JP2019119837A - Copper superfine particle-containing resin composition and manufacturing method therefor - Google Patents

Abstract

To provide a resin composition having no deterioration of a thermoplastic resin becoming a matrix and metal copper superfine particles uniformly dispersed, and a manufacturing method therefor.SOLUTION: There is provided a resin composition manufactured by containing metal copper superfine particles with an average particle diameter of 100 nm or less and an organic acid in a thermoplastic resin having an oxygen permeability coefficient of 2×10cc m/mday atm or less.SELECTED DRAWING: None

Description

  The present invention relates to a copper ultrafine particle-containing resin composition and a method for producing the same, and more particularly, a resin composition provided with antibacterial performance derived from metallic copper ultrafine particles, and metallic copper ultrafine particles efficiently heated The present invention relates to a method for producing a copper ultrafine particle-containing resin composition that can be produced in a plastic resin.

Since metal ultrafine particles have excellent antibacterial and adsorption properties, it is desirable that they be contained in a resin or the like to be used after being formed into a shape such as a sheet or fiber, but metal ultrafine particles have surface lubricity. There is a problem that the resin is decomposed and the moldability is significantly impaired. Furthermore, a dispersion was required from the point of handleability, and it was not sufficiently satisfactory for incorporation into a resin.
In order to solve such a problem, the present inventors reduce the direct contact between the metal surface and the resin by causing the organic acid component to exist on the metal ultrafine particle surface, and effectively suppress the decomposition of the resin. We have proposed an adsorptive metal ultrafine particle which can reduce the decrease in molecular weight of the resin and the like and does not inhibit the formability (Patent Document 1).

In Patent Document 1 above, a metal salt of an organic acid such as fatty acid silver, which is a starting material for metal ultrafine particles, is blended into a thermoplastic resin, and the mixture is heated and kneaded to uniformly disperse the metal ultrafine particles in the thermoplastic resin. There is. However, since the thermal decomposition temperature of copper compounds such as organic acid copper is higher than that of silver compounds etc., even though ultrafine particles of silver can be produced from organic acid silver etc. in a thermoplastic resin, thermoplastic resin It was not easy to produce copper ultrafine particles in a thermoplastic resin without causing deterioration of
Also, in order to uniformly disperse metal ultrafine particles in a thermoplastic resin, it is common to previously prepare a masterbatch containing a high concentration of a metal salt of an organic acid which is a starting material, and mix it with the resin, As a result, the dispersibility of the metal ultrafine particles in the resin can be improved, and the processing of the molded article can be facilitated. However, since the metal ultrafine particles exhibit adsorption performance, antibacterial performance, etc. even when contained in the master batch, there is a possibility that the adsorption performance etc. of the molded product formed by blending the master batch with the resin may be deteriorated. There is.
In order to solve such a problem, the present inventors proposed a masterbatch formed by blending an organic acid metal salt such as silver, copper, gold or the like into a polyolefin resin (Patent Document 2). By blending this masterbatch into a resin and heating and kneading it at a temperature at which the organic acid metal salt can be thermally decomposed, it becomes possible to form a resin molded product in which metal ultrafine particles are uniformly dispersed in the resin.

Patent No. 4448551 Patent No. 4948556

However, as described in Patent Document 2 above, in order to prevent the antibacterial performance etc. from being exhibited in the masterbatch state, the thermoplastic resin is blended with the copper compound as the starting material for the copper ultrafine particles as it is. In such a masterbatch, it is difficult to form ultrafine copper particles in a thermoplastic resin, even if it is mixed with a thermoplastic resin and heated and kneaded, as described above. That is, as described above, copper compounds such as organic acid copper have a large amount of heat required for thermal decomposition. For example, when fatty acid copper is heat-kneaded in polyolefin at around 300 ° C., resin deterioration is remarkable and remarkable Even if metallic copper is obtained because the formability is lowered, it is not possible to form a resin molded article industrially.
On the other hand, even if it can be reduced to metallic copper by blending fatty acid copper with polyamide resin whose melting point is higher than that of polyolefin and kneading it for a long time at a temperature that does not cause deterioration of the resin, aggregation occurs. It is not possible to form copper ultrafine particles in it.

  Therefore, an object of the present invention is to provide a resin composition in which metallic copper ultrafine particles are uniformly dispersed without deterioration of a thermoplastic resin as a matrix, and a method for producing the same.

According to the present invention, a thermoplastic resin having an oxygen permeability coefficient of 2 × 10 ⁻³ cc · m / m ² · day · atm or less contains metallic copper ultrafine particles having an average particle size of 100 nm or less and an organic acid There is provided a resin composition characterized in that
In the resin composition of the present invention,
1. The thermoplastic resin is a polyamide resin or a polyester resin,
2. The metal copper ultrafine particles are contained in an amount of 0.001 to 1% by weight,
3. The organic acid is a fatty acid, and is contained in an amount of less than 1 mole with respect to 1 mole of metallic copper;
Is preferred.

Further, according to the present invention, there is provided a method of producing the above resin composition, wherein a masterbatch containing a monovalent copper compound is compounded with the thermoplastic resin, and these are kneaded. A method of manufacture is provided.
In the method for producing a resin composition of the present invention, it is preferable that the monovalent copper compound is fatty acid copper.

In the resin composition of the present invention, since the metal copper ultrafine particles and the organic acid are contained, the metal copper ultrafine particles are uniformly dispersed in the thermoplastic resin without aggregation. In addition, since a thermoplastic resin excellent in oxygen barrier properties is used as a matrix, it is possible to stably exhibit performance such as antibacterial performance without the copper ultrafine particles being oxidized by the transmitted oxygen. In addition, since oxidation of the copper ultrafine particles is effectively prevented, discoloration is also suppressed in the molded article made of the resin composition of the present invention. Furthermore, since the metallic copper ultrafine particles are firmly fixed in the thermoplastic resin, they can exhibit performance such as antibacterial performance over a long period without falling off from the molded product.
Further, in the method for producing a resin composition of the present invention, by using a masterbatch containing a monovalent copper compound, metallic copper ultrafine particles are produced in a thermoplastic resin without causing deterioration of the thermoplastic resin. A resin composition which can be dispersed uniformly and contains copper ultrafine particles efficiently can be produced.

It is a TEM photograph of the copper ultrafine particle formed in the nylon fiber produced in Example 1.

(Resin composition)
The metal copper ultrafine particle-containing resin composition of the present invention has a oxygen permeability coefficient of 2 × 10 ⁻³ cc · m / m ² · day · atm or less in a thermoplastic resin having a thickness of 100 nm or less, particularly 10 to 50 nm. It is characterized in that it comprises ultrafine particles of metallic copper having an average particle size and an organic acid.
The copper ultrafine particles present in the resin composition of the present invention have a high heating temperature required for the formation of the copper ultrafine particles as described later. It consists of metallic copper from which the acid has been eliminated. For this reason, unlike the metal ultrafine particles whose surface is modified with an organic acid as in the prior art described above, they are easily oxidized, and there is a risk that the performance such as the antibacterial performance originally possessed by the copper ultrafine particles may deteriorate due to oxidation. In the present invention, by using a thermoplastic resin having an oxygen barrier property with an oxygen permeability coefficient equal to or less than the above value as a matrix containing copper ultrafine particles, oxidation of ultrafine particles consisting of metallic copper by transmitted oxygen from the outside Is prevented. In addition, the presence of the organic acid desorbed from the organic acid copper in the resin composition can effectively prevent the aggregation of the metal copper ultrafine particles which are easily aggregated, and the copper ultrafine particles are uniformly contained in the thermoplastic resin. It can be set as the resin composition disperse | distributed to this.

  In the resin composition of the present invention, the metallic copper ultrafine particles are preferably contained in the resin composition in an amount of 0.001 to 1% by weight, particularly 0.01 to 0.5% by weight. When the amount of the metallic copper ultrafine particles is smaller than the above range, the resin composition can not sufficiently exhibit the antibacterial performance etc. as compared with the above range, and on the other hand, the metallic copper than the above range When the amount of ultrafine particles is large, not only aggregation of the metal copper fine particles is likely to occur, but also it is economically disadvantageous as compared with the case of being in the above range.

[Thermoplastic resin]
The thermoplastic resin to be a matrix of the resin composition of the present invention is a thermoplastic resin having an oxygen barrier property having an oxygen permeability coefficient of 2 × 10 ⁻³ cc · m / m ² · day · atm or less, which will be described later. Preferably, the thermoplastic resin does not thermally deteriorate at a heating temperature capable of reducing the monovalent organic acid copper to metal copper ultrafine particles.
As such a thermoplastic resin, although it is not limited to this, polyester resin, polyamide resin, polycarbonate resin etc. can be used conveniently.

As the polyester resin, for example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, or blends of these polyester resins with polycarbonate and arylate resin can be used.
In particular, a polyethylene terephthalate having a majority (generally 80 mol% or more) of ester repeating units being ethylene terephthalate units, a glass transition point (Tg) of 50 to 80 ° C., and a melting point (Tm) of 240 to 270 ° C. PET) -based polyester can be suitably used. Although a homopolyethylene terephthalate is most suitable as the PET-based polyester, a copolyester having an ethylene terephthalate unit content in the above range can also be suitably used. In such a copolyester, as dibasic acids other than terephthalic acid, aromatic dicarboxylic acids such as isophthalic acid, phthalic acid and naphthalene dicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid; succinic acid, adipic acid, sebacine And aliphatic dicarboxylic acids such as dodecanedioic acid; and combinations of one or more such as, for example, propylene glycol, 1,4-butanediol, diethylene glycol, and the like as diol components other than ethylene glycol 1 type, or 2 or more types, such as 1, 6 hexylene glycol, cyclohexane dimethanol, the ethylene oxide adduct of bisphenol A, etc. are mentioned.
The intrinsic viscosity of the polyester resin is preferably in the range of 0.5 to 1 dL / g, although the range of the intrinsic viscosity required varies depending on the form of the molded product made of the resin composition, the molding method and the like.

Examples of the polyamide resin include polyamide resins such as nylon 6, nylon 6, 6, nylon 6/6, 6 copolymer, nylon 6, 10, nylon 11, nylon 12, nylon 13, and xylylene group-containing polyamide. And those having a glass transition point (Tg) of 40 to 60 ° C. and a melting point (Tm) of 220 to 250 ° C. can be suitably used.
Specific examples of the xylylene group-containing polyamide include polymetaxylylene adipamide, polymethaxylylene sebacamide, polymethaxylylene beramide, polyparaxylylene pimeramide, polymethaxylylene aceramide and the like. Polymer, and metaxylylene / paraxylylene adipamide copolymer, metaxylylene / paraxylylene pimeramide copolymer, metaxylylene / paraxylylene sebacamide copolymer, metaxylylene / paraxylylene azeramide copolymer Or copolymers thereof and aliphatic diamines such as hexamethylene diamine, alicyclic diamines such as piperazine, and aromatic diamines such as para-bis (2-aminoethyl) benzene , Aromatic dicarboxylic acids such as terephthalic acid, ε-caprolactone Such lactams, 7-amino such ω- amino acids heptanoic acid, para - copolymers thereof obtained by copolymerizing such aromatic amino acids of the amino methyl benzoate.

[Metal copper ultrafine particles]
In the resin composition of the present invention, metal copper ultrafine particles having an average particle diameter of 100 nm or less, particularly 10 to 50 nm, mix a master batch containing copper of monovalent organic acid described later with the thermoplastic resin; Through the heat treatment, nanoparticulated / nanodispersed ultrafine copper particles are produced in the thermoplastic resin while being reduced to metallic copper.

[Organic acid]
The resin composition of the present invention contains an organic acid derived from an organic acid copper which is a starting material of the metallic copper ultrafine particles. By containing this organic acid, it becomes possible to effectively prevent the aggregation of the metal copper ultrafine particles which tends to aggregate.
Organic acids include aliphatic carboxylic acids such as myristic acid, stearic acid, oleic acid, palmitic acid, n-decanoic acid, paratoic acid, succinic acid, malonic acid, tartaric acid, malic acid, glutaric acid, adipic acid, acetic acid, etc. Examples thereof include aromatic carboxylic acids such as acid, maleic acid, isophthalic acid, terephthalic acid, benzoic acid and naphthenic acid, and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid.
In the present invention, it is particularly preferable that the organic acid to be used is a higher fatty acid having 3 to 30 carbon atoms, as represented by myristic acid, stearic acid, palmitic acid and the like.
The organic acid is desirably contained in the thermoplastic resin in an amount of less than 1 mole, particularly 0.5 to 0.02 mole, per 1 mole of metallic copper. As described later, by heating and mixing a master batch containing monovalent organic acid copper in a thermoplastic resin, the monovalent organic acid copper is reduced, and one mole of organic acid is generated per mole of metallic copper. However, it is desirable not to overheat so that the amount of organic acid in the above range remains in the thermoplastic resin.

[Others]
The resin composition according to the present invention may contain various compounding agents known per se, such as fillers, plasticizers, leveling agents, thickeners, and the like, in addition to the metal copper ultrafine particles and the organic acid mentioned above, according to their use. A viscosity improver, a stabilizer, an antioxidant, an ultraviolet absorber, etc. can also be mix | blended according to a well-known prescription.

(Method for producing resin composition)
The resin composition of the present invention may be produced by blending separately formed metallic copper ultrafine particles with the above-described thermoplastic resin, but the metallic copper ultrafine particles are easily oxidized and easily agglomerated, Because of poor handleability, this method can not be prepared with high productivity.
Therefore, in the present invention, a masterbatch containing monovalent organic acid copper is compounded with the above-mentioned thermoplastic resin, and these are kneaded at a predetermined temperature, thereby simultaneously metal copper ultrafine particles and an organic acid in the thermoplastic resin. It is preferable to produce a resin composition in which metallic copper ultrafine particles are uniformly dispersed while being produced.

[Master Badge]
The masterbatch suitably used for the production of the resin composition of the present invention is a masterbatch containing a monovalent organic acid copper in a thermoplastic resin, and preferably is the same as the thermoplastic resin constituting the resin composition. It is desirable that it is a masterbatch which contains the monovalent organic acid copper of the above-mentioned organic acid in an amount of 0.1 to 5% by weight in the thermoplastic resin.
The masterbatch which can be suitably used in the present invention contains a divalent organic acid copper in a thermoplastic resin, and heat-kneaded this at a temperature at which the divalent organic acid copper is reduced to obtain 1 in the thermoplastic resin. A copper salt of a valent organic acid is produced. Specifically, the heating temperature of the thermoplastic resin and the divalent copper compound is within the range above the melting point of the thermoplastic resin and below the temperature at which the divalent copper compound used causes a weight loss of 5%. It is desirable to heat at a temperature of 30 to 600 seconds, especially 300 seconds. In addition, the temperature which produces 5% weight loss of a bivalent copper compound measured the mass of the bivalent copper compound to be used, and it heated up with the temperature rising rate of 10 degreeC per minute under inert atmosphere using the thermal analyzer In the heat loss curve (TG curve) obtained by measuring the weight change during the process, the temperature is lower than the temperature at which a 5% weight loss occurs.

As monovalent organic acid copper contained in the master batch, myristic acid, stearic acid, oleic acid, palmitic acid, n-decanoic acid, palatoic acid, succinic acid, malonic acid, tartaric acid, malic acid, glutaric acid, adipic acid Monovalents of organic acids such as aliphatic carboxylic acids such as acetic acid, phthalic acid, maleic acid, isophthalic acid, terephthalic acid, benzoic acid, naphthenic acid etc., and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid Copper salts can be mentioned.
In the present invention, particularly preferred are copper salts of higher fatty acids having 3 to 30 carbon atoms, represented by myristic acid, stearic acid, palmitic acid and the like. Further, by using one having a large number of carbon atoms, the organic acid component itself contained in the thermoplastic resin can also exhibit adsorption performance to further improve the adsorption performance.

[Preparation of Resin Composition]
As described above, the resin composition of the present invention contains a metallic copper ultrafine particle having an average particle diameter of 100 nm or less, particularly 10 to 50 nm, in an amount of 0.001 to 1% by weight in the thermoplastic resin. It is desirable to prepare by mixing and heat-mixing the said masterbatch in the quantity of 1 to 10 parts weight with respect to 100 parts weight of thermoplastic resins mentioned above.
The heating temperature is a temperature at which the monovalent organic acid copper in the master batch is reduced to metallic copper, and is a temperature which is not lower than the melting point of the thermoplastic resin to be used and does not cause thermal degradation. Specifically, it is important to select the thermoplastic resin and the organic acid copper so that the monovalent organic acid copper is reduced in the range of the molding processing temperature of the thermoplastic resin.
By heat-kneading the resin composition at a temperature in this range, the metal copper ultrafine particles are uniformly dispersed, and a resin composition containing an organic acid in an amount of less than 1 mol with respect to 1 mol of metal copper is prepared. it can. That is, by heating in the above temperature range, the monovalent copper compound is reduced to metallic copper, and the organic acid component that has modified the surface of the copper ultrafine particles is eliminated, and the presence of this organic acid component results in copper ultrafine particles. Cohesion of the metal copper is prevented, and a metallic copper ultrafine particle is uniformly dispersed in the thermoplastic resin to form a resin composition. It becomes possible to shape | mold in a desired molded article shape using the resin composition in this molten state.
The heating and kneading time is not particularly limited as long as the desired composition is formed, but 120 seconds or more, particularly, 200 to 600 seconds and 300 to 600 seconds are preferable.
For example, in the case of using a polyamide resin as a thermoplastic resin and blending a master batch containing monovalent fatty acid copper in the polyamide resin, melt kneading is carried out for a predetermined time at 250 to 280 ° C. for molding. Thus, a molded article in which the copper ultrafine particles are uniformly dispersed can be obtained.

Example 1
6 wt% of copper stearate is mixed with 6-nylon (Ube Industries, Ltd. 1013 B), and the extrusion molding machine has a set temperature of 250 ° C., Q (discharge amount) / N (screw rotation number) = 4/100 = 0.04 It extruded using a twin-screw extruder (made by Corporation | KK Technobel) on shaping | molding conditions, and produced the masterbatch. Next, the masterbatch is compounded so that the content of copper stearate is 0.05 wt% in the 6-nylon, and it is kneaded by a twin-screw extruder at a secondary molding temperature of 260 ° C., and the nozzle diameter is 600 μm It extruded and made to extend | stretch with an air ejector, and the nylon fiber was produced.

(Comparative example 1)
Fibers were produced in the same manner as in Example 1 except that the type, blending amount and molding temperature of the resin were changed as shown in Table 1. In Table 1, "LDPE" is low density polyethylene J5019 manufactured by Ube Maruzen Polyethylene Corporation.

(Confirmation of particles)
When the particles in the fiber produced as shown in Table 1 were observed by a transmission electron microscope (TEM), particles of about 80 nm were confirmed in the nylon fiber of Example 1 (FIG. 1). On the other hand, no particles could be confirmed in the polyethylene fiber of Comparative Example 1.

(Confirmation of antibacterial performance)
In addition, when the antibacterial activity value of the fibers prepared in Example 1 and Comparative Example 1 against Staphylococcus aureus was confirmed according to JIS L1902, in the nylon fiber of Example 1, the antibacterial activity value can be confirmed when the value is 2 or more. However, in the polyethylene fiber of Comparative Example 1, the antimicrobial activity could not be confirmed (Table 1).

  The resin composition of the present invention is a resin composition in which copper ultrafine particles having excellent antibacterial performance, adsorption performance and the like are uniformly dispersed, and can be molded into various forms, so that containers, films, sheets, etc. It can be suitably used for packaging materials, non-woven fabrics, textiles and the like.

Claims (6)

A thermoplastic resin having an oxygen permeability coefficient of 2 × 10 ⁻³ cc · m / m ² · day · atm or less is characterized by containing metal copper ultrafine particles having an average particle diameter of 100 nm or less and an organic acid. Resin composition.   The resin composition according to claim 1, wherein the thermoplastic resin is a polyamide resin or a polyester resin.   The resin composition according to claim 1 or 2, wherein the metallic copper ultrafine particles are contained in an amount of 0.001 to 1% by weight.   The resin composition according to any one of claims 1 to 3, wherein the organic acid is a fatty acid and is contained in an amount of less than 1 mole with respect to 1 mole of metallic copper.   The method for producing a resin composition according to any one of claims 1 to 4, wherein the thermoplastic resin is blended with a masterbatch containing a monovalent copper compound, and these are kneaded. Method of making the composition.   The method for producing a resin composition according to claim 5, wherein the monovalent copper compound is fatty acid copper.