JP2018172570A - Hollow molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow molded body that has excellent safety and antibacterial properties, and includes an antibacterial agent uniformly dispersed therein.SOLUTION: A hollow molded body comprises a molten mixture of a resin composition containing a thermoplastic resin (A) and a compound represented by formula (1), and a thermoplastic resin (B) (Ris a hydrogen atom or an alkali metal, Ris a C1 to 10 alkyl group or an aryl group).SELECTED DRAWING: None

Description

  The present invention relates to a hollow molded body composed of a melt-kneaded product of a resin composition containing parabens and a thermoplastic resin.

  In recent years, hollow molded articles of antibacterial processing made of a resin having an antibacterial function have increased and are widely used in general households. As a hollow molded body for antibacterial processing, for example, containers and tubes made of a resin mixed with inorganic antibacterial agents such as silver antibacterial agents and zinc antibacterial agents having high antibacterial functions and high safety have been proposed (patents) Literature 1, Patent Literature 2, Patent Literature 3).

  However, when an inorganic antibacterial agent is mixed in the resin, the antibacterial agent is an inorganic solid, and therefore dispersibility is poor in a thermoplastic organic resin. Therefore, as a conventional kneading method into the resin, the antibacterial masterbatch formed into a granular form once mixed with the antibacterial agent at a high concentration in the same resin as the resin of the product material, the resin material at the time of product molding A method of mixing a predetermined amount of the antibacterial masterbatch therein has been proposed (Patent Document 4). However, even when the antibacterial masterbatch is used, it cannot be said that the dispersibility of the inorganic antibacterial agent is sufficient, and the antibacterial property varies, and the inorganic antibacterial agent is discolored or clouded by light. However, a resin mixed with an inorganic antibacterial agent is not suitable for a hollow molded body.

  On the other hand, when the organic antibacterial agent is coated or kneaded on the surface, the antibacterial agent is easily volatilized, desorbed and separated from the substrate such as a container, and depending on the type of the organic antibacterial agent, a safety problem arises. Therefore, an insoluble immobilized antibacterial agent that does not exhibit toxicity and has been proposed in which an organic antibacterial agent is bound to a polymer material by an ionic bond or a covalent bond (Patent Document 5, Patent Document 6, Patent Document 7). However, in this method, it is necessary to immobilize a quaternary ammonium base or phosphonium base ionically bonded to an acidic group such as a carboxylic acid group or a sulfonic acid group, and the resin does not have a functional group such as polyolefin. It was difficult to fix the antibacterial agent.

  Therefore, there has been a demand for a hollow molded article that is free from restrictions on resins that can be used, is excellent in safety and antibacterial properties, and in which an antibacterial agent is uniformly dispersed.

JP 09-002537 A JP 09-118373 A JP 2002-331028 A JP 2004-250032 A Japanese Patent Laid-Open No. 54-086584 Japanese Patent Laid-Open No. 04-266912 JP 05-310820 A

  An object of the present invention is to provide a hollow molded article that is excellent in safety and antibacterial properties and in which an antibacterial agent is uniformly dispersed.

As a result of intensive studies on the hollow molded article, the inventors of the present invention have achieved excellent safety and antibacterial properties by using a masterbatch containing parabens (parahydroxybenzoate esters), and a hollow in which an antibacterial agent is uniformly dispersed. The present inventors have found that a molded body can be obtained and have completed the present invention.
That is, this invention provides the hollow molded object comprised from the melt-kneaded material of the resin composition containing the compound represented by a thermoplastic resin (A) and Formula (1), and a thermoplastic resin (B). .
(R ₁ represents a hydrogen atom or an alkali metal, and R ₂ represents an alkyl group or an aryl group having 1 to 10 carbon atoms.)

  Since the hollow molded body of the present invention is excellent in safety and antibacterial properties, it can also be used for products that come into contact with the human body. In addition, since the antibacterial agent is uniformly dispersed in the hollow molded body of the present invention, there is little bias in antibacterial power depending on the site.

2 is a scanning electron micrograph of the surface of a resin molded body obtained in Example 1. FIG. 6 is a scanning electron micrograph of the surface of a resin molded body obtained in Example 5. FIG. 4 is a scanning electron micrograph of the surface of a resin molded body obtained in Comparative Example 3. 1 is a view showing a container obtained in Example 1. FIG.

  The hollow molded body in the present invention is a molded body having an open space, a molded body having one end opened, such as a container such as a tank, a bottle, a cup, a tray, or a bowl, and a bag, a tube, or a hose. Further, a molded body having both ends opened like a pipe or the like is also included.

  Examples of the thermoplastic resin (A) and the thermoplastic resin (B) used in the present invention include polypropylene, polyethylene, polyoxymethylene, polyamide, polycarbonate, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), One or more resins selected from the group consisting of acrylonitrile-styrene copolymer resin (AS resin), polyester, and thermoplastic elastomer, or a copolymer resin thereof may be mentioned, and in particular, a phase with a compound represented by the formula (1) From the viewpoint of excellent solubility, polypropylene or polyethylene is preferred.

In the compound represented by the formula (1), R ₁ is preferably a hydrogen atom or sodium or potassium, more preferably a hydrogen atom.

In the compound represented by the formula (1), R ₂ is preferably an alkyl group having 1 to 6 carbon atoms or an aryl group, more preferably a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group or A benzyl group, more preferably a butyl group or a hexyl group.

  Examples of the compound represented by the formula (1) used in the present invention include methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, and 4-hydroxybenzoic acid. One or more selected from the group consisting of hexyl and benzyl 4-hydroxybenzoate can be mentioned, and butyl 4-hydroxybenzoate and hexyl 4-hydroxybenzoate are preferred because they have high antibacterial properties and are hardly sublimable.

  It is preferable that the resin composition in this invention contains 1-30 mass parts of compounds represented by Formula (1) with respect to 100 mass parts of thermoplastic resins (A), and contains 3-20 mass parts. More preferably, it is more preferably 5 to 15 parts by mass.

  The method for obtaining the compound represented by the formula (1) is not particularly limited, but may be a commercially available one, or 4-hydroxybenzoic acid and an aliphatic alcohol having 1 to 10 carbon atoms in the presence of a catalyst. You may use what was obtained by reaction with aryl alcohol.

  When the content of the compound represented by the formula (1) in the resin composition in the present invention is less than 1 part by mass with respect to 100 parts by mass of the thermoplastic resin (A), as a master batch of the resin composition When the compound represented by the formula (1) is more than 30 parts by mass with respect to 100 parts by mass of the thermoplastic resin (A), the compound represented by the formula (1) is hollow. There is a risk of precipitation or aggregation in the molded body.

  The resin composition in the present invention can be produced by mixing the thermoplastic resin (A) and the compound represented by the formula (1). The mixing may be performed by melt-mixing the thermoplastic resin and the compound represented by formula (1), and the resin melted by heating in a state where the compound represented by formula (1) is dissolved in a solvent. And the solvent may be removed from the molten resin in a gaseous state.

  When the thermoplastic resin (A) and the compound represented by the formula (1) are melt-mixed, they are mixed uniformly in advance with a mixer such as a tumbler blender, a Henschel mixer or a super mixer, Examples thereof include a method of melt-kneading with a shaft extruder, cutting the extruded strand with a cutter, etc., granulating, a method of melt-kneading with a kneader, Banbury mixer, etc., and granulating with an extruder.

  The heating conditions vary depending on the thermoplastic resin (A) and the compound represented by the formula (1), the type and amount of additives, or the conditions of the mixer to be used. It is desirable to heat for 1 to 600 seconds at a temperature not lower than the crystal melting temperature of the thermoplastic resin used and lower than the deterioration temperature.

  In the case where the compound represented by the formula (1) is dissolved in a solvent and mixed with the heat-melted resin, the solvent is particularly limited as long as it dissolves the compound represented by the formula (1). Organic solvents such as methanol, ethanol, propanol, isopropanol, ethylene glycol, propylene glycol, toluene, xylene, mesitylene, diethyl ether, tetrahydrofuran, dioxane, diphenyl ether, dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone , Dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like.

  Although it does not specifically limit as temperature which dissolves the compound represented by Formula (1) in a solvent, For example, you may be 10-80 degreeC. Moreover, the compound represented by Formula (1) can be dissolved in the quantity of the range of 10-200 mass parts with respect to 100 mass parts of solvents, for example.

  The mixed compound represented by the formula (1) is preferably dispersed in the thermoplastic resin (A) as particles having a particle diameter of 5 μm or less, that is, a state in which there are no particles having a particle diameter exceeding 5 μm. When the particle diameter of the compound represented by the formula (1) in the thermoplastic resin (A) exceeds 5 μm, sufficient antibacterial properties tend to be hardly obtained. The compound represented by the formula (1) in the thermoplastic resin is preferably dispersed as particles having a particle size of 2.5 μm or less in the thermoplastic resin, more preferably as particles having a particle size of 1 μm or less. More preferably, the particle is dispersed as particles having a particle diameter of 0.1 μm or less. The state of the particles can be confirmed by observing with a scanning electron microscope (SEM). The particle diameter was measured by an image analysis method for measuring the distance between two points which is the maximum dimension for one particle in a scanning electron microscope image. The particle size of the compound represented by the formula (1) in the resin composition tends to hardly change even after undergoing the manufacturing process of the hollow molded body. Therefore, the particle diameter of the compound represented by the formula (1) in the resin composition and the particle diameter of the compound represented by the formula (1) in the hollow molded body produced using the resin composition are: It becomes almost the same.

  In the present invention, the resin composition is preferably in the form of pellets. The method for producing pellets of the resin composition in the present invention is not particularly limited. For example, the resin composition containing the compound represented by the formula (1) is molded into a sheet by extrusion molding, and this is obtained. For example, a method of cutting a sheet-like molded product into an appropriate size by a cutter or the like and processing it into a pellet can be used.

  The shape of the pellet is not particularly limited, and may be, for example, a prismatic shape or a spherical shape. As the size of the pellet, the length of the maximum side is preferably 1 to 20 mm in the case of a prismatic shape, and the particle diameter is preferably 1 to 20 mm in the case of a spherical shape. When the size of the pellet is within the above range, the handleability is improved, and the pellet packaging operation and the like are facilitated.

  The resin composition of the present invention is used as a master batch. In the present invention, the master batch refers to a resin pellet containing the compound represented by the formula (1) at a high concentration of 1 part by mass or more with respect to 100 parts by mass of the thermoplastic resin (A). Are mixed with the thermoplastic resin (B), and a melt-kneaded product is formed together with the thermoplastic resin (B). When the master batch is used, the material is easy to handle and the weighing accuracy is improved as compared with the case where the compound represented by the formula (1) is directly added to the thermoplastic resin (B) and molded. Moreover, when a masterbatch is used, there also exists an advantage that the molded object containing the microparticles | fine-particles of the compound represented by Formula (1) can be manufactured using a general purpose molding machine.

  The melt-kneaded product is obtained by kneading a resin composition as a master batch and a base resin in a molten state. The melt-kneaded product in the present invention may be in a molten state, a solid state, or a mixed state thereof.

  As a thermoplastic resin (B), the thermoplastic resin illustrated above as a thermoplastic resin (A) contained in a masterbatch is mentioned. The thermoplastic resin (B) may be the same as or different from the thermoplastic resin (A), and is preferably highly compatible with the thermoplastic resin (A) contained in the masterbatch. The same thermoplastic resin as the thermoplastic resin (A) is more preferable.

  The melt-kneaded product in the present invention preferably contains 1 to 40 parts by mass, more preferably 10 to 30 parts by mass of the resin composition, with respect to 100 parts by mass of the thermoplastic resin (B). More preferably, it is contained in parts by mass.

  In the melt-kneaded product, the compound represented by the formula (1) is preferably 0.01 parts by mass or more, more preferably 0.3 parts by mass or more, still more preferably 0.00 parts by mass with respect to 100 parts by mass of the thermoplastic resin (B). It is preferable to contain 75 parts by mass or more. The melt-kneaded product is preferably 12 parts by mass or less, more preferably 6 parts by mass or less, and still more preferably 3.75 parts by mass of the compound represented by the formula (1) with respect to 100 parts by mass of the thermoplastic resin (B). Part or less, more preferably 1 part by weight or less, particularly preferably less than 1 part by weight.

  In the melt-kneaded product, the compound represented by formula (1) is dispersed as particles having a particle size of 5 μm or less, more preferably as particles having a particle size of 2.5 μm or less, and even more preferably as particles having a particle size of 1 μm or less. Has been.

  When the resin composition in the melt-kneaded product in the present invention is less than 1 part by mass with respect to 100 parts by mass of the thermoplastic resin (B), the antibacterial property of the hollow molded body of the present invention tends to be reduced, and the resin When a composition is more than 40 mass parts with respect to 100 mass parts of thermoplastic resins (B), the utility value as a masterbatch of a resin composition falls and there exists a tendency for production cost to become high.

  In the hollow molded body of the present invention, the compound represented by the formula (1) is preferably a particle having a particle size of 5 μm or less, more preferably a particle having a particle size of 2.5 μm or less, and further preferably a particle size. Dispersed in the thermoplastic resins (A) and (B) as particles of 1 μm or less. When the particle size of the compound represented by the formula (1) is 5 μm or less, sufficient antibacterial properties tend to be exhibited in the hollow molded body. The particle diameter can be determined by an image analysis method using the above-described scanning electron microscope.

  The antibacterial activity value of the hollow molded article of the present invention is preferably 2.0 or more, more preferably 2.5 or more, and further preferably 3.0 or more. In addition, the antibacterial activity value in this invention is measured based on JISZ2801: 2010.

  The hollow molded body of the present invention may contain additives in addition to the compound represented by the above formula (1) and the thermoplastic resin. Examples of the additives include colorants, flame retardants, heat stabilizers, One or more selected from the group consisting of plasticizers, light stabilizers (ultraviolet absorbers, etc.), various additives such as antistatic agents, dispersants, mold release agents, fillers such as reinforcing agents and powder extenders. It is done.

  A hollow molded article of the present invention was obtained by melt-kneading a thermoplastic resin (A) and a resin composition containing a compound represented by the formula (1) and a thermoplastic resin (B), and obtained. It is manufactured by a step of forming a melt-kneaded product into a hollow shape.

  In the melt-kneading step, the resin composition and the thermoplastic resin (B) are uniformly mixed in advance by a mixer such as a tumbler blender, a Henschel mixer or a super mixer, and then in a single-screw extruder or a multi-screw extruder. It can be performed by a melt kneading method.

  Melt-kneading differs depending on the type and blending amount of the additive or the conditions of the mixer to be used. Therefore, it cannot be generally specified, but it is heated at a temperature higher than the crystal melting temperature of the thermoplastic resin used and lower than the deterioration temperature. However, it is desirable to carry out for 1 to 600 seconds.

  The method for forming the melt-kneaded product into a hollow shape is not particularly limited, and an optimum method can be selected according to the use and shape of the hollow molded body. Examples of the molding method include injection molding, press molding by vacuum or pressure, blow molding, inflation molding, extrusion molding, and the like. Among these, injection molding is widely used for molding thermoplastic resins, and is suitable for producing a molded body having a complicated shape. At this time, the temperature during injection molding is preferably 180 to 280 ° C, more preferably 190 to 250 ° C. By setting the temperature at the time of injection molding to 180 ° C. or higher, the melt viscosity is lowered and the injection moldability is improved. Moreover, the thermal decomposition of a thermoplastic resin is suppressed by making the temperature at the time of injection molding into 280 degrees C or less.

  The step of melt-kneading and the step of forming the melt-kneaded product into a hollow shape may be performed continuously or separately.

  The hollow molded body of the present invention is a laminate as necessary, and in a range not impairing the effects of the present invention, a layer imparted with slipperiness, a barrier layer of gas such as oxygen or water vapor, a light shielding layer, an oxygen absorbing layer, An adhesive layer, a colored layer, a conductive layer, a recycled resin-containing layer, an ultraviolet blocking layer, a protective layer, an antistatic layer, an antireflection layer, an antifouling layer, a printed layer, and the like may be provided.

In order to mold the laminated body, for example, the molten resin is injected into the mold of the molded part and solidified by injecting the molten other resin onto the molded resin layer and solidifying. It can carry out by the method of shape | molding by repeating. However, when the above injection molding method is used, the mold must be removed after molding, so it is not possible to create a hollow molded body at the same time. A desired hollow molded body can be obtained by integrally bonding by means such as fusion and adhesion.
The hollow molded body of the present invention can also be obtained as a laminate by co-extrusion of the melt-kneaded product and other molten resin, followed by press molding.
As other resin, the thermoplastic resin illustrated above as a thermoplastic resin (A) contained in a masterbatch is mentioned.

  In the present invention, when the hollow molded body is the above laminate, melt kneading of the thermoplastic resin (A) and the resin composition containing the compound represented by the formula (1) with the thermoplastic resin (B). It is essential that the layer composed of the object is located in at least one of the innermost layer and the outermost layer.

  As a hollow molded object of this invention, 1 or more types selected from the group which consists of a container, a bottle, a tank, a bag, a tube, a hose, and a pipe is mentioned, It can be set as arbitrary shapes according to a use.

  Although the use of the hollow molded object of this invention is not specifically limited, For example, it is used for food preservation or medical use. The contents of the hollow molded body of the present invention include, for example, soy sauce, sauce, miso, mayonnaise, ketchup, grilled meat, kneaded meat, kneaded wasabi, garlic garlic, mineral water, soft drink, tea, edible oil , Shampoos, rinses, hand soaps, body soaps, laundry detergents, softeners, kitchen detergents, and other surfactants; pharmaceuticals such as internal medicines, eye drops, drops, enemas, etc. Oils such as hydraulic oils and lubricating oils; chemicals such as photographic developers, cleaning liquids, coolants, bactericides and bleaches; agricultural chemicals; feeds and the like.

  Hereinafter, although an example explains the present invention in detail, the present invention is not limited to this.

Antibacterial agents A to D used in Examples and Comparative Examples, and measurement methods are shown below.
≪Antimicrobial agent A≫
4-hydroxybenzoic acid butyl ester (obtained by reacting 4-hydroxybenzoic acid and butyl alcohol in the presence of a catalyst)
≪Antimicrobial agent B≫
4-Hydroxybenzoic acid hexyl ester (obtained by reacting 4-hydroxybenzoic acid with hexyl alcohol in the presence of a catalyst)
≪Antimicrobial agent C≫
Zeolite silver (manufactured by Fuji Chemical Co., Ltd., trade name: bacterite, product number: MP-102SVC13)
≪Antimicrobial agent D≫
Silver behenate (manufactured by Tokyo Chemical Industry Co., Ltd.)

(Measuring method)
(1) Antibacterial test method: JIS Z 2801: 2010
Test strain: E. coli Escherichia coli NBRC 3972
Test strain: Staphylococcus aureus Staphylococcus aureus NBRC 12732

  A bacterial solution containing Escherichia coli and Staphylococcus aureus was dropped onto the surface of the container, and a polyethylene film was adhered to the solution. The cells were cultured under conditions of a temperature of 35 ° C. and a humidity of 90% for 24 hours. After culturing, 1 mL of the liquid (VmL) obtained by washing the bacterial cells adhering to the polyethylene film and the test piece with SCDLP medium is taken, and 1 mL of the diluted (D-fold diluted) liquid is transferred to a petri dish, and about 20 mL of SPC medium is obtained. Add and mix. After the medium had solidified, the cells were cultured for 40 to 48 hours under conditions of a temperature of 35 ° C. and a humidity of 90%, and then the viable counts of Escherichia coli and Staphylococcus aureus were counted. As a standard for evaluation, a polypropylene non-processed resin molded body (hereinafter also referred to as a non-processed resin molded body) containing no antibacterial pellets was used. Each test was performed in triplicate.

The antibacterial test was calculated by the following method.
N = (C × D × V) / A
N: Number of viable bacteria (per 1 cm ² test piece)
C: Number of villages (average number of villages of the two petri dishes adopted)
D: Dilution factor (dilution ratio of the diluted solution dispensed to the adopted petri dish)
V: Volume of SCDLP medium used for washing out (mL)
A: Surface area of the coated film (cm ² )
However, when C is <1, C is set to 1 and the viable cell count is calculated.
For example, when V = 10 mL, A = 16 cm ² , and D = 1, N <0.63 is displayed.
R = (U _t −U ₀ ) − (A _t −U ₀ ) = U _t −A _t
R: antibacterial activity value U _0: No machining mean value of number of living bacteria logarithmic value immediately after inoculation of the resin molded body U _t: mean A _t logarithm of the number of viable bacteria after 24 hours of non-processed resin molding : Average value of logarithm of the number of viable bacteria after 24 hours of molded resin containing antibacterial pellets Antibacterial activity evaluation: 抗菌 when the antibacterial activity value R is 3.0 or more, 2.0 or more and less than 3.0 .5 or more and less than 2.0 was rated as Δ, and less than 1.5 as x.

(2) Observation of antibacterial agent particles The surface of the test specimen obtained in the examples and comparative examples was observed with the scanning electron microscope (SEM) magnification set as appropriate, and judged according to the following criteria.
○: Particles having a particle diameter exceeding 1 μm were not observed.
Δ: Particles having a particle diameter of more than 1 μm and not more than 5 μm were observed.
X: Particles having a particle diameter exceeding 5 μm were observed.

[Example 1]
(Preparation of resin composition)
100 g of antibacterial agent A was dissolved in 150 g at 50 ° C. The antibacterial agent A dissolved in methanol was melted at a temperature of 200 ° C. so that 11 parts by weight of the antibacterial agent A was mixed with 100 parts by weight of the polypropylene resin (manufactured by Prime Polymer Co., Ltd., J105G). Polypropylene resin was supplied to a twin screw extruder (Ikegai Co., Ltd., PCM-30), melt-kneaded, and methanol was removed in a gaseous state to pelletize the resin composition to obtain a resin composition. .

(Production of container)
The obtained resin composition and polypropylene resin (manufactured by Prime Polymer Co., Ltd., J105G) were mixed at the ratio shown in Table 1, and injected with an injection molding machine (Nissei Plastic Industries, Ltd. UH-1000-110). Molded to prepare a container having a thickness of 3 mm and a capacity of 25 mL shown in FIG. The produced container was evaluated for an antibacterial test. The results are shown in Table 1.

(Production of resin molding)
The obtained resin composition and polypropylene resin (manufactured by Prime Polymer Co., Ltd., J105G) are mixed in the same ratio as the container and injected using an injection molding machine (UH-1000-110 manufactured by Nissei Plastic Industry Co., Ltd.). Molded to obtain a resin molded body. When the surface of the obtained resin molded body was observed at a magnification of 10,000 times using a scanning electron microscope (SEM), no particles were observed. A scanning electron micrograph is shown in FIG.

[Examples 2 to 4]
A resin composition, a container, and a resin molded body were produced in the same manner as in Example 1 except that the mixing ratio of the resin composition and polypropylene was changed as shown in Table 1. The surface of the obtained resin molding was observed for organic antibacterial agent particles with a scanning electron microscope. Moreover, the antimicrobial test was evaluated about the produced container. The results are shown in Table 1.

[Examples 5 to 8]
(Preparation of resin composition)
A resin composition container and a resin molded body were obtained in the same manner as in Example 1 except that the type of antibacterial agent and the mixing ratio of the resin composition and polypropylene were changed as shown in Table 1. When the surface of the resin molded body was observed at a magnification of 10000 using a scanning electron microscope, no particles were observed. A scanning electron micrograph of the resin molding of Example 5 is shown in FIG. Moreover, the antimicrobial test was evaluated about the obtained container. The results are shown in Table 1.

[Examples 9 to 10]
(Preparation of resin composition)
A resin composition was obtained in the same manner as in Example 1 except that the ratio of the antibacterial agent A was changed as shown in Table 1.

(Production of container)
The obtained resin composition and polypropylene resin (manufactured by Prime Polymer Co., Ltd., J105G) were mixed at the ratio shown in Table 1, and a container was produced in the same manner as in Example 1. The produced container was evaluated for an antibacterial test. The results are shown in Table 1.

(Production of resin molding)
The obtained resin composition and polypropylene resin (manufactured by Prime Polymer Co., Ltd., J105G) are mixed in the same ratio as the container and injected using an injection molding machine (UH-1000-110 manufactured by Nissei Plastic Industry Co., Ltd.). Molded to obtain a resin molded body. The surface of the resin molding was magnified 10,000 times using a scanning electron microscope, and the organic antibacterial agent particles were observed. The results are shown in Table 1.

[Comparative Examples 1-2]
Except that the antibacterial agent was changed as shown in Table 1, a resin composition was obtained in the same manner as in Example 1, and then a container and a resin molded body were produced. Antibacterial agent particles were observed on the surface of the obtained resin molding with a scanning electron microscope. Moreover, the antibacterial property test was done about each produced container. The results are shown in Table 1.

[Comparative Example 3]
(Production of container)
Antibacterial agent A and polypropylene resin (manufactured by Prime Polymer Co., Ltd., J105G) were mixed without melting at the ratios shown in Table 1 to obtain a resin composition. Moreover, the container and the resin molding were produced like Example 1 using this resin composition. When the surface of the obtained resin molding was observed by magnifying it 3000 times using a scanning electron microscope (SEM), particles having a particle diameter exceeding 5 μm were observed. A scanning electron micrograph is shown in FIG. Moreover, the antimicrobial test was done about the produced container. The results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 10, Examples 1 to 10 using a thermoplastic resin (A) and a resin composition containing a compound represented by Formula (1) as an antibacterial agent as a master batch. Thus, it can be seen that no antibacterial agent particles are observed in the resin molded body, and that sufficient antibacterial activity is exhibited when a hollow molded body is formed. On the other hand, in Comparative Examples 1 and 2 using the inorganic antibacterial agent, it is understood that the antibacterial agent is not uniformly dispersed in the resin composition, and the antibacterial activity is not sufficiently obtained when the fiber product is used. Moreover, in the comparative example 3 which does not use a masterbatch, it turns out that an antibacterial agent is not disperse | distributed uniformly in a resin composition, but when a hollow molded article is used, antibacterial activity is not fully exhibited. Therefore, it is understood that the hollow molded body of the present invention can be suitably used in a field where antibacterial properties are required.

Claims (10)

A hollow molded article comprising a melt-kneaded product of a thermoplastic resin (A) and a resin composition containing a compound represented by formula (1) and a thermoplastic resin (B).
(R ₁ represents a hydrogen atom or an alkali metal, and R ₂ represents an alkyl group or an aryl group having 1 to 10 carbon atoms.)   The thermoplastic resin (A) and the thermoplastic resin (B) are each independently polypropylene, polyethylene, polyoxymethylene, polyamide, polycarbonate, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin. The hollow molded article according to claim 1, which is at least one selected from the group consisting of polyester and thermoplastic elastomer.   The hollow molded body according to claim 1 or 2, wherein the thermoplastic resin (A) and the thermoplastic resin (B) are each independently polypropylene or polyethylene.   The compound represented by formula (1) is methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, hexyl 4-hydroxybenzoate and 4-hydroxybenzoic acid. The hollow molded object according to any one of claims 1 to 3, which is at least one selected from the group consisting of benzyl.   The hollow molded object in any one of Claims 1-4 whose compound represented by Formula (1) is 4-hydroxybenzoate butyl or 4-hydroxybenzoate hexyl.   The hollow molded object in any one of Claims 1-5 in which the resin composition contains 1-30 mass parts of compounds represented by Formula (1) with respect to 100 mass parts of thermoplastic resins (A).   The hollow molded object in any one of Claims 1-6 comprised from 100 mass parts of thermoplastic resins (B) and the melt-kneaded material of 1-40 mass parts of resin compositions.   The hollow molded object in any one of Claims 1-7 in which the compound represented by Formula (1) disperse | distributed as a particle | grain with a particle diameter of 5 micrometers or less in a thermoplastic resin.   The hollow molded body according to any one of claims 1 to 8, wherein the hollow molded body is at least one selected from the group consisting of a container, a bottle, a tank, a bag, a tube, a hose and a pipe. A step of melt-kneading the thermoplastic resin (A) and a resin composition containing the compound represented by the formula (1) and the thermoplastic resin (B); and
The manufacturing method of the hollow molded object in any one of Claims 1-9 including the process of shape | molding the obtained melt-kneaded material in hollow shape.