Special hot melt adhesive film for magic tape and preparation method thereof

Abstract

The application belongs to the technical field of polymer hot melt adhesive film material preparation, and discloses a hot melt adhesive film special for magic tape and a preparation method thereof. The hot melt adhesive film comprises the following components in parts by weight: EVA 50 parts, EAA 30 parts and carbon five carbon nine blended hydrogenated petroleum resin 20 parts. The VA content of the EVA is greater than or equal to 28%, and the melt index is greater than or equal to 45 g / 10 min. The AA content of the EAA is greater than or equal to 18%, and the melt index is greater than or equal to 60 g / 10 min. The adhesive film obtained by the application has stable bonding strength, flowability and compatibility, solves the problems of dust, uneven particles and film surface defects, realizes integrated stable production of mixing-granulation-casting forming, and improves the adhesion, flatness and aging resistance of the finished product.

Description

Technical Field

[0001] This invention belongs to the field of polymer hot melt adhesive film material preparation technology, and specifically relates to a hot melt adhesive film for Velcro and its preparation method. Background Technology

[0002] Existing conventional hot melt adhesive films suffer from problems such as poor raw material compatibility, uneven mixing, numerous particulate impurities, many air bubbles on the film surface, unstable adhesion, and poor weather resistance. Conventional open mixing processes generate a lot of dust, produce loose particles, and result in uneven casting thickness, leading to low bond strength, poor batch stability, and low yield of finished products. Currently, the industry lacks a mature production solution that combines precise raw material specifications, specialized equipment, and an integrated closed-loop process.

[0003] Therefore, how to provide a hot melt adhesive film specifically for Velcro and its preparation method is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a release paper carrier hot melt adhesive film based on a compound system of EVA, EAA and hydrogenated petroleum resin and its preparation method. The adhesive film has stable bonding strength, flowability and compatibility, and solves the problems of dust, uneven particle size and film surface defects. It realizes stable integrated production of mixing, granulation and casting molding, and improves the adhesion, flatness and aging resistance of the finished product.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A hot melt adhesive film for Velcro, characterized in that, by weight, it comprises the following components: 50 parts EVA, 30 parts EAA, and 20 parts C5-C9 blended hydrogenated petroleum resin.

[0007] Preferably, the EVA has a VA content of ≥28% and a melt index of ≥45 g / 10min.

[0008] EVA has high flowability and high compatibility, ensuring melt flowability and molding smoothness.

[0009] Preferably, the AA content of the EAA is ≥18%, and the melt flow index is ≥60 g / 10min.

[0010] EAA has high polarity and high wettability, which greatly improves the adhesion of adhesive films.

[0011] The C5 and C9 blended hydrogenated petroleum resins are low in odor, light in color, and resistant to aging, while improving initial tack, holding power, and overall stability.

[0012] This invention also provides a method for preparing the above-mentioned hot melt adhesive film for hook and loop fasteners, comprising the following steps: (1) Closed-loop precision mixing EVA, EAA, and C5 / C9 blended hydrogenated petroleum resin are added in proportion, and the mixture is stirred and blended at high speed in a closed mixer to obtain the material. (2) Twin-screw underwater granulation The uniformly mixed material is fed into a twin-screw underwater granulator, where it undergoes high-temperature melting, strong shearing plasticization by the screw, underwater cooling, uniform pelletizing, dehydration and drying to obtain semi-finished granules. (3) Single-screw release paper casting film The semi-finished adhesive granules are fed into a single-screw casting machine with matching release paper. After being melted and plasticized at high temperature, they are evenly extruded through the die head and directly and continuously cast onto the surface of the release paper. After cooling, shaping, flattening and winding, they are finally formed into a hot melt adhesive film.

[0013] This invention employs a closed-loop precision mixing process, eliminating dust pollution and preventing material precipitation and stratification. This ensures complete compatibility and uniformity of the three polymer raw materials, providing a stable base material for subsequent granulation and casting. Twin-screw underwater granulation yields dense, uniform, clean, and pore-free semi-finished granules, eliminating the problems of loose particles and numerous impurities associated with conventional air-cooled granulation. A single-screw release paper casting process is used to finally form a hot melt adhesive film with a smooth surface, uniform thickness, and excellent adhesion.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention limits the VA / AA content and melt index of EVA and EAA, which are unconventional general-purpose materials, and have controllable performance and strong stability. EAA has high polarity, and the adhesion of the finished product is far superior to that of ordinary hot melt adhesive films. The use of C5 and C9 blended hydrogenated petroleum resin improves adhesion and aging resistance. The raw materials have high matching degree, good melt flowability, and the film surface is free of bubbles and particles, with high flatness.

[0015] (2) An integrated closed-loop process is adopted, from dust-free mixing to dense granulation and then to one-time casting film formation, with continuous processes and a significantly improved yield. The entire process is dust-free and free of impurities, and the product batch consistency is extremely strong. The process is simple, can be mass-produced on a large scale, and the finished product is resistant to aging, has stable viscosity, and has a wide range of applications. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 A hot melt adhesive film for Velcro, characterized in that, by weight, it comprises the following components: 50 parts EVA, 30 parts EAA, and 20 parts C5-C9 blended hydrogenated petroleum resin.

[0018] The EVA has a VA content of ≥28% and a melt index of ≥45 g / 10min.

[0019] The AA content of the EAA is ≥18%, and the melt flow index is ≥60 g / 10min.

[0020] The above-mentioned method for preparing a hot melt adhesive film for hook and loop fasteners includes the following steps: (1) Closed-loop precision mixing EVA, EAA, and C5 / C9 blended hydrogenated petroleum resin are added in proportion, and the mixture is stirred and blended at high speed in a closed mixer to obtain the material. (2) Twin-screw underwater granulation The uniformly mixed material is fed into a twin-screw underwater granulator, where it undergoes high-temperature melting, strong shearing plasticization by the screw, underwater cooling, uniform pelletizing, dehydration and drying to obtain semi-finished granules. (3) Single-screw release paper casting film The semi-finished adhesive granules are fed into a single-screw casting machine with matching release paper. After being melted and plasticized at high temperature, they are evenly extruded through the die head and directly and continuously cast onto the surface of the release paper. After cooling, shaping, flattening and winding, they are finally formed into a hot melt adhesive film with high flatness, high adhesion and high stability.

[0021] The finished hot melt adhesive film has a smooth surface, uniform thickness, high peel strength, and no defects, meeting the requirements for high-end composite adhesive materials.

[0022] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hot melt adhesive film specifically for Velcro, characterized in that, By weight, it includes the following components: 50 parts EVA, 30 parts EAA, and 20 parts C5-C9 blended hydrogenated petroleum resin.

2. The hot melt adhesive film for Velcro as described in claim 1, characterized in that, The EVA has a VA content of ≥28% and a melt index of ≥45 g / 10min.

3. The hot melt adhesive film for Velcro as described in claim 1, characterized in that, The AA content of the EAA is ≥18%, and the melt flow index is ≥60 g / 10min.

4. A method for preparing a hot melt adhesive film for hook and loop fasteners according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Closed-loop precision mixing EVA, EAA, and C5 / C9 blended hydrogenated petroleum resin are added in proportion, and the mixture is stirred and blended at high speed in a closed mixer to obtain the material. (2) Twin-screw underwater granulation The uniformly mixed material is fed into a twin-screw underwater granulator, where it undergoes high-temperature melting, strong shearing plasticization by the screw, underwater cooling, uniform pelletizing, dehydration and drying to obtain semi-finished granules. (3) Single-screw release paper casting film The semi-finished adhesive granules are fed into a single-screw casting machine with matching release paper. After being melted and plasticized at high temperature, they are evenly extruded through the die head and directly and continuously cast onto the surface of the release paper. After cooling, shaping, flattening and winding, they are finally formed into a hot melt adhesive film.

5. The application of the hot melt adhesive film according to any one of claims 1-3 in the preparation of hook and loop fasteners.