CN102952327B - A kind of resin composite materials, preparation method and application thereof - Google Patents

Abstract

The invention belongs to technical field of polymer materials, disclose a kind of resin composite materials, preparation method and application thereof.Resin composite materials of the present invention is made up of the component comprising following weight part: thermoplastic resin 70 ~ 100 parts, 0 ~ 5 part, oxidation inhibitor, fire retardant 0 ~ 5 part, expanding material 0 ~ 10 part, weather resisting agent 0 ~ 3 part, releasing agent 0 ~ 5 part, auxiliary agent 0 ~ 2 part.The preparation method of this resin composite materials comprises the following steps: the raw material of said ratio, in moderate-speed mixers, mix 3 ~ 7 minutes, fully joins forcing machine after mixing and extrudes pelletizing, obtain resin composite materials.The invention discloses the method for prepreg tape natural fiber/resin composite materials being prepared by above-mentioned resin composite materials, comprise the following steps: natural fiber is made cord fabrics, drawn, compression, heat drying dewater, at film forcing machine place, resin composite materials carries out preimpregnation, then impregnation cooling rolling, prepare the prepreg tape of natural fiber/resin composite materials, this prepreg tape porosity is low, mechanical strength is high.

Description

A kind of resin composite material, preparation method and application thereof

technical field

The invention belongs to the technical field of polymer materials, and relates to a resin composite material, a preparation method and an application thereof.

Background technique

Continuous fiber reinforced thermoplastic resin composite prepreg tape has excellent mechanical properties, such as high tensile strength, flexural strength/modulus, high and low temperature impact strength, etc., and has the characteristics of relatively low density and recyclability, so In recent years, it has developed rapidly, and the corresponding preparation technology has also made major breakthroughs. In Chinese patent CN200610070280, Fang Kun uses the mixed yarn method to prepare continuous glass fiber reinforced polypropylene PP pellets, mixes the composite mixed yarn containing glass fiber with PP resin and processing aids, heats, melts and blends, and passes through the extruder Extrusion granulation. The product produced by this method can fully adjust the content of reinforcing fibers, but this method is extruded and granulated to form chopped pellets, which cannot form continuous reinforced prepreg tapes. Chinese patent CN101474868A adopts continuous glass fiber, organic fiber, etc. to be drawn from the creel, and after tension adjustment, it is spread into a unidirectional fiber yarn with a certain range, and is in contact with two extrusion dies at different positions. The continuous fibers are impregnated and then passed through a three-roll impregnation unit, then cooled and rolled to shape. This method can be used to prepare thermoplastic resin prepreg tapes such as glass fiber and Kevlar fiber, but it is not suitable for natural fibers, because the length of natural fibers is limited and cannot form continuous single fibers, and must be twisted to form continuous natural fibers Fiber thread or rope, after twisting, the impregnation effect of the resin is poor, and there are more dry yarns. Chen Dakai and others prepared natural fiber-reinforced composite materials, using natural short fibers or natural long fibers (including ramie fibers, linen fibers, jute fibers, etc.) and PLA for melt blending and extrusion to prepare fully degradable natural fiber/PLA composite (Chen Dakai, Li Jing, Ren Jie; Research Progress of Natural Fiber Reinforced Polylactic Acid Composite Materials, Plastics, 2010(6): 108). This method prepares natural fiber-reinforced composite materials, the natural fiber breaks obviously, and its reinforcing effect is not obvious, and in the process of blending and extruding with PLA, the natural fiber causes the viscosity of the material to increase, which aggravates the wear and tear of the machine. In the Chinese patent CN200610037894.7, Dong Weiwei mixed natural fiber with PLA, antioxidant, nucleating agent and lubricant, and melt-extruded to obtain the product. The fiber long-diameter ratio of the natural fiber reinforced material prepared by this method is small, and its reinforcing effect is limited; moreover, the screw rod of the extruder is greatly worn.

Contents of the invention

Aiming at the problems existing in the prior art, the object of the present invention is to provide a resin composite material which can be stored for a long time.

Another object of the present invention is to provide a method for preparing the above-mentioned resin composite material.

The third object of the present invention is to provide a method for preparing the above-mentioned resin composite material into a prepreg tape of natural fiber/resin composite material.

Technical scheme of the present invention is as follows:

The invention provides a kind of resin composite material, and this resin composite material is made of the component that comprises following parts by weight:

70-100 parts of thermoplastic resin,

Antioxidant 0-5 parts,

Flame retardant 0-5 parts,

0-10 parts of compatibilizer,

0-3 parts of weather resistance agent,

Release agent 0-5 parts,

0-2 parts of additives.

The melt index of the thermoplastic resin is 10-100g/10min, selected from one or more of polyolefins, thermoplastic polyesters, polyamides or general-purpose resins; wherein: the polyolefins are further selected from homopolypropylene, copolymerized poly One or more of propylene or polyethylene; thermoplastic polyester is further selected from polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or polylactic acid One or more; polyamide is further selected from one or more of nylon 6, nylon 66, nylon 12, nylon 1212 or nylon 612; general-purpose resin is further selected from polyvinyl chloride (PVC) and/or polycarbonate (PC).

The antioxidant is selected from tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid}pentaerythritol ester, (3,5-di-tert-butyl-4-hydroxyphenyl) One or more of stearyl propionate, dilauryl thiodipropionate or phenylene diisodecyl phosphite, the purpose of antioxidant is to reduce the degradation of thermoplastic resin in the process of preparing composite materials and/or oxidation.

The flame retardant is selected from magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, octabromoether, triphenyl phosphate, hexabromocyclododecane, zinc borate, coated red phosphorus, decabromodiphenylethane , one or more of tetrabromobisphenol A bis(2,3-dibromopropyl) ether or hexabromocyclododecane; the function of adding a flame retardant is to make the flammable polymer difficult to burn.

Described compatibilizer is selected from one or more in polycaprolactone, polyhydroxyalkanoate or polyethylene glycol, and the effect of adding compatibilizer is to improve the compatibility between natural fiber and polylactic acid .

Described weather resistance agent is selected from bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2,4-dihydroxy-benzophenone, 2-(2'-hydroxyl One or more of -5'-)benzotriazole or 2-(2'-hydroxy-3'-tert-butyl-5'methylphenyl)-5-chlorobenzotriazole. The purpose of adding weather resistance agent is to inhibit or shield photoredox or photoaging.

The release agent is selected from one or more of silicone oil, polyethylene glycol or low-molecular-weight polyethylene. The function of the release agent is to prevent the resin from sticking to the pressed surface during the impregnation of the natural fiber and the resin. roll on.

The auxiliary agent is selected from isooctyl 3-mercaptopropionate, 4-diphenyl-4-methyl-1-pentene or 4,4-dimethyl-2,4-diphenyl-1- One or more of butenes.

The present invention also provides a kind of preparation method of above-mentioned resin composite material, and this method comprises the following steps:

Mix 70-100 parts of thermoplastic resin, 0-5 parts of antioxidant, 0-5 parts of flame retardant, 0-10 parts of compatibilizer, 0-3 parts of weather resistance agent, 0-5 parts of mold release agent and 0-2 parts 1 part of additives, mixed in a medium-speed mixer for 3 to 7 minutes, mixed thoroughly, then added to an extruder to extrude and pelletize to obtain a resin composite material.

The extruder is a twin-screw extruder, the screw speed is 10-250r/min, and the extrusion temperature is 150-190°C.

The present invention also provides a method for preparing the prepreg tape of the natural fiber/resin composite material from the resin composite material, the method comprising the following steps:

The natural fiber is made into a cord fabric, stretched, compressed, heated and dried to remove water, and the resin composite material is pre-impregnated at the coating extruder, and then dipped in glue, cooled and wound, and the natural fiber/resin composite material is prepared. Prepreg tape.

The number of yarn shafts required for the cord fabric is 1-500 rolls, preferably 50-200 rolls, more preferably 80-150 rolls.

The thickness of the cord fabric is 0.1-2 mm, and its warp is thermoplastic fiber such as polypropylene fiber, nylon fiber or polylactic acid fiber.

The stretching temperature mentioned is room temperature, and the stretching speed is the winding speed.

The pressing temperature is room temperature, and the pressure is 4-10 MPa.

The heating and drying temperature is 101-110° C., and the moisture content after drying is less than 1%.

The temperature of the pre-impregnation is 190-220° C., the extrusion speed of the resin is 1-5 kg/min, and the impregnation width is the same as the cord fabric or 10-100 mm wider than the cord fabric.

Described cooling is to be cooled to room temperature.

The said winding speed is 1-20m/min.

The natural fiber is selected from hemp fiber, cotton fiber, bamboo fiber, ramie fiber, flax fiber, jute fiber or silk fiber and/or their mixed yarn, and the cellulose content of the natural fiber is more than or equal to 60%.

The natural fiber is treated by one or more of plasma, alkali treatment or coupling agent treatment, twisted and then untwisted to become loose and expanded.

The prepreg tape of the present invention can be made into complex shaped parts such as mobile phone shells or computer shells as required.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. In the natural fiber/thermoplastic resin composite material prepreg tape of the present invention, the reinforcing phase natural fiber exists as a continuous phase, because the form of cord fabric is used to reinforce the thermoplastic resin, and the reinforcing phase in the prepreg tape is unidirectional, making The mechanical properties of the product can be designed.

2. The longitudinal length of the composite material prepared by the present invention can be adjusted, and the width can also be adjusted, which can meet the length requirement in later production.

3. The composite material prepared by the present invention can be stored for a long time, and the natural fiber is completely impregnated with resin without being exposed, so that the material, especially the natural fiber, can be kept dry, and the natural fiber will not become moldy or deteriorate.

4. The method of the present invention can adjust the content of natural fibers to prepare reinforced fiber prepreg tapes with different natural fiber contents.

5. The present invention adopts the method of cord fabric, which can ensure that the natural fibers are not broken when they are drawn, and act as a continuous phase to strengthen the natural fibers.

6. The present invention adopts the reinforced resin of the cord fabric, which can limit the width of the reinforced material, and will not change the position of the natural fiber because it is too wide or too narrow.

7. The method of the present invention can ensure that the resin is completely impregnated with natural fibers, and the resin is completely impregnated with natural fibers, which can ensure that the product has fewer defects and high mechanical strength during the process of preparing the product.

8. The porosity of the prepreg tape prepared by the present invention is low, less than 1%. When the porosity is low, the stability of product performance can be guaranteed.

Description of drawings

Figure 1 is a flow chart of the preparation of prepreg tapes of natural fiber/resin composites.

Among them, 1 is creel; 2 is yarn shaft; 3 is natural fiber; 4 is cord loom; 5 is tension control device; 6, 7 is natural fiber pressing roller; 8 is heating and drying system; 9 is tension control device ; 10 is a dipping cooling device; 11 is a coating extruder; 12 is a winding device.

detailed description

The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

In the present invention, all percentages, parts and ratios, etc. are by weight unless otherwise specified.

Suitable methods and materials are described herein, but materials and methods similar or equivalent to those described herein can be used in the practice or testing of the present invention.

Where numerical ranges are recited herein, unless otherwise indicated, such ranges are intended to include their endpoints and all integers and fractions within the range.

The terms "comprising", "comprising", "having" or any other variations thereof in the present invention are intended to cover a non-exclusive scope of inclusion. For example, selection of materials including a series of mechanical devices, specific locations of devices, etc. are not limited to those listed herein.

The materials, methods, and examples herein are illustrative only and not limiting unless otherwise indicated.

In the present invention, the natural fiber pinch rollers shown in Fig. 1 include 6, 7 and in order to improve product performance, and continue to add the pinch rolls, that is, the pinch rolls not only include two pairs shown in the figure, but three pairs , four pairs, five pairs, take this as an example.

The melt index of the thermoplastic resin used in the present invention is 10-100g/10min.

The natural fibers used in the following examples are treated with alkali, and the treatment method is as follows, the natural fibers are soaked in NaOH solution at normal temperature, the concentration is 5% (mass fraction), after 2h, the natural fibers are taken out, and washed 3 times with clear water , dried, and taken out at a temperature of 80°C.

Example 1

Get 87 parts of polylactic acid resin, 2 parts of tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate} pentaerythritol ester, 5 parts of polycaprolactone, 2 parts of bis(2,2, 6,6-Tetramethyl-4-piperidinyl) sebacate, 2 parts polyethylene glycol, 2 parts decabromodiphenylethane were mixed in a medium speed mixer for 4 minutes, mixed and added to the twin screw In the extruder, extrude and granulate, the screw speed is 75r/min, and the extruder head temperature is 190°C.

Figure 1 is a flow chart of the preparation of prepreg tapes of natural fiber/resin composites. The natural fiber used in this article refers to the long fiber length, which can be in a continuous state after twisting. The nominal count of a bundle of twisted fibers is 0.2-1; the cellulose content of natural fibers is ≥ 60%; the natural fibers are twisted After that, untwisting is carried out to form a loose and expanded form. Get 100 rolls of jute fiber thread through alkali treatment in the present embodiment, be placed on creel 1, because the product of commercial production of natural fiber is by twisting, makes it to exist in continuous state, after natural fiber is through twisting, resin It is not easy to impregnate. If a product with excellent performance is obtained, the twisted natural fiber must be untwisted. The yarn shafts on the creel here are all through untwisting; the natural fiber 3 on the yarn shaft 2 (the jute fiber on the yarn shaft at this time is through untwisting), here is the jute fiber, and the jute fiber is drawn to the cord fabric Loom 4, the cord fabric loom can produce cord fabrics with a width of 0.8-4.5m, and its warp is polylactic acid fiber, which is woven into a cord fabric with a width of 1m; the tension of the tension control device 5 is expanded to make the natural fiber The tension is basically the same, which promotes their uniform arrangement; the natural fiber pressing rollers 6 and 7 are pressed by pressing rollers, the pressure is 5MPa, and the thickness of the fibers after rolling is 0.8mm. The material of the natural fiber pressing rollers can be rubber , plastics, etc. (such materials will deform when subjected to greater pressure, and natural fibers will not break due to extrusion here). Natural fibers in natural fiber cord are bound, and the resin does not easily saturate the fibers. The function of the pinch roller here is to press the original thicker natural fiber into a thin layer, and the rotational speed of the pinch roller is consistent with that of the winding device; after the heating and drying system 8, the moisture regain of the natural fiber The rate is about 12%. A large amount of water in natural fibers will affect the various properties of the material, such as too much water. During the process of impregnating with resin, natural fibers release a large amount of water vapor, which will cause prepreg The porosity of the belt increases, and a large amount of water vapor will reduce the weather resistance of the material. Natural fibers will rot in an environment with a large amount of water vapor, which will affect the service life of the material. At this time, the temperature is 103 ° C, and the moisture content of jute fiber is 0.9 %, change the running direction of the jute fiber through the tension control device 9, and enter 11 places of the laminating extruder for pre-impregnation. The same width of the cord fabric, where the jute fiber is pre-impregnated, and then reaches the dipping cooling device 10, where the three rollers are all steel parts, and the rotation speed of the dipping cooling device 10 is the same as that of the winding device , after being cooled to room temperature and rolled, and rolled in the winding device 12, the linear speed of rotation is 5m/min, and the jute/polylactic acid prepreg tape is prepared. The performance test results are shown in Table 1.

Example 2

Take 72 parts of homopolypropylene resin, 3 parts of dilauryl thiodipropionate, 10 parts of polycaprolactone, 3 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl)decane Diacid ester, 3 parts low molecular weight polyethylene, 5 parts tetrabromobisphenol A bis(2,3-dibromopropyl) ether, 1 part 3-mercaptopropionate isooctyl, mix in a medium speed mixer for 4 Minutes, mixed and added to a twin-screw extruder, extruded and granulated, the screw speed was 75r/min, and the extruder head temperature was 190°C.

The natural fibers used in this example refer to those with longer fiber lengths, which can be in a continuous state after being twisted. The nominal count of a bundle of twisted fibers is 0.2 to 1; the cellulose content of natural fibers is ≥ 60%; the natural fibers After twisting, untwisting is performed to form a loose and expanded form. 100 volumes of alkali-treated jute fiber threads are pulled to the cord fabric loom, and the warp is polypropylene fiber, which is woven into a cord fabric with a width of 1m; the tension is unfolded by the tension control device, and the natural fiber is pressed and rolled The roller is compacted at room temperature with a pressure of 4MPa. After the roller is pressed, a cord fabric with a thickness of 0.7mm is formed. After passing through the heating and drying system, the heating temperature is 103°C, and the water is removed by drying. After drying, the moisture content is 0.9%, and the resin composite material is added. Pre-impregnation at the laminating extruder, the temperature is 210°C, the resin extrusion speed is 2kg/min, the width of the impregnation is 10mm wider than the cord fabric, and then cooled to room temperature, winding, and the winding speed is 10m/min to obtain jute /PP prepreg tape. The performance test results are shown in Table 1.

Example 3

Take 95 parts of homopolypropylene resin, 3 parts of tetrabromobisphenol A bis(2,3-dibromopropyl) ether, and 2 parts of low molecular weight polyethylene. Mix in a medium-speed mixer for 4 minutes, add to a twin-screw extruder after mixing, extrude and granulate, the screw speed is 75r/min, and the extruder head temperature is 190°C.

The natural fibers used in this example refer to those with longer fiber lengths, which can be in a continuous state after being twisted. The nominal count of a bundle of twisted fibers is 0.2 to 1; the cellulose content of natural fibers is ≥ 60%; the natural fibers After twisting, untwisting is performed to form a loose and expanded form. 100 volumes of alkali-treated jute fiber threads are pulled to the cord fabric loom, and the warp is polypropylene fiber, which is woven into a cord fabric with a width of 1m; the tension is unfolded by the tension control device, and the natural fiber is pressed and rolled The roller is compacted at room temperature with a pressure of 7MPa. After the roller is pressed, a cord fabric with a thickness of 0.8mm is formed. After passing through the heating and drying system, the heating temperature is 103°C, and the water is dried. After drying, the moisture content is 0.9%, and the resin composite material is added. Pre-impregnation at the laminating extruder, the temperature is 210°C, the resin extrusion speed is 2kg/min, the width of the impregnation is the same as the width of the cord fabric, then cooled to room temperature, and the winding speed is 10m/min to obtain jute /PP prepreg tape. The performance test results are shown in Table 1.

Example 4

The natural fibers used in this example refer to those with longer fiber lengths, which can be in a continuous state after being twisted. The nominal count of a bundle of twisted fibers is 0.2 to 1; the cellulose content of natural fibers is ≥ 60%; the natural fibers After twisting, untwisting is performed to form a loose and expanded form. Get 100 parts of homopolyethylene (PP) resin and directly put it into the coating extruder, 100 rolls of jute fiber thread through alkali treatment, and draw it to the cord loom, its warp thread is polypropylene fiber, and the width of weaving is The cord fabric of 1m is stretched by the tension control device, and the natural fiber pressing roller is pressed at room temperature with a pressure of 8MPa. After rolling, a cord fabric with a thickness of 0.6mm is formed. After passing through the heating and drying system, the heating temperature The temperature is 103°C, dry and remove water, the moisture content after drying is 0.9%, add resin composite material to the lamination extruder for pre-impregnation, the temperature is 210°C, the resin extrusion speed is 2kg/min, the dipping width is the same as the cord fabric , then cooled to room temperature, and rolled up at a speed of 10m/min to obtain a jute/PP prepreg tape. The performance test results are shown in Table 1.

Example 5

Get 70 parts of homopolypropylene resin, 5 parts of tetrakis {β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate} pentaerythritol ester, 10 parts of polycaprolactone, 3 parts of bis(2, 2,6,6-Tetramethyl-4-piperidinyl) sebacate, 5 parts low molecular weight polyethylene, 5 parts Tetrabromobisphenol A bis(2,3-dibromopropyl) ether, 2 parts Isooctyl 3-mercaptopropionate, mixed in a medium-speed mixer for 4 minutes, mixed and added to a twin-screw extruder, extruded and granulated, the screw speed is 75r/min, and the temperature of the extruder head is 190°C .

The natural fibers used in this example refer to those with longer fiber lengths, which can be in a continuous state after being twisted. The nominal count of a bundle of twisted fibers is 0.2 to 1; the cellulose content of natural fibers is ≥ 60%; the natural fibers After twisting, untwisting is performed to form a loose and expanded form. 120 rolls of alkali-treated jute fiber thread are drawn to the cord fabric loom, and the warp is polypropylene fiber, which is woven into a cord fabric with a width of 1.2m; the tension is unfolded by the tension control device, and the natural fiber is pressed by the roller The pressure roller is pressed at room temperature with a pressure of 10MPa. After the roller is pressed, a cord fabric with a thickness of 0.5mm is formed. After passing through the heating and drying system, the heating temperature is 104°C, and the water is dried. After drying, the moisture content is 0.8%, and the resin is added for compounding. The material is pre-impregnated at the lamination extruder, the temperature is 210°C, the resin extrusion speed is 3kg/min, the width of the impregnation is the same as the width of the cord fabric, and then cooled to room temperature, winding, and the winding speed is 10m/min. Jute/PP prepreg tape. The performance test results are shown in Table 1.

Example 6

Get 75 parts of homopolypropylene resin, 5 parts of tetrakis {β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate} pentaerythritol ester, 10 parts of polycaprolactone, 3 parts of bis(2, 2,6,6-Tetramethyl-4-piperidinyl) sebacate, 5 parts low molecular weight polyethylene, 2 parts isooctyl 3-mercaptopropionate, mix in a medium speed mixer for 4 minutes, mix After that, it is added into a twin-screw extruder, extruded and granulated, the screw speed is 75r/min, and the extruder head temperature is 190°C.

The natural fibers used in this example refer to those with longer fiber lengths, which can be in a continuous state after being twisted. The nominal count of a bundle of twisted fibers is 0.2 to 1; the cellulose content of natural fibers is ≥ 60%; the natural fibers After twisting, untwisting is performed to form a loose and expanded form. 100 volumes of alkali-treated jute fiber threads are pulled to the cord fabric loom, and the warp is polypropylene fiber, which is woven into a cord fabric with a width of 1m; the tension is unfolded by the tension control device, and the natural fiber is pressed and rolled The roller is compacted at room temperature with a pressure of 5MPa. After the roller is pressed, a cord fabric with a thickness of 0.8mm is formed. After passing through the heating and drying system, the heating temperature is 103°C, and the water is dried. After drying, the moisture content is 0.9%, and the resin composite material is added. Pre-impregnation at the coating extruder, the temperature is 205°C, the resin extrusion speed is 2kg/min, then cooled to room temperature, and the winding speed is 10m/min to obtain jute/PP prepreg tape. The performance test results are shown in Table 1.

Example 7

Get 76 parts of homopolypropylene resin, 5 parts of tetrakis {β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate} pentaerythritol ester, 10 parts of polycaprolactone, 3 parts of bis(2, 2,6,6-tetramethyl-4-piperidinyl) sebacate, 5 parts tetrabromobisphenol A bis(2,3-dibromopropyl) ether, 2 parts 3-mercaptopropionic acid isooctyl Esters were mixed in a medium-speed mixer for 8 minutes, mixed and then added to a twin-screw extruder, extruded and granulated, the screw speed was 75r/min, and the extruder head temperature was 190°C.

The natural fibers used in this example refer to those with longer fiber lengths, which can be in a continuous state after being twisted. The nominal count of a bundle of twisted fibers is 0.2 to 1; the cellulose content of natural fibers is ≥ 60%; the natural fibers After twisting, untwisting is performed to form a loose and expanded form. 120 rolls of alkali-treated jute fiber thread are drawn to the cord fabric loom, and the warp is polypropylene fiber, which is woven into a cord fabric with a width of 1.2m; the tension is unfolded by the tension control device, and the natural fiber is pressed by the roller The pressure roller is pressed at room temperature with a pressure of 5MPa. After rolling, a cord fabric with a thickness of 0.8mm is formed. After passing through the heating and drying system, the heating temperature is 103°C, and the water is removed by drying. After drying, the moisture content is 0.9%, and the resin is added. The material is pre-impregnated at the laminating extruder, the temperature is 215°C, the resin extrusion speed is 2kg/min, the impregnation width is 20mm wider than the cord fabric, and then cooled to room temperature, winding, and the winding speed is 20m/min. Jute/PP prepreg tape. The performance test results are shown in Table 1.

Table 1

Typical performance Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Jute content/% ^① 40 35 40 45 35 40 45 Tensile strength/MPa 106 92 101 115 90 98 98 Bending strength/MPa 124 102 105 110 100 104 112 Impact strength/J/m ² 45 43 50 56 40 46 46 Oxygen Index twenty four twenty three 19 19 twenty three 19 twenty three

①: The jute content here is tested by density method

Its test method is as follows: Utilize the exhaust air method to test respectively jute fiber density is ρ _jute , resin density is ρ _resin , and prepreg tape density is ρ _{prepreg tape} , utilizes formula C=(ρ _resin -ρ _{prepreg tape} )/(ρ _Resin -rho _jute ), the jute content was calculated.

The tensile strength test standard in Table 1 is GB/T3354-1999, the bending strength test standard is GB/T356-1999, the impact strength test standard is GB/T1451-1983, and the oxygen index test standard is GB8924.

It can be seen from Table 1 that the natural fiber content in the natural fiber/resin prepreg tape is between 35% and 45%, but this range is not fixed. The temperature is adjusted; the tensile strength and bending strength of the prepreg are not only related to the content of natural fibers, but also related to the content of thermoplastic resin in the resin composite material. The higher the content of natural fibers in the prepreg, the higher the tensile strength of the prepreg The higher the strength; the higher the content of thermoplastic resin in the resin composite, the higher the tensile strength of the prepreg tape. The bending strength is not only related to the content of natural fibers in the prepreg tape, but also related to the content of thermoplastic resin in the resin composite material. The more thermoplastic resin content in the resin composite material, the higher the value of the bending strength of the prepreg tape; prepreg The higher the natural fiber content in the tape, the higher the flexural strength value of the prepreg tape. The impact strength of the prepreg tape is not only related to the content of natural fibers in the prepreg tape, but also related to the content of thermoplastic resin in the resin composite material. The higher the content of natural fibers in the prepreg tape, the greater the impact strength of the prepreg tape; the resin The greater the content of thermoplastic resin in the composite material, the greater the impact strength of the prepreg tape. After adding the flame retardant, the oxygen index resin of the prepreg tape increases significantly, and the oxygen index of the prepreg tape without adding the flame retardant is very low, around 19, which is a flammable material, while the oxygen index of the flame retardant material is at 23, indicating that the addition of flame retardants can improve the combustion performance of materials.

Example 8

The produced prepreg material is cut into various shapes, put into a mold, melted and heated, and pressurized to prepare a mobile phone case. The casing of the mobile phone is shock-resistant, and can be degraded and recycled after being discarded, so it has little impact on the environment.

The present invention consists of the above method, through the untwisting of natural fibers, rolling into sheets, making it fully unfolded, in the dipping and cooling device, the two sides of the unfolded natural fibers are impregnated with resin to improve the impregnation of natural fibers As a result, the resin at this time is a thermoplastic resin in a molten state, and the prepreg tape is obtained after cooling and winding. This kind of prepreg tape can be used to produce internal components such as vehicles, replaceable mobile phone casings, and can solve the recycling problem of other non-degradable resins.

The above description of the embodiments is for those of ordinary skill in the art to understand and apply the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the embodiments herein. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (17)

1. a resin composite material prepares the method for the prepreg tape of natural fiber/resin composite material, it is characterized in that: the method may further comprise the steps: The natural fiber is made into a cord fabric, stretched, compressed, heated and dried to remove water, and the resin composite material is pre-impregnated at the coating extruder, and then dipped in glue, cooled and wound, and the natural fiber/resin composite material is prepared. Prepreg tape; The warps of the cord fabric are selected from polypropylene fibers, nylon fibers or polylactic acid fibers; The resin composite material is made of components comprising the following parts by weight: The antioxidant is selected from tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid}pentaerythritol ester, (3,5-di-tert-butyl-4-hydroxyphenyl) One or more of stearyl propionate, dilauryl thiodipropionate or phenylene diisodecyl phosphite; The flame retardant is selected from magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, octabromoether, triphenyl phosphate, hexabromocyclododecane, zinc borate, coated red phosphorus, decabromodiphenylethane , one or more of tetrabromobisphenol A bis(2,3-dibromopropyl) ether or hexabromocyclododecane; The compatibilizer is selected from one or more of polycaprolactone, polyhydroxyalkanoate or polyethylene glycol; Described weather resistance agent is selected from bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2,4-dihydroxy-benzophenone, 2-(2'-hydroxyl One or more of -5'-)benzotriazole or 2-(2'-hydroxy-3'-tert-butyl-5'methylphenyl)-5-chlorobenzotriazole; The release agent is selected from one or more of silicone oil, polyethylene glycol or low molecular weight polyethylene; The auxiliary agent is selected from isooctyl 3-mercaptopropionate, 4-diphenyl-4-methyl-1-pentene or 4,4-dimethyl-2,4-diphenyl-1- One or more of butenes; The natural fiber is selected from hemp fiber, cotton fiber, bamboo fiber, ramie fiber, flax fiber, jute fiber or silk fiber and/or their mixed yarn, and the natural fiber cellulose content is more than or equal to 60%; The natural fibers are treated by one or more of plasma, alkali treatment or coupling agent treatment, twisted and then untwisted. 2. The resin composite material according to claim 1 prepares the method for the prepreg tape of natural fiber/resin composite material, it is characterized in that: described thermoplastic resin melt index is 10～100g/10min, is selected from polyolefin, thermoplastic One or more of polyester, polyamide or general purpose resins. 3. resin composite material according to claim 2 prepares the method for the prepreg tape of natural fiber/resin composite material, it is characterized in that: described polyolefin is selected from homopolypropylene, copolymerized polypropylene or polyethylene one or more. 4. the resin composite material according to claim 2 prepares the method for the prepreg tape of natural fiber/resin composite material, it is characterized in that: described thermoplastic polyester is selected from polyethylene terephthalate, polyethylene terephthalate Trimethylene phthalate, polybutylene terephthalate, or polylactic acid. 5. the resin composite material according to claim 2 prepares the method for the prepreg tape of natural fiber/resin composite material, it is characterized in that: described polyamide is selected from nylon 6, nylon 66, nylon 12, nylon 1212 or nylon One or more of 612. 6. The method for preparing the prepreg tape of the natural fiber/resin composite material from the resin composite material according to claim 2, characterized in that: the general-purpose resin is selected from polyvinyl chloride and/or polycarbonate. 7. the method for preparing the prepreg tape of natural fiber/resin composite material from the resin composite material described in any one of claims 1 to 6, is characterized in that: the preparation method of described resin composite material comprises the following steps: Mix 70-100 parts of thermoplastic resin, 2-5 parts of antioxidant, 2-5 parts of flame retardant, 5-10 parts of compatibilizer, 2-3 parts of weather resistance agent, 2-5 parts of mold release agent and 1-2 parts 1 part of additives, mixed in a medium-speed mixer for 3 to 7 minutes, mixed thoroughly, then added to an extruder to extrude and pelletize to obtain a resin composite material. 8. The resin composite material according to claim 7 prepares the method for the prepreg tape of natural fiber/resin composite material, it is characterized in that: described extruder is a twin-screw extruder, and screw speed is 10～250r/ min, the extrusion temperature is 150-190°C. 9. The method for preparing the prepreg tape of natural fiber/resin composite material from the resin composite material according to claim 1, characterized in that: the number of yarn shafts required for the cord fabric is 1 to 500 rolls, and the cord fabric The cloth thickness is 0.1-2mm. 10. The method for preparing a prepreg tape of natural fiber/resin composite material from the resin composite material according to claim 1, characterized in that: the stretching temperature is room temperature, and the stretching speed is the winding speed. 11. The method for preparing a prepreg tape of natural fiber/resin composite material from the resin composite material according to claim 1, characterized in that: the compaction temperature is room temperature, and the pressure is 4-10 MPa. 12. The method for preparing a prepreg tape of a natural fiber/resin composite material from a resin composite material according to claim 9, characterized in that: the number of yarn shafts required for the cord fabric is 50-200 rolls. 13. The method for preparing a prepreg tape of a natural fiber/resin composite material from a resin composite material according to claim 9, characterized in that: the number of yarn shafts required for the cord fabric is 80-150 rolls. 14. The method for preparing a natural fiber/resin composite prepreg tape from the resin composite material according to claim 1, characterized in that: the heating and drying temperature is 101-110°C, and the moisture content after drying is <1% . 15. The method for preparing a prepreg tape of natural fiber/resin composite material from the resin composite material according to claim 1, characterized in that: the temperature of the prepreg is 190-220°C, and the extrusion speed of the resin is 1-5kg /min, the dipping width is the same width as the cord fabric or 10-100mm wider than the cord fabric. 16. The method for preparing a prepreg tape of a natural fiber/resin composite material from a resin composite material according to claim 1, characterized in that: said cooling is cooling to room temperature. 17. The method for preparing a prepreg tape of a natural fiber/resin composite material from a resin composite material according to claim 1, characterized in that: the speed of said winding is 1-20 m/min.