Low-temperature hot melt adhesive composite sheet containing fibrilia

Abstract

The invention discloses a low-temperature hot melt adhesive composite sheet containing fibrilia. A preparation method of the low-temperature hot melt adhesive composite sheet comprises the following steps: (1) crushing fibrilia or fibrilia yarn powder into fibrilia short fibers with the particle size of 0.1-1mm; (2) uniformly mixing hemp short fibers and hot melt adhesive particles according to a mass ratio of (30-70): (70-30), and carrying out hot press molding at 80-120 DEG C to form a middle base material layer with the thickness of 0.5-3mm; (3) coating a low-temperature hot melt adhesive layer on each of the upper surface and the lower surface of the middle base material layer; the melting point of the low-temperature hot melt adhesive layer is 60-100 DEG C, and the thickness of a single layer is 0.05-0.5 mm. According to the low-temperature hot melt adhesive composite sheet containing the jute fibers, the jute fibers are used in the middle base material layer, so that the low-temperature hot melt adhesive composite sheet has the antibacterial, mildew-proof and moisture-absorbing effects of the jute fibers, and can be applied to the fields of furniture, wallboards, automotive interiors, shoe materials and the like.

Description

Technical Field

[0001] This invention relates to a low-temperature hot melt adhesive composite sheet containing hemp fibers, belonging to the technical field of hot melt adhesive composite materials. Background Technology

[0002] Hot melt adhesives are a type of solid adhesive based on thermoplastic polymers (rubber, resin, etc.). They are solid at room temperature and become liquid when heated above their melting point, bonding with the substrate. Low-temperature hot melt adhesives are a type of thermoplastic hot melt adhesive, mainly used in furniture, wall panels, automotive interiors, and shoe materials. However, these products require low-temperature hot melt adhesives to have good weather resistance, as well as good antibacterial, antifungal, and moisture-absorbing properties. Therefore, how to prepare a low-temperature hot melt adhesive with good antibacterial, antifungal, and moisture-absorbing properties has become a problem to be solved. Summary of the Invention

[0003] The purpose of this invention is to provide a low-temperature hot melt adhesive composite sheet containing hemp fiber, which has good antibacterial, anti-mildew and moisture-absorbing effects.

[0004] To solve the above-mentioned technical problems, the objective of this invention is achieved as follows: The present invention relates to a low-temperature hot melt adhesive composite sheet containing hemp fibers, characterized by comprising the following preparation steps: (1) Pulverize hemp fibers or hemp fiber yarn powder into short hemp fibers with a particle size of 0.1-1 mm; (2) Mix the short hemp fibers and hot melt adhesive particles at a mass ratio of (30-70): (70-30) evenly, and hot press them at 80-120℃ to form an intermediate substrate layer with a thickness of 0.5-3mm; (3) A low-temperature hot melt adhesive layer is coated on the upper and lower surfaces of the intermediate substrate layer respectively; the melting point of the low-temperature hot melt adhesive layer is 60-100℃ and the thickness of a single layer is 0.05-0.5mm.

[0005] Based on the above scheme and as a preferred embodiment of the above scheme: the hemp fiber is selected from at least one of flax, ramie, and hemp, and the hemp fiber is pretreated.

[0006] Based on the above scheme and as a preferred embodiment of the above scheme, the preprocessing includes the following steps: (1.1) Disperse hemp fibers in an alkaline solution, wherein the mass ratio of hemp fibers to alkaline solution is (5-30):(70-95), the mass concentration of sodium hydroxide in the alkaline solution is 0.5%-10%, and the temperature of the alkaline solution is 35-70℃; (1.2) After the reaction is complete, separate the hemp fibers from the alkali solution and wash them with clean water; (1.3) Treating hemp fibers with a silane coupling agent; wherein the silane coupling agent is selected from: vinyltriethoxysilane, isobutyltriethoxysilane and vinyltrimethoxysilane; (1.4) Dry the hemp fibers and set aside for later use.

[0007] Based on the above scheme and as a preferred embodiment of the above scheme: the hot melt adhesive is at least one of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, nylon elastomer, and EPDM rubber; the mass concentration of nano-titanium dioxide in the low-temperature hot melt adhesive composite sheet is 0.1%-5%.

[0008] Based on the above scheme and as a preferred embodiment of the above scheme: the low-temperature hot melt adhesive layer contains 0.5-3wt% of a plant-derived antifungal agent, wherein the antifungal agent is vanillin or tea polyphenol extract.

[0009] Based on the above scheme and as a preferred embodiment of the above scheme: the low-temperature hot melt adhesive layer is made of one or more materials selected from ethylene-vinyl acetate copolymer, thermoplastic polyurethane, and nylon elastomer.

[0010] Based on the above scheme and as a preferred embodiment of the above scheme: the total thickness of the low-temperature hot melt adhesive composite sheet is 0.6-3.5mm, and the thickness ratio of the intermediate substrate layer to the single-sided low-temperature hot melt adhesive layer is (5-20):1.

[0011] Based on the above scheme and as a preferred embodiment of the above scheme: the low-temperature hot melt adhesive composite sheet is suitable for furniture, wall panels, automotive interiors, and shoe materials.

[0012] The beneficial effects of the present invention are as follows: The low-temperature hot melt adhesive composite sheet containing hemp fiber involved in the present invention uses hemp fiber in the middle substrate layer, so that the low-temperature hot melt adhesive composite sheet has the antibacterial, anti-mildew and moisture-absorbing effects of hemp fiber, and can be applied to furniture, wall panels, automotive interiors, shoe materials and other fields. Detailed Implementation

[0013] The present invention will be further described below with reference to specific embodiments.

[0014] Example 1 The low-temperature hot melt adhesive composite sheet containing hemp fibers involved in this embodiment includes the following preparation steps: Step (1) Pulverize hemp fibers or hemp fiber yarn powder into short hemp fibers with a particle size of 0.1-1 mm; in this embodiment, hemp fibers are used, specifically selected from at least one of flax, ramie, and hemp. The hemp fibers are pretreated and then pulverized. In this embodiment, flax fibers are selected.

[0015] The pretreatment of hemp fibers includes the following steps: Step (1.1) involves dispersing hemp fibers in an alkaline solution, wherein the mass ratio of hemp fibers to alkaline solution is (5-30):(70-95), the mass concentration of sodium hydroxide in the alkaline solution is 0.5%-10%, and the temperature of the alkaline solution is 35-70℃. Specifically, in this embodiment, the mass ratio of hemp fibers to alkaline solution is 10:90. The mass concentration of sodium hydroxide in the alkaline solution is 1%, and the temperature of the alkaline solution is 45℃.

[0016] Step (1.2) After the reaction is complete, separate the hemp fibers from the alkali solution and wash them with clean water.

[0017] Step (1.3) involves treating the hemp fibers with a silane coupling agent; the silane coupling agent is selected from vinyltriethoxysilane, isobutyltriethoxysilane, and vinyltrimethoxysilane, etc.; specifically, in this embodiment, the silane coupling agent is vinyltriethoxysilane. Specifically, the washed hemp fibers are placed in an aqueous solution of the silane coupling agent. The hydrolyzed silanol groups condense with the hydroxyl groups (-OH) on the surface of the hemp fibers to form chemical bonds, reducing interfacial defects. The amount of silane coupling agent used is excessive.

[0018] (1.4) Dry the hemp fibers and set aside for later use.

[0019] Step (2) Mix the short hemp fibers and hot melt adhesive particles evenly at a mass ratio of 30-70:70-30, and hot press them at 80-120℃ to form an intermediate substrate layer with a thickness of 0.5-3mm.

[0020] The hot melt adhesive is at least one of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, nylon elastomer, and EPDM rubber; in this embodiment, thermoplastic polyurethane is selected, which has a melting point 20-40°C higher than that of low-temperature hot melt adhesive.

[0021] Furthermore, in this embodiment, the mass ratio of hemp fiber to hot melt adhesive is 30:70, and the thickness is 1mm after hot pressing for 100 seconds at 100°C and 5MPa pressure.

[0022] (3) A low-temperature hot melt adhesive layer is coated on the upper and lower surfaces of the intermediate substrate layer respectively; the low-temperature hot melt adhesive layer has a melting point of 60-100℃ and a single layer thickness of 0.05-0.5mm, which is 0.1mm in this embodiment. The material of the low-temperature hot melt adhesive layer is selected from one or more of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, and nylon elastomer. In this embodiment, ethylene-vinyl acetate copolymer is selected.

[0023] Furthermore, the total thickness of the composite sheet is 0.6-3.5 mm, and the thickness ratio of the intermediate substrate layer to the single-sided low-temperature hot melt adhesive layer is (5-20):1.

[0024] The prepared low-temperature hot melt adhesive composite sheet is suitable for furniture, wall panels, automotive interiors, and shoe materials.

[0025] Example 2 The low-temperature hot melt adhesive composite sheet containing hemp fibers involved in this embodiment includes the following preparation steps: Step (1) Pulverize hemp fibers or hemp fiber yarn powder into short hemp fibers with a particle size of 0.1-1 mm; in this embodiment, hemp fibers are used, specifically selected from at least one of flax, ramie, and hemp. The hemp fibers are pretreated and then pulverized. In this embodiment, ramie fibers and hemp fibers are selected in a 1:1 mass ratio.

[0026] The pretreatment of hemp fibers includes the following steps: Step (1.1) involves dispersing hemp fibers in an alkaline solution, wherein the mass ratio of hemp fibers to alkaline solution is (5-30):(70-95), the mass concentration of sodium hydroxide in the alkaline solution is 0.5%-10%, and the temperature of the alkaline solution is 35-70℃. Specifically, in this embodiment, the mass ratio of hemp fibers to alkaline solution is 30:70. The mass concentration of sodium hydroxide in the alkaline solution is 5%, and the temperature of the alkaline solution is 60℃.

[0027] Step (1.2) After the reaction is complete, separate the hemp fibers from the alkali solution and wash them with clean water.

[0028] Step (1.3) involves treating the hemp fibers with a silane coupling agent; the silane coupling agent is selected from vinyltriethoxysilane, isobutyltriethoxysilane, and vinyltrimethoxysilane, etc.; specifically, in this embodiment, the silane coupling agent is isobutyltriethoxysilane. Specifically, the washed hemp fibers are placed in an aqueous solution of the silane coupling agent. The hydrolyzed silanol groups condense with the hydroxyl groups (-OH) on the surface of the hemp fibers to form chemical bonds, reducing interfacial defects. The amount of silane coupling agent used is excessive.

[0029] (1.4) Dry the hemp fibers and set aside for later use.

[0030] Step (2) Mix the short hemp fibers and hot melt adhesive particles evenly at a mass ratio of 30-70:70-30, and hot press them at 80-120℃ to form an intermediate substrate layer with a thickness of 0.5-3mm. The intermediate substrate layer also includes nano-titanium dioxide with a mass concentration of 0.1%-5%, and 2% is selected in this embodiment.

[0031] The hot melt adhesive is at least one of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, nylon elastomer, and EPDM rubber; in this embodiment, nylon elastomer is selected.

[0032] Furthermore, in this embodiment, the mass ratio of hemp fiber to hot melt adhesive is 70:30, and the thickness is 2.5 mm after hot pressing for 50 seconds at 120°C and 10 MPa pressure.

[0033] (3) A low-temperature hot melt adhesive layer is coated on the upper and lower surfaces of the intermediate substrate layer respectively; the melting point of the low-temperature hot melt adhesive layer is 60-100℃, and the thickness of a single layer is 0.05-0.5mm, which is 0.2mm in this embodiment. The material of the low-temperature hot melt adhesive layer is selected from one or more of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, and nylon elastomer. In this embodiment, ethylene-vinyl acetate copolymer is selected. The low-temperature hot melt adhesive layer contains 0.5-3wt% of a plant-derived antifungal agent, which is vanillin or tea polyphenol extract. In this embodiment, 2% tea polyphenol extract is included.

[0034] Furthermore, the total thickness of the composite sheet is 0.6-3.5 mm, and the thickness ratio of the intermediate substrate layer to the single-sided low-temperature hot melt adhesive layer is (5-20):1.

[0035] The low-temperature hot melt adhesive composite sheets prepared in Examples 1 and 2 were subjected to antibacterial and antifungal tests. The antibacterial rates against Escherichia coli reached 75% and 90% or more, respectively, and the antifungal level was Grade 1.

[0036] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A low-temperature hot melt adhesive composite sheet containing hemp fibers, characterized in that, The preparation steps include the following: (1) Pulverize hemp fibers or hemp fiber yarn powder into short hemp fibers with a particle size of 0.1-1 mm; (2) Mix the short hemp fibers and hot melt adhesive particles at a mass ratio of (30-70): (70-30) evenly, and hot press them at 80-120℃ to form an intermediate substrate layer with a thickness of 0.5-3mm; (3) A low-temperature hot melt adhesive layer is coated on the upper and lower surfaces of the intermediate substrate layer respectively; the melting point of the low-temperature hot melt adhesive layer is 60-100℃ and the thickness of a single layer is 0.05-0.5mm.

2. The low-temperature hot melt adhesive composite sheet containing hemp fibers according to claim 1, characterized in that, The hemp fiber is selected from at least one of flax, ramie, and hemp, and the hemp fiber is pretreated.

3. The low-temperature hot melt adhesive composite sheet containing hemp fibers according to claim 2, characterized in that, The preprocessing includes the following steps: (1.1) Disperse hemp fibers in an alkaline solution, wherein the mass ratio of hemp fibers to alkaline solution is (5-30):(70-95), the mass concentration of sodium hydroxide in the alkaline solution is 0.5%-10%, and the temperature of the alkaline solution is 35-70℃; (1.2) After the reaction is complete, separate the hemp fibers from the alkali solution and wash them with clean water; (1.3) Treating hemp fibers with a silane coupling agent; wherein the silane coupling agent is selected from: vinyltriethoxysilane, isobutyltriethoxysilane and vinyltrimethoxysilane; (1.4) Dry the hemp fibers and set aside for later use.

4. The low-temperature hot melt adhesive composite sheet containing hemp fibers according to claim 1, characterized in that, The hot melt adhesive is at least one of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, nylon elastomer, and ethylene propylene diene monomer (EPDM) rubber; the mass concentration of nano-titanium dioxide in the low-temperature hot melt adhesive composite sheet is 0.1%-5%.

5. The low-temperature hot melt adhesive composite sheet containing hemp fibers according to claim 1, characterized in that, The low-temperature hot melt adhesive layer contains 0.5-3 wt% of a plant-derived antifungal agent, which is vanillin or tea polyphenol extract.

6. The low-temperature hot melt adhesive composite sheet containing hemp fibers according to claim 1, characterized in that, The low-temperature hot melt adhesive layer is made of one or more materials selected from ethylene-vinyl acetate copolymer, thermoplastic polyurethane, and nylon elastomer.

7. The low-temperature hot melt adhesive composite sheet containing hemp fibers according to claim 1, characterized in that, The total thickness of the low-temperature hot melt adhesive composite sheet is 0.6-3.5mm, and the thickness ratio of the middle substrate layer to the single-sided low-temperature hot melt adhesive layer is (5-20):

1.

8. A low-temperature hot melt adhesive composite sheet containing hemp fibers according to any one of claims 1 to 7, characterized in that, The low-temperature hot melt adhesive composite sheet is suitable for furniture, wall panels, automotive interiors, and shoe materials.