KR20240104381A - Biodegradable prepreg using lyocell and manufacturing method thereof - Google Patents

Abstract

The present invention provides a unidirectional prepreg or fabric-type prepreg of Lyocell continuous fiber composite material uniformly impregnated with a biodegradable thermoplastic resin, a method for manufacturing the prepreg, and a method for improving the physical properties of the discontinuous resin layer composition using the prepreg. It relates to biodegradable prepreg composites.

Description

Biodegradable prepreg using lyocell and manufacturing method thereof {Biodegradable prepreg using lyocell and manufacturing method thereof}

The present invention relates to a unidirectional prepreg or fabric-type prepreg of Lyocell continuous fiber composite material uniformly impregnated with a biodegradable thermoplastic resin, a manufacturing method thereof, and a biodegradable prepreg composite.

Cellulose-based fibers and fabrics have good flexibility and are mainly used as tire cords due to their characteristics such as low thermal conductivity and ultra-high temperature abrasion resistance. They are also useful as precursors for high-temperature insulation materials in the aerospace field, such as rocket nozzles and missile warheads. Rayon fiber is mainly used as a competitive material, but manufacturing facilities are gradually shrinking because chemicals harmful to the human body, such as sulfuric acid (H2SO4) and carbon disulfide (CS2), are used during fiber manufacturing. As a result, rayon is being used worldwide. Research on an eco-friendly alternative, Lyocell, is increasing. Compared to existing rayon fibers, Lyocell has a simple manufacturing process, is harmless to the environment and the human body, and has excellent dimensional stability.

Lyocell is a fiber manufactured from natural pulp and amine oxide hydrate. It has fiber properties such as tensile properties and feel that are superior to regenerated fibers, but does not generate any contaminants during the production process, and the amine used is Oxide-based solvents are recyclable and biodegradable when disposed of, so they are used in various fields as eco-friendly fibers.

Existing technologies using rayon fibers show environmental pollution problems due to the rayon fiber process and slightly lower physical properties compared to Lyocell.

Lyocell fiber is a biodegradable reinforced fiber mainly composed of cellulose, but compared to existing carbon fiber or glass fiber, which has been widely used as a reinforcing fiber for polymer resins, the tensile strength and tensile modulus of natural fibers such as lyocell fiber are low. It is difficult to expect groundbreaking improvements in mechanical properties.

In particular, in the case of lyocell and cellulose-based discontinuous fiber biodegradable resin injection compositions, the physical properties are inferior to those of the base resin, and even if the content is increased to solve this problem, it becomes more brittle and the physical properties further decrease. There is a problem. In addition, damage to lyocell fibers is prone to occur during the drawing and impregnation process for manufacturing prepreg, making it difficult to manufacture prepreg with high physical properties.

Regarding reinforcing fibers or composite materials of polymer resin, Republic of Korea Patent Publication No. 2014-0080481 discloses a fiber-reinforced resin composition comprising a resin-impregnated long fiber bundle containing (A) a thermoplastic resin and (B) rayon fiber, ( The rayon fiber of component B) has a fiber diameter of 5 to 30 μm and an Disclosed is a fiber-reinforced resin composition in which a dog bundle is impregnated with the thermoplastic resin of component (A) in a molten state, integrated, and then cut to a length of 3 to 30 mm to obtain a lightweight molded article with high mechanical strength.

In addition, Republic of Korea Patent Publication No. 2017-0139108 discloses a fiber-reinforced thermoplastic resin composition containing continuous reinforcing fibers such as glass fiber, carbon fiber, or aramid fiber and a thermoplastic resin, wherein the thermoplastic resin is a vinyl monomer containing a cyano group and an aromatic resin. Disclosed is a fiber-reinforced thermoplastic resin composition comprising a copolymer of vinyl monomer.

However, in the above methods, the impact strength, tensile strength, and flexural strength of composite resin compositions in which cellulose-based long/short fibers are mixed in biodegradable compositions such as PLA, PBAT, and starch resin are often reduced compared to the base resin. Therefore, it is necessary to develop a composition to solve this problem.

Republic of Korea Patent Publication No. 2014-0080481 Republic of Korea Patent Publication No. 2017-0139108

The present invention seeks to provide a unidirectional prepreg or fabric-type prepreg of a Lyocell continuous fiber composite material uniformly impregnated with a biodegradable thermoplastic resin, and a method for manufacturing the prepreg.

In addition, the present invention seeks to provide a biodegradable prepreg composite material that can improve the physical properties of the discontinuous resin layer composition using the prepreg.

In order to solve the above problems,

In one embodiment, the present invention provides a biodegradable prepreg using Lyocell, which includes continuous Lyocell fibers impregnated with a biodegradable thermoplastic resin, and the Lyocell continuous fibers are unidirectional (UD).

The biodegradable prepreg using Lyocell may be a unidirectional prepreg or a fabric-type prepreg.

The fabric-type prepreg includes a biodegradable thermoplastic resin layer and a plain weave layer of Lyocell continuous fibers laminated in the thickness direction to form a single layer, and the fiber surface weight of the single layer is 50 to 300. It may be g/m ² .

The Lyocell continuous fiber may be a lead-free or flexible fiber with a 900 filament bundle of 900 to 1800 denier, preferably 1200 to 1700 denier. That is, the average denier of a single fiber may be 1 to 2 denier.

The biodegradable thermoplastic resin may include one or more selected from the group consisting of amino group, glycidyl group, and amine group silane-based interfacial adhesive, epoxy resin, and combinations thereof.

The biodegradable thermoplastic resin may include a glycidyl silane-based interfacial adhesive or epoxy resin containing 0.1 to 3 wt% of nanoclay, nanoparticles, bentonite, or graphene nanoparticles.

0.5 to 5 wt% of polyamide 6 polyketone, PLA (poly lactic acid), PBAT (poly-butylene adipate terephthalate), PSA (poly succinic acid), PBS (poly Butylene Succinate), and PCL ( Adding one or more selected from the group consisting of polycaprolactone), thermoplastic starch (TPS), PHB (Poly Hyroxy Butyrate), PHA (Poly Hyroxy Akanoate), cellulose acetate, polyvinyl alcohol, and combinations thereof. You can.

In addition, in one embodiment, the present invention includes the steps of (a) supplying lyocell continuous fibers; (b) aligning the supplied Lyocell continuous fibers; (c) coating a surface treatment agent on the Lyocell continuous fiber; (d) preheating and spreading the coated Lyocell continuous fiber; And, (e) manufacturing a biodegradable prepreg by extruding a biodegradable thermoplastic resin and impregnating the Lyocell continuous fiber that has undergone step (d) above to produce a biodegradable prepreg. to provide.

The surface treatment agent, which further includes the step of cooling the biodegradable prepreg after step (d), may be a silane coupling agent and an epoxy.

The biodegradable thermoplastic resin may include a glycidyl silane-based interfacial adhesive or epoxy resin containing 0.1 to 3 wt% of nanoparticles, bentonite, or graphene nanoparticles.

In step (e), the biodegradable thermoplastic resin may be a mixture of antioxidants and hydrolysis inhibitors.

It may contain 0.3 phr or more of the antioxidant and hydrolysis inhibitor.

In addition, in one embodiment, the present invention includes a prepreg layer including a biodegradable prepreg using lyocell according to the biodegradable prepreg using lyocell; and a discontinuous resin layer laminated on one cross-section of the prepreg layer.

The biodegradable prepreg according to the present invention can improve the physical properties of the composite composition of lyocell fiber and biodegradable thermoplastic resin, and is environmentally friendly because it is manufactured based on 100% biodegradable raw materials, so it is possible to solve environmental problems.

In addition, by using a biodegradable prepreg using Lyocell continuous fibers according to the present invention, it is possible to solve the phenomenon of a decrease in the physical properties of a biodegradable composition containing a discontinuous resin layer, that is, discontinuous reinforced fibers.

Lyocell continuous fiber according to the present invention has relatively high crystal orientation and low moisture characteristics compared to rayon, has dimensional stability due to a stable linear thermal expansion coefficient, and has high heat resistance stability compared to other natural fibers and rayon. There is an advantage to having it.

Figure 1 schematically shows a method for manufacturing biodegradable prepreg using lyocell continuous fibers according to the present invention.
Figure 2 is a photograph of the pellet and focusing tape of the prepreg manufactured according to an embodiment of the present invention.
Figures 3 and 4 show the tensile strength results of the injection molded product in one embodiment of the present invention.
Figures 5 and 6 show that when a specimen was manufactured by inserting continuous fibers, the flexural properties and tensile properties were greatly improved.
Figure 7 shows the results of analyzing the crystallization behavior of the injection specimen in one embodiment of the present invention.
Figure 8 is a graph comparing impact strength by fiber length in one embodiment of the present invention.
Figure 9 is a graph comparing ductility values of samples in one embodiment of the present invention.
Figures 10 and 11 show the tensile strength (Mpa) and tensile modulus (Gpa) for each fiber thickness, interface state, fabric direction, and base resin using 1260 denier fabric fibers and 1650 denier fibers, respectively.
Figures 12 and 13 show the flexural strength (Mpa) and flexural modulus (Gpa) for each fiber thickness, interface state, fabric direction, and base resin using 1260 denier fabric fibers and 1650 denier fibers, respectively.
Figure 14 shows the pellet morphology of samples in one embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

In the present invention, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

In the present invention, "prepreg" is an intermediate substrate for fiber-reinforced composite materials, and refers to a molding material in which reinforcing fibers are pre-impregnated with a matrix resin. Continuous fiber-reinforced composites are mainly made by adding resin to unidirectional fibers or fabrics. It is made from pre-impregnated prepreg. Conventionally, thermosetting resins have been mostly used as resins pre-impregnated in prepregs, and recently, thermoplastic resins that can be reused or remolded have been widely used. A prepreg impregnated with such a thermoplastic resin is called a “thermoplastic prepreg.”

Hereinafter, the present invention will be described in detail.

The present invention provides a biodegradable prepreg using Lyocell, which includes Lyocell continuous fibers impregnated with a biodegradable thermoplastic resin, and the Lyocell continuous fibers are unidirectional (UD).

The unidirectional fiber is a fiber material in which fibers are arranged and fixed in one direction. Compared to existing fabrics, knitted fabrics, non-woven fabrics, etc., the tensile strength in the direction of the fiber axis can be maximized, and the resistance to external force is superior to that of fabrics or knitted fabrics. has.

The biodegradable prepreg using Lyocell may be a unidirectional prepreg or a fabric-type prepreg.

The fabric-type prepreg includes a biodegradable thermoplastic resin layer and a plain weave layer of Lyocell continuous fibers laminated in the thickness direction to form a single layer, and the fiber surface weight of the single layer is 50 g/m. It may be ² to 300 g/m ² .

If the fiber surface weight is 50 g/m ² , the number of bobbins that must be handled in the process increases, which not only increases the process cost, but also increases damage to the fiber during impregnation. If it is 300 g/m ² , the number of bundled fiber strands is too large. Too high pressure or too much pressing time is required to induce sufficient impregnation by film lamination.

The Lyocell continuous fiber may have a denier of 900 to 1800, for example, 1200 to 1700 denier based on a 900 filament bundle, and may be a lead-free or flexible fiber. That is, the average denier of a single fiber may be 1 to 2 denier. If the average denier is less than 1, there is a risk that the unevenness of the fiber increases due to process variables during fiber production, and the damage rate of the fiber increases during impregnation. If the average denier is more than 2, the elongation of the fiber decreases. There is a problem in that the tensile strength of the yarn decreases and the elastic modulus of composite materials manufactured with the same fiber content decreases.

The Lyocell continuous fiber may have been surface treated with a surface treatment agent. The surface treatment agent may include epoxy resins with multiple epoxy functional groups or silane-based compounds (GMS) with epoxy ends. The moisture and water content of Lyocell continuous fibers can be improved by the surface treatment.

The biodegradable thermoplastic resin may include one or more selected from the group consisting of amino group, glycidyl group, and amine group silane-based interfacial adhesive, epoxy resin (bisphenol free epoxy resin), and combinations thereof. For example, the biodegradable thermoplastic resin may be an epoxy resin.

The biodegradable thermoplastic resin may include a glycidyl silane-based interfacial adhesive or epoxy resin containing 0.1 to 3 wt% of nanoparticles, bentonite, or graphene nanoparticles. If the nanoparticles are less than 0.1%, the reinforcing effect is minimal, and if the nanoparticles are more than 3 wt%, there may be a problem of deterioration of physical properties by interfering with impregnation of the resin into the fibers.

The biodegradable thermoplastic resin includes 0.5 to 5 wt% of polyamide 6, polyketone, PLA (poly lactic acid), PBAT (poly-butylene adipate terephthalate), PSA (poly succinic acid), PBS (poly butylene succinate), and PCL. (Polycaprolactone), thermoplastic starch (TPS), PHB (Poly Hyroxy Butyrate), PHA (Poly Hyroxy Akanoate), cellulose acetate, polyvinyl alcohol, and combinations thereof. You can. This can facilitate the process and increase the crystallization rate by using at least 0.5% or more of a release resin at a level of 5% or less that does not reduce the crystallinity of the resin, which has an effective effect in strengthening the physical properties when forming a composite material. Additionally, adding the above materials to the biodegradable thermoplastic resin can improve heat deflection temperature (HDT). For example, PLA can improve the elastic modulus and lower the processing temperature when processing prepreg, thereby preventing deterioration of the biodegradable thermoplastic resin during high temperature molding.

The biodegradable prepreg according to the present invention can improve the physical properties of the composite composition of lyocell fiber and biodegradable thermoplastic resin, and is environmentally friendly because it is manufactured based on 100% biodegradable raw materials, so it is possible to solve environmental problems.

Additionally, the present invention provides a method for producing biodegradable prepreg using the lyocell.

Figure 1 schematically shows a method for manufacturing biodegradable prepreg using lyocell continuous fibers according to the present invention.

Referring to Figure 1, the method for manufacturing biodegradable prepreg using Lyocell includes the steps of (a) supplying Lyocell continuous fibers; (b) aligning the supplied Lyocell continuous fibers; (c) coating a surface treatment agent on the Lyocell continuous fiber; (d) preheating and spreading the coated Lyocell continuous fiber; And, (e) extruding a biodegradable resin and impregnating the lyocell continuous fiber that has undergone step (d) to produce a biodegradable prepreg.

It may further include the step of cooling the biodegradable prepreg after step (d).

The biodegradable thermoplastic resin may include a glycidyl silane-based interfacial adhesive or epoxy resin containing 0.1 to 3 wt% of nanoclay, nanoparticles, bentonite, or graphene nanoparticles.

The surface treatment agent may be a silane coupling agent or epoxy resin.

In step (e), the biodegradable thermoplastic resin may be a mixture of antioxidants and hydrolysis inhibitors.

It may contain 0.3 phr or more of the antioxidant and hydrolysis inhibitor.

The biodegradable thermoplastic resin has a processing temperature of about 190 to 260°C, and considering the improvement of the interface at this processing temperature and the generation of decomposition radicals at high temperatures, the antioxidant and hydrolysis inhibitor are added to further improve the physical properties and appearance. It can be improved. For example, the antioxidant and antioxidant may each contain 0.3 to 1.0 phr.

Additionally, the biodegradable thermoplastic resin may include a heat stabilizer, nanoclay, and bentonite.

In addition, the present invention includes a prepreg layer containing a biodegradable prepreg using lyocell according to the biodegradable prepreg using lyocell; and a discontinuous resin layer laminated on one cross-section of the prepreg layer.

Mutual chemical reactivity between the prepreg layer composition and the discontinuous resin layer composition may be induced by laminating the prepreg layer and the discontinuous resin layer.

The discontinuous resin layer may include any one of carbon fiber, glass fiber, and basalt fiber. Alternatively, it may contain cellulose-based natural fibers (jute, kenaf, lamie, pulp, hemp, wood pulp, sisal, etc.).

The biodegradable prepreg composite can improve physical properties, which are problems with the discontinuous resin layer, and also improve lightness by laminating the prepreg layer and the discontinuous resin layer.

Hereinafter, the present invention will be described in more detail through examples according to the present invention, but the scope of the present invention is not limited to the examples presented below.

[Example]

Example 1: Preparation and analysis of Lyocell unidirectional continuous fiber biodegradable prepreg

Supply and align Lyocell continuous fibers (1650 denier, 1260 denier lead-free fiber or 1260 denier, 900fillaments/tow flexible fiber) and apply surface treatment agent [(3-Glycidyloxypropyl)trimethoxy silane, Difunctional epoxy or 4,4-diaminodiphenylene-methane] The fiber was coated with. Biodegradable thermoplastic resin with water decomposition inhibitor (Zico) - ZIKA-AH362, heat stabilizer (Zico) - ZIKANOX-549DF, nanoclay [MMT (Nanoko - na+ d 3.15nm, particle size 10um or less)] and bentonite [15A, d 3.15nm, particle size 10um or less, 54.5% Bentonite + 43% (ammonium compound + animal fatty acid Alkyldimetyl chloride)] were mixed and extruded to impregnate the fiber.

As shown in Figure 2, after manufacturing the strand, the prepreg was manufactured into a pellet (approximately 6 mm, approximately 10-12 mm pellet) and a focusing tape (12-20 str. width 10-20 cm, thickness 0.3 mm), respectively.

A comparison of properties after pelleting was conducted to enable simple comparison of impregnation states by composition. Detailed compositions of the strand and pelleting samples are shown in Table 1 below.

[Table 1]

The characteristics of the prepared samples are as follows.

- Long fiber pellets are made by drawing and impregnating natural fibers and lyocell.

- It is advantageous in terms of distribution and dispersion of fibers when manufacturing short-fiber pellets of 3 to 8 mm rather than long-fiber pellets of 10 mm or more, and long fiber length is advantageous in terms of impact resistance properties.

- In the case of short LFT pellets, the pellet shape is sensitive to the degree of resin impregnation (see Figure 14).

- If the degree of impregnation is low, cracking and clumping of unimpregnated fibers occur.

- The external appearance of the pellet shows a rough impregnation state: the less cracking and flying fibers, the better the impregnation state of the thermoplastic resin. When the fiber content increases, the cracking slightly increases even in a similar impregnation state.

- In the case of 1260 denier fiber, good pellet properties were shown despite the fiber content being higher than that of 1650 denier fiber.

Meanwhile, Table 2 below shows the blank composition by fiber diameter of the prepreg 0/(90/0) ₅ specimen manufactured by drawing and impregnating continuous fiber 1260 and 1650 denier lead-free fiber (blank).

[Table 2]

Table 3 below shows the blank physical properties by fiber diameter of the drawn and impregnated prepreg 0/(90/0) ₅ specimens manufactured with continuous fiber 1260 and 1650 denier-lead-free fiber (blank).

[Table 3]

The case of using 1260denia showed higher tensile strength, flexural strength, flexural modulus, and ILSS values despite having a lower content than that of 1650denia.

Example 2: Analysis of injection molding properties of long fiber composite materials

1) Lyocell and kenaf LFT (Long fiber thermoplastic) injection composition

Kenaf LFT and lyocell LFT on PLA, samples with 10% and 20% fiber content were compared, and tensile and flexural strengths were analyzed after forming the PLA base. The specific composition is shown in Table 4 below.

[Table 4]

2) Physical property analysis of Lyocell and kenaf LFT injection specimens

The physical property analysis results of Lyocell and kenaf LFT injection specimens are shown in Table 5 below.

[Table 5]

3) Tensile strength analysis of injection molded products

The tensile strength results of the injection molded product are shown in Figures 3 and 4.

Referring to Figures 3 and 4, the tensile strength of Lyocel LFT was higher than that of Kenaf LFT.

By improving the crystallinity of PLA and using a small amount of epoxy resin, the fiber interface adhesion was improved, resulting in an additional improvement in tensile strength: Blank (L175) < 3.5%, PLA D-type (D070) < 3.5% Epoxy (Kumho Poly) Chem KER3004)

When MAH-graft PP (MP600) and Poly Carprolactone, which are comparative examples, were added, the tensile/flexural properties actually decreased.

It was found that the tensile properties of PLA itself were very excellent, so it was not easy to further improve the properties through the manufacture of fiber-reinforced composite materials.

４）Analysis of bending properties of injection molded products

The flexural strength of the injection molded products was similar to the tensile strength trend. Compared to the base resin, the flexural modulus improved by 142% with 10% Flex, 200% when using 20% Flex, 130% with 10% Lyocell, and 170% when using 20% Lyocell, giving flex an advantage over lyocell. The flexural modulus is also very excellent in the physical properties of PLA itself, and although further improvement is achieved through the manufacture of fiber-reinforced composite materials, it is not significantly improved compared to other resins.

Meanwhile, referring to Figures 5 and 6, when a specimen was manufactured by inserting continuous fibers, the flexural properties and tensile properties were significantly improved.

Natural fiber and Lyocell injection specimens were molded by fiber content (10%, 20%, etc.), and Lyocell continuous fiber prepreg to be inserted was cut and prepared in advance.

The Lyocell continuous fiber prepreg was inserted in advance and then injected to combine the Lyocell continuous fiber prepreg.

The injection composition is composed of low-cost kenaf and milled Lyocell, and continuous fiber composite material with excellent physical properties is inserted and injected to efficiently improve the flexural modulus and flexural strength. The tensile strength and modulus of elasticity are greatly improved, and the ductility of the composite material is improved. was improved from 2 to 3 times.

5) Comparison of moisture content of injection specimens

The moisture content of the injection specimens was compared and shown in Table 6 below.

Moisture and water content were lower for the lyocell composite material compared to Kenaf, and the moisture content increased in proportion to the fiber content. Additionally, when epoxy resin was used, the moisture content decreased somewhat.

[Table 6]

6) Analysis of crystallization behavior of injection specimens

The crystallization behavior of the injection specimen was analyzed and shown in Figure 7.

As a result of DSC comparison before and after oven aging (105 degrees, 90 minutes), the high molecular weight epoxy resin induced crystallization similar to D-type PLA, and the tensile/flexural properties increased when using epoxy resin KER 3004 3.5phr.

Example 3: Improving impact strength through continuous fiber prepreg

1) Unnotched izod for specimens injection and compression molded by mixing milled fiber or long fiber lyocell and compressed specimens of Lyocell continuous fiber composite material (50% lyocell/PLA, 0/90/0/90/0 degrees) As a result of comparing the iimpac strength and the impact strength by fiber length, it was found that the impact strength was significantly improved by more than 4 times when continuous fibers were incorporated (see Figure 8, Table 7 and Table 8).

In the case of compressed and extruded specimens of discontinuous fibers, the impact strength increases as the length of the mixed fibers increases, but sufficiently improved values are not observed, and it is difficult to significantly improve the impact strength even when the fiber content increases by more than 30%.

Solution: Impact strength can be greatly improved through the incorporation of continuous fiber prepreg.

[Table 7]

[Table 8]

2) Improvement of impact strength through continuous fiber prepreg - surface impact strength (Instron Dynatub 9350)

Surface impact strength was compared with lyocell chopped fiber and PLA-based continuous fiber prepreg using dynatub (Instron) equipment and is shown in Table 9 below.

Among automotive parts, we compared whether WLFT 311BL, an advanced glass fiber composite mainly used in knee bolsters, lower impact bars, under covers, and load floors, could be replaced with biodegradable composite resin.

It was confirmed that the above target properties could be achieved by using cross-laminated or woven lyocell continuous fiber composites, and it was found that glass fiber composites could be replaced with only eco-friendly biodegradable composites.

[Table 9]

3) Improved impact strength through continuous fiber prepreg - Toughness

The effect of improving impact strength through continuous fiber reinforcement is also seen in a comparison of ductility values (cross-sectional area up to the point of fracture of the stress strain curve) that can be determined when measuring the tension of a specimen with B-CFRTP insert (see Figure 9). ). In other words, it was seen that the ductility value of the specimen with B-CFRTP insert increased by 2 to 3 times compared to the injection specimen.

Example 4; Manufacturing of Lyocell continuous fiber plain fabric biodegradable prepreg

The final prepreg was prepared by cooling the biodegradable prepreg.

Table 10 below shows the laminate composition between fabric and film during the impregnation process.

Specifically, Lyocell (1260d) fabric 105mm×3.5m dry weight 524g (142.58g/m2);

PBATfilm (PBAT /PLA(65/45)) 800*3.5 207.92g (74.26 g/m2),

PLA film(PLA/PBAT(95/5) 840*300mm 7.44 (29.52 g/m2)

[Table 10]

Figure 10 shows the tensile strength (Mpa) for each fiber thickness, interface state, and base resin using 1260 denier fibers and 1650 denier fibers.

Figure 11 shows the tensile modulus (Gpa) of fiber thickness, interface state, and base resin using 1260 denier fiber and 1650 denier fiber.

Figure 12 shows the flexural strength (Mpa) for each fiber thickness, interface state, and base resin using 1260 denier fiber and 1650 denier fiber.

Figure 13 shows the flexural modulus (Gpa) for each fiber thickness, interface state, and base resin using 1260 denier fiber and 1650 denier fiber.

Through the results of FIGS. 10 to 13, which are the experimental results of Example 4, when manufacturing a Lyocell continuous fiber composite through the method of melting and pressing a fabric film, the number of strands of the unit fiber bundle of Lyocell is about 800 filaments, and carbon fiber and Because it is produced with a smaller number of strands than glass fibers, the cotton weight of the woven fabric can be kept low at 50 to 300 g/m ² , so biodegradable prepreg using lyocell, which is characterized by this, is pressed and pressed with a film. It was found that it was possible to easily manufacture it using this method.

In addition, it can be seen that the physical properties are improved by about 70% or more by spray coating a compound having an epoxy functional group in which epoxy resin or nanoclay is dispersed as an interfacial binder for the fiber. This improved biodegradable prepreg can be used as an equivalent member to the unidirectional prepreg during insert injection as in Example 2. It is also useful for reinforcing other materials.

Claims (14)

It includes a prepreg made of Lyocell continuous fibers impregnated with a biodegradable thermoplastic resin,
The prepreg is a biodegradable prepreg using lyocell, characterized in that it is a unidirectional prepreg or a fabric-type prepreg.
In paragraph 1.
A biodegradable prepreg using lyocell, characterized in that the number of strands of fibers, which are the basic units of lyocell fibers constituting the prepreg, is about 600 to 1200 strands.
According to paragraph 2,
The fabric-type prepreg,
It includes one or more layers by laminating a biodegradable thermoplastic resin layer and a layer of lyocell continuous fibers woven in a plain weave in the thickness direction,
A biodegradable prepreg using lyocell, characterized in that the fiber surface weight of one layer is 50 to 300 g/m ² .
According to paragraph 1,
The Lyocell continuous fiber is a biodegradable prepreg using Lyocell, characterized in that it is a 1 to 2 denier lead-free or flexible fiber based on a single fiber.
According to paragraph 1,
The biodegradable thermoplastic resin is a biodegradable prepreg using Lyocell, wherein the biodegradable thermoplastic resin includes at least one selected from the group consisting of amino group, glycidyl group, and amine group silane-based interfacial adhesive, epoxy resin, and combinations thereof.
According to paragraph 1,
The biodegradable thermoplastic resin is a biodegradable prepreg using Lyocell, which includes a glycidyl group silane-based interfacial adhesive or epoxy resin containing 0.1 to 3 wt% of nanoclay, nanoparticles, bentonite, or graphene nanoparticles.
According to paragraph 1,
0.5 to 5 wt% of polyamide 6 polyketone, PLA (poly lactic acid), PBAT (poly-butylene adipate terephthalate), PSA (poly succinic acid), PBS (poly Butylene Succinate), and PCL ( Adding one or more selected from the group consisting of polycaprolactone), thermoplastic starch (TPS), PHB (Poly Hyroxy Butyrate), PHA (Poly Hyroxy Akanoate), cellulose acetate, polyvinyl alcohol, and combinations thereof. Characterized by biodegradable prepreg using lyocell.
(a) supplying lyocell continuous fibers;
(b) aligning the supplied Lyocell continuous fibers;
(c) coating a surface treatment agent on the Lyocell continuous fiber;
(d) preheating and spreading the coated Lyocell continuous fiber; and,
(e) manufacturing a biodegradable prepreg by extruding a biodegradable thermoplastic resin and impregnating the lyocell continuous fibers that have undergone step (d) above to produce a biodegradable prepreg.
According to clause 8,
A method for producing a biodegradable prepreg using lyocell, further comprising the step of cooling the biodegradable prepreg after step (d).
According to clause 8,
The biodegradable thermoplastic resin is a biodegradable prepreg using Lyocell, which includes a glycidyl group silane-based interfacial adhesive or epoxy resin containing 0.1 to 3 wt% of nanoclay, nanoparticles, bentonite, or graphene nanoparticles. Manufacturing method.
According to clause 8,
A method of producing a biodegradable prepreg using lyocell, wherein the surface treatment agent is a silane coupling agent and an epoxy resin.
According to clause 8,
In step (e), the biodegradable thermoplastic resin is a method of producing a biodegradable prepreg using lyocell, characterized in that the biodegradable thermoplastic resin is mixed with an antioxidant and a hydrolysis inhibitor.
According to clause 12,
A method for producing a biodegradable prepreg using lyocell, characterized in that it contains 0.3 phr or more of the antioxidant and hydrolysis inhibitor.
A prepreg layer containing a biodegradable prepreg using lyocell according to claim 1; and
A biodegradable prepreg composite comprising a discontinuous resin layer laminated on one cross section of the prepreg layer.