KR100836271B1 - Electronic parts case using biocomposites reinforced with sea algae fiber - Google Patents

Abstract

A method for manufacturing an electronic parts case using biocomposites reinforced with sea algae fibers is provided to prevent an electronic parts case from being detached together with electronic parts by reducing the thermal expansion coefficient of the electronic parts case. A method for manufacturing an electronic parts case using biocomposites reinforced with sea algae fibers comprises the steps of drying sea algae fibers(S100), shattering the dried sea algae fibers(S101), and drying, shattering and dissociating the sea algae fibers into fine fibers(S102). Polymer specimen is dried to remove moisture therefrom(S200). Polymer specimen including biodegradable and general polymer is fragmentated in the form of powder(S201). The sea algae fibers are mixed with the dried polymer powder to produce an integrated mixture thereof(S300). The mixture is filled in a metal mold(S400). The metal mold is compressed at the high temperature to form a case(S500).

Description

ELECTRONIC PARTS CASE USING BIOCOMPOSITES REINFORCED WITH SEA ALGAE FIBER}

Figure 1a is a process flow diagram showing a method for producing a biocomposite material using the seaweed fiber of the present invention.

Figure 1b is a process flow diagram showing a conventional biocomposite manufacturing method.

Figure 2 is a SEM image of the excellent bio-composite dispersion of the seaweed fiber reinforcement according to the present invention.

Figure 3 is a SEM photograph of the seaweed fiber reinforced biocomposite prepared by the prior art.

4a and 4b are graphs showing the storage modulus and Tan delta of the seaweed fiber reinforced biocomposite prepared according to the present invention.

Figure 5 is a graph of the crystallinity analysis of algae and cellulose fibers prepared according to the present invention.

6a and 6b are graphs of pyrolysis characteristics of algae fibers and cellulose fibers prepared according to the present invention.

7 is a graph comparing thermal expansion characteristics of various biocomposites prepared by matrixing a polybutylene succinate polymer and mixing natural fibers as a reinforcing agent.

8a and 8b is a graph comparing the thermal expansion characteristics according to the fiber content of the biocomposite material consisting of seaweed fibers and polybutylene succinate polymer.

The present invention relates to an electronic component case using a bio-composite material made of seaweed fiber as a reinforcing material, and more particularly, to an eco-friendly environment made by using a seaweed fiber manufactured by solvent extraction and decolorization from seaweed as a reinforcing material and made by a high-temperature press molding process. The biocomposite having excellent characteristics is an electronic component case using a biocomposite material, which can be applied to an electronic component case having a high heat generation rate, so that the electronic device can be stably protected because of its very low thermal expansion and excellent thermal stability. .

In general, polymer composite materials, which are widely used in the automobile and building industries, mostly use glass fiber as a reinforcing material. Glass fiber is harmful to the human body and is difficult to recycle, causing many problems in terms of energy and environment. Recently, in order to reduce the amount of glass fibers harmful to humans, biocomposites using natural fibers as reinforcement materials have been used.

Bio-composites are about 30% lighter than glass-fiber reinforced polymer composites, so when applied to automobile parts, they are high-tech materials that can be expected to save energy by improving fuel efficiency (1.6%). The wear rate of the machine is low and light, which can save 80% of production energy in the manufacturing process. In particular, natural fibers (about 5 won / g) are about one-fourth the price of glass fibers (20 won / g), and are lighter than glass fibers (density: 2.55 g / cm3), and are more tough and have specific modulus. great. Biocomposites manufactured and used until recently mostly use cellulose-based reinforcing materials, mainly powders or fibers obtained from wood and natural fiber non-wood. However, cellulose-based reinforcing materials have various characteristics depending on the growth conditions, growth sites, and growth periods of wood or natural fibers, and especially in the case of using one of these fibers as a reinforcing material because the composition and size of each fiber are often different. In many cases, each part of the biocomposite material has different characteristics. In addition, there is a fear of side effects due to forest damage by the use of wood-based reinforcement, or the cultivation of non-wood-specific special plants such as flax, hemp, which is widely used as a reinforcement of recent biocomposites.

Algae, on the other hand, contain many fibers called muscle muscles, which are several microns in diameter and are almost constant in all algae. The crystallinity of seaweed fibers is similar to that of cellulose fibers, in particular the thermal properties of bleached algae fibers are better than that of cellulose fibers.

The inner gel extract of algae is used as food additives, health supplements, agar materials, etc., but the algae fiber is often used as a waste because there is almost no field of use. Therefore, when the algae fiber is used as a reinforcing material for bio-composite materials and used for interior or exterior materials of automobiles and houses, it can be expected to utilize high value-added industrial materials of algae fiber and to protect the environment by reducing waste. In particular, since algae have a short growth period and can obtain algae fibers having a certain composition and size according to aquaculture methods, biocomposites made of seaweed fibers as reinforcement materials have relatively uniform mechanical properties compared to cellulosic fiber reinforced biocomposites. In addition, it can also be expected to reduce the carbon dioxide effect by photosynthesis of seaweeds when farming seaweeds for mass production of seaweed fibers.

Biocomposites using seaweed fibers as reinforcement materials have superior kinematic properties compared to existing natural fiber reinforced biocomposites, and the thermal stability of seaweed fibers is also better because of their superior thermal stability. Therefore, the concern about the thermal stability of the reinforcement material is relatively low in the manufacturing process of the biocomposite material, and the reinforcement material is introduced by introducing a high temperature grinding technology that can simultaneously dry, pulverize and dissociate the algae fiber during the preparation of the seaweed fiber reinforcement. It is possible to produce a biocomposite material having excellent dispersion.

In Korea, the technology disclosed in Patent No. 2004-0051814, filed by Yu Kuk-hyun, relates to a method of decolorization and purification of fiber extracted from seaweed, and hydrolyze and remove polysaccharides of seaweed, and bleaching seaweed fiber using oxidizing agent and reducing agent. There is no information on using it as a reinforcement material for biocomposites. In addition, the technique disclosed in Patent No. 2004-0049633 filed by the same applicant relates to the development of new materials using algae and seaweed processing by-products and to a method for producing an environmentally friendly resin composition. To produce new materials by polyolefin polymer and reaction extrusion for mass production method, food packaging film, biocompatible medical material, biodegradable plastic product development. However, this new material is mainly related to functional new material film, which is different from structural materials that can be applied to interior and exterior materials of automobiles and houses, and there is no information on the dispersion of reinforcement of seaweed fibers and their dynamic characteristics, which are closely related to the performance of new materials. It has a limit of application to packaging film.

In addition, the technique disclosed in Patent No. 2005-0096042 filed by Pegasus International Co., Ltd. is a technique for producing pulp having a low content of internal gel extract from red algae, and a pulp containing a small amount of internal gel for producing paper. It is a technique to manufacture. The technique disclosed in Patent No. 2005-0092297 filed by Yuhak Chul relates to pulp and paper made from red algae, and a manufacturing method thereof. There is a difference.

In the case of foreign patents, Cellulose microfibril-reinforced polymers and their applications in USA 6103790, registered in the United States by French Elf Atochem SA, are for the manufacture and application of polymer composites using cellulose fibers as reinforcements. It is different from this technology.

COMPOSITE YARN, ARTICLE CONTAINING SUCH YARN AND METHOD FOR MAKING IT technology of EP 1007774, filed and registered by TED LAPIDUS 75008 Paris, France, manufactures fabrics using algae to use seaweed fibers in biocomposites for structural materials. It is different from this technology.

The present invention has been made to solve the above problems,

It is an object of the present invention to provide an electronic parts case that can protect internal electronics stably with low thermal expansion and excellent thermal stability by applying to a bio-generated electronic part using bio-composite material made of seaweed fiber.

An electronic component case using a biocomposite material using the seaweed fiber of the present invention as a reinforcing material for solving the above technical problem,

Drying the algae fibers, pulverizing the dried algae fibers, drying, pulverizing and dissociating the algae fibers into fine fibers, drying the polymer sample to remove moisture, and using the biodegradable polymer and general purpose. Pulverizing the polymer sample made of a polymer into a powder form, mixing the algae fiber and the dried polymer powder to form an integral mixture of the algae fiber and the polymer powder, and molding the case by compression molding the mixture under high pressure. It is prepared by a manufacturing method including a.

In the step of dissociating the dry pulverization, the algae fibers firstly pulverized with a high temperature pulverization apparatus are pulverized at 5,000 to 10,000 rpm for 25 to 100 seconds to prepare microfibers, and the temperature of the biocomposite mixture is formed at a room temperature. After heating up to 135 ~ 180 ^o C by 5 ^o C per minute, melt and apply 1000 psi pressure for 2 ~ 15 minutes.

In addition, the biodegradable polymer of the polymer sample is a polylactic acid (PLA), polycaprolactone (PCL), a blend of PCL and starch, polybutylene succinate (PBS), which is a substance decomposed by the action of microorganisms. Used from the group consisting of

General purpose polymers of the polymer sample may be selected from the group consisting of thermoplastic resins such as polypropylene, polyethylene, and polycarbonate.

The algae fiber is used in a mixture of 20 to 70 wt% with respect to the mixture of the algae fiber and the polymer sample powder to provide an electronic part case having excellent thermal stability with low thermal expansion.

The invention will become more apparent through the preferred embodiments described below with reference to the accompanying drawings. Hereinafter will be described in detail to enable those skilled in the art to easily understand and reproduce through embodiments of the present invention.

Figure 1a is a process flow chart showing a manufacturing method of a biocomposite material reinforced with seaweed fibers used in the present invention, and compared with the conventional biocomposite manufacturing process flow chart of Figure 1b,

Production of an electronic component case using a biocomposite material using the seaweed fibers of the present invention as a reinforcing material,

Drying the algae fibers (S100), pulverizing the dried algae fibers (S101), drying, pulverizing and dissociating the pulverized algae fibers into fine fibers (S102) using a high-temperature grinding device, and biodegradable Drying the polymer pellets (S200), preparing a biodegradable polymer pellets in powder form (S201), and mixing the seaweed fibers and the biodegradable plastic material in powder form (S300), and And applying the biodegradable plastic powder and the algae fiber mixture into the mold (S400) and molding the case by high temperature compression in the mold (S500).

In the step of dissociating the dry pulverization (S102), the algae fibers primarily pulverized by the high temperature pulverization apparatus are pulverized at 5,000 to 10,000 rpm for 25 to 100 seconds to produce fine fibers.

In addition, the polymer sample of the polymer pellet is a biodegradable polymer and a general-purpose polymer, and the biodegradable polymer is a polylactic acid (PLA), a polycaprolactone (PCL), a blend of PCL and starch, and poly The polybutylene succinate (PBS) can be selected and used, and the general-purpose polymer is selected from the group consisting of thermoplastic resins such as polypropylene, polyethylene, and polycarbonate.

In addition, in the step of molding the mixture of the biocomposite material (S500), the temperature is increased by 5 ^o C per minute from 135 to 180 ^o C at room temperature to facilitate melting, and a pressure of 1000 psi after the melting process. The compression process takes place for 2 to 15 minutes.

Removing the internal gel and impurities from the algae and preparing the algae fiber through decolorization, the algae fiber by hot water treatment twice a hour at 120 ^o C and 3 ~ 3.5 Bar (about 44 psi), 1 hour, 100 ^o C After 1 hour at 1 bar (about 14.5psi) and stirred for 1 hour at 90 ^o C with chlorine dioxide and stirred for 1 hour twice at 90 ^o C with hydrogen peroxide, washed with fresh water and room temperature Drying at.

The step of drying the algae fiber (S100) is to dry the extracted and bleached algae fiber at 100 ^o C for 1 hour, and the step of crushing the dried algae fiber (S101) using a general household blender for 30 seconds small Grinding into algae fibers, drying, grinding, and dissociating the algae fibers into fine fibers (S102) refers to a step of pulverizing and dissociating the primary crushed algae fibers into fine fibers using a high temperature grinding device. The algae fiber is pulverized for more than 30 seconds at 6,000 rpm using a high temperature grinding device, and only the part that has passed through an 80 micrometer sieve is used. In the grinding process, the internal temperature of the grinding apparatus rises to 70-100 ^° C., so that the algae can be dried, ground and dissociated simultaneously. At this time, since the algae fibers are pulverized at a high temperature into fine fibers, it is possible to remove excess moisture.

The biodegradable plastic pellets are kept in a vacuum oven maintained at 80 ^° C. for 5 hours and dried to remove moisture. (S200) This indicates that the properties of the biocomposite are deteriorated due to the moisture contained in the biodegradable plastics. It is to prevent. The plastic pellet is crushed into a powder form using a domestic mixer (S201).

Here, biodegradable plastic is a substance decomposed by the action of microorganisms, polylactic acid (PLA), polycaprolactone (PCL), a blend of PCL and starch, polybutylene succinate (PBS), etc. are used Can be.

In the mixing step (S300), the algae fiber and the dried biodegradable polymer powder are mixed with a domestic mixer to form an integrated mixture of the seaweed fiber and the biodegradable polymer powder. The integral mixture refers to a mixture in which biodegradable polymer powder is uniformly infiltrated and dispersed in dried, pulverized and dissociated seaweed microfibers so that no separation of fiber and biodegradable polymer powder occurs.

The mixture is molded by hot pressing compression molding, injection molding (S400), or the like. Accordingly, an electronic component case having excellent dispersion characteristics made of seaweed fiber reinforcement material and biodegradable plastic is manufactured. (S500) The electronic component case is for manufacturing a heat generating electronic product protection case, and is typically a mobile phone or a rechargeable battery. It can be applied to various products such as, camera, mp3 player and television.

Next, in one embodiment of the present invention, the biodegradable plastic is selected from red algae and algae consisting of polybutylene succinate (PBS) and algae fibers as algae fibers and red algae as a biocomposite material. Was subjected to high temperature compression molding, whereby the biocomposites were molded into 50 mm × 50 mm sizes, respectively.

Here, if the mold size is 50mm × 50mm for the optimal condition of the biocomposite manufacturing process using PBS, the temperature is increased by 5 ^° C per minute from 135 ^° C to 135 ^° C at room temperature, and then the matrix is formed at 135 ^° C. A high temperature process is run with a residence time of about 15 minutes to allow sufficient melting and resin flow.

Then, the compression process is performed by applying a pressure of 1000 psi for 3 minutes, and the mold is lowered to room temperature by using cooling water to demold the completed biocomposite panel from the mold without external impact.

2 is a cross-sectional analysis picture of the biocomposite material prepared according to the present invention, Figure 3 is a cross-sectional analysis picture of the biocomposite material according to the prior art, referring to Figure 2 is a manufacturing process of the biocomposite material according to the present invention The high temperature grinding process was added at, which shows that the algae fibers are well dispersed in the biocomposite material. FIG. 3 shows that algae fibers are mixed with seaweed fibers and biodegradable polymer powders only by using a domestic mixer without hot grinding, and thus entanglement and dispersion of the algae fibers are not well performed.

As a result, as shown in Figure 2, according to the characteristic aspect of the present invention, the biocomposite material using the seaweed fibers dried and dissociated by the high temperature grinding process as a reinforcing material shows excellent dispersion and adhesion properties between the polymer matrix, As shown in the biocomposite material prepared by mixing algae fiber and biodegradable polymer powder, it can be seen that agglomerates of algae fibers are present in the biocomposite material, resulting in poor adhesion to biodegradable plastics.

Figure 4a is a graph comparing the storage modulus and Tan delta measured from -100 ^o C to 100 ^o C of the biocomposite according to the present invention and a matrix of conventional biocomposites and biocomposites, "a" is When the algae fiber according to the present invention is used as a reinforcing material of a biocomposite material, "b" is a bioreinforcement material of the biocomposite material when "c" is used as a reinforcing material of the biocomposite material. When used as a reinforcing material of the composite material, "d" is a case where only the biodegradable plastic is used as the matrix of the biocomposite material. Figure 4b is a graph comparing the storage modulus of the biocomposites according to the present invention measured at -100 ^o C and Tg with the matrix of the conventional biocomposites and biocomposites.

When the algae fiber dried and dissociated by the on-crush method according to the present invention is used as a reinforcing material, it shows that the algae fiber-reinforced biocomposite and the heneken natural fiber-reinforced biocomposite prepared by the general mixing method exhibit superior kinetics. Can be.

FIG. 5 is a graph of crystallinity characterization of algae fibers and cellulose fibers prepared according to the present invention. The crystallinity of algae fibers measured by XRD is the same as that of cellulose fibers having 2 theta peaking at 15.4, 22.5 and 34.6. Seems.

Figure 6a and 6b is a comparison of the thermal decomposition characteristics of the resulting seaweed fibers and cellulose fibers, seaweed and seaweed extracts analysis graph according to the present invention, seaweed fibers are shown up to the decomposition peak at 370 ^o C up to the decomposition peak at 350 ^o C It can be seen that the thermal stability is superior to the cellulose fibers showing. Seaweed and seaweed extract have a lower temperature thermal stability by the gel component contained therein and show a mixture of several peaks. In particular, the seaweed raw material is characterized by thermal decomposition in a wide range of 50 ~ 150 ^° C and 220 ~ 320 ^° C.

7 is a graph measuring thermal expansion characteristics of a biocomposite material formed by mixing a mixture of PBS and various natural fibers, wherein the mixed heneken, kenaf, hardwood powder, extracted algae fiber and bleached algae fiber are 60 wt% of the total mixture was mixed. As indicated, it can be seen that the bleached and purified algae fibers dried, pulverized and dissociated according to the present invention exhibit the lowest coefficient of thermal expansion in the biocomposite material used as the reinforcing material.

In addition, Figures 8a and 8b was measured the thermal expansion characteristics of the amount of seaweed fibers added algae fiber and the biocomposite material made of PBS. The measurement was carried out to measure the thermal expansion behavior for the biocomposite material formed using a biocomposite material in which the algae fibers are mixed in a 20wt%, 30wt%, 40wt%, 50wt%, 60wt% ratio (Fig. 8a), using The coefficient of thermal expansion was calculated and shown in FIG. 8B. As shown, the higher the mixing ratio of the algae fibers, the lower the coefficient of thermal expansion, which can be stably supported and protected electronics by minimizing the strain on heat when applied to the electronics case that generates heat will be.

As described above, the present invention uses a seaweed fiber as a reinforcing material to develop a biocomposite material having superior kinetics than the biocellulose based on existing cellulose, and to add a high-temperature grinding method to the existing biocomposite manufacturing process. By using micro-algae fibers which are simultaneously dried, pulverized and dissociated seaweed fibers, bio-composites are manufactured and molded and applied to electronic parts cases to have excellent dynamic characteristics as well as excellent algae fiber dispersion in bio-composites. The low thermal expansion prevents the electronic component from being removed and has a strong support.

Although the present invention has been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that many different and obvious modifications are possible without departing from the scope of the invention from this description. Therefore, the scope of the invention should be construed by the claims described to include many such variations.

Claims (6)

Drying the algae fibers (S100), crushing the dried algae fibers (S101), drying, pulverizing and dissociating the algae fibers into fine fibers (S102), and drying the polymer sample to remove moisture Step (S200), the step of crushing the polymer sample consisting of biodegradable polymer and universal polymer in the form of a powder (S201), and mixing the algae fibers and dried polymer powder to create an integrated mixture of seaweed fibers and polymer powder (S300), applying the mixture in a metal mold (S400), and the biocomposite material using the seaweed fibers prepared by the manufacturing method including the step of molding the case by compression molding at high pressure (S500) Used electronic parts case. The method of claim 1, In the step of dissociating the dry pulverization (S102), the algae fibers pulverized by the high-temperature pulverization apparatus are pulverized at 5,000 to 10,000 rpm for 25 to 100 seconds to produce fine fibers, In the molding step (S500) of the mixture of the biocomposite material, the temperature is increased by 5 ^o C per minute from 135 to 180 ^o C at room temperature to be melted, and then a compression process is performed by applying a pressure of 1000 psi for 2 to 15 minutes. An electronic component case using a biocomposite material made of seaweed fibers as a reinforcing material. The method of claim 1, The biodegradable polymer of the polymer sample is composed of polylactic acid (PLA), polycaprolactone (PCL), a blend of PCL and starch, and polybutylene succinate (PBS), which are decomposed by the action of microorganisms. Electronic parts case using bio-composite material with reinforcement of seaweed fiber, which is selected and used from the group. The method of claim 1, The general purpose polymer of the polymer sample is an electronic component case using a biocomposite material made of seaweed fibers as a reinforcing material, characterized in that it is selected from the group consisting of thermoplastic resins such as polypropylene, polyethylene, and polycarbonate. The method of claim 1, The seaweed fiber is an electronic component case using a biocomposite material as a reinforcing material for seaweed fibers, characterized in that it is selected from the group consisting of green algae, brown algae, red algae and freshwater algae. The method of claim 1, An electronic component case using a biocomposite material as a reinforcing material of an algae fiber, characterized in that the algae fiber is used in a mixture of 20 to 70 wt% with respect to the mixture of the algae fiber and the polymer sample powder.

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