrolyzed dimethoxymethylpropylsilane in silanol mixture B, and hydrolyzed methylphenyldimethoxysilane in silanol mixture C is 2:5:1.

[0111] Preparation Example 3 differs from Preparation Example 1 in that: Step 2, 224.0 g of silanol mixture B was transferred to a 1000 ml three-necked flask, heated in a water bath to 40 ° C, and 146.6 g of silanol mixture A and 116.4 g of silanol mixture C were added dropwise at 120 rpm under magnetic stirring. The dropping rate of silanol mixture A was 1.8 mL / min, and the dropping rate of silanol mixture C was 1.5 mL / min. After the addition of silanol mixture A and silanol mixture C was completed, the reaction was continued at 40 ° C for 90 min, and then 3.1 g of dimethoxydimethylsilane ( The mixture was stirred at 120 rpm for 2 minutes with CAS No. 1112-39-6. 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 5.5, and the end-capping reaction was carried out for 400 seconds. Then, a 0.1 mol / L aqueous NaOH solution was added to adjust the pH to 7. The resulting liquid was poured from the three-necked flask into a water separator for dehydration. The dehydrated polysiloxane mixture was poured into a three-necked flask equipped with a rectifying head for vacuum fractionation to remove low-boiling point materials (unreacted hydrolyzed silane monomers), thereby obtaining a side-chain acrylate-modified hydroxyl-terminated polysiloxane.

[0112] The number average molecular weight of the prepared side chain acrylate-modified hydroxyl-terminated polysiloxane was measured by vapor pressure (gas phase) osmosis. The number average molecular weight of the side chain acrylate-modified hydroxyl-terminated polysiloxane was 1052, and the molecular weight distribution width parameter D=1.31.

[0113] In step 2, what needs to be controlled is the addition amount of silanol mixture A and silanol mixture C. The limiting conditions are as follows: the molar ratio of hydrolyzed γ-methacryloxypropylmethyldimethoxysilane in silanol mixture A, hydrolyzed dimethoxymethylpropylsilane in silanol mixture B, and hydrolyzed methylphenyldimethoxysilane in silanol mixture C is 2:5:2.

[0114] Preparation Example 4: The preparation method of side chain acrylate modified hydroxyl terminated polysiloxane is as follows:

[0115] Step 1: 23.3 g of γ-methacryloxypropylmethyldimethoxysilane KH572 (CAS No.: 3978-58-3), 0.12 g of polymerization inhibitor - hydroquinone (CAS No.: 123-31-9) and 50 g of aqueous solution were mixed evenly, 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 6.0, and the mixture was subjected to alcoholysis reaction at 45°C for 30 min to obtain KH572 hydrolysis to obtain silanol mixed solution A;

[0116] 14.8 g of dimethoxymethylpropylsilane (CAS No. 18173-73-4) was mixed evenly with 30 g of aqueous solution, and 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 6.0. The dimethoxymethylpropylsilane was subjected to alcoholysis at 45°C for 30 min to obtain silanol mixture B.

[0117] Step 2: Transfer 224.0g of silanol mixture B to a 1000ml three-necked flask, heat it in a water bath to 40°C, and add 146.6g of silanol mixture A dropwise at 120rpm under magnetic stirring. The dropwise addition rate of silanol mixture A is 1.8mL / min. After the addition of silanol mixture A, the temperature is maintained at 40°C and the reaction is continued for 60min. Then, 3.1g of dimethoxydimethylsilane (CAS No. 1112-39-6) is added and magnetically stirred at 120rpm for 2min. 0.1 mol / L dilute hydrochloric acid was added to adjust the pH to 5.5, and the end-capping reaction was carried out for 400 seconds. Then, 0.1 mol / L aqueous NaOH solution was added to adjust the pH to 7. The resulting liquid was poured from the three-necked flask into a water separator for dehydration. The dehydrated polysiloxane mixture was poured into a three-necked flask equipped with a rectifying head for vacuum fractionation to remove low-boiling point materials - hydrolyzed silane monomers that did not participate in the reaction, thereby obtaining side chain acrylate-modified hydroxyl-terminated polysiloxane.

[0118] The number average molecular weight of the prepared side chain acrylate-modified hydroxyl-terminated polysiloxane was measured by vapor pressure (gas phase) osmosis. The number average molecular weight of the side chain acrylate-modified hydroxyl-terminated polysiloxane was 786, and the molecular weight distribution width parameter D=1.27.

[0119] In step 2, the amount of silanol mixture A added needs to be controlled, and the limiting conditions are as follows: the molar ratio of hydrolyzed γ-methacryloxypropylmethyldimethoxysilane in silanol mixture A to hydrolyzed dimethoxymethylpropylsilane in silanol mixture B is 2:5.

[0120] Specific preferred embodiments

[0121] Example 1: A glass fiber composite material for manufacturing special shoe toes is made by hot pressing multiple layers of glass fiber prepreg. The formula of the glass fiber prepreg is as follows:

[0122] 637.60 g of surface-modified EWR600 glass fiber mesh (thickness 600 ± 10 μm, warp density 2.50 ± 0.25 strands / cm, width 1000 mm);

[0123] 186.90 g of propyl methacrylate (CAS No. 2210-28-8);

[0124] 44.0 g of polyethylene glycol methyl ether methacrylate MPEG 1000MA (CAS No. 26915-72-0);

[0125] 33.0 g of the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1;

[0126] 33.0 g of low shrinkage resin - polycaprolactone NPG200;

[0127] 1.10g of benzoyl peroxide (BPO) (CAS No. 94-36-0);

[0128] 0.88g of tetraisopropyl titanate (CAS No.: 546-68-9);

[0129] 2.40 g of tripropylene glycol diacrylate (CAS No. 42978-66-5, high purity) as a crosslinker;

[0130] 41.78g of heat-resistant reinforcing monomer - styrene (CAS No.: 100-42-5);

[0131] 5.28g thickener - 325 mesh magnesium oxide (CAS No.: 1309-48-4);

[0132] 3.08 g of defoamer BASF Efka PB 2720;

[0133] 10.99g of 325 mesh zinc stearate (CAS No. 557-05-1) as a mold release agent.

[0134] Polyethylene glycol methyl ether methacrylate MPEG 1000MA, Hubei Shineng Chemical Technology Co., Ltd.

[0135] EWR600 fiberglass mesh, Taishan Fiberglass Co., Ltd.

[0136] A method for preparing a glass fiber composite material for manufacturing special shoe toes comprises the following steps:

[0137] Step 1: The preparation method of the finished glass fiber mesh cloth is as follows:

[0138] S1.1. Dissolve 0.11 mol (18.5 g) of HDI isocyanate (Wanhua HT-100) in 100 g of the organic solvent DMF to obtain a mixed solution. Mix 0.1 mol (14.4 g) of hydroxypropyl methacrylate (CAS No. 27813-02-1), 0.15 g of the polymerization inhibitor hydroquinone, and 0.02 g of dibutyltin dilaurate to obtain a dropwise solution. Heat the mixed solution to 70°C in a water bath under nitrogen protection and maintain the temperature at 70°C. Add the prepared dropwise solution to the mixed solution at a rate of 4 mL / min with magnetic stirring at 120 rpm. After the addition is complete, continue stirring and react for 45 min. Remove the organic solvent DMF by distillation under reduced pressure to obtain isocyanate-modified hydroxypropyl acrylate resin.

[0139] S1.2. Spray a 5wt% aqueous solution of methacryloxysilane KH570 on the surface of EWR600 glass fiber mesh at a spraying rate of 35g / m 2 Then put it into the oven and dry it at 65℃ for 10 minutes to obtain KH570 modified glass fiber mesh cloth. The measured weight of KH570 modified glass fiber mesh cloth is 601.6g / m 2 ;

[0140] S1.3. Apply the isocyanate modified hydroxypropyl acrylate resin in S1 to the surface of KH570 modified glass fiber mesh at a coating amount of 36g / m 2 After pre-curing at 75℃ for 15 minutes, the coated material is in gel state and then compounded with release paper and rolled up to obtain a gram weight of 637.6g / m 2 Finished glass fiber mesh cloth with surface modification treatment;

[0141] At the same time, a dipping resin composition was prepared by placing accurately measured 186.90 g of propyl methacrylate, 44.0 g of polyethylene glycol methyl ether methacrylate MPEG 1000MA, 33.0 g of the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1, 33.0 g of low-shrinkage resin - polycaprolactone NPG200, 0.88 g of tetraisopropyl titanate, 41.78 g of heat-resistant reinforcing monomer - styrene, 5.28 g of thickener - 325 mesh magnesium oxide, 3.08 g of defoamer BASF Efka PB2720, and 10.99 g of release agent - 325 mesh zinc stearate in a reaction kettle, stirring and degassing for 45 minutes under nitrogen protection, and after degassing, adding accurately measured 1.10 g of benzoyl peroxide BPO and 2.40 g of cross-linking agent - tripropylene glycol diacrylate, and mixing evenly to obtain the dipping resin composition;

[0142] Step 2: Divide 362.4 g of the impregnating resin composition prepared in step 1 into two equal portions, apply the two equal portions of the impregnating resin composition evenly on the surface of the release paper, and pre-curing at 60° C. into a gel film to obtain a thermosetting resin composition film composited with the release paper;

[0143] Step 3: Compound the two obtained thermosetting resin composition films on the upper and lower surfaces of the surface-modified finished glass fiber mesh prepared in Step 1 to obtain a glass fiber prepreg with a thickness of 0.6±0.005 mm. Compound a release paper on the surface of the glass fiber prepreg and age it at 40°C for 36 hours.

[0144] Step 4: Cut the aging treated glass fiber prepreg to obtain a finished glass fiber prepreg in the shape of a molding mold. The finished glass fiber prepreg is stacked into a preformed toe cap by manual lamination. The preformed toe cap is placed in a hot press for hot pressing. The hot pressing parameters are as follows: first pressurize to 20 MPa at 1 MPa / s, hold the pressure at a hot pressing temperature of 125°C for 60 seconds, then pressurize to 40 MPa at 2 MPa / s, hold the pressure at a hot pressing temperature of 155°C for 120 seconds, demold, trim, and polish to obtain a finished plastic steel toe cap with a wall thickness of 8.0 mm.

[0145] The difference between Example 2 and Example 1 is that: a preparation method of a glass fiber composite material for manufacturing a special shoe head is as follows, wherein step 1 is the same as Example 1, step 2, 362.4g of the impregnating resin composition in step 1 is divided into two parts, and the two equally divided impregnating resin compositions are evenly coated on the upper and lower surfaces of the finished glass fiber mesh cloth, respectively, and then compounded with release paper, and placed at 40°C for aging for 36h; step 3, the glass fiber prepreg after aging is cut to obtain a finished glass fiber prepreg in the shape of a molding mold, and the finished glass fiber prepreg is stacked into a preformed shoe head by a manual lamination method, and the preformed shoe head is placed in a hot press for hot pressing processing, and the hot pressing parameters are as follows: first pressurize to 20 MPa at 1MPa / s, maintain the pressure at a hot pressing temperature of 125°C for 60s, and then pressurize to 40 at 2MPa / s. MPa, maintain the pressure for 120s at a hot pressing temperature of 155℃, demould, trim and polish to obtain the finished plastic steel toe with a wall thickness of 8.0mm.

[0146] The difference between Example 3 and Example 1 is that polyethylene glycol methyl ether methacrylate MPEG1000MA in the glass fiber prepreg is replaced by hydroxypropyl methacrylate, and the other components remain unchanged.

[0147] The difference between Example 4 and Example 1 is that 44g of polyethylene glycol methyl ether methacrylate MPEG 1000MA and 33g of the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 in the glass fiber prepreg are replaced by 77g of hydroxypropyl methacrylate, and the other components remain unchanged.

[0148] The difference between Example 5 and Example 1 is that the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 in the glass fiber prepreg is replaced by the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 2.

[0149] The difference between Example 6 and Example 1 is that the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 in the glass fiber prepreg is replaced by the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 3.

[0150] The difference between Example 7 and Example 1 is that the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 in the glass fiber prepreg is replaced by the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 4.

[0151] The difference between Example 8 and Example 1 is that the side-chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 in the glass fiber prepreg is replaced with side-chain acrylate-modified silicone oil IOTA 170. Side-chain acrylate-modified silicone oil IOTA 170 was provided by Anhui Aiyota Silicone Oil Co., Ltd.

[0152] The difference between Comparative Example 1 and Example 1 is that 186.9 g of propyl methacrylate, 44 g of polyethylene glycol methyl ether methacrylate MPEG 1000MA, and 33 g of the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 in the glass fiber prepreg are replaced by 263.9 g of propyl methacrylate, and the other components are the same.

[0153] The difference between Control Group A and Example 1 is that: Step 1 of the preparation method of the glass fiber composite material for manufacturing special shoe toes, the preparation method of the glass fiber mesh cloth finished product is as follows:

[0154] S1.1. EWR600 glass fiber mesh cloth is sprayed with 5wt% methacryloyloxysilane KH570 aqueous solution, with a spraying amount of 32g / m 2 , then put it into an oven and dry it at 65℃ for 10 minutes to obtain KH570 modified glass fiber mesh cloth;

[0155] S1.2. Apply hydroxypropyl methacrylate (CAS No. 27813-02-1) prepared in S1 to the surface of KH570 modified glass fiber mesh cloth at a coating weight of 36 g / m 2 After pre-curing and molding at 75℃ for 15 minutes, the coated material is in a gel state and then compounded with release paper and rolled up to obtain the finished glass fiber prepreg.

[0156] The difference between Control Group B and Example 1 is that the preparation method of the glass fiber composite material used to manufacture the special shoe toe is as follows:

[0157] Step 1: Preparation of fiberglass mesh cloth: Spray 5wt% methacryloyloxysilane KH570 aqueous solution on the surface of EWR600 fiberglass mesh cloth, with a spraying amount of 32g / m 2 , then put it into an oven and dry it at 65℃ for 10min to obtain KH570 modified glass fiber mesh cloth, without using interface modification resin for modification;

[0158] Step 2: Divide 362.4 g of the impregnating resin composition in step 1 into two equal parts, evenly apply the two equal parts of the impregnating resin composition on the surface of the release paper, pre-cured at 60° C. into a gel film state to obtain a thermosetting resin composition film composited with release paper, and composite the two obtained thermosetting resin composition films onto the upper and lower surfaces of the surface-modified finished glass fiber mesh cloth prepared in step 1 to obtain a glass fiber prepreg with a thickness of 0.6±0.005 mm, composite the release paper on the surface of the glass fiber prepreg, and place it at 40° C. for aging for 36 hours;

[0159] Step three, the glass fiber prepreg after aging treatment is cut to obtain the finished glass fiber prepreg in the shape of the forming mold, the finished glass fiber prepreg is stacked into a preformed toe by manual lamination method, and the preformed toe is placed in a hot press for hot pressing molding. The hot pressing molding parameters are as follows: first pressurize to 20 MPa at 1 MPa / s, hold the pressure at a hot pressing temperature of 125°C for 60 seconds, then pressurize to 40 MPa at 2 MPa / s, hold the pressure at a hot pressing temperature of 155°C for 120 seconds, demold, trim and polish to obtain a finished plastic steel toe with a wall thickness of 8.0 mm.

[0160] Performance test: The safety shoe toe size tested is 8#.

[0161] 1. Residual height after 200J impact (mm): measured in accordance with the requirements of European standard EN22568-2019.

[0162] 2. Residual height after 15kN impact (mm): measured in accordance with the requirements of European standard EN22568-2019.

[0163] Table 1: Test parameters of glass fiber composite materials used to manufacture special shoe toe 8# in Examples 1-8, Comparative Example 1 and Control Groups AB

[0164]

[0165] Combining Examples 1-8 and Comparative Example 1 with Table 1, it can be seen that the thermosetting resin composition in the thermosetting resin composition includes an acrylate resin and a hydroxyacrylate resin, and the prepared plastic-steel toe has good compressive strength and impact toughness.

[0166] From Examples 1-2 and 2-3 and Table 1, it can be seen that the plastic-steel toe cap prepared from the thermosetting resin composition composed of propyl methacrylate, polyethylene glycol methyl ether methacrylate, and homemade side chain acrylate-modified hydroxyl-terminated polysiloxane has excellent compressive strength and impact toughness.

[0167] In combination with Examples 1, 5-7 and Example 7 and in combination with Table 1, it can be seen that the compressive strength and impact toughness of the plastic-steel toe cap prepared by the thermosetting resin composition composed of the self-made side chain acrylate-modified hydroxyl-terminated polysiloxane in the present invention are better than the compressive strength and impact toughness of the plastic-steel toe cap prepared by the thermosetting resin composition composed of the commercially available side chain acrylate-modified silicone oil IOTA 170 in Example 8. However, from the perspective of the component composition of the thermosetting resin composition, the compressive strength and impact toughness of the plastic-steel toe cap prepared by adding the thermosetting resin composition composed of the self-made side chain acrylate-modified hydroxyl-terminated polysiloxane or the side chain acrylate-modified silicone oil IOTA 170 are better than those of Examples 3-4, that is, the addition of the self-made side chain acrylate-modified hydroxyl-terminated polysiloxane or the side chain acrylate-modified silicone oil IOTA 170 has an enhancing and toughening effect on the plastic-steel toe cap finally prepared.

[0168] The difference between Example 9 and Example 1 is that the total amount of the thermosetting resin composition added to the glass fiber prepreg remains unchanged, and the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 is adjusted from 85:20:15 in Example 1 to a mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 of 108:6:6.

[0169] The difference between Example 10 and Example 1 is that the total amount of the thermosetting resin composition added to the glass fiber prepreg remains unchanged, and the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 is adjusted from 85:20:15 in Example 1 to a mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 of 96:12:12.

[0170] The difference between Example 11 and Example 1 is that the total amount of the thermosetting resin composition added to the glass fiber prepreg remains unchanged, and the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 is adjusted from 85:20:15 in Example 1 to a mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 of 84:18:18.

[0171] The difference between Example 12 and Example 1 is that the total amount of the thermosetting resin composition added to the glass fiber prepreg remains unchanged, and the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 is adjusted from 85:20:15 in Example 1 to a mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 of 84:24:12.

[0172] The difference between Example 13 and Example 1 is that the total amount of the thermosetting resin composition added to the glass fiber prepreg remains unchanged, and the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 is adjusted from 85:20:15 in Example 1 to a mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 of 78:30:18.

[0173] The difference between the test control group C and Example 1 is that the total amount of the thermosetting resin composition added to the glass fiber prepreg remains unchanged, and the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 is adjusted from 85:20:15 in Example 1 to a mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate MPEG 1000MA, and the side chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1 of 60:30:30.

[0174] The test control group C also falls within the scope of protection of claim 2. In order to allow readers to better understand the effect of the ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate, and side chain acrylate modified hydroxyl-terminated polysiloxane on the impact strength and compressive strength of the final prepared glass fiber safety shoe head, the technical solution of the test control group C is used as a comparative test solution.

[0175] The technical solution of Control Group C also meets the requirements of European Standard EN22568, CSA Standard, and American Standard ASTM: the fiberglass safety toe can provide impact protection during 200J energy testing and pressure resistance protection during 15kN pressure testing. During the test, the minimum spacing inside the toe is ≥21.0mm.

[0176] Table 2: Test parameters of glass fiber composite materials used to manufacture special shoe toes in Example 1, Examples 9-13 and Control Group C

[0177]

[0178] In combination with Example 1, Examples 9-13 and Control Group C and Table 2, it can be seen that the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate, and side chain acrylate-modified hydroxyl-terminated polysiloxane in the thermosetting resin composition affects the mechanical strength and impact strength of the glass fiber safety shoe toe. Preferably, the mass ratio of propyl methacrylate, polyethylene glycol methyl ether methacrylate, and side chain acrylate-modified hydroxyl-terminated polysiloxane is (80-100): (5-30): (5-20), which can ensure the mechanical strength and impact strength of the glass fiber safety shoe toe, and the thermosetting resin composition in Example 1 is the preferred solution.

[0179] The difference between Example 14 and Example 1 is that the cross-linking agent tripropylene glycol diacrylate in the glass fiber prepreg resin is replaced by trimethylolpropane triacrylate (CAS No.: 15625-89-5, premium grade).

[0180] The difference between Example 15 and Example 1 is that the crosslinking agent tripropylene glycol diacrylate in the glass fiber prepreg is replaced by HDI trimer curing agent PB39009 (Guangdong Wengjiang Chemical Reagent Co., Ltd.).

[0181] The difference between Example 16 and Example 1 is that the crosslinking agent tripropylene glycol diacrylate in the glass fiber prepreg resin is replaced by pentaerythritol triacrylate (CAS No.: 3524-68-3, synthetic grade).

[0182] The difference between Example 17 and Example 1 is that 2.4 g of the crosslinking agent, tripropylene glycol diacrylate, in the glass fiber prepreg resin is replaced by 1.3 g of HDI trimer curing agent PB39009 and 1.1 g of trimethylolpropane triacrylate.

[0183] The difference between Comparative Example 2 and Example 1 is that 2.40 g of the cross-linking agent - tripropylene glycol diacrylate is not added to the glass fiber prepreg resin, and 2.40 g of the cross-linking agent - tripropylene glycol diacrylate is replaced by 110 g of propyl methacrylate, and the other components are the same.

[0184] The difference between Comparative Example 3 and Example 1 is that the glass fiber prepreg is made of the following raw materials:

[0185] 637.60g of surface-modified EWR600 fiberglass mesh; 219.18g of propyl methacrylate; 51.57g of polyethylene glycol methyl ether methacrylate (MPEG 1000MA); 38.68g of the side-chain acrylate-modified hydroxyl-terminated polysiloxane synthesized in Preparation Example 1; 33.0g of polycaprolactone NPG200 (low-shrinkage resin); 1.10g of benzoyl peroxide (BPO); 0.88g of tetraisopropyl titanate; 2.40g of tripropylene glycol diacrylate (crosslinking agent); 5.28g of 325-mesh magnesium oxide (thickener); 3.08g of BASF Efka PB 2720 (defoaming agent); and 10.99g of 325-mesh zinc stearate (release agent). The preparation method for Comparative Example 3 was the same as that for Example 1.

[0186] Table 3: Test parameters of glass fiber composite materials used to manufacture special shoe toes in Examples 1, 14-17 and Comparative Examples 2-3

[0187]

[0188] From Examples 1, 14-17 and Comparative Examples 2-3 and Table 3, it can be seen that the appropriate addition of at least one cross-linking agent selected from tripropylene glycol diacrylate, trimethylolpropane triacrylate, HDI trimer curing agent, and pentaerythritol triacrylate in the thermosetting resin composition can improve the compressive strength and impact strength of the plastic-steel safety shoe head. Excessive addition will increase the brittleness of the plastic-steel safety shoe head and affect the impact toughness of the plastic-steel safety shoe head.

[0189] Combining Examples 1, 14-17 and Comparative Example 3 with Table 3, it can be seen that the addition of styrene to the thermosetting resin composition can improve the compressive strength and impact strength of the plastic-steel safety shoe toe.

[0190] The difference between Example 18 and Example 1 is that the finished glass fiber prepreg after aging treatment is stacked into a preformed toe cap by a manual lamination method, and the preformed toe cap is placed in a hot press for hot pressing treatment. The hot pressing molding parameters are as follows: first pressurize to 10 MPa at 0.5 MPa / s, maintain the pressure at a hot pressing temperature of 120°C for 60 seconds, then pressurize to 30 MPa at 2 MPa / s, maintain the pressure at a hot pressing temperature of 160°C for 120 seconds, and then demold, trim and polish to obtain the finished plastic steel toe cap.

[0191] The difference between Example 19 and Example 1 is that the finished glass fiber prepreg after aging treatment is stacked into a preformed toe by a manual lamination method, and the preformed toe is placed in a hot press for hot pressing treatment. The hot pressing molding parameters are as follows: first pressurize to 20 MPa at 0.5 MPa / s, maintain the pressure at a hot pressing temperature of 130°C for 60 seconds, then pressurize to 40 MPa at 2.5 MPa / s, maintain the pressure at a hot pressing temperature of 140°C for 120 seconds, and then demold, trim and polish to obtain the finished plastic steel toe.

[0192] The difference between Example 20 and Example 1 is that the finished glass fiber prepreg after aging treatment is stacked into a preformed toe cap by manual lamination, and the preformed toe cap is placed in a hot press for hot pressing treatment. The hot pressing molding parameters are as follows: first pressurize to 20 MPa at 0.5 MPa / s, maintain the pressure at a hot pressing temperature of 120°C for 60 seconds, then pressurize to 40 MPa at 2.5 MPa / s, maintain the pressure at a hot pressing temperature of 160°C for 120 seconds, and then demold, trim and polish to obtain the finished plastic steel toe cap.

[0193] The difference between Comparative Example 4 and Example 1 is that the finished glass fiber prepreg after aging treatment is stacked into a preformed toe by a manual lamination method, and the preformed toe is placed in a hot press for hot pressing. The hot pressing molding parameters are as follows: pressurizing at 2 MPa / s to 40 MPa, maintaining the pressure at a hot pressing temperature of 160°C for 120 seconds, demolding, trimming, and polishing to obtain the finished plastic steel toe.

[0194] Table 4: Test parameters of glass fiber composite materials used to manufacture special shoe toes in Examples 1, 18-20 and Comparative Example 4

[0195]

[0196] Combining Examples 1, 18-20 and Comparative Example 4 and Table 4, it can be seen that the compressive strength and impact strength of the plastic-steel safety shoe toe manufactured by the asynchronous hot pressing process of the present invention are more excellent.

[0197] To sum up, the plastic-steel special shoe head prepared by the present invention is not only light in texture, meeting the lightweight design requirements of shoe products, but also has excellent compressive strength and impact strength, and has a relatively broad range of applications. It can be applied to safety shoes, labor protection shoes, work shoes, hiking shoes and other shoe products.

Claims

1. A glass fiber composite material for manufacturing special shoe toes, characterized by: The glass fiber composite material used to make special toe caps is made by hot pressing multiple layers of glass fiber prepreg; The glass fiber prepreg is made of the following raw materials in percentage by weight: 60-65 wt% of glass fiber mesh, 24-28 wt% of thermosetting resin composition, 3.0-4.0 wt% of low shrinkage resin, 0.15-2.0 wt% of initiator, 0.20-0.30 wt% of cross-linking agent, 4.0-6.0 wt% of heat-resistant reinforcing monomer, 0.4-0.6 wt% of thickener, 0.25-0.35 wt% of defoaming agent, and 0.8-1.2 wt% of release agent; The glass fiber mesh is prepared by impregnating the surface of the glass fiber mesh with an interface modification resin after surface modification with a silane coupling agent, and then drying and curing the surface of the glass fiber mesh; the silane coupling agent is methacryloxysilane; The interface modification resin is isocyanate-modified hydroxypropyl acrylate resin; The thermosetting resin composition at least includes acrylate resin and hydroxyacrylate resin.

2. The glass fiber composite material for manufacturing special shoe toes according to claim 1, characterized in that: The thermosetting resin composition is composed of propyl methacrylate, polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000, and a hydroxyl-terminated polysiloxane modified with a side chain acrylate with a number average molecular weight of 800-2000. The mass ratio of the propyl methacrylate, the polyethylene glycol methyl ether methacrylate with a number average molecular weight of 400-1000, and the hydroxyl-terminated polysiloxane modified with a side chain acrylate with a number average molecular weight of 800-2000 is (80-100):(5-30):(5-20).

3. The glass fiber composite material for manufacturing special shoe toes according to claim 2, characterized in that: The side chain acrylate modified hydroxyl-terminated polysiloxane includes γ-methacryloxypropylmethyldimethoxysilane, dimethoxymethylpropylsilane, and methylphenyldimethoxysilane; the molar ratio of the γ-methacryloxypropylmethyldimethoxysilane, dimethoxymethylpropylsilane, and methylphenyldimethoxysilane is (1-2):5:(1-2).

4. The glass fiber composite material for manufacturing special shoe toes according to claim 2, characterized in that: The preparation method of the side chain acrylate modified hydroxyl terminated polysiloxane is as follows: 10 parts by weight of γ-methacryloxypropylmethyldimethoxysilane, 0.05-0.20 parts by weight of hydroquinone as a polymerization inhibitor and 20-30 parts by weight of an aqueous solution were mixed evenly, acid was added to adjust the pH to 5-6.5, and alcoholysis reaction was carried out at 40-60° C. for 15-60 minutes to obtain a silanol mixture A; 10 parts by weight of dimethoxymethylpropylsilane and 20-30 parts by weight of an aqueous solution were mixed evenly, acid was added to adjust the pH to 5-6.5, and alcoholysis reaction was carried out at 40-60° C. for 15-60 minutes to obtain a silanol mixture B; 10 parts by weight of methylphenyldimethoxysilane and 20-30 parts by weight of an aqueous solution were mixed evenly, acid was added to adjust the pH to 5-6.5, and alcoholysis reaction was carried out at 40-60° C. for 15-60 minutes to obtain a silanol mixture C; Transfer the silanol mixture B to a three-necked flask, heat it to 35-45°C in a water bath, and simultaneously add silanol mixture A and silanol mixture C dropwise with magnetic stirring at 80-160rpm. The dropping speed of silanol mixture A is 1-5mL / min, and the dropping speed of silanol mixture C is 1-5mL / min. After the addition of silanol mixture A and silanol mixture C is completed, the temperature is maintained at 35-45°C for 60-90min, and then dimethoxydimethylsilane and acid are added to adjust the pH to 5-6 and carry out end-capping reaction for 5-10min. After adding alkali solution to adjust the pH to 7, the mixture is dehydrated in a water separator, and the obtained liquid is subjected to vacuum fractionation to remove the hydrolyzed silane monomer that does not participate in the reaction to obtain side chain acrylate-modified hydroxyl-terminated polysiloxane.

5. The glass fiber composite material for manufacturing special shoe toes according to claim 1, characterized in that: The crosslinking agent is at least one of tripropylene glycol diacrylate, trimethylolpropane triacrylate, HDI trimer curing agent, and pentaerythritol triacrylate.

6. The glass fiber composite material for manufacturing special shoe toes according to claim 1, characterized in that: The low shrinkage resin is polycaprolactone NPG200; the heat-resistant reinforcing monomer is at least one of styrene and stilbene.

7. The glass fiber composite material for manufacturing special shoe toes according to claim 1, characterized in that: The initiator is composed of at least one of benzoyl peroxide BPO, tert-butyl peroxy 2-ethylhexanoate TBPO, and azobisisobutyronitrile AIBN, and at least one of tetraisopropyl titanate and dibutyltin dilaurate.

8. The glass fiber composite material for manufacturing special shoe toes according to claim 1, characterized in that: The thickener is at least one of magnesium oxide, fumed silica, organic bentonite, and montmorillonite; the defoamer is BASFEfka PB 2720 defoamer or BYK 051N defoamer; and the release agent is at least one of stearate, molybdenum disulfide, talc powder, and mica powder.

9. A method for preparing a glass fiber composite material for manufacturing special shoe toes according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Pre-treatment of glass fiber mesh cloth; and simultaneously preparing a thermosetting resin composition; Step 2: uniformly mixing accurately measured amounts of a thermosetting resin composition, a low-shrinkage resin, an initiator, a cross-linking agent, a heat-resistant reinforcing monomer, a thickener, a defoaming agent, and a release agent to obtain a film-forming slurry; uniformly coating the obtained film-forming slurry on the surface of a release paper; and pre-curing the film-forming slurry on the surface of the release paper until the film-forming slurry is in a gel film state, thereby obtaining a thermosetting resin composition film sheet; Step 3: Compounding two sheets of the obtained thermosetting resin composition film on the upper and lower surfaces of the pretreated glass fiber mesh cloth to prepare a glass fiber prepreg cloth, and curing the glass fiber prepreg cloth at 40-50° C. for 36-48 hours; Step 4: Cut the aging treated glass fiber prepreg to obtain a finished glass fiber prepreg in the shape of a forming mold. The finished glass fiber prepreg is stacked into a preformed toe by a manual lamination method. After hot pressing, the preformed toe is demoulded, trimmed, and polished to obtain a finished plastic steel toe. The hot pressing parameters are as follows: first pressurize to 10-20 MPa at 0.5-1 MPa / s, hold the pressure at a hot pressing temperature of 120-130°C for 60±5s, then pressurize to 30-40 MPa at 2-2.5 MPa / s, and hold the pressure at a hot pressing temperature of 140-160°C for 120±5s.

10. The method for preparing a glass fiber composite material for manufacturing special shoe toes according to claim 9, characterized in that: The pretreatment preparation method of the glass fiber mesh in step 1 is as follows: first, spray a methacryloxysilane aqueous solution on the surface of the glass fiber mesh, wherein the concentration of methacryloxysilane in the methacryloxysilane aqueous solution is 4-8wt%, and the spraying amount is 5-40g / m 2 Then put it into the oven for drying at a temperature of 50-70°C and a drying time of 5-10 minutes. Finally, apply isocyanate-modified hydroxypropyl acrylate resin on the surface of the methacryloxysilane-modified glass fiber mesh cloth with a coating amount of 5-50g / m 2 , pre-cured and formed at 60-75℃ for 15-20min, then compounded with release paper and rolled up to obtain the finished glass fiber mesh cloth.

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