A surface modifier for shoe-making mesh cloth and a preparation method thereof

Abstract

The present application relates to a kind of shoemaking mesh cloth surface modifier and its preparation method, belong to composite material preparation technical field.The modifier is formed by reactive mixture and polyvinyl butyral resin melt blending;Reactive mixture is prepared by hydrogenated petroleum resin, polar ester plasticizer, maleic anhydride, styrene and peroxide initiator by melt grafting reaction.The modifier is hot melt type material, when using, heated melt coating is applied to the surface of PET mesh cloth, and strong and tough interface transition layer can be formed by short time hot pressing.The transition layer is combined with PET surface by the strong polar anhydride group of grafting on one side, and is strongly combined with polyurethane and other adhesives by the hydroxyl group of PVB on the other side.The composite material obtained by the present application has high peel strength, excellent wet heat aging performance, and can meet the application requirements of PET mesh cloth material.

Description

Technical Field

[0001] This invention belongs to the field of composite material preparation technology, and relates to a surface modifier for shoe mesh and its preparation method. Background Technology

[0002] Polyethylene terephthalate (PET) mesh is widely used in textile composites such as sports footwear, bags, and outdoor equipment due to its excellent strength, dimensional stability, and chemical resistance. However, the smooth surface, high crystallinity, and strong chemical inertness of PET fibers result in insufficient interfacial adhesion between them and commonly used adhesives such as polyurethane (PU), becoming an industry bottleneck restricting product reliability and lightweight design.

[0003] To improve the bonding performance of PET mesh, traditional industries generally rely on pretreatment processes such as physical roughening (e.g., belt sanding) or chemical roughening (e.g., corona treatment, flame treatment). While these methods have some effect, they have significant drawbacks: physical roughening can damage the strength of the fiber itself, generate dust pollution, and result in poor process consistency; chemical roughening suffers from rapid degradation of treatment effect, high energy consumption, and may cause yellowing or embrittlement of the fabric, and cannot meet increasingly stringent environmental protection production requirements.

[0004] In recent years, to circumvent the drawbacks of roughing processes, "roughing-free" treatment solutions have gradually gained attention. Among them, "roughing-free" liquid modifiers, represented by waterborne polyurethane or acrylic emulsions, have been increasingly applied. Although these products avoid physical damage, they still suffer from drawbacks in practical use, such as volatile organic compound (VOC) emissions, high energy consumption, and insufficient hydrolysis resistance and durability of the coating. Therefore, developing a new PET mesh treatment solution that combines efficient adhesion, durable performance, and no damage to the substrate has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a surface modifier for shoe mesh and its preparation method, which can form a strong and tough adhesive interface layer on the surface of PET mesh.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a mesh surface modifier, which is formed by melt blending a reactive mixture with polyvinyl butyral resin (PVB); The reactive mixture is prepared by melt grafting reaction of raw materials comprising hydrogenated petroleum resin, polar ester plasticizer, maleic anhydride, styrene and peroxide initiator.

[0007] The "reactive mixture" is a key intermediate; it is not a single pure compound, but a complex mixture formed by grafting highly polar maleic anhydride monomers and their copolymers with styrene onto the resin chain through a melt free radical grafting reaction, using hydrogenated petroleum resin as a backbone. This design aims to introduce high-density anchors into the originally inert PET surface. Polyvinyl butyral resin (PVB) serves as a high-performance adhesive bridge; its hydroxyl groups form a strong bond with subsequent adhesives (such as polyurethane PU), while the butyral groups provide flexibility and compatibility. The blending of these two components essentially constructs an adhesive interface transition layer.

[0008] Preferably, the polar ester plasticizer is at least one of dioctyl phthalate (DOTP), diisononyl phthalate (DINP), or epoxidized soybean oil.

[0009] Preferably, the amount of the polar ester plasticizer added is 3%-15% of the mass of the hydrogenated petroleum resin.

[0010] The core function of adding polar ester plasticizers (such as DOTP) is to reduce the melt viscosity of the system by premixing before the grafting reaction, promote the diffusion of monomers and free radicals, and make the grafting reaction more uniform and efficient. During the hot pressing process of the final application, these polar small molecules can preferentially migrate to the PET interface, instantly reduce the interfacial tension, and greatly improve the wettability of the polymer melt on the smooth PET surface.

[0011] Preferably, the softening point of the hydrogenated petroleum resin is 80-120°C.

[0012] Preferably, the mass ratio of styrene to maleic anhydride is 0.2:1 to 0.8:1.

[0013] By controlling the ratio of styrene (St) to maleic anhydride (MAH), which tends to form a 1:1 alternating copolymer, this ratio ensures a proper excess of MAH during the reaction. The excess MAH and its active groups are retained in the reactive mixture, providing an active source for potential in-situ esterification reactions that may occur during subsequent blending with PVB resin. This achieves chemical compatibilization between the two resins, rather than simple physical mixing, significantly improving the blend's properties.

[0014] Preferably, the peroxide initiator is dicumyl peroxide, and its addition amount is 3%-8% of the mass of maleic anhydride.

[0015] Preferably, the butyraldehyde content of the polyvinyl butyral resin is 65%-85%. Within this range, the resin achieves a balance between flexibility, compatibility with nonpolar systems (provided by the butyral groups), and reactivity with polar substances (provided by the residual hydroxyl groups), thereby adapting to the requirements of this system.

[0016] Preferably, the mass ratio of the reactive mixture to polyvinyl butyral resin is 40:60 to 70:30. If too much reactive mixture is present, the coating will be too hard and brittle, affecting the feel of the final product; if too much PVB is present, the coating's cohesive strength will be insufficient. This preferred ratio ensures that the final modifier can form a strong substrate through strong interaction with PET, while also bonding with the upper adhesive layer through sufficient PVB, thus maintaining good flexibility of the coating.

[0017] Secondly, the present invention provides a method for preparing a surface modifier for a mesh fabric, comprising the following steps: (1) Heat the hydrogenated petroleum resin to 140-160℃ to melt it, add polar ester plasticizer and mix evenly; then add maleic anhydride and styrene, mix evenly and then add peroxide initiator, keep the reaction at 140-160℃ for 10-40 minutes to obtain the reactive mixture. (2) The reactive mixture obtained in step (1) is melt-blended with polyvinyl butyral resin at 110-140°C for 10-30 minutes to obtain the modifier.

[0018] Thirdly, the present invention provides a method for surface modification of PET mesh fabric, comprising the following steps: heating the modifier to a molten state and coating it onto the surface of the PET mesh fabric, with a coating amount of 10-20 g / m². 2 Then, it is hot-pressed at a temperature of 100-130℃ and a pressure of 0.2-0.8 MPa for 30-120 seconds.

[0019] The beneficial effects of this invention are: This invention constructs an amphiphilic interfacial transition layer by melt blending maleic anhydride / styrene-grafted hydrogenated petroleum resin with polyvinyl butyral (PVB) resin. One side of this transition layer achieves strong chemical anchoring and physical adsorption to the PET surface through grafted, highly polar anhydride groups, while the other side bonds with industry-standard adhesives through the abundant hydroxyl groups of PVB. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0021] Main ingredients: Matrix resin: hydrogenated C9 petroleum resin.

[0022] Plasticizer: Dioctyl phthalate (DOTP), chemically pure.

[0023] Grafting monomers: maleic anhydride (MAH), styrene (St), chemically pure.

[0024] Initiator: dicumyl peroxide (DCP), chemically pure.

[0025] PVB resin: Polyvinyl butyral (PVB).

[0026] Main equipment: reaction vessel, precision electronic balance, electric heating drying oven, two-roll mill, small single-screw extruder granulator, hot melt adhesive coating machine, flat vulcanizing machine, universal material testing machine (equipped with T-type peeling fixture), constant temperature and humidity test chamber.

[0027] All synthesis reactions were carried out under nitrogen protection to prevent oxidation. Blending and granulation processes were performed under conventional polymer processing conditions.

[0028] A method for preparing a surface modifier for mesh fabric includes the following steps: (1) Add 100.0g of hydrogenated C9 petroleum resin (HM-1000, Henghe Materials) to the reactor, purge with nitrogen, and heat to 150℃ to completely melt it. Under uniform stirring, add 10.0g of DOTP and maintain the temperature at 150℃ for 10 minutes. While maintaining the temperature, add 12.0g of MAH and 6.0g of styrene (St:MAH mass ratio = 0.5:1) sequentially and stir for 10 minutes. Add 0.6g of DCP (5% of the mass of MAH) and react at 150℃ for 30 minutes. After the reaction is complete, a light yellow viscous liquid is obtained, which is the reactive mixture (acid value 25.4 mg KOH / g).

[0029] (2) Keep the reactive mixture at 150°C and add 100.0g of PVB resin powder (B-03HX, Changchun Group) (i.e., the mass ratio of reactive mixture to PVB is 50:50). Adjust the system temperature to 125°C and melt-blend for 20 minutes under high-speed stirring. Transfer the blend to a preheated two-roll mill and pass it through several times. After sheeting and cooling, granulate it using a pelletizer to obtain modifier particles. The product is designated as sample A.

[0030] Example 2 A method for preparing a surface modifier for mesh fabric includes the following steps: Except for the following changes, the preparation steps are the same as in Example 1: DOTP addition amount: 3.00g (3% of the mass of hydrogenated petroleum resin) Styrene addition: 2.40g (Maintaining MAH addition at 12.00g, St:MAH mass ratio = 0.2:1) Step (2) Blending mass: Take 40.00g of reactive mixture and blend it with 60.00g of PVB resin (i.e., reactive mixture:PVB = 40:60). Modifier sample B was prepared. Example 3 A method for preparing a surface modifier for mesh fabric includes the following steps: Except for the following changes, the preparation steps are the same as in Example 1: DOTP addition amount: 15.00g (15% of the mass of hydrogenated petroleum resin) MAH addition amount: 10.00g, St addition amount: 8.00g (then the St:MAH mass ratio = 0.8:1) Step (2) Blending mass: Take 70.00g of reactive mixture and blend it with 30.00g of PVB resin (i.e., reactive mixture:PVB = 70:30). Modifier sample C was prepared Example 4 A method for preparing a surface modifier for mesh fabric includes the following steps: Except for the following changes, the preparation steps are the same as in Example 1: The hydrogenated petroleum resin has been replaced with a type that has a softening point of 85℃ (Bailing New Materials). Modifier sample D was prepared. Comparative Example 1 The formula and process are the same as in Example 1, except that DOTP is not added.

[0031] The acid value of the prepared reactive mixture was 21.5 mg KOH / g.

[0032] The final product is labeled as sample C1.

[0033] Comparative Example 2 (1) Prepare a reactive mixture according to step (1) of Example 1, but without adding DOTP. That is, only hydrogenated petroleum resin, MAH, St and DCP are reacted in the same proportion and under the same conditions to obtain mixture RM-C2 (acid value 22.8 mg KOH / g).

[0034] (2) Keep RM-C2 at 150°C, add 10.00g DOTP and 100.00g PVB resin to it at the same time, and then melt-blend at 125°C for 20 minutes.

[0035] The subsequent granulation steps are the same as in Example 1.

[0036] The product is labeled as sample C2.

[0037] Comparative Example 3 No grafting reaction is performed. Specific procedure: 100.00g of hydrogenated petroleum resin HR-100 and 10.00g of DOTP are melt-mixed at 150°C for 10 minutes. Then, 100.00g of PVB resin powder is added directly to this mixture, and the mixture is melt-blended at 125°C for 20 minutes.

[0038] Subsequent granulation was performed in the same manner as in Example 1.

[0039] The product is marked as sample C3.

[0040] Comparative Example 4 Following the formulation and process steps of Example 1, only 100.00g of hydrogenated petroleum resin was replaced with an equal amount of EVA resin (VA content 28%).

[0041] The final product sample C4 was obtained.

[0042] Comparative Example 5 According to the formulation and process steps of Example 1, only the 100.00g PVB resin in step (2) was replaced with an equal amount of SEBS elastomer (H1062).

[0043] The final product sample C5 was obtained.

[0044] Performance testing: Sample preparation: Experimental group: Sample particles from Examples 1-4 and Comparative Examples 1-5 were melted at 150°C on a hot melt adhesive machine, with a concentration of 10.0 g / m³. 2 The coating is evenly applied to the surface of the PET mesh. It is then transferred to a flat vulcanizing machine and hot-pressed at 120℃ and 0.5 MPa for 60 seconds, followed by cooling.

[0045] Control group: No modifier was applied to the PET mesh. The surface of the PET mesh was uniformly polished three times in one direction under constant pressure (0.2 kg / cm) using 180-mesh alumina sandpaper.

[0046] Adhesive bonding: Apply adhesive to the surface of the PET mesh at a concentration of 20.0 g / m². 2 A layer of PU adhesive (YY-1177, Yuyang) was evenly applied and activated at 70℃ for 3 minutes. Then, it was hot-pressed with standard PU synthetic leather at 70℃ and 0.6 MPa for 15 seconds. After curing, it was cut into standard T-shaped peel test specimens with a width of 25.0 mm.

[0047] Test method: Peel strength test: Following national standard GB / T 2791, a T-type peel test was performed on a universal testing machine at a tensile speed of 100 mm / min. The average load during the peeling process was recorded, and the peel strength (unit: N / cm) was calculated. At least five valid specimens were tested for each sample, and the arithmetic mean was taken.

[0048] Moist heat aging test: Some peeled samples were placed in a constant temperature and humidity chamber at 70°C and 95% relative humidity for 168 hours (7 days). After being removed, they were conditioned for 24 hours under standard conditions (23°C, 50% relative humidity) before peel strength testing was performed, and the strength retention rate was calculated.

[0049] Damage mode analysis: Visual inspection and low-magnification microscopy were used to observe the residue on the PET surface after peeling to determine the damage type: cohesive damage (CF, tearing inside the adhesive layer), interfacial damage (AF, complete peeling from the PET surface), or mixed damage (MF).

[0050] Performance test results: Table 1: Initial Adhesion Performance Table 2: Resistance to Damp Heat Aging The peel strength of Example 1 (Sample A) reached 15.5 N / cm, and Examples B and D performed excellently within the parameter range (12.8-15.2 N / cm). Comparative Example 3 (without grafting reaction) showed a strength of only 4.5 N / cm, indicating that the maleic anhydride / styrene grafting reaction is fundamental to imparting strong chemical anchoring of the modifier to the PET surface. Comparative Example 1 demonstrates that the plasticizer promotes wetting and reaction. Comparative Examples 4 and 5 demonstrate that the melt grafting process of this invention is specific to the chemical structure of the matrix resin.

[0051] The above examples and comparative examples demonstrate that by using a specific hydrogenated petroleum resin as a matrix, and through a process of grafting with a premixed plasticizer, and then blending it with a specific PVB resin in an optimized ratio, surface modification of PET mesh fabric without roughening can be successfully achieved.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A surface modifier for mesh fabric, characterized in that, It is made by melt blending a reactive mixture with polyvinyl butyral resin; The reactive mixture is prepared by melt grafting reaction of raw materials comprising hydrogenated petroleum resin, polar ester plasticizer, maleic anhydride, styrene and peroxide initiator.

2. The mesh fabric surface modifier according to claim 1, characterized in that, The polar ester plasticizer is at least one of dioctyl phthalate, diisononyl phthalate, or epoxidized soybean oil.

3. The mesh fabric surface modifier according to claim 2, characterized in that, The amount of the polar ester plasticizer added is 3%-15% of the mass of the hydrogenated petroleum resin.

4. The mesh fabric surface modifier according to claim 1, characterized in that, The softening point of the hydrogenated petroleum resin is 80-120℃.

5. The mesh fabric surface modifier according to claim 1, characterized in that, The mass ratio of styrene to maleic anhydride is from 0.2:1 to 0.8:

1.

6. The mesh fabric surface modifier according to claim 1, characterized in that, The peroxide initiator is dicumyl peroxide, and its addition amount is 3%-8% of the mass of maleic anhydride.

7. The mesh fabric surface modifier according to claim 1, characterized in that, The butyraldehyde content of the polyvinyl butyral resin is 65%-85%.

8. The mesh fabric surface modifier according to claim 1, characterized in that, The mass ratio of the reactive mixture to polyvinyl butyral resin is 40:60 to 70:

30.

9. A method for preparing a mesh surface modifier as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Heat the hydrogenated petroleum resin to 140-160℃ to melt it, add polar ester plasticizer and mix evenly; then add maleic anhydride and styrene, mix evenly and then add peroxide initiator, keep the reaction at 140-160℃ for 10-40 minutes to obtain the reactive mixture. (2) The reactive mixture obtained in step (1) is melt-blended with polyvinyl butyral resin at 110-140°C for 10-30 minutes to obtain the modifier.

10. A method for surface modification of PET mesh fabric, characterized in that, Includes the following steps: The modifier as described in any one of claims 1-8 is heated to a molten state and coated onto the surface of PET mesh fabric, with a coating amount of 10-20 g / m². 2 Then, it is hot-pressed at a temperature of 100-130℃ and a pressure of 0.2-0.8 MPa for 30-120 seconds.

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