A nylon moisturizing film and its preparation method

Abstract

This application relates to the field of protective films. More specifically, it relates to a nylon moisture retention film and a preparation method thereof. It is composed of the following raw materials in percentage by weight: 40-63% of nylon, 10-30% of PP, 10-20% of PHA, 0.5-2% of cooling masterbatch, 3-8% of maleic anhydride grafted product, 0.3-1% of polyisobutylene succinimide, 1-8% of nano-inorganic filler, and the balance is processing aids. In this application, the combination of nylon, PP, and PHA can integrate their properties, resulting in better mechanical properties and barrier properties against water vapor and the like. In addition, through the interaction of the maleic anhydride grafted product, polyisobutylene succinimide, and cooling masterbatch, the mixing uniformity between nylon, PP, and PHA is further improved. Moreover, the maleic anhydride grafted product and polyisobutylene succinimide promote the compatibility of the nano-inorganic filler in the raw material system, further improving the moisture retention performance and mechanical properties.

Description

Technical Field

[0001] This application relates to the field of protective films, and more specifically, it relates to a nylon moisture-preserving film and a preparation method thereof. Background Art

[0002] As an important part of the building materials technology field, nylon moisture-preserving films are increasingly widely used in the construction industry. This film is mainly used to improve the moisture-preserving effect of cast concrete, thereby improving the heat-insulating effect, reducing the manual maintenance workload, and effectively preventing concrete cracking. The use of nylon moisture-preserving films can significantly improve the construction quality and efficiency of concrete, reduce construction costs, and improve the safety and reliability of the construction process.

[0003] Currently, to solve the problem of water loss during the concrete construction process, common solutions include using plastic films, moisture-preserving agents, and fiber-reinforced materials. Plastic film is a common moisture-preserving method that can reduce water evaporation by covering the surface of cast concrete; moisture-preserving agents can be directly added to concrete to achieve a moisture-preserving effect by absorbing and retaining water; fiber-reinforced materials can improve the mechanical properties of concrete and indirectly reduce water loss.

[0004] However, the above technical solutions still have some defects. Plastic films can only simply cover the surface, unable to provide good barrier performance and mechanical strength, and are easily torn by the wind; the effect of moisture-preserving agents is greatly affected by environmental factors, and the addition amount is not easy to control; although fiber-reinforced materials can improve the mechanical properties of concrete, their role in moisture preservation is limited and they cannot effectively prevent the rapid loss of water during construction. These defects limit the wide application of the above technical solutions in actual projects. Summary of the Invention

[0005] In order to improve the moisture-preserving effect of nylon moisture-preserving films on concrete and at the same time obtain better mechanical properties, this application provides a nylon moisture-preserving film and a preparation method thereof.

[0006] In the first aspect, this application provides a nylon moisture-preserving film, which is composed of the following raw materials in percentage by weight:

[0007] Nylon: 40 - 63%

[0008] PP: 10 - 30%

[0009] PHA: 10 - 20%

[0010] Cooling masterbatch 0.5 - 2%

[0011] Maleic anhydride graft: 3 - 8%

[0012] Polyisobutylene succinimide 0.3 - 1%

[0013] Nano-inorganic filler: 1-8%

[0014] The balance is processing aids.

[0015] By adopting the above technical solution, while ensuring good moisture retention effect, the nylon moisture retention film has excellent flexibility and heat resistance, can effectively prevent water loss, and improve the usability and durability during construction. Specifically, the blending modification of nylon and PP improves the processing fluidity and impact strength of the material. The cooling masterbatch reduces the processing temperature and helps to improve the blending effect. The introduction of PHA enhances the barrier performance and biodegradability and improves the mechanical properties. The maleic anhydride graft promotes the compatibility between components and ensures the uniform dispersion of the material. The selection of nano-inorganic filler makes the nylon moisture retention film have a denser microstructure and enhances the ability to block gases and water molecules. Polyisobutylene succinimide and maleic anhydride graft play a synergistic role to further improve the compatibility between nano-inorganic filler and polymer matrix and promote the uniform dispersion of nano-inorganic filler.

[0016] In summary, the present application can combine the properties of nylon, PP, and PHA by compounding them, making its mechanical properties and barrier properties to water vapor and the like better. In addition, through the interaction of maleic anhydride graft and cooling masterbatch, the mixing uniformity between nylon, PP, and PHA is further improved, and polyisobutylene succinimide and maleic anhydride graft play a synergistic role to promote the compatibility and dispersion of nano-inorganic filler in the raw material system. Combining with nylon, PP, and PHA, the moisture retention performance and mechanical properties of the nylon moisture retention film are further improved.

[0017] The nylon moisture retention film of the present application not only has better ability to block water vapor permeation, but also has better mechanical properties, so that the nylon moisture retention film is applied to the forming process of building bridges, etc., plays a role in blocking water vapor, enables buildings, bridges, etc. to maintain better moisture retention, and at the same time reduces the possibility of damage during construction or use. The practicability of the nylon moisture retention film is improved.

[0018] Preferably, the maleic anhydride graft is composed of one or more of maleic rosin, ethylene-butyl acrylate-glycidyl methacrylate terpolymer, and maleic anhydride-vinyl acetate copolymer.

[0019] By adopting the above technical solution, the maleic anhydride graft is selected from one or more of maleic rosin, ethylene-butyl acrylate-glycidyl methacrylate terpolymer, and maleic anhydride-vinyl acetate copolymer, which not only improves the compatibility between PHA and nylon + PP, but also promotes the dispersion and compatibility of hexagonal silica, mica-like calcium carbonate, and wurtzite powder with the raw materials, further prevents the penetration of gases and water molecules, and makes the nylon moisture retention film have better mechanical properties and reduces the possibility of damage.

[0020] Preferably, the maleic anhydride graft is composed of maleic rosin, ethylene-butyl acrylate-glycidyl methacrylate terpolymer, and maleic anhydride-vinyl acetate copolymer in a weight ratio of 1:(1-2):(1-5).

[0021] By adopting the above technical solution, the maleic anhydride graft is composed of maleic rosin, ethylene-butyl acrylate-glycidyl methacrylate terpolymer, and maleic anhydride-vinyl acetate copolymer in a specific ratio, which improves the compatibility between PHA and nylon+PP, and at the same time promotes the dispersion and compatibility of hexagonal silica, mica-like calcium carbonate, and wurtzite powder, thereby enhancing the mechanical properties of the nylon moisture-proof film and reducing the possibility of breakage.

[0022] Preferably, the particle size of the nano-inorganic filler is 100-200nm.

[0023] By adopting the above technical solution, the particle size of the nano-inorganic filler is controlled within the range of 50-200nm, effectively improving the compactness of the nylon moisture-proof film, preventing the penetration of gas and water molecules, and thus enhancing the moisture-proof effect and barrier performance.

[0024] Preferably, the nano-inorganic filler is composed of one or more of hexagonal silica, mica-like calcium carbonate, and wurtzite powder.

[0025] By adopting the above technical solution, hexagonal silica, mica-like calcium carbonate, and wurtzite powder all have a hexagonal crystal system structure, showing a high filling density. As nano-inorganic fillers, they can significantly improve the compactness and barrier performance of the nylon moisture-proof film, effectively prevent the penetration of gas and water molecules, thereby better maintaining the moisture inside the cement, improving the heat preservation effect, and reducing the risk of concrete cracking.

[0026] Preferably, the nano-inorganic filler is composed of hexagonal silica, mica-like calcium carbonate, and wurtzite powder in a weight ratio of 3:(1-1.5):(0.3-0.8).

[0027] By adopting the above technical solution, hexagonal silica, mica-like calcium carbonate, and wurtzite powder are combined according to a specific weight ratio, which can give full play to their respective characteristics, effectively improve the compactness and barrier performance of the nylon moisture-proof film, enhance the waterproof and gas-proof effects of the material, and reduce the possibility of material breakage.

[0028] Preferably, the number-average molecular weight of the nylon is 15000-30000; the number-average molecular weight of the PP is 40000-60000; the number-average molecular weight of the PHA is 30000-50000.

[0029] By adopting the above technical solutions, the number-average molecular weight of nylon in the nylon moisture retention film is controlled within the range of 15,000 - 30,000, the number-average molecular weight of PP is controlled within the range of 40,000 - 60,000, and the number-average molecular weight of PHA is controlled within the range of 30,000 - 50,000, enabling the material to have more excellent mechanical properties and processing properties, and further improving the overall performance and stability of the nylon moisture retention film.

[0030] Preferably, the processing aid is composed of one or more of an antioxidant, an anti-UV agent, a lubricant, a plasticizer, and a colorant.

[0031] By adopting the above technical solutions, the nylon moisture retention film has comprehensive protection functions, specifically manifested as the characteristics of antioxidant, anti-ultraviolet, lubrication, and plasticizing. The combined action of these characteristics, together with nylon, PP, PHA, cooling masterbatch, maleic anhydride graft, and nano-inorganic filler, enhances the overall stability and service life of the nylon moisture retention film, ensuring excellent moisture retention effect and mechanical properties even in harsh environments, and reducing the damage caused by external factors to the nylon moisture retention film. For example, when applied to the moisture retention of seaside bridge piers, it can reduce breakage caused by wind blowing or excessive water loss of the cement bridge piers during the exposure process, affecting the construction efficiency.

[0032] Preferably, the antioxidant is composed of one or more of antioxidant 1010, antioxidant 168, antioxidant 264, and antioxidant 1076; the anti-UV agent is UV-329 and / or UV-531; the lubricant is paraffin; the plasticizer is a citrate plasticizer.

[0033] By adopting the above technical solutions, the nylon moisture retention film has more excellent antioxidant, anti-UV, lubrication, and plasticizing effects, effectively improving the stability and service life of the nylon moisture retention film, reducing film breakage and performance degradation caused by external environmental factors during construction, and further enhancing the moisture retention effect and durability.

[0034] The present application provides a preparation method of a nylon moisture retention film, comprising the following steps:

[0035] Weigh nylon, PP, cooling masterbatch, and 1 / 2 maleic anhydride graft according to weight percentage, mix them evenly, heat to melting, and stir evenly to obtain mixture A;

[0036] Weigh PHA, polyisobutylene succinimide, nano-inorganic filler, processing aid, and 1 / 2 maleic anhydride graft, mix them evenly, heat to melting, and stir evenly to obtain mixture B;

[0037] Cool down mixture A, and add it to mixture C while it is still hot, stir evenly, and then extrude and calender to obtain the nylon moisture retention film.

[0038] By adopting the above technical solution, the preparation method ensures that nylon, PP, the cooling masterbatch, and part of the maleic anhydride grafted product are fully and evenly mixed, and a mixture A is obtained in a molten state; PHA, the nano-inorganic filler, the processing aid, and the remaining maleic anhydride grafted product are also fully and evenly mixed and melted to obtain a mixture B. By cooling the mixture A and then mixing it with the mixture B, it is ensured that the materials are fully mixed at an appropriate temperature. Finally, the nylon moisture-proof film prepared by the extrusion and calendering processes has excellent moisture-proof effect, high barrier performance, good flexibility, and excellent biodegradability.

[0039] In summary, this application includes at least one of the following beneficial technical effects:

[0040] 1. By blending and modifying nylon with PP and adding PHA, the cooling masterbatch, polyisobutylene succinimide, the maleic anhydride grafted product, and the nano-inorganic filler, the processing fluidity and mechanical properties of the nylon moisture-proof film, such as impact strength and toughness, can be significantly improved, thereby reducing damage caused by factors such as wind during the construction process.

[0041] 2. By using hexagonal silica, mica-like calcium carbonate, and wurtzite powder as the nano-inorganic filler and adopting a specific proportion, the compactness of the material can be effectively improved, further enhancing the barrier performance, preventing the penetration of gas and water molecules, and effectively avoiding water loss during the concrete construction process.

[0042] 3. Using the cooling masterbatch to reduce the processing temperature and using the maleic anhydride grafted product to improve the compatibility between raw materials, the nylon moisture-proof film has good flexibility and heat preservation effect, effectively improving the construction effect, while reducing the manual maintenance workload and preventing concrete cracking. Specific embodiments

[0043] The following further elaborates on this application with reference to embodiments.

[0044] Introduction of some raw materials:

[0045] The number average molecular weight of nylon is 100,000 - 200,000;

[0046] The number average molecular weight of PP is 40,000 - 60,000;

[0047] The number average molecular weight of PHA is 100,000 - 200,000;

[0048] The preferred manufacturer model of the cooling masterbatch is YP027 of Huizhou Yupu Chemical Co., Ltd.;

[0049] The preferred manufacturer model of maleic rosin is MR-115# of Xiamen Weier Chemical Co., Ltd.;

[0050] The ethylene-butyl acrylate-glycidyl methacrylate terpolymer has the brand model of DuPont PTW-1 toughening agent from the United States;

[0051] The number-average molecular weight of the maleic anhydride-vinyl acetate copolymer is 850-1000;

[0052] The number-average molecular weight of the polyisobutylene succinimide is 10,000-2,000.

[0053] Examples

[0054] Example 1

[0055] A preparation method of a nylon moisture-preserving film includes the following steps:

[0056] Weigh 40% nylon, 30% PP, 2% cooling masterbatch, and 4% maleic anhydride grafted product by weight percentage, mix them evenly, heat to 230°C to make them all melt, and stir at a rotation speed of 30 r / min for 10 min to make them fully stirred and evenly mixed to obtain mixture A;

[0057] Weigh 10% PHA, 1% polyisobutylene succinimide, 8% nano-inorganic filler, 2% processing aid, and 4% maleic anhydride grafted product, put them into a heating and stirring device, mix them evenly, and then heat to 180°C to melt PHA, maleic anhydride grafted product, and processing aid. Stir at a rotation speed of 30 r / min for 10 min to make them fully stirred and evenly mixed to obtain mixture B;

[0058] Cool mixture A to 185°C, add it to mixture C while it is hot, continue to stir for 10 min to make them fully mixed evenly to obtain mixture C, then transfer it to an extruder for extrusion, and then calender it through a calendering device to obtain a nylon moisture-preserving film with a thickness of 125 microns.

[0059] Among them, the processing aid is composed of an antioxidant, a UV-resistant agent, and a plasticizer in a weight ratio of 1:1:2; the antioxidant is antioxidant 1010; the UV-resistant agent is UV-329; the plasticizer is tributyl citrate. The number-average molecular weight of nylon is 30,000 g / mol; the number-average molecular weight of PP is 40,000 g / mol; the number-average molecular weight of PHA is 30,000 g / mol.

[0060] Examples 2-3

[0061] The differences between Examples 2-3 and Example 1 are that the raw material dosages of the nylon moisture-preserving film are different, as shown in Table 1 specifically:

[0062] Table 1 Raw material dosages of Examples 1-3 %

[0063]

[0064]

[0065] Example 4

[0066] Example 4 is different from Example 2 in that the maleic anhydride graft is a terpolymer of ethylene-butyl acrylate-glycidyl methacrylate.

[0067] Example 5

[0068] Example 5 is different from Example 2 in that the maleic anhydride graft is a copolymer of maleic anhydride-vinyl acetate.

[0069] Example 6

[0070] Example 6 is different from Example 2 in that the maleic anhydride graft is composed of maleic rosin and a terpolymer of ethylene-butyl acrylate-glycidyl methacrylate in a weight ratio of 1:1.

[0071] Example 7

[0072] Example 7 is different from Example 2 in that the maleic anhydride graft is composed of maleic rosin, a terpolymer of ethylene-butyl acrylate-glycidyl methacrylate, and a copolymer of maleic anhydride-vinyl acetate in a weight ratio of 1:1:1.

[0073] Example 8

[0074] Example 8 is different from Example 2 in that the maleic anhydride graft is composed of maleic rosin, a terpolymer of ethylene-butyl acrylate-glycidyl methacrylate, and a copolymer of maleic anhydride-vinyl acetate in a weight ratio of 1:2:3.

[0075] Example 9

[0076] Example 9 is different from Example 2 in that the maleic anhydride graft is composed of maleic rosin, a terpolymer of ethylene-butyl acrylate-glycidyl methacrylate, and a copolymer of maleic anhydride-vinyl acetate in a weight ratio of 1:2:5.

[0077] Example 10

[0078] Example 10 is different from Example 8 in that the nano-inorganic filler is mica-like calcium carbonate.

[0079] Example 11

[0080] Example 11 is different from Example 8 in that the nano-inorganic filler is wurtzite powder.

[0081] Example 12

[0082] Example 12 is different from Example 8 in that the nano-inorganic filler consists of mica-shaped calcium carbonate and wurtzite powder in a weight ratio of

[0083] 1:2.

[0084] Example 13

[0085] Example 13 is different from Example 8 in that the nano-inorganic filler consists of hexagonal silica, mica-shaped calcium carbonate and wurtzite powder in a weight ratio of 3:1:0.3.

[0086] Example 14

[0087] Example 14 is different from Example 8 in that the nano-inorganic filler consists of hexagonal silica, mica-shaped calcium carbonate and wurtzite powder in a weight ratio of 3:1.5:0.5.

[0088] Example 15

[0089] Example 15 is different from Example 8 in that the nano-inorganic filler consists of hexagonal silica, mica-shaped calcium carbonate and wurtzite powder in a weight ratio of 3:1.1:0.8.

[0090] Comparative example

[0091] Comparative example 1

[0092] Comparative example 1 is different from Example 1 in that PHA is replaced with nylon in equal amount.

[0093] Comparative example 2

[0094] Comparative example 2 is different from Example 1 in that PP is replaced with nylon in equal amount.

[0095] Comparative example 3

[0096] Comparative example 3 is different from Example 1 in that nylon is replaced with PP in equal amount.

[0097] Comparative example 4

[0098] Comparative example 4 is different from Example 1 in that polyisobutylene succinimide is replaced with nylon in equal amount.

[0099] Performance detection test

[0100] Detection method / Test method

[0101] Moisture permeability test: The water vapor transmission rate is tested in accordance with "GB1037-88 Test Method for Water Vapor Transmission of Plastic Films and Sheets".

[0102] Mechanical properties: The mixture C obtained in Examples 1-15 and Comparative Examples 1-4 was transferred to an injection molding machine, and injection molding was performed at 190° C. to form a test specimen, and the elongation at break and tensile strength were tested with reference to ASTM D638.

[0103] The above experiments were tested 5 times and the average value was taken;

[0104] Table 2 Experimental data of Examples 1-15 and Comparative Examples 1-4

[0105]

[0106]

[0107] Combining Example 1 and Comparative Examples 1-4 and Table 2, it can be seen that the water vapor permeability of Comparative Examples 1-3 is significantly increased, and the tensile strength and elongation at break of Comparative Examples 1-3 are lower than those of Example 1, indicating that the use of the PHA, PP, nylon, combined nylon, PP, PHA, cooling masterbatch, maleic anhydride graft, nano inorganic filler, etc. of the present application for compounding has better water vapor barrier properties and mechanical properties, reduces the phenomenon of damage to the nylon protective film, and improves its moisture retention and practicality.

[0108] Comparing Example 2 with Example 8 and combining with Table 2, it can be seen that the water vapor transmission rate is reduced to 13g / m 2 ·24h (Example 2 is 23g / m 2 ·24h), and the tensile strength and elongation at break of Example 8 are both improved, indicating that the maleic rosin, ethylene-butyl acrylate-glycidyl methacrylate terpolymer, and maleic anhydride-vinyl acetate copolymer used in Examples 7-9 are compounded to play a synergistic role and further improve the comprehensive properties of the nylon film.

[0109] Comparing Example 8 and Example 14 and combining with Table 2, it can be seen that the water vapor transmission rate is reduced to 5g / m 2 ·24h (Example 8 is 13g / m 2 ·24h), and the tensile strength of Example 8 reaches 58Mpa (Example 8 is 50Mpa), and the elongation at break is increased by 223% (Example 8 is 185%), which shows that when hexagonal silica, mica-like calcium carbonate, and wurtzite powder are compounded, a synergistic effect is played, and the mechanical properties and water vapor barrier properties of the nylon moisturizing film are further improved, thereby having a better moisturizing effect on concrete and improving its practicability.

[0110] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A nylon moisturizing film, characterized in that: The following weight percentages of raw materials composition: Nylon: 40-63% PP: 10-30% PHA: 10-20% Cooling masterbatch 0.5-2% Maleic anhydride grafted compound: 3-8% Polyisobutylene succinimide: 0.3-1% Nano inorganic filler: 1-8% The balance is processing aids; The maleic anhydride grafted material is composed of maleic rosin, ethylene-butyl acrylate-glycidyl methacrylate terpolymer, and maleic anhydride-vinyl acetate copolymer in a weight ratio of 1: (1-2): (1-5); The nano inorganic filler is composed of hexagonal silicon dioxide, mica-like calcium carbonate and wurtzite powder in a weight ratio of 3: (1-1.5): (0.3-0.8).

2. A nylon moisturizing film according to claim 1, characterized in that: The particle size of the nano inorganic filler is 100-200nm.

3. A nylon moisturizing film according to claim 1, characterized in that: The number average molecular weight of the nylon is 15000-30000; the number average molecular weight of the PP is 40000-60000; and the number average molecular weight of the PHA is 30000-50000.

4. The nylon moisturizing film according to claim 1, characterized in that: The processing aid is one or more of an antioxidant, an anti-UV agent, a lubricant, a plasticizer, and a colorant.

5. A nylon moisturizing film according to claim 4, characterized in that: The antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 264, and antioxidant 1076; the anti-UV agent is UV-329 and / or UV-531; the lubricant is paraffin; and the plasticizer is a citrate plasticizer.

6. A method for preparing a nylon moisturizing film according to any one of claims 1 to 5, characterized in that: The following steps are involved: According to weight percentage, nylon, PP, cooling masterbatch and 1 / 2 maleic anhydride grafted product are weighed and mixed evenly, heated until melted, and stirred evenly to obtain a mixture A; Weigh PHA, polyisobutylene succinimide, nano inorganic filler, processing aid, and 1 / 2 maleic anhydride grafted product, mix them evenly, heat until melted, and stir evenly to obtain a mixture B; The mixture A is cooled, and is added to the mixture B while it is hot, and stirred evenly, and then extruded and calendered to obtain a nylon moisturizing film.

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