KR20070059750A - Nontoxic and antibiotic composition and baby-cellular phones produced by them - Google Patents

Abstract

Provided is an antimicrobial polycarbonate resin composition, which has nontoxicity and an antibacterial property, is suitable for a molded product of a baby cellular phone body having excellent transparency and impact resistance, and does not contain low-molecular-weight components. The antimicrobial polycarbonate resin composition comprises a polycarbonate resin having a residual bisphenol A content of 30ppm or less, a melt index(300°C, 1.2Kg) of 3-30g/10min, and a polydispersity(Mw/Mn) of 3 or less, and silver particles having an average particle size of 50nm or smaller, which are contained in an amount of 10-500ppm. The polycarbonate has a fraction of low molecules with a weight average molecular weight of 1000 or less of 1wt% or less.

Description

Nontoxic and antibiotic composition and baby-cellular phones produced by them

The present invention relates to a compound composition suitable for an infant cell phone body molded article having a non-toxic, antibacterial and excellent transparency and impact resistance, and an infant cell phone using the same.

   In modern life, mobile phones have become a necessity of life with the development of the information industry, and the amount is increasing rapidly. In particular, the demand for mobile phones was initially adult, but gradually expanded to middle and high school students, and is now expanding to elementary school students.

   Korea's MBC TV was aired on December 26, 2004. In the program called "Real!", The theme of "Baby's favorite cell phone lives with bugs" was introduced about infants and cell phones. This information breaks the popular belief that infants are much more fond of pretty dolls than cell phones and introduces them as extremely mobile phones. In comparison experiments with infants, they preferred mobile phones rather than pretty dolls, and mobile phones, rather than brick-shaped, old-fashioned, older mobile phones. Is showing. In the opinions of the experts introduced here, infants usually rely on animal senses such as hearing and vision, rather than reason, and are stimulated by cheerful ringtones and brilliant colors. They also use mobile phones as powerful beings to control their best believing mother. Recognition increases the desire to possess more and more. Because of this, infants cannot tolerate the torch, so mothers usually give mobile phones to infants, causing serious problems. In other words, unlike adults, infants bite their cell phones for a long time, which can cause corrosion of the battery. In addition, unlike adults, they can be pierced by antennas and sometimes thrown at random, which can easily be damaged if they are made of a material with poor impact resistance, resulting in economic loss as well as injury to infants.

In addition, the cell phone handed to the infant is full of bacteria that can cause various diseases. First, the ATP test, which is useful for monitoring hygiene in the food field, was performed on the mothers' hands, indicating that the mother's hands were more dirty than the standard 1,500 RLU. Subsequently, a large number of bacteria and Staphylococcus aureus were detected in the bacterial test incubated for 48 hours in a 35 ° C incubator. According to the expert in charge of evaluation, unlike mobile phones, mobile phones are not suitable for germ growth, but unlike adults, infants like to suck and have a very high immunity. Pointing out. As such, there is an urgent need for new breakthrough products that can solve the above problems in mobile phones with high preference for infants. That is, there is an urgent need for the emergence of mobile phones exclusively for infants, which are safe for infants to bite or suck for long periods of time, satisfying their favorite auditory and visual elements, and not throwing them into action by throwing them. In order to satisfy such a mobile phone, in the case of a mobile phone body, non-toxic and antibacterial material is essential to ensure safety, and a material capable of easily expressing colorful colors to satisfy visual elements is desirable. Transparency is required. In addition, excellent impact resistance is required at the same time in order not to be damaged by sudden action such as throwing. In other words, the emergence of a baby cell phone body molded article based on a non-toxic, anti-bacterial and excellent transparency and impact resistance at the same time, and the emergence of infant-only cell phones using the same.

MEANS TO SOLVE THE PROBLEM In order to solve the said problem, the present inventors earnestly studied and came to this invention.

That is, the present invention is to provide a compound composition suitable for an infant cell phone body molded article having a non-toxic, antibacterial and excellent transparency and impact resistance, and an infant cell phone using the same.

In another aspect, the present invention provides a manufacturing composition of the cellular phone for infants made of a polycarbonate having a transparency and impact resistance of little low-molecular weight component leaked by use during use without compromising the health of the infant.

In order to solve the above problems, the present invention contains a residual bisphenol A content of 30ppm or less, preferably 10ppm or less, melt index (300 ℃, 1.2Kg) 3 ~ 30g / 10min, polydispersity (Mw / Mn) 3 It is to provide a compound composition characterized in that the polycarbonate resin is composed of 10 to 500ppm of silver particles having an average particle diameter of 50nm or less.

In addition, the present invention contains a residual bisphenol A content of 30ppm or less, preferably 10ppm or less, melt index (300 ℃, 1.2Kg) 3 ~ 30g / 10min, polydispersity (Mw / Mn) 3 or less, Polycarbonate resin having an average molecular weight of 1,000 or less by gel permeation chromatography of less than 1% by weight, preferably 0.5% by weight or less, containing 10 to 500 ppm of silver particles having an average particle diameter of 50 nm or less It is to provide a compound composition, characterized in that.

In another aspect, the present invention is to provide a mobile phone body molded article characterized in that obtained by injection molding the obtained compound composition, and a mobile phone for infants comprising such a body molded article for the mobile phone.

The polycarbonate resin used in the present invention may be prepared using a raw material such as bisphenol A, phosgene, or the like as described in Korean Patent Laid-Open Publication No. 2005-62621 in the presence of a suitable catalyst. However, due to the nature of the polymer, a considerable amount of unreacted residual monomer may be present depending on the polymerization method and conditions, and have various molecular weights (weight average molecular weight Mw, number average molecular weight Mn, etc.) and molecular weight distribution. In particular, bisphenol A, which is an unreacted residual monomer of polycarbonate resin, is classified as a representative environmental hormone, and the polycarbonate according to the present invention preferably has a residual bisphenol A content of 30 ppm or less, and preferably a polycarbonate content of 10 ppm or less. Carbonate should be used, but if the residual bisphenol A content exceeds 30ppm, infants with insufficient immunity may be eluted by saliva when sucked, causing fatal diseases.

In addition, low molecular weight components with a molecular weight of 1,000 or less can be absorbed by the human body by shifting over time when the infant bites or sucks, and preventing them is particularly important for infants. The molecular weight distribution is usually evaluated in terms of polydispersity (Mw / Mn). If the polydispersity is large, the molecular weight distribution is wide, and if it is small, the molecular weight distribution is narrow. Therefore, if the polydispersity is large, there is a high possibility that a large number of low molecular weight components are present. The polycarbonate resin according to the present invention preferably has a polydispersity of 3 or less. If the polydispersity exceeds 3, there is an advantage in that the processability is excellent, but since a large amount of low molecular weight components having a molecular weight of several thousand or less is present, the risk of eluting by saliva or sweat of infants cannot be achieved. .

In addition, in the present invention, the weight average molecular weight measured by gel permeation chromatography is very high, as well as the molecular weight distribution (polydispersity) as described above, as well as the high risk of substantially eluting by saliva or sweat of infants. The lower molecular weight components below were further limited to 1% by weight, preferably 0.5% by weight, thereby minimizing the body absorption of the infants.

In addition, the polycarbonate resin according to the present invention can be molded in the body for a mobile phone by the usual injection processing, the melt index (300 ℃, 1.2Kg) is preferably in the range of 3 ~ 30g / 10min. If it is less than 3, the impact resistance is excellent, but fluidity is poor, and workability is poor. If it exceeds 30, fluidity is good, and workability is excellent, but satisfactory impact resistance cannot be secured.

In the present invention, the method for minimizing the unreacted monomer of the low molecular weight and bisphenol A is to adjust the molar ratio of the monomers, or to remove the low molecular weight by sufficiently leaving the polymerization temperature and reaction time, the method of extraction with poor solvent after polymerization Can be used. Polycarbonate resins satisfying the conditions of the present invention include, for example, Lexan 144R, HF1140R, etc., which have passed US Food and Drug Administration (FDA) regulations.

Recently, the products of cellular phone body made of acrylonitrile-butadiene-styrene copolymers are corroded with chromic acid and plated with nickel-chromium, and they are widely used. Loss can often be found. When using this type of material in a baby cell phone, it is not desirable because it is easy to wear due to the characteristics of infants who handle roughly, and it can be peeled off by sweat and saliva, so that the nickel-chromium particles, which are a kind of heavy metals, fall off and are ingested by those with weak immunity. . Therefore, the brilliant color to stimulate the eyes of the infant can be secured by selecting and adding a variety of pigments and dyes known to be safe to the polycarbonate resin according to the present invention excellent in transparency rather than the plating product as described above. In addition, the acrylonitrile-butadiene-styrene copolymer used in adult mobile phones as described above is more economical compared to the polycarbonate resin according to the present invention, but infants are less powerful than adults, although they are inferior in strength. High impact resistance is required and the acrylonitrile-butadiene-styrene copolymer is not sufficient and the polycarbonate resin according to the present invention satisfies these quality requirements well.

However, only the polycarbonate resin according to the present invention is insufficient in securing safety as a tool for mobile phones used by infants. In other words, the lack of safety due to the elution of residual unreacted substances and low molecular weight components present in the resin is also serious, but the lack of safety by the bacteria that nourish saliva, sweat, milk, etc. secreted by infants is also very serious.

Therefore, to prevent this, it is not possible to boil the phone and cleaning the surface of the phone frequently is very cumbersome. What was introduced as a means to solve this problem is to use a compound composition containing 10 ~ 500ppm of silver particles having an average particle diameter of 50nm or less in the polycarbonate resin according to the present invention as a portable body molded material.

The antimicrobial properties of finely pulverized fine particles of metal elements such as silver, copper, nickel, chromium, cobalt and zinc have been well known for a long time. Nevertheless, most of the metals except silver are not suitable for the purposes of the present invention because they are heavy metals and have a lethal toxicity to the human body. Therefore, the antimicrobial property provision by silver particle is preferable. Yet another object of the present invention is to require excellent transparency in order to impart a gorgeous aesthetics. Therefore, silver particles having a large average particle diameter usually obtained by mechanical grinding are well dispersed through the compounding process, but there is a problem of impairing transparency due to diffuse reflection when present in the resin. The solution to this problem is the introduction of so-called silver nanoparticles of silver particles having an average particle diameter of 50 nm or less. These silver nanoparticles have a very small particle size, so the surface area is wider and the antimicrobial effect on the same weight is greater.However, the silver nanoparticles are difficult to disperse due to their small size. In view of this, it is suitable for the purpose of the present invention. Such silver nanoparticles can be obtained in colloidal form or powder form, for example, by the method described in Korean Patent No. 2005-479847. However, since a small amount of silver nanoparticles are dispersed in the polycarbonate resin, the powder form is highly concentrated on one side, but the colloidal form is a kind of liquid, which is more advantageous for uniform dispersion. However, the colloidal form is advantageous in the dispersion, but the removal of the solvent of the intrinsic alcohol is a problem, for example, it can be solved to some extent by evaporating and venting through the fine outlet during the compounding process in a single screw or twin screw compounding compound. In order to remove such a perfect solvent and to further improve the dispersibility, the colloidal or powdered silver nanocomponents are mixed with polycarbonate pellets, and then agitated in a high speed stirrer and subjected to collision friction with the pellets in the stirrer. The outer surface is slightly melted and adsorbed onto the surface of the polycarbonate, and is then extruded through an extruder to prepare a polycarbonate masterbatch containing silver nanoparticles, which is then blended in an extruder with a polycarbonate resin to completely remove the solvent. In addition, the dispersibility of the silver nanoparticles is more perfect to maintain transparency. In the present invention, the processing conditions such as extrusion for producing the master batch is carried out in the same temperature and pressure range as the conditions for injecting the molded article.

The silver nanoparticles used in the present invention have an average particle diameter of 50 nm or less, preferably 20 nm or less, and preferably 10 to 500 ppm, preferably 20 to 100 ppm, in the polycarbonate resin. If it is less than 10ppm, satisfactory antimicrobial activity cannot be obtained, and if it exceeds 500ppm, the transparency is inferior and the economy is deteriorated due to the high price. In addition, the silver nanoparticles are preferably in the form of a composition by compounding with a polycarbonate resin, and the coating on the surface of a molded product made of a polycarbonate resin is preferable because of the high risk of abrasion and wear due to rough behavior and sweat, saliva, etc. of infants. Not.

The compound composition according to the present invention thus obtained can be used for various toys for infants as well as the body for infant mobile phones.

As described above, the compound composition according to the present invention and the body for a mobile phone molded therefrom have extremely low content of bisphenol A, an unreacted residual monomer classified as an environmental hormone, and very low molecular weight components due to a narrow molecular weight distribution. There is no risk of elution even if it is bitten and sucked. Since there are nano-sized silver particles with excellent antimicrobial properties, it is safer to sterilize germs that may exist in the body of a mobile phone. By adding and adding pigments and dyes, it is possible to secure aesthetics and have excellent impact resistance.

Through the following examples will be described in more detail the present invention. The following examples are merely examples and are not limited to the examples.

The polydispersity and low molecular weight content of the compound composition for a baby cell phone prepared according to the following Examples and Comparative Examples was measured, and the cytotoxicity, antimicrobial activity, light transmittance and the like for the cell phone body prepared using the compound composition. Impact strength was measured as follows.

(Content of polydispersity and low molecular weight component)

The polydispersity (Mw / Mn) and the content (%) of low molecular weight components having an average molecular weight of 1,000 or less were measured using a gel permeation chromatograph (Waters) using polystyrene as a standard for the compound composition.

(Cytotoxicity)

The test was conducted in accordance with the KP plastic pharmaceutical container test method, eluate test method and cytotoxicity test method. That is, the body for the mobile phone was taken to be 600m ² , finely cut it again, washed with water, dried, put in a flask, and 200ml water was refluxed at 50 ° C. for 72 hours, and then subjected to cytotoxicity test using the extracted solution. Cell lines used L925 cells (ATCC. CCL1). A sample concentration (IC50 (%)) of 50% colony formation for standard and test specimens is determined to be negative if greater than 90%, and to be positive if not. Negative means no toxicity and positive means toxic.

(Antibacterial)

Using E. coli (ATCC 25922) and Staphylococcus (ATCC 6538) as strains, the number of bacteria was measured after 24 hours shaking culture at 35 ℃.

(Light transmittance)

Light transmittance (%) was measured according to ASTM D1004 as a measure of transparency.

(Impact strength)

The drop daart impact strength (cm-kg) was measured according to ASTM D3029 (23 ° C).

Example 1

Polycarbonate with 5 ppm residual bisphenol A content, melt index (300 ℃, 1.2Kg), 10.5 g / 10min, polydispersity (Mw / Mn) 2.6 and low molecular weight component with weight average molecular weight of 1,000 or less (0.4%) 500 ppm of silver particles having an average particle diameter of 7 nm was added to the resin (A) and stirred in a high speed stirrer to melt the surface of the polycarbonate pellets to adsorb the silver particles. The polycarbonate pellets to which the silver nanoparticles were adsorbed were introduced into a twin screw extruder and extruded at 295 ° C. to prepare a polycarbonate masterbatch containing silver nanoparticles.

The prepared master batch was mixed with the same polycarbonate resin (A) so as to be 10% by weight, and kneaded and injected at 302 ° C to obtain a body molded product sample containing 50 ppm of silver particles having an average particle diameter of 7 nm. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured for the obtained samples, and the results are shown in Table 1.

Example 2

The polycarbonate masterbatch containing 500 ppm of silver particles having an average particle diameter of 7 nm obtained in Example 1 was mixed with the polycarbonate (resin (A)), kneaded and injected in the same manner as in Example 1, and then average particle size A sample of a body molded article for a mobile phone containing 15 ppm of silver particles having a thickness of 7 nm was obtained. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured for the obtained samples, and the results are shown in Table 1.

Example 3

Polycarbonate with 8 ppm residual bisphenol A content, melt index (300 ℃, 1.2Kg) 25 g / 10min, polydispersity (Mw / Mn) 2.3, low molecular weight component with weight average molecular weight of 1,000 or less 0.3% A mixture containing 5 wt% of a colloidal solution containing 500 ppm of silver particles having an average particle diameter of 5 nm in (resin (B)) was obtained. This mixture was compounded in a biaxial screw compounding machine, and was carried out in the same manner as in Example 2 except that resin (B) containing 25 ppm of silver particles having an average particle diameter of 5 nm was prepared as a compound composition. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured on the obtained body molded product samples for mobile phones, and the results are shown in Table 1.

Example 4

Polycarbonate having a residual bisphenol A content of 3 ppm, a melt index (300 ° C., 1.2 Kg) of 5 g / 10 min, a polydispersity (Mw / Mn) of 2.8, and a low molecular weight component having a weight average molecular weight of 1,000 or less (0.6%) A mixture obtained by containing 4% by weight of a colloidal solution containing 500 ppm of silver particles having an average particle diameter of 5 nm was obtained in Resin (C). This mixture was compounded in a biaxial screw compounding machine, and was carried out in the same manner as in Example 2 except that resin (C) containing 20 ppm of silver particles having an average particle diameter of 5 nm was prepared as a compound composition. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured on the obtained body molded product samples for mobile phones, and the results are shown in Table 1.

Comparative Example 1

Polycarbonate having a residual bisphenol A content of 120 ppm, a melt index (300 ° C., 1.2 Kg) of 40 g / 10 min, a polydispersity (Mw / Mn) of 2.9, and a low molecular weight component with a weight average molecular weight of 1,000 or less (0.7%) Except for using only the resin (D)) as a raw material for the body molded products for mobile phones it was carried out as in Example 1. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured on the obtained body molded product samples for mobile phones, and the results are shown in Table 1.

Comparative Example 2

The same procedure as in Example 1 was carried out except that only acrylonitrile-butadiene-styrene copolymer (resin (E)) having a melt index (230 ° C., 3.8 Kg) of 13 g / 10 min was used as a raw material for body molded articles for mobile phones. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured on the obtained body molded product samples for mobile phones, and the results are shown in Table 1.

Comparative Example 3

Polycarbonate having a residual bisphenol A content of 25 ppm, a melt index (300 ° C., 1.2 Kg), 12 g / 10 min, a polydispersity (Mw / Mn) 3.5, and a low molecular weight component having a weight average molecular weight of 1,000 or less (2.5%) 500 ppm of silver particles having an average particle diameter of 7 nm was added to the resin (E) to carry out the same procedure as in Example 1 to prepare a polycarbonate masterbatch containing silver nanoparticles. The prepared master batch was mixed with the same polycarbonate resin (E) so as to be 10% by weight, and kneaded and injected at 302 ° C. to obtain a body molded product sample containing 50 ppm of silver particles having an average particle diameter of 7 nm. Cytotoxicity, antimicrobial activity, light transmittance and drop dart impact strength were measured for the obtained body molded product samples for mobile phones, and the results are shown in Table 1.

[Table 1] Evaluation results of the body molded article physical properties for mobile phones obtained according to Examples 1 to 4 and Comparative Examples 1 to 3

Residual bisphenol A content, as seen in Comparative Example 1, in the evaluation method according to the Korean Pharmacopoeia (KP) for medical plastic products adopted as a method of simulating that infants can inhale eluate by saliva and sweat. It can be seen that the high cytotoxic reaction, and as shown in Comparative Example 2, the acrylonitrile-butadiene-styrene copolymer, which is known to have high residual acrylonitrile monomer content, also shows a cytotoxic reaction. . In addition, it can be seen from the examples that the antimicrobial properties of the microorganisms contained in the compound composition according to the present invention exhibited excellent antimicrobial activity with almost no bacteria present after 1 day, whereas Comparative Example 1 and Comparative Example 2 If you look at the general polycarbonate resin or acrylonitrile-butadiene-styrene copolymer that does not contain nano-sized silver particles, it can be seen that the bacteria increase 40 to 50 times after one day. On the other hand, in Comparative Example 3, the antimicrobial activity showed a similar antimicrobial activity but a cytotoxic reaction, which is high in the content of low molecular weight components with an average molecular weight of 1,000 or less. It is thought to be. In addition, despite the inclusion of nano-sized silver particles, it can be seen that the transparency is excellent as in the polycarbonate resin of Comparative Example 1 containing no silver particles. In addition, as can be seen in the examples, the polycarbonate resin according to the present invention can be seen that the impact resistance is very excellent, as can be seen in Comparative Example 1, the same polycarbonate resin, but it can be seen that the impact strength is low, which is too melt index It is presumed to be due to the large molecular weight, and when acrylonitrile-butadiene-styrene copolymer is used as in Comparative Example 2, the impact resistance is very poor, so that the actual throwing is different from the other qualitative evaluation results. It can be seen that it is easily broken for the purpose of the present invention was not suitable for use for infant cell phones. In addition, as shown in Example 1, when preparing a polycarbonate masterbatch containing silver nanoparticles, the dispersibility of the silver nanoparticles was greatly increased, and the average particle diameter of the silver nanoparticles contained in the final molded product was finer, resulting in agglomerates. It can be seen that less, and thus can be given a more transparent effect.

Claims (7)

Polycarbonate resin with residual bisphenol A content of 30ppm or less, melt index (300 ℃, 1.2Kg) 3 ~ 30g / 10min, polydispersity (Mw / Mn) 3 or less, silver particles with average particle size of 50nm or less 10 ~ 500ppm Polycarbonate resin composition having antibacterial properties. The method of claim 1, The polycarbonate is a polycarbonate resin composition having an antimicrobial activity, characterized in that the fraction of the low molecular weight of the weight average molecular weight of 1000 or less 1% by weight or less. The method of claim 1, The polycarbonate composition kneaded and extruded the polycarbonate resin and the silver particles to produce a polycarbonate masterbatch containing silver particles, and has a high dispersion and high transparency antibacterial properties prepared by kneading it with a polycarbonate resin having the same physical properties Polycarbonate resin composition. The method of claim 2, The polycarbonate composition kneaded and extruded the polycarbonate resin and the silver particles to produce a polycarbonate masterbatch containing silver particles, and has a high dispersion and high transparency antibacterial properties prepared by kneading it with a polycarbonate resin having the same physical properties Polycarbonate resin composition. The molded article obtained by injection-molding the polycarbonate resin composition of any one of Claims 1-4. The method of claim 5, Molded article, characterized in that the molded article is a body of a mobile phone for infants. An infant cellular phone comprising the cellular phone body molded article of claim 6.