Non-woven fabric impregnation sizing material and preparation method thereof

Abstract

The invention relates to a non-woven fabric impregnation sizing material and a preparation method thereof, and relates to the field of non-woven fabric production, and the non-woven fabric impregnation sizing material comprises the following raw materials by weight: 50-70 parts of a modified vinyl acetate-ethylene copolymer emulsion; 1-3 parts of sodium tripolyphosphate; 5-9 parts of a filler; 0.5-1 part of a dispersant; 0.5 to 1 part of a defoaming agent; 35 to 45 parts of water; the modified vinyl acetate-ethylene copolymer emulsion comprises the following raw materials: 32-37 parts of vinyl acetate; 10 to 14 parts of ethylene; 4-8 parts of an organosilicon monomer; 0.15 to 0.4 part of an oxidizing agent; 0.1-0.3 part of a reducing agent; 0.3 to 0.5 part of an emulsifier; 1.7 to 2.8 parts of polyvinyl alcohol; 0.04 to 0.08 part of a pH regulator; 42 to 48 parts of deionized water; 0.2 to 0.5 part of an initiator; and 7 to 12 parts of N-hydroxymethyl acrylamide. The method has the effect of improving the water resistance, heat resistance and adhesive force of the non-woven fabric impregnation sizing material.

Description

Technical Field

[0001] The invention relates to the field of non-woven fabric production, in particular to a non-woven fabric dipping adhesive and a preparation method thereof. Background Art

[0002] In the production of non-woven fabrics, the dipping and drying method is often used. The adhesive is placed in a dipping tank for heating and heat preservation, and the non-woven fabric is unrolled and immersed in the adhesive in the dipping tank. The non-woven fabric after dipping is immersed in a large room-type drying equipment for straightening and drying, and then rolled up to obtain a semi-finished leather fabric. When the non-woven fabric is immersed in the adhesive, a layer of adhesive will be covered on the surface, thereby enhancing the strength, wear resistance, waterproofness or other specific properties of the non-woven fabric.

[0003] Non-woven fabric dipping rubber is specially used for non-woven fabric dipping treatment. The rubber is composed of emulsion and emulsion compounding agent. The emulsion can be rubber emulsion, polyacrylate emulsion, vinyl acetate-ethylene copolymer emulsion, etc. Vinyl acetate-ethylene copolymer emulsion, namely VAE emulsion, is made by copolymerization of vinyl acetate and ethylene under high pressure conditions. It has the advantages of environmental protection, storage stability and fast curing speed. The non-woven fabric produced has excellent flexibility and durability.

[0004] The existing vinyl acetate-ethylene copolymer emulsion has the defects of poor water resistance, poor heat resistance and insufficient adhesion, which affects the use of the prepared non-woven fabric. Summary of the invention

[0005] In order to improve the water resistance, heat resistance and adhesion of a non-woven fabric dipping rubber material, the present application provides a non-woven fabric dipping rubber material and a preparation method thereof.

[0006] The present application provides a non-woven fabric dipping adhesive and a preparation method thereof using the following technical solutions: In a first aspect, the present application provides a non-woven fabric dipping adhesive material, comprising the following raw materials in parts by weight: 50-70 parts of modified vinyl acetate-ethylene copolymer emulsion; 1-3 parts of sodium tripolyphosphate; 5-9 parts of filler; Dispersant 0.5-1 part; Defoaming agent 0.5-1 part; 35-45 parts water; The modified vinyl acetate-ethylene copolymer emulsion is prepared from the following raw materials in parts by weight: Monomer: 32-37 parts of vinyl acetate; 10-14 parts of ethylene; 4-8 parts of silicone monomer; Initiation system: 0.15-0.4 parts of oxidant; 0.1-0.3 parts of reducing agent; Emulsification system: emulsifier 0.3-0.5 parts; polyvinyl alcohol 1.7-2.8 parts; pH regulator 0.04-0.08 parts; 42-48 parts of deionized water; Initiator 0.2-0.5 parts; 7-12 parts of N-hydroxymethyl acrylamide.

[0007] By adopting the above technical solution, the vinyl acetate-ethylene copolymer emulsion is used as the matrix, and the silicone monomer and N-hydroxymethyl acrylamide are used for modification. The silicone monomer has the properties of water resistance, weather resistance and high temperature resistance, thereby improving the performance of the vinyl acetate-ethylene copolymer emulsion, and the heat resistance of the emulsion is enhanced by cross-linking of the monomers. On the basis of the vinyl acetate-ethylene copolymer emulsion, N-hydroxymethyl acrylamide is polymerized, so that N-hydroxymethyl acrylamide is adsorbed and wrapped on the surface of the particles, and the cross-linking of the emulsion system is enhanced, so that the modified vinyl acetate-ethylene copolymer emulsion can obtain a self-cross-linking function, without the need to add an additional external cross-linking agent, and the water resistance, stability and adhesion of the modified emulsion are improved.

[0008] Modified vinyl acetate-ethylene copolymer emulsion is selected as the film-forming material, which cures quickly. The addition of sodium tripolyphosphate makes it easier for the rubber to penetrate and adhere to the fiber surface of the non-woven fabric. Combined with the dispersant and defoamer, the adhesion between the impregnated rubber and the non-woven fabric is enhanced.

[0009] Optionally, the organic silicon monomer is selected from one or more of pentamethylcyclopentadienylsilane, (tert-butylcyclopentadienyl)trimethylsilane, and di(cyclopentadienyl)dimethylsilane.

[0010] By adopting the above technical scheme, a silicone monomer with a longer molecular chain and containing a cyclopentadiene group is selected, which has a large steric hindrance and can hinder the hydrolysis of silane in water. The cross-linking effect between the silicone monomer and vinyl acetate and ethylene is enhanced, thereby making the emulsion system more stable and having better performance.

[0011] Optionally, the polyvinyl alcohol is acetylated polyvinyl alcohol, and the acetylated polyvinyl alcohol is prepared from the following raw materials in parts by weight: Polyvinyl alcohol 5-7 parts; Ethyl acetoacetate 6.5-9 parts; 16-20 parts of dimethyl sulfoxide.

[0012] By adopting the above technical solution, acetylated polyvinyl alcohol is selected as the protective colloid, which reduces the formation of hydrogen bonds with water molecules, forms a tight cross-linking network with the emulsion system, improves the water resistance and heat resistance of the original polyvinyl alcohol, and makes the performance of the dipping rubber better.

[0013] Optionally, the filler is one or more of silicon dioxide, hollow microspheres, bentonite, light calcium carbonate and talc.

[0014] By adopting the above technical solution, the latex is reinforced by fillers, thereby improving the wear resistance and mechanical properties of the impregnated rubber material.

[0015] Optionally, the filler is a mixture of bentonite and light calcium carbonate, and the weight ratio of the bentonite to the light calcium carbonate is: (0.9-1.2): (0.6-0.8).

[0016] By adopting the above technical solution, bentonite and light calcium carbonate are selected for compounding, which has good dispersibility in the emulsion system and can better play the role of improving heat resistance and wear resistance.

[0017] Optionally, the emulsifier is selected from two or more of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric carbon tridecanedeloxane, sodium lauryl sulfate, sodium stearate, and sodium α-olefin sulfonate.

[0018] By adopting the technical scheme and selecting a composite emulsifier, the emulsification effect is improved, so that the dispersion liquid and solution of the dipping process have good stability.

[0019] Optionally, the oxidant is selected from one or more of hydrogen peroxide, sodium persulfate and potassium persulfate; the reducing agent is selected from one or more of ascorbate, tartrate and vitamin C.

[0020] Optionally, the initiator is a mixture of tert-butyl hydroperoxide and zinc formaldehyde sulfoxylate, wherein the tert-butyl hydroperoxide is 0.15-0.3 parts; the zinc formaldehyde sulfoxylate is 0.05-0.2 parts.

[0021] By adopting the above technical solution and selecting tert-butyl hydroperoxide as the lipophilic initiator, the combination of N-hydroxymethyl acrylamide and the emulsion particles can be made tighter, thereby improving the adhesion of the dipping rubber material.

[0022] In a second aspect, the present application discloses a method for preparing a non-woven fabric dipping adhesive, characterized in that it comprises the following steps: Adding an oxidant and deionized water into an oxidant tank to prepare an oxidant solution; adding a reductant and deionized water into a reductant tank to prepare a reductant solution; adding polyvinyl alcohol and deionized water into an emulsifier tank, heating until the polyvinyl alcohol is completely dissolved, and then adding an emulsifier to obtain an emulsifier solution; Add emulsifier solution and deionized water into the polymerization reactor, stir evenly, then add 45-60% of vinyl acetate, increase the temperature and introduce ethylene to increase the pressure; when the temperature rises to 50-60°C and the pressure reaches 2-3MPa, start to drip the oxidant solution and the reducing agent solution at a rate of 3.5-5kg / min, and when the temperature rises to 55-65°C, drip the oxidant solution and the reducing agent solution at a rate of 1-1.5kg / min; When the temperature in the autoclave reaches 75-80°C and the ethylene pressure rises to 4.0-5.0MPa, the reaction temperature is controlled to drip the remaining vinyl acetate and silicone monomer mixture within 60-100min. After the mixture is added, the ethylene is turned off, and the remaining oxidant solution and reductant solution are dripped at a speed of 2-4kg / min, then the pressure is reduced to normal and a pH adjuster is added; Keeping the temperature at 75-80°C, adding the mixed solution of initiator and N-hydroxymethyl acrylamide into the polymerization reactor, adding dropwise within 60-80 minutes, raising the reaction temperature to 80-84°C, and keeping the temperature for 40-50 minutes. After the insulation is completed, cooling to below 35°C, adding a pH adjuster, and then filtering and discharging to obtain a modified vinyl acetate-ethylene copolymer emulsion; The water, dispersant and defoamer are mixed, fillers are added under stirring, and then modified vinyl acetate-ethylene copolymer emulsion and sodium tripolyphosphate are added, and the mixture is evenly mixed to obtain a non-woven fabric dipping rubber material.

[0023] By adopting the above technical scheme, the remaining vinyl acetate and silicone monomers are added in the later stage of the preparation of the vinyl acetate-ethylene copolymer emulsion, the possibility of hydrolysis of the silicone monomer is reduced, and the silicone monomer, vinyl acetate and ethylene are promoted to cross-link into a network system. After the emulsion is prepared, N-hydroxymethyl acrylamide is polymerized, so that N-hydroxymethyl acrylamide is tightly wrapped on the emulsion particles, thereby improving heat resistance, water resistance and adhesion.

[0024] Optionally, when the polyvinyl alcohol is acetoacetylated polyvinyl alcohol, the acetoacetylated polyvinyl alcohol is prepared by the following steps: Add polyvinyl alcohol to dimethyl sulfoxide, stir and heat to 90-95°C until the polyvinyl alcohol is completely dissolved to obtain a dissolved solution, add the dissolved solution to a reactor, heat to 100-110°C, stir and introduce nitrogen, add ethyl acetoacetate dropwise to react, and after the reaction is completed, add the solution to ethanol for precipitation, filter and dry to obtain acetylated polyvinyl alcohol.

[0025] By adopting the above technical scheme and selecting dimethyl sulfoxide as a solvent, the contact and ester exchange reaction of polyvinyl alcohol and ethyl acetoacetate are promoted, thereby improving the modification efficiency.

[0026] In summary, this application has the following beneficial effects: Taking vinyl acetate-ethylene copolymer emulsion as the matrix, silicone monomer and N-hydroxymethyl acrylamide are used for modification. The silicone monomer has water resistance, weather resistance and high temperature resistance, thereby improving the performance of vinyl acetate-ethylene copolymer emulsion. Through the cross-linking of the monomer, the heat resistance of the emulsion is enhanced. On the basis of vinyl acetate-ethylene copolymer emulsion, N-hydroxymethyl acrylamide is polymerized, so that N-hydroxymethyl acrylamide is adsorbed and wrapped on the surface of particles, and the cross-linking of the emulsion system is enhanced, so that the modified vinyl acetate-ethylene copolymer emulsion can obtain self-cross-linking function, without the need to add external cross-linking agent, and the water resistance, stability and adhesion of the modified emulsion are improved.

[0027] Modified vinyl acetate-ethylene copolymer emulsion is selected as the film-forming material, which cures quickly. The addition of sodium tripolyphosphate makes it easier for the rubber to penetrate and adhere to the fiber surface of the non-woven fabric. Combined with the dispersant and defoamer, the adhesion between the impregnated rubber and the non-woven fabric is enhanced. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with Examples 1-8 and Comparative Examples 1-3.

[0029] Preparation Example Preparation Example 1 A preparation method of acetoacetylated polyvinyl alcohol Acetoacetylated polyvinyl alcohol comprises the following raw materials: Polyvinyl alcohol 5kg; Ethyl acetoacetate 6.5 kg; Dimethyl sulfoxide 16 kg; In this preparation example, the preparation method of acetoacetylated polyvinyl alcohol comprises the following steps: Add polyvinyl alcohol to dimethyl sulfoxide, stir and heat to 90°C until the polyvinyl alcohol is completely dissolved to obtain a dissolved solution, add the dissolved solution to a reactor, heat to 100°C, stir and introduce nitrogen, add ethyl acetoacetate dropwise to react, and after the reaction is completed, add the solution to ethanol for precipitation, filter and dry to obtain acetylated polyvinyl alcohol.

[0030] Preparation Example 2 Preparation of acetoacetylated polyvinyl alcohol Acetoacetylated polyvinyl alcohol, comprising the following raw materials: Polyvinyl alcohol 7kg; Ethyl acetoacetate 9kg; Dimethyl sulfoxide 20 kg; In this preparation example, the preparation method of acetoacetylated polyvinyl alcohol comprises the following steps: Add polyvinyl alcohol to dimethyl sulfoxide, stir and heat to 95°C until the polyvinyl alcohol is completely dissolved to obtain a dissolved solution, add the dissolved solution to a reactor, heat to 110°C, stir and introduce nitrogen, add ethyl acetoacetate dropwise to react, and after the reaction is completed, add the solution to ethanol for precipitation, filter and dry to obtain acetylated polyvinyl alcohol. Example

[0031] Example 1 Preparation of non-woven fabric dipping rubber material Non-woven fabric dipping rubber, including the following raw materials: Modified vinyl acetate-ethylene copolymer emulsion 50kg; Sodium tripolyphosphate 1kg; 5 kg of filler; in this embodiment, the filler is silicon dioxide with an average particle size of 20 μm; 0.5 kg of dispersant; in this embodiment, the dispersant is a water-based dispersant with a brand number of 4061 from BASF of Germany; 0.5 kg of defoaming agent; in this embodiment, the defoaming agent is an acrylate defoaming agent of BYK-0359 produced by German BYK company; 35kg water; The modified vinyl acetate-ethylene copolymer emulsion includes the following raw materials: Monomer: 32 kg of vinyl acetate; 10 kg of ethylene; 4 kg of organosilicon monomer; in this embodiment, pentamethylcyclopentadienylsilane is used as the organosilicon monomer; Initiation system: 0.15 kg of oxidant; in this embodiment, hydrogen peroxide is used as the oxidant; 0.1 kg of reducing agent; in this embodiment, ascorbate is used as the reducing agent; Emulsifying system: 0.3 kg of emulsifier; in this embodiment, the emulsifier is selected from 0.2 kg of nonylphenol polyoxyethylene ether and 0.1 kg of sodium lauryl sulfate; Polyvinyl alcohol 1.7 kg; 0.04 kg of pH regulator; in this embodiment, the pH regulator is ammonia water; Deionized water 42kg; Initiator 0.2 kg; in this embodiment, the initiator is selected from 0.15 kg tert-butyl hydroperoxide and 0.05 kg zinc formaldehyde sulfoxylate; N-hydroxymethyl acrylamide 7 kg.

[0032] In this embodiment, the preparation method of the non-woven fabric impregnated adhesive comprises the following steps: Add an oxidant and 2kg of deionized water into an oxidant tank to prepare an oxidant solution; add a reductant and 1kg of deionized water into a reductant tank to prepare a reductant solution; add polyvinyl alcohol and 8kg of deionized water into an emulsifier tank, heat it to 85°C to completely dissolve the polyvinyl alcohol, cool it to 25°C and then add an emulsifier to obtain an emulsifier solution; Add emulsifier solution and 31kg deionized water into the polymerization reactor, stir evenly, then add 14.4kg vinyl acetate, heat up and introduce ethylene to increase the pressure; when the temperature reaches 50°C and the pressure reaches 2MPa, start dripping oxidant solution and reducing agent solution at a rate of 3.5kg / min, and when the temperature reaches 55°C, drip oxidant solution and reducing agent solution at a rate of 1kg / min; when the temperature in the reactor reaches 75°C and the ethylene pressure rises to 4.0MPa, control the reaction temperature and drip the remaining vinyl acetate and silicone monomer mixture within 60min, turn off ethylene after the mixture is added, control the remaining oxidant solution and reducing agent solution to drip at a rate of 2kg / min, then drain to normal pressure and add pH adjuster until the pH is between 7-8; The temperature is maintained at 75° C., and a mixed solution of an initiator and N-hydroxymethyl acrylamide is added to a polymerization reaction kettle, and the addition is completed within 60 minutes. The reaction temperature is raised to 80° C., and the reaction is kept warm for 40 minutes. After the insulation is completed, the temperature is lowered to below 35° C., a pH regulator is added until the pH is between 6 and 7, and then filtered and discharged to obtain a modified vinyl acetate-ethylene copolymer emulsion; water, a dispersant, and a defoaming agent are mixed, and a filler is added under stirring, and then the modified vinyl acetate-ethylene copolymer emulsion and sodium tripolyphosphate are added, and mixed evenly to obtain a non-woven fabric dipping rubber material.

[0033] Example 2 Preparation of non-woven fabric dipping rubber material Non-woven fabric dipping rubber, including the following raw materials: Modified vinyl acetate-ethylene copolymer emulsion 70kg; Sodium tripolyphosphate 3kg; 9 kg of filler; in this embodiment, the filler is light calcium carbonate with an average particle size of 20 μm; Dispersant 1g; In this embodiment, the dispersant is an aqueous dispersant with a brand number of 4620 from BASF of Germany; 1 kg of defoaming agent; in this embodiment, the defoaming agent is a mineral oil defoaming agent of BYK-033 produced by German BYK Company; 45 kg of water; The modified vinyl acetate-ethylene copolymer emulsion includes the following raw materials: Monomer: 37 kg of vinyl acetate; 14 kg of ethylene; 8 kg of organosilicon monomer; in this embodiment, the organosilicon monomer is (tert-butylcyclopentadienyl)trimethylsilane; Initiation system: 0.4 kg oxidant; in this embodiment, the oxidant is sodium persulfate; 0.3 kg of reducing agent; in this embodiment, tartrate is used as the reducing agent; Emulsifying system: 0.5 kg of emulsifier; in this embodiment, the emulsifier is 0.35 kg of fatty alcohol polyoxyethylene ether and 0.15 kg of sodium α-olefin sulfonate; Polyvinyl alcohol 2.8 kg; 0.08 kg of pH regulator; in this embodiment, the pH regulator is ammonia water; Deionized water 48kg; Initiator 0.5 kg; In this embodiment, the initiator is selected from 0.3 kg tert-butyl hydroperoxide and 0.2 kg zinc formaldehyde sulfoxylate; 12kg of N-hydroxymethyl acrylamide.

[0034] In this embodiment, the preparation method of the non-woven fabric impregnated adhesive comprises the following steps: Add an oxidant and 3.5 kg of deionized water into an oxidant tank to prepare an oxidant solution; add a reductant and 2.5 kg of deionized water into a reductant tank to prepare a reductant solution; add polyvinyl alcohol and 12 kg of deionized water into an emulsifier tank, heat it to 85° C. to completely dissolve the polyvinyl alcohol, cool it to 25° C., and then add an emulsifier to obtain an emulsifier solution; Add emulsifier solution and 30kg deionized water into the polymerization reactor, stir evenly, then add 22.2kg vinyl acetate, heat up and introduce ethylene to increase the pressure; when the temperature reaches 60°C and the pressure reaches 3MPa, start dripping oxidant solution and reducing agent solution at a rate of 5kg / min, and when the temperature reaches 65°C, drip oxidant solution and reducing agent solution at a rate of 1.5kg / min; when the temperature in the reactor reaches 80°C and the ethylene pressure rises to 5.0MPa, control the reaction temperature and drip the remaining vinyl acetate and silicone monomer mixture within 100min, turn off ethylene after the mixture is added, control the remaining oxidant solution and reducing agent solution to drip at a rate of 4kg / min, then drain to normal pressure and add pH adjuster until the pH is between 7-8; The temperature is maintained at 80° C., and a mixed solution of an initiator and N-hydroxymethyl acrylamide is added into a polymerization reaction kettle, and the addition is completed within 80 minutes. The reaction temperature is raised to 84° C., and the reaction is kept warm for 50 minutes. After the insulation is completed, the temperature is lowered to below 35° C., a pH regulator is added until the pH is between 6 and 7, and then filtered and discharged to obtain a modified vinyl acetate-ethylene copolymer emulsion; water, a dispersant, and a defoaming agent are mixed, and a filler is added under stirring, and then the modified vinyl acetate-ethylene copolymer emulsion and sodium tripolyphosphate are added, and mixed evenly to obtain a non-woven fabric dipping rubber material.

[0035] Example 3 Preparation of non-woven fabric dipping rubber material Non-woven fabric dipping rubber, including the following raw materials: Modified vinyl acetate-ethylene copolymer emulsion 60kg; Sodium tripolyphosphate 2kg; 7kg of filler; in this embodiment, the filler is talcum powder with an average particle size of 20 μm; Dispersant 0.8g; In this embodiment, the dispersant is an aqueous dispersant with a brand number of 4620 from BASF of Germany; 0.7 kg of defoaming agent; in this embodiment, the defoaming agent is an acrylate defoaming agent of BYK-0359 produced by German BYK company; Water 40kg; The modified vinyl acetate-ethylene copolymer emulsion includes the following raw materials: Monomer: 34 kg of vinyl acetate; 12 kg of ethylene; 6 kg of organosilicon monomer; in this embodiment, the organosilicon monomer is di(cyclopentadiene)dimethylsilane; Initiation system: 0.25 kg of oxidant; in this embodiment, potassium persulfate is used as the oxidant; 0.2 kg of reducing agent; in this embodiment, the reducing agent is vitamin C; Emulsifying system: 0.4 kg of emulsifier; in this embodiment, the emulsifier is 0.3 kg of isomeric carbon tridecaned polyoxyethylene ether and 0.1 kg of sodium stearate; Polyvinyl alcohol 2.3 kg; 0.06 kg of pH regulator; in this embodiment, sodium hydroxide is used as the pH regulator; Deionized water 45kg; Initiator 0.3kg; In this embodiment, the initiator is selected from 0.2kg tert-butyl hydroperoxide and 0.1kg zinc formaldehyde sulfoxylate; N-hydroxymethyl acrylamide 10kg.

[0036] In this embodiment, the preparation method of the non-woven fabric impregnated adhesive comprises the following steps: Add an oxidant and 2.5 kg of deionized water into an oxidant tank to prepare an oxidant solution; add a reductant and 2 kg of deionized water into a reductant tank to prepare a reductant solution; add polyvinyl alcohol and 10 kg of deionized water into an emulsifier tank, heat it to 85° C. to completely dissolve the polyvinyl alcohol, cool it to 25° C., and then add an emulsifier to obtain an emulsifier solution; Add emulsifier solution and 30.5 kg of deionized water into the polymerization reactor, stir evenly, then add 17 kg of vinyl acetate, increase the temperature and introduce ethylene to increase the pressure; when the temperature reaches 55°C and the pressure reaches 2.5 MPa, start to drip the oxidant solution and the reducing agent solution at a rate of 4 kg / min, and when the temperature reaches 60°C, drip the oxidant solution and the reducing agent solution at a rate of 1.5 kg / min; When the temperature in the autoclave reaches 78°C and the ethylene pressure rises to 4.5MPa, the reaction temperature is controlled to drip the remaining vinyl acetate and silicone monomer mixture within 80 minutes. After the mixture is added, the ethylene is turned off, and the remaining oxidant solution and reductant solution are dripped at a rate of 3kg / min. Then, the pressure is reduced to normal and a pH adjuster is added until the pH is between 7-8. The temperature is maintained at 78° C., and a mixed solution of an initiator and N-hydroxymethyl acrylamide is added to the polymerization reactor, and the addition is completed within 70 minutes. The reaction temperature is raised to 82° C., and the reaction is kept warm for 45 minutes. After the insulation is completed, the temperature is lowered to below 35° C., a pH regulator is added until the pH is between 6 and 7, and then filtered and discharged to obtain a modified vinyl acetate-ethylene copolymer emulsion; water, a dispersant, and a defoaming agent are mixed, and a filler is added under stirring, and then the modified vinyl acetate-ethylene copolymer emulsion and sodium tripolyphosphate are added, and mixed evenly to obtain a non-woven fabric dipping rubber material.

[0037] Example 4 The difference between the present application and Example 1 is that the fillers are different.

[0038] In this embodiment, the filler is a mixture of bentonite and light calcium carbonate, specifically 2.7 kg of bentonite and 2.3 kg of light calcium carbonate.

[0039] Example 5 The difference between the present application and Example 1 is that the fillers are different.

[0040] In this embodiment, the filler is a mixture of bentonite and light calcium carbonate, specifically 3.3 kg of bentonite and 1.7 kg of light calcium carbonate.

[0041] Example 6 The difference between the present application and Example 1 is that the polyvinyl alcohol is different.

[0042] In this embodiment, the polyvinyl alcohol is the acetylated polyvinyl alcohol prepared in Preparation Example 1.

[0043] Example 7 The difference between the present application and Example 1 is that the polyvinyl alcohol is different.

[0044] In this embodiment, the polyvinyl alcohol is the acetylated polyvinyl alcohol prepared in Preparation Example 2.

[0045] Example 8 The present application is different from Example 1 in that the filler and the polyvinyl alcohol are different.

[0046] In this embodiment, the filler is a mixture of bentonite and light calcium carbonate, specifically 3.3 kg of bentonite and 1.7 kg of light calcium carbonate; the polyvinyl alcohol is the acetylated polyvinyl alcohol prepared in Preparation Example 1.

[0047] Comparative Example Comparative Example 1 The difference between this comparative example and Example 1 is that no sodium tripolyphosphate is added to the raw materials of the dipping rubber material.

[0048] Comparative Example 2 The difference between this comparative example and Example 1 is that no organosilicon monomer is added to the raw materials of the modified vinyl acetate-ethylene copolymer emulsion.

[0049] Comparative Example 3 The difference between this comparative example and Example 1 is that no initiator and N-hydroxymethyl acrylamide are added to the raw materials of the modified vinyl acetate-ethylene copolymer emulsion.

[0050] Performance Testing The non-woven fabrics prepared in Examples 1-8 and Comparative Examples 1-3 were placed in a dipping tank, the non-woven fabrics were unwound and immersed in the dipping tank, so that the surface of the non-woven fabrics was covered with a layer of adhesive, and the performance of the non-woven fabrics and the adhesive layer was tested.

[0051] (1) Water absorption rate: The nonwoven fabrics prepared in Examples 1-8 and Comparative Examples 1-3 were dried at 120°C to a size of 20 mm×20 mm×1 mm, placed in water at 25°C, and taken out after 24 hours to dry the surface water with absorbent paper, and the water absorption rate was measured. The results of water absorption rate are recorded in Table 1.

[0052] The lower the water absorption rate, the better the water resistance of the adhesive layer.

[0053] (2) Tensile strength and elongation at break: The nonwoven fabrics prepared in Examples 1-8 and Comparative Examples 1-3 were dried at 120° C. and cut into strips 35 cm long and 5 cm wide in the transverse direction. The tensile strength and elongation at break were measured using an electronic textile strength tester. The results are recorded in Table 1.

[0054] The greater the tensile strength, the more complete the cross-linking of the adhesive layer is and the stronger the adhesion is; the longer the elongation at break, the better the flexibility of the non-woven fabric.

[0055] (3) Storage stability Take the dipped rubber and place it in a 60℃ oven for 7 days. Observe the condition of the rubber. If the viscosity suddenly increases or there is precipitation, it indicates that the storage stability is poor and the test fails. Record the results in Table 1.

[0056] (4) Heat resistance Place the dipped rubber in an oven at 150°C for 4 hours, and observe whether the rubber thickens, solidifies or decomposes. Record the results in Table 1.

[0057] Table 1 Performance Analysis: Referring to the data in Table 1, it can be seen that the non-woven fabric dipping rubber prepared in the present application is a mixture of modified vinyl acetate-ethylene copolymer, sodium tripolyphosphate and filler. The water resistance, high temperature resistance and cross-linking strength of the modified vinyl acetate-ethylene copolymer are improved, so that the obtained non-woven fabric has good water resistance, tensile properties and high temperature resistance.

[0058] Compared with Examples 1-3, Examples 4-5 use a mixture of bentonite and the light calcium carbonate in the selection of fillers, so that the compatibility of the system is better, and the water resistance and mechanical properties of the non-woven fabric are further enhanced.

[0059] Compared with Examples 1-3, Examples 6-7 use acetylated polyvinyl alcohol instead of polyvinyl alcohol in the selection of protective colloid, which improves the crosslinking of polyvinyl alcohol and the emulsion system, and at the same time improves the water resistance and heat resistance, so that the performance of the dipping rubber is improved.

[0060] In Comparative Examples 1-3, no silicone monomer, sodium tripolyphosphate, initiator, or N-hydroxymethyl acrylamide was added to the raw materials of the dipping rubber. According to the comparison of performance data, it is shown that the selection and proportion of the raw materials of the dipping rubber according to the method of the present application can significantly improve the water resistance, high temperature resistance, storage stability, and tensile properties of the prepared non-woven fabric.

[0061] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A non-woven fabric dipping rubber material, characterized in that: The invention comprises the following raw materials in parts by weight: 50-70 parts of modified vinyl acetate-ethylene copolymer emulsion; 1-3 parts of sodium tripolyphosphate; 5-9 parts of filler; Dispersant 0.5-1 part; Defoaming agent 0.5-1 part; 35-45 parts water; The modified vinyl acetate-ethylene copolymer emulsion is prepared from the following raw materials in parts by weight: Monomer: 32-37 parts of vinyl acetate; 10-14 parts of ethylene; 4-8 parts of silicone monomer; Initiation system: 0.15-0.4 parts of oxidant; 0.1-0.3 parts of reducing agent; Emulsification system: emulsifier 0.3-0.5 parts; polyvinyl alcohol 1.7-2.8 parts; pH regulator 0.04-0.08 parts; 42-48 parts of deionized water; Initiator 0.2-0.5 parts; 7-12 parts of N-hydroxymethyl acrylamide.

2. The non-woven fabric dipping adhesive according to claim 1, characterized in that: The organic silicon monomer is selected from one or more of pentamethylcyclopentadienylsilane, (tert-butylcyclopentadienyl)trimethylsilane, and di(cyclopentadienyl)dimethylsilane.

3. The non-woven fabric dipping rubber material according to claim 1, characterized in that: The polyvinyl alcohol is acetylated polyvinyl alcohol, and the acetylated polyvinyl alcohol is prepared from the following raw materials in parts by weight: Polyvinyl alcohol 5-7 parts; 6.5-9 parts of ethyl acetoacetate; 16-20 parts of dimethyl sulfoxide.

4. The non-woven fabric dipping rubber material according to claim 1, characterized in that: The filler is selected from one or more of silicon dioxide, hollow microspheres, bentonite, light calcium carbonate and talcum powder.

5. The non-woven fabric dipping adhesive material according to claim 4, characterized in that: The filler is a mixture of bentonite and light calcium carbonate, and the weight ratio of the bentonite to the light calcium carbonate is: (0.9-1.2): (0.6-0.8).

6. The non-woven fabric dipping rubber material according to claim 1, characterized in that: The emulsifier is selected from two or more of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric carbon tridecaned polyoxyethylene ether, sodium lauryl sulfate, sodium stearate, and sodium α-olefin sulfonate.

7. The non-woven fabric dipping adhesive according to claim 1, characterized in that: The oxidant is selected from one or more of hydrogen peroxide, sodium persulfate and potassium persulfate; the reducing agent is selected from one or more of ascorbate, tartrate and vitamin C.

8. The non-woven fabric dipping adhesive according to claim 1, characterized in that: The initiator is a mixture of tert-butyl hydroperoxide and zinc formaldehyde sulfoxylate, wherein the tert-butyl hydroperoxide is 0.15-0.3 parts and the zinc formaldehyde sulfoxylate is 0.05-0.2 parts.

9. The method for preparing a non-woven fabric dipping rubber material according to any one of claims 1 to 8, characterized in that: The steps include: Adding an oxidant and deionized water into an oxidant tank to prepare an oxidant solution; adding a reductant and deionized water into a reductant tank to prepare a reductant solution; adding polyvinyl alcohol and deionized water into an emulsifier tank, heating until the polyvinyl alcohol is completely dissolved, and then adding an emulsifier to obtain an emulsifier solution; Add emulsifier solution and deionized water into the polymerization reactor, stir evenly, then add 45-60% of vinyl acetate, increase the temperature and introduce ethylene to increase the pressure; when the temperature rises to 50-60°C and the pressure reaches 2-3MPa, start to drip the oxidant solution and the reducing agent solution at a rate of 3.5-5kg / min, and when the temperature rises to 55-65°C, drip the oxidant solution and the reducing agent solution at a rate of 1-1.5kg / min; When the temperature in the autoclave reaches 75-80°C and the ethylene pressure rises to 4.0-5.0MPa, the reaction temperature is controlled to drip the remaining vinyl acetate and silicone monomer mixture within 60-100min. After the mixture is added, the ethylene is turned off, and the remaining oxidant solution and reductant solution are dripped at a speed of 2-4kg / min, then the pressure is reduced to normal and a pH adjuster is added; Keeping the temperature at 75-80°C, adding the mixed solution of initiator and N-hydroxymethyl acrylamide into the polymerization reactor, adding dropwise within 60-80 minutes, raising the reaction temperature to 80-84°C, and keeping the temperature for 40-50 minutes. After the insulation is completed, cooling to below 35°C, adding a pH adjuster, and then filtering and discharging to obtain a modified vinyl acetate-ethylene copolymer emulsion; The water, dispersant and defoamer are mixed, fillers are added under stirring, and then modified vinyl acetate-ethylene copolymer emulsion and sodium tripolyphosphate are added, and the mixture is evenly mixed to obtain a non-woven fabric dipping rubber material.

10. The method for preparing a non-woven fabric dipping rubber material according to claim 9, characterized in that: When the polyvinyl alcohol is acetoacetylated polyvinyl alcohol, the acetoacetylated polyvinyl alcohol is prepared by the following steps: Add polyvinyl alcohol to dimethyl sulfoxide, stir and heat to 90-95°C until the polyvinyl alcohol is completely dissolved to obtain a dissolved solution, add the dissolved solution to a reactor, heat to 100-110°C, stir and introduce nitrogen, add ethyl acetoacetate dropwise to react, and after the reaction is completed, add the solution to ethanol for precipitation, filter and dry to obtain acetylated polyvinyl alcohol.

Images